296 research outputs found

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    Analyticity and Integrabiity in the Chiral Potts Model

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    We study the perturbation theory for the general non-integrable chiral Potts model depending on two chiral angles and a strength parameter and show how the analyticity of the ground state energy and correlation functions dramatically increases when the angles and the strength parameter satisfy the integrability condition. We further specialize to the superintegrable case and verify that a sum rule is obeyed.Comment: 31 pages in harvmac including 9 tables, several misprints eliminate

    E. coli catheter-associated urinary tract infections are associated with distinctive virulence and biofilm gene determinants

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    Urinary catheterization facilitates urinary tract colonization by E. coli and increases infection risk. Here, we aimed to identify strain-specific characteristics associated with the transition from colonization to infection in catheterized patients. In a single-site study population, we compared E. coli isolates from patients with catheter-associated asymptomatic bacteriuria (CAASB) to those with catheter-associated urinary tract infection (CAUTI). CAUTI isolates were dominated by a phylotype B2 subclade containing the multidrug-resistant ST131 lineage relative to CAASB isolates, which were phylogenetically more diverse. A distinctive combination of virulence-associated genes was present in the CAUTI-associated B2 subclade. Catheter-associated biofilm formation was widespread among isolates and did not distinguish CAUTI from CAASB strains. Preincubation with CAASB strains could inhibit catheter colonization by multiple ST131 CAUTI isolates. Comparative genomic analysis identified a group of variable genes associated with high catheter biofilm formation present in both CAUTI and CAASB strains. Among these, ferric citrate transport (Fec) system genes were experimentally associated with enhanced catheter biofilm formation using reporter and fecA deletion strains. These results are consistent with a variable role for catheter biofilm formation in promoting CAUTI by ST131-like strains or resisting CAUTI by lower-risk strains that engage in niche exclusion

    Optimizing the efficiency and implementation of cash transfers to improve adherence to antiretroviral therapy: study protocol for a cluster randomized controlled trial.

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    BACKGROUND: Antiretroviral therapy (ART) for HIV, taken daily, is an effective strategy to clinically suppress the virus, providing the dual benefit of improved survival and vastly decreasing the risk of transmission. However, this highly effective intervention has not yet reached all who could benefit. Cash transfers are increasingly recognized as an effective strategy to motivate behavior change and improve HIV care and treatment outcomes, including engagement in HIV care and adherence to ART. Despite a growing evidence base and strong theoretical foundation for the cash transfer approach, key questions remain. To address these questions and begin to bridge the "know-do gap" with respect to cash transfers, our team is employing an implementation science approach to iterative development of an incentive-based intervention to promote ART uptake and adherence among people living with HIV (PLHIV) in the Lake Zone region, Tanzania. METHODS: We will conduct a type I hybrid implementation-effectiveness trial to test the effectiveness of a cash transfer intervention on the outcome of HIV viral suppression, and concurrently examine the potential for real-world implementation with a mobile health technology (mHealth) system. Specifically, our team will expand the intervention to 32 clinics and enroll 1984 PLHIV to (a) evaluate its effectiveness by conducting a cluster randomized controlled trial with clinics as the unit of randomization and 12-month viral suppression as the primary outcome and (b) evaluate the implementation challenges and successes at multiple levels (patient, provider, clinic). DISCUSSION: This trial will provide evidence not only about the real-world effectiveness of cash transfers for retention in HIV care and viral suppression, but also on the implementation challenges and successes that will facilitate or hinder wider scale-up within Tanzania and beyond. TRIAL REGISTRATION: ClinicalTrials.gov NCT04201353 . Registered on December 17, 2019

    Prophylactic methylprednisolone to reduce inflammation and improve outcomes from one lung ventilation in children: a randomized clinical trial.

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    BACKGROUND: One lung ventilation (OLV) results in inflammatory and mechanical injury, leading to intraoperative and postoperative complications in children. No interventions have been studied in children to minimize such injury. OBJECTIVE: We hypothesized that a single 2-mg·kg(-1) dose of methylprednisolone given 45-60 min prior to lung collapse would minimize injury from OLV and improve physiological stability. METHODS: Twenty-eight children scheduled to undergo OLV were randomly assigned to receive 2 mg·kg(-1) methylprednisolone (MP) or normal saline (placebo group) prior to OLV. Anesthetic management was standardized, and data were collected for physiological stability (bronchospasm, respiratory resistance, and compliance). Plasma was assayed for inflammatory markers related to lung injury at timed intervals related to administration of methylprednisolone. RESULTS: Three children in the placebo group experienced clinically significant intraoperative and postoperative respiratory complications. Respiratory resistance was lower (P = 0.04) in the methylprednisolone group. Pro-inflammatory cytokine IL-6 was lower (P = 0.01), and anti-inflammatory cytokine IL-10 was higher (P = 0.001) in the methylprednisolone group. Tryptase, measured before and after OLV, was lower (P = 0.03) in the methylprednisolone group while increased levels of tryptase were seen in placebo group after OLV (did not achieve significance). There were no side effects observed that could be attributed to methylprednisolone in this study. CONCLUSIONS: Methylprednisolone at 2 mg·kg(-1) given as a single dose prior to OLV provides physiological stability to children undergoing OLV. In addition, methylprednisolone results in lower pro-inflammatory markers and higher anti-inflammatory markers in the children\u27s plasma

    Life cycle assessment of emerging technologies: Evaluation techniques at different stages of market and technical maturity

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    Life cycle assessment (LCA) analysts are increasingly being asked to conduct life cycleâ based systems level analysis at the earliest stages of technology development. While early assessments provide the greatest opportunity to influence design and ultimately environmental performance, it is the stage with the least available data, greatest uncertainty, and a paucity of analytic tools for addressing these challenges. While the fundamental approach to conducting an LCA of emerging technologies is akin to that of LCA of existing technologies, emerging technologies pose additional challenges. In this paper, we present a broad set of market and technology characteristics that typically influence an LCA of emerging technologies and identify questions that researchers must address to account for the most important aspects of the systems they are studying. The paper presents: (a) guidance to identify the specific technology characteristics and dynamic market context that are most relevant and unique to a particular study, (b) an overview of the challenges faced by early stage assessments that are unique because of these conditions, (c) questions that researchers should ask themselves for such a study to be conducted, and (d) illustrative examples from the transportation sector to demonstrate the factors to consider when conducting LCAs of emerging technologies. The paper is intended to be used as an organizing platform to synthesize existing methods, procedures and insights and guide researchers, analysts and technology developer to better recognize key study design elements and to manage expectations of study outcomes.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154465/1/jiec12954-sup-0001-SuppMat.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154465/2/jiec12954.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154465/3/jiec12954_am.pd
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