370 research outputs found
Predicting mental imagery based BCI performance from personality, cognitive profile and neurophysiological patterns
Mental-Imagery based Brain-Computer Interfaces (MI-BCIs) allow their users to send commands
to a computer using their brain-activity alone (typically measured by ElectroEncephaloGraphy—
EEG), which is processed while they perform specific mental tasks. While very
promising, MI-BCIs remain barely used outside laboratories because of the difficulty
encountered by users to control them. Indeed, although some users obtain good control
performances after training, a substantial proportion remains unable to reliably control an
MI-BCI. This huge variability in user-performance led the community to look for predictors of
MI-BCI control ability. However, these predictors were only explored for motor-imagery
based BCIs, and mostly for a single training session per subject. In this study, 18 participants
were instructed to learn to control an EEG-based MI-BCI by performing 3 MI-tasks, 2
of which were non-motor tasks, across 6 training sessions, on 6 different days. Relationships
between the participants’ BCI control performances and their personality, cognitive
profile and neurophysiological markers were explored. While no relevant relationships with
neurophysiological markers were found, strong correlations between MI-BCI performances
and mental-rotation scores (reflecting spatial abilities) were revealed. Also, a predictive
model of MI-BCI performance based on psychometric questionnaire scores was proposed.
A leave-one-subject-out cross validation process revealed the stability and reliability of this
model: it enabled to predict participants’ performance with a mean error of less than 3
points. This study determined how users’ profiles impact their MI-BCI control ability and
thus clears the way for designing novel MI-BCI training protocols, adapted to the profile of
each user
Differences in allergen-induced T cell activation between allergic asthma and rhinitis: Role of CD28, ICOS and CTLA-4
<p>Abstract</p> <p>Background</p> <p>Th2 cell activation and T regulatory cell (Treg) deficiency are key features of allergy. This applies for asthma and rhinitis. However with a same atopic background, some patients will develop rhinitis and asthma, whereas others will display rhinitis only. Co-receptors are pivotal in determining the type of T cell activation, but their role in allergic asthma and rhinitis has not been explored. Our objective was to assess whether allergen-induced T cell activation differs from allergic rhinitis to allergic rhinitis with asthma, and explore the role of ICOS, CD28 and CTLA-4.</p> <p>Methods</p> <p>T cell co-receptor and cytokine expressions were assessed by flow cytometry in PBMC from 18 house dust mite (HDM) allergic rhinitics (R), 18 HDM allergic rhinitics and asthmatics (AR), 13 non allergic asthmatics (A) and 20 controls, with or without anti-co-receptors antibodies.</p> <p>Results</p> <p>In asthmatics (A+AR), a constitutive decrease of CTLA-4+ and of CD4+CD25+Foxp3+ cells was found, with an increase of IFN-γ+ cells. In allergic subjects (R + AR), allergen stimulation induced CD28 together with IL-4 and IL-13, and decreased the proportion of CTLA-4+, IL-10+ and CD4+CD25+Foxp3+ cells. Anti-ICOS and anti-CD28 antibodies blocked allergen-induced IL-4 and IL-13. IL-13 production also involved CTLA-4.</p> <p>Conclusions</p> <p>T cell activation differs between allergic rhinitis and asthma. In asthma, a constitutive, co-receptor independent, Th1 activation and Treg deficiency is found. In allergic rhinitis, an allergen-induced Treg cell deficiency is seen, as well as an ICOS-, CD28- and CTLA-4-dependent Th2 activation. Allergic asthmatics display both characteristics.</p
Dissociation by steroids of eosinophilic inflammation from airway hyperresponsiveness in murine airways
