568 research outputs found
Dipyridamole plus aspirin versus aspirin alone in the secondary prevention after TIA or stroke: a meta-analysis by risk
Objectives: Our aim was to study the effect of combination therapy with aspirin and dipyridamole (A+D) over aspirin alone (ASA) in secondary prevention after transient
ischemic attack or minor stroke of presumed arterial origin and to perform subgroup analyses to identify patients that might benefit most from secondary prevention with A+D.
Data sources: The previously published meta-analysis of individual patient data was updated with data from ESPRIT (N=2,739); trials without data on the comparison of A+D versus ASA were excluded.
Review methods: A meta-analysis was performed using Cox regression, including several subgroup analyses and following baseline risk stratification.
Results: A total of 7,612 patients (5 trials) were included in the analyses, 3,800 allocated to A+D and 3,812 to ASA alone. The trial-adjusted hazard ratio for the composite event of vascular death, non-fatal myocardial infarction and non-fatal stroke was 0.82 (95% confidence interval 0.72-0.92). Hazard ratios did not differ in subgroup analyses based on age, sex, qualifying event, hypertension, diabetes, previous stroke, ischemic heart disease,
aspirin dose, type of vessel disease and dipyridamole formulation, nor across baseline risk strata as assessed with two different risk scores. A+D were also more effective than ASA alone in preventing recurrent stroke, HR 0.78 (95% CI 0.68 â 0.90).
Conclusion: The combination of aspirin and dipyridamole is more effective than aspirin alone in patients with TIA or ischemic stroke of presumed arterial origin in the secondary
prevention of stroke and other vascular events. This superiority was found in all subgroups and was independent of baseline risk. ---------------------------7dc3521430776
Content-Disposition: form-data; name="c14_creators_1_name_family"
Halke
Environmental and genetic influences on neurocognitive development: the importance of multiple methodologies and time-dependent intervention
Genetic mutations and environmental factors dynamically influence gene expression and developmental trajectories at the neural, cognitive, and behavioral levels. The examples in this article cover different periods of neurocognitive developmentâearly childhood, adolescence, and adulthoodâand focus on studies in which researchers have used a variety of methodologies to illustrate the early effects of socioeconomic status and stress on brain function, as well as how allelic differences explain why some individuals respond to intervention and others do not. These studies highlight how similar behaviors can be driven by different underlying neural processes and show how a neurocomputational model of early development can account for neurodevelopmental syndromes, such as autism spectrum disorders, with novel implications for intervention. Finally, these studies illustrate the importance of the timing of environmental and genetic factors on development, consistent with our view that phenotypes are emergent, not predetermined
Modelo de cabalgamiento profundo para el Alto Atlas (Marruecos). Implicaciones sĂsmicas en la zona de colisiĂłn entre Eurasia y Africa
Previous crustal models of the High Atlas suppose the existence of a mid-crustal detachment where all the surface thrusts merged and below which the lower crust was continuous. However, both seismic refraction data and gravity modeling detected a jump in crustal thickness between the High Atlas and the northern plains. Here we show that this rapid and vertical jump in the depth of Moho discontinuity suggests that a thrust fault may penetrate the lower crust and offset the Moho (deep-rooted âthick skinnedâ model). The distribution of Neogene and Quaternary volcanisms along and at the northern part of the High Atlas lineament can be related to the beginning of a partial continental subduction of the West African plate to the north underneath Moroccan microplate. Allowing from the complex problem of the plate boundary in the western zone of the Mediterranean, we propose to interpret the South-Atlasic fault zone as the actual northwestern boundary of the stable part of the African plate rather than the Azores-Gibraltar fault currently used.Los modelos geodinĂĄmicos existentes sobre la estructura profunda del alto Atlas suponen la existencia de un despegue medio-cortical donde convergen los cabalgamientos superficiales y bajo el cual la corteza inferior es continua. Los datos de sĂsmica de refracciĂłn y gravimetrĂa, sin embargo, indican la existencia de una discontinuidad en el grosor de la corteza (profundidad del Moho) bajo el Alto Atlas. En este artĂculo ponemos de manifiesto que este salto rĂĄpido en la profundidad del Moho puede ser causado por un cabalgamiento que penetra la corteza inferior, desplazando la base de la misma (âdeeprooted thick skinned modelâ). La distribuciĂłn del volcanismo NeĂłgeno y Cuaternario a lo largo de y al norte de la alineaciĂłn del Alto Atlas pueden estar relacionados con el comienzo de una subducciĂłn continental parcial de la placa Africana occidental hacia el norte, bajo la microplaca marroquĂ. La expresiĂłn en superficie de este cabalgamiento, la zona de falla sud-atlĂĄsica, refleja la influencia de una sutura continental heredada de orogenias anteriores (panafricana, hercĂnica y rifting JurĂĄsico). Por tanto, proponemos que este frente heredado representa el lĂmite meridional de la zona de colisiĂłn mediterrĂĄnea y el margen noroccidental de la porciĂłn estable de la placa africana
