3,024 research outputs found

    The Milky Way Heart: Investigating molecular gas and gamma-ray morphologies in the Central Molecular Zone

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    Since the discovery of a broad distribution of very high energy (VHE; >0.1 TeV) gamma-rays in the Central Molecular Zone (CMZ) of the Galaxy in 2006 by the HESS collaboration, the correlation of this emission with the integrated intensity of the CS(1-0) molecular line emission has inferred a hadronic origin for the gamma-rays. Here we describe the beginning of our investigation into the strength of this correlation utilising new multi-line millimeter data from the Mopra CMZ and HOP surveys and multi-wavelength GBT radio continuum observations towards the CMZ and compare these in detail with the diffuse TeV gamma-ray emission from HESS. The benefit of these new data is that they allow us to simultaneously observe and analyse correlations using a large number (>10) of molecular species, some of which contain their isotopologue pairs. The use of isotopologue pairs is especially powerful, since it allows one to analyse the optical depth of a number of different molecular species, thus investigating the nature of the correlation over a range of different physical conditions. Here we begin by comparing the integrated line emission and continuum radio emission with the diffuse gamma-ray emission, and, by using isotopologue pairs such as HCN/H13^{13}CN, obtain optical depths throughout the CMZ corresponding to regions of both strong and weak gamma-ray emission. We find that the radio continuum better matches the peak of the gamma-ray emission, which corresponds to the more compact -- compared to the relatively coarse resolution of the gamma-ray images -- sources in the CMZ. Using the isotopologue pairs, we find that the optical depth at all positions and velocities within the CMZ are about 2--4. This is similar to that found for the CS(1--0) line and would underestimate the mass of the CMZ, potentially explaining why molecular line emission peaks appear offset from the gamma-ray peaks.Comment: 8 pages, 5 figures. Accepted to the Proceedings of the 25th Texas Symposium on Relativistic Astrophysics (Heidelberg, 2010

    Natural history of asymptomatic pancreatic cystic neoplasms

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    AbstractBackgroundThe management of asymptomatic pancreatic cysts is controversial and indications for excision are based on pathology and natural history.ObjectivesThis study aimed to examine outcomes of asymptomatic lesions using a protocol based on size and cyst fluid analysis.MethodsAsymptomatic cysts were identified from a prospectively maintained database. Sequential cross‐sectional imaging studies were assessed, and results of endoscopic ultrasound‐guided aspiration were co‐analysed.ResultsA total of 338 asymptomatic patients underwent evaluation. Overall, 84 cysts were <1.5 cm and 254 were ≥1.5 cm in diameter. Median patient follow‐up was 5.1 years [interquartile range (IQR): 4.1–6.9 years]. In the group in which cysts measured <1.5 cm in diameter, median cyst size was 1.0 cm (IQR: 0.6–1.2 cm) at presentation and increased to 1.2 cm (IQR: 0.7–1.6 cm) during follow‐up. Five (6.0%) patients underwent resection, all within 2 months of presentation. In the group in which cysts measured ≥1.5 cm in diameter, median cyst size was 2.5 cm (IQR: 2.0–3.4 cm) at presentation and increased to 2.7 cm (IQR: 3.0–4.2 cm). A total of 63 (24.8%) patients underwent resection. Surgery was performed with 2 months in 53 (84.1%) patients, within 12 months in four (6.3%) patients and at >12 months post‐presentation in six (9.5%) patients. A total of 70.6% of resected specimens were identified as malignancies or mucinous lesions.conclusionsAsymptomatic cysts of <1.5 cm in diameter can safely be followed by imaging and are expected to undergo little change. A quarter of all asymptomatic cysts measuring ≥1.5 cm are appropriately resected based on imaging and cyst fluid analysis

    Impact of early initiation versus national standard of care of antiretroviral therapy in Swaziland's public sector health system : study protocol for a stepped-wedge randomized trial

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    Background: There is robust clinical evidence to support offering early access to antiretroviral treatment (ART) to all HIV-positive individuals, irrespective of disease stage, to both improve patient health outcomes and reduce HIV incidence. However, as the global treatment guidelines shift to meet this evidence, it is still largely unknown if early access to ART for all (also referred to as "treatment as prevention" or " universal test and treat") is a feasible intervention in the resource-limited countries where this approach could have the biggest impact on the course of the HIV epidemics. The MaxART Early Access to ART for All (EAAA) implementation study was designed to determine the feasibility, acceptability, clinical outcomes, affordability, and scalability of offering early antiretroviral treatment to all HIV-positive individuals in Swaziland's public sector health system. Methods: This is a three-year stepped-wedge randomized design with open enrollment for all adults aged 18 years and older across 14 government-managed health facilities in Swaziland's Hhohho Region. Primary endpoints are retention and viral suppression. Secondary endpoints include ART initiation, adherence, drug resistance, tuberculosis, HIV disease progression, patient satisfaction, and cost per patient per year. Sites are grouped to transition two at a time from the control (standard of care) to intervention (EAAA) stage at each four-month step. This design will result in approximately one half of the total observation time to accrue in the intervention arm and the other half in the control arm. Our estimated enrolment number, which is supported by conservative power calculations, is 4501 patients over the course of the 36-month study period. A multidisciplinary, mixed-methods approach will be adopted to supplement the randomized controlled trial and meet the study aims. Additional study components include implementation science, social science, economic evaluation, and predictive HIV incidence modeling. Discussion: A stepped-wedge randomized design is a causally strong and robust approach to determine if providing antiretroviral treatment for all HIV-positive individuals is a feasible intervention in a resource-limited, public sector health system. We expect our study results to contribute to health policy decisions related to the HIV response in Swaziland and other countries in sub-Saharan Africa

    Interpreter-Assisted Interviews: Examining Investigators’ and Interpreters’ Views on Their Practice

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    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The investigative interviewing of victims, witnesses and suspects is one of the most frequent and important tasks undertaken by those conducting law enforcement investigations. Over the past 20 years or so, there has been a substantial growth in the amount of research examining the practice. Nonetheless, little research has been conducted into those interviews where an interpreter is increasingly present. Using a self-administered questionnaire, the present study examined the beliefs of 66 investigators and 40 interpreters in the context of international criminal investigations, concerning certain key tasks in such interpreter-assisted interviews. It was regularly found that there was not always a consensus of opinion either within or between these two groups of professionals concerning whether (when participating in investigative interviews) (1) they prepared jointly with each other; (2) interpreters assisted (or otherwise) with rapport building; (3) interpreters could interpret accurately; and (4) interpreter interventions were disruptive or not. Given such divisions of opinion, our findings tend to suggest that there is a lack of clarity as to the role of interpreters and, indeed, only personalised views as to what is best practice. The implications of our findings are discussed, and recommendations are made to enable practice enhancement
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