119 research outputs found

    Interactions between microbial community structure and pathogen survival in soil

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    Manure and slurry are valuable resources that may enhance many soil properties. However, organic amendments can pose a significant health risk to both humans and livestock if not managed correctly due to pathogenic loads that may be carried within them. Therefore it is crucial to identify the factors that affect pathogen survival in soil, in order to gain maximum benefit from such resources, whilst minimising the threat to public and animal welfare. This research aimed to elucidate the impact of microbial community structure on pathogen decline following entry of such organisms into the soil. It was hypothesised that pathogen survival would be significantly influenced by both diversity and phenotypic configuration of the microbial community. This was experimentally investigated within three distinctly different biological contexts. Firstly, it was shown that the survival of Escherichia coli 0157 was significantly affected by the presence of an intact microbial community. Microcosms consisting of sterile and non-sterile sand and clay soils were inoculated with E. coli and destructively sampled over time. The pathogen remained stable at 4°C, irrespective of biological status. However at 18°C, the pathogen grew in sterile soil and declined in non-sterile soil. This result was attributed to microbial antagonism in non-sterile soil, which only became apparent at 18°C, due to increased metabolic activity of the native community. The next experiment was designed to investigate the impact of microbial diversity and community configuration on the survival of a suite of model pathogens. A gradient of community complexity was created by inoculation of gamma-irradiated soil mesocosms with a serial-dilution of a suspension of a field soil. Soils were incubated to allow biomass equilibration and the establishment of distinct community phenotypes. Sub-samples were then inoculated with Listeria, Salmonella and E. coli strains and survival was monitored over 160 days. Death rates were calculated and plotted as a function of dilution, which represented diversity, and of principal component (PC) scores from PLFA profiles, which represented the phenotypic community context. There was some evidence of a diversity effect as weak negative linear correlations were observed between death rate and dilution for S. Dublin and environmentally-persistent E. coli. However, a much stronger correlation was observed between death rate and certain PC scores for these organisms. No effect of diversity or phenotype was detected on either L. monocytogenes or E. coli 0157. These results suggest that pathogen survival was affected by diversity, but the phenotypic community context was apparently much more influential. Additionally, such community effects were specific to pathogen type. Pathogen survival was also investigated in the context of highly-contrasting communities within a range of naturally-derived field soils. PLFA analysis was used to determine phenotypic community structure and soils were also characterized for a range of physico-chemical properties. They were inoculated with Listeria, Salmonella and E. coli strains as above. Pathogen survival was monitored over 110 days and death rates were calculated. Physicochemical and biotic data, including PC scores derived from PLFA profiles, were used in stepwise regression analysis to determine the predominant factor influencing pathogen-specific death rates. PC scores were identified as the most significant factor in pathogen decay for all organisms tested, with the exception of an environmentally-persistent E. coli isolate. Overall, these results demonstrate the importance of soil biological quality, specifically the configuration of the microbial community, in pathogen suppression, and provide a possible means to assess the inherent potential of soils to regulate pathogen survival. This may lead to the identification of management strategies which will ultimately accelerate pathogen decay, and therefore improve the safety of agricultural practice.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Screening for low energy availability in male athletes : Attempted validation of LEAM-Q

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    A questionnaire-based screening tool for male athletes at risk of low energy availability (LEA) could facilitate both research and clinical practice. The present options rely on proxies for LEA such screening tools for disordered eating, exercise dependence, or those validated in female athlete populations. in which the female-specific sections are excluded. To overcome these limitations and support progress in understanding LEA in males, centres in Australia, Norway, Denmark, and Sweden collaborated to develop a screening tool (LEAM-Q) based on clinical investigations of elite and sub-elite male athletes from multiple countries and ethnicities, and a variety of endurance and weight-sensitive sports. A bank of questions was developed from previously validated questionnaires and expert opinion on various clinical markers of LEA in athletic or eating disorder populations, dizziness, thermoregulation, gastrointestinal symptoms, injury, illness, wellbeing, recovery, sleep and sex drive. The validation process covered reliability, content validity, a multivariate analysis of associations between variable responses and clinical markers, and Receiver Operating Characteristics (ROC) curve analysis of variables, with the inclusion threshold being set at 60% sensitivity. Comparison of the scores of the retained questionnaire variables between subjects classified as cases or controls based on clinical markers of LEA revealed an internal consistency and reliability of 0.71. Scores for sleep and thermoregulation were not associated with any clinical marker and were excluded from any further analysis. Of the remaining variables, dizziness, illness, fatigue, and sex drive had sufficient sensitivity to be retained in the questionnaire, but only low sex drive was able to distinguish between LEA cases and controls and was associated with perturbations in key clinical markers and questionnaire responses. In summary, in this large and international cohort, low sex drive was the most effective self-reported symptom in identifying male athletes requiring further clinical assessment for LEA

    Effect of low energy diet for eight weeks to adults with overweight or obesity on folate, retinol, vitamin B<sub>12</sub>, D and e status and the degree of inflammation: a post hoc analysis of a randomized intervention trial

