Assessing the impact of a movement network on the spatiotemporal spread of infectious diseases

Summary Linking information on a movement network with space-time data on disease incidence is one of the key challenges in infectious disease epidemiology. In this article, we propose and compare two statistical frameworks for this purpose, namely, parameter-driven (PD) and observation-driven (OD) models. Bayesian inference in PD models is done using integrated nested Laplace approximations, while OD models can be easily fitted with existing software using maximum likelihood. The predictive performance of both formulations is assessed using proper scoring rules. As a case study, the impact of cattle trade on the spatiotemporal spread of Coxiellosis in Swiss cows, 2004-2009, is finally investigated.     

一次性氧气湿化瓶与重复使用湿化瓶应用的对比观察

目的：检测一次性氧气湿化瓶与重复使用湿化瓶用后细菌污染的程度和患者对噪音感受的舒适程度,对比两者的成本效益。方法：随机选出心内科病房内持续吸氧时间超过10天的患者100名,以随机分组的方法分出A组50名、B组50名。A组使用一次性氧气湿化瓶,B组使用重复使用的氧气湿化瓶。按照《医疗卫生机构消毒技术规范》进行采样后送微生物检验室进行病原学检验;同时对两组患者进行噪音感受舒适度的调查;根据使用的氧气湿化瓶成本费用、氧气湿化用灭菌注射用水的价格、含氯消毒剂健之素的费用计算成本。结果：50只一次性氧气湿化瓶使用时间120小时（5天）,微生物学检测未发现致病菌,成本费用9-3元／日,患者噪音感受舒适度满意度调查结果为100％;重复使用氧气湿化瓶使用24小时染茵率28％,成本费用9．6元／日,患者噪音感受舒适度满意度调查结果为60％。结论：使用合格的一次性氧气湿化瓶,在患者费用不会增加的前提下,减少了医院感染机会,增加了患者的舒适度,值得推广使用。     

How much effort is required for proper monitoring? Assessing the effects of different survey scenarios in a dry acidic grassland

Questions: The quality of any inferences derived from field studies or monitoring programmes depends on expenditure of time and effort to make the underlying observations. Here, we used a long‐term data set from a succession‐monitoring scheme to assess the effect of different survey scenarios. We asked: (1) how well does a survey reflect successional processes if sampling effort varies (a) in space (b) in length of total observation period, (c) in observation frequency and (d) with a combination of these factors? (2) What are the practical implications for devising monitoring programmes? Location: Lignite mining region of Central Germany, post‐mining landscape of Goitzsche (Saxony‐Anhalt). Methods: Based on our full data set, we constructed subsamples. For the full data set and all subsets, we constructed Markov models and compared them based on the predictions made. We assessed effects of survey intensity on model performance using generalized linear models and multiple logistic regressions. Results: Exploring the effects of different survey scenarios revealed significant effects of all three main features of survey intensity (sample size, length, frequency). The most important sampling feature was study length. However, we found interactive effects of sample size with study length and observation interval on model predictions. This indicates that for long‐term observations with multiple recording intervals a lower sample size in space is required to reveal the same amount of information as required in a shorter study or one with fewer intervals. Conversely, a high sample size may, to some degree, compensate for relatively short study periods. Conclusions: Monitoring activities should not be restricted to intensive sampling over only a few years. With clearly limited resources, a decrease of sampling intensity in space, and stretching these resources over a longer period would probably pay off much better than totally abandoning monitoring activities after an intensive, but short, campaign.     

From pattern to process: identifying predator–prey models from time-series data

Fitting nonlinear models to time-series is a technique of increasing importance in population ecology. In this article, we apply it to assess the importance of predator dependence in the predation process by comparing two alternative models of equal complexity (one with and one without predator dependence) to predator–prey time-series. Stochasticities in such data come from both observation error and process error. We consider how these errors must be taken into account in the fitting process, and we develop eight different model selection criteria. Applying these criteria to laboratory data on simple protozoan and arthropod predator–prey systems shows that little predator dependence is present, with one interesting exception. Field data are more ambiguous (either selection depends on the particular criterion or no significant differences can be detected), and we show that both models fit reasonably well. We conclude that, within our modeling framework, predator dependence is in general insignificant in simple systems in homogeneous environments. Relatively complex systems show significant predator dependence more often than simple ones but the data are also often inconclusive. The analysis of such systems should rely on several models to detect predictions that are sensitive to predator dependence and to direct further research if necessary. Received: July 13, 2000 / Accepted: September 25, 2001     

Method in macroecology

Macroecology is concerned with understanding the abundance and distribution of species at large spatial and temporal scales. Understanding pattern and process in macroecology thus presents a considerable methodological challenge, as the scales of interest are simply too large for the traditional ecological approach of experimental manipulation to be possible or ethical. Here, I summarise the methods that have been most commonly employed to explore macroecological questions, discuss important methodological issues that need to be considered when interpreting macroecological data, and suggest likely future developments in macroecological methodology.

