2,027 research outputs found

    Antecedents of academic performance of university students: academic engagement and psychological capital resources

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    Predicting academic performance is of key importance to the success, wellbeing and prosperity of students, their families, the economy, and the society at large. This study investigates the relationship between academic engagement, psychological capital (PsyCap) and academic performance. Data were collected in two different universities, one in Spain and another in Portugal. Students completed two self-report questionnaires regarding academic engagement and Psychological Capital. Academic performance was assessed through Grade Point Average, provided by the universities at the end of the exam period. The samples consisted of 389 and 243 undergraduate students, respectively. Results showed a positive relationship between academic engagement and PsyCap, on the one hand, and academic performance on the other, in both samples. Results also supported PsyCap as a full mediator in the relationship between academic engagement and academic performance. Exploration of alternative models yielded superior fit for the proposed model. Accordingly, academically engaged students were likely to experience higher levels of PsyCap, which in turn positively impacted their academic performance. The results point to the importance of considering psychological predictors, rather than the prevalent reliance on traditional predictors of academic performance

    Spectraleletromagnetic and topographic informations on the determination of soil compounds

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    A obtenção de informações quantitativas do solo por técnicas não destrutivas, como o sensoriamento remoto e os modelos digitais do terreno (MDT), abre a possibilidade de avaliações mais rápidas e menos onerosas no estudo de solos. O objetivo deste trabalho foi verificar a possibilidade de quantificar atributos do solo utilizando informações extraídas de sensor orbital ASTER conjugados com parâmetros topográficos. A área de estudo com 184 ha, localizada em Rafard (SP), foi amostrada em forma de grid sendo coletada uma amostra por hectare. A reflectância foi obtida da imagem ASTER e os dados topográficos a partir do MDT. Em seguida, utilizando os dados orbitais e de relevo foram gerados os modelos de regressão para os atributos do solo. As variáveis dependentes foram selecionadas a partir do método stepwise. Posteriormente, os modelos com R² > 0,50 foram testados em amostras desconhecidas de terra e os valores estimados pelas equações (VE) e os valores determinados em laboratório (VD) foram avaliados através de gráficos de dispersão. Os componentes SiO2, Fe2O3, TiO2 e argila foram os atributos testados, e Fe2O3 e argila obtiveram os melhores coeficientes de determinação. Conclui-se que os modelos gerados pelos dados espectrais e de relevo permitem quantificar os referidos componentes do solo.The obtention of soil quantitative information by non destructive techniques, like remote sensing and digital elevation model (DEM) open a possibility of faster and cheaper evaluation on soil studies. This study aims at verifying the possibility of quantifying soil atributtes through ASTER orbital sensor data and topographic features. The study area, with 184 ha, located in Rafard County, São Paulo State, Brazil, was sampled in a grid way collecting 1 sample/ha. Reflectance data was obtained from ASTER image and topographic features from DEM. Then, using orbital an topographic data were generated a multiple regression equation for soil attributes. The dependent variables were selected by a forward stepwise method. After that, the models with R² > 0.50 were tested with unknown soil samples and the estimated values (VE) and the determined values (VD) were evaluated through scatterplots. SiO2, Fe2O3, TiO2 and clay attributes were tested and, Fe2O3 and clay obtained higher values of determination coefficient. It is conclude that the models generated with spectral data and topographic information allowed the quantification of the above cited soil components

    Ara romana reaproveitada na capela de S. João (Lobão da Beira, Tondela) (Conventus Scallabitanus)

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    A revista Ficheiro Epigráfico é um suplemento da revista Conimbriga e destina-se a dar a conhecer inscrições romanas inéditas da Hispânia. Não tem periodicidade estipulada e é coordenada pelo Professor José d’Encarnação.Durante as obras de restauro da estrutura do altar-mor da capela de S. João, em Lobão da Beira, freguesia do concelho de Tondela (distrito de Viseu), realizadas neste ano de 2017, foi encontrada uma ara romana, cuja tipologia aponta para o século I d. C.; não ostentava nenhuma inscrição primitiva, mas, em contrapartida, um letreiro datado do século XVII. Leu-se: S / IOM / 1604 (ou 1609) – o que dá a entender que quem fez a gravação, aproveitando um monumento romano, tinha algumas luzes do tipo de inscrições habituais. Assim, o S inicial poderia significar o comum S(acrum) e houve a intenção de dar a entender que se tratava de uma dedicatória a Júpiter Óptimo Máximo, uma das divindades mais veneradas neste ambiente lusitano

