首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
Climate change translates into insecure water provision and produces new uncertainties for farmers and politicians in Colca Valley, Southern Peru. Anthropological studies of climate change have mainly focused on adaptation, resilience and so-called indigenous traditional knowledge. This article argues that a stronger ethnographic focus on material practices – including knowledge practices – can contribute to a more nuanced understanding of climate change effects, responses and forms of water management. The author aims to see responses to climate change as more than cultural representations, and therefore focuses on water practices and the realities that these practices make, as well as the relational webs of humans, environment, infrastructure and other-than-human beings. The article explores different practices that enact multiple versions of water, and multiple – yet related and entangled – water worlds. The author suggests that this has implications for how we understand politics of climate and water: as tensions between singularizing practices and multiplicity.  相似文献   

2.
We explore whether a Rawlsian approach might provide a guiding philosophy for the development of a healthcare system, in particular with regard to resolving tensions between different groups within it. We argue that an approach developed from some of Rawls’ principles – using his ‘veil of ignorance’ and both the ‘difference’ and ‘just savings’ principles which it generates – provides a compelling basis for policy making around certain areas of conflict. We ask what policies might be made if those making them did not know if one was patient, doctor, nurse or manager – in this generation or the next. We first offer a brief summary of Rawls’ approach and how we intend to extrapolate from it. We examine how this adapted Rawlsian framework could be applied to specific examples of conflict within healthcare; we demonstrate how this framework can be used to develop a healthcare service which is both sustainable (in its training and treatment of staff, and in encouraging research and innovation) and open (to protect the powers and opportunities of those using the health service). We conclude that while Rawls’ approach has previously been rejected as a means to address specific healthcare decisions, an adapted veil of ignorance can be a useful tool for the consideration of how a just health service should be constructed and sustained. Turning the theoretical into the practical (and combining Rawls’ thought experiment with Scanlonian contractarianism), managers, doctors, patients, carers and nurses could come together and debate conflicting issues behind a hypothetical veil.  相似文献   

3.
News: Plastics from E. coli – Looking again (carefully) at thalidomide – Don't kiss the chimps – Imaging microbial interactions – Probiotics prevent intestinal diseases – Drug resistance in cancer stem cell populations – Triple tag technique turns up tight and loose complexes – It pays to have an immune mother – DNA hybridization mechanisms – Chip-based breast tissue analysis – Nutrient support for engineered tissue – Nano-spheres support axon recovery – Bop-a-hepcidin Environmental News: Blueprint for molecular basis of global warming – Environmental biosensors – Predicting the fate of underground carbon Journal Highlights: Focus on Biochips – Neglected tropical diseases – New online portal Opinion: Outwitting evolution: We should pay as much for strategy as technology Most Read Industry News: Life Sciences Industry – Collaboration on forensics – New center for Systems Biology Tips and tricks: Melting your DNA Special Broadcast: Watch 50 years of B&B on YouTube Writing Tips: Get the figures right – Figure or Table? – Figure legend Algae and plants in brief: Plasmid-based methods in mosses – Antibody production in algal chloroplasts – Polysaccharides from foam cultures Test your knowledge: Do you recognize this? WIREs Author Spotlight: Toxicity of Nanomaterials  相似文献   

4.
Aim Humans have dramatically transformed landscapes along the US–Mexico border. We aim to assess the risk of barriers that may significantly impede animal migrations within this ecologically sensitive region. Location United States and Mexico. Methods We examined the intersection of current and possible future barriers along the border with the geographic ranges of 313 amphibian, reptile and non‐volant mammal species. We considered the areas of intensive human land use and ~ 600 km of pedestrian fence as current barriers along the border. We evaluated the impacts of two scenarios of dispersal barriers – continuation of existing and construction of new barriers – and identified species vulnerable to global and local extinction. Results Among the species most at risk from current barriers are four species listed as threatened globally or by both nations, 23 species for which the larger of their two national subranges is < 105 km2 and 29 species whose ranges cross the border only marginally. Three border regions, California, Madrean archipelago and Gulf coast, emerge as being of particular concern. These regions are characterized by high overall species richness and high richness of species at risk from existing barriers and from construction of potential new barriers. Main conclusions New barriers along the border would increase the number of species at risk, especially in the three identified regions, which should be prioritized for mitigation of the impacts of current barriers. The species we identified as being potentially at risk merit further study to determine impacts of border dispersal barriers.  相似文献   

