172 research outputs found
Scattering of Elastic Waves in a Quasi-one-dimensional Cavity: Theory and Experiment
We study the scattering of torsional waves through a quasi-one-dimensional
cavity both, from the experimental and theoretical points of view. The
experiment consists of an elastic rod with square cross section. In order to
form a cavity, a notch at a certain distance of one end of the rod was grooved.
To absorb the waves, at the other side of the rod, a wedge, covered by an
absorbing foam, was machined. In the theoretical description, the scattering
matrix S of the torsional waves was obtained. The distribution of S is given by
Poisson's kernel. The theoretical predictions show an excellent agreement with
the experimental results. This experiment corresponds, in quantum mechanics, to
the scattering by a delta potential, in one dimension, located at a certain
distance from an impenetrable wall
Electromagnetic prompt response in an elastic wave cavity
A rapid, or prompt response, of an electromagnetic nature, is found in an
elastic wave scattering experiment. The experiment is performed with torsional
elastic waves in a quasi-one-dimensional cavity with one port, formed by a
notch grooved at a certain distance from the free end of a beam. The stationary
patterns are diminished using a passive vibration isolation system at the other
end of the beam. The measurement of the resonances is performed with
non-contact electromagnetic-acoustic transducers outside the cavity. In the
Argand plane, each resonance describes a circle over a base impedance curve
which comes from the electromagnetic components of the equipment. A model,
based on a variation of Poisson's kernel is developed. Excellent agreement
between theory and experiment is obtained.Comment: 4 pages, 5 figure
Tuberculosis y SIDA pediátrico: a propósito de un caso en Mozambique / Tuberculosis and pediatric AIDS: a case report in Mozambique
La Tuberculosis (TB), es una enfermedad producida por el Mycobacterium tuberculosis hominis, bacilo débilmente Gram positivo, aerobio, ácido-alcohol resistente, de aspecto curvo, inmóvil, no esporulado, constituye una de las enfermedades re - emergentes en la infancia a nivel mundial, el Síndrome de inmunodeficiencia adquirida (sida) es el factor de riesgo mayor para la progresión de la TB. a pesar de que la incidencia de ambas enfermedades es baja con relación a las estadísticas mundiales según la OMS; los estados y autoridades sanitarias ponen el mayor empeño para un control eficaz y manejo adecuado de los casos registrados. Motivados con la presencia del Internacionalismo médico cubano en diversos países fue considerado de interés transmitir una experiencia, presentando el caso de un niño de 4 años de edad, raza negra, procedente de un área rural en Nampula, Mozambique (África), donde el cuadro clínico y los complementarios confirmaron una TB pulmonar, constatando además la presencia de sida (VIH positivo y linfocitos CD4+ en < 15 %). Se aplicó la terapéutica adecuada siguiendo los protocolos establecidos en Mozambique para ambas enfermedades, que permitió una mejoría del estado clínico e hizo posible un cambio en la calidad y esperanza de vida de este.Palabras clave: TUBERCULOSIS/diagnóstico, VIH, SÍNDROME DE INMUNODEFICIENCIA ADQUIRIDA/terapia. ABSTRACT Tuberculosis (abbreviated TB for tubercle bacillus or Tuberculosis), is a disease caused by Mycobacterium Tuberculosis Hominis, weakly Gram-positive bacillus, aerobic, acid-alcohol resistance, of curved aspect, motionless and sporeless. TB constitutes one of the re-emergent diseases in the childhood all over the world. Acquired Immunodeficiency Syndrome (AIDS) is the most important risk factor to the TB development. Despite the incidence of both diseases is low in relation to the worldwide statistics; and according to the World Health Organization (WHO), the states and sanitary authorities are making a great effort to carry out an effective control and an adequate management of the cases recorded. Encouraged by the presence of the Cuban Medical Internationalist Missions in several countries the case is presented in order to transmit experience. A 4-year-old, black boy, coming from a rural region in Mampula City, Mozambique, sub-Saharan Africa; the clinical and laboratory findings confirmed a pulmonary TB, also the presence of AIDS was verified (positive HIV and lymphocytes CD4+ in 15%). An adequate therapeutic taking into account the protocols established in Mozambique for both diseases was followed with the purpose of improving the clinical conditions of the patient, which made possible changes in the quality of life and life expectancy. Key words: Tuberculosis/diagnosis, HIV, ACQUIRED IMMUNODEFICIENCY SYNDROME/therapy
Tuberculosis y SIDA pediátrico: a propósito de un caso en Mozambique / Tuberculosis and pediatric AIDS: a case report in Mozambique
