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Considerable Advances (considerable + advance)
Selected AbstractsConservation Biogeography: assessment and prospectDIVERSITY AND DISTRIBUTIONS, Issue 1 2005Robert J. Whittaker ABSTRACT There is general agreement among scientists that biodiversity is under assault on a global basis and that species are being lost at a greatly enhanced rate. This article examines the role played by biogeographical science in the emergence of conservation guidance and makes the case for the recognition of Conservation Biogeography as a key subfield of conservation biology delimited as: the application of biogeographical principles, theories, and analyses, being those concerned with the distributional dynamics of taxa individually and collectively, to problems concerning the conservation of biodiversity. Conservation biogeography thus encompasses both a substantial body of theory and analysis, and some of the most prominent planning frameworks used in conservation. Considerable advances in conservation guidelines have been made over the last few decades by applying biogeographical methods and principles. Herein we provide a critical review focussed on the sensitivity to assumptions inherent in the applications we examine. In particular, we focus on four inter-related factors: (i) scale dependency (both spatial and temporal); (ii) inadequacies in taxonomic and distributional data (the so-called Linnean and Wallacean shortfalls); (iii) effects of model structure and parameterisation; and (iv) inadequacies of theory. These generic problems are illustrated by reference to studies ranging from the application of historical biogeography, through island biogeography, and complementarity analyses to bioclimatic envelope modelling. There is a great deal of uncertainty inherent in predictive analyses in conservation biogeography and this area in particular presents considerable challenges. Protected area planning frameworks and their resulting map outputs are amongst the most powerful and influential applications within conservation biogeography, and at the global scale are characterised by the production, by a small number of prominent NGOs, of bespoke schemes, which serve both to mobilise funds and channel efforts in a highly targeted fashion. We provide a simple typology of protected area planning frameworks, with particular reference to the global scale, and provide a brief critique of some of their strengths and weaknesses. Finally, we discuss the importance, especially at regional scales, of developing more responsive analyses and models that integrate pattern (the compositionalist approach) and processes (the functionalist approach) such as range collapse and climate change, again noting the sensitivity of outcomes to starting assumptions. We make the case for the greater engagement of the biogeographical community in a programme of evaluation and refinement of all such schemes to test their robustness and their sensitivity to alternative conservation priorities and goals. [source] Unravelling response-specificity in Ca2+ signalling pathways in plant cellsNEW PHYTOLOGIST, Issue 1 2001Jason J. Rudd Summary Considerable advances have been made, both in the technologies available to study changes in intracellular cytosolic free Ca2+ ([Ca2+]i), and in our understanding of Ca2+ signalling cascades in plant cells, but how specificity can be generated from such a ubiquitous component as Ca2+ is questionable. Recently the concept of ,Ca2+ signatures' has been formulated; tight control of the temporal and spatial characteristics of alterations in [Ca2+]i signals is thought to be responsible, at least in part, for the specificity of the response. However, the way in which Ca2+ signatures are decoded, which depends on the nature and location of the targets of the Ca2+ signals, has received little attention. In a few key systems, progress is being made on how diverse Ca2+ signatures might be transduced within cells in response to specific signals. Valuable pieces of the signal-specificity puzzle are being put together and this is illustrated here using some key examples; these emphasize the global importance of Ca2+ -mediated signal-transduction cascades in the responses of plants to a wide diversity of extracellular signals. However, the way in which signal specificity is encoded and transduced is still far from clear. [source] Developing native fish species for aquaculture: the interacting demands of biodiversity, sustainable aquaculture and livelihoodsAQUACULTURE RESEARCH, Issue 7 2008Lindsay G Ross Abstract Aquaculture continues to be the fastest growing animal production industry and this rate of expansion must continue if aquaculture is to satisfy global demand for fish products in the face of dwindling capture fisheries. The relationship between aquaculture and biodiversity is complex, with examples of positive and negative impacts having been reported. To enable this expansion while avoiding negative impacts from introductions of exotic species, the investigation of indigenous species becomes important and worthwhile. This paper establishes the background