368 research outputs found

    PHARMACOGNOSTIC STANDARDISATION AND CHROMATOGRAPHIC FINGERPRINTING OF LEAVES AND FRUITS OF ZANTHOXYLUM RHETSA

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    Objective: To conduct pharmacognostic standardisation and chromatographic fingerprinting of leaves and fruits of Zanthoxylum rhetsa.Methods: The macroscopic, microscopic and physicochemical evaluation of the crude drugs were conducted as per I. P and WHO guidelines. The chromatographic fingerprint was also developed for the leaves and fruits.Results: The microscopic characteristics of leaves exhibited anomocytic stomata, fibrovascular tissue, lignfied pericyclic fibers and pitted xylem vessels. The fruits exhibited pericarp, oil cells, stone cells, xylem and endosperm. The physicochemical analysis was also conducted. The leaf and fruit powders complied with WHO prescribed limits for microbial load NMT 1× 105 CFU/ml and were found to be free from pathogenic organisms. The HPTLC fingerprint was established for methanol extract of leaves and fruits using Dichloromethane: chloroform: ethanol (4:4:1) as solvent and 10% methanolic sulphuric acid as spray reagent.Conclusion: The present work provides referential information for the correct identification and standardisation of the plant

    Generation of Geochemical Exploration Targets from Regional Stream Sediment Data Using Principal Component and Factor Analysis: A Case Study of Kibaya-Kiteto, Manyara-Tanzania

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    A regional-scale stream sediment geochemical sampling was carried out with an average sampling density of one sample per nine square-kilometre in Kiteto District, Manyara Region. A total of 358 stream sediment samples were collected and analysed for major and trace elements by X-ray fluorescence (XRF) and fire assay with atomic absorption spectrometry (AAS) finish methods. In this study, Factor and Principal Component Multivariate (FPCM) analyses have been used to the stream geochemical data to delineate potential mineralization zones by plotting correlated factors as geochemical anomaly maps. Four factors that account for 73.7% of the total variance of the stream sediment geochemical data were established. Factor 1: Ni–Ba–Co–Cu–Sr which possibly defines the underlying metamorphosed granitic units with some contribution from mafic and ultramafic rocks. Factor 2: Cr–Zn–Mn which defines crustal forming elements reflecting the mafic rocks. Factor 3 which entails Rb and Pb probably attributed to metamorphosed granitic lithology. Factor 4 is arsenic, a chalcophile element with affinity to sulfide phases. The FPCM analyses have been successfully in delineating potential target areas for gold, nickel and copper exploration in the study area. Keywords:    Stream sediment; principal component; factor analysis; exploration targets; Kibaya-Kiteto, Manyara

    Adding New Tasks to a Single Network with Weight Transformations using Binary Masks

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    Visual recognition algorithms are required today to exhibit adaptive abilities. Given a deep model trained on a specific, given task, it would be highly desirable to be able to adapt incrementally to new tasks, preserving scalability as the number of new tasks increases, while at the same time avoiding catastrophic forgetting issues. Recent work has shown that masking the internal weights of a given original conv-net through learned binary variables is a promising strategy. We build upon this intuition and take into account more elaborated affine transformations of the convolutional weights that include learned binary masks. We show that with our generalization it is possible to achieve significantly higher levels of adaptation to new tasks, enabling the approach to compete with fine tuning strategies by requiring slightly more than 1 bit per network parameter per additional task. Experiments on two popular benchmarks showcase the power of our approach, that achieves the new state of the art on the Visual Decathlon Challenge

    Addition of NOCl to cyclic vinylsilanes: An unexpected reversal of regiochemistry

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    NOCl adds to cyclic vinylsilanes in a syn manner with NO+ bonding to the β-carbon and Cl- to the α-carbon, which is a reversal of the regiochemistry expected from the β-silicon effect. The adducts dimerize to a single diastereomer containing enantiomeric pairs and/or give secondary products on further reaction. © 2001 Elsevier Science Ltd

    Influence of land use change on nitrate sources and pollutant enrichment in surface and groundwater of a growing urban area in Tanzania

