5,602 research outputs found

    Propriétés psychométriques de l’échelle de satisfaction des cours académiques (ESCA) chez les étudiants universitaires brésiliens

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    Academic satisfaction has been studied from different perspectives that considerate distinct ways of measurement. However, the plurality of evaluated facets prevents a more parsimonious assessment of the general students’ academic satisfaction. In the article, we aimed to provide psychometric evidence of the validity and reliability for the AMSS in Brazil in two studies (N = 893). In Study 1, an exploratory factor analysis and item parameters (Item Response Theory) support the one-factor solution and the suitability of the six items. Moreover, evidence for factorial invariance across gender and convergent validity with the PANAS and with the SWLS was also presented in Study 2. In conclusion, the present paper provides evidence of the adequacy of the AMSS to evaluate global satisfaction with the academics course in Brazil.Propiedades psicométricas de la Escala de Satisfacción del Curso Académico (ESCA) en estudiantes universitarios brasileños La satisfacción académica ha sido estudiada bajo diferentes perspectivas, produciendo dife- rentes formas de medición. Sin embargo, la pluralidad de facetas evaluadas impide una evaluación más parsimoniosa de la satisfacción académica de los estudiantes en general. En este artículo, objetivamos proporcionar evidencias psicométricas de la validez y con- fiabilidad para el ESCA en Brasil en dos estudios (N = 893). En el Estudio 1, un análisis factorial exploratorio y los parámetros de los ítems (Teoría de Respuesta al Item) soportan la solución unifatorial y la adecuación de los seis ítems. Además, se presentaron evidencias de invariancia factorial entre género y validez convergente con el PANAS y con el ESV en el Estudio 2. En conclusión, este estudio proporciona evidencias de la adecuación de la ESCA para evaluar la satisfacción global con el curso académico en Brasil.A satisfação acadêmica tem sido estudada sob diferentes perspectivas que contemplam formas distintas de mensuração. Entretanto, a pluralidade de facetas avaliadas impede uma avaliação mais parcimoniosa da satisfação acadêmica dos estudantes em geral. O presente estudo tem por objetivo fornecer evidências psicométricas da validade e confiabilidade para o ESCA no Brasil em dois estudos (N = 893). No Estudo 1, uma análise fatorial exploratória e os parâmetros dos itens (Teoria de Resposta ao Item) suportam a solução unifatorial e a adequação dos seis itens. Além disso, foram apresentadas evidências de invariância fatorial entre gênero e validade convergente com o PANAS e com o ESV no Estudo 2. Em con- clusão, este estudo fornece evidências da adequação da ESCA para avaliar a satisfação global com o curso acadêmico na versão em português.La satisfaction académique a été étudiée sous différentes perspectives qui envisagent différentes formes de mesure. Cependant, la pluralité des facettes évaluées empêche une évaluation plus parcimonieuse de la satisfaction académique des étudiants en général. La pré- sente étude vise à fournir des preuves psychométriques de validité et de fiabilité pour ESCA au Brésil dans deux études (N = 893). Dans l’étude 1, une analyse factorielle exploratoire et les paramètres d’item (Théorie de la réponse à l’item) corroborent la solution à un facteur et l’adéquation des six items. En outre, nous avons présenté des preuves d’invariance factorielle entre le sexe et la validité convergentes avec PANAS et ESV dans l’étude 2. En conclusion, cette étude fournit des preuves de l’aptitude de l’ESCA à évaluer la satisfaction générale à l’égard du cours universitaire dans la version portugaise

    Reverse micelles with spines: L-2 phases of surfactant ion-polyion complex salts, n-alcohols and water investigated by rheology, NMR diffusion and SAXS measurements

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Homogeneous alcoholic isotropic solutions (L-2 phases) of "complex salts'' of hexadecyltrimethylammonium neutralized by polyacrylate CTAPA(n) (n = 30 or 6000), in the presence of water were examined at 25 degrees C by means of small-angle X-ray scattering (SAXS), rheology and NMR self-diffusion measurements for different n-alcohols (octanol, hexanol and butanol) and at varying water contents. The greater water solubility and the slower water self-diffusion coefficients in these L-2 phases, when compared to results with surfactant-free alcohols, suggested that these phases are composed of reverse aggregates with water in their cores. A comparatively rapid self-diffusion of the surfactant ion in butanol suggested a significant fraction of "free'' surfactant ions, dissociated from the reverse aggregates. Rheological data confirmed that the obtained viscoelastic properties were consistent with a system containing entangled elongated micelles, whose properties were controlled by the polyion chain length. NMR diffusion measurements for complex salt solutions with the shorter counter-polyion (CTAPA(30)) produced estimates of the aggregate lengths that were close to the extended length of one PA(30) chain. In summary, these results support the formation of aggregates composed by surfactant decorated polyion chains with a water core, whose properties are determined by the polyion chain length, behaving like reverse micelles with spines.61144153Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Swedish Research CouncilFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Computer-Generated Ovaries to Assist Follicle Counting Experiments

