1,562 research outputs found

    Passive harmonic mode-locking by mode selection in Fabry-Perot diode lasers with patterned effective index

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    We demonstrate passive harmonic mode-locking of a quantum well laser diode designed to support a discrete comb of Fabry-Perot modes. Spectral filtering of the mode spectrum was achieved using a non-periodic patterning of the cavity effective index. By selecting six modes spaced at twice the fundamental mode spacing, near-transform limited pulsed output with 2 ps pulse duration was obtained at a repetition rate of 100 GHz.Comment: 3 page

    All-Wales licensed premises intervention (AWLPI): a randomised controlled trial to reduce alcohol-related violence

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    Background: Alcohol-related violence in and in the vicinity of licensed premises continues to place a considerable burden on the United Kingdom’s (UK) health services. Robust interventions targeted at licensed premises are therefore required to reduce the costs of alcohol-related harm. Previous evaluations of interventions in licensed premises have a number of methodological limitations and none have been conducted in the UK. The aim of the trial was to determine the effectiveness of the Safety Management in Licensed Environments intervention designed to reduce alcohol-related violence in licensed premises, delivered by Environmental Health Officers, under their statutory authority to intervene in cases of violence in the workplace.<p></p> Methods/Design: A national randomised controlled trial, with licensed premises as the unit of allocation. Premises were identified from all 22 Local Authorities in Wales. Eligible premises were those with identifiable violent incidents on premises, using police recorded violence data. Premises were allocated to intervention or control by optimally balancing by Environmental Health Officer capacity in each Local Authority, number of violent incidents in the 12 months leading up to the start of the project and opening hours. The primary outcome measure is the difference in frequency of violence between intervention and control premises over a 12 month follow-up period, based on a recurrent event model. The trial incorporates an embedded process evaluation to assess intervention implementation, fidelity, reach and reception, and to interpret outcome effects, as well as investigate its economic impact.<p></p> Discussion: The results of the trial will be applicable to all statutory authorities directly involved with managing violence in the night time economy and will provide the first formal test of Health and Safety policy in this environment. If successful, opportunities for replication and generalisation will be considered.<p></p&gt

    Indigenous Emancipation: The Fight Against Marginalisation, Criminalisation, and Oppression

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    This thematic issue addresses the challenges faced by Indigenous peoples in protecting their rights and maintaining their unique cultures and ways of life. Despite residing on all continents and possessing distinct social, cultural, economic, and political characteristics, Indigenous peoples have historically faced oppression and violation of their rights. Measures to protect Indigenous rights are gradually being recognized by the international community, but ongoing issues such as illegal deforestation, mining, and land clearances continue to desecrate sacred sites and oppress Indigenous peoples. Indigenous women and youth are particularly vulnerable, facing higher levels of gender‐based violence and overrepresentation in judicial sentencing statistics. Land rights continue to be threatened by natural resource extraction, infrastructure projects, large‐scale agricultural expansion, and conservation orders. There is also a heightened risk of statelessness for Indigenous peoples whose traditional lands cross national borders, leading to displacement, attacks, killings, and criminalization

    Relationship of cognition and Alzheimer’s disease with gastrointestinal tract disorders: A large-scale genetic overlap and mendelian randomisation analysis

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    Emerging observational evidence suggests links between cognitive impairment and a range of gastrointestinal tract (GIT) disorders; however, the mechanisms underlying their relationships remain unclear. Leveraging large-scale genome-wide association studies’ summary statistics, we comprehensively assessed genetic overlap and potential causality of cognitive traits and Alzheimer’s disease (AD) with several GIT disorders. We demonstrate a strong and highly significant inverse global genetic correlation between cognitive traits and GIT disorders — peptic ulcer disease (PUD), gastritis-duodenitis, diverticulosis, irritable bowel syndrome, and gastroesophageal reflux disease (GERD), but not inflammatory bowel disease (IBD). Further analysis detects 35 significant (p \u3c 4.37 × 10 − 5) bivariate local genetic correlations between cognitive traits, AD, and GIT disorders (including IBD). Mendelian randomisation analysis suggests a risk-decreasing causality of educational attainment, intelligence, and other cognitive traits on PUD and GERD, but not IBD, and a putative association of GERD with cognitive function decline. Gene-based analysis reveals a significant gene-level genetic overlap of cognitive traits with AD and GIT disorders (IBD inclusive, pbinomial-test = 1.18 × 10 − 3 – 2.20 × 10 − 16). Our study supports the protective roles of genetically-influenced educational attainments and other cognitive traits on the risk of GIT disorders and highlights a putative association of GERD with cognitive function decline. Findings from local genetic correlation analysis provide novel insights, indicating that the relationship of IBD with cognitive traits (and AD) will depend largely on their local effects across the genome

