660 research outputs found
La condición de las mujeres : el caso de Italia después de la guerra
El artÃculo estudia las caracterÃsticas de la fuerza de trabajo femenina italiana desde los años sesenta en adelante. En comparación con el trabajo femenino en otros paÃses europeos, la mujer italiana trabaja en la producción en menor proporción que en estos paÃses, no se reintegra a partir de los cuarenta años y su trabajo forma parte de las actividades más marginales y peor pagadas. La razón de esta situación laboral parece encontrarse en las caracterÃsticas y funciones de la familia italiana. Esta estructura y funciones se describen para el caso de una categorÃa social especÃfica, la «capa intermedia», que es mayoritaria en la sociedad italiana. Finalmente se indican algunos datos relativos a la participación polÃtica y sindical de las mujeres
HESS J1632-478: an energetic relic
HESS J1632-478 is an extended and still unidentified TeV source in the
galactic plane. In order to identify the source of the very high energy
emission and to constrain its spectral energy distribution, we used a deep
observation of the field obtained with XMM-Newton together with data from
Molonglo, Spitzer and Fermi to detect counterparts at other wavelengths. The
flux density emitted by HESS J1632-478 peaks at very high energies and is more
than 20 times weaker at all other wavelengths probed. The source spectrum
features two large prominent bumps with the synchrotron emission peaking in the
ultraviolet and the external inverse Compton emission peaking in the TeV. HESS
J1632-478 is an energetic pulsar wind nebula with an age of the order of 10^4
years. Its bolometric (mostly GeV-TeV) luminosity reaches 10% of the current
pulsar spin down power. The synchrotron nebula has a size of 1 pc and contains
an unresolved point-like X-ray source, probably the pulsar with its wind
termination shock.Comment: A&A accepted, 9 pages, 5 figures, 4 table
Analysis of Petri Net Models through Stochastic Differential Equations
It is well known, mainly because of the work of Kurtz, that density dependent
Markov chains can be approximated by sets of ordinary differential equations
(ODEs) when their indexing parameter grows very large. This approximation
cannot capture the stochastic nature of the process and, consequently, it can
provide an erroneous view of the behavior of the Markov chain if the indexing
parameter is not sufficiently high. Important phenomena that cannot be revealed
include non-negligible variance and bi-modal population distributions. A
less-known approximation proposed by Kurtz applies stochastic differential
equations (SDEs) and provides information about the stochastic nature of the
process. In this paper we apply and extend this diffusion approximation to
study stochastic Petri nets. We identify a class of nets whose underlying
stochastic process is a density dependent Markov chain whose indexing parameter
is a multiplicative constant which identifies the population level expressed by
the initial marking and we provide means to automatically construct the
associated set of SDEs. Since the diffusion approximation of Kurtz considers
the process only up to the time when it first exits an open interval, we extend
the approximation by a machinery that mimics the behavior of the Markov chain
at the boundary and allows thus to apply the approach to a wider set of
problems. The resulting process is of the jump-diffusion type. We illustrate by
examples that the jump-diffusion approximation which extends to bounded domains
can be much more informative than that based on ODEs as it can provide accurate
quantity distributions even when they are multi-modal and even for relatively
small population levels. Moreover, we show that the method is faster than
simulating the original Markov chain
HESS J1632-478: An energetic relic
HESS J1632-478 is an extended and still unidentified TeV source in the galactic plane. In order to identify the source of the very high energy emission and to constrain its spectral energy distribution, we used a deep observation
of the field obtained with XMM-Newton together with data from Molonglo, Spitzer and Fermi to detect counterparts at other wavelengths. The spectral energy density features two large prominent bumps with the synchrotron emission peaking
in the ultraviolet and the external inverse Compton emission peaking in the TeV. HESS J1632-478 is an energetic pulsar wind nebula with an age of the order of 104 years. Its bolometric (mostly GeV-TeV) luminosity reaches 10% of the current pulsar spin down power. The synchrotron nebula has a size of 1 pc and contains an unresolved point-like X-ray source, probably the pulsar with its wind termination
