6,161 research outputs found

    Students’ perceptions of assessment: a comparative analysis between Portugal and Sweden

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    This paper aims at investigating students’ perceptions about assessment, especially the ways in which it is put into practice. Data were collected through questionnaires in different programmes in Portugal and Sweden. In total, 173 students from Portugal and 72 from Sweden participated in the study. Findings showed that students had similar ideas about assessment, such as verification of knowledge and learning, tests and grades. Their experiences of assessment methods used varied in the two countries, which can partly be explained by differences in national education systems. A learner-oriented perspective is prominent in the use of assessment methods, but at the same time student influence on assessment is perceived as low in both countries. Implications of the findings are analysed, namely issues regarding a learner-oriented perspective and the effectiveness, influence, trust, times and methods of assessment.Understanding the assessment process, including the concepts and methods used, is essential to educational practice. In recent years new trends on assessment have emerged from an integrated perspective of the teaching, learning and assessment process (Rust 2007). In contrast to summative assessment, which can be perceived as mainly using assessment to certify student achievement (Boud and Falchikov 2006; Hernández 2012), formative assessment supports and monitors the students’ learning, providing continuous feedback during the process (Yorke 2003; Weurlander et al. 2012), and informing them about their performance (Boud 1990; Brown and Knight 1994; Brew et al. 2009). These trends have introduced new methods of assessment (Brew et al. 2009) and more participatory practices, such as self, peer, and co-assessment (Dochy, Segers and Sluijsmans 1999).National Funds through the FCT (Foundation for Science and Technology) and co-financed by European Regional Development Funds (FEDER) through the Competitiveness and Internationalization Operational Program (POCI) through CIEC (Research Centre on Child Studies, of the University of Minho) with the reference POCI-01-0145-FEDER-007562Strategic Project UID/CED/00317/2013CIEC – Research Centre on Child Studies, IE, UMinho (FCT R&D unit 317), Portugalinfo:eu-repo/semantics/publishedVersio

    Effect of chitosan-Aloe vera coating on postharvest quality of blueberry (Vaccinium corymbosum) fruit

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    The present study was carried out to evaluate the effect of chitosan-based edible coatings with Aloe vera extract on the postharvest blueberry fruit quality during storage at 5 °C. Firstly, A. vera fractions (pulp and liquid) were extracted from leaves and evaluated in terms of antifungal and antioxidant capacities. The choice of the most adequate chitosan and A. vera fraction concentrations to be incorporated in coating formulation was made based on the wettability of the corresponding coating solutions. Coatings with 0.5% (w/v) chitosan + 0.5% (w/v) glycerol + 0.1% (w/v) Tween 80 + 0.5% (v/v) A. vera liquid fraction presented the best characteristics to uniformly coat blueberry surface. Physico-chemical (i.e., titratable acidity, pH, weight loss) and microbiological analyses of coated blueberries (non-inoculated or artificially inoculated with Botrytis cinerea) were performed during 25 d. Microbiological growth and water loss levels were approximately reduced by 50% and 42%, respectively, in coated blueberries after 25 d compared to uncoated blueberries. After 15 d, weight loss values were 6.2% and 3.7% for uncoated and chitosanA. vera coated blueberries, respectively. Uncoated fruits presented mold contamination after 2 d of storage (2.0 ± 0.32 log CFU g1), whilst fruits with chitosan-based coatings with A. vera presented mold contamination only after 9 d of storage (1.3 ± 0.35 log CFU g1). Overall, coatings developed in this study extend blueberries shelf-life for about 5 d, demonstrating for the first time that the combination of chitosan and A. vera liquid fraction as edible coating materials has great potential in expanding the shelf-life of fruits.Joana T. Martins (SFRH/BPD/89992/2012) is the recipient of a fellowship from the Fundação para a Ciência e Tecnologia (FCT, Portugal). María L. Flores-López thanks Mexican Science and Technology Council(CONACYT, Mexico) for PhD fellowship support (CONACYT Grant number: 215499/310847). The authors thank the FCT the strategic funding of UID/BIO/04469/2013 unit and the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER- 027462)

    Teacher evaluation in Portugal: persisting challenges and perceived effects

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    This paper reports on findings from a broader piece of research aimed at investigating the ways in which head teachers experience a new teacher evaluation policy in Portugal, particularly in regard to the challenges and perceived effects of the policy on school and on teacher development. Data were collected through a questionnaire with open and closed-ended questions. In total, 134 head teachers participated in the study. Findings suggest a number of tensions and problems, most of which are related to the key features of the model of teacher evaluation itself. Others issues pertain to the lack of recognition of the appraisers and to the emergence of tensions amongst staff leading to the deterioration of the school climate. Persisting challenges to policy implementation, perceived effects on teachers and schools as well as the dilemmas of head teachers are analysed. The article concludes with the discussion of ways forward.Financial Support by CIEC (Research Centre on Child Studies, IE, UMinho; FCT R&D unit 317, Portugal) by the Strategic Project UID/CED/00317/2013, with financial support of National Funds through the FCT (Foundation for Science and Technology) and co-financed by European Regional Development Funds (FEDER) through the COMPETE 2020 - Competitiveness and Internationalization Operational Program (POCI) with the reference POCI-01-0145-FEDER-00756

