68 research outputs found

    Outflowing activity in the UCHII region G045.47+0.05

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    Aims. This work aims at investigating the molecular gas in the surroundings of the ultra-compact HII region G045.47+0.05 looking for evidence of molecular outflows. Methods. We carried out observations towards a region of 2 arcmin x 2 arcmin centered at RA=19h 14m 25.6s, dec.= 11deg 09m 27.6s (J2000) using the Atacama Submillimeter Telescope Experiment (ASTE; Chile) in the 12CO J=3-2, 13CO J=3-2, HCO+ J=4-3 and CS J=7-6 lines with an angular resolution of 22 arcsec. We complement these observations with public infrared data. Results. We characterize the physical parameters of the molecular clump where G045.47+0.0 is embedded. The detection of the CS J=7-6 line emission in the region reveals that the ultra-compact HII region G045.47+0.0 has not completely disrupted the dense gas where it was born. The HCO+ abundance observed towards G045.47+0.0 suggests the presence of molecular outflow activity in the region. From the analysis of the 12CO J=3-2 transition we report the presence of bipolar molecular outflows with a total mass of about 300 solar masses . We derive a dynamical time (flow's age) of about 10^5 yr for the outflow gas, in agreement with the presence of an ultra-compact HII region. We identify the source 2MASS 19142564+1109283 as the massive protostar candidate to drive the molecular outflows. Based on the analysis of its spectral energy distribution we infer that it is an early B-type star of about 15 solar masses. The results of this work support the scenario where the formation of massive stars, at least up to early B-type stars, is similar to that of low mass stars.Comment: Recently accepted for publication in A&

    N2H+ depletion in the massive protostellar cluster AFGL 5142

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    We aim at investigating with high angular resolution the NH3/N2H+ ratio toward the high-mass star-forming region AFGL 5142 in order to study whether this ratio behaves similarly to the low-mass case, for which the ratio decreases from starless cores to cores associated with YSOs. CARMA was used to observe the 3.2 mm continuum and N2H+(1-0) emission. We used NH3(1,1) and (2,2), HCO+(1-0) and H13CO+(1-0) data from the literature and we performed a time-dependent chemical modeling of the region. The 3.2 mm continuum emission reveals a dust condensation of ~23 Msun associated with the massive YSOs, deeply embedded in the strongest NH3 core (hereafter central core). The N2H+ emission reveals two main cores, the western and eastern core, located to the west and to the east of the mm condensation, and surrounded by a more extended and complex structure of ~0.5 pc. Toward the central core the N2H+ emission drops significantly, indicating a clear chemical differentiation in the region. We found low values of the NH3/N2H+ ratio ~50-100 toward the western/eastern cores, and high values up to 1000 in the central core. The chemical model indicates that density, and in particular temperature, are key parameters in determining the NH3/N2H+ ratio. The high density and temperature reached in the central core allow molecules like CO to evaporate from grain mantles. The CO desorption causes a significant destruction of N2H+, favoring the formation of HCO+. This result is supported by our observations, which show that N2H+ and HCO+ are anticorrelated in the central core. The observed values of the NH3/N2H+ ratio in the central core can be reproduced by our model for times t~4.5-5.3x10^5 yr (central) and t~10^4-3x10^6 yr (western/eastern). The NH3/N2H+ ratio in AFGL 5142 does not follow the same trend as in regions of low-mass star formation mainly due to the high temperature reached in hot cores.Comment: Accepted for publication in A&A. 14 pages, 9 Figures, 5 Table

    Latent Structures based-Multivariate Statistical Process Control: a paradigm shift

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    The basic fundamentals of statistical process control (SPC) were proposed by Walter Shewhart for data-starved production environments typical in the 1920s and 1930s. In the 21st century, the traditional scarcity of data has given way to a data-rich environment typical of highly automated and computerized modern processes. These data often exhibit high correlation, rank deficiency, low signal-to-noise ratio, multistage and multiway structures, and missing values. Conventional univariate and multivariate SPC techniques are not suitable in these environments. This article discusses the paradigm shift to which those working in the quality improvement field should pay keen attention. We advocate the use of latent structure based multivariate statistical process control methods as efficient quality improvement tools in these massive data contexts. This is a strategic issue for industrial success in the tremendously competitive global market.This research work was partially supported by the Spanish Ministry of Economy and Competitiveness under the project DPI2011-28112-C04-02.Ferrer, A. (2014). Latent Structures based-Multivariate Statistical Process Control: a paradigm shift. Quality Engineering. 26(1):72-91. https://doi.org/10.1080/08982112.2013.846093S7291261Aparisi, F., Jabaioyes, J., & Carrion, A. (1999). Statistical properties of the lsi multivariate control chart. Communications in Statistics - Theory and Methods, 28(11), 2671-2686. doi:10.1080/03610929908832445Arteaga, F., & Ferrer, A. (2002). Dealing with missing data in MSPC: several methods, different interpretations, some examples. Journal of Chemometrics, 16(8-10), 408-418. doi:10.1002/cem.750Bersimis, S., Psarakis, S., & Panaretos, J. (2007). Multivariate statistical process control charts: an overview. 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    Revisiting projected shifts in the climate envelopes of North American trees using updated general circulation models

