An approach for post‐market monitoring of potential environmental effects of Bt‐maize expressing Cry1Ab on natural enemies

Post‐market monitoring (PMM) consistent with Swiss and European Union legislation should ensure the detection and prevention of adverse effects on the environment possibly deriving from commercial cultivation of genetically modified (GM) crops. Insect‐resistant GM crops (such as Bt‐maize) raise particular questions regarding disturbances of biological control functions provided by beneficial insects such as predators and parasitoids (so‐called natural enemies). Consensus among regulators, scientists and the agricultural biotech industry on appropriate PMM plans allowing the detection and possibly prevention of such adverse effects is still lacking. The aims of this study were to identify the necessity for PMM of Bt‐maize expressing Cry1Ab on natural enemies and to develop an appropriate PMM plan. The approach chosen consisted in determining what type of monitoring is most appropriate to address potential effects of Bt‐maize on natural enemies during commercial cultivation. This included identifying whether there remain substantial scientific uncertainties that would support case‐specific monitoring. Existing pre‐market risk assessment data indicate that Bt‐maize (Cry1Ab) comprises a negligible risk for disturbances in biological control functions of natural enemies. As a consequence, a faunistic monitoring of specific groups of natural enemies is not considered an appropriate approach to detect failures in biological control functions. Alternatively, an approach is proposed that consists in indirectly analysing biological control functions by surveying outbreaks of maize herbivores. Unusual herbivore outbreaks could indicate failures in biological control functions of natural enemies. Data could be collected via questionnaires addressed to farmers growing Bt‐maize. Significant correlations between unusual occurrences of specific maize herbivores and the cultivation of Bt‐maize would subsequently need specific studies to determine possible causalities in more detail. The here proposed approach has the advantage of covering different natural enemy groups. It represents a cost‐effective strategy to obtain scientifically sound data as a basis for regulatory decision‐making.     

Molecular genetic variation and geographical structuring in Fusarium graminearum

Inter‐simple sequence repeat markers were employed to study the genetic structure of Fusarium graminearum populations collected from three Canadian provinces. Our study suggested high genetic diversity and frequent gene flow among population samples analysed. The analysis of molecular variance indicated that most of the gene diversity (91.78% to 97.23%) was distributed within populations. Frequent gene flow among the western prairie provinces and cluster analysis results indicated that the population sample from Alberta was closer to Saskatchewan than Manitoba, which could be the result of movement of the pathogen via infected grain or through wind‐borne ascospore dispersal. Analysis of multilocus associations showed that all populations were in linkage equilibrium, indicating that sexual recombination is a frequent phenomenon in F. graminearum populations from western Canada.     

On‐line yeast propagation process monitoring and control using an intelligent automatic control system

The monitoring and control of bioprocesses is a challenging task. This applies particularly if the actions to the process have to be carried out in real‐time. This work presents a system for on‐line monitoring and control of batch yeast propagation under limiting conditions based on a virtual plant operator, which uses the concept of intelligent control algorithms by means of fuzzy logic theory. Process information is provided on‐line using a sensor array comprising the measurement of OD, operating temperature, pressure, density, dissolved oxygen, and pH value. In this context practical problems arising through on‐line sensing and signal processing are addressed. The preprocessed sensor data are fed to a neural network for on‐line biomass estimation. The root mean squared error of prediction is 4 × 10⁶ cells/mL. The proposed system then triggers temperature and aeration by usage of a temperature dependent metabolic growth model and sensor data. The deviation of the predicted biomass from that of the reference trajectory as modeled by the metabolic growth model and its temporal derivative are used as inputs for the fuzzy temperature controller. The inputs used by the fuzzy aeration controller are the deviation of measured extract from that of the reference trajectory, the predicted cell count, and the dissolved oxygen concentration. The fuzzy‐based expert system allows to provide the desired yeast cell concentration of 100–120 × 10⁶ cells/mL at a minimum residual extract limit of 6.0 g/100 g at the required point of time. Thus, a dynamic adjustment of the propagation process to the overall production schedule is possible in order to produce the required amount of biomass at the right time.     

