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  • 1
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The influence of environmental parameters (temperature, salinity and available food) on the condition, reproductive activity and biochemical composition of a native population of Ostrea edulis L. in San Cibran (Galicia, Spain) was studied between September 1988 and December 1989. Histological preparations of gonads showed that gametogenesis started when temperature was at its lowest in winter. The water temperature in San Cibran never fell low enough to interrupt it. Gametogenesis proceeded slowly and spawning took place in May–June, although the predicted time of ripening was early March. Salinity in San Cibran was relatively stable throughout the year; it did not seem to have any influence on gametogenesis. Available food appeared to be a very important factor in controlling gonad growth, once gametogenesis was initiated. The major concentration of suspended organic particulate matter was present in the spring at the time of rapid gonadal maturation. Only one spawning period was observed. Larvae were released when the food in the water was high. Seasonal changes in the main biochemical components of this oyster were determined for a standard individual. Lipids and carbohydrates presented a similar time-course whereas proteins were constant. When food was abundant, energy reserves were built up. Spawning produced a decrease in biochemical constituent levels, and recovery coincided with the phytoplankton bloom. The stored reserves, mainly lipids, were used to overcome a state of energy imbalance in late autumn associated with low food availability. Results show this oyster to be an opportunist organism which concentrates its reproductive effort during a short period of favourable conditions and which is directly dependent on nutritive availability in the environment.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Small-scale population densities of tidal creek eastern mudsnails, Ilyanassa obsoleta Say (studied in 1986 and in 1992 at West Meadow Creek, Stony Brook, New York) corresponded more to variation in water flow velocity than to surface sediment chlorophyll a. Higher densities were found at low flow sites. Short-term behavioral responses are likely to be responsible for density variation. Experiments using laboratory flumes and field observations both demonstrated that the snails responded to strong flow by burrowing into the substratum. Burrowing may prevent dislodgment from the sediment surface, but it also appears to be disadvantageous since burrowed mudsnails have smaller amounts of food in their guts. Snails released in sites of periodic high flow conditions moved greater distances and were soon found near the quiet-water periphery of the creek, whereas snails released at the quiet-water periphery moved far less. It is not clear whether movement from the high flow site was through crawling or through hydrodynamic transport. Laboratory flume experiments demonstrated an active crawling movement towards areas of lower current velocity. This evidence suggests that strong bottom flow in the creek center results in a combined response of burial to avoid dislodgment and a net movement towards quiet water, which reduces exposure to the high velocity conditions of the creek center.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Applied microbiology and biotechnology 9 (1980), S. 189-197 
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Clostridium thermocellum ATCC 27405 (and its improved cellulase-producing mutant, AS-39) is an anaerobic thermophile that produces endo-β-glucanase and exo-β-glucanase when grown on cellobiose or cellulose as major carbon source (Shinmyo et al. 1979). The site of cellulase accumulation was at least 95% extracellular. Optimum conditions for endo-β-glucanase production in flasks included 1% (w/v) cellobiose, 0.2% (w/v) urea as a nitrogen source, 0.1 M morpholinopropane-sulfonic acid buffer, an initial pH of 7.4, and a yeast extract concentration of 0.6% (w/v). An improved medium (GS medium) was devised for future studies. Xylan was degraded by an extracellular enzyme (s) produced during cultivation on cellobiose, although C. thermocellum does not grow on xylan.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 537-538 (Feb. 2007), p. 533-540 
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The process known as Tempcore is used to produce high resistance rods by the formationof a surface layer of quenched and tempered martensite that surrounds a core made of ferrite andpearlite. Such a mixed structure is result of processing hot rolled rods through waters headers thatreduce the temperature at the surface below that for the transformation into martensite. Thisstructure is tempered by the heat flowing from the core of the rod, which transforms into ferrite andpearlite while the rod is in the cooling beds. Such processing produces a significant increase in yieldand ultimate tensile strength, while maintaining adequate ductility. The economic advantages of thisprocess are huge in comparison with those that require alloying elements or further metal workingto improve mechanical properties. A series of experimental trials were carried out in a pilot plant inwhich parameters such as reheating temperature, water flow and processing time were varied tostudy their effect on the mechanical properties of carbon steel rods and on the structures formed inthe bars. The study is being complemented by the thermal modelling by the finite element method
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1248-9204
    Keywords: Inguinal hernia ; Diagnosis ; Laparoscopy ; Surgery
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The preoperative diagnosis of inguinal hernias is one of the surgeon's most commonplace duties yet one of the least valued aspects in the treatment of this pathology. The introduction of the laparoscopic technique for inguinal hernia repair may stimulate an interest in this problem. The aim of the study is to analyse the diagnostic accuracy of clinical examination of inguinal and femoral hernias. 278 patients with a possible inguinal and femoral hernia received from the same surgeon a thorough clinical examination and preoperative diagnosis of the type of hernia (indirect or direct inguinal, and femoral). The data obtained were compared to the intra-operative findings. The influence of age, sex and site was studied with regard to the sensitivity of the clinical diagnosis. Direct inguinal hernias accounted for 35% of the total. Indirect inguinal hernias were diagnosed more accurately (85%) than direct (64%) and femoral (39%) hernias. Clinical diagnosis was not influenced by age, sex or site of the femoral hernia. Statistically significant differences were revealed only for inguinal hernias in the group of patients aged over 50 years and with a unilateral site (p〈0.05). Thorough physical exploration should never be underrated in the diagnosis of inguinal hernias as it may help classify hernias with great accuracy.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1248-9204
    Keywords: Incisional hernia ; Prosthesis ; Expanded polytetrafluorethylene ; Mesh repair ; Recurrence rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Incisional hernia is a common problem seen by the general surgeon, with one alternative for repair being the use of a prosthetic material. This study analyzes the results obtained with an expanded polytetrafluoroethylene patch (e-PTFE) in the management of 53 moderate and large incisional hernias, using a predesigned operating approach. A specific technique was indicated depending on the result of evaluation of the transverse diameter of the hernial orifice and the status and trophy of the rectal muscles and their sheaths. The PTFE prosthesis was used in 30 cases as reinforcement, while in the remaining 23 cases it was placed as the only retention plane. All patients were reviewed a minimum of 6 months and a maximum of 78 months postoperatively, with an average follow-up of 40 months. There were no postoperative respiratory or haemodynamic complications and there was no operating mortality. There was wound infection in two cases (3.7%), and four recurrences were detected (7.5%). On the basis of our clinical experience, we believe that e-PTFE is an acceptable mode of treatment for incisional hernias. With the predesigned operative approach, the infection rate was low with a recurrence rate of 7.5% at a mean follow-up of 40 months.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Journal of Chromatography B: Biomedical Sciences and Applications 528 (1990), S. 459-463 
    ISSN: 0378-4347
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Analytica Chimica Acta 263 (1992), S. 143-146 
    ISSN: 0003-2670
    Keywords: Gold ; Kinetic analysis ; Minerals ; Piezoelectric sensing
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Archives of Biochemistry and Biophysics 148 (1972), S. 224-227 
    ISSN: 0003-9861
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Child Abuse & Neglect 18 (1994), S. 969-976 
    ISSN: 0145-2134
    Keywords: [Keyword] Adolescence ; [Keyword] Sex offenses ; [Keyword] Treatment
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Psychology
    Type of Medium: Electronic Resource
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