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Search Results: 1 - 10 of 328043 matches for " Lucas S. Baltzell "
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Clinical Use of Aided Cortical Auditory Evoked Potentials as a Measure of Physiological Detection or Physiological Discrimination
Curtis J. Billings,Melissa A. Papesh,Tina M. Penman,Lucas S. Baltzell,Frederick J. Gallun
International Journal of Otolaryngology , 2012, DOI: 10.1155/2012/365752
Abstract: The clinical usefulness of aided cortical auditory evoked potentials (CAEPs) remains unclear despite several decades of research. One major contributor to this ambiguity is the wide range of variability across published studies and across individuals within a given study; some results demonstrate expected amplification effects, while others demonstrate limited or no amplification effects. Recent evidence indicates that some of the variability in amplification effects may be explained by distinguishing between experiments that focused on physiological detection of a stimulus versus those that differentiate responses to two audible signals, or physiological discrimination. Herein, we ask if either of these approaches is clinically feasible given the inherent challenges with aided CAEPs. N1 and P2 waves were elicited from 12 noise-masked normal-hearing individuals using hearing-aid-processed 1000-Hz pure tones. Stimulus levels were varied to study the effect of hearing-aid-signal/hearing-aid-noise audibility relative to the noise-masked thresholds. Results demonstrate that clinical use of aided CAEPs may be justified when determining whether audible stimuli are physiologically detectable relative to inaudible signals. However, differentiating aided CAEPs elicited from two suprathreshold stimuli (i.e., physiological discrimination) is problematic and should not be used for clinical decision making until a better understanding of the interaction between hearing-aid-processed stimuli and CAEPs can be established.
Clinical Use of Aided Cortical Auditory Evoked Potentials as a Measure of Physiological Detection or Physiological Discrimination
Curtis J. Billings,Melissa A. Papesh,Tina M. Penman,Lucas S. Baltzell,Frederick J. Gallun
International Journal of Otolaryngology , 2012, DOI: 10.1155/2012/365752
Abstract: The clinical usefulness of aided cortical auditory evoked potentials (CAEPs) remains unclear despite several decades of research. One major contributor to this ambiguity is the wide range of variability across published studies and across individuals within a given study; some results demonstrate expected amplification effects, while others demonstrate limited or no amplification effects. Recent evidence indicates that some of the variability in amplification effects may be explained by distinguishing between experiments that focused on physiological detection of a stimulus versus those that differentiate responses to two audible signals, or physiological discrimination. Herein, we ask if either of these approaches is clinically feasible given the inherent challenges with aided CAEPs. N1 and P2 waves were elicited from 12 noise-masked normal-hearing individuals using hearing-aid-processed 1000-Hz pure tones. Stimulus levels were varied to study the effect of hearing-aid-signal/hearing-aid-noise audibility relative to the noise-masked thresholds. Results demonstrate that clinical use of aided CAEPs may be justified when determining whether audible stimuli are physiologically detectable relative to inaudible signals. However, differentiating aided CAEPs elicited from two suprathreshold stimuli (i.e., physiological discrimination) is problematic and should not be used for clinical decision making until a better understanding of the interaction between hearing-aid-processed stimuli and CAEPs can be established. 1. Introduction The potential clinical benefits of a measure of brain encoding and plasticity in hearing aid users have driven a growing interest in aided cortical auditory evoked potentials (CAEPs). A better understanding of the effects of hearing aids on brain function, and resulting behavior, may improve the current science underlying successful rehabilitation of hearing loss. CAEPs, a type of event-related electroencephalography (i.e., scalp-recorded electrical brain activity) recorded 50–300?ms following stimulus onset, are thought to reflect neural activity in reverberant thalamocortical circuits (for a review see [1, 2]). Aided CAEPs, or potentials recorded when stimuli are presented via a hearing aid, have been proposed as a possible physiological measure of the effects of amplification on the brain. Many studies have explored the potential use of aided CAEPs, demonstrating considerable variability in results across experiments and individual participants [3–21]. The variability across studies highlights the current uncertainty surrounding
El lugar de las mujeres pobres: el caso de las beneficiarias de planes sociales
Bustos,Lucas Andrés;
La aljaba , 2009,
Abstract: this article's aim is to think and analyse the situation of those women who receive any of the social plans implemented in the last years in our country (such as programa de empleo transitorio "entre nosotros", the programa "madres" and the plan jefes y jefas de hogar desocupados), in the light of theoretical arguments developed from cultural geography and specially from the so called gender geography. this discipline's contributions provide analytical perspectives to enrich the process of thinking about the gender relationships, the place occupied by the women in the society, the identities built according to the place women occupy in the social structure, and the role played by the social policy in the construction of such identities. in the analysed cases, it can be appreciated how the different places occupied by the beneficiaries of programs acquire different values and meanings, which produces a search for spaces that have a positive social valuation and that contribute to the construction of new identities.
