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1.
This paper defends a gestural origins hypothesis about the evolution of enhanced communication and language in the hominin lineage. The paper shows that we can develop an incremental model of language evolution on that hypothesis, but not if we suppose that language originated in an expansion of great ape vocalization. On the basis of the gestural origins hypothesis, the paper then advances solutions to four classic problems about the evolution of language: (i) why did language evolve only in the hominin lineage? (ii) why is language use an evolutionarily stable form of informational cooperation, despite the fact that hominins have diverging evolutionary interests? (iii) how did stimulus independent symbols emerge? (iv) what were the origins of complex, syntactically organized symbols? The paper concludes by confronting two challenges: those of testability and of explaining the gesture-to-speech transition; crucial issues for any gestural origins hypothesis.  相似文献   

2.
The study of mammals in Britain has progressed from studies of distribution and differentiation to the present time, when new challenges face mammal workers. We need to build upon past achievements and use both new technology and old-fashioned dedicated observation to learn why what mammal is whew.  相似文献   

3.
In the last two decades, predicting protein subcellular locations has become a hot topic in bioinformatics. A number of algorithms and online services have been developed to computationally assign a subcellular location to a given protein sequence. With the progress of many proteome projects, more and more proteins are annotated with more than one subcellular location. However, multisite prediction has only been considered in a handful of recent studies, in which there are several common challenges. In this special report, the authors discuss what these challenges are, why these challenges are important and how the existing studies gave their solutions. Finally, a vision of the future of predicting multisite protein subcellular locations is given.  相似文献   

4.
The reason for holding a meeting to discuss biological challenges to vaccines is simple: not all vaccines work equally well in all settings. This special issue reviews the performance of vaccines in challenging environments, summarizes current thinking on the reasons why vaccines underperform and considers what approaches are necessary to understand the heterogeneity in responses and to improve vaccine immunogenicity and efficacy.  相似文献   

5.
We address criticism that the Transport, Establishment, Abundance, Spread, Impact (TEASI) framework does not facilitate objective mapping of risk assessment methods nor defines best practice. We explain why TEASI is appropriate for mapping, despite inherent challenges, and how TEASI offers considerations for best practices, rather than suggesting one best practice.  相似文献   

6.
One of the major environmental challenges of the twenty-first century is the continued rapid deforestation of Amazonia. The 2005 dieback crisis emphasizes the unprecedented challenges facing Brazil. The examination of past and present institutions for ecosystem management, in Amazonia, shows structural barriers across public, private and community arrangements. The adaptive governance concept helps to understand why these institutions are failing to deliver sustainable futures. In looking forward, it is encouraging to see that important networks of knowledge and a number of novel initiatives are emerging in Brazil. These new arrangements are novel in the way that they seem to be adaptive and navigate structures in the hope of overcoming insurmountable drivers of deforestation.  相似文献   

7.
8.
The ease with which genotyping technologies generate tremendous amounts of data on research participants has been well chronicled, a feat that continues to become both faster and cheaper to perform. In parallel to these advances come additional ethical considerations and debates, one of which centers on providing individual research results and incidental findings back to research participants taking part in genetic research efforts. In 2006 the Industry Pharmacogenomics Working Group (I‐PWG) offered some ‘Points‐to‐Consider’ on this topic within the context of the drug development process from those who are affiliated to pharmaceutical companies. Today many of these points remain applicable to the discussion but will be expanded upon in this updated viewpoint from the I‐PWG. The exploratory nature of pharmacogenomic work in the pharmaceutical industry is discussed to provide context for why these results typically are not best suited for return. Operational challenges unique to this industry which cause barriers to returning this information are also explained.  相似文献   

9.
10.
Father studies, in general, are classified into two broad groups, depending on whether the focus is primarily on (1) becoming a father or (2) being a father. This article discusses the challenges researchers face when designing studies to examine the process of being a father and the approaches that are used to meet these challenges. Studies of men's involvement with their children must decide on which men to include and not to include as fathers, the steps that must be taken to identify fathers, how to obtain fathers' cooperation, and how to measure father involvement. This article discusses each of these and how decisions are influenced why whether or not fathers who do not live with their children are included in the study. The father component of the Early Childhood Longitudinal Study, Birth Cohort is used to illustrate how one being a father study approached these challenges.  相似文献   