BACKGROUND: The link between eosinophils and the development of airway hyperresponsiveness (AHR) in asthma is still controversial. This question was assessed in a murine model of asthma in which we performed a dose ranging study to establish whether the dose of steroid needed to inhibit the eosinophil infiltration correlated with that needed to block AHR. METHODS: The sensitised BALB/c mice were dosed with vehicle or dexamethasone (0.01–3 mg/kg) 2 hours before and 6 hours after each challenge (once daily for 6 days) and 2 hours before AHR determination by whole-body plethysmography. At 30 minutes after the AHR to aerosolised methacholine the mice were lavaged and differential white cell counts were determined. Challenging with antigen caused a significant increase in eosinophils in the bronchoalveolar lavage (BAL) fluid and lung tissue, and increased AHR. RESULTS: Dexamethasone reduced BAL and lung tissue eosinophilia (ED(50 )values of 0.06 and 0.08 mg/kg, respectively), whereas a higher dose was needed to block AHR (ED(50 )of 0.32 mg/kg at 3 mg/ml methacholine. Dissociation was observed between the dose of steroid needed to affect AHR in comparison with eosinophilia and suggests that AHR is not a direct consequence of eosinophilia. CONCLUSION: This novel pharmacological approach has revealed a clear dissociation between eosinophilia and AHR by using steroids that are the mainstay of asthma therapy. These data suggest that eosinophilia is not associated with AHR and questions the rationale that many pharmaceutical companies are adopting in developing low-molecular-mass compounds that target eosinophil activation/recruitment for the treatment of asthma
Exploring the role of organizational policies and procedures in promoting research utilization in registered nurses
<p>Abstract</p> <p>Background</p> <p>Policies and procedures (P&Ps) have been suggested as one possible strategy for moving research evidence into practice among nursing staff in hospitals. Research in the area of P&Ps is limited, however. This paper explores: 1) nurses' use of eight specific research-based practices (RBPs) and RBP overall, 2) nurses' use and understanding of P&Ps, and 3) the role of P&Ps in promoting research utilization.</p> <p>Methods</p> <p>Staff nurses from the eight health regions governing acute care services across the Canadian province of Newfoundland and Labrador completed an anonymous questionnaire regarding their use of eight RBPs and associated P&Ps. Data were also obtained from authorities in six of the eight regions about existing relevant P&Ps. We used descriptive statistics and multivariate regression analysis to assess the relationship between key independent variables and self-reported use of RBP.</p> <p>Results</p> <p>Use of the eight RBPs ranged from 7.8% to 88.6%, depending on the practice. Nurses ranked P&P manuals as their number one source of practice knowledge. Most respondents (84.8%) reported that the main reason they consult the P&P manual is to confirm they are practicing according to agency rules. Multivariate regression analysis identified three significant predictors of being a user versus non-user of RBP overall: awareness, awareness by regular use, and persuasion. Six significant predictors of being a consistent versus less consistent user of RBP overall were also identified: perception of P&P existence, unit, nursing experience, personal experience as a source of practice knowledge, number of existing research-based P&Ps, and lack of time as a barrier to consulting P&P manuals.</p> <p>Conclusion</p> <p>Findings suggest that nurses use P&Ps to guide their practice. However, the mere existence of P&Ps is not sufficient to translate research into nursing practice. Individual and organizational factors related to nurses' understanding and use of P&Ps also play key roles. Thus, moving research evidence into practice will require careful interplay between the organization and the individual. P&Ps may be the interface through which this occurs.</p
Regulatory role of CD8(+ )T lymphocytes in bone marrow eosinophilopoiesis
BACKGROUND: There is a growing body of evidence to suggest that CD8(+ )T lymphocytes contribute to local allergen-induced eosinophilic inflammation. Since bone marrow (BM) responses are intricately involved in the induction of airway eosinophilia, we hypothesized that CD8(+ )T lymphocytes, as well as CD4(+ )T lymphocytes, may be involved in this process. METHODS: Several approaches were utilized. Firstly, mice overexpressing interleukin-5 (IL-5) in CD3(+ )T lymphocytes (NJ.1638; CD3(IL-5+ )mice) were bred with gene knockout mice lacking either CD4(+ )T lymphocytes (CD4(-/-)) or CD8(+ )T lymphocytes (CD8(-/-)) to produce CD3(IL-5+ )knockout mice deficient in CD4(+ )T lymphocytes (CD3(IL-5+)/CD4(-/-)) and CD8(+ )T lymphocytes (CD3(IL-5+)/CD8(-/-)), respectively. Secondly, CD3(+), CD4(+ )and CD8(+ )T lymphocytes from naïve CD3(IL-5+ )and C57BL/6 mice were adoptively transferred to immunodeficient SCID-bg mice to determine their effect on BM eosinophilia. Thirdly, CD3(IL-5+), CD3(IL-5+)/CD8(-/- )and CD3(IL-5+)/CD4(-/- )mice were sensitized and allergen challenged. Bone marrow and blood samples were collected in all experiments. RESULTS: The number of BM eosinophils was significantly reduced in CD3(IL-5+)/CD8(-/- )mice compared to CD3(IL-5+ )mice and CD3(IL-5+)/CD4(-/- )mice. Serum IL-5 was significantly higher in CD3(IL-5+)/CD4(-/- )mice compared to CD3(IL-5+ )mice but there was no difference in serum IL-5 between CD3(IL-5+)/CD4(-/- )and CD3(IL-5+)/CD8(-/- )mice. Adoptive transfer of CD8(+), but not CD4(+ )T lymphocytes from naïve CD3(IL-5+ )and C57BL/6 mice restored BM eosinophilia in immunodeficient SCID-bg mice. Additionally, allergen challenged CD3(IL-5+)/CD8(-/- )mice developed lower numbers of BM eosinophils compared to CD3(IL-5+ )mice and CD3(IL-5+)/CD4(-/- )mice. CONCLUSION: This study shows that CD8(+ )T lymphocytes are intricately involved in the regulation of BM eosinophilopoiesis, both in non-sensitized as well as sensitized and allergen challenged mice
Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine
In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown
The utilisation of health research in policy-making: Concepts, examples and methods of assessment
The importance of health research utilisation in policy-making, and of understanding the
mechanisms involved, is increasingly recognised. Recent reports calling for more resources to
improve health in developing countries, and global pressures for accountability, draw greater
attention to research-informed policy-making. Key utilisation issues have been described for at
least twenty years, but the growing focus on health research systems creates additional dimensions.
The utilisation of health research in policy-making should contribute to policies that may eventually
lead to desired outcomes, including health gains. In this article, exploration of these issues is
combined with a review of various forms of policy-making. When this is linked to analysis of
different types of health research, it assists in building a comprehensive account of the diverse
meanings of research utilisation.
Previous studies report methods and conceptual frameworks that have been applied, if with varying
degrees of success, to record utilisation in policy-making. These studies reveal various examples of
research impact within a general picture of underutilisation.
Factors potentially enhancing utilisation can be identified by exploration of: priority setting;
activities of the health research system at the interface between research and policy-making; and
the role of the recipients, or 'receptors', of health research. An interfaces and receptors model
provides a framework for analysis.
Recommendations about possible methods for assessing health research utilisation follow
identification of the purposes of such assessments. Our conclusion is that research utilisation can
be better understood, and enhanced, by developing assessment methods informed by conceptual
analysis and review of previous studies
Effects of high-intensity intermittent training on carnitine palmitoyl transferase activity in the gastrocnemius muscle of rats
New Insights into Blastocystis spp.: A Potential Link with Irritable Bowel Syndrome
International audienceBlastocystis spp. belong to the phylum Stramenopila, a complex and heterogeneous evolutionary assemblage of heterotrophic and photosynthetic protozoa [1]. Interestingly, this is the only stramenopile living in the lower digestive tract of humans, and it also lives in other mammals, birds, reptiles, amphibians, and insects [1]. Even though isolates were reported to be morphologically indistinguishable, an extensive genetic variation among isolates from both humans and animals has been observed. Thirteen subtypes (ST1-ST13), with the first nine being found in humans, have been identified based on genes coding for the small-subunit ribosomal RNA [2]. Preferential repartition of STs exists among animals that appear to constitute the main reservoir for environmental dissemination and human contamination
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