1,144 research outputs found

    Advancing characterisation with statistics from correlative electron diffraction and X-ray spectroscopy, in the scanning electron microscope.

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    The routine and unique determination of minor phases in microstructures is critical to materials science. In metallurgy alone, applications include alloy and process development and the understanding of degradation in service. We develop a correlative method, exploring superalloy microstructures, which are examined in the scanning electron microscope (SEM) using simultaneous energy dispersive X-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD). This is performed at an appropriate length scale for characterisation of carbide phases' shape, size, location, and distribution. EDS and EBSD data are generated using two different physical processes, but each provide a signature of the material interacting with the incoming electron beam. Recent advances in post-processing, driven by 'big data' approaches, include use of principal component analysis (PCA). Components are subsequently characterised to assign labels to a mapped region. To provide physically meaningful signals, the principal components may be rotated to control the distribution of variance. In this work, we develop this method further through a weighted PCA approach. We use the EDS and EBSD signals concurrently, thereby labelling each region using both EDS (chemistry) and EBSD (crystal structure) information. This provides a new method of amplifying signal-to-noise for very small phases in mapped regions, especially where the EDS or EBSD signal is not unique enough alone for classification

    Effect of Prophylactic Ketoconazole and Nystatin on Fungal Flora

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    The effect of prophylactic antifungal drugs on oropharyngeal and anterior nares fungal colonization was studied in 20 patients receiving nystatin and 19 patients receiving ketoconazole. Surveillance cultures were obtained weekly for a mean of 27.1 ± 4.8 days in the nystatin group and 44.0 ±6.7 days in the ketoconazole group. Initially, 63.2% of nystatin patients and 77.8% of ketoconazole patients had yeasts in their oropharynx. Neither drug eliminated oropharyngeal yeast colonization; by the end of the first four weeks of surveillance, 66.7% of the nystatin group and 63.6% of the ketoconazole group still had yeasts in the oropharynx. However, both drugs caused a reduction in the quantity of yeasts grown on successive cultures. Filamentous fungi were isolated in baseline cultures in 42.1% of the nystatin patients and 33.3% of the ketoconazole patients. Prophylaxis did not appear to alter carriage of filamentous fungi in the upper airways. Pathogenic filamentous fungi were only rarely isolated, and this rate did not increase with prophylaxis. Resistance to polyene antifungals (nystatin, amphotericin B) or to ketoconazole did not occur as a result of prophylaxis. Zusammenfassung : Untersuchung Über die Pilzflora im Oropharynx und im vorderen Nasenraum unter dem Einfluß einer prophylaktischen antimykotischen Behandlung. 20 Patienten erhielten Nystatin und 19 Patienten Ketoconazol. WÖchentliche Kontrollkulturen wurden in der Nystatin-Gruppe Über einen durchschnittlichen Zeitraum von 27,1 ± 4,8 Tagen und in der Ketoconazol-Gruppe Über 44,0 ± 6,7 Tage durchgefÜhrt. Zu Beginn der Untersuchung hatten 63,2% der Nystatin-Patienten und 77,8% der Ketoconazol-Patienten Hefen im Oropharynx. Keines der beiden Antimykotika eliminierte die oropharyngeale Hefebesiedlung. Nach 4wÖchiger Beobachtung wurden Hefen in der Nystatin-Gruppe bei 76,7% und in der Ketoconazol-Gruppe bei 63,6% im Oropharynx festgestellt. Durch beide Antimykotika wurde jedoch eine Verringerung der kulturell nachweisbaren Hefemengen hervorgerufen. Schimmelpilze fanden sich zu Beginn der Untersuchung bei 42,1% der Nystatin-Patienten und bei 33,3% der Ketoconazol-Patienten. Unter der prophylaktischen Behandlung war keine Verringerung des Vorkommens derartiger Pilze in den oberen Luftwegen feststellbar. Pathogene Schimmelpilze wurden nur sehr selten isoliert und das Vorkommen dieser Pilze stieg unter der prophylaktischen Behandlung nicht an. Eine Resistenz gegenÜber Polyen-Antimykotika (Nystatin, Amphotericin B) oder Ketoconazol trat unter der prophylaktischen Behandlung nicht auf.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74832/1/j.1439-0507.1984.tb02016.x.pd

    Season and vitamin D status are independently associated with glucose homeostasis in pregnancy

