Hydrodynamic fluctuations in relativistic superfluids

The Hamiltonian formulation of superfluids based on noncanonical Poisson brackets is studied in detail. The assumption that the momentum density is proportional to the flow of the conserved energy is shown to lead to the covariant relativistic theory previously suggested by Khalatnikov, Lebedev and Carter, and some potentials in this theory are given explicitly. We discuss hydrodynamic fluctuations in the presence of dissipative effects and we derive the corresponding set of hydrodynamic correlation functions. Kubo relations for the transport coefficients are obtained.Comment: 13 pages, no figures, two references adde

Lucky imaging speckle statistics applied to halo suppression

In ground based astronomy, the Lucky Imaging (LI) technique consists of selecting the best quality pictures among those that have been taken with a short exposure time to freeze the atmosphere distortions. Although it has different advantages, the peak intensity of a star is always surrounded by speckled light which, once averaged, provides the halo. The halo can make it difficult to detect faint companions immersed in it. In this paper, we take advantage of the speckle statistics to remove the halo and so to make more effective current detection techniques. Theoretical predictions are confirmed using experimental LI data. Finally, a photometry algorithm is also proposed.Funding by Ministerio de Economía y Competitividad, project AYA2016-78773-C2-1-P

Enhanced electrocatalytic effects of Pd particles immobilized on GC surface on the nitrite oxidation reactions

Ajuts: Manel del Valle thanks the support from program ICREA Academia.Nitrite (NO 2− ) oxidation reactions (NOR) have been performed using a pristine glassy carbon (GC) electrode and Pd modified GC electrode to investigate catalysis and kinetics of oxidation reaction. The XPS analysis revealed that Pd nanoparticles (NPs) on GC is differed electronically from Pd particles alone. Electrochemical observations entailed that the Pd-GC electrode improved the catalytic efficiency by lowering peak potential and improving peak current compared to those obtained by GC or Pd electrode alone. Additionally, the onset potential (E i ) of kinetic process concerning NOR was appeared at 0.63 V for Pd-GC electrode which is smaller than 0.81 V and 0.75 V observed by GC and Pd electrodes, respectively. These observations suggest that the Pd-GC electrode can obtain faster electron transfer and maximum catalytic sites. The validation of Pd-GC as noble catalyst is also supported by observing least free energy of activation at peak (ΔG p‡ = 0.461 eV). The nitrite ions involve a single electron transfer reaction with NO 2 molecules being the product, which later undergoes through a dispropornation reaction yielding NO 2− and NO 3− as final products. The precise observations by RDE experiments revealed that the charge transfer reaction followed by an irreversible first order kinetics with standard rate constant (k 0 ) of 1.98 × 10 −4 cm/s and formal potential (E o ' ) of 0.03 V

Homogeneous Boltzmann equation in quantum relativistic kinetic theory.

Abstract Some mathematical questions about Boltzmann equations for quantum particles, relativistic or not, are considered. Relevant particular cases as Bose, Bose-Fermi, photon-electron gases are studied as well as some simplifications (such as the isotropy of the distribution functions) and asymptotic limits (systems where one of the species is at equilibrium) of special interest from a physical point of view and which give rise to interesting mathematical questions. New results about the existence and long time behaviour of the solutions to some of these problems are exposed

Could road safety education (RSE) help parents protect children? Examining their driving crashes with children on board

Recent evidence suggests that driving behavior and traffic safety outcomes of parents may be influenced by the extent to which they receive information and education on road safety, as well as the fact of driving with their children on board, which may increase their risk perception. However, there are no studies specifically addressing the case of crashes suffered while driving with children. Hence, this study aimed to describe the relationship between road safety education-related variables and parents' traffic safety outcomes while driving with children on board. For this cross-sectional study, data was retrieved from a sample composed of 165 Spanish parents¿all of them licensed drivers¿with a mean age of 45.3 years. Through binary logistic regression (logit) analysis, it was found that factors such as gender, having received road safety education (RSE), and having been sanctioned for the performance of risky driving behavior contribute to modulating the likelihood of suffering crashes while driving with children on board. Gender differences showed a riskier status for male parents. In this study, a set of risk factors explaining the involvement in traffic crashes when driving with children as passengers was identified among parents: gender, traffic sanctions, valuation, and exposure to road safety campaigns. Also, substantial limitations in the self-reported degree of received RSE were found, especially considering that risky driving behavior and traffic crash rates with children on board still have a high prevalence among parent