11.
Today's research into mental conditions and disorders such as autism, ADHD and dyslexia appears to be focused on identifying dysfunctions. Given the slow speed at which neurons fire and connectivity challenges between different parts of the brain, there is another possibility: capacity bottlenecks.Capacity bottlenecks are a common phenomenon. For an architect, avoiding bottlenecks is a fundamental requirement for the whole to function flawlessly – whether one is designing a skyscraper, a new airport, a highway or a computer. Small disturbances can create bottlenecks in a system that works well otherwise. Next to this, it appears certain treatments for mental conditions use techniques that are the same as those used to remove capacity bottlenecks in large computers.Overall, it is hard to see why capacity bottlenecks would not play an important role in causing mental conditions and disorders. If confirmed, this possibility implies capacity management techniques should provide a strong basis for the development of new treatments.  相似文献   

12.
In this article, I argue that second-generation migrants can engage in cross-border ties as a result of first-generation migrants mediating relationships between their children and those abroad. This paper draws on interviews with second-generation Filipino-Americans to demonstrate how and why respondents engage in mediated social and economic cross-border ties collectively with first-generation migrant parents. Second-generation Filipino-Americans feel an obligation, not necessarily to those in the Philippines, but to parents who request that their children engage in transnational social and economic ties. Just as parents serve as the means and reasoning for why these transnational connections persist among their children, parents play a role in why ties fail to manifest. By looking into why some engage in social and economic cross-border ties while others do not, I provide insight into how the children of migrants participate in the transnational social field.  相似文献   

13.
Storz JF  Opazo JC  Hoffmann FG 《IUBMB life》2011,63(5):313-322
Phylogenetic reconstructions provide a means of inferring the branching relationships among members of multigene families that have diversified via successive rounds of gene duplication and divergence. Such reconstructions can illuminate the pathways by which particular expression patterns and protein functions evolved. For example, phylogenetic analyses can reveal cases in which similar expression patterns or functional properties evolved independently in different lineages, either through convergence, parallelism, or evolutionary reversals. The purpose of this article is to provide a robust phylogenetic framework for interpreting experimental data and for generating hypotheses about the functional evolution of globin proteins in chordate animals. To do this, we present a consensus phylogeny of the chordate globin gene superfamily. We document the relative roles of gene duplication and whole-genome duplication in fueling the functional diversification of vertebrate globins, and we unravel patterns of shared ancestry among globin genes from representatives of the three chordate subphyla (Craniata, Urochordata, and Cephalochordata). Our results demonstrate the value of integrating phylogenetic analyses with genomic analyses of conserved synteny to infer the duplicative origins and evolutionary histories of globin genes. We also discuss a number of case studies that illustrate the importance of phylogenetic information when making inferences about the evolution of globin gene expression and protein function. Finally, we discuss why the globin gene superfamily presents special challenges for phylogenetic analysis, and we describe methodological approaches that can be used to meet those challenges.  相似文献   

14.
This article analyses revolutionary social change by exploring how people attempt to create a radically different future by taking action in the present, and the challenges that beset this transformation. Examining the relationship between the future, the present, and the past, the article takes the case of the spread of armed underground Maoist guerrillas in India to ask two questions: First, why does India hang on to this form of utopianism when the rest of the world appears to have abandoned it? Second, how and why does the ‘muck of the past’ influence the production of a radically different future? In answering these questions, this article suggests that for both processes of radical social change and our theories of them, we need to reinsert our analyses of politico‐economic conditions into our ideologies of social change.  相似文献   

15.
占全球陆地面积约15%的喀斯特地区,有着不同于绝大多数非喀斯特地区的水文地质结构,使得许多在非喀斯特地区行之有效的研究方法难以直接用于喀斯特地区,而且这种限制在植物水分来源的研究上体现得尤为明显.本文从为什么要在喀斯特地区开展植物水分来源的研究、为什么一定要用稳定同位素的方法、使用该方法在喀斯特地区有何挑战,以及应对这些挑战的可能解决方案是什么等4个方面,综述了喀斯特地区植物水分来源研究普遍关注问题的由来和可能应对方案.文中重点阐述了与其他方法相比,稳定同位素技术在喀斯特地区植物水分来源研究中的优势以及难以完全满足其前提条件的挑战,结合现有相关研究的有益探索,提出在喀斯特地区的研究不必过分追求对各水源在具体深度上的细致划分,从水源特性的角度进行区分是更为适宜的途径.  相似文献   

