tropical

热带
  • 文章类型: Journal Article
    背景:狂犬病仍然是全球公共卫生的严重威胁,危害着人们的健康和公共卫生安全。在中华人民共和国,多部门和全面的预防和控制策略旨在广泛遏制人类狂犬病传播。这里,我们研究了中国狂犬病感染的现状,探索为响应世卫组织“到2030年零狂犬病死亡”的雄心而采取的战略干预措施,并严格评估在中国消除狗介导的狂犬病的制约因素和可行性。
    方法:本研究从五个角度分析和评估了中国犬介导狂犬病的消除过程:人类,狗,政策,挑战,和前景。关于中国狗介导狂犬病消除进展的循证数据来自许多来源;使用PubMed进行了文献检索,WebofScience和CNKI数据库,来自中国公共卫生科学数据中心的人类狂犬病病例分布数据以及政策和文件数据均来自中国相关部委的官方网站。
    结果:自2007年以来,中国狂犬病病例的发病率呈逐年下降趋势。实行政府主导,到2020年,多部门“一个健康”的方法已经将全国狂犬病死亡总数降至200人左右。报告人类狂犬病病例的省级行政区划(PLAD)数量在2020年也减少到21个,其中13个报告的病例少于10个。此外,在过去的二十年中,寻求狂犬病暴露后预防的门诊病人数量急剧增加,需求比最初高15倍。然而,仍然存在,中国不同地区狂犬病消除结果存在显著差距。迄今为止,尚未达到达到>75%的犬狂犬病疫苗接种率的目标。在欠发达城市和农村地区,狗的狂犬病免疫接种和狗管理的挑战需要与更有效的动物监测和野生动植物和牲畜的狂犬病风险一起解决。
    结论:中国政府主导,多部门“一个健康”的方法来打击狂犬病,并在过去十年取得了重大进展。制定和采用更具成本效益的“一个健康”战略可以实现更多有益于全国的狂犬病消除结果。“到2030年狂犬病零死亡”的宏伟目标可以通过狗大规模疫苗接种运动在狗中建立持久的群体免疫力来实现,狗种群管理,流行病学监测和大规模口服狂犬病疫苗的应用,以消除野生动物中的狂犬病,并部署具有成本效益的人类暴露后预防,和社区教育。
    BACKGROUND: Rabies continues to be a serious threat to global public health endangering people\'s health and public health safety. In the People\'s Republic of China, multi-sectoral and comprehensive prevention and control strategies have aimed to extensively curb human rabies transmission. Here, we examine the current state of rabies infection in China, explore strategic interventions put in place in response to WHO\'s ambition of \"Zero rabies deaths by 2030\" and critically assess the constraints and feasibility of dog-mediated rabies elimination in China.
    METHODS: This study analyzed and evaluated the process towards dog-mediated rabies elimination in China from five perspectives: namely, human, dog, policy, challenge, and prospects. Evidence-based data on progress of dog-mediated rabies elimination in China was derived from a number of sources; a literature search was undertaken using PubMed, Web of Science and CNKI databases, distribution data for human rabies cases as derived from the Data-center of the China Public Health Science and policy and document data were obtained from official websites of the relevant China ministries and commissions.
    RESULTS: The incidence of human rabies cases in China have shown a downward trend year-on-year since 2007. Implementation of a government-led, multi-sectoral \"One Health\" approach to combating rabies has driven down the total number of rabies deaths nationwide to around 200 in 2020. The number of provincial-level administrative divisions (PLADs) reporting human cases of rabies has also decreased to 21 in 2020, 13 of which reported less than 10 cases. Furthermore, the number of outpatient visits seeking rabies post-exposure prophylaxis has risen dramatically over the past two decades, with demand being 15 times higher than it was initially. There remain however, significant gaps in rabies elimination outcomes across the different regions of China. To date the target of achieving a canine rabies vaccination rate of > 75% has not been met. The challenges of rabies immunization of dogs and dog management in underdeveloped cities and rural areas need to be addressed together with more effective animal surveillance and rabies risk from and too wildlife and livestock.
    CONCLUSIONS: The Chinese government-led, multi-sectoral \"One Health\" approach to combating rabies and has made significant progress over the past decade. Development and adoption of more cost-effective One Health strategies can achieve more nationally beneficial rabies elimination outcomes. The ambitious target of \"Zero rabies deaths by 2030\" can be met through establishment of long-lasting herd immunity in dogs by means of dog mass vaccination campaigns, dog population management, epidemiological surveillance and the application of large-scale oral rabies vaccine to eliminate rabies in wild animals coupled with deployment of cost-effective human post-exposure prophylaxis, and community education.
