5,935 research outputs found

    Cloxacillin-Resistant Staphylococcus aureus in a Children's Hospital

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    A group of cultures of cloxacillin-resistant Staphylococcus aureus was collected over a period of 6 months. The method of determination of resistance to cloxacillin is described. The use of the disc diffusion test for cloxacillin was found to be unsatisfactory. The incidence of cloxacillin-resistant Staph. aureus at the Red Cross War Memorial Children's Hospital (inpatients as well as outpatients) is slightly less than 2% of all isolates of Staph. aureus. Of the total non-White ward patients with penicillin-resistant Staph. aureus infections, 6,5% have staphylococci resistant to cloxacillin. Reaction of these isolates to Fucidin, c1indamycin and erythromycin is described.S. Afr. Med. J., 48, 1341 (1974)

    Seasonal phosphorus and carbon dynamics in a temperate shelf sea (Celtic Sea): uptake, partitioning, release, turnover and stoichiometry.

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    The seasonal cycle of resource availability in shelf seas has a strong selective pressure on phytoplankton diversity and the biogeochemical cycling of key elements, such as carbon (C) and phosphorus (P). Shifts in carbon consumption relative to P availability, via changes in cellular stoichiometry for example, can lead to an apparent ‘excess’ of carbon production. We made measurements of inorganic P (Pi) uptake, in parallel to C-fixation, by plankton communities in the Celtic Sea (NW European Shelf) in spring (April 2015), summer (July 2015) and autumn (November 2014). Short-term (< 8 h) Pi-uptake coupled with dissolved organic phosphorus (DOP) release, in parallel to net (24 h) primary production (NPP), were all measured across an irradiance gradient designed to typify vertically and seasonally varying light conditions. Rates of Pi-uptake were highest during spring and lowest in the low light conditions of autumn, although biomass-normalised Pi-uptake was highest in the summer. The release of DOP was highest in November and declined to low levels in July, indicative of efficient utilization and recycling of the low levels of Pi available. Examination of daily turnover times of the different particulate pools, including estimates of phytoplankton and bacterial carbon, indicated a differing seasonal influence of autotrophs and heterotrophs in P-dynamics, with summer conditions associated with a strong bacterial influence and the early spring period with fast growing phytoplankton. These seasonal changes in autotrophic and heterotrophic influence, coupled with changes in resource availability (Pi, light) resulted in seasonal changes in the stoichiometry of NPP to daily Pi-uptake (C:P ratio); from relatively C-rich uptake in November and late April, to P-rich uptake in early April and July. Overall, these results highlight the seasonally varying influence of both autotrophic and heterotrophic components of shelf sea ecosystems on the relative uptake of C and P

    Scavenger 0.1: A Theorem Prover Based on Conflict Resolution

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    This paper introduces Scavenger, the first theorem prover for pure first-order logic without equality based on the new conflict resolution calculus. Conflict resolution has a restricted resolution inference rule that resembles (a first-order generalization of) unit propagation as well as a rule for assuming decision literals and a rule for deriving new clauses by (a first-order generalization of) conflict-driven clause learning.Comment: Published at CADE 201

    Seasonal and spatial variability in the optical characteristics of DOM in a temperate shelf sea

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    The Celtic Sea is a productive temperate sea located on the Northwest European Shelf. It is an important pathway for the delivery of land-derived material to the North Atlantic Ocean, including dissolved organic matter (DOM). The aim of this study was to determine the seasonal and spatial variability in the magnitude, source and composition of DOM at three sites representing on shelf, central shelf and shelf edge regions in the Celtic Sea, using observations collected during the UK Shelf Sea Biogeochemistry (SSB) research programme (November 2014 – August 2015). The concentration of dissolved organic carbon (DOC) alongside DOM absorbance and fluorescence indices were measured and fluorescence Excitation and Emission Matrices (EEMs) combined with Parallel Factor Analysis (PARAFAC) were used to assess DOM composition and lability. The PARAFAC model identified four unique fluorescent components for autumn (November 2014), winter (March 2015), spring (April 2015) and summer (July 2015) consisting of two humic-like components attributed to terrestrial (C1) and marine sources (C2), and two protein components identified as tyrosine-like (C3) and tryptophan-like (C4) attributed to in situ production. DOC varied seasonally and there were strong cross shelf trends. The protein components (C3 and C4) exhibited large seasonal and within season variability particularly during productive periods. In contrast, there were persistent cross shelf gradients in the CDOM absorption coefficient at 305 nm (a305), the UV specific absorbance at 280 nm (SUVA280), the humification index (HIX), and the humic-like fluorescent components (C1 and C2), which were higher in the on shelf region and decreased towards the shelf edge. The humic-like components and the slope ratio (SR) were significantly correlated with salinity throughout all seasons, indicating a strong influence of terrestrially-derived organic matter in the Celtic Sea, with potentially up to 35% of DOC in the central shelf during winter originating from terrestrial inputs. Results from this study illustrate the importance of monitoring DOM quantitatively and qualitatively for a better understanding of the supply, production, cycling and export of this dynamic organic carbon pool in shelf seas

