Evaluation of inorganic arsenic species in drinking water of the southeastern of the Buenos Aires province, Argentina

Arsenic in natural water is a worldwide concern due to chronic health effects in people exposed through the drinking water. The aim was to evaluate the distribution of As(III) and As(V), through ASV, in an Argentine area with low or absent information about these contaminant. The species of inorganic arsenic were quantified in groundwater, surface and drinking water, by Anodic Stripping Voltammetry (ASV) using a gold disc electrode. Total As was analyzed after the reduction step, calculated As(V) by difference. In some sites, total As values exceed the maximum limit for human consumption (10 µg/l), but the As(III)/As(V) ratio was significantly low. The lowest levels of total As were found in those sites related to possible anthropogenic activities, indicating that the content of it in the studied water is coming from natural environment. This study constitutes the first report of inorganic As speciation for the southeastern of Buenos Aires province.Fil: Robles, A. D. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras. Departamento de Ciencias Marinas. Toxicología Ambiental; Argentina.Fil: Robles, A. D. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Cohen, M. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras. Departamento de Ciencias Marinas. Toxicología Ambiental; Argentina.Fil: Romero, M. B. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras. Departamento de Ciencias Marinas. Toxicología Ambiental; Argentina.Fil: Romero, M. B. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Garay, F. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Físico Química; Argentina.Fil: Garay, F. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Bioquímica de Córdoba; Argentina.Fil: Gerpe, M. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras. Departamento de Ciencias Marinas. Toxicología Ambiental; Argentina.Fil: Gerpe, M. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Química Analític

Very low latitude (L = 1.08) whistlers and correlation with lightning activity

We present analysis of more than 2000 lightning-generated whistlers recorded at a low-latitude station, located at Allahabad (geographic latitude, 25.40N; geographic longitude, 81.93E; L = 1.081), India, during December 2010 to November 2011. The main focus of this work is on the correlation between observed low-latitude whistlers and lightning activity detected by the World-Wide Lightning Location Network near the conjugate point (geography 9.87S, 83.59E) of Allahabad. Whistler occurrence is higher in the postmidnight period as compared to the premidnight period. Whistlers were observed in the daytime only on 2 days that too before 8:30 LT (morning). Seasonally, occurrence is maximum during winter months, which is due to more lightning activity in the conjugate region and favorable ionospheric conditions. About 63% of whistlers were correlated with lightning strokes in the vicinity of the conjugate point within spatial extent of 1000 km (conjugate area). Most (about 53%) whistlers were found to be associated with lightning strokes that were offset to the southeast of the conjugate point. The results indicate that an energy range of 7.5-17.5 kJ of lightning strokes generate most of whistlers at this station. The L shell calculations show that propagation paths of the observed whistlers were embedded in the topside ionosphere. Based on these results we suggest a possibility of ducted mode of propagation even for such very low latitude whistlers. ©2015. American Geophysical Union. All Rights Reserved

Sums of products of Ramanujan sums

The Ramanujan sum $c_n(k)$ is defined as the sum of $k$-th powers of the primitive $n$-th roots of unity. We investigate arithmetic functions of $r$ variables defined as certain sums of the products $c_{m_1}(g_1(k))...c_{m_r}(g_r(k))$, where $g_1,..., g_r$ are polynomials with integer coefficients. A modified orthogonality relation of the Ramanujan sums is also derived.Comment: 13 pages, revise

Towards a Nonequilibrium Quantum Field Theory Approach to Electroweak Baryogenesis

We propose a general method to compute $CP$-violating observables from extensions of the standard model in the context of electroweak baryogenesis. It is alternative to the one recently developed by Huet and Nelson and relies on a nonequilibrium quantum field theory approach. The method is valid for all shapes and sizes of the bubble wall expanding in the thermal bath during a first-order electroweak phase transition. The quantum physics of $CP$-violation and its suppression coming from the incoherent nature of thermal processes are also made explicit.Comment: 19 pages, 1 figure available upon e-mail reques

