Multifrequency Radio Observations of a SNR in the LMC. The Case of SNR J0527-6549 (DEM l204)

We present a detailed study and results of new Australia Telescope Compact Array (ATCA) observations of supernova remnant, SNR J0527-6549. This Large Magellanic Cloud (LMC) ob ject follows a typical supernova remnant (SNR) horseshoe morphology with a diameter of D=(66x58)+-1 pc which is among the largest SNRs in the LMC. Its relatively large size indicates older age while a steeper than expected radio spectral index of aplha=-0.92+-0.11 is more typical for younger and energetic SNRs. Also, we report detections of regions with a high order of polarization at a peak value of ~54+-17% at 6 cm.Comment: 9 Pages, 6 figures, accepted for publication in SA

Potential Of Sugarcane In Modern Energy Development In Southern Africa

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)For more than half of the Southern African population, human development is limited by a lack of access to electricity and modern energy for cooking. Modern bioenergy merits consideration as one means to address this situation in areas where sufficient arable land is available. While numerous studies have concluded that Africa has significant biomass potential, they do not indicate by how much it can effectively reduce the use of traditional biomass and provide more accessible energy, especially at a country level. Here, we evaluate the potential of sugarcane to replace traditional biomass and fossil fuel and enlarge the access to electricity in Southern Africa. By using its current molasses for ethanol production, Swaziland could increase electricity generation by 40% using bagasse and replace 60% of cooking fuel or 30% of liquid fossil fuel. Sugarcane expansion over 1% of the pasture land in Angola, Mozambique, and Zambia could replace greater than 70% of cooking fuel. Bioelectricity generation from modest sugarcane expansion could be increased by 10% in Malawi, Mozambique, and Zambia and by 20% in Angola. Our results support the potential of sugarcane as a modern energy alternative for Southern Africa.4Sao Paulo Research Foundation (FAPESP) [2012/00282-3, 2015/02270-0]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Prevalence of high blood pressure in 122, 053 adolescents: A systematic review and meta-regression

Several studies have reported high prevalence of risk factors for cardiovascular disease in adolescents. To perform: i) systematically review the literature on the prevalence of high blood pressure (HBP) in adolescents; ii) analyze the possible methodological factors associated with HBP; and iii) compare the prevalence between developed and developing countries. We revised 10 electronic databases up to August 11, 2013. Only original articles using international diagnosis of HBP were considered. The pooled prevalence's of HBP were estimated by random effects. Meta-regression analysis was used to identify the sources of heterogeneity across studies. Fifty-five studies met the inclusion criteria and total of 122,053 adolescents included. The pooled-prevalence of HBP was 11.2%, 13% for boys, and 9.6% for girls (P < 0.01). Method of measurement of BP and year in which the survey was conducted were associated with heterogeneity in the estimates of HBP among boys. The data indicate that HBP is higher among boys than girls, and that the method of measurement plays an important role in the overall heterogeneity of HBP value distributions, particularly in boys

Multivariate analysis of morphology, behaviour, growth and developmental timing in hybrids brings new insights into the divergence of sympatric Arctic charr morphs

This work was fully funded by the Icelandic Centre of Research, RANNÍS (Icelandic Research Fund grant no.173802-051).Background: Studying the development of fitness related traits in hybrids from populations diverging in sympatry is a fundamental approach to understand the processes of speciation. However, such traits are often affected by covariance structures that complicate the comprehension of these processes, especially because the interactive relationships between traits of different nature (e.g. morphology, behaviour, life-history) remain largely unknown in this context. In a common garden setup, we conducted an extensive examination of a large suit of traits putatively involved in the divergence of two morphs of Arctic charr (Salvelinus alpinus), and investigated the consequences of potential patterns of trait covariance on the phenotype of their hybrids. These traits were measured along ontogeny and involved growth, yolk sac resorption, developmental timing (hatching and the onset of exogeneous feeding), head morphology and feeding behaviour. Results: Growth trajectories provided the strongest signal of phenotypic divergence between the two charr. Strikingly, the first-generation hybrids did not show intermediate nor delayed growth but were similar to the smallest morph, suggesting parental biases in the inheritance of growth patterns. However, we did not observe extensive multivariate trait differences  between the two morphs and their hybrids. Growth was linked to head morphology (suggesting that morphological variations in early juveniles relate to simple allometric effects) but this was the only strong signal of covariance observed between all the measured traits. Furthermore, we did not report evidence for differences in overall phenotypic variance between morphs, nor for enhanced phenotypic variability in their hybrids. Conclusion: Our study shed light on the multivariate aspect of development in a context of adaptive divergence. The lack of evidence for the integration of most traits into a single covariance structure suggested that phenotypic constraints may not always favour nor impede divergence toward ecological niches differing in numerous physical and ecological variables, as observed in the respective habitats of the two charr. Likewise, the role of hybridization as a disruptive agent of trait covariance may not necessarily be significant in the evolution of populations undergoing resource polymorphism.Publisher PDFPeer reviewe

Subtidal benthic marine algae of the Marine State Park of Laje de Santos (São Paulo, Brazil)

