127 research outputs found

    Impactos del riego con aguas cloacales en las propiedades del suelo de una granja en China: Una revisión

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    El agua limpia es un recurso valioso y juega un rol importante en mantener los desarrollos económico y social. La limitación de recursos hídricos ciertamente no permitirá un desarrollo sostenible de las industrias básicas en China en un futuro cercano, considerando su gran población y potencial de consumo. La aplicación de aguas cloacales, hasta cierto punto, se observó como un camino alternativo para resolver el problema de la escasez de agua en agricultura en algunas áreas (tales como en el Norte de China). Sin embargo, acompañado con una implementación extensiva de riego con aguas cloacales, algunos problemas se hicieron obvios, especialmente aquellos relacionados con la contaminación y destrucción de granjas. En este manuscrito se revisaron los efectos del riego con aguas cloacales en granjas en China sobre algunas características físicas (densidad aparente del suelo, resistencia del suelo a la penetración y capacidad de campo), químicas (pH, materia orgánica del suelo, nitrógeno, fósforo, potasio, metales pesados y contaminantes orgánicos) y biológicas de suelo (microorganismos del suelo, y actividad enzimática). Esto se basó en el grado actual de utilización del riego con aguas cloacales de las granjas de China. Se propusieron algunas sugerencias posibles con respecto a las perspectivas de desarrollo en el futuro. Esta revisión será benéfica para promover un desarrollo saludable del riego con aguas cloacales y proveer un apoyo teórico para el reclamo y un gran uso eficiente de los efluentes en China.Fresh water is a valuable nonrenewable resource and plays an important role in maintaining economic and social development. Considering its large population and consumption potential, water resource deficits will certainly not allow a sustainable development of basic industries in China in the near future. Application of sewage irrigation, to some extent, was regarded as an alternative way to solve the problem of agricultural water shortage in some areas (such as North China). However, accompanied with an extensive implementation of sewage irrigation, some problems with sewage irrigation became gradually obvious in agriculture, especially those related with pollution and destruction of farmlands. In this paper, the effects of sewage irrigation on soil physical (soil bulk density, soil resistance to penetration and field capacity), chemical (pH, soil organic matter, nitrogen, phosphorus, potassium, heavy metal and organic pollutants) and biological characteristics (soil microorganisms and enzyme activities) were systematically reviewed on farmlands in China, based on the current utilization status of China’s farmland sewage irrigation. Some feasible suggestions were put forward to the development prospects in the future. This review will be beneficial for promoting a healthy development of sewage irrigation and providing a theoretical support for reclamation and a high efficiency use of effluents in China.Fil: Li, Q.K.. Yellow River Conservancy Commission. Yellow River Institute of Hydraulic Research; ChinaFil: Tang, J.. Henan Institute of Science and Technology. School of Resource and Environment ; ChinaFil: Wang, T.. Henan Bureau of Geo-Exploration & Mineral Development. Third Institute of Geo-exploration Institute; ChinaFil: Wu, D.. Henan Institute of Science and Technology. School of Resource and Environment ; ChinaFil: Busso, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Jiao, R.F.. Henan Institute of Science and Technology. School of Resource and Environment ; ChinaFil: Ren, J.X.. Henan Institute of Science and Technology. School of Resource and Environment ; Chin

    Diagnosis of early stage knee osteoarthritis based on early clinical course: data from the CHECK cohort