Criterios de distinción en el folclore juje?o: Usos de la categoría ?festivalero?
Perassi,Lucas Andrés;
Cuadernos de la Facultad de Humanidades y Ciencias Sociales. Universidad Nacional de Jujuy , 2009,
Abstract: our research on jujenian musical folklore follows the giddens's ?double hermeneutic? notion (1987), which implies as task for scientific thought to interpret what has been interpreted by social actors. in this regard, a productive research on the folkloric field is to identify the categories from which subjects judged the musicians (soloists or groups), to establish their provenance, see if they show regularities in their users (socio-economic status, membership or not to folkloric field, gender, etc.) and, last but not least, whether use of that category in some sense has its counterpart in social action of subject. in this particular job, we analize uses of ?festivalero? category, usually employed in folkloric music field, but not always to refer to same reality. from this analysis, we trying to emphasize the importance, for understanding social phenomena, of consideration of socio-cultural conditions where ?festivalero? takes different meanings in discourses of different social sectors. we believe that in this way we can better apprehend the senses that in each case this category takes within the jujenian folkloric field.
Aproximación al folclore moderno juje?o: Imágenes predominante en las letras de sus canciones
Perassi,Lucas Andrés;
Cuadernos de la Facultad de Humanidades y Ciencias Sociales. Universidad Nacional de Jujuy , 2007,
Abstract: 'folklore from jujuy' construction designates certain specific musical practices daily. it includes a heterogeneous group of artists, poetic and musical genre. however this heterogeneity is perceived as unit that starts from dissimilar approaches, it takes into account to certain features characteristic of geographical and human environment. in this work we try to analyze which are those constituents of the juje?idad from the perspective of the modern folklore. i mean the identity speech that promotes this field, analyzing the rhetorical elements that characterize the letters of their songs. the corpus is made up of two songbooks: it from ideas sueltas editions and todo jujuy en canciones from cor-for editions. the objective is to describe the predominant images in the rhetoric of the letters of the modern folklore of jujuy and its breaking relationships or continuity with regard to those of the argentine modern folklore.
El lugar de las mujeres pobres: el caso de las beneficiarias de planes sociales Poor women's place: the social plans beneficiaries' case
Lucas Andrés Bustos
La Aljaba (Luján) , 2009,
Abstract: El presente artículo se propone reflexionar y analizar la situación de las mujeres beneficiarias de planes sociales implementados en los últimos a os en nuestro país, como el Programa de Empleo Transitorio "Entre Nosotros", el Programa "Madres" y el Plan Jefes y Jefas de Hogar Desocupados, a la luz de los aportes teóricos desarrollados por la geografía cultural y especialmente por las llamadas geografías de género. Los aportes de esta disciplina ofrecen perspectivas de análisis enriquecedoras para reflexionar acerca de las relaciones de género, el lugar ocupado por la mujer en la sociedad, las identidades que se construyen en función de los lugares que éstas ocupan en la estructura social, y el rol jugado por las políticas sociales en la construcción de sus identidades. En los casos analizados, puede apreciarse cómo los diferentes lugares ocupados por las beneficiarias de los programas adquieren valoraciones y significaciones diferentes, por lo cual se produce un movimiento de búsqueda de espacios que adquieren una valoración social positiva y que contribuyen a la construcción de nuevas identidades. This article's aim is to think and analyse the situation of those women who receive any of the social plans implemented in the last years in our country (such as Programa de Empleo Transitorio "Entre Nosotros", the Programa "Madres" and the plan Jefes y Jefas de Hogar Desocupados), in the light of theoretical arguments developed from cultural geography and specially from the so called gender geography. This discipline's contributions provide analytical perspectives to enrich the process of thinking about the gender relationships, the place occupied by the women in the society, the identities built according to the place women occupy in the social structure, and the role played by the social policy in the construction of such identities. In the analysed cases, it can be appreciated how the different places occupied by the beneficiaries of programs acquire different values and meanings, which produces a search for spaces that have a positive social valuation and that contribute to the construction of new identities.
On Some Applications of Nanoparticles Synthesized in the Gas Phase by Magnetron Discharges  [PDF]
Virginie Bouchat, N. Moreau, J.-F. Colomer, S. Lucas
Journal of Surface Engineered Materials and Advanced Technology (JSEMAT) , 2013, DOI: 10.4236/jsemat.2013.33025
Abstract:

For the seventies, scientists focused their researches to find techniques to produce high quality films. One of the ideas, for example, was to generate an ionized cluster beam (ICB) formed by inert gas condensation (IGC) from evaporation of material. This method generates non-agglomerated nanoparticles to be deposited onto any substrate. However, the synthesis of spherical and well-dispersed nanoparticles remains, today, a major technological issue. Several trials have been performed with magnetron sputtering that has the advantage of producing very pure atomic vapour from a wide variety of solid materials or composites, and therefore in this configuration offers the possibility to synthesize nanoparticles in a gaz phase with potential numerous applications. In this paper, we describe several results of our laboratory and we show how it is possible to synthesize non-agglomerated nanoparticles with a narrow size distribution in the nm range. Detailed examples of Ag, TiO2, Au, Y, C, Co and Fe are given. We illustrate their current use in applications including catalyst to produce aligned Multi-Wall Carbon Nanotubes, seeding layer to promote anatase TiO2 crystallisation for photocatalytic material, superhydrophobic material and nanoparticle for nanomedecine.

