143 research outputs found

    EVAPOTRANSPIRATION ESTIMATION USING SSEBop METHOD WITH SENTINEL -2 AND LANDSAT-8 DATA SET

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    Estimation of evapotranspiration (ET) parameters is essential for understanding crop water requirements and to find out the ground water recharge. In situ data collection procedures are generally adopted to measure the parameters required to find ET. Latest remote sensing technologies accompanied by newly launched satellite datasets can supplement the field data collection and analysis by finding out some of the parameters such as land surface temperature, normalized difference vegetation index (NDVI), albedo, emissivity, etc. The Upper Ganga Canal Command Area (UGC) lying between two rivers Ganga and Yamuna situated between two states, namely Uttarakhand and Uttar Pradesh in North India is selected as the study area for this research work. Operational Simplified Surface Energy Balance (SSEBop) method is used to derive high resolution (10m) ET map for the Upper Ganga Canal Command Area. Sentinel-2 multi spectral images were used to derive land use, land cover (LU/LC) maps, NDVI, albedo, etc. Downscaled Landsat 8 images were used to derive land surface temperature of the command area. Meteorological data retrieved from the Indian Meteorological Department (IMD) was used to calculate reference evapotranspiration. ET map of the study area was generated using the above estimated parameters. Further, validation of the obtained ET values was accomplished by gridded ET data obtained from IMD

    Population density controls on microbial pollution across the Ganga catchment

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    For millions of people worldwide, sewage-polluted surface waters threaten water security, food security and human health. Yet the extent of the problem and its causes are poorly understood. Given rapid widespread global urbanisation, the impact of urban versus rural populations is particularly important but unknown. Exploiting previously unpublished archival data for the Ganga (Ganges) catchment, we find a strong non-linear relationship between upstream population density and microbial pollution, and predict that these river systems would fail faecal coliform standards for irrigation waters available to 79% of the catchment’s 500 million inhabitants. Overall, this work shows that microbial pollution is conditioned by the continental-scale network structure of rivers, compounded by the location of cities whose growing populations contribute c. 100 times more microbial pollutants per capita than their rural counterparts

    Review Paper - High Utility Item sets Mining on Incremental Transactions using UP-Growth and UP-Growth+ Algorithm

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    One of the important research area in data mining is high utility pattern mining. Discovering itemsets with high utility like profit from database is known as high utility itemset mining. There are number of existing algorithms have been work on this issue. Some of them incurs problem of generating large number of candidate itemsets. This leads to degrade the performance of mining in case of execution time and space. In this paper we have focus on UP-Growth and UP-Growth+ algorithm which overcomes this limitation. This technique uses tree based data structure, UP-Tree for generating candidate itemsets with two scan of database. In this paper we extend the functionality of these algorithms on incremental database.

    Detection of Taura Syndrome Virus (TSV) in Litopenaeus vannamei in the Philippines

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    Farming of Litopenaeus vannamei in the Philippines was seen as a measure to increase shrimp production in the country. Taura Syndrome Virus (TSV) is a viral pathogen reported to be associated with Litopenaeus vannamei and other shrimp species. TSV outbreak impedes the production of Litopenaeus vannamei population and other species susceptible to the virus. Detection of TSV in L. vannamei in the Philippines calls for proper mitigation and appropriate actions for aquaculture and environmental management towards sustainable development. This study embarked on the detection of TSV using a purposive sampling method. Samples showing morphological symptoms of TSV such as redness of the carapace and pleopods and necrotic gill tissue collected from sites in Luzon and Visayas in the Philippines were processed. Viral RNA was extracted from the gills, the central area of infiltration and replication site of the virus. Complementary DNA (cDNA) was synthesized from the RNA templates and were subjected to RT-PCR under specific conditions using TSV specific primers against a positive control. Selected sites in the Philippines were proven to be positive of infection as they showed morphological symptoms and RT-PCR result in having a band at around 200 base pairs (bp). Percentage of prevalence results were obtained: Bulacan with 5 out of 15 samples (33%), Batangas with 7 out of 15 samples (47%), Bohol with 1 out of 15 samples (7%) and Cebu with 2 out of 15 samples (13%). The Batangas samples showed the highest prevalence of 47% (7 out of 15 samples) that were positive of the infection. This study reported the presence of TSV in L. vannamei in the country using morphological and molecular techniques

    A cartilage tissue engineering approach combining starch-polycaprolactone fibre mesh scaffolds with bovine articular chondrocytes

