390 research outputs found
Verbal Learning and Memory After Cochlear Implantation in Postlingually Deaf Adults: Some New Findings with the CVLT-II
OBJECTIVES:
Despite the importance of verbal learning and memory in speech and language processing, this domain of cognitive functioning has been virtually ignored in clinical studies of hearing loss and cochlear implants in both adults and children. In this article, we report the results of two studies that used a newly developed visually based version of the California Verbal Learning Test-Second Edition (CVLT-II), a well-known normed neuropsychological measure of verbal learning and memory.
DESIGN:
The first study established the validity and feasibility of a computer-controlled visual version of the CVLT-II, which eliminates the effects of audibility of spoken stimuli, in groups of young normal-hearing and older normal-hearing (ONH) adults. A second study was then carried out using the visual CVLT-II format with a group of older postlingually deaf experienced cochlear implant (ECI) users (N = 25) and a group of ONH controls (N = 25) who were matched to ECI users for age, socioeconomic status, and nonverbal IQ. In addition to the visual CVLT-II, subjects provided data on demographics, hearing history, nonverbal IQ, reading fluency, vocabulary, and short-term memory span for visually presented digits. ECI participants were also tested for speech recognition in quiet.
RESULTS:
The ECI and ONH groups did not differ on most measures of verbal learning and memory obtained with the visual CVLT-II, but deficits were identified in ECI participants that were related to recency recall, the buildup of proactive interference, and retrieval-induced forgetting. Within the ECI group, nonverbal fluid IQ, reading fluency, and resistance to the buildup of proactive interference from the CVLT-II consistently predicted better speech recognition outcomes.
CONCLUSIONS:
Results from this study suggest that several underlying foundational neurocognitive abilities are related to core speech perception outcomes after implantation in older adults. Implications of these findings for explaining individual differences and variability and predicting speech recognition outcomes after implantation are discussed
Efecto antiinflamatorio de la izalpinina derivada de Chromolaena leivensis: edema de la pata inducido por λ-carragenina y modelo in silico
El flavonoide izalpinina se aisló de las partes aéreas de Chromolaena leivensis. Su determinación estructural se llevó a cabo mediante técnicas espectroscópicas de EM y RMN (1H, 13C). Se evaluó el efecto antiinflamatorio de este compuesto en un modelo de edema plantar inducido por carragenina en ratas. La inflamación de la pata se midió a intervalos de una hora durante siete horas tras la administración de -carragenano. Se evaluaron los niveles séricos de creatina quinasa (CK), obteniéndose resultados estadísticamente significativos con los tratamientos a dosis de 10 mg/kg (* p < 0,01) y 20 mg/kg (** p < 0,005). El efecto antiinflamatorio del compuesto se evaluó mediante pletismografía, y los resultados mostraron diferencias significativas en las tres concentraciones (10 mg/kg, 20 mg/kg, 40 mg/kg) en la primera y tercera hora tras el tratamiento. * p < 0,05; ** p < 0,001; **** p < 0,0001 frente al grupo de control negativo tratado con vehículo (DMSO). Por último, los análisis de acoplamiento molecular revelan que la izalpinina tiene una fuerte afinidad de unión con cinco proteínas diana implicadas en el proceso inflamatorio. El análisis mediante dinámica molecular permitió demostrar que los complejos ligando-proteína presentan una estabilidad aceptable, con valores de RMSD dentro del rango permitido.The flavonoid izalpinin was isolated from the aerial parts of Chromolaena leivensis. Its structural determination was carried out using MS and NMR spectroscopic techniques (1H, 13C). This compound was evaluated for its anti-inflammatory effect in a rat model on -carrageenan-induced plantar edema. Paw inflammation was measured at one-hour intervals for seven hours following the administration of -carrageenan. Serum creatine kinase (CK) levels were evaluated, obtaining statistically significant results with the treatments at doses of 10 mg/kg (* p < 0.01) and 20 mg/kg (** p < 0.005). The anti-inflammatory effect of the compound was evaluated by using plethysmography, and the results showed significant differences at the three concentrations (10 mg/kg, 20 mg/kg, 40 mg/kg) in the first and third hours after treatment. * p < 0.05; ** p < 0.001; **** p < 0.0001 vs. the negative control group treated with vehicle (DMSO). Lastly, molecular docking analyses reveal that izalpinin has a strong binding affinity with five target proteins involved in the inflammatory process. The analysis using molecular dynamics allowed demonstrating that the ligand–protein complexes present acceptable stability, with RMSD values within the allowed range
