Distribution by Scientific Domains
Distribution within Business, Economics, Finance and Accounting

Kinds of Ranking

  • journal ranking
  • performance ranking
  • similar ranking

  • Terms modified by Ranking

  • ranking approach
  • ranking methods
  • ranking problem

  • Selected Abstracts


    First page of article [source]


    This paper reviews the literature that ranks universities and economics departments. In international rankings Australian universities fare well, but the most popular (ARWU and THES) measures are biased in ways that favour Australian universities. In international rankings of economics departments by their research performance, Australian universities fare poorly, relative to natural comparators. Several hypotheses can explain this phenomenon: inappropriate measures, low productivity, time spent on non-research activities, age and cohort effects and lack of resources. [source]

    A new method for scoring additive multi-attribute value models using pairwise rankings of alternatives

    Paul Hansen
    Abstract We present a new method for determining the point values for additive multi-attribute value models with performance categories. The method, which we refer to as PAPRIKA (Potentially All Pairwise RanKings of all possible Alternatives), involves the decision-maker pairwise ranking potentially all undominated pairs of all possible alternatives represented by the value model. The number of pairs to be explicitly ranked is minimized by the method identifying all pairs implicitly ranked as corollaries of the explicitly ranked pairs. We report on simulations of the method's use and show that if the decision-maker explicitly ranks pairs defined on just two criteria at-a-time, the overall ranking of alternatives produced by the value model is very highly correlated with the true ranking. Therefore, for most practical purposes decision-makers are unlikely to need to rank pairs defined on more than two criteria, thereby reducing the elicitation burden. We also describe a successful real-world application involving the scoring of a value model for prioritizing patients for cardiac surgery in New Zealand. We conclude that although the new method entails more judgments than traditional scoring methods, the type of judgment (pairwise rankings of undominated pairs) is arguably simpler and might reasonably be expected to reflect the preferences of decision-makers more accurately. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    An overview of the use of quantitative structure-activity relationships for ranking and prioritizing large chemical inventories for environmental risk assessments

    Christine L. Russom
    Abstract Ecological risk assessments for chemical stressors are used to establish linkages between likely exposure concentrations and adverse effects to ecological receptors. At times, it is useful to conduct screening risk assessments to assist in prioritizing or ranking chemicals on the basis of potential hazard and exposure assessment parameters. Ranking of large chemical inventories can provide evidence for focusing research and/or cleanup efforts on specific chemicals of concern. Because of financial and time constraints, data gaps exist, and the risk assessor is left with decisions on which models to use to estimate the parameter of concern. In this review, several methods are presented for using quantitative structure-activity relationships (QSARs) in conducting hazard screening or screening-level risk assessments. The ranking methods described include those related to current regulatory issues associated with chemical inventories from Canada, Europe, and the United States and an example of a screening-level risk assessment conducted on chemicals associated with a watershed in the midwest region of the United States. [source]

    A Ranking of Journals in Economics and Related Fields

    Klaus Ritzberger
    Journal ranking; economics journals; business administration journals; finance journals; citations Abstract. This paper presents an update of the ranking of economics journals by the invariant method, as introduced by Palacio-Huerta and Volij, with a broader sample of journals. By comparison with the two other most prominent rankings, it also proposes a list of ,target journals', ranked according to their quality, as a standard for the field of economics. [source]

    Ranking and selecting terms for text categorization via SVM discriminate boundary

    Tien-Fang Kuo
    The problem of natural language document categorization consists of classifying documents into predetermined categories based on their contents. Each distinct term, or word, in the documents is a feature for representing a document. In general, the number of terms may be extremely large and the dozens of redundant terms may be included, which may reduce the classification performance. In this paper, a support vector machine (SVM)-based feature ranking and selecting method for text categorization is proposed. The contribution of each term for classification is calculated based on the nonlinear discriminant boundary, which is generated by the SVM. The results of experiments on several real-world data sets show that the proposed method is powerful enough to extract a smaller number of important terms and achieves a higher classification performance than existing feature selecting methods based on latent semantic indexing and ,2 statistics values. © 2009 Wiley Periodicals, Inc. [source]

