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  • 1
    Publication Date: 2020-08-05
    Description: Das heutige Leben ist durchdrungen von komplexen Technologien. Ohne Kommunikationsnetze, Internet, Mobilfunk, Logistik, Verkehrstechnik, medizinische Apparate, etc. könnte die moderne Gesellschaft nicht funktionieren. Fast alle dieser Technologien haben einen hohen Mathematikanteil. Der "normale Bürger"' weiss davon nichts, der Schulunterricht könnte dem ein wenig abhelfen. Einige mathematische Aspekte dieser Technologien sind einfach und sogar spielerisch intuitiv zugänglich. Solche Anwendungen, die zusätzlich noch der Lebensumwelt der Schüler zugehören, können dazu genutzt werden, die mathematische Modellierung, also die mathematische Herangehensweise an die Lösung praktischer Fragen, anschaulich zu erläutern. Gerade in der diskreten Mathematik können hier, quasi "nebenbei" mathematische Theorien erarbeitet und Teilaspekte (Definitionen, Fragestellungen, einfache Sachverhalte) durch eigenständiges Entdecken der Schüler entwickelt werden. Wir beginnen mit einigen Beispielen.
    Keywords: ddc:510
    Language: German
    Type: reportzib , doc-type:preprint
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  • 2
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    Publication Date: 2020-08-05
    Description: Den kürzesten Weg in einem Graphen zu finden ist ein klassisches Problem der Graphentheorie. Über einen Vortrag zu diesem Thema beim Tag der Mathematik 2007 von R. Borndörfer kam ich in Kontakt mit dem Konrad-Zuse-Zentrum (ZIB), das sich u.a. mit Wegeoptimierung beschäftigt. Ein Forschungsschwerpunkt dort ist im Rahmen eines Projekts zur Chipverifikation das Zählen von Lösungen, das, wie wir sehen werden, eng mit dem Zählen von Wegen zusammenhängt. Anhand von zwei Fragen aus der Graphentheorie soll diese Facharbeit unterschiedliche Lösungsmethoden untersuchen. Wie bestimmt man den kürzesten Weg zwischen zwei Knoten in einem Graphen und wie findet man alle möglichen Wege? Nach einer Einführung in die Graphentheorie und einer Konkretisierung der Probleme wird zunächst für beide eine Lösung mit auf Graphen basierenden Algorithmen vorgestellt. Während der Algorithmus von Dijkstra sehr bekannt ist, habe ich für das Zählen von Wegen einen eigenen Algorithmus auf der Basis der Tiefensuche entwickelt. Im zweiten Teil der Arbeit wird das Konzept der ganzzahligen Programmierung vorgestellt und die Lösungsmöglichkeiten für Wegeprobleme, die sich darüber ergeben. Schließlich wurden die vorgestellten Algorithmen am Beispiel des S- und U-Bahnnetzes von Berlin implementiert und mit Programmen, die die gleichen Fragen über ganzzahlige Programmierung lösen, verglichen.
    Keywords: ddc:510
    Language: German
    Type: reportzib , doc-type:preprint
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  • 3
    Publication Date: 2016-06-09
    Description: This paper is intended to be a first step towards the continuous dependence of dynamical contact problems on the initial data as well as the uniqueness of a solution. Moreover, it provides the basis for a proof of the convergence of popular time integration schemes as the Newmark method. We study a frictionless dynamical contact problem between both linearly elastic and viscoelastic bodies which is formulated via the Signorini contact conditions. For viscoelastic materials fulfilling the Kelvin-Voigt constitutive law, we find a characterization of the class of problems which satisfy a perturbation result in a non-trivial mix of norms in function space. This characterization is given in the form of a stability condition on the contact stresses at the contact boundaries. Furthermore, we present perturbation results for two well-established approximations of the classical Signorini condition: The Signorini condition formulated in velocities and the model of normal compliance, both satisfying even a sharper version of our stability condition.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 4
    Publication Date: 2020-08-05
    Description: Most data networks nowadays use shortest path protocols to route the traffic. Given administrative routing lengths for the links of the network, all data packets are sent along shortest paths with respect to these lengths from their source to their destination. In this paper, we present an integer programming algorithm for the minimum congestion unsplittable shortest path routing problem, which arises in the operational planning of such networks. Given a capacitated directed graph and a set of communication demands, the goal is to find routing lengths that define a unique shortest path for each demand and minimize the maximum congestion over all links in the resulting routing. We illustrate the general decomposition approach our algorithm is based on, present the integer and linear programming models used to solve the master and the client problem, and discuss the most important implementational aspects. Finally, we report computational results for various benchmark problems, which demonstrate the efficiency of our algorithm.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 5
    Publication Date: 2020-12-15
    Description: This paper introduces the "line connectivity problem", a generalization of the Steiner tree problem and a special case of the line planning problem. We study its complexity and give an IP formulation in terms of an exponential number of constraints associated with "line cut constraints". These inequalities can be separated in polynomial time. We also generalize the Steiner partition inequalities.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 6
    Publication Date: 2020-08-05
    Description: Testing is the process of stimulating a system with inputs in order to reveal hidden parts of the system state. In the case of non-deterministic systems, the difficulty arises that an input pattern can generate several possible outcomes. Some of these outcomes allow to distinguish between different hypotheses about the system state, while others do~not. In this paper, we present a novel approach to find, for non-deterministic systems modeled as constraints over variables, tests that allow to distinguish among the hypotheses as good as possible. The idea is to assess the quality of a test by determining the ratio of distinguishing (good) and not distinguishing (bad) outcomes. This measure refines previous notions proposed in the literature on model-based testing and can be computed using model counting techniques. We propose and analyze a greedy-type algorithm to solve this test optimization problem, using existing model counters as a building block. We give preliminary experimental results of our method, and discuss possible improvements.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 7
    Publication Date: 2021-08-05
    Description: Starting with the description of the Traveling Salesmen Problem formulation as given by van Vyve and Wolsey in the article Approximate extended formulations'', we investigate the effects of small variations onto the performance of contemporary mixed integer programming solvers. We will show that even minor changes in the formulation of the model can result in performance difference of more than a factor of 1000. As the results show it is not obvious which changes will result in performance improvements and which not.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 8
    Publication Date: 2022-03-14
    Description: Orbitopes can be used to handle symmetries which arise in integer programming formulations with an inherent assignment structure. We investigate the detection of symmetries appearing in this approach. We show that detecting so-called orbitopal symmetries is graph-isomorphism hard in general, but can be performed in linear time if the assignment structure is known.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 9
    Publication Date: 2019-01-29
    Description: Regional hyperthermia is a cancer therapy aiming at heating tumors using phased array applicators. This article provides an overview over current mathematical challenges of delivering individually optimal treatments. The focus is on therapy planning and identification of technical as well as physiological quantities from MR thermometry measurements.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 10
    Publication Date: 2019-05-10
    Description: Reasons for the failure of adaptive methods to deliver improved efficiency when integrating monodomain models for myocardiac excitation are discussed. Two closely related techniques for reducing the computational complexity of linearly implicit integrators, deliberate sparsing and splitting, are investigated with respect to their impact on computing time and accuracy.
    Keywords: ddc:510
    Language: English
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  • 11
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    Publication Date: 2020-08-05
    Description: We investigate the computation of periodic timetables for public transport by mixed integer programming. After introducing the problem, we describe two mathematical models for periodic timetabling, the PERIODIC EVENT SCHEDULING PROBLEM (PESP) and the QUADRATIC SEMI-ASSIGNMENT PROBLEM. Specifically, we give an overview of existing integer programming (IP) formulations for both models. An important contribution of our work are new IP formulations for the PESP based on time discretization. We provide an analytical comparison of these formulations and describe different techniques that allow a more efficient solution by mixed integer programming. In a preliminary computational study, on the basis of standard IP solvers, we compare different formulations for computing periodic timetables. Our results justify a further investigation of the time discretization approach. Typically the timetable is optimized for the current traffic situation. The main difficulty with this approach is that after introducing the new timetable the passengers’ travel behavior may differ from that assumed for the computation. Motivated by this problem, we examine an iterative timetabling procedure that is a combination of timetable computation and passenger routing. We discuss the algorithmic issues of the passenger routing and study properties of the computed timetables. Finally, we confirm our theoretical results on the basis of an own implementation.
    Description: Wir untersuchen die Berechnung von Taktfahrplänen für den öffentlichen Verkehr mit gemischt-ganzzahliger Programmierung (MIP). Im Anschluss an die Problembeschreibung, stellen wir zwei mathematische Modellierungen vor, das PERIODIC EVENT SCHEDULING PROBLEM (PESP) und das QUADRATIC SEMI-ASSIGNMENT PROBLEM. Wichtiger Bestandteil ist ein Überblick über existierende ganzzahlige Formulierungen beider Modelle. Wir entwickeln neue ganzzahlige Formulierungen für das PESP auf der Basis von Zeitdiskretisierung. Diese werden analytisch miteinander verglichen und wir beschreiben verschiedene Techniken, die eine effizientere Lösung der Formulierungen mit gemischt-ganzzahliger Programmierung ermöglichen. In einer ersten Rechenstudie, unter Verwendung gängiger MIP-Löser, vergleichen wir verschiedene ganzzahlige Formulierungen zur Berechnung von Taktfahrplänen. Unsere Ergebnisse rechtfertigen eine weitere Untersuchung des Zeitdiskretisierungsansatzes. In der Regel werden Fahrpläne mit Bezug auf die gegenwärtige Verkehrssituation optimiert. Dies birgt jedoch folgendes Problem. Wenn der neue Fahrplan eingeführt wird, ist es möglich, dass die Passagiere ein anderes Fahrverhalten zu Tage legen, als für die Berechnung des Fahrplans angenommen wurde. Vor diesem Hintergrund behandeln wir ein iteratives Verfahren zur Berechnung von Taktfahrplänen. Dieses ist eine Kombination aus Fahrplanberechnung und Passagierrouting. Neben den algorithmischen Details des Passagierroutings untersuchen wir Eigenschaften der berechneten Fahrpläne. Abschließend bestätigen wir unsere theoretischen Ergebnisse auf Grundlage einer eigenen Implementierung des Verfahrens.
