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  • 1
    Electronic Resource
    Electronic Resource
    Oxford BSL : Blackwell Science Ltd
    Molecular microbiology 31 (1999), S. 0 
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: TonB couples the cytoplasmic membrane protonmotive force (pmf) to active transport across the outer membrane, potentially through a series of conformational changes. Previous studies of a TonB transmembrane domain mutant (TonB-ΔV17) and its phenotypical suppressor (ExbB-A39E) suggested that TonB is conformationally sensitive. Here, two new mutations of the conserved TonB transmembrane domain SHLS motif were isolated, TonB-S16L and -H20Y, as were two new suppressors, ExbB-V35E and -V36D. Each suppressor ExbB restored at least partial function to the TonB mutants, although TonB-ΔV17, for which both the conserved motif and the register of the predicted transmembrane domain α-helix are affected, was the most refractory. As demonstrated previously, TonB can undergo at least one conformational change, provided both ExbB and a functional TonB transmembrane domain are present. Here, we show that this conformational change reflects the ability of TonB to respond to the cytoplasmic membrane proton gradient, and occurs in proportion to the level of TonB activity attained by mutant–suppressor pairs. The phenotype of TonB-ΔV17 was more complex than the -S16L and -H20Y mutations, in that, beyond the inability to be energized efficiently, it was also conditionally unstable. This second defect was evident only after suppression by the ExbB mutants, which allow transmembrane domain mutants to be energized, and presented as the rapid turnover of TonB-ΔV17. Importantly, this degradation was dependent upon the presence of a TonB-dependent ligand, suggesting that TonB conformation also changes following the energy transduction event. Together, these observations support a dynamic model of energy transduction in which TonB cycles through a set of conformations that differ in potential energy, with a transition to a higher energy state driven by pmf and a transition to a lower energy state accompanying release of stored potential energy to an outer membrane receptor.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Bingley : Emerald
    Library review 45 (1996), S. 18-24 
    ISSN: 0024-2535
    Source: Emerald Fulltext Archive Database 1994-2005
    Topics: Information Science and Librarianship
    Notes: Examines the Tanzanian political system and reviews the new role of Parliament within it. Outlines information needs of Members of Parliament and the role of the parliamentary library and research services. Examines the Tanzania Parliamentary Library and suggests additional services to be provided. Points out that the parliamentary library and research services are enjoined to be neutral rather than hold party allegiance, in order to serve all parties represented equally and fairly.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Bingley : Emerald
    Marketing intelligence & planning 15 (1997), S. 54-59 
    ISSN: 0263-4503
    Source: Emerald Fulltext Archive Database 1994-2005
    Topics: Economics
    Notes: Based on an address to the Swedish Marketing Federation, considers how much longer conventional methods of consumer market research can be considered state of the art when academic study has moved into its postmodern phase.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1546-170X
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Medicine
    Notes: [Auszug] Xenotransplanted adrenocortical tissue of clonal origin was formed in immunodeficient (scid) mice by using techniques of cell transplantation. The experiments reported here used a single clone of bovine adrenocortical cells, but 5 of 20 other randomly selected clones also formed tissue. Most ...