    Ranking of alternatives with ordered weighted averaging operators

    M. Teresa Lamata
    Multiattribute decision making is an important part of the decision process for both individual and group problems. We incorporate the fuzzy set theory and the basic nature of subjectivity due to ambiguity to achieve a flexible decision approach suitable for uncertain and fuzzy environments. Let us consider the analytic hierarchy process (AHP) in which the labels are structured as fuzzy numbers. To obtain the scoring that corresponds to the best alternative or the ranking of the alternatives, we need to use a total order for the fuzzy numbers involved in the problem. In this article, we consider a definition of such a total order, which is based on two subjective aspects: the degree of optimism/pessimism reflected with the ordered weighted averaging (OWA) operators. A numerical example is given to illustrate the approach. © 2004 Wiley Periodicals, Inc. [source]

    Ranking projects for an electricity utility using ELECTRE III

    John Buchanan
    Abstract Ranking and selecting projects is a common yet often difficult task with typically more than one dimension for measuring project impacts and more than one decision maker. We describe a project selection methodology developed and used since 1998 for Mighty River Power, a New Zealand electricity generator, which incorporates the ELECTRE III decision support tool. Although several other multiple criteria approaches could have been used, features of ELECTRE III such as outranking, and indifference and preference thresholds were well received by our decision makers. More than the use of a specific decision support tool, we focus particularly on the successful implementation of a simple, structured multicriteria methodology for a yearly project selection exercise and document this over 8 years in a changing managerial context. [source]

    Benchmarking productive efficiency of selected wheat areas in Pakistan and India using data envelopment analysis,

    Naeem M. Malana
    MEG (/DEA); analyse comparative; productivité de l'irrigation; productivité; blé; Pakistan; Inde Abstract Food demand is bound to increase significantly in future as a result of a growing world population. As a large proportion of the available land and water resources have been developed, there is limited scope for further increase in the use of these resources. Thus future increases in food production will originate from improvements in performance of existing agriculture rather than development of new resources. It is anticipated that wheat demand in the South Asia will rise significantly in future. In order to increase production and overcome diminishing water availability for irrigation, performance of wheat farms must increase. This paper describes the process of benchmarking the productive efficiency of wheat in selected areas of Pakistan and India. Data envelopment analysis (DEA) is used to evaluate and rank productivity performance of wheat growing areas in both countries based on three inputs: irrigation (m3,ha,1), seed (kg,ha,1) and fertiliser use (kg,ha,1). The results of analysis show that DEA is an effective tool for analysing and benchmarking productive efficiency of agricultural units. Ranking of productive efficiency based on three inputs is also shown to differ significantly from that based on a single resource (irrigation). Copyright © 2006 John Wiley & Sons, Ltd. La demande de nourriture est appelée à augmenter de façon significative du fait de la croissance de la population mondiale. Une forte proportion des ressources en terre et en eau ayant déjà été utilisée, leur potentiel d'accroissement est faible. La production supplémentaire de nourriture devra donc venir de l'amélioration des performances de l'agriculture plutôt que du développement de nouvelles ressources. Il est prévu que la demande de blé en Asie du Sud-Est augmente significativement dans le future. Afin d'augmenter la production et de surmonter la raréfaction de l'eau pour l'irrigation, la performance de la culture du blé doit progresser. Cet article décrit le processus d'analyse comparative appliquée à la productivité de certaines zones à blé du Pakistan et de l'Inde. La Méthode d'Enveloppe Graphique (MEG) est utilisée pour évaluer et classer les productivités des zones à blé de ces deux pays sur la base de trois intrants: l'irrigation (m3/ha), les semences (kg/ha) et les engrais (kg/ha). Les résultats de l'analyse montrent que la MEG est un outil efficace pour l'analyse comparative des productivités d'exploitations agricoles. Le classement des productivités à partir de trois intrants est également différent de celui obtenu à partir d'une seule ressource (l'irrigation). Copyright © 2006 John Wiley & Sons, Ltd. [source]

    A Global Ranking of Political Science Departments

    Simon Hix
    Rankings of academic institutions are key information tools for universities, funding agencies, students and faculty. The main method for ranking departments in political science, through peer evaluations, is subjective, biased towards established institutions, and costly in terms of time and money. The alternative method, based on supposedly ,objective' measures of outputs in scientific journals, has thus far only been applied narrowly in political science, using publications in a small number of US-based journals. An alternative method is proposed in this paper , that of ranking departments based on the quantity and impact of their publications in the 63 main political science journals in a given five-year period. The result is a series of global and easily updatable rankings that compare well with results produced by applying a similar method in economics. [source]

