El desempleo : su incidencia en la identidad y la violencia personal y social : un desafío para el orientador

Nuestra sociedad actual sufre de contradicciones y las personas de incertidumbre. Para elegir en el presente inmediato, se necesita saber qué opciones existen y qué condiciones se tienen, pero para decidir un futuro ocupacional, se debe poder imaginarlo con los datos del presente y con su proyección en el porvenir. Creemos que si se percibe al futuro con alta ambigüedad y desconfianza, mal se puede responder a la propuesta - exigencia de elegir hoy un camino para el mañana. Nuestra hipótesis es que la incertidumbre es un mal mayor que tener una imagen negativa, ya que ésta puede derivar en propuestas correctoras. La incertidumbre paraliza o mueve la violencia que exige definiciones o descarga frustraciones. La desocupación y el desempleo aumentan la desesperanza y la violencia, razón por la cual debe prepararse el orientador vocacional ocupacional para incluirlas en su tarea, en tanto y en cuanto los factores estudiados son vividos por los consultantes como amenaza a la identidad personal y ocupacional

Binding and uptake of H-ferritin are mediated by human transferrin receptor-1

Ferritin is a spherical molecule composed of 24 subunits of two types, ferritin H chain (FHC) and ferritin L chain (FLC). Ferritin stores iron within cells, but it also circulates and binds specifically and saturably to a variety of cell types. For most cell types, this binding can be mediated by ferritin composed only of FHC (HFt) but not by ferritin composed only of FLC (LFt), indicating that binding of ferritin to cells is mediated by FHC but not FLC. By using expression cloning, we identified human transferrin receptor-1 (TfR1) as an important receptor for HFt with little or no binding to LFt. In vitro, HFt can be precipitated by soluble TfR1, showing that this interaction is not dependent on other proteins. Binding of HFt to TfR1 is partially inhibited by diferric transferrin, but it is hindered little, if at all, by HFE. After binding of HFt to TfR1 on the cell surface, HFt enters both endosomes and lysosomes. TfR1 accounts for most, if not all, of the binding of HFt to mitogen-activated T and B cells, circulating reticulocytes, and all cell lines that we have studied. The demonstration that TfR1 can bind HFt as well as Tf raises the possibility that this dual receptor function may coordinate the processing and use of iron by these iron-binding molecules

Myxobacteria: Moving, Killing, Feeding, and Surviving Together

The Supplementary Material for this article can be found online at: http://journal.frontiersin.org/article/10.3389/fmicb.2016.00781Myxococcus xanthus, like other myxobacteria, is a social bacterium that moves and feeds cooperatively in predatory groups. On surfaces, rod-shaped vegetative cells move in search of the prey in a coordinated manner, forming dynamic multicellular groups referred to as swarms. Within the swarms, cells interact with one another and use two separate locomotion systems. Adventurous motility, which drives the movement of individual cells, is associated with the secretion of slime that forms trails at the leading edge of the swarms. It has been proposed that cellular traffic along these trails contributes to M. xanthus social behavior via stigmergic regulation. However, most of the cells travel in groups by using social motility, which is cell contact-dependent and requires a large number of individuals. Exopolysaccharides and the retraction of type IV pili at alternate poles of the cells are the engines associated with social motility. When the swarms encounter prey, the population of M. xanthus lyses and takes up nutrients from nearby cells. This cooperative and highly density-dependent feeding behavior has the advantage that the pool of hydrolytic enzymes and other secondary metabolites secreted by the entire group is shared by the community to optimize the use of the degradation products. This multicellular behavior is especially observed in the absence of nutrients. In this condition, M. xanthus swarms have the ability to organize the gliding movements of 1000s of rods, synchronizing rippling waves of oscillating cells, to form macroscopic fruiting bodies, with three subpopulations of cells showing division of labor. A small fraction of cells either develop into resistant myxospores or remain as peripheral rods, while the majority of cells die, probably to provide nutrients to allow aggregation and spore differentiation. Sporulation within multicellular fruiting bodies has the benefit of enabling survival in hostile environments, and increases germination and growth rates when cells encounter favorable conditions. Herein, we review how these social bacteria cooperate and review the main cell–cell signaling systems used for communication to maintain multicellularity.This work has been funded by the Spanish Government (grants CSD2009-00006 and BFU2012-33248, 70% funded by FEDER) and Junta de Andalucía (group BIO318)

Prevención del Burnout de docentes de nivel medio

Premios: Ayudas a la Investidación Ignacio Larramendi, 201