6,391 research outputs found
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
Monopulse system with an electronic scanner
Electronic and mechanical scanning control system for monopulse tracking antenn
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
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
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
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 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
Case history : a magnetic and GPR prospection on a Roman rural villa in western Piedmont (Italy )
To explore an archaeological site in western Piedmont we proceed to a multimethod survey using fast methods and taking
also into account the information achievable after a 2D or 3D data processing and/or rendering.
This choice restricted the methodologies to magnetic and GPR prospecting. The non contact
resistance imaging, in our opinion, still gives too smeared results even if indicative of resistivity
anomalies. We selected the magnetic prospecting because of the remarkable size of some of
the walls actually excavated even if, as we explain in the geological context, the probability of
collecting a significant amount of noise was high
Case history: a magnetic and GPR prospection on a Roman rural villa in western Piedmont (Italy)
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