2,079 research outputs found

    Questioning Classic Patient Classification Techniques in Gait Rehabilitation: Insights from Wearable Haptic Technology

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    Classifying stroke survivors based on their walking abilities is an important part of the gait rehabilitation process. It can act as powerful indicator of function and prognosis in both the early days after a stroke and long after a survivor receives rehabilitation. This classification often relies solely on walking speed; a quick and easy measure, with only a stopwatch needed. However, walking speed may not be the most accurate way of judging individual’s walking ability. Advances in technology mean we are now in a position where ubiquitous and wearable technologies can be used to elicit much richer measures to characterise gait. In this paper we present a case study from one of our studies, where within a homogenous group of stroke survivors (based on walking speed classification) important differences in individual results and the way they responded to rhythmic haptic cueing were identified during the piloting of a novel gait rehabilitation technique

    Vascular tissue contractility changes following late gestational exposure to multi-walled carbon nanotubes or their dispersing vehicle in Sprague Dawley rats

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    Multi-walled carbon nanotubes (MWCNTs) are increasingly used in industry and in nanomedicine raising safety concerns, especially during unique life-stages such as pregnancy. We hypothesized that MWCNT exposure during pregnancy will increase vascular tissue contractile responses by increasing Rho kinase signaling. Pregnant (17-19 gestational days) and non-pregnant Sprague Dawley rats were exposed to 100 μg/kg of MWCNTs by intratracheal instillation or intravenous administration. Vasoactive responses of uterine, mesenteric, aortic and umbilical vessels were studied 24 hours post-exposure by wire myography. The contractile responses of the vessel segments were different between the pregnant and non-pregnant rats, following MWCNT exposure. Maximum stress generation in the uterine artery segments from the pregnant rats following pulmonary MWCNT exposure was increased in response to angiotensin II by 4.9 mN/mm2 (+118%), as compared to the naïve response and by 2.6 mN/mm2 (+40.7%) as compared to the vehicle exposed group. Following MWCNT exposure, serotonin induced approximately 4 mN/mm2 increase in stress generation of the mesenteric artery from both pregnant and non-pregnant rats as compared to the vehicle response. A significant contribution of the dispersion medium was identified as inducing changes in the contractile properties following both pulmonary and intravenous exposure to MWCNTs. Wire myographic studies in the presence of a Rho kinase inhibitor and RhoA and Rho kinase mRNA/protein expression of rat aortic endothelial cells were unaltered following exposure to MWCNTs, suggesting absent/minimal contribution of Rho kinase to the enhanced contractile responses following MWCNT exposure. The reactivity of the umbilical vein was not changed; however, mean fetal weight gain was reduced with dispersion media and MWCNT exposure by both routes. These results suggest a susceptibility of the vasculature during gestation to MWCNT and their dispersion media-induced vasoconstriction, predisposing reduced fetal growth during pregnancy

    A Note on Encodings of Phylogenetic Networks of Bounded Level

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    Driven by the need for better models that allow one to shed light into the question how life's diversity has evolved, phylogenetic networks have now joined phylogenetic trees in the center of phylogenetics research. Like phylogenetic trees, such networks canonically induce collections of phylogenetic trees, clusters, and triplets, respectively. Thus it is not surprising that many network approaches aim to reconstruct a phylogenetic network from such collections. Related to the well-studied perfect phylogeny problem, the following question is of fundamental importance in this context: When does one of the above collections encode (i.e. uniquely describe) the network that induces it? In this note, we present a complete answer to this question for the special case of a level-1 (phylogenetic) network by characterizing those level-1 networks for which an encoding in terms of one (or equivalently all) of the above collections exists. Given that this type of network forms the first layer of the rich hierarchy of level-k networks, k a non-negative integer, it is natural to wonder whether our arguments could be extended to members of that hierarchy for higher values for k. By giving examples, we show that this is not the case

    The DNA methylome of human sperm is distinct from blood with little evidence for tissue-consistent obesity associations

