430 research outputs found
Scalar dispersion in strongly curved open-channel flows
Large-eddy simulations (LES) and Reynolds-averaged numerical simulations (RANS) are performed for the flow and scalar dispersion through a strongly curved open-channel bend. The aim of the study is to investigate the performance of both LES and RANS as regards the reproduction of the key bend flow features and the associated prediction of scalar spreading along the flume. In this respect, three different issues are addressed. Firstly, the influence of the water depth on the flow behavior as computed by LES and RANS is considered. Secondly, the plume statistics of the case with a continuous vertical line source is investigated. And thirdly, the dispersion behavior of a scalar tracer is studied by means of the case in which a blob of the scalar tracer is instantaneously injected. It is found that the LES computations fairly well reproduce the main flow features, whereas RANS computations experience severe difficulties in predicting the flow field. Moreover, it was found that the gradient-hypothesis of diffusion is only limitedly valid; even counter-gradient diffusion is observed. In addition, the residence time characteristics of the instantaneously injected blob of the scalar tracer in the bend are addressed as well
Detecting Environmental Contamination of MRSA in Ambulances: A Novel and Efficient Sampling Methodology
Background: Methicillin-resistant Staphylococcus aureus (MRSA) can be found in emergency medical services (EMS) ambulances. This poses an occupational risk and patient safety hazard. Screening for environmental contamination is often not performed due to limited resources and logistical challenges. This study’s objective was to compare traditional screening of individual surfaces versus “pooled sampling” to efficiently identify contamination.
Methods: A cross-sectional study, conducted among 145 Ohio EMS ambulances from 84 agencies, tested a novel pooled sampling methodology to detect MRSA contaminated ambulances. For ambulances screened using pooled sampling, 3 samples were collected within each ambulance. Pool One included cabinets, doorways, and ceiling bar. Pool Two included cot, seats, and backboard. Pool Three included steering wheel, kits, and clipboard. For ambulances screened with the traditional detection technique, each of the 9 aforementioned surfaces were sampled individually. Descriptive statistics and unadjusted and adjusted odds ratios (OR) were calculated to compare the 2 methods.
Results: Forty-seven of 145 ambulances (32.4%) had at least 1 of the 9 locations contaminated with MRSA. When comparing the 2 screening methodologies, no significant difference was observed regarding the overall detection of MRSA contaminated ambulances (24/60 [40%] versus 23/85 [27.6%], P value: 0.1000). This indicates that pooled sampling appears as an efficient method for identification of MRSA contaminated ambulances.
Conclusion: One-third of Ohio ambulances had MRSA contamination in this study. Therefore, an efficient methodology to identify contaminated ambulances with hazardous pathogens is incredibly valuable. Pooling can help save resources and simplify sampling logistics, all which could positively impact infection control practices in emergency medical services
Parametric Optimization Of Magneto-Rheological Fluid Damper Using Particle Swarm Optimization
This paper presents a parametric modeling of a magneto-rheological (MR) damper using a Particle Swarm Optimization (PSO) method. The objective of this paper is to
optimize the parameter values of the MR fluid damper behavior using the Bouc-Wen model. The parametric identification was imposed beforehand in replicating the
behavior of the MR fluid damper. The algebraic function from a number of hysteresis models was steered by comparing selected models: Bingham, Bouc-Wen and BoucWen by Kwok. A simulation method was operated in investigating these models by employing MATLAB reliant from the model intricacy. The experimental data was presented in terms of the time histories of the displacement, the velocity and the force parameters, measured for both constant and variable current settings and at a selected frequency applied to the damper. The model parameters were determined using a set of experimental measurements corresponding to different current constant values. It has been shown that the MR damper model’s response via the proposed approach is in good agreement with the MR damper test rig counterpar
The effect of office based flexible and rigid cystoscopy on pain experience in female patients
Purpose: Rigid and flexible cystoscopies are both routinely used in female patients. Literature is conflicting whether flexible cystoscopy
is less painful compared to rigid cystoscopy. The aim of this study was therefore to investigate whether using flexible cystoscopy
leads to less discomfort and pain compared to rigid cystoscopy in female patients who underwent first time cystoscopy.
Materials and Methods: One hundred eighty-nine female patients, who never had undergone cystoscopy, were randomized into
2 groups: 92 patients underwent rigid cystoscopy and 97 patients flexible cystoscopy. Directly after the cystoscopy procedure all
patients were asked to fill out their pain experience on a 100-mm visual analogue pain scale (VAS).
Results: Median VAS score was significantly lower for women undergoing flexible cystoscopy (0 [0–20]) compared to rigid cystoscopy
(15 [0–38], p<0.001). In addition, age was inversely associated with VAS score, indicating that younger females experienced
more pain (R=−0.30, p=0.001). The use of flexible cystoscopy was associated with a decrease in VAS score and remained significant
after adjustment for age, sex of urologist, performing urologist and indication (standardized β =−0.17, p=0.048).
Conclusions: The use of flexible cystoscopy resulted in a significantly lower pain experience compared to rigid cystoscopy. Based
on patient’s pain experience during cystoscopy, this study implicates to use flexible cystoscopy in female patients who undergo
first time cystoscopy
Participatory policy analysis in health policy and systems research: reflections from a study in Nepal.