5.
6.
The distribution of contractile forces generated in cytoskeletal stress fibers (SFs) contributes to cellular dynamic functions such as migration and mechanotransduction. Here we describe a novel (to our knowledge) method for measuring local tensions in SFs based on the following procedure: 1), known forces of different magnitudes are applied to an SF in the direction perpendicular to its longitudinal axis; 2), force balance equations are used to calculate the resulting tensions in the SF from changes in the SF angle; and 3), the relationship between tension and applied force thus established is extrapolated to an applied force of zero to determine the preexisting tension in the SF. In this study, we measured tensions in SFs by attaching magnetic particles to them and applying known forces with an electromagnetic needle. Fluorescence microscopy was used to capture images of SFs fluorescently labeled with myosin II antibodies, and analysis of these images allowed the tension in the SFs to be measured. The average tension measured in this study was comparable to previous reports, which indicates that this method may become a powerful tool for elucidating the mechanisms by which cytoskeletal tensions affect cellular functions.  相似文献   

7.
We studied the medicinal plants used by the Popoluca of the Sierra de Santa Marta (eastern Mexico). Using Moerman’s method of regression analysis we determined which ethnomedically used taxa are over-represented in the Popolucan pharmacopoeia (e.g., Asteraceae) and which are underrepresented (e.g., Orchidaceae). Moerman et al. (1999) found high correlation between the holarctic pharmacopoeias and assumed that apart from the relatedness of the northern floras a “global pattern of human knowledge“ may account for this finding. Although the Popoluca dwell in a habitat dominated by a neotropical flora but intermixed with important holarctic elements, they include considerably fewer neotropical taxa in their pharmacopoeia as one would expect if the historical transmitted knowledge were influencing their selection. This finding confirms the theory stated by Moerman et al. However, the Popoluca include some neotropical taxa in their pharmacopoeia and thus a moderate correlation exists between the Popolucan pharmacopoeia and the neotropical pharmacopoeia analysed by Moerman et al. We therefore conclude that apart from historically transmitted knowledge about specific taxa the “global pattern of human knowledge” addressed by Moerman et al. is largely based on “common selection criteria.”  相似文献   

8.
We present a review on the conservation status and population trends of the 372 amphibian species currently recognized for Mexico. We based our analyses on the information gathered by the International Union for the Conservation of Nature-the Global Amphibian Assessment (IUCN-GAA) as well as on available literature about imminent or potential threats to these organisms in Mexico. This country has the fifth largest amphibian fauna in the world and almost 58% of the species that inhabit this country are considered as threatened. We highlight the proportion of species per order, family, and genus that are currently under severe risk in Mexico. In addition, we prepared a detailed list of the main factors that are threatening amphibians in this country. Evidence is provided that the six main mechanisms that are globally leading amphibians to extinction (alien species, over-exploitation, land use change, global changes, pollution, and infectious diseases) are indeed currently operating in Mexico. We discuss the relative importance of each of these causes. We also highlight the paucity of quantitative studies that support the current conservation status of Mexican amphibian species.  相似文献   

9.
The ongoing SARS (severe acute respiratory syndrome)-CoV (coronavirus)-2 pandemic has exposed major gaps in our knowledge on the origin, ecology, evolution, and spread of animal coronaviruses. Porcine epidemic diarrhea virus (PEDV) is a member of the genus Alphacoronavirus in the family Coronaviridae that may have originated from bats and leads to significant hazards and widespread epidemics in the swine population. The role of local and global trade of live swine and swine-related products in disseminating PEDV remains unclear, especially in developing countries with complex swine production systems. Here, we undertake an in-depth phylogeographic analysis of PEDV sequence data (including 247 newly sequenced samples) and employ an extension of this inference framework that enables formally testing the contribution of a range of predictor variables to the geographic spread of PEDV. Within China, the provinces of Guangdong and Henan were identified as primary hubs for the spread of PEDV, for which we estimate live swine trade to play a very important role. On a global scale, the United States and China maintain the highest number of PEDV lineages. We estimate that, after an initial introduction out of China, the United States acted as an important source of PEDV introductions into Japan, Korea, China, and Mexico. Live swine trade also explains the dispersal of PEDV on a global scale. Given the increasingly global trade of live swine, our findings have important implications for designing prevention and containment measures to combat a wide range of livestock coronaviruses.  相似文献   