    “How to have a good first year experience in chemistry – as easy as from Part A to Part B.”

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    The challenge: First Year Chemistry classes are characterised by being an increasingly large cohort of students in multiple different degree programs; with very diverse incoming skills and knowledge base. This paper reports our research activities this year developing a series of workshop classes with a relatively high staff : student ratio to address student difficulties in this key foundation subject. The strategy: To provide a fortnightly structured workshop for active learning and engagement in conversations to develop chemistry language, content knowledge and skills: POGIL based activities incorporating small group work (3), individual roles in group, quiz assessment, peer group marking, immediate feedback and tutor moderated marking. Compulsory workshops in two concurrent sections: Part A, 1 hr Non HSC CHEM students, Part B, 2 hrs all students. We report: the good: Student feedback and our observations indicating comprehensive networking of content and ideas via lectures, workshops, labs, assignments, appreciated by the majority of students. the bad: insufficient understanding of the student body why this teaching mode had been adopted, some tutors struggling with managing workshops and adapting to this new model. the ugly: the paradox that students were most productive when only one was writing but they report needing to make individual notes to take away. We look to this forum for ideas on this, our most pressing issue

    Click-click, who’s there? Acoustically derived estimates of sperm whale size distribution off western Ireland

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    Understanding the structure of populations is a critical element to the establishment of management and conservation measures. Sperm whales Physeter macrocephalus are characterised by a demographic spatial segregation, associated with a conspicuous sexual dimorphism reflected in their vocalisations. These characteristics make acoustic techniques very relevant to the study of sperm whale population structure, especially in remote, challenging environments. The reliability of using inter-pulse intervals of sperm whale clicks to infer body size has long been verified and extensively used. We provide the first size structure estimates of the sperm whale population in an area where assumptions on population structure mainly relied on sparse observations at sea, whaling records and stranding data. Over 10,000 hours of acoustic data collected using both static acoustic recorders and towed hydrophone arrays in Irish offshore waters were processed using a machine learning-based tool aimed at automatically extracting inter-pulse intervals from sperm whale recordings. Our analyses suggested that, unlike previously thought, large males would not account for the majority of the animals recorded in the area. We showed that adult females/juvenile males (length 9-12 m) were predominant, accounting for 49% (n = 788) of the number of individuals recorded (n = 1,595), while the proportions of immature individuals (length<9 m) and adult males (length >12 m) were well balanced, accounting for 25% (n = 394) and 26% (n = 413) of the recorded whales, respectively. Our data also suggested some size segregation may be occurring within the area, with smaller individuals to the south. The implications of such findings are crucial to the management of the population and provide an important baseline to monitor changes in population structure, particularly relevant under changing habitat conditions

    Design of the VLT-CUBES image slicers: Field re-formatters to provide two spectral resolutions

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    CUBES is a high efficiency spectrograph designed for a Cassegrain focus of the Very Large Telescope and is expected to be in operation in 2028. It is designed to observe point or compact sources in a spectral range from 300 to 405nm. CUBES will provide two spectral resolving powers: R≥20,000 for high resolution (HR) and R≥5,000 for low resolution (LR). This is achieved by using an image slicer for each resolution mode. The image slicers re-format a rectangular on-sky field of view of either 1.5arcsec by 10arcsec (HR) or 6arcsec by 10arcsec (LR) into six side-by-side slitlets which form the spectrograph slit. The slit dimensions are 0.19mm × 88mm for HR and 0.77mm × 88mm for LR. The on-sky and physical widths of the slicer mirrors are 0.25arcsec/0.5mm (HR) and 1arcsec/2mm (LR). The image slicers reduce the spectrograph entrance slit etendue and hence the size of the spectrograph optics without associated slit losses. Each of the proposed image slicers consists of two arrays of six spherical mirrors (slicer mirror and camera mirror arrays) which provide a straight entrance slit to the spectrograph with almost diffraction-limited optical quality. This paper presents the description of the image slicers at the end of the Phase A conceptual design, including their optical design and expected performance