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1572-8870
    Keywords: Polyorganosiloxanes ; mineral silicates ; low temperature-formed glasses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The reaction of the two model polyorganosiloxanes. QM4 and Q2M6, with ethanolic sodium hydroxide is reported (Q=SiO4 2 andM=Me3SiO1 2). Removal of theM groups from QM4 was rapid and led to the formation of a sodium silicate species which was insoluble in organic solvents. The reaction with Q2M6, however, was incomplete and gave hybrid structures of the type Q2M6 (O1 2Na). A possible pathway for the formation of the sodium silicate species from QM4 is proposed.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1572-851X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Sociology
    Notes: Abstract This paper examines an excerpt from a larger (televised) interview, wherein various married couples are asked to characterize their living situations in the aftermath of job loss and on the work of description and assessment by interview parties. It thus focuses on features of affiliation and disaffiliation and analyzes how both procedures work, particularly within an environment in which affiliated parties are engaged in attempting to figure out an "unpredictable" outcome of some (mutually experienced or experienceable) situation. In the excerpt, there are instances of both affiliation and disaffiliation. Using such conversation analytic structures as topic organization, story organization, preference structures, and distinguishing between content and structural affiliations, the interview excerpt is shown to contain a series of story stages, each of which is an element of the overall work of collaborative assessment. Within this assessment, parties make use of "content affiliations," wherein they reference their lived affiliation with one another, while at the same time, structuring their talk so as to disagree and disaffiliate with one another's stance. In contrast to such classical theorists as Durkheim, Simmel, Toennies and Cooley, who viewed affiliation as resulting from internal, emotive sources, or as Durkheim put it, saw this as being a non-directly measurable condition of "primary group" relationships, this report argues for the possibility of seeing affiliation as a performed, or achieved, activity. In this latter conception, one made evident through ethnomethodology and conversation analysis, affiliation - along with its counterpart, disaffiliation, are indeed external and measurable actions.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1433-0431
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Vom 18. bis 20. Juni 1998 fand unter der wissenschaftlichen Leitung des Tagungspräsidenten Prof. Dr. Georg Freiherr von Salis-Soglio im Congress Center der Neuen Messe Leipzig die 47. Jahrestagung der Norddeutschen Orthopädenvereinigung statt. Die 1100 Teilnehmer kamen überwiegend aus Deutschland, Österreich und der Schweiz, darüber hinaus konnten aber auch Gäste aus Japan und aus den USA begrüßt werden. Das Tagungskonzept war durch eine deutliche Konzentration des wissenschaftlichen Programms gekennzeichnet, was durch folgende Festlegungen gewährleistet wurde: Beschränkung auf 5 Hauptthemen, Freie Themen und 5 zeitversetzte Seminare Maximal 3 Parallelveranstaltungen Einleitende Übersichtsreferate von aufgeforderten Referenten Einheitliche Redezeit von 10 Minuten mit unmittelbar anschließender Diskussion Aufwertung der Posterausstellung mit 100 Exponaten im großzügigen Foyer Die partnerschaftliche Einbeziehung der Industrie dokumentierte sich nicht nur in großzügigen Ausstellungsflächen und langen Pausen, sondern darüber hinaus in der Integration zahlreicher Workshops in das wissenschaftliche Programm. Im Folgenden sollten einige wesentliche Inhalte der verschiedenen Sitzungen kurz referiert werden, wobei naturgemäß nicht jeder einzelne Beitrag erwähnt werden kann.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1433-0423
    Keywords: Key words Perimetry • Suprathreshhold • Threshhold • Duration of examination • Tübinger Automatic Perimeter ; Schlüsselwörter Perimetrie •Überschwellig • Schwellenwert • Untersuchungsdauer • Tübinger Automatikperimeter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Einleitung: Am Tübinger Automatikperimeter CC wurde eine vergleichende Studie zwischen der bekannten, schwellenorientiert überschwelligen Strategie und einer Schwellenwertstrategie mit 2 facher Eingabelung in 4- und 2-dB-Schritten durchgeführt. Ziel der Untersuchung war es, festzustellen, ob die Schwellenwertstrategie Vorteile gegenüber der bisher eingesetzten schwellenorientiert überschwelligen Strategie bietet. Methode: 49 freiwillige Patienten wurden am gleichen Tag mit der schwellenorientiert überschwelligen Perimetrie und der Schwellenwertperimetrie am Tübinger Automatikperimeter im 30 °-Gesichtsfeld untersucht. Die Untersuchung erfolgte mit 191 Punkten bei der schwellenorientiert überschwelligen Strategie. 67 Punkte wurden bei der Schwellenwertstrategie eingesetzt, ähnlich der Prüfpunktanordnung anderer Perimeter mit Schwellenwertstrategie. Einschlußkriterien waren: zentrale Lichtunterschiedsempfindlichkeit 〉 25 dB, Fixation 〉 80 %, geprüfte Leuchtdichteklasse 〈 − 2. Ergebnisse/Diskussion: Bei unauffälligen Gesichtsfeldbefunden oder kleinen Skotomen war die schwellenorientiert überschwellige Strategie um 2–3 min schneller als die Schwellenwertstrategie, bei großen Skotomen um bis zu 15 min langsamer. Auch in der subjektiven Prüfung der Ausfallskonfiguration fanden sich Unterschiede. Bei großflächigen Skotomen war die Erkennbarkeit der Ausfallskonfiguration für beide Strategien gegeben. Mit Abnahme der Skotomgröße führte das grobe, bei der Schwellenwertperimetrie verwendete Raster dazu, daß im Vergleich zur schwellenorientiert überschwelligen Perimetrie mit größerer Rasterdichte die Erkennbarkeit der Ausfallskonfiguration nachließ.
