1,303 research outputs found

    Impact of injection settings operating with the gasoline Partially Premixed Combustion concept in a 2-stroke HSDI compression ignition engine

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    [EN] Partially Premixed Combustion (PPC) using gasoline-like fuels has proven its potential to control or even break the NOx and soot emissions trade-off, retaining the high efficiency levels characteristic of the conventional diesel combustion (CDC) concept. However, selecting an appropriate fuel and a suitable injection strategy is essential to assure a successful PPC operation in the full engine map. Additionally, extending the limit of PPC beyond 10 bar IMEP was not possible due to excessively high pressure gradients and onset of knocking-like combustion, so the CDC concept has to be adopted and the conventional trade-off between NOx and soot emissions was recovered. Present investigation focuses on evaluating the use of a multiple injection strategy for extending the load range of the PPC concept to medium/high load conditions, when using a commercial RON95 gasoline in a 2-stroke engine under development. Experimental results confirm how with a fine tuned triple injection strategy it is possible to reach extremely low NOx and soot levels keeping combustion efficiency over 96%, while indicated efficiency is improved compared to a well-optimized point obtained operating with the CDC concept. Finally, the research work is completed by including 3D-CFD modeling activities that are carried out to contribute to the understanding on how the mixture preparation and stratification prior to the start of combustion impacts its development and particularly the experimentally observed pollutant emissions trends.This work was partly funded by the Generalitat Valenciana Spain, project PROMETEOII/2014/043. The authors kindly recognize the technical support provided by Mr. Pascal Tribotte from RENAULT SAS - France in the frame of the DREAM-DELTA-68530-13-3205 ProjectBenajes, J.; Novella Rosa, R.; De Lima, D.; Thein, KJL. (2017). Impact of injection settings operating with the gasoline Partially Premixed Combustion concept in a 2-stroke HSDI compression ignition engine. Applied Energy. 193:515-530. https://doi.org/10.1016/j.apenergy.2017.02.044S51553019

    Combined extracellular matrix cross-linking activity of the peroxidase MLT-7 and the dual oxidase BLI-3 is critical for post-embryonic viability in <i>Caenorhabditis elegans</i>

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    The nematode cuticle is a protective collagenous extracellular matrix that is modified, cross-linked, and processed by a number of key enzymes. This Ecdysozoan-specific structure is synthesized repeatedly and allows growth and development in a linked degradative and biosynthetic process known as molting. A targeted RNA interference screen using a cuticle collagen marker has been employed to identify components of the cuticle biosynthetic pathway. We have characterized an essential peroxidase, MoLT-7 (MLT-7), that is responsible for proper cuticle molting and re-synthesis. MLT-7 is an active, inhibitable peroxidase that is expressed in the cuticle-synthesizing hypodermis coincident with each larval molt. mlt-7 mutants show a range of body morphology defects, most notably molt, dumpy, and early larval stage arrest phenotypes that can all be complemented with a wild type copy of mlt-7. The cuticles of these mutants lacks di-tyrosine cross-links, becomes permeable to dye and accessible to tyrosine iodination, and have aberrant collagen protein expression patterns. Overexpression of MLT-7 causes mutant phenotypes further supporting its proposed enzymatic role. In combination with BLI-3, an H2O2-generating NADPH dual oxidase, MLT-7 is essential for post-embryonic development. Disruption of mlt-7, and particularly bli-3, via RNA interference also causes dramatic changes to the in vivo cross-linking patterns of the cuticle collagens DPY-13 and COL-12. This points toward a functionally cooperative relationship for these two hypodermally expressed proteins that is essential for collagen cross-linking and proper extracellular matrix formation

    Health-state utilities in a prisoner population : a cross-sectional survey

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    Background: Health-state utilities for prisoners have not been described. Methods: We used data from a 1996 cross-sectional survey of Australian prisoners (n = 734). Respondent-level SF-36 data was transformed into utility scores by both the SF-6D and Nichol's method. Socio-demographic and clinical predictors of SF-6D utility were assessed in univariate analyses and a multivariate general linear model. Results: The overall mean SF-6D utility was 0.725 (SD 0.119). When subdivided by various medical conditions, prisoner SF-6D utilities ranged from 0.620 for angina to 0.764 for those with none/mild depressive symptoms. Utilities derived by the Nichol's method were higher than SF-6D scores, often by more than 0.1. In multivariate analysis, significant independent predictors of worse utility included female gender, increasing age, increasing number of comorbidities and more severe depressive symptoms. Conclusion: The utilities presented may prove useful for future economic and decision models evaluating prison-based health programs

    Tuberculosis screening at a diabetes clinic in the Republic of the Marshall Islands

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    AbstractSettingTuberculosis (TB) and diabetes mellitus (DM) are prominent public health problems in the Republic of the Marshall Islands, a small island nation with high rates of tuberculosis and diabetes.ObjectiveEvaluate the rate of active and latent TB in a Pacific Island DM clinic.DesignIn one DM clinic on the island of Ebeye, 213 adult patients aged 27–86 years completed tuberculin skin testing and TB work-up between April 2010 and March 2012.ResultsScreening for TB led to the diagnosis of 77 patients with TB infection and 11 patients with TB disease. From these data, the prevalence of TB disease among DM patients in the clinic exceeded 5% (95% CI 2.2%–8.1%). All patients who completed TB screening were at high risk of TB disease, and those with DM aged ≤50 years had a higher risk of TB disease than those with DM over age 50 (RR 3.1, C.I. 1.0–9.7, p= 0.05).ConclusionThe experience at the Ebeye Diabetes Clinic demonstrates that screening DM patients for TB can identify significant rates of TB infection and TB disease, and should be considered for other settings with a high background TB incidence. Further assessment of TB risks should explore age, gender, and level of diabetes control

