3,535 research outputs found
Hybrid EEG-fNIRS asynchronous brain-computer interface for multiple motor tasks
Non-invasive Brain-Computer Interfaces (BCI) have demonstrated great promise for neuroprosthetics and assistive devices. Here we aim to investigate methods to combine Electroencephalography (EEG) and functional Near-Infrared Spectroscopy (fNIRS) in an asynchronous Sensory Motor rhythm (SMR)-based BCI. We attempted to classify 4 different executed movements, namely, Right-ArmâLeft-ArmâRight-HandâLeft-Hand tasks. Previous studies demonstrated the benefit of EEG-fNIRS combination. However, since normally fNIRS hemodynamic response shows a long delay, we investigated new features, involving slope indicators, in order to immediately detect changes in the signals. Moreover, Common Spatial Patterns (CSPs) have been applied to both EEG and fNIRS signals. 15 healthy subjects took part in the experiments and since 25 trials per class were available, CSPs have been regularized with information from the entire population of participants and optimized using genetic algorithms. The different features have been compared in terms of performance and the dynamic accuracy over trials shows that the introduced methods diminish the fNIRS delay in the detection of changes
Rectovaginal fistula following sexual intercourse.
Female genital fistula is an important feature of the developing countries gynecology. Most of the rectovaginal fistulae encountered in the tropics are due to obstetrics causes and genital malignancies. In developed countries, radiation injury and Crohnâs disease are also common etiological factors. Theindex case is reported to highlight the rare situation, where a 24-year old married nullipara sustained low rectovaginal fistula following normal coitus. She was later divorced by her husband
Decentralized learning with budgeted network load using Gaussian copulas and classifier ensembles
We examine a network of learners which address the same classification task
but must learn from different data sets. The learners cannot share data but
instead share their models. Models are shared only one time so as to preserve
the network load. We introduce DELCO (standing for Decentralized Ensemble
Learning with COpulas), a new approach allowing to aggregate the predictions of
the classifiers trained by each learner. The proposed method aggregates the
base classifiers using a probabilistic model relying on Gaussian copulas.
Experiments on logistic regressor ensembles demonstrate competing accuracy and
increased robustness in case of dependent classifiers. A companion python
implementation can be downloaded at https://github.com/john-klein/DELC
Heteromeric TRPV4/TRPC1 channels mediate calcium-sensing receptor-induced nitric oxide production and vasorelaxation in rabbit mesenteric arteries.
Stimulation of calcium-sensing receptors (CaSR) by increasing the external calcium concentration (Ca(2+)]o) induces endothelium-dependent vasorelaxation through nitric oxide (NO) production and activation of intermediate Ca(2+)-activated K(+) currents (IKCa) channels in rabbit mesenteric arteries. The present study investigates the potential role of heteromeric TRPV4-TRPC1 channels in mediating these CaSR-induced vascular responses. Immunocytochemical and proximity ligation assays showed that TRPV4 and TRPC1 proteins were expressed and co-localised at the plasma membrane of freshly isolated endothelial cells (ECs). In wire myography studies, increasing [Ca(2+)]o between 1 and 6mM induced concentration-dependent relaxations of methoxamine (MO)-induced pre-contracted tone, which were inhibited by the TRPV4 antagonists RN1734 and HC067047, and the externally-acting TRPC1 blocking antibody T1E3. In addition, CaSR-evoked NO production in ECs measured using the fluorescent NO indicator DAF-FM was reduced by RN1734 and T1E3. In contrast, [Ca(2+)]o-evoked perforated-patch IKCa currents in ECs were unaffected by RN1734 and T1E3. The TRPV4 agonist GSK1016790A (GSK) induced endothelium-dependent relaxation of MO-evoked pre-contracted tone and increased NO production, which were inhibited by the NO synthase inhibitor L-NAME, RN1734 and T1E3. GSK activated 6pS cation channel activity in cell-attached patches from ECs which was blocked by RN1734 and T1E3. These findings indicate that heteromeric TRPV4-TRPC1 channels mediate CaSR-induced vasorelaxation through NO production but not IKCa channel activation in rabbit mesenteric arteries. This further implicates CaSR-induced pathways and heteromeric TRPV4-TRPC1 channels in regulating vascular tone
Quantum Spacetimes in the Year 1
We review certain emergent notions on the nature of spacetime from
noncommutative geometry and their radical implications. These ideas of
spacetime are suggested from developments in fuzzy physics, string theory, and
deformation quantisation. The review focuses on the ideas coming from fuzzy
physics. We find models of quantum spacetime like fuzzy on which states
cannot be localised, but which fluctuate into other manifolds like .