10.
Global patterns of plant diversity and floristic knowledge   总被引:10,自引:0,他引:10  
Aims We present the first global map of vascular plant species richness by ecoregion and compare these results with the published literature on global priorities for plant conservation. In so doing, we assess the state of floristic knowledge across ecoregions as described in floras, checklists, and other published documents and pinpoint geographical gaps in our understanding of the global vascular plant flora. Finally, we explore the relationships between plant species richness by ecoregion and our knowledge of the flora, and between plant richness and the human footprint – a spatially explicit measure of the loss and degradation of natural habitats and ecosystems as a result of human activities. Location Global. Methods Richness estimates for the 867 terrestrial ecoregions of the world were derived from published richness data of c. 1800 geographical units. We applied one of four methods to assess richness, depending on data quality. These included collation and interpretation of published data, use of species–area curves to extrapolate richness, use of taxon‐based data, and estimates derived from other ecoregions within the same biome. Results The highest estimate of plant species richness is in the Borneo lowlands ecoregion (10,000 species) followed by nine ecoregions located in Central and South America with ≥ 8000 species; all are found within the Tropical and Subtropical Moist Broadleaf Forests biome. Among the 51 ecoregions with ≥ 5000 species, only five are located in temperate regions. For 43% of the 867 ecoregions, data quality was considered good or moderate. Among biomes, adequate data are especially lacking for flooded grasslands and flooded savannas. We found a significant correlation between species richness and data quality for only a few biomes, and, in all of these cases, our results indicated that species‐rich ecoregions are better studied than those poor in vascular plants. Similarly, only in a few biomes did we find significant correlations between species richness and the human footprint, all of which were positive. Main conclusions The work presented here sets the stage for comparisons of degree of concordance of plant species richness with plant endemism and vertebrate species richness: important analyses for a comprehensive global biodiversity strategy. We suggest: (1) that current global plant conservation strategies be reviewed to check if they cover the most outstanding examples of regions from each of the world's major biomes, even if these examples are species‐poor compared with other biomes; (2) that flooded grasslands and flooded savannas should become a global priority in collecting and compiling richness data for vascular plants; and (3) that future studies which rely upon species–area calculations do not use a uniform parameter value but instead use values derived separately for subregions.  相似文献   

11.
The global distribution of the reddish egret is characterized by disjunct colonies occurring from the Pacific side of Northwest Mexico to the Caribbean. We examined distantly isolated colonies of reddish egret to determine global population genetic structure. We used seven polymorphic microsatellites to accomplish five goals: (1) to assess range wide population differentiation among reddish egret (Egretta rufescens) populations, (2) identify extent of gene flow, (3) determine any historical occurrence of bottlenecks, (4) assess genetic differentiation between color morphs, (5) clarify subspecies status of E. r. dickeyi, a completely dark morph population located in and around the Baja California peninsula, Mexico. Genetic differentiation was dramatic (global Fst = 0.161) throughout the reddish egrets range extending from Baja California, Mexico to Great Inagua, Bahamas. Differentiation occurred among three distinct regions (Fst = 0.238) but not among colonies/islands within regions suggesting regional philopatry. Genetic diversity (alleles per locus, and heterozygosity) in Baja California Sur, Mexico and Great Inagua, Bahamas populations is lower than in the Texas/Mexico population due to minimal dispersal between regions and smaller population sizes. Dark and white color morphs when present within the same region showed no differentiation. Patterns of recent population bottlenecks are not evident in each of the three regional populations. With evidence of limited gene flow in addition to low genetic diversity and prospects of habitat loss we recommend that reddish egrets be managed as three distinct or evolutionary significant units.  相似文献   

12.
Historically, views and measurements of biodiversity have had a narrow focus, for instance, characterizing the attributes of observable patterns but affording less attention to processes. Here, we explore the question: how does a systems thinking view – one where the world is seen as elements and processes that connect and interact in dynamic ways to form a whole – affect the way we understand biodiversity and practice conservation? We answer this question by illustrating the systemic properties of biodiversity at multiple levels, and show that biodiversity is a collection of dynamic systems linking seemingly disparate biological and cultural components and requiring an understanding of the system as a whole. We conclude that systems thinking calls traditional views of species, ecosystem function, and human relationships with the rest of biodiversity into question. Finally, we suggest some of the ways in which this view can impact the science and practice of conservation, particularly through affecting our conservation targets and strategies.  相似文献   

