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Selected AbstractsA Detailed Account of a Convenient Lab-Scale Preparation of AsF5 via Direct Fluorination as AsF3.CHEMINFORM, Issue 1 2006Damian R. Aris Abstract For Abstract see ChemInform Abstract in Full Text. [source] The birth and postnatal development of purinergic signallingACTA PHYSIOLOGICA, Issue 2 2010G. Burnstock Abstract The purinergic signalling system is one of the most ancient and arguably the most widespread intercellular signalling system in living tissues. In this review we present a detailed account of the early developments and current status of purinergic signalling. We summarize the current knowledge on purinoceptors, their distribution and role in signal transduction in various tissues in physiological and pathophysiological conditions. [source] From phagocyte diversity and activation to probiotics: Back to MetchnikoffEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2008Alberto Mantovani Abstract In this issue of the European Journal of Immunology, Siamon Gordon gives a detailed account of Metchnikoff's life and his achievements (Eur. J. Immunol. 2008. 38: 3257,3264). Looking back at the roots of innate immunity stimulates reflections on open issues in the field. Here, I give a personal view of some of these issues, including myeloid-derived suppressor cells, macrophage polarization and adaptive responses of mononuclear phagocytes. [source] Moduli stabilisation and applications in IIB string theoryFORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 3 2007J.P. Conlon String compactifications represent the most promising approach towards unifying general relativity with particle physics. However, naive compactifications give rise to massless particles (moduli) which would mediate unobserved long-range forces, and it is therefore necessary to generate a potential for the moduli. In the introductory chapters I review this problem and recall how in IIB compactifications the dilaton and complex structure moduli can be stabilised by 3-form fluxes. There exist very many possible discrete flux choices which motivates the use of statistical techniques to analyse this discretuum of choices. Such approaches generate formulae predicting the distribution of vacua and I describe numerical tests of these formulae on the Calabi-Yau ,4[1,1,2,2,6]. Stabilising the Kähler moduli requires nonperturbative superpotential effects. I review the KKLT construction and explain why this must in general be supplemented with perturbative Kähler corrections. I show how the incorporation of such corrections generically leads to non-supersymmetric minima at exponentially large volumes, giving a detailed account of the,, expansion and its relation to Kähler corrections. I illustrate this with explicit computations for the Calabi-Yau ,4[1,1,1,6,9]. The next part of the article examines phenomenological applications of this construction. I first describe how the magnitude of the soft supersymmetry parameters may be computed. In the large-volume models the gravitino mass and soft terms are volume-suppressed. As we naturally have ,, ,1, this gives a dynamical solution of the hierarchy problem. I also demonstrate the existence of a fine structure in the soft terms, with gaugino masses naturally lighter than the gravitino mass by a factor ln (MP/m3/2). A second section gives a detailed analysis of the relationship of moduli stabilisation to the QCD axions relevant to the strong CP problem, proving a no-go theorem on the compatibility of a QCD axion with supersymmetric moduli stabilisation. I describe how QCD axions can coexist with nonsupersymmetric perturbative stabilisation and how the large-volume models naturally contain axions with decay constants that are phenomenologically allowed and satisfy the appealing relationship fa2 ,MPMsusy. A further section describe how a simple and predictive inflationary model can be built in the context of the above large-volume construction, using the no-scale Kähler potential to avoid the , problem. I finally conclude, summarising the phenomenological scenario and outlining the prospects for future work. [source] Nanomaterials for Neural InterfacesADVANCED MATERIALS, Issue 40 2009Nicholas A. Kotov Abstract This review focuses on the application of nanomaterials for neural interfacing. The junction between nanotechnology and neural tissues can be particularly worthy of scientific attention for several reasons: (i) Neural cells are electroactive, and the electronic properties of nanostructures can be tailored to match the charge transport requirements of electrical cellular interfacing. (ii) The unique mechanical and chemical properties of nanomaterials are critical for integration with neural tissue as long-term implants. (iii) Solutions to many critical problems in neural biology/medicine are limited by the availability of specialized materials. (iv) Neuronal stimulation is needed for a variety of common and severe health problems. This confluence of need, accumulated expertise, and potential impact on the well-being of