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    Abstract Background Obesity is associated with vitamin insufficiency and low grade inflammation. The purpose of this study was to investigate the effect of weight loss on folate, retinol, vitamin B12, D and E status and the degree of inflammation. Methods Out of 110, 85 individuals (75% women) aged 39 ± 11 years with a mean ± SD BMI of 33 ± 4 kg/m2, completed an eight-week low energy diet (LED). Serum concentration of folate, retinol, B12, D and E and C-reactive protein and homocysteine (Hcy) were measured at baseline and at end of the LED. Results At baseline, 8% of the participants were deficient in folate, 13% in vitamin B12, 2% in retinol, 28% in vitamin D (72% were insufficient in vitamin D), and none were deficient in vitamin E. At baseline, BMI was inversely associated with retinol (P < 0.05) as was total and abdominal fat percentage with folate (P < 0.05); further BMI and measures of adiposity were positively associated with CRP (P < 0.01) and Hcy (P < 0.05). Homocysteine was inversely associated with all vitamins but retinol (P < 0.001). After the LED, the participants lost a mean [95% confidence intervals] of 12.3 [− 13.1,-11.6] kg. The serum concentration of folate, vitamin B12 and D were increased (P < 0.001) after the LED whereas the concentration of retinol and vitamin E were reduced (P < 0.001). Conclusion Eight-weeks LED resulted in 13% weight loss and an increase in the serum concentrations of folate, vitamin B12 and D. Baseline adiposity was inversely associated with folate and retinol, and positively associated with markers of inflammation. Trial registration Ethical Committee of Copenhagen as no. H-4-2013-135, NCT01561131

    The role of leptin and other hormones related to bone metabolism and appetite regulation as determinants of gain in body fat and fat-free mass in 8-11-year-old children.

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    BACKGROUND: Regulation of body composition during childhood is complex. Numerous hormones are potentially involved. Leptin has been proposed to restrain weight gain, but results are inconsistent. OBJECTIVE: We examined whether baseline fasting levels of ghrelin, adiponectin, leptin, insulin, IGF-I, osteocalcin, and intact parathyroid hormone (iPTH) were associated with body composition cross sectionally and longitudinally in 633 8-11-year-olds. DESIGN: Data on hormones and body composition by dual-energy x-ray absorptiometry from the OPUS School Meal Study were used. We looked at baseline hormones as predictors of baseline fat mass index (FMI) or fat-free mass index (FFMI), and also subsequent changes (3 and 6 months) in FMI or FFMI using models with hormones individually or combined. RESULTS: Cross-sectionally, baseline leptin was positively associated with FMI in girls (0.211 kg/m(2) pr. Îźg/mL; 97.5% confidence interval [CI],0.186-0.236; P < .001) and boys (0.231 kg/m(2) pr. Îźg/mL; 97.5% CI, 0.200-0.261; P < .001). IGF-I in both sexes and iPTH in boys were positively associated with FMI. An inverse association between adiponectin and FFMI in boys and a positive association between IGF-I and FFMI were found in girls. In longitudinal models, baseline leptin was inversely associated with subsequent changes in FMI (-0.018 kg/m(2) pr. Îźg/mL; 97.5% CI, -0.034 - -0.002; P = .028) and FFMI (-0.014 kg/m(2) pr. Îźg/mL; 97.5% CI, -0.024 - -0.003; P = .006) in girls. CONCLUSIONS: Cross-sectional findings support that leptin is produced in proportion to body fat mass, but the longitudinal observations support that leptin inhibits gains in FMI and FFMI in girls, a finding that may reflect preserved leptin sensitivity in this predominantly normal weight population.Address all correspondence and requests for reprints to: Stine-Mathilde Dalskov, Department of Nutrition, Exercise and Sports, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark. E-mail: [email protected]. This study was registered inClinicalTrials.gov as trial number NCT01457794. The OPUS study was financed by a Grant from the Nordea Foundation (grant number 02-2010-478 0389). A complete list of food suppliers providing full or partial food sponsorships to the study can be found at the website: http://foodoflife.ku.dk/ opus/wp/skolemadsprojektet/leverandorer. Sources of funding and donation had no role in the trial design; collection, analysis, interpretation of data or decision to publish.This is the accepted manuscript for a paper published in Journal of Clinical Endocrinology and Metabolism, March 2015, 100(3):1196 –1205, DOI: 10.1210/jc.2014-370

    A Prospective Open Trial of Guanfacine in Children with Pervasive Developmental Disorders

