2,878 research outputs found
Evolutionary conservation of transcription factors affecting longevity
Gene expression can be optimised for health and longevity through manipulation of transcription factor (TF) activity. The effects of many such TFs are conserved between animal species indicating evolutionary conservation of underlying mechanisms.
Lifespan-determining TFs regulate a plethora of cellular and organismal functions, including stress resistance, metabolism and growth. They interact with each other both within and between cells. Manipulating their activity in a single cell type can often be sufficient to insure longevity.
The evolutionary conservation of their effects on ageing is most likely a reflection of the conservation of their function in processes, such as reproduction, growth, and metabolism, that are important earlier in life. Their effects on early and late life can, however, often be uncoupled
The Chandra Dust Scattering Halo of Galactic Center transient Swift J174540.7-290015
We report the detection of a dust scattering halo around a recently
discovered X-ray transient, Swift J174540.7-290015, which in early February of
2016 underwent one of the brightest outbursts (F_X ~ 5e-10 erg/cm^2/s) observed
from a compact object in the Galactic Center field. We analyze four Chandra
images that were taken as follow-up observations to Swift discoveries of new
Galactic Center transients. After adjusting our spectral extraction for the
effects of detector pileup, we construct a point spread function for each
observation and compare it to the GC field before the outburst. We find
residual surface brightness around Swift J174540.7-290015, which has a shape
and temporal evolution consistent with the behavior expected from X-rays
scattered by foreground dust. We examine the spectral properties of the source,
which shows evidence that the object transitioned from a soft to hard spectral
state as it faded below L_X ~ 1e36 erg/s. This behavior is consistent with the
hypothesis that the object is a low mass X-ray binary in the Galactic Center.Comment: Accepted for publication in Ap
Dust in the Circumgalactic Medium of Low-Redshift Galaxies
Using spectroscopically selected galaxies from the Sloan Digital Sky Survey
we present a detection of reddening due to dust in the circumgalactic medium of
galaxies. We detect the mean change in the colors of "standard crayons"
correlated with the presence of foreground galaxies at z ~0.05 as a function of
angular separation. Following Peek & Graves (2010), we create standard crayons
using passively evolving galaxies corrected for Milky Way reddening and
color-redshift trends, leading to a sample with as little as 2% scatter in
color. We devise methods to ameliorate possible systematic effects related to
the estimation of colors, and we find an excess reddening induced by foreground
galaxies at a level ranging from 10 to 0.5 millimagnitudes on scales ranging
from 30 kpc to 1 Mpc. We attribute this effect to a large-scale distribution of
dust around galaxies similar to the findings of Menard et al. 2010. We find
that circumgalactic reddening is a weak function of stellar mass over the range
-- and note that this
behavior appears to be consistent with recent results on the distribution of
metals in the gas phase.Comment: Submitted to Ap
Importance of the temperature in the interaction plant-geminivirus
Introduction. Geminivirusare plant viruses that have circular single-stranded DNA (ssDNA) genome encapsidated in twinned quasi-icosahedral (geminate) virionsand are a serious threat to diverse economically important crops such as tomato, pepper and cassava. TYLCV (Tomato yellow leaf curl virus) belongs to the genus begomovirus which is by far, the largest of the seven genera in the family Geminiviridae and it is a pathogen that induces a devastating disease in tomato in the Mediterranean region. Cultured tomatoes are often exposed to a combination of extreme heat and infection with TYLCV and this combination leads to intense disease symptoms and yield losses.The impact of temperature over the interaction tomato-
TYLCVhas been characterized (Ghandi et al., 2016) but these results seem to be contradictory to our findings.
Objective. The main objective of this work is to improve our understanding of the impact that high temperature has in the interaction plant-geminivirus.Material and methods. Nicotianabenthamiana plants were infected with TYLCV and growth in a chamber at 21 ºC or at 35 ºC. The amount of virus, symptoms, plant height and number of leaves were monitored at 14, 21 and 28 dpi (days post-infection). Three biological replicates were performed, each containing 15 infected plants and 10 non-infected plants (mock).
Results. No differences were observed between non-infected and infected plants at both temperatures, in plant height or in the number of leaves, but the amount of virus and the severity of symptoms were significantly reduced in plants at high temperature.
