Thermal Decomposition of Diphenyl Tetroxane in Chlorobenzene Solution

The thermal decomposition of Cyclic Diperoxide of Benzaldehyde 3,6-diphenyl-1,2,4,5-tetroxane, (DFT) in chlorobenzene solution in the studied temperature range (130°C - 166°C) satisfactorily satisfies a first order law up to 60% conversions of diperoxide. DFT would decompose through a mechanism in stages and initiated by the homolytic breakdown of one of the peroxidic bonds of the molecule, with the formation of the corresponding intermediate biradical. The concentration studied was very low, so that the effects of secondary reactions of decomposition induced by free radicals originated in the reaction medium can be considered minimal or negligible. The activation parameters for the unimolecular thermal decomposition reaction of the DFT are ΔH# = 30.52 ± 0.3 kcal·mol-1 and ΔS# = -6.38 ± 0.6 cal·mol-1 K-1. The support for a step-by-step mechanism instead of a process concerted is made by comparison with the theoretically calculated activation energy for the thermal decomposition of 1,2,4,5-tetroxane.Fil: Bordón, Alexander Germán. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; ArgentinaFil: Pila, Andrea Natalia. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; ArgentinaFil: Profeta, Mariela Inés. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; ArgentinaFil: Jorge, María J.. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; ArgentinaFil: Jorge, Lilian Cristina. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Romero, Jorge Marcelo. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; ArgentinaFil: Jorge, Nelly Lidia. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; Argentin

On the impact of exchange rate regimes on tourism

The main objective of this paper is to analyze the effect of the exchange rate arrangements on international tourism. The ambiguity of literature about the effect of exchange rate volatility contrasts with the magnitude of the impact of a common currency on trade. On the basis of a gravity equation we estimate a moderate effect of a currency union on tourism of almost 12%. Furthermore, we estimate a gravity equation for international trade, obtaining that the common currency effect on trade is reduced when tourism is introduced as a regressor. This suggests that tourism flows may contribute to explain the excessive magnitude of the estimated effect of a common currency on trade in this literature. Finally, we analyze the impact of several de facto exchange rate arrangements on tourism, finding that less flexible exchange rates promotes tourism flows.Tourism, Exchange Rate Regime, Common Currency

Revisiting Rose's common currency debate

The main objective of this research is to revisit the estimation of the effect of a common currency on international trade by applying the new methodology proposed by Helpman, Melitz and Rubistein (2008) and incorporating tourism to the theoretical framework. Rose (2000) estimates an empirical model of bilateral trade, finding a significant coefficient for a currency union variable of 1.2, suggesting an effect of currency unions on trade of over a 200%. Rose (2000)’s finding did not receive full acceptance and further research was consequently devoted to find reasons of such high effect. This still remains as a major puzzle in the International Economics. Rose and Van Wincoop (2001) hold that there may still be some omitted factors that drives countries to both participate in currency unions and trade more. In this research a gravity equation for trade is estimated controlling by international tourism.Common currency, tourism, gravity equation

Adding Recognition Discriminability Index to the Delayed Recall Is Useful to Predict Conversion from Mild Cognitive Impairment to Alzheimer's Disease in the Alzheimer's Disease Neuroimaging Initiative

Background: Ongoing research is focusing on the identification of those individuals with mild cognitive impairment (MCI) who are most likely to convert to Alzheimer's disease (AD). We investigated whether recognition memory tasks in combination with delayed recall measure of episodic memory and CSF biomarkers can predict MCI to AD conversion at 24-month follow-up. Methods: A total of 397 amnestic-MCI subjects from Alzheimer's disease Neuroimaging Initiative were included. Logistic regression modeling was done to assess the predictive value of all RAVLT measures, risk factors such as age, sex, education, APOE genotype, and CSF biomarkers for progression to AD. Estimating adjusted odds ratios was used to determine which variables would produce an optimal predictive model, and whether adding tests of interaction between the RAVLT Delayed Recall and recognition measures (traditional score and d-prime) would improve prediction of the conversion from a-MCI to AD. Results: 112 (28.2%) subjects developed dementia and 285 (71.8%) subjects did not. Of the all included variables, CSF Aβ1-42 levels, RAVLT Delayed Recall, and the combination of RAVLT Delayed Recall and d-prime were predictive of progression to AD (χ2 = 38.23, df = 14, p < 0.001). Conclusions: The combination of RAVLT Delayed Recall and d-prime measures may be predictor of conversion from MCI to AD in the ADNI cohort, especially in combination with amyloid biomarkers. A predictive model to help identify individuals at-risk for dementia should include not only traditional episodic memory measures (delayed recall or recognition), but also additional variables (d-prime) that allow the homogenization of the assessment procedures in the diagnosis of MCI.Fil: Russo, María Julieta. Fundación para la Lucha Contra las Enfermedades Neurológicas de la Infancia. Instituto de Investigaciones Neurológicas "Raúl Carrea"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Campos, Jorge. Fundación para la Lucha Contra las Enfermedades Neurológicas de la Infancia. Instituto de Investigaciones Neurológicas "Raúl Carrea"; ArgentinaFil: Vázquez, Silvia. Fundación para la Lucha Contra las Enfermedades Neurológicas de la Infancia. Instituto de Investigaciones Neurológicas "Raúl Carrea"; ArgentinaFil: Sevlever, Gustavo. Fundación para la Lucha Contra las Enfermedades Neurológicas de la Infancia. Instituto de Investigaciones Neurológicas "Raúl Carrea"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Allegri, Ricardo Francisco. Fundación para la Lucha Contra las Enfermedades Neurológicas de la Infancia. Instituto de Investigaciones Neurológicas "Raúl Carrea"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Classification, characterisation and strategies for improvement of cattle and sheep pasture systems in marginal areas of Southern Chile

