471 research outputs found
Global gene expression analysis provides insight into local adaptation to geothermal streams in tadpoles of the Andean toad Rhinella spinulosa
Indexación: Web of Science; Scopus.The anuran Rhinella spinulosa is distributed along the Andes Range at altitudes that undergo wide daily and seasonal variation in temperature. One of the populations inhabits geothermal streams, a stable environment that influences life history traits such as the timing of metamorphosis. To investigate whether this population has undergone local adaptation to this unique habitat, we carried out transcriptome analyses in animals from two localities in two developmental stages (prometamorphic and metamorphic) and exposed them to two temperatures (20 and 25 degrees C). RNA-Seq, de novo assembly and annotation defined a transcriptome revealing 194,469 high quality SNPs, with 1,507 genes under positive selection. Comparisons among the experimental conditions yielded 1,593 differentially expressed genes. A bioinformatics search for candidates revealed a total of 70 genes that are highly likely to be implicated in the adaptive response of the population living in a stable environment, compared to those living in an environment with variable temperatures. Most importantly, the population inhabiting the geothermal environment showed decreased transcriptional plasticity and reduced genetic variation compared to its counterpart from the non-stable environment. This analysis will help to advance the understanding of the molecular mechanisms that account for the local adaptation to geothermal streams in anurans.https://www.nature.com/articles/s41598-017-01982-
Role of surface microgeometries on electron escape probability and secondary electron yield of metal surfaces
The influence of microgeometries on the Secondary Electron Yield (SEY) of surfaces is investigated. Laser written structures of different aspect ratio (height to width) on a copper surface tuned the SEY of the surface and reduced its value to less than unity. The aspect ratio of microstructures was methodically controlled by varying the laser parameters. The results obtained corroborate a recent theoretical model of SEY reduction as a function of the aspect ratio of microstructures. Nanostructures - which are formed inside the microstructures during the interaction with the laser beam - provided further reduction in SEY comparable to that obtained in the simulation of structures which were coated with an absorptive layer suppressing secondary electron emission
Capacidad antioxidante en ratas diabéticas rol de la vitamina E
The antioxiclant action of vitamin E was analyzed, the vitamin being administered to diabetic rats, and the changes in glicemia, glycosilated hemoglobin (HbA1c) lipid peroxidation, total antioxidant, albumin and total proteins were evaluated. Four groups of rats were employed: I control II control plus vit E, III diabetics by streptozotocin, IV diabetic plus vit E. After 8 weeks of treatment with insulin (4 U/Kg weight) diabetic animals dosed with vit E improved their glicemia and their HbA1c level decreased. In diabetic and control groups that received vit E lipid peroxidation decreased 25%, compared with those who didn't receive the supplement. These findings suggest that vit E tends to improve glicemia, decrease the HbA1c levels and total antioxidants in diabetic groups.En el presente estudio se analizó el rol antioxidante de la vitamina E, administrada a ratas diabéticas, evaluando los cambios en la glicemia, hemoglobina glicosilada (HbA1c), lipoperoxidación, antioxidantes totales, albúmina y proteínas totales. Se trabajó con 4 grupos de animales de experimentación: I Control, II control más vitamina E (25 mg/día), III Diabético inducidos con estreptozotocina (35 mg/kg) y IV Diabético más vitamina E. Después de 8 semanas de tratamiento, con insulina 4 U/kg de peso observamos que en animales diabéticos con suplemento vitamínico mejora la glicemia y disminuyen los niveles de HbA1c. En los grupos diabéticos y control que recibieron vitamina E disminuyen los niveles de lipoperoxidación en un 25%, comparados con los que no recibieron el suplemento. Nuestros resultados sugieren que la vitamina E tiende a mejorar la glicemia, disminuir la HbA1c y peroxidación lipídica y aumenta los antioxidantes totales en el grupo diabético
Utilización de data almacenada con posicionamiento gps en pen drives o en memorias mmc/sd para la elaboración de mapas que permitan interactuar con google earth para la localización de objetivos y definición de trayectorias
El objetivo de este proyecto es la realización de un software que permita interactuar con GOOGLE EARTH, dado que para lograr su funcionamiento es necesario de las coordenadas enviadas en una trama GPLL, provenientes del módulo GPS. Este software fue desarrollado con la ayuda de JAVA, implementado en NETBEANS. Este programa al recibir las tramas del GPS llamadas NMEA; las convierte en un formato compatible con GOOGLE EARTH, GOOGLE MAPS llamado KML. A lo largo de la explicación en la elaboración de nuestro programa, se van a detallar las herramientas utilizadas en NETBEANS, que nos fue de gran ayuda para lograr el principal objetivo del proyecto, que es la gráfica de rutas. También se explicará todo concerniente a las tramas NMEA, como también la estructura KML. Por último se adjuntará un pequeño tutorial acerca de la utilización de códigos utilizado en nuestro software.FIEC-ESPO
Revisión de los criterios audiométricos en el tratamiento de la hipoacusia neurosensorial mediante audífonos y prótesis auditivas implantables
Sensorineural hearing loss has a high incidence in our population;
as a matter of fact, 50 % of people above 75 years
of age suffer this impairment.
Due to the advances in the devices to alleviate this condition
and their verified efficacy, it is now appropriate to review
the indications for these devices and provide a detailed
description of the audioprosthetic systems used.