    Keywords: ddc:510
    Language: English
    Type: masterthesis , doc-type:masterThesis
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  • 12
    Publication Date: 2020-08-05
    Description: This paper describes several experiments to explore the options for solving a class of mixed integer nonlinear programming problems that stem from a real-world mine production planning project. The only type of nonlinear constraints in these problems are bilinear equalities involving continuous variables, which enforce the ratios between elements in mixed material streams. A branch-and-bound algorithm to handle the integer variables has been tried in another project. However, this branch-and-bound algorithm is not effective for handling the nonlinear constraints. Therefore state-of-the-art nonlinear solvers are utilized to solve the resulting nonlinear subproblems in this work. The experiments were carried out using the NEOS server for optimization. After finding that current nonlinear programming solvers seem to lack suitable preprocessing capabilities, we preprocess the instances beforehand and use an heuristic approach to solve the nonlinear subproblems. In the appendix, we explain how to add a polynomial constraint handler that uses IPOPT as embedded nonlinear programming solver for the constraint programming framework SCIP. This is one of the crucial steps for implementing our algorithm in SCIP. We briefly described our approach and give an idea of the work involved.
    Keywords: ddc:510
    Language: English
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  • 13
    Publication Date: 2020-08-05
    Description: Dieser kurze Aufsatz zur Algorithmengeschichte ist Eberhard Knobloch, meinem Lieblings-Mathematikhistoriker, zum 65. Geburtstag gewidmet. Eberhard Knobloch hat immer, wenn ich ihm eine historische Frage zur Mathematik stellte, eine Antwort gewusst – fast immer auch sofort. Erst als ich mich selbst ein wenig und dazu amateurhaft mit Mathematikgeschichte beschäftigte, wurde mir bewusst, wie schwierig dieses „Geschäft“ ist. Man muss nicht nur mehrere (alte) Sprachen beherrschen, sondern auch die wissenschaftliche Bedeutung von Begriffen und Symbolen in früheren Zeiten kennen. Man muss zusätzlich herausfinden, was zur Zeit der Entstehung der Texte „allgemeines Wissen“ war, insbesondere, was seinerzeit gültige Beweisideen und -schritte waren, und daher damals keiner präzisen Definition oder Einführung bedurfte. Es gibt aber noch eine Steigerung des historischen Schwierigkeitsgrades: Algorithmengeschichte. Dies möchte ich in diesem Artikel kurz darlegen in der Hoffnung, dass sich Wissenschaftshistoriker dieses Themas noch intensiver annehmen, als sie das bisher tun. Der Grund ist, dass heute Algorithmen viele Bereiche unserer Alltagswelt steuern und unser tägliches Leben oft von funktionierenden Algorithmen abhängt. Daher wäre eine bessere Kenntnis der Algorithmengeschichte von großem Interesse.
    Keywords: ddc:510
    Language: German
    Type: reportzib , doc-type:preprint
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  • 14
    Publication Date: 2016-06-09
    Description: We consider first order optimality conditions for state constrained optimal control problems. In particular we study the case where the state equation has not enough regularity to admit existence of a Slater point in function space. We overcome this difficulty by a special transformation. Under a density condition we show existence of Lagrange multipliers, which have a representation via measures and additional regularity properties.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 15
    Publication Date: 2016-06-09
    Description: The enormous time lag between fast atomic motion and complex pro- tein folding events makes it almost impossible to compute molecular dy- namics on a high resolution. A common way to tackle this problem is to model the system dynamics as a Markov process. Yet for large molec- ular systems the resulting Markov chains can hardly be handled due to the curse of dimensionality. Coarse graining methods can be used to re- duce the dimension of a Markov chain, but it is still unclear how far the coarse grained Markov chain resembles the original system. In order to answer this question, two different coarse-graining methods were analysed and compared: a classical set-based reduction method and an alternative subspace-based approach, which is based on membership vectors instead of sets. On the basis of a small toy system, it could be shown, that in con- trast to the subset-based approach, the subspace-based reduction method preserves the Markov property as well as the essential dynamics of the original system.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 16
    Publication Date: 2021-02-19
    Description: Line planning is an important step in the strategic planning process of a public transportation system. In this paper, we discuss an optimization model for this problem in order to minimize operation costs while guaranteeing a certain level of quality of service, in terms of available transport capacity. We analyze the problem for path and tree network topologies as well as several categories of line operation that are important for the Quito Trolebus system. It turns out that, from a computational complexity worst case point of view, the problem is hard in all but the most simple variants. In practice, however, instances based on real data from the Trolebus System in Quito can be solved quite well, and significant optimization potentials can be demonstrated.
    Keywords: ddc:510
    Language: English
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  • 17
    Publication Date: 2020-08-05
    Description: It is well known that competitive analysis yields too pessimistic results when applied to the paging problem and it also cannot make a distinction between many paging strategies. Many deterministic paging algorithms achieve the same competitive ratio, ranging from inefficient strategies as flush-when-full to the good performing least-recently-used (LRU). In this paper, we study this fundamental online problem from the viewpoint of stochastic dominance. We show that when sequences are drawn from distributions modelling locality of reference, LRU is stochastically better than any other online paging algorithm.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 18
    Publication Date: 2020-12-15
    Description: Die Angebotsplanung im öffentlichen Nahverkehr umfasst die Aufgaben der Netz-, Linien-,Fahr- und Preisplanung. Wir stellen zwei mathematische Optimierungsmodelle zur Linien- und Preisplanung vor. Wir zeigen anhand von Berechnungen für die Verkehrsbetriebe in Potsdam(ViP), dass sich damit komplexe Zusammenhänge quantitativ analysieren lassen. Auf diese Weise untersuchen wir die Auswirkungen von Freiheitsgraden auf die Konstruktion von Linien und die Wahl von Reisewegen der Passagiere, Abhängigkeiten zwischen Kosten und Reisezeiten sowie den Einfluss verschiedener Preissysteme auf Nachfrage und Kostendeckung.
    Keywords: ddc:510
    Language: German
    Type: reportzib , doc-type:preprint
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  • 19
    Publication Date: 2022-03-14
    Description: This article introduces constraint integer programming (CIP), which is a novel way to combine constraint programming (CP) and mixed integer programming (MIP) methodologies. CIP is a generalization of MIP that supports the notion of general constraints as in CP. This approach is supported by the CIP framework SCIP, which also integrates techniques from SAT solving. SCIP is available in source code and free for non-commercial use. We demonstrate the usefulness of CIP on two tasks. First, we apply the constraint integer programming approach to pure mixed integer programs. Computational experiments show that SCIP is almost competitive to current state-of-the-art commercial MIP solvers. Second, we employ the CIP framework to solve chip design verification problems, which involve some highly non-linear constraint types that are very hard to handle by pure MIP solvers. The CIP approach is very effective here: it can apply the full sophisticated MIP machinery to the linear part of the problem, while dealing with the non-linear constraints by employing constraint programming techniques.
    Keywords: ddc:510
    Language: English
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  • 20
    Publication Date: 2016-06-09
    Description: An extended mathematical framework for barrier methods for state constrained optimal control compared to [Schiela, ZIB-Report 07-07] is considered. This allows to apply the results derived there to more general classes of optimal control problems, in particular to boundary control and finite dimensional control.
    Keywords: ddc:510
    Language: English
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  • 21
    Publication Date: 2021-08-05
    Description: In the recent years there has been tremendous progress in the development of algorithms to find optimal solutions for integer programs. In many applications it is, however, desirable (or even necessary) to generate all feasible solutions. Examples arise in the areas of hardware and software verification and discrete geometry. In this paper, we investigate how to extend branch-and-cut integer programming frameworks to support the generation of all solutions. We propose a method to detect so-called unrestricted subtrees, which allows us to prune the integer program search tree and to collect several solutions simultaneously. We present computational results of this branch-and-count paradigm which show the potential of the unrestricted subtree detection.
    Keywords: ddc:510
    Language: English
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  • 22
    Publication Date: 2020-08-05
    Description: Edmonds showed that the so-called rank inequalities and the nonnegativity constraints provide a complete linear description of the matroid polytope. By essentially adding Grötschel's cardinality forcing inequalities, we obtain a complete linear description of the cardinality constrained matroid polytope which is the convex hull of the incidence vectors of those independent sets that have a feasible cardinality. Moreover, we show how the separation problem for the cardinality forcing inequalities can be reduced to that for the rank inequalities. We also give necessary and sufficient conditions for a cardinality forcing inequality to be facet defining.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 23
    Publication Date: 2020-08-05
    Description: The paper describes a method for solution of very large overdetermined algebraic polynomial systems on an example that appears from a classification of all integrable 3-dimensional scalar discrete quasilinear equations $Q_3=0$ on an elementary cubic cell of the lattice ${\mathbb Z}^3$. The overdetermined polynomial algebraic system that has to be solved is far too large to be formulated. A probing' technique which replaces independent variables by random integers or zero allows to formulate subsets of this system. An automatic alteration of equation formulating steps and equation solving steps leads to an iteration process that solves the computational problem.
