Reliability analysis of a timber truss system subjected to decay

Assessing the safety of existing timber structures is of paramount importance for taking reliable decisions on repair actions and their extent. The results obtained through semi-probabilistic methods are unrealistic, as the partial safety factors present in codes are calibrated considering the uncertainty exhibited by new structures. In order to overcome these limitations, and also to include the e ects of decay in the safety analysis, probabilistic methods, based on Monte-Carlo simulation are applied here to assess the safety of existing timber structures. In particular, the impact of decay on structural safety is analyzed and discussed using a simple structural model, similar to that used for current semi-probabilistic analysis.Fundação para a Ciência e a Tecnologia (FCT

Escape from Vela X

While the Vela pulsar and its associated nebula are often considered as the archetype of a system powered by a {approx} 10{sup 4} year old isolated neutron star, many features of the spectral energy distribution of this pulsar wind nebula are both puzzling and unusual. Here we develop a model that for the first time relates the main structures in the system, the extended radio nebula (ERN) and the X-ray cocoon through continuous injection of particles with a fixed spectral shape. We argue that diffusive escape of particles from the ERN can explain the steep Fermi-LAT spectrum. In this scenario Vela X should produce a distinct feature in the locally-measured cosmic ray electron spectrum at very high energies. This prediction can be tested in the future using the Cherenkov Telescope Array (CTA). If particles are indeed released early in the evolution of PWNe and can avoid severe adiabatic losses, PWN provide a natural explanation for the rising positron fraction in the local CR spectrum

Analysis of international residential solar PV self-consumption

How much does installing solar photovoltaic (‘PV’) panels reduce domestic electricity bills? Despite over 800,000 households with solar panels in the UK today, we do not have a firm answer to this simple question. This is because the empirical data necessary to calculate solar self-consumption is not widely available; an issue common to many countries. Without electricity metering that records solar PV generation, imports and exports, it is impossible to know exactly how much solar power is being used directly in the household, and as a result, how much solar panels actually reduce electricity bills. As many countries reduce state subsidies, the revenue stream from avoided grid imports (i.e. self-consumption) becomes increasingly critical for the economic viability of PV. Quantifying this potential revenue is also vital for the solar industry to evaluate the potential benefits of battery storage and flexibility services. This paper will help to address this knowledge gap by analysing a previously unused dataset of electricity readings from over 1,300 households with solar panels located across the UK, USA, Australia, Germany, the Netherlands, and Belgium. The results show there is considerable variation in self-consumption between different households, but this is relatively well explained by differences in the amount of solar electricity generated and the amount of electricity consumed during the day (r-squared 0.915), and that the factors affecting self-consumption are similar between the different countries analysed here. The findings will be relevant to regulators for making evidence-based decisions about solar energy policy, provide better information about potential self-consumption to people interested in adopting solar panels, and highlight the importance of improving data availability for ‘behind-the-meter’ micro-generation

Fire and fury in Iceland: tracking volcanic eruptions

Volcanic eruptions in Iceland have fascinated writers for centuries. In 1783 Benjamin Franklin correctly identified the cause of the terrible weather that summer in Europe as caused by an eruption in Iceland, which turned out to be the biggest ever historic eruption. In 1864 Jules Verne based his ‘Journey to the Centre of the Earth’ on a presumed volcanic conduit beneath the Icelandic volcano Hekla. In 2014 we were fortunate to capture the largest eruption in Iceland since 1783, this time with modern instrumentation. We were able to track the molten rock as it travelled underground for 50 km at a depth of about 6 km before erupting in central Iceland, using the 50,000 tiny earthquakes it generated as it cracked its way forwards. This was one of the first times in the world that molten rock has been captured with such detail in the act of propagating underground

Mood instability, mental illness and suicidal ideas : results from a household survey