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    Precise estimation of the number of follicles in ovaries is of key importance in the field of reproductive biology, both from a developmental point of view, where follicle numbers are determined at specific time points, as well as from a therapeutic perspective, determining the adverse effects of environmental toxins and cancer chemotherapeutics on the reproductive system. The two main factors affecting follicle number estimates are the sampling method and the variation in follicle numbers within animals of the same strain, due to biological variability. This study aims at assessing the effect of these two factors, when estimating ovarian follicle numbers of neonatal mice. We developed computer algorithms, which generate models of neonatal mouse ovaries (simulated ovaries), with characteristics derived from experimental measurements already available in the published literature. The simulated ovaries are used to reproduce in-silico counting experiments based on unbiased stereological techniques; the proposed approach provides the necessary number of ovaries and sampling frequency to be used in the experiments given a specific biological variability and a desirable degree of accuracy. The simulated ovary is a novel, versatile tool which can be used in the planning phase of experiments to estimate the expected number of animals and workload, ensuring appropriate statistical power of the resulting measurements. Moreover, the idea of the simulated ovary can be applied to other organs made up of large numbers of individual functional units

    Structural brain network abnormalities and the probability of seizure recurrence after epilepsy surgery

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    OBJECTIVE: We assessed preoperative structural brain networks and clinical characteristics of patients with drug-resistant temporal lobe epilepsy (TLE) to identify correlates of postsurgical seizure recurrences. METHODS: We examined data from 51 patients with TLE who underwent anterior temporal lobe resection (ATLR) and 29 healthy controls. For each patient, using the preoperative structural, diffusion, and postoperative structural MRI, we generated 2 networks: presurgery network and surgically spared network. Standardizing these networks with respect to controls, we determined the number of abnormal nodes before surgery and expected to be spared by surgery. We incorporated these 2 abnormality measures and 13 commonly acquired clinical data from each patient into a robust machine learning framework to estimate patient-specific chances of seizures persisting after surgery. RESULTS: Patients with more abnormal nodes had a lower chance of complete seizure freedom at 1 year and, even if seizure-free at 1 year, were more likely to relapse within 5 years. The number of abnormal nodes was greater and their locations more widespread in the surgically spared networks of patients with poor outcome than in patients with good outcome. We achieved an area under the curve of 0.84 ± 0.06 and specificity of 0.89 ± 0.09 in predicting unsuccessful seizure outcomes (International League Against Epilepsy [ILAE] 3–5) as opposed to complete seizure freedom (ILAE 1) at 1 year. Moreover, the model-predicted likelihood of seizure relapse was significantly correlated with the grade of surgical outcome at year 1 and associated with relapses up to 5 years after surgery. CONCLUSION: Node abnormality offers a personalized, noninvasive marker that can be combined with clinical data to better estimate the chances of seizure freedom at 1 year and subsequent relapse up to 5 years after ATLR. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that node abnormality predicts postsurgical seizure recurrence

    Non-puerperal uterine inversion due to submucous myoma in a young woman: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Inversion of the uterus is an uncommon complication of the puerperium and it is an even rarer complication of the non-puerperal period. A submucous myoma is mostly the cause of the non-puerperal inversion but diagnosis can be difficult. In young women, non-puerperal uterine inversion is likely associated with a malignancy.</p> <p>Case presentation</p> <p>A 19-year-old nulliparous woman presented with abnormal vaginal bleeding, dysmenorrhoea, and a large mass protruding from her cervix. The mass was interpreted as a prolapsed pedunculated submucosal myoma. After extirpation of the mass by clamping and twisting its pedicle, a laparotomy was required under suspicion of a uterine rupture. The diagnosis was confirmed and the patient's uterus could be preserved. Pathological examination revealed a submucous myoma. The uterine inversion happened when the uterus retracted to expel the submucous myoma with fundal attachment. By extirpating the stalk the fundus was also resected, causing a uterine rupture.</p> <p>Conclusion</p> <p>We report a case of non-puerperal uterine inversion associated with a benign submucous myoma. Non-puerperal uterine inversion is very uncommon in women of reproductive age and is usually caused by a malignant tumour. However, uterine-sparing surgery should be attempted in young women until the final pathology is known.</p