    Keywords: ddc:510
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  • 24
    Publication Date: 2020-08-05
    Description: An algorithmic method using conservation law multipliers is introduced that yields necessary and sufficient conditions to find invertible mappings of a given nonlinear PDE to some linear PDE and to construct such a mapping when it exists. Previous methods yielded such conditions from admitted point or contact symmetries of the nonlinear PDE. Through examples, these two linearization approaches are contrasted.
    Keywords: ddc:510
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  • 25
    Publication Date: 2021-02-26
    Description: We classify all integrable 3-dimensional scalar discrete affine linear equations $Q_3=0$ on an elementary cubic cell of the lattice ${\mathbb Z}^3$. An equation $Q_3=0$ %of such form is called integrable if it may be consistently imposed on all $3$-dimensional elementary faces of the lattice ${\mathbb Z}^4$. Under the natural requirement of invariance of the equation under the action of the complete group of symmetries of the cube we prove that the only ontrivial(non-linearizable) integrable equation from this class is the well-known dBKP-system.
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  • 26
    Publication Date: 2020-12-11
    Description: The article describes the online mathematics test {\tt http://lie.math.brocku.ca/mathtest}, its typical applications and experiences gathered.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 27
    Publication Date: 2020-08-05
    Description: We introduce (TTPlib), a data library for train timetabling problems that can be accessed at http://ttplib.zib.de. In version 1.0, the library contains data related to 50 scenarios. Most instances result from the combination of macroscopic railway networks and several train request sets for the German long distance area containing Hannover, Kassel and Fulda, short denoted by Ha-Ka-Fu. In this paper, we introduce the data concepts of TTPlib, describe the scenarios included in the library and provide a free visualization tool TraVis.
    Keywords: ddc:510
    Language: English
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  • 28
    Publication Date: 2020-08-05
    Description: The purpose of this paper is twofold. An immediate practical use of the presented algorithm is its applicability to the parametric solution of underdetermined linear ordinary differential equations (ODEs) with coefficients that are arbitrary analytic functions in the independent variable. A second conceptual aim is to present an algorithm that is in some sense dual to the fundamental Euclids algorithm, and thus an alternative to the special case of a Gr\"{o}bner basis algorithm as it is used for solving linear ODE-systems. In the paper Euclids algorithm and the new dual version' are compared and their complementary strengths are analysed on the task of solving underdetermined ODEs. An implementation of the described algorithm is interactively accessible at http://lie.math.brocku.ca/crack/uode.
    Keywords: ddc:510
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  • 29
    Publication Date: 2020-08-05
    Description: This paper proposes a new method for probabilistic analysis of online algorithms that is based on the notion of stochastic dominance. We develop the method for the Online Bin Coloring problem introduced by Krumke et al. Using methods for the stochastic comparison of Markov chains we establish the strong result that the performance of the online algorithm GreedyFit is stochastically dominated by the performance of the algorithm OneBin for any number of items processed. This result gives a more realistic picture than competitive analysis and explains the behavior observed in simulations.
    Keywords: ddc:510
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  • 30
    Publication Date: 2020-12-15
    Description: The optimization of fare systems in public transit allows to pursue objectives such as the maximization of demand, revenue, profit, or social welfare. We propose a non-linear optimization approach to fare planning that is based on a detailed discrete choice model of user behavior. The approach allows to analyze different fare structures, optimization objectives, and operational scenarios involving, e.g., subsidies. We use the resulting models to compute optimized fare systems for the city of Potsdam, Germany.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 31
    Publication Date: 2022-03-14
    Description: Pseudo-Boolean problems generalize SAT problems by allowing linear constraints and a linear objective function. Different solvers, mainly having their roots in the SAT domain, have been proposed and compared,for instance, in Pseudo-Boolean evaluations. One can also formulate Pseudo-Boolean models as integer programming models. That is,Pseudo-Boolean problems lie on the border between the SAT domain and the integer programming field. In this paper, we approach Pseudo-Boolean problems from the integer programming side. We introduce the framework SCIP that implements constraint integer programming techniques. It integrates methods from constraint programming, integer programming, and SAT-solving: the solution of linear programming relaxations, propagation of linear as well as nonlinear constraints, and conflict analysis. We argue that this approach is suitable for Pseudo-Boolean instances containing general linear constraints, while it is less efficient for pure SAT problems. We present extensive computational experiments on the test set used for the Pseudo-Boolean evaluation 2007. We show that our approach is very efficient for optimization instances and competitive for feasibility problems. For the nonlinear parts, we also investigate the influence of linear programming relaxations and propagation methods on the performance. It turns out that both techniques are helpful for obtaining an efficient solution method.
    Keywords: ddc:510
    Language: English
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  • 32
    Publication Date: 2020-08-05
    Description: Millionen von Menschen werden allein in Deutschland täglich von Bussen, Bahnen und Flugzeugen transportiert. Der öffentliche Personenverkehr (ÖV) ist von großer Bedeutung für die Lebensqualität einzelner aber auch für die Leistungsfähigkeit ganzer Regionen. Qualität und Effizienz von ÖV-Systemen hängen ab von politischen Rahmenbedingungen (staatlich geplant, wettbewerblich organisiert) und der Eignung der Infrastruktur (Schienensysteme, Flughafenstandorte), vom vorhandenen Verkehrsangebot (Fahr- und Flugplan), von der Verwendung angemessener Technologien (Informations-, Kontroll- und Buchungssysteme) und dem bestmöglichen Einsatz der Betriebsmittel (Energie, Fahrzeuge und Personal). Die hierbei auftretenden Entscheidungs-, Planungs- und Optimierungsprobleme sind z.T. gigantisch und "schreien" aufgrund ihrer hohen Komplexität nach Unterstützung durch Mathematik. Dieser Artikel skizziert den Stand und die Bedeutung des Einsatzes von Mathematik bei der Planung und Durchführung von öffentlichem Personenverkehr, beschreibt die bestehenden Herausforderungen und regt zukunftsweisende Maßnahmen an.
    Keywords: ddc:510
    Language: German
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  • 33
    Publication Date: 2019-05-10
    Description: Pulse thermography of concrete structures is used in civil engineering for detecting voids, honeycombing and delamination. The physical situation is readily modeled by Fourier's law. Despite the simplicity of the PDE structure, quantitatively realistic numerical 3D simulation faces two major obstacles. First, the short heating pulse induces a thin boundary layer at the heated surface which encapsulates all information and therefore has to be resolved faithfully. Even with adaptive mesh refinement techniques, obtaining useful accuracies requires an unsatisfactorily fine discretization. Second, bulk material parameters and boundary conditions are barely known exactly. We address both issues by a semi-analytic reformulation of the heat transport problem and by parameter identification. Numerical results are compared with measurements of test specimens.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 34
    Publication Date: 2016-06-09
    Description: In this paper we are concerned with the application of interior point methods in function space to gradient constrained optimal control problems, governed by partial differential equations. We will derive existence of solutions together with first order optimality conditions. Afterwards we show continuity of the central path, together with convergence rates depending on the interior point parameter.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 35
    Publication Date: 2016-06-09
    Description: We consider an interior point method in function space for PDE constrained optimal control problems with state constraints. Our emphasis is on the construction and analysis of an algorithm that integrates a Newton path-following method with adaptive grid refinement. This is done in the framework of inexact Newton methods in function space, where the discretization error of each Newton step is controlled by adaptive grid refinement in the innermost loop. This allows to perform most of the required Newton steps on coarse grids, such that the overall computational time is dominated by the last few steps. For this purpose we propose an a-posteriori error estimator for a problem suited norm.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 36
    Publication Date: 2020-08-05
    Description: Ticket pricing in public transport usually takes a welfare or mnemonics maximization point of view. These approaches do not consider fairness in the sense that users of a shared infrastructure should pay for the costs that they generate. We propose an ansatz to determine fair ticket prices that combines concepts from cooperative game theory and integer programming. An application to pricing railway tickets for the intercity network of the Netherlands demonstrates that, in this sense, prices that are much fairer than standard ones can be computed in this way.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 37
    Publication Date: 2014-02-26
    Description: We present a second order sharp interface finite volume method for the solution of the three-dimensional poisson equation with variable coefficients on Cartesian grids. In particular, we focus on interface problems with discontinuities in the coefficient, the source term, the solution, and the fluxes across the interface. The method uses standard piecewiese trilinear finite elements for normal cells and a double piecewise trilinear ansatz for the solution on cells intersected by the interface resulting always in a compact 27-point stencil. Singularities associated with vanishing partial volumes of intersected grid cells are removed by a two-term asymptotic approach. In contrast to the 2D method presented by two of the authors in [M.~Oevermann, R.~Klein: A Cartesian grid finite volume method for elliptic equations with variable coefficients and embedded interfaces, J.~Comp.~Phys.~219 (2006)] we use a minimization technique to determine the unknown coefficients of the double trilinear ansatz. This simplifies the treatment of the different cut-cell types and avoids additional special operations for degenerated interface topologies. The resulting set of linear equations has been solved with a BiCGSTAB solver preconditioned with an algebraic multigrid. In various testcases -- including large coefficient ratios and non-smooth interfaces -- the method achieves second order of accuracy in the L_inf and L_2 norm.
