Effective Majorana neutrino decay

We study the decay of heavy sterile Majorana neutrinos according to the interactions obtained from an effective general theory. We describe the two and three-body decays for a wide range of neutrino masses. The results obtained and presented in this work could be useful for the study of the production and detection of this particles in a variety of high energy physics experiments and astrophysical observations. We show in different figures the dominant branching ratios and the total decay width.Comment: 22 pages, 9 figures. arXiv admin note: text overlap with arXiv:1508.0158

The iso-Nazarov reaction

The construction of five-membered rings is essential in organic chemistry. In this context, pentannulation reactions that provide a straightforward access to cyclopentenones are of particular interest, as these structures are not only embedded in important molecules such as some prostaglandins, but also serve as versatile building blocks in organic synthesis. This review documents the acid-promoted cycloisomerization of conjugated dienals and linearly-conjugated dienones for the construction of cyclopentenones, a transformation that has been largely eclipsed by the well-known Nazarov reaction, i.e. the acid-promoted cycloisomerization of cross-conjugated ketones.Fil: Riveira, Martín Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Marsili, Lucía A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Mischne, Mirta Paulina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentin

Corporate social responsibility and inventory policy

In this article, we study the impact of implementing corporate social responsible (CSR) practices on a firm’s inventory policy. Our proposal is that there is an inverted U-shape relationship between firms’ CSR and their inventory levels. Two elements explain such proposal. First, stakeholders have different interests regarding the outcome of the inventory system. Specifically, we hypothesize that customers pressure firms to increase inventories; employees have conflicting views regarding inventories and, for this reason, they do not pressure firms in a particular direction; and environmental activists force firms to reduce inventories. The second reason is that there is different level of stakeholder proactiveness contingent on the intensity in the implementation of social responsible policies. In particular, we posit that for low levels of CSR, customers are more relevant, while for larger levels other stakeholders gain more importance. We test this theoretical prediction by crossing two databases, COMPUSTAT, for financial data, and KLD for data on social responsibility. Our final database contains data on 1881 different US companies for the period 1996-2006. The results found conform to our theoretical prediction. Our analysis will be helpful to strategic and tactical decision-making processes on inventory management and will allow researchers to offer concrete advice on the likely outcomes of various stakeholder relationship practices in order to improve the effectiveness of inventory systems. Additionally, the connection between CSR and inventory policies has interest at a macroeconomic level given that, on the one hand, there is a growing tendency for firms to behave in a socially responsible way. On the other, inventories are responsible for up to 87% of the total peak-to-trough movement in GDP. Thus, our results suggest that this tendency to incorporate the social dimension in firms’ strategy should smooth out the overall economic cycle given that firms apply more intensive CSR policies in the expansive periods (decreasing inventories) rather than during the downturns (increasing inventories).Corporate social responsibility, Stakeholders, Inventories

Uniqueness of the Fock quantization of scalar fields under mode preserving canonical transformations varying in time

We study the Fock quantization of scalar fields of Klein-Gordon type in nonstationary scenarios propagating in spacetimes with compact spatial sections, allowing for different field descriptions that are related by means of certain nonlocal linear canonical transformations that depend on time. More specifically, we consider transformations that do not mix eigenmodes of the Laplace-Beltrami operator, which are supposed to be dynamically decoupled. In addition, we assume that the canonical transformations admit an asymptotic expansion for large eigenvalues (in norm) of the Laplace-Beltrami operator in the form of a series of half integer powers. Canonical transformations of this kind are found in the study of scalar perturbations in inflationary cosmologies, relating for instance the physical degrees of freedom of these perturbations after gauge fixing with gauge invariant canonical pairs of Bardeen quantities. We characterize all possible transformations of this type and show that, independently of the initial field description, the combined criterion of requiring (i) invariance of the vacuum under the spatial symmetries and (ii) a unitary implementation of the dynamics, leads to a unique equivalence class of Fock quantizations, all of them related by unitary transformations. This conclusion provides even further robustness to the validity of the proposed criterion, completing the results that have already appeared in the literature about the uniqueness of the Fock quantization under changes of field description when one permits exclusively local time dependent canonical transformations that scale the field configuration.Comment: 12 pages, submitted to Phys. Rev.

Distribution of sea-air CO 2 fluxes in the Patagonian Sea: Seasonal, biological and thermal effects

Sea-air CO2 fluxes (FCO2) in the Patagonian Sea (PS) were studied using observations collected in 2000-2006. Based on the PS frontal structures and the thermal and biological contributions to FCO2 we present a regional subdivision between distinct regimes that provide new insights on the processes that control these fluxes. The coastal regime (CR) is a net source of atmospheric CO2 (4.9 x 10-3mol.m-2.d-1) while the open shelf regime (SHR) is a net CO2 sink (-6.0 x 10-3mol.m-2.d-1). The interface between these two regions closely follows the location of along-shore fronts. In addition, based on the nature of the processes that drive the FCO2, the PS is subdivided between northern (NR) and southern (SR) regions. Both, NR and SR are CO2 sinks, but the CO2 uptake is significantly higher in NR (-6.4 x 10-3mol.m-2.d-1) than in SR (-0.5 x 10-3mol.m-2.d-1). The data reveal a strong seasonality in FCO2. The mean CO2 capture throughout the PS in austral spring is -5.8 x 10-3mol.m-2.d-1, reaching values lower than -50 x 10-3mol.m-2.d-1 in NR, while in winter FCO2 is close to equilibrium in SR. The analysis of the biological and thermal effects (BE and TE, respectively) on seasonal pCO2 variability indicates that regions of CO2 emission are dominated by the TE while regions of CO2 uptake are dominated by the BE. Our results indicate that the biological pump is the dominant process determining the sea-air CO2 flux in the PS.Fil: Kahl, Lucía Carolina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval. Departamento Oceanografía; ArgentinaFil: Bianchi, Alejandro A.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval. Departamento Oceanografía; ArgentinaFil: Osiroff, Ana Paula. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval. Departamento Oceanografía; ArgentinaFil: Pino, Diana Ruiz. Universite Pierre et Marie Curie; FranciaFil: Piola, Alberto Ricardo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval. Departamento Oceanografía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Thrashed sweet corn : refrigerated storage