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  • 文章类型: Journal Article
    海洋环境的温度和盐度变化不断波动,这些变化对贝类生存的影响是显著的。在这项研究中,在温度范围(20°C,25°C,30°C)和盐度(23,28,33)。消化(淀粉酶,脂肪酶,胰蛋白酶和胃蛋白酶活性)和抗氧化性能(SOD和GPX基因表达;SOD,GPX和CAT活性;GSH和MDA浓度)进行测量,并使用某些因素(温度(T),盐度(S)和温度×盐度(T×S))和成活率。T和T×S均显着影响亚洲绿贻贝的成活率。在实验范围内,绿脓杆菌的存活率与T和S之间的总体关系可以通过以下公式来概括:ln(存活率)=54.9282-2.5627×T-3.6180×S0.1857×T×S0.0156×T20.0520×S2-0.0012×T2×S-0.0023×T×S2。最佳温度-盐度组合为23.698°C/30.7602。T,S和T×S对亚洲绿贻贝的淀粉酶和脂肪酶活性均有显著影响。在肝胰腺中,吉尔,Mantle,内收肌,亚洲绿贻贝的性腺和足组织,SOD和GPX基因表达对温度-盐度变化有响应。远离最佳温度-盐度组合的组合的抗氧化性能显著提高。我们的结果表明,温度和盐度的综合影响对亚洲绿贻贝的存活有规律的影响,并且存活与消化和抗氧化性能之间存在联系。
    Changes in temperature and salinity of the marine environment fluctuate continuously, and the effects of these changes on shellfish survival are significant. In this study, the survival rate of adult Asian green mussels (Perna viridis) was measured after short-term treatments (7 days) for a range of temperature (20 °C, 25 °C, 30 °C) and salinity (23‱, 28‱, 33‱). The digestive (amylase, lipase, trypsin and pepsin activities) and antioxidant performance (SOD and GPX gene expression; SOD, GPX and CAT activities; GSH and MDA Concentration) were measured and MANOVA results were obtained using a generalized linear model between certain factors (temperature (T), salinity (S) and temperature × salinity (T × S)) and survival rate. Both T and T × S significantly affected the survival rate of Asian green mussels. The overall relationship between the survival rate of P. viridis and T and S within the experimental range can be summarised by the equation: ln(Survival rate) = 54.9282 - 2.5627 × T - 3.6180 × S + 0.1857 × T × S + 0.0156 × T2 + 0.0520 × S2 - 0.0012 × T2 × S - 0.0023 × T × S2. The optimal temperature-salinity combination was 23.698 °C/30.760‱. T, S and T × S all had a significant impact on amylase and lipase activities of Asian green mussels. In the hepatopancreas, gill, mantle, adductor muscle, gonad and foot tissues of Asian green mussel, the SOD and GPX gene expression were responsive to temperature-salinity changes. The antioxidant performance of the combinations far from the optimal temperature-salinity combination were significantly improved. Our results suggest that combined temperature and salinity effects have a regular impact on the survival of Asian green mussels and that there is a link between survival and digestive and antioxidant performance.