    Keywords: ddc:510
    Language: English
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  • 38
    Publication Date: 2020-08-05
    Description: Given a combinatorial optimization problem and a subset $N$ of natural numbers, we obtain a cardinality constrained version of this problem by permitting only those feasible solutions whose cardinalities are elements of $N$. In this paper we briefly touch on questions that addresses common grounds and differences of the complexity of a combinatorial optimization problem and its cardinality constrained version. Afterwards we focus on polytopes associated with cardinality constrained combinatorial optimization problems. Given an integer programming formulation for a combinatorial optimization problem, by essentially adding Grötschel's cardinality forcing inequalities, we obtain an integer programming formulation for its cardinality restricted version. Since the cardinality forcing inequalities in their original form are mostly not facet defining for the associated polyhedra, we discuss possibilities to strengthen them.
    Keywords: ddc:510
    Language: English
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  • 39
    Publication Date: 2020-08-05
    Description: This survey concerns optimization problems arising in the design of survivable communication networks. It turns out that such problems can be modeled in a natural way as non-compact linear programming formulations based on multicommodity flow network models. These non-compact formulations involve an exponential number of path flow variables, and therefore require column generation to be solved to optimality. We consider several path-based survivability mechanisms and present results, both known and new, on the complexity of the corresponding column generation problems (called the pricing problems). We discuss results for the case of the single link (or node) failures scenarios, and extend the considerations to multiple link failures. Further, we classify the design problems corresponding to different survivability mechanisms according to the structure of their pricing problem. Finally, we show that almost all encountered pricing problems are hard to solve for scenarios admitting multiple failures.
    Keywords: ddc:510
    Language: English
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  • 40
    Publication Date: 2021-02-19
    Description: We introduce an optimization model for the line planning problem in a public transportation system that aims at minimizing operational costs while ensuring a given level of quality of service in terms of available transport capacity. We discuss the computational complexity of the model for tree network topologies and line structures that arise in a real-world application at the Trolebus Integrated System in Quito. Computational results for this system are reported.
    Keywords: ddc:510
    Language: English
    Type: reportzib , doc-type:preprint
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  • 41
    Publication Date: 2021-02-19
    Description: Line planning is an important step in the strategic planning process of a public transportation system. In this paper, we discuss an optimization model for this problem in order to minimize operation costs while guaranteeing a certain level of quality of service, in terms of available transport capacity. We analyze the problem for path and tree network topologies as well as several categories of line operation that are important for the Quito Trolebus system. It turns out that, from a computational complexity worst case point of view, the problem is hard in all but the most simple variants. In practice, however, instances based on real data from the Trolebus System in Quito can be solved quite well, and significant optimization potentials can be demonstrated.
    Keywords: ddc:510
    Language: English
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  • 42
    Publication Date: 2016-06-09
    Keywords: ddc:510
    Language: English
    Type: doctoralthesis , doc-type:doctoralThesis
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  • 43
    Publication Date: 2020-08-05
    Description: wird nachgereicht
    Keywords: ddc:510
    Language: English
    Type: doctoralthesis , doc-type:doctoralThesis
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  • 44
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Additional Material: 3 Tab.
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  • 45
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 149 (1964), S. 309-312 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: In the normal parathyroid gland of the mouse there is only one type of cell which is small with a large nucleus and small amount of cytoplasm. In order to investigate the effect of relaxin on parathyroid histology, mice were injected with relaxin, the degree of pubic separation was measured by the x-ray technique, and the parathyroid glands were studied histologically. After one day of relaxin injection, the pubic symphysis showed a distinct separation and in part of the parathyroid gland the cells were larger and stained lighter and pinker than the normal cells with hematoxylin, eosin, and azur II. After four days of relaxin treatment, the whole gland had changed so that all the cells were of the second type. Glands of pregnant mice near term also were composed of cells of this type. These results indicate a relationship between relaxin and the parathyroid gland.
    Additional Material: 1 Tab.
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  • 46
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Thalidomide injury to an implanted armadillo blastocyst is presented. This finding confirms the specific damage by thalidomide to the embryoblastic cells. The lack of damage to the trophoblast at this stage permits a normal implantation of the blastocyst in the uterine mucosa.
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  • 47
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 149 (1964), S. 181-189 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Although melanoctyes appear to be limited to the hair folicles of adult belly skin of the PET mouse, they are found throughout the integument of the newborn. Trauma applied to the ventral belly skin of newborn PET mice results in the maintenance and augmentation of the melanocytes within the skin, even after the formation and growth of hair. The area immediately surrounding the site of trauma shows an increase in the number of melanocytes, apparently due in part to the disruption of the developing follicles and the consequent release of their pigment cells to the skin. UV irradiation also maintains a system of melanocytes within the ventral belly skin of PET mice.The significance of the maintenance and augmentation of melanocytes from the newborn into the adult by surgical trauma or UV radiation is discussed.
    Additional Material: 1 Ill.
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  • 48
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The histology of the anterior hypophysis, thyroid and gonads of dwarf (dw) and Ames dwarf (df) mutants of Mus musculus was compared. Orange G, aldehyde fuchsin and PAS stains were used to differentiate cells of the hypophysis. In both types of dwarf the anterior hypophysis was small, acidophils were lacking and the number of thyrotropic hormone producing cells was reduced. The thyroids were reduced in size, the follicles were small and some tissue was not organized into follicles. Testes were nearly normal. Ovaries were small and large follicles and corpora lutea were lacking.Growth hormone (STH) and thyrotropic hormone (TSH) were administered to both types of dwarfs. The treatment had no effect on the anterior hypophysis but number and size of follicles in the thyroid was increased The response was greater in df dwarfs; STH and TSH had more effect than STH alone. Testes of treated mice were only slightly changed but most of the df and some dw males became fertile. The ovaries became large and functional. Thyroids of dwarfs treated with thyroxine were not changed.It is concluded that the primary hormone deficiencies in both types of dwarf are the same, but that there are physiological differences as revealed by responses to STH and TSH treatment.
    Additional Material: 2 Tab.
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  • 49
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: This study was undertaken to determine the relationship between Marshall's metalophilic reticular cells and the cells exhibiting non-specific esterase and acid phosphatase activity in the rat spleen. Untreated and stimulated animals were used. Observations were made chiefly on the marginal metalophils of Snook. These cells showed strong acid phosphatase activity but only slight non-specific esterase activity in untreated animals. Following stimulation non-specific esterase activity increased in these cells. Within the nodules metalophilic reticular cells were always more numerous than cells with enzyme activity. Many of these metalophilic cells developed enzyme activity following stimulation. By the use of a restaining technique it was shown that all reticular cells possessing enzyme activity were also metalophilic but that the converse was not true. No mitotic activity was present in these cells.The results suggest that Marshall's metalophils are cells of the reticuloendothelial system in various stages of maturation and that, following stimulation, they may differentiate into mature phagocytic cells.
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  • 50
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 149 (1964) 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 51
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Densities of the various bone fractions i.e., water, organic, volatile inorganic and ash fractions, as well as fat in the various animals have been studied. However. values reported by various workers failed to show consistency and uniformity, especially with respect to the volatile inorganic (often called “CO2 fraction”) and the ash fractions. These densities are prerequisite to the study of the volumetric composition of bone and bone marrow.In our study, the fat and organic densities found were similar to those previously reported. The volatile and non-volatile inorganic (ash) fractions, had density values of 1.684 and 3.180, respectively. The ash density was much higher than values previously reported but it verifies a theoretical value deduced by the authors from published work.Our higher ash density was due to a smaller measured volume of this fraction obtained by applying a negative pressure to remove the small entrapped air bubbles from the ash sample prior to the water displacement measurement. Because a smaller portion of the total inorganic volume was used for the ash calculation, giving it a higher density, a larger balance of the total inorganic volume was left for the volatile inorganic density calculation. This accounted for ash and volatile inorganic densities which were higher and lower, respectively, than such values previously reported.Prior to the determination of the density of the non-volatile inorganic fraction, the ashing time and temperature were studied. Curves plotted from the results of such studies were described and explained.
    Additional Material: 3 Ill.
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  • 52
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The two uterine horns in the adult are joined caudally to form an externally undivided segment consisting of a cranial and a caudal part. The cranial part becomes wide and swollen at its junction with the horns. It contains two lumina separated by a midline septum and is designated as the uterine body or corpus. The narrow and slightly tapered caudal part projects into the cranial portion of the vagina. It contains a single lumen or canal and is designated as the uterine neck or cervix. The wall of the cranial two-thirds of the adult cervix contains a relatively large amount of circularly arranged smooth muscle fibers. In contrast, its caudal one-third consists chiefly of a network of collagen fibers. During cervical development argyrophilic fibers first appear in sections of cervical wall from mice sacrificed at birth. Collagen and smooth muscle fibers are first stainable with the Mallory method in cervical wall sections from mice one week old. During pregnancy and after combined treatment with estradiol, progesterone and relaxin the collagenous fiber bundles of the cervix become looser and more widely separated. This is associated with an increased dilatability of the cervical canal and increased stainability of the ground substance. The muccopolysaccharide(s) demonstrable histochemically in the cervix of the mouse was digestible with testicular hyaluronidase.
