859 research outputs found
System thermal-hydraulic modelling of the phénix dissymmetric test benchmark
Phénix is a French pool-type sodium-cooled prototype reactor; before the definitive shutdown, occurred in 2009, a final set of experimental tests are carried out in order to increase the knowledge on the operation and the safety aspect of the pool-type liquid metal-cooled reactors. One of the experiments was the Dissymmetric End-of-Life Test which was selected for the validation benchmark activity in the frame of SESAME project. The computer code validation plays a key role in the safety assessment of the innovative nuclear reactors and the Phénix dissymmetric test provides useful experimental data to verify the computer codes capability in the asymmetric thermal-hydraulic behaviour into a pool-type liquid metal-cooled reactor. This paper shows the comparison of the outcomes obtained with six different System Thermal-Hydraulic (STH) codes: RELAP5-3D©, SPECTRA, ATHLET, SAS4A/SASSYS-1, ASTEC-Na and CATHARE. The nodalization scheme of the reactor was individually achieved by the participants; during the development of the thermal-hydraulic model, the pool nodalization methodology had a special attention in order to investigate the capability of the STH codes to reproduce the dissymmetric effects which occur in each loop and into pools, caused by the azimuthal asymmetry of the boundary conditions. The modelling methodology of the participants is discussed and the main results are compared in this paper to obtain useful guide lines for the future modelling of innovative liquid metal pool-type reactors
A retrospective cohort study of predictors and interventions that influence cooperation with mask induction in children
BackgroundUncooperative pediatric mask induction is linked to perioperative anxiety. Although some risk factors for uncooperative inductions have been reported, there are no large cohort studies that identify intrinsic patient characteristics associated with cooperation.AimThe primary aim was to identify patient characteristics associated with cooperative mask inductions. The secondary aim was to determine whether preoperative interventions were associated with increased cooperation.MethodsThis retrospective cohort study included patients 2- 11 years old and ASA class I- IV who underwent mask induction. Our primary outcome of interest was cooperation with mask induction, which was correlated against the Induction Compliance Checklist. The variables analyzed for association with cooperation were age, sex, ASA class, class of surgery, preferred language, and race. Interventions examined for association with induction cooperation included premedication with midazolam, exposure to distraction technology, parental presence, and the presence of a Child Life Specialist. Multivariate mixed- effects logistic regression was used to assess the relationship between patient characteristics and cooperation. A separate multivariate mixed- effects logistic regression was used to examine the association between preoperative interventions and cooperation.Results9692 patients underwent 23 474 procedures during the study period. 3372 patients undergoing 5980 procedures met inclusion criteria. The only patient characteristic associated with increased cooperation was age (OR 1.20, p- value 0.03). Involvement of Child Life Specialists was associated with increased cooperation (OR 4.44, p- value = 0.048) while parental/guardian presence was associated with decreased cooperation (OR 0.38, p- value = 0.002).ConclusionIn this cohort, increasing age was the only patient characteristic found to be associated with increased cooperation with mask induction. Preoperative intervention by a Child Life Specialists was the sole intervention associated with improved cooperation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162757/2/pan13930.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162757/1/pan13930_am.pd
A multifaceted quality improvement project improves intraoperative redosing of surgical antimicrobial prophylaxis during pediatric surgery
BackgroundAccurate intraoperative antibiotic redosing contributes to prevention of surgical site infections in pediatric patients. Ensuring compliance with evolving national guidelines of weight‐based, intraoperative redosing of antibiotics is challenging to pediatric anesthesiologists.AimsOur primary aim was to increase compliance of antibiotic redoses at the appropriate time and appropriate weight‐based dose to 70%. Secondary aims included a subset analysis of time compliance and dose compliance individually, and compliance based on order entry method of the first dose (verbal or electronic).MethodsAt a freestanding, academic pediatric hospital, we reviewed surgical cases between May 1, 2014, and October 31, 2017 requiring antibiotic redoses. After an institutional change in cefazolin dosing in May 2015, phased interventions to improve compliance included electronic countermeasures to display previous and next dose timing, an alert 5 minutes prior to next dose, and weight‐based dose recommendation (September 2015). Physical countermeasures include badge cards, posting of guidelines, and updates to housestaff manual (September 2015). Statistical process control charts were used to assess overall antibiotic redose compliance, time compliance, and dose compliance. The chi‐square test was used to analyze group differences.ResultsA total of 3015 antibiotic redoses were administered during 2341 operative cases between May 1, 2014, and October 31, 2017. Mean monthly compliance with redosing was 4.3% (May 2014‐April 2015) and 73% (November 2015‐October 2017) (P < 0.001). Dose‐only compliance increased from 76% to 89% (P < 0.001), and time‐only compliance increased from 4.9% to 82% (P < 0.001). After implementation of countermeasures, electronic order entry compared with verbal order was associated with higher dose compliance, 90% vs 86% (P = 0.015).ConclusionThis quality improvement project, utilizing electronic and physical interventions, was effective in improving overall prophylactic antibiotic redosing compliance in accordance with institutional redosing guidelines.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150557/1/pan13651_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150557/2/pan13651.pd
D-Dimensional Radiative Plasma: A Kinetic Approach
The covariant kinetic approach for the radiative plasma, a mixture of a
relativistic moving gas plus radiation quanta (photons, neutrinos, or
gravitons) is generalized to D spatial dimensions. The operational and physical
meaning of Eckart's temperature is reexamined and the D-dimensional expressions
for the transport coefficients (heat conduction, bulk and shear viscosity) are
explicitly evaluated to first order in the mean free time of the radiation
quanta. Weinberg's conclusion that the mixture behaves like a relativistic
imperfect simple fluid (in Eckart's formulation) depends neither on the number
of spatial dimensions nor on the details of the collisional term. The case of
Thomson scaterring is studied in detail, and some consequences for higher
dimensional cosmologies are also discussed.Comment: 28 pages, 1 figure, uses REVTE
Effect of a low-cost, behaviour-change intervention on latrine use and safe disposal of child faeces in rural Odisha, India: a cluster-randomised controlled trial.