    A Multidimensional Ranking of Australian Economics Departments

    THE ECONOMIC RECORD, Issue 256 2006
    This study uses cluster analysis to classify Australian economics departments into groups that have similar quantities of research output, measured by two publication counts, and similar quality of research output, measured by a citation count. Three groups of departments are identified and factor analysis is used to rank the groups. Whether research output is measured in total or on a per staff basis, Melbourne is in the group that ranks first, the remaining members of the ,group of eight' are in one or other of the top two groups, and at least 15 other departments are in the third-ranked group. [source]

    Evaluating medical grand rounds

    Dr. Arthur I. Rothman EdD Director
    Abstract Introduction: Since January 2000, standard presenter evaluation forms have been made available to grand rounds organizers in the Department of Medicine, University of Toronto. During the 2000,2001 academic year, effort was directed at the accumulation of evidence for the validity of the results generated. Method: Two issues were addressed: The integrity or coherence of the form itself and the number of forms or evaluations required to achieve a stable estimate of the construct "presenter effectiveness" for an individual presenter. Results: Positive evidence relating to the integrity of the form is presented and the number of evaluations or ratings required to provide a stable estimate of presenter effectiveness is suggested. Discussion: Most presenters' ratings were distributed in a narrow range. Ranking of individual presentations would require exceptionally high precision. Separation into groups requires less precision. This type of classification appears sufficient to enable planning decisions. [source]

    Ranking of High-Affinity Ligands by NMR Spectroscopy,

    ANGEWANDTE CHEMIE, Issue 36 2009
    Xiaolu Zhang Dr.
    Das Protein wählt seinen Liganden, und NMR-Spektroskopie enthüllt, welchen es genommen hat (siehe Schema). So gelingen eine sehr genaue Bestimmung der relativen Bindungsaffinitäten zweier Liganden bezüglich eines Proteinrezeptors und zum ersten Mal die Bestimmung der Affinitäten fest bindender Liganden durch NMR-Spektroskopie. Dieser Ansatz sollte nützlich für die Leitstrukturoptimierung sein. [source]

    On Gene Ranking Using Replicated Microarray Time Course Data

    BIOMETRICS, Issue 1 2009
    Yu Chuan Tai
    Summary Consider the ranking of genes using data from replicated microarray time course experiments, where there are multiple biological conditions, and the genes of interest are those whose temporal profiles differ across conditions. We derive a multisample multivariate empirical Bayes' statistic for ranking genes in the order of differential expression, from both longitudinal and cross-sectional replicated developmental microarray time course data. Our longitudinal multisample model assumes that time course replicates are independent and identically distributed multivariate normal vectors. On the other hand, we construct a cross-sectional model using a normal regression framework with any appropriate basis for the design matrices. In both cases, we use natural conjugate priors in our empirical Bayes' setting which guarantee closed form solutions for the posterior odds. The simulations and two case studies using published worm and mouse microarray time course datasets indicate that the proposed approaches perform satisfactorily. [source]

    Assessment of infant physiology and neuronal development using magnetic resonance imaging

    B. Morgan
    Abstract Previous work has demonstrated both that there are substantial individual differences in the rate of physiological development, and that infants with risk factors for Sudden Infant Death Syndrome (SIDS) develop more slowly, suggesting that their increased vulnerability may be due to delayed neuronal development associated with compromised development in fetal or early neonatal life. This project aims to test the hypothesis that individual differences in the rate of physiological development of infants correlate with measurable differences in the rate of brain development as assessed by magnetic resonance imaging (MRI). Sixty infants were recruited to this study in three different groups that are known to have differing rates of physiological development. MRI was performed successfully in 49 cases at 6 weeks of age without sedation. Forty-one of these cases had full follow-up (15 normal; 19 IUGR; 11 ,high risk'). Postnatal physiological development was assessed by measuring age-related deep body temperature patterns during sleep. Neuronal development was assessed by subjective analysis of MRI images and objective measurements relating to myelination using T1 and diffusion weighted (23 cases) MRI images. As expected the normal group acquired the adult temperature pattern earlier, but this was not statistically significant. All MRI scan appearances were within normal limits. Ranking cases subjectively in order of maturity revealed no significant pattern. The normal group had a significantly higher myelination score than the IUGR and ,high risk' groups (P = 0.001). This trend was also shown by the diffusion weighted myelination score but did not reach statistical significance. No significant differences were seen in both the subjective and objective MRI measurements and development of nocturnal temperature patterns. The results suggest there may be differences in neurodevelopment between the different groups at 6 weeks of age but these are not linked to late development of temperature patterns. It is therefore unlikely that this related to a global delay in maturation. [source]