    Engaging Stigmatised Communities in Australia with Digital Health Systems: Towards Data Justice in Public Health

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    Introduction: In 2018, following government policy changes to Australia’s national electronic health record system, ‘My Health Record’, consumer advocates—including organisations representing people living with HIV, people who use drugs and sex workers—raised concerns about privacy and data security. Responding to these controversies, this study explores the practical, ethical and political complexities of engaging stigmatised communities with digital health systems. Methods: We conducted 16 qualitative semi-structured interviews in 2020 with key informants representing communities who experience stigma, discrimination and marginalisation in Australia. These communities included people living with HIV, sex workers, people who inject drugs, gay and bisexual men and transgender and gender diverse people. We conducted a reflexive thematic analysis. Results: Key informants were sceptical of proposed benefits of electronic health records for their communities, and concerned about privacy risks and the potential for discrimination. Meaningful consultation, consent mechanisms and tackling structural stigma were raised as solutions for engaging communities. Conclusions: Although communities could benefit from being included in digital health systems, significant cultural, legal and social reforms from government were believed to be necessary to build trust in digital health systems. We argue that these forms of data justice are necessary for effective future systems. Policy Implications: Engaging stigmatised communities—including in relation to gender, sexuality, sex work, drug use, HIV—requires a commitment to data justice. The design and implementation of digital health systems requires investment in ongoing and meaningful consultation with communities and representative organisations

    The relationship between unsupervised time after school and physical activity in adolescent girls

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    BACKGROUND: Rising obesity and declining physical activity levels are of great concern because of the associated health risks. Many children are left unsupervised after the school day ends, but little is known about the association between unsupervised time and physical activity levels. This paper seeks to determine whether adolescent girls who are without adult supervision after school are more or less active than their peers who have a caregiver at home. METHODS: A random sample of girls from 36 middle schools at 6 field sites across the U.S. was selected during the fall of the 2002–2003 school year to participate in the baseline measurement activities of the Trial of Activity for Adolescent Girls (TAAG). Information was collected using six-day objectively measured physical activity, self-reported physical activity using a three-day recall, and socioeconomic and psychosocial measures. Complete information was available for 1422 out of a total of 1596 respondents. Categorical variables were analyzed using chi square and continuous variables were analyzed by t-tests. The four categories of time alone were compared using a mixed linear model controlling for clustering effects by study center. RESULTS: Girls who spent more time after school (≥2 hours per day, ≥2 days per week) without adult supervision were more active than those with adult supervision (p = 0.01). Girls alone for ≥2 hours after school, ≥2 days a week, on average accrue 7.55 minutes more moderate to vigorous physical activity (MVPA) per day than do girls who are supervised (95% confidence interval ([C.I]). These results adjusted for ethnicity, parent's education, participation in the free/reduced lunch program, neighborhood resources, or available transportation. Unsupervised girls (n = 279) did less homework (53.1% vs. 63.3%), spent less time riding in a car or bus (48.0% vs. 56.6%), talked on the phone more (35.5% vs. 21.1%), and watched more television (59.9% vs. 52.6%) than supervised girls (n = 569). However, unsupervised girls also were more likely to be dancing (14.0% vs. 9.3%) and listening to music (20.8% vs. 12.0%) (p < .05). CONCLUSION: Girls in an unsupervised environment engaged in fewer structured activities and did not immediately do their homework, but they were more likely to be physically active than supervised girls. These results may have implications for parents, school, and community agencies as to how to structure activities in order to encourage teenage girls to be more physically active

    A roadmap to realist interviews in health professions education research: Recommendations based on a critical analysis

