Synthesis of the nuclear protein cyclin in growing, senescent and morphologically transformed human skin fibroblasts

AbstractQuantitative two-dimensional gel electrophoretic analysis (IEF) of the nuclear polypeptide cyclin in normal human skin biopsies, growing and senescent fibroblasts and morphologically transformed skin fibroblasts (limited life span) has revealed a direct correlation between the levels of this protein and the proliferative state of the cells. These results strengthen the notion that cyclin may be a key component of the pathway(s) that control cell proliferation

El suministro de personal en el ordenamiento juridico chileno: recepcion de la figura y regulacion aplicable.

38 p.El objeto de estudio del presente trabajo es la relación laboral contenida en la figura del suministro de personal. El problema jurídico consiste en determinar a qué parte de dicha figura corresponde el rol de empleador. Dado que nuestra legislación laboral carece de regulación para ésta figura, tres son las hipótesis planteadas, el rol de empleador corresponde a: 1. suministrador y usuario conjuntamente. 2. únicamente al suministrador, por estar vinculado al trabajador mediante un contrato de trabajo. 3. al usuario, por ser quién efectivamente utiliza los servicios del trabajador. Para investigar y responder adecuadamente el problema planteado, se realizará primeramente un examen legislativo tendiente a analizar las normas aplicables a la relación de trabajo en estudio, luego de lo cual se efectuará un estudio jurisprudencial a fin de conocer las doctrinas adheridas tanto por la jurisprudencia judicial como administrativa. Finalmente, se expondrá la doctrina sostenida por la autora

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Cambios morfofisiológicos y riesgo de caídas en el adulto mayor: una revisión

El envejecimiento es un proceso universal, irreversible e individual que provoca cambios morfofisiológicos en los sistemas músculo-esquelético, sistema nervioso central y los sistemas sensoriales (visual, vestibular y propiocepción), ocasionando mayor riesgo de caídas. Las caídas tienen una alta prevalencia y se han transformado en un importante problema de salud pública debido a los altos costos económicos y funcionales que representan en el adulto mayor. Para evitar éstos eventos es importante conocer los cambios anatomofisiológicos asociados al envejecimiento y planear estrategias de salud en donde se incorpore estimulación ósea, muscular, somatosensorial (propioceptiva) y cognitiva con el propósito de evitar el deterioro funcional y la discapacidad. En base a lo anterior, el objetivo de esta revisión es exponer el conocimiento actual de los cambios morfofisiológicos involucrados en el riesgo de caídas del adulto mayor

Electrical coupling in the retina ganglion cell layer increases the dynamic range

CAPESCNPqFrom The Twenty Third Annual Computational Neuroscience Meeting: CNS*2014 Québec City, Canada. 26-31 July 201

Joint effect of physical activity and sedentary behaviour on cardiovascular risk factors in Chilean adults

Background: To investigate the associations between combined categories of moderate-to-vigorous physical activity (MVPA) and sedentary behaviour (SB) with markers of adiposity and cardiovascular risk in adults. Methods: Overall, 5040 participants (mean age 46.4 years and 59.3% women) from the cross-sectional Chilean National Health Survey 2009–2010 were included in this study. MVPA and SB were measured using the Global Physical Activity questionnaire. Four categories were computed using MVPA- and SB-specific cut-offs (‘High-SB & Active’, ‘Low-SB & Active’, ‘High-SB & Inactive’ and ‘Low-SB & Inactive’). Results: Compared to the reference group (‘High-SB & Inactive’), those in ‘High-SB & Active’ and ‘Low-SB & Active’ were less likely to have an obese BMI (OR: 0.67 [0.54; 0.85], P = 0.0001 and 0.74 [0.59; 0.92] P = 0.0007, respectively) and less likely to have metabolic syndrome (OR: 0.63 [0.49; 0.82], P < 0.0001 and 0.72 [0.57; 0.91], P = 0.007), central obesity (OR: 0.79 [0.65; 0.96], P = 0.016 and 0.71 [0.59; 0.84], P < 0.0001), diabetes (OR: 0.45 [0.35; 0.59], P < 0.0001 and 0.44 [0.34; 0.56], P < 0.0001) and hypertension (OR: 0.52 [0.43; 0.63], P < 0.0001 and 0.60 [0.50; 0.72], P < 0.0001), respectively. Conclusions: Being physically active and spending less time in SBs was associated with lower adiposity and improvements in cardiovascular risk factors

Dynamic Range of Vertebrate Retina Ganglion Cells: Importance of Active Dendrites and Coupling by Electrical Synapses

The vertebrate retina has a very high dynamic range. This is due to the concerted action of its diverse cell types. Ganglion cells, which are the output cells of the retina, have to preserve this high dynamic range to convey it to higher brain areas. Experimental evidence shows that the firing response of ganglion cells is strongly correlated with their total dendritic area and only weakly correlated with their dendritic branching complexity. On the other hand, theoretical studies with simple neuron models claim that active and large dendritic trees enhance the dynamic range of single neurons. Theoretical models also claim that electrical coupling between ganglion cells via gap junctions enhances their collective dynamic range. In this work we use morphologically reconstructed multi-compartmental ganglion cell models to perform two studies. In the first study we investigate the relationship between single ganglion cell dynamic range and number of dendritic branches/total dendritic area for both active and passive dendrites. Our results support the claim that large and active dendrites enhance the dynamic range of a single ganglion cell and show that total dendritic area has stronger correlation with dynamic range than with number of dendritic branches. In the second study we investigate the dynamic range of a square array of ganglion cells with passive or active dendritic trees coupled with each other via dendrodendritic gap junctions. Our results suggest that electrical coupling between active dendritic trees enhances the dynamic range of the ganglion cell array in comparison with both the uncoupled case and the coupled case with cells with passive dendrites. The results from our detailed computational modeling studies suggest that the key properties of the ganglion cells that endow them with a large dynamic range are large and active dendritic trees and electrical coupling via gap junctions.Fundacao de Amparo a Pesquisa do Estado de Sa Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de SA Paulo FAPESPCNPq (Brazil)CNPq (Brazil

El sedentarismo se asocia a un incremento de factores de riesgo cardiovascular y metabólicos independiente de los niveles de actividad física = Sedentary lifestyle is associated with metabolic and cardiovascular risk factors independent of physical activity

Background: Sedentary behavior is a main risk factor for cardiovascular disease and mortality. Aim: To investigate the association between sedentary behavior and metabolic and cardiovascular risk factors. Material and Methods: We assessed 322 participants aged between 18 to 65 years. Physical activity and sedentary behavior were measured with accelerometers (Actigraph®). Body mass index (BMI), waist circumference, percentage of body fat, diet and blood markers (glucose, lipid profile, insulin and HOMA-IR) were measured with standardized protocols. Results: Thirty four percent of participants were physically inactive and spent on average 8.7 h/day on sedentary activities. Per one hour increase in sedentary behavior there were significant adverse changes in glucose (4.79 mg/dl), insulin (2.73 pmol/l), HOMA-IR (0.75), BMI (0.69 kg/m2), waist circumference (1.95 cm), fat mass (1.03%), total cholesterol (9.73 mg/dl), HDL-cholesterol (-3.50 mg/dl), LDL-cholesterol (10.7 mg/dl) and triglycerides (12.4 mg/dl). These findings were independent of main confounding factors including total physical activity, dietary factors, BMI and socio-demographics. Conclusions: The detrimental effect of sedentary behaviors on cardiometabolic and obesity-related traits is independent of physical activity levels. Therefore, reducing sedentary time should be targeted in the population apart from increasing their physical activity levels