    Case-Mix Adjusting Performance Measures in a Veteran Population: Pharmacy- and Diagnosis-Based Approaches

    Chuan-Fen Liu
    Objective. To compare the rankings for health care utilization performance measures at the facility level in a Veterans Health Administration (VHA) health care delivery network using pharmacy- and diagnosis-based case-mix adjustment measures. Data Sources/Study Setting. The study included veterans who used inpatient or outpatient services in Veterans Integrated Service Network (VISN) 20 during fiscal year 1998 (October 1997 to September 1998; N=126,076). Utilization and pharmacy data were extracted from VHA national databases and the VISN 20 data warehouse. Study Design. We estimated concurrent regression models using pharmacy or diagnosis information in the base year (FY1998) to predict health service utilization in the same year. Utilization measures included bed days of care for inpatient care and provider visits for outpatient care. Principal Findings. Rankings of predicted utilization measures across facilities vary by case-mix adjustment measure. There is greater consistency within the diagnosis-based models than between the diagnosis- and pharmacy-based models. The eight facilities were ranked differently by the diagnosis- and pharmacy-based models. Conclusions. Choice of case-mix adjustment measure affects rankings of facilities on performance measures, raising concerns about the validity of profiling practices. Differences in rankings may reflect differences in comparability of data capture across facilities between pharmacy and diagnosis data sources, and unstable estimates due to small numbers of patients in a facility. [source]

    Financial Times Business School Rankings: A Nontraditional Assurance Case in Three Parts,

    Andrea B. Davies
    ABSTRACT The Financial Times of London (FT) is a business newspaper, with daily editions published in the United Kingdom, continental Europe, the United States, and Asia, and an estimated daily readership of 10 million people. In 1999 the FT began to publish a ranking of what it considered to be the top business schools in the world. Since their inception, these rankings have become increasingly relied upon by potential students and business school administrators worldwide. The FT's ranking is unique compared with other rankings because of its special international focus. Given the prominence of these rankings and the FT's position as a well-respected business newspaper, the question of providing assurance over the business school rankings that the FT provides is particularly challenging. [source]

    Comparison of models for genetic evaluation of survival traits in dairy cattle: a simulation study

    J. Jamrozik
    Summary Three models for the analysis of functional survival data in dairy cattle were compared using stochastic simulation. The simulated phenotype for survival was defined as a month after the first calving (from 1 to 100) in which a cow was involuntarily removed from the herd. Parameters for simulation were based on survival data of the Canadian Jersey population. Three different levels of heritability of survival (0.100, 0.050 and 0.025) and two levels of numbers of females per generation (2000 or 4000) were considered in the simulation. Twenty generations of random mating and selection (on a second trait, uncorrelated with survival) with 20 replicates were simulated for each scenario. Sires were evaluated for survival of their daughters by three models: proportional hazard (PH), linear multiple-trait (MT), and random regression (RR) animal models. Different models gave different ranking of sires with respect to survival of their daughters. Correlations between true and estimated breeding values for survival to five different points in a cow's lifetime after the first calving (120 and 240 days in milk after first, second, third and fourth calving) favoured the PH model, followed by the RR model evaluations. Rankings of models were independent of the heritability level, female population size and sire progeny group size (20 or 100). The RR model, however, showed a slight superiority over MT and PH models in predicting the proportion of sire's daughters that survived to the five different end-points after the first calving. [source]

    Scopus's source normalized impact per paper (SNIP) versus a journal impact factor based on fractional counting of citations

    Loet Leydesdorff
    Impact factors (and similar measures such as the Scimago Journal Rankings) suffer from two problems: (a) citation behavior varies among fields of science and, therefore, leads to systematic differences, and (b) there are no statistics to inform us whether differences are significant. The recently introduced "source normalized impact per paper" indicator of Scopus tries to remedy the first of these two problems, but a number of normalization decisions are involved, which makes it impossible to test for significance. Using fractional counting of citations,based on the assumption that impact is proportionate to the number of references in the citing documents,citations can be contextualized at the paper level and aggregated impacts of sets can be tested for their significance. It can be shown that the weighted impact of Annals of Mathematics (0.247) is not so much lower than that of Molecular Cell (0.386) despite a five-f old difference between their impact factors (2.793 and 13.156, respectively). [source]

