RDF-TR: Exploiting structural redundancies to boost RDF compression

The number and volume of semantic data have grown impressively over the last decade, promoting compression as an essential tool for RDF preservation, sharing and management. In contrast to universal compressors, RDF compression techniques are able to detect and exploit specific forms of redundancy in RDF data. Thus, state-of-the-art RDF compressors excel at exploiting syntactic and semantic redundancies, i.e., repetitions in the serialization format and information that can be inferred implicitly. However, little attention has been paid to the existence of structural patterns within the RDF dataset; i.e. structural redundancy. In this paper, we analyze structural regularities in real-world datasets, and show three schema-based sources of redundancies that underpin the schema-relaxed nature of RDF. Then, we propose RDF-Tr (RDF Triples Reorganizer), a preprocessing technique that discovers and removes this kind of redundancy before the RDF dataset is effectively compressed. In particular, RDF-Tr groups subjects that are described by the same predicates, and locally re-codes the objects related to these predicates. Finally, we integrate RDF-Tr with two RDF compressors, HDT and k2-triples. Our experiments show that using RDF-Tr with these compressors improves by up to 2.3 times their original effectiveness, outperforming the most prominent state-of-the-art techniques

Lubrication of DLC Coatings with Two Tris(pentafluoroethyl)trifluorophosphate Anion-Based Ionic Liquids

The lubrication of a Cr-DLC coating with ethyl-dimethyl-2-methoxyethylammonium tris(pentafluoroethyl)trifluoropho-sphate [(NEMM)MOE][FAP] and 1-butyl-1-methylpyrro-lidinium tris(pentafluoroethyl)trifluorophosphate [BMP] [FAP] ionic liquids (ILs) as 1 wt% additives to a polyalphaolefin (PAO 6) was studied. Zinc dialkyldithiophosphate (ZDDP) was also used as reference in order to evaluate the effectiveness of the ILs. Reciprocating ball-on-plate tribological tests at loads of 20 and 40 N were performed. The results showed that both ILs exhibited a friction reduction, especially at the lowest load tested. Antiwear properties were also improved; the PAO 6 + 1% [BMP][FAP] mixture was slightly better, close to the values for PAO 6 + 1% ZDDP. Scanning electron microscopy (SEM) images and X-ray photoelectron spectroscopy (XPS) analysis indicated that the additive–surface interaction was responsible for the tribological improvement

Neutrino mixing and masses in a left-right model with mirror fermions

In the framework of a left-right model containing mirror fermions with gauge group SU(3)$_{C} \otimes SU(2)_{L} \otimes SU(2)_{R} \otimes U(1)_{Y^\prime}$, we estimate the neutrino masses, which are found to be consistent with their experimental bounds and hierarchy. We evaluate the decay rates of the Lepton Flavor Violation (LFV) processes $\mu \rightarrow e \gamma$, $\tau \rightarrow \mu \gamma$ and $\tau \rightarrow e\gamma$. We obtain upper limits for the flavor-changing branching ratios in agreement with their present experimental bounds. We also estimate the decay rates of heavy Majorana neutrinos in the channels $N \rightarrow W^{\pm} l^{\mp}$, $N \rightarrow Z \nu_{l}$ and $N \rightarrow H \nu_{l}$, which are roughly equal for large values of the heavy neutrino mass. Starting from the most general Majorana neutrino mass matrix, the smallness of active neutrino masses turns out from the interplay of the hierarchy of the involved scales and the double application of seesaw mechanism. An appropriate parameterization on the structure of the neutrino mass matrix imposing a symmetric mixing of electron neutrino with muon and tau neutrinos leads to Tri-bimaximal mixing matrix for light neutrinos.Comment: Accepted by European Physical Journal

Lumbalgia de origen desconocido: a propósito de un caso

Varón toxicómano de 35 años que presenta un cuadro de lumbalgia aguda. Los estudios analíticos hacen sospechar una etiología infecciosa pero la RM realizada en el momento del ingreso es normal. Ante la persistencia de la sintomatología se confirma dicho diagnóstico en una segunda RM. El paciente es tratado de manera conservadora con antibioterapia intravenosa, lográndose la resolución del proceso clínica y radiológicamente.A man drug addict of 35 years presents an acute lumbar pain. The analytical studies make suspect an infec- tious etiology but the RM made in the moment of the entrance is normal. As symptoms persist, this diagnose is confirmed in one second RM. The patient is dealed with preservative way with intravenous antibiotherapy, being obtained the resolu- tion of the clinical process and radiological images