    Caracterización exomorfológica y micrográfica de Cheilanthes pruinata, especie tóxica para el ganado y medicinal en humanos en la región Andina

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    El objetivo del trabajo fue definir, mediante la aplicación del método micrográfico, los caracteres anatómicos de valor diagnóstico requeridos para identificar la parte aérea de la especie denominada comúnmente "doradilla" (Cheilanthes pruinata Kaulf.) causal de intoxicaciones en el ganado menor en el NO de Argentina y que también es utilizada en medicina herbolaria en los Andes de Perú y Bolivia como analgésico y antihemorrágico. Se aplicó la técnica de disociado leve a hojas, órganos presumiblemente tóxicos y/o medicinales. Los resultados indican que, en láminas foliares, los pelos glandulares de pie uni y bicelulares, y cabeza secretora unicelular, las esporas triletes y los leptosporangios con anillo de dehiscencia vertical son las referencias válidas y en raquis y pecíolos los pelos tectores bicelulares de célula basal recta o acodada y célula apical aguzada fácilmente separable y fibro y macroesclereidas. Esta información es útil para reconocer la especie, tanto en contenido ruminal en caso de sospecha de intoxicación, como para realizar controles de calidad botánicos en muestras de herboristería.Exomorfologic and micrographic characterization of "doradilla", toxic specie to livestock and also medicinal for humans in Andean region. The study aimed to define, through the application of the micrographic method, those anatomical characters of diagnostic value required to identify the aerial parts of the specie commonly referred as "doradilla" (Cheilanthes pruinata Kaulf.) cause of poisoning in small livestock in the NW of Argentina, and which is also used in herbal medicine as analgesic and anti-haemorrhagic in the Andes of Bolivia and Peru. Mild dissociated technique was applied to leaves, presumably toxics and/or medicinal organs. Results show that, in leaf blades, glandular hairs with one- and two-cell stalk and single-cell secretory head as well as the trilete spores and leptosporangia with vertical ring dehiscence are valid references; and in rachis and petioles, bicellular protector hairs with basal straight or angled cell and easily separable sharp apical cell, along with fibro and macroesclereidas. Such information is useful to recognize the species both in ruminal contents in case of suspicion of intoxication as for quality control of botanical herbal samples.EEA Abra PampaFil: Flores, Estela N. Universidad Nacional de Jujuy. Facultad de Ciencias Agrarias. Cátedra de Botánica Sistemática y Fitogeografía. Laboratorio de Botánica Sistemática y Etnobotánica; ArgentinaFil: Califano, Laura Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Abra Pampa; ArgentinaFil: Gurni, Alberto A. Universidad Nacional de Jujuy. Facultad de Ciencias Agrarias. Cátedra de Botánica Sistemática y Fitogeografía. Laboratorio de Botánica Sistemática y Etnobotánica; ArgentinaFil: Vignale, Nilda D. Universidad Nacional de Jujuy. Facultad de Ciencias Agrarias. Cátedra de Botánica Sistemática y Fitogeografía. Laboratorio de Botánica Sistemática y Etnobotánica; Argentin

    Reduced Intellectual Development in Children with Prenatal Lead Exposure

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    OBJECTIVE: Low-level postnatal lead exposure is associated with poor intellectual development in children, although effects of prenatal exposure are less well studied. We hypothesized that prenatal lead exposure would have a more powerful and lasting impact on child development than postnatal exposure. DESIGN: We used generalized linear mixed models with random intercept and slope to analyze the pattern of lead effect of the cohort from pregnancy through 10 years of age on child IQ from 6 to 10 years. We statistically evaluated dose–response nonlinearity. PARTICIPANTS: A cohort of 175 children, 150 of whom had complete data for all included covariates, attended the National Institute of Perinatology in Mexico City from 1987 through 2002. EVALUATIONS/MEASUREMENTS: We used the Wechsler Intelligence Scale for Children–Revised, Spanish version, to measure IQ. Blood lead (BPb) was measured by a reference laboratory of the Centers for Disease Control and Prevention (CDC) quality assurance program for BPb. RESULTS: Geometric mean BPb during pregnancy was 8.0 μg/dL (range, 1–33 μg/dL), from 1 through 5 years was 9.8 μg/dL (2.8–36.4 μg/dL), and from 6 through 10 years was 6.2 μg/dL (2.2–18.6 μg/dL). IQ at 6–10 years decreased significantly only with increasing natural-log third-trimester BPb (β = −3.90; 95% confidence interval, −6.45 to −1.36), controlling for other BPb and covariates. The dose–response BPb–IQ function was log-linear, not linear–linear. CONCLUSIONS: Lead exposure around 28 weeks gestation is a critical period for later child intellectual development, with lasting and possibly permanent effects. There was no evidence of a threshold; the strongest lead effects on IQ occurred within the first few micrograms of BPb. RELEVANCE TO CLINICAL PRACTICE: Current CDC action limits for children applied to pregnant women permit most lead-associated child IQ decreases measured over the studied BPb range