La Tuberculosis (TB), es una enfermedad producida por el Mycobacterium tuberculosis hominis, bacilo débilmente Gram positivo, aerobio, ácido-alcohol resistente, de aspecto curvo, inmóvil, no esporulado, constituye una de las enfermedades re - emergentes en la infancia a nivel mundial, el Síndrome de inmunodeficiencia adquirida (sida) es el factor de riesgo mayor para la progresión de la TB. a pesar de que la incidencia de ambas enfermedades es baja con relación a las estadísticas mundiales según la OMS; los estados y autoridades sanitarias ponen el mayor empeño para un control eficaz y manejo adecuado de los casos registrados. Motivados con la presencia del Internacionalismo médico cubano en diversos países fue considerado de interés transmitir una experiencia, presentando el caso de un niño de 4 años de edad, raza negra, procedente de un área rural en Nampula, Mozambique (África), donde el cuadro clínico y los complementarios confirmaron una TB pulmonar, constatando además la presencia de sida (VIH positivo y linfocitos CD4+ en < 15 %). Se aplicó la terapéutica adecuada siguiendo los protocolos establecidos en Mozambique para ambas enfermedades, que permitió una mejoría del estado clínico e hizo posible un cambio en la calidad y esperanza de vida de este.Palabras clave: TUBERCULOSIS/diagnóstico, VIH, SÍNDROME DE INMUNODEFICIENCIA ADQUIRIDA/terapia. ABSTRACT Tuberculosis (abbreviated TB for tubercle bacillus or Tuberculosis), is a disease caused by Mycobacterium Tuberculosis Hominis, weakly Gram-positive bacillus, aerobic, acid-alcohol resistance, of curved aspect, motionless and sporeless. TB constitutes one of the re-emergent diseases in the childhood all over the world. Acquired Immunodeficiency Syndrome (AIDS) is the most important risk factor to the TB development. Despite the incidence of both diseases is low in relation to the worldwide statistics; and according to the World Health Organization (WHO), the states and sanitary authorities are making a great effort to carry out an effective control and an adequate management of the cases recorded. Encouraged by the presence of the Cuban Medical Internationalist Missions in several countries the case is presented in order to transmit experience. A 4-year-old, black boy, coming from a rural region in Mampula City, Mozambique, sub-Saharan Africa; the clinical and laboratory findings confirmed a pulmonary TB, also the presence of AIDS was verified (positive HIV and lymphocytes CD4+ in 15%). An adequate therapeutic taking into account the protocols established in Mozambique for both diseases was followed with the purpose of improving the clinical conditions of the patient, which made possible changes in the quality of life and life expectancy. Key words: Tuberculosis/diagnosis, HIV, ACQUIRED IMMUNODEFICIENCY SYNDROME/therapy
Schistosomiasis en la infancia. Una experiencia para el internacionalismo médico cubano / Schistosomiasis in childhood: an experience to the Cuban Medical Internationalist Missions
El Schistosoma es un parásito no endémico de Cuba, pero con una elevada frecuencia en los países de África, Asia y América Latina; de ellos, cinco especies infectan al hombre. No existen evidencias de dicho parasitismo en nuestro país. Con la presencia del internacionalismo médico cubano en las diversas tierras del mundo es que fue considerado útil transmitir la experiencia profesional en un país africano. Se presenta un caso clínico de un paciente de 7 años de edad, sexo masculino y estado nutricional adecuado, procedente de un área suburbana de la Cuidad de Nampula, Mozambique, África Subsahariana que al examen físico se constató que tenía lesiones de dermatitis en las manos y los pies, de varias semanas en evolución; acude por la aparición de edemas en miembros inferiores, dificultad para orinar y orinas oscuras. Se sospecha una posible Glomerulonefritis Difusa Aguda según la frecuencia de la entidad en nuestro medio. Después de una respuesta terapéutica escasa, un cambio en la visión epidemiológica y los resultados complementarios, se confirma una forma de presentación infantil de esquistosomiasis masiva, entidad frecuente en las regiones geográficas donde hoy en día está presente el internacionalismo médico cubano. Después de una revisión bibliográfica se consideró útil trasmitir la experiencia al médico internacionalista y se hacen algunas consideraciones al respecto. Palabras Clave: Esquistosomiasis, glomerulonefritis, diagnóstico. ABSTRACT Schistosome is a non-endemic parasite in Cuba, but with an elevated frequency in Africa, Asia and Latin-America; of them, five species infest man. No evidences of this parasite are found in Cuba. Considering the presence of Cuban Medical Internationalist Missions in other parts of the world, it is useful to transmit the professional experience in an African country. A 7-year-old-male patient, presenting an adequate nutritional status, coming from a sub-urban district of Mampula City. Mozambique, sub-Saharan Africa, at physical examination showed dermatitis in hands and feet for several weeks in evolution. The patient attended to the clinic presenting edema in the lower limbs, difficulties to urinate and dark urines. Suspecting, a possible Acute Diffuse Glomerulonephritis according to the frequency of the disease in that environment. After a limited therapeutic response, and a change in the epidemiologic view and the laboratory results; a childhood presentation of a form of massive schistosomiasis was confirmed, a frequent entity in the geographic regions where Cuban medical missions work. Some suggestions to transmit the experience to the medical missions were made taking into consideration several aspects after a medical literature review. Key words: Schistosomiasis, glomerulonephritis, diagnosis
Semiconductor thin films by chemical bath deposition for solar energy related applications.