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  • 53
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 150 (1964) 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 54
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The in situ thymus of the guinea pig was labeled locally with H3-thymidine and sections of various tissues analyzed by radioautography for the location of labeled cells which might have left the thymus from 30 minutes to three days after labeling. Labeled lymphocytes were located especially in the mesenteric lymph nodes and spleen, giving direct evidence for the migration of thymocytes under near-physiological conditions. Only a few cells were found in the bone marrow, and none in the liver. The identified cells were not seen to be undergoing subsequent proliferation, but about one-fourth of them were transforming to other cell types - plasma cells, heterophil granulocytes, reticular cells, and macrophages. The fate of another portion of the cells seemed to be loss to the gut lumen through the mucosa. These data suggest that a normal function of the thymus of the adult guinea pig is the proliferation of a population of pluripotential stem cells which, after migration to other tissues, may further differentiate under appropriate stimulus. Possible applications of the local labeling technique are indicated.
    Additional Material: 15 Ill.
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  • 55
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The rate of skeletal maturation as indicated by ossification of bony elements of the central and appendicular skeleton was compared in two groups of hypothyroid young rats, raised at 20°C and 30°C constant environment respectively.Hypothyroidism was induced by feeding 0.2% propylthiouracil mixed with the food in powdered form to pregnant rats starting on the fifteenth day of gestation and continuing this treatment to the suckling mother until their litters had reached weaning age.The appearance of epiphyseal centers, of carpal and tarsal centers, middle phalanges and femoral and tibial processes and caudal vertebrae 7-27 is delayed in hypothyroid newborn rats over that of normal controls. Hypothyroid rats raised at 20°C lag more severely behind the controls with respect to skeletal maturation, than do hypothyroid rats raised at 30°C. The latter are intermediate or in some instances their rate of skeletal maturation resembles that of the control group.The possible significance of the demonstration of diminished requirements for thyroid hormone by the developing rat for studies attempting to identify mechanisms of hormone action in development is briefly discussed.
    Additional Material: 2 Ill.
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  • 56
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A cephalometric radiographic appraisal of vertical skull growth occurring during the interim of one year was made on 71 caucasoid males at the Baylor University College of Dentistry, Dallas, Texas. The subjects were from 22 to 34 years of age. The dimensions assessed were the total skull height, the anterior cranial height, total facial height, upper facial height. and lower facial height. A significant increase was shown to occur in all the dimensions over a period of one year except in the dimension of anterior cranial height. It was concluded that skull growth does occur in male adults after the age generally accepted as that of maturity.
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  • 57
    Electronic Resource
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 150 (1964), S. 243-247 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: To ascertain the pathway (s) along which forces are conducted from the hand to the humerus in the human cadaver specially designed pressure sensitive transducers were introduced into the radio-capitular and ulnar-trochlear components of the elbow joint. A constant force was applied to the hand, and changes in electrical resistance and hence pressure across the elbow joint where recorded. It was observed that 57% of the force applied crossed the radio-capitular joint while 43% crossed the ulnar-trochlear joint. The pathway of this force transmission is discussed with particular reference to the involvement of the interosseous membrane.
    Additional Material: 4 Ill.
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  • 58
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 150 (1964), S. 257-263 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Implants from the midbrain and cerebellum of neonatal rats were cultured in roller tubes for 20 to 30 days. The cultures were incubated in a tryptamine-tetrazolium solution which demonstrated the enzyme activity of monoamine oxidase (MAO) by the formation of a formazan precipitation. Some cultures were incubated without fixation, while others were fixed in a glutaraldehyde solution prior to incubation. The specificity of the reaction was controlled by withholding the substrate or by treatment of the cultures with an MAO inhibitor. An intracellular localization of the enzyme was observed in small and medium sized neurons, but was absent in the largest neurons. Neuroglial cells, including ependyma, and mesenchymal cells and phagocytes were MAO positive. The formazan granules were scattered throughout cell bodies and into cytoplasmic processes. Glutaraldehyde fixation of cultures prior to incubation for MAO preserved the details of cell structure and enhanced the differentiation of cell types. When fixed and unfixed cultures were compared, glutaraldehyde did not appear to interfere or interact with enzyme localization; however, there was evidence that this aldehyde might be interfering with MAO concentration, since a longer incubation period for prefixed tissue was required to obtain a formazan reaction comparable to that of unfixed cultures.
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  • 59
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Lymphatic plexuses from certain areas of serous cavities can be injected by a simple procedure which simulates the normal mechanism of absorption. Apparatus consists of a 500 ml filtration flask with side arm attached to a vacuum apparatus. Excised serous membranes are draped over the mouth of the flask and flooded with ink. Vacuum is applied intermittently, resulting in absorption and flow. The method can be applied to frozen and thawed tissue and is suitable for human autopsy material.
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  • 60
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 150 (1964), S. 363-364 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: An anomaly of the termination of the aorta is described which is apparently unique. The aorta divided directly into two internal iliac arteries and two external iliac arteries.
    Additional Material: 1 Ill.
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  • 61
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 150 (1964), S. 383-390 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A simple method leading to growth and mitosis in over 95% of shortterm cultures of lymphocytes from the blood, lymph or thymus of the rat is described. The method which is modified from Moorhead's original technique (′60) employs standard tissue culture medium (Eagles MEM or TC no. 199), 20% fresh rat serum, washed lymphocytes, penicillin, and phytohemagglutinin-P (0.01 cm3/cm3 of culture of a 1:5 dilution of stock solution). Details of culture technique and factors contributing to growth failures are discussed.The chromosomes of male and female Lewis rats were studied in metaphase spreads of cultured cells. The karyotypes of these rats are presented and found to be in agreement with those recently reported by Hungerford and Nowell (′63).
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  • 62
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The first statistically significant decline in the mean number of young born to female golden hamsters occurred in the fourth litters. The decreased size of fifth litters was highly significant and few females bore six litters.Hamsters unilaterally ovariectomized at 30 days of age had a significantly lower number of litters containing live young during their lifetime. Despite increased unilateral ovulaton, they bore less than half as many total young per female as intact controls and fetal resorptions and stillbirths occurred at an earlier age.The results of matings during the period of reproductive decline were observed in females from the age of ten months until death or sacrifice at an advanced age. Final litters contained few young, some born dead. One or two subsequent pregnancies were of term length but all conceptuses were resorbed. Few females beyond 15 months of age had implantation sites and most of these resorbed. Regular four day estrous cycles continued until a terminal illness and matings resulted in pseudopregnancy. Blastocysts were found at four and one-half days of gestation in some old females but not at 6 to 8 days. Failure of implantation appeared to be due to an inadequate uterine decidual reaction in the old animals.It appeared from the above observations that decreasing uterine adaptability limited reproductive capacity in aging hamsters.
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  • 63
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Castrated and castrated and hypophysectomized female mice (BALB/c) were injected subcutaneously with estradiol-17β (0.5 μg or 1.0 μg/day) and progesterone (1.0 mg or 3 mg/day) in addition to prolactin (1.0 mg), oxytocin (1.0 IU) or growth hormone (1.0 mg), alone and in combination for 10 or 15 days. Twenty-four hours after the last hormonal treatment, tritiated thymidine (0.7 μc/gram body weight) was injected intravenously, and the mice sacrificed six hours later. Tissue from the inguinal mammary glands was removed and processed for radioautographic, histological and whole mount study.Radioautographs of hematoxylin stained sections of mammary tissue from each animal were selected. Under oil immersion, 2,000 epithelial cells were consecutively counted and the number of labeled cells noted. Results are expressed as the per cent of labeled epithelial cells.All hormonal treatment, except oxytocin alone, caused a significant increase in per cent of labeled cells as compared to castrated, untreated animals. The per cent of labeled cells depended, in general, on the dosage and duration of treatment. Combinations of growth hormone with estradiol-17β and progesterone did not augment epithelial proliferation. The addition of oxytocin or prolactin to the estradiol-17β (0.5 μg)  -  progesterone (1.0 mg) combination significantly increased the per cent of labeled cells.Prolactin, but not oxytocin, augmented epithelial proliferation in similarly treated castrated and hypophysectomized mice. Combinations of estradiol-17β (1.0 μg) and progesterone (3.0 mg) with oxytocin or prolactin did not significantly augment epithelial proliferation as compared to ovarian steroid treatment alone.
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  • 64
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    The @Anatomical Record 150 (1964), S. 503-504 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 65
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    The @Anatomical Record 150 (1964), S. 449-461 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The prenatal development of the mandibular joint in mice was studied in fetuses at 15 to 20 days insemination age. The ramus of the mandible can be delineated as early as the fifteenth day by distinct differences in the degree of condensation of mesenchyme at the site of the future joint. The future condylar process of the mandible can be recognized in its relationship to the external pterygoid muscle, inferior alveolar nerve, Meckel's cartilage, pre-cartilaginous alisphenoid process of the future basisphenoid bone, and the anlage of the squamosal bone with its zygomatic process.Differentiation is rapid through the twentieth day of gestation at which time the following major elements of the joint can be recognized: a fibrous intra-articular disc continuous with the tendon of the external pterygoid muscle; a vascular synovial mesenchyme with upper and lower synovial spaces; an ossified squamosal bone with a fibrous joint lining; and a well developed condylar process with good representation of differentiating cells in the zones of chondrification and ossification.Among the elements not yet evident, however, are (1) hemopoietic marrow in the condyle, (2) a constricted neck at the base of the condyle, and (3) a fibrous capsule or capsular ligament.
