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991.
James P Morton Don P M MacLaren Nigel T Cable Thomas Bongers Richard D Griffiths Iain T Campbell Louise Evans Anna Kayani Anne McArdle Barry Drust 《Journal of applied physiology》2006,101(1):176-182
The exercise-induced expression of heat shock proteins (HSPs) in rodent models is relatively well defined. In contrast, comparable data from human studies are limited and the exercise-induced stress response of human skeletal muscle is far from understood. This study has characterized the time course and magnitude of the HSP response in the skeletal muscles of a healthy active, but untrained, young male population following a running exercise protocol. Eight subjects performed 45 min of treadmill running at a speed corresponding to their lactate threshold (11.7 +/- 0.5 km/h; 69.8 +/- 4.8% maximum O2 uptake). Muscle biopsies were obtained from the vastus lateralis muscle immediately before and at 24 h, 48 h, 72 h, and 7 days postexercise. Exercise induced a significant (P < 0.05) but variable increase in HSP70, heat shock cognate (HSC) 70, and HSP60 expression with peak increases (typically occurring at 48 h postexercise) to 210, 170, and 139% of preexercise levels, respectively. In contrast, exercise did not induce a significant increase in either HSP27, alphaB-crystallin, SOD 2 (MnSOD) protein content, or the activity of SOD and catalase. When examining baseline protein levels, HSC70, HSP27, and alphaB-crystallin appeared consistently expressed between subjects, whereas HSP70 and MnSOD displayed marked individual variation of up to 3- and 1.5-fold, respectively. These data are the first to define the time course and extent of HSP production in human skeletal muscle following a moderately demanding and nondamaging running exercise protocol. Data demonstrate a differential effect of aerobic exercise on specific HSPs. 相似文献
992.
993.
Don Conway-Long 《American anthropologist》1998,100(3):810-811
Entering the Field: New Perspectives on World Football. Gary Armstrong and Richard Giulianotti. eds. New York: New York University Press, 1997.320 pp. 相似文献
994.
Isolation of Typical Marine Bacteria by Dilution Culture: Growth, Maintenance, and Characteristics of Isolates under Laboratory Conditions 总被引:28,自引:18,他引:10
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Frits Schut Egbert J. de Vries Jan C. Gottschal Betsy R. Robertson Wim Harder Rudolf A. Prins Don K. Button 《Applied microbiology》1993,59(7):2150-2160
Marine bacteria in Resurrection Bay near Seward, Alaska, and in the central North Sea off the Dutch coast were cultured in filtered autoclaved seawater following dilution to extinction. The populations present before dilution varied from 0.11 × 109 to 1.07 × 109 cells per liter. The mean cell volume varied between 0.042 and 0.074 μm3, and the mean apparent DNA content of the cells ranged from 2.5 to 4.7 fg of DNA per cell. All three parameters were determined by high-resolution flow cytometry. All 37 strains that were obtained from very high dilutions of Resurrection Bay and North Sea samples represented facultatively oligotrophic bacteria. However, 15 of these isolates were eventually obtained from dilution cultures that could initially be cultured only on very low-nutrient media and that could initially not form visible colonies on any of the agar media tested, indicating that these cultures contained obligately oligotrophic bacteria. It was concluded that the cells in these 15 dilution cultures had adapted to growth under laboratory conditions after several months of nutrient deprivation prior to isolation. From the North Sea experiment, it was concluded that the contribution of facultative oligotrophs and eutrophs to the total population was less than 1% and that while more than half of the population behaved as obligately oligotrophic bacteria upon first cultivation in the dilution culture media, around 50% could not be cultured at all. During one of the Resurrection Bay experiments, 53% of the dilution cultures obtained from samples diluted more than 2.5 × 105 times consisted of such obligate oligotrophs. These cultures invariably harbored a small rod-shaped bacterium with a mean cell volume of 0.05 to 0.06 μm3 and an apparent DNA content of 1 to 1.5 fg per cell. This cell type had the dimensions of ultramicrobacteria. Isolates of these ultramicrobacterial cultures that were eventually obtained on relatively high-nutrient agar plates were, with respect to cell volume and apparent DNA content, identical to the cells in the initially obligately oligotrophic bacterial dilution culture. Determination of kinetic parameters from one of these small rod-shaped strains revealed a high specific affinity for the uptake of mixed amino acids (a°A, 1,860 liters/g of cells per h), but not for glucose or alanine as the sole source of carbon and energy (a°A, ± 200 liters/g of cells per h). The ultramicrobial strains obtained are potentially a very important part of picoplankton biomass in the areas investigated. 相似文献
995.