16.
Our ability to harness the advances in microelectronics over the past decade(s) for X-ray detection has resulted in significant improvements in the state of the art. Biology with X-ray free-electron lasers present daunting detector challenges: all of the photons arrive at the same time, and individual high peak power pulses must be read out shot-by-shot. Direct X-ray detection in silicon pixel detectors—monolithic or hybrid—are the standard for XFELs today. For structural biology, improvements are needed for today''s 10–100 Hz XFELs, and further improvements are required for tomorrow''s 10+ kHz XFELs. This article will discuss detector challenges, why they arise and ways to overcome them, along with the current state of the art.  相似文献   

17.
Although most wildlife professionals agree that science should inform wildlife management decisions, disconnect still exists between researchers and managers. If researchers are not striving to incorporate their findings into management decisions, support for research programs by managers can wane. If managers are not using research findings to inform management decisions, those decisions may be less effective or more vulnerable to legal challenges. Both of these situations can have negative consequences for wildlife conservation. We outline a collaborative research-management approach to bridging the gap between wildlife managers and researchers. We describe differences in perspectives, perceptions, and priorities between managers and researchers; outline how and why the divide between researchers and managers has likely occurred and continues to grow; and present specific strategies and recommendations to foster stronger collaborations between managers and researchers. We advocate increased synergy between managers and researchers based on a shared vision of conservation and a collaborative structure that rewards researchers and managers. Most importantly, we suggest that relationships and communication between managers and researchers must be established early in research development and decision-making processes, fostering the trust needed for collaboration. Institutions and agencies can facilitate these relationships by creating opportunities and incentives for integrating collaborative research into management decisions. We suggest this approach will strengthen ties between researchers and managers, increase relevance of research to management decisions, promote effectiveness of management decisions, reduce legal challenges, and ultimately produce positive, tangible, and lasting effects on wildlife conservation. © 2019 The Wildlife Society.  相似文献   

18.
The Physiological Mechanisms of Acclimatization in Tropical Reef Corals   总被引:12,自引:1,他引:11  
SYNOPSIS. The ability of scleractinian corals to survive changesthat are predicted in the global environment over the next centurywill lie in their physiological mechanisms of acclimatization.Corals display rapid modifications in behavior, morphology andphysiology enabling them to photoacclimate to changing lightconditions, a scenario that demonstrates considerable biologicalflexibility. Here we argue that the acclimatization mechanismsin corals are fundamentally similar to those exhibited by otherinvertebrate taxa. We discuss protein metabolism as a mechanismunderlying acclimatization responses in reef corals, and explorethe relationship between protein turnover, metabolic rate, growthrate, and acclimatization capacity. Our preliminary analysessuggest that corals with low growth rates (µCa/mgN/h)and high metabolic rates (µO2/cm2/hr), such as the massivespecies, acclimatize more effectively than those with high growthrates and low metabolic rates, a feature that is characteristicof branching species. We conclude that studies of protein turnover,combined with temporally relevant investigations into the dynamicaspects of coral dinoflagellate symbioses will provide considerableinsight into why corals exhibit such a high level of variationin response to the same environmental challenge. Furthermore,a more detailed understanding of acclimatization mechanismsis essential if we are to predict how a coral assemblage willrespond to present and future environmental challenges.  相似文献   

19.
The scientific challenges and ethical controversies facing human embryonic stem cell (hESC) research continue to command attention. The issues posed by patenting hESC technologies have, however, largely failed to penetrate the discourse, much less result in political action. This paper examines U.S. and European patent systems, illustrating discrepancies in the patentability of hESC technologies and identifying potential negative consequences associated with efforts to make available hESC research tools for basic research purposes while at same time strengthening the position of certain patent-holders' rights. Differences between the U.S. and the European contexts may in part explain why the course of hESC research in those jurisdictions ultimately diverges. Nevertheless, questions about whether and how patenting, related agreements, and licensing practices progress and shape the field of hESC research in both the U.S., Europe, and elsewhere must no longer be marginalised. These questions are fundamentally important in determining what benefits are likely to result from hESC research. Assuring these benefits is the moral issue with which patent systems are most intrinsically concerned, and that governments must begin to directly address rather than assume or ignore.  相似文献   

20.
To exploit ecological niches where constraints have favoured selection for group living and cooperation, both vertebrates and invertebrates have evolved elaborate social systems. In mammals, numerous divergent taxa have converged at similar solutions to these ecological challenges (such as food distribution and predator avoidance), culminating in the social insect-like behaviour of the naked mole-rat. Characteristically, breeding is partitioned unequally in such groups, resulting in a 'reproductive skew'. New research linking studies of physiology, behaviour and molecular ecology in African mole-rats is helping us to elucidate why different proximate mechanisms that control groups of cooperative breeders might have evolved.  相似文献   

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