On the cohomology of some exceptional symmetric spaces

This is a survey on the construction of a canonical or "octonionic K\"ahler" 8-form, representing one of the generators of the cohomology of the four Cayley-Rosenfeld projective planes. The construction, in terms of the associated even Clifford structures, draws a parallel with that of the quaternion K\"ahler 4-form. We point out how these notions allow to describe the primitive Betti numbers with respect to different even Clifford structures, on most of the exceptional symmetric spaces of compact type.Comment: 12 pages. Proc. INdAM Workshop "New Perspectives in Differential Geometry" held in Rome, Nov. 2015, to appear in Springer-INdAM Serie

Routh reduction for singular Lagrangians

This paper concerns the Routh reduction procedure for Lagrangians systems with symmetry. It differs from the existing results on geometric Routh reduction in the fact that no regularity conditions on either the Lagrangian $L$ or the momentum map $J_L$ are required apart from the momentum being a regular value of $J_L$. The main results of this paper are: the description of a general Routh reduction procedure that preserves the Euler-Lagrange nature of the original system and the presentation of a presymplectic framework for Routh reduced systems. In addition, we provide a detailed description and interpretation of the Euler-Lagrange equations for the reduced system. The proposed procedure includes Lagrangian systems with a non-positively definite kinetic energy metric.Comment: 34 pages, 2 figures, accepted for publicaton in International Journal of Geometric Methods in Modern Physics (IJGMMP

Comorbidity and osteoporotic fracture: approach through predictive modeling techniques using the OSTEOMED registry

Purpose To examine the response to anti-osteoporotic treatment, considered as incident fragility fractures after a minimum follow-up of 1 year, according to sex, age, and number of comorbidities of the patients. Methods For this retrospective observational study, data from baseline and follow-up visits on the number of comorbidities, prescribed anti-osteoporotic treatment and vertebral, humerus or hip fractures in 993 patients from the OSTEOMED registry were analyzed using logistic regression and an artificial network model. Results Logistic regression showed that the probability of reducing fractures for each anti-osteoporotic treatment consid- ered was independent of sex, age, and the number of comorbidities, increasing significantly only in males taking vitamin D (OR = 7.918), patients without comorbidities taking vitamin D (OR = 4.197) and patients with ≥ 3 comorbidities taking calcium (OR = 9.412). Logistic regression correctly classified 96% of patients (Hosmer–Lemeshow = 0.492) compared with the artificial neural network model, which correctly classified 95% of patients (AUC = 0.6). Conclusion In general, sex, age and the number of comorbidities did not influence the likelihood that a given anti-osteoporotic treatment improved the risk of incident fragility fractures after 1 year, but this appeared to increase when patients had been treated with risedronate, strontium or teriparatide. The two models used classified patients similarly, but predicted differently in terms of the probability of improvement, with logistic regression being the better fit

On some aspects of the geometry of differential equations in physics

In this review paper, we consider three kinds of systems of differential equations, which are relevant in physics, control theory and other applications in engineering and applied mathematics; namely: Hamilton equations, singular differential equations, and partial differential equations in field theories. The geometric structures underlying these systems are presented and commented. The main results concerning these structures are stated and discussed, as well as their influence on the study of the differential equations with which they are related. Furthermore, research to be developed in these areas is also commented.Comment: 21 page

Incidência de fungos em sementes de Manhiot esculenta Crantz. Uma comparação entre variedades do Amazonas e de São Paulo

The fungi incidence in five varieties of Manhiot seeds from Amazonas and São Paulo were studied Aspergillus sp. and Penicillium sp. were the most common genus of Fungi found in all the varieties. The Amazonian Variety "Poré" was the less susceptible of the varieties analyses for fungi development. The most affected variety for fungi development was "Yara x Vassouras" from São Paulo. No differences were found between the three types of treatments concerning on fungi development in seeds. It was also observed no significant differences on fungi development between stored seeds and those used immediately after the abrupt deiscence.Foi estudada a incidência de fungos em sementes de cinco variedades de Mandioca do Amazonas e de São Paulo. Aspergillus e Penicillium foram os gêneros mais comuns encontrados em todas as variedades. A variedade Amazônica "Poré", foi a menos susceptível das variedades analisadas para o desenvolvimento de fungos. A mais afetada foi "Yara x Vassouras", proveniente de São Paulo. Não foram observadas diferenças entre os três tipos de tratamentos quanto ao desenvolvimento de fungos em sementes. Não houve, também, diferenças significativas quanto ao desenvolvimento desses microrganismos em sementes armazenadas e aquelas usadas imediatamente após a deiscência abrupt

