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1.
A. Bottéro 《PSN》2010,8(3):138-151
What are the implications of an approach to schizophrenia using a cognitive remediation and what is the case for such an approach? What are its strengths and its weaknesses? More critically, can we find supporting evidence of its efficacy? Overall, what do we really know of the cognitive disorders associated with the schizophrenias? Opening on a review of the existing literature in order to investigate such questions, the paper develops a critical assessment of the issue.  相似文献   

2.
As scientists, we are at least as excited about the open questions—the things we do not know—as the discoveries. Here, we asked 15 experts to describe the most compelling open questions in plant cell biology. These are their questions: How are organelle identity, domains, and boundaries maintained under the continuous flux of vesicle trafficking and membrane remodeling? Is the plant cortical microtubule cytoskeleton a mechanosensory apparatus? How are the cellular pathways of cell wall synthesis, assembly, modification, and integrity sensing linked in plants? Why do plasmodesmata open and close? Is there retrograde signaling from vacuoles to the nucleus? How do root cells accommodate fungal endosymbionts? What is the role of cell edges in plant morphogenesis? How is the cell division site determined? What are the emergent effects of polyploidy on the biology of the cell, and how are any such “rules” conditioned by cell type? Can mechanical forces trigger new cell fates in plants? How does a single differentiated somatic cell reprogram and gain pluripotency? How does polarity develop de-novo in isolated plant cells? What is the spectrum of cellular functions for membraneless organelles and intrinsically disordered proteins? How do plants deal with internal noise? How does order emerge in cells and propagate to organs and organisms from complex dynamical processes? We hope you find the discussions of these questions thought provoking and inspiring.

We asked 15 experts to address what they consider to be the most compelling open questions in plant cell biology and these are their questions.  相似文献   

3.
We review published records of laboratory experiments on peripatric and vicariance allopatric speciation to address the following three questions: (1) What was the true effect size of reproductive isolation? (2) Was the reproductive isolation persistent? (3) What influenced the development of isolation? Contrary to popular belief, laboratory evidence for allopatric speciation is quite weak. Assortative mating was only found among derived populations in vicariance experiments. Reproductive isolation against control populations was only intermittent, so there is reason to doubt if some cases showing significant reproductive isolation really should be attributed to speciation. The method of testing was at least as important as the speciation model. Experimental populations tested against each other were the most likely to demonstrate reproductive isolation. This study suggests that allopatric speciation experiments are more likely to yield conclusive results under divergent selection than under drift, and points to the benefits of large populations and many generations.  相似文献   

4.
The formation of specific protein interactions plays a crucial role in most, if not all, biological processes, including signal transduction, cell regulation, the immune response and others. Recent advances in our understanding of the molecular architecture of protein-protein binding sites, which facilitates such diversity in binding affinity and specificity, are enabling us to address key questions. What is the amino acid composition of binding sites? What are interface hotspots? How are binding sites organized? What are the differences between tight and weak interacting complexes? How does water contribute to binding? Can the knowledge gained be translated into protein design? And does a universal code for binding exist, or is it the architecture and chemistry of the interface that enable diverse but specific binding solutions?  相似文献   

5.
In this paper I discuss two questions. What does Kant understand by mechanical explanation in the Critique of judgment? And why does he think that mechanical explanation is the only type of the explanation of nature available to us? According to the interpretation proposed, mechanical explanations in the Critique of judgment refer to a particular species of empirical causal laws. Mechanical laws aim to explain nature by reference to the causal interaction between the forces of the parts of matter and the way in which they form into complex material wholes. Just like any other empirical causal law, however, mechanical laws can never be known with full certainty. The conception according to which we can explain all of nature by means of mechanical laws, it turns out, is based on what Kant calls 'regulative' or 'reflective' considerations about nature. Nothing in Kant's Critique of judgment suggests that these considerations can ever be justified by reference to how the natural world really is. I suggest that what, upon first consideration, appears to be a thoroughly mechanistic conception of nature in Kant is much more limited than one might have expected.  相似文献   

6.
Subcellular Size     
All of the same conceptual questions about size in organisms apply equally at the level of single cells. What determines the size, not only of the whole cell, but of all of its parts? What ensures that subcellular components are properly proportioned relative to the whole cell? How does alteration in organelle size affect biochemical function? Answering such fundamental questions requires us to understand how the size of individual organelles and other cellular structures is determined. Knowledge of organelle biogenesis and dynamics has advanced rapidly in recent years. Does this knowledge give us enough information to formulate reasonable models for organelle size control, or are we still missing something?  相似文献   

