2,654 research outputs found

    Exercises for improving quick perception grades I, II, III.

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    Thesis (Ed.M.)--Boston University N.B.: Page 242 is misnumbered. No content is missing from thesis

    Constrained and Unconstrained Maximum Likelihood Estimation of a Variance Components Model of Cross- Sections Pooled Over Time

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    The authors report on simulations on the quality of parameter estimates of regression coefficients with lagged variables. Results showed that the quality of estimates varied with the amount of serial error correlation and with the relative strength of effects of lagged variables. Estimates of the coefficient of an exogenous variable should be very similar by maximum likelihood estimates and modified generalized least squares. If they are not close to identical, an investigator should suspect misspecification of the model

    The nasal cavity microbiota of healthy adults

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    Abstract Background The microbiota of the nares has been widely studied. However, relatively few studies have investigated the microbiota of the nasal cavity posterior to the nares. This distinct environment has the potential to contain a distinct microbiota and play an important role in health. Results We obtained 35,142 high-quality bacterial 16S rRNA-encoding gene sequence reads from the nasal cavity and oral cavity (the dorsum of the tongue and the buccal mucosa) of 12 healthy adult humans and deposited these data in the Sequence Read Archive (SRA) of the National Center for Biotechnology Information (NCBI) (Bioproject: PRJNA248297). In our initial analysis, we compared the bacterial communities of the nasal cavity and the oral cavity from ten of these subjects. The nasal cavity bacterial communities were dominated by Actinobacteria, Firmicutes, and Proteobacteria and were statistically distinct from those on the tongue and buccal mucosa. For example, the same Staphylococcaceae operational taxonomic unit (OTU) was present in all of the nasal cavity samples, comprising up to 55% of the community, but Staphylococcaceae was comparatively uncommon in the oral cavity. Conclusions There are clear differences between nasal cavity microbiota and oral cavity microbiota in healthy adults. This study expands our knowledge of the nasal cavity microbiota and the relationship between the microbiota of the nasal and oral cavities.http://deepblue.lib.umich.edu/bitstream/2027.42/109547/1/40168_2014_Article_56.pd

    Estimation in Panel Models: Results in Pooling Cross-Sections and Time Series

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    The authors describe methodological issues of panel analysis designs; in particular, autocorrelation of errors across waves. They recommend constructing a “pooled” model of data from all waves to deal with design and estimation problems, and present results from a simulation of the behavior of alternate estimators for pooled models

    A reverse metabolic approach to weaning: in silico identification of immune-beneficial infant gut bacteria, mining their metabolism for prebiotic feeds and sourcing these feeds in the natural product space

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    Weaning is a period of marked physiological change. The introduction of solid foods and the changes in milk consumption are accompanied by significant gastrointestinal, immune, developmental, and microbial adaptations. Defining a reduced number of infections as the desired health benefit for infants around weaning, we identified in silico (i.e., by advanced public domain mining) infant gut microbes as potential deliverers of this benefit. We then investigated the requirements of these bacteria for exogenous metabolites as potential prebiotic feeds that were subsequently searched for in the natural product space