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    Background: Vitamin D status and season are intrinsically linked, and both have been proposed to be associated with glucose homeostasis in pregnancy, with conflicting results. We aimed to determine if exposure to winter and low maternal 25 hydroxyvitamin D (25OHD) in early pregnancy were associated with maternal glucose metabolism.Methods: This is a secondary data analysis of 334 pregnant women enrolled in the ROLO study, Dublin. Serum 25OHD, fasting glucose, insulin and insulin resistance (HOMA-IR) were measured in early (12 weeks' gestation) and late pregnancy (28 weeks' gestation). Season of first antenatal visit was categorised as extended winter (November–April) or extended summer (May–October). Multiple linear regression models, adjusted for confounders, were used for analysis.Results: Those who attended their first antenatal visit in extended winter had lower 25OHD compared to extended summer (32.9 nmol/L vs. 44.1 nmol/L, P < 0.001). Compared to those who attended their first antenatal visit during extended summer, extended winter was associated with increased HOMA-IR in early-pregnancy (46.7%) and late pregnancy (53.7%), independent of 25OHD <30 nmol/L and confounders. Early pregnancy 25OHD <30 nmol/L and extended winter were independently associated with significantly higher fasting glucose in late pregnancy (B = 0.15 and 0.13, respectively).Conclusions: Women who attended their first antenatal visit during the months of extended winter were more likely to have raised insulin resistance in early pregnancy, which had a lasting association to 28 weeks, and was independent of 25OHD. Our novel findings imply that seasonal variation in insulin resistance may not be fully explained by differences in vitamin D status. This could reflect circannual rhythm or seasonal lifestyle behaviours, and requires further exploration.Trial registration: ISRCTN registry, ISRCTN54392969, date of registration: 22/04/2009, retrospectively registered

    The mechanism of twin thickening and the elastic strain state of TWIP steel nanotwins

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    A Twinning Induced Plasticity (TWIP) steel with a nominal composition of Fe-16.4Mn-0.9C-0.5Si-0.05Nb-0.05V was deformed to an engineering strain of 6\%. The strain around the deformation twins were mapped using the 4D-STEM technique. Strain mapping showed a large average elastic strain of approximately 6\% in the directions parallel and perpendicular to the twinning direction. However, the large average strain comprised of several hot spots of even larger strains of up to 12\%. These hot spots could be attributed to a high density of sessile Frank dislocations on the twin boundary and correspond to shear stresses of 1--1.5 GPa. The strain and therefore stress fields are significantly larger than other materials known to twin and are speculated to be responsible for the early thickness saturation of TWIP steel nanotwins. The ability to keep twins extremely thin helps improve grain fragmentation, \textit{i.e.} the dynamic Hall-Petch effect, and underpins the large elongations and strain hardening rates in TWIP steels

    Response of soil health indicators to dung, urine and mineral fertilizer application in temperate pastures

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    Healthy soils are key to sustainability and food security. In temperate grasslands, not many studies have focused on soil health comparisons between contrasting pasture systems under different management strategies and treatment applications (e.g. manures and inorganic fertilisers). The aim of this study was to assess the responses of soil health indicators to dung, urine and inorganic N fertiliser in three temperate swards: permanent pasture not ploughed for at least 20 years (PP), high sugar ryegrass with white clover targeted at 30% coverage reseeded in 2013 (WC), and high sugar ryegrass reseeded in 2014 (HG). This study was conducted on the North Wyke Farm Platform (UK) from April 2017 to October 2017. Soil health indicators including soil organic carbon (SOC, measured by loss of ignition and elemental analyser), dissolved organic carbon (DOC), total nitrogen (TN), C:N ratio, soil C and N bulk isotopes, pH, bulk density (BD), aggregate stability, ergosterol concentration (as a proxy for fungi biomass), and earthworms (abundance, mass and density) were measured and analysed before and after application of dung and N fertilizer, urine and N fertiliser, and only N fertiliser. The highest SOC, TN, DOC, ergosterol concentration and earthworms as well as the lowest BD were found in PP, likely due to the lack of ploughing. Differences among treatments were observed due to the application of dung, resulting in an improvement in chemical indicators of soil health after 50 days of its application. Ergosterol concentration was significantly higher before treatment applications than at the end of the experiment. No changes were detected in BD and aggregate stability after treatment applications. We conclude that not enough time had passed for the soil to recover after the ploughing and reseeding of the permanent pasture, independently of the sward composition (HG or WC). Our results highlight the strong influence of the soil management legacy in temperate pasture and the positive effects of dung application on soil health over the short term. In addition, we point out the relevance of using standardised methods to report soil health indicators and some methodological limitations

    An Observational Analysis of Meal Patterns in Overweight and Obese Pregnancy

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    Background Nutrient intakes are known to be poorer among pregnant women with raised body mass index (BMI) than those with a healthy BMI. While meal patterns have the potential to influence obstetric, metabolic and anthropometric measures for mother and infant, limited data exists regarding meal patterns among pregnant women with raised BMI. Aim To identify categories of meal patterns among pregnant women with overweight and obesity and determine whether patterns change with advancing gestation. To determine if maternal meal patterns are associated with dietary intakes and pregnancy outcomes. Methods Prospective, observational analysis of pregnant women (n = 143) (BMI 25–39.9 kg/m2). Meal pattern data were analysed from 3-day food diaries at 16 and 28 weeks’ gestation. Outcomes include maternal blood glucose, insulin resistance, gestational diabetes, gestational weight gain and infant anthropometry. Results Three meal pattern categories were identified: ‘main meal dominant’ (3 main eating occasions + 0–3 snacks), ‘large meal dominant’ (≀ 2 main eating occasions + \u3c 2 snacks), and ‘snack dominant’ (3 main eating occasions + \u3e 3 snacks and ≀2main + ≄ 2 snacks). A main meal–dominant pattern prevailed at 16 weeks’ (85.3%) and a snack-dominant pattern at 28 weeks’ (68.5%). Dietary glycaemic index was lower among the main meal versus large meal–dominant pattern at 28 weeks (P = 0.018). Infant birth weight (kg) and macrosomia were highest among participants with a large meal–dominant pattern at 28 weeks (P = 0.030 and P = 0.008, respectively). Conclusion Women with raised BMI changed eating patterns as pregnancy progressed, moving from main meal–dominant to snack-dominant patterns. Large meal–dominant meal patterns in later pregnancy were associated with higher glycaemic index and greater prevalence of macrosomia