    Frutapin, a lectin from Artocarpus incisa (breadfruit): cloning, expression and molecular insights

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    Artocarpus incisa (breadfruit) seeds contain three different lectins (Frutalin, Frutapin and Frutackin) with distinct carbohydrate specificities. The most abundant lectin is Frutalin, an α-D-galactose-specific carbohydrate-binding glycoprotein with antitumour properties and potential for tumour biomarker discovery as already reported. Frutapin (FTP) is the second most abundant, but proved difficult to purify with very low yields and contamination with Frutalin frustrating its characterization. Here, we report for the first time high-level production and isolation of biologically-active recombinant FTP in E. coli BL21, optimizing conditions with the best set yielding >40 mg/L culture of soluble active FTP. The minimal concentration for agglutination of red blood cells was 62.5 µg/mL of FTP, a process effectively inhibited by mannose. Apo-FTP, FTP-mannose and FTP-glucose crystals were obtained and diffracted X-rays to a resolution of 1.58 (P212121), 1.70 (P3121) and 1.60 (P3121) Å, respectively. The best solution showed four monomers per asymmetric unit. Molecular Dynamics simulation suggested FTP displays higher affinity for mannose than glucose. Cell studies revealed FTP was non-cytotoxic to cultured mouse fibroblast 3T3 cells below 0.5 mg/mL and also capable of stimulating cell migration at 50 µg/mL. In conclusion, our optimized expression system allowed high amounts of correctly-folded soluble FTP to be isolated. This recombinant bioactive lectin will now be tested in future studies for therapeutic potential; for example, in wound healing and tissue regeneration

    Imbedding HACCP principles in dairy herd health and production management: case report on calf rearing

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    Driven by consumer demands, European legislation has suggested the use of HACCP (Hazard Analysis Critical Control Point) as the quality risk management programme for the whole dairy chain. Until now, an exception has been made for primary producers, but as regulations evolve, on-farm HACCP-like programmes should be ready to assure food safety as well as animal health and animal welfare. In our field experiment, the HACCP-concept was used to combine both optimal farm management and formalisation of quality assurance in an on-farm situation in the Netherlands. The process of young stock rearing was chosen, since its importance for the future of the farm is often underestimated. Hazards and their associated risk factors can be controlled within the farm-specific standards and tolerances, as targets can be controlled by corrective measures and by implementation of farm-specific worksheets. The veterinarian is pivotal for the facility-based HACCP team, since he/she has knowledge about on-farm risk assessment and relations between clinical pathology, feed and farm management. The HACCP concept in combination with veterinary herd health and production management programmes offers a promising approach to optimise on-farm production processes (i.e., young stock rearing) in addition to a structural approach for quality risk management on dairy farms

    Comparative study of nonlinear properties of EEG signals of a normal person and an epileptic patient

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    Background: Investigation of the functioning of the brain in living systems has been a major effort amongst scientists and medical practitioners. Amongst the various disorder of the brain, epilepsy has drawn the most attention because this disorder can affect the quality of life of a person. In this paper we have reinvestigated the EEGs for normal and epileptic patients using surrogate analysis, probability distribution function and Hurst exponent. Results: Using random shuffled surrogate analysis, we have obtained some of the nonlinear features that was obtained by Andrzejak \textit{et al.} [Phys Rev E 2001, 64:061907], for the epileptic patients during seizure. Probability distribution function shows that the activity of an epileptic brain is nongaussian in nature. Hurst exponent has been shown to be useful to characterize a normal and an epileptic brain and it shows that the epileptic brain is long term anticorrelated whereas, the normal brain is more or less stochastic. Among all the techniques, used here, Hurst exponent is found very useful for characterization different cases. Conclusions: In this article, differences in characteristics for normal subjects with eyes open and closed, epileptic subjects during seizure and seizure free intervals have been shown mainly using Hurst exponent. The H shows that the brain activity of a normal man is uncorrelated in nature whereas, epileptic brain activity shows long range anticorrelation.Comment: Keywords:EEG, epilepsy, Correlation dimension, Surrogate analysis, Hurst exponent. 9 page
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