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    In the present work we originally tested the suitability of corn starch-polycaprolactone (SPCL) scaffolds for pursuing a cartilage tissue engineering approach. Bovine articular chondrocytes were seeded on SPCL scaffolds under dynamic conditions using spinner flasks (total of 4 scaffolds per spinner flask using cell suspensions of 0.5×106 cells/ml) and cultured under orbital agitation for a total of 6 weeks. Poly(glycolic acid) (PGA) non-woven scaffolds and bovine native articular cartilage were used as standard controls for the conducted experiments. PGA is a kind of standard in tissue engineering approaches and it was used as a control in that sense. The tissue engineered constructs were characterized at different time periods by scanning electron microscopy (SEM), hematoxylin-eosin (H&E) and toluidine blue stainings, immunolocalisation of collagen types I and II, and dimethylmethylene blue (DMB) assay for glycosaminoglycans (GAG) quantification assay. SEM results for SPCL constructs showed that the chondrocytes presented normal morphological features, with extensive cells presence at the surface of the support structures, and penetrating the scaffolds pores. These observations were further corroborated by H&E staining. Toluidine blue and immunohistochemistry exhibited extracellular matrix deposition throughout the 3D structure. Glycosaminoglycans, and collagen types I and II were detected. However, stronger staining for collagen type II was observed when compared to collagen type I. The PGA constructs presented similar features toSPCLat the end of the 6 weeks. PGA constructs exhibited higher amounts of matrix glycosaminoglycans when compared to the SPCL scaffolds. However, we also observed a lack of tissue in the central area of the PGA scaffolds. Reasons for these occurrences may include inefficient cells penetration, necrosis due to high cell densities, or necrosis related with acidic by-products degradation. Such situation was not detected in the SPCL scaffolds, indicating the much better biocompatibility of the starch based scaffolds

    Vitamin D deficiency causes inward hypertrophic remodeling and alters vascular reactivity of rat cerebral arterioles

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    BACKGROUND AND PURPOSE: Vitamin D deficiency (VDD) is a global health problem, which can lead to several pathophysiological consequences including cardiovascular diseases. Its impact on the cerebrovascular system is not well understood. The goal of the present work was to examine the effects of VDD on the morphological, biomechanical and functional properties of cerebral arterioles. METHODS: Four-week-old male Wistar rats (n = 11 per group) were either fed with vitamin D deficient diet or received conventional rat chow with per os vitamin D supplementation. Cardiovascular parameters and hormone levels (testosterone, androstenedione, progesterone and 25-hydroxyvitamin D) were measured during the study. After 8 weeks of treatment anterior cerebral artery segments were prepared and their morphological, biomechanical and functional properties were examined using pressure microangiometry. Resorcin-fuchsin and smooth muscle actin staining were used to detect elastic fiber density and smooth muscle cell counts in the vessel wall, respectively. Sections were immunostained for eNOS and COX-2 as well. RESULTS: VDD markedly increased the wall thickness, the wall-to-lumen ratio and the wall cross-sectional area of arterioles as well as the number of smooth muscle cells in the tunica media. As a consequence, tangential wall stress was significantly lower in the VDD group. In addition, VDD increased the myogenic as well as the uridine 5'-triphosphate-induced tone and impaired bradykinin-induced relaxation. Decreased eNOS and increased COX-2 expression were also observed in the endothelium of VDD animals. CONCLUSIONS: VDD causes inward hypertrophic remodeling due to vascular smooth muscle cell proliferation and enhances the vessel tone probably because of increased vasoconstrictor prostanoid levels in young adult rats. In addition, the decreased eNOS expression results in endothelial dysfunction. These morphological and functional alterations can potentially compromise the cerebral circulation and lead to cerebrovascular disorders in VDD

    Diet-Induced Obesity Impairs Endothelium-Derived Hyperpolarization via Altered Potassium Channel Signaling Mechanisms