These systems can be classified as external non-implantable
devices (hearing aids) and implantable prostheses. The latter
can be sub-divided into active implants in the external
ear or middle ear, cochlear implants, and auditory brainstem
implants (ABI).
Indications for each group are determined by the type and
location of the underlying condition as well as by the
anatomic, functional, and social characteristics of each patient.
It must be stressed that the selection and monitoring
of the treatment is up to the specialist. Generally speaking,
an attempt is made to facilitate the integration of the hypoacusic
patients to their sound setting by enhancing their
understanding of the spoken word and restoring binaurality,
while at the same time, seeking to retain the plasticity of
central auditory routes through the stimulation provided
by any of these systems.
In the course of this review, we refer to newly-emerging
indications in both the field of cochlear implants (bimodal
stimulation, implantation in patients with residual hearing,
bilateral implants, etc) and in the area of ABI in patients
with tumoural disease previously treated with radiosurgery
or patients with non-tumour pathologies presenting malformations
or bilateral cochlear ossification
¿Cuál es su diagnóstico?
ResumenSe trata de un paciente masculino de 58 años de edad, procedente de área rural, que refiere dolor torácico y disfagia, asociado a disnea leve, de inicio hace varios meses. Tiene como antecedente haber presentado cáncer de esófago hace tres años, por lo cual fue operado y sometido a radioterapia; no aporta más información relacionada ni trae estudios previos. Niega otros antecedentes. El examen fisico no muestra hallazgos de importancia
Los sistemas de información en la toma de decisiones gerenciales en las empresas comerciales de Portoviejo: Information systems on managerial decision making in the commercial enterprises of Portoviejo
El presente estudio tiene como objetivo analizar la importancia de los sistemas de información en la toma de decisiones gerenciales en las empresas comerciales de Portoviejo, mediante la aplicación de encuestas a gerentes y directivos a través de un conjunto de preguntas. La metodología aplicada en la investigación permitió describir con exactitud la realidad del problema. El estudio demuestra en qué medida las empresas comerciales de Portoviejo han innovado sus negocios implementando algún sistema de información gerencial y cuán significativa ha sido esta herramienta tecnológica a la hora de tomar decisiones gerenciales en las empresas para renovar su estrategia de negocio y sobrevivir en un contexto donde la calidad y la agilidad son requisitos de competitividad.
Palabras clave: Innovación, Cambios Tecnológicos, Estrategias de negocios, Gestión, Competitividad.
ABSTRACT
This study aims to analyze the importance of the information systems and their impact on managerial decision making in the commercial enterprises of Portoviejo with the implementation of surveys to managers and senior executives applying a set of questions. The methodology applied in the research allowed the researchers to describe accurately the problem. The study demonstrates how commercial enterprises of Portoviejo have changed their business, implementing a management information system and how significant this technological tool is when making managerial decisions in its organization, to change their business strategy and survive in a context where quality and quickness are requirements of competitiveness.
Key words: Innovation, Change of Technology, Business Strategies, Management, Competitiveness
Effect of strain rate on tensile mechanical properties of high-purity niobium single crystals for SRF applications
An investigation of the mechanical properties of high-purity niobium single crystals is presented. Specimens were cut with different crystallographic orientations from a large grain niobium disk and uniaxial tensile tests were conducted at strain rates between 10-4 and 103 s-1. The logarithmic strain rate sensitivity for crystals oriented close to the center of a tensile axis inverse pole figure (IPF) is ~0.14 for all strain rates. The strain at failure (ranging from 0.4 to 0.9) is very sensitive to crystal orientation and maximal at ~10-2 s-1 for crystals oriented close to the center of an IPF. The high anisotropy observed at quasi-static strain rates decreased with increasing strain rate. The activation of multiple slip systems in the dynamic tests could account for this reduction in anisotropy. A transition from strain hardening to softening in the plastic domain was observed at strain rates greater than approximately 6 × 10-2 s-1 for crystals oriented close to the center of a tensile axis IPF. Shear bands were observed in specimens with orientations having similarly high Schmid factors on both {110} and {112} slip families, and they are correlated with reduced ductility. Crystal rotations at fracture are compared for the different orientations using scanning electron microscopy images and EBSD orientation maps. A rotation toward the terminal stable [101] orientation was measured for the majority of specimens (with tensile axes more than ~17° from the [001] direction) at strain rates between 1.28 × 10-2 and 1000 s-1.The authors would like to acknowledge the work of CERN's Materials, Metrology and Non-Destructive Testing (EN-MME-MM) section for granting access to their equipment for specimen preparation and scanning electron microscope (SEM) analyses. The authors would also like to thank Mr. Larry Vladic of Elite Motion LLC for lending us the high-speed camera during the high strain rate tests performed ASU. This Marie Sklodowska-Curie Action (MSCA) Innovative Training Network (ITN) receives funding from the European Union's H2020 Framework Programme under grant agreement no. 764879. T.R. Bieler, D. Kang, E. Pai Kulyadi, P. Eisenlohr, C. Kale, and K.N. Solanki acknowledge support from DOE/OHEP grant DE-SC0009962
Structures of Leishmania Fructose-1,6-Bisphosphatase Reveal Species-Specific Differences in the Mechanism of Allosteric Inhibition
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