In this paper we present the basic concepts underlying the chemical bath deposition technique and the recipes developed in our laboratory during the past ten years for the deposition of good-quality thin films of CdS, CdSe, ZnS, ZnSe, PbS, SnS, Bi2 S 3 , Bi2 Se3 , Sb2 S 3 , CuS, CuSe, etc. Typical growth curves, and optical and electrical properties of these films are presented. The effect of annealing the films in air on their structure and composition and on the electrical properties is notable: CdS and ZnS films become conductive through a partial conversion to oxide phase; CdSe becomes photosensitive, SnS converts to SnO2 , etc. The use of precipitates formed during deposition for screen printing and sintering, in polymer composites and as a source for vapor-phase deposition is presented. Some examples of the application of the films in solar energy related work are presented
Light scattering from self-affine fractal silver surfaces with nanoscale cutoff: Far-field and near-field calculations
We study the light scattered from randomly rough, one-dimensional self-affine
fractal silver surfaces with nanoscale lower cutoff, illuminated by s- or
p-polarized Gaussian beams a few microns wide. By means of rigorous numerical
calculations based on the Green theorem integral equation formulation, we
obtain both the far- and near-field scattered intensities. The influence of
diminishing the fractal lower scale cutoff (from below a hundred, down to a few
nanometers) is analyzed in the case of both single realizations and ensemble
average magnitudes. For s polarization, variations are small in the far field,
being only significant in the higher spatial frequency components of evanescent
character in the near field. In the case of p polarization, however, the
nanoscale cutoff has remarkable effects stemming from the roughness-induced
excitation of surface-plasmon polaritons. In the far field, the effect is
noticed both in the speckle pattern variation and in the decrease of the total
reflected energy upon ensemble averaging, due to increased absorption. In the
near field, more efficient excitation of localized optical modes is achieved
with smaller cutoff, which in turn leads to huge surface electric field
enhancements.Comment: REVTeX 4, 10 page
Loss of microRNA-135b Enhances Bone Metastasis in Prostate Cancer and Predicts Aggressiveness in Human Prostate Samples
About 70% of advanced-stage prostate cancer (PCa) patients will experience bone metastasis, which severely affects patients' quality of life and progresses to lethal PCa in most cases. Hence, understanding the molecular heterogeneity of PCa cell populations and the signaling pathways associated with bone tropism is crucial. For this purpose, we generated an animal model with high penetrance to metastasize to bone using an intracardiac percutaneous injection of PC3 cells to identify PCa metastasis-promoting factors. Using genomic high-throughput analysis we identified a miRNA signature involved in bone metastasis that also presents potential as a biomarker of PCa progression in human samples. In particular, the downregulation of miR-135b favored the incidence of bone metastases by significantly increasing PCa cells' migratory capacity. Moreover, the PLAG1, JAKMIP2, PDGFA, and VTI1b target genes were identified as potential mediators of miR-135b's role in the dissemination to bone. In this study, we provide a genomic signature involved in PCa bone growth, contributing to a better understanding of the mechanisms responsible for this process. In the future, our results could ultimately translate into promising new therapeutic targets for the treatment of lethal PCa
Introgression and pyramiding into common bean market class fabada of genes conferring resistance to anthracnose and potyvirus
Anthracnose and bean common mosaic (BCM) are considered major diseases in common bean crop causing severe yield losses worldwide. This work describes the introgression and pyramiding of genes conferring genetic resistance to BCM and anthracnose local races into line A25, a bean genotype classified as market class fabada. Resistant plants were selected using resistance tests or combining resistance tests and marker-assisted selection. Lines A252, A321, A493, Sanilac BC6-Are, and BRB130 were used as resistance sources. Resistance genes to anthracnose (Co-2 ( C ), Co-2 ( A252 ) and Co-3/9) and/or BCM (I and bc-3) were introgressed in line A25 through six parallel backcrossing programs, and six breeding lines showing a fabada seed phenotype were obtained after six backcross generations: line A1258 from A252; A1231 from A321; A1220 from A493; A1183 and A1878 from Sanilac BC6-Are; and line A2418 from