175 research outputs found

    Power in voting rules with abstention: an axiomatization of a two components power index

    Get PDF
    The final publication is available at Springer via http://dx.doi.org/10.1007/s10479-016-2124-5In order to study voting situations when voters can also abstain and the output is binary, i.e., either approval or rejection, a new extended model of voting rule was defined. Accordingly, indices of power, in particular Banzhaf’s index, were considered. In this paper we argue that in this context a power index should be a pair of real numbers, since this better highlights the power of a voter in two different cases, i.e., her being crucial when switching from being in favor to abstain, and from abstain to be contrary. We also provide an axiomatization for both indices, and from this a characterization as well of the standard Banzhaf index (the sum of the former two) is obtained. Some examples are provided to show how the indices behave.Peer ReviewedPostprint (author's final draft

    Strong Proximal Continuity and Convergence

    Get PDF
    In several situations the notion of uniform continuity can be strengthened to strong uniform continuity to produce interesting properties, especially in constrained problems. The same happens in the setting of proximity spaces. While a parallel theory for uniform and strong uniform convergence was recently developed, and a notion of proximal convergence is present in the literature, the notion of strong proximal convergence was never considered. In this paper, we propose several possible convergence notions, and we provide complete comparisons among these concepts and the notion of strong uniform convergence in uniform spaces. It is also shown that in particularly meaningful classes of functions these notions are equivalent and can be considered as natural definitions of strong proximal convergence. Finally we consider a function acting between two proximity spaces and we connect its continuity/strong continuity to convergence in the respective hyperspaces of a natural functor associated to the function itself

    Medical students, spirituality and religiosity-results from the multicenter study SBRAME

    Get PDF
    Background: To evaluate the relationship between spirituality/religiosity (S/R) and the attitudes, beliefs and experiences of medical students in Brazil with respect to S/R in their undergraduate training and clinical practice.Methods: SBRAME (Spirituality and Brazilian Medical Education) is a multicenter study involving 12 Brazilian medical schools with 5950 medical students (MS). Participants completed a questionnaire that collected information on socio-demographic data and S/R in their undergraduate training and practice.Results: of all MS, 3630 participated in the survey (61.0%). the sample was 53.8% women and the mean age was 22.5 years. the majority of MS believed that spirituality has an impact on patients' health (71.2%) and that this impact was positive (68.2%). the majority also wanted to address S/R in their clinical practice (58.0%) and considered it relevant (75.3%), although nearly one-half (48.7%) felt unprepared to do so. Concerning their training, most MS reported that they had never participated in a spirituality and health activity (81.0%) and that their medical instructors had never or rarely addressed this issue (78.3%). the majority also believed that they should be prepared to address spiritual issues related to the health of their patients (61.6%) and that this content should be included in the medical curriculum (62.6%).Conclusion: There is a large gap between MS attitudes and expectations and the S/R training that they are receiving during their undergraduate training. the majority of MS surveyed believe that patients should have their beliefs addressed and that these beliefs could have important effects on their health and the doctor-patient relationship. These results should stimulate discussion about the place that S/R training should have in the medical curriculum.Univ Fed Juiz de Fora, Juiz de Fora, BrazilBrazilian Med Spiritist Assoc, SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, SĂŁo Paulo, BrazilDuke Univ, Med Ctr, Durham, NC USAKing Abdulaziz Univ, Jeddah 21413, Saudi ArabiaUniversidade Federal de SĂŁo Paulo, SĂŁo Paulo, BrazilWeb of Scienc

    Stability in Linear Optimization Under Perturbations of the Left-Hand Side Coefficients

    Get PDF
    This paper studies stability properties of linear optimization problems with finitely many variables and an arbitrary number of constraints, when only left hand side coefficients can be perturbed. The coefficients of the constraints are assumed to be continuous functions with respect to an index which ranges on certain compact Hausdorff topological space, and these properties are preserved by the admissible perturbations. More in detail, the paper analyzes the continuity properties of the feasible set, the optimal set and the optimal value, as well as the preservation of desirable properties (boundedness, uniqueness) of the feasible and of the optimal sets, under sufficiently small perturbations.Research supported by the grants: BASAL PFB-03 (Chile), FONDECYT 1130176 (Chile) and MTM2011-29064-C03-01 (Spain). Research supported by the grant MTM2014-59179-C2-1-P (Spain) and the Discovery Projects DP120100467 and DP110102011 (Australian Research Council). Research supported by the MIUR project ’Variational and Topological Methods in the Study of Nonlinear Phenomena” (2009)

    Gamma-Glutamyltransferase is a Reliable Marker for Tubular Effects of Contrast Media

    Get PDF
    The aim of this study was to evaluate the usefulness of the measurement of urinary excretion of the brush-border enzyme gamma glutamyl-transferase (GGT), in comparison with that of alanine aminopeptidase (AAP), as a marker for tubular toxicity due to contrast media (CM). Urinary activities of AAP and GGT were measured prior to the administration of CM and 1, 3 and 5 days after in forty-nine adult renal patients undergoing a radiological examination with intravascular administration of CM. The behavior of GGT was similar to that of AAP. In fact, urinary activities of both AAP and GGT increased greatly after CM. This effect was maximal on the 1st day and statistically significant for both enzymes. Furthermore, on the 1st day a relevant increase of enzyme activity (at least +50% over the basal value) was observed in the same number of patients (67%) for AAP and GGT. The concordance between GGT and AAP variations was high and statistically significant. Finally, different variables (osmolarity, dose of CM, and baseline renal function of the patients) had a similar effect on urinary excretion of AAP and GGT. The repeatability of duplicated determinations of GGT resulted better than that of AAP. In conclusion, the good concordance of the results of GGT with those of AAP justifies the use of GGT as a marker for tubular effects due to CM. Furthermore, the measurement of GGT has a better repeatability than that of AAP

