1,095 research outputs found

    What is in a radio loud NLS1?

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    A fraction of Narrow Line Seyfert 1 galaxies (NLS1) are hosted by galaxies that present a disturbed morphology, in some cases hinting for merger processes, that are putative sources of gas replenishment. We have been investigating the poorly studied population of radio loud NLS1 (RL-NLS1) showing a flat radio spectrum, assumed to be the manifestation of the presence of a radio jet. In some of the objects the infrared emission is well fitted by a combination of an AGN component and an "active" host galaxy component like M82, the estimate SFR being in the LIRG/ULIRG range (10-500 Msun/year). In order to better characterize that component, we have been investigating the sub-millimeter/millimeter emission of the sources using APEX. Here we present the results concerning a pilot sample of 2 representative objects.Comment: 5 pages, published on Proceedings of Science - volume "Revisiting narrow-line Seyfert 1 galaxies and their place in the Universe

    Inference on graphs via semidefinite programming

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    Inference problems on graphs arise naturally when trying to make sense of network data. Oftentimes, these problems are formulated as intractable optimization programs. This renders the need for fast heuristics to find adequate solutions and for the study of their performance. For a certain class of problems, Javanmard et al. (1) successfully use tools from statistical physics to analyze the performance of semidefinite programming relaxations, an important heuristic for intractable problems.National Science Foundation (U.S.) (Grant DMS- 1317308

    The structural and size evolution of star-forming galaxies over the last 11 Gyrs

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    We present new results on the evolution of rest-frame blue/UV sizes and Sersic indices of Hα\alpha-selected star-forming galaxies over the last 11 Gyrs. We investigate how the perceived evolution can be affected by a range of biases and systematics such as cosmological dimming and resolution effects. We use GALFIT and an artificial redshifting technique, which includes the luminosity evolution of Hα\alpha-selected galaxies, to quantify the change on the measured structural parameters with redshift. We find typical sizes of 2 to 3 kpc and Sersic indices of n~1.2, close to pure exponential disks all the way from z=2.23 to z=0.4. At z=0 we find typical sizes of 4-5 kpc. Our results show that, when using GALFIT, cosmological dimming has a negligible impact on the derived effective radius for galaxies with

    Leishmania infection and host-blood feeding preferences of phlebotomine sandflies and canine leishmaniasis in an endemic European area, the Algarve Region in Portugal

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    The Algarve Region (AR) in southern Portugal, which is an international tourist destination, has been considered an endemic region of zoonotic leishmaniasis caused by Leishmania infantum since the 1980s. In the present study, phlebotomine and canine surveys were conducted to identify sandfly blood meal sources and to update the occurrence of Leishmania infection in vectors and dogs. Four sandfly species were captured: Phlebotomus perniciosus, Phlebotomus ariasi, Phlebotomus sergenti and Sergentomyia minuta. In one P. perniciosus female, L. infantum DNA was detected. Blood meal tests showed that this species had no host preferences and was an opportunistic feeder. An overall canine leishmaniasis (CanL) seroprevalence of 16.06% was found; the seroprevalence was 3.88% in dogs housed in kennels and 40.63% in dogs that attended veterinary clinics. The simultaneous occurrence of dogs and P. perniciosus infected with L. infantum in the AR indicates that the region continues to be an endemic area for CanL. Our results reinforce the need for the systematic spatial distribution of phlebotomine populations and their Leishmania infection rates and the need to simultaneously perform pathogen monitoring in both invertebrate and vertebrate hosts to investigate the transmission, distribution and spreading of Leishmania infection.EU/FEDER/FCT [POCI/CVT/56357/2004]; EU [FP7-261504 EDENext (091)]; FCT fellowship [SFRH/BPD/44082/2008]info:eu-repo/semantics/publishedVersio

    Talking into account food and nutrition security in the measurement and assessment of human development

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    Human Development Index (HDI) has become a very useful tool for measuring development and making inter-country comparisons. The observation of its trajectory and evolution by country arouses the curiosity of students of development and invites them to question the underlying causes of the behaviour of the index. In order to provide answers to such questions the Human Development Report complements the HDI by offering varied, valuable and relevant statistical information related with every dimensions of human development. From its very beginning, experts have debated about the strengths and weaknesses of the report and have acknowledged a need to include new indicators in the measurement of human development. It is in this context that Mahbub ul Haq, the creator of the Human Development Reports said: “Here we have a broad framework; if you want something to be included in this list, which may deserve a table in the Human Development Report tell us what, and explain why it must figure in this accounting. We will listen”. As a response to this demand, this paper proposes the inclusion of food security in the measurement of human development, as well-being can only be achieved when there is not food insecurity

    Low-cost I-V tracer for photovoltaic modules and strings

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    This paper presents new developments of a robust and low-cost instrument-less than 600 (sic)-for monitoring and processing I-V and P-V characteristics of photovoltaic (PV) modules and high voltage strings. The characteristics can be traced on an oscilloscope or using a developed a LabVIEW application. It is a simple instrument because only fundamental electronic circuits are used. The equipment consists of a flexible configuration, developed from a previous work, based on a fast varying load based on a power MOSFET. The MOSFET was controlled by means of suitable gate-source voltage control signal in order to improve the tracing of I-V and P-V characteristics on an oscilloscope. The contribution of this work includes new developments of a previous I-V tracer in order to be use with high voltage strings and a low-cost DAQ monitoring system based on two applications developed in LabVIEW-one for PV modules and the other for PV strings. On the other hand, the robustness for high voltage strings was strongly improved in view of field tests for fault diagnosis analysis. Experimental results obtained with the new instrument are presented with modules and different strings available with voltages up to 1000 volt

    Target Costing: Exploring The Concept And Its Relation To Competitiveness In Agribusiness

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    How can the practice of Target Costing enhance agribusiness competitiveness? Though the management accounting literature has been enriched by various artifacts such as ABC Costing, Product Life Cycle Costing, Total Cost of Ownership and Target Costing, there is still need for managers to understand how these artifacts may increase the ability of agribusinesses to compete in a hypercompetitive environment. In this essay, the concept of Target Costing is explored as a managerial accounting artifact as its various definitions, distinctiveness and applicability as an organizational and managerial process are discussed. Then, it is argued how it should contribute to building competitive advantage in an uncertain and increasing competitive environment, specifically but not restricted to the agribusiness industry. It is concluded that Target Costing should be of great importance in aiding the development and marketing of innovative food products by Small agribusinesses.123112

    Counting, scoring and classifying hunger to allocate resources targeted to solve the problem

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    A proper allocation of resources targeted to solve hunger is essential to optimize the efficacy of actions and maximize results. This requires an adequate measurement and formulation of the problem as, paraphrasing Einstein, the formulation of a problem is essential to reach a solution. Different measurement methods have been designed to count, score, classify and compare hunger at local level and to allow comparisons between different places. However, the alternative methods produce significantly reach different results. These discrepancies make decisions on the targeting of resource allocations difficult. To assist decision makers, a new method taking into account the dimension of hunger and the coping capacities of countries, is proposed enabling to establish both geographical and sectoral priorities for the allocation of resources
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