Local abundance of Ixodes scapularis in forests: Effects of environmental moisture,vegetation characteristics,and host abundance

Ixodes scapularis is the primary vector of Lyme disease spirochetes in eastern and central North America, and local densities of this tick can affect human disease risk. We sampled larvae and nymphs from sites in Massachusetts and Wisconsin, USA, using flag/drag devices and by collecting ticks from hosts, and measured environmental variables to evaluate the environmental factors that affect local distribution and abundance of I. scapularis. Our sites were all forested areas with known I. scapularis populations. Environmental variables included those associated with weather (e.g., temperature and relative humidity), vegetation characteristics (at canopy, shrub, and ground levels), and host abundance (small and medium-sized mammals and reptiles). The numbers of larvae on animals at a given site and season showed a logarithmic relationship to the numbers in flag/drag samples, suggesting limitation in the numbers on host animals. The numbers of nymphs on animals showed no relationship to the numbers in flag/drag samples. These results suggest that only a small proportion of larvae and nymphs found hosts because in neither stage did the numbers of host-seeking ticks decline with increased numbers on hosts. Canopy cover was predictive of larval and nymphal numbers in flag/drag samples, but not of numbers on hosts. Numbers of small and medium-sized mammal hosts the previous year were generally not predictive of the current year’s tick numbers, except that mouse abundance predicted log numbers of nymphs on all hosts the following year. Some measures of larval abundance were predictive of nymphal numbers the following year. The mean number of larvae per mouse was well predicted by measures of overall larval abundance (based on flag/drag samples and samples from all hosts), and some environmental factors contributed significantly to the model. In contrast, the mean numbers of nymphs per mouse were not well predicted by environmental variables, only by overall nymphal abundance on hosts. Therefore, larvae respond differently than nymphs to environmental factors. Furthermore, flag/drag samples provide different information about nymphal numbers than do samples from hosts. Flag/drag samples can provide information about human risk of acquiring nymph-borne pathogens because they provide information on the densities of ticks that might encounter humans, but to understand the epizootiology of tick-borne agents both flag/drag and host infestation data are needed.     

Studies on the parasite fauna of juvenile Atlantic salmon,Salmo salar L., cultured in fresh water in eastern Scotland

The parasite fauna of juvenile Atlantic salmon,Salmo salar L., at a smolt-rearing unit in eastern Scotland was monitored from two weeks after first-feeding until smolting occurred (May 1973–April 1975). A total of 625 fish was examined. Wild salmon from the river supplying the unit with unfiltered water were also examined.The cultured fish yielded eight protozoan and seven metazoan parasite species, all derived from wild fish. The parasite fauna of cultured fish became established quickly, subsequent changes involving loss of some species and increasing abundance of others. The metazoan parasite fauna was restricted to those species with free-swimming infective stages capable of entering the tanks.     

EGFR突变丰度的检测及其临床意义

具有表皮生长因子受体(epidermal growth factor receptor,EGFR)敏感突变的非小细胞肺癌患者对酪氨酸激酶抑制剂(tyrosine kinase inhibitors,TKIs)具有良好反应,但是即使存在相同突变,不同患者对TKIs的反应也不一致.推测突变分子含量的不同是TKIs反应不一的部分原因,具有更高EGFR突变"丰度"的肿瘤患者可能从TKIs中获益更多.EGFR突变可根据检测方法敏感性的不同,定量检测突变分子比例以及突变蛋白表达等进行半定量或定量检测.EGFR突变丰度可能有助于反映肿瘤异质性,评估疾病进程,预测TKIs药物敏感性,早期发现耐药,具有重要的临床意义.     

Does more medicine make us sicker? Ivan Illich revisited

A proper understanding of health is a social and political challenge, the modern social medicine approach to public health and health approaches more generally tend to minimise this, making the isolated individual the primary unit of health. Ivan Illich, social critic and philosopher, was at the forefront of arguing for a collective health approach and challenging medical hegemony. His theories of institutional counter-productivity, proportionality and his critique of the medical model which he argued was entrenched within an economics of scarcity are as relevant today as they were at their height of popularity, in the 1970s. Applying his analysis to current trends in health approaches I conclude, as did he, that beyond a certain institutional scale or intensity more medicine is making us sicker. Therefore public health requires a dramatic shift away from a focus on individual deficits, lifestyle diseases, behaviour change and health promotion approaches towards genuine community building and significant political investment in the health creation of local communities. Moreover, there is need for more resolute regulation of the marketplace to prevent the health-harming behaviours of industrial and other institutional interests, including public sector and third sector organisations engaged in institutional overreach.     