    A Global Ranking of Political Science Departments

    Simon Hix
    Rankings of academic institutions are key information tools for universities, funding agencies, students and faculty. The main method for ranking departments in political science, through peer evaluations, is subjective, biased towards established institutions, and costly in terms of time and money. The alternative method, based on supposedly ,objective' measures of outputs in scientific journals, has thus far only been applied narrowly in political science, using publications in a small number of US-based journals. An alternative method is proposed in this paper , that of ranking departments based on the quantity and impact of their publications in the 63 main political science journals in a given five-year period. The result is a series of global and easily updatable rankings that compare well with results produced by applying a similar method in economics. [source]

    Rankings of Australian Economics Departments, 1988,2000

    THE ECONOMIC RECORD, Issue 241 2002
    Dipendra Sinha
    This paper provides new rankings for Australian university economics departments for the periods 1988,2000, 1988,1994 and 1994,2000 using the ECONLIT database. We rank economics departments using two different journal ranking criteria - one based on citations and the other based on perceptions of journal quality. In addition, we provide updates on the rankings using the Towe and Wright (1995) methodology. We find that the perception-based rankings are quite different from the citation-based rankings. [source]

    Producing Spaces for Academic Discourse: The Impact of Research Assessment Exercises and Journal Quality Rankings

    Deryl Northcott
    This study examines the impact of national research assessment exercises (NRAEs) and associated journal quality rankings on the development, scope and sustainability of the academic journals in which accounting research is disseminated. The reported exploratory study focused on the United Kingdom (UK), Australia and New Zealand as three countries in which NRAEs are well developed or imminent. Data were collected via a survey of authors, interviews with journal editors, and feedback from publishers responsible for producing academic accounting journals. The findings suggest that, despite cynicism around the reliability of published journal quality rankings, the entrenchment of NRAE ,rules' and journal quality perceptions has changed authors' submission choices and left lower ranked journals struggling with a diminished quantity and quality of submissions. A clear perception is that NRAEs have done little to improve the overall quality of the accounting literature, but are impeding the diversity, originality and practical relevance of accounting research. Although strategies are suggested for meeting these challenges, they require strategic partnerships with publishers to enhance the profile and distribution of emerging journals, and depend on the willingness of accounting researchers to form supportive communities around journals that facilitate their research interests. The alternative may be a withering of the spaces for academic discourse, a stifling of innovation and a further entrenchment of current perceptions of what counts as ,quality' research. [source]

    Journal Rankings in Business and Management and the 2001 Research Assessment Exercise in the UK

    Janet Geary
    The public availability of detailed data from the 2001 Research Assessment Exercise in the UK allows an analysis of the publications cited in submissions to the Business and Management panel. Eighty per cent of the 9,942 publications submitted were journal articles. Submissions to the RAE can be scored in terms of the number of citations they make to journals that appear on various lists, such as the Financial Times list. The concentration of articles in a minority of journals, with 50% of all citations to just 126 journals, means that a core list of business and management journals can be compiled. The core list presented contains 562 journals out of the 1582 journal titles that were cited in Business and Management submissions. It includes all journals with more than two citations overall at least one citation in a 5*, 5 or 4 rated submission. It also includes all journals cited in the RAE from Starbuck's ranked lists of journals and the Financial Times list. [source]


    Isabelle Bichindaritz
    Mémoire proposes a general framework for reasoning from cases in biology and medicine. Part of this project is to propose a memory organization capable of handling large cases and case bases as occur in biomedical domains. This article presents the essential principles for an efficient memory organization based on pertinent work in information retrieval (IR). IR systems have been able to scale up to terabytes of data taking advantage of large databases research to build Internet search engines. They search for pertinent documents to answer a query using term-based ranking and/or global ranking schemes. Similarly, case-based reasoning (CBR) systems search for pertinent cases using a scoring function for ranking the cases. Mémoire proposes a memory organization based on inverted indexes which may be powered by databases to search and rank efficiently through large case bases. It can be seen as a first step toward large-scale CBR systems, and in addition provides a framework for tight cooperation between CBR and IR. [source]