Search for the $Θ^+$ pentaquark in the reactions $γp \to \bar K^0K^+n$ and $γp \to \bar K^0K^0p$
R. De Vita,M. Battaglieri,V. Kubarovsky,N. A. Baltzell,M. Bellis,J. Goett,L. Guo,G. S. Mutchler,P. Stoler,M. Ungaro,D. P. Weygand,the CLAS Collaboration
Physics , 2006, DOI: 10.1103/PhysRevD.74.032001
Abstract: The exclusive reactions $\gamma p \to \bar K^0 K^+ n$ and $\gamma p \to \bar K^0 K^0 p$ have been studied in the photon energy range 1.6--3.8 GeV, searching for evidence of the exotic baryon $\Theta^+(1540)$ in the decays $\Theta^+\to nK^+$ and $\Theta^+\to p K^0$. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The integrated luminosity was about 70 pb$^{-1}$. The reactions have been isolated by detecting the $K^+$ and proton directly, the neutral kaon via its decay to $K_S \to \pi^+ \pi^-$ and the neutron or neutral kaon via the missing mass technique. The mass and width of known hyperons such as $\Sigma^+$, $\Sigma^-$ and $\Lambda(1116)$ were used as a check of the mass determination accuracy and experimental resolution. Approximately 100,000 $\Lambda^*(1520)$'s and 150,000 $\phi$'s were observed in the $\bar K^0 K^+ n$ and $\bar K^0 K^0 p$ final state respectively. No evidence for the $\Theta^+$ pentaquark was found in the $nK^+$ or $pK_S$ invariant mass spectra. Upper limits were set on the production cross section of the reaction $\gamma p \to \Theta^+ \bar K^0$ as functions of center-of-mass angle, $nK^+$ and $pK_S$ masses. Combining the results of the two reactions, the 95% C.L. upper limit on the total cross section for a resonance peaked at 1540 MeV was found to be 0.7 nb. Within most of the available theoretical models, this corresponds to an upper limit on the $\Theta^+$ width, $\Gamma_{\Theta^{+}}$, ranging between 0.01 and 7 MeV.
Maintenance of scorpions of the genus Tityus Koch (Scorpiones, Buthidae) for venom obtention at Instituto Butantan, S?o Paulo, Brazil
Candido, D. M.;Lucas, S.;
Journal of Venomous Animals and Toxins including Tropical Diseases , 2004, DOI: 10.1590/S1678-91992004000100007
Abstract: this work presents the experience of the laboratory of arthropods at instituto butantan, which maintains scorpions in captivity in order to obtain the venom used in the production of anti-arachnid serum. between 1993 and 2000, the laboratory received 24.781 specimens of tityus serrulatus in order to obtain poison for the production of anti-scorpion serum. in the first extraction, performed by electrical stimulation, the animals gave an average quantity of 0.4 mg venom per specimen. animal acquisition and involved professional safety are considered. in addition, the captivity, handling and feeding techniques are described, as well as the method and equipment used for venom extraction. it shows the importance of regular campaigns, offering information to the general population in order to motivate these to catch and send alive scorpions to the institute to assuring a regular entrance of scorpions.
Improvement of soluble coffee aroma using an integrated process of supercritical CO2 extraction with selective removal of the pungent volatiles by adsorption on activates carbon
Lucas, S.;Cocero, M. J.;
Brazilian Journal of Chemical Engineering , 2006, DOI: 10.1590/S0104-66322006000200006
Abstract: in this paper a two-step integrated process consisting of co2 supercritical extraction of volatile coffee compounds (the most valuable) from roasted and milled coffee, and a subsequent step of selective removal of pungent volatiles by adsorption on activated carbon is presented. some experiments were carried out with key compounds from roasted coffee aroma in order to study the adsorption step: ethyl acetate as a desirable compound and furfural as a pungent component. operational parameters such as adsorption pressure and temperature and co2 flowrate were optimized. experiments were conducted at adsorption pressures of 12-17 mpa, adsorption temperatures of 35-50oc and a solvent flow rate of 3-5 kg/h. in all cases, the solute concentration and the activated particle size were kept constant. results show that low pressures (12 mpa), low temperatures (35oc) and low co2 flowrates (3 kg/h) are suitable for removing the undesirable pungent and smell components (e.g. furfural) and retaining the desirable aroma compounds (e.g. ethyl acetate). the later operation with real roasted coffee has corroborated the previous results obtained with the key compounds.
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