Purpose: There is weak and inconsistent evidence that mood instability (MI) is associated with depression, post traumatic stress disorder (PTSD) and suicidality although the basis of this is unclear. Our objectives were first to test whether there is an association between depression and PTSD, and MI and secondly whether MI exerts an independent effect on suicidal thinking over and above that explained by common mental disorders. Methods: We used data from the Adult Psychiatric Morbidity Survey 2007 (N = 7,131). Chi-square tests were used to examine associations between depression and PTSD, and MI, followed by regression modelling to examine associations between MI and depression, and with PTSD. Multiple logistic regression analyses were used to assess the independent effect of MI on suicidal thinking, after adjustment for demographic factors and the effects of common mental disorder diagnoses. Results: There are high rates of MI in depression and PTSD and the presence of MI increases the odds of depression by 10.66 [95 % confidence interval (CI) 7.51–15.13] and PTSD by 8.69 (95 % CI 5.90–12.79), respectively, after adjusting for other factors. Mood instability independently explained suicidal thinking, multiplying the odds by nearly five (odds ratio 4.82; 95 % CI 3.39–6.85), and was individually by some way the most important single factor in explaining suicidal thoughts. Conclusions: MI is strongly associated with depression and PTSD. In people with common mental disorders MI is clinically significant as it acts as an additional factor exacerbating the risk of suicidal thinking. It is important to enquire about MI as part of clinical assessment and treatment studies are required

BUMC Annual Report

Annual report of the Boston University Medical Center

The utilisation of health research in policy-making: Concepts, examples and methods of assessment

The importance of health research utilisation in policy-making, and of understanding the mechanisms involved, is increasingly recognised. Recent reports calling for more resources to improve health in developing countries, and global pressures for accountability, draw greater attention to research-informed policy-making. Key utilisation issues have been described for at least twenty years, but the growing focus on health research systems creates additional dimensions. The utilisation of health research in policy-making should contribute to policies that may eventually lead to desired outcomes, including health gains. In this article, exploration of these issues is combined with a review of various forms of policy-making. When this is linked to analysis of different types of health research, it assists in building a comprehensive account of the diverse meanings of research utilisation. Previous studies report methods and conceptual frameworks that have been applied, if with varying degrees of success, to record utilisation in policy-making. These studies reveal various examples of research impact within a general picture of underutilisation. Factors potentially enhancing utilisation can be identified by exploration of: priority setting; activities of the health research system at the interface between research and policy-making; and the role of the recipients, or 'receptors', of health research. An interfaces and receptors model provides a framework for analysis. Recommendations about possible methods for assessing health research utilisation follow identification of the purposes of such assessments. Our conclusion is that research utilisation can be better understood, and enhanced, by developing assessment methods informed by conceptual analysis and review of previous studies

Hidden Voices: Disabled Women's Experiences of Violence and Support Over the Life Course

Violence against women is a worldwide social and human rights problem that cuts across cultural, geographic, religious, social, and economic boundaries. It affects women in countries around the world, regardless of class, religion, disability, age, or sexual identity. International evidence shows that approximately three in five women experienced physical and/or sexual violence by an intimate partner. However, across the globe, women and girls with impairments or life-limiting illnesses are more susceptible to different forms of violence across a range of environments and by different perpetrators including professionals and family members as well as partners. However, they are likely to be seriously disadvantaged in gaining information and support to escape the abusive relationships. This article stems from the United Kingdom part of a comparative study with three other countries (Austria, Germany, and Iceland) funded by the European Commission (EC; 2013-2015). It presents preliminary findings, generated from life history interviews, about disabled women's experiences of violence and access to support (both formal and informal) over their life course and their aspirations for the prevention of violence in the future. The article includes examples of impairment-specific violence that non-disabled women do not experience. By bringing the voices of disabled women into the public domain, the article will facilitate a historically marginalized group to contribute to the debate about disability, violence, and support

Intergovernmental Relations in Scotland: what was the SNP effect?

In Scotland, the formation of a minority government in 2007 by the Scottish National Party (SNP) provided the potential for profound changes in intergovernmental relations. This followed eight years of a Scottish Labour-led coalition government characterised by a low-key and informal relationship with the UK Labour government. From 1999 to 2007, discussions were conducted informally and almost entirely through political parties and executives (ministers and civil servants). Although formal mechanisms for negotiation and dispute resolution existed-including the courts, concordats and Joint Ministerial Committees-they were used rarely. The Scottish Executive also played a minimal role in EU policy-making. Yet, an ‘explosive' new era of relations between the Scottish and UK governments did not arrive in tandem with the new era of party incongruence. The aim of this article is to explore these issues by asking two main questions: why were formal mechanisms used so rarely from 1999 to 2007, and what factors produced muted rather than problematic IGR in the third parliamentary session, between 2007 and 2011