1,677 research outputs found
Interseccionalidade e igualdade de gĂȘnero em tensĂŁo: polĂticas pĂșblicas de saĂșde em Cuba
Neste trabalho sĂŁo apresentadas as reflexĂ”es que surgem da interlocução entre a teoria da interseccionalidade e duas polĂticas pĂșblicas do MinistĂ©rio de SaĂșde cubano: O Programa Nacional Materno-Infantil e o Programa Nacional de Atendimento ao Casal InfĂ©rtil, com o objetivo de debater as enunciaçÔes discursivas acerca da igualdade de gĂȘnero que estas polĂticas pĂșblicas constroem. Adotando a perspectiva da interseccionalidade discute-se o quanto os discursos de igualdade, assentes na ideia de universalismo, estabelecem identidades de gĂȘnero reificadas e produzem exclusĂ”es. Identifica-se como principal desafio das polĂticas a necessidade de atentar para o modo como o gĂȘnero, em suas articulaçÔes com outros marcadores sociais, constrĂłi vulnerabilidades interseccionais que precisam ser consideradas nas agendas de polĂticas que busquem promover a igualdade de gĂȘnero.info:eu-repo/semantics/publishedVersio
Anharmonic transitions in nearly dry L-cysteine I
Two special dynamical transitions of universal character have been recently
observed in macromolecules at K and K.
Despite their relevance, a complete understanding of the nature of these
transitions and their consequences for the bio-activity of the macromolecule is
still lacking. Our results and analysis concerning the temperature dependence
of structural, vibrational and thermodynamical properties of the orthorhombic
polymorph of the amino acid L-cysteine (at a hydration level of 3.5%) indicated
that the two referred temperatures define the triggering of very simple and
specific events that govern all the biochemical interactions of the
biomolecule: activation of rigid rotors (), phonon-phonon interactions
with phonons of water dimer (), and water rotational barriers
surpassing ().Comment: 4 pages, 4 figures, submitted to Physical Review Letter
No evidence for mass segregation in massive young clusters
Aims. We investigate the validity of the mass segregation indicators commonly
used in analysing young stellar clusters. Methods. We simulate observations by
constructing synthetic seeing-limited images of a 1000 massive clusters (10^4
Msun) with a standard IMF and a King-density distribution function. Results. We
find that commonly used indicators are highly sensitive to sample
incompleteness in observational data and that radial completeness
determinations do not provide satisfactory corrections, rendering the studies
of radial properties highly uncertain. On the other hand, we find that, under
certain conditions, the global completeness can be estimated accurately,
allowing for the correction of the global luminosity and mass functions of the
cluster. Conclusions. We argue that there is currently no observational
evidence of mass segregation in young compact clusters since there is no robust
way to differentiate between true mass segregation and sample incompleteness
effects. Caution should then be exercised when interpreting results from
observations as evidence of mass segregation.Comment: 10 pages, 12 figures, typos corrected. Download a high-resolution
version at http://www.astro.up.pt/~jascenso/mseg_v2.pdf (1 MB
Palisadegrass effects on N fertilizer dynamic in intercropping systems with corn.
Corn grain yield, nitrogen (N) fertilizer efficiency and distribution to corn alone and three forms of corn and palisadegrass (Urochloa spp.) intercropping implantation was investigated. A field experiment with 15N labeling fertilizer was performed in randomized block design. No form of palisadegrass intercropping implantation affected corn grain yield, total N accumulation and N use efficiency (NUE), which were 8.7 t ha-1, 205 kg ha-1 and 37% respectively. The palisadegrass produced on average 1.9 t of dry mass, absorbing a maximum of 6 kg ha-1 or 5.5% of N fertilizer during corn growing. Furthermore, the palisadegrass did not affect N fertilizer distribution in soil-plant system, in which 28.2% was recovered in the soil and 40.4% in the plants (corn + palisadegrass). The results show that for the three intercropping implantation methods the palisadegrass did not compete with corn for N fertilizer
Dissociation of the benzene molecule by UV and soft X-rays in circumstellar environment
Benzene molecules, present in the proto-planetary nebula CRL 618, are ionized
and dissociated by UV and X-ray photons originated from the hot central star
and by its fast wind. Ionic species and free radicals produced by these
processes can lead to the formation of new organic molecules. The aim of this
work is to study the photoionization and photodissociation processes of the
benzene molecule, using synchrotron radiation and time of flight mass
spectrometry. Mass spectra were recorded at different energies corresponding to
the vacuum ultraviolet (21.21 eV) and soft X-ray (282-310 eV) spectral regions.
