593 research outputs found

    The ACS LCID Project: Variable Stars in Tucana and LGS3

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    We present preliminary results concerning the search for short-period variable stars in Tucana and LGS3 based on very deep HST/ACS imaging. In the one chip per galaxy we studied so far, a total of 230 and 80 candidates variables were found, respectively. For Tucana, we identified 134 of them as RR Lyrae stars (RRL) pulsating in the fundamental mode (RRab), 51 in the first-overtone mode (RRc), and 37 in both modes simultaneoulsy (RRd), as well as four candidate anomalous Cepheids (AC). In the case of LGS3, we found 45 RRab and 5 RRc, plus three candidates RRd and five candidate AC. The metallicities obtained from the mean period of the RRab are [Fe/H]_{Tuc}=-1.7 and [Fe/H]_{LGS3}=-1.8.Comment: 2 pages, 1 figure. To appear in the Proceedings of IAU Symposium 241: "Stellar Populations as Building Blocks of Galaxies", 10-16 December, 2006 at La Palma, Canary Islands, Spai

    Dynamic Collection Scheduling Using Remote Asset Monitoring: Case Study in the UK Charity Sector

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    Remote sensing technology is now coming onto the market in the waste collection sector. This technology allows waste and recycling receptacles to report their fill levels at regular intervals. This reporting enables collection schedules to be optimized dynamically to meet true servicing needs in a better way and so reduce transport costs and ensure that visits to clients are made in a timely fashion. This paper describes a real-life logistics problem faced by a leading UK charity that services its textile and book donation banks and its high street stores by using a common fleet of vehicles with various carrying capacities. Use of a common fleet gives rise to a vehicle routing problem in which visits to stores are on fixed days of the week with time window constraints and visits to banks (fitted with remote fill-monitoring technology) are made in a timely fashion so that the banks do not become full before collection. A tabu search algorithm was developed to provide vehicle routes for the next day of operation on the basis of the maximization of profit. A longer look-ahead period was not considered because donation rates to banks are highly variable. The algorithm included parameters that specified the minimum fill level (e.g., 50%) required to allow a visit to a bank and a penalty function used to encourage visits to banks that are becoming full. The results showed that the algorithm significantly reduced visits to banks and increased profit by up to 2.4%, with the best performance obtained when the donation rates were more variable

    Shift of the western boundary of the distribution area of Micromeria cristata (Hampe) Griseb. and Steptorhamphus tuberosus (Jacq.) Grossh.

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    During field investigations of Mt Rumija, two new taxa for the flora of Montenegro were recorded: Micromeria cristata (Hampe) Griseb. and Steptorhamphus tuberosus (Jacq.) Grossh. From the phytogeographic point of view these data indicate a change in the distribution area of both taxa, which have shifted to the west. Ashort overview of the taxonomic treatment of both genera is given

    Etiologia viral e bacteriana de casos de gastroenterite infantil: uma caracterização clínica

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    In a survey of children with gastroenteritis admitted to the "Instituto da Criança do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo" S. Paulo, Brazil, rotavirus was found in 35.2% of patients and bacterial pathogens in 37.0%; in 38.9% of the patients it was not possible to detect either rotavirus or bacterial pathogens, whereas rotavirus was found in association with bacterial pathogens in 11.1% of the patients. In addition, an analysis of age distribution, nutritional status, type and degree of dehydration, and eletrolite balance was included in this study.Numa pesquisa sobre gastroenterites infantis, feita em crianças internadas no Instituto da Criança do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brasil, foram identificados rotavírus em 35,2% dos pacientes e bactérias patogênicas em 37,0%; em 38,9% não foi possível identificar rotavírus ou bactérias patogênicas; foram identificados rotavírus em associação com bactérias patogênicas em 11,1% dos casos. Esta pesquisa compreendeu, além do estudo etiológico, outros aspectos, como distribuição etária, estado nutricional, tipo e grau de desidratação e duração média da diarréia

    α-Synuclein Aggregated with Tau and β-Amyloid in Human Platelets from Healthy Subjects: Correlation with Physical Exercise

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    The loss of protein homeostasis that has been associated with aging leads to altered levels and conformational instability of proteins, which tend to form toxic aggregates. In particular, brain aging presents characteristic patterns of misfolded oligomers, primarily constituted of β-amyloid (Aβ), tau, and α-synuclein (α-syn), which can accumulate in neuronal membranes or extracellular compartments. Such aging-related proteins can also reach peripheral compartments, thus suggesting the possibility to monitor their accumulation in more accessible fluids. In this respect, we have demonstrated that α-syn forms detectable hetero-aggregates with Aβ or tau in red blood cells (RBCs) of healthy subjects. In particular, α-syn levels and its heteromeric interactions are modulated by plasma antioxidant capability (AOC), which increases in turn with physical activity. In order to understand if a specific distribution of misfolded proteins can occur in other blood cells, a cohort of human subjects was enrolled to establish a correlation among AOC, the level of physical exercise and the concentrations of aging-related proteins in platelets. The healthy subjects were divided depending on their level of physical exercise (i.e., athletes and sedentary subjects) and their age (young and older subjects). Herein, aging-related proteins (i.e., α-syn, tau and Aβ) were confirmed to be present in human platelets. Among such proteins, platelet tau concentration was demonstrated to decrease in athletes, while α-syn and Aβ did not correlate with physical exercise. For the first time, α-syn was shown to directly interact with Aβ and tau in platelets, forming detectable hetero-complexes. Interestingly, α-syn interaction with tau was inversely related to plasma AOC and to the level of physical activity. These results suggested that α-syn heterocomplexes, particularly with tau, could represent novel indicators to monitor aging-related proteins in platelets

    Fiscal policy and asset prices

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    We assess the role played by scal policy in explaining the dynamics of asset markets. Using a panel of ten industrialized countries, we show that a positive scal shock has a negative impact in both stock and housing prices. However, while stock prices immediately adjust to the shock and the e¤ect of scal policy is temporary, housing prices gradually and persistently fall. As a result, the attempts of scal policy to mitigate stock price developments may severely de-stabilize housing markets. The empirical ndings also point to: (i) a contractionary e¤ect of scal policy on output in line with the existence of crowding-out e¤ects; (ii) a weakening of the e¤ectiveness of scal policy in recent times; (iii) signi cant scal multiplier e¤ects in the context of severe housing busts; and (iv) an increase of the sensitivity of asset prices to scal policy shocks following the process of nancial deregulation and mortgage liberalization. Finally, the evidence suggests that changes in equity prices may help governments towards consolidation of public nances.COMPETE; QREN; UE Fundo Europeu de Desenvolvimento Regional; Fundação para a Ciência e a Tecnologia (FCT

    Freight distribution performance indicators for service quality planning in large transportation networks

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    This paper studies the use of performance indicators in routing problems to estimate how transportation cost is affected by the quality of service offered. The quality of service is assumed to be directly dependent on the size of the time windows. Smaller time windows mean better service. Three performance indicators are introduced. These indicators are calculated directly from the data without the need of a solution method. The introduced indicators are based mainly on a "request compatibility", which describes whether two visits can be scheduled consecutively in a route. Other two indicators are introduced, which get their values from a greedy constructive heuristic. After introducing the indicators, the correlation between indicators and transportation cost is examined. It is concluded that the indicators give a good first estimation on the transportation cost incurred when providing a certain quality of service. These indicators can be calculated easily in one of the first planning steps without the need of a sophisticated solution tool. The contribution of the paper is the introduction of a simple set of performance indicators that can be used to estimate the transportation cost of a routing problem with time window
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