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1.
Tick‐borne diseases (TBDs) have a large impact on animal health and the livelihood of livestock owners, particularly in developing countries. Although climatic and ecological conditions in Pakistan may favour the transmission of tick‐borne pathogens (TBPs), only a few systematic studies have been carried out on TBPs and the diseases that they cause in this country. To improve our understanding of the distribution of TBPs, 3,807 ticks were collected from ruminants (n = 369) on 108 livestock farms (semi‐arid zone = 36, arid zone = 72) in Punjab Province. After morphological identification ticks were pooled into 405 pools (Hyalomma anatolicum = 300, Rhipicephalus microplus = 89, Hyalomma dromedarii = 9, Rhipicephalus turanicus = 7) based on their species, locality of collection, and the host. DNA from each pool was screened by a Reverse Line Blot (RLB) hybridization assay for the presence of Anaplasma, Ehrlichia, Rickettsia, Babesia, and Theileria species. DNA from at least one TBP was found in 142 (35.1%) pools. Among the positive pools, 91 (64.1%) had a mixed infection with two or more TBPs, whereas 51 (35.9%) pools were infected with a single TBP. The detected pathogens not only included species that were known to be endemic in Pakistan, such as Theileria annulata (6.7%), Theileria orientalis (3.5%), Anaplasma marginale (5.7%), Anaplasma centrale (2.7%), Anaplasma ovis (1.5%), Babesia bigemina (0.7%), and Babesia bovis (0.2%), but also several TBPs that had not been reported to occur in Pakistan before. This included Ehrlichia minasensis (3.2%), an Anaplasma platys‐like organism (1.2%), Babesia occultans (0.2%), and Rickettsia massiliae (0.2%), as well as two previously uncharacterized species: Ehrlichia sp. Multan (18.0%) and Anaplasma sp. (BL099‐6) (2.22%). The pathogenicity of these novel species remains to be examined. This study shows that a much broader spectrum of TBPs is present in Pakistan than previously thought, including several zoonotic pathogens.  相似文献   
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Cultural determinants of obesity prevalence have been little studied but could explain significant variations in body mass index (BMI) trajectories among countries. This ecological study quantified longitudinal associations between six dimensions of national culture and mean population BMI over 25 years. National mean male and female BMI data 1990 to 2014 provided dependent variables. National dimensions of culture (from the Hofstede database for up to 87 countries) were independent variables: Individualism, Uncertainty avoidance, Indulgence, Long‐term orientation, Power distance, and Masculinity. Analyses used mixed models for repeated measures for each dimension of national culture with male and female adult BMI trajectories, controlling for confounders. A higher mean BMI was significantly associated with higher Individualism, Uncertainty avoidance, Indulgence, and Masculine orientation and with lower Power distance (males only) and lower Long‐term orientation (males only). Overall, the national cultural dimensions explained 62.4% (males) and 53.5% (females) of the variance in mean BMI among countries. National cultural characteristics, especially Individualism and Uncertainty avoidance, are strongly related to obesity prevalence, explaining over half of the variance among countries. More research and theory development is needed to understand the pathways for these associations so that cultural contexts can be better accounted for in policies, social marketing messages, and community‐based actions for obesity prevention.  相似文献   
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The dietary specialist fruit fly Drosophila sechellia has evolved resistance to the secondary defence compounds produced by the fruit of its host plant, Morinda citrifolia. The primary chemicals that contribute to lethality of M. citrifolia are the medium‐chain fatty acids octanoic acid (OA) and hexanoic acid. At least five genomic regions contribute to this adaptation in D. sechellia and whereas the fine‐mapped major effect locus for OA resistance on chromosome 3R has been thoroughly analysed, the remaining four genomic regions that contribute to toxin resistance remain uncharacterized. To begin to identify the genetic basis of toxin resistance in this species, we removed the function of well‐known detoxification gene families to determine whether they contribute to toxin resistance. Previous work found that evolution of cytochrome P450 enzymatic activity or expression is not responsible for the OA resistance in D. sechellia. Here, we tested the role of the two other major detoxification gene families in resistance to Morinda fruit toxins – glutathione‐S‐transferases and esterases – through the use of the pesticide synergists diethyl maleate and tribufos that inhibit the function of these gene families. This work suggests that one or more esterase(s) contribute to evolved OA resistance in D. sechellia.  相似文献   