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    This research article published by Springer Nature Switzerland AG., 2021In the present study, 3-year (1997, 2008 and 2017) satellite images as well as different hydro-chemical parameters, nitrogen and oxygen isotopic composition of nitrate were used to examine the impacts of land use and land cover change on surface and groundwater quality. Through isotopic composition, sources of surface and groundwater pollutants were also elucidated. The results showed significant land use transition whereby land use changed from forest and bare land to agricultural land and built-up areas. A slight reduction in the size of areas covered by water bodies was also observed. Results indicate differences in nitrate concentration that mirror land use changes. Samples with elevated levels of nitrate above 10 mg/L were located near agricultural fields and areas with intensive livestock keeping activities. In groundwater, ẟ15N-nitrate and ẟ18O-nitrate ranged from 3.2‰ to 20.1‰ with a mean value of 11.7 ± 1.8‰ and from 2.1‰ to 12.0‰ with mean value of 5.4 ± 1.8‰, respectively. In surface water, ẟ15N-nitrate and ẟ18O-nitrate ranged from 2.4‰ to 19.3‰ with mean value of 4.9 ± 1.4‰ and from 1.5‰ to 21.9‰ with a mean value of 13.5 ± 2.8‰, respectively. Isotopic composition data suggest sources of nitrate in both ground and surface water dominated by synthetic and organic fertilizer application and to a lesser extent a natural soil nitrate source

    Transcriptional Profiling of Peripheral Blood Mononuclear Cells in Pancreatic Cancer Patients Identifies Novel Genes with Potential Diagnostic Utility

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    Background: It is well known that many malignancies, including pancreatic cancer (PC), possess the ability to evade the immune system by indirectly downregulating the mononuclear cell machinery necessary to launch an effective immune response. This knowledge, in conjunction with the fact that the trancriptome of peripheral blood mononuclear cells has been shown to be altered in the context of many diseases, including renal cell carcinoma, lead us to study if any such alteration in gene expression exists in PC as it may have diagnostic utility. Methods and Findings: PBMC samples from 26 PC patients and 33 matched healthy controls were analyzed by whole genome cDNA microarray. Three hundred eighty-three genes were found to be significantly different between PC and healthy controls, with 65 having at least a 1.5 fold change in expression. Pathway analysis revealed that many of these genes fell into pathways responsible for hematopoietic differentiation, cytokine signaling, and natural killer (NK) cell and CD8+ T-cell cytotoxic response. Unsupervised hierarchical clustering analysis identified an eight-gene predictor set, consisting of SSBP2, Ube2b-rs1, CA5B, F5, TBC1D8, ANXA3, ARG1, and ADAMTS20, that could distinguish PC patients from healthy controls with an accuracy of 79% in a blinded subset of samples from treatment naïve patients, giving a sensitivity of 83% and a specificity of 75%. Conclusions: In summary, we report the first in-depth comparison of global gene expression profiles of PBMCs between PC patients and healthy controls. We have also identified a gene predictor set that can potentially be developed further for use in diagnostic algorithms in PC. Future directions of this research should include analysis of PBMC expression profiles in patients with chronic pancreatitis as well as increasing the number of early-stage patients to assess the utility of PBMCs in the early diagnosis of PC. © 2011 Baine et al

    A needs assessment of people living with diabetes and diabetic retinopathy

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    BACKGROUND: The Kilimanjaro Diabetic Programme was initiated in response to the needs of people living with diabetes (PWLD) to identify barriers to uptake of screening for diabetic retinopathy, to improve management of diabetes, and establish an affordable, sustainable eye screening and treatment programme for diabetic retinopathy. Intervention Mapping was used as the framework for the needs assessment. METHODS: A mixed methods approach was used. Five psychometric measures, Diabetes Knowledge Questionnaire, Diabetes Health Beliefs, Self-Efficacy scale, Problem Areas in Diabetes scale, and Hopkins Scale Checklist-25 and a structured interview relating to self-efficacy, addressing disclosure of living with diabetes and life-style changes were used to triangulate the quantitative findings. These were administered to 26 PWLD presenting to rural district hospitals. RESULTS: The interviewees demonstrated low levels of perceived stigma regarding disclosure of living with diabetes and high levels of self-efficacy in raising community awareness of diabetes, seeking on going treatment from Western medicine over traditional healers and in seeking care on sick days. Self-efficacy was high for adjusting diet, although comprehensive dietary knowledge was poor. Negative emotions expressed at diagnosis, changes in life style and altered quality of life were reflected in high levels of anxiety and depression. CONCLUSIONS: Low levels of stigma surrounding living with diabetes were linked to a desire to raise community awareness of diabetes, help others live with diabetes and to secure social support to access hospital services. Confusion over what constituted a healthy diet showed the importance of comprehensive, accessible diabetes education, essential to ensuring good glycaemic control, and preventing diabetic complications, including diabetic retinopathy. Low levels of self-efficacy along with high levels of anxiety and depression may have a negative impact on the uptake of screening for Diabetic Retinopathy. The findings of this needs assessment led to the planning and delivery of a comprehensive health intervention programme for PLWD in Kilimanjaro Region. The programme has provided them with support, resources, education, and screening for diabetic retinopathy at the regional hospital and at district level with mobile digital retinal cameras, an electronic diabetic database and computerised follow up to ensure continuity of care
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