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  • 66
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Thin slices of rat liver, kidney, and M. rectus femoris and thin, flat pieces of albumin-gelatin gels (which approximated the tissue slices in mass, dimensions and protein content) were immersed in formalin solutions at various concentrations, in some cases with variable amounts of NaCl (0.11-0.25M) added, and in some cases buffered at pH values ranging from 3.5-7.0. The slices were weighed at frequent intervals for the first 20 hours of immersion. Weight changes occurred rapidly. With the exception of the neutral buffered formalin curves, three families of response curves were obtained for the three tissues. With both formalin and formalinsaline solutions weight gain was inversely proportional to the solute concentration, but the formaldehyde particles apparently are not involved osmotically. The total osmotic concentration of formalin solutions, therefore, is not a factor in the swelling or shrinking of tissue slices. The presence of contaminants could be responsible for the effective osmotic concentration observed with these solutions. The weight response of slices is influenced by the pH of the formalin. Although the response of the gel system to any particular solution was quantitatively greater, it was qualitatively the same as the tissue slice response.
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  • 67
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The numerical variations observed in the dentition of the northern sea lions, fur seals and seals are summarized as follows: (1) There is a reappearance of the right maxillary second molar in the northern sea lion dentition and of the first deciduous premolar in the fur seal dentition, which may be interpreted as examples of evolutionary recession towards the full mammalian dentition. (2) There is a complete tooth reduction of the molars in the sea lion dentition. (3) There is the presence of a “Dentes geminati” of the second premolar and the supernumerary tooth in the right upper jaw and of the supernumerary tooth between the second and third premolars in the left upper jaw of an adult fur seal, which may be associated with the division of the second premolar tooth germ. (4) There is an appearance of a pair of supernumerary teeth lying lingually to the root of lower permanent central (second) incisors, being of interest in suggesting that they are either the appearance of the successors of the recent central incisors or the reappearance of the permanent first incisors, in the fur seal dentition. (5) There is a tooth reduction in the permanent dental formula from \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm I}\,\frac{{\rm 3}}{{\rm 2}}{\rm C}\,\frac{{\rm 1}}{{\rm 1}}{\rm P}\,\frac{{\rm 4}}{{\rm 4}}{\rm M}\frac{{\rm 1}}{{\rm 1}}\,{\rm to}\,{\rm I}\,\frac{{\rm 3}}{{\rm 1}}{\rm C}\,\frac{{\rm 1}}{{\rm 1}}{\rm P}\,\frac{{\rm 3}}{{\rm 4}}{\rm M}\frac{{\rm 1}}{{\rm 1}} $\end{document} in the seal, which was associated with a “Dentes confusi” in the same category of the dentition.
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  • 68
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    The @Anatomical Record 148 (1964) 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 69
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    The @Anatomical Record 148 (1964), S. 67-74 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Neuroanatomical nuclear configuration corresponding to the projection regions for the chorda tympani, the IXth, and the lingual nerves was studied in the cat thalamus by a combination of electrophysiological, stereotaxic, and histological techniques. Each of the three nerves innervating the tongue was dissected for stimulation in cats deeply anesthetized with Nembutal. Maps of the extent of the thalamic projection for a particular nerve were obtained by recording evoked potentials in the thalamus during the stimulation of one of these nerves. Such maps were correlated with the anatomical structures of the cat thalamus by reconstructing the recording sites from histological sections of the cat brain. It was found that the chorda tympani and the IXth nerve projection regions correspond closely to the ventromedial nuclear complex with slight encorachment on the lingual nerve projection region in the ventrobasal complex. The most medial portions of the taste nerve projection regions do not relay any tactile afferent impulses and the most lateral portion of the lingual nerve projection is not activated by impulses in the taste nerves. Therefore, it is suggested that the thalamic relay of taste is not coextensive with other lingual modalities in the cat thalamus but it has an independent representation in the ventromedial nuclear complex.
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  • 70
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Analysis of age changes in physical characteristics of mouse limb bones requires a sensitive, consistent and relatively simple apparatus for determination of transverse breaking strength. The developed instrument is essentially a one meter counter-balanced 4-to-1 lever with a tracked, motor-driven weight on its upper surface. At the beam's short end a loading tool impinges upward on a bone mounted in an adjacent holder; at the opposite end is a mercury switch connected to a relay halting the weight motor when fracture occurs. Bones, with proximal ends embedded in convex securing blocks of impression medium, may be positioned in a standard relationship to the holder, loading tool edge, and the balanced beam.Repetitive loading of a steel spring indicates instrument error of 1.8%. Preliminary tests with a random series of paired mouse femora show no significant difference between left and right bones. In the long-term study it will be possible to correlate physical strength with other characteristics of opposite bones.An air-gap capacitor across loading tool and bone holder and coupled to a variable frequency oscillator permits monitoring of specimen elasticity on a strip-chart recorder.
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  • 71
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    The @Anatomical Record 148 (1964), S. 103-109 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A malformed human fetus with multiple congenital anomalies including absence of an umbilical artery is described. These anomalies include malpositioning of the apex of the heart; a “mirror image” position of the liver; mal-rotation of the gut with absence of external demarcation into small and large intestine; failure of development of the cloacal region with imperforate anus and absence of a urethra; undescended testes and bilaterally mal-placed scrotal sacs, but the presence of a median phallus in spite of the failure of the ventral abdominal wall to develop fully.Factors known to influence the production of fetal anomalies in man and animals are discussed and a brief review of the literature on single umbilical arteries, which are known to be associated frequently with congenital anomalies, is given.
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  • 72
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Electron microscopic studies reveal that the red pulp of the rabbit spleen is composed of reticular cells, reticulum and elements of the blood circulating through it. The three types of reticular cells described follow no definite pattern as to types of spaces they line and are not always adjacent to a basement membrane. Similar or dissimilar cells may line a basement membrane on the same or opposing sides. The entire red pulp area is intercommunicating through pores and junctions of the several spaces and in that area in which no basement membrane exists, the cytoplasmic projections of the reticular cells form a meshwork of spaces. Terminal arterioles are seen to end in collapsed type channels with a change from endothelium to Type I reticular cells. These rapidly join dilated areas. The reticular network of the spleen appears as four types: homogeneous, fibrillar, a combination of these, and reticular cells only. Isolated cilia are found in the reticular cell cytoplasm and are shown to be associated with a basal body and a centriole. The investigation supported the hypothesis that the red pulp of the spleen in the adult rabbit is a functionally dynamic area constantly changing its histological structure, both regarding cells and state of the vascular channels.
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  • 73
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    The @Anatomical Record 148 (1964), S. 121-122 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 74
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    The @Anatomical Record 148 (1964) 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 75
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    The @Anatomical Record 148 (1964) 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 76
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Colloidal mercuric sulfide injected into the rete testis adhered to the stereocilia of the epithelial cells and subsequently moved into a highly developed canalicular system in the apical cytoplasm. The canalicular invaginations of the cell surface arising between the stereocilia lead to cytoplasmic vacuoles that concentrate the particulate matter. The limiting membrane of the stereocilia and of the canaliculi and vacuoles is covered by a layer of amorphous material. It is speculated that this may bind particles, molecules, and ions as does an ion exchange resin, and that it may, in this way, act as a carrier in the uptake and transport of substances by cells.
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  • 77
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    The @Anatomical Record 148 (1964), S. 507-516 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: In this study the distribution of mast cells in the cephalic, middle, or caudal portions of the uterine horns did not differ. In cross-sections, however, mast cells were most numerous in the myometrium, intermediate in the tunica vasculare of the endometrium and least in the mucosa. In the endometrium, the mast cells were most numerous in the antimesometrial, least in the mesometrial and intermediate in the lateral quadrants. In the myometrium, however, the relative numbers of mast cells between the quadrants varied according to the day in the estrous cycle.On days 1 (the day after estrus), 2, 3, and 4, (the day of proestrus) of the estrous cycle, there were respectively 42.7, 21.8, 22.5 and 10.7 mast cells in the endometrium per 12 μ sections. The differences in means between groups was highly significant (P 〈 0.001). In mated females on 67, 79, 91, 103, 115, and 151 hours after ovulation, there were respectively 9.4, 8.4, 4.7, 5.6, 2.1, and 2.2 mast cells in the endometrium per 12 μ cross-section. The differences in the means were not significant.The mean number of mast cells per 12 μ cross-sections of uteri of ovariectomized females was 20 ± 8. Subcutaneous injections of 0.3 gamma estrogen did not significantly alter the number of mast cells but 0.6 gamma depressed the mean count to 11 ± 7.It appeared from these studies that the uterine mast cell numbers were related to the cyclic phenomena of estrous, but that the numerical relationship to the time of nidation was not clear.
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  • 78
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    The @Anatomical Record 148 (1964), S. 552-552 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 79
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: An analysis was made on 140 adult chickens of the relationship between visual estimation of the degree of encroachment of the lumen of the vessel by plaques and such morphometric variables as weight, length, circumference, thickness, density, and combinations thereof of the thoracic and abdominal segments of the aorta. Aortic weight and thickness functions were found to be significantly correlated to scores, accounting in the two highest cases (thickness and weight/area of the abdominal segment, body weight held constant) for 46% (r = 0.68) and 42% (r = 0.65) respectively, of the variability in score. Correlations were considerably lower in the thoracic segment, the highest being r = 0.36 for weight/circumference. The scoring thoracic segment, the highest being r = 0.36 for weight/circumference. The scoring system thus has a basis in measurable physical changes in the wall of the blood vessel, but scoring apparently evaluates considerably more than was measured by the morphometric variables. The morphometric variables would probably serve best as means of comparing different scoring systems and as objective supplements to scoring. The procedure of choice would appear to be weight/area with body weight held constant (i.e.  -  partial correlation and/or covariance analysis).
