39 research outputs found

    Space-time variation of malaria incidence in Yunnan province, China

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    Abstract Background Understanding spatio-temporal variation in malaria incidence provides a basis for effective disease control planning and monitoring. Methods Monthly surveillance data between 1991 and 2006 for Plasmodium vivax and Plasmodium falciparum malaria across 128 counties were assembled for Yunnan, a province of China with one of the highest burdens of malaria. County-level Bayesian Poisson regression models of incidence were constructed, with effects for rainfall, maximum temperature and temporal trend. The model also allowed for spatial variation in county-level incidence and temporal trend, and dependence between incidence in June–September and the preceding January–February. Results Models revealed strong associations between malaria incidence and both rainfall and maximum temperature. There was a significant association between incidence in June–September and the preceding January–February. Raw standardised morbidity ratios showed a high incidence in some counties bordering Myanmar, Laos and Vietnam, and counties in the Red River valley. Clusters of counties in south-western and northern Yunnan were identified that had high incidence not explained by climate. The overall trend in incidence decreased, but there was significant variation between counties. Conclusion Dependence between incidence in summer and the preceding January–February suggests a role of intrinsic host-pathogen dynamics. Incidence during the summer peak might be predictable based on incidence in January–February, facilitating malaria control planning, scaled months in advance to the magnitude of the summer malaria burden. Heterogeneities in county-level temporal trends suggest that reductions in the burden of malaria have been unevenly distributed throughout the province

    Biogeography of Amazonian fishes: deconstructing river basins as biogeographic units

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    Purinergic signalling and immune cells

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    This review article provides a historical perspective on the role of purinergic signalling in the regulation of various subsets of immune cells from early discoveries to current understanding. It is now recognised that adenosine 5'-triphosphate (ATP) and other nucleotides are released from cells following stress or injury. They can act on virtually all subsets of immune cells through a spectrum of P2X ligand-gated ion channels and G protein-coupled P2Y receptors. Furthermore, ATP is rapidly degraded into adenosine by ectonucleotidases such as CD39 and CD73, and adenosine exerts additional regulatory effects through its own receptors. The resulting effect ranges from stimulation to tolerance depending on the amount and time courses of nucleotides released, and the balance between ATP and adenosine. This review identifies the various receptors involved in the different subsets of immune cells and their effects on the function of these cells

    Likelihood analysis of supersymmetric SU(5) GUTs

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    Assessing farmers’ perspectives on climate change for effective farm-level adaptation measures in Khyber Pakhtunkhwa, Pakistan

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    Agriculture is considered as the backbone of the economy of Pakistan. However, current changes in climate have been adversely affecting agricultural productivity. In this paper, perceived impacts of climate change on agriculture and adaptation towards it have been studied in Charsadda district (lowlands) of Khyber Pakhtunkhwa province of Pakistan through extensive field surveys, involving 116 farm households. Results have revealed that climate change factors including fluctuating temperature, evidence of yearly long droughts, and a steady shift in rainfall patterns have pressured the agriculture sector and livelihoods of the local peasants. The staggering floods of 2010 and 2011 in Pakistan have evidenced severe climatic changes in Pakistan. These countrywide floods have washed fertile soil in the study area that has directly contributed to losses in agricultural yield and increased vector-borne diseases in crops. The local farmers have commonly deployed adaptive measure such as crops diversification, changing fertilizer, and planting shaded trees to minimize the impacts of changes in climate. However, these adjustments measures are perceived as not appropriate for improving farm yield. Therefore, the study suggests that improved understanding of the climate change impacts and knowledge on adapting adequately will lead to no-regret adaptation. It will also help protecting farmer's lives and livelihoods and will boost their resilience towards changing climatic conditions
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