5,038 research outputs found
Feminisme i patriarcat: del reconeixement de drets reproductius a l'assoliment de la plena autonomia
El naixement de les societats modernes a arrel de les revolucions liberals suposen l'eliminació del vell privilegi jurídic que atorgava drets civils i polítics basats en les diferències naturals entre els éssers humans. Malgrat tot, hi ha una diferència natural que no s'esborra: la diferència sexual. Les dones seran excloses de la caracterització com a éssers individuals i lliures ( per tant, amb drets civils i polítics com a ciutadanes) per raó de l'adscripció a la seva naturalesa, bàsicament a la seva capacitat reproductiva. Categoritzades com a naturalment inferiors als homes, seran incorporades a la societat sota el prisma del continu tutelatge masculí. La superació de la discriminació per raó de gènere ha d'implicar l'esforç conjunt d'homes i dones (encotitllats tots dos per raó del gènere assignat socialment). Aquest esforç ha de portar a la reconceptualització del vell principi d'autonomia i permetre la construcció d'una nova ciutadania, on l'ordre constructor de les subjectivitats dels individus no pivoti exclusivament en el gènere assigna
A state-of-the-art analysis of the dwarf irregular galaxy NGC 6822
We present a detailed photometric study of the dwarf irregular galaxy NGC
6822 aimed at investigating the properties of its stellar populations and, in
particular, the presence of stellar radial gradients. Our goal is to analyse
the stellar populations in six fields, which cover the whole bar of this dwarf
galaxy. We derived the quantitative star formation history (SFH) of the six
fields using the IAC method, involving IAC-pop/MinnIAC codes. The solutions we
derived show an enhanced star formation rate (SFR) in Fields 1 and 3 during the
past 500 Myr. The SFRs of the other fields are almost extinguished at very
recent epochs and. We study the radial gradients of the SFR and consider the
total mass converted into stars in two time intervals (between 0 and 0.5 Gyr
ago and between 0.5 and 13.5 Gyr ago). We find that the scale lengths of the
young and intermediate-to-old populations are perfectly compatible, with the
exception of the young populations in Fields 1 and 3. The recent SF in these
two fields is greater than in the other ones. This might be an indication that
in these two fields we are sampling incipient spiral arms. Further evidence and
new observations are required to prove this hypothesis. In addition, we derived
the age-metallicity relations. As expected, the metallicity increases with time
for all of the fields. We do not observe any radial gradient in the
metallicity.Comment: 9 pages, 11 figures, Accepted to A&
Rotation of Hot Horizontal Branch Stars in the Globular Clusters NGC 1904, NGC 2808, NGC 6093 and NGC 7078
We present high resolution UVES+VLT spectroscopic observations of 56 stars in
the extended horizontal branch (EHB) of the Galactic globular clusters NGC
1904, NGC 2808, NGC 6093, and NGC 7078. Our data reveal for the first time the
presence in NGC 1904 of a sizable population of fast (vsini > 20 km/s)
horizontal branch (HB) rotators, confined to the cool end of the EHB, similar
to that found in M13. We also confirm the fast rotators already observed in NGC
7078. The cooler stars (Teff < 11,500 K) in these three clusters show a range
of rotation rates, with a group of stars rotating at ~ 15 km/s or less, and a
fast rotating group at ~ 30 km/s. Apparently, the fast rotators are relatively
more abundant in NGC 1904 and M13, than in NGC 7078. No fast rotators have been
identified in NGC 2808 and NGC 6093. All the stars hotter than Teff ~ 11,500 K
have projected rotational velocities vsini < 12 km/s, but less than 20% have
vsini < 2 km/s. The connection between photometric gaps in the HB and the
change in the projected rotational velocities is not confirmed by the new data.
However, our data are consistent with a relation between this discontinuity and
the HB jump. We discuss a number of possibilities for the origin of the stellar
rotation distribution along the HB. We conclude that none of them can yet
provide a satisfactory explanation of the observations.Comment: 12 pages, 3 figures, ApJ Letter, accepte
Spatially resolved LMC star formation history: I. Outside in evolution of the outer LMC disk
We study the evolution of three fields in the outer LMC disk Rgc=3.5-6.2 Kpc.
Their star formation history indicates a stellar populations gradient such that
younger stellar populations are more centrally concentrated. We identify two
main star forming epochs, separated by a period of lower activity between ~7
and ~4 Gyr ago. Their relative importance varies from a similar amount of stars
formed in the two epochs in the innermost field, to only 40% of the stars
formed in the more recent epoch in the outermost field. The young star forming
epoch continues to the present time in the innermost field, but lasted only
till ~0.8 and 1.3 Gyr ago at Rgc=5.5 degrees and 7.1 degrees, respectively.
This gradient is correlated with the measured HI column density and implies an
outside-in quenching of the star formation, possibly related to a variation of
the size of the HI disk. This could either result from gas depletion due to
star formation or ram-pressure stripping, or from to the compression of the gas
disk as ram-pressure from the Milky Way halo acted on the LMC interstellar
medium. The latter two situations may have occurred when the LMC first
approached the Milky Way.Comment: 15 pages, 13 figures, 4 tables. MNRAS, in pres
A theoretical study on trehalose + water mixtures for dry preservation purposes
The properties of trehalose + water mixtures are studied as a function of mixture composition and temperature using molecular dynamics simulations. As trehalose disaccharide has been proposed for dry preservation purposes, the objective of this work is to analyse the nanoscopic properties of the considered mixtures, in terms of aggregation, clustering, interactions energies, and local dynamics, and their relationships with hydrogen bonding. The reported results allow a detailed characterization of hydrogen bonding and its evolution with mixture composition and thus inferring the effects of trehalose on water structuring providing results to justify the mechanisms of trehalose acting as preservation agent
Attracting the Entrepreneurial Potential: A Multilevel Institutional Approach
The research on institutions’ role in entrepreneurship acknowledges that formal and informal institutions matter. However, previous research has stressed less the co-existence and interaction between individual- and country-level factors that shape entrepreneurial potential, population of skill-full individuals with no entrepreneurial intentions, across countries. In this study, we investigate the multilevel influence of informal institutions on entrepreneurial potential. Drawing from institutional theory and multilevel approach in a sample of 880,576 individuals for the period 2006–2016, we find that the informal country-level institutional forces compensate the lack of individual-level factors among those with low entrepreneurial potential. For instance, media coverage on entrepreneurship or education can enhance the entrepreneurial potential in its lower end. Hence, our findings provide novel evidence on the relevance and interaction of the informal institutions among potential entrepreneurs. Our findings suggest policy implications regarding educational programs to close the gap between entrepreneurially skilled non-potential and skilled potential individual
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