Monopulse system with an electronic scanner

Electronic and mechanical scanning control system for monopulse tracking antenn

The segregation of starless and protostellar clumps in the Hi-GAL l=224deg region

Stars form in dense, dusty structures, which are embedded in larger clumps of molecular clouds often showing a clear filamentary structure on large scales (> 1pc). One of the best-studied regions in the Hi-GAL survey can be observed toward the l=224deg field. Here, a filamentary region has been studied and it has been found that protostellar clumps are mostly located along the main filament, whereas starless clumps are detected off this filament and are instead found on secondary, less prominent filaments. We want to investigate this segregation effect and how it may affect the clumps properties. We mapped the 12CO(1-0) line and its main three isotopologues toward the two most prominent filaments observed toward the l=224deg field using the Mopra radio telescope, in order to set observational constraints on the dynamics of these structures and the associated starless and protostellar clumps. Compared to the starless clumps, the protostellar clumps are more luminous, more turbulent and lie in regions where the filamentary ambient gas shows larger linewidths. We see evidence of gas flowing along the main filament, but we do not find any signs of accretion flow from the filament onto the Hi-GAL clumps. We analyze the radial column density profile of the filaments and their gravitational stability. The more massive and highly fragmented main filament appears to be thermally supercritical and gravitationally bound, assuming that all of the non-thermal motion is contributing thermal-like support, suggesting a later stage of evolution compared to the secondary filament. The status and evolutionary phase of the Hi-GAL clumps would then appear to correlate with that of the host filament.Comment: Accepted for publication on "Astronomy and Astrophysics

Self-assessed health as a key determinant of lifestyles: An application to tobacco consumption in Argentina

The relationship between lifestyle choices and health has been widely studied in the epidemiological and economic literature. In the last years, empirical research was directed towards the use of recursive systems with structural equations for a health production function and reduced form equations for lifestyles. As a result, behaviors toward health are taken to be determined by exogenous socio-economic variables. In this article, we show that health is a key determinant of health habits. When people feel well, they adopt less healthy behaviors. We use maximum simulated likelihood for a multivariate 5 equation probit model. In that model, lifestyles (diet, exercise, alcohol consumption and smoking) are a function of exogenous socioeconomic variables and self-reported health. Self-reported health varies with socio-economic characteristics and depends on health indicators that are the consequence of lifestyles undertaken in the past (i.e., overweight, blood pressure, diabetes and cholesterol levels). Data is that of adults in Argentina´s 2005 Risk Factors National Survey. We find that health partial effects on lifestyle are much larger having accounted for health endogeneity. Accounting for unobservable variables that jointly determine all lifestyles does not change much the magnitude of our results. Our findings are robust to different specifications.lifestyles, health

Salt intake, stroke, and cardiovascular disease : meta-analysis of prospective studies

Objective: To assess the relation between the level of habitual salt intake and stroke or total cardiovascular disease outcome. Design: Systematic review and meta-analysis of prospective studies published 1966-2008. Data sources: Medline (1966-2008), Embase (from 1988), AMED (from 1985), CINAHL (from 1982), Psychinfo (from 1985), and the Cochrane Library. Review methods: For each study, relative risks and 95% confidence intervals were extracted and pooled with a random effect model, weighting for the inverse of the variance. Heterogeneity, publication bias, subgroup, and meta-regression analyses were performed. Criteria for inclusion were prospective adult population study, assessment of salt intake as baseline exposure, assessment of either stroke or total cardiovascular disease as outcome, follow-up of at least three years, indication of number of participants exposed and number of events across different salt intake categories. Results: There were 19 independent cohort samples from 13 studies, with 177 025 participants (follow-up 3.5-19 years) and over 11 000 vascular events. Higher salt intake was associated with greater risk of stroke (pooled relative risk 1.23, 95% confidence interval 1.06 to 1.43; P=0.007) and cardiovascular disease (1.14, 0.99 to 1.32; P=0.07), with no significant evidence of publication bias. For cardiovascular disease, sensitivity analysis showed that the exclusion of a single study led to a pooled estimate of 1.17 (1.02 to 1.34; P=0.02). The associations observed were greater the larger the difference in sodium intake and the longer the follow-up. Conclusions: High salt intake is associated with significantly increased risk of stroke and total cardiovascular disease. Because of imprecision in measurement of salt intake, these effect sizes are likely to be underestimated. These results support the role of a substantial population reduction in salt intake for the prevention of cardiovascular disease

Antenna simulator permits preinstallation system checkout

Antenna simulator provides for evaluation checkout of corporate feeds, monopulse sum-and-difference networks, etc., in a shielded environment prior to system checkout on an antenna pattern range. This technique is useful wherever simulation of monopulse antenna element characteristics is desired for checkout of ancillary equipment in a controlled environment

Not a galaxy: IRAS 04186+5143, a new young stellar cluster in the outer Galaxy

We report the discovery of a new young stellar cluster in the outer Galaxy located at the position of an IRAS PSC source that has been previously mis-identified as an external galaxy. The cluster is seen in our near-infrared imaging towards IRAS 04186+5143 and in archive Spitzer images confirming the young stellar nature of the sources detected. There is also evidence of sub-clustering seen in the spatial distributions of young stars and of gas and dust. Near- and mid-infrared photometry indicates that the stars exhibit colours compatible with reddening by interstellar and circumstellar dust and are likely to be low- and intermediate-mass YSOs with a large proportion of Class I YSOs. Ammonia and CO lines were detected, with the CO emission well centred near the position of the richest part of the cluster. The velocity of the CO and NH$_3$ lines indicates that the gas is Galactic and located at a distance of about 5.5 kpc, in the outer Galaxy. Herschel data of this region characterise the dust environment of this molecular cloud core where the young cluster is embedded. We derive masses, luminosities and temperatures of the molecular clumps where the young stars reside and discuss their evolutionary stages.Comment: 14 pages, 15 figure

