1,010 research outputs found

    Numerical characterization of protein sequences based on the generalized Chou\u27s pseudo amino acid composition

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    The technique of comparison and analysis of biological sequences is playing an increasingly important role in the field of Computational Biology and Bioinformatics. One of the key steps in developing the technique is to identify an appropriate manner to represent a biological sequence. In this paper, on the basis of three physical-chemical properties of amino acids, a protein primary sequence is reduced into a six-letter sequence, and then a set of elements which reflect the global and local sequence-order information is extracted. Combining these elements with the frequencies of 20 native amino acids, a (21+λ) dimensional vector is constructed to characterize the protein sequence. The utility of the proposed approach is illustrated by phylogenetic analysis and identification of DNA-binding proteins

    Application of GIS Based Ecological Vulnerability Evaluation in Environmental Impact Assessment of Master Plan of Coal Mining Area

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    AbstractCoal accounts for more than 70% of total energy consumption in China. Kinds of ecological problems resulting from coal mining have become increasingly serious, which directly threaten regional ecological security and people's normal production and livelihood in some areas. Ecological vulnerability is the overall performance of the ecosystem change under mining development, thus evaluation of ecological vulnerability based on GIS in Fuxin mining master plan environmental impact assessment was presented in this article. According to ecological condition of Fuxin, the ecological vulnerability index was established synthetically reflecting ecological environmental status, ecological sensitivity and landscape spatial structure, including 9 indictors. The study area was divided into 247 grids, then the EVI value of each grid was calculated by comprehensive evaluation and the results were divided into 5 levels by Zonal Statistic analysis of ArcGIS. Combining the distribution of vulnerability classification with the important ecological function area and natural reserves in the scope of planning, the research area was plotted into five types of zone, i.e., appropriate exploitation zone, optimized exploitation zone, moderate exploitation zone, restrictive exploitation zone and forbidden exploitation zone. Several adjustment suggestions were put forward to optimize the layout of Fuxin mining area and guide the ecological protection during coal exploitation

    The Spatial and Temporal Characteristics of the Urban Thermal Environment in East Africa: Implications for Sustainable Urban Development

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    Targeting cities in East Africa, where urbanisation and climate change are posing unprecedented threats to livelihoods and ecosystems, this thesis focuses on the combined effects of rapid urbanisation and climate change on Land Surface Temperature (LST), Surface Urban Heat Island (SUHI) effects and the role of Blue Green infrastructure (BGI) and vegetation dynamics. The aim of this thesis is to advance understanding of the urban thermal environment and the role of factors such as climate, vegetation and urbanisation patterns that add to its complexity. Through the use of satellite and remote sensing data (e.g., Google Earth Engine), spatial and statistical analyses, conducted in ArcGIS, Geoda and R, this thesis provides analyses of temporal trends between 2003 and 2017, and spatial differences in LST and SUHI in five East African cities (Khartoum, Addis Ababa, Kampala, Nairobi, Dar es Salaam). It advances understanding of how the configuration of urban areas affects the urban thermal environment, the amount of vegetation and surface water, and demonstrates the influence of urban density on the changes in SUHI intensity in both space and time. By linking the findings from the three results chapters and placing this in the context of the broader literature, corresponding policy implications and solutions are presented. The urgent need to provide a more detailed understanding of urban thermal environments, including macroclimate differences, seasonal variation and urban morphological characteristics, is highlighted. Recommendations emphasise the use of cloud-based analysis methods to overcome data scarcity, while the results point towards the utility of nature-based solutions for urban sustainable development. The methods and lessons emerging from this study can also be applied in other rapidly urbanising cities, where climate change is posing an unprecedented threat to livelihoods and ecosystems, and where resources are limited

    2-Iodo-3-meth­oxy-6-methyl­pyridine

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    The title compound, C7H8INO, which crystallizes with three independent mol­ecules in the asymmetric unit, was prepared by the reaction of 3-meth­oxy-6-methyl­pyridine with KI and I2 in tetra­hydro­furan solution. In the crystal structure, the three independent mol­ecules are arranged in a similar orientation with the three polar meth­oxy groups aligned on one side and the three non-polar methyl groups on the other side. The three mol­ecules, excluding methyl H atoms, are essentially planar, with r.m.s. deviations of 0.0141 (1), 0.0081 (1) and 0.0066 (2)Å. The three pyridine rings make dihedral angles of 58.09 (3) 66.64 (4) and 71.5 (3)°. The crystal structure features rather weak inter­molecular C—H⋯O hydrogen bonds, which link two mol­ecules into dimers, and short I⋯N contacts [4.046 (3) Å]