    Condition Assessment by Visual Inspection for a Bridge Management System

    Vincenzo Gattulli
    This article deals with a procedure for bridge condition assessment by visual inspection developed during the planning and preliminary design of the BMS for the public railway networks in Italy. The main modules adopted in the procedure are: bridge inventory, computer-aided visual inspection, automated defect catalog, and priority-ranking procedure. The probabilistic models used to calibrate the condition evaluation algorithm are discussed. Different levels of deficiency have been individuated for each class of bridge structure belonging to the managed stock. The procedure allows comparison and relative ranking of deficiency conditions across different types of bridge structures. The results of a visual inspection campaign conducted for a set of bridges with different structural characteristics are reported and evaluated within the framework of the developed BMS. [source]

    A role for Pareto optimality in mining performance data

    Joël M. Malard
    Abstract Improvements in performance modeling and identification of computational regimes within software libraries is a critical first step in developing software libraries that are truly agile with respect to the application as well as to the hardware. It is shown here that Pareto ranking, a concept from multi-objective optimization, can be an effective tool for mining large performance datasets. The approach is illustrated using software performance data gathered using both the public domain LAPACK library and an asynchronous communication library based on IBM LAPI active message library. Copyright © 2005 John Wiley & Sons, Ltd. [source]

    Conservation Status as a Biodiversity Trend Indicator: Recommendations from a Decade of Listing Species at Risk in British Columbia

    especies amenazadas; especies en peligro; estado del ambiente Abstract:,Species conservation status is commonly used as a broad-scale indicator of the state of biological diversity. To learn about its value for tracking trends, we examined provincial lists of terrestrial vertebrate species and subspecies at risk in British Columbia, Canada, for 1992 and 2002 to see whether changes in these lists reflected changes in the status of the taxa they represent. Examination of the case histories of individual species and subspecies showed that 65% of additions and deletions to the British Columbia Red List were the result of improvement in knowledge of species status, changes in assessment procedures, and refinements in taxonomy rather than actual changes in a species' status. Comparison to an alternate set of rank scores provided by NatureServe for taxa that appeared on both 1992 and 2002 British Columbia Red Lists revealed changes in status that were not reflected by movement from the list. Estimates of historical conservation status for species on the 1992 British Columbia Red List demonstrated ambiguity around the natural baseline with regard to tracking changes in list composition over time. We discourage the continued use of indicators based solely on conservation status as a means of tracking biodiversity. Instead we recommend advancing strategic indicators around species at risk based on long-term monitoring data, deliberate and explicitly stated baselines, and consistent methods of conservation ranking. Resumen:,El estatus de conservación de las especies comúnmente es utilizado como un indicador de escala amplia del estado de la diversidad biológica. En un esfuerzo por aprender sobre su valor para el seguimiento de tendencias, examinamos listas provinciales, para 1992 y 2002, de especies y subespecies de vertebrados terrestres en riesgo en Columbia Británica, Canadá, para ver si los cambios en estas listas reflejaban cambios en el estatus de los taxa que representan. El examen de la historia del caso de especies y subespecies individuales mostró que 65% de las adiciones y supresiones en la Lista Roja de Columbia Británica fueron el resultado de avances en el conocimiento del estatus de la especie, de cambios en los procedimientos de evaluación y de refinamientos en la taxonomía y no de cambios en el estatus de una especie. La comparación con un conjunto alternativo de valores de clasificación proporcionado por NatureServe para taxa que aparecieron tanto en la Lista Roja de Columbia Británica de 1992 como de 2002 reveló cambios en el estatus que no se reflejaron en movimientos en la lista. Estimaciones del estatus de conservación histórico de especies en la Lista Roja de Columbia Británica de 1992 demostraron ambigüedad alrededor de la línea de base natural en relación con el seguimiento de cambios en el tiempo en la composición de la lista. Desalentamos el uso continuo de indicadores basados solamente en el estatus de conservación como un medio para el seguimiento de biodiversidad. En cambio, recomendamos avanzar con indicadores estratégicos en torno a especies en riesgo con base en datos de monitoreo de largo plazo, en líneas básicas puestas de manifiesto deliberada y explícitamente y en métodos consistentes para la clasificación de la conservación. [source]

    An evidence-based appraisal of splinting luxated, avulsed and root-fractured teeth

