Ansiedad y locus de control en relación con el autoconcepto y rendimiento académico de los alumnos.

El estudio parte de los supuestos siguientes: A) El autoconcepto que el sujeto elabora como alumno, guarda relación con el rendimiento académico. B) Variables como ansiedad, y locus de control, deben mediar en esta relación acentuándola o debilitándola en función de las características que configuran la personalidad de los sujetos. Compuesta por 189 alumnos de 12 a 16 años, pertenecientes a octavo de EGB, distribuídos en 7 unidades mixtas de 3 colegios rurales y un colegio de enclave urbano de Albacete. Las variables con las que se trabaja son: autoconcepto global, autoconcepto académico, imágen académica global, rendimiento académico, ansiedad y locus de control. Cuestionario de Piers y Harris adaptado por Valero Zamora, para el autoconcepto global; procedimiento de Gimeno para el autoconcepto académico; calificaciones obtenidas por los alumnos en: Lenguaje, Idioma, Matemáticas, Naturales y Sociales; cuestionario de ansiedad estado-rasgo de Spielberger y otros para la ansiedad y escala ECNC de Palenzuela para el locus de control. El trabajo se ha realizado mediante la aplicación de los instrumentos o pruebas mencionadas en el apartado anterior y el análisis de los datos en función de los objetivos a través de: análisis estadístico de cada variable para sus características globales; análisis de varianza para establecer las diferencias de cada variable en función del sexo, medio e interacción de ambos y un análisis correlacional para estudiar las relaciones en el conjunto de variables estudiadas. El autoconcepto global se relaciona negativamente con las variables de ansiedad y factores externalidad y suerte del locus de control. El autoconcepto académico se relaciona con el autoconcepto global. La ansiedad tiene una debil relación negativa con el autoconcepto académico y con el rendimiento. Los rendimientos están muy relacionados entre sí y correlacionan significativamente con el rendimiento académico. Correlacionan positivamente los rendimientos totales y el autoconcepto académico comparado, y con la imágen académica grupal. Teniendo en cuenta que en esta fase evolutiva la acción orientadora tutorial tiene especial relieve, no sólo propone el autor la intervención para reducir ansiedad o incentivación positiva en alumnos problemáticos, sino que expone la necesidad de una estructuración de actividades que posibiliten resultados exitosos en los alumnos insuficientes, y una programación adecuada de acciones preventivas.

Expectativas, locus de controlo e auto-eficácia face à actual crise : uma realidade em estudantes universitários

O objectivo principal desta dissertação foi estudar a questão das expectativas de empregabilidade em estudantes universitários, no contexto actual de dificuldades do mercado de trabalho. Serão também abordados os conceitos de Locus de Controlo e a Auto-Eficácia, como variavéis determinantes neste processo. Foi feito um estudo com 141 participantes, dos quais 48 são alunos que frequentam a licenciatura e 93 frequentam o mestrado, os quais responderam a um questionário que incluía abordagens face à empregabilidade actual, à procura de emprego na área de formação e à visão global de um emprego. Os resultados vão ao encontro das hipóteses formuladas e acabam por traduzir que mesmo perante o panorama actual de dificuldades, os jovens não desistem e pretendem conseguir um emprego na sua área de formação.

Do EU direct payments to beef producers belong in the 'blue box'?

In the Uruguay Round Agreement on Agriculture, so-called 'blue box' support measures were exempted from reduction commitments, provided they were delivered under 'production-limiting' programs. Although classified as 'blue box', the EU system of direct payments (DP) to beef farmers imposes 'claim-limiting' restrictions rather than 'production-limiting' restrictions, allowing farmers to keep additional animals over and above the number upon which they are eligible to claim DP. The present paper provides empirical evidence that EU direct payments capitalise into the market prices of male calves and young steers in Ireland. It is also likely that DP capitalises into the prices of beef cows and heifers. Given this capitalisation process, some farmers can obtain 'capitalised' DP on animals produced over and above the 'claim-limiting' restrictions, by selling these animals through auction markets. Thus, 'capitalised' DP probably encourages production over and above the limiting measures.