Kristina J. Macdonald Don A. Driscoll Kimberley J. Macdonald Bronwyn Hradsky Tim S. Doherty 《Global Change Biology》2023,29(17):4949-4965
Ecosystem disturbance is increasing in extent, severity and frequency across the globe. To date, research has largely focussed on the impacts of disturbance on animal population size, extinction risk and species richness. However, individual responses, such as changes in body condition, can act as more sensitive metrics and may provide early warning signs of reduced fitness and population declines. We conducted the first global systematic review and meta-analysis investigating the impacts of ecosystem disturbance on reptile and amphibian body condition. We collated 384 effect sizes representing 137 species from 133 studies. We tested how disturbance type, species traits, biome and taxon moderate the impacts of disturbance on body condition. We found an overall negative effect of disturbance on herpetofauna body condition (Hedges' g = −0.37, 95% CI: −0.57, −0.18). Disturbance type was an influential predictor of body condition response and all disturbance types had a negative mean effect. Drought, invasive species and agriculture had the largest effects. The impact of disturbance varied in strength and direction across biomes, with the largest negative effects found within Mediterranean and temperate biomes. In contrast, taxon, body size, habitat specialisation and conservation status were not influential predictors of disturbance effects. Our findings reveal the widespread effects of disturbance on herpetofauna body condition and highlight the potential role of individual-level response metrics in enhancing wildlife monitoring. The use of individual response metrics alongside population and community metrics would deepen our understanding of disturbance impacts by revealing both early impacts and chronic effects within affected populations. This could enable early and more informed conservation management. 相似文献
996.
Steven R. Miller Don Bergmann 《Journal of industrial microbiology & biotechnology》1993,11(4):223-234
Summary This article highlights biocontainment design considerations for biopharmaceutical manufacturing facilities. The major focus of this report is on industry's use and interpretation of the regulations with specific design recommendations for a Biosafety Level 2 — Large-Scale physical containment level as described by the National Institutes of Health Guidelines. 相似文献
997.
A novel 205-kilodalton testis-specific serine/threonine protein kinase associated with microtubules of the spermatid manchette. 总被引:4,自引:0,他引:4
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To identify proteins which interact with and potentially modulate the function of microtubules during spermatogenesis, we prepared a total testis MAP (microtubule-associated protein) antiserum and used it to isolate cDNA clones from a mouse testis cDNA expression library. Antibodies affinity purified by using one expression clone recognized a 205-kDa protein, termed MAST205, which colocalizes with the spermatid manchette. Sequencing of full-length cDNA clones encoding MAST205 revealed it to be a novel serine/threonine kinase with a catalytic domain related to those of the A and C families. The testis-specific MAST205 RNA increases in abundance during prepuberal testis development, peaking at the spermatid stage. The microtubule-binding region of MAST205 occupies a central region of the molecule including the kinase domain and sequences C terminal to this domain. Binding of MAST205 to microtubules requires interaction with other MAPs, since it does not bind to MAP-free tubulin. A 75-kDa protein associated with immunoprecipitates of MAST205 from extracts of both whole testis and testis microtubules becomes phosphorylated in in vitro kinase assays. This 75-kDa substrate of the MAST205 kinase may form part of the MAST205 protein complex which binds microtubules. The MAST205 protein complex may function to link the signal transduction pathway with the organization of manchette microtubules. 相似文献
998.
A cell-free system prepared from exocarp of Citrus sinensisfruits converted [14C]-all-trans-ß-carotene into zeaxanthin,antheraxanthin, violaxanthin and abscisic acid (ABA). ABA wasunequivocally characterized by combined capillary GC-MS. (Received August 3, 1993; Accepted August 6, 1993) 相似文献
999.
1000.
Richard S. Cowan 《Brittonia》1979,31(1):72-78
A monotypic new genus,Harleyodendron, is described from the relict coastal rainforest of eastern Brazil. Gross morphology, wood and leaf anatomy, and pollen morphology are considered. 相似文献