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    Background Early diagnosis of knee osteoarthritis (OA) is important in managing this disease, but such an early diagnostic tool is still lacking in clinical practice. The purpose of this study was to develop diagnostic models for early stage knee OA based on the first 2-year clinical course after the patient's initial presentation in primary care and to identify whether these course factors had additive discriminative value over baseline factors. Methods We extracted eligible patients' clinical and radiographic data from the CHECK cohort and formed the first 2-year course factors according to the factors' changes over the 2 years. Clinical expert consensus-based diagnosis, which was made via evaluating patients' 5- to 10-year follow-up data, was used as the outcome factor. Four models were developed: model 1, included clinical course factors only; model 2, included clinical and radiographic course factors; model 3, clinical baseline factors + clinical course factors; and model 4, clinical and radiographic baseline factors + clinical and radiographic course factors. All the models were built by a generalized estimating equation with a backward selection method. Area under the receiver operating characteristic curve (AUC) and its 95% confidence interval (CI) were calculated for assessing model discrimination. Delong's method compared AUCs. Results Seven hundred sixty-one patients with 1185 symptomatic knees were included in this study. Thirty-seven percent knees were diagnosed as OA at follow-up. Model 1 contained 6 clinical course factors; model 2: 6 clinical and 3 radiographic course factors; model 3: 6 baseline clinical factors combined with 5 clinical course factors; and model 4: 4 clinical and 1 radiographic baseline factors combined with 5 clinical and 3 radiographic course factors. Model discriminations are as follows: model 1, AUC 0.70 (95% CI 0.67-0.74); model 2, 0.74 (95% CI 0.71-0.77); model 3, 0.77 (95% CI 0.74-0.80); and model 4, 0.80 (95% CI 0.77-0.82). AUCs of model 3 and model 4 were slightly but significantly higher than corresponding baseline-factor models (model 3 0.77 vs 0.75, p = 0.031; model 4 0.80 vs 0.76, p = 0.003). Conclusions Four diagnostic models were developed with "fair" to "good" discriminations. First 2-year course factors had additive discriminative value over baseline factors.Clinical epidemiolog

    The added value of radiographs in diagnosing knee osteoarthritis is similar for general practitioners and secondary care physicians: data from the CHECK early osteoarthritis cohort

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    Objective: The purpose of this study was to evaluate the added value of radiographs for diagnosing knee osteoarthritis (KOA) by general practitioners (GPs) and secondary care physicians (SPs). Methods: Seventeen GPs and nineteen SPs were recruited to evaluate 1185 knees from the CHECK cohort (presenters with knee pain in primary care) for the presence of clinically relevant osteoarthritis (OA) during follow-up. Experts were required to make diagnoses independently, first based on clinical data only and then on clinical plus radiographic data, and to provide certainty scores (ranging from 1 to 100, where 1 was "certainly no OA" and 100 was "certainly OA"). Next, experts held consensus meetings to agree on the final diagnosis. With the final diagnosis as gold standard, diagnostic indicators were calculated (sensitivity, specificity, positive/negative predictive value, accuracy and positive/negative likelihood ratio) for all knees, as well as for clinically "certain" and "uncertain" knees, respectively. Student paired t-tests compared certainty scores. Results: Most diagnoses of GPs (86%) and SPs (82%) were "consistent" after assessment of radiographic data. Diagnostic indicators improved similarly for GPs and SPs after evaluating the radiographic data, but only improved relevantly in clinically "uncertain" knees. Radiographs added some certainty to "consistent" OA knees (GP 69 vs. 72, p < 0.001; SP 70 vs. 77, p < 0.001), but not to the consistent no OA knees (GP 21 vs. 22, p = 0.16; SP 20 vs. 21, p = 0.04). Conclusions: The added value of radiographs is similar for GP and SP, in terms of diagnostic accuracy and certainty. Radiographs appear to be redundant when clinicians are certain of their clinical diagnosis.Pathophysiology and treatment of rheumatic disease

    H∞ filtering for non-linear systems with stochastic sensor saturations and Markov time delays: The asymptotic stability in probability

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    This study is concerned with the filtering problem for a class of non-linear systems with stochastic sensor saturations and Markovian measurement transmission delays, where the asymptotic stability in probability is considered. The sensors are subject to random saturations characterised by a Bernoulli distributed sequence. The transmission time delays are governed by a discrete-time Markov chain with finite states. In the presence of the non-linearities, stochastic sensor saturations and Markovian time delays, sufficient conditions are established to guarantee that the filtering process is asymptotically stable in probability without disturbances and also satisfies the H∞ criterion with respect to non-zero exogenous disturbances under the zero-initial condition. Moreover, it is illustrated that the results can be specialised to linear filters. Two simulation examples are presented to show the effectiveness of the proposed algorithms.This work was supported by National Natural Science Foundation of China under Grants 61490701, 61290324, 61273156, 61473163, and 61210012, and Research Fund for the Taishan Scholar Project of Shandong Province of China, and Jiangsu Provincial Key Laboratory of E-business at Nanjing University of Finance and Economics of China under Grant JSEB201301, and Tsinghua University Initiative Scientific Research Program

