Vocalizations and courtship displays of the Bittern Botaurus stellaris

Capsule We report on the courtship behaviour of the Eurasian Bittern from direct observation in rice fields.     

Reception and learning of electric fields in bees

Honeybees, like other insects, accumulate electric charge in flight, and when their body parts are moved or rubbed together. We report that bees emit constant and modulated electric fields when flying, landing, walking and during the waggle dance. The electric fields emitted by dancing bees consist of low- and high-frequency components. Both components induce passive antennal movements in stationary bees according to Coulomb''s law. Bees learn both the constant and the modulated electric field components in the context of appetitive proboscis extension response conditioning. Using this paradigm, we identify mechanoreceptors in both joints of the antennae as sensors. Other mechanoreceptors on the bee body are potentially involved but are less sensitive. Using laser vibrometry, we show that the electrically charged flagellum is moved by constant and modulated electric fields and more strongly so if sound and electric fields interact. Recordings from axons of the Johnston organ document its sensitivity to electric field stimuli. Our analyses identify electric fields emanating from the surface charge of bees as stimuli for mechanoreceptors, and as biologically relevant stimuli, which may play a role in social communication.     

专项整治对综合医院抗菌药物使用强度的影响

??????? 目的 探讨抗菌药物临床应用专项整治活动对综合医院住院患者抗菌药物使用强度的影响。方法 以限定日剂量（DDD）为单位,对某综合性医院在实施专项整治前、后住院患者抗菌药物使用强度（AUD）进行统计、分析。结果 专项整治活动降低了住院患者累计AUD值,大环内酯类等药物AUD明显下降,第二代、第三代和第四代头孢菌素和不同管理级别抗菌药物AUD均下降。但还存在用药集中、注射用头孢哌酮钠舒巴坦钠AUD下降不明显等问题。结论 专项整治有效降低了综合医院住院患者AUD,但与卫生行政部门标准仍存在差距,应进一步加强管理。     

某三甲医院抗菌药物临床规范化应用的现状分析

??????? 目的 分析和调查抗菌药物临床应用的情况,研究规范化应用抗菌药物在临床使用的效果。方法 根据计算机管理系统提供的抗菌药物用药信息,对某三甲综合医院抗菌药物临床应用专项整治前、后医院门诊患者抗菌药物处方比例及住院患者抗菌药物使用率、使用强度、I类手术预防用药率等指标进行调查及分析。结果 门诊患者抗菌药物处方比例降低至6.2﹪;住院患者抗菌药物使用率降低至49.7﹪;抗菌药物使用强度降低至42.48;I类手术预防用药率降低至32.1﹪。结论 抗菌药物临床规范化应用,促进医院抗菌药物临床合理使用的效果显著。     

根际CO2浓度升高对网纹甜瓜光合特性及产量和品质的影响

采用雾培植株根际通CO₂处理方式,研究了开花结果期根际CO₂浓度升高对网纹甜瓜光合作用及产量和品质的影响.结果表明：在网纹甜瓜果实发育期间,与350 μL·L^-1（对照）处理相比,根际2500和5000 μL CO₂·L^-1处理的叶片光合色素含量、净光合速率（P_n）、气孔导度（g_s）、胞间CO₂浓度（C_i）及PSⅡ最大光化学效率（F_v/F_m）均不同程度降低,而气孔限制值（L_s）显著提高,且5000 μL CO₂·L^-1处理的变化幅度高于2500 μL CO₂·L^-1处理;单株产量、果实中维生素C和可溶性糖含量显著降低,有机酸含量显著提高.可见,网纹甜瓜果实发育期间根际CO₂浓度超过2500 μL·L^-1时,其光合作用及果实发育会受到显著抑制,从而导致产量和品质降低.
     

Seed germination requirements of Trembleya laniflora (Melastomataceae), an endemic species from neotropical montane rocky savannas

Trembleya laniflora is an endemic shrub from neotropical montane rocky savannas of southeastern Brazil. It has been indicated as a potential candidate for ecological restoration of abandoned iron‐ore mines due to heavy metal accumulation. Here, we evaluated the seed germination requirements of T. laniflora. Seeds collected in 2005 and 2008 were set to germinate under a broad range of temperature and light conditions. Seed viability was estimated by dissecting seeds under a dissecting microscope for embryo presence/absence. Seeds were photoblastic and optimum temperature range was 20–25°C, coinciding with the onset of the rainy season. Seeds were viable after 42 months of storage, which together with small seeds that easily get buried and light requirement for germination suggest formation of soil seed banks. Except the large fraction of embryoless seeds, almost all tested seeds germinated when incubated under light conditions; therefore, T. laniflora should be regarded to have nondormant seeds. Easiness of burial resulting from small seed size and positive photoblastism may both contribute to incorporation into soil seed banks. Our data suggest that the long‐term storage of T. laniflora seeds provides a useful strategy for plant reintroduction.     

Comparative effects of insecticides with different mechanisms of action on Chrysoperla externa （Neuroptera＂ Chrysopidae）＂ Lethal,sublethal and dose-response effects

The comprehensive knowledge that the delayed systemic and reproduction side effects can be even more deleterious than acute toxicity, has caused a shift in focus toward sublethal effects assessment on physiology and behavior of beneficial insects. In this study, we assessed the risks posed by some insecticides with different mode of action through lethal and delayed systemic sublethal effects on the pupation, adult emergence, and repro- duction of the chrysopid Chrysoperla externa （Hagen, 1861; Neuroptera： Chrysopidae）, an important predator in pest biological control. The maximum field recommended dose （MFRD） and twice （2xMFRD） for chlorantraniliprole, tebufenozide, and pyriproxyfen were harmless to C. externa. In contrast, all the tested chitin synthesis inhibitors （CSIs） were highly detrimental to the predator, despite of their lack of acute lethal toxicity. There- fore, the safety assumed by using IGRs toward beneficial insects is not valid for chrysopids. Dose-response data showed that although all CSIs have a similar mechanism of action, the relative extent of toxicity may differ （novaluron 〉 lufenuron 〉 teflubenzuron）. For CSIs, the delayed systemic effects became obvious at adult emergence, where the predicted no observable effect dose （NOED） was 1/2 048 of the MFRD for novaluron （0.085 ng/insect）, and 1/256 of the MFRD for both lufenuron （0.25 ng/insect） and teflubenzuron （0.6 ng/insect）. Finally, this work emphasized the significance of performing toxicity risk assessments with an adequate posttreatment period to avoid underestimating the toxicities of insecticides, as the acute lethal toxicity assays may not provide accurate information regarding the long-range effects of hazardous compounds.     

HepG2.2.15细胞中联合应用siRNA抑制HBV复制和表达的研究

观察联合应用siRNA对HepG2．2．15细胞中HBV抗原表达和复制的抑制作用。应用ELISA方法检测HBeAg和HBsAg;HBVDNA水平用实时定量PCR测定;用RT—PCR检测HBVmRNA水平。结果显示,实验中应用的HBV特异性siRNA均具有明显的抗HBV抗原表达和病毒复制作用;联合应用siRNA较单独应用具有更强的抗HBV作用。可见,HepG2．2．15细胞中联合应用siRNA对HBV复制的抑制作用比单独应用siRNA更有效。