people suggests the potential of nanomaterials to revolutionize the field of neural interfacing. In this review, we begin with foundational topics, such as the current status of neural electrode (NE) technology, the key challenges facing the practical utilization of NEs, and the potential advantages of nanostructures as components of chronic implants. After that the detailed account of toxicology and biocompatibility of nanomaterials in respect to neural tissues is given. Next, we cover a variety of specific applications of nanoengineered devices, including drug delivery, imaging, topographic patterning, electrode design, nanoscale transistors for high-resolution neural interfacing, and photoactivated interfaces. We also critically evaluate the specific properties of particular nanomaterials,including nanoparticles, nanowires, and carbon nanotubes,that can be taken advantage of in neuroprosthetic devices. The most promising future areas of research and practical device engineering are discussed as a conclusion to the review. [source] Globalized Horticulture: The Formation and Global Integration of Export Grape Production in North East BrazilJOURNAL OF AGRARIAN CHANGE, Issue 4 2010BEN SELWYN In horticulture contemporary globalization is associated with (at least) two connected processes , the concentration, centralization and expanding reach of global retailers and the emergence of numerous new sites of export horticulture specializing in fresh fruit and vegetable production aimed at metropolitan markets. Whilst there have been numerous studies about developmental impacts, conditions of labour, and producers' upgrading strategies within this new context, few studies give much, if any, space to explaining and analyzing the processes through which these new regions have come into being. This article provides a detailed account of the emergence and global integration of one of these new sites , the São Francisco valley grape branch in North East Brazil, within the context of the wider regional fruiticulture sector. It focuses on state activities and incentives, the provenance of grape producers and their organizations, and grape branch composition. [source] What is Genetic Information, and why is it Significant?JOURNAL OF APPLIED PHILOSOPHY, Issue 1 2006A Contextual, Approach, Contrastive abstract Is genetic information of special ethical significance? Does it require special regulation? There is considerable contemporary debate about this question (the ,genetic exceptionalism' debate). ,Genetic information' is an ambiguous term and, as an aid to avoiding conflation in the genetic exceptionalism debate, a detailed account is given of just how and why ,genetic information' is ambiguous. Whilst ambiguity is a ubiquitous problem of communication, it is suggested that ,genetic information' is ambiguous in a particular way, one that gives rise to the problem of ,significance creep' (i.e., where claims about the significance of certain kinds of genetic information in one context influence our thinking about the significance of other kinds of genetic information in other contexts). A contextual and contrastive methodology is proposed: evaluating the significance of genetic information requires us to be sensitive to the polysemy of ,genetic information' across contexts and then examine the contrast in significance (if any) of genetic, as opposed to nongenetic, information within contexts. This, in turn, suggests that a proper solution to the regulatory question requires us to pay more attention to how and why information, and its acquisition, possession and use, come to be of ethical significance. [source] Spatial patterns in species,area relationships and species distribution in a West African forest,savanna mosaicJOURNAL OF BIOGEOGRAPHY, Issue 4 2005Thomas Hovestadt Abstract Aim, To investigate the relationship between the slope z of the species,area relationship (SAR) and the intensity of spatial patterns in species number and dissimilarity for woody plants with different modes of seed dispersal. According to island theory we expect, for any given archipelago, steeper slopes and more pronounced spatial patterns for groups of less dispersive species. Location, Ivory Coast, West Africa. Methods, In a West African forest,savanna mosaic we collected presence,absence data for woody plant species in 49 forest islands. The parameters of the SARs were fitted by nonlinear regressions and then compared for plant species aggregated according to their mode of seed dispersal. We used the Mantel test to calculate the intensity of spatial patterns in species number, i.e. residual deviation from SAR, and species dissimilarity. Results, The z -value for bird-dispersed species was lower (0.11) than that for wind-dispersed species (0.27), with mammal-dispersed species taking an intermediate value (0.16). This result suggests that, as a group, bird-dispersed species are better colonizers. The spatial pattern in species number as well as species similarity was more pronounced for bird- compared with wind-dispersed species. Main