Demographic History of Indigenous Populations in Mesoamerica Based on mtDNA Sequence Data

The genetic characterization of Native American groups provides insights into their history and demographic events. We sequenced the mitochondrial D-loop region (control region) of 520 samples from eight Mexican indigenous groups. In addition to an analysis of the genetic diversity, structure and genetic relationship between 28 Native American populations, we applied Bayesian skyline methodology for a deeper insight into the history of Mesoamerica. AMOVA tests applying cultural, linguistic and geographic criteria were performed. MDS plots showed a central cluster of Oaxaca and Maya populations, whereas those from the North and West were located on the periphery. Demographic reconstruction indicates higher values of the effective number of breeding females (Nef) in Central Mesoamerica during the Preclassic period, whereas this pattern moves toward the Classic period for groups in the North and West. Conversely, Nef minimum values are distributed either in the Lithic period (i.e. founder effects) or in recent periods (i.e. population declines). The Mesomerican regions showed differences in population fluctuation as indicated by the maximum Inter-Generational Rate (IGRmax): i) Center-South from the lithic period until the Preclassic; ii) West from the beginning of the Preclassic period until early Classic; iii) North characterized by a wide range of temporal variation from the Lithic to the Preclassic. Our findings are consistent with the genetic variations observed between central, South and Southeast Mesoamerica and the North-West region that are related to differences in genetic drift, structure, and temporal survival strategies (agriculture versus hunter-gathering, respectively). Interestingly, although the European contact had a major negative demographic impact, we detect a previous decline in Mesoamerica that had begun a few hundred years before

Performance Sensitivity to the High-Order Statistics of Time Interval Variables in Cellular Networks

Cell dwell time (DT) and unencumbered interruption time (IT) are fundamental time interval variables in the teletraffic analysis for the performance evaluation of mobile cellular networks. Although a diverse set of general distributions has been proposed to model these time interval variables, the effect of their moments higher than the expected value on system performance has not been reported in the literature. In this paper, sensitivity of teletraffic performance metrics of mobile cellular networks to the first three standardized moments of both DT and IT is investigated in a comprehensive manner. Mathematical analysis is developed considering that both DT and IT are phase-type distributed random variables. This work includes substantial numerical results for quantifying the dependence of system level performance metrics to the values of the first three standardized moments of both DT and IT. For instance, for a high mobility scenario where DT is modeled by a hyper-Erlang distribution, we found that call forced termination probability decreases around 60% as the coefficient of variation (CoV) and skewness of DT simultaneously change from 1 to 20 and from 60 to 2, respectively. Also, numerical results confirm that as link unreliability increases the forced termination probability increases while both new call blocking and handoff failure probabilities decrease. Numerical results also indicate that for low values of skewness, performance metrics are highly sensitive to changes in the CoV of either the IT or DT. In general, it is observed that system performance is more sensitive to the statistics of the IT than to those of the DT. Such understanding of teletraffic engineering issues is vital for planning, designing, dimensioning, and optimizing mobile cellular networks

Progressive vaccinia acquired through zoonotic transmission in a patient with HIV/AIDS, Colombia

In March 2015, a patient in Colombia with HIV/AIDS was hospitalized for disseminated ulcers after milking cows that had vesicular lesions on their udders. Vaccinia virus was detected, and the case met criteria for progressive vaccinia acquired by zoonotic transmission. Adherence to an optimized antiretroviral regimen resulted in recovery. © 2020 Centers for Disease Control and Prevention (CDC). All rights reserved

Progressive vaccinia acquired through zoonotic transmission in a patient with HIV/AIDS, Colombia

In March 2015, a patient in Colombia with HIV/AIDS was hospitalized for disseminated ulcers after milking cows that had vesicular lesions on their udders. Vaccinia virus was detected, and the case met criteria for progressive vaccinia acquired by zoonotic transmission. Adherence to an optimized antiretroviral regimen resulted in recovery. © 2020 Centers for Disease Control and Prevention (CDC). All rights reserved

Progressive vaccinia acquired through zoonotic transmission in a patient with HIV/AIDS, Colombia

In March 2015, a patient in Colombia with HIV/AIDS was hospitalized for disseminated ulcers after milking cows that had vesicular lesions on their udders. Vaccinia virus was detected, and the case met criteria for progressive vaccinia acquired by zoonotic transmission. Adherence to an optimized antiretroviral regimen resulted in recovery

Familia, escuela y desarrollo humano : rutas de investigación educativa

Hay una ruptura entre familia y escuela. La familia tiende a mirar la escuela como guardería, o el sitio seguro donde sus hijos pueden estar mientras los padres trabajan; y la tiende a considerar como lo mínimo que puede ofrecer para que su descendencia sea alguien en la vida. La escuela, por su parte, tiende a observar a la familia como un contexto lejano a ella que no debe entrometerse en los asuntos curriculares ni en la planeación institucional. Las relaciones de la escuela con la familia suelen ser más burocráticas y sancionatorias que de colaboración. Frente a esto, no es banal indagar acerca de las relaciones entre familia y escuela, entre familia y profesionales de la educación, pues se plantea la necesidad de un entendimiento mutuo entre ambos contextos de desarrollo y aprovechar el potencial educativo de la relación entre las dos instituciones