Predicting emotions and meta-emotions at the movies

Audiences are attracted to dramas and horror movies even though negative and ambivalent emotions are likely to be experienced. Research into the seemingly paradoxical enjoyment of this kind of media entertainment has typically focused on gender- and genre-specific needs and viewing motivations. Extending this line of research, the authors focus the role of the need for affect as a more general, gender- and genre-independent predictor of individual differences in the experience of emotions and meta-emotions (i.e., evaluative thoughts and feelings about one’s emotions). The article discusses a field study of moviegoers who attended the regular screening of a drama or a horror film. Results support the assumption that individuals high in need for affect experience higher levels of negative and ambivalent emotions and evaluate their emotions more positively on the level of meta-emotions. Controlling for the Big Five personality factors does not alter these effects. The results are discussed within an extended meta-emotion framework

Deconstruction, Lattice Supersymmetry, Anomalies and Branes

We study the realization of anomalous Ward identities in deconstructed (latticized) supersymmetric theories. In a deconstructed four-dimensional theory with N=2 supersymmetry, we show that the chiral symmetries only appear in the infrared and that the anomaly is reproduced in the usual framework of lattice perturbation theory with Wilson fermions. We then realize the theory on the world-volume of fractional D-branes on an orbifold. In this brane realization, we show how deconstructed theory anomalies can be computed via classical supergravity. Our methods and observations are more generally applicable to deconstructed/latticized supersymmetric theories in various dimensions.Comment: 1+27 pages, 2 figures, references adde

Spontaneous breaking of chiral symmetry, and eventually of parity, in a σ\sigma-model with two Mexican hats

A sigma-model with two linked Mexican hats is discussed. This scenario could be realized in low-energy QCD when the ground state and the first excited (pseudo)scalar mesons are included, and where not only in the subspace of the ground states, but also in that of the first excited states, a Mexican hat potential is present. This possibility can change some basic features of a low-energy hadronic theory of QCD. It is also shown that spontaneous breaking of parity can occur in the vacuum for some parameter choice of the model.Comment: 10 pages, 1 figur

Standard Model CP-violation and Baryon asymmetry

Simply based on CP arguments, we argue against a Standard Model explanation of the baryon asymmetry of the universe in the presence of a first order phase transition. A CP-asymmetry is found in the reflection coefficients of quarks hitting the phase boundary created during the electroweak transition. The problem is analyzed both in an academic zero temperature case and in the realistic finite temperature one. The building blocks are similar in both cases: Kobayashi-Maskawa CP-violation, CP-even phases in the reflection coefficients of quarks, and physical transitions due to fermion self-energies. In both cases an effect is present at order $\alpha_W^2$ in rate. A standard GIM behaviour is found as intuitively expected. In the finite temperature case, a crucial role is played by the damping rate of quasi-particles in a hot plasma, which is a relevant scale together with $M_W$ and the temperature. The effect is many orders of magnitude below what observation requires, and indicates that non standard physics is indeed needed in the cosmological scenario.Comment: 15p, LaTeX (3figs incl.), CERN 93/7081,LPTHE Orsay-93/48,HUTP-93/A036,HD-THEP-93-4

Electroweak Phase Transitions in left-right symmetric models

We study the finite-temperature effective potential of minimal left-right symmetric models containing a bidoublet and two triplets in the scalar sector. We perform a numerical analysis of the parameter space compatible with the requirement that baryon asymmetry is not washed out by sphaleron processes after the electroweak phase transition. We find that the spectrum of scalar particles for these acceptable cases is consistent with present experimental bounds.Comment: 20 pages, 5 figures (included), some comments added, typos corrected and new references included. Final version to appear in PR

Proton Decay in Minimal Supersymmetric SU(5)

We systematically study proton decay in the minimal supersymmetric SU(5) grand unified theory. We find that although the available parameter space of soft masses and mixings is quite constrained, the theory is still in accord with experiment.Comment: 12 pages, uses axodraw.sty, few more comments, one new referenc