conclusions, The standard interpretation of the theory of island biogeography claims that shallow slopes in the SAR imply low isolation of islands, i.e. good dispersal abilities of species. The results of our study appear to contradict this statement. The contradiction can eventually be resolved by a more detailed account of the colonization process, i.e. by distinguishing between dispersal and consecutive establishment of populations. [source] Exploring the mathematics of motion through construction and collaborationJOURNAL OF COMPUTER ASSISTED LEARNING, Issue 2 2006G. Simpson Abstract In this paper, we give a detailed account of the design principles and construction of activities designed for learning about the relationships between position, velocity and acceleration, and corresponding kinematics graphs. Our approach is model-based, that is, it focuses attention on the idea that students constructed their own models , in the form of programs , to formalise and thus extend their existing knowledge. In these activities, students controlled the movement of objects in a programming environment, recording the motion data and plotting corresponding position,time and velocity,time graphs. They shared their findings on a specially designed Web-based collaboration system, and posted cross-site challenges to which others could react. We present learning episodes that provide evidence of students making discoveries about the relationships between different representations of motion. We conjecture that these discoveries arose from their activity in building models of motion and their participation in classroom and online communities. [source] Ontogeny of the complex sperm in the macrostomid flatworm Macrostomum lignano (Macrostomorpha, Rhabditophora)JOURNAL OF MORPHOLOGY, Issue 2 2009Maxime Willems Abstract Spermiogenesis in Macrostomum lignano (Macrostomorpha, Rhabditophora) is described using light- and electron microscopy of the successive stages in sperm development. Ovoid spermatids develop to highly complex, elongated sperm possessing an undulating distal (anterior) process (or "feeler"), bristles, and a proximal (posterior) brush. In particular, we present a detailed account of the morphology and ontogeny of the bristles, describing for the first time the formation of a highly specialized bristle complex consisting of several parts. This complex is ultimately reduced when sperm are mature. The implications of the development of this bristle complex on both sperm maturation and the evolution and function of the bristles are discussed. The assumed homology between bristles and flagellae questioned. J. Morphol., 2009. © 2008 Wiley-Liss, Inc. [source] Patterns of spatial and temporal cranial muscle development in the African clawed frog, Xenopus laevis (Anura: Pipidae)JOURNAL OF MORPHOLOGY, Issue 9 2007Janine M. Ziermann Abstract The African Clawed Toad, Xenopus laevis, has been a major vertebrate model organism for developmental studies for half a century. Because most studies have focused on the early stages of development, this has had the effect that many aspects of organogenesis and later development remain relatively poorly known in this species. In particular, little is known about cranial muscle development even at the level of morphology and histological differentiation of muscle anlagen and muscle fibers. In this study, we document the morphogenesis and histological differentiation of cranial muscles in X. laevis. We provide a detailed account of the timing of development for each of the cranial muscles, and also describe a new muscle, the m. transversus anterior. The cranial musculature of X. laevis larvae generally develops in a rostrocaudal sequence. The first muscles to differentiate are the extrinsic eye muscles. Muscles of the mandibular and hyoid arches develop almost simultaneously, and are followed by the muscles of the branchial arches and the larynx, and by the mm. geniohyoideus and rectus cervicis. Despite the fact that differentiation starts at different stages in the different muscles, most are fully developed at Stage 14. These baseline data on the timing of muscle differentiation in the X. laevis can serve as a foundation for comparative studies of heterochronic changes in cranial muscle development in frogs and other lissamphibians. J. Morphol., 2007. © 2007 Wiley-Liss, Inc. [source] Locally targeted initiatives to recruit and retain nurses in EnglandJOURNAL OF NURSING MANAGEMENT, Issue 4 2006DINAH GOULD BSc MPhil PhD RGN RNT Aim, The aim of this study is to provide a detailed account of the locally targeted strategies to improve staffing levels by senior nurses responsible for recruitment and retention in acute trusts in the National Health Service in England. Background, There is a shortfall in nursing numbers throughout England. Some trusts have employed senior nurses with a specific remit to improve recruitment and retention, but little has been published about their work or its success. Methods, Data were collected by telephone using semi-structured interviews with standard probes. The