    Explore Transplant at Home: A randomized control trial of an educational intervention to increase transplant knowledge for Black and White socioeconomically disadvantaged dialysis patients

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    BackgroundCompared to others, dialysis patients who are socioeconomically disadvantaged or Black are less likely to receive education about deceased donor kidney transplant (DDKT) and living donor kidney transplant (LDKT) before they reach transplant centers, often due to limited availability of transplant education within dialysis centers. Since these patients are often less knowledgeable or ready to pursue transplant, educational content must be simplified, made culturally sensitive, and presented gradually across multiple sessions to increase learning and honor where they are in their decision-making about transplant. The Explore Transplant at Home (ETH) program was developed to help patients learn more about DDKT and LDKT at home, with and without telephone conversations with an educator.Methods and study designIn this randomized controlled trial (RCT), 540 low-income Black and White dialysis patients with household incomes at or below 250&nbsp;% of the federal poverty line, some of whom receive financial assistance from the Missouri Kidney Program, will be randomly assigned to one of three education conditions: (1) standard-of-care transplant education provided by the dialysis center, (2) patient-guided ETH (ETH-PG), and (3) health educator-guided ETH (ETH-EG). Patients in the standard-of-care condition will only receive education provided in their dialysis centers. Those in the two ETH conditions will receive four video and print modules delivered over an 8 month period by mail, with the option of receiving supplementary text messages weekly. In addition, patients in the ETH-EG condition will participate in multiple telephonic educational sessions with a health educator. Changes in transplant knowledge, decisional balance, self-efficacy, and informed decision making will be captured with surveys administered before and after the ETH education.DiscussionAt the conclusion of this RCT, we will have determined whether an education program administered to socioeconomically disadvantaged dialysis patients, over several months directly in their homes, can help more individuals learn about the options of DDKT and LDKT. We also will be able to examine the efficacy of different educational delivery approaches to further understand whether the addition of a telephone educator is necessary for increasing transplant knowledge.Trial registrationClinicalTrials.gov, NCT02268682

    The Political Economy of Myanmar's Transition

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    This is an Author's Original Manuscript of an article whose final and definitive form, the Version of Record, has been published in the JOURNAL OF CONTEMPORARY ASIA, 07 Feb 2013, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/00472336.2013.764143.Since holding elections in 2010, Myanmar has transitioned from a direct military dictatorship to a formally democratic system and has embarked on a period of rapid economic reform. After two decades of military rule, the pace of change has startled almost everyone and led to a great deal of cautious optimism. To make sense of the transition and assess the case for optimism, this article explores the political economy of Myanmar's dual transition from state socialism to capitalism and from dictatorship to democracy. It analyses changes within Myanmar society from a critical political economy perspective in order to both situate these developments within broader regional trends and to evaluate the country's current trajectory. In particular, the emergence of state-mediated capitalism and politico-business complexes in Myanmar's borderlands are emphasised. These dynamics, which have empowered a narrow oligarchy, are less likely to be undone by the reform process than to fundamentally shape the contours of reform. Consequently, Myanmar's future may not be unlike those of other Southeast Asian states that have experienced similar developmental trajectories

    Qualitative methods: are you enchanted or are you alienated?

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    Copyright © 2007 SAGE Publications. Author's draft version; post-print. Final version published by Sage available on Sage Journals Online http://online.sagepub.com/Since the last report on qualitative methods (Crang, 2005), many of the practical procedures of doing qualitative research remain the same. Human geographers continue to study texts, to conduct interviews, to convene focus groups and to engage in ethnography. Indeed, it is hard, though perhaps not impossible, to imagine what a radically new form of qualitative research practice might look like. So, for the time being, this suite of methods remains the backbone of qualitative research in human geography. Yet we would like to contend that, while these activities continue as before, there are changes in the way they are being conceived and carried out, and related to this there are transformations in the way these methods are being used to make claims to understanding and intervening in the world. In the first of our three reports, it is this link between qualitative methodologies and interpretative strategies we would like to reflect on

    National scale-up of tuberculosis-human immunodeficiency virus collaborative activities in Myanmar from 2005 to 2016 and tuberculosis treatment outcomes for patients with human immunodeficiency virus-positive tuberculosis in the Mandalay Region in 2015.

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    Background: HIV-associated TB is a serious public health problem in Myanmar. Study objectives were to describe national scale-up of collaborative activities to reduce the double burden of TB and HIV from 2005 to 2016 and to describe TB treatment outcomes of individuals registered with HIV-associated TB in 2015 in the Mandalay Region. Methods: Secondary analysis of national aggregate data and, for treatment outcomes, a cohort study of patients with HIV-associated TB in the Mandalay Region. Results: The number of townships implementing collaborative activities increased from 7 to 330 by 2016. The number of registered TB patients increased from 1577 to 139 625 in 2016, with the number of individuals tested for HIV increasing from 432 to 114 180 (82%) in 2016: 10 971 (10%) were diagnosed as HIV positive. Uptake of co-trimoxazole preventive therapy (CPT) and antiretroviral therapy (ART) nationally in 2016 was 77% and 52%, respectively. In the Mandalay Region, treatment success was 77% and mortality was 18% in 815 HIV-associated TB patients. Risk factors for unfavourable outcomes and death were older age (≥45 years) and not taking CPT and/or ART. Conclusion: Myanmar is making good progress with reducing the HIV burden in TB patients, but better implementation is needed to reach 100% HIV testing and 100% CPT and ART uptake in TB-HIV co-infected patients
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