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31.
Different values have resulted in conflicts between anglers and conservation lobbies in the management of trout in South Africa. Key to the conflict is the demarcation of boundaries to areas in which brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss currently occur, or are likely to establish following stocking for angling. To provide a longer-term perspective on these areas, we developed models to link salmonid biological thermal thresholds to elevation. These, when applied spatially using a digital elevation model with a probability of occurrence model, provided the basis for estimating potentially available thermal habitat for these two cold water species. Here, we acknowledge that other variables (stocking history; river connectivity) also play a role in understanding trout distributions. Using a simple scenario of an increase in mean daily water temperatures of 2 °C, we demonstrated that both brown and rainbow trout are likely to exhibit considerable range reductions in the future. Because it is possible that these range restrictions will result in an increasing desire to introduce trout into areas above their current distribution limits for the maintenance of angling opportunities, conservation managers should prioritise these areas, with management interventions seeking to understand what will help to limit introductions. 相似文献
32.
Cryptococcus neoformans cell and culture supernatant extracts were fractionated by ion exchange and gel filtration column chromatography. Various fractions were used to immunize mice, and to assess the release of migration inhibition factor, delayed type hypersensitivity, and protective immunity after challenge with C. neoformans. Results suggest that the C. neoformans fractions, which protect mice, contain a high molecular weight, predominantly carbohydrate antigen that can be distinguished from the capsular polysaccharide. 相似文献
33.
报道了小菇科小菇属真菌10个中国新记录种,香菌组:橙盖小菇Mycena aurantiidisca、黄白小菇Mycena flavoalba、粉黄小菇Mycena floridula;棘刺组:异刺小菇Mycena heteracantha;纤柄组:碱味小菇Mycena amygdalina;脆足组:粉被小菇Mycena zephirus;冬生组:绣线菊小菇Mycena speirea、冬生小菇Mycena hiemalis;小菇组:绒柄小菇Mycena flos-nivium,分别来自吉林等11个省份、自治区。提供了每个物种的形态描述和线条图,以及与相近种的讨论。共计90条自测及下载ITS序列,在采用贝叶斯法和最大似然法构建的小菇属系统发育树中,新记录种均得到分子数据支持。凭证标本存放于吉林农业大学菌物标本馆(HMJAU)。 相似文献
34.
Major neutral glycosphingolipid components were extracted from Sporothrix schenckii, a dimorphic fungus exhibiting a hyphal saprophytic phase and a yeast parasitic phase responsible for chronic mycotic infections in mammalian hosts. These components, one from the mycelial form and two from the yeast form, were purified and their structures were elucidated by (1)H nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization mass spectrometry (ESI-MS), and tandem ESI-MS/MS. All three were characterized as cerebrosides (monohexosylceramides) containing (4E, 8E)-9-methyl-4,8-sphingadienine as the long-chain base attached to N-2'-hydroxyoctadecanoate and N-2'-hydroxy-(E)-Delta(3)-octadecenoate as the fatty acyl components. However, while the mycelial form expressed only beta-glucopyranosylceramide, the yeast form expressed both beta-gluco- and beta-galactopyranosylceramides in approximately equal amounts. In addition, while the glucosylceramides of both mycelial and yeast forms had similar proportions of saturated and (E)-Delta(3) unsaturated 2-hydroxy fatty acid, the galactocerebroside of the yeast form had significantly higher levels of (E)-Delta(3) unsaturation.The differences in cerebroside hexose structure represent a novel type of glycosphingolipid dimorphism not previously reported in fungi. Possible implications of these findings with respect to regulation of morphological transitions in S. schenckii and other dimorphic fungi are discussed. 相似文献
35.
从茎花葱臭木种子中分离得到5个化合物,经理化与波谱分析鉴定为β-谷甾醇(1)、没食子酸乙酯(2)、胡萝卜苷(3)、1-O-β-D-吡喃葡萄糖基-(2S,3S,4R,8Z)-2-N-(2 ′-羟基二十四烷酰氨基)十八二氧鞘氨-8-烯(4)和2,3,2″,3″-四氢穗花杉双黄酮(5).这5个化合物均首次从该植物中分离得到.其中化合物5进行细胞毒活性测试,没有显示抑制活性. 相似文献
36.
