Seasonal variation in resistance of chrysanthemum cultivars to Frankliniella occidentalis (Thysanoptera: Thripidae)

Seasonal variation in the level of host plant resistance can have important consequences for the repeatability of tests to measure host plant resistance to insect pests. In the present study, the levels of resistance to Frankliniella occidentalis of a susceptible and a partially resistant cultivar of chrysanthemum, Dendranthema grandiflora, were determined throughout the year. Thrips damage, reproduction and adult female survival were determined on excised leaves in Petri dishes under uniform conditions. Strong seasonal fluctuations were observed in these three characteristics. On leaves from plants grown in winter, damage, reproduction, and survival were higher than on leaves from plants grown in summer. Clear differences in resistance were observed between the susceptible and the partially resistant cultivar on leaves from plants grown in winter, while differences disappeared in summer. Damage on both cultivars and survival on the susceptible cultivar were negatively correlated with mean daily solar radiation during plant growth, suggesting that the level of resistance depends on light intensity during plant growth. This was confirmed in an experiment carried out in summertime with shaded and unshaded plants. Leaves from control plants, grown under high light intensity had a higher level of resistance than leaves from shaded plants grown under reduced light intensity. There were clear differences in resistance between the cultivars under shaded conditions (low light intensity), but not under unshaded control conditions (high light intensity). This revised version was published online in July 2006 with corrections to the Cover Date.     

Precipitation and Erosivity in Southern Portugal: Seasonal Variability and Trends (1950–2008)

Southern Portugal experiences the lowest amounts of annual precipitation and the highest level of susceptibility to soil erosion, drought events and desertification phenomena in mainland Portugal. The first goal of this paper was to analyse spatial variability and trends in annual precipitation and erosivity in southern mainland Portugal for the period 1950/1951–2007/2008. The second objective was to evaluate seasonality in relation to precipitation distribution, erosivity and concentration over the same period and to evaluate and detect possible changes in the time trend for precipitation erosivity. In order to achieve these objectives, the annual and seasonal precipitation figures, corresponding to data from 90 rain gauges, were analysed and the Modified Fournier Index and Precipitation Concentration Index calculated for each station. The results obtained revealed distinct behaviour patterns for yearly precipitation, erosivity and concentration trends. Decreases in annual precipitation and erosivity figures accompanied by increases in precipitation concentration were found. Nevertheless, no generalised significant trends have been detected for these variables. In seasonal terms, there was a general trend towards an increase in amount, concentration and precipitation erosivity in autumn and summer, and a significantly reducing in winter. The increase in precipitation erosivity, particularly in the autumn, the most water‐erosive season, suggests a rising in potential soil erosion risk in southern Portugal. Copyright © 2014 John Wiley & Sons, Ltd.     

盐碱土微生物功能群季节动态与土壤理化因子的关系

选取河西走廊东端永登县6种盐碱土壤类型,对各样地微生物功能群的季节动态与土壤理化因子之间的关系进行分析.结果表明:①盐碱环境中土壤细菌＞放线菌＞真菌,细菌和放线菌数量在夏季出现峰值,真菌数量在秋季和冬季出现峰值;不同微生物功能群基本上只有一个峰值且峰值出现的季节不同,与碳循环相关的纤维素分解菌功能群的峰值出现在冬季,与...     

基于Box—Jenkins方法的黄河水质时间序列分析与预测

采用基于Box-Jenkins方法的时间序列分析技术,对黄河上游甘肃兰州段、中游吴堡和下游山东利津段的水质进行了趋势分析和预测。选取对水质产生影响较大的两个污染因子化学需氧量（CODMn）和溶解氧（D0O1994—2003连续10a的月平均水质监测数据,借助Matlab和SAS统计软件,建立了ARIMA模型和乘积季节时间序列模型,并分析了这两个污染因子随时间推移的变化规律。结果表明：ARIMA模型和乘积季节模型能够用于短期水质预测,并且预测效果较好。黄河流域从上游到下游水质总体状况呈逐渐下降趋势,上游水质一般为Ⅱ和Ⅲ类,而中游和下游水质基本为Ⅳ、Ⅴ和超Ⅴ类。     

成都桃园昆虫群落季节格局研究

本文应用最优分割法研究了成都桃园昆虫群落的季节演变格局和规律,将桃园昆虫群落年季节变化分割成3～5月、6～7月、8～9月和10～11月4个阶段,并结合气候及物候变化,讨论了各阶段内主要害虫、天敌的发生特点和治理策略。     

Programme to Vaccinate Poultry Workers Against Seasonal Influenza: Options for Delivery in the East of England

