A priori reliability of tests with cut score

The theoretical probability of misclassification in a mastery test is exactly computed using the raw score probability distribution (in the Rasch model) as a function of the examinee???s latent ability. The resulting misclassification probability curve, together with the latent ability distribution in the group of examinees, completely determines the expected rate of classification errors. It is shown that several distinct ability thresholds, playing different roles in connection to classification reliability, can be associated to a test with a single cut score. In particular, it is possible to define (and compute) two relevant ability intervals, which encapsulate the functioning of a mastery test (about and far from the cut score, respectively); the dependence of these intervals on the item difficulty spectrum is investigated. Extension to the 2PL model is also discussed, with emphasis on the effects of weighted scoring

Impaired gallbladder motility and delayed orocecal transit contribute to pigment gallstone and biliary sludge formation in β-thalassemia major adults

Aim: Gallbladder and gastrointestinal motility defects exist in gallstones patients and to a lesser extent in pigment gallstone patients. To investigated the role of gallbladder and gastrointestinal motility disorders in pigment gallstone formation in β-thalassemia major. Methods: Twenty-three patients with β-thalassemia major (16 females; age range 18-37 years) and 70 controls (47 females, age range 18-40 years) were studied for gallbladder and gastric emptying (functional ultrasonography), orocecal transit (OCTT, H2-breath test), autonomic dysfunction (sweat-spot, cardiorespiratory reflex tests), bowel habits, gastrointestinal symptoms and quality of life (all with questionnaires). Gallbladder content (ultrasonography) was examined before and during 8-12 mo follow-up. Results: Gallstones and/or biliary sludge were found in 13 (56%) patients. β-thalassemia major patients had increased fasting (38.0±4.8 mL vs 20.3±0.7 mL, P = 0.0001) and residual (7.9±1.3 mL vs 5.1±0.3 mL, P = 0.002) volume and slightly slower emptying (24.9±1.7 min vs 20.1±0.7 min, P = 0.04) of the gallbladder, together with longer OCTT (132.2±7.8 min vs 99.7±2.3 min, P = 0.00003) than controls. No differences in gastric emptying and bowel habits were found. Also, patients had higher dyspepsia (score: 6.7±1.2 vs 4.9±0.2, P = 0.027), greater appetite (P = 0.000004) and lower health perception (P = 0.00002) than controls. Autonomic dysfunction was diagnosed in 52% of patients (positive tests: 76.2% and 66.7% for parasympathetic and sympathetic involvement, respectively). Patients developing sludge during follow-up (38%, 2 with prior stones) had increased fasting and residual gallbladder volume. Conclusion: Adult β-thalassemia major patients have gallbladder dysmotility associated with delayed small intestinal transit and autonomic dysfunction. These abnormalities apparently contribute together with haemolytic hyperbilirubinemia to the pathogenesis of pigment gallstones/ sludge in β-thalassemia major. Copyright © 2004 by The WJG Press

Stimulation scale of the living environment: validation by experts in ageing

peer reviewe

Bioética e direitos fundamentais: a recusa às transfusões de sangue pelas Testemunhas de Jeová

This paper will examine the Institute of Bioethics and fundamental rights in the face of the refusal of blood transfusions by Jehovah's Witnesses. Based on investigating the motives involved in this decision and what legal support they have for their will to be recognized. It is a right provided for in the Federal Constitution that guarantees the patient's autonomy to avail himself of his existential choices, however, that is in conflict with the divergent position of the doctors who seek the judicial route to impose on the patient the use of hemotherapy against his will , provoking state intervention based on the claim that the individual's decision causes the collision of fundamental principles, such as the right to life and the right to religious freedom. For this, we studied bibliographies, laws of the current legal order, articles and jurisprudence, what remained for demonstrating the non-occurrence of a collision of fundamental rights, bearing in mind that Jehovah's Witnesses do not want to have their right to life, for religious reasons, but to guarantee it in its integral form by accepting the use of alternative methods. The existence of legitimacy in refusing blood transfusions based on fundamental principles, especially on the right to life, made possible by the recognition of blood as a risk treatment and the use of alternatives to blood transfusion.Trabalho de Conclusão de Curso (Graduação)Este trabalho analisará o instituto da Bioética e direitos fundamentais diante da recusa das transfusões de sangue pelas Testemunhas de Jeová. Tendo por base investigar os motivos que envolvem essa decisão e qual o respaldo legal possuem para que se reconheça a sua vontade. Trata-se de direito previsto na Constituição Federal que garante a autonomia do paciente de se valer de suas escolhas existenciais, porém que se choca com o divergente posicionamento dos médicos que buscam a via judicial para impor ao paciente o uso da hemoterapia contra sua vontade provocando a intervenção estatal fundamentada na alegação de que a decisão do indivíduo causa a colisão de princípios fundamentais (direito à vida versus direito à liberdade religiosa). Para isso, foram estudadas bibliografias, leis do ordenamento jurídico vigente; artigos e jurisprudências; que restaram por demonstrar a não ocorrência de colisão de direitos fundamentais, tendo em vista que as Testemunhas de Jeová não querem dispor de seu direito à vida, por fundamento religioso, e sim de garanti-lo em sua forma integral por aceitar a utilização de melhores métodos. Portanto, comprovando-se a existência de legitimidade na recusa às transfusões de sangue com base nos princípios fundamentais, principalmente no direito à vida, possibilitada pelo reconhecimento do sangue como um tratamento de risco e a utilização de alternativas a estes