    Notes: Background: We compared the standard suprathreshhold strategy to the so-called threshhold splitting strategy with 5 and 2 dB steps. The aim of the study was to establish whether the threshhold splitting strategy had advantages over the suprathreshhold strategy that has been used to date. Method: We examined the 30 ° visual field in 49 volunteers using suprathreshhold perimetry and on the same day threshhold splitting perimetry on the Tübinger Automatic Perimeter CC. A total of 191 test points were examined in suprathreshhold strategy. Using the threshhold splitting strategy, 67 test points were examined, with a test-point design similar to other perimeters with the threshhold splitting strategy. The criteria for inclusion in the study were central light sensitivity differences greater than 25 dB, fixation better than 80 % and an illumination class density 〈 2. Results/Discussion: The average duration of the examination using the suprathreshhold strategy was 2–3 min quicker than the threshhold splitting strategy in normal visual fields or small scotomas, but it took up to 15 min longer if large scotomas were present. Interpretation of the scotoma configuration showed subjective differences: the smaller the scotoma, the greater the differences because of the fact that threshhold splitting perimetry utilizes test points that are farther apart than those used in suprathreshhold perimetry.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1573-7217
    Keywords: breast cancer ; cell proliferation ; dietary fat ; Ki-67 ; mammographic densities ; PCNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Increased dietary fat intake and rate of breastepithelial cell proliferation have each been associated withthe development of breast cancer. The goal ofthis study was to measure the effect ofa low fat, high carbohydrate diet on therate of breast epithelial cell proliferation in womenat high risk for breast cancer. Women wererecruited from the intervention and control groups ofa randomized low fat dietary intervention trial, breastepithelial cells were obtained by fine needle aspiration,and cell proliferation was assessed in these samplesusing immunofluorescent detection of Ki-67 and PCNA. Theeffects of needle size and study group oncell yield and cytologic features of the cellswere also examined. Fifty three women (20 inthe intervention group and 33 in the controlgroup) underwent the biopsy procedure. Slides from 38subjects were stained for Ki-67 and from 14subjects for PCNA. No cell proliferation (fluorescence) wasdetected for either Ki-67 or PCNA in anyof the slides. Epithelial cell yield and numberof stromal fragments were greater with a largerneedle size. Numbers of stromal fragments and bipolarnaked nuclei were greater in the low fatas compared to the control group but nodifferences in epithelial cell yield were observed betweenthe two groups. This study confirms that fineneedle aspiration biopsy is a feasible method ofobtaining epithelial cells from women without discrete breastmasses, but suggests that cell proliferation cannot beassessed using Ki-67 and PCNA in such samples.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    The environmentalist 18 (1998), S. 139-148 
    ISSN: 1573-2991
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract This is a report of a social environmental audit of urban renewal schemes based on an investigation of environmental hazard risk perceptions of people in their homes, workplaces and other places of urban activity, in the vicinity of five major renewal sites in Sandwell, West Midlands, UK. The selection of the renewal schemes was designed to incorporate a range of the types of contemporary urban development in the UK. People were asked to give a scaled score response reflecting the perceived magnitude of risk of each of a series of hazards. Each person was asked to give two responses to each hazard, one response referring to the actual present situation post-renewal and the second response referring to an imagined present situation as if renewal had not occurred. The statistical analysis of the responses suggested that urban renewal had brought about an increase in certain perceived environmental risks and not necessarily a more desirable perceived environmental state than the alternative of dereliction.
    Type of Medium: Electronic Resource
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