Learning assessment, particularly in admission processes for undergraduate courses at higher education institutions, is a crucial step and constitutes a constant challenge for these educational institutions. Ensuring quality and equity in these processes is essential to ensure that the selection process is fair and that the candidates admitted have the appropriate profile. At the Instituto Superior de Ciências da Educação de Cabinda (ISCED-Cabinda/Angola), the entrance exam for the Mathematics Teaching course is the main instrument used to select candidates with the necessary profile to face the challenges of this degree. Item Response Theory (IRT) and Multidimensional Item Response Theory (MIRT) were applied to achieve some insights about students’ abilities and quality of the main instrument of selection. The single factor analysis showed that the items were well-designed, but allowed us to identify two problematic items, suggesting improvements for the construction of future exams. The Multidimensional Item Response Analysis revealed the presence of two main latent factors of “Analytical Geometry and Algebra”, and, “Calculus and Trigonometry”, suggesting that the entrance exam is capable of adequately capturing these two core competencies for the course. In general, the results show that the test has good internal consistency and is composed of discriminative and very discriminative items and that there are items of all levels of difficulty. Therefore, there are reasons to agree that the test produces the expected results, that is, it measures the skills of candidates in the ISCED-Cabinda/Angola entrance exam.

The aim of this study was to verify the effect of Ag and Pt with different loadings (0.1 and 0.5wt.%) as dopants on TiO2for the degradation of a mixture of five parabens through photocatalytic ozonation. The effect of the treatment on the mixture toxicity over different species was also analyzed. The best catalyst in terms of parabens degradation was 0.5%Ag-TiO2.The decrease of metal loading on TiO2 decreased the parabens degradation efficiency as well as COD and TOC removal. Also this decrease has a slight effect over the treated solution toxicity over the different species tested.

The ferroelectric switching behaviour and piezoelectric response of poly(vinylidene fluoride) (PVDF) prepared by drawing at stretching ratios from 1 to 5 and temperatures from 80 to 140 ºC has been studied. Stretching ratio and temperature deeply influences the α (non ferroelectric) to β (ferroelectric) phase transformation. The variations in the phase content are accompanied by changes in the degree of crystallinity and the microstructure, all of them influencing the macroscopic piezoelectric and ferroelectric response of the material. This work shows how the piezo- and ferroelectric behaviour of PVDF depend on the aforementioned parameters and, in particular, on the crystalline β-phase content. Coercive electric field, remnant polarization and saturation polarization increase with increasing ferroelectric β-phase content in the sample. In a similar way, samples with higher β-phase content show higher d33 piezoelectric coefficients.

Damage to peripheral nerve fibers results in axonal loss and demyelination followed by regeneration and remyelination under optimal conditions with the possibility of some functional recovery. The experimental challenge is to accelerate axonal regeneration to promote reinnervation and improve functional recovery after peripheral nerve injury. In the past few decades, different types of biological or artificial guide tubes have been developed to bridge the gap of a sectioned nerve, to limit the fibrosis process and to orient the regenerating fibers towards the distal stump. Chitosan is widely used for biomedical applications, including crosslinked with other materials. In this work, chitosan guide tubes were produced and implanted using the rat sciatic nerve animal model. Functional tests were performed as well as a mechanical and structural characterization of the guide tubes. (c) 2017 IEEE.