to development of new species for culture and describes the example of the Mexican silverside Menidia estor, which has for centuries been the principal species in an artesanal fishery in Lake Pátzcuaro, Mexico. The species is geographically isolated and is unique but is now endangered because of a range of factors including overfishing, environmental degradation and introduction of exotic species. Considerable advances have been made recently in developing a closed reproductive cycle, understanding feeding and small-scale on-growing technology for the species. Based on this, a Darwin Initiative programme was developed focused on technology transfer to implement small-scale pilot on-growing thus helping to conserve the species and to improve livelihoods. This has allowed successful pilot scale development of aquaculture for the species while at the same time addressing the objectives of the international Convention on Biodiversity. [source] Protein crystallization for genomics: towards high-throughput optimization techniquesACTA CRYSTALLOGRAPHICA SECTION D, Issue 6-2 2002Naomi E. Chayen Protein crystallization has gained a new strategic and commercial relevance in the next phase of the genome projects, in which X-ray crystallography will play a major role. Considerable advances have been made in the automation of protein preparation and also in the X-ray analysis and bioinformatics stages once diffraction-quality crystals are available. These advances have not yet been matched by equally good methods for the crystallization process itself. In the area of crystallization, the main effort and resources are currently being invested into the automation of screening procedures to identify potential crystallization conditions. However, in spite of the ability to generate numerous trials, so far only a small percentage of the proteins produced have led to structure determinations. This is because screening in itself is not usually enough; it has to be complemented by an equally important procedure in crystal production, namely crystal optimization. In the rush towards structural genomics, optimization techniques have been somewhat neglected, mainly because it was hoped that large-scale screening alone would produce the desired results. In addition, optimization has relied on particular individual methods that are often difficult to automate and to adapt to high throughput. This article addresses a major gap in the field of structural genomics by describing practical ways of automating individual optimization methods in order to adapt them to high-throughput techniques. [source] Reduced Surfactant Uptake in Three Dimensional Assemblies of VOx Nanotubes Improves Reversible Li+ Intercalation and Charge CapacityADVANCED FUNCTIONAL MATERIALS, Issue 11 2009Colm O'Dwyer Abstract The relationship between the nanoscale structure of vanadium pentoxide nanotubes and their ability to accommodate Li+ during intercalation/deintercalation is explored. The nanotubes are synthesized using two different precursors through a surfactant-assisted templating method, resulting in standalone VOx (vanadium oxide) nanotubes and also "nano-urchin". Under highly reducing conditions, where the interlaminar uptake of primary alkylamines is maximized, standalone nanotubes exhibit near-perfect scrolled layers and long-range structural order even at the molecular level. Under less reducing conditions, the degree of amine uptake is reduced due to a lower density of V4+ sites and less V2O5 is functionalized with adsorbed alkylammonium cations. This is typical of the nano-urchin structure. High-resolution TEM studies revealed the unique observation of nanometer-scale nanocrystals of pristine unreacted V2O5 throughout the length of the nanotubes in the nano-urchin. Electrochemical intercalation studies revealed that the very well ordered xerogel-based nanotubes exhibit similar specific capacities (235,mA h g,1) to Na+ -exchange nanorolls of VOx (200,mA h g,1). By comparison, the theoretical maximum value is reported to be 240,mA h g,1. The VOTPP-based nanotubes of the nano-urchin 3D assemblies, however, exhibit useful charge capacities exceeding 437,mA h g,1, which is a considerable advance for VOx based nanomaterials and one of the highest known capacities for Li+ intercalated laminar vanadates. [source] The Interactorium: Visualising proteins, complexes and interaction networks in a virtual 3-D cellPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 23 2009Yose Y. Widjaja Abstract Here, we describe the Interactorium, a tool in which a Virtual Cell is used as the context for the seamless visualisation of the yeast protein interaction network, protein complexes and protein 3-D structures. The tool has been designed to display very complex networks of up to 40,000 proteins or 6000 multiprotein complexes and has a series of toolboxes and menus to allow real-time data manipulation and control the manner in which data are displayed. It incorporates new algorithms that reduce the complexity of the visualisation by the generation of putative new complexes from existing data and by the reduction of edges through the