Alternative methodologies - stretching the in vitro box

Current gas-based in vitro evaluation systems are extremely powerful research techniques. However they have the potential to generate a great deal more than simple fermentation dynamics. Details from four experiments are presented in which adaptation, and novel application, of an in vitro system allowed widely differing objectives to be examined. In the first two studies, complement methodologies were utilised. In such assays, an activity or outcome is inferred through the occurrence of a secondary event rather than by direct observation. Using an N-deficient incubation medium, the increase in starch fermentation, when supplemented with individual amino acids (i.e., known level of N) relative to that of urea (i.e., known quantity and N availability), provided an estimate of their microbial utilisation. Due to the low level of response observed with some arnino acids (notably methionine and lysine), it was concluded, that they may not need to be offered in a rumen-inert form to escape rumen microbial degradation. In another experiment, the extent to which degradation of plant cell wall components was inhibited by lipid supplementation was evaluated using fermentation gas release profiles of washed hay. The different responses due to lipid source and level of inclusion suggested that the degree of rumen protection required to ameliorate this depression was supplement dependent. That in vitro inocula differ in their microbial composition is of little interest per se, as long as the outcome is the same (i.e., that similar substrates are degraded at comparable rates and end-product release is equivalent). However where a microbial population is deficient in a particular activity, increasing the level of inoculation will have no benefit. Estimates of hydrolytic activity were obtained by examining fermentation kinetics of specific substrates. A number of studies identified a fundamental difference between rumen fluid and faecal inocula, with the latter having a lower fibrolytic activity, which could not be completely attributed to microbial numbers. The majority of forage maize is offered as an ensiled feed, however most of the information on which decisions such as choice of variety, crop management and harvesting date are made is based on fresh crop measurements. As such, an attempt was made to estimate ensiled maize quality from an in vitro analysis of the fresh crop. Fermentation profiles and chemical analysis confirmed changes in crop composition over the growing season, and loss of labile carbohydrates during ensiling. In addition, examination of degradation residues allowed metabolizable energy (ME) contents to be estimated. Due to difficulties associated with starch analysis, the observation that this parameter could be predicted by difference (together with an assumed degradability), allowed an estimate of ensiled maize ME to be developed from fresh material. In addition, the contribution of the main carbohydrates towards ME showed the importance of delaying harvest until maximum starch content has been achieved. (c) 2005 Elsevier B.V. All rights reserved.

Decoupling EU farm support: Does the new single payment scheme fit within the green box?

Recent reform of the EU’s Common Agricultural Policy (CAP) has led to a further decoupling of farm support. The EU believes that the new Single Payment Scheme, which replaces the former system of area and headage payments to farmers, tied to production, will qualify for green-box status in the WTO. We examine this contention, particularly in light of the recent WTO panel report on upland cotton.

The development of ISSR-derived SCAR markers around the Seasonal Flowering Locus (SFL) in fragaria vesca

Fragaria vesca is a short-lived perennial with a seasonal-flowering habit. Seasonality of flowering is widespread in the Rosaceae and is also found in the majority of temperate polycarpic perennials. Genetic analysis has shown that seasonal flowering is controlled by a single gene in F. vesca, the SEASONAL FLOWERING LOCUS (SFL). Here, we report progress towards the marker-assisted selection and positional cloning of SFL, in which three ISSR markers linked to SFL were converted to locus-specific sequence-characterized amplified region (SCAR1–SCAR3) markers to allow large-scale screening of mapping progenies. We believe this is the first study describing the development of SCAR markers from ISSR profiles. The work also provides useful insight into the nature of polymorphisms generated by the ISSR marker system. Our results indicate that the ISSR polymorphisms originally detected were probably caused by point mutations in the positions targeted by primer anchors (causing differential PCR failure), by indels within the amplicon (leading to variation in amplicon size) and by internal sequence differences (leading to variation in DNA folding and so in band mobility). The cause of the original ISSR polymorphism was important in the selection of appropriate strategies for SCAR-marker development. The SCAR markers produced were mapped using a F. vesca f. vesca × F. vesca f. semperflorens testcross population. Marker SCAR2 was inseparable from the SFL, whereas SCAR1 mapped 3.0 cM to the north of the gene and SCAR3 1.7 cM to its south.

HAWAIIAN SKIRT: an F-box gene that regulates organ fusion and growth in arabidopsis

A fast neutron-mutagenized population of Arabidopsis ( Arabidopsis thaliana) Columbia-0 wild-type plants was screened for floral phenotypes and a novel mutant, termed hawaiian skirt ( hws), was identified that failed to shed its reproductive organs. The mutation is the consequence of a 28 bp deletion that introduces a premature amber termination codon into the open reading frame of a putative F-box protein ( At3g61590). The most striking anatomical characteristic of hws plants is seen in flowers where individual sepals are fused along the lower part of their margins. Crossing of the abscission marker, Pro(PGAZAT):beta-glucuronidase, into the mutant reveals that while floral organs are retained it is not the consequence of a failure of abscission zone cells to differentiate. Anatomical analysis indicates that the fusion of sepal margins precludes shedding even though abscission, albeit delayed, does occur. Spatial and temporal characterization, using Pro(HWS):beta-glucuronidase or Pro(HWS):green fluorescent protein fusions, has identified HWS expression to be restricted to the stele and lateral root cap, cotyledonary margins, tip of the stigma, pollen, abscission zones, and developing seeds. Comparative phenotypic analyses performed on the hws mutant, Columbia-0 wild type, and Pro(35S):HWS ectopically expressing lines has revealed that loss of HWS results in greater growth of both aerial and below-ground organs while overexpressing the gene brings about a converse effect. These observations are consistent with HWS playing an important role in regulating plant growth and development.

Grey-box radial basis function modelling: the art of incorporating prior knowledge

A basic principle in data modelling is to incorporate available a priori information regarding the underlying data generating mechanism into the modelling process. We adopt this principle and consider grey-box radial basis function (RBF) modelling capable of incorporating prior knowledge. Specifically, we show how to explicitly incorporate the two types of prior knowledge: the underlying data generating mechanism exhibits known symmetric property and the underlying process obeys a set of given boundary value constraints. The class of orthogonal least squares regression algorithms can readily be applied to construct parsimonious grey-box RBF models with enhanced generalisation capability.