13.
Social foraging provides animals with opportunities to gain knowledge about available food. Studies indicate that animals are influenced by social context during exploration and are able to learn socially. Carrion and hooded crows, which are opportunistic generalists with flexible social systems, have so far received little focus in this area. We combined observational and experimental approaches to investigate social interactions during foraging and social influences on crow behaviour within a free‐ranging population at Vienna Zoo, which included 115 individually marked crows. We expected the crows to be tolerant of conspecifics during foraging due to high food abundance. We predicted that social context would enhance familiar object exploration, as well as a specific foraging strategy: predation by crows on other species. We found that crows were highly tolerant of one another, as reflected by their high rates of cofeeding – where they fed directly beside conspecific(s) – relative to affiliative or agonistic interactions. Evidence for social facilitation – when the observer's behaviour is affected by the mere presence of a model – was found in both object exploration and predation behaviour. Specifically, crows touched the objects more frequently when others were present (whilst only approaching the objects when alone), and conspecifics were present more frequently during predation events involving the high‐risk target species. Evidence for enhancement during object exploration – where the observer's attention is drawn to a place or object by a model's actions – was not confirmed in this context. Our results highlight the role played by the presence of conspecifics across different contexts: natural foraging behaviour, familiar object exploration and a specific foraging strategy. To our knowledge, this is one of the first corvid studies aimed at teasing apart specific social influence and learning mechanisms in the field. These crows therefore make promising candidates for studying social learning and its consequences under naturalistic conditions.  相似文献   

14.
With the aim of protecting Mexican diversity, one current governmental task is to complete national biological inventories. In the case of odonate insects, several researchers have hypothesized that species richness is complete (205 dragonflies and 151 damselflies), but there has not been any formal exercise to test this. Thus, we have investigated whether odonate species richness (for Mexican endemics, dragonflies (suborder Anisoptera), damselflies (suborder Zygoptera) and total species) is complete using sample-based and coverage-based rarefaction curves. Along with this, we also showed how good distribution data are in the country. The rarefaction curves have indicated 100% completeness for all groups suggesting that the inventory is complete. However, species' distribution data is highly patchy regarding areas either well (e.g. central Mexico) or badly (e.g. coast of Guerrero and Oaxaca) collected. We encourage researchers to continue odonate sampling in order to support at least three conservation actions: (i) conservation assessment of endangered species; (ii) knowledge of range shifts given rising global temperatures; and (iii) increase public interest and awareness in protected, touristic areas.  相似文献   

15.
Aim Biotic interactions – within guilds or across trophic levels – have widely been ignored in species distribution models (SDMs). This synthesis outlines the development of ‘species interaction distribution models’ (SIDMs), which aim to incorporate multispecies interactions at large spatial extents using interaction matrices. Location Local to global. Methods We review recent approaches for extending classical SDMs to incorporate biotic interactions, and identify some methodological and conceptual limitations. To illustrate possible directions for conceptual advancement we explore three principal ways of modelling multispecies interactions using interaction matrices: simple qualitative linkages between species, quantitative interaction coefficients reflecting interaction strengths, and interactions mediated by interaction currencies. We explain methodological advancements for static interaction data and multispecies time series, and outline methods to reduce complexity when modelling multispecies interactions. Results Classical SDMs ignore biotic interactions and recent SDM extensions only include the unidirectional influence of one or a few species. However, novel methods using error matrices in multivariate regression models allow interactions between multiple species to be modelled explicitly with spatial co‐occurrence data. If time series are available, multivariate versions of population dynamic models can be applied that account for the effects and relative importance of species interactions and environmental drivers. These methods need to be extended by incorporating the non‐stationarity in interaction coefficients across space and time, and are challenged by the limited empirical knowledge on spatio‐temporal variation in the existence and strength of species interactions. Model complexity may be reduced by: (1) using prior ecological knowledge to set a subset of interaction coefficients to zero, (2) modelling guilds and functional groups rather than individual species, and (3) modelling interaction currencies and species’ effect and response traits. Main conclusions There is great potential for developing novel approaches that incorporate multispecies interactions into the projection of species distributions and community structure at large spatial extents. Progress can be made by: (1) developing statistical models with interaction matrices for multispecies co‐occurrence datasets across large‐scale environmental gradients, (2) testing the potential and limitations of methods for complexity reduction, and (3) sampling and monitoring comprehensive spatio‐temporal data on biotic interactions in multispecies communities.  相似文献   