BACKGROUND: Uptake of Government-promoted sanitation remains a challenge in India. We aimed to investigate a low-cost, theory-driven, behavioural intervention designed to increase latrine use and safe disposal of child faeces in India. METHODS: We did a cluster-randomised controlled trial between Jan 30, 2018, and Feb 18, 2019, in 66 rural villages in Puri, Odisha, India. Villages were eligible if not adjacent to another included village and not designated by the Government to be open-defecation free. All latrine-owning households in selected villages were eligible. We assigned 33 villages to the intervention via stratified randomisation. The intervention was required to meet a limit of US$20 per household and included a folk performance, transect walk, community meeting, recognition banners, community wall painting, mothers' meetings, household visits, and latrine repairs. Control villages received no intervention. Neither participants nor field assessors were masked to study group assignment. We estimated intervention effects on reported latrine use and safe disposal of child faeces 4 months after completion of the intervention delivery using a difference-in-differences analysis and stratified results by sex. This study is registered at ClinicalTrials.gov, NCT03274245. FINDINGS: We enrolled 3723 households (1807 [48·5%] in the intervention group and 1916 [51·5%] in the control group). Analysis included 14 181 individuals (6921 [48·8%] in the intervention group and 7260 [51·2%] in the control group). We found an increase of 6·4 percentage points (95% CI 2·0-10·7) in latrine use and an increase of 15·2 percentage points (7·9-22·5) in safe disposal of child faeces. No adverse events were reported. INTERPRETATION: A low-cost behavioural intervention achieved modest increases in latrine use and marked increases in safe disposal of child faeces in the short term but was unlikely to reduce exposure to faecal pathogens to a level necessary to achieve health gains. FUNDING: The Bill & Melinda Gates Foundation and International Initiative for Impact Evaluation
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Aging and chronic inflammation: highlights from a multidisciplinary workshop
: Aging is a gradual, continuous series of natural changes in biological, physiological, immunological, environmental, psychological, behavioral, and social processes. Aging entails changes in the immune system characterized by a decrease in thymic output of naïve lymphocytes, an accumulated chronic antigenic stress notably caused by chronic infections such as cytomegalovirus (CMV), and immune cell senescence with acquisition of an inflammatory senescence-associated secretory phenotype (SASP). For this reason, and due to the SASP originating from other tissues, aging is commonly accompanied by low-grade chronic inflammation, termed "inflammaging". After decades of accumulating evidence regarding age-related processes and chronic inflammation, the domain now appears mature enough to allow an integrative reinterpretation of old data. Here, we provide an overview of the topics discussed in a recent workshop "Aging and Chronic Inflammation" to which many of the major players in the field contributed. We highlight advances in systematic measurement and interpretation of biological markers of aging, as well as their implications for human health and longevity and the interventions that can be envisaged to maintain or improve immune function in older people
The Pierre Auger Observatory III: Other Astrophysical Observations
Astrophysical observations of ultra-high-energy cosmic rays with the Pierre
Auger ObservatoryComment: Contributions to the 32nd International Cosmic Ray Conference,
Beijing, China, August 201
Operations of and Future Plans for the Pierre Auger Observatory
Technical reports on operations and features of the Pierre Auger Observatory,
including ongoing and planned enhancements and the status of the future
northern hemisphere portion of the Observatory. Contributions to the 31st
International Cosmic Ray Conference, Lodz, Poland, July 2009.Comment: Contributions to the 31st ICRC, Lodz, Poland, July 200
Measurement of the Depth of Maximum of Extensive Air Showers above 10^18 eV
We describe the measurement of the depth of maximum, Xmax, of the
longitudinal development of air showers induced by cosmic rays. Almost four
thousand events above 10^18 eV observed by the fluorescence detector of the
Pierre Auger Observatory in coincidence with at least one surface detector
station are selected for the analysis. The average shower maximum was found to
evolve with energy at a rate of (106 +35/-21) g/cm^2/decade below 10^(18.24 +/-
0.05) eV and (24 +/- 3) g/cm^2/decade above this energy. The measured
shower-to-shower fluctuations decrease from about 55 to 26 g/cm^2. The
interpretation of these results in terms of the cosmic ray mass composition is
briefly discussed.Comment: Accepted for publication by PR
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