Aprovechamiento del residuo agroindustrial del mango común (Mangifera indica L.) en la obtención de azúcares fermentables

The common mango waste (Mangifera indica L.) is a vegetable material containing a high level of lignocelluloses tissue which can be used to obtain fermentable metabolites and fermentation products. In this study hydrolysis treatments were applied to the common mango in order to make the conversion of its polysaccharides to fermentable sugar units. Acid hydrolysis was applied to three different concentrations of dilute sulphuric acid. An enzymatic hydrolysis with two types of commercial enzymes to different concentrations in standard work conditions, was also applied. In addition, a thermic hydrolysis was applied at two different temperatures. At each treatment, the following tests were applied: total sugar concentration, reduced sugar concentration, and percentage of cellulose and hemicellulose residuals. Based on the data obtained from the tests, the best treatments were identified and so the best combinations of the best hydrolysis treatments were carried out. The most significant treatment for individual tests was acid hydrolysis at 0, 50% v/v sulphuric acid at 80◦C for one hour. In the combined treatments the most relevant result was the treatment that combined the enzymatic hydrolysis (as pretreatment) plus a thermic hydrolysis and acid hydrolysis. For security reasons in the reagents use, as well as in the elimination of collateral adverse effects for further alcoholic fermentation, a procedure involving thermic hydrolysis as pretreatment and enzymatic hydrolysis, was chosen as the main treatment with the most appropriate application in the fermentable metabolites production from common mango waste in order to produce alcohol. Further studies have allowed approaching the hydrolysis via microbial with Aspergillus niger and Trichoderma viride, as well as the alcoholic fermentation post-treatment hydrolytic using previous studies. The simultaneous hydrolysis and alcoholic fermentation, and recently performing the simultaneity of the processes, adding a recombining yeast that has the capacity to ferment sugars from five carbons.El residuo del mango común (Mangifera indica L.) es un material vegetal que contiene gran cantidad de tejido lignocelulósico, el cual puede ser aprovechado para la obtención de metabolitos fermentables y productos de la fermentación. En este trabajo se aplicaron tratamientos de hidrólisis al residuo del mango común con el fin de hacer la conversión de sus polisacáridos a unidades de azúcares fermentables. Se aplicó hidrólisis ácida a tres concentraciones diferentes de ácido sulfúrico diluido. También, se aplicó hidrólisis enzimática con dos tipos de enzimas comerciales a diferentes concentraciones en las condiciones de trabajo estándar. De igual manera se aplicó hidrólisis térmica a dos temperaturas diferentes. A cada tratamiento aplicado se le efectuaron pruebas de concentración de azúcares totales, concentración de azúcares reductores, porcentaje de celulosa y hemicelulosa residual, datos con los cuales se determinaron los mejores tratamientos y se procedió a efectuar combinaciones de los mejores tratamientos de hidrólisis. El tratamiento más significativo de las pruebas individuales fue el de hidrólisis ácida a 0,50% v/v de ácido sulfúrico a 80◦C por una hora. En los tratamientos combinados el resultado más significativo fue el tratamiento en el que se combinaron la hidrólisis enzimática (como pretratamiento) más una hidrólisis térmica e hidrólisis ácida. Por razones de seguridad en el uso de reactivos, así como eliminación de efectos colaterales adversos para la fermentación alcohólica posterior, se seleccionó el procedimiento que involucra la hidrólisis térmica como pretratamiento y la hidrólisis enzimática como tratamiento principal, como el tratamiento de mejor aplicación en la producción de metabolitos fermentables a partir de residuos de mango común con finalidad producción de alcohol posteriormente. Estudios posteriores han permitido abordar la hidrólisis por vía microbiana con Aspergillus niger y Trichoderma viride, así como la fermentación alcohólica postratamiento hidrolítico usando los estudios previos. La hidrólisis y fermentación alcohólica simultáneas, y más recientemente y en ejecución la simultaneidad de los procesos adicionando una levadura recombinante que tiene capacidad de fermentar azúcares de cinco carbonos.PACS: 88.20.jm, 88.20.dr, 88.20.R

Aprovechamiento del residuo agroindustrial del mango común (Mangifera indica L.) en la obtención de azúcares fermentables

