玉米品种抗蚜性鉴定评价方法与标准研究

本研究以玉米蚜为研究对象,在云南省昭通地区通过田间调查和相关数据分析,研究了玉米蚜田间种群动态,评价了27个不同品种玉米的抗蚜性,探索了更为简便的玉米抗蚜性评价方法。结果表明:玉米蚜在田间的发生有两个高峰期,分别是抽雄散粉期和蜡熟期;采用玉米整个生育期蚜量比值法比较不同品种玉米的抗性,发现高抗品种有6个、抗性品种有6个、中抗品种有6个、感虫品种有4个、高感品种有5个,玉米蚜的种群数量在不同品种玉米间存在显著差异;采用玉米蚜暴发时期到玉米完熟期的蚜量比值来评价玉米抗蚜性可行。     

A 3-D Propagation Model for Emerging Land Mobile Radio Cellular Environments

A tunable stochastic geometry based Three-Dimensional (3-D) scattering model for emerging land mobile radio cellular systems is proposed. Uniformly distributed scattering objects are assumed around the Mobile Station (MS) bounded within an ellipsoidal shaped Scattering Region (SR) hollowed with an elliptically-cylindric scattering free region in immediate vicinity of MS. To ensure the degree of expected accuracy, the proposed model is designed to be tunable (as required) with nine degrees of freedom, unlike its counterparts in the existing literature. The outer and inner boundaries of SR are designed as independently scalable along all the axes and rotatable in horizontal plane around their origin centered at MS. The elevated Base Station (BS) is considered outside the SR at a certain adjustable distance and height w.r.t. position of MS. Closed-form analytical expressions for joint and marginal Probability Density Functions (PDFs) of Angle-of-Arrival (AoA) and Time-of-Arrival (ToA) are derived for both up- and down-links. The obtained analytical results for angular and temporal statistics of the channel are presented along with a thorough analysis. The impact of various physical model parameters on angular and temporal characteristics of the channel is presented, which reveals the comprehensive insight on the proposed results. To evaluate the robustness of the proposed analytical model, a comparison with experimental datasets and simulation results is also presented. The obtained analytical results for PDF of AoA observed at BS are seen to fit a vast range of empirical datasets in the literature taken for various outdoor propagation environments. In order to establish the validity of the obtained analytical results for spatial and temporal characteristics of the channel, a comparison of the proposed analytical results with the simulation results is shown, which illustrates a good fit for 10⁷ scattering points. Moreover, the proposed model is shown to degenerate to various notable geometric models in the literature by an appropriate choice of a few parameters.     

Physical and Emotional Health Problems Experienced by Youth Engaged in Physical Fighting and Weapon Carrying

Then aims of the current study were 1) to provide cross-national estimates of the prevalence of physical fighting and weapon carrying among adolescents aged 11–15 years; (2) To examine the possible effects of physical fighting and weapon carrying on the occurrence of physical (medically treated injuries) and emotional health outcomes (multiple health complaints) among adolescents within the theoretical framework of Problem Behaviour Theory. 20,125 adolescents aged 11–15 in five countries (Belgium, Israel, USA, Canada, FYR Macedonia) were surveyed via the 2006 Health Behaviour in School Aged Children survey. Prevalence was calculated for physical fighting and weapon carrying along with physical and emotional measures that potentially result from violence. Regression analyses were used to quantify associations between violence/weapon carrying and the potential health consequences within each country. Large variations in fighting and weapon carrying were observed across countries. Boys reported more frequent episodes of fighting/weapon carrying and medically attended injuries in every country, while girls reported more emotional symptoms. Although there were some notable variations in findings between different participating countries, increased weapon carrying and physical fighting were both independently and consistently associated with more frequent reports of the potential health outcomes. Adolescents engaging in fighting and weapon carrying are also at risk for physical and emotional health outcomes. Involvement in fighting and weapon carrying can be seen as part of a constellation of risk behaviours with obvious health implications. Our findings also highlight the importance of the cultural context when examining the nature of violent behaviour for adolescents.     

New perspectives in diet analysis based on DNA barcoding and parallel pyrosequencing: the trnL approach

The development of DNA barcoding (species identification using a standardized DNA sequence), and the availability of recent DNA sequencing techniques offer new possibilities in diet analysis. DNA fragments shorter than 100-150 bp remain in a much higher proportion in degraded DNA samples and can be recovered from faeces. As a consequence, by using universal primers that amplify a very short but informative DNA fragment, it is possible to reliably identify the plant taxon that has been eaten. According to our experience and using this identification system, about 50% of the taxa can be identified to species using the trnL approach, that is, using the P6 loop of the chloroplast trnL (UAA) intron. We demonstrated that this new method is fast, simple to implement, and very robust. It can be applied for diet analyses of a wide range of phytophagous species at large scales. We also demonstrated that our approach is efficient for mammals, birds, insects and molluscs. This method opens new perspectives in ecology, not only by allowing large-scale studies on diet, but also by enhancing studies on resource partitioning among competing species, and describing food webs in ecosystems.     

