170 research outputs found

    Increasing incidence of hemorrhagic fever with renal syndrome could be associated with livestock husbandry in Changchun, Northeastern China

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    Background: Since the end of the 1990s, the incidence of hemorrhagic fever with renal syndrome (HFRS) has been increasing dramatically in Changchun, northeastern China. However, it is unknown which, and how, underlying risk factors have been involved in the reemergence of the disease.Methods: Data on HFRS cases at the county scale were collected from 1998 to 2012. Data on livestock husbandry including the numbers of large animals (cattle, horses, donkeys and mules), sheep, and deer, and on climatic and land cover variables were also collected. Epidemiological features, including the spatial, temporal and human patterns of disease were characterized. The potential factors related to spatial heterogeneity and temporal trends were analyzed using standard and time-series Poisson regression analysis, respectively.Results: Annual incidence varied among the 10 counties. Shuangyang County in southeastern Changchun had the highest number of cases (1,525 cases; 35.9% of all cases), but its population only accounted for 5.6% of the total population. Based on seasonal pattern in HFRS incidence, two epidemic phases were identified. One was a single epidemic peak at the end of each year from 1988 to 1997 and the other consisted of dual epidemic peaks at both the end and the beginning of each year from 1998 to the end of the study period. HFRS incidence was higher in males compared to females, and most of the HFRS cases occurred in peasant populations. The results of the Poisson regression analysis indicated that the spatial distribution and the increasing incidence of HFRS were significantly associated with livestock husbandry and climate factors, particularly with deer cultivation.Conclusions: Our results indicate that the re-emergence of HFRS in Changchun has been accompanied by changing seasonal patterns over the past 25 years. Integrated measures focusing on areas related to local livestock husbandry could be helpful for the prevention and control of HFRS

    Periodicities in the Daily Proton Fluxes from 2011 to 2019 Measured by the Alpha Magnetic Spectrometer on the International Space Station from 1 to 100 GV

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    We present the precision measurement of the daily proton fluxes in cosmic rays from May 20, 2011 to October 29, 2019 (a total of 2824 days or 114 Bartels rotations) in the rigidity interval from 1 to 100 GV based on 5.5×109 protons collected with the Alpha Magnetic Spectrometer aboard the International Space Station. The proton fluxes exhibit variations on multiple timescales. From 2014 to 2018, we observed recurrent flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities changes with time and rigidity. The rigidity dependence of the 27-day periodicity is different from the rigidity dependences of 9-day and 13.5-day periods. Unexpectedly, the strength of 9-day and 13.5-day periodicities increases with increasing rigidities up to ∌10 GV and ∌20 GV, respectively. Then the strength of the periodicities decreases with increasing rigidity up to 100 GV.</p

    Precision Measurement of the Proton Flux in Primary Cosmic Rays from Rigidity 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station

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    A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of cosmic rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.</p

    Dairy buffalo breeding in countryside of China

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    Chinese buffalo is of swamp type, mainly distributed in countryside of 18 provinces in southern China. China has the third population of buffalo in the world. There are 22.75 million buffaloes in China in 2005, representing 17.37% of all cattle in the whole country. Historically Chinese buffalo is mainly used for drought since their milk production is very low with an annual milk yield of 500-700 kg. Therefore, it is important to improve them to change into dairy buffalo through crossbreeding with exotic river type dairy buffalo breeds. Murrah and Nili-Ravi, the most famous river type dairy buffalo breeds in the world, were introduced from India and Pakistan in 1957 and 1974, respectively and used to crossbreed with indigenous Chinese buffalo for genetic improvement. The effect is very prominent that the performance of crossbred has been improved significantly after several decades and the milk yield reaches 1200-2000 kg. Recent years in countryside of China, buffalo rearing has been changed from extensive and dispersive model in the past into specialized small or medium dairy herd model for the present along with the rapid development of dairy buffalo breeding and the model of dairy buffalo breeding sub-district has been formed. This article introduces briefly that the system of dairy buffalo breeding as well as producing, processing and selling of buffalo milk under the current condition and the prospects of dairy buffalo development in countryside of China

    Age and geochemistry of Silurian gabbroic rocks in the Tongbai orogen, central China: implications for the geodynamic evolution of the North Qinling arc–back-arc system

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    The tectonic properties of the Erlangping unit and the subduction polarity of oceanic basins in the North Qinling-Tongbai orogen have been the focus of debate for more than twenty years. The resolution of these controversies hinges on the refined constraints on the location and nature of subduction-related magmatism. In this contribution, we provide a combined study of zircon U-Pb ages, major and trace element geochemistry, and Sr-Nd-Hf isotope compositions of gabbroic rocks from the Erlangping unit in the Tongbai orogen. U-Pb dating of zircons from two gabbroic diorite samples yielded two weighted mean ages of 443±3 and 440±4Ma. The Erlangping gabbroic rocks are tholeiitic in composition with variable MgO (4.48-8.17%), and low

    Three new C 21

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