Revisiting the Relationship of Transient-storage and Aggregated Dead Zone Models of Longitudinal Solute Transport in Streams

Eco-Hydraulics and Eco-Hydrolog

WKB formalism and a lower limit for the energy eigenstates of bound states for some potentials

In the present work the conditions appearing in the WKB approximation formalism of quantum mechanics are analyzed. It is shown that, in general, a careful definition of an approximation method requires the introduction of two length parameters, one of them always considered in the text books on quantum mechanics, whereas the second one is usually neglected. Afterwards we define a particular family of potentials and prove, resorting to the aforementioned length parameters, that we may find an energy which is a lower bound to the ground energy of the system. The idea is applied to the case of a harmonic oscillator and also to a particle freely falling in a homogeneous gravitational field, and in both cases the consistency of our method is corroborated. This approach, together with the Rayleigh--Ritz formalism, allows us to define an energy interval in which the ground energy of any potential, belonging to our family, must lie.Comment: Accepted in Modern Physics Letters

Cell Cycle–related Changes in the Conducting Properties of r-eag K+ Channels

Release from arrest in G2 phase of the cell cycle causes profound changes in rat ether-à-go-go (r-eag) K+ channels heterologously expressed in Xenopus oocytes. The most evident consequence of the onset of maturation is the appearance of rectification in the r-eag current. The trigger for these changes is located downstream of the activation of mitosis-promoting factor (MPF). We demonstrate here that the rectification is due to a voltage-dependent block by intracellular Na+ ions. Manipulation of the intracellular Na+ concentration indicates that the site of Na+ block is located ∼45% into the electrical distance of the pore and is only present in oocytes undergoing maturation. Since the currents through excised patches from immature oocytes exhibited a fast rundown, we studied CHO-K1 cells permanently transfected with r-eag. These cells displayed currents with a variable degree of block by Na+ and variable permeability to Cs+. Partial synchronization of the cultures in G0/G1 or M phases of the cell cycle greatly reduced the variability. The combined data obtained from mammalian cells and oocytes strongly suggest that the permeability properties of r-eag K+ channels are modulated during cell cycle–related processes

Salud e inmigración en el contexto de esta crisis económica y de valores:el ejemplo de España

Los principales determinantes de la salud de las personas y de las comunidades son sociales y por tanto así deberán ser sus soluciones. En el caso de la población inmigración existe una excepción a esta regla ya que a su llegada por diversos motivos (que pueden resumirse en el 'healthy migration effect') suelen presentar una salud superior a la población que los acoge. No obstante, con el transcurso de los años está salud tiende a deteriorarse. Los Sistemas Sanitarios Públicos de cobertura Universal han demostrado su capacidad de reducir las desigualdades sanitarias. La Unión Europea en diversos documentos ha enfatizado la importancia de garantizar una adecuada atención sanitaria a toda la población incluyendo la inmigrante. España era un referente mundial en este sentido al garantizar la accesibilidad al Sistema Sanitario de todos los inmigrantes independientemente de su situación administrativa. No obstante, a raíz del Real Decreto Ley 12/2012, el Gobierno Español ha excluido a unas 900.000 de este Derecho provocando un grave problema humano, ético y sanitario ante el que distintos colectivos sociales y profesionales han manifestado su oposición

Optimal Control in the Treatment of Retinitis Pigmentosa

Numerous therapies have been implemented in an effort to minimize the debilitating effects of the degenerative eye disease Retinitis Pigmentosa (RP), yet none have provided satisfactory long-term solution. To date there is no treatment that can halt the degeneration of photoreceptors. The recent discovery of the RdCVF protein has provided researchers with a potential therapy that could slow the secondary wave of cone death. In this work, we build on an existing mathematical model of photoreceptor interactions in the presence of RP and incorporate various treatment regiments via RdCVF. Our results show that an optimal control exists for the administration of RdCVF. In addition, our numerical solutions show the experimentally observed rescue effect that the RdCVF has on the cones

