Migración de retorno de Estados Unidos a los municipios metropolitanos del Estado de México 2000-2010

Análisis de las condiciones sociodemográficas de los migrantes retornados a México entre 2000 y 2010.La migración de mexicanos hacia otros países, principalmente a Estados Unidos de Norteamérica, es un fenómeno que ha sido estudiado desde diversos enfoques y metodologías. Uno de las dimensiones del sistema migratorio que mayor atención se ha dado desde 2008 a la fecha es el asociado a la migración de retorno, y llama la atención que los flujos de retorno se han modificado en su dinámica e intensidad, particularmente los que tienen como destino los conglomerados urbanos. Por ello, el presente estudio tiene como objeto analizar, a través de técnicas estadísticas descriptivas y de correlación de variables, las relaciones principales de la migración de retorno en los municipios metropolitanos vs los no metropolitanos del Estado de México con la intensidad migratoria, la marginación y la pobreza; así como describir las características sociodemográficas de quienes retornaron a la entidad diferenciados entre lo metropolitano y no metropolitano para con ello aportar elementos para la definición de estrategias de política públicaCentro de Investigación y Estudios Avanzados de la Población UAEMé

GABAergic synaptic scaling is triggered by changes in spiking activity rather than transmitter receptor activation

Homeostatic plasticity represents a set of mechanisms that are thought to recover some aspect of neural function. One such mechanism called AMPAergic scaling was thought to be a likely candidate to homeostatically control spiking activity. However, recent findings have forced us to reconsider this idea as several studies suggest AMPAergic scaling is not directly triggered by changes in spiking. Moreover, studies examining homeostatic perturbations in vivo have suggested that GABAergic synapses may be more critical in terms of spiking homeostasis. Here we show results that GABAergic scaling can act to homeostatically control spiking levels. We find that increased or decreased spiking in cortical cultures triggers multiplicative GABAergic upscaling and downscaling, respectively. In contrast, we find that changes in AMPAR or GABAR transmission only influence GABAergic scaling through their indirect effect on spiking. We propose that GABAergic scaling, rather than glutamatergic scaling, is a key player in spike rate homeostasis

Cambios en el estilo de vida y nutrición durante el confinamiento por SARS-CoV-2 (COVID-19) en México: un estudio observacional

Introduction: To evaluate the changes implemented in lifestyle and nutrition in the mexican population during the lockdown due to SARS-CoV-2 (COVID-19).Material and methods: Transversal study performed during the lockdown in Mexico. Data was obtained through a digital questionnaire, which was spread through social media. The questionnaire evaluated aspects related to: nutrition, well-being and lifestyle (tobacco and alcohol consumption, physical activity and sleep problems) as well as demographic variables. For the statistical analyses, the chi-square test was used to compare differences between genders, with a statistical significance of 5%, using SPSS 23.0 software.Results: A total of 1084 surveys were analyzed. The average age was 35.5±13.9 years and 66.5% (n=721) were women. In relation to eating before lockdown, 69.8% (n=757) considered their diet healthy, 6.5% (n=99) very healthy and 23.7% (n=228) unhealthy, and 2.3% (n=26) have improved their diet, despite this 17.1% (n=186) of people say they eat all the time these days. In relation to sleep, women sleep less during the period of lockdown (p=0.002) and wake up more during the night when compared to men (p<0.001).Conclusions: Factors like nutrition and sleep have alteration in that time of the lockdown. It is important to mention the relevance of these factors because the good nutrition and rest contribute for a better/ strengthening immunological system.Introducción: Evaluar el consumo de alimentos no saludables y prácticas de estilo de vida en mexicanos durante el confinamiento por SARS-CoV-2 (COVID-19).Material y métodos: Estudio transversal realizado durante parte del confinamiento en México. La recolección de datos fue realizada a través de una encuesta digital. Fueron evaluados aspectos de alimentación, bienestar y estilo de vida (consumo de alcohol y tabaco, actividad física y sueño), además de variables sociodemográficas. Para los análisis estadísticos fueron utilizadas la prueba χ2 para comparar diferencias entre género, con significancia estadística del 5%, utilizando el software SPSS 23.0.Resultados: Fueron analizadas 1084 encuestas. La edad promedio fue de 35,5±13,9 años y el 66,5% (n=721) fueron mujeres. En relación a la alimentación antes del confinamiento, 69,8% (n=757) consideraban su alimentación saludable, 6,5% (n=99) muy saludable y 23,7% (n=228) poco saludable, y el 2,3% (n=26) ha mejorado su alimentación, a pesar de esto el 17,1% (n=186) de las personas dice que en estos días come todo el tiempo. En relación al sueño, las mujeres duermen menos durante el periodo del confinamiento (p=0,002) y despiertan más durante la noche cuando se compara con los hombres (p<0,001).Conclusiones: Factores como la alimentación y el sueño presentaron alteraciones en ese período del confinamiento. Es importante destacar la relevancia de esos factores pues una buena alimentación y el descanso contribuyen para un mejor/fortalecimiento del sistema inmunológico

