Genetic diversity and genetic structure of an endemic Mexican Dusky Rattlesnake (Crotalus triseriatus) in a highly modified agricultural landscape: implications for conservation

ArtículoIt is necessary to determine genetic diversity of fragmented populations in highly modified landscapes to understand how populations respond to land-use change. This information will help guide future conservation and management strategies. We conducted a population genetic study on an endemic Mexican Dusky Rattlesnake (Crotalus triseriatus) in a highly modified landscape near the Toluca metropolitan area, in order to provide crucial information for the conservation of this species. There was medium levels of genetic diversity, with a few alleles and genotypes. We identified three genetically differentiated clusters, likely as a result of different habitat cover type. We also found evidence of an ancestral genetic bottleneck and medium values of effective population size. Inbreeding coefficients were low and there was a moderate gene flow. Our results can be used as a basis for future research and C. triseriatus conservation efforts, particularly considering that the Trans-Mexican Volcanic Belt is heavily impacted by destructive land-use practices

Corrector de factor de potencia con lazo PID sintonizado por algoritmos genéticos

The boost converter is widely used in voltage regulation applications and active power factor correction (PFC), its proper operation and performance are directly related to final design of its control loop. The design of this control is somewhat complex due to the nonlinearity of its behavior; the commutation of a switch (power transistor) makes the equivalent circuit change continually over time (two alternating circuits in time). In this work, it is defined the poles of the transfer function in closed loop for the average model (linear model approximate) of the boost converter using evolutionary principles of genetic algorithms, with the idea of improving the dynamic response of voltage regulator. The design outline is successfully verified by simulation and on a laboratory prototype, and improvements were found in the dynamic (voltage overshoot and response time) compared to classical schemes.El convertidor boost es ampliamente utilizado en aplicaciones de regulación de voltaje y corrección activa del factor de potencia (PFC), su adecuada operación y desempeño están directamente relacionados al diseño final de su lazo de control. El diseño de éste control es bastante complejo debido a la no linealidad de su comportamiento; la conmutación de un interruptor (transistor de potencia) hace que el circuito equivalente cambie continuamente a lo largo del tiempo (dos circuitos alternados en el tiempo). En éste trabajo, se definen los polos de la function de transferencia en lazo cerrado para el modelo promedio (modelo lineal aproximado) del convertidor boost utilizando los principios evolutivos de los algoritmos genéticos, con la idea de mejorar la respuesta dinámica del regulador de voltaje. El principio de diseño es verificado exitosamente por simulación y sobre un prototipo de laboratorio, sobre los cuales se encontró mejoras en la respuesta dinámica (sobrepaso de voltaje y tiempo de respuesta) frente a esquemas clásicos

Carcinoma epidermoide en párpados. Presentación de un caso

Desde el punto de vista clínico muchas de las lesiones neoplásicas y seudoneoplásicas del párpado y la conjuntiva son confundibles, por lo que se hace necesario realizar un examen anatomopatológico para el diagnóstico y tratamiento correcto. Se presenta el caso de una paciente de 84 años, atendida en el Servicio de Oftalmología del Hospital Gustavo Aldereguía Lima, de Cienfuegos, por presentar una lesión amplia, ulcerada y vascularizada que se encontraba en párpado superior en su porción interna, cabeza de la ceja del ojo derecho y párpado inferior del ojo izquierdo. Se le realizó biopsia, mediante la que se detectó un carcinoma epidermoide, para lo que se le realizó una exéresis amplia de la región afectada mediante tratamiento quirúrgico y se le reconstruyó toda la zona a través de la técnica de Tenzel para poder mejorar la calidad de vida de la paciente. Por haberse presentado de manera bilateral, lo que es poco frecuente, se decidió la presentación del caso

Salinity induces specific metabolic changes in sugarcane shoot explants in temporary immersion bioreactors

There is a great demand of salt-tolerant sugarcane planting material in Cuba. Temporary immersion bioreactors (TIB) are effective to significantly increase sugarcane in vitro shoot proliferation rate from 1:4 in conventional containers to about 1:35. Sugarcane micropropagation in TIBs under NaCl stress may help screen mutants with salinity tolerance. We developed the experiment shown here to identify a NaCl concentration able to stress shoot in TIBs. At 30 days of culture initiation with different NaCl levels (0 - 200 mM), explant multiplication rate, shoot cluster fresh mass, and levels of aldehydes, chlorophylls, carotenoids and phenolics were determined in the plant material. Content of soluble phenolics in the culture medium was also evaluated. Addition of NaCl decreased shoot multiplication rate and fresh mass. Other statistically significant differences were recorded but the most important were noted in the increased contents of carotenoids, malondialdehyde, other aldehydes and soluble phenolics in the plants, and in the soluble phenolics in the culture medium. This research may be useful for future experiments of in vitro selection of new sugarcane genetic materials with NaCl tolerance. Fifty percent of multiplication rate was reduced with 89 mM NaCl which can be used to stress shoots during micropropagation in TIBs and eventually detect mutants with salt tolerance

Publicidad en la revista Proa durante los años cincuenta. Estudio gráfico e inventariado

More than a half of the pages from any classic issue of Proa Magazine are dedicated to advertising. Although it is a vital content for Proa, it has been traditionally treated as secondary material. Through a graphic study and an inventory, this research provides data about which design technics were used for the elaboration of the adverts, which were its references, what kind of companies advertised and what commitment did they have with the Colombian architectural associations of that time. This study shows the importance of advertising in Proa as a primary source of documentation, and tests research tools that could be applied to the analysis of advertising in architecture magazines outside the Colombian context

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

Planificación y diseño de recursos para poner en marcha la versión on-line del Máster oficial las TIC en Educación

Memoria ID-0180. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2014-2015