207 research outputs found

    Detection of high-frequency gravitational waves using high-energy pulsed lasers

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    We propose a new method for detecting high-frequency gravitational waves (GWs) using high-energy pulsed lasers. Through the inverse Gertsenshtein effect, the interaction between a GW and the laser beam results in the creation of an electromagnetic signal. The latter can be detected using single-photon counting techniques. We compute the minimal strain of a detectable GW which only depends on the laser parameters. We find that a resonance occurs in this process when the frequency of the GW is twice the frequency of the laser. With this method, the frequency range 1013−101910^{13}-10^{19} Hz is explored non-continuously for strains h≳10−20h \gtrsim 10^{-20} for current laser systems and can be extended to h≳10−26h \gtrsim 10^{-26} with future generation facilities.Comment: 15 pages, 2 figures, v2 matches the published versio

    Development of materials to support parents whose babies cry excessively: findings and health service implications

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    Aim: To develop evidence-based materials which provide information and support for parents who are concerned about their baby's excessive crying. As well as meeting these parents' needs, the aim was to develop a package of materials suitable for use by the UK National Health Service (NHS). Background: Parents report that around 20% of 1-4 month-old infants in western countries cry excessively without apparent reason. Traditionally, research has focused on the crying and its causes. However, evidence is growing that how parents evaluate and respond to the crying needs to receive equal attention. This focus encompasses parental resources, vulnerabilities, wellbeing, and mental health. At present, the UK NHS lacks a set of routine provisions to support parents who are concerned about their baby's excessive crying. The rationales, methods and findings from a study developing materials for this purpose are reported. Method: Following a literature review, 20 parents whose babies previously cried excessively took part in focus groups or interviews. They provided reports on their experiences and the supports they would have liked when their baby was crying excessively. In addition, they identified their preferred delivery methods and devices for accessing information and rated four example support packages identified by the literature review. Findings: During the period their baby cried excessively, most parents visited a health service professional and most considered these direct contacts to have provided helpful information and support. Websites were similarly popular. Telephones and tablets were the preferred means of accessing online information. Groups to meet other parents were considered an important additional resource by all the parents. Three package elements - a Surviving Crying website, a printed version of the website, and a programme of Cognitive Behaviour Therapy-based support sessions delivered to parents by a qualified practitioner, were developed for further evaluation

    Development of materials to support parents whose babies cry excessively: findings and health service implications

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    Aim: To develop evidence-based materials which provide information and support for parents who are concerned about their baby's excessive crying. As well as meeting these parents' needs, the aim was to develop a package of materials suitable for use by the UK National Health Service (NHS). Background: Parents report that around 20% of 1-4 month-old infants in western countries cry excessively without apparent reason. Traditionally, research has focused on the crying and its causes. However, evidence is growing that how parents evaluate and respond to the crying needs to receive equal attention. This focus encompasses parental resources, vulnerabilities, wellbeing, and mental health. At present, the UK NHS lacks a set of routine provisions to support parents who are concerned about their baby's excessive crying. The rationales, methods and findings from a study developing materials for this purpose are reported. Method: Following a literature review, 20 parents whose babies previously cried excessively took part in focus groups or interviews. They provided reports on their experiences and the supports they would have liked when their baby was crying excessively. In addition, they identified their preferred delivery methods and devices for accessing information and rated four example support packages identified by the literature review. Findings: During the period their baby cried excessively, most parents visited a health service professional and most considered these direct contacts to have provided helpful information and support. Websites were similarly popular. Telephones and tablets were the preferred means of accessing online information. Groups to meet other parents were considered an important additional resource by all the parents. Three package elements - a Surviving Crying website, a printed version of the website, and a programme of Cognitive Behaviour Therapy-based support sessions delivered to parents by a qualified practitioner, were developed for further evaluation

    GRDzhadzha: A code for evolving relativistic matter on analytic metric backgrounds

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    GRDzhadzha is an open-source code for relativistic simulations of matter fields on curved spacetimes that admit an analytic description (e.g. stationary black holes). It is based on the publicly available 3+1D numerical relativity code GRChombo. Such a description is valid where the density of the matter is small compared to the curvature scale of the spacetime, which is the case for many physical scenarios - for example, dark matter environments. The approach offers significant savings on memory and speed compared to running full numerical relativity simulations, since the metric variables and their derivatives are calculated analytically, and therefore are not evolved or stored on the grid. This brief paper introduces the code and gives details of some applications for which it has already been used.Comment: Submitted for review in the Journal of Open Source Software; Comments welcome; The code can be found at https://github.com/GRChombo/GRDzhadzha.gi