Coupled channel effects in the scattering of 6,7Li BY 58Ni

Using a single-particle description of 6,7Li and Woods-Saxon generated wavefunctions for 58Ni matter density distribution, the diagonal and transition densities are calculated. Folding these densities with the M3Y effective interaction, the coupling and diagonal potentials are obtained. Coupled channel calculations for 6,7Li on 58Ni at bombarding energies in a range from 12 to 74 MeV are performed. It is shown that the predictions of the coupled channel calculations are consistent with those of optical model calculations using folded potentials renormalized by a factor 0.6 in the entire range of energies

Avaliação do bem-estar de cavalos montados no desfile nacional de cavalos da Costa Rica

The National Horse Parade of Costa Rica (NHPCR) is an equestrian event held annually to celebrate the national day of the horse rider. Public concern regarding the welfare of horses and riders during the event has increased due to the removal of horses in poor body condition, spine injuries, and hoof problems. An Assessment of horse behavior and stress response during these events has never been conducted. The objective of this study was to evaluate the horse behavior, fecal glucocorticoid metabolites and body weight as indicators of welfare during the NHPCR. In the Experiment 1, body weight and fecal glucocorticoid metabolites were measured in 13 Costarricense de Paso horses participating in the NHPCR. All measures were recorded at the horses' home stable 48 hours before and 24 hours after the event. In Experiment 2, three stations (equally spaced along the 3-kilometer parade route) were used to randomly conduct a scan sampling of the behavior of 513 horses. Eye-wrinkle and eye-white presence were recorded on 48 horses using photographs taken during the event. Fecal glucocorticoid metabolites showed no significant differences (p>0.05) at the two time points in the horses evaluated, and there was a significant weight loss (-7.08 kg) 24 hours after the event (p=0.00034). The scan sampling provided evidence that traits such as sweating (60.74%), bit chewing (54.70%), and active gait (65%) were more common than head tossing (28.88%), neck above the withers (6.83%), hyperflexion (28.71%), and ears pinned backwards (31.19%). A strong eye wrinkle was detected on 70% of the horses, while only 16% had the presence of eye-white. Although our results for fecal glucocorticoid metabolites were not conclusive, other behavioral traits indicated that over fifty per cent of the horses attending the NHPCR experience some level of stress.El Tope Nacional de Costa Rica (NHPCR) es un evento ecuestre realizado anualmente para celebrar el día nacional del caballista. La preocupación pública sobre el bienestar de los caballos y jinetes ha aumentado debido a mala condición corporal, lesiones en columna, problemas de cascos y dificultades en carga y descarga. Aunque se han implementado acciones para salvaguardar el bienestar de los caballos en años recientes, no se ha evaluado su comportamiento y los niveles de estrés durante este evento. El objetivo del estudio fue evaluar el comportamiento, los metabolitos de glucocorticoides en heces y el peso corporal como indicadores de bienestar de caballos durante el NHPCR. En el Experimento 1 se determinó el peso corporal y los niveles de cortisol fecal en 13caballos Costarricense de Paso 48-horas antes y 24-horas después del evento. En el Experimento 2, tres estaciones (equidistantes a lo largo de la ruta de 3 kilómetros del recorrido) se usaron para evaluar el comportamiento de 513caballos. Se registró la presencia de arrugas y conjuntiva del ojo en 48caballos con fotografías tomadas en el evento. No hubo diferencias significativas (p>0,05) en el análisis de metabolitos de glucocorticoides fecales en los dos momentos de muestreo y hubo una pérdida significativa (p=0,00034) de peso 24-horas después del evento (-7,08kg). Se halló evidencia de que características como la sudoración (60,74%), mordisqueo del bocado (54,70%) y paso activo (65%) fueron más comunes que la sacudida de cabeza (28,88%), cuello levantado (6,83%), hiperflexión del cuello (28,71%) y orejas posicionadas hacia atrás (31,19%) durante el evento. Se detectó una arruga fuerte en los ojos (70%) y presencia de la conjuntiva (16%) en los caballos. Aunque los resultados de glucocorticoides fecales no fueron concluyentes, otras características de comportamiento indicaron que más de la mitad de los caballos asistentes al NHPCR experimentan algún nivel de estrés.O Tope Nacional de Costa Rica (NHPCR) é um evento equestre realizado anualmente para celebrar o Dia Nacional do Cavaleiro. A preocupação do público com o bem-estar dos cavalos e cavaleiros aumentou devido ao número de cavalos retirados do evento com inadequadas condições corporais, lesões na coluna vertebral, problemas nos cascos e dificuldades de carga e descarga. Embora ações tenham sido implementadas para salvaguardar o bem-estar dos cavalos nos últimos anos, seu comportamento e os níveis de estresse durante este evento não foram avaliados. O objetivo do estudo foi avaliar ocomportamento, os metabolitos de glicocorticoides em fezes e o peso corporal como indicadores de bem-estar dos equinos durante o NHPCR. No Experimento 1, o peso corporal e os níveis de cortisol fecal foram medidos em 13 cavalos da Costa Rica Paso 48 horas antes e 24 horas após o evento. No Experimento 2, três estações (igualmente espaçadas ao longo do percurso de 3 quilômetros) foram usadas para avaliar o comportamento de 513 cavalos. A presença de rugas e conjuntiva ocular foi registrada em 48 cavalos com fotografias tiradas no evento. Não houve diferenças significativas (p>0,05) na análise dos metabólitos fecais de glicocorticoides nos dois momentos de amostragem e houve perda de peso significativa (p=0,00034) 24 horas após o evento (-7,08 kg). Evidenciou-se que características como sudorese (60,74%), mordeduras (54,70%) e marcha ativa (65%) foram mais comuns do que sacudir a cabeça (28,88%), pescoço levantado (6,83%), hiperflexão do pescoço (28,71). %) e orelhas posicionadas para trás (31,19%) durante o evento. Forte enrugamento dos olhos (70%) e presença da conjuntiva (16%) foram detectados nos cavalos. Embora os resultados de glicocorticoides fecais tenham sido inconclusivos, outras características comportamentais indicaram que mais da metade dos cavalos atendidos no NHPCR experimentam algum nível de estresse

