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现代科学技术中的生态研究问题   总被引:1,自引:0,他引:1  
环境污染、生态问题是当今世界所面临的主要问题,研究环境的保护与改善,首先必须解决生态失调问题。生态问题已成为众多学科涉足研究的课题。生态学的基本理论和方法就客观成为各学科处理生态问题所依据的准则,  相似文献   

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The authors illustrate an effective lessonplanning technique known as unpacking for the broad topic of water. Interconnections among science disciplines are shown for numerous possible subtopics. Two lesson sets are included, the first dealing with properties of water and the second dealing with water as a resource.  相似文献   

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We present two stochastic models of individual and social learningthat count the number of individuals exhibiting a learned, resource-producingtrait in a group of social foragers. The novelty of our modelingresults from incorporating the empirically based assumptionthat rates of both individual and social learning should dependon the frequency of the learned trait within the group. Whenresources occur as clumps shared by group members, a naive individual'sacquisition of the skill required for clump discovery/productionshould involve opposing processes of frequency dependence. Theopportunity to learn via cultural transmission should increasewith the trait's frequency, but the opportunity for learningindividually should decrease as the trait's frequency increases.The results of the model suggest that the evolution of the capacityfor cultural transmission may be promoted in environments wherescrounging at resource clumps inhibits rates of individual learning.  相似文献   

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The Precautionary Principle came out of European efforts to clean-up and protect marine ecosystems in the 1980s. Since then, several North American activities have elaborated on this approach in U.S. environmental programs. Unfortunately, US organizations and agencies have not developed strategies and guidelines for implementing the Precautionary Principle in either statutory or voluntary environmental programs. Recent interest in this approach from some members of the scientific, non-profit, and regulatory communities highlights the need to understand the history and conceptual basis of the Precautionary Principle. In this paper we address several of these issues. First, we summarize the pertinent US history of the Precautionary Principle. Next, we describe the scientific framework for the principle. Finally, we make the case that this provides unique opportunities for scientists to obtain meaning in their work by fulfilling what has been called the new Social Contract.  相似文献   

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James Scott's The Moral Economy of the Peasant (1976) appeared at a time when "peasant studies" had begun to occupy an important place in the social sciences. The book's focus on Vietnam, as well as its novel argument about the causes of rural rebellion, attracted widespread attention and unleashed acerbic debates about peasants' "rationality" and the applicability of concepts from neoclassical economics to smallholding agriculturalists. In this article, I analyze E. P. Thompson's notion of "moral economy" and Scott's use of it to develop an experiential theory of exploitation. I then discuss other influences on Scott, including Karl Polanyi, A. V. Chayanov, and the Annales historians. "Moral economy" and "subsistence crisis" are concepts that Scott elaborated mainly in relation to village or national politics. In the final section of the article, I outline changes affecting peasantries in the globalization era and the continuing relevance of moral economic discourses in agriculturalists' transnational campaigns against the WTO.  相似文献   

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Human societies maintain between-group variation despite mixing of people and ideas. In order for variation to remain, migrants or their children must preferentially adopt local norms, customs, and beliefs. Yet the details of how cultural variation is maintained, despite mixing, remain unknown. This article addresses this problem by using a simple model of the evolution of cultural learning to interpret the results of a study of cultural variation in a small region of East Africa. I argue that the manner in which migrants of two diverse regions adapt to local beliefs and behavior depends on the costs and accuracy of learning in each domain. Observational studies are never definitive tests of any hypothesis, but these results suggest that conclusions about the significance of cultural learning for understanding individual attitudes and behavior depend strongly upon the domain of investigation.  相似文献   

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新的农业科技革命与农业生态学研究   总被引:1,自引:0,他引:1  
阐述了以“双重绿芭革命”为主要特征的世界农业科技革命的趋势,指出中国新的农业科技革命是超出世界农业科技革命目标的多重绿色革命。农业生态学是实现多重以革命目标的两大关键技术之一。为了能使生态学家研究在新的农业科技革命中发挥应用的作用,必须进行生态研究的革命,即强化对农业生态学基本生态学过程听研究,面向农产品产量与品质提高的需求,加强产量生态学和品质生态学的研究,针对薄弱环节和社会发展急而开展促进中国  相似文献   