    Mental health and wellbeing in parents of excessively crying infants: prospective evaluation of a support package

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    Background During the first four months of age, approximately 20% of infants cry a lot without an apparent reason. Most research has targeted the crying and its causes, but there is a need for equal attention to the impact of the crying on parents and subsequent outcomes. This study reports the findings from a prospective evaluation of a package of materials designed to support the wellbeing and mental health of parents who judge their infant to be crying excessively. The resulting ‘Surviving Crying’ package comprised a website, printed materials, and a programme of Cognitive Behaviour Therapy - based support sessions delivered to parents by a qualified practitioner. It was designed to be suitable for National Health Service (NHS) use. Methods Parents were referred to the study by NHS Health Visitors or Community Public Health Nurses. Fifty seven parents of excessively crying babies received the support package and provided rating scale measures of depression, anxiety, frustration because of the crying, and other measures before receiving the support package, together with outcome measures afterwards. Results Significant reductions in depression and anxiety were found with the number of parents meeting clinical criteria for depression or anxiety halving between baseline and outcome. These improvements were not explained by changes in infant crying. Reductions also occurred in the number of parents reporting the crying to be a large or severe problem (from 28 to 3 parents) or feeling very or extremely frustrated by the crying (from 31 to 1 parent). Other findings included increases in parents’ confidence, knowledge of infant crying and improvements in parents’ sleep. Conclusions The findings suggest that the Surviving Crying package may be effective in supporting the wellbeing and mental health of parents of excessively crying babies. Further, large-scale controlled trials of the package in NHS settings are warranted

    Manager- und transaktionsspezifische Determinanten der Performance von Arbitrage CLOs

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    Der vorliegende Beitrag untersucht die Determinanten der Performance europäischer Arbitrage Collateralized Loan Obligations für das Jahr 2009. Der Fokus liegt dabei auf der Bedeutung der performanceabhängigen Vergütung des CLO-Managers, den Eigenschaften des CLO-Managers und der Transaktionscharakteristika als mögliche Einflussfaktoren der Rating Performance. Es wird gezeigt, dass Transaktionen, bei denen dem CLO-Manager eine Incentive Management Fee gewährt wird, mit einer höheren Wahrscheinlichkeit herabgestuft werden als Transaktionen ohne Incentive Fee. Dieser Befund bestätigt die Hypothese, dass durch die Incentive Fee Risikoanreize für CLO-Manager geschaffen werden. Des Weiteren wird ein positiver Zusammenhang zwischen der Erfahrung bzw. der Größe eines CLO-Managers und der Rating Performance festgestellt. Der Einfluss des Managers auf die Performance einer CLO-Transaktion wird auch an den weiteren in der Studie herangezogenen managerspezifischen Charakteristika wie Typ und Unternehmenssitz bestätigt. Für die Transaktionscharakteristika wird hingegen im betrachteten Untersuchungszeitraum kein signifikanter Einfluss auf die Rating Performance nachgewiesen

    The Bristol CMIP6 Data Hackathon

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    The Bristol CMIP6 Data Hackathon formed part of the Met Office Climate Data Challenge Hackathon series during 2021, bringing together around 100 UK early career researchers from a wide range of environmental disciplines. The purpose was to interrogate the under-utilised but currently most advanced climate model inter-comparison project datasets to develop new research ideas, create new networks and outreach opportunities in the lead up to COP26. Experts in different science fields, supported by a core team of scientists and data specialists at Bristol, had the unique opportunity to explore together interdisciplinary environmental topics summarised in this article

    Towards an ethical ecology of international service learning

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    International Service-Learning (ISL) is a pedagogical activity that seeks to blend student learning with community engagement overseas and the development of a more just society. ISL programmes have grown as educational institutions and non-governmental organisations have sought to achieve the goal of developing ‘global citizens’. However, Service Learning (SL) in general and International Service-Learning (ISL) in particular remain deeply under theorised. These educational initiatives provide policy makers with a practical response to their quest for a ‘Big Society’and present alluring pedagogical approaches for Universities as they react to reforms in Higher Education and seek to enhance both the student learning experience and graduate employability. After outlining the development of ISL in policy and practice, this paper draws on the rich tradition of ISL at one British university to argue that ISL is a form of engagement that has the potential to be ethical in character although we identify a number of factors that militate against this. Our contention is that ISL which promotes rationaland instrumental learning represents a deficit model and we therefore conceptualise ISL here as a transformative learning experience that evinces distinctly aesthetic and even spiritual dimensions. Upon this theoretical groundwork we lay the foundations for conceptualizing ISL in ways that ensure its ethical integrity
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