    Abnormalities on 1q and 7q are associated with poor outcome in sporadic Burkitt's lymphoma. A cytogenetic and comparative genomic hybridization study

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    Comparative genomic hybridization (CGH) studies have demonstrated a high incidence of chromosomal imbalances in non-Hodgkin's lymphoma. However, the information on the genomic imbalances in Burkitt's Lymphoma (BL) is scanty. Conventional cytogenetics was performed in 34 cases, and long-distance PCR for t(8;14) was performed in 18 cases. A total of 170 changes were present with a median of four changes per case (range 1-22). Gains of chromosomal material (143) were more frequent than amplifications (5) or losses (22). The most frequent aberrations were gains on chromosomes 12q (26%), Xq (22%), 22q (20%), 20q (17%) and 9q (15%). Losses predominantly involved chromosomes 13q (17%) and 4q (9%). High-level amplifications were present in the regions 1q23-31 (three cases), 6p12-p25 and 8p22-p23. Upon comparing BL vs Burkitt's cell leukemia (BCL), the latter had more changes (mean 4.3 +/- 2.2) than BL (mean 2.7 +/- 3.2). In addition, BCL cases showed more frequently gains on 8q, 9q, 14q, 20q, and 20q, 9q, 8q and 14q, as well as losses on 13q and 4q. Concerning outcome, the presence of abnormalities on 1q (ascertained either by cytogenetics or by CGH), and imbalances on 7q (P=0.01) were associated with a short survival

    Synthesis, screening for antiacetylcholinesterase activity and binding mode prediction of a new series of [3-(disubstituted-phosphate)-4,4,4-trifluoro-butyl]-carbamic acid ethyl esters

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    A series of nine new [3-(disubstituted-phosphate)-4,4,4-trifluoro-butyl]-carbamic acid ethyl esters (phosphate-carbamate compounds) was obtained through the reaction of (4,4,4-trifluoro-3-hydroxybut-1-yl)-carbamic acid ethyl esters with phosphorus oxychloride followed by the addition of alcohols. The products were characterized by ¹H, 13C, 31P, and 19F NMR spectroscopy, GC-MS, and elemental analysis. All the synthesized compounds were screened for acetylcholinesterase (AChE) inhibitory activity using the Ellman method. All compounds containing phosphate and carbamate pharmacophores in their structures showed enzyme inhibition, being the compound bearing the diethoxy phosphate group (2b) the most active compound. Molecular modeling studies were performed to investigate the detailed interactions between AChE active site and small-molecule inhibitor candidates, providing valuable structural insights into AChE inhibition.Uma nova série de nove 3-fosfato-(4,4,4-trifluor-butil)-carbamatos de etila (compostos fosfato-carbamato), foram obtidos através da reação de (4,4,4-trifluor-3-hidroxibut-1-il)-etil carbamatos com oxicloreto de fósforo seguido de adição de álcoois. Os produtos foram caracterizados por espectroscopia de RMN de ¹H, 13C, 31P e 19F, CG-EM e análise elementar. Todos os compostos sintetizados foram testados para a inibição da enzima acetilcolinesterase (AChE) usando o método de Ellman. Todos os compostos analisados contendo os grupos carbamato e fosfato em sua estrutura, mostraram inibição enzimática, sendo que o composto contendo o grupo dietóxi (2b) apresentou a maior atividade inibitória. Estudos de modelagem molecular foram realizados para obter informações detalhadas entre o sítio ativo da enzima acetilcolinesterase e os compostos candidatos a inibição, obtendo-se valiosas informações estruturais com relação à inibição de enzima acetilcolinesterase.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPES

    TOX3 rs3803662 Polymorphism Is Associated With Breast Cancer Protection In Northeastern Mexican Woman

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    Introduction: Low penetrance genes are involved in breast cancer (BC) and confer risk for the development of this neoplasia. Different single nucleotide polymorphisms (SNPs) associated with BC have been identified, such as rs3803662 (TOX3), which is related to estrogen receptors in European and African-American women. The contribution of this variant in the Mexican population is unknown. The objective of this study was to evaluate, through a case-control design, the association of the SNP rs3803662 (TOX3), with the risk of BC in women from northeastern Mexico. Methods: We included 434 cases and 228 controls. Genotyping was carried out using RFLPs. The SPSS 7.0 statistical program was used to determine the gene frequencies, the estimation of the relative risk (Odds ratio [OR]), and the Hardy-Weinberg equilibrium (EHW). Results: The homocygote (T/T) genotype of the SNP TOX3 rs3803662 was identified as a protective allele for BC (OR: 0.47, 95% CI: 0.29 - 0.78). Conclusions; The T allele of the SNP rs3803662 can be considered as a protective factor for BC from northeastern Mexico women
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