    A search for the decay B+K+ννˉB^+ \to K^+ \nu \bar{\nu}

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    We search for the rare flavor-changing neutral-current decay B+K+ννˉB^+ \to K^+ \nu \bar{\nu} in a data sample of 82 fb1^{-1} collected with the {\sl BABAR} detector at the PEP-II B-factory. Signal events are selected by examining the properties of the system recoiling against either a reconstructed hadronic or semileptonic charged-B decay. Using these two independent samples we obtain a combined limit of B(B+K+ννˉ)<5.2×105{\mathcal B}(B^+ \to K^+ \nu \bar{\nu})<5.2 \times 10^{-5} at the 90% confidence level. In addition, by selecting for pions rather than kaons, we obtain a limit of B(B+π+ννˉ)<1.0×104{\mathcal B}(B^+ \to \pi^+ \nu \bar{\nu})<1.0 \times 10^{-4} using only the hadronic B reconstruction method.Comment: 7 pages, 8 postscript figures, submitted to Phys. Rev. Let

    High-reflectivity broadband distributed Bragg reflector lattice matched to ZnTe

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    We report on the realization of a high quality distributed Bragg reflector with both high and low refractive index layers lattice matched to ZnTe. Our structure is grown by molecular beam epitaxy and is based on binary compounds only. The high refractive index layer is made of ZnTe, while the low index material is made of a short period triple superlattice containing MgSe, MgTe, and ZnTe. The high refractive index step of Delta_n=0.5 in the structure results in a broad stopband and the reflectivity coefficient exceeding 99% for only 15 Bragg pairs.Comment: 4 pages, 3 figure

    EuFe2_2As2_2 under high pressure: an antiferromagnetic bulk superconductor

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    We report the ac magnetic susceptibility χac\chi_{ac} and resistivity ρ\rho measurements of EuFe2_2As2_2 under high pressure PP. By observing nearly 100% superconducting shielding and zero resistivity at PP = 28 kbar, we establish that PP-induced superconductivity occurs at TcT_c \sim~30 K in EuFe2_2As2_2. ρ\rho shows an anomalous nearly linear temperature dependence from room temperature down to TcT_c at the same PP. χac\chi_{ac} indicates that an antiferromagnetic order of Eu2+^{2+} moments with TNT_N \sim~20 K persists in the superconducting phase. The temperature dependence of the upper critical field is also determined.Comment: To appear in J. Phys. Soc. Jpn., Vol. 78 No.

    Measurement of the electron energy spectrum and its moments in inclusive B -> Xe nu decays

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    We report a measurement of the inclusive electron energy spectrum for semileptonic decays of B mesons in a data sample of 52 million Y(4S)-->B(B) over bar decays collected with the BABAR detector at the PEP-II asymmetric-energy B-meson factory at SLAC. We determine the branching fraction, first, second, and third moments of the spectrum for lower cutoffs on the electron energy between 0.6 and 1.5 GeV. We measure the partial branching fraction to be B(B-->Xenu,E-e>0.6 GeV)=[10.36+/-0.06(stat.)+/-0.23(sys.)]%

    Improved measurement of CP asymmetries in B-0 ->(c(c)over-bar)K0((*)) decays

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    We present results on time-dependent CP asymmetries in neutral B decays to several CP eigenstates. The measurements use a data sample of about 227x10(6) Upsilon(4S)-> B (B) over bar decays collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The amplitude of the CPasymmetry, sin2 beta in the standard model, is derived from decay-time distributions from events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the other B meson is determined to be either a B-0 or (0) from its decay products. We measure sin2 beta=0.722 +/- 0.040(stat)+/- 0.023(syst) in agreement with the standard model expectation
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