160 research outputs found
A graphical approach to relational reasoning
Relational reasoning is concerned with relations over an unspecified domain of discourse. Two limitations to which it is customarily subject are: only dyadic relations are taken into account; all formulas are equations, having the same expressive power as first-order sentences in three variables. The relational formalism inherits from the Peirce-Schröder tradition, through contributions of Tarski and many others.
Algebraic manipulation of relational expressions (equations in particular) is much less natural than developing inferences in first-order logic; it may in fact appear to be overly machine-oriented for direct hand-based exploitation.
The situation radically changes when one resorts to a convenient representation of relations based on labeled graphs. The paper provides details of this representation, which abstracts w.r.t. inessential features of expressions.
Formal techniques illustrating three uses of the graph representation of relations are discussed: one technique deals with translating first-order specifications into the calculus of relations; another one, with inferring equalities within this calculus with the aid of convenient diagram-rewriting rules; a third one with checking, in the specialized framework of set theory, the definability of particular set operations. Examples of use of these techniques are produced; moreover, a promising approach to mechanization of graphical relational reasoning is outlined
The Social Position and Intellectual Identity of the Renaissance Mathematician-Physicist Giovanni Battista Benedetti: A Case Study in the Socio-Political History of Mechanics
Teleology and Realism in Leibniz's Philosophy of Science
This paper argues for an interpretation of Leibnizâs claim that physics requires both mechanical and teleological principles as a view regarding the interpretation of physical theories. Granting that Leibnizâs fundamental ontology remains non-physical, or mentalistic, it argues that teleological principles nevertheless ground a realist commitment about mechanical descriptions of phenomena. The empirical results of the new sciences, according to Leibniz, have genuine truth conditions: there is a fact of the matter about the regularities observed in experience. Taking this stance, however, requires bringing non-empirical reasons to bear upon mechanical causal claims. This paper first evaluates extant interpretations of Leibnizâs thesis that there are two realms in physics as describing parallel, self-sufficient sets of laws. It then examines Leibnizâs use of teleological principles to interpret scientific results in the context of his interventions in debates in seventeenth-century kinematic theory, and in the teaching of Copernicanism. Leibnizâs use of the principle of continuity and the principle of simplicity, for instance, reveal an underlying commitment to the truth-aptness, or approximate truth-aptness, of the new natural sciences. The paper concludes with a brief remark on the relation between metaphysics, theology, and physics in Leibniz
Best practice in psychological activities in cardiovascular prevention and rehabilitation: Position Paper
Recent guidelines on cardiovascular disease prevention suggest multimodal behavioral interventions for psychosocial risk factors and referral for psychotherapy in the case of clinically significant symptoms of depression and anxiety overall. Accordingly, psychologists of the Italian Association for Cardiovascular Prevention, Rehabilitation and Epidemiology (GICR-IACPR) have reviewed the key components of psychological activities in cardiovascular prevention and rehabilitation (CPR). The aim of this study was to elaborate a position paper on the best practice in routine psychological activities in CPR based on efficacy, effectiveness and sustainability. The steps followed were: i) a review of the latest international guidelines and position papers; ii) analysis of the evidence-based literature; iii) a qualitative analysis of the psychological services operating in some reference Italian cardiac rehabilitation facilities; iv) classification of the psychological activities in CPR as low or high intensity based on the NICE Guidelines on psychological interventions on anxiety and depression. We confirm the existence of an association between depression, anxiety, social factors, stress, personality and illness onset/outcome and coronary heart disease. Evidence for an association between depression, social factors and disease outcome emerges particularly for chronic heart failure. Some positive psychological variables (e.g., optimism) are associated to illness outcome. Evidence is reported on the impact of psychological activities on \u2018new\u2019 conditions which are now indicated for cardiac