Zusammenfassung

Die Makroökologie befasst sich mit dem Verständnis der Abundanz und der Verbreitung der Arten in großen räumlichen und zeitlichen Maßstäben. Das Verständnis von Mustern und Prozessen in der Makroökologie stellt deshalb eine beträchtliche methodische Herausforderung dar, weil die Skalen von Interesse für die traditionelle ökologische Vorgehensweise der experimentellen Manipulation einfach zu groß sind, als dass sie möglich oder ethisch vertretbar wäre. Hier fasse ich die Methoden zusammen, die am häufigsten zum Einsatz kommen, um makroökologische Fragen zu erforschen, diskutiere wichtige methodische Punkte, die beachtet werden müssen, wenn makroökologische Daten interpretiert werden, und deute auf wahrscheinliche zukünftige Entwicklungen in der makroökologischen Methodik hin.     

Suppression of the Root-knot Nematode Meloidogyne javanica by Alginate Pellets Containing the Nematophagous Fungi Hirsutella rhossiliensis , Monacrosporium cionopagum and M. ellipsosporum

The endoparasitic fungus Hirsutella rhossiliensis and the nematode-trapping fungi Monacrosporium cionopagum and M. ellipsosporum were formulated as hyphae in alginate pellets. In a soil microcosm experiment, dried pellets of all three fungi decreased the invasion of cabbage seedlings by the root-knot nematode Meloidogyne javanica when juvenile nematodes were placed 2 cm from roots; M. cionopagum was more effective than the other two fungi, reducing nematode invasion by 40-95% with 0.24-0.94 pellets cm - 3 of soil. In a field microplot experiment, in which neither H. rhossiliensis nor M. ellipsosporum suppressed nematodes, 0.5 pellets of M. cionopagum cm - 3 of soil suppressed M. javanica invasion of tomato seedlings by 73%. In a second microplot experiment with only M. cionopagum , again at 0.5 pellets cm - 3 of soil, the fungus suppressed the invasion of tomato seedlings whether the pellets were added 0, 5 or 14 days before planting; the population density of M. cionopagum increased to nearly 3000 propagules g - 1 of soil by day 8 and then declined to less than 300 by day 22. Enchytraeid worms were observed in and around damaged and apparently destroyed pellets in both microplot experiments. Whether enchytraeids consumed the fungi or otherwise affected biological control requires additional research.     

蜜蜂蜂群温湿度调节研究进展

环境温度的变化直接影响蜜蜂的个体发育、群体活动、蜂群繁殖、群势强弱等方面,蜂群温湿度是对蜜蜂生命活动影响最大的环境因素,蜜蜂会积极地响应环境温度变化。在巢群内温度高于或低于子脾要求温度,蜜蜂就会采取各种解决办法。研究蜂群温度的分布、变化规律以及调控机制是当前蜂学领域的热点问题,而掌握了蜂群温度变化规律,也能更好的进行科学养蜂,提高蜂产品的产量和质量,同时对人类认知、环境保护也具有非常重要的借鉴价值。近年来随着基因组学、生物学、高新科学技术等的应用,蜜蜂温湿度调节的研究不断深入。整合当前国内外蜜蜂蜂群温湿度调节的研究报道,对蜜蜂蜂群温湿度调节现象和行为进行综合阐述,并对蜂群温湿度内在调控机理方面的进一步研究提出新思路。     

Artificial surveillance cues do not increase generosity: two meta-analyses

Many studies have seemingly demonstrated that anonymous individuals who are shown artificial cues of being watched behave as if they are being watched by real people. However, several studies have failed to replicate this surveillance cue effect. In light of these mixed results, we conducted two meta-analyses investigating the effect of artificial observation cues on generosity. Overall, our meta-analyses found no evidence to support the claim that artificial surveillance cues increase generosity, either by increasing how generous individuals are, or by increasing the probability that individuals will show any generosity at all. Therefore, surveillance cue effects should be interpreted cautiously.     

8种不同方法保藏病原菌效果的对比观察

采用８种不同的菌种保藏方法,对１８种常见病原菌的保藏时间及生物学特性的影响进行了对比观察。结果表明：冷冻干燥法保藏菌种时间最长（本实验室已保存１５年）;肉浸汤琼脂平板法保藏菌种时间最短（２～３月）。保藏时间由长到短依次为：冷冻干燥法＞半固体冷冻法≥半固体斜面加液体石蜡覆盖法＞半固体斜面法＞肉浸汤加液体石蜡覆盖法＞血琼脂平板法＞肉浸汤法＞肉浸汤琼脂平板法。且相同方法对不同菌种保藏时间不同。保藏时间在１年以内的菌种,其生物学特性无明显变异;而经冷冻干燥法保藏时间较长的白喉棒状杆菌、金黄色葡萄球菌、甲型副伤寒沙     

Pathways of Androgenesis and Observations on Cultured Pollen Grains in Rice (Oryza saliva Subsp. Keng)

(1) Pathways A-V, A-G, A-GV, and B existed in androgenesis of rice. Usually B pathway was predominant. Degeneration could happen on androgenic grains via each pathway during the early stage of androgenesis. (2) Statistics suggested that the multinucleate grains might be converted to multicellular grains by a later formation of cell walls and were consequently one of the sources of callus. (3) Androgenic grains was usually of medium size (35–40 μm) with dense protoplasm. In isolated pollen culture, the diameter of androgenic grains increased 2.5–5μm per day. Before the breakdown of exine, the cell walls seemed to be thickened and the grains would contract abruptly. (4) Small, slowly-moving starch granules were usually contained within multicellular grains cultured isolately. They were speculated to participate actively in the metabolism of androgenic grains.