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    Global climate models are constantly being upgraded, but it is often not clear what these changes have on climate change impact projections. We used difference maps to directly compare downscaled projections of temperature and precipitation across North America for two versions (or generations) of three different Atmospheric‐Ocean General Circulation Models (AOGCM)s. We found that AOGCM versions differed in their projections for the end of the current century by up to 4 °C for annual mean temperature and 60% for annual precipitation. To place these changes in an ecological context, we reanalyzed our work on shifts in tree climate envelopes (CEs) using the newer‐generation AOGCM projections. Based on the updated AOGCMs, by the 2071–2100 period, tree CEs shifted up to 2.4 degrees further north or 2.6 degrees further south (depending on the AOGCM) and were about 10% larger in size. Despite considerable differences between versions of a given AOGCM, projections made by the newer version of each AOGCM were in general agreement, suggesting convergence across the three models studied here. Assessing the AOGCM outputs in this way provides insight into the magnitude and importance of change associated with AOGCM upgrades as they continue to evolve through time.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86847/1/j.1365-2486.2011.02413.x.pd

    The garden as a laboratory: the role of domestic gardens as places of scientific exploration in the long 18th century

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Post-Medieval Archaeology on 24/06/2014, available online: http://www.tandfonline.com/doi/full/10.1179/0079423614Z.00000000054Eighteenth-century gardens have traditionally been viewed as spaces designed for leisure, and as representations of political status, power and taste. In contrast, this paper will explore the concept that gardens in this period could be seen as dynamic spaces where scientific experiment and medical practice could occur. Two examples have been explored in the pilot study which has led to this paper — the designed landscapes associated with John Hunter’s Earl’s Court residence, in London, and the garden at Edward Jenner’s house in Berkeley, Gloucestershire. Garden history methodologies have been implemented in order to consider the extent to which these domestic gardens can be viewed as experimental spaces

    An evidence-based framework on community-centred approaches for health: England, UK

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    Community participation is a central concept for health promotion, covering a breadth of approaches, purposes and activities. This paper reports on a national knowledge translation project in England, UK, which resulted in a conceptual framework and typology of community-based approaches, published as national guidance. A key objective was to develop a conceptual framework linked to sources of evidence that could be used to support increased uptake of participatory methods across the health system. It was recognised that legitimacy of community participation was being undermined by a scattered evidence base, absence of a common terminology and low visibility of community practice. A scoping review, combined with stakeholder consultation, was undertaken and 168 review and conceptual publications were identified and a map produced. A ‘family of community-centred approaches for health and wellbeing’ was then produced as way of organising the evidence and visually representing the range of intervention types. There are four main groups, with sub-categories: (i) Strengthening communities (ii) Volunteer and peer roles (iii) Collaborations and partnerships and (iv) Access to community resources. Each group is differentiated using key concepts and theoretical justifications around increasing equity, control and social connectedness. An open access bibliography is available to accompany the framework. The paper discusses the application of the family of community-centred approaches as a flexible planning tool for health promotion practice and its potential to be used as a framework for organising and synthesising evidence from a range of participatory methods

    A qualitative synthesis of the positive and negative impacts related to delivery of peer-based health interventions in prison settings

