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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 70 (1999), S. 2253-2256 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: We have measured the absolute average photon flux, the spectral characteristics, and the time structure of x rays emitted from Ar clusters which were irradiated by a 100 fs laser with an intensity of 1017 W/cm2. The measured photon flux was 107 photons per shot in the Kα (at 3 keV) line in a 4π sr solid angle. The temporal structure was measured using a streak camera with a 10 ps time resolution. It was found that less than 1% of the photons were emitted within the 10 ps time-response function of the streak camera. The emission profile is roughly exponential with a time constant of 3 ns. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Aquaculture research 28 (1997), S. 0 
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: We review estimates of the spatial ecosystem support required to run a typical semi-intensive shrimp farm in a coastal mangrove area in Carribean Colombia, and to produce food inputs and process wastes for large-scale industrially managed tilapia cage culture and small-scale, semi-intensive tilapia pond farming in Lake Kariba, Zimbabwe. The tilapia farming is discussed in relation to the pelagic kapenta, Limnothrissa miodon (Boulenger), fishery and to inshore fisheries in the Lake.The results show that a semi-intensive shrimp farm needs a spatial ecosystem support—the ecological footprint—35 to 190 times the surface area of the pond, mainly mangrove area. Based on the analysis, we conclude that shrimp farming in Colombia is already utilizing close to the full support capacity of its coastal environment. In intensive tilapia cage farming, the ecological footprint for feed production is 10 000 times larger than the area of the cages. In contrast, a tilapia pond farm maintained on offals from fisheries, agriculture and households depends very little on external ecosystem areas. As long as there is a direct market for human consumption of all kapenta caught in the Lake, fish cage farming based on fish meal from kapenta would be doubtful from ethical, ecological as well as resource management points of view, even if it was economically feasible.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-0630
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1420-908X
    Keywords: Key words: Glucocorticoids — Neutrophil leukocytes — Surgical flaps — Stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Objective: Because glucocorticoid treatment can improve the survival of surgical skin flaps, we examined the influence of environmental stress on skin flap survival in the rat.¶Material: Female Sprague-Dawley rats.¶Treatment: Dexamethasone (1 mg/kg i.p.).¶Methods: A standardized dorsal skin flap was raised and sutured back into position, and six days later the percentage of flap survival was assessed. Corticosterone in rat plasma was measured using radioimmuno assay, and skin flap myeloperoxidase accumulation (reflecting neutrophil recruitment) was determined spectrophotometrically.¶Results: Skin flap survival decreased gradually during a 10 day acclimatization period after transportation of the animals from the supplier, and plasma corticosterone levels were increased during the first 5 days of acclimatization compared to day 7 and 10. Dexamethasone treatment of rats accustomed to their new environment for 10 days increased flap survival to a level close to that observed in animals operated at day 1 after arrival. Flap surgery induced pronounced neutrophil recruitment into flap tissue, and this cell accumulation was greatly reduced in both the dexamethasone treated rats and in rats with elevated corticosterone levels.¶Conclusions: Skin flap survival in rats exposed to environmental stress may be significantly increased as compared to animals accustomed to their new environment for one week, possibly as a consequence of anti-inflammatory actions exerted by stress-induced elevations in plasma corticosterone. These findings emphasize the importance of strictly controlling environmental stress factors in studies of inflammation and tissue damage after surgical skin trauma.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Annales geophysicae 14 (1996), S. 304-308 
    ISSN: 0992-7689
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The resonant interaction between three acoustic gravity waves is considered. We improve on the results of previous authors and write the new coupling coefficients in a symmetric form. Particular attention is paid to the low-frequency limit.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Computational mechanics 24 (1999), S. 293-303 
    ISSN: 1432-0924
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  The paper concerns the issue of progressive development of shear bands in drained and undrained porous media. The main focus is on the design of an overall numerical algorithm to solve the coupled set of non-linear FE-equations that arise from the embedded band approach. In particular, we are concerned with the proper numerical treatment of the condition for onset of localization in conjunction with ductile material failure, whereby failure occurs after significant amount of plastic deformation. In order to arrive at the proper design of the algorithm, we resort to a staggering between the continuous (global) problem and the discontinuous (element) problems. At the application to the numerical examples, the algorithm is shown to work well in terms its ability to capture onset of localization as well as post-localized behavior in conjunction with ductile material failure characteristics.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    International orthopaedics 21 (1997), S. 104-108 
    ISSN: 1432-5195
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé. L’objectif de cette étude prospective a été d’étudier si une augmentation de l’apport nutritionnel peut ameliorer la cicatrisation et réduire la mortalité chez les malades ayant subi une amputation de jambe en raison d’une maladie vasculaire. L’état nutritionnel de trente-deux patients consécutifs ayant subi une amputation de jambe a étéévalué. Vingt-huit ont été considérés comme malnutris. Une nutrition additionnelle leur a été donnée avec un apport moyen de 2098 kcal par jour pendant 11 jours. Chez 24 malades une nutrition additionnelle, de cinq jours au moins en préopératoire, a été suivie par un traitement postopératoire pour atteindre un total de 11 jours. Quatre malades necessitant une amputation en urgence n’ont re*u le traitement que postopératoire et quatre malades ont été exclus. Trente deux amputés de jambe venant d’un hopital universitaire voisin ont été utilisés comme contrôle, après associations des cas tenant compte de l’age, le sexe, du diabète, de la consommation de tabac, des opérations vasculaires précédentes et des conditions de vie antérieure à l’amputation. L’étude de la cicatrisation a montré que 26 amputés étaient cicatrisés dans le groupe ayant bénéficié d’un apport nutritionnel contre 13 dans le groupe de controle, P = 0.001. Neuf patients sont morts dans les premier six mois dans le groupe ayant bénéficié d’un apport nutritionnel contre 14 dans le groupe de controle, (n. s.). Cette étude montre clairement que près de 90% des amputés de jambe étaient malnutris et qu’un apport nutritionnel a amelioré la cicatrisation du moignon sans pour autant augmenter la survie.