Efficacy of Metarhizium anisopliae in controlling the two‐spotted spider mite Tetranychus urticae on common bean in screenhouse and field experiments

The efficacy of aqueous and emulsifiable formulations of the fungus Metarhizium anisopliae isolate ICIPE78 was evaluated on the population density of Tetranychus urticae infesting common bean plants under screenhouse and field conditions. Synthetic acaricide abamectin was included as a check. Bean plants were artificially infested with T. urticae and allowed to multiply. Three treatments were applied in the screenhouse and 1 treatment in field trials. Mite density was recorded 2 d before spraying and weekly postspraying. The number of pods per plant, number of seeds per pod, and the dry weight of seeds per plant were recorded only in the screenhouse trials. In both screenhouse and field trials, fungal formulations applied at the concentration of 10⁸ conidia/mL and the acaricide reduced the population density of mites as compared to the controls. There were significant differences in T. urticae population densities between the treatments at the various post‐spraying sampling dates. In the screenhouse, the mite densities were near zero from 3‐week postspraying in the treated leaves. At 4‐week postspraying, there were no more leaves in the untreated control (T1) and in the control water + Silwet‐L77 (T2). Fungal formulations were as effective as abamectin in reducing mite densities in both screenhouse and field experiments. There were significant differences in the production parameters during the 2 screenhouse trials, with fungal and abamectin treatments generally having the highest yield. Results of this study underline the potential of the M. anisopliae isolate ICIPE78 as an alternative to acaricides for T. urticae management.     

Knowing your enemies: Integrating molecular and ecological methods to assess the impact of arthropod predators on crop pests

The importance of natural enemies as the foundation of integrated pest management (IPM) is widely accepted, but few studies conduct the manipulative field experiments necessary to directly quantify their impact on pest populations in this context. This is particularly true for predators. Studying arthropod predator–prey interactions is inherently difficult: prey items are often completely consumed, individual predator–prey interactions are ephemeral (rendering their detection difficult) and the typically fluid or soft‐bodied meals cannot be easily identified visually within predator guts. Serological techniques have long been used in arthropod predator gut‐contents analysis, and current enzyme linked immunosorbent assays (ELISA) are highly specific and sensitive. Recently, polymerase chain reaction (PCR) methods for gut‐contents analysis have developed rapidly and they now dominate the diagnostic methods used for gut‐contents analysis in field‐based research. This work has identified trophic linkages within food webs, determined predator diet breadth and preference, demonstrated the importance of cannibalism and intraguild predation within and between certain taxa, and confirmed the benefits (predator persistence) and potential disadvantages (reduced feeding on pest species) of the availability of alternative nonpest prey. Despite considerable efforts to calibrate gut‐contents assays, these methods remain qualitative. Available techniques for predator gut‐contents analysis can provide rapid, accurate, cost‐effective identification of predation events. As such, they perfectly compliment the ecological methods developed to directly assess predator impacts on prey populations but which are imperfect at identifying the key predators. These diagnostic methods for gut‐contents analysis are underexploited in agricultural research and they are almost never applied in unison with the critical field experiments to measure predator impact. This paper stresses the need for a combined approach and suggests a framework that would make this possible, so that appropriate natural enemies can be targeted in conservation biological control.     

线粒体功能障碍在糖尿病肾病进展的作用

糖尿病肾病是糖尿病微血管并发症之一,亦是引起终末期肾脏病的主要原因。目前各种临床治疗手段并没有阻止糖尿病肾病患者肾功能的进行性减退。因此,当务之急是进一步研究糖尿病肾病的发病机制,并从中寻找新的治疗靶点。大量研究结果显示线粒体功能障碍在糖尿病肾病的发生发展过程中具有重要作用。正常线粒体功能的维持依赖于多方面因素的共同参与,如线粒体质量控制机制、线粒体DNA等。这篇综述回顾了关于线粒体与糖尿病肾病相关文献,阐述线粒体功能障碍在糖尿病肾病进展中可能的作用。     

孕妇孕期营养指导及体质量控制对妊娠结局的影响

目的:对孕妇进行孕期营养指导及体质量控制,探究其对妊娠结局的影响。方法:将2011年2月-2014年2月期间我院收治的孕产妇150例纳入本次研究,所有研究对象随机均衡分为研究组和对照组,每组各75例。对照组孕产妇仅行常规妇科检查,研究组孕产妇在医护人员指导下行孕期营养指导和体质量控制,比较两组分娩方式,妊娠过程状况及围产儿情况。结果:研究组剖宫产率为17.33%低于对照组的57.33%,组间差异存在统计学意义(P0.05)。研究组贫血、羊水过少、产后出血率均低于对照组,差异有统计学意义(P0.05)。研究组胎龄及巨大儿及胎儿窘迫率均低于对照组,差异有统计学意义(P0.05)。结论:孕产妇在孕期进行营养膳食指导,控制体质量在合理范围内,可以改善孕妇妊娠结局,降低妊娠过程中并发症发病率,提高围产儿状况,保证孕妇和婴儿健康。     

