341 research outputs found

    Nitrogen fertiliser interactions with urine deposit affect nitrous oxide emissions from grazed grasslands

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    Cattle excreta deposited on grazed pastures are responsible for one fifth of the global anthropogenic nitrous oxide (N2O) emissions. One of the key nitrogen (N) sources is urine deposited from grazing animals, which contributes to very large N loadings within small areas. The main objective of this plot study was to establish whether the application of N fertiliser and urine deposit from dairy cows synergistically interacts and thereby increases N2O emissions, and how such interaction is influenced by the timing of application. The combined application of fertiliser (calcium ammonium nitrate) and urine significantly increased the cumulative N2O emissions as well as the N2O emission factor (EF) from 0.35 to 0.74 % in spring and from 0.26 to 0.52 % in summer. By contrast, EFs were lower when only fertiliser (0.31 % in spring, 0.07 % in summer) or urine was applied (0.33 % in spring, 0.28 % in summer). In autumn, N2O emissions were larger than in other seasons and the emissions from the combined application were not statistically different to those from either the separately applied urine or N fertiliser (EF ranging from 0.72 to 0.83, p-value < 0.05). The absence of significant synergistic effect could be explained by weather conditions, particularly rainfall during the three days prior to and after application in autumn. This study implies that the interactive effects of N fertilisation and urine deposit, as well as the timing of the application on N2O emission need to be taken into account in greenhouse gas emission inventories

    Nutrition support practices and opinions toward gastrostomy use in pediatric bone marrow transplant centers : a national survey

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    Objective: Previous surveys have shown deviations in nutritional practices from international guidelines during bone marrow transplant (BMT). Guidelines recommend enteral nutrition first-line and nasogastric tubes are the mainstay for its provision. Gastrostomies provide an alternative, yet their use is less common. This national survey investigated nutrition support practices in pediatric allogeneic BMT centers and compared clinicians’ opinions on gastrostomy use. The aim of this study was to identify the national picture of nutritional support practices across pediatric allogeneic BMT centers, including use and opinions of dietitians, clinical nurse specialists, and physicians, toward gastrostomy feeding. Methods: An online survey was administered to 12 centers. The lead dietitian answered questions regarding nutritional counseling, screening, assessment, and interventions. Questions regarding current use, perceived advantages, and problems of gastrostomies were answered by the dietitian, lead clinical nurse specialist, and physician. Results: A 100% response rate was achieved from 12 centers (N = 36 clinicians). Nutritional counseling was provided in 92% of centers before and routinely throughout admission, 83% screened on and regularly throughout admission, 83% assessed nutritional status before transplant, and 92% used enteral nutrition first-line. Forty-two percent of the centers used gastrostomies. In those not using gastrostomies, 76% of clinicians felt some children should be offered a gastrostomy. Clinicians perceived less displacements (78%) and cosmetic appearance (69%) as the most common advantages of gastrostomies over nasogastric tubes. Risks associated with surgery (92%) and tube/stoma complications (58%) were the most common perceived problems. Conclusions: A similar approach was shown on many aspects of nutritional support. Gastrostomy use divided opinion with differences in use and perceived advantages, but agreement on potential complications. Despite their risks, clinicians wanted to use gastrostomies more. Placement requires careful consideration of the risks, benefits, and family preferences

    Systematic review of gastrostomy complications and outcomes in pediatric cancer and bone marrow transplant

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    Background Nutrition support is essential in children with cancer, including those undergoing bone marrow transplant (BMT), to reduce the risk of malnutrition and associated deleterious outcomes. Enteral nutrition is more commonly provided via nasogastric than gastrostomy tubes because of safety concerns with the latter in immunocompromised children. This systematic review investigated the incidence and type of complications and outcomes in pediatric cancer patients fed by gastrostomy. Methods Databases were searched for randomized and observational studies investigating the use of any gastrostomy device in children aged <18 years with any cancer diagnosis, including those undergoing BMT. Five cohort and 11 case series studies were included. Owing to clinical heterogeneity, meta-analyses were not performed. Results Quality of evidence varied, with five studies judged at serious risk of bias and poor quality; however, the remaining 11 were considered to range from moderate to good quality. Across studies, 54.6% of children developed one or more complications, of which 76.6% were classified as minor, 23.4% major. The most frequent complications included inflammation (52% of episodes), infection (42.1%), leakage (22.3%), and granuloma (21%). Evidence regarding infection rates in cancer/BMT patients compared with other disease states was inconclusive. Gastrostomy feeding was associated with improvement or stabilization of nutrition status in 77%–92.7% of children. Conclusion Gastrostomy feeding in this population is relatively safe and effective in stabilizing or improving nutrition status throughout treatment. Complications are frequent but mostly minor. Placement requires careful consideration of the complications, benefits, nutrition risk and status at diagnosis, and quality of life

    Confirmation of co-denitrification in grazed grassland

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    Pasture-based livestock systems are often associated with losses of reactive forms of nitrogen (N) to the environment. Research has focused on losses to air and water due to the health, economic and environmental impacts of reactive N. Di-nitrogen (N₂) emissions are still poorly characterized, both in terms of the processes involved and their magnitude, due to financial and methodological constraints. Relatively few studies have focused on quantifying N₂ losses in vivo and fewer still have examined the relative contribution of the different N₂ emission processes, particularly in grazed pastures. We used a combination of a high Âč⁔N isotopic enrichment of applied N with a high precision of determination of Âč⁔N isotopic enrichment by isotope-ratio mass spectrometry to measure N₂ emissions in the field. We report that 55.8 g N m⁻ÂČ (95%, CI 38 to 77 g m⁻ÂČ) was emitted as N₂ by the process of co-denitrification in pastoral soils over 123 days following urine deposition (100 g N m⁻ÂČ), compared to only 1.1 g N m⁻ÂČ (0.4 to 2.8 g m⁻ÂČ) from denitrification. This study provides strong evidence for co-denitrification as a major N₂ production pathway, which has significant implications for understanding the N budgets of pastoral ecosystems