Proteomic analysis of nasal mucus samples of healthy patients and patients with chronic rhinosinusitis

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北京东灵山地区鼠类体外寄生虫群落种-多度分布

目的 :了解北京东灵山地区鼠类体外寄生虫种类和数量分布情况。方法 :1998年 6月至 1999年 5月在该地区的 3类生境按常规方法共捕获鼠类 7种 5 68只 ,采集体外寄生虫 48种 3 85 9只 ,其中蚤类 16种 5 82只 ,蜱类 3种416只 ,革螨 2 2种 10 81只 ,恙螨 7种 1780只。结果 :3类生境鼠类体外寄生虫群落中低度物种 (个体数 <11)数多 ,约占总物种数的 5 8%～ 88% ,中度物种 (个体数在 11～ 10 0之间 )少 ,较富集物种 (个体数 >10 0 )更少。结论 :鼠类体外各寄生虫群落物种丰富度和多度随宿主动物种类不同而变化较大     

Alien species in a brackish water temperate ecosystem: annual-scale dynamics in response to environmental variability

Alien species contribute to global change in all marine ecosystems. Environmental variability can affect species distribution and population sizes, and is therefore expected to influence alien species. In this study, we have investigated temporal variability of 11 alien species representing different trophic levels and ecological functions in two gulfs of the brackish Baltic Sea in relation to environmental change. Independent of the invasion time, organism group or the life-history stage, abundance and/or biomass of the investigated alien species was either stable or displayed abrupt increases over time. Timing in population shifts was species-specific and exhibited no generic patterns, indicating that the observed large shifts in environmental parameters have no uniform consequences to the alien biota. In general, the inter-annual dynamics of alien and native species was not largely different, though native species tended to exhibit more diverse variability patterns compared to the alien species. There were no key environmental factors that affected most of the alien species, instead, the effects varied among the studied gulfs and species. Non-indigenous species have caused prominent structural changes in invaded communities as a result of exponential increase in the most recent invasions, as well as increased densities of the already established alien species.     

Distribution of taste buds on the lips and inside the mouth in the minnow, Pseudorasbora parva

The distribution and abundance of taste buds were quantitatively examined by observing silver impregnated serial sections. The taste buds were widely dispersed on the skin, the lips, the mucosa in the oro-pharyngeal cavity, the esophagus, and the branchial apparatus. The great majority of them was found on the lips and inside the mouth. The external buds were concentrated especially on the outer lips and the adjacent skin, while their number diminished in a caudal direction. Very few were found on the scaled skin. The total number of external buds in a specimen of 6 cm in length was 1,486. The number of taste buds inside the mouth was 6,600. On the inner lips and the palatal organ densities were found to reach over 140 per mm². High concentrations of taste buds were also found on the gill arches and rakers. These taste buds varied to some extent in size and shape, depending on the thickness of the epithelial layer. It is suggested that the minnow may use the lips, gills and palatal organ as its main taste organs.     

Manuscript prepared for submission to environmental toxicology and pharmacology pollution in drinking water source areas: Microplastics in the Danjiangkou Reservoir,China

As the source of water for the South-to-North Water Diversion Project of China, the water quality of the Danjiangkou Reservoir (DJKR) is related to the safety of drinking water for billions of residents. Consequently, microplastics in surface water and sediment samples of the DJKR were investigated in this study. Microplastics were observed in all water and sediment samples with abundances varying from 467 to 15,017 n/m³ and 15 to 40 n/kg wet weight, respectively. Microplastics were rich in colour and dominated by fibrous items. Small-sized particles (< 2 mm) were more frequently observed than other sizes. Analysis by micro-Raman spectroscopy showed that polypropylene was the major polymer type. These systematic results demonstrated that the DJKR is suffering from the pollution of microplastics, which should be paid more attention based on its potential threat to the aquatic organisms and residents impacted by the drinking water source pollution.     

移植NAFLD患者和健康人粪菌对高脂饮食大鼠肠道菌群的影响*

目的 探讨粪菌移植干预对非酒精性脂肪性肝病(NAFLD)动物肠道菌群的影响。方法 将32 只大鼠随机分为ABCD四组,其中3组用混合抗生素抑菌1周后,予以高脂饮食建立NAFLD模型,再分别给予NAFLD患者粪菌或和正常人粪菌移植,检测肠粘膜组织16sDNA菌群。结果 模型组Rodentibacter菌群丰度较对照组升高,在NAFLD粪菌移植组升高更显著,而在正常人粪菌移植组则有所下降。结论 NAFLD粪菌群可能是肝脏脂肪变性的一个危险因素,而应用健康人粪菌移植可以改善高脂饮食大鼠脂肪肝病变。