Pasture-based livestock systems in farms with medium or low size are especially important in less favored areas and are valuable for society. For these systems to survive, it is necessary to obtain an acceptable level of productivity and ensure commercialization of the products. This study was carried out in the district of Rio Ibáñez, General Carrera Province, in the XI (Aysén) Region of Chile. The sample consisted of 28 small-scale livestock farmers with dual-purpose cattle production; 16 of them also produced sheep for meat. The empirical data produced 55 variables which were subjected to multivariate analysis; three main components were obtained which explain 72.1 % of the variance. By cluster analysis it was obtained four groups with characteristics which varied by farm size, age and personal situation of farmers, farm management and farm profitability. The principal problems found are low productivity in the herds and the poor marketing channels of animals produced. In two groups, due to the low size and poor management, the profitability of the farms is very low and this may compromise their future. To improve production systems, the training and advice of farmers should be strengthened, investment should be supported, especially for young people, and the farmer partnership should be promoted. There is also a need to diversify the families' sources of income (sale of other farm products or handicrafts and touristic activities).Ministerio de Economía de Chile Innova-CORFO Project 11 NTEC 1279

Insoluble soybean polysaccharides: Obtaining and evaluation of their O/W emulsifying properties

The aims of this work were to obtain different samples of insoluble soybean polysaccharides (ISPS) from defatted soy flour and to study their potential application as O/W emulsifier. In this regard, the insoluble residue (okara) resulting from an aqueous extraction (60 °C, pH 9.0), was submitted to an acidic extraction (pH 3.5, 120 °C) without or with a pretreatment (high pressure homogenization or sonication treatment). The insoluble residues of these extractions were dried (oven, 70 °C or vacuum post-treatment with 2-propanol, 40 °C) yielding different ISPS samples. Aqueous dispersions of ISPS samples (1?2% w/w, pH 3 and 7), were used to prepare coarse and fine O/W emulsions. Emulsion stability against creaming and coalescence processes, and the rheological behavior were analyzed. ISPS samples obtained by okara pretreatment and vacuum dried post-treatment with 2-propanol allow to produces emulsions with high values of flocculation degree, increasing the stability of the particle size, and allowing the formation of stronger gel-like emulsions. These pretreatments expose internal sites of the polysaccharide and protein structures, increasing their superficial hydrophobicity and, therefore, allow a strong absorption of the macromolecules at the oil-water interface and/or the formation of external layers, increasing the rigidity of the interfacial film and contributing to the formation of hydrated flocs, Also, these treatments could solubilize certain compounds in okara that would interfere negatively in the formation of the interfacial film. Particularly, sample obtained by high pressures homogenization of the okara presented the best emulsifying properties and it was not significantly affected by variations in the pH of the emulsion. The results of this research work demonstrate a high potential of application of the ISPS samples as O/W emulsifier, under acid and neutral conditions, increasing the added value of an important by-product of the soybean industry.Fil: Porfiri, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; ArgentinaFil: Vaccaro, J.. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; ArgentinaFil: Stortz, Carlos Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Navarro, Diego Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Wagner, Jorge Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; ArgentinaFil: Cabezas, Dario Marcelino. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; Argentin

Classification, characterisation and strategies for improvement of cattle and sheep pasture systems in marginal areas of Southern Chile

Pasture-based livestock systems in farms with medium or low size are especially important in less favored areas and are valuable for society. For these systems to survive, it is necessary to obtain an acceptable level of productivity and ensure commercialization of the products. This study was carried out in the district of Rio Ibáñez, General Carrera Province, in the XI (Aysén) Region of Chile. The sample consisted of 28 small-scale livestock farmers with dual-purpose cattle production; 16 of them also produced sheep for meat. The empirical data produced 55 variables which were subjected to multivariate analysis; three main components were obtained which explain 72.1 % of the variance. By cluster analysis it was obtained four groups with characteristics which varied by farm size, age and personal situation of farmers, farm management and farm profitability. The principal problems found are low productivity in the herds and the poor marketing channels of animals produced. In two groups, due to the low size and poor management, the profitability of the farms is very low and this may compromise their future. To improve production systems, the training and advice of farmers should be strengthened, investment should be supported, especially for young people, and the farmer partnership should be promoted. There is also a need to diversify the families' sources of income (sale of other farm products or handicrafts and touristic activities).Ministerio de Economía de Chile Innova-CORFO Project 11 NTEC 1279

Parallelization of ARACNe, an Algorithm for the Reconstruction of Gene Regulatory Networks

[Abstract] Gene regulatory networks are graphical representations of molecular regulators that interact with each other and with other substances in the cell to govern the gene expression. There are different computational approaches for the reverse engineering of these networks. Most of them require all gene-gene evaluations using different mathematical methods such as Pearson/Spearman correlation, Mutual Information or topology patterns, among others. The Algorithm for the Reconstruction of Accurate Cellular Networks (ARACNe) is one of the most effective and widely used tools to reconstruct gene regulatory networks. However, the high computational cost of ARACNe prevents its use over large biologic datasets. In this work, we present a hybrid MPI/OpenMP parallel implementation of ARACNe to accelerate its execution on multi-core clusters, obtaining a speedup of 430.46 using as input a dataset with 41,100 genes and 108 samples and 32 nodes (each of them with 24 cores).Ministerio de Economía y Competitividad; TIN2016-75845-PXunta de Galicia; ED431G/01Xunta de Galicia; ED431C 2017/0