298 research outputs found
Context-dependent selection of visuomotor maps
Behavior results from the integration of ongoing sensory signals and
contextual information in various forms, such as past experience, expectations,
current goals, etc. Thus, the response to a specific stimulus, say the ringing
of a doorbell, varies depending on whether you are at home or in someone else's
house. What is the neural basis of this flexibility? What mechanism is capable
of selecting, in a context-dependent way, an adequate response to a given
stimulus? One possibility is based on a nonlinear neural representation in
which context information regulates the gain of stimulus-evoked responses. Here
I explore the properties of this mechanism. By means of three hypothetical
visuomotor tasks, I study a class of neural network models in which any one of
several possible stimulus-response maps or rules can be selected according to
context. The underlying mechanism based on gain modulation has three key
features: (1) modulating the sensory responses is equivalent to switching on or
off different subpopulations of neurons, (2) context does not need to be
represented continuously, although this is advantageous for generalization, and
(3) context-dependent selection is independent of the discriminability of the
stimuli. In all cases, the contextual cues can quickly turn on or off a
sensory-motor map, effectively changing the functional connectivity between
inputs and outputs in the networks. The model predicts that sensory responses
that are nonlinearly modulated by arbitrary context signals should be found in
behavioral situations that involve choosing or switching between multiple
sensory-motor maps.Comment: 22 pages, 10 figures. Article available from:
http://www.biomedcentral.com/1471-2202/5/4
Big differences in primary care celiac disease serological markers request in Spain
Introduction: Celiac disease (CD) prevalence is increasing but the disorder remains undiagnosed. The study compares CD serology markers requested by General Practitioners (GPs) over time and geographical areas. The aim of the current research is to assess the inter-practice and temporal variability in the request of CD serology markers by GPs in Spain, and the differences between regions.
Materials and methods: A cross-sectional study was conducted enrolling Spanish clinical laboratories. Primary care CD serology markers request in 2010, 2012 and 2014 from 15 autonomous communities (AACC), with more participants was reported. Test-utilization rates were calculated (tissue transglutaminase IgA antibodies (tTG-IgA) and deaminated peptide gliadine IgA antibodies (DGP-IgA) per 1000 inhabitants), and also the ratio of both tests request (DGP-IgA /tTG-IgA).
Results: The request of tTG-IgA per 1000 inhabitants increased significantly along years (from 3.99 to 5.90 (P < 0.001)). The demand of DGP-IgA per 1000 inhabitants was maintained in 2010 and 2012 (0.68 and 0.6), and decreased in 2014 (0.35) (P = 0.927). DGP-IgA /tTG-IgA diminished over time (from 0.16 to 0.06 (P = 0.548)), and in the 2014 edition, there was a significant regional difference, ranging from 0.01 to 0.57 (P < 0.001).
Conclusions: The variability in the request in CD serology markers emphasizes the need of inter-regional cooperation to develop strategies to optimize the use of laboratory test
Estrategia para mejorar la difusión de los resultados de investigación con la Web 2.0.
Scientific communication is being enriched by the
introduction of new ways of storage, publication and dissemination of the results. These include the services of the Web 2.0 which are still largely unknown to researchers. In this context the objective of this paper is to illustrate how we can strategically use Web Services 2.0 to disseminate and give greater visibility to scientific publications. To this end we present a series of services of interest to scientific communication (Blogger, Twitter, Facebook, Slideshare y E-Lis) and explain the role they can play in communicating scientific results. It also shows how these services should be logically interrelated, which we call the strategic dissemination cycle. In the last section, the authors collected a set of webmetric indicators
classified into three groups (social influence, use, recognition) to evaluate the success of the dissemination strategy and the visibility of a work in the Web 2.0
Additional technician tasks and turnaround time in the clinical Stat laboratory.
Introduction: Many additional tasks in the Stat laboratory (SL) increase the workload. It is necessary to control them because they can affect the service provided by the laboratory. Our aim is to calculate these tasks, study their evolution over a 10 year period, and compare turnaround times (TAT) in summer period to the rest of the year.
Materials and methods: Additional tasks were classified as “additional test request” and “additional sample”. We collected those incidences from the laboratory information system (LIS), and calculated their evolution over time. We also calculated the monthly TAT for troponin for Emergency department (ED) patients, as the difference between the verification and LIS registration time. A median time of 30 minutes was our indicator target. TAT results and tests workload in summer were compared to the rest of the year.