Subspace Hybrid MVDR Beamforming for Augmented Hearing
Signal-dependent beamformers are advantageous over signal-independent
beamformers when the acoustic scenario - be it real-world or simulated - is
straightforward in terms of the number of sound sources, the ambient sound
field and their dynamics. However, in the context of augmented reality audio
using head-worn microphone arrays, the acoustic scenarios encountered are often
far from straightforward. The design of robust, high-performance, adaptive
beamformers for such scenarios is an on-going challenge. This is due to the
violation of the typically required assumptions on the noise field caused by,
for example, rapid variations resulting from complex acoustic environments,
and/or rotations of the listener's head. This work proposes a multi-channel
speech enhancement algorithm which utilises the adaptability of
signal-dependent beamformers while still benefiting from the computational
efficiency and robust performance of signal-independent super-directive
beamformers. The algorithm has two stages. (i) The first stage is a hybrid
beamformer based on a dictionary of weights corresponding to a set of noise
field models. (ii) The second stage is a wide-band subspace post-filter to
remove any artifacts resulting from (i). The algorithm is evaluated using both
real-world recordings and simulations of a cocktail-party scenario. Noise
suppression, intelligibility and speech quality results show a significant
performance improvement by the proposed algorithm compared to the baseline
super-directive beamformer. A data-driven implementation of the noise field
dictionary is shown to provide more noise suppression, and similar speech
intelligibility and quality, compared to a parametric dictionary.Comment: 14 pages, 10 figures, submitted for IEEE/ACM Transactions on Audio,
Speech, and Language Processing on 23-Nov-202
Effets de scenarios de changements climatiques sur la cacaoculture en Cote dâIvoire
Lâinfluence des scenarios de changements climatiques a Ă©tĂ© analysĂ©e pour les rĂ©gions Centre et Sud de production cacaoyĂšre en CĂŽte dâIvoire. A partir des modĂšles RCP 4.5 et 8.5 de concentration des Gaz Ă Effets de Serre (GES), les paramĂštres tempĂ©rature et pluviomĂ©trie ont Ă©tĂ© projetĂ©s sur les horizons 2021-2050 et 2041-2070 en comparaison Ă la pĂ©riode de rĂ©fĂ©rence 1980-2010. Les rĂ©sultats ont montrĂ© quâen dehors du nombre Ă©levĂ© de jours chauds qui pourrait provoquer la disparition de la cacaoculture dans les zones marginales de la rĂ©gion Centre, les indices climatiques se situent dans des conditions normales de production du cacaoyer dans les deux rĂ©gions. Les risques liĂ©s aux maladies et ravageurs pourraient ĂȘtre similaires ou potentiellement rĂ©duits. En rĂ©gion Sud, les variations climatiques nâauraient aucun impact sur la cacaoculture. Comme stratĂ©gies de rĂ©silience, les programmes de sĂ©lection variĂ©tale devront mettre Ă la disposition des producteurs un matĂ©riel vĂ©gĂ©tal tolĂ©rant Ă la sĂ©cheresse et aux maladies accompagnĂ©e de formations sur les bonnes pratiques agricoles dont lâagroforesterie. Toutefois, lâaccĂšs des producteurs Ă lâinformation mĂ©tĂ©orologique devra ĂȘtre renforcĂ©.
English title: Climate change effects in cocoa cultivation
Abstract
The influence of climate change scenarios was analyzed for the Center and South regions of cocoa farming in CĂŽte dâIvoire. From greenhouse gas (GHG) concentration models RCP 4.5 and 8.5, the parameters of temperature and rainfall were projected over the time in years 2021-2050 and 2041- 2070 compared to year 1980-2010 as reference period. The results showed that apart from the high number of hot days which could cause the disappearance of cocoa farming in marginal areas of the Center region, the climatic indices are normal within cocoa production conditions in both regions. Risks on cocoa pests and disease could be similar or potentially reduced. In the South region, climatic variations would have no impact on cocoa farming. As resilience adaptation strategies, tolerant germplasm to drought and pest and disease should be provided to farmers by cocoa research program with training package on good agricultural practices (GAP) including agroforestry. Therefore, theaccess to meteorological information has to be strengthened for smallholders cocoa farmers.