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  • 文章类型: Journal Article
    在极端的高温环境中,由于与温度随机变化相关的风险,生物要最大限度地提高性能是具有挑战性的,随后,在进化过程中,将风险暴露降至最低可以作为导致生物体偏好次优温度的机制之一。我们在热带岩石海岸上缓慢移动的潮间带蜗牛中测试了这一假设,以30分钟的间隔记录时,温度变异性随时间从30分钟增加到20小时(由于短期环境自相关,与长时间的温度相比,时间上更接近的温度更相似)。无法通过选择凉爽的栖息地来适应热应力的时间变化可能会导致死亡。测量了不同性状(心率和运动)的热性能曲线,并将其与野外和实验室中蜗牛的热偏好进行了比较。根据多个时间尺度上不同性状的热性能曲线和模拟的结转效应,模拟了蜗牛的预测性能。在蜗牛的生理和行为热最大值之间发现了强烈的不匹配(生理热最大值高于约7°C),但是蜗牛避免了这些最大值,并寻求7-14°C的温度。这种规避风险的策略可以通过它们的预测表现来解释,其中蜗牛应根据≥5小时的时间段来决定首选温度,以避免低估体温的时间变化。在极端和随机环境中,其中环境条件的时间变化可能导致瞬时和时间平均热性能之间的实质性分歧,“凉爽更好”和“次优”体温是首选,因为它们提供了足够的缓冲来降低热应激导致的死亡风险。
    In thermally extreme environments, it is challenging for organisms to maximize performance due to risks associated with stochastic variation in temperature and, subsequently, over evolutionary time minimizing the exposure to risk can serve as one of the mechanisms that result in organisms preferring suboptimal temperatures. We tested this hypothesis in a slow-moving intertidal snail on tropical rocky shores, where temperature variability increases with time from 30 min to 20 hr when recorded at 30 min intervals (due to short-term environmental autocorrelation where temperatures closer in time are more similar as compared to temperatures over a long period of time). Failure to accommodate temporal variation in thermal stress by selecting cool habitats can result in mortality. Thermal performance curves for different traits (heart rate and locomotion) were measured and compared to the snail\'s thermal preferences in both the field and laboratory. Predicted performances of the snails were simulated based on thermal performance curves for different traits over multiple time-scales and simulated carryover effects. A strong mismatch was found between physiological and behavioural thermal maxima of the snails (physiological thermal maximum being higher by ~7°C), but the snails avoided these maxima and sought temperatures 7-14°C cooler. Such a risk-averse strategy can be explained by their predicted performances where the snails should make decisions about preferred temperatures based on time periods ≥5 hr to avoid underestimating the temporal variation in body temperature. In extreme and stochastic environments, where the temporal variation in environmental conditions can lead to substantial divergence between instantaneous and time-averaged thermal performances, \'cooler is better\' and \'suboptimal\' body temperatures are preferred as they provide sufficient buffer to reduce mortality risk from heat stress.
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  • 文章类型: Journal Article
    Temperature is considered to be the main factor controlling the growth and eco-distribution of seagrasses. In this study, the joint effects of temperature (27, 24, 21, 18 and 15 °C) combined with three light intensities (0, 200 and 800 μmol m-2 s-1) on chlorophyll fluorescence and activities of antioxidative enzymes were examined for three tropical seagrasses Enhalus acoroides, Thalassia hemperichii and Cymodocea rotundata. The results showed that low temperature could damage the PSII donor side, PSII reaction centers and end electron acceptor pool, thereby directly injured their photosynthetic performance. Furthermore, the lower the temperature and the higher the light intensity, the greater the damage incurred. The antioxidant defense system of seagrass cannot sufficiently counter low temperature stress (for temperatures below 21 °C) under high light. These results help explain why the ecological distribution of these three tropical seagrasses is limited to the low tidal coastal area of warm tropical regions.
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  • 文章类型: Journal Article
    Microplastics (MP < 5 mm) are eroding oceanic health and coastal development at a planetary scale. Coastlines in Southeast Asia (SEA) are plagued with plastic litters, but how MP are dispersed within SEA region is poorly understood, which can vary dramatically under the tropical climate. We systematically quantified MP in equatorial Singapore, to assess how prevailing Monsoons and other factors impact MP distributions in beaches and mangroves. Data highlighted spatial preponderance differed broadly by seasons (p < 0.05) and were strongly modulated by wind speediness (p < 0.05; r = 0.6-0.7) and promoted transboundary migrations of MP. Conversely, an inverse relationship existed between sediment MP and rainfall (r = -0.54) possibly due to re-entrainment of surficial MP. Elevated concentrations in mangrove\'s compartments (p < 0.05) suggest effective repository hotspots. Coastal MP consisted assorted morphologies and commonest polymers including 34% polypropylene (PP), 26% polyethelene (PE), and 23% Low Density PE. Further comparisons revealed coastal MP in Singapore accelerated by two orders of magnitude since 2014, implying cumulative pollution which is not reversible. We synthesized the first seasonal coastal MP report in SEA which is useful for source apportionment, prediction study, and mitigation planning under tropical circumstances.