Avian influenza A (H5N1) has spread to the UK causing outbreaks in commercial poultry. Vaccination of poultry workers with seasonal influenza has been advised to prevent a viral mutation that could facilitate human‐to‐human transmission, causing a new pandemic strain. This project aimed to determine delivery options and costs of a vaccination programme targeted at poultry workers. Data from the Great Britain Poultry Register were used to understand the distribution of the target population. A stakeholders group in the East of England (EoE) discussed delivery options. An options appraisal is used to prioritize these options. There are over 10 000 poultry workers distributed throughout the EoE. Five delivery options were considered (industry’s occupational health services, via general practitioners as a Directed or Locally Enhanced Services, via other community healthcare providers and a commercial provider). Delivery is likely to cost between £35 414 and £182 899 (or £10.18–£48.93 per person vaccinated) in the EoE, depending on delivery mechanism, target threshold and level of uptake. Delivering through a commercial provider was the preferred option. Whichever way the programme is delivered it should be cost‐neutral to the Primary Care Trust (PCT). Otherwise PCTs may see themselves having to prioritize between vaccinating poultry workers against other pressing programmes.     

江苏省全社会固定资产投资预测

采用Holter-Winter非季节指数平滑模型、GM(1,1)模型和分段线性回归模型,对江苏省1978～2005年的全社会固定资产投资总额进行研究.结果表明,与其他两模型相比,分段线性回归模型具有较好的拟合效果,并预测了"十一五"期间的固定资产投资总额.     

自然冻融条件下黄土丘陵区不同土地利用方式原状土的抗冲性

[目的]研究冻融对3种土地利用方式(坡耕地、草地和灌木地)土壤抗冲性的影响,旨在为黄土高原季节性冻融区植被恢复建设提供理论依据.[方法]基于一系列野外自然冻融、野外监测和原状土冲刷试验,以确定冻融对3种土地利用方式土壤抗冲性的影响.[结果]①相较于坡耕地,草地与灌木地的冻结程度更低,其中,灌木地冻结程度最低,抗冻性最好...     

On the Health Benefits vs. Risks of Seaweeds and Their Constituents: The Curious Case of the Polymer Paradigm

To exploit the nutraceutical and biomedical potential of selected seaweed-derived polymers in an economically viable way, it is necessary to analyze and understand their quality and yield fluctuations throughout the seasons. In this study, the seasonal polysaccharide yield and respective quality were evaluated in three selected seaweeds, namely the agarophyte Gracilaria gracilis, the carrageenophyte Calliblepharis jubata (both red seaweeds) and the alginophyte Sargassum muticum (brown seaweed). It was found that the agar synthesis of G. gracilis did not significantly differ with the seasons (27.04% seaweed dry weight (DW)). In contrast, the carrageenan content in C. jubata varied seasonally, being synthesized in higher concentrations during the summer (18.73% DW). Meanwhile, the alginate synthesis of S. muticum exhibited a higher concentration (36.88% DW) during the winter. Therefore, there is a need to assess the threshold at which seaweed-derived polymers may have positive effects or negative impacts on human nutrition. Furthermore, this study highlights the three polymers, along with their known thresholds, at which they can have positive and/or negative health impacts. Such knowledge is key to recognizing the paradigm governing their successful deployment and related beneficial applications in humans.     

The Coconut Rhinoceros Beetle Oryctes rhinoceros (L)[Coleoptera: Scarabaeidae: Dynastinae]

Abstract

Field experiments were conducted during two dry seasons in northern Nigeria to identify suitable pre‐transplant herbicides for weed control in irrigated tomatoes. At Samaru in the northern Guinea savanna, diphenamid at 1.5 kg a.i./ha followed by supplementary hoe‐weeding, metribuzin at 0.5 kg a.i./ha, diphenamid at 3.0 kg a.i./ha, metolachlor plus metobromuron at 1.0 + 1.0 kg a.i./ha and two or three hoe‐weedings, resulted in higher tomato yields than the untreated controls, and most of these treatments reduced weed infestations significantly in both years. At Bakura, in the Sudan savanna zone, metribuzin at 0.25 and 0.5 kg a.i./ha, diphenamid at 3.0 g a.i./ha and chloramben at 1.5 kg a.i./ha plus supplementary weeding consistently resulted in yields that were similar to two hoe‐weedings and higher than the untreated controls. Three kg a.i./ha of chloramben depressed yields in all the trials. At both sites hoe‐weeding once six weeks after transplanting gave unacceptably low crop yields, but similar high yields were obtained with two or three hoe‐weedings. Supplementary hoe‐weedings were unnecessary with the application of metribuzin at 0.5 kg and metolachlor plus metobromuron at 1.0 + 1.0 kg a.i./ha. Uncontrolled weed growth resulted in a 53–67% reduction in tomato fruit yield.