    The impact of training non-physician clinicians in Malawi on maternal and perinatal mortality : a cluster randomised controlled evaluation of the enhancing training and appropriate technologies for mothers and babies in Africa (ETATMBA) project

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    Background: Maternal mortality in much of sub-Saharan Africa is very high whereas there has been a steady decline in over the past 60 years in Europe. Perinatal mortality is 12 times higher than maternal mortality accounting for about 7 million neonatal deaths; many of these in sub-Saharan countries. Many of these deaths are preventable. Countries, like Malawi, do not have the resources nor highly trained medical specialists using complex technologies within their healthcare system. Much of the burden falls on healthcare staff other than doctors including non-physician clinicians (NPCs) such as clinical officers, midwives and community health-workers. The aim of this trial is to evaluate a project which is training NPCs as advanced leaders by providing them with skills and knowledge in advanced neonatal and obstetric care. Training that will hopefully be cascaded to their colleagues (other NPCs, midwives, nurses). Methods/design: This is a cluster randomised controlled trial with the unit of randomisation being the 14 districts of central and northern Malawi (one large district was divided into two giving an overall total of 15). Eight districts will be randomly allocated the intervention. Within these eight districts 50 NPCs will be selected and will be enrolled on the training programme (the intervention). Primary outcome will be maternal and perinatal (defined as until discharge from health facility) mortality. Data will be harvested from all facilities in both intervention and control districts for the lifetime of the project (3–4 years) and comparisons made. In addition a process evaluation using both quantitative and qualitative (e.g. interviews) will be undertaken to evaluate the intervention implementation. Discussion: Education and training of NPCs is a key to improving healthcare for mothers and babies in countries like Malawi. Some of the challenges faced are discussed as are the potential limitations. It is hoped that the findings from this trial will lead to a sustainable improvement in healthcare and workforce development and training. Trial registration: ISRCTN6329415

    Ecological Factors and Childhood Eating Behaviours at 5 Years of Age: findings from the ROLO longitudinal birth cohort study

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    Individual differences in children eating behaviours have been linked with childhood overweight and obesity. The determinants of childhood eating behaviours are influenced by a complex combination of hereditary and ecological factors. This study examines if key ecological predictors of childhood overweight; maternal socio-economic status (SES), children’s screen time, and childcare arrangements, are associated with eating behaviours in children aged 5-years-old

    Farm-level emission intensities of smallholder cattle (Bos indicus; B. indicus–B. taurus crosses) production systems in highlands and semi-arid regions

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    Ruminants are central to the economic and nutritional life of much of sub-Saharan Africa, but cattle are now blamed for having a disproportionately large negative environmental impact through emissions of greenhouse gas (GHG). However, the mechanism underlying excessive emissions occurring only on some farms is imperfectly understood. Reliable estimates of emissions themselves are frequently lacking due to a paucity of reliable data. Employing individual animal records obtained at regular farm visits, this study quantified farm-level emission intensities (EIs) of greenhouse gases of smallholder farms in three counties in Western Kenya. CP was chosen as the functional unit to capture the outputs of both milk and meat. The results showed that milk is responsible for 80–85% of total CP output. Farm EI ranged widely from 20 to >1 000 kg CO2_{2}-eq/kg CP. Median EIs were 60 (Nandi), 71 (Bomet), and 90 (Nyando) kg CO2_{2}-eq/kg. Although median EIs referenced to milk alone (2.3 kg CO2_{2}-eq/kg milk) were almost twice that reported for Europe, up to 50% of farms had EIs comparable to the mean Pan-European EIs. Enteric methane (CH4_{4}) contributed >95% of emissions and manure ∌4%, with negligible emissions attributed to inputs to the production system. Collecting data from individual animals on smallholder farms enabled the demonstration of extremely heterogeneous EI status among similar geographical spaces and provides clear indicators on how low EI status may be achieved in these environments. Contrary to common belief, our data show that industrial-style intensification is not required to achieve low EI. Enteric CH4_{4} production overwhelmingly drives farm emissions in these systems and as this is strongly collinear with nutrition and intake, an effort will be required to achieve an “efficient frontier” between feed intake, productivity, and GHG emissions
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