tape-recorded interview data were transcribed verbatim and analysed by content. Results, Of the 156 acute trusts in England, 36 employed a senior nurse to deal with recruitment and retention. Twenty-nine were interviewed. All were using a range of locally targeted initiatives to attract and retain health-care assistants, newly qualified and more experienced practitioners. They also worked closely with university staff to attract and retain student nurses who would later seek employment locally. Different approaches were used to secure the services of different types of staff. Conclusion, This exploratory study has revealed a wealth of valuable data concerning locally targeted recruitment and retention strategies. Further research is needed to examine the effectiveness and cost-effectiveness of the initiatives described. [source] Users want more sophisticated search assistants: Results of a task-based evaluationJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 13 2005Udo Kruschwitz The Web provides a massive knowledge source, as do intranets and other electronic document collections. However, much of that knowledge is encoded implicitly and cannot be applied directly without processing into some more appropriate structures. Searching, browsing, question answering, for example, could all benefit from domain-specific knowledge contained in the documents, and in applications such as simple search we do not actually need very "deep" knowledge structures such as ontologies, but we can get a long way with a model of the domain that consists of term hierarchies. We combine domain knowledge automatically acquired by exploiting the documents' markup structure with knowledge extracted on the fly to assist a user with ad hoc search requests. Such a search system can suggest query modification options derived from the actual data and thus guide a user through the space of documents. This article gives a detailed account of a task-based evaluation that compares a search system that uses the outlined domain knowledge with a standard search system. We found that users do use the query modification suggestions proposed by the system. The main conclusion we can draw from this evaluation, however, is that users prefer a system that can suggest query modifications over a standard search engine, which simply presents a ranked list of documents. Most interestingly, we observe this user preference despite the fact that the baseline system even performs slightly better under certain criteria. [source] Schema Theory and Knowledge-Based Processes in Second Language Reading Comprehension: A Need for Alternative PerspectivesLANGUAGE LEARNING, Issue 2007Hossein Nassaji How is knowledge represented and organized in the mind? What role does it play in discourse comprehension and interpretation? What are the exact mechanisms whereby knowledge-based processes are utilised in comprehension? These are questions that have puzzled psycholinguists and cognitive psychologists for years. Despite major developments in the field of second language (L2) reading over the last two decades, many attempts at explaining the role of knowledge in L2 comprehension have been made almost exclusively in the context of schema theory, a perspective that provides an expectation-driven conception of the role of knowledge and considers that preexisting knowledge provides the main guiding context through which information is processed and interpreted. In this article, I first review and critically analyze the major assumptions underlying schema theory and the processes that it postulates underlie knowledge representation and comprehension. Then I consider an alternative perspective, a construction-integration model of discourse comprehension, and discuss how this perspective, when applied to L2 reading comprehension, offers a fundamentally different and more detailed account of the role of knowledge and knowledge-based processes that L2 researchers had previously tried to explain within schema-theoretic principles. [source] CLARIFYING THE CONCEPT OF GENOCIDEMETAPHILOSOPHY, Issue 3-4 2006MOHAMMED ABED Abstract: This essay develops a detailed account of the features that make a group susceptible to the harm of genocide. If the members of a group consent to a life in common, if the culture of the group is comprehensive, and if the social structure of the group is such that membership cannot easily be renounced, then the flourishing of the group's culture and social ethos will have profound and far-reaching effects on the well-being of its individual members. Systematic destruction of cultural and social institutions under these conditions will eventuate in individuals suffering the harms and deprivations peculiar to the crime of genocide. The later sections of the essay illustrate and further defend the thesis that "social death" is the harm that distinguishes genocide from other forms of political violence. [source] The Debate in the House of Lords on ,No Peace without Spain', 7 December 1711: A New SourcePARLIAMENTARY HISTORY, Issue 1 2009CLYVE JONES The