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    Epidemiological research suggests that paternal obesity may increase the risk of fathering small for gestational age offspring. Studies in non-human mammals indicate that such associations could be mediated by DNA methylation changes in spermatozoa that influence offspring development in utero. Human obesity is associated with differential DNA methylation in peripheral blood. It is unclear, however, whether this differential DNA methylation is reflected in spermatozoa. We profiled genome-wide DNA methylation using the Illumina MethylationEPIC array in a cross-sectional study of matched human blood and sperm from lean (discovery n = 47; replication n = 21) and obese (n = 22) males to analyse tissue covariation of DNA methylation, and identify obesity-associated methylomic signatures. We found that DNA methylation signatures of human blood and spermatozoa are highly discordant, and methylation levels are correlated at only a minority of CpG sites (~1%). At the majority of these sites, DNA methylation appears to be influenced by genetic variation. Obesity-associated DNA methylation in blood was not generally reflected in spermatozoa, and obesity was not associated with altered covariation patterns or accelerated epigenetic ageing in the two tissues. However, one cross-tissue obesity-specific hypermethylated site (cg19357369; chr4:2429884; P = 8.95 × 10^{-8}; 2% DNA methylation difference) was identified, warranting replication and further investigation. When compared to a wide range of human somatic tissue samples (n = 5,917), spermatozoa displayed differential DNA methylation across pathways enriched in transcriptional regulation. Overall, human sperm displays a unique DNA methylation profile that is highly discordant to, and practically uncorrelated with, that of matched peripheral blood. We observed that obesity was only nominally associated with differential DNA methylation in sperm, and therefore suggest that spermatozoal DNA methylation is an unlikely mediator of intergenerational effects of metabolic traits

    Multi-membership gene regulation in pathway based microarray analysis

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    This article is available through the Brunel Open Access Publishing Fund. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Gene expression analysis has been intensively researched for more than a decade. Recently, there has been elevated interest in the integration of microarray data analysis with other types of biological knowledge in a holistic analytical approach. We propose a methodology that can be facilitated for pathway based microarray data analysis, based on the observation that a substantial proportion of genes present in biochemical pathway databases are members of a number of distinct pathways. Our methodology aims towards establishing the state of individual pathways, by identifying those truly affected by the experimental conditions based on the behaviour of such genes. For that purpose it considers all the pathways in which a gene participates and the general census of gene expression per pathway. Results: We utilise hill climbing, simulated annealing and a genetic algorithm to analyse the consistency of the produced results, through the application of fuzzy adjusted rand indexes and hamming distance. All algorithms produce highly consistent genes to pathways allocations, revealing the contribution of genes to pathway functionality, in agreement with current pathway state visualisation techniques, with the simulated annealing search proving slightly superior in terms of efficiency. Conclusions: We show that the expression values of genes, which are members of a number of biochemical pathways or modules, are the net effect of the contribution of each gene to these biochemical processes. We show that by manipulating the pathway and module contribution of such genes to follow underlying trends we can interpret microarray results centred on the behaviour of these genes.The work was sponsored by the studentship scheme of the School of Information Systems, Computing and Mathematics, Brunel Universit

    Prepared to practice? Perception of career preparation and guidance of recent medical graduates at two campuses of a transnational medical school: a cross-sectional study.

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    BACKGROUND: Graduating medical students enter the workforce with substantial medical knowledge and experience, yet little is known about how well they are prepared for the transition to medical practice in diverse settings. We set out to compare perceptions of medical school graduates\u27 career guidance with their perceptions of preparedness to practice as interns. We also set out to compare perceptions of preparedness for hospital practice between graduates from two transnational medical schools. METHODS: This was a cross-sectional study. A Preparedness for Hospital Practice (PHPQ) survey and career guidance questionnaire was sent to recent medical graduates, incorporating additional free text responses on career preparation. Data was analyzed using descriptive statistics and tests of association including Chi-square, Mann-Whitney U and Kruskal-Wallis H tests. RESULTS: Forty three percent (240/555) of graduates responded to the survey: 39 % of respondents were domestic (Dublin, Ireland or Manama, Kingdom of Bahrain) and interning locally; 15 % were overseas students interning locally; 42 % were overseas students interning internationally and 4 % had not started internship. Two variables explained 13 % of the variation in preparedness for hospital practice score: having planned postgraduate education prior to entering medical school and having helpful career guidance in medical school. Overseas graduates interning internationally were more likely to have planned their postgraduate career path prior to entering medical school. Dublin graduates found their career guidance more helpful than Bahrain counterparts. The most cited shortcomings were lack of structured career advice and lack of advice on the Irish and Bahraini postgraduate systems. CONCLUSIONS: This study has demonstrated that early consideration of postgraduate career preparation and helpful medical school career guidance has a strong association with perceptions of preparedness of medical graduates for hospital practice. In an era of increasing globalization of medical education, these findings can direct ongoing efforts to ensure all medical students receive career guidance and preparation for internship appropriate to their destination

    Statistical Inference for Valued-Edge Networks: Generalized Exponential Random Graph Models

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    Across the sciences, the statistical analysis of networks is central to the production of knowledge on relational phenomena. Because of their ability to model the structural generation of networks, exponential random graph models are a ubiquitous means of analysis. However, they are limited by an inability to model networks with valued edges. We solve this problem by introducing a class of generalized exponential random graph models capable of modeling networks whose edges are valued, thus greatly expanding the scope of networks applied researchers can subject to statistical analysis