Optimal control with MANF treatment of photoreceptor degeneration

People afflicted with diseases such as retinitis pigmentosa and age-related macular degeneration experience a decline in vision due to photoreceptor degeneration, which is currently unstoppable and irreversible. Currently there is no cure for diseases linked to photoreceptor degeneration. Recent experimental work showed that mesencephalic astrocyte-derived neurotrophic factor (MANF) can reduce neuron death and, in particular, photoreceptor death by reducing the number of cells that undergo apoptosis. In this work, we build on an existing system of ordinary differential equations that represent photoreceptor interactions and incorporate MANF treatment for three experimental mouse models having undergone varying degrees of photoreceptor degeneration. Using MANF treatment levels as controls, we investigate optimal control results in the three mouse models. In addition, our numerical solutions match the experimentally observed surviving percentage of photoreceptors and our uncertainty and sensitivity analysis identifies significant parameters in the math model both with and without MANF treatment

Evidence of strong effects of the 11Be halo structure on reaction processes at energies around the Coulomb barrier

The collision induced by the three Beryllium isotopes, 9,10,11Be, on 64Zn target were investigated at Ec.m. ¿ 1.4 the Coulomb barrier. Elastic scattering angular distributions were measured for the 9,10Be collisions whereas, in the 11Be case the quasielastic scattering angular distribution was obtained. A strong damping of the quasielastic cross-section was observed in the 11Be case, especially in the angular range around the Coulomb-nuclear interference peak. In this latter case a large total-reaction cross-section is found, more than a factor of two larger than the ones extracted in the reactions induced by the non-halo Beryllium isotopes. A large contribution to the total-reaction cross-section in the 11Be case could be attributed to transfer and/or break-up events

Gravity or turbulence? -III. Evidence of pure thermal Jeans fragmentation at ~0.1 pc scale

We combine previously published interferometric and single-dish data of relatively nearby massive dense cores that are actively forming stars to test whether their `fragmentation level' is controlled by turbulent or thermal support. We find no clear correlation between the fragmentation level and velocity dispersion, nor between the observed number of fragments and the number of fragments expected when the gravitationally unstable mass is calculated including various prescriptions for `turbulent support'. On the other hand, the best correlation is found for the case of pure thermal Jeans fragmentation, for which we infer a core formation efficiency around 13 per cent, consistent with previous works. We conclude that the dominant factor determining the fragmentation level of star-forming massive dense cores at 0.1 pc scale seems to be thermal Jeans fragmentation.Comment: accepted in MNRA