O Parque Estadual Marinho da Laje de Santos tem sido apontado como local de elevada diversidade marinha. Apesar de sua importância para a conservação da biota marinha não existem resultados efetivamente publicados. O objetivo deste trabalho é o de caracterizar a flora marinha bentônica desse Parque Marinho. Amostragens foram realizadas por mergulho autônomo: uma qualitativa que incluiu a zona do sublitoral até a profundidade de 26 m e outra quantitativa em duas profundidades pré-determinadas, 10 e 20 m.. Dentre os 129 táxons encontrados, foram identificadas pela primeira vez, 5 espécies para o Estado de São Paulo, 3 espécies para o litoral brasileiro e 1 espécie para o Atlântico sul. As algas mais abundantes foram Sargasum vulgare e tufos compostos de coralináceas geniculadas e algas filamentosas. A freqüência de ocorrência dos táxons revelou que a maioria deles ocorreu em menos de 20 % das amostras. A análise da flora marinha bentônica demonstra que o Parque Estadual Marinho da Laje de Santos é um local de elevada riqueza e que sua composição florística esta relacionada a uma estrutura de comunidade bentônica dominada por populações de S. vulgare e grupos formadores de tufos.Laje de Santos Marine State Park has been pointed out as a site of high marine diversity. In spite of its importance to conservation of marine biota no results of investigations about its marine biodiversity have been published. The aim of this work was to characterize the subtidal seaweed flora of this Marine Park. Samplings were performed by scuba diving: a qualitative one that included the subtidal zone down to 26 m depth and other quantitative at two pre-determined depths, 10 and 20 m. Among the 129 taxa identified, 5 species were identified for the first time for the São Paulo State, 3 for the Brazilian coast and 1 for the South Atlantic Ocean. The most abundant algae were Sargassum vulgare and turf composed by geniculate coralline and filamentous groups. The frequency of occurrence of taxa revealed that most of species are restricted to frequencies less than 20 % in all samples. The analyses of the subtidal marine benthic algal flora indicate the Marine State Park of Laje de Santos as a site of elevated species richness and that its floristic composition is related to a benthic community structure dominated by turf-forming groups and population of S. vulgare

Could we find any signal of the stratosphere-ionosphere coupling in Antarctica?

An investigation searching for a possible coupling between the lower ionosphere and the middle atmosphere in Antarctica is here performed on the basis of stratospheric vertical temperature profiles and ionospheric absorption data observed at the Antarctic Italian Base of Terra Nova Bay (74.69S, 164.12E) during local summer time. The result obtained by applying a multi-regression analysis and a Superimposed Epoch Analysis (SEA) shows a statistically significant ionosphere-stratosphere interaction. In particular, by selecting stratospheric temperature maxima occurring at different heights as the referring epoch for the SEA approach, the ionospheric absorption is found to show a positive and/or negative trend (several days) around it. The tendency for an increasing/decreasing absorption is obtained for temperature maxima occurring below/above the stratospheric level of about 17-19 km, respectively

The first observed stellar occultations by the irregular satellite Phoebe (Saturn IX) and improved rotational period

peer reviewedWe report six stellar occultations by Phoebe (Saturn IX), an irregular satellite of Saturn, obtained between mid-2017 and mid-2019. The 2017 July 6 event was the first stellar occultation by an irregular satellite ever observed. The occultation chords were compared to a 3D shape model of the satellite obtained from Cassini observations. The rotation period available in the literature led to a sub-observer point at the moment of the observed occultations where the chords could not fit the 3D model. A procedure was developed to identify the correct sub-observer longitude. It allowed us to obtain the rotation period with improved precision compared to the currently known value from literature. We show that the difference between the observed and the predicted sub-observer longitude suggests two possible solutions for the rotation period. By comparing these values with recently observed rotational light curves and single- chord stellar occultations, we can identify the best solution for Phoebe's rotational period as 9.27365 ± 0.00002 h. From the stellar occultations, we also obtained six geocentric astrometric positions in the ICRS as realized by the Gaia DR2 with uncertainties at the 1-mas level

Investigating aquifer vulnerability employing DRASTIC model and GIS techniques in Menzel Habib Shallow Aquifer, South-Eastern Tunisia

Groundwater vulnerability assessment shows an extreme sensitivity to in situ anthropogenic pollutants. A dichotomous assessment of geological and hydrological (inter alia) characteristics makes it possible to determine the vulnerability of an aquifer system. The natural vulnerability of an aquifer can be severely compromised by human activities. The physical structure and material composition of aquifers shows resistance to contaminants transport from surface to groundwater. Currently, numerous methods have been posited evaluating aquifer's vulnerability. Similarly, the DRASTIC and DRASTIC pesticides models utilize computer algorithms and hydro-geological data within a Geographical Information System (GIS) to compute spatial aquifer vulnerability. The DRASTIC and DRASTIC pesticides models are constructed using combined spatial datasets on Depth to groundwater (D), Aquifer Recharge (R), Aquifer media (A), Soil media (S), Topography (T), Impact of the Vadose Zone (I) and Hydraulic Conductivity (C) of the aquifer. The degree of vulnerability of the aquifer system can be evaluated by computing sensitivity analysis of DRASTIC index using GIS, showing the contribution of each parameter to vulnerability sensitivity. The GIS was used to develop a vulnerability map for Menzel Habib aquifer area. The obtained results indicated that moderately vulnerable areas are of 5%, while areas of no risk correspond to 95% using DRASTIC index. Otherwise, DRASTIC pesticide index indicated that 15% area of low vulnerability, 84% moderately vulnerable and 1% high vulnerability. The central area of Menzel Habib aquifer showed a low vulnerability due to dense human settlement and a deeper water level. However, agricultural areas recorded high vulnerability risk. Menzel Habib's environmental and socio-economic development is dependent on policy makers and planner's ability to use information effectively for decision making. The obtained groundwater vulnerability maps provide a basis for this aimed at protecting the aquifer from pollutants. Additionally, land use and development activities can be informed by mapping variables, showing that agriculture areas are highly vulnerable as compare to settlement areas