rehabilitation: pulmonary hypertension, grown-up congenital heart, end-stage heart failure, implantable cardioverter-defribrillator and mechanical ventricular assist devices, frail and oldest-old patients, and end-of-life care. We also report evidence related to caregivers. The Panel divided evidence-based psychological interventions into: i) low intensity (counseling, psycho-education, self-care, self-management, telemedicine, self-help); or ii) high intensity (individual, couples and/or family and group psychotherapy, such as stress management). The results show that psychotherapy is mainly consisting of cognitive-behavior therapy, interpersonal therapy, and short-term psycho-dynamic therapy. The current data further refine the working tools available for psychological activities in CPR, giving clear directions about the choice of interventions, which should be evidence-based and have at least a minimum standard. This document provides a comprehensive update on new knowledge and new paths for psychologists working in the CPR settings
Adherence issues related to sublingual immunotherapy as perceived by allergists
Objectives: Sublingual immunotherapy (SLIT) is a viable alternative to subcutaneous immunotherapy to treat allergic rhinitis and asthma, and is widely used in clinical practice in many European countries. The clinical efficacy of SLIT has been established in a number of clinical trials and meta-analyses. However, because SLIT is self-administered by patients without medical supervision, the degree of patient adherence with treatment is still a concern. The objective of this study was to evaluate the perception by allergists of issues related to SLIT adherence. Methods: We performed a questionnaire-based survey of 296 Italian allergists, based on the adherence issues known from previous studies. The perception of importance of each item was assessed by a VAS scale ranging from 0 to 10. Results: Patient perception of clinical efficacy was considered the most important factor (ranked 1 by 54% of allergists), followed by the possibility of reimbursement (ranked 1 by 34%), and by the absence of side effects (ranked 1 by 21%). Patient education, regular follow-up, and ease of use of SLIT were ranked first by less than 20% of allergists. Conclusion: These findings indicate that clinical efficacy, cost, and side effects are perceived as the major issues influencing patient adherence to SLIT, and that further improvement of adherence is likely to be achieved by improving the patient information provided by prescribers. © 2010 Scurati et al, publisher and licensee Dove Medical Press Ltd
Investigating trophic ecology and dietary niche overlap among morphs of Lake Trout in Lake Superior
Four morphs of Lake Trout (Salvelinus namaycush, Walbaum 1792) have been identified in Lake Superior: leans, siscowets, humpers, and redfins. In this comprehensive study, the trophic ecology of Lake Trout morphs were characterized using stomach content, fatty acid, and stable isotope data. Stomach content results indicated a predominately piscivorous diet for leans, siscowets, and redfins, whereas humper diets were comprised of 50% fish and 50% Mysis by mass. Humper and siscowets were most similar in their dietary fatty acid profiles, whereas redfins had the most distinct dietary fatty acid profile. Results from stable isotope analysis revealed some among-morph differences along a pelagic-profundal consumption gradient (34S), but there were no significant differences in trophic position (15N) or basal carbon sources among morphs (13C). Using the recently developed nicheROVER software package, 4-dimensional trophic niches for each morph were quantified using stable isotope ratios (ÎŽ13C, ÎŽ15N, and ÎŽ34S) and fatty acid profiles (30 dietary fatty acids, condensed to one axis). Humpers had the largest 4-dimensional niche regions of all four morphs, and redfins had the smallest. Pairwise probability of overlap among morphs in these four-dimensional niche regions was determined to be < 50% in most cases. Overall, stomach content results indicate that humpers diets were more planktivorous than the other morphs, consistent with previous research. Results of the niche overlap analysis suggests some degree of generalist feeding for all morphs. Better characterization of seasonal variation in diet using tracers that reflect more recent feeding (e.g., fatty acids, stomach contents, and/or stable isotope analyses performed on tissues that turnover more quickly than muscle) are needed to further elucidate among-morph differences and similarities in diet and trophic ecology
Changes in lipid composition during sexual development of the malaria parasite Plasmodium falciparum
Differential induction of malaria liver pathology in mice infected with Plasmodium chabaudi AS or Plasmodium berghei NK65
- âŠ