Dynamic Mechanical Interactions Between Neighboring Airspaces Determine Cyclic Opening and Closure in Injured Lung

OBJECTIVES:: Positive pressure ventilation exposes the lung to mechanical stresses that can exacerbate injury. The exact mechanism of this pathologic process remains elusive. The goal of this study was to describe recruitment/derecruitment at acinar length scales over short-time frames and test the hypothesis that mechanical interdependence between neighboring lung units determines the spatial and temporal distributions of recruitment/derecruitment, using a computational model. DESIGN:: Experimental animal study. SETTING:: International synchrotron radiation laboratory. SUBJECTS:: Four anesthetized rabbits, ventilated in pressure controlled mode. INTERVENTIONS:: The lung was consecutively imaged at ~ 1.5-minute intervals using phase-contrast synchrotron imaging, at positive end-expiratory pressures of 12, 9, 6, 3, and 0 cm H2O before and after lavage and mechanical ventilation induced injury. The extent and spatial distribution of recruitment/derecruitment was analyzed by subtracting subsequent images. In a realistic lung structure, we implemented a mechanistic model in which each unit has individual pressures and speeds of opening and closing. Derecruited and recruited lung fractions (Fderecruited, Frecruited) were computed based on the comparison of the aerated volumes at successive time points. MEASUREMENTS AND MAIN RESULTS:: Alternative recruitment/derecruitment occurred in neighboring alveoli over short-time scales in all tested positive end-expiratory pressure levels and despite stable pressure controlled mode. The computational model reproduced this behavior only when parenchymal interdependence between neighboring acini was accounted for. Simulations closely mimicked the experimental magnitude of Fderecruited and Frecruited when mechanical interdependence was included, while its exclusion gave Frecruited values of zero at positive end-expiratory pressure greater than or equal to 3 cm H2O. CONCLUSIONS:: These findings give further insight into the microscopic behavior of the injured lung and provide a means of testing protective-ventilation strategies to prevent recruitment/derecruitment and subsequent lung damage

Zero expiratory pressure and low oxygen concentration promote heterogeneity of regional ventilation and lung densities

BackgroundIt is not well known what is the main mechanism causing lung heterogeneity in healthy lungs under mechanical ventilation. We aimed to investigate the mechanisms causing heterogeneity of regional ventilation and parenchymal densities in healthy lungs under anesthesia and mechanical ventilation. MethodsIn a small animal model, synchrotron imaging was used to measure lung aeration and regional-specific ventilation (sV.). Heterogeneity of ventilation was calculated as the coefficient of variation in sV. (CVsV.). The coefficient of variation in lung densities (CVD) was calculated for all lung tissue, and within hyperinflated, normally and poorly aerated areas. Three conditions were studied: zero end-expiratory pressure (ZEEP) and FIO2 0.21; ZEEP and FIO2 1.0; PEEP 12 cmH(2)O and F(I)O(2)1.0 (Open Lung-PEEP = OLP). ResultsThe mean tissue density at OLP was lower than ZEEP-1.0 and ZEEP-0.21. There were larger subregions with low sV. and poor aeration at ZEEP-0.21 than at OLP: 12.9 9.0 vs. 0.6 +/- 0.4% in the non-dependent level, and 17.5 +/- 8.2 vs. 0.4 +/- 0.1% in the dependent one (P = 0.041). The CVsV. of the total imaged lung at PEEP 12 cmH(2)O was significantly lower than on ZEEP, regardless of FIO2, indicating more heterogeneity of ventilation during ZEEP (0.23 +/- 0.03 vs. 0.54 +/- 0.37, P = 0.049). CVD changed over the different mechanical ventilation settings (P = 0.011); predominantly, CVD increased during ZEEP. The spatial distribution of the CVD calculated for the poorly aerated density category changed with the mechanical ventilation settings, increasing in the dependent level during ZEEP. ConclusionZEEP together with low FIO2 promoted heterogeneity of ventilation and lung tissue densities, fostering a greater amount of airway closure and ventilation inhomogeneities in poorly aerated regions.Peer reviewe