支气管哮喘患儿血清25 羟维生素D3水平对病情评估及临床转归的意义

目的：探讨支气管哮喘患儿血清25 羟维生素D3[25-(OH)D3］水平对病情严重程度及临床转归的影响。方法：选取144 例 支气管哮喘患儿为研究对象,依据病情严重程度分为轻度间歇组、轻度持续组、中度持续组及重度持续组,选取60 例健康儿童作 为对照组,检测血清25-(OH)D3 水平;在治疗4 周后应用儿童哮喘控制测试评分系统(C-ACT)对患儿哮喘控制情况给予评价,将 所有患儿分为未控制组、部分控制组及完全控制组,比较各组血清25-(OH)D3 水平的差异。结果：对照组、轻度间歇组、轻度持续 组、中度持续组、重度持续组5 组之间血清25-(OH)D3 水平存在显著的统计学差异(P＜0.05),从对照组到重度持续组血清25- (OH)D3 水平逐渐降低(P＜0.05);完全控制组、部分控制组及未控制组三组血清25-(OH)D3 水平亦存在显著的统计学差异(P＜ 0.05),从完全控制组到未控制组血清25-(OH)D3 水平亦呈现逐渐降低趋势(P＜0.05);血清25-(OH)D3 水平与病情严重程度呈负 相关(rs =-0.489, P＜0.05),血清25-(OH)D3 水平与C-ACT 评分亦呈负相关(rs =-0.470, P＜0.05);随着血清25-(OH)D3 水平下降 程度的加重,患儿发生重度持续发作、出现C-ACT 评分＜19 分的风险值(OR)则逐渐增大。结论：血清25-(OH)D3 水平与哮喘患儿 病情严重程度及病情控制情况密切相关,早期血清维生素D 水平对于哮喘患儿病情及近期预后具有一定意义。     

高效氯氟氰菊酯微囊悬浮剂与二阶段法对红火蚁的田间防治效果评价

研究了高效氯氟氰菊酯微囊悬浮剂与二阶段法对红火蚁的田间防治效果。结果表明,0.25 g/L高效氯氟氰菊酯微囊悬浮剂施药后击倒红火蚁迅速,14 d后活动蚁巢减退率、工蚁减退率、蚁巢级别降低率、综合防治效果均达到100%。使用0.045%茚虫威饵剂搭配0.25 g/L高效氯氟氰菊酯微囊悬浮剂的二阶段法,5 d后红火蚁的活动蚁巢和工蚁数量均显著下降,14 d后活动蚁巢减退率、工蚁减退率、蚁巢级别降低率、综合防治效果均达到100%。结果表明,0.25 g/L高效氯氟氰菊酯微囊悬浮剂对红火蚁具有高效的控制作用,在实际使用时可根据防治面积的大小选择单独灌巢还是配合饵剂的二阶段法。     

Evaluation of the pathogenicity and infectivity of entomopathogenic hypocrealean fungi,isolated from wild mosquitoes in Japan and Burkina Faso,against female adult Anopheles stephensi mosquitoes

We investigated the potential of entomopathogenic hypocrealean fungi that naturally occur in or on adult mosquitoes for use as biocontrol agents of vector mosquitoes. The fungi were isolated from wild mosquitoes collected in Japan and Burkina Faso using two isolation methods (with and without surface sterilization). Detected fungal species included Beauveria bassiana sensu lato, Isaria spp., Paecilomyces spp., Lecanicillium spp., and Simplicillium spp. These isolates were used in bioassays against adult female Anopheles stephensi mosquitoes. The median survival time ranged from 5.8 to 14.9 d (control, 17.0 d). Reduced survival times were observed in the isolates from surface-sterilized mosquitoes from Japan, with the isolate B. bassiana s.l. 60-2 exhibiting the highest virulence. This study indicates that adult mosquitoes are naturally infected with various entomopathogenic hypocrealean fungi, and that some of these isolates have the potential for use as fungal pesticides to control vector mosquitoes.