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131.
Third-instar nymphs of the Australian assassin bug, Pristhesancus plagipennis (Walker), were released into cotton plots at two release densities and two crop growth stages to test their biological control potential. Release rates of 2 and 5 nymphs per metre row resulted in field populations of 0.51 and 1.38 nymphs per metre row, respectively, indicating that over 70% of nymphs died or emigrated within two weeks of release. Effective release rates of 1.38 nymphs per metre row reduced the number of Helicoverpa spp. larvae in the plots for a 7-week period. Crop yields were significantly greater in the plots to which P. plagipennis nymphs were released, with the effective release rate of 1.38 nymphs per metre row providing equivalent yields as insecticide treated plots. The data suggest that P. plagipennis has the capacity to reduce Helicoverpa spp. larvae densities in cotton crops when augmented through inundative release.  相似文献   
132.
Factors influencing the probability, distance, and direction of swimming in bay scallops (Argopectenirradions Lamarck, 1819) were studied through a series of experimental releases in the field and in a 3-m tank. The probability of a scallop swimming was significantly influenced by the type of substratum on which it was released (sand vs. grassbed), by contact with two natural gastropod predators (Murex, Fasciolaria), and by the amount of rest allowed after a previous swim. The horizontal distance traveled by a swimming scallop was significantly influenced by artificial weight of a magnitude equivalent to a normal load of shell-encrusting organisms, by the amount of rest allowed after a previous swim, by the height attained in the water column, and by the scallop's size. The direction of scallop swimming was significantly influenced by the location along the mantle edge where a predator was contacted, and by factors probably related to the asymmetrical water flow pattern through the mantle cavity. Swimming in bay scallops apparently serves to maintain position in grassbeds and to avoid predators.  相似文献   
133.
Abstract:  The polymerase chain reaction (PCR) revolutionized the field of diagnostics, and today it has routine applications in medical, veterinary, forensic and botanical sciences. The fields of biological control and insect pest management have generally been slow to adopt PCR-based diagnostics in comparison with other fields of science. However, there has been increasing interest in the use of molecular diagnostic tools in arthropod biological control. In applied entomology, molecular techniques have generally been used for insect identification and systematics; however, PCR-based techniques are increasingly becoming recognized as valuable tools in ecological studies. Here, we review research that has used PCR-based techniques for parasitoid and predator/prey identification and detection, and place these studies in the context of their contributions to biological control of arthropods. The status and future directions of diagnostic molecular markers in applied entomology and insect pest management are also discussed.  相似文献   
134.
1. We investigated the diet and prey electivity of Rhyacophila obliterata, a slow‐moving invertebrate predator capable of hunting in high‐flow microhabitats, and quantified the components of the predation sequence of fifth‐instar larvae foraging on mobile (Baetis mayflies, Amphinemura stoneflies) versus semi‐sessile (larval blackflies) prey. 2. In the field, fifth‐instar Rhyacophila consistently took more larval blackflies than more mobile prey. In behavioural trials, the number of attacks by Rhyacophila differed significantly between prey types, mobile prey being attacked more often than blackflies. Capture success, by contrast, was highest for blackflies, whereas Amphinemura and Baetis were rarely captured. In mixed‐prey feeding trials, Rhyacophila showed strong preference for blackflies and equally strong avoidance of Amphinemura and Baetis. 3. For mobile prey, the risk of being captured by this sluggish predator is very low, so they can afford to be in close contact with it. Rhyacophila was almost unable to capture any other prey but blackflies, resulting in strong passive selection for blackflies. 4. Therefore, the diet of fifth‐instar Rhyacophila can be predicted from laboratory observations and prey behaviour is the major determinant of the diet of this invertebrate predator.  相似文献   
135.
Increasing plant diversity in agroecosystems (i.e. intercropping) has been widely accepted as a means of promoting conservation biological control of mites and insect pests. Nevertheless, the contribution from underlying mechanisms such as the provision of non‐prey alternative food (i.e. pollen and nectar) and shelter have not been properly disentangled; and additionally, it remains unexplored whether the performance of nocturnal and diurnal natural enemies is improved when provided with diverse plant communities. Using open field experiments and a greenhouse microcosm, we investigated whether intercropping collards with parsley could create shelter for natural enemies in the lower stratum (parsley), and whether or not nocturnal and diurnal natural enemies would carry out aphid biological control equally well in this increased plant diversity scenario (intercropping). The results showed that the shelter alone provided by the lower stratum/companion plants (parsley) mediated an increase in the abundance of natural enemies without involving the provision of non‐prey alternative food. However, the biological control of aphids exerted by nocturnal predators was negatively affected by intercropping. The lower stratum (parsley) appeared to hamper the ability of nocturnal predators to reach aphids more quickly on the collard host plants (higher stratum). In total, our findings indicate that intercropping non‐flowering companion plants is likely enough to mediate an increase of natural enemies via shelter provision. In addition, the results suggest that nocturnal predators, or non‐flying predators for that matter, are hampered by complex lower stratum vegetation. Thus, considering natural enemy behaviour and plant characteristics when designing polyculture systems are vital for attaining conservation biological control success.  相似文献   
136.
