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Almost all primates experience seasonal fluctuations in the availability of key food sources. However, the degree to which this fluctuation impacts foraging behavior varies considerably. Eastern chimpanzees (Pan troglodytes schweinfurthii) in Nyungwe National Park, Rwanda, live in a montane forest environment characterized by lower primary productivity and resource diversity than low‐elevation forests. Little is known about chimpanzee feeding ecology in montane forests, and research to date predominantly relies on indirect methods such as fecal analyses. This study is the first to use mostly observational data to examine how seasonal food availability impacts the feeding ecology of montane forest chimpanzees. We examine seasonal changes in chimpanzee diet and fallback foods (FBFs) using instantaneous scan samples and fecal analyses, supported by inspection of feeding remains. Chimpanzee fruit abundance peaked during the major dry season, with a consequent change in chimpanzee diet reflecting the abundance and diversity of key fruit species. Terrestrial herbaceous vegetation was consumed throughout the year and is defined as a “filler” FBF. In contrast to studies conducted in lower‐elevation chimpanzee sites, figs (especially Ficus lutea) were preferred resources, flowers were consumed at seasonally high rates and the proportion of non‐fig fruits in the diet were relatively low in the current study. These divergences likely result from the comparatively low environmental diversity and productivity in higher‐elevation environments.  相似文献   
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Y Jaya  S Sulochana 《Acta anatomica》1989,136(2):112-114
The localization of lipid globules was studied in the adrenal glands from 35 fetuses and 10 adult humans by histochemistry. The fetal adrenal showed the presence of numerous lipid globules in the zona glomerulosa, whereas in the adult the lipid globules were mainly found in the zona fasciculata. These lipid globules were confirmed as cholesterol in the fetal adrenals.  相似文献   
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A new species of the genus Cirrhimuraena (Anguilliformes: Ophichthidae), Cirrhimuraena indica sp. nov., is described based on eight specimens collected from the Paradip (Odisha) and Petuaghat harbours (West Bengal) along the Bay of Bengal. The species is distinct in having the upper jaw fringed with 16–17 cirri before posterior nostril and 4–5 in between the anterior and posterior nostrils on the side; dorsal fin originates above the level of gill opening, predorsal length is 9.3–10.9 in total length; the head is relatively large, the length is 9.3–9.8 in total length; no infraorbital pores are observed between the nostrils; teeth are numerous, small, conical and in bands on each jaw; pores are present before the gill opening 10–11 and before anus 47–48; pectoral-fin length is 2.4–2.8 in head length; predorsal vertebrae are 8–10, pre-anal vertebrae 43–47 and total vertebrae 164–169. In the maximum likelihood tree analysis for COI gene, the new species belongs to the same clade as the other congener of Cirrhimuraena chinensis and is separated from the species morphologically and genetically.  相似文献   
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We report the purification and characterization of a nitrilase (E.C. 3.5.5.1) (Nit11764) essential for the assimilation of cyanide as the sole nitrogen source by the cyanotroph, Pseudomonas fluorescens NCIMB 11764. Nit11764, is a member of a family of homologous proteins (nitrile_sll0784) for which the genes typically reside in a conserved seven-gene cluster known as Nit1C. The physical properties and substrate specificity of Nit11764 resemble those of Nit6803, the current reference protein for the family, and the only true nitrilase that has been crystallized. The substrate binding pocket of the two enzymes places the substrate in direct proximity to the active site nucleophile (C160) and conserved catalytic triad (Glu44, Lys126). The two enzymes exhibit a similar substrate profile, however, for Nit11764, cinnamonitrile, was found to be an even better substrate than fumaronitrile the best substrate previously identified for Nit6803. A higher affinity for cinnamonitrile (Km 1.27 mM) compared to fumaronitrile (Km 8.57 mM) is consistent with docking studies predicting a more favorable interaction with hydrophobic residues lining the binding pocket. By comparison, 3,4-dimethoxycinnamonitrile was a poorer substrate the substituted methoxyl groups apparently hindering entry into the binding pocket. in situ 1H NMR studies revealed that only one of the two nitrile substituents in the dinitrile, fumaronitrile, was attacked yielding trans-3-cyanoacrylate (plus ammonia) as a product. The essentiality of Nit11764 for cyanotrophy remains uncertain given that cyanide itself is a poor substrate and the catalytic efficiencies for even the best of nitrile substrates (~5 × 103 M?1 s?1) is less than stellar.  相似文献   
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Altered proteolysis of amyloid precursor protein is an important determinant of pathology development in Alzheimer''s disease. Here, we describe the detection of two novel fragments of amyloid precursor protein in H4 neuroglioma cells undergoing apoptosis. Immunoreactivity of these 25–35 kDa fragments to two different amyloid precursor protein antibodies suggests that they contain the amyloid-β region and an epitope near the C-terminus of amyloid precursor protein. Generation of these fragments is associated with cleavage of caspase-3 and caspase-7, suggesting activation of these caspases. Studies in neurons undergoing DNA damage-induced apoptosis also showed similar results. Inclusion of caspase inhibitors prevented the generation of these novel fragments, suggesting that they are generated by a caspase-dependent mechanism. Molecular weight prediction and immunoreactivity of the fragments generated suggested that such fragments could not be generated by cleavage at any previously identified caspase, secretase, or calpain site on amyloid precursor protein. Bioinformatic analysis of the amino acid sequence of amyloid precursor protein revealed that fragments fitting the observed size and immunoreactivity could be generated by either cleavage at a novel, hitherto unidentified, caspase site or at a previously identified matrix metalloproteinase site in the extracellular domain. Proteolytic cleavage at any of these sites leads to a decrease in the generation of α-secretase cleaved secreted APP, which has both anti-apoptotic and neuroprotective properties, and thus may contribute to neurodegeneration in Alzheimer''s disease.  相似文献   
8.
