1,198 research outputs found
Accidental Drownings are Predictable and Preventable
Drowning is the 3rd leading cause of unintentional injury-related death in the world for all age groups, with one third of fatal and nonfatal drownings occurring with the hours of 4pm and 8pm. This data slice gives helpful advice on how to stay safe while cooling off
The comprehensive cohort model in a pilot trial in orthopaedic trauma
Background: The primary aim of this study was to provide an estimate of effect size for the functional outcome of
operative versus non-operative treatment for patients with an acute rupture of the Achilles tendon using
accelerated rehabilitation for both groups of patients. The secondary aim was to assess the use of a
comprehensive cohort research design (i.e. a parallel patient-preference group alongside a randomised group) in
improving the accuracy of this estimate within an orthopaedic trauma setting.
Methods: Pragmatic randomised controlled trial and comprehensive cohort study within a level 1 trauma centre.
Twenty randomised participants (10 operative and 10 non-operative) and 29 preference participants (3 operative
and 26 non-operative). The ge range was 22-72 years and 37 of the 52 patients were men. All participants had an
acute rupture of their Achilles tendon and no other injuries. All of the patients in the operative group had a simple
end-to-end repair of the tendon with no augmentation. Both groups then followed the same eight-week
immediate weight-bearing rehabilitation programme using an off-the-shelf orthotic. The disability rating index (DRI;
primary outcome), EQ-5D, Achilles Total Rupture Score and complications were assessed ed at two weeks, six
weeks, three months, six months and nine months after initial injury.
Results: At nine months, there was no significant difference in DRI between patients randomised to operative or
non-operative management. There was no difference in DRI between the randomised group and the parallel
patient preference group. The use of a comprehensive cohort of patients did not provide useful additional
information as to the treatment effect size because the majority of patients chose non-operative management.
Conclusions: Recruitment to clinical trials that compare operative and non-operative interventions is notoriously
difficult; especially within the trauma setting. Including a parallel patient preference group to create a
comprehensive cohort of patients has been suggested as a way of increasing the power of such trials. In our
study, the comprehensive cohort model doubled the number of patients involved in the study. However, a strong
preference for non-operative treatment meant that the increased number of patients did not significantly increase
the ability of the trial to detect a difference between the two interventions
On neoclassical impurity transport in stellarator geometry
The impurity dynamics in stellarators has become an issue of moderate concern
due to the inherent tendency of the impurities to accumulate in the core when
the neoclassical ambipolar radial electric field points radially inwards (ion
root regime). This accumulation can lead to collapse of the plasma due to
radiative losses, and thus limit high performance plasma discharges in
non-axisymmetric devices.\\ A quantitative description of the neoclassical
impurity transport is complicated by the breakdown of the assumption of small
drift and trapping due to the electrostatic
potential variation on a flux surface compared to those due to
the magnetic field gradient. The present work examines the impact of this
potential variation on neoclassical impurity transport in the Large Helical
Device (LHD) stellarator. It shows that the neoclassical impurity transport can
be strongly affected by . The central numerical tool used is the
particle in cell (PIC) Monte Carlo code EUTERPE. The
used in the calculations is provided by the neoclassical code GSRAKE. The
possibility of obtaining a more general self-consistently with
EUTERPE is also addressed and a preliminary calculation is presented.Comment: 11 pages, 15 figures, presented at Joint Varenna-Lausanne
International Workshop on Theory of Fusion Plasmas, 2012. Accepted for
publication to Plasma Phys. and Control. Fusio
Systemic fungal endophytes and ploidy level in Festuca vivipara populations in North European Islands
Exploring the regional pattern of variation in traits driven by symbiotic interactions may provide insights to understand the evolutionary processes that operate over plant populations. Polyploidy, which is associated with fitness improvement, is expected to increase with latitude and altitude. However, it has never been explored in relation with the occurrence of epichloid fungal endophytes in plants. Both, variation in ploidy level and in the incidence of fungal endophytes, are known to occur in species of fine fescues. Here, we surveyed the occurrence of systemic fungal endophytes in natural Festuca vivipara populations in North European islands. In addition, we identified the fungal species associated with this grass and determined the predominant ploidy level for each population. Endophytes were found in four of six, two of three, and one of three populations for Faroe Islands, Iceland and Great Britain, respectively. With an average low incidence level of 15 % in infected populations, there was no relationship between infection level and either latitude or altitude. The phylogenetic analysis based on sequences ITS and the tub2 genes, supports that the endophytic species is EpichloA << festucae, the same as in other fine fescues. We found no variation in ploidy level as all the plants were tetraploid (4X) with 28 chromosomes, a pattern which contrasts with the variation reported in previous antecedents. Our results suggest that apart from low and variable benefits of the endophyte to the plants, there would be a complex dynamics between epichloid endophytes and species of the fine fescue complex which merits further studies.</p
