1,915 research outputs found

    Tip Vortex and Crenulation Effects in a Compressor Cascade with Moving Endwall

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    The effects of changing Reynolds number and flow coefficients on the velocity and pressure flow fields within a linear cascade with moving endwall were investigated in this experimental thesis. All flow field measurements were taken at a constant compressor blade tip gap clearance of 1.0 % chord and endwall speed of 318.6 ft/s (97.1 m/s), with flow coefficients of 0.40, 0.52, 0.62 and 0.72. All data acquisition occurred in a plane 23 % chord downstream of the trailing edge plane of the linear cascade. Hotwire probes determined the complete passage, three-dimensional fowled behind both crenulated and regular blade geometries. Vector plots showed that the mid-span crenulations aligned the flow axially, increasing the wake mixing and reducing the spanwise flow evident in the regular blade\u27s wake region. A total pressure rake measured the pressure fowled behind the blades, showing that the crenulated blade geometry produced larger, less intense areas of total pressure loss than for the regular blades. Overall, the crenulated blade tested showed equal passage total pressure losses, increased wake mixing, reduced wake deficit and a reduced flow turning angle compared to a regular blade of similar overall dimensions

    Urban agriculture : evaluating informal and formal practices

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    Urban agriculture (UA) is a fast-increasing element in many settlements in the Global North. This paper reviews the diversity of UA activity, ranging from legal to illegal, formal to informal. Focusing particularly on current research on UA projects in England, including small-scale guerrilla gardening and large community projects supported by community and government funding, we look at the realities of UA. We suggest that it is under-theorised as previous research has focused on practicalities and activism. In particular, we highlight the problematic contribution of UA to food production, the wider value in terms of community development, health and wellbeing, and warn of the danger of the ‘local trap’

    Effect of Chorda Tympani Nerve Transection on Salt Taste Perception in Mice

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    Effects of gustatory nerve transection on salt taste have been studied extensively in rats and hamsters but have not been well explored in the mouse. We examined the effects of chorda tympani (CT) nerve transection on NaCl taste preferences and thresholds in outbred CD-1 mice using a high-throughput phenotyping method developed in our laboratory. To measure taste thresholds, mice were conditioned by oral self-administration of LiCl or NaCl and then presented with NaCl concentration series in 2-bottle preference tests. LiCl-conditioned and control NaCl-exposed mice were given bilateral transections of the CT nerve (LiCl-CTX, NaCl-CTX) or were left intact as controls (LiCl-CNT, NaCl-CNT). After recovery from surgery, mice received a concentration series of NaCl (0–300 mM) in 48-h 2-bottle tests. CT transection increased NaCl taste thresholds in LiCl-conditioned mice and eliminated avoidance of concentrated NaCl in control NaCl-exposed mice. This demonstrates that in mice, the CT nerve is important for detection and recognition of NaCl taste and is necessary for the normal avoidance of high concentrations of NaCl. The results of this experiment also show that the method of high-throughput phenotyping of salt taste thresholds is suitable for detecting changes in the taste periphery in mouse genetic studies

    General and age-specific fertility rates in non-affective psychosis : population-based analysis of Scottish women

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    The study was funded by Chief Scientist Office, Scottish Government Health and Social Care Directorate (Grant CZH/4/951), NHS Research Scotland (NHS Research Scotland Career Research Fellowship).Peer reviewedPublisher PD

    Faecal neutrophil elastase-antiprotease balance reflects colitis severity

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    Given the global burden of diarrheal diseases on healthcare it is surprising how little is known about the drivers of disease severity. Colitis caused by infection and inflammatory bowel disease (IBD) is characterised by neutrophil infiltration into the intestinal mucosa and yet our understanding of neutrophil responses during colitis is incomplete. Using infectious (Citrobacter rodentium) and chemical (dextran sulphate sodium; DSS) murine colitis models, as well as human IBD samples, we find that faecal neutrophil elastase (NE) activity reflects disease severity. During C. rodentium infection intestinal epithelial cells secrete the serine protease inhibitor SerpinA3N to inhibit and mitigate tissue damage caused by extracellular NE. Mice suffering from severe infection produce insufficient SerpinA3N to control excessive NE activity. This activity contributes to colitis severity as infection of these mice with a recombinant C. rodentium strain producing and secreting SerpinA3N reduces tissue damage. Thus, uncontrolled luminal NE activity is involved in severe colitis. Taken together, our findings suggest that NE activity could be a useful faecal biomarker for assessing disease severity as well as therapeutic target for both infectious and chronic inflammatory colitis

    Using biomarkers to predict TB treatment duration (Predict TB): a prospective, randomized, noninferiority, treatment shortening clinical trial