use of protein "twins" when they occur in multiple locations. Since the Interactorium permits multi-level viewing of the molecular biology of the cell, it is a considerable advance over existing approaches. We illustrate its use for Saccharomyces cerevisiae but note that it will also be useful for the analysis of data from simpler prokaryotes and higher eukaryotes, including humans. The Interactorium is available for download at http://www.interactorium.net. [source] Genetic manipulation, whole-cell recordings and functional imaging of the sensorimotor cortex of behaving miceACTA PHYSIOLOGICA, Issue 1 2009C. C. H. Petersen Abstract Sensory processing, sensorimotor integration and motor control are amongst the most basic functions of the brain and yet our understanding of how the underlying neuronal networks operate and contribute to behaviour is very limited. The relative simplicity of the mouse whisker sensorimotor system is helpful for detailed quantitative analyses of motor control and perception during active sensory processing. Recent technical advances now allow the measurement of membrane potential in awake-behaving mice, using whole-cell recordings and voltage-sensitive dye imaging. With these recording techniques, it is possible to directly correlate neuronal activity with behaviour. However, in order to obtain causal evidence for the specific contributions of different neuronal networks to behaviour, it is critical to manipulate the system in a highly controlled manner. Advances in molecular neurobiology, gene delivery and mouse genetics provide techniques capable of layer, column and cell-type specific control of gene expression in the mouse neocortex. Over the next years, we anticipate considerable advances in our understanding of brain function through measuring and manipulating neuronal activity with unprecedented precision to probe the molecular and synaptic mechanisms underlying simple forms of active sensory perception and associative learning. [source] Beyond biological control: non-pest insects and their pathogens in a changing worldINSECT CONSERVATION AND DIVERSITY, Issue 2 2009HELEN E. ROY Abstract. 1Over the last few decades, there have been considerable advances in the fields of insect pathology and insect conservation but the two disciplines rarely meet. The potential of entomopathogens as biological control agents of pest insects is widely recognised but information on the role of pathogens in insect population regulation, more generally, is limited. For example, the role of pathogens as natural enemies of non-pest insects, including those of conservation value, is seldom considered beyond their context as ,non-targets' of microbial control agents. 2Entomopathogens are prevalent in natural systems and should receive greater attention in life-history studies. There is no doubt that viruses, bacteria and fungi are major mortality agents of insects but their significance tends to be overshadowed by the attention given to predators and parasitoids. 3We highlight the critical function that entomopathogens could have in insect population dynamics with particular reference fragmented habitats as illustrated by the theoretical literature. However, we emphasise that there are few empirical studies to test theoretical predictions. 4We suggest that since an increase in the incidence of disease is predicted in most environmental change scenarios, it is more important than ever to turn our attention to insect pathology when we consider insect population dynamics. [source] The Sociology of Adolescence and Youth in the 1990s: A Critical CommentaryJOURNAL OF MARRIAGE AND FAMILY, Issue 4 2000Frank F. Furstenberg The 1990s saw considerable advances in the state of research on adolescence and youth. This article provides a critical commentary on a subset of this research, focusing on the causes and consequences of the lengthened period in which the transition to adulthood occurs. It provides a brief history of adolescence research, identifying a select set of topics, themes, and research problems that will guide research on adolescence and youth over the next decade. These research foci, which include peer group relations, biological influences on adolescence, employment experiences, increased autonomy, and racial and gender differences, are described as representing either continuities or advances in adolescence research. The strengths and shortcomings of this research are detailed. The paper concludes by suggesting promising areas for future research and by providing guidelines for undertaking such research. [source] Polypropylene Hollow Fiber Oxygenators: Effect of the Sorption of PerfluoropolyethersARTIFICIAL ORGANS, Issue 3 2000Flávia Cassiola Abstract: The introduction of microporous polypropylene hollow fibers in recent years has brought considerable advances to blood oxygenators. However, lifetime and assembly problems are still unresolved. In this work we tried to rate the oxygen permeation velocity by turning the fibers more hydrophobic through the sorption of a perfluorocarbon. Fomblin HC/25, a perfluoropolyether, is well known for its low surface tension and