A Bibliometric Study on Authorship Trends and Research Themes in Knowledge Management Literature
This is the author accepted manuscript. The final version is available from IFKAD via the link in this record.The aim of the study is to identify the contribution of authors in the domain of Knowledge Management (KM). The underlying data is from two leading KM journals, namely, the Journal of Knowledge Management (JKM) and the Journal of Intellectual
Capital (JIC). We downloaded articles from Thomson Reuters Web of Science (WoS),with JKM and JIC-specific searches resulting in 508 and 73 citing articles respectively. The timeframe of analysis was 2009-2016. This dataset was used to create co-citation network visualisations to provide insights into the clusters of authors and research topics. Measures such as Betweenness centrality and hubs-authorities (HITS) were used to identify significant authors and their key themes of interest. More specifically, network analysis identified six dominant research themes, it revealed a total of 14,422 authors
being cited (depicted as nodes in the visualisation) with a total of 1,023,123 citations (edges). Based on the findings of this study, the paper will explore the specific themes and the intellectual turning points in KM research and its evolution. Our bibliometric analysis has practical significance for researchers since it recognises the dominant research areas, and by extension, it identifies those that are still in their infancy; the latter having the potential of representing an interesting research gap. The limitation of the study is that the underlying data is only from two journals (albeit, from the top two journals in KM), which may lead to partially biased results. In future, the aim is to also leverage the analysis to more KM journals, e.g., the top ten journals within the Serenko & Bontis (2013) most updated list
Collisional damping rates for plasma waves
The distinction between the plasma dynamics dominated by collisional
transport versus collective processes has never been rigorously addressed until
recently. A recent paper [Yoon et al., Phys. Rev. E 93, 033203 (2016)]
formulates for the first time, a unified kinetic theory in which collective
processes and collisional dynamics are systematically incorporated from first
principles. One of the outcomes of such a formalism is the rigorous derivation
of collisional damping rates for Langmuir and ion-acoustic waves, which can be
contrasted to the heuristic customary approach. However, the results are given
only in formal mathematical expressions. The present Brief Communication
numerically evaluates the rigorous collisional damping rates by considering the
case of plasma particles with Maxwellian velocity distribution function so as
to assess the consequence of the rigorous formalism in a quantitative manner.
Comparison with the heuristic ("Spitzer") formula shows that the accurate
damping rates are much lower in magnitude than the conventional expression,
which implies that the traditional approach over-estimates the importance of
attenuation of plasma waves by collisional relaxation process. Such a finding
may have a wide applicability ranging from laboratory to space and
astrophysical plasmas.Comment: 5 pages, 2 figures; Published in Physics of Plasmas, volume/Issue
23/6. Publisher: AIP Publishing LLC. Date: Jun 1, 2016. URL:
http://aip.scitation.org/doi/10.1063/1.4953802 Rights managed by AIP
Publishing LL
Fast electron slowing-down and diffusion in a high temperature coronal X-ray source
Finite thermal velocity modifications to electron slowing-down rates may be important for the deduction of solar flare total electron energy. Here we treat both slowing-down and velocity diffusion of electrons in the corona at flare temperatures, for the case of a simple, spatially homogeneous source. Including velocity diffusion yields a consistent treatment of both "accelerated" and "thermal" electrons. It also emphasises that one may not invoke finite thermal velocity target effects on electron lifetimes without simultaneously treating the contribution to the observed X-ray spectrum from thermal electrons. We present model calculations of the X-ray spectra resulting from injection of a power-law energy distribution of electrons into a source with finite temperature. Reducing the power-law distribution low-energy cutoff to lower and lower energies only increases the relative magnitude of the thermal component of the spectrum, because the lowest energy electrons simply join the background thermal distribution. Acceptable fits to RHESSI flare data are obtained using this model. These also demonstrate, however, that observed spectra may in consequence be acceptably consistent with rather a wide range of injected electron parameters
Endophytic phyllosphere fungi and nutrient cycling in terrestrial ecosystems
The importance of phyllosphere fungi to ecosystem functioning via soil processes has aroused increasing interest during the last decade. Here, we briefly review the current knowledge of how the foliar endophytic fungi and nutrient cycling interact. Recent findings suggest that endophytes may affect plant litter quality, organisms that control litter decomposition and the availability of nutrients in plant communities. However, the results obtained so far are highly variable. We attempt to integrate these observations with the knowledge of ecology and life-history strategies of endophytic fungi, and highlight general rules and gaps in our knowledge. Finally, we suggest testable hypotheses for future studies.</p
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