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

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

Machine learning algorithms applied to weed management in integrated crop-livestock systems: a systematic literature review.

In recent times, there has been an environmental pressure to reduce the amount of pesticides applied to crops and, consequently, the crop production costs. Therefore, investments have been made in technologies that could potentially reduce the usage of herbicides on weeds. Among such technologies, Machine Learning approaches are rising in number of applications and potential impact. Therefore, this article aims to identify the main machine learning algorithms used in integrated crop-livestock systems for weed management. Based on a systematic literature review, it was possible to determine where the selected studies were performed and which crop types were mostly used. The main research terms in this study were: "machine learning algorithms" + "weed management" + "integrated crop-livestock system". Although no results were found for the three terms altogether, the combinations involving "weed management" + "integrated crop-livestock system" and "machine learning algorithms" + "weed management" returned a significant number of studies which were subjected to a second layer of refinement by applying an eligibility criteria. The achieved results show that most of the studies were from the United States and from nations in Asia. Machine vision and deep learning were the most used machine learning models, representing 28% and 19% of all cases, respectively. These systems were applied to different practical solutions, the most prevalent being smart sprayers, which allow for a site-specific herbicide application

Early life diarrhoea and later blood pressure in a developing country: the 1982 Pelotas (Brazil) birth cohort study

Background: It has recently been hypothesised that acute dehydration in early childhood may "programme'' increased blood pressure via salt retention. We examined whether there was an association between episodes of diarrhoea (a proxy for acute dehydration) and later measured blood pressure.Methods: In the 1982 Pelotas birth cohort study (Brazil), parents/carers reported hospital admissions for diarrhoea in the first 12 and 20 months of study members' lives. Blood pressure was subsequently measured directly in adolescence (aged 15, 18, 19 years) and early adulthood (aged 23 years).Results: We found no evidence of an association between diarrhoea in the first 12 months of life and blood pressure measured at any point in adolescence or early adulthood. These findings were unchanged after adjustment for a range of covariates. Equally null results were apparent when diarrhoea admissions in the first 20 months of life, access to home sanitation and use of piped water were the exposures of interest.Conclusions: Early life proxies for dehydration and diarrhoea were unrelated to later blood pressure in this examination, the most comprehensive to date, of the potential association