7.
In ethics, the use of empirical data has become more and more popular, leading to a distinct form of applied ethics, namely empirical ethics. This ‘empirical turn’ is especially visible in bioethics. There are various ways of combining empirical research and ethical reflection. In this paper we discuss the use of empirical data in a special form of Reflective Equilibrium (RE), namely the Network Model with Third Person Moral Experiences. In this model, the empirical data consist of the moral experiences of people in a practice. Although inclusion of these moral experiences in this specific model of RE can be well defended, their use in the application of the model still raises important questions. What precisely are moral experiences? How to determine relevance of experiences, in other words: should there be a selection of the moral experiences that are eventually used in the RE? How much weight should the empirical data have in the RE? And the key question: can the use of RE by empirical ethicists really produce answers to practical moral questions? In this paper we start to answer the above questions by giving examples taken from our research project on understanding the norm of informed consent in the field of pediatric oncology. We especially emphasize that incorporation of empirical data in a network model can reduce the risk of self‐justification and bias and can increase the credibility of the RE reached.  相似文献   

8.
In the Greek village of Mavrolefki in Thrace, a small number of women and men. about ten in number, once a year, on the feast day of St. Constantine, undertake a series of rites, ranging from dancing to the icons, blood sacrifice, to the most spectacular fire‐walking (pyrovasia). It is the last which brings spectators from all over Greece and further afield. The principal participants, however, are known as the anastenarides (shakers, tremblers). Several concerns are addressed in the paper. Given the peculiar mix of proceedings, the first is to lay out the components of the affair, asking what's going on? Furthermore, there are the conceptual issues. What aesthetic is being implicated? What emotions are being brought into play? What does the event amount to? In addressing such questions the paper draws on certain aesthetic formulations of the Hindu rasa theory.  相似文献   

9.
赵士洞  任毅 《生物多样性》2001,9(2):196-200
生物多样性观察年(IBOY)的核心项目包括4个大的主题:1)全球生物多样性现状;2)生物多样性的变化方式;3)生物多样性对人类生活的价值;4)人类如何保护生物多样性。本文对这些主题内的不同课题进行了介绍,同时对我国生物多样性科学的发展提出了相应的建议。  相似文献   

10.
Many types of data are best analyzed by fitting a curve using nonlinear regression, and computer programs that perform these calculations are readily available. Like every scientific technique, however, a nonlinear regression program can produce misleading results when used inappropriately. This article reviews the use of nonlinear regression in a practical and nonmathematical manner to answer the following questions: Why is nonlinear regression superior to linear regression of transformed data? How does nonlinear regression differ from polynomial regression and cubic spline? How do nonlinear regression programs work? What choices must an investigator make before performing nonlinear regression? What do the final results mean? How can two sets of data or two fits to one set of data be compared? What problems can cause the results to be wrong? This review is designed to demystify nonlinear regression so that both its power and its limitations will be appreciated.  相似文献   

11.
D. Tammam  P. Bensa  J. Vion Dury 《PSN》2011,9(4):208-220
In this article, we address the issue of nothingness on the basis of perceptive experience in its phenomenological dimension. Through an analysis of the visual perception and various types of memories related to it, we will try to answer three questions: what is phenomenological nothingness? What role does it play in the emergence of determinations within the consciousness? What are its relationships with disappearance and forgetting involved in all the stages of object donation in consciousness?  相似文献   

12.
13.
Reiczigel J 《Biometrics》1999,55(4):1059-1063
Summary. Experimental data often consist of serial measurements on subjects after a treatment. Typical questions concerning such data are: (A) Do subjects really react to treatment or are the fluctuations just random? (B) What are the numerical characteristics of the response? (C) Is the response identical in all groups? Differences between the individuals in the dynamics of the reaction make it difficult to apply standard statistical procedures. This paper proposes to answer questions (A) and (B) at the individual level, then to give an answer to (C) on the basis of this information. This kind of analysis may be useful since it can separate subjects giving response from those that do not and can identify individual response patterns and compare treatments with respect to each numerical characteristic separately. To answer question (A), a permutation test is proposed and its power is evaluated by simulation.  相似文献   

14.
González-Gaitán M  Stenmark H 《Cell》2003,115(5):513-521
The ability to internalize macromolecules by endocytosis is a property of all eukaryotic cells. Frontline research on endocytosis has been presented in a successful series of biannual meetings in Europe. This year's meeting on "Membrane Dynamics in Endocytosis" was held September 13-18 in Acquafredda di Maratea, on the coast of southern Italy. Four key questions were addressed: What are the molecular mechanisms of endocytic membrane trafficking? How does endocytosis modulate receptor signaling and vice versa? What is the importance of endocytosis during development? How do endocytic organelles contribute to immunity or susceptibility to pathogens?  相似文献   

