1,957 research outputs found

    A decision support system for planning promotion time slots

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    We report on the development of a Decision Support System (DSS) to plan the best assignment for the weekly promotion space of a TV station. Each product to promote has a given target audience that is best reached at specific time periods during the week. The DSS aims to maximize the total viewing for each product within its target audience while fulfilling a set of constraints defined by the user. The purpose of this paper is to describe the development and successful implementation of a heuristic-based scheduling software system that has been developed for a major Portuguese TV station.Fundação para a Ciência e a Tecnologia (FCT)- FCT/POCI 2010/FEDER, Projecto POCTI/MAT/61842/2004Estação de Televisão SI

    A genetic algorithm approach for the TV self-promotion assignment problem

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    We report on the development of a Genetic Algorithm (GA), which has been integrated into a Decision Support System to plan the best assignment of the weekly self-promotion space for a TV station. The problem addressed consists on deciding which shows to advertise and when such that the number of viewers, of an intended group or target, is maximized. The GA proposed incorporates a greedy heuristic to find good initial solutions. These solutions, as well as the solutions later obtained through the use of the GA, go then through a repair procedure. This is used with two objectives, which are addressed in turn. Firstly, it checks the solution feasibility and if unfeasible it is fixed by removing some shows. Secondly, it tries to improve the solution by adding some extra shows. Since the problem faced by the commercial TV station is too big and has too many features it cannot be solved exactly. Therefore, in order to test the quality of the solutions provided by the proposed GA we have randomly generated some smaller problem instances. For these problems we have obtained solutions on average within 1% of the optimal solution value

    Entry by research-based spin-offs: the determinants of regional variation

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    Reflecting the increasing number of research based spin-offs (RBSOs) created since the nineties, previous studies focus their analysis on the factors that influence university entrepreneurship. However, empirical studies that investigate the determinants of variation on RBSO creation across regions are scarce. Using a unique self-collected dataset that comprehends the population of RBSOs created in Portugal from 1979 until to 2007 we investigate the intensity of spin-offs creation across regions, by focusing on the characteristics of the universities and the region in which the spin-off is located. Our results suggest that the quality and prestige of the universities located in a municipality, as well as the presence of university-affiliated incubators and/or university research parks have a positive impact on the intensity of RBSO creation. Regarding the regional characteristics, the availability of qualified human capital and the regional demand size seem to exert an important effect on spin-off activity across regions.FC

    Evidence for engraftment of human bone marrow cells in non-lethally irradiated baboons

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    Background. Prior to organ harvesting, an attempt was made to modulate the donor's immune responses against prospective xenogeneic recipients by infusion of 'recipient-type' bone marrow. Methods. For this purpose, baboons conditioned with total lymphoid irradiation were given 6x108 unmodified human bone marrow cells/kg body weight with no subsequent treatment. Results. Animals survived until they were euthanized at 18 months. Using primers specific for human chorionic gonadotrophin gene, the presence of human DNA was confirmed by polymerase chain reaction in the blood of one animal for up to 18 months after cell transplantation; in the other animal, xenogeneic chimerism became undetectable in the blood at 6 months after bone marrow infusion. However, tissue samples obtained from both animals at the time they were euthanized bad evidence of donor (human) DNA. Additionally, the presence of donor DNA in individually harvested colonies of erythroid and myeloid lineages suggested that infused human bone marrow cells had engrafted across the xenogeneic barrier in both baboons. Conclusions. Bone marrow transplantation from human to baboon leads to establishment of chimerism and modulation of donor-specific immune reactivity, which suggests that this strategy could be reproducibly employed to crease 'surrogate' tolerogenesis in prospective donors for subsequent organ transplantation across xenogeneic barriers

    23 years of ozone episodes in Portugal: photochemical and/or stratospheric intrusion

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    Ponencia presentada en: XXXII Jornadas Científicas de la AME y el XIII Encuentro Hispano Luso de Meteorología celebrado en Alcobendas (Madrid), del 28 al 30 de mayo de 2012.This work was supported by Fundação para a Ciência e Tecnologia (FCT) that funded the DYNOZONE Project (Ref.º PTDC/CTE - ATM/105507/2008

    Immune status of recipients following bone marrow - Augmented solid organ transplantation

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    It has been postulated that the resident “passenger” leukocytes of hematolymphoid origin that migrate from whole organ grafts and subsequently establish systemic chimerism are essential for graft acceptance and the induction of donor-specific nonreactivity. This phenomenon was augmented by infusing 3 × 108 unmodified donor bone-marrow cells into 40 patients at the time of organ transplantation. Fifteen of the first 18 analyzable patients had sequential immunological evaluation over postoperative intervals of 5 to 17 months, (which included 7 kidney (two with islets), 7 liver (one with islets), and one heart recipient). The evolution of changes was compared with that in 16 kidney and liver nonmarrow controls followed for 4 to5 months. The generic immune reactivity of peripheral blood mononuclear cells (PBMC) was determined by their proliferative responses to mitogens (PHA, ConA). Alloreactivity was measured by the recipient mixed lymphocyte reaction (MLR) to donor and HLA-mis-matched third-party panel cells. Based on all 3 tests,the recipients were classified as donor-specific hyporeactive, intermediate, and responsive; patients who were globally suppressed made up a fourth category. Eight (53%) of the 15 marrow-treated recipients exhibited progressive modulation of donor-specific reactivity (3 hyporeactive and 5 intermediate) while 7 remained antidonor-responsive. In the nonmarrow controls, 2 (12.5%) of the 16 patients showed donor-specific hyporeactivity, 10 (62.5%) were reactive, and 4 (25%) studied during a CMV infection had global suppression of responsiveness to all stimuli. © 1995 by Williams and Wilkins
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