Gravitating monopoles in SU(3) gauge theory

We consider the Einstein-Yang-Mills-Higgs equations for an SU(3) gauge group in a spherically symmetric ansatz. Several properties of the gravitating monopole solutions are obtained an compared with their SU(2) counterpart.Comment: 7 pages, Latex, 3 figure

Formation of extended topological defects during symmetry breaking phase transitions in O(2) and O(3) models

The density of extended topological defects created during symmetry-breaking phase transitions depends on the ratio between the correlation length in the symmetric phase near $T_c$ and the winding length of the defects as determined by the momentaneous effective action after a typical relaxation time. Conservation of winding number in numerical simulations requires a suitable embedding of the field variables and the appropriate geometrical implementation of the winding density on the discrete lattice. We define a modified Kibble limit for the square lattice and obtain defect densities as functions of winding lengths in O(2) and O(3) models. The latter allows to observe formation of disoriented aligned domains within the easy plane. Their extent is severely limited by the momentaneous defect density during the course of the quench.Comment: 16 pages, 9 figure

d dimensional SO(d)-Higgs Models with Instanton and Sphaleron: d=2,3

The Abelian Higgs model and the Georgi-Glashow model in 2 and 3 Euclidean dimensions respectively, support both finite size instantons and sphalerons. The instantons are the familiar Nielsen-Oleson vortices and the 't Hooft-Polyakov monopole solutions respectively. We have constructed the sphaleron solutions and calculated the Chern-Simons charges N_cs for sphalerons of both models and have constructed two types of noncontractible loops between topologically distinct vacuua. In the 3 dimensional model, the sphaleron and the vacuua have zero magnetic and electric flux while the configurations on the loops have non vanishing magnetic flux.Comment: 24 pages, 3 figures, LaTe

DNA Dosimetry Assessment for Sunscreen Genotoxic Photoprotection

Background: Due to the increase of solar ultraviolet radiation (UV) incidence over the last few decades, the use of sunscreen has been widely adopted for skin protection. However, considering the high efficiency of sunlight-induced DNA lesions, it is critical to improve upon the current approaches that are used to evaluate protection factors. An alternative approach to evaluate the photoprotection provided by sunscreens against daily UV radiation-induced DNA damage is provided by the systematic use of a DNA dosimeter. Methodology/Principal Findings: The Sun Protection Factor for DNA (DNA-SPF) is calculated by using specific DNA repair enzymes, and it is defined as the capacity for inhibiting the generation of cyclobutane pyrimidine dimers (CPD) and oxidised DNA bases compared with unprotected control samples. Five different commercial brands of sunscreen were initially evaluated, and further studies extended the analysis to include 17 other products representing various formulations and Sun Protection Factors (SPF). Overall, all of the commercial brands of SPF 30 sunscreens provided sufficient protection against simulated sunlight genotoxicity. In addition, this DNA biosensor was useful for rapidly screening the biological protection properties of the various sunscreen formulations. Conclusions/Significance: The application of the DNA dosimeter is demonstrated as an alternative, complementary, and reliable method for the quantification of sunscreen photoprotection at the level of DNA damage.Natura Inovacao e Tecnologia de Produtos LTDA (Sao Paulo, Brazil)Natura Inovacao e Tecnologia de Produtos LTDA (Sao Paulo, Brazil)FAPESP (Sao Paulo, Brazil)FAPESP (Sao Paulo, Brazil)CNPq (Brasilia, Brazil)CNPq (Brasilia, Brazil)Natura Inovacao e Tecnologia de Produtos LTDANatura Inovacao e Tecnologia de Produtos LTD

Recent changes in the distribution of a marine gastropod, <i>Patella rustica</i> Linnaeus, 1758, and their relationship to unusual climatic events

Aim: Recent colonization of northern Portuguese shores by Patella rustica Linnaeus, 1758, led to the bridging of a historical gap in the distribution known since the 1900s. Long-term oceanographic data collected over the last half-century were examined in order to detect possible mechanisms for the observed change in its distribution.Location: This study was carried out along the entire Portuguese coastline, from 41°50' to 37°06' N. Time-series of hydrographical variables (sea surface temperature and salinity) were derived for the Atlantic coast of the Iberian Peninsula.Methods: Abundance and size-frequency distributions of the newly observed limpet populations were compared with those from well-established populations in southern Portugal. Anomalies were computed for sea surface temperature (1950–2000) and sea surface salinity (1958–2001) data, covering the whole Atlantic coast of the Iberian Peninsula. An upwelling index (1967–2005) was derived for a single location within the distributional gap of P. rustica. Split moving window analysis was performed to detect significant discontinuities in hydrographical data sets.Results: Patella rustica has gradually been expanding in northern Iberia, and in the late 1990s the historical gap in distribution in northern Portugal was bridged. Size-frequency distribution differed between historical and recent populations, the latter lacking small-sized individuals. At the same time, several anomalous oceanographic events occurred off the Portuguese coast and were probably related to this expansion.Main conclusions: Although sea surface temperature might be a major determinant of the reproductive success of P. rustica and hence its dispersal potential, it is more likely that a coincidence of several factors occurring in the late 1990s provided exceptional conditions that allowed the geographical expansion of this species

‘We thought if it’s going to take two years then we need to start that now’: Age, infertility risk and the timing of pregnancy in older first-time mothers

Over the past few decades, the number of women having their first babies over the age of thirty-five in most developed societies has steadily increased. Concerns have been raised over this trend amidst warnings of both the increased risk of fertility problems and health risks to mother and child. Despite this, research into the timing of pregnancy in the context of decreasing fertility has been somewhat neglected, with research typically framed in biomedical rather than social terms. However, this area merits closer attention given the contradictory nature of societal messages that simultaneously encourage women to pursue careers and enhance lifestyle, whilst warning of ‘risks’ of infertility and problems in ‘delaying’ motherhood. This article is based on a small-scale qualitative study that uses data drawn from eleven in-depth interviews with ‘older mothers’ about their transition to motherhood. The data was thematically analysed. We found that the women drew upon risk discourses around decreasing fertility and advancing maternal age, and that these discourses impacted on their decisions about the timing of their pregnancies. Some mothers felt that they started trying to conceive at ‘non-ideal’ times, owing to expectations they held about decreasing fertility. We suggest that the impact of contradictory societal messages around the timing of motherhood need to be more clearly considered for their potential effects on the timing of pregnancy and note how this topic brings the personal, and, by implication, the societal, into conflict with the (narrated) biological