Self-Assembling Peptides for Cartilage Regeneration

Loss of glycosaminoglycans (GAGs) in osteoarthritic (OA) cartilage contributes to a decrease in mechanical properties and function in vitro, and is considered to be a major contributor to disease progression. The aims of this investigation were to test the hypothesis that a combination of self-assembling peptides (SAPs) and chondroitin sulfate (glycosaminoglycan; GAG) would restore the biomechanical properties of GAG depleted porcine condylar cartilage, ideally to a level intrinsic to native porcine condylar cartilage. The SAPs investigated were members of the P11 series which have been designed to spontaneously self-assemble into three-dimensional fibrilar hydrogels, in response to physiological conditions. Initial studies were carried out to determine which of three peptides (P11-4, P11-8 and P11-12) demonstrated high β-sheet percentage, long-woven fibrilar networks and high stiffness; when mixed with chondroitin sulfate at two different GAG molar ratios (1:16 and 1:64) in physiological conditions, using FTIR analysis, transmission electron microscopy and rheology. The β-sheet percentage, dimensions of fibrils and stiffness were dependent upon the peptide, GAG molar ratio and Na2+ salt concentration. P11-4 and P11-8: GAG mixtures had high β-sheet percentage ranging from 50.6-91 % and 81.7-92 %, respectively. Fibril lengths of the P11-4 and P11-8: GAG mixtures were in the range 498- 3518 nm and the elastic shear modulus (G’) ranged from 4,479-10,720 Pa and 7,722-26,854 Pa, respectively. P11-4 and P11-8: GAG mixtures were selected for further investigation. In order to produce a GAG depleted cartilage model, porcine femoral condylar cartilage was subjected to three different methods of GAG depletion (1) coating the surface with chondroitinase ABC (2) injecting chondroitinase ABC into the cartilage (3) washing the condyles in sodium dodecyl sulfate (SDS). GAG depletion was successfully achieved following two 24 hour washes in 0.1 % (w/v) SDS and buffer washes. Histological analysis of safranin O stained sections revealed an absence of GAGs. Quantification of GAGs using the dimethylemethylene blue assay revealed that 75 % of GAGs had been removed. In order to assess the effects of peptide: GAG mixtures on the biomechanical properties of the GAG depleted porcine condylar cartilage a biomechanical test method was developed. A series of indentation tests using different loads, followed by finite element analysis of the data were performed on native and GAG depleted porcine condylar cartilage; to identify a suitable load for detection of a significant difference in the deformation, equilibrium elastic modulus and permeability between the native and GAG depleted porcine condylar cartilages. A load of 0.31 N was identified as the most appropriate. GAG depleted porcine condylar cartilage was injected with P11-4 and P11-8 alone, P11-4 and P11-8 : GAG mixtures at a molar ratio of 1:64 and chondroitin sulfate alone. The average percentage deformation of the medial condylar cartilage samples injected with P11-4 alone and P11-4: GAG mixture was 15.5 % and 8.7 % and for P11-8 alone and P11-8: GAG mixture was 11.4 % and 9.1 % respectively; compared to 6.3 % for the native cartilage and 12.6 % for the GAG depleted cartilage. The average equilibrium elastic modulus of the medial cartilage samples injected with P11-4 alone and P11-4: GAG mixture was 0.16 MPa and 0.43 MPa and for P11-8 alone and P11-8: GAG, 0.23 MPa and 0.35 MPa, respectively; compared to 0.49 MPa for the native cartilage and 0.21 MPa for the GAG depleted cartilage. Statistical analysis (ANOVA) showed that a mixture of P11-4: GAG, but not P11-8: GAG restored both the percentage deformation and equilibrium elastic modulus of the GAG depleted cartilage to levels that were not significantly different to the native cartilage. This study has shown that the use of P11-4 in combination with chondroitin sulfate has future potential for development as a minimally invasive treatment for early stage osteoarthritis

Situación del crédito hipotecario en el Perú

Durante los últimos años se ha observado en el Perú un notable crecimiento del crédito hipotecario. Sin embargo, su tamaño con relación al PBI es todavía pequeño (3,3 por ciento), en comparación con otros países de la región.

Going beyond traditional QA systems: challenges and keys in opinion question answering

The treatment of factual data has been widely studied in different areas of Natural Language Processing (NLP). However, processing subjective information still poses important challenges. This paper presents research aimed at assessing techniques that have been suggested as appropriate in the context of subjective - Opinion Question Answering (OQA). We evaluate the performance of an OQA with these new components and propose methods to optimally tackle the issues encountered. We assess the impact of including additional resources and processes with the purpose of improving the system performance on two distinct blog datasets. The improvements obtained for the different combination of tools are statistically significant. We thus conclude that the proposed approach is adequate for the OQA task, offering a good strategy to deal with opinionated questions.This paper has been partially supported by Ministerio de Ciencia e Innovación - Spanish Government (grant no. TIN2009-13391-C04-01), and Conselleria d'Educación - Generalitat Valenciana (grant no. PROMETEO/2009/119 and ACOMP/2010/286)