We describe a young woman who presented with a progressive myopathy since the age of 9. Spectrophotometric analysis of the respiratory chain in muscle tissue revealed combined and profound complex I, III, II+III, and IV deficiency ranging from 60% to 95% associated with morphological and histochemical abnormalities of the muscle. An exhaustive screening of mitochondrial transfer and ribosomal RNAs showed a novel G>A substitution at nucleotide position 3090 which was detected only in urine sediment and muscle of the patient and was not found in her mother's blood cells and urine sample. We suggest that this novel de novo mutation in the 16S ribosomal RNA, a nucleotide which is highly conserved in different species, would impair mitochondrial protein synthesis and would cause a severe myopathy.  相似文献   
137.
We compared the response to resource enhancement of a simple empirical model of intra‐guild predation (IGP) to the predictions of published, simple mathematical models of asymmetric IGP (a generalist IG Predator that feeds both on a specialist IG Prey and a Resource that it shares with the IG Prey). The empirical model was a food‐web module created by pooling species abundances across many families in a speciose community of soil micro‐arthropods into three categories: IG Predator (large predatory mites), IG Prey (small predatory mites), and a shared Resource (fungivorous mites and springtails). By pooling abundances of species belonging to broadly defined functional groups, we tested the hypothesis that IGP is a dominant organizing principle in this community. Simple mathematical models of asymmetric IGP predict that increased input of nutrients and energy to the shared Resource will increase the equilibrium density of Resource and IG Predator, but will decrease that of IG Prey. In a field experiment, we observed how the three categories of the empirical model responded to two rates of addition of artificial detritus, which enhanced the food of fungivores, the Resource of the IGP module. By the experiment''s end, fungivore densities had increased ~1.5× (ratio of pooled fungivore densities in the higher‐input treatment to plots with no addition of detritus), and densities of IG Predators had increased ~4×. Contrary to the prediction of mathematical models, IG Prey had not decreased, but instead had increased ~1.5×. We discuss possible reasons for the failure of the empirical model to agree with IGP theory. We then explore analogies between the behavior of the empirical model and another mathematical model of trophic interactions as one way to gain insights into the trophic connections in this community. We also propose one way forward for reporting comparisons of simple empirical and mathematical models.  相似文献   
138.
目的:研究药剂科积极参与下中西药联合使用对消化内科患者用药合理性的影响。方法:选取我院2014年1月至2015年12月收治且确诊为消化性疾病患者184例,通过随机数表法将患者平均分为对照组和实验组,对照组给予临床常规中西药联合治疗,观察并统计临床反应;实验组给予中西药联合治疗,由本院药剂科参与人员、临床医师联合管理。统计并分析两组疗效、用药合理性及不良反应。结果:对照组总有效率为82.60%,明显低于实验组的94.56%(X~2=5.944,p=0.015);对照组用药合理率为77.17%,明显低于实验组的89.13%(X~2=5.102,p=0.024);对照组不良反应合理率为61.96%,明显低于实验组的88.04%(X~2=18.026,p0.001)。结论:药剂科的积极参与提高了中西药联合使用对消化内科患者的疗效,也降低了不良反应的发生率。  相似文献   
139.
目的:以永磁体构建静磁柱体内植入物,应用Micro-CT技术,探索研究内植静磁柱联合脉冲电磁场对骨组织的修复作用。方法:选取新西兰兔24只建立右侧股骨髁骨缺损模型,并随机分为联合磁场组,脉冲电磁场组和对照组。联合磁场组自兔右侧股骨干远端向髓内植入静磁柱,并联合施加体外脉冲电磁场(1 h/d);脉冲电磁场组及对照组均将无磁性钛合金棒植入右侧股骨干髓腔,同时,脉冲电磁场组于体外加载脉冲电磁场(1 h/d)。术后5周处死取材,应用Micro-CT对股骨远端样本进行扫描检测,并对骨缺损区域显微结构进行三维重建分析。结果:与非磁场组相比,联合磁场组骨缺损区域骨小梁相对体积及数目明显增加(P均0.05),骨小梁分离度下降(P0.01)。与传统脉冲电磁场组相比,联合磁场组骨小梁数目增加(P0.05),骨小梁分离度下降(P0.01)。扫描及重建图像可见,联合磁场组骨缺损区域骨量增多,外侧皮质区愈合完整,骨小梁结构连续致密,具有更好的骨显微结构。结论:内植静磁柱与脉冲电磁场的联合磁场干预方式能够在早期获得更好的成骨修复能力,为磁场治疗相关骨病的临床及基础研究提供了新的方向。  相似文献   
140.
目的:探讨罗哌卡因腰麻-硬膜外联合麻醉对剖宫产初产妇血清泌乳素水平的影响并评估其安全性。方法:收集我院就诊的90例剖宫产足月单胎初产妇,随机分为实验组和对照组,每组45例。实验组组均采用1%罗哌卡因1.5 mL+生理盐水1.5 mL,对照组产妇给予硬膜外麻醉。术后,比较两组产妇的泌乳素、感觉以及运动阻滞情况、麻醉效果以及不良反应发生率。结果:与手术前相比,两组产妇术后的泌乳素水平升高,且实验组产妇的泌乳素水平显著高于对照组(P0.05)。与对照组相比,实验组产妇感觉阻滞起效时间、运动阻滞起效时间较短,感觉恢复时间以及运动恢复时间较长,麻醉效果较好,不良反应的发生率较低(P0.05)。结论:罗哌卡因腰麻-硬膜外联合麻醉对剖宫产患者血清泌乳素水平的变化影响较硬膜外麻醉小,且麻醉效果及安全性更高。  相似文献   
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