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  • 80
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: In the literature the nutrient artery to the diaphysis of the canine femur has been described as arising from the medial circumflex femoral artery which is a branch of the deep femoral artery. However in 19% to 100 canine hind extremities dissected after injection with colored media, the femoral nutrient artery arose from a large muscular branch (the proximal posterior femoral) of the superficial femoral artery. In 17% of 42 dogs one femur only was supplied by this variant. In three additional femurs other variations occurred.
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  • 81
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Following surgical removal of one eye, rats were permitted to survive for three days, one, two and four months, and before killing them they were injected with 2 mc of leucine-H3 intraperitoneally. The utilization of this radiochemical was investigated in the brain autoradiographically. In all groups of animals the uptake of radioleucine, as determined by microdensitometry, was significantly higher in the “degenerated” optic nerve and tract than in their “normal” counterparts, with the relative difference increasing with longer postoperative survival within the periods tested. This progressive net increase in the utilization of leucine-H3 was associated with an absolute increase in the number of glia cells. Similar, but attenuated, density differences were also obtained with relatively large-aperture measurements over the stratum griseum of the superior colliculus in which the optic tract fibers terminate. In contrast, small-aperture measurements of grain density over single neurons in the lateral geniculate nucleus showed no difference in the utilization of leucine-H3 between the normal and subtotally deafferented sides. This suggests an absence of transneuronal changes in protein metabolism in the visual system of the rat as long as four months after unilateral enucleation.
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  • 82
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    The @Anatomical Record 148 (1964), S. 573-579 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Fixation of the thyroid gland with formaldehyde-ethanol-acetic acid retains a larger proportion of colloid constituents than aqueous formaldehyde.Comparative histochemistry has revealed a larger proportion of protein, arginine, cabohydrates and iodinated material.The heterogeneous staining pattern was not observed after aqueous formaldehyde fixation.The intracellular globules and the early iodinated fraction of the colloid were similarly stained.Intracellular globules were not observed in aqueous formaldehyde-fixed tissues.Only the more slowly labeled fraction of the colloid (large follicles), was stained by toluidine blue and also by bromphenol blue without mercury, indicative of basic proteins.
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  • 83
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    The @Anatomical Record 148 (1964), S. 553-559 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The pleural cupola is covered by a distinct dome-shaped suprapleural membrane (Sibson's fascia) formed by a condensation of endothoracic fascia and continuous at its periphery with the more diffuse, loose endothoracic connective tissue lying between the ribs and the parietal pleura. This does not agree with the classic description of Sibson's fascia. It forms a discreet cervicothoracic cloison which can be readily separated from the pleura and adjacent mediastinal structures. Attaching to the membrane are the vertebromembranous, transversomembranous, and costomembranous bands which are formed by prevertebral fascia. In addition, the last two suprapleural bands receive contributions from the fibrous remains of the scalenus minimus muscle. The muscle was found to be present on one or both sides in 30 out of 64 bodies (46.8%). The suprapleural membrane and bands can become hypertrophied and fibrous as a result of pathology in this cupola area of the lung. The bands have been implicated in certain clinical syndromes.
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  • 84
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    The @Anatomical Record 148 (1964), S. 561-571 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Wistar strain albino rats were injected with 1 cm3 of a 1% solution of trypan blue. Three types of dye were used: Matheson, Coleman and Bell, Chroma-Gesellschaft and a highly purified sample. The dyes were injected on days 6, 7, and 8 of gestation. Fetuses were excised from days 16 through 20, fixed, decalcified where necessary, embedded in paraffin, serially sectioned and stained. Newborn young were treated similarly. Chroma-Gesellaschaft trypan blue was without reproductive or teratogenic effect at the above doses. Increasing the dose did not increase the teratogenicity but did yield a decrease in litter size. Both Matheson, Coleman and Bell trypan blue and the purified sample were teratogenic. The most frequent neural defect observed was hydrocephalus. Serial sections of the newborn hydrocephalics showed an occluded or extremely tenotic aqueduct of Sylvius in 31 of 33 sectioned animals. The fetuses collected from days 18 through 20 also had occluded or stenotic aqueducts if hydrocephalic. Aqueductal stenosis or occlusion was present in 17-day-old fetuses, but hydrocephalic was not conclusively demonstrated at this age. Sixteen-day-old fetuses did not have aqueductal occlusion in any of those examined, but stenosis was evident. It is concluded that the defect predisposing to hydrocephalus in the young of trypan blue treated rats of this strain is aqueductal stenosis or occlusion.
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  • 85
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Testicular fragments from newborn, 4, 14, 24, 37-day old and mature rats were cultured using a modification of Trowell's method. Eagle's medium supplemented with amino acids, Na-pyruvate and 10% calf serum was employed. Tissue fragments were fixed at time intervals for histologic study. In cultures of fragments from newborn and four-day rats, gonocytes persisted and showed mitotic activity. In fragments from older but still immature animals, gonocyte-like cells occasionally undergoing mitosis, appeared in the germinal epithelium after the fourth day in culture. Spermatocytes survived for approximately four weeks. More rapid degeneration of the germinal elements beyond spermatogonia was observed in cultures of mature testes. During the first six days in culture, cells resembling gonocytes, some in mitosis, appeared in the tubules. The studies have shown that under the conditions employed, Sertoli cells and gonocyte-like could be maintained for at least four months in cultured fragments of testes from animals of various ages. In fragments from older animals, gonocyte-like cells appeared shortly after initiation of culture while the more mature germinal elements ultimately degenerated.
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  • 86
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    The @Anatomical Record 148 (1964), S. 605-609 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Follicular activity in the ovary of the pregnant hamster is divided into two periods. During the first eight days (corresponding to the duration of pseudopregnancy) an average of 11 follicles per ovary from 277 to 553 μ are present. From day 10 to 16 of pregnancy, the ovary contains 22 follicles ranging from 277 to 600 μ and larger. The day after parturition, atresia destroys all large multilayered and vesicular follicles.Hamsters injected with human chorionic gonadotropin on day 4 of pregnancy ovulated ten ova, whereas similary treated day 12 animals ovulated 35 eggs. No cyclic follicular activity corresponding to the length of the estrous cycle occurred during gestation. On the contrary, a constant increment of small follicles took place throughout pregnancy.
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  • 87
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    The @Anatomical Record 148 (1964), S. 591-597 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The morphology of the cecal mucosa and the topographic distribution of certain mucosal enzymes were compared in conventional and germfree mice to investigate the phenomenon of cecal enlargement observed in germfree animals. The cecal mucosa is predominantly non-villous in the conventional, but has a villous structure in the germfree mice. Alkaline phosphatase, in the conventional mice, is present in the striated border of a limited number of the epithelial cells lining the cecum; in the germfree mice almost all these epithelial cells show enzymatic activity. Acid phosphatase is more abundant in the epithelial cells and macrophages of the cecal mucosa of the conventional than of the germfree animals. Both groups show similar monoamine oxidase and reduced diphosphopyridine nucleotide diaphorase activity. The reduction of the villi, and the decrease in alkaline phosphatase activity in the conventional mice point to an involution of the mucosa as an absorptive organ. Barka ('63) has suggested that acid phosphatase may have a defensive function; its increase in the conventional animal would support this interpretation. The two oxidative enzymes studied apparently are not influenced by the intestinal flora.
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  • 88
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    The @Anatomical Record 148 (1964), S. 599-603 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: With the object of investigating the so-called “feed-back” mechanism whereby hormones from the various endocrine glands presumably influence the hypothalamus in its regulation of the hypophyseal tropic hormones, the effect of hypophysectomy, ovariectomy, thyroidectomy, adrenalectomy and adrenal medullectomy on the nucleolar size of neurons in 16 hypothalamic nuclei was studied. A total of forty-five female albino rats was used. The nucleoli were measured under oil by means of a Cooke AEI image splitting eyepiece. For every rat 50 nucleoli in each of the 16 hypothalamic nuclei was measured, a total of 36,000 measurements. Hypophysectomy was found to affect all of the nuclei either after a short period (5 days) or after 60 days. Ovariectomy (20 days) caused nucleolar size changes in six nuclei, thyroidectomy (30 days) in eight, adrenalectomy (14 days) in all of the nuclei and adrenal medullectomy (30 days) in all of the nuclei. The results indicate that the absence of the various hormones does affect the activity of hypothalamic neurons as determined by nucleolar size changes. The use of the present methods also appears to “localize” centers for specific activities in the hypothalamus in some instances (e.g. ovariectomy) but not in others (e.g. adrenalectomy).
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  • 89
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The gross arterial blood supply to the trachea, primary bronchi, and esophagus of six normal domestic rabbits has been studied by the use of injection techniques followed by careful in situ dissections. Several patterns are described with more variation being apparent on the left side.
    Additional Material: 5 Ill.
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  • 90
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 148 (1964), S. 631-632 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A plastic sealing compound for museum jars is described. It has the consistancy of toothpaste and is applied in a similar manner directly to the museum jar from a tube. No catalyst or mixing is required. Moisture in the air cures the plastic in 12-24 hours. After the extruded “rope” is applied, the lid is placed on the jar and the jar set aside for the cure. After cure any excess can be trimmed with a scalpel.