On the shape of the mass-function of dense clumps in the Hi-GAL fields. II. Using Bayesian inference to study the clump mass function

Context. Stars form in dense, dusty clumps of molecular clouds, but little is known about their origin, their evolution and their detailed physical properties. In particular, the relationship between the mass distribution of these clumps (also known as the "clump mass function", or CMF) and the stellar initial mass function (IMF), is still poorly understood. Aims. In order to better understand how the CMF evolve toward the IMF, and to discern the "true" shape of the CMF, large samples of bona-fide pre- and proto-stellar clumps are required. Two such datasets obtained from the Herschel infrared GALactic Plane Survey (Hi-GAL) have been described in paper I. Robust statistical methods are needed in order to infer the parameters describing the models used to fit the CMF, and to compare the competing models themselves. Methods. In this paper we apply Bayesian inference to the analysis of the CMF of the two regions discussed in Paper I. First, we determine the Bayesian posterior probability distribution for each of the fitted parameters. Then, we carry out a quantitative comparison of the models used to fit the CMF. Results. We have compared the results from several methods implementing Bayesian inference, and we have also analyzed the impact of the choice of priors and the influence of various constraints on the statistical conclusions for the preferred values of the parameters. We find that both parameter estimation and model comparison depend on the choice of parameter priors. Conclusions. Our results confirm our earlier conclusion that the CMFs of the two Hi-GAL regions studied here have very similar shapes but different mass scales. Furthermore, the lognormal model appears to better describe the CMF measured in the two Hi-GAL regions studied here. However, this preliminary conclusion is dependent on the choice of parameters priors.Comment: Submitted for publication to A&A on November 12, 2013. This paper contains 11 pages and 7 figure

Efecto de la defoliación post-quema sobre el crecimiento de dos gramíneas nativas en el Caldenal, Argentina

El crecimiento en los pastizales naturales semiáridos puede ser afectado por la longitud de tiempo que el pastoreo es excluido durante el período de regeneración post-fuego. El objetivo de este trabajo a campo fue estudiar el efecto de la defoliación post-fuego en diferentes estados fenológicos: vegetativo (defoliación temprana) y elongación de entrenudos (defoliación tardía) sobre el crecimiento de Piptochaetium napostaense y Poa ligularis, dos gramíneas nativas perennes muy importantes en la región semiárida templada central de Argentina (Caldenal). En general, los tratamientos de defoliación post-quema no afectaron el número de hojas verdes en las macollas de P. napostaense. La defoliación temprana después del tratamiento de fuego generalmente redujo el número de hojas verdes en las macollas de P. ligularis con respecto a las plantas control. Contrariamente, la defoliación tardía usualmente incrementó el número de hojas verdes en las macollas de P. ligularis. Sin embargo, en ambos casos, muy pocas de las diferencias detectadas fueron significativas (p0,05) a aquellas de las plantas no defoliadas. Inmediatamente después de los tratamientos de defoliación temprana y tardía, las tasas de crecimiento relativas de la altura y la longitud verde total de las macollas de las plantas de ambas especies fueron reducidas (p0.05) than values on non-defoliated plants, respectively. Immediately after early- and late-season defoliation treatments, relative growth rates for tiller height and total green length were reduced (p<0.05) on plants of both species with respect to control plants. Our results suggest that a one-year-period without severe defoliations after fire would be at least necessary for not risking the persistence of these perennial grasses in the Caldenal community.Fil: Pelaez, Daniel Valerio. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Boo, Roberto Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Mayor, M. D.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Elia, Omar Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Martinez, S. A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentin

Environmental news and stock markets performance: Further evidence for Argentina

More and more firms tend nowadays to adopt environment-friendly attitudes. Their motivation originates in local environmental regulations or requirements of foreign markets to which firms export (both induced by consumers and investors' valuation of pro-environment initiatives). There is a well-established literature capturing the impact on stock prices of environmental information releases using the event study methodology. Studies are usually based on information environmental regulation (i.e., the regulator announcement of emissions or compliance status with respect to standards) or on simple media coverage of environmental news. Dasgupta, Laplante and Mamingi (2001) is one of the few references to show that public information on environmental behavior has impact on stock prices in the developing world. It includes Argentina in its analysis together with Chile, Mexico and the Philippines. In this manuscript, we focus specifically on Argentina. We find that positive environmental news have no impact, while negative news do have an effect on average rates of return a few days following its appearance. But, when focusing on different types of positive news, we find that ISO certification has no effect whatsoever, while investment decisions do have some positive significant influence on returns. On the other side, negative news influence on stock returns is particularly significant for events linked to citizen complaints and government rulings (confirming other studies results) and for media coverage of oil company issues. However, we find abnormal returns of a much smaller magnitude than other studies for developing countries. We believe that is readonable because there seem to be no reason why the level of abnormal returns (not its volatility) should be larger for environmental news in developing countries than in developed ones