shock
Multi-proxy survey of open-air surface scatters in drylands: Archaeological and physico-chemical characterisation of fossilised dunes in North Gujarat (India)
This research aims at improving our understanding of open-air archaeological surface scatters in drylands, their extension and the intensity of human activities during their occupation. To do so, the study of physico-chemical proxies is integrated to that of archaeological artefacts by means of systematic field survey combined with laboratory sedimentary analyses and a robust statistical approach. In most dry regions, archaeological survey has traditionally aimed at the collection of artefacts. When present, the study of physical and geochemical samples has been limited to excavated archaeological levels. In this work, we evaluate the archaeological significance of physico-chemical proxies from surface samples collected within and around four mid and late-Holocene surface scatters in North Gujarat, a semi-arid region located at the south-west margin of the Thar Desert in India. The four archaeological scatters are found on top of fossilised sand dunes. Archaeologically, they represent subsistence strategies based on hunting and gathering, agro-pastoralism, or a succession/mixture of the two. The four locations were systematically sampled across a linear transect. For each sampling unit, the archaeological materials were quantified and classified by means of a Linear Discriminant Analyses. Physio-chemical variables were ordinated in a PCA space and clustered through a Hierarchical Clustering. Results were displayed along the dune transect and integrated into a Correspondence Analysis. Significant differences are attested in the spatial distribution and content of Ca, P and grain size, allowing us to suggest a set of distinct cultural soilscapes that characterise the dunes of the study area: vertisols (agric horizons in interdunal lower slopes), aridisols (relict dune surfaces in the mid-slope), and anthrosols (top dune). The last show a strong correspondence with the presence of archaeological artefacts, and the different intensity of human footprint are discussed accordingly to potential past subsistence strategies and the intensity of human occupation. © 2016 Elsevier Ltd and INQUA.This research arises from collaboration between the MS University of Baroda and the IMF-CSIC (Spanish National Research Council) within the framework of the North Gujarat Archaeological Project (NoGAP) and the SimulPast Project CSD2010-00034). F.C.Conesa acknowledges worked on this paper with funding from the JAE-PreDoc program (CSIC and European Social Found). A. L. Balbo worked on this paper under the Juan de la Cierva Programme (MINECO JCI-2011-10734), and with a Research Fellowship from the Alexander von Humboldt Foundation/Stiftung.Peer reviewe
Early management of COPD: Where are we now and where do we go from here? a delphi consensus project
Purpose: There is a lack of consensus on the most appropriate early diagnostic strategy, criteria for early access to treatment and follow-up approach for patients with COPD.Materials and methods: A Delphi consensus project investigated the early management of COPD. We formulated two questionnaires for completion by pneumologists in Italy.Results: A total of 207 specialists completed questionnaire 1 and 184 of them questionnaire 2, between November 2016 and October 2017. Early diagnosis of COPD was considered uncommon for 93.2% of the expert panel. Regardless of the definition of "early diagnosis" - a diagnosis made before the clinical manifestation of the disease for most responders (60.4%) - experts were confident of the positive effects of early disease management, which they consider is effective in modifying the natural history of the disease. Lack of awareness of the disease was considered the first limiting factor to early COPD management for 78% of respondents. The most effective steps to reduce functional decline were considered to be smoking cessation, followed by long-acting beta 2-agonist (LABA)/long-acting muscarinic antagonist (LAMA), LAMA, LABA, and finally inhaled corticosteroid/LABA (P<0.01 for each paired comparison). Specialists considered it "inappropriate" for general practitioners to perform both the early diagnosis and therapy of COPD without the involvement of a specialist.Conclusion: Early management of COPD is uncommon, and although data on the effects of early disease management on long-term outcomes are limited, Italian experts are confident of the clinical efficacy of this approach
- …