    Functional analysis of the mouse Nodal antagonist, Cerl2, during left-right axis formation

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    Although recently our understanding of how the LR asymmetry is generated in vertebrate embryos has seen rapid progress, many important questions remain to be explained. In mouse embryos, the leftward flow of the extra-embryonic fluid in the node cavity, called nodal flow, seems to be the symmetry-breaking event. However, it is not yet know how this flow functions or how the asymmetric signal(s) generated in the node is/are transferred to the lateral plate mesoderm. The mouse gene cerberus-like2(cerl2) encodes a 20-kDa protein with a predicted signal peptide sequence and a cysteine-rich domain (CRD) containing nine cysteines characteristic of the Cerberus/DAN family. Whole-mount in situ hybridization studies showed that cerl2 transcripts could be first detected in a horseshoe-shaped expression pattern in the perinodal region of the mouse embryo (E7.0), resembling Nodal expression at this stage. At stage E7.5, expression of cerl2 begins to decrease in intensity on the left side, and by early somitogenesis (E8.0), it can be strongly detected in the right side of the node, assuming a complementary expression pattern to that observed in Nodal. Furthermore, it was shown that Cerl2 activity is upstream of the Nodal receptor inhibiting Nodal and its downstream targets. A physical interaction between these two proteins exists, which suggests that Cerl2 is a secreted Nodal antagonist. Here, to elucidate the role of Cerl2 protein in the early events of symmetry breaking the functional activity of this Nodal antagonist will be discussed.info:eu-repo/semantics/publishedVersio

    Enhancing the superconducting transition temperature of BaSi2 by structural tuning

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    We present a joint experimental and theoretical study of the superconducting phase of the layered binary silicide BaSi2. Compared with the layered AlB2 structure of graphite or diboride-like superconductors, in the hexagonal structure of binary silicides the sp3 arrangement of silicon atoms leads to corrugated sheets. Through a high-pressure synthesis procedure we are able to modify the buckling of these sheets, obtaining the enhancement of the superconducting transition temperature from 4 K to 8.7 K when the silicon planes flatten out. By performing ab-initio calculations based on density functional theory we explain how the electronic and phononic properties of the system are strongly affected by changes in the buckling. This mechanism is likely present in other intercalated layered superconductors, opening the way to the tuning of superconductivity through the control of internal structural parameters.Comment: Submitte

    Unintentional staining of lens posterior capsule with trypan blue during extracapsular cataract extraction: case report

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    Report of a complication related to the use of 0.1% trypan blue during capsular staining of the anterior crystalline lens capsule in an extracapsular cataract extraction with intraocular lens implantation. The capsular dye was injected using an air-bubble technique, inadvertently, it was done using high pressure dispersing the dye through the zonules leading to a complete losts of red reflex, the following steps of the procedure becoming more difficult after the cataract extraction and causing a temporary disturbance of visual acuity in the postoperative period. In order to avoid this complication, the authors also describe the use of Modified air-bubble technique where dispersive viscoelastic is placed into the iridolenticular space 360° to create a protection barrier.Relato de complicação relacionada ao uso do azul de tripano 0,1% ocorrida ao corar a cápsula anterior do cristalino em facectomia extracapsular com implante de lente intra-ocular. O corante foi injetado sob alta pressão utilizando a técnica de bolha de ar ocasionando a migração deste através da zônula e conseqüente perda do reflexo vermelho no peroperatório dificultando os passos subseqüentes à extração da catarata e comprometendo temporariamente a acuidade visual no pós-operatório. Tendo como objetivo evitar esta complicação, os autores descrevem ainda, o uso da Técnica de bolha de ar modificada no qual o viscoelástico dispersivo é injetado no espaço iridolenticular 360° para compor uma barreira de proteção.Universidade Federal de São Paulo (UNIFESP)Faculdade de Medicina do ABC Departamento de OftalmologiaUniversidade Federal de São Paulo, EPM, São Paulo, BrazilSciEL