    Copper Mining in the Bronze Age at Mynydd Parys, Anglesey, Wales

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    Acknowledgements This article was researched and written by David Jenkins. The final editing was undertaken by Andrew Davidson and Jane Kenney (Gwynedd Archaeological Trust) and Dr Simon Timberlake (Early Mines Research Group and McDonald Institute, University of Cambridge), who contributed additional background information. Further contributions and corrections were provided by Peter Marshall (Historic England) and Tim Mighall (University of Aberdeen) who oversaw the palaeoenvironmental study. Cadw generously funded the work through grant aid. The suggestion to edit and publish the article came from John Llywelyn Williams, who has worked closely with David Jenkins on this and a number of other significant projects. The editors are also very grateful for the help and encouragement provided by Paul Jenkins (David’s son). Members of the Parys Underground Group, particularly Oliver Burrows, and the Early Mines Research Group have helped source illustrations, provided corrections and comments, and supported the work. Thanks also to Anglesey Mining plc.Peer reviewedPostprin

    BUDGET PERSPECTIVES 2009. RESEARCH SERIES NUMBER 4 OCTOBER 2008

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    The context for this year’s Budget differs sharply from most of those in the past decade and a half. The global economy has been buffeted by crises in financial markets. Oil prices, even after recent falls, are at very high levels. Furthermore, the sharp decline in housing activity in Ireland carries negative implications both for employment and for tax revenues. A consequence of the changed situation is that the date of the 2009 Budget has been brought forward by eight weeks. This year’s Budget Perspectives Conference, co-hosted by The Economic and Social Research Institute and the Foundation for Fiscal Studies, provides several inputs to inform macroeconomic decision making in these challenging times. In addition, two longer-term issues are addressed. The first of these deals with the policy framework for climate change, an issue that has risen rapidly on the Irish policy horizon in recent years. The second issue is the effectiveness of public spending in achieving its objectives in the area of sport, which is now recognised as an important contributor to health and quality of life in modern society

    Intensive HST, RXTE and ASCA Monitoring of NGC 3516: Evidence Against Thermal Reprocessing

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    During 1998 April 13-16, NGC 3516 was monitored almost continuously with HST for 10.3 hr in the UV and 2.8 d in the optical, and simultaneous RXTE and ASCA monitoring covered the same period. The X-rays were strongly variable with the soft (0.5-2 keV) showing stronger variations (~65% peak-to-peak) than the hard (2-10 keV; ~50% peak-to-peak). The optical continuum showed much smaller but highly significant variations: a slow ~2.5% rise followed by a faster ~3.5% decline. The short UV observation did not show significant variability. The soft and hard X-ray light curves were strongly correlated with no significant lag. Likewise, the optical continuum bands (3590 and 5510 A) were also strongly correlated with no measurable lag above limits of <0.15 d. However no significant correlation or simple relationship could be found for the optical and X-ray light curves. These results appear difficult to reconcile with previous reports of correlations between X-ray and optical variations and of measurable lags within the optical band for some other Seyfert 1s. These results also present serious problems for "reprocessing" models in which the X-ray source heats a stratified accretion disk which then reemits in the optical/ultraviolet: the synchronous variations within the optical would suggest that the emitting region is <0.3 lt-d across, while the lack of correlation between X-ray and optical variations would indicate, in the context of this model, that any reprocessing region must be >1 lt-d in size. It may be possible to resolve this conflict by invoking anisotropic emission or special geometry, but the most natural explanation appears to be that the bulk of the optical luminosity is generated by some other mechanism than reprocessing.Comment: 23 pages including 6 figures, accepted for publication in Ap
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