New uncertainty principles concerning such lack of localisability on quantum
spacetimes are formulated.Such investigations show the possibility of
formulating and answering questions like the probabilty of finding a point of a
quantum manifold in a state localised on another one. Additional striking
possibilities indicated by these developments is the (generic) failure of
theorem and the conventional spin-statistics connection. They even suggest that
Planck's `` constant '' may not be a constant, but an operator which does not
commute with all observables. All these novel possibilities arise within the
rules of conventional quantum physics,and with no serious input from gravity
physics.Comment: 11 pages, LaTeX; talks given at Utica and Kolkata .Minor corrections
made and references adde
Modelling control of Schistosoma haematobium infection: predictions of the long-term impact of mass drug administration in Africa.
BACKGROUND: Effective control of schistosomiasis remains a challenging problem for endemic areas of the world. Given knowledge of the biology of transmission and past experience with mass drug administration (MDA) programs, it is important to critically evaluate the likelihood that MDA programs will achieve substantial reductions in Schistosoma prevalence. In implementing the World Health Organization Roadmap for Neglected Tropical Diseases it would useful for policymaking to model projections of the status of Schistosoma control in MDA-treated areas in the next 5-10 years. METHODS: Calibrated mathematical models were used to project the effects of different frequency and coverage of MDA for schistosomiasis haematobia control in present-day endemic communities, taking into account uncertainties of parasite biology and input data. The modeling approach in this analysis was the Stratified Worm Burden model developed in our earlier works, calibrated using data from longitudinal S. haematobium control trials in Kenya. RESULTS: Model-based simulations of MDA control in typical low-risk and higher-risk communities indicated that infection prevalence can be substantially reduced within 10Â years only when there is a high degree of community participation (>70Â %) with at least annual MDA. Significant risk for re-emergence of infection remains if MDA is suspended. CONCLUSIONS: In a stable (stationary) ecosystem, Schistosoma reproduction and transmission are sufficiently robust that the process of human infection continues, even under pressure from aggressive MDA. MDA alone is unlikely to interrupt transmission, and once mass treatment is suspended, the prevalence of human infection is likely to rebound to pre-control levels over a period of 25-30 years. MDA success in achieving very low levels of infection prevalence is highly dependent on treatment coverage and frequency within the local human population, and requires that both adults and children be included in drug delivery coverage. Ultimately, supplemental snail control and significant improvements in sanitation will be required to achieve full control of schistosomiasis by elimination of ongoing Schistosoma transmission
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On the discovery of K-enhanced and possibly Mg-depleted stars throughout the Milky Way
Stars with unusual elemental abundances offer clues about rare astrophysical
events or nucleosynthetic pathways. Stars with significantly depleted magnesium
and enhanced potassium ([Mg/Fe] 1) have to date only been
found in the massive globular cluster NGC 2419 and, to a lesser extent, NGC
2808. The origin of this abundance signature remains unknown, as does the
reason for its apparent exclusivity to these two globular clusters. Here we
present 112 field stars, identified from 454,180 LAMOST giants, that show
significantly enhanced [K/Fe] and possibly depleted [Mg/Fe] abundance ratios.
Our sample spans a wide range of metallicities (-1.5 < [Fe/H] < 0.3), yet none
show abundance ratios of [K/Fe] or [Mg/Fe] that are as extreme as those
observed in NGC 2419. If confirmed, the identified sample of stars represents
evidence that the nucleosynthetic process producing the anomalous abundances
ratios of [K/Fe] and [Mg/Fe] probably occurs at a wide range of metallicities.
This would suggest that pollution scenarios that are limited to early epochs
(such as Population III supernovae) are an unlikely explanation, although they
cannot be ruled out entirely. This sample is expected to help guide modelling
attempts to explain the origin of the Mg-K abundance signature
Majorana Zero-modes and Topological Phases of Multi-flavored Jackiw-Rebbi model
Motivated by the recent Kitaev's K-theory analysis of topological insulators
and superconductors, we adopt the same framework to study the topological phase
structure of Jackiw-Rebbi model in 3+1 dimensions. According to the K-theory
analysis based on the properties of the charge conjugation and time reversal
symmetries, we classify the topological phases of the model. In particular, we
find that there exist Majorana zero-modes hosted by the
hedgehogs/t'Hooft-Polyakov monopoles, if the model has a time reversal
symmetry. Guided by the K-theory results, we then explicitly show that a single
Majorana zero mode solution exists for the SU(2) doublet fermions in some
co-dimensional one planes of the mass parameter space. It turns out we can see
the existence of none or a single zero mode when the fermion doublet is only
two. We then take a step further to consider four-fermion case and find there
can be zero, one or two normalizable zero mode in some particular choices of
mass matrices. Our results also indicate that a single normalizable Majorana
zero mode can be compatible with the cancellation of SU(2) Witten anomaly.Comment: 29 pages, 3 figures; v2, typos correcte
The clinical effectiveness of transurethral incision of the prostate : a systematic review of randomised controlled trials
The original publication is available at www.springerlink.com.Peer reviewedPostprin
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