Reduction of power line interference in electrocardiographic signals by dual Kalman filtering
[EN] This paper presents a filter for reducing powerline interference in electrocardiographic signals (ECG), based on dual parameter and state estimation using with a Kalman filter. Two models were used to represent power-line interference and ECG signal. Both models were combined to simulate the ECG signal whose state was estimated for separating the ECG signal from the interference. The proposed algorithm was fine-tuned and compared using a set of tests relying on the QT arrhythmia database. Tuning tests were done for tracking clean ECG; these results were used for setting the algorithm¿s parameters for later filtering tests. Exhaustive filtering tests were carried out on artificially corrupted database registers for given signal to noise ratios; performance curves were thus obtained, leading to comparing the proposed algorithm with other filtering methods. The proposed algorithm was compared to an recursive infinite impulse response filter (IIR) and a Kalman filter based on a simpler model. A filtering algorithm was thus obtained which is robust for changes in interference amplitude and keeps these properties for different types of ECG morphologies.[ES] En este artículo se presenta el desarrollo de un filtro para la reducción de la interferencia de línea de potencia en señales electrocardiográficas (ECG), basado en estimación dual de parámetros y de estado, empleando la filtración Kalman, en el cual se consideran modelos independientes entre la interferencia de línea de potencia y la señal ECG. Ambos modelos son combinados para simular la señal ECG medida sobre la que se realiza la estimación de estado para separar la señal de la interferencia. El algoritmo propuesto es sintonizado y comparado en un conjunto de pruebas realizadas sobre la base de datos QT de electrocardiografía. Inicialmente se hacen pruebas de sintonización del algoritmo para el rastreo de la señal ECG limpia, cuyos resultados son utilizados después para las pruebas de filtrado. Luego se llevan a cabo pruebas exhaustivas sobre la base de datos QT en la filtración de interferencia de línea de potencia, la cual ha sido introducida artificialmente en los registros, para una relación de señal a ruido (SNR) dada, obteniendo así curvas del desempeño del algoritmo, que permiten a su vez comparar con el desempeño de otros algoritmos de filtración, a saber, un filtro notch recursivo de respuesta infinita al impulso (IIR) y un filtro de Kalman, basado en un modelo más simple para la señal ECG. Como resultado, se demuestra que el algoritmo de filtrado obtenido es robusto a los cambios de amplitud de la interferencia; además, conserva sus propiedades para los diferentes tipos de morfologías de señales ECG normales y patológicas.Este trabajo se realiza en el marco del proyecto de la DIMA Técnicas de Computación de Alto Rendimiento en la Interpretación Automatizada de Imágenes Médicas y Bioseñales.Avendaño-Valencia, LD.; Avendaño, LE.; Ferrero De Loma-Osorio, JM.; Castellanos-Domínguez, G. (2007). Reducción de interferencia de línea de potencia en señales electrocardiográficas mediante el filtro dual de Kalman. Ingeniería e Investigación. 27(3):77-88. http://hdl.handle.net/10251/150636S778827
Efecto de las intervenciones con ingesta de leguminosas y/o ejercicio supervisado sobre el perfil lipídico de mujeres jóvenes, sanas y sedentarias
Objective: To contribute to the knowledge of some aspects of the Healthy Life Style by studying the effects of including
legumes in the diet and exercise at two intensity levels, along with the lipid profile of young sedentary women living at 2640
meters above sea level.
Materials and methods: The study included a non-randomized clinical trial with four intervention groups: exercise at 45%
VO2 peak plus legumes in diet, exercise at 65% VO2 peak plus legumes in diet, only exercise at 65% VO2 peak, and only inclusion
of legumes in diet. In each group, 20 to 23 sedentary women were included. The intervention was carried out for four weeks,
three days a week. Exercise prescription was based on measurement of VO2 peak by ergospirometry; and the current
intervention was monitored with heart-rate monitors. The outcome variables were total serum cholesterol, LDL cholesterol,
HDL cholesterol, and triacylglycerols measured at baseline and after two and four weeks of intervention.
Results: The measurements taken of participants in the group of exercise at 65% VO2 peak plus legumes in diet showed
a reduction of 19.8 mg/dl in total cholesterol, of 21.8 mg/dl of LDL cholesterol, of 20.7 mg/dl of tracylglycerol, and an increase
of 6.2 mg/dl of HDL cholesterol. The serum levels of HDL also increased in the group of only exercise at 65% VO2 peak. No
significant changes in serum levels were documented for participants in the group with only dietary modifications.