BRB130. Pyramiding of different genes were developed using the pedigree method from a single cross between lines obtained in the introgression step: line A1699 (derived from cross A1258 × A1220), A2438 (A1220 × A1183), A2806 (A1878 × A2418), and A3308 (A1699 × A2806). A characterization based on eight morpho-agronomic traits revealed a limited differentiation among the obtained breeding lines and the recurrent line A25. However, using a set of seven molecular markers linked to the loci used in the breeding programs it was possible to differentiate the 11 fabada lines. Considering the genetic control of the resistance in resistant donor lines, the observed segregations in the last backcrossing generation, the reaction against the pathogens, and the expression of the molecular markers it was also possible to infer the genotype conferring resistance in the ten fabada breeding lines obtained. As a result of these breeding programs, genetic resistance to three anthracnose races controlled by genes included in clusters Co-2 and Co-3/9, and genetic resistance to BCM controlled by genotype I + bc-3 was combined in the fabada line A3308
Determinación de biomasa forestal mediante la utilización de técnicas de teledetección con imágenes radar. Estudio piloto en ámbito de la provincia de Huelva. REDIAM
Revista oficial de la Asociación Española de Teledetección[EN] Biomass is a very important forest resource in Andalusia. “Forest Biomass in Andalusia” web tool, developed by the Andalusian Government, provides information about the location and biomass stock for the main pine forest species. It is important to mention that information needs to be regularly, quickly, effectively and inexpensively updated. These requirements could be covered with the help of Earth Observation technologies. In this project, radar images have been acquired from ALOS-PALSAR sensor from different years (2008 and 2010) over two pilot areas located in Huelva. The aim of the study has been to develop a methodology to estimate wood volumes based on the statistic correlation between radar signal and wood volume, variable extracted of forest management plans contemporary to images. As result, correlations of 0.8 and 0.7 have been obtained for pine and eucalyptus respectively. Forest biomass has been calculated using species-specific allometric equations. Three key sources of information have been used: a sample of plots distributed homogeneously, an accurate digital terrain model and a current forest map. Furthermore, the study of the variability of estimated volumes between these dates has been carried out. Methodologies obtained could be extrapolated to the whole region.[ES] La biomasa es un recurso forestal de gran importancia en Andalucía. Por ejemplo, la aplicación WEB “Biomasa Forestal en Andalucía” (Consejería de Medio Ambiente y Ordenación del Territorio, 2014) informa al usuario acerca de la ubicación y existencias de biomasa de las principales especies forestales de pino. No obstante, se trata de una información que demanda ser actualizada periódicamente, con rapidez, eficacia y a bajo coste, requisitos que podría cubrir la tecnología basada en Observación de la Tierra. En este artículo se presenta un estudio piloto donde se ha evaluado la tecnología radar, concretamente el sensor ALOS-PALSAR (Advanced Land Observing Satellite - Phased Array type L-band Synthetic Aperture Radar), para medir la biomasa forestal de dos montes públicos de Huelva en Junio de 2008 y de 2010. El objetivo ha sido desarrollar una metodología para la estimación de volúmenes maderables a partir de la correlación estadística de la señal radar con datos coetáneos de volumen maderable, variable extraída de planes de ordenación forestal. Como resultado, se han logrado correlaciones en torno a 0,8 y 0,7 en pino y eucalipto respectivamente. Para la obtención de biomasa a partir de los volúmenes estimados se han usado ecuaciones alométricas específicas para cada especie. Tres son las fuentes de información claves: una muestra de parcelas homogéneamente distribuidas, un modelo digital del terreno preciso y un mapa forestal actual. Por otro lado, se ha llevado a cabo el estudio de la variabilidad de volúmenes estimados entre las fechas mencionadas. La metodología obtenida podría extrapolarse a todo el territorio regional.Méndez, E.; Vales, JJ.; Pino, I.; Granado, L.; Montoya, G.; Prieto, R.; Carpintero, IR.... (2016). Determination of forest biomass using remote sensing techniques with radar images. Pilot study in area of the province of Huelva. REDIAM. Revista de Teledetección. (Special Issue):71-86. doi:10.4995/raet.2016.3984.SWORD7186Special Issu
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