On the nature of the AGILE galactic transient sources

The Italian gamma-ray satellite AGILE has recently reported the detection of some variable high-energy sources likely of galactic origin. These sources do not have any obvious counterpart at lower energies. We propose that these sources are produced in proton-dominated jets of galactic microquasars. We develop a model for microquasar jets that takes into account both primary leptons and protons and all relevant radiative processes, including secondary particle emission and gamma-ray attenuation due to pair creation in the jet. We obtain spectral energy distributions that correspond to what is observed by AGILE, with most of the power concentrated between 100 MeV and 10 GeV and reaching luminosities of $10^{34-35}$ erg s$^{-1}$. We make detailed spectral predictions that can be tested by the Fermi gamma-ray telescope in the immediate future. We conclude that hadronic jets in galactic accreting sources can be responsible for the variable unidentified gamma-ray sources detected by AGILE.Comment: 4 pages, 2 figures. Accepted for publication in Astronomy & Astrophysics (Letters

Aprenentatge i ensenyament de les habilitats amb patins

A partir del model conceptual que identifica les habilitats dels esportistes en funció de l’entorn amb el qual interactuen, dels objectius a assolir i dels instruments que s’utilitzen, s’ha abordat l’aprenentatge i l’ensenyament de les habilitats bàsiques amb patins. En les habilitats bàsiques, l’equilibri en el medi és essencial, però els patins introdueixen variabilitat en la relació amb el medi i, per tant, dominar les habilitats amb patins, requereix un llarg període d’aprenentatge. Per acostar-nos a la comprensió de l’aprenentatge d’aquestes habilitats, hem entrevistat practicants experts (skaters) i entrenadors de patinatge amb experiència en la iniciació del patinatge artístic i de l’hoquei patins. A partir de les opinions dels experts, es poden deduir algunes pautes per a l’ensenyament eficaç de les habilitats amb patins

Estudi de l'inventari d'assertivitat de Gambrill i Richey en una mostra d'estudiants de Psicologia de la Universitat Autònoma de Barcelona

En el presente trabajo se analizan los resultados obtenidos mediante la aplicación del inventario de Gambrill i Richey a una muestra de estudiantes de Psicología de la Universitat Autdnoma de Barcelona En el análisis factorial hemos hallado un primer factor con una saturación en asertividad más alta que los hallados por las autoras. En nuestro estudio se confirma la utilidad del inventario para una primera evaluación de la conducta asertiva.This paper is an analysis ofthe results obtained in the application ofthe Gambrill & Richey Inventory to a sample of students of Psychology of the UAB. In the factorial analysis we found one factor (the first) more highly saturated in assertiveness than the Gambrill and Richey's factors. Our study confirms the usefulness of the inventory for a first assessment of assertive behavior

Planificación estratégica de la capacidad en una empresa del sector alimentación (Strategic multi-site capacity planning for a food industry)

This paper describes the proposed procedure for the multi-site capacity planning of a food company that was obliged to move one of its production sites to a new location. Due to this change the managers of the company wanted to know the capacity requirement of the new site, the assigned products to this plant and the impact of these decisions over the other manufacturing sites. In brief, they wanted to know the efficient production map of the company for the next 3 - 5 years. The company had 6 manufacturing sites which produced about 100 products grouped in 22 families. Each family was associated to a production line. The most demanded products could be produced in several plants, at the same time, whereas some other products only on a certain site. Only one raw material was critical and with influence on the productive map, therefore, it was considered in the problem formulation. The plants sent their output to 5 regional centres which were in charge of supplying the demand of 38 distribution centres. This distribution centres, in turn, were in charge of serving the requirements of the points of sale. Therefore, the supply chain consisted of 4 levels: suppliers, plants, regional centres and distribution centres. The problem was formulated as a mathematical program. The main variables were the quantity to produce of each product at each plant, in a certain period of time, the quantity to be transported of each product from the manufacturing sites to the regional centres and the raw material supplied for each supplier to each plant. The mathematical constraints described the production constraints, the supply and transport constraints and the rules established by the company. The parameters were the availability of raw materials from each supplier, the minimum lot size of each product, the capacity of vehicles from transport the products, the demand of each product per distribution centre and the cost associated to suppliers, to the transport, with the set up of lines and the changeover cost in each line. The objective was to minimize the operating cost. The mathematical model had to allow simulating several scenarios of demand, capacity and configuration of plants. The system was implemented in three modules. The first module was a pre-processor to set the information and scenario to simulate with different hypothesis of demand, minimum lot size, and constraints. Next, the processor implemented in Lindo and finally, the postprocessor to summarize the obtained and to prepare and show several reports. Finally, the results and conclusions were presented to the steering committee. Our proposal was not the cheapest but was the one that demanded less inversion and changes. The implemented system was transferred to the company who continued with the study to take the final decision.Peer ReviewedPostprint (author's final draft