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Neural Coding of Finger and Wrist Movements   总被引:2,自引:0,他引:2  
Previous work (Schieber and Hibbard, 1993) has shown that single motor cortical neurons do not discharge specifically for a particular flexion-extension finger movement but instead are active with movements of different fingers. In addition, neuronal populations active with movements of different fingers overlap extensively in their spatial locations in the motor cortex. These data suggested that control of any finger movement utilizes a distributed population of neurons. In this study we applied the neuronal population vector analysis (Georgopoulos et al., 1983) to these same data to determine (1) whether single cells are tuned in an abstract, three-dimensional (3D) instructed finger and wrist movement space with hand-like geometry and (2) whether the neuronal population encodes specific finger movements. We found that the activity of 132/176 (75%) motor cortical neurons related to finger movements was indeed tuned in this space. Moreover, the population vector computed in this space predicted well the instructed finger movement. Thus, although single neurons may be related to several disparate finger movements, and neurons related to different finger movements are intermingled throughout the hand area of the motor cortex, the neuronal population activity does specify particular finger movements.  相似文献   

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This inquiry-based activity designed for the fifth through 12th grade allows students to engage in an outdoor, place-based experience, working collaboratively both in groups and as a class to accomplish the class goal of creating a local tree map linked to student-collected data about each tree. During Local Tree Mapping, students explore the local trees in the yard or neighborhood of the school, while learning basic skills in geographical information systems and Microsoft Excel. Through this activity, students gain a deeper understanding of and appreciation for the role of trees within the Earth's ecosystems, as they collect data on tree type, height, diameter, age, and the longitude and latitude of the trees. An extension activity is described in which students can enter their tree data into a carbon dioxide (CO2) emissions reduction calculator to determine how much CO2 is sequestered by the trees in their research site. Local Tree Mapping provides an opportunity for students to gain inquiry skills in science, mathematics, and geography as they participate firsthand in the collection, analysis, and presentation of real-world data that can be utilized by the local community.  相似文献   

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Using the case of the African American Olympic protest movement that grew out of the crisis of the civil rights struggle in the late 1960s, this article is an attempt to argue that work involving identity, culture and popular culture is crucial to the study of race and ethnicity in the contemporary world. A reconstruction of this movement demonstrates, first of all, how a cultural arena like sport can make it possible for otherwise powerless racial and ethnic minorities to draw attention to their cause. Of course, as with most insurgent movements, such initiatives ultimately (and often very quickly) come up against structural impediments that work to reject or absorb their challenge and reinforce the hegemony of the established regime. But the precise nature of the structural constraints operating in this particular case provides profound insight into the construction of social order in liberal democratic settings and the threat posed by cultural politics to this order. More specifically, I argue that athletic protest was overwhelmingly condemned and rejected because it threatened to rupture the homologies between sport culture and liberal democratic ideology that otherwise legitimated a fundamentally individualist, assimilationist vision of racial justice and civil rights in the United States. In more general theoretical terms, then, culturally‐oriented movements expose the ways in which domination itself is deeply structured in and through culture. The article concludes by suggesting that this, especially in an age when capital and power have discovered techniques to insulate themselves against traditional, materialist forms of resistance, is why cultural forums and identity politics have become primary sites of the struggle for hegemony.  相似文献   