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Abiotic niche lability reduces extinction risk by allowing species to adapt to changing environmental conditions in situ. In contrast, species with static niches must keep pace with the velocity of climate change as they track suitable habitat. The rate and frequency of niche lability have been studied on human timescales (months to decades) and geological timescales (millions of years), but lability on intermediate timescales (millennia) remains largely uninvestigated. Here, we quantified abiotic niche lability at 8-ka resolution across the last 700 ka of glacial–interglacial climate fluctuations, using the exceptionally well-known fossil record of planktonic foraminifera coupled with Atmosphere–Ocean Global Climate Model reconstructions of paleoclimate. We tracked foraminiferal niches through time along the univariate axis of mean annual temperature, measured both at the sea surface and at species’ depth habitats. Species’ temperature preferences were uncoupled from the global temperature regime, undermining a hypothesis of local adaptation to changing environmental conditions. Furthermore, intraspecific niches were equally similar through time, regardless of climate change magnitude on short timescales (8 ka) and across contrasts of glacial and interglacial extremes. Evolutionary trait models fitted to time series of occupied temperature values supported widespread niche stasis above randomly wandering or directional change. Ecotype explained little variation in species-level differences in niche lability after accounting for evolutionary relatedness. Together, these results suggest that warming and ocean acidification over the next hundreds to thousands of years could redistribute and reduce populations of foraminifera and other calcifying plankton, which are primary components of marine food webs and biogeochemical cycles.

Abiotic niche dynamics determine patterns of community composition over space and regulate trajectories of diversity over time (1). Both niche lability (2, 3) and conservatism (1, 4) have been proposed to spur speciation, and abiotic niche lability has been associated with ecological invasions (57) and with reduced risk of extinction during times of climate change (8). Thus, a deeper understanding of species’ propensity for niche stasis versus lability could improve predictions of biodiversity restructuring in response to anthropogenic climate change (9).Stasis in species’ abiotic niches through time has been documented in empirical research, but most such studies have been limited to ecological niche modeling on decadal scales (reviewed in ref. 10) or paleoecological examination on 106 to 107 y scales (5, 11, 12). Since empirical rates of niche change are scarce and difficult to acquire, many studies merely assume that niche evolution occurs at a constant rate along branches of a phylogeny (2, 3, 6, 7). Niche dynamics at intermediate timescales of centuries to millennia are particularly poorly documented (10), and studies at this meso scale have been restricted to terrestrial systems (e.g., refs. 1315) or to comparisons between the present day and the single historical time step of the Last Glacial Maximum, ∼21 ka (1620). Quantifying the rate and relative frequency of niche change in marine species over timescales of 102 to 105 years is important, however, because species will adapt or go extinct in response to anthropogenic ocean changes over this timescale (21).Here, we investigated climatic niche lability from the rich sedimentary archive of global planktonic foraminifera across the last 700 ka of glacial–interglacial cycles at 8-ka resolution. Planktonic foraminifera (Protista) construct “shells” (tests) of calcite, thereby sequestering carbon and recording an isotopic signature of past ocean conditions. Tests readily accumulate over large expanses of the seafloor. Consequently, the fossil