debate in the house of lords on ,No Peace without Spain' in December 1711 was the first test of the strength of the administration of Robert Harley, earl of Oxford, in the upper House. Though there are more sources for this debate than is normal for proceedings in the Lords, few can claim to be by eyewitnesses. A newly ,discovered' anonymous letter from an eyewitness found in the papers of the lord great chamberlain's office in the Parliamentary Archives gives a detailed account of this important debate. [source] How Are Basic Belief-Forming Methods Justified?PHILOSOPHY AND PHENOMENOLOGICAL RESEARCH, Issue 3 2008DAVID ENOCH In this paper, we present an account of in virtue of what thinkers are justified in employing certain basic belief-forming methods. The guiding idea is inspired by Reichenbach's work on induction. There are certain projects in which thinkers are rationally required to engage. Thinkers are epistemically justified in employing a belief-forming method that is indispensable for successfully engaging in such a project. We present a detailed account based on this intuitive thought, and address objections to it. We conclude by commenting on the implications that our account may have for other important epistemological debates. [source] Predictability of early stages of primary succession in post-mining landscapes of Lower Lusatia, GermanyAPPLIED VEGETATION SCIENCE, Issue 1 2001Gerhard Wiegleb Abstract. The predictability of early primary succession in post-mining landscapes of eastern Germany was studied at sites 5,70 yr following dumping. This chronosequence was investigated using indirect ordination methods. The position of the vegetation types in the ordination diagram was found not to infer any temporal sequence. Independent observations show that the change of vegetation type is slow and does not necessarily occur among types adjacent in the ordination diagram. Furthermore, direct ordination revealed that environmental parameters such as pH, the levels of available phosphate and organic carbon as well as the age of the study sites do not significantly account for the variance. Instead, attention needs to be paid to the influence of spatial aspects and also what recultivation measures have been carried out. A detailed account of the vegetation dynamics of individual sample plots showed - depending on the respective vegetation type - divergence, convergence, and fluctuation at the smallest spatial scale. While the species richness of the sample plots remained more or less constant after initial colonization, mean vegetation cover continuously increases with age, although some sites still remain free of vegetation after as long as 70 yr. No general trend in dominant life forms was indicated. A conceptual model of early succession mechanisms is outlined and five basic mechanisms are identified (i.e. site availability, site suitability, availability of diaspores, strategies of colonizing species and biotic interactions). Their respective importance in three different stages of early succession is estimated and compared. The predictability of vegetation dynamics at each stage is rated differently. [source] Asian Currency Crisis and the International Monetary Fund, 10 Years Later: Overview*ASIAN ECONOMIC POLICY REVIEW, Issue 1 2007Takatoshi ITO This paper is an overview of the Asian currency crisis in Thailand, Indonesia, and South Korea in 1997,1998, with an emphasis on the role of the International Monetary Fund (IMF). It provides a detailed account of the development of the crisis and analyses and evaluates the content of IMF advice and its consequences. The size of the IMF package for each of these three countries is judged to have been too small. This paper also has a comparative perspective; the Mexican crisis is reviewed as a precursor to the Asian crisis to see what the IMF learned, and how it prepared, for future crises. The causes of the crises and IMF conditionality for the post-Asian crisis countries, Russia, Brazil, Turkey, and Argentina, are also compared to the Asian crisis countries. By agreeing to maintain a fixed exchange rate, for example, the IMF is judged to have been "softer" in its approach to the post-Asian crisis countries. [source] The Problematic Relation between Direct Democracy and Accountability in Latin America: Evidence from the Bolivian CaseBULLETIN OF LATIN AMERICAN RESEARCH, Issue 1 2008ANITA BREUER During the wave of constitutional reforms, which started in the late 1980s, Institutions of Direct Democracy (IDD) have been incorporated into most Latin American constitutions, and over the past fifteen years, an increased use of these instruments by Latin American governments has been observed. This article deals with two questions related to this phenomenon: (1) what motivated the adoption and use of these institutions; and (2) what consequences can be expected with regard to democratic accountability in the region? To answer these questions, first, a classification of IDD is developed. In this, special attention is paid to the ability of the various types of IDD