MWA rapid follow-up of gravitational wave transients: prospects for detecting prompt radio counterparts

We present and evaluate the prospects for detecting coherent radio counterparts to gravitational wave (GW) events using Murchison Widefield Array (MWA) triggered observations. The MWA rapid-response system, combined with its buffering mode ($\sim4$ minutes negative latency), enables us to catch any radio signals produced from seconds prior to hours after a binary neutron star (BNS) merger. The large field of view of the MWA ($\sim1000\,\text{deg}^2$ at 120\,MHz) and its location under the high sensitivity sky region of the LIGO-Virgo-KAGRA (LVK) detector network, forecast a high chance of being on-target for a GW event. We consider three observing configurations for the MWA to follow up GW BNS merger events, including a single dipole per tile, the full array, and four sub-arrays. We then perform a population synthesis of BNS systems to predict the radio detectable fraction of GW events using these configurations. We find that the configuration with four sub-arrays is the best compromise between sky coverage and sensitivity as it is capable of placing meaningful constraints on the radio emission from 12.6\% of GW BNS detections. Based on the timescales of four BNS merger coherent radio emission models, we propose an observing strategy that involves triggering the buffering mode to target coherent signals emitted prior to, during or shortly following the merger, which is then followed by continued recording for up to three hours to target later time post-merger emission. We expect MWA to trigger on $\sim5\text{--}22$ BNS merger events during the LVK O4 observing run, which could potentially result in two detections of predicted coherent emission.Comment: Accepted for publication in PAS

What are the health benefits of active travel? A systematic review of trials and cohort studies.

BACKGROUND: Increasing active travel (primarily walking and cycling) has been widely advocated for reducing obesity levels and achieving other population health benefits. However, the strength of evidence underpinning this strategy is unclear. This study aimed to assess the evidence that active travel has significant health benefits. METHODS: The study design was a systematic review of (i) non-randomised and randomised controlled trials, and (ii) prospective observational studies examining either (a) the effects of interventions to promote active travel or (b) the association between active travel and health outcomes. Reports of studies were identified by searching 11 electronic databases, websites, reference lists and papers identified by experts in the field. Prospective observational and intervention studies measuring any health outcome of active travel in the general population were included. Studies of patient groups were excluded. RESULTS: Twenty-four studies from 12 countries were included, of which six were studies conducted with children. Five studies evaluated active travel interventions. Nineteen were prospective cohort studies which did not evaluate the impact of a specific intervention. No studies were identified with obesity as an outcome in adults; one of five prospective cohort studies in children found an association between obesity and active travel. Small positive effects on other health outcomes were found in five intervention studies, but these were all at risk of selection bias. Modest benefits for other health outcomes were identified in five prospective studies. There is suggestive evidence that active travel may have a positive effect on diabetes prevention, which may be an important area for future research. CONCLUSIONS: Active travel may have positive effects on health outcomes, but there is little robust evidence to date of the effectiveness of active transport interventions for reducing obesity. Future evaluations of such interventions should include an assessment of their impacts on obesity and other health outcomes

Experiências de Estágio: Contribuições para a Transição Universidade-Trabalho

As experiências de formação no ensino superior são fundamentais para o desenvolvimento profissional. Este estudo teve por objetivo compreender de que forma as experiências de estágio contribuem para o desenvolvimento da adaptabilidade de carreira e para a transição entre os papéis de estudante a profissional em formandos universitários. Participaram seis formandos de um curso de Engenharia Civil, com idades entre 22 e 29 anos. Foram realizadas entrevistas semi-estruturadas individuais, posteriormente analisadas quanto ao conteúdo. Os resultados revelaram que as experiências de estágio influenciam o desenvolvimento da adaptabilidade de carreira, especialmente nas dimensões de curiosidade e confiança. Além disso, várias características dos estágios mencionadas pelos entrevistados mostraram-se relacionadas ao desenvolvimento de carreira, revelando sua importância para o processo de transição do papel de estudante para o de profissional. O artigo conclui com implicações para a prática e a pesquisa

Factors affecting the germination of orchid seeds

The effects of sugars and other carbohydrates, vitamins, hormones, complex additives, temperature, light, pH, atmosphere and its components, and moisture are reviewed. Orchid mycorrhiza, symbiosis and asymbiotic nutrition are also reviewed