Dimensionamiento óptimo y validación de la operación de una microrred conectada utilizando HOMER Pro y DIgSILENT

Microgrids adoption around all world is increasing with different aims as to integrate renewable generation, providing energy to rural zones, reducing CO2 emissions, or simply as an alternative for energy independence. However, the planning and operation of microgrids can be a challenging task because it involves many economical, technical, environmental aspects. This work presents a methodology for planning and validating a grid-connected microgrid using two well-known software that facilitates the design. The planning process is performed in HOMER Pro to size and select appropriate generation sources, while the possible implementation on a real distribution network is validated in DigSILENT. Numerical results show the optimal sizing process of a grid-connected microgrid for a university campus based on real data and the technical validation based on Colombian regulatory aspects.La adopción de microrredes está creciendo en todo el mundo con diferentes propósitos, entre ellos integrar la generación renovable, proporcionar energía a las zonas rurales, reducir las emisiones de CO2 o simplemente como una alternativa para la independencia energética. Sin embargo, la planificación y operación de microrredes puede ser una tarea desafiante porque involucra muchos aspectos económicos, técnicos y ambientales. Este trabajo presenta una metodología para la planificación y validación de una microrred conectada a la red utilizando dos herramientas software muy conocidas en el ámbito de la ingeniería eléctrica. El proceso de planificación a la medida se realiza en HOMER Pro y selecciona las fuentes de generación adecuadas, mientras que la posible implementación en una red de distribución real se valida en DigSILENT. Los resultados numéricos muestran el proceso de dimensionamiento óptimo de una microrred conectada a la red con base en datos reales para un campus universitario. Además, se presenta resultados de la validación técnica de la operación considerando aspectos regulatorios de Colombia

Dimensionamiento óptimo y validación de la operación de una microrred conectada utilizando HOMER Pro y DIgSILENT

Microgrids adoption around all world is increasing with different aims as to integrate renewable generation, providing energy to rural zones, reducing CO2 emissions, or simply as an alternative for energy independence. However, the planning and operation of microgrids can be a challenging task because it involves many economical, technical, environmental aspects. This work presents a methodology for planning and validating a grid-connected microgrid using two well-known software that facilitates the design. The planning process is performed in HOMER Pro to size and select appropriate generation sources, while the possible implementation on a real distribution network is validated in DigSILENT. Numerical results show the optimal sizing process of a grid-connected microgrid for a university campus based on real data and the technical validation based on Colombian regulatory aspects.La adopción de microrredes está creciendo en todo el mundo con diferentes propósitos, entre ellos integrar la generación renovable, proporcionar energía a las zonas rurales, reducir las emisiones de CO2 o simplemente como una alternativa para la independencia energética. Sin embargo, la planificación y operación de microrredes puede ser una tarea desafiante porque involucra muchos aspectos económicos, técnicos y ambientales. Este trabajo presenta una metodología para la planificación y validación de una microrred conectada a la red utilizando dos herramientas software muy conocidas en el ámbito de la ingeniería eléctrica. El proceso de planificación a la medida se realiza en HOMER Pro y selecciona las fuentes de generación adecuadas, mientras que la posible implementación en una red de distribución real se valida en DigSILENT. Los resultados numéricos muestran el proceso de dimensionamiento óptimo de una microrred conectada a la red con base en datos reales para un campus universitario. Además, se presenta resultados de la validación técnica de la operación considerando aspectos regulatorios de Colombia

