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Thirty-two soil samples were collected from six sites in the vicinity of Lonar lake, a meteorite crater and screened for presence of keratinophilic fungi using hair baiting techniques for isolation. Seventeen isolates were recovered and identified. The cultures were identified by recognition of their macro- and micromorphological features. Their identification was also confirmed by the BLAST search of sequences of ITS1-5.8S-ITS2 rDNA region against the NCBI/Gene bank data and compared with deposited sequences for identification purpose. Seven species of four genera were isolated viz. Aphanoascus durus (9.38%), Aphanoascus punsolae (3.125%), Auxarthron kuehnii (3.125%), Chrysosporium indicum (25.00%), Chrysosporium tropicum (3.125%), Chrysosporium sp. (3.125%), Chrysosporium state of Ctenomyces serratus (6.25%).  相似文献   
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The hippocampus receives its major cortical input from the medial entorhinal cortex (MEC) and the lateral entorhinal cortex (LEC). It is commonly believed that the MEC provides spatial input to the hippocampus, whereas the LEC provides non-spatial input. We review new data which suggest that this simple dichotomy between ‘where’ versus ‘what’ needs revision. We propose a refinement of this model, which is more complex than the simple spatial–non-spatial dichotomy. MEC is proposed to be involved in path integration computations based on a global frame of reference, primarily using internally generated, self-motion cues and external input about environmental boundaries and scenes; it provides the hippocampus with a coordinate system that underlies the spatial context of an experience. LEC is proposed to process information about individual items and locations based on a local frame of reference, primarily using external sensory input; it provides the hippocampus with information about the content of an experience.  相似文献   
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Climate change is shifting the timing of organismal life-history events. Although consequential food-web mismatches can emerge if predators and prey shift at different rates, research on phenological shifts has traditionally focused on single trophic levels. Here, we analysed >2000 long-term, monthly time series of phytoplankton, zooplankton, and fish abundance or biomass for the San Francisco, Chesapeake, and Massachusetts bays. Phenological shifts occurred in over a quarter (28%) of the combined series across all three estuaries. However, phenological trends for many taxa (ca. 29–68%) did not track the changing environment. While planktonic taxa largely advanced their phenologies, fishes displayed broad patterns of both advanced and delayed timing of peak abundance. Overall, these divergent patterns illustrate the potential for climate-driven trophic mismatches. Our results suggest that even if signatures of global climate change differ locally, widespread phenological change has the potential to disrupt estuarine food webs.  相似文献   
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Bacillus thuringiensis is a bacterium of great agronomic and scientific interest. The subspecies of this bacterium colonize and kill a large variety of host insects and even nematodes, but each strain does so with a high degree of specificity. Therefore molecular typing and diversity analysis of B. thuringiensis has enormous importance for discrimination of strains isolated from different sources. In this study, 113 native B. thuringiensis isolates collected from diverse habitats and locations in India and 27 B. thuringiensis type strains obtained from the Bacillus Genetic Stock Centre (BGSC), Ohio State University, USA and used as reference, were analyzed for molecular typing. Genotypic data of 140 B. thuringiensis isolates and type strains was generated by using REP-PCR and ERIC-PCR primers and unweighted pair group method with arithmetic mean (UPGMA) analysis using NTSYSpc2.2 and grouped into 4 main clusters. All the groups have isolates from diverse origins. No group was found to represent any specific origin or location. The observed patterns of REP-PCR and ERIC-PCR pattern were discriminatory enough to reveal differences in the B. thuringiensis isolates and reference strains. The resolution power and marker index of the ERIC-PCR (RP 9.39, MI 6.34) was found to be higher than that of the REP-PCR (RP 6.20, MI 4.48). The REP-PCR and ERIC-PCR markers have been found to be useful for discrimination of B. thuringiensis isolates and reference strains. ERIC-PCR was the more informative of the two techniques. This study showed that the B. thuringiensis isolates collected from diverse habitats in India had a high degree of genetic diversity.  相似文献   
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The nonribosomal biosynthesis of the dipeptide antibiotic bacilysin is achieved by the concerted action of multiple enzymes in the Bacillus subtilis bac operon. BacF (YwfG), encoded by the bacF gene, is a fold type I pyridoxal 5‐phosphate (PLP)‐dependent stereospecific transaminase. Activity assays with l ‐phenylalanine and 4‐hydroxyphenylpyruvic acid (4HPP), a chemical analogue of tetrahydrohydroxyphenylpyruvic acid (H4HPP), revealed stereospecific substrate preferences, a finding that was consistent with previous reports on the role of this enzyme in bacilysin synthesis. The crystal structure of this dimeric enzyme was determined in its apo form as well as in substrate‐bound and product‐bound conformations. Two ligand‐bound structures were determined by soaking BacF crystals with substrates (l ‐phenylalanine and 4‐hydroxyphenylpyruvate). These structures reveal multiple catalytic steps: the internal aldimine with PLP and two external aldimine conformations that show the rearrangement of the external aldimine to generate product (l ‐tyrosine). Together, these structural snapshots provide an insight into the catalytic mechanism of this transaminase.  相似文献   
7.
4-(1,1-Dioxo-1,4-dihydro-1lambda(6)-benzo[1,4]thiazin-3-yl)-5-hydroxy-2H-pyridazin-3-one analogs were discovered as a novel class of inhibitors of HCV NS5B polymerase. Structure-based design led to the identification of compound 3a that displayed potent inhibitory activities in biochemical and replicon assays (1b IC(50)<10 nM; 1b EC(50)=1.1 nM) as well as good stability toward human liver microsomes (HLM t(1/2)>60 min).  相似文献   
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Recently we reported an affinity chromatography method to purify alpha-aminoadipate aminotransferase (AadAT) activity from rat kidney supernatant fraction. Using the same affinity column, we purified AadAT activities from rat kidney and liver mitochondria. The physical and kinetic properties such as pH optima, Km for substrates, molecular weight, subunit structure, isoelectric pH, electrophoretic mobility and inhibition by dicarboxylic acids of mitochondrial AadAT were similar to those of the AadAT from rat kidney supernatant fraction. These results indicate that AadAT from different subcellular fractions is structurally and immunologically identical.  相似文献   
10.
The toxicity of synthetic pyrethroids was found to be negatively correlated with temperature, whereas contrasting correlation was observed with the toxicity of organophosphorous compounds chlorpyriphos and quinalphos, which was most toxic at higher temperature. A similar phenomenon was observed in endosulfan at higher temperature and humidity combination. The insecticide molecules indoxacarb and spinosad were effective among the insecticides tested. Indoxacarb was effective at lower temperature, and spinosad was effective at all the temperature and relative humidity combinations with minor difference in LD50 values. During both the years, however, the levels of resistance were higher in second year compared with previous year.  相似文献   
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