The common mango residue (Mangifera indica L.) is a plant material that contains a large amount of lignocellulosic tissue, which can be used to obtain fermentable metabolites and fermentation products. In this work, hydrolysis treatments were applied to the common mango residue in order to convert its polysaccharides to fermentable sugar units. Acid hydrolysis was applied at three different concentrations of dilute sulfuric acid. Also, enzymatic hydrolysis was applied with two types of commercial enzymes at different concentrations under standard working conditions. Similarly, thermal hydrolysis was applied at two different temperatures. For each applied treatment, tests were carried out on the concentration of total sugars, concentration of reducing sugars, percentage of cellulose and residual hemicellulose, data with which the best treatments were determined and combinations of the best hydrolysis treatments were carried out. The most significant treatment of the individual tests was that of acid hydrolysis at 0.50% v / v sulfuric acid at 80 ° C for one hour. In the combined treatments the most significant result was the treatment in which enzymatic hydrolysis (as pretreatment) plus thermal hydrolysis and acid hydrolysis were combined. For reasons of safety in the use of reagents, as well as elimination of adverse side effects for subsequent alcoholic fermentation, the procedure involving thermal hydrolysis as a pretreatment and enzymatic hydrolysis as the main treatment was selected, as the treatment of best application in production of fermentable metabolites from common mango residues with the purpose of producing alcohol later. Subsequent studies have allowed microbial hydrolysis to be addressed with Aspergillus niger and Trichoderma viride, as well as alcoholic fermentation after hydrolytic treatment using previous studies. Simultaneous hydrolysis and alcoholic fermentation, and more recently and in execution the simultaneity of the processes by adding a recombinant yeast that has the ability to ferment five-carbon sugars.El residuo del mango común (Mangifera indica L.) es un material vegetal que contiene gran cantidad de tejido lignocelulósico, el cual puede ser aprovechado para la obtención de metabolitos fermentables y productos de la fermentación. En este trabajo se aplicaron tratamientos de hidrólisis al residuo del mango común con el fin de hacer la conversión de sus polisacáridos a unidades de azúcares fermentables. Se aplicó hidrólisis ácida a tres concentraciones diferentes de ácido sulfúrico diluido. También, se aplicó hidrólisis enzimática con dos tipos de enzimas comerciales a diferentes concentraciones en las condiciones de trabajo estándar. De igual manera se aplicó hidrólisis térmica a dos temperaturas diferentes. A cada tratamiento aplicado se le efectuaron pruebas de concentración de azúcares totales, concentración de azúcares reductores, porcentaje de celulosa y hemicelulosa residual, datos con los cuales se determinaron los mejores tratamientos y se procedió a efectuar combinaciones de los mejores tratamientos de hidrólisis. El tratamiento más significativo de las pruebas individuales fue el de hidrólisis ácida a 0,50% v/v de ácido sulfúrico a 80◦C por una hora. En los tratamientos combinados el resultado más significativo fue el tratamiento en el que se combinaron la hidrólisis enzimática (como pretratamiento) más una hidrólisis térmica e hidrólisis ácida. Por razones de seguridad en el uso de reactivos, así como eliminación de efectos colaterales adversos para la fermentación alcohólica posterior, se seleccionó el procedimiento que involucra la hidrólisis térmica como pretratamiento y la hidrólisis enzimática como tratamiento principal, como el tratamiento de mejor aplicación en la producción de metabolitos fermentables a partir de residuos de mango común con finalidad producción de alcohol posteriormente. Estudios posteriores han permitido abordar la hidrólisis por vía microbiana con Aspergillus niger y Trichoderma viride, así como la fermentación alcohólica postratamiento hidrolítico usando los estudios previos. La hidrólisis y fermentación alcohólica simultáneas, y más recientemente y en ejecución la simultaneidad de los procesos adicionando una levadura recombinante que tiene capacidad de fermentar azúcares de cinco carbonos

Morphology of supported polymer electrolyte ultra-thin films: a numerical study

Morphology of polymer electrolytes membranes (PEM), e.g., Nafion, inside PEM fuel cell catalyst layers has significant impact on the electrochemical activity and transport phenomena that determine cell performance. In those regions, Nafion can be found as an ultra-thin film, coating the catalyst and the catalyst support surfaces. The impact of the hydrophilic/hydrophobic character of these surfaces on the structural formation of the films has not been sufficiently explored yet. Here, we report about Molecular Dynamics simulation investigation of the substrate effects on the ionomer ultra-thin film morphology at different hydration levels. We use a mean-field-like model we introduced in previous publications for the interaction of the hydrated Nafion ionomer with a substrate, characterized by a tunable degree of hydrophilicity. We show that the affinity of the substrate with water plays a crucial role in the molecular rearrangement of the ionomer film, resulting in completely different morphologies. Detailed structural description in different regions of the film shows evidences of strongly heterogeneous behavior. A qualitative discussion of the implications of our observations on the PEMFC catalyst layer performance is finally proposed