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    Background Peer interventions involving prisoners in delivering peer education and peer support in a prison setting can address health need and add capacity for health services operating in this setting. This paper reports on a qualitative synthesis conducted as part of a systematic review of prison-based peer interventions. One of the review questions aimed to investigate the positive and negative impacts of delivering peer interventions within prison settings. This covered organisational and process issues relating to peer interventions, including prisoner and staff views. Methods A qualitative synthesis of qualitative and mixed method studies was undertaken. The overall study design comprised a systematic review involving searching, study selection, data extraction and validity assessment. Studies reporting interventions with prisoners or ex-prisoners delivering education or support to prisoners resident in any type of prison or young offender institution, all ages, male and female, were included. A thematic synthesis was undertaken with a subset of studies reporting qualitative data (n=33). This involved free coding of text reporting qualitative findings to develop a set of codes, which were then grouped into thematic categories and mapped back to the review question. Results Themes on process issues and wider impacts were grouped into four thematic categories: peer recruitment training and support; organisational support; prisoner relationships; prison life. There was consistent qualitative evidence on the need for organisational support within the prison to ensure smooth implementation and on managing security risks when prisoners were involved in service delivery. A suite of factors affecting the delivery of peer interventions and the wider organisation of prison life were identified. Alongside reported benefits of peer delivery, some reasons for non-utilisation of services by other prisoners were found. There was weak qualitative evidence on wider impacts on the prison system, including better communication between staff and prisoners. Gaps in evidence were identified. Conclusions The quality of included studies limited the strength of the conclusions. The main conclusion is that peer interventions cannot be seen as independent of prison life and health services need to work in partnership with prison services to deliver peer interventions. More research is needed on long-term impacts

    A systematic review of the effectiveness and cost-effectiveness of peer education and peer support in prisons.

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    BACKGROUND: Prisoners experience significantly worse health than the general population. This review examines the effectiveness and cost-effectiveness of peer interventions in prison settings. METHODS: A mixed methods systematic review of effectiveness and cost-effectiveness studies, including qualitative and quantitative synthesis was conducted. In addition to grey literature identified and searches of websites, nineteen electronic databases were searched from 1985 to 2012. Study selection criteria were: Population: Prisoners resident in adult prisons and children resident in Young Offender Institutions (YOIs). INTERVENTION: Peer-based interventions Comparators: Review questions 3 and 4 compared peer and professionally led approaches. OUTCOMES: Prisoner health or determinants of health; organisational/ process outcomes; views of prison populations. STUDY DESIGNS: Quantitative, qualitative and mixed method evaluations. RESULTS: Fifty-seven studies were included in the effectiveness review and one study in the cost-effectiveness review; most were of poor methodological quality. Evidence suggested that peer education interventions are effective at reducing risky behaviours, and that peer support services are acceptable within the prison environment and have a positive effect on recipients, practically or emotionally. Consistent evidence from many, predominantly qualitative, studies, suggested that being a peer deliverer was associated with positive effects. There was little evidence on cost-effectiveness of peer-based interventions. CONCLUSIONS: There is consistent evidence from a large number of studies that being a peer worker is associated with positive health; peer support services are also an acceptable source of help within the prison environment and can have a positive effect on recipients. Research into cost-effectiveness is sparse. SYSTEMATIC REVIEW REGISTRATION: PROSPERO ref: CRD42012002349

    Health Outcome Prioritization in Alzheimer's Disease:Understanding the Ethical Landscape

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    Objective: Health outcome prioritisation is the ranking in order of desirability or importance of a set of disease related objectives and their associated cost or risk. We analyse the complex ethical landscape in which this takes place in the most common dementia, Alzheimer’s disease. Background: Dementia has been described as the greatest global health challenge in the 21st century on account of longevity gains increasing its incidence, escalating health and social care pressures. These pressures highlight ethical, social, political challenges about healthcare resource allocation, what health improvements matter to patients, and how they are measured. This study highlights the complexity of the ethical landscape, relating particularly to the balances that need to be struck when allocating resources; when measuring and prioritising outcomes; and when individual preferences are sought. Methods: Narrative review of literature published since 2007, incorporating snowball sampling where necessary. We identified, thematised and discussed key issues of ethical salience. Results: Eight areas of ethical salience for outcome prioritisation emerged: (1) Public health and distributive justice, (2) Scarcity of resources, (3) Heterogeneity and changing circumstances, (4) Knowledge of treatment, (5) Values and circumstances, (6) Conflicting priorities, (7) Communication, autonomy and Caregiver issues, (8) Disclosure of risk. Conclusion: These areas highlight the difficult balance to be struck when allocating resources, when measuring and prioritising outcomes, and when individual preferences are sought. We conclude by reflecting on how tools in social sciences and ethics can help address challenges posed by resource allocation, measuring and prioritising outcomes, and eliciting stakeholder preferences.</p
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