Análisis de una generalización del modelo de crecimiento cíclico de Goodwin

Gomblowski y Krüger (1986) introducen varias generalizaciones en el modelo de crecimiento cíclico de Goodwin (1967), obteniendo interesantes resultados sobre la estabilidad y el período del ciclo económico. El objetivo de nuestro artículo es el de mejorar la aportación de Gomblowski y Krüger introduciendo nuevas funciones de inversión y de negociación de los salarios nominales que parecen más adecuadas a la realidad económica. Con estas modificaciones se obtienen ciclos de 12-13 años y se observa que la consideración del efecto de la histéresis en el proceso de negociación de los salarios nominales así como la existencia de ilusión monetaria tienen un efecto estabilizador sobre el sistema económico.Gomblowski and Krüger (1986) introduce several generalizations in the Goodwin's model of cyclical growth (1967), obtaining interesting results on the stability and the period of the economic cycle. The objective of our article is improve the contribution of Gomblowski and Krüger introducing new investment function and money wage bargaining equation that seem more adequate to the economic reality. With these modifications are obtained cycles from 12-13 years and is observed that the consideration of the effect of hysteresis in the bargaining of the money wage as well as the money illusion existence have a stabilizing effect on the economic system

Consecuencias de la introducción de la teoría insider-outsider dentro del modelo de crecimiento cíclico de Goodwin

In the Goodwin's model (1967) of cyclical growth is observed that is produced a conflict of interest between the workers employed and the unemployed. Since the theory insider-outsider referred to the labour market analyses the consequences of this conflict and, furthermore, it seems to represent adequately the salary negotiation process that takes place in the European countries, we incorporate within Goodwin's model the postulates of this theory. This modification alters the qualitative characteristics of the original model that, though continues being stable, abandons his characteristic movement of closed orbits about the equilibrium due to the presence of histeresis in the labour market.En el modelo de crecimiento cíclico de Goodwin (1967) se observa que se produce un conflicto de intereses entre los trabajadores empleados y los desempleados. Dado que la teoría insider-outsider referida al mercado de trabajo analiza las consecuencias de dicho conflicto y, además, parece representar adecuadamente el proceso de negociación salarial que tiene lugar en los países europeos, incorporamos dentro del modelo de Goodwin los postulados de dicha teoría. Esta modificación altera las características cualitativas del modelo original que, aunque sigue siendo estable, abandona su característico movimiento de órbitas cerradas alrededor del equilibrio debido a la presencia de histéresis

Limos Arcillosos colapsables. Estudio experimental, teórico y aplicación a un caso práctico

Se ha realizado el estudio geotécnico de limos arcillosos colapsables en dos emplazamientos: la Presa d l'Albagés (Les Garrigues, Lérida) y el canal Segarra-Garrigues. Se ha realizado una completa caracterización mecánica e hidráulica de los limos en condición natural y compactados. A los resultados obtenidos se ha aplicado el modelo elastoplástico para simular los colapsos observados en los limos arcillosos. Pôr último, en un caso práctico, el canal Segarra-Garrigues, se ha analizado el comportamiento de terraplenes construidos sobre estos terrenos naturaleso sobre el mismo terreno compactado, analizando la estabilidad de los taludes y la deformabilidda secundaria del terraplén del canal

Music education in context: the construction of the teacher's identity within cross-disciplinary collaboration in the arts

This study was part of a research project that examined innovative practices in a primary school with an integrated arts curriculum. While the school started an expansion of its curriculum, a music teacher was hired to become part of the arts learning area. Her commitment to the overall project determines that she works in collaboration with the other arts teachers, namely, Visual Arts and Drama. Baring in mind a theoretical background that traces the lines of a liberating, autonomy promoting, and collaborative education, the development of the identity process of the music teacher was analyzed through her diary, fi eld notes, and other observational data, gathered by the research team. Findings indicate that, while signifi cant gains were brought about by crossdisciplinary collaboration, some problems remain to solve, concerning the role of specifi c musical skills development. The implications for music education research are suggested, with reference to the relationship between music skills development and integrated art projects