15.
Summary The question of cell death is accessible to study by histochemists and many questions remain to be resolved. From a physiological point of view, the most important are the causal relationships. (1) At what phase in cell death is the synthesis of RNA disrupted and at what phase is the rate of degradation of RNA increased? (2) Does the disruption of synthesis result from a direct genetic command, or does it result indirectly from gradual deterioration of energy resources or optimal ionic conditions? (3) What properties, presumably of the substrate organelles, marks them for specific absorption into autophagic vacuoles? (4) What proteases and other hydrolases operate currently undetected in the cytoplasm? How are they controlled and regulated? (5) Why does the physiologically dying cell shrink and appear more dense? To what extent is a cell in this state able to regulate any metabolic parameter? The advent of newer, more sensitive and quantitative techniques, and greater attention to the controls and causes as opposed to the phenomena, should help to resolve these questions.  相似文献   

16.
Microbiome predators shape the soil microbiome and thereby soil functions. However, this knowledge has been obtained from small-scale observations in fundamental rather than applied settings and has focused on a few species under ambient conditions. Therefore, there are several unaddressed questions on soil microbiome predators: (1) What is the role of microbiome predators in soil functioning? (2) How does global change affect microbiome predators and their functions? (3) How can microbiome predators be applied in agriculture? We show that there is sufficient evidence for the vital role of microbiome predators in soils and stress that global changes impact their functions, something that urgently needs to be addressed to better understand soil functioning as a whole. We are convinced that there is a potential for the application of microbiome predators in agricultural settings, as they may help to sustainably increase plant growth. Therefore, we plea for more applied research on microbiome predators.  相似文献   

17.
In the last few decades, assisted reproduction has introduced new challenges to the way people conceive and build their families. While the numbers of donor-conceived (DC) individuals have increased worldwide, there are still many controversies concerning access to donor information. Is there a fundamental moral right to know one’s genetic background? What does identity in DC families mean? Is there any relationship between identity formation and disclosure of genetic origins? These questions are addressed by analysing core regulatory discourse (ethical recommendations and codes of practice). This analysis shows that the notion of narrative identity is suitable for defining and answering these questions. This review analyses the meaning of resemblance in DC families and the way donors are selected following affinity-ties and discusses disclosure strategies and agreements. As a preliminary conclusion, it could be said that, in the field of third-party reproduction, knowing about the donor conception significantly contributes towards the development of a narrative identity and also serves as a moral basis for the child’s right to know.  相似文献   

18.
Significant progress in understanding and treating acquired immunodeficiency syndrome (AIDS) has been made over the last 5 years. Current multi drug therapies prolong patients' lives and reduce the incidence of neurobehavioural symptoms. However, the impact of therapy on human immunodeficiency virus type one (HIV-1), the causative agent of AIDS, in the brain, is unknown. Some patients develop dementia in spite of the multi drug therapies and others develop subtle neurobehavioural changes that diminish the quality of their prolonged lives. Thus, HIV-1 infection of the central nervous system remains an important clinical concern. Although much is known about neuropathology of HIV-1 infection, major questions about neuropathogenesis remain. How does HIV-1 reach the brain? Is it present in neurons and glial cells? What is the biological and therapeutic significance of neurotropism of HIV-1? What causes neuronal damage and loss? And, is CNS a resevoir of HIV-1? More research in vivo and in situ in humans and in animals, is needed to answer these outstanding questions. Specific experiments addressing these questions are proposed.  相似文献   

19.
Previous empirical work suggests that firms with high environmental performance tend to be profitable, but questions persist about the nature of the relationship. Does stronger environmental performance really lead to better financial performance, or is the observed relationship the outcome of some other underlying firm attribute? Does it pay to have cleanrunning facilities or to have facilities in relatively clean industries? To explore these questions, we analyze 652 U.S. manufacturing firms over the time period 1987–1996. Although we find evidence of an association between lower pollution and higher financial valuation, we find that a firm's fixed characteristics and strategic position might cause this association. Our findings suggest that “When does it pay to be green?” may be a more important question than “Does it pay to be green?”  相似文献   

20.
中国是典型缺硒大国,一条马鞍形土壤缺硒带呈东北-西南走向分布,占主要农耕区土壤面积的33.34%,但同时也存在点状分布的富硒-高硒地区,占主要农耕区土壤面积的8.69%,成为湖北恩施、陕西安康、安徽石台、广西巴马、江西宜春等地方农业转型升级的新抓手,得到大力开发利用。伴随着硒资源的开发利用,一些科学问题被广泛提出,如:硒摄入有何健康效果?天然富硒区人群是否有实证研究数据?硒-镉共生导致天然富硒农产品富硒的同时是否存在镉含量超标问题?硒资源中的硒形态组成有何重要意义?硒超积累植物-壶瓶碎米荠的超积累硒的机制是什么?这些关键科学问题亟待解答。基于对天然硒资源近10年的研究成果,对以上科学问题进行了一些有益探讨,以期为未来高效安全科学地利用硒资源提供一些研究思路。  相似文献   

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