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  • 文章类型: Journal Article
    Plant functional traits often show strong latitudinal trends. To explain these trends, studies have often focused on environmental variables, correlations with other traits that themselves show latitudinal trends, and phylogenetic conservatism. However, few studies have systematically disentangled the relative contributions of these factors. Using a dataset consisting of 9,370 plant species from Southwest China, we investigated factors affecting fruit type (fleshy vs. dry): plant growth form, environmental constraints (summarized by climate region), and phylogenetic conservatism. Growth form and climate region are often cited in the literature as important explanations for the higher proportion of fleshy fruited species in the tropics. Nonetheless, in our analyses using partial R2 , growth form and climate region explained only 1.7% and 0.3%, respectively, of the variance in fruit type in a model including phylogeny, while phylogenetic conservatism explained 79.5%. Furthermore, phylogenetic conservatism was evenly distributed along the phylogeny, implying that fruit type reflects both ancient and recent phylogenetic relationships. Our findings illustrate the value of parsing out the contributions of explanatory variables and phylogeny to the variance in species\' traits. Methods using phylogenies that calculate partial R2 give a more informative tool than traditional methods to explore the phylogenetic patterns of functional traits.
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  • 文章类型: Journal Article
    日益城市化的世界是全球环境变化的最突出例子之一。在全球范围内,城市公园的设计和管理方式类似,导致视觉上令人愉悦的草坪扩展,并散布着具有不同外观和功能特征的单独种植的树木。这些大型城市绿地有能力提供各种生态系统服务,包括与土壤理化性质相关的物质。我们的目的是探索城市公园中的土壤特性是否在产生不稳定或顽固凋落物的植被下发散,以及影响是否受气候带(从北方到温带到热带城市)的影响。我们还将这些特性与城市以外的(半)天然林中的特性进行了比较,以评估城市化对植物性状效应的影响。我们表明,植被类型影响土壤有机质(OM)的百分比,总碳(C)和总氮(N),但是在气候带之间不一致。在北方和温带地区的旧公园中,植物性状效应特别弱,而在这些地区的年轻公园里,两种树型下的土壤积累了明显更多的OM,C和N与草坪相比。在气候带内,人为驱动主导自然驱动,与森林相比,在公园中产生不稳定或顽固凋落物的树木下与有机物相关的土壤性质的值始终较低。城市化的主要作用还反映在其使三个城市的公园土壤特性均一的能力上,尤其是在草坪土壤和树木下的土壤中,无论其功能特性如何。我们的研究表明,与碳和氮动态相关的土壤功能-甚至在植物-土壤相互作用历史悠久的古老城市绿地中-与自然生态系统中的功能明显不同,暗示人为驱动因素对土壤生态系统服务的长期影响。
    An increasingly urbanized world is one of the most prominent examples of global environmental change. Across the globe, urban parks are designed and managed in a similar way, resulting in visually pleasing expansions of lawn interspersed with individually planted trees of varying appearances and functional traits. These large urban greenspaces have the capacity to provide various ecosystem services, including those associated with soil physicochemical properties. Our aim was to explore whether soil properties in urban parks diverge underneath vegetation producing labile or recalcitrant litter, and whether the impact is affected by climatic zone (from a boreal to temperate to tropical city). We also compared these properties to those in (semi)natural forests outside the cities to assess the influence of urbanization on plant-trait effects. We showed that vegetation type affected percentage soil organic matter (OM), total carbon (C) and total nitrogen (N), but inconsistently across climatic zones. Plant-trait effects were particularly weak in old parks in the boreal and temperate zones, whereas in young parks in these zones, soils underneath the two tree types accumulated significantly more OM, C and N compared to lawns. Within climatic zones, anthropogenic drivers dominated natural ones, with consistently lower values of organic-matter-related soil properties under trees producing labile or recalcitrant litter in parks compared to forests. The dominating effect of urbanization is also reflected in its ability to homogenize soil properties in parks across the three cities, especially in lawn soils and soils under trees irrespective of functional trait. Our study demonstrates that soil functions that relate to carbon and nitrogen dynamics-even in old urban greenspaces where plant-soil interactions have a long history-clearly diverged from those in natural ecosystems, implying a long-lasting influence of anthropogenic drivers on soil ecosystem services.
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  • 文章类型: Journal Article
    Plant architecture strongly influences ecological performance, yet its role in plant evolution has not been explored in depth. By testing both phylogenetic and environmental signals, it is possible to separate architectural traits into four categories: development constraints (phylogenetic signal only); convergences (environmental dependency only); key confluences to the environmental driver (both); unknown (neither). We analysed the evolutionary history of the genus Euphorbia, a model clade with both high architectural diversity and a wide environmental range. We conducted comparative analyses of 193 Euphorbia species world-wide using 73 architectural traits, a dated phylogeny, and climate data. We identified 14 architectural types in Euphorbia based on trait combinations. We found 22 traits and three types representing convergences under climate groups, 21 traits and four types showing phylogenetic signal but no relation to climate, and 16 traits and five types with both climate and phylogenetic signals. Major drivers of architectural trait evolution likely include water stress in deserts (selected for succulence, continuous branching), frost disturbance in temperate systems (selected for simple, prostrate, short-lived shoots) and light competition (selected for arborescence). Simple architectures allowed resilience to disturbance, and frequent transitions into new forms. Complex architectures with functional specialisation developed under stable climates but have low evolvability.