Health outcomes of road-traffic pollution among exposed roadside workers in Rawalpindi City,Pakistan

To document ill-health effects of air pollution on the local inhabitants, we analyzed the self-reported health issues associated with the inhalation of road traffic on daily basis. For this purpose, a revised version of ALS-DLD-78S questionnaire was administered, comprising the personal information and details related to the clinical history of the surveyed population (i.e. n = 580). Five dependent (outcome) variables, including chest pain, redness of eyes, shortness of breath, eye-tearing, and skin-itching were taken into account. The results revealed that ～80% of the surveyed population were directly or indirectly exposed to road traffic, and the incidence of chest pain among exposed individuals was estimated to increase with age (odds ratio (OR) = 6.49; 95% confidence interval (CI) = 1.46–28.81), especially among cardiac patients (OR = 13.87; 95%-CI = 3.28–58.61). However, the shortness of breath was predominantly observed among those who reported to have asthmatic symptoms (OR = 32.84; 95%-CI = 15.59–69.15) and cardiovascular symptoms (OR = 13.8: 95%-CI = 3.63–52.41). In case of itching, the population along the roadside were more vulnerable to exposure (OR = 5.79; 95%-CI = 2.81–11.93). While, exposure to traffic exhaust could be attributed to ～3.13% rise in the incidences of redness of eyes among general population, the outcomes of this survey show that daily exposure to traffic pollution is an important health concern for the urban population in general, as well as for various occupational groups in particular, working in outdoor environment.     

Do psychiatric diseases follow annual cyclic seasonality?

Seasonal affective disorder (SAD) famously follows annual cycles, with incidence elevation in the fall and spring. Should some version of cyclic annual pattern be expected from other psychiatric disorders? Would annual cycles be similar for distinct psychiatric conditions? This study probes these questions using 2 very large datasets describing the health histories of 150 million unique U.S. citizens and the entire Swedish population. We performed 2 types of analysis, using “uncorrected” and “corrected” observations. The former analysis focused on counts of daily patient visits associated with each disease. The latter analysis instead looked at the proportion of disease-specific visits within the total volume of visits for a time interval. In the uncorrected analysis, we found that psychiatric disorders’ annual patterns were remarkably similar across the studied diseases in both countries, with the magnitude of annual variation significantly higher in Sweden than in the United States for psychiatric, but not infectious diseases. In the corrected analysis, only 1 group of patients—11 to 20 years old—reproduced all regularities we observed for psychiatric disorders in the uncorrected analysis; the annual healthcare-seeking visit patterns associated with other age-groups changed drastically. Analogous analyses over infectious diseases were less divergent over these 2 types of computation. Comparing these 2 sets of results in the context of published psychiatric disorder seasonality studies, we tend to believe that our uncorrected results are more likely to capture the real trends, while the corrected results perhaps reflect mostly artifacts determined by dominantly fluctuating, health-seeking visits across a given year. However, the divergent results are ultimately inconclusive; thus, we present both sets of results unredacted, and, in the spirit of full disclosure, leave the verdict to the reader.

Should we expect psychiatric disorders to show a cyclic annual pattern? This study reveals that psychiatric diseases’ annual patterns were remarkably similar across the studied diseases in both the US and Sweden, with the magnitude of annual variation significantly higher in Sweden than in the US for psychiatric, but not infectious, diseases.     

Optimization of condition(s) towards establishment of primary islet cell cultures from WNIN/Ob mutant rat

WNIN/Ob, a mutant rat strain, developed at the National Center for Laboratory Animal Sciences (NCLAS) facility of National Institute of Nutrition (NIN), is a new animal model to study the metabolic syndrome. These animals have 47% fat in their body and isolation of islets from these animals were compounded due to the formation of amorphous viscous and jelly like material which reduced the islet yield. However, islets isolated from WNIN adult (≥12 months) control rats gave a good islet recovery, under standard isolation procedures using collagenase digestion. In the present study we optimized culture conditions in WNIN/Ob rats to isolate islets with higher yield, and also established primary islet cell cultures from these mutant rats, retaining cellular integrity and functionality.