Diseño y validación de un cuestionario de gestión motivacional

Atendiendo a la necesidad de desarrollar herramientas fiables, válidas y prácticas para evaluar la regulación de la motivación de los estudiantes, esta investigación informa acerca del desarrollo y la validación inicial de un Cuestionario de Gestión Motivacional (CGM). Se elaboró un cuestionario de 47 ítems en torno a mecanismos motivacionales a los que recurren los estudiantes con el propósito de mantener y dirigir la motivación hacia la consecución de sus metas académicas. En un primer estudio, la versión inicial del cuestionario con tres escalas teóricas -escala de gestión de las creencias, escala de gestión de los motivos y el valor y escala de gestión de la emoción- se aplicó a 133 estudiantes universitarios. Posteriormente el CGM se revisó y se aplicó a una muestra más amplia de 255 estudiantes en el estudio 2. A partir de los datos obtenidos en este primer estudio se usaron análisis de fiabilidad y factoriales confirmatorios para evaluar las propiedades psicométricas de las tres escalas del CGM.In adherence to recent calls for the development of reliable, valid and practical tools to assess students´ motivation regulation, this investigation reports on the development and initial validation of a Motivational Management Questionnaire (MMQ). 47-item questionnaire on motivational mechanism to generate and/or maintain the students´ commitment in difficult emotional situations was elaborated. The development of the MMQ consisted of two steps. In the first study, the initial version of the questionnaire using three theoretical scales -beliefs management scale, reason and value management scale and emotion management scale- was administered to 133 university students. The MMQ was then revised and administered to a larger sample of 255 students in the second study. Drawing from data obtained from the study 1, reliability and confirmatory factor analysis would be used to assess the psychometric properties of the three scales of the MMQ

On the reuse of SLS Polyamide 12 powder

In the Selective Laser Sintering (SLS) technique, the great majority of the powder involved is not included in the final printed parts, being just used as a support material. However, the quality of this powder is negatively affected during the process since it is subjected to high temperatures (close to its melting temperature) during a long time, i.e., the printing cycle time, especially in the neighborhood of the printed part contour. This type of powder is relatively expensive and large amounts of used powder result after each printing cycle. The present paper focuses on the reuse of Polyamide 12 (PA 12) powder. For this sake, the same PA 12 powder was used in consecutive printing cycles. After each cycle, the remaining non-used powder was milled and filtered before subsequent use. Properties of the powder and corresponding prints were characterized in each cycle, using differential scanning calorimetry (DSC), scanning electron microscopy (SEM), computed tomography (CT), and tensile tests. It was concluded that subjecting the same powder to multiple SLS printing cycles affects the properties of the printed parts essentially regarding their morphology (voids content), mechanical properties reproducibility, and aesthetical aspect. However, post-processing treatment of the powder enabled to maintain the mechanical performance of the prints during the first six printing cycles without the need to add virgin powder.O.S.C. acknowledges funding by National Funds through the FCT—Portuguese Foundation for Science and Technology, References UIDB/05256/2020 and UIDP/05256/2020. A.C.A. acknowledges the partial support of the Portuguese Foundation for Science and Technology (FCT), Portugal, under the UIDB/04436/2020 project

Enhanced dimerization of TiOCl under pressure: spin-Peierls - to - Peierls transition

We report high-pressure x-ray diffraction and magnetization measurements combined with ab-initio calculations to demonstrate that the high-pressure optical and transport transitions recently reported in TiOCl, correspond in fact to an enhanced Ti3+-Ti3+ dimerization existing already at room temperature. Our results confirm the formation of a metal-metal bond between Ti3+ ions along the b-axis of TiOCl, accompanied by a strong reduction of the electronic gap. The evolution of the dimerization with pressure suggests a crossover from the spin-Peierls to a conventional Peierls situation at high pressures.Comment: 9pages, 4 figure

Fermiology and transport properties of the half-metallic itinerant ferromagnet CoS2_2: influence of spin orbit coupling

Electronic structure calculations were performed on the compound CoS$_2$, an itinerant ferromagnet whose magnetic properties can be understood in terms of spin fluctuation theory. We have identified nesting features in the Fermi surface of the compound, active for long wavelength spin fluctuations. The electronic structure of the material is close to a half-metal. We show the importance of introducing spin-orbit coupling (SOC) in the calculations, that partially destroys the half-metallicity of the material. By means of transport properties calculations, we have quantified the influence of SOC in the conductivity at room temperature, with an important decrease comparing to the GGA alone conductivity. SOC also helps to understand the negative 0 of the material, whose conductivity varies by a few percent with the introduction of small perturbations in the states around the Fermi level.Comment: 8 pages, 8 figure

