Uso del tabaco entre los jóvenes colombianos Retos para los profesionales en salud pública

Resumen El incremento en el índice del uso del tabaco y sus derivados entre los jóvenes colombianos representa un llamado para los especialistas en salud pública para que consideren el control del tabaco una prioridad en el área de prevención. El objetivo de este artículo es documentar los daños del tabaco en el cuerpo humano, el incremento del tabaquismo entre los jóvenes colombianos, y explorar el papel de los programas de prevención en la reducción de este problema. Palabra claves: Salud, juventud, tabaco, prevención. Abstract Increasing tobacco use rates among Colombian youth exemplify the need to make prevention top public health priority. The purpose of this article is to document the adverse effects of tobacco in the human body, the increases in tobacco use among Colombian youth, and to explore the role of prevention in decreasing this public health problem. Key words: Healt, young, tabacco, prevention

Chern-Simons theory encoded on a spin chain

We construct a 1d spin chain Hamiltonian with generic interactions and prove that the thermal correlation functions of the model admit an explicit random matrix representation. As an application of the result, we show how the observables of $U(N)$ Chern-Simons theory on $S^{3}$ can be reproduced with the thermal correlation functions of the 1d spin chain, which is of the XX type, with a suitable choice of exponentially decaying interactions between infinitely many neighbours. We show that for this model, the correlation functions of the spin chain at a finite temperature $\beta =1$ give the Chern-Simons partition function, quantum dimensions and the full topological $S$-matrix.Comment: v2, 11 pages. Expanded, more detailed version. Misprints correcte

Change in groundwater chemistry as a consequence of suppression of floods: the case of the Rhine floodplain

Spatio-temporal variations of nitrogen, phosphorus and base cation concentrations in groundwater were related to the drastic change in hydrological conditions of the Rhine alluvial floodplain (Eastern France), which has been disconnected from the river by canalisation. The Groundwater chemistry was studied in two alluvial forests with contrasting hydrological conditions: one in a sector unflooded for 30 years, the second one in a sector still subject to flooding. Nutrient concentrations were measured at two levels, in the root zone (1.5 m depth) and in the gravel below the root layer (4.5 m depth). In the unflooded sector, the average nitrate concentration was significantly lower in the shallow groundwater (2.06 mg l−1 NO3−) than in the deeper layer (5.84 mg l−1NO3−). In contrast, in the flooded sector the nitrate concentrations in the shallow groundwater (5.02 mg l−1 NO3−) were not significantly different from those in the deep groundwater (3.98 mg l−1 NO3−). The concentration of phosphate was similar in shallow and deep groundwater in the unflooded sector (46 and 35 μg l−1, respectively) but significantly lower in the deep groundwater of the flooded sector (47 μg l−1), than in the shallow groundwater (58 μg l−1). The major elements (cations: Ca2+, Mg2+, Na+ and associated anions: HCO3−, SO4−2, Cl−) concentrations were significantly higher in the groundwaters than in the surface water. The results are discussed in terms of changes that accompanied suppression of floods, and processes that take place during the transfer of nutrients through the groundwater–soil–plant compartments. The reduction of groundwater fluctuations in the unflooded sector modified the transfer of nitrate by reducing the resolubilisation of locally produced nitrate, and/or denitrification. The transfer of phosphate was affected to a lesser extent, because of precipitation and adsorption. Base cation concentrations reflect exchange between groundwater and the calcareous gravel

Light transmission in nanocellular polymers: Are semi-transparent cellular polymers possible?

This work presents the light transmission through a collection of solid cellular polymers based on poly (methyl methacrylate) (PMMA) with cells sizes covering the micro and nano-scale. The obtained results showed that the behavior of light transmission when cell size is in the nano-scale is opposite to the one shown by microcellular foams or the one predicted by theoretical models of light scattering (LS). In fact, the expected trend is that a reduction of cell size increases the opacity of the samples. However, for nanocellular polymers based on amorphous polymers reducing the cell size increases the light transmission. Therefore, this result indicates that a further reduction of the cell size could result in cellular polymers optically semi-transparen

On the Analysis of the Contact Conditions in Temporomandibular Joint Prostheses

Temporomandibular joint replacement (TMJR) is a complex surgical procedure in which the artificial joints available must assure the anatomical reconstruction and guarantee a good range of the natural temporomandibular joint (TMJ) movements. With this aim, different types of TMJ prostheses, including the stock prosthetic system and custom-made prostheses, are being currently implanted. Although temporomandibular joint replacements (TMJRs) are expected to accomplish their function during a number of years, they might actually fail and need to be replaced. This paper analyzes different design factors affecting the contact stress distributions within the TMJ prosthesis interface, which are consequently involved in their deterioration and final failure of the prosthetic device. With this purpose, a numerical model based on finite elements has been carried out in order to evaluate the stress states attained in different prosthesis configurations corresponding to general types of TMJ prostheses. On the other hand, the actual degradation of resected implants has been evaluated via optical microscopy. The linkage between the numerical simulations performed and experimental evidence allowed the authors to establish the different wear and damage mechanisms involved in the failure of stock TMJ prostheses. Indeed, the results obtained show that the contact stresses at the interface between the mandible and the glenoid fossa components play a key role in the failure process of the TMJR devices

El léxico de los documentos navarro-aragoneses de la "Crestomatía del español medieval" (Segunda serie: Documentos de la España Cristiana: 1067-1140. Segunda parte)

Las páginas precedentes contienen una compilación del vocabulario común del tercer documento notarial de Navarra y Aragón pertenecientes a la segunda serie publicada por M. Pidal en su Crestomía del Español Medieval (Madrid 1971) “Documentos de la España cristiana”(1067-1140). El vocabulario se enumera en forma de índice indicando para cada palabra la fuente del documento y el año así como la página y la línea donde puede encontrarse la palabra en la Crestomatía y el documento, respectivamente. Además se presenta una breve investigación léxica de las palabras más interesantes, haciendo algunas distinciones sobre su origen, arabismos, romances galos…The preceding pages contain a compilation of the common vocabulary of the Third notarial document of Navarre and Aragon, belonging to the second series, published by M. Pidal.in his Crestomía del Español Medieval (Madrid, 1971): "Documentos de la España Cristiana (1067-1140). The vocabulary is listed in index form indicating for each word the source of the document and the year as well as the page and line where the word is mentioned in the Crestomía... and in the document respectively. In addition, it presents a brief lexical research of his most interesting words, marking some distinctions about their origin: Arabicism, Gallic, Romance, etc.notPeerReviewe

Herminio, sempre amigo

[Resumo] Herminio Barreiro tiña a difícil virtude de buscar os puntos de consenso e o que unía, máis que as discrepancia. Probablemente porque tiña esa ollada de futuro, que facía que non se arredara dos obxectivos últimos