DNA及其蛋白质复合体的电镜观察及研究应用

对生物大分子形状的正确了解有助于对其功能的解析。事实上,借助于电子显微镜观察法,使我们在对构成细胞各组分功能的探讨和研究方面收益匪浅。自从生物学家们认识到DNA在细胞行使其功能中的重要性以来,电子显微镜便成为一种最重要的技术手段而被用于分析DNA的结构,研究DNA的复制、重组和转录机制。近年来,这一领域的研究技术又有了非常大的改进,使人们已经能够借助于电子显微镜,观察介入DNA复制、重组和转录等过程中的DNA蛋白质复合体的活体状态。今后,在对生物大分子的活体行为进行探讨时,电子显微镜技术将发挥越来越重要的作用。     

Measurement error in a random walk model with applications to population dynamics

Population abundances are rarely, if ever, known. Instead, they are estimated with some amount of uncertainty. The resulting measurement error has its consequences on subsequent analyses that model population dynamics and estimate probabilities about abundances at future points in time. This article addresses some outstanding questions on the consequences of measurement error in one such dynamic model, the random walk with drift model, and proposes some new ways to correct for measurement error. We present a broad and realistic class of measurement error models that allows both heteroskedasticity and possible correlation in the measurement errors, and we provide analytical results about the biases of estimators that ignore the measurement error. Our new estimators include both method of moments estimators and "pseudo"-estimators that proceed from both observed estimates of population abundance and estimates of parameters in the measurement error model. We derive the asymptotic properties of our methods and existing methods, and we compare their finite-sample performance with a simulation experiment. We also examine the practical implications of the methods by using them to analyze two existing population dynamics data sets.     

First report on the emergency dance of Apis cerana japonica,which induces odorous plant material collection in response to Vespa mandarinia japonica scouting

Previously, we observed several instances in which Apis cerana japonica performed dancing around the hive entrance and smeared plant materials there immediately after scouting of Vespa mandarinia japonica. In this study, we conducted a series of attack simulation experiments with three hornet species to investigate whether the hive entrance dance is a specific response to V. m. japonica scouting. We also tracked dancing bees and dance‐follower bees to observe whether they perform hive entrance smearing. Only V. m. japonica scouting induced dancing, and we confirmed that dancing and dance‐follower bees performed smearing behavior at the hive entrance. These results suggest that the hive entrance dance informs nestmates of a specific emergency and of the urgent need to collect odorous plant materials as a counter‐attack strategy.     

Essential ocean variables for global sustained observations of biodiversity and ecosystem changes

Sustained observations of marine biodiversity and ecosystems focused on specific conservation and management problems are needed around the world to effectively mitigate or manage changes resulting from anthropogenic pressures. These observations, while complex and expensive, are required by the international scientific, governance and policy communities to provide baselines against which the effects of human pressures and climate change may be measured and reported, and resources allocated to implement solutions. To identify biological and ecological essential ocean variables (EOVs) for implementation within a global ocean observing system that is relevant for science, informs society, and technologically feasible, we used a driver‐pressure‐state‐impact‐response (DPSIR) model. We (1) examined relevant international agreements to identify societal drivers and pressures on marine resources and ecosystems, (2) evaluated the temporal and spatial scales of variables measured by 100+ observing programs, and (3) analysed the impact and scalability of these variables and how they contribute to address societal and scientific issues. EOVs were related to the status of ecosystem components (phytoplankton and zooplankton biomass and diversity, and abundance and distribution of fish, marine turtles, birds and mammals), and to the extent and health of ecosystems (cover and composition of hard coral, seagrass, mangrove and macroalgal canopy). Benthic invertebrate abundance and distribution and microbe diversity and biomass were identified as emerging EOVs to be developed based on emerging requirements and new technologies. The temporal scale at which any shifts in biological systems will be detected will vary across the EOVs, the properties being monitored and the length of the existing time‐series. Global implementation to deliver useful products will require collaboration of the scientific and policy sectors and a significant commitment to improve human and infrastructure capacity across the globe, including the development of new, more automated observing technologies, and encouraging the application of international standards and best practices.     

不同类型蜂箱对中华蜜蜂Apis cerana cerana Fabricius生产性能的影响

【目的】为了研究不同类型蜂箱对中华蜜蜂Apis cerana cerana Fabricius生产性能的影响。【方法】我们在综合考虑甘肃南部地区中华蜜蜂饲养模式、规模、当地环境等因素的基础上,选用标准蜂箱、原始蜂箱和生态蜂箱3种类型蜂箱在当地主要流蜜期进行蜂蜜生产试验。【结果】结果发现,蜂箱类型对蜂群的年产蜜量、存蜜量和取蜜次数存在显著影响(P<0.05),其中标准蜂箱在4个试验点的年产蜜量最高,原始蜂箱的存蜜量最高,而生态蜂箱在这2个指标上表现适中,标准蜂箱的年取蜜次数稍多。本研究中海拔和蜜源植物对蜂群生产性能没有明显影响。【结论】采用何种类型蜂箱进行中华蜜蜂养殖,应根据当地的环境状况、蜜源条件、文化及养蜂基础等多种因素综合考虑。     