high affinity for oxygen. Celgard X10, X20, and X30 commercial hollow fibers were tested. The hollow fibers showed high affinity for the perfluoropolyether; swelling was clearly shown. A new system for the measurement of oxygen permeation velocity was developed. The oxygen transport velocity was not significantly changed after sorption. The Celgard microporous hollow fibers impregnated with perfluoropolyether showed no water permeation after 2 months of use, reducing one of the most serious problems in the lifetime of these types of fibers. [source] The learning credit card: A tool for managing personal development,BRITISH JOURNAL OF EDUCATIONAL TECHNOLOGY, Issue 2 2008Nick Rushby This is the report of a five month study, undertaken by Sundridge Park Training Technologies in association with Guildford Educational Services to assess the potential of smart card technology to support learning and the management of learning. The study had two strands,the state of the art of the technology and its potential for supporting, delivering and managing learning. In addition to a study of the literature and extensive discussions with people using smart cards, potential users of smart card and visionaries, the project team developed two illustrative systems using cards to store personal data relating to education and training. The term ,smart card' is often used loosely to describe three different types of card, each of which is similar in general shape and size to a traditional credit card. These are: memory cards, laser cards,and true smart cards incorporating a processor and memory. This study has been concerned with memory cards and smart cards. The focus for smart card applications has been predominantly financial: there are relatively few applications in education or training. A notable exception is the large scale project at the University of Bologna which uses smart cards to manage the progress and achievements of a large number of students in the Department of Electronics. The two illustrative systems provided valuable experience of using memory cards and smart cards in quasi-real education and training applications. They highlighted the problems of limited memory capacities and confirmed the high level of user acceptance reported by other trials. We can expect considerable advances in the technology of both memory cards and smart cards over the next months and years. The memory capacities of both types of cards will increase many-fold and the unit costs will fall as large quantities of cards are produced for financial applications. Education and training applications will benefit from this expanding market. The major surprise from the study was the level of interest in the work and the enthusiasm expressed by almost all of those who came to hear of it. The general level of awareness of smart card technology was found to be low. However, the requirement for a system which will enable individuals to manage and own their learning on an extended timescale was generally recognised. Some of the possible applications for smart cards and memory cards in education and training had emerged before the official start of the study and it is clear that the technology is potentially pervasive. The project team and those consulted identified a wide range of possible applications both in education and in training. These focussed on assessment, personal course planning and management, identification of relevant learning opportunities, and the ownership of learning. It was felt that, over the next few years, smart cards are very likely to be in common use as credit cards for financial applications. Therefore, their use for education and training should be planned now. The recommendations from the study are that: More detailed studies are needed to find out how smart cards and memory cards could be used by different organisations in a fully operational system; Standards should be established for smart card applications in education and training, similar to those governing financial applications; Applications should be developed after the standards have been established. To be convincing, these should take a case study approach with small pilot studies in a variety of contexts and must follow real needs rather than attempt to drive them; The case studies would then form the basis for a campaign to increase awareness of smart cards and their potential for education and training, together with a programme for building an infrastructure to support the proposed systems. The public sector should fund the task of developing standards and providing interfaces with existing educational systems and projects to demonstrate the feasibility of various applications. Since educational standards have a European dimension, the European Community may be a source of support for work in the area of standards. At the same time, private sector funding should be sought for skill development and career development systems in industry and in education. The Training Agency itself should consider the application of smart card technology to the control and management of the Youth Training Scheme (YTS). [source] | |||||||||||||