Background
Participatory policy analysis (PPA) as a method in health policy and system research remains underexplored. Using our experiences of conducting PPA workshops in Nepal to explore the impact of the country’s move to federalism on its health system, we reflect on the method’s strengths and challenges. We provide an account of the study context, the design and implementation of the workshops, and our reflections on the approach’s strengths and challenges. Findings on the impact of federalism on the health system are beyond the scope of this manuscript.
Main body
We conducted PPA workshops with a wide range of health system stakeholders (political, administrative and service-level workforce) at the local and provincial levels in Nepal. The workshops consisted of three activities: river of life, brainstorming and prioritization, and problem-tree analysis. Our experiences show that PPA workshops can be a valuable approach to explore health policy and system issues – especially in a context of widespread systemic change which impacts all stakeholders within the health system. Effective engagement of stakeholders and activities that encourage both individual- and system-level reflections and discussions not only help in generating rich qualitative data, but can also address gaps in participants’ understanding of practical, technical and political aspects of the health system, aid policy dissemination of research findings, and assist in identifying short- and long-term practice and policy issues that need to be addressed for better health system performance and outcomes. Conducting PPA workshops is, however, challenging for a number of reasons, including the influence of gatekeepers and power dynamics between stakeholders/participants. The role and skills of researchers/facilitators in navigating such challenges are vital for success. Although the long-term impact of such workshops needs further research, our study shows the usefulness of PPA workshops for researchers, for participants and for the wider health system.
Conclusions
PPA workshops can effectively generate and synthesize health policy and system evidence through collaborative engagement of health system stakeholders with varied roles. When designed with careful consideration for context and stakeholders’ needs, it has great potential as a method in health policy and systems research
Life-history innovation to climate change:Can single-brooded migrant birds become multiple breeders?
When climatic conditions change and become outside the range experienced in the past, species may show life-history innovations allowing them to adapt in new ways. We report such an innovation for pied flycatchers Ficedula hypoleuca. Decades of breeding biological studies on pied flycatchers have rarely reported multiple breeding in this long-distance migrant. In two populations, we found 12 recent incidents of females with second broods, all produced by extremely early laying females in warm springs. As such early first broods are a recent phenomenon, because laying dates have gradually advanced over time, this innovation now allows individual females to enhance their reproductive success considerably. If laying dates continue advancing, potentially more females may become multiple breeders and selection for early (and multiple) breeding phenotypes increases, which may accelerate adaptation to climatic change
The COVID-19 pandemic in Nepal: Emerging evidence on the effectiveness of action by, and cooperation between, different levels of government in a federal system
A new coronavirus disease (COVID-19) caused by a novel pathogen (SARS-CoV-2) spread rapidly around the world in the early months of 2020, and was declared a pandemic by the World Health Organization (WHO) on 11 March. COVID-19 has, and continues to have, large implications for individuals, societies, and for national health systems across the globe. Due to its novelty and impact, it has challenged all health care systems where the virus has taken hold. The ways in which governments and health systems have responded have varied widely across the world. In the case of Nepal, the pandemic represented a major test for the newly decentralised health system, created as a result of the implementation of the 2015 federal constitution. This paper, which forms a part of our large on-going study of the decentralisation of the health system in the country, presents some of the early evidence on the effectiveness of the actions taken by Federal, Provincial and Local Governments and the levels of cooperation and coordination between them
Geolocators lead to better measures of timing and renesting in black-tailed godwits and reveal the bias of traditional observational methods
Long-term population studies can identify changes in population dynamics over time. However, to realize meaningful conclusions, these studies rely on accurate measurements of individual traits and population characteristics. Here, we evaluate the accuracy of the observational methods used to measure reproductive traits in individually marked black-tailed godwits (Limosa limosa limosa). By comparing estimates from traditional methods with data obtained from light-level geolocators, we provide an accurate estimate of the likelihood of renesting in godwits and the repeatability of the lay dates of first clutches. From 2012 to 2018, we used periods of shading recorded on the light-level geolocators carried by 68 individual godwits to document their nesting behaviour. We then compared these estimates to those simultaneously obtained by our long-term observational study. We found that among recaptured geolocator-carrying godwits, all birds renested after a failed first clutch, regardless of the date of nest loss or the number of days already spent incubating. We also found that 43% of these godwits laid a second replacement clutch after a failed first replacement, and that 21% of these godwits renested after a hatched first clutch. However, the observational study correctly identified only 3% of the replacement clutches produced by geolocator-carrying individuals and designated as first clutches a number of nests that were actually replacement clutches. Additionally, on the basis of the observational study, the repeatability of lay date was 0.24 (95% CI 0.17-0.31), whereas it was 0.54 (95% CI 0.28-0.75) using geolocator-carrying individuals. We use examples from our own and other godwit studies to illustrate how the biases in our observational study discovered here may have affected the outcome of demographic estimates, individual-level comparisons, and the design, implementation and evaluation of conservation practices. These examples emphasize the importance of improving and validating field methodologies and show how the addition of new tools can be transformational
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