Key words: Climate change scenarios, impact, cocoa farming, CĂŽte dâIvoire
Atypical audiovisual speech integration in infants at risk for autism
The language difficulties often seen in individuals with autism might stem from an inability to integrate audiovisual information, a skill important for language development. We investigated whether 9-month-old siblings of older children with autism, who are at an increased risk of developing autism, are able to integrate audiovisual speech cues. We used an eye-tracker to record where infants looked when shown a screen displaying two faces of the same model, where one face is articulating/ba/and the other/ga/, with one face congruent with the syllable sound being presented simultaneously, the other face incongruent. This method was successful in showing that infants at low risk can integrate audiovisual speech: they looked for the same amount of time at the mouths in both the fusible visual/ga/â audio/ba/and the congruent visual/ba/â audio/ba/displays, indicating that the auditory and visual streams fuse into a McGurk-type of syllabic percept in the incongruent condition. It also showed that low-risk infants could perceive a mismatch between auditory and visual cues: they looked longer at the mouth in the mismatched, non-fusible visual/ba/â audio/ga/display compared with the congruent visual/ga/â audio/ga/display, demonstrating that they perceive an uncommon, and therefore interesting, speech-like percept when looking at the incongruent mouth (repeated ANOVA: displays x fusion/mismatch conditions interaction: F(1,16) = 17.153, p = 0.001). The looking behaviour of high-risk infants did not differ according to the type of display, suggesting difficulties in matching auditory and visual information (repeated ANOVA, displays x conditions interaction: F(1,25) = 0.09, p = 0.767), in contrast to low-risk infants (repeated ANOVA: displays x conditions x low/high-risk groups interaction: F(1,41) = 4.466, p = 0.041). In some cases this reduced ability might lead to the poor communication skills characteristic of autism
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Operationalising and measuring language dominance
The paper offers a new way to measure language ability in bilinguals, based on measures of lexical richness. The validity of proposed approach is tested in a variety of ways
Differential habituation to repeated sounds in infants at high risk for autism
It has been suggested that poor habituation to stimuli might explain atypical sensory behaviours in autism, i.e. over-responsiveness to some stimuli and under-sensitivity to other. We investigated habituation to repeated sounds using an oddball paradigm in 9 month-old infants with an older sibling with autism and hence at high risk for developing autism. Auditory evoked responses to repeated sounds in control infants (at low risk of developing autism) decreased over time, demonstrating habituation, and their responses to deviant sounds were larger than responses to standard sounds, indicating discrimination. In contrast, neural responses in infants at high risk showed no habituation, and reduced sensitivity to changes in frequency. Reduced sensory habituation may be present at a younger age than the emergence of autistic behaviour in some individuals, and we propose that this could play a role in the sensory atypicalities observed in autism
Integrate and Fire Neural Networks, Piecewise Contractive Maps and Limit Cycles
We study the global dynamics of integrate and fire neural networks composed
of an arbitrary number of identical neurons interacting by inhibition and
excitation. We prove that if the interactions are strong enough, then the
support of the stable asymptotic dynamics consists of limit cycles. We also
find sufficient conditions for the synchronization of networks containing
excitatory neurons. The proofs are based on the analysis of the equivalent
dynamics of a piecewise continuous Poincar\'e map associated to the system. We
show that for strong interactions the Poincar\'e map is piecewise contractive.
Using this contraction property, we prove that there exist a countable number
of limit cycles attracting all the orbits dropping into the stable subset of
the phase space. This result applies not only to the Poincar\'e map under
study, but also to a wide class of general n-dimensional piecewise contractive
maps.Comment: 46 pages. In this version we added many comments suggested by the
referees all along the paper, we changed the introduction and the section
containing the conclusions. The final version will appear in Journal of
Mathematical Biology of SPRINGER and will be available at
http://www.springerlink.com/content/0303-681
Functional near infrared spectroscopy (fNIRS) to assess cognitive function in infants in rural Africa
Cortical mapping of cognitive function during infancy is poorly understood in low-income countries due to the lack of transportable neuroimaging methods. We have successfully piloted functional near infrared spectroscopy (fNIRS) as a neuroimaging tool in rural Gambia. Four-to-eight month old infants watched videos of Gambian adults perform social movements, while haemodynamic responses were recorded using fNIRS. We found distinct regions of the posterior superior temporal and inferior frontal cortex that evidenced either visual-social activation or vocally selective activation (vocal > non-vocal). The patterns of selective cortical activation in Gambian infants replicated those observed within similar aged infants in the UK. These are the first reported data on the measurement of localized functional brain activity in young infants in Africa and demonstrate the potential that fNIRS offers for field-based neuroimaging research of cognitive function in resource-poor rural communities
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