37.
Willemen MJ Mantel-Teeuwisse AK Straus SM Leufkens HG Egberts AC 《Obesity (Silver Spring, Md.)》2008,16(10):2331-2335
The aim of the study was to assess whether the baseline risk of psychiatric and cardiovascular disease in patients with diabetes mellitus differs between those starting to use antiobesity drugs and those not starting to use these drugs. A retrospective nested case-control study within the General Practice Research Database (1987-2002) was done. The cohort included all patients with diabetes mellitus (n = 141,164). Information on patient characteristics (general, cardiovascular, and psychiatric characteristics) was extracted from the medical records. Crude odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. A total of 511 patients starting to use antiobesity drugs (cases) and 3,065 controls were included in the study cohort. Starters were younger and more frequently female. Of the starters, 91.8% did not receive any dietary advice before starting treatment. Depression (in the year before index date) was associated with the use of antiobesity drugs (OR 2.2; 95% CI 1.7-2.8), as was anxiety (OR 1.6; 95% CI 1.1-2.4). Of the cases, 25.2% had multiple cardiovascular risk factors (>4) compared to 19.0% of the controls. The baseline risk for psychiatric disorders and cardiovascular disease was found to be higher in patients with diabetes mellitus starting to use antiobesity drugs compared to patients with diabetes mellitus not starting such treatment. 相似文献
38.
T. NGAMSIRI Y. OHASHI N. SUKUMASAVIN M. NAKAJIMA U. NA‐NAKORN N. TANIGUCHI 《Molecular ecology resources》2006,6(2):313-315
Microsatellite DNA markers for a critically endangered Mekong giant catfish (Pangasianodon gigas Roberts and Vidthayanon, 1991) were developed from fin clips collected from captive fish using (GT)15 probe. The number of alleles per locus ranged from two to four. The expected heterozygosities ranged from 0.13 to 0.68. Also, these primers were successfully amplified in four closely related species, Pangasius bocourti, Pangasius conchophilus, Pangasius larnaudii and Pangasius sanitwongsei with the number of alleles per locus ranged from 1 to 13, 1 to 16, 1 to 12 and 1 to 4, respectively. These markers should prove to be very useful for the evaluation of genetic diversity for this species and other related Pangasius species. 相似文献
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40.
It was recently demonstrated that herpes simplex virus (HSV) successfully infects Chinese hamster ovary (CHO) cells expressing glycoprotein D (gD) receptors and HeLa cells by an endocytic mechanism (A. V. Nicola, A. M. McEvoy, and S. E. Straus, J. Virol. 77:5324-5332, 2003). Here we define cellular and viral requirements of this pathway. Uptake of intact, enveloped HSV from the cell surface into endocytic vesicles was rapid (t(1/2) of 8 to 9 min) and independent of the known cell surface gD receptors. Following uptake from the surface, recovery of intracellular, infectious virions increased steadily up to 20 min postinfection (p.i.), which corresponds to accumulation of enveloped virus in intracellular compartments. There was a sharp decline in recovery by 30 min p.i., suggesting loss of the virus envelope as a result of capsid penetration from endocytic organelles into the cytosol. In the absence of gD receptors, endocytosed virions did not successfully penetrate into the cytosol but were instead transported to lysosomes for degradation. Inhibitors of phosphatidylinositol (PI) 3-kinase, such as wortmannin, blocked transport of incoming HSV to the nuclear periphery and virus-induced gene expression but had no effect on virus binding or uptake. This suggests a role for PI 3-kinase activity in trafficking of HSV through the cytosol. Viruses that lack viral glycoproteins gB, gD, or gH-gL were defective in transport to the nucleus and had reduced infectivity. Thus, similar to entry via direct penetration at the cell surface, HSV entry into cells by wortmannin-sensitive endocytosis is efficient, involves rapid cellular uptake of viral particles, and requires gB, gD, and gH-gL. 相似文献