Agroecology in large scale farming:A research agenda

Agroecology promises a third way between common global agriculture tradeoffs such as food production and nature conservation, environmental sustainability and ecosystem services. However, most successful examples of mainstreaming agroecology come from smallholder, family agriculture, that represents only about 30% of the world agricultural area. Mainstreaming agroecology among large scale farmers is urgently needed, but it requires addressing specific questions in research, technology and policy development to support sustainable transitions. Here we take stock of the existing knowledge on some key aspects necessary to support agroecological transitions in large scale farming, considering two contrasting starting points: highly subsidized and heavily taxed agricultural contexts, represented here by the examples of Western Europe and temperate South America. We summarize existing knowledge and gaps around service crops, arthropod-mediated functions, landscape and watershed regulation, graze-based livestock, nature-inclusive landscapes, and policy mechanisms to support transitions. We propose a research agenda for agroecology in large scale farming organized in five domains: (i) Breeding for diversity, (ii) Scalable complexity, (iii) Managing cycles beyond fields and farms, (iv) Sharing the cultivated landscape, and (v) Co-innovation with farmers, value chains and policy makers. Agroecology may result in a renewed impetus in large scale farming, to attract the youth, foster clean technological innovation, and to promote a new generation of large-scale farmers that take pride in contributing to feeding the world while serving the planet and its people

Deseo y actividad sexual en hombres y mujeres mayores

Considering that, aging is associated with changes that could significantly affect sexuality, and that individuals over 65 years are a group of great sexual heterogeneity, the main purpose of this work is to explore the differences between older men and women in terms of sexual desire, activity, and practices. This study was carried out through a questionnaire survey in order to analyse the differences between the men and women in terms of sexual activity during the past year, sexual desire and practices. Results show us that sexual activity in general, and the type of sexual practice in particular, as well as the frequency of such practices, reflect relevant differences between older women and men. Specifically, results of this work reveal that there are men who acknowledge a greater concern about the decrease in frequency of sexual practices; however, a significantly more pronounced decrease in the frequency of these practices in the past year occurs among women. Although there may be significant differences in some specific sexual practices and in the level of sexual desire and impulse between men and women, a significant number of men and women are sexually active throughout their old ageConsiderando que la edad está asociada con cambios que podrían afectar significativamente a la sexualidad, y que los individuos de más de 65 años son un grupo de importante heterogeneidad sexual, el propósito de este trabajo es observar las diferencias entre hombres y mujeres mayores en términos de deseo, prácticas y actividad sexual. Este estudio se llevó a cabo mediante la implementación de un cuestionario para analizar las diferencias entre mujeres y hombres mayores de 65 años en base a su actividad, deseo y prácticas sexuales en el último año. Los resultados muestran que la actividad sexual en general y el tipo de práctica sexual en particular, así como la frecuencia de dichas prácticas, reflejan diferencias relevantes entre mujeres y hombres mayores. Específicamente, los resultados de este trabajo revelan que hay hombres que reconocen una mayor preocupación por el descenso en la frecuencia de las prácticas sexuales; sin embargo, es entre las mujeres donde se produce un mayor descenso en la frecuencia de estas prácticas durante el último año. Aunque parecen existir diferencias significativas en algunas prácticas sexuales específicas y en el nivel de deseo sexual entre hombres y mujeres, un número significativo de hombres y mujeres son sexualmente activos durante su vejezS

Recapping and mite removal behaviour in Cuba: home to the world's largest population of Varroa-resistant European honeybees

The Varroa destructor ectoparasitic mite has spread globally and in conjunction with Deformed Wing Virus has killed millions of honeybee (Apis mellifera) colonies. This has forced Northern hemisphere beekeepers into using miticides to avoid mass colony losses. However, in many Southern hemisphere countries widespread treatment did not occur since miticides were prohibitively expensive, or a centralised choice was made not to treat, both allowing natural selection to act. The Varroa mite initially caused high losses before mite-resistance appeared in the honeybee populations. Initially, mite-resistance was only associated with African and Africanised honeybees. Although recently, several isolated mite-resistant European honeybee populations have appeared. Here we studied the mite-resistance in Cuba and found high rates of recapping of infested worker cells (77%), high removal of mites (80%) and corresponding low mite fertility (r = 0.77). These are all traits found in all naturally evolved Varroa-resistant populations. We can confirm Cuba has the world's largest European mite-resistant population with 220,000 colonies that have been treatment-free for over two decades and illustrating the power of natural selection. Cuban honeybees are also highly productive, 40-70 kg of honey produced annually, and are mild mannered. Cuba is an excellent example of what is possible when honeybees are allowed to adapt naturally to Varroa with minimal human interference. [Abstract copyright: © 2022. The Author(s).