    Notes: Summary. The objective of this prospective study of matched controls was to find out whether supplementary nutrition would improve wound healing and decrease mortality in patients undergoing transtibial amputation for occlusive arterial disease. The nutritional status of 32 consecutive transtibial amputees was assessed and 28 were classified as malnourished. Supplementary nutrition was given reaching an average intake of 2098 kcal/day for a total of 11 days. In 24 patients, at least 5 days of preoperative supplementary nutrition were given, followed by postoperative treatment for a total of 11 days. Four patients who had an immediate operation were given only postoperative treatment, and 4 were excluded. The controls were 32 amputees in another hospital and matching procedures were carried out with corrections for diabetes, sex, age, smoking habits, previous vascular surgery and living conditions before amputation. Healing, including those healed before death in both groups, occurred in 26 of the nutrition group compared to 13 in the control group, which was statistically significant. Nine patients died within 6 months in the nutrition group compared to 14 of the controls (not significant). Malnutrition was present in nearly 90% of transtibial amputees and supplementary nutrition improved healing, but not mortality.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 256 (1997), S. 652-660 
    ISSN: 1617-4623
    Keywords: Key words S-adenosylmethionine decarboxylase ; Polyamine synthesis ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract S-adenosylmethionine decarboxylase is a key enzyme in the synthesis of polyamines. These small cationic molecules are required for growth and development in all organisms. A wealth of biological processes, including synthesis of DNA and protein and condensation of chromatin, involve polyamines. Inhibition of polyamine synthesis has been proposed for treatment of cancer but this requires more knowledge about the in vivo function of polyamines. We report here the cloning of the S-adenosylmethionine decarboxylase gene from Drosophila melanogaster and the analysis of corresponding mutants. The mutant phenotypes are similar to those previously described for ribosomal protein genes (Minutes) and rRNA genes (bobbed ). This work elucidates the in vivo consequences of impaired polyamine synthesis with respect to the development of a whole animal.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Graefe's archive for clinical and experimental ophthalmology 237 (1999), S. 82-85 
    ISSN: 1435-702X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  · Background: The major histocompatibility complexes, MHC class I and II, are found only sparsely or not at all in the retina. Since the eye is immunoprivileged, we decided to investigate how the MHC class I and II antigens were influenced by a retinal transplant and whether this could be correlated to rejection of the transplant. · Methods: Fetal neural retinas of Sprague-Dawley (SD) rats were implanted in the subretinal space of adult Lewis and SD rats. After 5 weeks the retinas and the transplants were evaluated with antibodies against MHC class I and II antigens as well as microglia. · Results: In the syngeneic transplants no upregulation of MHC class I antigen was seen and no MHC class II-positive cells could be detected. In the allogeneic transplants, on the other hand, there was marked upregulation of MHC class I antigen. Numerous MHC class II antigen-positive cells were seen in the subretinal transplant but also in the host retina. · Conclusion: Allogeneic retinal transplants seem to grow and thrive just as well as syngeneic transplants, but in the former there is considerable upregulation of MHC expression. Our interpretation of these results is that the allogeneic transplants are recognized as non-self, but that there is also something that modifies this reaction of the immune system at this level, preventing the rejection that would normally ensue.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 67 (1998), S. 41-55 
    ISSN: 0020-7608
    Keywords: Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The CNM (characterization of normal modes) method for extracting chemical information out of vibrational spectra is tested for vibrational spectra of molecules with relatively strong or relatively weak coupling between internal vibrational modes. Symmetry, parameter set stability, and frequency uncertainty tests are applied to check whether internal vibrational modes, internal mode frequencies, and amplitudes Anμ comply with symmetry, are independent of the set of internal parameters ζn used to describe molecular geometry or fulfill a Lorentzian correlation between amplitudes Anμ and frequency differences Δωnμ=ωn-ωμ. In all cases considered, amplitudes Anμ based on adiabatic internal modes and mass or force constant matrices as metric O are superior to any other definition of amplitude. They represent the basic elements of the new CNM method that leads to chemically reasonable results and presents a new way of extracting chemical information out of vibrational spectra. A number of deficiencies of the potential energy distribution (PED) analysis is discussed.   © 1998 John Wiley & Sons, Inc. Int J Quant Chem 67: 41-55, 1998
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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