Actividade física e qualidade de vida na gravidez

Pouco se conhece acerca da actividade física e qualidade de vida da mulher na gravidez. Este estudo teve como objectivos 1) comparar os padrões de actividade física antes e durante a gravidez, 2) avaliar a percepção da qualidade de vida relacionada com a saúde durante os primeiros seis meses de gestação, e 3) comparar a percepção da qualidade de vida nas mulheres activas e insuficientemente activas considerando as recomendações de saúde pública. Método: Estudo longitudinal com 59 grávidas seleccionadas em consultórios médicos privados. Às 10-15 semanas foi recolhida informação sociodemográfica e médica, bem como informação sobre a actividade física três meses antes da concepção. Medidas de auto-relato foram administradas entre as 10-15 semanas e as 19-24 semanas de gestação para avaliar o tempo de actividade física (QAFG) (no trabalho, lazer, deslocações) e a qualidade de vida (SF-36). Resultados: A prevalência de actividade física recomendada é menor durante do que antes da gravidez (16.7% e 17.5% nos 1.º e 2.º trimestres, respectivamente vs. 47.4% antes da gravidez). Com a gravidez, não se verificaram alterações no tempo médio em diferentes tipos de actividade física, mas a actividade física no lazer registou uma diminuição significativa no 1.º trimestre face ao período anterior à concepção. Em comparação com uma amostra normativa de mulheres portuguesas, as grávidas apresentam, nos dois primeiros trimestres de gestação, uma percepção de qualidade da vida mais positiva na generalidade das dimensões do SF-36. No 2.º trimestre, o nível de limitação é significativamente maior nas dimensões físicas, à excepção da Dor Corporal, e nos resultados sumários do Componentes Físico e Mental. As mulheres que no 1.º trimestre atingem os níveis recomendados de actividade física no lazer (≥150 minutos por semana) apresentam melhor estado de saúde geral e estados de humor mais positivos do que as menos activas. Conclusão: A actividade física no lazer, embora diminua após a concepção, tem um impacto positivo na percepção do estado saúde geral e estados de humor da grávida, o que sugere a sua importância para a saúde da mulher também durante este período da vida.Background: Little is know about the impact of pregnancy in health-related quality of life (HRQoL) and in physical activity patterns. The objectives of this study were 1) to compare physical activity patterns before and during pregnancy, 2) to evaluate HRQoL among pregnant women until six months pregnancy and 3) to compare HRQoL between sufficiently and insufficiently active women considering the public health recommendations. Methods: Longitudinal study with 59 pregnant women (20-39 years of age) recruited in private obstetric clinics. At 10-15 weeks gestation, socio-demographic and medical information was collected, as well as physical activity levels three months prior to conception. Self-report measures were administered at 10-15 weeks and 19-24 weeks gestation to assess work, leisure and transportation-time physical activity and HRQoL. Results: The prevalence of recommended activity is lower during pregnancy than prepregnancy (16.7% and 17.5% in 1st and 2nd trimesters, respectively, vs. 47.4% prepregnancy). After conception, there were no changes in physical activity time, but leisure-time physical activity showed a decrease from prepregnancy to 1st trimester of gestation. Compared to Portuguese normative data, pregnant women demonstrate a more positive HRQoL on almost every domains of SF-36 in the first two trimesters of pregnancy. In the 2nd trimester of pregnancy, the level of impairment is significantly higher in physical HRQoL, with the exception of Bodily Pain, as well as on the SF-36 physical and mental component summary score. Women meeting recommended levels of leisure physical activity at 10-15 weeks (≥150 minutes per week) reported better general health and more positive mood states compared to less active women. Conclusions: In spite of the decline observed during pregnancy, leisure-time physical activity has a positive impact in pregnant’s general health status and mood states suggesting its importance for women’s health also during this life period

Tackling Nitrosomonas europaea culture problems for future applications in inshore aquaculture