草鱼出血病病毒人工感染稀有鼩鲫出血病鱼的组织病理观察

草鱼出血病病毒人工感染稀有鲫出血病病鱼组织病理切片观察,发现肌肉系统血外渗,出现微血栓,红血球浸润于肌纤维之间;鳃小片上皮细胞增生和肥大导致相互融合,血外渗和红血球裂解,形成微血栓和血泡;肠上皮细胞脱落,红血球散布于整个肠壁;肝细胞肥大和细胞实质空泡化,细胞间隙增大;脾组织黄褐色的“小结”增多。而对照鱼未出现上述变化,说明这些病理变化确由ＧＣＨＶ感染所致。     

Worker brood survival in honeybees

The brood survival in honeybee workers was measured in order to obtain the data basic to the preparation of life tables. Under normal condition, that is, at the center of brood area, the survival is high. The survival/stage function runs 100.0 eggs, 94.2 unsealed brood (=feeding larvae), 86.4 sealed brood (=post-feeding larvae and pupae) and 85.1 adults. The total duration of immature stages is 20 days in 87.1%, 21 days in 8.3% and 19 days or more than 22 days in the residual fraction of successfully emerging workers. The survival remarkably decreases at peripheral areas within the hive. Various factors affecting the brood survival are discussed and the importance of a dense worker cover on the brood area is stressed in relation to the maintenance of thermal conditions optimal to the brood. The occurrence of one factor, which is not expected in solitary animals, the self-control of population by egg eating, is pointed out.     

长江白鱀豚行为的观察

1979—1990年,作者在长江中下游江段,对白鱀豚的行为作了47次航行朋察。根据观察记录,对白鱀豚出水呼吸时所表现的集群,抚幼、觅食、求偶、玩耍、歇息、逃避等行为,作了较全面的描述和分析。     

Harvest-based Bayesian estimation of sika deer populations using state-space models

We have estimated the number of sika deer, Cervus nippon, in Hokkaido, Japan, with the aim of developing a management program that will reduce the level of agricultural damage caused by these deer. A population index that is defined by the population divided by the population of 1993 is first estimated from the data obtained during a spotlight survey. A generalized linear mixed model (GLMM) with corner point constraints is used in this estimation. We then estimate the population from the index by evaluating the response of index to the known amount of harvest, including hunting. A stage-structured model is used in this harvest-based estimation. It is well-known that estimates of indices suffer from large observation errors when the probability of the observation fluctuates widely; therefore, we apply state-space modeling to the harvest-based estimation to remove the observation errors. We propose the use of Bayesian estimation with uniform prior-distributions as an approximation of the maximum likelihood estimation, without permitting an arbitrary assumption that the parameters fluctuate following prior-distributions. We are able to demonstrate that the harvest-based Bayesian estimation is effective in reducing the observation errors in sika deer populations, but the stage-structured model requires many demographic parameters to be known prior to running the analyses. These parameters cannot be estimated from the observed time-series of the index if there is insufficient data. We then construct a univariate model by simplifying the stage-structured model and show that the simplified model yields estimates that are nearly identical to those obtained from the stage-structured model. This simplification of the model simultaneously clarifies which parameter is important in estimating the population. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Hirsutella thompsonii and Metarhizium anisopliae as potential microbial control agents of Varroa destructor,a honey bee parasite

The potential of Hirsutella thompsonii Fisher and Metarhizium anisopliae (Metschinkoff) as biological control agents of the parasitic mite, Varroa destructor Anderson and Trueman was evaluated in the laboratory and in observation hives. In the laboratory, time required for 90% cumulative mortality of mites (LT(90)) was 4.16 (3.98-4.42) days for H. thompsonii and 5.85 (5.48-7.43) days for M. anisopliae at 1.1 x 10(3) conidia mm(-2). At a temperature (34+/-1 degrees C) similar to that of the broodnest in a honey bee colony, Apis mellifera L., H. thompsonii [LC(90)=9.90 x 10(1) (5.86-19.35) conidia mm(-2) at Day 7] and M. anisopliae [LC(90)=7.13 x 10(3) (2.80-23.45) conidia mm(-2) at Day 7] both showed significant virulence against V. destructor. The applications of H. thompsonii to observation hives resulted in significant mortality of mites, and reduction of the number of mites per bee 21 and 42 days post-treatments. The treatments did not significantly affect the mite population in sealed brood. However, the fungus must have persisted because infected mites were still observed [82.97+/-(0.6)%] 42 days post-treatment. In addition, the fungus was found to sporulate on the host. A small percentage [2.86+/-(0.2)%] of dead mites found in the control hives also showed fungal infection, suggesting that adult bees drifted between hives and disseminated the fungus. H. thompsonii was harmless to the honey bees at the concentrations applied and did not have any deleterious effects on the fecundity of the queens. Microbial control with fungal pathogens provides promising new avenues for control of V. destructor and could be a useful component of an integrated pest management program for the honey bee industry.