    life cycle approach a critical review in the tourism sector

    Get PDF
    The concept of sustainability comes from the scientific literature that defines sustainable the management of a resource if, being known his ability to play, is not exceeded in its exploitation beyond a certain threshold defined critical natural capital [1]. In the past, economic growth has been achieved at the expense of natural resource depletion, without stocks being allowed to regenerate. Ecosystems have been widely degraded and biodiversity has been lost at an unprecedented pace [2,3]. In this sense, the concept of sustainability and development are not compatible with the degradation of heritage and natural resources (non-renewable and potentially exhaustible), but also with concepts mostly related to ethical and social values such as the violation of the human dignity and freedom, with poverty and economic decline and the lack of recognition of the rights and equal opportunities [4,5]. The three basic components of sustainability are therefore: - the ability to generate income and employment for the people's livelihood (economic sustainability) - the ability to generate conditions of human well-being, understood as the territory security, an equal distribution of health and civil rights (social sustainability); - the ability to maintain the same level of quality and reproducibility of natural resources (environmental sustainability

    The 75-Gram Glucose Load in Pregnancy

    Get PDF
    OBJECTIVE—To investigate, in pregnant women without gestational diabetes mellitus (GDM), the relation among obstetric/demographic characteristics; fasting, 1-h, and 2-h plasma glucose values resulting from a 75-g glucose load; and the risk of abnormal neonatal anthropometric features and then to verify the presence of a threshold glucose value for a 75-g glucose load above which there is an increased risk for abnormal neonatal anthropometric characteristics. RESEARCH DESIGN AND METHODS—The study group consisted of 829 Caucasian pregnant women with singleton pregnancy who had no history of pregestational diabetes or GDM, who were tested for GDM with a 75-g, 2-h glucose load, used as a glucose challenge test, in two periods of pregnancy (early, 16–20 weeks; late, 26–30 weeks), and who did not meet the criteria for a GDM diagnosis. In the newborns, the following abnormal anthropometric characteristics were considered as outcome measures: cranial/thoracic circumference (CC/TC) ratio ≤10th percentile for gestational age (GA), ponderal index (birth weight/length3 × 100) ≥90th percentile for GA, and macrosomia (birth weight ≥90th percentile for GA), on the basis of growth standard development for our population. For the first part of the objective, logistic regression models were used to identify 75-g glucose load values as well as obstetric and demographic variables as markers for abnormal neonatal anthropometric characteristics. For the second part, the receiver operating characteristic (ROC) curve was performed for the 75-g glucose load values to determine the plasma glucose threshold value that yielded the highest combined sensitivity and specificity for the prediction of abnormal neonatal anthropometric characteristics. RESULTS—In both early and late periods, maternal age >35 years was a predictor of neonatal CC/TC ratio ≤10th percentile and macrosomia, with fasting 75-g glucose load values being independent predictors of neonatal CC/TC ratio ≤10th percentile. In both periods, 1-h values gave a strong association with all abnormal neonatal anthropometric characteristics chosen as outcome measures, with maternal age >35 years being an independent predictor for macrosomia. The 2-h, 75-g glucose load values were significantly associated in both periods with neonatal CC/TC ratio ≤10th percentile and ponderal index ≥90th percentile, whereas maternal age >35 years was an independent predictor of both neonatal CC/TC ratio ≤10th percentile and macrosomia. In the ROC curves for the prediction of neonatal CC/TC ratio ≤10th percentile for GA in both early and late periods of pregnancy, inflection points were identified for a 1-h, 75-g glucose load threshold value of 150 mg/dl in the early period and 160 mg/dl in the late period. CONCLUSIONS—This study documented a significant association, seen even in the early period of pregnancy, between 1-h, 75-g glucose load values and abnormal neonatal anthropometric features, and provided evidence of a threshold relation between 75-g glucose load results and clinical outcome. Our results would therefore suggest the possibility of using a 75-g, 1-h oral glucose load as a single test for the diagnosis of GDM, adopting a threshold value of 150 mg/dl at 16–20 weeks and 160 mg/dl at 26–30 weeks

    Mediumship: review of quantitatives studies published in the 21st century

    Get PDF
    Background Mediumship can be defined as the alleged ability to communicate with deceased persons. The last decade has been particularly productive for this field of research and the study of mediumship can help the understanding of the human mind-brain relationship and provide objective data to the scientific community and to the general population. Objective The aim of this review is to summarize and discuss the results found on recent studies investigating mediumship. Furthermore, we aim to discuss the psychophysiology underlying mediumship and future perspectives for this study topic. Methods A literature search for articles in English, Portuguese and Spanish published from January 2000 up to June 2015 was conducted using three electronic databases (PubMed, Lilacs and Web of Science). Review articles, qualitative studies and studies investigating altered states of consciousness caused by psychoactive substances were excluded. The original search returned 150 articles, but the application of exclusion criteria resulted in the inclusion of 19 articles for final analysis. Results The general findings were: (1) an association of mediumship with good mental health, predominantly in experienced mediums, (2) heterogeneous findings regarding the ability of mediums to provide accurate information what may be due to different study methodologies and (3) incipient studies assessing physiological correlations during mediumistic communications (i.e. hypoactivation of brain regions responsible for cognitive processing and writing planning during psychography compared to a control task; electroencephalographic (EEG) changes and a slight predominance of the sympathetic nervous system). Discussion There is a paucity of empirical data available in this controversial research field. New studies employing rigorous design (e.g.triple-blind protocols to test accuracy of mediumistic communications), and sensitive methods are required
    • …
    corecore