9,068 research outputs found
Nonbanks in the payments system
Nonbanks have always been a key component of the nation's payments system. In recent years, however, nonbanks have become even more prominent. This heightened visibility raises several questions. In which payments activities are nonbanks engaged? What roles do nonbanks play in specific payments types? What types of risk are potentially associated with nonbank participation? This paper begins to address these questions. Preliminary findings include: (1) Nonbanks are involved in a myriad of activities and roles, both in traditional and emerging payments types; (2) Nonbank business relationships with banks and other participants in the payments systems are often highly complex and interrelated; (3) Nonbanks are rarely directly involved in settlement activities and, hence, appear to be associated with limited settlement and systemic risk; (4) Both nonbanks and banks appear to be increasingly susceptible to operational risk factors. ; Published as a book in 2003.Payment systems ; Nonbank financial institutions ; Nonbank activities
Optimal taxation in a growth model with public consumption and home production
In a neoclassical growth model with public consumption, we show the following Pareto optimal tax rules. The government should tax leisure and private consumption at the same rate, and subsidize net investment at the same rate it taxes net capital income. Also, it should tax capital income more heavily than labor income. In an extension for home production, the additional rule is to tax investment for home production at the same rate of the tax on private market consumption. These tax and subsidy rates should be constant over time except the initial tax rate on capital income.
Clonal analysis of meningococci during a 26 year period prior to the introduction of meningococcal serogroup C vaccines
Meningococcal disease remains a public health burden in the UK and elsewhere. Invasive Neisseria meningitidis, isolated in Scotland between 1972 and 1998, were characterised retrospectively to examine the serogroup and clonal structure of the circulating population. 2607 isolates causing invasive disease were available for serogroup and MLST analysis whilst 2517 were available for multilocus sequence typing (MLST) analysis only. Serogroup distribution changed from year to year but serogroups B and C were dominant throughout. Serogroup B was dominant throughout the 1970s and early 1980s until serogroup C became dominant during the mid-1980s. The increase in serogroup C was not associated with one particular sequence type (ST) but was associated with a number of STs, including ST-8, ST-11, ST-206 and ST-334. This is in contrast to the increase in serogroup C disease seen in the 1990s that was due to expansion of the ST-11 clonal complex. While there was considerable diversity among the isolates (309 different STs among the 2607 isolates), a large proportion of isolates (59.9%) were associated with only 10 STs. These data highlight meningococcal diversity over time and the need for ongoing surveillance during the introduction of new meningococcal vaccines
Cellular responses to potential biomaterials
The aim of this study was to systematically investigate the factors considered to be responsible for anchorage-dependent cell behaviour to determine which, if any, of these factors exerts greater influence. An efficient means of doing so is the in vitro fibroblast cell culture model. The interaction of fibroblasts with novel substrata gives information about how a biological system reacts to a foreign material. The may ultimately lead to the development of improved biomaterials. This interdisciplinary study combines the elements of surface characterisation and biological testing to determine the nature of the biomaterial/host interface. Polarity and surface charge were found to have an important influence on fibroblast adhesion to hydrogel polymers, by virtue of their water-structuring effects. The same factors were found to affect cell adhesion on undegraded PHB-HV copolymers and their blends with polysaccharides. On degraded PHB-HV copolymers, the degradation process itself played the greatest role in influencing cell response. Increasing surface charge and mechanical instability in these polymers inhibited cell adhesion. Based on the observations of hydrogels and PHB-copolymers a novel material, gel-spun PHB was designed for use as a wound scaffold. In vitro tests using human and mammalian fibroblasts accentuated the importance of polarity and surface charge in determining cellular response. The overall view of cellular behaviour on a broad spectrum of materials highlighted the effects that polarity and surface charge have on water-structuring, and how this affects interfacial conversion. In degradable systems, mechanical stability also plays an inportant role in determining anchorage-dependent cell behaviour
Proporcions de domesticació mesurables en blats i ordis silvestres en conreus primitius, i les seves implicacions arqueològiques
Coordination of Foliar and Wood Anatomical Traits Contributes to Tropical Tree Distributions and Productivity along the Malay-Thai Peninsula
Drought is a critical factor in plant species distributions. Much research points to its relevance even in moist tropical regions. Recent studies have begun to elucidate mechanisms underlying the distributions of tropical tree species with respect to drought; however, how such desiccation tolerance mechanisms correspond with the coordination of hydraulic and photosynthetic traits in determining species distributions with respect to rainfall seasonality deserves attention. In the present study, we used a common garden approach to quantify inherent differences in wood anatomical and foliar physiological traits in 21 tropical tree species with either widespread (occupying both seasonal and aseasonal climates) or southern (restricted to aseasonal forests) distributions with respect to rainfall seasonality. Use of congeneric species pairs and phylogenetically independent contrast analyses allowed examination of this question in a phylogenetic framework. Widespread species opted for wood traits that provide biomechanical support and prevent xylem cavitation and showed associated reductions in canopy productivity and consequently growth rates compared with southern species. These data support the hypothesis that species having broader distributions with respect to climatic variability will be characterized by traits conducive to abiotic stress tolerance. This study highlights the importance of the well-established performance vs. stress tolerance trade-off as a contributor to species distributions at larger scales
A Logical Approach to Reasoning by Analogy
We analyze the logical form of the domain knowledge that grounds analogical inferences and generalizations from a single instance. The form of the assumptions which justify analogies is given schematically as the "determination rule", so called because it expresses the relation of one set of variables determining the values of another set. The determination relation is a logical generalization of the different types of dependency relations defined in database theory. Specifically, we define determination as a relation between schemata of first order logic that have two kinds of free variables: (1) object variables and (2) what we call "polar" variables, which hold the place of truth values. Determination rules facilitate sound rule inference and valid conclusions projected by analogy from single instances, without implying what the conclusion should be prior to an inspection of the instance. They also provide a way to specify what information is sufficiently relevant to decide a question, prior to knowledge of the answer to the question
Computerised peer-assessment that supports the rewarding of evaluative skills in essay writing (CAP) and programming (Coursemaker)
This short paper details recent innovations in the development of peer-assessed environments that support the automated rewarding of the higher order skills of evaluation in two areas of higher education, namely essay writing and computer programming.
The work builds upon past uses and developments of the CAP (computerised assessment by peers) system that has been used as a means of providing a safe, anonymous and qualitative method of assessing student peer-assessment for the past four years within the School of Computing at the University of Glamorgan, South Wales
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