record of foraminifera—arguably “the best fossil record on Earth” (22)—affords an exceptionally high-resolution view into past species distributions. This detailed record fuels studies of biostratigraphy, paleoclimatology, and paleoecology (20, 2225). Moreover, the complete species diversity of planktonic foraminifera has been described for the Plio–Pleistocene, with good agreement between morphological and molecular phylogenies (22, 2527). Although some have speculated that foraminifera competitively exclude each other (24), recent work found that planktonic foraminifera species seldom restrict each other’s distributions (28). Presumably, therefore, species occupy the full envelope of existing environmental conditions within their tolerance limits, and geographic distributions are determined almost entirely by physical ocean conditions.We developed five analyses to investigate the degree of abiotic niche lability in foraminifera. All methods examined the univariate niche axis of temperature, which is the single most important explanatory variable in regard to geographic distributions of foraminifera (20, 2932) and is a climate-related stressor and extinction driver for diverse marine fauna across timescales (33, 34). The adaptive potential of thermal niches has been taken as a key determinant of global community structure and genetic connectance in plankton (35). Primary productivity and other environmental variables, however, may also structure abiotic niches of plankton (36). Our suite of analyses quantified whether and by how much planktonic foraminiferal niches shifted along a temperature axis. First, we correlated time series of species’ thermal optima with global temperature to determine whether species tracked suitable habitat or experienced environmental fluctuations in situ. We then quantified species’ niche dissimilarity between pairs of time bins—either tracking niches across bin boundaries or contrasting niches at climatic extremes of glacial maxima and interglacial thermal peaks. To characterize niche change we applied trait evolution models to time series of temperatures at occupied sites. Lastly, we explored variation in intraspecific niche lability among ecotypes while accounting for phylogenetic relatedness. SI Appendix, Table S1 lists the response variable and sample size for each analysis.  相似文献   
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通过对生态扶贫视域下中药材生态种植现状及发展要点进行概述,梳理生态扶贫、生态种植、中药材生态种植现状和面临的问题,着重分析中药材生态种植,探究其与生态扶贫的关联性;通过走访调研,分析中药材生态种植的经济潜力和助力脱贫发挥的作用,为依托中药材种植产业推进生态扶贫、构建优质中药材产业的发展布局、促进生态扶贫效益发展提供参考。  相似文献   
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ObjectiveWe developed a mobile cognitive test of verbal learning and memory, the mobile verbal learning test (mVLT), to allow for brief, repeated and portable delivery of a 12‐item list learning test through a smartphone. This study examined the psychometric properties of the mVLT among older persons with and without human immunodeficiency virus (HIV).MethodsSixty‐eight persons with HIV and 36 HIV‐negative individuals (aged 50–74) completed three trials of the mVLT on a smartphone once daily for 14 days. A different word list was administered each day.ResultsParticipants completed 80% of the 14 mVLT administrations, equating to 1166 valid and complete mVLTs. Neither adherence nor mean mVLT total score (number correct in 3 recall trials) differed by HIV status. No practice effects from repeated mVLT administration were observed, and there were moderately strong correlations of mVLT performance with performance on the in‐lab version of the task and with traditional cognitive assessments of cognitive processes contributing to memory. We found evidence of within‐person learning across mVLT trials, with persons with HIV demonstrating less learning from trials 1 to 3 compared to HIV‐negative participants.ConclusionsThe mVLT is a valid method to assess learning in the real world in older adults with and without HIV.  相似文献   
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李璐  董诚明  朱畇昊  夏伟 《中草药》2019,50(15):3673-3680
目的研究不同居群连翘的遗传多样性。方法采用ISSR分子标记技术对连翘25个自然居群的样本进行分析,利用POPGENE32软件分析多态位点百分率(P)、Nei’s基因多样性指数(H)及Shannon多样性指数(I);居群间遗传一致度采用NTSYSpc-2.10软件进行聚类分析。结果选出13条ISSR引物,扩增出353条清晰条带,物种水平P为100%,H为0.252 3,I为0.394 0,遗传分化系数(Gst)为0.331 8,居群间基因流(Nm)为1.007 0,遗传距离0.031 0~0.155 5;NTSYSpc软件进行系统聚类,将25个聚群划分为2大类,7分组;连翘个体间进行聚类分析,195份连翘样品划分为2大类,5分组。结论连翘种群遗传多样性水平较高,但连翘种群间遗传距离与地理距离没有相关性,与生态因子和生长环境有关。  相似文献   
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