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    Background : By the early 1980s, tuberculosis treatment was shortened from 24 to 6 months, maintaining relapse rates of 1-2%. Subsequent trials attempting shorter durations have failed, with 4-month arms consistently having relapse rates of 15-20%. One trial shortened treatment only among those without baseline cavity on chest x-ray and whose month 2 sputum culture converted to negative. The 4-month arm relapse rate decreased to 7% but was still significantly worse than the 6-month arm (1.6%, P<0.01).  We hypothesize that PET/CT characteristics at baseline, PET/CT changes at one month, and markers of residual bacterial load will identify patients with tuberculosis who can be cured with 4 months (16 weeks) of standard treatment.Methods: This is a prospective, multicenter, randomized, phase 2b, noninferiority clinical trial of pulmonary tuberculosis participants. Those eligible start standard of care treatment. PET/CT scans are done at weeks 0, 4, and 16 or 24. Participants who do not meet early treatment completion criteria (baseline radiologic severity, radiologic response at one month, and GeneXpert-detectable bacilli at four months) are placed in Arm A (24 weeks of standard therapy). Those who meet the early treatment completion criteria are randomized at week 16 to continue treatment to week 24 (Arm B) or complete treatment at week 16 (Arm C). The primary endpoint compares the treatment success rate at 18 months between Arms B and C.Discussion: Multiple biomarkers have been assessed to predict TB treatment outcomes. This study uses PET/CT scans and GeneXpert (Xpert) cycle threshold to risk stratify participants. PET/CT scans are not applicable to global public health but could be used in clinical trials to stratify participants and possibly become a surrogate endpoint. If the Predict TB trial is successful, other immunological biomarkers or transcriptional signatures that correlate with treatment outcome may be identified. TRIAL REGISTRATION: NCT02821832

    Stepping through the door – exploring low-threshold services in Norwegian family centres

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    Author's accepted version (postprint).This is the peer reviewed version of the following article: Bulling, I.S. (2016). Stepping through the door – exploring low‐threshold servicesin Norwegian family centres. Child and Family Social Work, which has been published in final form at http://dx.doi.org/10.1111/cfs.12343. This article may be used for non‐commercial purposes in accordance with Wiley Terms and Conditions for Self‐Archiving.Available from 30/11/2018.Public policies encourage the service system to work in new ways to promote health and increase social equality. This paper presents four categories that show the character of the low-threshold services in Norwegian family centres from the professionals' and parents' perspectives, focusing on accessibility and participation: easy access, low level of bureaucracy, collaborative competences and inclusive arena. This paper is based on an inductive study in three municipalities that have chosen to establish family centres as interdisciplinary co-located services that aim to offer low-threshold services for children and their families. Data were generated through a fieldwork, and participatory observation and interviews were the main source of data. The methodological framework for the analysis was grounded theory, in which the data generation and analysis interchanged throughout the study, and theoretical sampling set the focus for the fieldwork. Exploring the actor's perspective highlighted both strengths and challenges with the low-threshold services in the family centres. The four elements presented emphasize that the value of these low-threshold services are not found in one single hallmark; rather, the value depends on an interaction between different elements that must be addressed when establishing, evaluating and developing low-threshold services in family centres

    The application of predictive modelling for determining bio-environmental factors affecting the distribution of blackflies (Diptera: Simuliidae) in the Gilgel Gibe watershed in Southwest Ethiopia

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    Blackflies are important macroinvertebrate groups from a public health as well as ecological point of view. Determining the biological and environmental factors favouring or inhibiting the existence of blackflies could facilitate biomonitoring of rivers as well as control of disease vectors. The combined use of different predictive modelling techniques is known to improve identification of presence/absence and abundance of taxa in a given habitat. This approach enables better identification of the suitable habitat conditions or environmental constraints of a given taxon. Simuliidae larvae are important biological indicators as they are abundant in tropical aquatic ecosystems. Some of the blackfly groups are also important disease vectors in poor tropical countries. Our investigations aim to establish a combination of models able to identify the environmental factors and macroinvertebrate organisms that are favourable or inhibiting blackfly larvae existence in aquatic ecosystems. The models developed using macroinvertebrate predictors showed better performance than those based on environmental predictors. The identified environmental and macroinvertebrate parameters can be used to determine the distribution of blackflies, which in turn can help control river blindness in endemic tropical places. Through a combination of modelling techniques, a reliable method has been developed that explains environmental and biological relationships with the target organism, and, thus, can serve as a decision support tool for ecological management strategies

    Accuracy of SenseWear Pro2 armband to predict resting energy expenditure in childhood obesity.

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    OBJECTIVE: We evaluate the accuracy of the SenseWear Pro2 Armband (SWA) in estimating resting energy expenditure (REE) in children and adolescents with obesity, using indirect calorimetry (IC) as a reference. DESIGN AND METHODS: REE was assessed using both the SWA and IC in 40 obese subjects (26 M/14 F, age 11.5±2.57 years, z-score BMI 3.14±0.53). The agreement between methods was assessed by the Bland-Altman procedure. The relationship between REE assessments and patients' characteristics was also analyzed. RESULTS: SWA- and IC-derived estimates of REE showed a significant correlation (r=0.614; P<0.001), but the SWA overestimated mean REE by 13% (P<0.001). Age and kg of fat-free mass (kgFFM) were significantly correlated with both REE estimation by SWA (r=0.434 and r=0.564; respectively) and IC (r=0.401 and r=0.518; respectively). Only kgFFM was demonstrated to be the main predictor factor of REE variability (r2 79% SWA; 75% IC). CONCLUSIONS: The SWA overestimated mean REE in childhood obesity, suggesting that the SWA and IC are not yet interchangeable methods. This would require improving the SWA by developing better algorithms for predicting REE and, probably, bias in each individual REE could be reduced by an adjustment for subjects' kgFFM
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