Background: Identifying locale-specific patterns regarding the variation in stroke incidence throughout the year and with atmospheric temperature may be useful to the organization of stroke care, especially in low-resource settings. Goal: We aimed to describe the variation in the incidence of stroke hospitalizations across seasons and with short-term temperature variation, in Maputo, Mozambique. Methods: Between August 1, 2005, and July 31, 2006, we identified 651 stroke events in Maputo dwellers, according to the World Health Organization’s STEPwise approach. The day of symptom onset was defined as the index date. We computed crude and adjusted (humidity, precipitation and temperature) incidence rate ratios (IRRs) and 95% confidence intervals (CIs) with Poisson regression. Results: Stroke incidence did not vary significantly with season (dry versus wet: crude IRR = .98, 95% CI: .84-1.15), atmospheric temperature at the index date, or average atmospheric temperature in the preceding 2 weeks. The incidence rates of stroke were approximately 30% higher when in the previous 10 days there was a decline in the minimum temperature greater than or equal to 3°C between any 2 consecutive days (variation in minimum temperature −5.1 to −3.0 versus −2.3 to −.4, adjusted IRR = 1.31, 95% CI: 1.09-1.57). No significant associations were observed according to the variation in maximum temperatures. Conclusions: Sudden declines in the minimum temperatures were associated with a higher incidence of stroke hospitalizations in Maputo. This provides important information for prediction of periods of higher hospital affluence because of stroke and to understand the mechanisms underlying the triggering of a stroke event.

A acumulação de herbicidas no ambiente em virtude de sua larga utilização em sistemas agrícolas, associada à alta persistência, é extremamente preocupante, considerando os efeitos maléficos que alguns destes compostos causam à flora e à fauna. A atrazina (2-cloro-4-etilamino-6-isopropilamino-s-triazina) é um dos herbicidas mais utilizados na atualidade e tem sido detectada em teores consideráveis em mananciais e solos. O objetivo deste estudo foi avaliar o comportamento sortivo da atrazina comercial em Cambissolo Húmico em condições naturais e em ausência de matéria orgânica. Foram determinadas isotermas de sorção de atrazina comercial em amostras do horizonte A na sua forma natural e na forma oxidada. A quantidade máxima de herbicida sorvido variou de 8 % (amostra oxidada) a 49 % (amostra natural) da quantidade adicionada. A aplicação do modelo de Freundlich na forma linear aos dados experimentais forneceu altos coeficientes de correlação para a sorção em amostra natural (r = 0,960, P < 0,01) e na amostra oxidada (r = 0,937, P < 0,01). O coeficiente n f (modelo de Freundlich) obtido na amostra natural (1,40) indica que a afinidade do sorbato pelo sorvente aumentou com o progresso da sorção, enquanto, na amostra oxidada, o comportamento foi inverso (n f = 0,78). O valor do coeficiente Kf foi de 1,10 L kg-1 na amostra natural e de 0,84 L kg-1 na amostra oxidada, enquanto o coeficiente de distribuição da atrazina (Kd) foi de 4,64 e 0,33 L kg-1, respectivamente. Estes resultados mostram que a matéria orgânica foi o sorvente determinante na retenção de atrazina no Cambissolo húmico. Adicionalmente, o valor de Koc de 103 L kg-1 obtido classifica a atrazina comercial como de alta mobilidade para o sistema atrazina-solo estudado.

Objectives: To determine clinical and histopathological differences between melanoma associated with nevus (MAN) and de novo melanoma (MN). Methods: Retrospective study of all cases of cutaneous melanoma diagnosed between 2001 and 2009 in Centro de Dermatologia Médico-Cirúrgica de Lisboa. Results: Of the 397 melanomas included, 52.6% were of feminine sex and 47.4% of the masculine. Of these melanomas only 9.3% were histologically associated with nevus, with discrete predominance of cases in the feminine sex (54%, p=0,033). In the group of the MAN the average of ages was slightly inferior (56,5 vs 59,3 years, p=0,577). The trunk was the preferential localization of all the melanomas (42.1%, p=0,005). Histologically the superficial spreading subtype was more frequently associated with MAN. The MAN were thinner than the MN (1,42 versus 2,13 mm, p=0,030), specially in the feminine sex (0,99mm, p=0,031). The Breslow tumor thickness and the presence of ulceration had a significant statistical correlation with the metastatic spread and the mortality by melanoma. Conclusions: The majority of the melanomas seem to arise de novo. In our study, factors that were significantly associated with MAN include feminine sex, trunk location, younger age, inferior Breslow thickness and superficial spreading subtype.