Neurobiological Mechanisms That Contribute to Stress-related Cocaine Use

The ability of stressful life events to trigger drug use is particularly problematic for the management of cocaine addiction due to the unpredictable and often uncontrollable nature of stress. For this reason, understanding the neurobiological processes that contribute to stress-related drug use is important for the development of new and more effective treatment strategies aimed at minimizing the role of stress in the addiction cycle. In this review we discuss the neurocircuitry that has been implicated in stress-induced drug use with an emphasis on corticotropin releasing factor actions in the ventral tegmental area (VTA) and an important pathway from the bed nucleus of the stria terminalis to the VTA that is regulated by norepinephrine via actions at beta adrenergic receptors. In addition to the neurobiological mechanisms that underlie stress-induced cocaine seeking, we review findings suggesting that the ability of stressful stimuli to trigger cocaine use emerges and intensifies in an intake-dependent manner with repeated cocaine self-administration. Further, we discuss evidence that the drug-induced neuroadaptations that are necessary for heightened susceptibility to stress-induced drug use are reliant on elevated levels of glucocorticoid hormones at the time of cocaine use. Finally, the potential ability of stress to function as a “stage setter” for drug use – increasing sensitivity to cocaine and drug-associated cues – under conditions where it does not directly trigger cocaine seeking is discussed. As our understanding of the mechanisms through which stress promotes drug use advances, the hope is that so too will the available tools for effectively managing addiction, particularly in cocaine addicts whose drug use is stress-driven

Recent trends and developments in pyrolysis-gas chromatography: review

Pyrolysis-gas chromatography (Py-GC) has become well established as a simple, quick and reliable analytical technique for a range of applications including the analysis of polymeric materials. Recent developments in Py-GC technology and instrumentation include laser pyrolysis and non-discriminating pyrolysis. Progress has also been made in the detection of low level polymer additives with the use of novel Py-GC devices. Furthermore, it has been predicted that future advances in separation technology such as the use of comprehensive two-dimensional gas chromatography will further enhance the analytical scope of Py-GC

Atmospheric deposition of soluble trace elements along the Atlantic Meridional Transect (AMT)

We briefly review the role of atmospheric deposition measurements within the Atlantic Meridional Transect (AMT) programme and then go on to present new data on the soluble concentrations of a range of trace metals (Fe, Al, Mn, Ti, Zn, V, Ni and Cu) and major ions in aerosols collected along the AMT transect. The results allow us to identify emission sources of the trace metals particularly in terms of the relative importance of anthropogenic versus crustal sources. We identify strong gradients in concentrations and deposition for both crustal and anthropogenically sourced metals with much higher inputs to the North Atlantic compared to the South Atlantic, reflecting stronger land based emission sources in the Northern Hemisphere. We suggest anthropogenic sources of Ni and V may include an important component from shipping. We consider the extent to which these gradients are reflected in surface water concentrations of these metals based on the GEOTRACES water column trace metal data. We find there is a clear difference in the concentrations of surface water dissolved Al and Fe between the north and south Atlantic gyres reflecting atmospheric inputs. However for Mn, V or Ni, higher inputs to the North Atlantic compared to the South Atlantic are not clearly reflected in their water column concentrations

Ventrolateral Origin of Each Cycle of Rhythmic Activity Generated by the Spinal Cord of the Chick Embryo