    Involvement of TIP60 acetyltransferase in intracellular Salmonella replication

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    <p>Abstract</p> <p>Background</p> <p><it>Salmonella </it>enterica is a facultative intracellular pathogen that replicates within a membrane-bound compartment termed <it>Salmonella </it>containing vacuole (SCV). The biogenesis of SCV requires <it>Salmonella </it>type III protein secretion/translocation system and their effector proteins which are translocated into host cells to exploit the vesicle trafficking pathways. SseF is one of these effectors required for SCV formation and Intracellular <it>Salmonella </it>replication through unknown mechanisms.</p> <p>Results</p> <p>In an attempt to identify host proteins that interact with SseF, we conduct a yeast two-hybrid screening of human cell cDNA library using SseF as the bait. We identified that TIP60, an acetyltransferase, interacts with SseF. We showed that the TIP60 acetylation activity was increased in the presence of SseF, and TIP60 was upregulated upon <it>Salmonella </it>infection. In addition, TIP60 is required for efficient intracellular <it>Salmonella </it>replication in macrophages.</p> <p>Conclusion</p> <p>Taken together, our data suggest that <it>Salmonella </it>may use SseF to exploit the host TIP60 acetyltransferase activity to promote efficient <it>Salmonella </it>replication inside host cells.</p

    Characterization and antitumor activity of camptothecin from endophytic fungus Fusarium solani isolated from Camptotheca acuminate

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    Background: Camptothecin (CPT) is a potent drug against cancers, originally from plants. The endophytic fungi could produce the secondary metabolite same as the host and is used as medicine.Objectives: The aim of this paper was to investigate an endophytic fungal CPT with anti-neoplastic activity.Methods: Endophytic fungi were isolated from Camptotheca acuminata in China. CPT from strain S-019 was characterized by TLC, HPLC and EI-MS analysis. Anti-tumor activity of fungal CPT was detected by MTT and fluorescent dye methods using Vero and PC-3 cells.Results: A total of 94 endophytic fungi strains were isolated from tissues of C. acuminata and 16 fungi strains displayed cytotoxic activity on Vero or PC3 cells. Of which, the fungal strain S-019, classified as Fusarium solani, displayed impressive cytotoxic activity on cancer cells and was found to produce CPT by analysis of TLC, HPLC and EI-MS methods. Bioassay studies confirmed that the fungi CPT had potent cytotoxicity on Vero cells and induced apoptosis of Vero cells.Conclusion: The endophytic fungi from camptotheca trees are a reliable source for natural anticancer compounds. The endophytic fungi could produce CPT same as plant. The fungal CPT exhibited effective activity at inhibiting cell growth and inducing apoptosis on Vero cells.Keywords: Endophytic fungi, camptothecin, anti-tumor, Camptotheca acuminat

    The nuclear factor-κB inhibitor pyrrolidine dithiocarbamate reduces polyinosinic-polycytidilic acid-induced immune response in pregnant rats and the behavioral defects of their adult offspring

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    <p>Abstract</p> <p>Background</p> <p>Epidemiological studies have indicated that maternal infection during pregnancy may lead to a higher incidence of schizophrenia in the offspring. It is assumed that the maternal infection increases the immune response, leading to neurodevelopmental disorders in the offspring. Maternal polyinosinic-polycytidilic acid (PolyI:C) treatment induces a wide range of characteristics in the offspring mimicking some schizophrenia symptoms in humans. These observations are consistent with the neurodevelopmental hypothesis of schizophrenia.</p> <p>Methods</p> <p>We examined whether suppression of the maternal immune response could prevent neurodevelopmental disorders in adult offspring. PolyI:C or saline was administered to early pregnant rats to mimic maternal infection, and the maternal immune response represented by tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10) levels was determined by enzyme-linked immunosorbent assays (ELISA). The NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) was used to suppress the maternal immune response. Neurodevelopmental disorders in adult offspring were examined by prepulse inhibition (PPI), passive avoidance, and active avoidance tests.</p> <p>Results</p> <p>PolyI:C administration to early pregnant rats led to elevated serum cytokine levels as shown by massive increases in serum TNF-α and IL-10 levels. The adult offspring showed defects in prepulse inhibition, and passive avoidance and active avoidance tests. PDTC intervention in early pregnant rats suppressed cytokine increases and reduced the severity of neurodevelopmental defects in adult offspring.</p> <p>Conclusions</p> <p>Our findings suggest that PDTC can suppress the maternal immune response induced by PolyI:C and partially prevent neurodevelopmental disorders of adult offspring.</p
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