The Effect of Positive End-Expiratory Pressure on Lung Micromechanics Assessed by Synchrotron Radiation Computed Tomography in an Animal Model of ARDS

Modern ventilatory strategies are based on the assumption that lung terminal airspaces act as isotropic balloons that progressively accommodate gas. Phase contrast synchrotron radiation computed tomography (PCSRCT) has recently challenged this concept, showing that in healthy lungs, deflation mechanisms are based on the sequential de-recruitment of airspaces. Using PCSRCT scans in an animal model of acute respiratory distress syndrome (ARDS), this study examined whether the numerosity (ASnum) and dimension (ASdim) of lung airspaces change during a deflation maneuver at decreasing levels of positive end-expiratory pressure (PEEP) at 12, 9, 6, 3, and 0 cmH(2)O. Deflation was associated with significant reduction of ASdim both in the whole lung section (passing from from 13.1 +/- 2.0 at PEEP 12 to 7.6 +/- 4.2 voxels at PEEP 0) and in single concentric regions of interest (ROIs). However, the regression between applied PEEP and ASnum was significant in the whole slice (ranging from 188 +/- 52 at PEEP 12 to 146.4 +/- 96.7 at PEEP 0) but not in the single ROIs. This mechanism of deflation in which reduction of ASdim is predominant, differs from the one observed in healthy conditions, suggesting that the peculiar alveolar micromechanics of ARDS might play a role in the deflation process.Peer reviewe

The senior village as a new housing model for older people? Case study in Wallonia

Ce travail de fin d’études se penche sur un défi majeur de la société actuelle : faire face à la transition démographique causée par le vieillissement de la population et par la diminution du taux de fécondité. Dans ce contexte, la question du logement senior est devenue essentielle. L’objectif de cette recherche est de comprendre la société dans laquelle nous vivons en abordant des thématiques liées aux personnes âgées, tels que leurs besoins en termes de logement, d’équipements, de soins de santé et de création de liens sociaux. Ce travail se penche ensuite sur un cas particulier de village senior en Wallonie. Ce modèle, encore peu développé en Belgique, représente une alternative intéressante face à la population vieillissante en constante augmentation, et aux modèles d’hébergements existants comme les maisons de repos. Dès lors, l’objectif est de mettre en évidence les avantages et les limites du village senior par l’analyse d’un cas spécifique en Wallonie, permettant également d’en apprendre davantage sur les conditions de vie des habitants de ce type de village. En conclusion, ce travail de fin d’études cherche à déterminer si le village senior pourrait constituer une partie de la solution aux problèmes du logement des personnes âgées, en leur offrant une solution viable et adaptée à leurs besoins spécifiques

A PRIORI RELIABILITY OF TESTS WITH CUT SCORE

The theoretical probability of misclassification in a mastery test is exactly computed using the raw score probability distribution (in the Rasch model) as a function of the examinee???s latent ability. The resulting misclassification probability curve, together with the latent ability distribution in the group of examinees, completely determines the expected rate of classification errors. It is shown that several distinct ability thresholds, playing different roles in connection to classification reliability, can be associated to a test with a single cut score. In particular, it is possible to define (and compute) two relevant ability intervals, which encapsulate the functioning of a mastery test (about and far from the cut score, respectively); the dependence of these intervals on the item difficulty spectrum is investigated. Extension to the 2PL model is also discussed, with emphasis on the effects of weighted scoring