to introduce accountability into the representative structures of presidential systems. This classification is subsequently applied to analyse constitutional frameworks and direct democratic experience in the region. The findings suggest that the rise of IDD in Latin America was mainly induced by executive-legislative conflict and has done little to foster accountability. Finally, therefore, a detailed account of the specific constellation that led to the adoption of IDD in Bolivia is analysed in order to illustrate under which circumstances political actors choose to adopt and employ these tools. [source] Total Synthesis of Potent Antitumor Agent (,)-Lasonolide,A: A Cycloaddition-Based StrategyCHEMISTRY - AN ASIAN JOURNAL, Issue 10 2008Abstract A detailed account of the enantioselective total synthesis of (,)-lasonolide,A is described. Our initial synthetic route to the top tetrahydropyran ring involved Evans asymmetric alkylation as the key step. Initially, we relied on the diastereoselective alkylation of an ,-alkoxyacetimide derivative containing an ,, stereogenic center and investigated such an asymmetric alkylation reaction. Although alkylation proceeded in good yield, the lack of diastereoselectivity prompted us to explore alternative routes. Our subsequent successful synthetic strategies involved highly diastereoselective cycloaddition routes to both tetrahydropyran rings of lasonolide,A. The top tetrahydropyran ring was constructed stereoselectively by an intramolecular 1,3-dipolar cycloaddition reaction. The overall process constructed a bicyclic isoxazoline, which was later unravelled to a functionalized tetrahydropyran ring as well as a quaternary stereocenter present in the molecule. The lower tetrahydropyran ring was assembled by a Jacobsen catalytic asymmetric hetero-Diels,Alder reaction as the key step. The synthesis also features a Lewis acid catalyzed epoxide opening to form a substituted ether stereoselectively. [source] Genesis of solitons arising from individual Flows of the Camassa-Holm hierarchyCOMMUNICATIONS ON PURE & APPLIED MATHEMATICS, Issue 3 2006Enrique Loubet The present work offers a detailed account of the large-time development of the velocity profile run by a single "individual" Hamiltonian flow of the Camassa-Holm (CH) hierarchy, the Hamiltonian employed being the reciprocal of any eigenvalue of the underlying spectral problem. In this simpler scenario, I prove some of the conjectures raised by McKean [27]. Notably, I confirm the ultimate shaping into solitons of the cusps that appear, near blowup sites, of any velocity profile emanating from an initial disposition for which breakdown of the wave in finite time is sure to happen. The careful large-time asymptotic analysis is carried from exact expressions describing the velocity in terms of initial data, the integration involving a "Lagrangian" scale and three "theta functions," the rates at which the latter reach their common values at each end of the line characterizing the region where soliton genesis is expected. In fact, the present method also suggests how solitons may arise from initial conditions not leading to breakdown. The full CH flow is nothing but a superposition of such commuting "individual" actions. Therein lies the hope that the present account will pave the way to elucidate soliton formation for more complex flows, in particular for the CH flow itself. © 2005 Wiley Periodicals, Inc. [source] Two little known Acacia species from Mexico Plate 444.CURTIS'S BOTANICAL MAGAZINE, Issue 3 2002Acacia anisophylla Plate 445. Some background information on the large, widespread genus Acacia (Leguminosae) is provided, followed by more detailed accounts of two rare and vulnerable Mexican species, A. anisophylla S. Watson and A. reniformis Benth. There are illustrations of both species, historical information, comprehensive descriptions and details of their cultivation at Kew. [source] Invited reaction: The utilization of training program evaluation in corporate universitiesHUMAN RESOURCE DEVELOPMENT QUARTERLY, Issue 4 2004Rosalie T. Torres This reaction piece briefly reviews the findings from the Bober and Bartlett study of training evaluation use in corporate universities. It then focuses on the importance of context in understanding and facilitating evaluation use. The author suggests an alternative interpretation of particular findings based on a deeper consideration of the evaluation context in the settings studied. Additional suggestions for considering context are to identify the role of evaluation in organizational decision-making processes and identify the how and why of less prevalent uses of evaluation at particular sites. The piece concludes with a discussion of the purposes that the Bober and Bartlett study serve (their detailed accounts of the evaluation use literature and their methodology, and findings about instrumental uses of training evaluation), as well as a call for empirical studies investigating how evaluation use can best facilitate organizational learning. [source] | |||||||||||||||||||||||||