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  • 文章类型: Journal Article
    从热带到亚热带(暖温带)常绿森林的转变在东亚更为明显,从尼泊尔到西太平洋海岸,比热带其他地方都多。我们回顾了这种转变的性质,并假设了物理,最终气候,可能维持它的因素,特别关注气候的不稳定和变暖将如何影响这些森林。提出了过渡的主要气候中介,从而为气候-森林过渡关系提供了可检验的假设。在赤道亚洲森林形成的海拔分区到树线的主要气候介质的背景下,总结了这种转变的已知情况,在印度-印度-缅甸北部热带边缘的喜马拉雅山,以及中国南方的海拔和纬度分区。描述了喜马拉雅山随之而来的二次土壤和其他物理变化,并假设为中国南方。森林过渡带主要由树木植物区系变化来定义,决定了结构和地貌的变化。喜马拉雅的山地热带-亚热带过渡区域狭窄,并观察到与尚未确定的霜冻线相关。在中国西南山区发现了独特的热带-亚热带过渡森林。喜马拉雅过渡带的冠层物种发生了全面变化,但是亚冠层热带物种沿着c的海拔下降持续存在。400米。中国南方的纬度过渡是类似的,但是这里的热带亚冠层部分向北延伸超过十度纬度,虽然在下降。在东亚,热带-亚热带过渡是唯一明确的,因为仅在这里,热带夏季潮湿-干燥的冬季季风就延伸到北纬35°,包括亚热带常绿森林,而其他地方的亚热带常绿森林则存在于较干燥的温带夏季气候条件下。
    The transition from tropical to subtropical (warm temperate) evergreen forests is more clearly apparent in East Asia, from Nepal to the western Pacific coast, than elsewhere in the tropics. We review the nature of this transition and hypothesize the physical, ultimately climatic, factors that may maintain it, with a special focus on how the increasing instability and warming of climates will affect these forests. A primary climatic mediator of the transition is proposed, thereby offering a testable hypothesis for the climate-forest transition relationship. What is known of this transition is summarized in context of the primary climatic mediators of elevational zonation of forest formations in equatorial Asia to the tree line, in the Himalaya at the India-Indo-Burma northern tropical margin, and as both elevational and latitudinal zonation in southern China. Consequent secondary edaphic and other physical changes are described for the Himalaya, and hypothesized for southern China. The forest ecotones are seen to be primarily defined by tree floristic change, on which account changes in structure and physiognomy are determined. The montane tropical-subtropical transition in the Himalaya is narrow and observed to correlate with an as yet ill-defined frost line. A distinct tropical-subtropical transition forest is recognized in the southwest China mountains. There is a total change in canopy species at the Himalayan ecotone, but subcanopy tropical species persist along an elevational decline of c. 400 m. The latitudinal transition in South China is analogous, but here the tropical subcanopy component extends north over ten degrees latitude, albeit in decline. The tropical-subtropical transition is uniquely clear in East Asia because here alone a tropical wet summer-dry winter monsoon extends to 35° north latitude, encompassing the subtropical evergreen forest, whereas subtropical evergreen forests elsewhere exist under drier temperate summer climate regimes.
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  • 文章类型: Journal Article
    Vapour pressure deficit is a major driver of seasonal changes in transpiration, but photoperiod also modulates leaf responses. Climate warming might enhance transpiration by increasing atmospheric water demand and the length of the growing season, but photoperiod-sensitive species could show dampened responses. Here, we document that day length is a significant driver of the seasonal variation in stomatal conductance. We performed weekly gas exchange measurements across a common garden experiment with 12 oak species from contrasting geographical origins, and we observed that the influence of day length was of similar strength to that of vapour pressure deficit in driving the seasonal pattern. We then examined the generality of our findings by incorporating day-length regulation into well-known stomatal models. For both angiosperm and gymnosperm species, the models improved significantly when adding day-length dependences. Photoperiod control over stomatal conductance could play a large yet underexplored role on the plant and ecosystem water balances.
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