1,615 research outputs found

    Multifrequency radio observations of SNR J0536-6735 (N 59B) with associated pulsar

    Get PDF
    We present a study of new Australian Telescope Compact Array (ATCA) observations of supernova remnant, SNR J0536-6735. This remnant appears to follow a shell morphology with a diameter of D=36x29 pc (with 1 pc uncertainty in each direction). There is an embedded Hii region on the northern limb of the remnant which made various analysis and measurements (such as flux density, spectral index and polarisation) difficult. The radio-continuum emission followed the same structure as the optical emission, allowing for extent and flux density estimates at 20 cm. We estimate a surface brightness for the SNR at 1 GHz of 2.55x10^-21 W m^-2 Hz^-1 sr^-1. Also, we detect a distinctive radio-continuum point source which confirms the previous suggestion of this remnant being associated with a pulsar wind nebulae (PWN). The tail of this remnant isn't seen in the radio-continuum images and is only seen in the optical and X-ray images.Comment: 10 pages 4 figures, accepted for publication in SA

    The Strongest 100 Point Radio Sources in the LMC at 1.4 GHz

    Full text link
    We present the 100 strongest 1.4 GHz point sources from a new mosaic image in the direction of the Large Magellanic Cloud (LMC). The observations making up the mosaic were made over a ten year period and were combined with Parkes single dish data at 1.4 GHz to complete the image for short spacing. An initial list of co-identifications within 10" at 0.843, 4.8 and 8.6 GHz consisted of 2682 sources. Elimination of extended objects and artifact noise allowed the creation of a refined list containing 1988 point sources. Most of these are presumed to be background objects seen through the LMC; a small portion may represent compact H II regions, young SNRs and radio planetary nebulae. For the 1988 point sources we find a preliminary average spectral index of -0.53 and present a 1.4 GHz image showing source location in the direction of the LMC.Comment: 8 pages, 2 figure

    Multi-frequency study of Local Group Supernova Remnants The curious case of the Large Magellanic Cloud SNR J0528-6714

    Full text link
    Aims. Recent ATCA, XMM-Newton and MCELS observations of the Magellanic Clouds (MCs) cover a number of new and known SNRs which are poorly studied, such as SNR J0528-6714 . This particular SNR exhibits luminous radio-continuum emission, but is one of the unusual and rare cases without detectable optical and very faint X-ray emission (initially detected by ROSAT and listed as object [HP99] 498). We used new multi-frequency radio-continuum surveys and new optical observations at H{\alpha}, [S ii] and [O iii] wavelengths, in combination with XMM-Newton X-ray data, to investigate the SNR properties and to search for a physical explanation for the unusual appearance of this SNR. Methods. We analysed the X-ray and Radio-Continuum spectra and present multi-wavelength morphological studies of this SNR. Results. We present the results of new moderate resolution ATCA observations of SNR J0528-6714. We found that this object is a typical older SNR with a radio spectral index of {\alpha}=-0.36 \pm 0.09 and a diameter of D=52.4 \pm 1.0 pc. Regions of moderate and somewhat irregular polarisation were detected which are also indicative of an older SNR. Using a non-equilibrium ionisation collisional plasma model to describe the X-ray spectrum, we find temperatures kT of 0.26 keV for the remnant. The low temperature, low surface brightness, and large extent of the remnant all indicate a relatively advanced age. The near circular morphology indicates a Type Ia event. Conclusions. Our study revealed one of the most unusual cases of SNRs in the Local Group of galaxies - a luminous radio SNR without optical counterpart and, at the same time, very faint X-ray emission. While it is not unusual to not detect an SNR in the optical, the combination of faint X-ray and no optical detection makes this SNR very unique.Comment: 6 pages, 5 figures, Accepted for publication in A&

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

    Full text link
    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

    Study on Doping Prevention: A map of Legal, Regulatory and Prevention Practice Provisions in EU 28

    Get PDF
    Historically, anti-doping efforts have focused on the detection and deterrence of doping in elite and competitive sport. There is, however, a growing concern that doping is occurring outside the organised sporting system; giving rise to the belief that the misuse of doping agents in recreational sport has become a societal problem and a public health issue that must be addressed. The EU Commission awarded a contract (EAC/2013/0617) to a Consortium to undertake this Study with the aim of developing the evidence-base for policies designed to combat doping in recreational sport. Fourteen internationally recognised experts shaped the Study which comprised (i) the collection of primary data through a structured survey, and (ii) secondary data through literature searches and website analysis. All 28 Member States participated in the information-gathering process. Specifically, this involved a systematic study of the ethical considerations, legal position, prevention research landscape, and current practise in relation to the prevention of doping in recreational sport. The Study provides a comprehensive overview of current practice and legislation as it applies to the prevention of doping and promotes and supports the sharing of best practices in the EU regarding the fight against doping in recreational sport. It concludes with seven recommendations for future action that focus on the need for a coordinated response in relation to the problems arising from doping in recreational sport

    Langley's CSI evolutionary model: Phase O

    Get PDF
    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

    Age at menarche associated with subsequent educational attainment and risk-taking behaviours: the Pelotas 1982 Birth Cohort.

    Get PDF
    Background: Earlier age at menarche (AAM), a marker of puberty timing in females, has been associated with a higher likelihood of adolescent risk-taking behaviours and variably associated with educational attainment.Aim: To examine the association between AAM and educational attainment in the Pelotas, Brazil, 1982 Birth Cohort.Subjects and methods: AAM was categorised as Early (7-11 years), Average (12-13 years), or Late (14+ years). Primary outcome: years of education (age 30). Secondary outcomes: risk-taking behaviours, adult income and school grade failure.Results: In adjusted models, compared to Average AAM, Late AAM was associated with 0.64 fewer years of education (95% CI: -1.15, -0.13). Early AAM was associated with earlier age at first sexual intercourse (-0.25 years; 95% CI: -0.39, -0.12), whereas Late AAM was associated with 17% lower adult income (0.83; 95% CI: 0.71, 0.95) and 0.31 years older age at first alcohol consumption (95% CI: 0.10, 0.52).Conclusions: Our findings confirm the association between earlier puberty timing in females and a greater likelihood of risk-taking behaviours in this setting of recent secular changes towards earlier puberty. However, the association between Late AAM and lower education was surprising and may support a psychosocial rather than biological link between puberty timing and educational outcomes

    Radio continuum observations of LMC SNR J0550-6823

    Get PDF
    We report on new Australia Telescope Compact Array (ATCA) observations of the Large Magellanic Cloud (LMC) supernova remnant (SNR) J0550-6823 (DEM L328). This object is a typical horseshoe SNR with a diameter of 373" x 282" +- 4" (90 x 68 +- 1), making it one of the largest known SNRs in the Local Group. We estimate a relatively steep radio spectral index of alpha = -0.79 +- 0.27. However, its stronger than expected polarisation of 50% +- 10% is atypical for older and more evolved SNRs. We also note a strong correlation between [Oiii] and radio images, classifying this SNR as oxygen dominant.Comment: 10 pages, 5 figures, submitted to Revista Mexicana de Astronomia y Astrofisic

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

    Get PDF
    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
    corecore