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    This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: The data provided in this paper as part of the illustrative cases are not publicly available due to ethical constraints.CONTEXT: Realist evaluation is increasingly employed in health professions education research (HPER) because it can unpack the extent to which complex educational interventions work (or not), for whom under what circumstances and how. While realist evaluation is not wedded to particular methods, realist interviews are commonly the primary, if not only, data collection method in realist evaluations. While qualitative interviewing from an interpretivist standpoint has been well-articulated in the HPER literature, realist interviewing differs substantially. The former elicits participants' views and experiences of a topic of inquiry, whereas realist interviewing focuses on building, testing and/or refining programme theory. Therefore, this article aims to help readers better understand, conduct, report and critique realist interviews as part of realist evaluations. METHODS: In this paper, we describe what realist approaches are, what realist interviewing is and why realist interviewing matters. We outline five stages to realist interviewing (developing initial programme theory, realist sampling/samples, the interview itself, realist analysis and reporting realist interviews), drawing on two illustrative cases from our own realist evaluations employing interviewing to bring theory to life. We provide a critical analysis of 12 realist evaluations employing interviewing in the HPER literature. Alongside reporting standards, and our own realist interviewing experiences, this critical analysis of published articles serves to foreground our recommendations for realist interviewing. CONCLUSIONS: We encourage HPE researchers to consider realist interviews as part of realist evaluations of complex interventions. Our critical analysis reveals that realist interviews can provide unique insights into HPE, but authors now need to report their sampling approach, type of interviewing and interview questions more explicitly. Studies should also more explicitly draw on existing realist interviewing literature and follow reporting guidelines for realist evaluations. We hope this paper provides a useful roadmap to conducting, reporting and critically appraising realist interviews in HPER

    Evaluation of the impact of a school gardening intervention on children's fruit and vegetable intake: a randomised controlled trial.

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    Background: Current academic literature suggests that school gardening programmes can provide an interactive environment with the potential to change children’s fruit and vegetable intake. This is the first cluster randomised controlled trial (RCT) designed to evaluate whether a school gardening programme can have an effect on children’s fruit and vegetable intake. Methods: The trial included children from 23 schools; these schools were randomised into two groups, one to receive the Royal Horticultural Society (RHS)-led intervention and the other to receive the less involved Teacher-led intervention. A 24-hour food diary (CADET) was used to collect baseline and follow-up dietary intake 18 months apart. Questionnaires were also administered to evaluate the intervention implementation. Results: A total of 641 children completed the trial with a mean age of 8.1 years (95% CI: 8.0, 8.4). The unadjusted results from multilevel regression analysis revealed that for combined daily fruit and vegetable intake the Teacher-led group had a higher daily mean change of 8 g (95% CI: −19, 36) compared to the RHS-led group -32 g (95% CI: −60, −3). However, after adjusting for possible confounders this difference was not significant (intervention effect: −40 g, 95% CI: −88, 1; p = 0.06). The adjusted analysis of process measures identified that if schools improved their gardening score by 3 levels (a measure of school gardening involvement - the scale has 6 levels from 0 ‘no garden’ to 5 ‘community involvement’), irrespective of group allocation, children had, on average, a daily increase of 81 g of fruit and vegetable intake (95% CI: 0, 163; p = 0.05) compared to schools that had no change in gardening score. Conclusions: This study is the first cluster randomised controlled trial designed to evaluate a school gardening intervention. The results have found very little evidence to support the claims that school gardening alone can improve children’s daily fruit and vegetable intake. However, when a gardening intervention is implemented at a high level within the school it may improve children’s daily fruit and vegetable intake by a portion. Improving children’s fruit and vegetable intake remains a challenging task

    The increase of the functional entropy of the human brain with age

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    We use entropy to characterize intrinsic ageing properties of the human brain. Analysis of fMRI data from a large dataset of individuals, using resting state BOLD signals, demonstrated that a functional entropy associated with brain activity increases with age. During an average lifespan, the entropy, which was calculated from a population of individuals, increased by approximately 0.1 bits, due to correlations in BOLD activity becoming more widely distributed. We attribute this to the number of excitatory neurons and the excitatory conductance decreasing with age. Incorporating these properties into a computational model leads to quantitatively similar results to the fMRI data. Our dataset involved males and females and we found significant differences between them. The entropy of males at birth was lower than that of females. However, the entropies of the two sexes increase at different rates, and intersect at approximately 50 years; after this age, males have a larger entropy
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