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    BACKGROUND: The vascular endothelium plays a critical role in the control of blood flow. Altered endothelium-mediated vasodilator and vasoconstrictor mechanisms underlie key aspects of cardiovascular disease, including those in obesity. Whilst the mechanism of nitric oxide (NO)-mediated vasodilation has been extensively studied in obesity, little is known about the impact of obesity on vasodilation to the endothelium-derived hyperpolarization (EDH) mechanism; which predominates in smaller resistance vessels and is characterized in this study. METHODOLOGY/PRINCIPAL FINDINGS: Membrane potential, vessel diameter and luminal pressure were recorded in 4(th) order mesenteric arteries with pressure-induced myogenic tone, in control and diet-induced obese rats. Obesity, reflecting that of human dietary etiology, was induced with a cafeteria-style diet (∼30 kJ, fat) over 16-20 weeks. Age and sexed matched controls received standard chow (∼12 kJ, fat). Channel protein distribution, expression and vessel morphology were determined using immunohistochemistry, Western blotting and ultrastructural techniques. In control and obese rat vessels, acetylcholine-mediated EDH was abolished by small and intermediate conductance calcium-activated potassium channel (SK(Ca)/IK(Ca)) inhibition; with such activity being impaired in obesity. SK(Ca)-IK(Ca) activation with cyclohexyl-[2-(3,5-dimethyl-pyrazol-1-yl)-6-methyl-pyrimidin-4-yl]-amine (CyPPA) and 1-ethyl-2-benzimidazolinone (1-EBIO), respectively, hyperpolarized and relaxed vessels from control and obese rats. IK(Ca)-mediated EDH contribution was increased in obesity, and associated with altered IK(Ca) distribution and elevated expression. In contrast, the SK(Ca)-dependent-EDH component was reduced in obesity. Inward-rectifying potassium channel (K(ir)) and Na(+)/K(+)-ATPase inhibition by barium/ouabain, respectively, attenuated and abolished EDH in arteries from control and obese rats, respectively; reflecting differential K(ir) expression and distribution. Although changes in medial properties occurred, obesity had no effect on myoendothelial gap junction density. CONCLUSION/SIGNIFICANCE: In obese rats, vasodilation to EDH is impaired due to changes in the underlying potassium channel signaling mechanisms. Whilst myoendothelial gap junction density is unchanged in arteries of obese compared to control, increased IK(Ca) and Na(+)/K(+)-ATPase, and decreased K(ir) underlie changes in the EDH mechanism

    Altered mRNA expression of genes related to nerve cell activity in the fracture callus of older rats: A randomized, controlled, microarray study

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    BACKGROUND: The time required for radiographic union following femoral fracture increases with age in both humans and rats for unknown reasons. Since abnormalities in fracture innervation will slow skeletal healing, we explored whether abnormal mRNA expression of genes related to nerve cell activity in the older rats was associated with the slowing of skeletal repair. METHODS: Simple, transverse, mid-shaft, femoral fractures with intramedullary rod fixation were induced in anaesthetized female Sprague-Dawley rats at 6, 26, and 52 weeks of age. At 0, 0.4, 1, 2, 4, and 6 weeks after fracture, a bony segment, one-third the length of the femur, centered on the fracture site, including the external callus, cortical bone, and marrow elements, was harvested. cRNA was prepared and hybridized to 54 Affymetrix U34A microarrays (3/age/time point). RESULTS: The mRNA levels of 62 genes related to neural function were affected by fracture. Of the total, 38 genes were altered by fracture to a similar extent at the three ages. In contrast, eight neural genes showed prolonged down-regulation in the older rats compared to the more rapid return to pre-fracture levels in younger rats. Seven genes were up-regulated by fracture more in the younger rats than in the older rats, while nine genes were up-regulated more in the older rats than in the younger. CONCLUSIONS: mRNA of 24 nerve-related genes responded differently to fracture in older rats compared to young rats. This differential expression may reflect altered cell function at the fracture site that may be causally related to the slowing of fracture healing with age or may be an effect of the delayed healing

    Large-Scale Gene-Centric Meta-Analysis across 39 Studies Identifies Type 2 Diabetes Loci

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    To identify genetic factors contributing to type 2 diabetes (T2D), we performed large-scale meta-analyses by using a custom similar to 50,000 SNP genotyping array (the ITMAT-Broad-CARe array) with similar to 2000 candidate genes in 39 multiethnic population-based studies, case-control studies, and clinical trials totaling 17,418 cases and 70,298 controls. First, meta-analysis of 25 studies comprising 14,073 cases and 57,489 controls of European descent confirmed eight established T2D loci at genome-wide significance. In silico follow-up analysis of putative association signals found in independent genome-wide association studies (including 8,130 cases and 38,987 controls) performed by the DIAGRAM consortium identified a T2D locus at genome-wide significance (GATAD2A/CILP2/PBX4; p = 5.7 x 10(-9)) and two loci exceeding study-wide significance (SREBF1, and TH/INS; p <2.4 x 10(-6)). Second, meta-analyses of 1,986 cases and 7,695 controls from eight African-American studies identified study-wide-significant (p = 2.4 x 10(-7)) variants in HMGA2 and replicated variants in TCF7L2 (p = 5.1 x 10(-15)). Third, conditional analysis revealed multiple known and novel independent signals within five T2D-associated genes in samples of European ancestry and within HMGA2 in African-American samples. Fourth, a multiethnic meta-analysis of all 39 studies identified T2D-associated variants in BCL2 (p = 2.1 x 10(-8)). Finally, a composite genetic score of SNPs from new and established T2D signals was significantly associated with increased risk of diabetes in African-American, Hispanic, and Asian populations. In summary, large-scale meta-analysis involving a dense gene-centric approach has uncovered additional loci and variants that contribute to T2D risk and suggests substantial overlap of T2D association signals across multiple ethnic groups
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