    Data Package of Samples Collected for Hydrogeologic and Geochemical Characterization: 300 Area RI/FS Sediment Cores

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    This is a data package for sediment samples received from the 300 FF 5 OU. This report was prepared for CHPRC. Between August 16, 2010 and April 25, 2011 sediment samples were received from 300-FF-5 for geochemical studies. The analyses for this project were performed at the 331 building located in the 300 Area of the Hanford Site. The analyses were performed according to Pacific Northwest National Laboratory (PNNL) approved procedures and/or nationally recognized test procedures. The data sets include the sample identification numbers, analytical results, estimated quantification limits (EQL), and quality control data. The preparatory and analytical quality control requirements, calibration requirements, acceptance criteria, and failure actions are defined in the on-line QA plan 'Conducting Analytical Work in Support of Regulatory Programs' (CAW). This QA plan implements the Hanford Analytical Services Quality Assurance Requirements Documents (HASQARD) for PNNL

    Bifidobacterial biofilm formation is a multifactorial adaptive phenomenon in response to bile exposure

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    In the current study, we show that biofilm formation by various strains and species belonging to Bifidobacterium, a genus that includes gut commensals with reported health-promoting activities, is induced by high concentrations of bile (0.5% (w/v) or higher) and individual bile salts (20&nbsp;mM or higher), rather than by acid or osmotic stress. The transcriptomic response of a bifidobacterial prototype Bifidobacterium breve UCC2003 to such high bile concentrations was investigated and a random transposon bank of B. breve UCC2003 was screened for mutants that affect biofilm formation in order to identify genes involved in this adaptive process. Eleven mutants affected in their ability to form a biofilm were identified, while biofilm formation capacity of an insertional mutation in luxS and an exopolysaccharide (EPS) negative B. breve UCC2003 was also studied. Reduced capacity to form biofilm also caused reduced viability when exposed to porcine bile. We propose that bifidobacterial biofilm formation is an adaptive response to high concentrations of bile in order to avoid bactericidal effects of high bile concentrations in the gastrointestinal environment. Biofilm formation appears to be a multi-factorial process involving EPS production, proteins and extracellular DNA release, representing a crucial strategy in response to bile stress in order to enhance fitness in the gut environment

    Nitrogen fertiliser interactions with urine deposit affect nitrous oxide emissions from grazed grasslands

    Get PDF
    peer-reviewedCattle excreta deposited on grazed pastures are responsible for one fifth of the global anthropogenic nitrous oxide (N2O) emissions. One of the key nitrogen (N) sources is urine deposited from grazing animals, which contributes to very large N loadings within small areas. The main objective of this plot study was to establish whether the application of N fertiliser and urine deposit from dairy cows synergistically interacts and thereby increases N2O emissions, and how such interaction is influenced by the timing of application. The combined application of fertiliser (calcium ammonium nitrate) and urine significantly increased the cumulative N2O emissions as well as the N2O emission factor (EF) from 0.35 to 0.74 % in spring and from 0.26 to 0.52 % in summer. By contrast, EFs were lower when only fertiliser (0.31 % in spring, 0.07 % in summer) or urine was applied (0.33 % in spring, 0.28 % in summer). In autumn, N2O emissions were larger than in other seasons and the emissions from the combined application were not statistically different to those from either the separately applied urine or N fertiliser (EF ranging from 0.72 to 0.83, p-value < 0.05). The absence of significant synergistic effect could be explained by weather conditions, particularly rainfall during the three days prior to and after application in autumn. This study implies that the interactive effects of N fertilisation and urine deposit, as well as the timing of the application on N2O emission need to be taken into account in greenhouse gas emission inventories.Teagas

    Quantitative metaproteomics of medieval dental calculus reveals individual oral health status

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    Mineralized plaque, or dental calculus, is a valuable reservoir of the ancient oral microbiome. Here, the authors use quantitative metaproteomics to analyze the dental calculus of 21 individuals from a medieval cemetery, identifying human and microbial proteins that shed light on their oral health status

    An analysis of the quality of experimental design and reliability of results in tribology research

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    In recent years several high profile projects have questioned the repeatability and validity of scientific research in the fields of psychology and medicine. In general, these studies have shown or estimated that less than 50% of published research findings are true or replicable even when no breaches of ethics are made. This high percentage stems from widespread poor study design; either through the use of underpowered studies or designs that allow the introduction of bias into the results. In this work, we have aimed to assess, for the first time, the prevalence of good study design in the field of tribology. A set of simple criteria for factors such as randomisation, blinding, use of control and repeated tests has been made. These criteria have been used in a mass review of the output of five highly regarded tribology journals for the year 2017. In total 379 papers were reviewed by 26 reviewers, 28% of the total output of the journals selected for 2017. Our results show that the prevalence of these simple aspects of study design is poor. Out of 290 experimental studies, 2.2% used any form of blinding, 3.2% used randomisation of either the tests or the test samples, while none randomised both. 30% repeated experiments 3 or more times and 86% of those who repeated tests used single batches of test materials. 4.4% completed statistical tests on their data. Due to the low prevalence of repeated tests and statistical analysis it is impossible to give a realistic indication of the percentage of the published works that are likely to be false positives, however these results compare poorly to other more well studied fields. Finally, recommendations for improved study design for researchers and group design for research group leaders are given
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