16.
Genetic ancestry testing (GAT) is marketed as a way to make up for missing knowledge about one’s ancestry. Previous research questions the GAT industry’s ability to fulfill this promise in terms of the validity and reliability of test results. We instead explore the demand side of GAT, evaluating who is most and least likely to express interest in GAT. Using data from an original, nationwide survey of over 100,000 American adults, we find that GAT interest is related to both self-identified race and immigrant generation, with Asian Americans and first-generation immigrants expressing the least interest. Our quantitative and qualitative evidence suggests interest is further shaped by a pre-existing sense of ancestral certainty, leading some individuals to decline GAT, even if it were free. How interest and ancestral certainty are patterned has implications for who is included in – and thus for the conclusions that can be drawn from – genetic ancestry databases.  相似文献   

17.
Abstract

In the late twentieth and early twenty-first centuries, the USA has experienced large-scale and continuing immigration from around the world, especially Latin America and, within Latin America, from Mexico. One dimension of these transnational processes is dietary change. In this paper, we qualitatively assess the effects of migration from Oaxaca, Mexico to central New Jersey on the ecology and economy of dietary patterns. We explore multiple factors at the micro and macro levels. Data come from focus groups held among Mexican migrants in New Jersey, and in Oaxaca among people from their sending communities. Economic constraints and lack of culturally appropriate foods are larger barriers to healthy eating than lack of knowledge about appropriate diets. We end with recommendations for nutrition education and interventions.  相似文献   

18.
The United States is currently experiencing its worst man-made environmental disaster, the BP Deepwater Horizon oil leak. The Gulf of Mexico oil spill is severe in its impact, but it is only one of several global oil spill disasters in history. Students can utilize the technology of Google Earth to explore the spatial and temporal distribution of oil spills. In addition to increasing content knowledge of oil spills, Google Earth assists in developing student geographic and technologic literacy. Designed for a middle school science class, this activity may also be used in English, history, math, art, and poster-making.  相似文献   

19.
Distribution of Herbal Remedy Knowledge in Tabi, Yucatan, Mexico. The distribution of herbal remedy knowledge among a group of people is studied for two main reasons: (1) to identify plants that are promising for pharmacological analysis, and (2) to examine the factors that lead to herbal remedy knowledge erosion as opposed to dynamism in the acquisition of knowledge. The goal of this particular study, which is aligned with the second reason, is to establish the variation in herbal remedy knowledge among the Yucatec Maya in Tabi, Yucatan, Mexico. Free listing and cultural consensus analysis revealed that knowledge about a few medicinal plants and herbal remedies was distributed widely among the Yucatec Maya in Tabi, whereas the majority of knowledge was idiosyncratic. This finding was consistent with other studies of herbal remedy knowledge distribution among indigenous groups in Latin America and Africa. Assessing patterns in the distribution of herbal remedy knowledge is an important next step in determining the degree of dynamism or erosion in knowledge acquisition and transmission in Tabi.  相似文献   

20.
Forests contribute to climate change mitigation through carbon storage and uptake, but the extent to which this carbon pool varies in space and time is still poorly known. Several Earth Observation missions have been specifically designed to address this issue, for example, NASA's GEDI, NASA-ISRO's NISAR and ESA's BIOMASS. Yet, all these missions' products require independent and consistent validation. A permanent, global, in situ, site-based forest biomass reference measurement system relying on ground data of the highest possible quality is therefore needed. Here, we have assembled a list of almost 200 high-quality sites through an in-depth review of the literature and expert knowledge. In this study, we explore how representative these sites are in terms of their coverage of environmental conditions, geographical space and biomass-related forest structure, compared to those experienced by forests worldwide. This work also aims at identifying which sites are the most representative, and where to invest to improve the representativeness of the proposed system. We show that the environmental coverage of the system does not seem to improve after at least the 175 most representative sites are included, but geographical and structural coverages continue to improve as more sites are added. We highlight the areas of poor environmental, geographical, or structural coverage, including, but not limited to, Canada, the western half of the USA, Mexico, Patagonia, Angola, Zambia, eastern Russia, and tropical and subtropical highlands (e.g. in Colombia, the Himalayas, Borneo, Papua). For the proposed system to succeed, we stress that (1) data must be collected and processed applying the same standards across all countries and continents; (2) system establishment and management must be inclusive and equitable, with careful consideration of working conditions; and (3) training and site partner involvement in downstream activities should be mandatory.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号