    Reaction of rat connective tissue to mineral trioxide aggregate and diaket

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to compare the reaction of rat connective tissue to two root-end filling materials: white Mineral Trioxide Aggregate (WMTA) and Diaket.</p> <p>Methods</p> <p>Each of the materials was placed in dentine tubes and implanted subcutaneously in the dorsal connective tissue of 21 Wistar albino rats. Tissue biopsies were collected 7, 30, and 60 days after the implantation procedure. The specimens were processed and stained with hematoxylin and eosin and examined microscopically. After determining inflammatory cell numbers in sections from each specimen, inflammatory reaction scores were defined as follows: 0; no or few inflammatory cells (no reaction), 1; less than 25 cells (mild reaction), 2; 25 to 125 cells, (moderate reaction), and 3; 125 or more cells (severe reaction). Statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney tests.</p> <p>Results</p> <p>There were statistically significant differences in the median inflammatory cell numbers throughout the three test periods, with the most severe degree of inflammation observed at the one-week period. Few cases of necrosis were observed with WMTA. Diaket exhibited the most severe degree of inflammation and necrosis. After 30 days, both materials provoked moderate inflammatory reaction. The eight-week period showed the least severe degree of inflammation in all groups.</p> <p>Conclusions</p> <p>It was concluded that WMTA exhibits a more favourable tissue response compared with Diaket which induced more severe inflammatory reaction than WMTA and the control.</p

    Sequential Effects in Judgements of Attractiveness: The Influences of Face Race and Sex

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    In perceptual decision-making, a person’s response on a given trial is influenced by their response on the immediately preceding trial. This sequential effect was initially demonstrated in psychophysical tasks, but has now been found in more complex, real-world judgements. The similarity of the current and previous stimuli determines the nature of the effect, with more similar items producing assimilation in judgements, while less similarity can cause a contrast effect. Previous research found assimilation in ratings of facial attractiveness, and here, we investigated whether this effect is influenced by the social categories of the faces presented. Over three experiments, participants rated the attractiveness of own- (White) and other-race (Chinese) faces of both sexes that appeared successively. Through blocking trials by race (Experiment 1), sex (Experiment 2), or both dimensions (Experiment 3), we could examine how sequential judgements were altered by the salience of different social categories in face sequences. For sequences that varied in sex alone, own-race faces showed significantly less opposite-sex assimilation (male and female faces perceived as dissimilar), while other-race faces showed equal assimilation for opposite- and same-sex sequences (male and female faces were not differentiated). For sequences that varied in race alone, categorisation by race resulted in no opposite-race assimilation for either sex of face (White and Chinese faces perceived as dissimilar). For sequences that varied in both race and sex, same-category assimilation was significantly greater than opposite-category. Our results suggest that the race of a face represents a superordinate category relative to sex. These findings demonstrate the importance of social categories when considering sequential judgements of faces, and also highlight a novel approach for investigating how multiple social dimensions interact during decision-making

    Transfusion of fresh frozen plasma in non-bleeding ICU patients -TOPIC TRIAL: study protocol for a randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Fresh frozen plasma (FFP) is an effective therapy to correct for a deficiency of multiple coagulation factors during bleeding. In past years, use of FFP has increased, in particular in patients on the Intensive Care Unit (ICU), and has expanded to include prophylactic use in patients with a coagulopathy prior to undergoing an invasive procedure. Retrospective studies suggest that prophylactic use of FFP does not prevent bleeding, but carries the risk of transfusion-related morbidity. However, up to 50% of FFP is administered to non-bleeding ICU patients. With the aim to investigate whether prophylactic FFP transfusions to critically ill patients can be safely omitted, a multi-center randomized clinical trial is conducted in ICU patients with a coagulopathy undergoing an invasive procedure.</p> <p>Methods</p> <p>A non-inferiority, prospective, multicenter randomized open-label, blinded end point evaluation (PROBE) trial. In the intervention group, a prophylactic transfusion of FFP prior to an invasive procedure is omitted compared to transfusion of a fixed dose of 12 ml/kg in the control group. Primary outcome measure is relevant bleeding. Secondary outcome measures are minor bleeding, correction of International Normalized Ratio, onset of acute lung injury, length of ventilation days and length of Intensive Care Unit stay.</p> <p>Discussion</p> <p>The Transfusion of Fresh Frozen Plasma in non-bleeding ICU patients (TOPIC) trial is the first multi-center randomized controlled trial powered to investigate whether it is safe to withhold FFP transfusion to coagulopathic critically ill patients undergoing an invasive procedure.</p> <p>Trial Registration</p> <p>Trial registration: Dutch Trial Register NTR2262 and ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01143909">NCT01143909</a></p
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