MOTHER-TO-CHILD TRANSMISSION OF HUMAN IMMUNODEFICIENCY VIRUS TYPE 1 INFECTION

Introdução: A Infeção pelo Vírus da Imunodeficiência Humana do tipo 1 (VIH1) na criança ocorre quase exclusivamente por transmissão mãe-filho (TMF). Sem profilaxia ocorrem taxas de transmissão de 15-25%, diminuindo para <2% quando são adotadas medidas adequadas. Objetivo: Avaliar a TMF da Infeção VIH numa maternidade. Material e Métodos: Estudo retrospetivo, com consulta do processo clínico, de crianças de mães com Infeção VIH1, nascidas na Maternidade Júlio Dinis de Janeiro de 2006 a Dezembro de 2011. Definida não Infeção se 2 testes virológicos negativos (um após os 4 meses) e ausência de clínica. Analise estatística – programa Epi-InfoR v.3.5.1 (Teste Fisher, p <0,05). Resultados: Nasceram 77 crianças com risco de transmissão VIH1, 45 do sexo masculino (58.4%) e 15 (19.5%) prematuros. Diagnostico de Infeção materna ocorreu na gestação em 24 (31.6%) e no parto numa (1.3%). Sete (9.2%) Não efetuaram terapêutica anti retrovirica (TARV) na gravidez e 9 (12.3%) apresentavam carga vírica >1.000 copias no parto. Nasceram por parto eutocico 4 (5.2%) e 10 (13%) tiveram rotura membranas (RM) ≥4h. Nenhum efetuou leite materno e todos fizeram profilaxia no periodo neonatal; 17 (22.1%) efetuaram profilaxia com 3 fármacos, associado a ausência de TARV na gravidez e parto, carga vírica materna >1.000 copias, RM≥4h, RM espontânea e prematuridade. Um recém-nascido (1.3%) faleceu. Nenhuma criança foi infetada. Cerca de um terço (35.5%) apresentou alterações hematológicas e 23 (30.3%) na função hepática, ambas reversíveis. Conclusão: Na população estudada não ocorreu TMF da Infeção VIH1, apesar de apresentar fatores que aumentam o risco de transmissão numa elevada percentagem de casos.Introduction: Human Immunodeficiency Virus type 1 (HIV1) infection in children is almost related to mother-to-child transmission (MTCT). Without prophylaxis transmission rates are 15-25%. With appropriate prophylaxis <2% rates are achieved. Objective: Evaluate the MTCT of HIV infection in a maternity. Materials and Methods: Retrospective study, with review of clinical files of children whose mothers have HIV1 infection, born at Julio Dinis Maternity from January 2006 to December 2011. Not infected was defined if 2 virologic tests were negative (one after 4 months of age) with no clinical signs of infection. Statistical analysis was performed with Epi-Info R v.3.5.1 (Fisher test, p <0.05). Results: Seventy seven children were born from HIV1 infected mothers, 45 (58.4%) males and 15 (19.5%) preterm infants. Diagnosis of maternal infection during pregnancy occurred in 24 (31.6%) and one at childbirth (1.3%). Seven (9.2%) hadn’t had antiretroviral therapy (ART) during pregnancy and 9 (12.3%) had viral load> 1,000 copies at childbirth. Normal delivery occurred in 4 (5.2%) and 10 (13%) had rupture of membranes (RM) ≥ 4h. None was breastfed. All received prophylaxis in the neonatal period; 17 (22.1%) with 3 drugs, associated with absence of ART in pregnancy and at childbirth, maternal viral load> 1,000 copies, RM ≥ 4h, spontaneous RM and prematurity. One newborn (1.3%) died. No child became infected. Almost a third (35.5%) had hematological toxicity and 23 (30.3%) had hepatic toxicity, both reversible. Conclusion: In the population studied no MTCT of HIV1 infection occurred, despite the presence of factors that increase the risk of transmission in a high percentage of cases

Langley's CSI evolutionary model: Phase O

A testbed for the development of Controls Structures Interaction (CSI) technology to improve space science platform pointing is described. The evolutionary nature of the testbed will permit the study of global line-of-sight pointing in phases 0 and 1, whereas, multipayload pointing systems will be studied beginning with phase 2. The design, capabilities, and typical dynamic behavior of the phase 0 version of the CSI evolutionary model (CEM) is documented for investigator both internal and external to NASA. The model description includes line-of-sight pointing measurement, testbed structure, actuators, sensors, and real time computers, as well as finite element and state space models of major components

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

Major loss of coralline algal diversity in response to ocean acidification

Calcified coralline algae are ecologically important in rocky habitats in the marine photic zone worldwide and there is growing concern that ocean acidification will severely impact them. Laboratory studies of these algae in simulated ocean acidification conditions have revealed wide variability in growth, photosynthesis and calcification responses, making it difficult to assess their future biodiversity, abundance and contribution to ecosystem function. Here, we apply molecular systematic tools to assess the impact of natural gradients in seawater carbonate chemistry on the biodiversity of coralline algae in the Mediterranean and the NW Pacific, link this to their evolutionary history and evaluate their potential future biodiversity and abundance. We found a decrease in the taxonomic diversity of coralline algae with increasing acidification with more than half of the species lost in high pCO2 conditions. Sporolithales is the oldest order (Lower Cretaceous) and diversified when ocean chemistry favoured low Mg calcite deposition; it is less diverse today and was the most sensitive to ocean acidification. Corallinales were also reduced in cover and diversity but several species survived at high pCO2; it is the most recent order of coralline algae and originated when ocean chemistry favoured aragonite and high Mg calcite deposition. The sharp decline in cover and thickness of coralline algal carbonate deposits at high pCO2 highlighted their lower fitness in response to ocean acidification. Reductions in CO2 emissions are needed to limit the risk of losing coralline algal diversity

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