Results: Over a 10-year period, the technologists in the SL performed 51,385 additional tasks, a median of 475 per month. The workload was significantly higher during the summer (45,496 tests) than the rest of the year (44,555 tests) (P = 0.019). The troponin TAT did not show this variation between summer and the rest of the year, complying always with our 30 minutes indicator target.
Conclusion: The technicians accomplished a significant number of additional tasks, and the workload kept increasing over the period of 10 years. That did not affect the TAT results
Inhibitory synchrony as a mechanism for attentional gain modulation
Recordings from area V4 of monkeys have revealed that when the focus of
attention is on a visual stimulus within the receptive field of a cortical
neuron, two distinct changes can occur: The firing rate of the neuron can
change and there can be an increase in the coherence between spikes and the
local field potential in the gamma-frequency range (30-50 Hz). The hypothesis
explored here is that these observed effects of attention could be a
consequence of changes in the synchrony of local interneuron networks. We
performed computer simulations of a Hodgkin-Huxley type neuron driven by a
constant depolarizing current, I, representing visual stimulation and a
modulatory inhibitory input representing the effects of attention via local
interneuron networks. We observed that the neuron's firing rate and the
coherence of its output spike train with the synaptic inputs was modulated by
the degree of synchrony of the inhibitory inputs. The model suggest that the
observed changes in firing rate and coherence of neurons in the visual cortex
could be controlled by top-down inputs that regulated the coherence in the
activity of a local inhibitory network discharging at gamma frequencies.Comment: J.Physiology (Paris) in press, 11 figure
Guía metodológica para la enseñanza del violín del nivel inicial, para niños del primer año del Conservatorio de Música de Loja "Salvador Bustamante Celi"
La educación como el pilar más importante de una sociedad, tiene como objetivo fundamental transmitir la información de una generación a otra, dentro de cada nueva generación se debe formar hábitos, costumbres, conocimientos, y arte, que constituyen la identidad cultural de un pueblo. Las manifestaciones artísticas son la síntesis de cómo piensa y siente el ser humano expresadas en formas plástica, musical y objetiva, que pretenden dar un mensaje a las generaciones, para identificar la realidad social, y afectiva de una comunidad. La música, como expresión artística, sintetiza de mejor manera las características sociales, sus aspiraciones y sentimientos de los pueblos, por lo que su enseñanza es parte esencial de los procesos formativos de la nuevas generaciones y quienes se dediquen a este menester deben hacerlo en las mejores condiciones metodológicas, y mucho más si son instituciones como los conservatorios los que toman a su cargo esta labor, deberán respaldarse metodológicamente, técnicamente y didácticamente para obtener los mejores resultados y sacar músicos de calidad. El violín es uno de los más importantes instrumentos musicales creados por el ser humano, con el se puede interpretar toda composición musical, sin excepción, desde obras elementales hasta muy virtuosas, pasando de lo popular a lo clásico. Su repertorio es extenso y casi sin limitación alguna para su ejecución. La enseñanza de un instrumento requiere un apoyo de carácter pedagógico, que permita diseñar estrategias metodológicas acordes a las edades de los estudiantes, lastimosamente en nuestro país, las instituciones dedicadas a la enseñanza de la música, no disponen de una buena formación artística y no existe una referencia en el campo de la didáctica correspondiente a los instrumentos y su aprendizaje. En el caso del violín, considerado como un instrumento completo, se requiere una mejor aplicación didáctica en su enseñanza y una formación pedagógica de quienes se dedican no sólo a la interpretación sino también son maestros que imparten sus conocimientos a estudiantes de distintos niveles y edades, por tal motivo se plantea la investigación enfocada en la elaboración de una Guía Metodológica para la Enseñanza del Violín del Nivel Inicial, para Niños del primer año del Conservatorio de Música de Loja “Salvador Bustamante Celi”. El Conservatorio de Loja se encuentra en Loja, sector Jipiro en la Av. Salvador Bustamante Celi. Este trabajo busca lograr un sincretismo entre las escuelas de enseñanza más tradicionales e importantes que tiene la pedagogía del violín a nivel mundial, con los elementos musicales cercanos a nuestra población, procurando adaptar melodías y
técnica para el proceso enseñanza - aprendizaje del violín a los niños de Conservatorio
con importantes temas musicales ecuatorianos y latinoamericanos, pretendiendo de esta
manera que el estudio del violín acerque a nuevos sectores de la población educativa
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