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    Objective: A common complaint for children with pervasive developmental disorder (PDD) is hyperactivity. The purpose of this pilot study was to gather preliminary information on the efficacy of guanfacine in children with PDD and hyperactivity. Methods: Children with PDD accompanied by hyperactivity entered the open-label trial if there was a recent history of failed treatment with methylphenidate or the child did not improve on methylphenidate in a multisite, placebo-controlled trial. Results: Children (23 boys and 2 girls) with a mean age of 9.03 (±3.14) years entered the open-label trial. After 8 weeks of treatment, the parent-rated Hyperactivity subscale of the Aberrant Behavior Checklist (ABC) went from a mean of 31.3 (±8.89) at baseline to 18.9 (±10.37) (effect size = 1.4; p < 0.001). The teacher-rated Hyperactivity subscale decreased from a mean of 29.9 (±9.12) at baseline to 22.3 (±9.44) (effect size = 0.83; p < 0.01). Twelve children (48%) were rated as Much Improved or Very Much Improved on the Clinical Global Impressions– Improvement. Doses ranged from 1.0 to 3.0 mg/day in two or three divided doses. Common adverse effects included irritability, sedation, sleep disturbance (insomnia or midsleep awakening), and constipation. Irritability led to discontinuation in 3 subjects. There were no significant changes in pulse, blood pressure, or electrocardiogram. Conclusions: Guanfacine may be useful for the treatment of hyperactivity in children with PDD. Placebocontrolled studies are needed to guide clinical practice

    地震防災計画策定における戦略的計画論の構造と論理

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    AbstractSufficient summer/autumn vitamin D status appears important to mitigate winter nadirs at northern latitudes. We conducted a cross-sectional study to evaluate autumn vitamin D status and its determinants in 782 Danish 8–11-year-old children (55°N) using baseline data from the Optimal well-being, development and health for Danish children through a healthy New Nordic Diet (OPUS) School Meal Study, a large randomised controlled trial. Blood samples and demographic and behavioural data, including 7-d dietary recordings, objectively measured physical activity, and time spent outdoors during school hours, were collected during September–November. Mean serum 25-hydroxyvitamin D (25(OH)D) was 60·8 (sd 18·7) nmol/l. Serum 25(OH)D levels ≤50 nmol/l were found in 28·4 % of the children and 2·4 % had concentrations &lt;25 nmol/l. Upon multivariate adjustment, increasing age (per year) (β −2·9; 95 % CI −5·1, −0·7 nmol/l), female sex (β −3·3; 95 % CI −5·9, −0·7 nmol/l), sampling in October (β −5·2; 95 % CI −10·1, −0·4 nmol/l) and November (β −13·3; 95 % CI −17·7, −9·1), and non-white ethnicity (β −5·7; 95 % CI −11·1, −0·3 nmol/l) were negatively associated with 25(OH)D (all P&lt;0·05). Likewise, immigrant/descendant background was negatively associated with 25(OH)D, particularly in females (β −16·3; 95 % CI −21·9, −10·7) (P&lt;0·001) (Pinteraction=0·003). Moderate-to-vigorous physical activity (MVPA) (min/d) (β 0·06; 95 % CI 0·01, 0·12), outdoor walking during school hours (min/week) (β 0·4; 95 % CI 0·1, 0·6) and intake of vitamin D-containing supplements ≥3 d/week (β 8·7; 95 % CI 6·4, 11·0) were positively associated with 25(OH)D (all P&lt;0·05). The high proportion of children with vitamin D status below the recommended sufficiency level of 50 nmol/l raises concern as levels expectedly drop further during winter months. Frequent intake of vitamin D supplements was strongly associated with status. MVPA and outdoor activity during school hours should be investigated further in interventions to improve autumn vitamin D status in children at northern latitudes.</jats:p

    Patient profiling for success after weight loss surgery (GO Bypass study):An interdisciplinary study protocol

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    Despite substantial research efforts, the mechanisms proposed to explain weight loss after gastric bypass (RYGB) and sleeve gastrectomy (SL) do not explain the large individual variation seen after these treatments. A complex set of factors are involved in the onset and development of obesity and these may also be relevant for the understanding of why success with treatments vary considerably between individuals. This calls for explanatory models that take into account not only biological determinants but also behavioral, affective and contextual factors. In this prospective study, we recruited 47 women and 8 men, aged 25–56 years old, with a BMI of 45.8 ± 7.1 kg/m2 from the waiting list for RYGB and SL at Køge hospital, Denmark. Pre-surgery and 1.5, 6 and 18 months after surgery we assessed various endpoints spanning multiple domains. Endpoints were selected on basis of previous studies and include: physiological measures: anthropometrics, vital signs, biochemical measures and appetite hormones, genetics, gut microbiota, appetite sensation, food and taste preferences, neural sensitivity, sensory perception and movement behaviors; psychological measures: general psychiatric symptom-load, depression, eating disorders, ADHD, personality disorder, impulsivity, emotion regulation, attachment pattern, general self-efficacy, alexithymia, internalization of weight bias, addiction, quality of life and trauma; and sociological and anthropological measures: sociodemographic measures, eating behavior, weight control practices and psycho-social factors.Joining these many endpoints and methodologies from different scientific disciplines and creating a multi-dimensional predictive model has not previously been attempted. Data on the primary endpoint are expected to be published in 2018. Trial registration: Clinicaltrials. gov ID NCT02070081. Keywords: Gastric bypass (RYGB), Sleeve gastrectomy, Weight loss, Interdisciplinary, Study protoco
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