A population model provides support for management decisions,enables ongoing research and reinforces strong partnerships to manage a threatened freshwater crayfish     

Nick S. Whiterod  Charles R. Todd  Sylvia Zukowski  Scott M.C. Raymond  Martin Asmus  Macgregor J. Todd 《水产资源保护:海洋与淡水生态系统》2020,30(9):1836-1840

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Cross-protective immunity and the serological classification system for Bacteroides nodosus     

DJ STEWART  JA VAUGHAN  TC ELLEMAN†  PA HOYNE†  KJ BURNS  JH DUFTY 《Australian veterinary journal》1991,68(2):50-53

The relationship between the serological classification system for serogroup B and for serogroup H of Bacteroides nodosus and cross-protection between subgroups within these serogroups was examined. Protection against ovine footrot following vaccination was achieved against other subgroup strains provided sufficient cross-reactive antibody was induced by shared pilus antigens. Within serogroup B, better cross-protection against one subgroup was obtained with a pili vaccine than a whole cell vaccine which correlated with higher pilus antibody titres induced by the former. For serogroup H, a lack of cross-protection and serological reactivity between subgroups was demonstrated, which indicates that the prototype strain of subgroup H2 should be designated a new serogroup.  相似文献   

Inclusion body myositis in spring peepers (Pseudacris crucifer).     

James T Raymond  Tim Reichard  Wynona Shellabarger  Robert Nordhausen  Michael M Garner 《Journal of veterinary diagnostic investigation》2002,14(6):501-503

In 2000, 2 adult captive spring peepers (Pseudacris crucifer) from the same zoological park were humanely euthanized. Histologically, both frogs had degeneration, atrophy, and necrosis of striated myofibers of the tongue admixed with chronic lymphohistiocytic inflammation. One frog had similar lesions in the skeletal muscles of the body wall. Several degenerate and necrotic myofibers contained single, eosinophilic, intranuclear inclusion bodies. Ultrastructural examination of the inclusions revealed nonenveloped, icosahedral, virus-like particles averaging 20-24 nm in diameter. This is the first reported case of inclusion body myositis in frogs and is believed to be due to parvoviral infection.  相似文献   

Causes of mortality in captive Attwater's prairie chickens (Tympanuchus cupido attwateri) at the San Antonio Zoo, 1997-2000.     

Gary D West  Michael M Garner  James T Raymond 《Journal of zoo and wildlife medicine》2002,33(3):236-241

Necropsy records for 102 Attwater's prairie chickens (Tympanuchus cupido attwateri) that had been captive-reared and had died at the San Antonio Zoo over a 4-yr period were evaluated to determine the causes of mortality. Gross necropsy, histopathology, and bacterial culture findings are summarized. Mortality was highest in young birds (<6 mo) and embryos. Husbandry- and gastrointestinal-related diseases were the most common causes of mortality.  相似文献   

Ability of possible DMS precursors to release DMS during wine aging and in the conditions of heat-alkaline treatment     

Segurel MA  Razungles AJ  Riou C  Trigueiro MG  Baumes RL 《Journal of agricultural and food chemistry》2005,53(7):2637-2645

The origin of dimethyl sulfide (DMS) produced during wine aging was examined through different assays. The production of DMS during the model aging of a wine and the concomitant decrease of residual potential DMS (PDMS), as DMS released by heat-alkaline treatment in 0.5 M sodium hydroxide at 100 degrees C for 1 h, were demonstrated. Then, dimethyl sulfoxide (DMSO), methionine sulfoxide (MSO), S-methylmethionine (SMM), and dimethylsulfonium propanoic acid (DMSPA), reported previously as possible DMS precursors, were investigated for their ability to be DMS precursors in wine in the conditions of this model aging and of the heat-alkaline treatment. The results showed that DMSO, MSO, and DMSPA could hardly be DMS precursors in the conditions used, whereas SMM appeared to be a good candidate. Finally, the use of [(2)H(6)]-DMSPA as an internal standard for PDMS determination was proposed, because it provided better reproducibility than [(2)H(6)]-DMS used as an external standard.  相似文献   