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  • 91
    Electronic Resource
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 149 (1964) 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 92
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Recent Primate research projejcts utilizing the squirrel monkey (Saimiri sciureus) established the need for basic biological data concerning this animal. Included in this present report are discussions of laboratory maintenance, dietary requirements, and antihelminthic thearpy. Original data on birth weight (90-100 gm) and the gestation period (167 ± 2 days) are recorded. The weight distribution of a colony of adult animals maintained in captivity for a period of three years is included. Fresh organ weights from ten animals obtained at necropsy were recorded for brain, pituitary, heart, lungs, spleen, liver, pancreas, kidney, adrenals, and gonads. Body weight, body length, and the length of the esophagus, stomach, duodenum, small intestine, cecum, and colon were recorded. Determination of hematologic values included erythrocyte and leukocyte counts, hemoglobin and hematocrit determination and differential count of white blood cells. Various blood chemistry values are included. Data on heart rate, respiratory rate and body temperature of animals restrained for a 24 hour period are tabulated. Environmental stress and neuroanatomical studies using the squirrel monkey are reviewed.
    Additional Material: 3 Ill.
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  • 93
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The course of development of parabiotic anastomosis was followed with respect to time in Holtzman (Sprague-Dawley) parabionts. Comparison of non-irradiated pairs was made to pairs in which one of the partners had received 800 r. The development of the anastomosis was studied by determining the per cent transfer of CR51 labeled erythrocytes (which represented a cellular element) and radio-iodinated serum albumin (which represented a molecular element) from one partner to the other. Erythrocytes were found in the non-injected animal in small numbers at 22 hours after pairing; at 47 hours the rate of transfer became much more rapid. RISA was detected in the non-injected partner as early as five hours after pairing and accumulated steadily thereafter. Irradiation had no effect on the course of development of the parabiotic anastomosis as evidenced by similarity of accumulation rates of Cr51 labeled erythrocytes and RISA when compared to the non-irradiated pairs.
    Additional Material: 3 Ill.
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  • 94
    Electronic Resource
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 149 (1964), S. 23-35 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A light and electron microscopic study of the early changes which occur in cadmium necrosis of the testis of the mouse was made in an effort to identify the site of action of cadmium. Mice were given a single, intraperitoneal injection of 1% CdCl2 at a dosage of 0.1 ml/10 g body weight and then the testes were fixed for light and electron microscopy at various hourly intervals. The earliest changes which were appreciated by light microscopy consisted of an edema of the intertubular spaces, congestion of blood vessels, and an increased amount of granular precipitate in the connective tissue spaces. By electron microscopy the earlies changes were observed in the endothelium of the testicular vascular bed and consisted of a striking and rapid increase in the prevalence of pinocytotic vesticles suggesting an increased interchanges of fluid between the blood and extravascular spaces. All of these changes preceded any appreciable alteration in the cells of the seminal epithelium. The fact that the earliest alterations are observed in blood vessels suggests that the site of action of cadmium in the production of testicular necrosis is upon the endothelium of the vascular bed.A comparative series of animals (frog, pigeon, rooster, armadillo, opossum) was also investigated as to their susceptibility to the toxic effects of cadmium. the results from these species, and other species reported by previous investigators, suggest the generality that cadmium necrosis is a phenomenon common to species possessing scrotal testes and absent from those possessing abdominal testes. The opossum is an exception to this generality. These findings are discussed in relation to the blood supply of the testis.
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  • 95
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: First, using the methods of H3-thymidine autoradiography and counting mitotic index, cytokinetics of the matrix cells were studied in the telencephalon of normal mouse embryos at ten-days-postconcetpion, and various kinetic constants of the matrix cells were determined: Generation time, five hours 20 minutes; mitotic duration, 24 minutes; presynthetic resting time, two hours 36 minutes-one hour 36 minutes; DNA synthetic time, one hour 20 minutes; and post synthetic resting time, one-two hours. Based on this information, effects of two teratogenetic agents, x-rays and thio-TEPA, on the cellular proliferation were analyzed. By x-ray irradiation (200 r) only proliferating matrix cells are damaged in the neural tube, but not neuroblasts. The radiation induces a temporary block of the flow of the matrix cells through the cell cycle at the late t2 period so that the mitotic and DNA synthetic cells subsequently decrease in number. Some of the matrix cells that are captured at t2 period fail to tolerate the block, degenerate and are eliminated from the matrix layer. On the other hand, thio-TEPA, which was proved non teratogenetic to the C. N. S. in this experimental condition, causes a slight prologation of t2 duration, but does not significantly influence the proliferative process in the neural tube.
    Additional Material: 6 Ill.
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  • 96
    Electronic Resource
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 149 (1964), S. 49-55 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A purified diet lacking folic acid and containing 20 mg% of the antimetabolite, 9-methyl pteroylglutamic (folic) acid was fed to female Long-Evans rats during days eight and nine of pregnancy. Embryos were removed at autopsy on the tenth day of gestation for study and comparison with embryos from normal control pregnancies.Analysis of mitotic counts revealed that 18.6% of the cells in control embryos were in mitosis in contrast to only 5.7% in PGA-deficient embryos. A disproportionate reduction in anaphase and telophase stages was observed in conjunction with an increased percentage of cell at metaphase. Concomitantly with these mitotic changes a marked reduction in histochemically demonstrable RNA and in numbers of ribosomes as revealed by electron microscopy was observed.
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  • 97
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 149 (1964), S. 397-404 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A 79 year-old European female cadaver presented the usual features of second stage arrested mid-gut rotation accompanied by unusual mesenteric attachments and pancreatico-duodenal relationships.The mesentery, whose root extended from the lower pole of the right kidney diagonally across the posterior abdominal wall to end just medial to the left sacroiliac joint, enclosed most of the small bowel and the proximal large bowel. The unusually short duodenum began 2.5 cm to the left of the mid-line and described a 13 cm U loop with an upward concavity in which rested the pancreas; this loop and the related pancreas were enclosed in a persistent, transversely placed mesoduodenum. The common bile duct crossed the anterior surface of the pancreas to open at the greater duodenal papilla 2.5 cm from the pylorus. the main pancreatic duct lay much closer to the anterior than to the posterior aspect of the gland. The lesser duodenal papilla was situated on the posterior wall of the duodenum. The hepatic artery arose in common with the superior mesenteric artery and encircled the pancreas. The pancreatico-duodenal vessels were predominantly distributed upon the posterior aspect of the pancreas and duodenum.It appears that in this specimen the anterior and posterior aspects of the duodenum are transposed, the reversal of surfaces also involving the pancreas. Causative factors are discussed with reference to the literature.
    Additional Material: 7 Ill.
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  • 98
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A number of histologic and histochemical techniques have been used to study 42 human fetal thyroids from fresh specimens ranging in crown-rump length from 22 to 201 mm. Three periods of differentiation (colloid production) were defined. The first or precolloid stage was found in fetuses of 22 to 65 mm and consisted of strands of compact epithelial cells separated by loose connective tissue which contained only a few vessels. The early colloid production period from 65 to 80 mm was characterized by the appearance of small accumulations of colloid in the center of the follicles. The blood vessels between follicles increased during this period. In the last period during maturation of the colloid cavities, the spaces between the epithelium were more reduced and almost completely filled with blood vessels. No change in the average cell height was found during differentiation.With differentiation, the nuclei of epithelium became less compact and RNAase-removable cytoplasmic material increased. Also of interest was the marked decrease in glycogen at the time of colloid production.The staining characteristics of the early colloid showed little change during the period studied. The colloid was stained by the following reagents: periodic-acid Schiff, mercury organge, toluidine, ninhydrin-Schiff, Millon's and Sakaguchi's. The larger colloid spaces took slightly more toluidine stain than the smaller ones.The enzyme reaction for alkaline phosphatase was found only in the vascular system, and acid phosphatase was found in the cytoplasm of epithelium and, especially in the differentiated specimens, it was concentrated at the apex of the cell. Lactic and succinic dehydrogenase activity did not seem to change with maturation and was located in the cytoplasm around the nucleus and toward the apex of the cell.Thin rays of colloid-like material were observed to radiate out between cells from early colloid cavities. Based on unpublished electron microscopic data, organ cultures of human thyroid and observations from the developing chick, these spaces probably represent intercellular dilatations which have been filled with colloid from the central cavity. These spaces may be a secondary or safety mechanism which allows the circumference of the follicle to increase in size.
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  • 99
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 150 (1964) 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 100
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 150 (1964), S. 11-24 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The topography of nasal glands in rats, guinea-pigs, rabbits, cats, and monkeys was studied in osmium tetroxide and PAS-stained whole mounts and ordinary sections. In rats Bowman's glands in the olfactory region were arranged in rows between the branches of the olfactory nerve. Mucous acini were only found on the rat septum in connection with Jacobson's organ, and serous acini were found on the septum posteriorly in the respiratory region, and on the lateral wall of the nasal cavity around the maxillary sinus ostium. No mixed glands were present. All the serous glands discharged their secretion through long excretory ducts into the ostium internum of the vestibule of the nose. In this area rats had 15-20 duct openings on each side. On the basis of considerations regarding airstream and pressure in the vestibule, the hypothesis is advanced that the openings act as small nozzles humidifying the inspired air by their atomized secretion. Since no serous or mucous glands in the rat open on the surface in the nasal cavity proper, it is concluded that the surface mucous sheet is derived exclusively from the goblet cells and Bowman's glands. In the other mammals the opening of the serous glands showed a similar pattern.
    Additional Material: 10 Ill.
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