The present study was undertaken to investigate short-term (21 days) effects of oral administration of Azadirachta indica leaf extract and vanadate, separately and in combination, on the activities of antioxidant enzymes in streptozotocin-induced diabetic rats. Vanadate is a remarkable antidiabetic agent and shows insulin mimetic effect. However, severe toxicity is associated with vanadate when used in high concentration while at lower concentration the hypoglycemic property of vanadate is reduced. So, we used a low dose of vanadate in combination with A. indica leaf extract and evaluated their effect on the antioxidant defense system. Streptozotocin-diabetic rats were treated separately with insulin, vanadate (0.6 mg/ml), A. indica, and with combined dose of vanadate (0.2 mg/ml) and A. indica. At the end of the experiment, rats were sacrificed and serum glucose levels and activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase were determined in cytosolic fraction of liver and kidney. Diabetic rats showed hyperglycemic condition and alteration in antioxidant enzyme activities. Treatment with antidiabetic compounds resulted in the reduction of glucose levels and restoration of enzyme activities to normal. Results showed that combined treatment of vanadate and A. indica leaf extract was the most effective in normalizing altered antioxidant enzyme system.  相似文献   
9.
Pancreatic adenocarcinoma or pancreatic cancer is often diagnosed at a very late stage at which point treatment options are minimal. Current chemotherapeutic interventions prolong survival marginally, thereby emphasizing the acute need for better treatment options to effectively manage this disease. Studies from different laboratories have shown that the Alzheimer disease-associated amyloid precursor protein (APP) is overexpressed in various cancers but its significance is not known. Here we sought to determine the role of APP in pancreatic cancer cell survival and proliferation. Our results show that pancreatic cancer cells secrete high levels of sAPPα, the α-secretase cleaved ectodomain fragment of APP, as compared with normal non-cancerous cells. Treatment of cells with batimastat or GI254023X, inhibitors of the α-secretase ADAM10, prevented sAPPα generation and reduced cell survival. Additionally, inhibition of sAPPα significantly reduced anchorage independent growth of the cancer cells. The effect of batimastat on cell survival and colony formation was enhanced when sAPPα downregulation was combined with gemcitabine treatment. Moreover, treatment of batimastat-treated cells with recombinant sAPPα reversed the inhibitory effect of the drug thereby indicating that sAPPα can indeed induce proliferation of cancer cells. Down-regulation of APP and ADAM10 brought about similar results, as did batimastat treatment, thereby confirming that APP processing is important for growth and proliferation of these cells. These results suggest that inhibition of sAPPα generation might enhance the effectiveness of the existing chemotherapeutic regimen for a better outcome.  相似文献   
10.
Solanum galapagense is closely related to the cultivated tomato and can show a very good resistance towards whitefly. A segregating population resulting from a cross between the cultivated tomato and a whitefly resistant S. galapagense was created and used for mapping whitefly resistance and related traits, which made it possible to study the genetic basis of the resistance. Quantitative trait loci (QTL) for adult survival co-localized with type IV trichome characteristics (presence, density, gland longevity and gland size). A major QTL (Wf-1) was found for adult survival and trichome characters on Chromosome 2. This QTL explained 54.1 % of the variation in adult survival and 81.5 % of the occurrence of type IV trichomes. A minor QTL (Wf-2) for adult survival and trichome characters was identified on Chromosome 9. The major QTL was confirmed in F3 populations. Comprehensive metabolomics, based on GCMS profiling, revealed that 16 metabolites segregating in the F2 mapping population were associated with Wf-1 and/or Wf-2. Analysis of the 10 most resistant and susceptible F2 genotypes by LCMS showed that several acyl sugars were present in significantly higher concentration in the whitefly resistant genotypes, suggesting a role for these components in the resistance as well. Our results show that whitefly resistance in S. galapagense seems to inherit relatively simple compared to whitefly resistance from other sources and this offers great prospects for resistance breeding as well as elucidating the underlying molecular mechanism(s) of the resistance.  相似文献   
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