En este trabajo se estudia la conservación del maíz dulce híbrido desgranado variedad GH 2684 conservado por refrigeración a OoC y 80 % HR Y por congelación a -18º C. Antes de iniciar la conservación se realizaron tratamientos de inmersión en solución de ácido ascórbico 0,5 %, agua clorada 150 p.p.m. y escaldado en agua hirviente. Durante la conservación y al término de la misma se controló: sólidos solubles y totales sólidos insolubles en alcohol pigmentos carotenoides acidez titulable y potencial vitamina C. Duración de los ensayos: dos semanas para los refrigerados y cinco meses para los congelados. Se efectuaron evaluaciones sensoriales utilizando un panel no entrenado y escalas estructuradas.In this work was studied the storage of thrashed sweet corn, hibrid varo GH 2684. It was staraged by refrigeration at Oº C and 80 % RH, and by freezing at -18 oC. Befare the storage there were made inmersion treatments with ascorbic acid 0,5 %, water with 150 p.p.m. of chlorine, and blanched. During the storage there were controled the following variables: soluble and total solids, insoluble solids in alcoholic solution caroten titulable acidíty and pH ascorbic acid. The total duration of the experiment was lwo weeks for the refrigerated corn and five months tor the frozen ones. There was made sensorial evaluation by non trained panel and by structure scales.Fil: Vignoni, Lucía A.. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Tecnología AgroindustrialFil: Ventrera, Nancy. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Tecnología Agroindustria

Extra-Heavy Crude Oil Viscosity Reduction Using and Reusing Magnetic Copper Ferrite Nanospheres

The main objective of this study is the synthesis, use, and reuse of magnetic copper ferrite nanospheres (CFNS) for extra-heavy oil viscosity reduction. The CFNS were synthesized using a solvothermal method resulting in mean particle size of 150 nm. Interactions of CFNS with the crude oil were evaluated through asphaltene adsorption isotherms, as well as static and dynamic rheology measurements for two cycles at 25◦ C. Adsorption and desorption experiments corroborated that most of the asphaltenes adsorbed can be removed for nanoparticle reuse. During the rheology tests, nanoparticles were evaluated in the first cycle at different concentrations from 300 to 1500 mg/L, leading to the highest degree of viscosity reduction of 18% at 500 mg/L. SiO2 nanoparticles were evaluated for comparison issues, obtaining similar results regarding the viscosity reduction. After measurements, the CFNS were removed with a magnet, washed with toluene, and further dried for the second cycle of viscosity reduction. Rheology tests were performed for a second time at a fixed concentration of 500 mg/L, and slight differences were observed regarding the first cycle. Finally, changes in the extra-heavy oil microstructure upon CFNS addition were observed according to the significant decrease in elastic and viscous moduli

Regulation of mitochondrial permeability transition pore by PINK1

Background: Loss-of-function mutations in PTEN-induced kinase 1 (PINK1) have been linked to familial Parkinson’s disease, but the underlying pathogenic mechanism remains unclear. We previously reported that loss of PINK1 impairs mitochondrial respiratory activity in mouse brains. Results: In this study, we investigate how loss of PINK1 impairs mitochondrial respiration using cultured primary fibroblasts and neurons. We found that intact mitochondria in PINK1−/− cells recapitulate the respiratory defect in isolated mitochondria from PINK1−/− mouse brains, suggesting that these PINK1−/− cells are a valid experimental system to study the underlying mechanisms. Enzymatic activities of the electron transport system complexes are normal in PINK1−/− cells, but mitochondrial transmembrane potential is reduced. Interestingly, the opening of the mitochondrial permeability transition pore (mPTP) is increased in PINK1−/− cells, and this genotypic difference between PINK1−/− and control cells is eliminated by agonists or inhibitors of the mPTP. Furthermore, inhibition of mPTP opening rescues the defects in transmembrane potential and respiration in PINK1−/− cells. Consistent with our earlier findings in mouse brains, mitochondrial morphology is similar between PINK1−/− and wild-type cells, indicating that the observed mitochondrial functional defects are not due to morphological changes. Following FCCP treatment, calcium increases in the cytosol are higher in PINK1−/− compared to wild-type cells, suggesting that intra-mitochondrial calcium concentration is higher in the absence of PINK1. Conclusions: Our findings show that loss of PINK1 causes selective increases in mPTP opening and mitochondrial calcium, and that the excessive mPTP opening may underlie the mitochondrial functional defects observed in PINK1−/− cells