Monitoring the State of Unconstitutional Things in the Prison System

Este artículo de investigación ofrece una reflexión analítica acerca del estado de cosas inconstitucionales en el sistema penitenciario en Colombia, fenómeno que evidencia la crisis actual que presenta la población carcelaria en la cual se evidencia la violación de derechos Fundamentales, situación que crea la necesidad de implementar políticas públicas que reglamenten las instituciones responsables de garantizar derechos a quienes se encuentren en privación de libertad, y con las que se pretenda mitigar el impacto de este fenómeno social. A raíz de esto, la Corte Constitucional ha ordenado al Estado ejecutar estrategias y acciones que vayan en pro de la resocialización de los presos mediante la asistencia social al interior de las cárceles del país, sin embargo, las estrategias enfocadas en ello parecen no ser suficientes, ya que la violación de los derechos humanos sigue siendo una constante para aquellos que intentan cumplir las penas. Asimismo, se logra una reflexión alrededor de los informes emitidos por la Comisión de Seguimiento de la sentencia T-388 de 2013 , cuyo interés es que existan mecanismos de protección de derechos fundamentales dentro los centros de reclusión, pues se suelen presentar múltiples denuncias por la falta de garantías de derechos en el proceso de resocialización. Para ello, no solo el Estado debe tener en cuenta lo ordenado en las leyes y sentencias, sino también las teorías existentes en el campo de la resocialización del individuo, las cuales aportan con sus observaciones y análisis unas posibles soluciones a la problemática social del hacinamiento carcelario. Por consiguiente, superar el estado de cosas inconstitucional será el objetivo primordial de un Estado social de derecho. Las medidas y controles con los que se pretende que las personas se resocialicen para que luego de cumplida su condena se reincorporen de nuevo a la sociedad se ha vuelto un reto para las instituciones que deben garantizar los derechos fundamentales, teniendo en cuenta la situación actual, los resultados no son acordes a lo que se ha planteado. Por último, este ejercicio también evalúa otras alternativas de estudios alrededor de la temática, ya que su estudio jurídico no presenta agotamiento, por el contrario, pueden abrirse otras líneas de análisis que enriquezcan los acercamientos críticos.Universidad Libre Seccional Pereira -- Facultad de Derecho, Ciencias Políticas y Sociales -- Especialización en Derecho Penal y CriminologíaThis research article is an academic invitation to review the unconstitutional state of affairs (hereinafter ECI) that is present within the prison system in Colombia, which evidences an apparent contradiction that is served from the institutional point of view. The Constitutional Court has tried to overcome the ECI, however, the strategies focused on it do not seem to be enough, since the violation of human rights continues to be a constant for those who try to serve their sentences according to the Law. Likewise, a reflection is achieved around the reports issued by the Follow-up Commission of Judgment T-388 of 2013, whose interest is that there are protection mechanisms for communities in prisons, since multiple complaints are usually filed due to the lack of guarantees in the resocialization models that are intended to be achieved. To this end, not only an important compilation of laws and sentences that explain the processes involved is taken into account, but also a network of theoreticians who contribute with their observations and analysis to the debate that is generated. Therefore, overcoming the unconstitutional state of affairs will be the primary objective of a Social State of Law; the measures and controls to recover the good honor of prisoners is an unpostponable proposal for Colombia and its democracies, but taking into account the current situation, the results are not in accordance with what has been proposed. Finally, this exercise also evaluates other alternatives of studies on the subject, since its legal study is not exhausted; on the contrary, other lines of analysis can be opened to enrich the critical approaches

IBEREVAL OM: Minería de opiniones en los nuevos géneros textuales

The increasing amount of subjective data on the Web is creating the need to develop effective Question Answering systems able to discriminate such information from factual data, and subsequently process it with specific methods. The participants in the IBEREVAL OM tasks will be given a set of opinion questions (in Spanish and English). Optionally, they will also be able to receive the same set of opinion questions, in which the source, target and expected polarity, as well as the time span the question is referring to are given. They will also be provided with a collection of blog posts, extracted using the Technorati blog search engine (in Spanish and English), in which the answers to the opinion questions should be found The gold standard for this blog posts collection will previously be annotated using the EmotiBlog scheme, by a number of 3 annotators. The EmotiBlog corpus and the set of questions presented in (Balahur et al., 2009) – in their present state will be provided for system training. The participants will be able to participate in two subtasks : 1) in the first one, they will be asked to provide the list of answers to each of the questions (in the same language as the questions, or in the other language); 2) in the second one, they will be asked to provide a summary of the question answers – the top x% of the most important answers, in a non-redundant manner. The Gold Standard for the summaries will be automatically extracted from the manual annotations, taking into account the “intensity” parameter of the opinions expressed.Con el grande aumento de la información subjetiva en la Web, hay una importante necesidad de desarrollar sistemas de Question Answering que sean eficientes y capaces de discriminar entre datos objetivos y subjetivos. Los participantes tendrán una colección de preguntas de opinión (Español e Inglés) en las cuales se deberán encontrar las respuestas. El Gold Standard será anotado previamente con el esquema de anotación EmotiBlog por 3 anotadores. El corpus EmotiBlog y la colección de preguntas presentados en (Balahur et al. 2009) se pondrá a disposición para el entrenamiento del sistema. Los participantes deberán devolver un listado de respuestas para cada una de las preguntas, (en el mismo idioma que la pregunta o en otro), un resumen de las respuestas –de las x% de las respuestas más importantes, de una manera no redundante, el Gold Standard para los resúmenes será extraído automáticamente de las anotaciones manuales teniendo en consideración el parámetro de “intensidad” de la opinión expresada.This evaluation task proposal has been partially supported by Ministerio de Ciencia e Innovación - Spanish Government (grant no. TIN2009-13391-C04-01), and Conselleria d'Educació - Generalitat Valenciana (grant no. PROMETEO/2009/119 and ACOMP/2010/288

Butterfly Hysteresis and Slow Relaxation of the Magnetization in (Et4N)3Fe2F9: Manifestations of a Single-Molecule Magnet

(Et4N)3Fe2F9 exhibits a butterfly--shaped hysteresis below 5 K when the magnetic field is parallel to the threefold axis, in accordance with a very slow magnetization relaxation in the timescale of minutes. This is attributed to an energy barrier Delta=2.40 K resulting from the S=5 dimer ground state of [Fe2F9]^{3-} and a negative axial anisotropy. The relaxation partly occurs via thermally assisted quantum tunneling. These features of a single-molecule magnet are observable at temperatures comparable to the barrier height, due to an extremely inefficient energy exchange between the spin system and the phonons. The butterfly shape of the hysteresis arises from a phonon avalanche effect.Comment: 18 pages, 5 eps figures, latex (elsart