L-Citrulline and its effect in endurance sports, a sistematic review

En los últimos años, el estudio del suplemento L-Citrulina ha cobrado importancia debido a sus posibles efectos sobre el rendimiento deportivo. La L-Citrulina es un aminoácido no esencial que se obtiene a través de fuentes tanto vegetales como animales. Es precursor del Óxido Nítrico y de la Arginina, que intervienen de forma protagonista durante el ciclo de la urea. Estos factores presuponen que el consumo de este suplemento podrá tener ciertos beneficios sobre el rendimiento deportivo. Por lo tanto, el objetivo de este estudio fue el de realizar una revisión sistemática con la que comprobar la eficacia de la L-Citrulina o el Malato de L-Citrulina sobre varios parámetros determinantes en el rendimiento deportivo: potencia, resistencia, trabajo, así como en las siguientes otras variables: percepción subjetiva del esfuerzo y factores fisiológicos. El estudió estuvo centrado en deportes de resistencia en concreto. Para ello, se realizó una búsqueda de la literatura existente hasta la fecha de aquellos estudios que analizaban el rendimiento deportivo en deportes de resistencia tras el consumo de L-Citrulina. Se obtuvieron un total de 7 trabajos con los que se realizó esta revisión sistemática. Tras el análisis de los trabajos encontrados, se podría decir que la L-Citrulina o Malato de L-Citrulina tiene un efecto positivo sobre el rendimiento deportivo. Sin embargo, se debería de establecer un consenso en la estandarización de los test realizados en los estudios para poder afirmar con evidencia significativa que este suplemento tiene una afectación clara sobre el rendimiento de los deportistas.In the last years, the study of L-Citrulline as a supplement has been gaining interest due to its possible applications over the performance in sports. L-Citrulline is a non-essential aminoacid which can be obtained from vegetable or animal sources. This supplement is a precursor of Nitric Oxide, Arginine and has a principal role in the urea cycle. These factors presuppose that the consume of this ergogenic aid could have positive effects over the sport performance. The purpose of this study was to make a systematic review with which verify the efficacy of L-Citrulline or Citrulline Malate over various determinants parameters over the sport performance and other variables such as perception of effort and physiological factors in endurance sports. To achieve this objective, a research of the existent studies referred to the analysis of the sport performance after the consumption L-Citrulline was made. Finally, 7 studies were obtained and used to make this systematic review. After the analysis of the collected data it can be said that L-Citrulline or Citrulline Malate might have a positive impact over the sport performance. Nevertheless, a consensus must be made in order to achieve the standardization of the protocols and test used in the different studies to say that this supplement has a significant positive impact over the athletes performance

Cierre quirúrgico en flexión versus extensión en artroplastias totales de rodilla

Se ha realizado un estudio prospectivo de 44 pacientes con gonartrosis primaria que fueron intervenidos con artroplastia total de rodilla con el objeto de determinar las diferencies en cuanto a la movilidad final de la rodilla dependiendo del cierre quirúrgico en flexión o en extensión. Se formaron dos grupos con similares características de homogeneidad respecto al sexo, edad, peso corporal y arco de movilidad previa, no existiendo diferencies significativas entre los grupos en la valoración preoperatoria. En el primer grupo se incluyeron 22 pacientes donde se había realizado la sutura de la cápsula articular y del plano muscular y cutáneo en flexión de 70º a 90º; el segundo grupo estaba formado por otros 22 pacientes en los que se realizó la sutura con la rodilla en extensión completa. En todos los pacientes se implantó el mismo modelo artroplástico y todos siguieron el mismo protocolo de rehabilitación postoperatoria. La evaluación clínica se realizó en el momento del alta hospitalaria, al mes, tres y seis meses, siguiendo la escala del Hospital for Special Surgery. Se apreció un arco de movilidad y puntuación clínica mayor en el grupo de rodillas suturadas en extensión, con una diferencia estadísticamente significativa, en los controles realizados en el alta hospitalaria y al mes de la intervención. A los seis meses no se apreciaron diferencias entre ambos grupos. La posición de la rodilla en el cierre quirúrgico de una artroplastia no afecta a su funcionalidad.In a prospective study, 44 patients with primary osteoarthritis of the knee undergoing total knee arthroplasty were compared to determine whether surgical closure of the entire wound in flexion had any effect on the postoperative range of motion over a period of six months. In twenty-two patients the knee was surgically closed in 70º to 90º flexion. In the second group of 22 patients, knees were closed in extension. There was no significant difference between groups respect to age, gender, weight and preoperative range of motion. All of the patients were operated on by the same team of surgeons and with the same type of prosthesis. Both groups of patients received a standardized exercise program during their hospitalization. All patients were evaluated following the parameters of the Hospital for Special Surgery score at discharge from the hospital, at first month, third and sixth month after operation. At all the intervals, both the flexion measurements and function scores were better in the flexion closure group, although we only found statically significant difference at discharge and at the first month postoperatively. The position of the knee in the surgical closing of an arthroplasty doesn't affected o functionality

A note on complex plane curve singularities up to diffeomorphism and their rigidity

We prove that, if two germs of plane curves $(C,0)$ and $(C',0)$ with at least one singular branch are equivalent by a (real) smooth diffeomorphism, then $C$ is complex isomorphic to $C'$ or to $\overline{C'}$. A similar result was shown by Ephraim for irreducible hypersurfaces before, but his proof is not constructive. Indeed, we show that the complex isomorphism is given by the Taylor series of the diffeomorphism. We also prove an analogous result for the case of non-irreducible hypersurfaces containing an irreducible component of zero-dimensional isosingular locus. Moreover, we provide a general overview of the different classifications of plane curve singularities