BACKGROUND: The mechanisms responsible for generating rhythmic motor activity in the developing spinal cord of the chick embryo are poorly understood. Here we investigate whether the activity of motoneurons occurs before other neuronal populations at the beginning of each cycle of rhythmic discharge. METHODOLOGY/PRINCIPAL FINDINGS: The spatiotemporal organization of neural activity in transverse slices of the lumbosacral cord of the chick embryo (E8-E11) was investigated using intrinsic and voltage-sensitive dye (VSD) imaging. VSD signals accompanying episodes of activity comprised a rhythmic decrease in light transmission that corresponded to each cycle of electrical activity recorded from the ipsilateral ventral root. The rhythmic signals were widely synchronized across the cord face, and the largest signal amplitude was in the ventrolateral region where motoneurons are located. In unstained slices we recorded two classes of intrinsic signal. In the first, an episode of rhythmic activity was accompanied by a slow decrease in light transmission that peaked in the dorsal horn and decayed dorsoventrally. Superimposed on this signal was a much smaller rhythmic increase in transmission that was coincident with each cycle of discharge and whose amplitude and spatial distribution was similar to that of the VSD signals. At the onset of a spontaneously occurring episode and each subsequent cycle, both the intrinsic and VSD signals originated within the lateral motor column and spread medially and then dorsally. By contrast, following a dorsal root stimulus, the optical signals originated within the dorsal horn and traveled ventrally to reach the lateral motor column. CONCLUSIONS/SIGNIFICANCE: These findings suggest that motoneuron activity contributes to the initiation of each cycle of rhythmic activity, and that motoneuron and/or R-interneuron synapses are a plausible site for the activity-dependent synaptic depression that modeling studies have identified as a critical mechanism for cycling within an episode

Planeación, gobernanza y sustentabilidad Retos y desafíos desde el enfoque territorial

Frente a la compleja realidad actual, resulta ineludible el desarrollo de la investigación científica de los fenómenos y procesos urbanos, territoriales y ambientales, que contribuya a su comprensión y la construcción de alternativas de solución a los retos y desafíos vigentes. En este contexto, el abordaje de las ciudades y regiones metropolitanas, el ordenamiento del territorio y la ocupación del espacio, así como la relación sociedad-naturaleza y la complejidad ambiental, precisa la generación de metodologías y procesos de investigación multi e inter disciplinarios que contribuyan a la comprensión de los procesos socioterritoriales, el mejoramiento de las condiciones de vida y la conservación ambiental.Programa de Fortalecimiento de la Calidad Educativa PFCE-2016 proyecto K0313101

Inhibition of Electrical Activity by Retroviral Infection with Kir2.1 Transgenes Disrupts Electrical Differentiation of Motoneurons

Network-driven spontaneous electrical activity in the chicken spinal cord regulates a variety of developmental processes including neuronal differentiation and formation of neuromuscular structures. In this study we have examined the effect of chronic inhibition of spinal cord activity on motoneuron survival and differentiation. Early spinal cord activity in chick embryos was blocked using an avian replication-competent retroviral vector RCASBP (B) carrying the inward rectifier potassium channel Kir2.1. Chicken embryos were infected with one of the following constructs: RCASBP(B), RCASBP(B)-Kir2.1, or RCASBP(B)-GFP. Infection of chicken embryos at E2 resulted in widespread expression of the viral protein marker p27 gag throughout the spinal cord. Electrophysiological recordings revealed the presence of functional Kir2.1 channels in RCASBP(B)-Kir2.1 but not in RCASBP(B)-infected embryos. Kir2.1 expression significantly reduced the generation of spontaneous motor movements in chicken embryos developing in ovo. Suppression of spontaneous electrical activity was not due to a reduction in the number of surviving motoneurons or the number of synapses in hindlimb muscle tissue. Disruption of the normal pattern of activity in chicken embryos resulted in a significant downregulation in the functional expression of large-conductance Ca2+-dependent K+ channels. Reduction of spinal cord activity also generates a significant acceleration in the inactivation rate of A-type K+ currents without any significant change in current density. Kir2.1 expression did not affect the expression of voltage-gated Na+ channels or cell capacitance. These experiments demonstrate that chronic inhibition of chicken spinal cord activity causes a significant change in the electrical properties of developing motoneurons