Conclusions. We conclude that TYLCV yield decreases in N. benthamiana due to high temperature and ongoing experiments in tomato TYLCV-infected plants will let us determine the
importance of this finding in an agronomical important crop and to compare our results with the published data.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
El método de laboratorio utilizando computación simbólica : una alternativa de aprendizaje en el curso de cálculo de primer año de la Licenciatura en matemática.
El estudio que se presenta determinó las ventajas y limitaciones de implementar el
método de laboratorios, utilizando computación simbólica, en el curso de Cálculo 1 de la
Licenciatura en Matemática. Los fundamentos teóncos que apoyan la ejecución de los
laboratorios a través de la computación simbólica, particularmente en el área de Cálculo,
en matemáticas, fueron sustentados en el marco teórico de la investigación En cuanto a
la metodología empleada se desarrolló un estudio de corte experimental solo con postprueba, en el grupo de estudiantes de primer año de la Licenciatura en Matemática. El
grupo fue subdividido en dos-uno denominado grupo expenrnental quienes
complementaron sus jornadas de clases con laboratorios de computación simbólica El
otro, grupo control, utilizó el método expositivo y solución de prácticas para
complementar la teoría Se comprobó, por medio de la aplicación de la prueba t de
Student para diferencia de medias, la hipótesis planteada de que el rendimiento
académico de los estudiantes que utilizan el método de laboratorios es supenor al que
desarrolla sus ciases por medio de la metodología tradicional expositiva. Los hallazgos
encontrados en esta investigación nos permiten presentar una propuesta para el desarrollo
de un seminario taller en el cual se promueva la implementación del método de
laboratorios, utilizando computación simbólica, en el curso de Cálculo 1 que se ofrecen en
la Licenciatura en Matemática De igual forma, se recomienda la implementación de la
computación simbólica en los diferentes cursos de cálculo que se imparten en la
Universidad de Panamá y en los distintos Centros Regionale
A femtosecond velocity map imaging study on B-band predissociation in CH 3I. II. the 2 0 1 and 3 0 1 vibronic levels
Femtosecond time-resolved velocity map imaging experiments are reported on several vibronic levels of the second absorption band (B-band) of CH 3I, including vibrational excitation in the 2 and 3 modes of the bound 3R 1(E) Rydberg state. Specific predissociation lifetimes have been determined for the 201 and 301 vibronic levels from measurements of time-resolved I*( 2P 12) and CH 3 fragment images, parent decay, and photoelectron images obtained through both resonant and non-resonant multiphoton ionization. The results are compared with our previously reported predissociation lifetime measurements for the band origin 000 [Gitzinger, J. Chem. Phys. 132, 234313 (2010)10.1063/1.3455207]. The result, previously reported in the literature, where vibrational excitation to the C-I stretching mode ( 3) of the CH 3I 3R 1(E) Rydberg state yields a predissociation lifetime about four times slower than that corresponding to the vibrationless state, whereas predissociation is twice faster if the vibrational excitation is to the umbrella mode ( 2), is confirmed in the present experiments. In addition to the specific vibrational state lifetimes, which were found to be 0.85 0.04 ps and 4.34 0.13 ps for the 201 and 301 vibronic levels, respectively, the time evolution of the fragment anisotropy and the vibrational activity of the CH 3 fragment are presented. Additional striking results found in the present work are the evidence of ground state I( 2P 32) fragment production when excitation is produced specifically to the 301 vibronic level, which is attributed to predissociation via the A-band 1Q 1 potential energy surface, and the indication of a fast adiabatic photodissociation process through the repulsive A-band 3A 1(4E) state, after direct absorption to this state, competing with absorption to the 301 vibronic level of the 3R 1(E) Rydberg state of the B-band.Peer Reviewe
MOBFLOW: Movilidad para los procesos de negocio de la organización
Este artículo presenta la plataforma MobFlow (Mobile Flow); un sistema que permite particionar, distribuir, y ejecutar en entornos móviles, procesos de negocio descritos a través del estándar BPEL. También, MobFlow realiza el monitoreo de la ejecución de los procesos de negocio de la organización, los cuales son consumidos en tiempo real en los dispositivos móviles de los empleados. Además de exponer los módulos que componen la plataforma, el artículo presenta la implementación de un prototipo que valida la arquitectura propuesta, y un caso de estudio práctico de un proceso de ventas, que expone el funcionamiento de la plataforma
FtsZ of filamentous, heterocyst-forming cyanobacteria has a conserved N-Terminal peptide required for normal FtsZ polymerization and cell division