    Bill Kahler
    For this systematic review of splinting of teeth that have been luxated, avulsed or root-fractured, the clinical PICO question is (P) what are splinting intervention decisions for luxated, avulsed and root-fractured teeth (I) considering that the splinting intervention choice may include (i) no splinting, (ii) rigid or functional splinting for the different types of trauma and (iii) different durations of the splinting period (C) when comparing these splinting choices for the different types of trauma and their effect on (O) healing outcomes for the teeth. A keyword search of PubMed was used. Reference lists from identified articles and dental traumatology texts were also appraised. The inclusion criterion for this review was either a multivariate analysis or controlled stratified analyses as many variables have the potential to confound the assessment and evaluation of healing outcomes for teeth that have been luxated, avulsed or root-fractured. A positive statistical test is not proof of a causal conclusion, as a positive statistical relationship can arise by chance, and so this review also appraises animal studies that reportedly explain biological mechanisms that relate to healing outcomes of splinted teeth. The clinical studies were ranked using the ,Centre of Evidence-based Medicine' categorization (levels 1,5). All 12 clinical studies selected were ranked as level 4. The studies generally indicate that the prognosis is determined by the type of injury rather than factors associated with splinting. The results indicate that the types of splint and the fixation period are generally not significant variables when related to healing outcomes. This appraisal identified difficulties in the design of animal experimentation to correctly simulate some dental injuries. Some of the studies employed rigid splinting techniques, which are not representative of current recommendations. Recommended splinting treatment protocols for teeth that have been luxated, avulsed or root-fractured teeth are formulated on the strength of research evidence. Despite the ranking of these studies in this appraisal as low levels of evidence, these recommendations should be considered ,best practice', a core philosophy of evidence-based dentistry. [source]

    Agro-Food Preferences in the EU's GSP Scheme: An Analysis of Changes Between 2004 and 2006

    Federica DeMaria
    This article examines the extent to which the 2006 revisions to the EU's Generalised System of Preferences improved market-access opportunities for developing-country agro-food exports. It shows that they resulted in only a slight increase in the percentage preferential margin, but that there has been a significant increase in the value of preferential trade and of the preferential margin enjoyed by exporters. This was accompanied by changes in the ranking of beneficiaries. Countries such as China, Brazil, Argentina, India and South Africa maintained their significant shares of GSP agro-food exports, but other countries such as Thailand and Vietnam have now emerged as major GSP beneficiaries. [source]

    Antidiabetic and toxicological evaluations of naringenin in normoglycaemic and NIDDM rat models and its implications on extra-pancreatic glucose regulation

    R. R Ortiz-Andrade
    Aim:, The present investigation was designed to determine the in vivo antidiabetic effect of naringenin (NG) in normoglycaemic and diabetic rat models through blood glucose (GLU) measurements following acute and subchronic time periods. Possible modes of action of NG were investigated and its acute toxicity determined. Methods:, Normoglycaemic and non-insulin-dependent diabetes mellitus (NIDDM) rat models were treated for acute and subchronic (5 days) time periods with 50 mg/kg/day of NG. Blood biochemical profiles were determined after 5 days of the treatment in normoglycaemic and NIDDM rats using commercial kits for GLU, triglycerides (TG), total cholesterol (CHOL) and high-density lipoprotein (HDL). In order to elucidate its antidiabetic mode of action, NG was administered intragastrically and an oral glucose tolerance test performed using GLU and sucrose (2 g/kg) as substrates. The inhibitory effect of a single concentration of NG (10 ,M) on 11,-hydroxysteroid dehydrogenase type 1 (11,-HSD1) activity in vitro was determined. Finally, the preclinical safety and tolerability of NG was determined by toxicological evaluation in mice and rats using Organization for Economic Cooperation and Development (OECD) protocols. Results:, Intragastrically administered NG (50 mg/kg) induced a significant decrease in plasma GLU in normoglycaemic and NIDDM rat models (p < 0.05) following acute and subchronic time periods. After 5 days of administration, NG produced significant diminished blood GLU and TG levels in streptozotocin,nicotinamide,induced diabetic rats. The administration of NG to normal rats significantly increased the levels of TG, CHOL and HDL (p < 0.05). NG (5 and 50 mg/kg) induced a total suppression in the increase of plasma GLU levels after administration of substrates (p < 0.01), but NG did not produce inhibition of ,-glucosidase activity in vitro. However, NG (10 ,M) was shown to inhibit 11,-HSD1 activity by 39.49% in a cellular enzyme assay. Finally, NG showed a Medium Lethal Dose LD50 > 5000 mg/kg and ranking at level five based on OECD protocols. Conclusion:, Our findings suggest that NG may exert its antidiabetic effect by extra-pancreatic action and by suppressing carbohydrate absorption from intestine, thereby reducing the postprandial increase in blood GLU levels. [source]