Sex and seasonal differences in the spatial terrestrial distribution of gray treefrog (Hyla versicolor) populations     

Jarrett R. Johnson  Jason H. Knouft  Raymond D. Semlitsch 《Biological conservation》2007,140(3-4):250-258

Fragmentation of terrestrial landscapes has exacerbated the need to understand the spatial requirements of organisms, especially those that undergo seasonal migrations, such as pond-breeding amphibians. Pond-breeding amphibians spend much of their lives in terrestrial habitat at some distance from aquatic breeding sites. The terrestrial habitat required by a particular individual encompasses the area adjacent to a breeding pond that is used for activities such as foraging or overwintering, as well as the expanses of habitat through which it moves. To elucidate amphibian spatial habitat requirements, we monitored gray treefrog (Hyla versicolor) movements through terrestrial habitat adjacent to breeding ponds using radiotelemetry and mark–recapture along transects of artificial refugia. Results indicate that gray treefrogs frequently make migrations between foraging grounds, overwintering sites, and breeding ponds of 200 m or more, with a maximum-recorded movement distance of 330 m. Additionally, females travel farther than males for reasons independent of body size, and the distribution of males during the breeding season is biased towards breeding ponds relative to the non-breeding season. The data illustrate the importance of habitat directly adjacent to breeding sites for males, and indicate that habitat loss resulting in small patches may have a greater negative impact on females than males, and consequently may have disproportionately large effects on population persistence. These results emphasize that effective management of amphibian breeding locations via protection of both aquatic and adjacent upland terrestrial resources likely requires detailed information regarding variation in movements between the sexes and among seasonal activity periods.  相似文献   

Tissue iron distribution and adaptation of iron absorption in rats exposed to a high dietary level of NaFeEDTA     

Yeung CK  Zhu L  Glahn RP  Miller DD 《Journal of agricultural and food chemistry》2005,53(20):8087-8091

Although it has been shown that iron absorption from NaFeEDTA, a promising iron fortificant, is effectively down-regulated in iron-loaded rats, effects of prolonged exposure to high dietary levels of NaFeEDTA are not well understood. The objectives of this study were to determine whether rats can adapt to a high dietary level of NaFeEDTA by down-regulating iron absorption, and to determine effects on tissue iron distribution, with or without an iron absorption inhibitor. Male Sprague-Dawley rats were exposed to diets supplemented with FeSO4 or NaFeEDTA at 1200 mg of Fe/kg of diet, with or without tea, for 27 days. Iron absorption measured by whole-body counting before and after exposure showed that rats adapted to the high dietary level of FeSO4 or NaFeEDTA by down-regulating iron absorption to a similar extent. However, nonheme iron concentrations in liver and spleen were about 35-50% lower, whereas the concentration in kidney was about 300% higher in rats fed NaFeEDTA, compared to rats fed FeSO4. Tea had no major impact on iron absorption or iron status, regardless of iron source. Our results showed that although iron absorption was down-regulated similarly, body iron distribution was markedly different between rats exposed to FeSO4 and those exposed to NaFeEDTA. Further studies are warranted to determine the effects of prolonged exposure to dietary NaFeEDTA on kidney iron accumulation and kidney function.  相似文献   

Fatty acid composition and squalene content of the marine microalga Schizochytrium mangrovei     

Jiang Y  Fan KW  Wong RT  Chen F 《Journal of agricultural and food chemistry》2004,52(5):1196-1200