Filamentous cyanobacteria grow by intercalary cell division, which should involve distinct steps compared to those producing separate daughter cells. The N-terminal region of FtsZ is highly conserved in the clade of filamentous cyanobacteria capable of cell differentiation. A derivative of the model strain Anabaena sp. PCC 7120 expressing only an FtsZ lacking the amino acids 2-51 of the N-terminal peptide (1N-FtsZ) could not be segregated. Strain CSL110 expresses both 1N-FtsZ, from the endogenous ftsZ gene promoter, and the native FtsZ from a synthetic regulated promoter. Under conditions of 1N-FtsZ predominance, cells of strain CSL110 progressively enlarge, reflecting reduced cell division, and show instances of asymmetric cell division and aberrant Z-structures notably differing from the Z-ring formed by FtsZ in the wild type. In bacterial 2-hybrid assays FtsZ interacted with 1N-FtsZ. However, 1N-FtsZ-GFP appeared impaired for incorporation into Z-rings when expressed together with FtsZ. FtsZ, but not 1N-FtsZ, interacted with the essential protein SepF. Both FtsZ and 1N-FtsZ polymerize in vitro exhibiting comparable GTPase activities. However, filaments of FtsZ show a distinct curling forming toroids, whereas 1N-FtsZ form thick bundles of straight filaments. Thus, the N-terminal FtsZ sequence appears to contribute to a distinct FtsZ polymerization mode that is essential for cell division and division plane location in Anabaena.Agencia Estatal de Investigación BFU2013-44686-P BFU2016-77097-
Morphological Study of Granular-Granular Impact Craters through Time-of-Flight Cameras: from Concept to Automation in Python
Laboratory made granular-granular impact craters have been used as model
analogues of planetary impact craters. These kind of craters have been observed
and studied using profilometry techniques that allow to retrieve important
morphologic features from the impacted surface. In this work, we propose to use
a Time-of-Flight camera (Microsoft Kinect One) for the acquisition of depth
data. We show comparisons between the typically used technique and the analysis
derived from the Time-of-Flight data. We also release craterslab, a Python
library developed to automate most of the tasks from the process of studying
impact craters produced by granular projectiles hitting on the surface of
granular targets. The library is able to acquire, identify, and measure
morphological features of impacted surfaces through the reconstruction of 3D
topographic maps. Our results show that using a Time-of-Flight camera and
automating the data processing with a software library for the systematic study
of impact craters can produce very accurate results while reducing the time
spent on different stages of the process
Propuesta educativa innovadora para el autocontrol del diabético del Hospital Nicolás A. Solano. Año 2001
Este estudio es descriptivo-transversal, con un diseño cuali-cuantitativo En la
recolección de información se utilizó una encuesta estructurada y guías de
entrevistas a profundidad. Se aplicó el Modelo PRECEDE para la formulación de
una propuesta de capacitación a pacientes diabéticos Este método de
planificación estratégica de educación para la salud exige el diagnóstico de
todos los factores importantes (predisponentes, facilitadores y reforzadores del
comportamiento), antes de diseñar la intervención educativa Para ello, se
realizaron los diagnósticos Social, en el que se hicieron consideraciones sobre
la calidad de vida de los pacientes; el Diagnóstico Epidemiológico, mediante la
utilización de datos proporcionados por los registros estadísticos y la encuesta
estructurada, el Diagnóstico Conductual para identificar las conductas
relacionadas con la salud y el autocontrol de la Diabetes Mellitus, así como los
factores no conductuales del problema, el Diagnóstico Educativo para identificar
y categonzar los factores que tienen impacto directo en las conductas y un
Diagnóstico Administrativo para conocer las limitaciones de la organización
Esto facilitó el diseño de una propuesta de capacitación para el autocontrol de
los pacientes diabéticos. La misma se desarrolla en cuatro sesiones, mediante
un diseño modular por cada contenido educativo. El estudio refleja que la
mayoría de estos pacientes depende económicamente de su familia, tiene un
nivel de escolandad aceptable. Un gran porcentaje es casado o unido
Identifican correctamente la enfermedad y sus complicaciones Creen que su
enfermedad es controlable y que son capaces de su autocontrol, saben que el
ejercicio y la actividad física son importantes, pero un alto porcentaje es
sedentario. Manifiestan que siguen su dieta, sin embargo, un número importante
no come a horas fijas y cree que su alimentación es diferente a la del resto de la
familia Estos elementos fueron considerados en la formulación de la propuesta
educativa
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