    Investigation of free-living honey bee colonies in Ireland

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    Apis mellifera mellifera (Linnaeus), the Western European honey bee, is considered extinct in the wild over most of its range due largely to hybridisation and replacement by other subspecies, parasitism by Varroa destructor, habitat loss, and effects from agricultural pesticides. The purity of the subspecies within the managed cohort is also at risk over much of its range. Here, we investigated if honey bee colonies inhabited locations outside of the apiaries. In those we located, we explored how long the colony persisted and we investigated the genotypes of the bees using multiple markers. We show here that unmanaged free-living honey bee colonies are present and widespread in Ireland, inhabiting a mixture of nesting habitats with some colonies persisting naturally and unaided over multiple years. Molecular data including mitochondrial, microsatellite, and SNPs evidence indicate that the free-living population sampled is largely comprised of pure A. m. mellifera. Finally, we discuss the implications of conserving free-living A. m. mellifera in Ireland and its possible role in improving the fitness of the managed population both in Ireland and the rest of its European range.We particularly thank the custodians of the free-living honey bee colonies and the Native Irish Honey Bee Society (NIHBS) for their assistance. KAB is a recipient of an Irish Research Council postgraduate fellowship (GOIPG/2015/2767) and a Tony Ryan Postgraduate fellowship. Additional funding was gratefully received from the Department of Agriculture, Food and the Marine [grant number GRGAS 16/GR/09], the Federation of Irish Beekeeping Associations, the Eva Crane Trust [grant number ECTA20160303] and The Native Irish Honey Bee Society. Financial support for DH was provided through the program COMPETE 2020 – POCI (Programa Operacional para a Competividade e Internacionalizac¸~ao) and by Portuguese funds through FCT (Fundac¸~ao para a Ci^encia e a Tecnologia) in the framework of the project BeeHappy (POCI-01-0145-FEDER-029871).info:eu-repo/semantics/publishedVersio

    Implementing a theory-based intradialytic exercise programme in practice: a quality improvement project

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    Background Research evidence outlines the benefits of intradialytic exercise (IDE), yet implementation into practice has been slow, ostensibly due to lack of patient and staff engagement. The aim of this quality improvement project was to improve patient outcomes via the introduction of an IDE programme; evaluate patient uptake, sustainability and enhance the engagement of routine haemodialysis (HD) staff with the delivery of the IDE programme. Methods We developed and refined an IDE programme, including interventions designed to increase patient and staff engagement that were based upon the Theoretical Domains Framework, using a series of ‘Plan, Do, Study, Act’ cycles. The programme was introduced at two UK NHS HD units. Process measures included patient uptake, withdrawals, adherence and HD staff involvement. Outcomes measures were patient-reported functional capacity, anxiety, depression and symptomology. All measures were collected over 12 months. Results 95 patients enrolled in the IDE programme. 64 (75%) were still participating at three months, dropping to 41 (48%) at 12 months. Adherence was high (78%) at three months, dropping to 63% by 12 months. Provision of IDE by HD staff accounted for a mean of 2 (5%) sessions per three-month time point. Patients displayed significant improvements in functional ability (p=0.01), and reduction in depression (p=0.02) over 12 months, but effects seen were limited to those who completed the programme. Conclusions A theory-based IDE programme is feasible and leads to improvement in functional capacity and depression. Sustaining IDE over time is marred by high levels of patient withdrawal from the programme. Significant change at an organisational level is required to enhance sustainability by increasing HD staff engagement or access to exercise professional support

    Evaluation of cataract formation in fish exposed to environmental radiation at Chernobyl and Fukushima

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    Recent studies apparently finding deleterious effects of radiation exposure on cataract formation in birds and voles living near Chernobyl represent a major challenge to current radiation protection regulations. This study conducted an integrated assessment of radiation exposure on cataractogenesis using the most advanced technologies available to assess the cataract status of lenses extracted from fish caught at both Chernobyl in Ukraine and Fukushima in Japan. It was hypothesised that these novel data would reveal positive correlations between radiation dose and early indicators of cataract formation.The structure, function and optical properties of lenses were analysed from atomic to millimetre length scales. We measured the short-range order of the lens crystallin proteins using Small Angle X-Ray Scattering (SAXS) at both the SPring-8 and DIAMOND synchrotrons, the profile of the graded refractive index generated by these proteins, the epithelial cell density and organisation and finally the focal length of each lens.The results showed no evidence of a difference between the focal length, the epithelial cell densities, the refractive indices, the interference functions and the short-range order of crystallin proteins (X-ray diffraction patterns) in lens from fish exposed to different radiation doses. It could be argued that animals in the natural environment which developed cataract would be more likely, for example, to suffer predation leading to survivor bias. But the cross-length scale study presented here, by evaluating small scale molecular and cellular changes in the lens (pre-cataract formation) significantly mitigates against this issue
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