The production of ions from the benzene dissociative photoionization is here
quantified, indicating that C6H6 is more efficiently fragmented by soft X-ray
than UV radiation, where 50% of the ionized benzene molecules survive to UV
dissociation while only about 4% resist to X-rays. Partial ion yields of H+ and
small hydrocarbons such as C2H2+, C3H3+ and C4H2+ are determined as a function
of photon energy. Absolute photoionization and dissociative photoionization
cross sections have also been determined. From these values, half-life of
benzene molecule due to UV and X-ray photon fluxes in CRL 618 were obtained.Comment: The paper contains 8 pages, 9 figures and 4 tables. Accepted to be
published on MNRAS on 2008 November 2
Revealing hidden clonal complexity in Mycobacterium tuberculosis infection by qualitative and quantitative improvement of sampling
AbstractThe analysis of microevolution events, its functional relevance and impact on molecular epidemiology strategies, constitutes one of the most challenging aspects of the study of clonal complexity in infection by Mycobacterium tuberculosis. In this study, we retrospectively evaluated whether two improved sampling schemes could provide access to the clonal complexity that is undetected by the current standards (analysis of one isolate from one sputum). We evaluated in 48 patients the analysis by mycobacterial interspersed repetitive unitâvariable number tandem repeat of M. tuberculosis isolates cultured from bronchial aspirate (BAS) or bronchoalveolar lavage (BAL) and, in another 16 cases, the analysis of a higher number of isolates from independent sputum samples. Analysis of the isolates from BAS/BAL specimens revealed clonal complexity in a very high proportion of cases (5/48); in most of these cases, complexity was not detected when the isolates from sputum samples were analysed. Systematic analysis of isolates from multiple sputum samples also improved the detection of clonal complexity. We found coexisting clonal variants in two of 16 cases that would have gone undetected in the analysis of the isolate from a single sputum specimen. Our results suggest that analysis of isolates from BAS/BAL specimens is highly efficient for recording the true clonal composition of M. tuberculosis in the lungs. When these samples are not available, we recommend increasing the number of isolates from independent sputum specimens, because they might not harbour the same pool of bacteria. Our data suggest that the degree of clonal complexity in tuberculosis has been underestimated because of the deficiencies inherent in a simplified procedure
Grain yield, efficiency and the allocation of foliar N applied to soybean canopies.
Soybean [Glycine max (L.) Merr.] grain yield is closely associated with the level of optimal nitrogen (N) supply, especially during the reproductive stages. Foliar fertilization with low rates of N have been considered as a strategy for furnishing additional N and enhancing grain yields. Field studies using 15N tracer were conducted over two growing seasons to investigate the impact of foliar N fertilization on grain yield, plant N content, the amount of N derived from fertilizer (NDFF) and N recovery efficiency (NRE). Four foliar N rates (0, 1300, 2600 and 3900 g ha?1) were supplied by two equal split applications at the R1 and R3 stages. Foliar N fertilization of soybean canopies did not affect grain yield, grain N content, shoot N content nor plant N content. Total NDFF was increased from 0.7 to 2.0 kg ha?1 across the N rates. Nonetheless, NRE was unaffected by foliar N fertilization, which averaged 53 %. Soybean plants allocated the same amount of N fertilizer to both grains and shoots. No significant effects of low rate foliar N fertilization were registered on soybean grain yield nor plant N content, despite considerable N fertilizer recovery by plant organs
Challenges and opportunities in the use of ponds and pondscapes as Nature-based Solutions
Ponds and âpondscapesâ (networks of ponds) are crucial habitats for biodiversity and for delivering multiple benefits to humans, so-called âNatureâs Contribution to Peopleâ, such as climate mitigation and adaptation to climate change, creation, and maintenance of habitat for biodiversity, water purification, flood mitigation and cultural benefits (e.g., recreational possibilities). However, ponds are not often considered as Nature-based Solutions to provide all these benefits. In addition, there is insufficient knowledge on how to manage and restore ponds to maximise their role to increase the resilience of ecosystems and society to climate change. To facilitate improved implementation of ponds as Nature-based Solutions for the delivery of a wide range of Nature Contributions to People, it is important to generate and integrate biodiversity, ecosystems, societal, economic and policy knowledge. Hence, there is a need for evidence-based guidance to support the broader use of ponds. Here, we review the role of ponds and pondscapes in delivering Natureâs Contributions to People and provide an overview of the challenges and opportunities for their broader implementation as Nature-based Solutions. Finally, we propose a conceptual framework that can help the implementation of pond Nature-based Solutions, and that outlines future research needs
Ising model in small-world networks
The Ising model in small-world networks generated from two- and
three-dimensional regular lattices has been studied. Monte Carlo simulations
were carried out to characterize the ferromagnetic transition appearing in
these systems. In the thermodynamic limit, the phase transition has a
mean-field character for any finite value of the rewiring probability p, which
measures the disorder strength of a given network. For small values of p, both
the transition temperature and critical energy change with p as a power law. In
the limit p -> 0, the heat capacity at the transition temperature diverges
logarithmically in two-dimensional (2D) networks and as a power law in 3D.Comment: 6 pages, 7 figure
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