Conclusions: The results suggest that different interventions that meet some of the criteria for healthy eating and life style
show different effects with regards to the level of change in the lipid profile components. Objetivo: Contribuir al conocimiento de algunos aspectos prácticos para llevar a cabo una alimentación y estilo de vida
saludable, mediante el estudio de los efectos en el perfil lipídico de la inclusión de leguminosas (fríjol, lenteja y garbanzos)
en la dieta de mujeres sanas pero sedentarias, acompañada de ejercicio con dos niveles de intensidad, moderada y alta,
efectuados a una altura de 2,640 metros sobre el nivel del mar (msnm)
Material y métodos: Estudio de intervención clínica no aleatorizada con cuatro grupos de intervención: ejercicio a 45%
VO2 pico + leguminosas, ejercicio a 65% VO2 pico + leguminosas, sólo ejercicio a 45% VO2 picoy sólo inclusión de leguminosas
en la dieta. En cada grupo se incluyeron de 20 a 23 mujeres jóvenes sedentarias evaluadas mediante el International Physical
Activity Questionnaire (IPAQ), y la intervención se llevó a cabo durante 4 semanas. La prescripción del ejercicio se hizo previa
determinación del VO2 pico por ergo espirometría, y su realización se monitoreó con sensores de frecuencia cardíaca. El efecto de la intervención se evaluó mediante los cambios en los
niveles séricos de colesterol total (CT), colesterol LDL (cLDL),
colesterol HDL (cHDL) y triacilgliceroles (TAG), tomados a
las semanas cero, dos y cuatro.
Resultados: En el grupo «ejercicio a 65% del VO2 pico,
más inclusión de leguminosas en la dieta» se obtuvieron los
siguientes resultados significantes: una reducción promedio
del colesterol total de 19.8 mg/dl (p=0.0015), del colesterol
LDL de 21.8 mg/dl (p=0.0001), un aumento de colesterol HDL
de 6.2 mg/dl (p=0.0001) y una disminución de los
triacilgliceroles de 20.7 mg/dl (p=0.0001). En el grupo de sólo
ejercicio a 65% del VO2 pico se obtuvo un aumento del HDL.
No hubo modificaciones al perfil lipídico en el grupo correspondiente
a sólo inclusión de leguminosas en la alimentación.
Conclusiones: Los resultados sugieren que en mujeres
jóvenes sedentarias que viven a 2,640 metros sobre el nivel
del mar, la combinación de ejercicio de intensidad alta e
inclusión de leguminosas (fríjol, lenteja o garbanzos) producen
un mayor cambio benéfico en el perfil lipídico que una
intervención con sólo ejercicio de intensidad alta o sólo
inclusión de leguminosas en la alimentación. Los cambios
benéficos significantes se obtuvieron luego de 4 semanas de
intervención en el colesterol total, colesterol LDL, colesterol
HDL y triacilgliceroles, lo que pone de presente la bondad de
esta intervención, así como la utilidad del perfil lipídico como
indicador temprano de cambios en los estilos de vida. Las
intervenciones estudiadas, compatibles con alimentación y
estilo de vida saludables, producen efectos diferentes en los
niveles del perfil lipídico estudiados, y al poner de presente
las debilidades de un diseño no aleatorizado, se puede recomendar
que se insista en las intervenciones de salud pública
que contemplen cambios en la dieta y cambios en la actividad
física
Latin America Climate- Smart Villages AR4D sites: 2017 Inventory
Inventory of CSA practices in Latin America's Climate-Smart Villages
Three-dimensional transesophageal echocardiography of the atrial septal defects
Transesophageal echocardiography has advantages over transthoracic technique in defining morphology of atrial structures. Even though real time three-dimensional echocardiographic imaging is a reality, the off-line reconstruction technique usually allows to obtain higher spatial resolution images. The purpose of this study was to explore the accuracy of off-line three-dimensional transesophageal echocardiography in a spectrum of atrial septal defects by comparing them with representative anatomic specimens
Very high energy particle acceleration powered by the jets of the microquasar SS 433
SS 433 is a binary system containing a supergiant star that is overflowing
its Roche lobe with matter accreting onto a compact object (either a black hole
or neutron star). Two jets of ionized matter with a bulk velocity of
extend from the binary, perpendicular to the line of sight, and
terminate inside W50, a supernova remnant that is being distorted by the jets.
SS 433 differs from other microquasars in that the accretion is believed to be
super-Eddington, and the luminosity of the system is erg
s. The lobes of W50 in which the jets terminate, about 40 pc from the
central source, are expected to accelerate charged particles, and indeed radio
and X-ray emission consistent with electron synchrotron emission in a magnetic
field have been observed. At higher energies (>100 GeV), the particle fluxes of
rays from X-ray hotspots around SS 433 have been reported as flux
upper limits. In this energy regime, it has been unclear whether the emission
is dominated by electrons that are interacting with photons from the cosmic
microwave background through inverse-Compton scattering or by protons
interacting with the ambient gas. Here we report TeV -ray observations
of the SS 433/W50 system where the lobes are spatially resolved. The TeV
emission is localized to structures in the lobes, far from the center of the
system where the jets are formed. We have measured photon energies of at least
25 TeV, and these are certainly not Doppler boosted, because of the viewing
geometry. We conclude that the emission from radio to TeV energies is
consistent with a single population of electrons with energies extending to at
least hundreds of TeV in a magnetic field of ~micro-Gauss.Comment: Preprint version of Nature paper. Contacts: S. BenZvi, B. Dingus, K.
Fang, C.D. Rho , H. Zhang, H. Zho
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