Worldwide aquaculture production represents nearly 160 million tonnes per year, roughly the double of captured fish. Technological improvements are required to provide and improve sustainability to the constant aquaculture production growth. Inshore aquaculture reduces dramatically the risk of infection of the cultured organisms, as sea water is treated before use. Contrariwise, to prevent the increase of operational costs, water must be recirculated multiple times. The high cumulative load of ammonium produced during the fish metabolism requires an especially efficient water treatment, namely for the denitrification process, which usually relies on biological consortium processes to be cost-efficient. Thus, nitrifying and denitrifying microorganisms must be further studied and their production scaled up in order to allow the development of novel technologies and fulfil the increasing demand of denitrification units. Nitrosomonas europaea is the most extensively studied ammonia oxidizing bacteria, being a ubiquitous nitrification organism. Its vital role in the nitrogen cycle is however impaired by the limited energy achieved by this inefficient source of energy, which is partially dedicated to fixate carbon from gaseous carbon dioxide, restricting biomass production. For scale up purposes the design of a culture medium with no precipitation of its constituents is essential, since inorganic debris may significantly impair downstream processing. Moreover, a non-precipitating medium allows a maximum bioavailability of all elements present in its recipe and improves recirculation effectiveness. A new formulation for N. europaea culturing was studied and optimized, fulfilling the addressed objective. This formulation was further tested using moderate pressure displaying positive results in biomass output. The higher N. europaea cell concentration allowed an immobilization in a latex based biocoating, which was evaluated for a possible denitrifying cartridge application

Bioactivity against Bursaphelenchus xylophilus: Nematotoxics from essential oils, essential oils fractions and decoction waters

The Portuguese pine forest has become dangerously threatened by pine wilt disease (PWD), caused by the pinewood nematode (PWN), Bursaphelenchus xylophilus. Synthetic chemicals are the most common pesticides used against phytoparasitic nematodes but its use has negative ecological impacts. Phytochemicals may prove to be environmentally friendly alternatives. Essential oils (EOs) and decoction waters, isolated from 84 plant samples, were tested against B. xylophilus, in direct contact assays. Some successful EOs were fractionated and the fractions containing hydrocarbons or oxygen-containing molecules tested separately. Twenty EOs showed corrected mortalities P96% at 2 lL/mL. These were further tested at lower concentrations. Ruta graveolens, Satureja montana and Thymbra capitata EOs showed lethal concentrations (LC100) < 0.4 lL/mL. Oxygen-containing molecules fractions showing corrected mortality P96% did not always show LC100 values similar to the corresponding EOs, suggesting additive and/or synergistic relationships among fractions. Nine decoction waters (remaining hydrodistillation waters) revealed 100% mortality at a minimum concentration of 12.5 lL/mL. R. graveolens, S. montana and T. capitata EOs are potential environmentally friendly alternatives for B. xylophilus control given their high nematotoxic properties. Nematotoxic activity of an EO should be taken in its entirety, as its different components may contribute, in distinct ways, to the overall EO activity

Nutritional and physical activity knowledge association with body fat in adolescents

Knowledge enhancement hás been referred as a mean to improve nutrition and physical activity, and reduce obesity. This work aimed to identify the difference ofnutrition and physical activity knowledge according to body fat and physical activity leveis in adolescents. Methods: This study vvas a cross sectional analysis involving 734 adolescents. Body fat was detennined using electric bioimpedance, and physical activity was assessed by accelerometer. Adolescents were divided in groups according to physical activity leveis (high versus low) aiid body fat (overfat veisus non-overfat). Thcy were then divided into four groups: "high physical activity/ non-overfat"; "high physical activity/ overfat"; "low physical activity/ non-overfat"; and "lowphysical activity/ overfat". Nutrition and Physical knowledge was assessed by questionnaires. Results: Body tat percentage exposed 30.8 % overfatí obcsc adolescents, and daily moderate to vigoroiis physical activity lasted in average 47.9 (SD=27. 49) minutes. High physical activity adolescents presented higher physical activity knowledge (p=. 044) and the low physical activity/overfat group scored fhe worst on experts' nutritional recommendations knowledge.info:eu-repo/semantics/publishedVersio