    In situ measurement of hydraulic conductivity of mountain soils: a case study in Serra da Estrela mountain (Central Portugal)

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    Understanding the role of the vadose zone is essential to accurately assess hydrogeological systems and the respective groundwater resources. The study area (Manteigas – Nave de Santo António – Torre sector, Serra da Estrela Mountain, Central Portugal) presents specific geological, morphotectonical and climatic characteristics with significant influence on the hydrogeologic regime. The vadose zone has particular features that contribute to control both the quantity and the quality of the groundwater resources. In situ hydraulic conductivity tests were carried out in A and H soil horizons, by means of the constant head permeameter (Guelph permeameter) method. The mean value of the field saturated hydraulic conductivity is high (around 6 cm/h) and is typical of coarse textured soils. Unsaturated hydraulic conductivity was estimated using the Gardner mathematical model

    How groups react to disloyalty in the context of intergroup competition: Evaluations of group deserters and defectors

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    Groups strongly value loyalty, especially in the context of intergroup competition. However, research has yet to investigate how groups respond to members who leave the group or join a competing outgroup. Three studies investigated groups' reactions to defectors (Experiment 1) and deserting members (Experiments 2 and 3). Experiment 1 used a minimal group paradigm to demonstrate that defectors trigger a stronger derogation of ingroup deviants than outgroup deviants vis-à-vis normative members. Experiments 2 and 3 compared group members' responses to defection versus desertion from minimal and self-assigned groups, respectively. Experiment 3 also explored an explanation for the evaluations of disloyalty. Across studies, participants evaluated normative ingroup members more positively than defectors and deserters. Outgroup deserting and defecting members were evaluated similarly. Derogation of ingroup as compared to outgroup targets emerged only for defectors. In addition, Experiment 3 demonstrated that negativity toward the outgroup was related to stronger derogation of disloyal targets. Negative outgroup attitudes trigger stricter criteria for responding to disloyalty. Directions for future research are discussed

    Analytical methodologies for the determination of biogenic amines in wines: an overview of the recent trends

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    Biogenic amines are naturally present in grapes or can occur during the vinification and aging processes, essentially due to the microorganism’s activity. When present in wines in high amount, biogenic amines may cause not only organoleptic defects but also adverse effects in sensitive human individuals, namely due to the toxicity of histamine, tyramine and putrescine. Even though there are no legal limits for the concentration of biogenic amines in wines, some European countries only recommend maximum limits for histamine. In this sense, biogenic amines in wines have been widely studied. The determination of amines in wines is commonly achieved by liquid chromatography, using derivatization reagents in order to promote its separation and detection. In alternative, other promising methodologies have been developed using capillary electrophoresis or biosensors, revealing lower costs and faster results, without needing a derivatization step. Nowadays, it is still a challenge to develop faster and inexpensive techniques or methodologies to apply in the wine industry. Thus, this review will be focused on the studies published in the last decade that involves the determination of biogenic amines in wines, highlighting the novelty, improvement and optimization of the analytical methods. The sample preparation procedures (such as derivatization reagents), the analytical methodologies and the new trends being followed by the wine industry are also described and discussed.info:eu-repo/semantics/publishedVersio

    Conception, development and validation of a software interface to assess human’s horizontal intra-cyclic velocity with a mechanical speedo-meter

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    The aim of this paper was to: (i) calibrate the Swimsportec® speedo-meter; (ii) concept and develop a software’s interface for it (iii) validate the full system. Calibration was done with an industrial robot. The robot arm’s performed a linear and horizontal path at a uniform movement for a set of wide range of velocities (0.5<v<4.5m/s) being the tension data acquire for each specific linear velocity. Software’s interface was developed in LabVIEW® to acquire, display and process pair wises velocity-time data on-line during the subject’s locomotion bout. To transfer data from speedo-meter to the software an acquisition card is used. System validation was done for a set of land-based human locomotion techniques (from slow walk to maximal running) in four subjects and comparing it with a Doppler radar gun. Linear regression models between speedo-meter system and radar gun where very high for both the coefficient of variation of the subject’s velocity within the full gait cycle and his maximal velocity. The 95% of interval confidence agreement limits were very close together in both variables. More than 80% of the Bland- Altman plots were with the 1.96 standard-deviation criteria used on regular basis as rule thumb for techniques validation
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