Certain species of thraustochytrids are being explored as potential producer of polyunsaturated fatty acids for nutritional enrichment of food products and use as feed additives in aquaculture. The fatty acid composition and squalene content were determined in the thraustochytrid, Schizochytrium mangrovei that was newly isolated from decaying Kandelia candel leaves in Hong Kong mangrove habitat. The major fatty acid constituents identified in all three S. mangrovei strains were tetradeanoic acid (C14:0), hexadecanoic acid (C16:0), docosapentaenoic acid (C22:5 n-6, DPA) and docosahexaenoic acid (C22:6 n-3, DHA). DHA was the most predominant polyunsaturated fatty acid, and the percentage of DHA (of total fatty acids) in all these strains varied from 32.29 to 39.14%. Only slight changes were observed in fatty acid composition of the S. mangrovei strains harvested at their early (day 3) and late stationary (day 5) phases. In contrast, the cellular squalene content was affected significantly by the culture time; the largest decrease of squalene content from 0.162 mg/g to 0.035 mg/g was found in S. mangrovei FB1 as the culture aged.  相似文献   

Quantitative determination of sulfur-containing wine odorants at sub parts per billion levels. 2. Development and application of a stable isotope dilution assay     

Schneider R  Kotseridis Y  Ray JL  Augier C  Baumes R 《Journal of agricultural and food chemistry》2003,51(11):3243-3248

[(2)H(10)]-4-Mercapto-4-methylpentan-2-one (d(10)-1), [(2)H(2)]-3-mercaptohexan-1-ol (d(2)-2), and [(2)H(5)]-3-mercaptohex-1-yl acetate (d(5)-3), deuterated analogues of impact odorants of wines, were used to determine quantitatively the natural compounds in white wines (Muscadet, Sauvignon, and Bacchus) with a stable isotope dilution assay using gas chromatography coupled either with ion trap tandem mass spectrometry (GC-ITMS-MS) or with atomic emission detection monitored on sulfur-selective acquisition (GC-AED). The thiol compounds were recovered from wines by liquid-liquid extraction, then purified from the wine extracts by covalent chromatography, and analyzed. The quantitative determination of 4-mercapto-4-methylpentan-2-one 1 in the wines that were analyzed was performed better with GC-AED than with GC-ITMS-MS under the conditions that were used. However, the detection limit of the method was higher than the odor threshold of 4-mercapto-4-methylpentan-2-one 1 in wine (5 vs 0.8 ng/L). The levels of this compound in the Sauvignon and Bacchus wines were much higher than its odor threshold, but it was not detectable in the Muscadet wines. On the contrary, GC-ITMS-MS was much more sensitive than GC-AED for detection of 3-mercaptohexan-1-ol 2 and 3-mercaptohex-1-yl acetate 3, and the detection limits were much lower than their odor thresholds in wine. The former compound was detected in all of the Muscadet wines that were analyzed at levels always higher than its odor detection threshold, while the latter occurred at levels higher than its odor threshold in only one Muscadet wine.  相似文献   

Synthesis and stable isotope dilution assay of ethanethiol and diethyl disulfide in wine using solid phase microextraction. Effect of aging on their levels in wine     

Belancic Majcenovic A  Schneider R  Lepoutre JP  Lempereur V  Baumes R 《Journal of agricultural and food chemistry》2002,50(23):6653-6658

Ethanethiol and diethyl disulfide (DEDS) most often occurred at levels above their olfactive threshold in wines with nauseous sulfur-linked smells. As ethanethiol is very oxidizable and chemically reactive, a stable isotopic dilution analysis of both ethanethiol and its disulfide in wines using solid phase microextraction and GC-MS was developed. The latter involved the determination of the proportion of DEDS formed by oxidation of the thiol during the analysis conditions, which was obtained by the use of two differently labeled disulfide standards. An original synthesis of labeled ethanethiol standards in conditions minimizing oxidation was developed, and the corresponding labeled diethyl disulfides were obtained from these thiols. This analytical method was used to follow the levels of these sulfur compounds during aging in a young red wine spiked with ethanethiol and added with enological tannins, with or without oxygen addition. The total levels of these two sulfur compounds were shown to decrease steadily after 60 days of aging, up to 83%. The effect of oxygen sped this decrease, but the effect of enological tannins was very slight. Residual ethanethiol was detected in its disulfide form from approximately 36% in the nonoxygenated wines to 69% in the oxygenated samples.  相似文献