Impaired autophagic flux is associated with increased endoplasmic reticulum stress during the development of NAFLD

This work is licensed under a Creative Commons Attribution-NonCommercialNoDerivs 3.0 Unported License.-- et al.The pathogenic mechanisms underlying the progression of non-alcoholic fatty liver disease (NAFLD) are not fully understood. In this study, we aimed to assess the relationship between endoplasmic reticulum (ER) stress and autophagy in human and mouse hepatocytes during NAFLD. ER stress and autophagy markers were analyzed in livers from patients with biopsy-proven non-alcoholic steatosis (NAS) or non-alcoholic steatohepatitis (NASH) compared with livers from subjects with histologically normal liver, in livers from mice fed with chow diet (CHD) compared with mice fed with high fat diet (HFD) or methionine-choline-deficient (MCD) diet and in primary and Huh7 human hepatocytes loaded with palmitic acid (PA). In NASH patients, significant increases in hepatic messenger RNA levels of markers of ER stress (activating transcription factor 4 (ATF4), glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP)) and autophagy (BCN1) were found compared with NAS patients. Likewise, protein levels of GRP78, CHOP and p62/SQSTM1 (p62) autophagic substrate were significantly elevated in NASH compared with NAS patients. In livers from mice fed with HFD or MCD, ER stress-mediated signaling was parallel to the blockade of the autophagic flux assessed by increases in p62, microtubule-associated protein 2 light chain 3 (LC3-II)/LC3-I ratio and accumulation of autophagosomes compared with CHD fed mice. In Huh7 hepatic cells, treatment with PA for 8 h triggered activation of both unfolding protein response and the autophagic flux. Conversely, prolonged treatment with PA (24 h) induced ER stress and cell death together with a blockade of the autophagic flux. Under these conditions, cotreatment with rapamycin or CHOP silencing ameliorated these effects and decreased apoptosis. Our results demonstrated that the autophagic flux is impaired in the liver from both NAFLD patients and murine models of NAFLD, as well as in lipid-overloaded human hepatocytes, and it could be due to elevated ER stress leading to apoptosis. Consequently, therapies aimed to restore the autophagic flux might attenuate or prevent the progression of NAFLD.We acknowledge the following grant support: SAF2012-33283 (MINECO, Spain), Comunidad de Madrid S2010/BMD-2423, EFSD and Amylin Paul Langerhans Grant and Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM, ISCIII, Barcelona, Spain) to AMV.; SAF2010-16037, SAF2013-43713-R (MINECO) and Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD, ISCIII) to PMS. RD12/0042/0019 (ISCIII) and S2010/BMD-2478 (Comunidad de Madrid) to LB, PI 13/01299 and Fundación Mutua Madrileña 2012 to C G-M and AIRC IG-2012 to GMF.Peer Reviewe

Haplotypes of intron 4 of the estrogen receptor alpha gene and hip fractures: a replication study in Caucasians

<p>Abstract</p> <p>Background</p> <p>Despite their great impact, few genetic association studies have used hip fractures as an endpoint. However, the association of two polymorphisms on intron 4 of estrogen receptor alpha (<it>ESR1</it>) with hip fractures was recently reported in a Chinese population. The aim of this study was to investigate whether such association is also present in Caucasians.</p> <p>Methods</p> <p>We analyzed those two SNPs and another neighbour SNP located on the exon 4 of <it>ESR1 </it>in 787 patients with hip fractures and 953 controls from Spain.</p> <p>Results</p> <p>The allelic frequencies differed markedly from those reported in Asian populations. Nevertheless, haplotypes including the rs3020314 and rs1884051 loci in intron 4 showed a significant association with hip fractures (omnibus test p = 0.006 in the whole group and 0.00005 in women). In the sex-stratified analysis, the association was significant in females, but not in males. In women, the CA haplotype appeared to have a protective influence, being present in 6.5% of the controls, but only in 3% of patients with fractures (odds ratio 0.39; 95% confidence interval 0.26-0.59; estimated population preventive fraction 3.5%). The inclusion of the rs1801132 SNP of exon 4 further increased the statistical significance of the association (odds ratio 0.17; 95% CI 0.08-0.37; p = 0.00001). Each SNP appeared to contribute independently to the association. No genotype-related differences in gene expression were found in 42 femoral bone samples.</p> <p>Conclusions</p> <p>This study confirms the association of some polymorphisms in the region of exon 4/intron 4 of <it>ESR1 </it>and hip fractures in women. However, there are marked differences in allele frequencies between Asian and Caucasian populations.</p