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Abstract

Movements of tui (Prosthetnadera novaeseelandiae) breeding on Tiritiri Matangi Island were followed and related to changes in nectar access. The island has limited nectar sources and birds must move to gain access to nectar year round. All tui leave the island, although the extent and timing of movement varies for different individuals. Tui return for breeding but again the timing of the return varies for individuals. Nectar sources were typically concentrated in both time and space, and access was related to individual asymmetries such as sex, residential status and age. These same asymmetries also relate to the timing of individuals movements, and where individuals nest relative to nectar sources. At concentrated food sources, access was determined by an absolute social hierarchy. Although tui defend exclusive feeding territories, breeding territories are not exclusive and access to nectar is determined by distance to nest site. Such variability in spatial organisation is related to a continuum concept of social organisation.  相似文献   

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Recent events related to police brutality and the evolution of #BlackLivesMatter provides an empirical case to explore the vitality of social media data for social movements and the evolution of collective identities. Social media data provide a portal into how organizing and communicating generate narratives that survive over time. We analyse 31.65 million tweets about Ferguson across four meaningful time periods: the death of Michael Brown, the non-indictment of police officer Darren Wilson, the Department of Justice report on Ferguson, and the one year aftermath of Brown’s death. Our analysis shows that #BlackLivesMatter evolved in concert with protests opposing police brutality occurring on the ground. We also show how #TCOT (Top Conservatives on Twitter) has operated as the primary counter narrative to #BlackLivesMatter. We conclude by discussing the implications our research has for the #BlackLivesMatter movement and increased political polarization following the election of Donald Trump.  相似文献   

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数字透出的信息——生命科学正在蓬勃发展   总被引:2,自引:0,他引:2  
生命科学和信息科学是近年来发展很快因而备受科学界关注的学科。我们以国际、国内的有关科学论坛、科学会议、科学评论及有关网站的统计数据为基础 ,对生命科学和信息科学进行了初步的比较研究 ,并对生命科学和信息科学的发展趋势进行了简略的探讨。  相似文献   

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This Special Issue of Evolutionary Anthropology grew out of a symposium at the 2012 Society for American Archaeology (SAA) meeting in Memphis, Tennessee (April 18–22). The goal of the symposium was to explore what we will argue is one of the most important and promising opportunities in the global archeological enterprise. In late prehistoric North America, the initial rise of cultures of strikingly enhanced complexity and the local introduction of a novel weapon technology, the bow, apparently correlate intimately in a diverse set of independent cases across the continent, as originally pointed out by Blitz. 1 If this empirical relationship ultimately proves robust, it gives us an unprecedented opportunity to evaluate hypotheses for the causal processes producing social complexity and, by extension, to assess the possibility of a universal theory of history. The rise of comparably complex cultures was much more recent in North America than it was elsewhere and the resulting fresher archeological record is relatively well explored. These and other features make prehistoric North America a unique empirical environment. Together, the symposium and this issue have brought together outstanding investigators with both empirical and theoretical expertise. The strong cross‐feeding and extended interactions between these investigators have given us all the opportunity to advance the promising exploration of what we call the North American Neolithic transitions. Our goal in this paper is to contextualize this issue.  相似文献   

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Based on concrete examples gathered from the Mediterranean region, this article shows why restoration ecology around the Mediterranean Basin must go beyond ecological science to embrace a contrasting local vision which integrates social and political realities. By taking into account the growing gap between the northern and southern/eastern shores of the Mediterranean, we propose the adoption of a double agenda for restoration around the Mediterranean to overcome the fact that restoration objectives are often jeopardized by political decisions initially aimed to promote conservation and lack of available technical means (even when appropriate scientific and political means are secured), and to enhance local actions with lasting impacts on the ecosystems. Our discussion illustrates how current ecological problems have become extremely complex and how the success of restoration projects depends on effective social interactions. Here, the simple juxtaposition of disciplines is no longer sufficient. We suggest going beyond existing ecological and socioeconomic frontiers to fill three main gaps. To fill the “design gap” it is important from the outset to promote a full debate for correct definition of the project's objectives and success indicators. Second, to fill the “implementation gap” ecological restoration science should be linked to information technology and cognition science to develop tools adapted for ecological debate. Third, to fill the “evaluation gap” aesthetic, social, cultural, and economic indicators should be defined during the debate process.  相似文献   

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