Rapid field identification of subjects involved in firearm-related crimes based on electroanalysis coupled with advanced chemometric data treatment

We demonstrate a novel system for the detection and discrimination of varying levels of exposure to gunshot residue from subjects in various control scenarios. Our aim is to address the key challenge of minimizing the false positive identification of individuals suspected of discharging a firearm. The chemometric treatment of voltammetric data from different controls using Canonical Variate Analysis (CVA) provides several distinct clusters for each scenario examined. Multiple samples were taken from subjects in controlled tests such as secondary contact with gunshot residue (GSR), loading a firearm, and postdischarge of a firearm. These controls were examined at both bare carbon and gold-modified screen-printed electrodes using different sampling methods: the 'swipe' method with integrated sampling and electroanalysis and a more traditional acid-assisted q-tip swabbing method. The electroanalytical fingerprint of each sample was examined using square-wave voltammetry; the resulting data were preprocessed with Fast Fourier Transform (FFT), followed by CVA treatment. High levels of discrimination were thus achieved in each case over 3 classes of samples (reflecting different levels of involvement), achieving maximum accuracy, sensitivity, and specificity values of 100% employing the leave-one-out validation method. Further validation with the 'jack-knife' technique was performed, and the resulting values were in good agreement with the former method. Additionally, samples from subjects in daily contact with relevant metallic constituents were analyzed to assess possible false positives. This system may serve as a potential method for a portable, field-deployable system aimed at rapidly identifying a subject who has loaded or discharged a firearm to verify involvement in a crime, hence providing law enforcement personnel with an invaluable forensic tool in the field

Caracterización productiva y demográfica de la raza ovina montesina

La raza ovina Montesina se ha explotado tradicionalmente en zonas muy hostiles de alta montaña (por encima de 1.000 metros sobre nivel del mar), caracterizadas por la escasa pluviosidad y su mal reparto a lo largo del año, donde aprovecha los pastos de zonas marginales: ralos, escasos y de mala calidad. En los últimos años, el número de efectivos ha sufrido un fuerte retroceso, pasando de los 300.000 ejemplares, criados en pureza, censados durante la década de los 80 a sólo 1.366 en la actualidad. Este descenso se ha producido en beneficio de razas mejorantes como la Merina o la Segureña. En este trabajo se presentan las características del sistema de producción, el censo actual, la distribución geográfica y las principales características productivas de la raza. Según nuestros resultados, se trata de una raza explotada en régimen extensivo, de un enorme potencial cárnico, gran adaptabilidad al medio y una enorme capacidad de aprovechamiento de los recursos naturales, siendo escasa la necesidad de realizar suplementación. Es una raza con una prolificidad del 123 %, cuyos corderos tienen un peso medio al nacimiento de 3,97 kg, alcanzando su máxima tasa de crecimiento (280 g/día) hacia la 4ª semana de vida.Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria RZ-03-01

Effective theory for the Goldstone field in the BCS-BEC crossover at T=0

We perform a detailed study of the effective Lagrangian for the Goldstone mode of a superfluid Fermi gas at zero temperature in the whole BCS-BEC crossover. By using a derivative expansion of the response functions, we derive the most general form of this Lagrangian at the next to leading order in the momentum expansion in terms of four coefficient functions. This involves the elimination of all the higher order time derivatives by careful use of the leading order field equations. In the infinite scattering length limit where conformal invariance is realized, we show that the effective Lagrangian must contain an unnoticed invariant combination of higher spatial gradients of the Goldstone mode, while explicit couplings to spatial gradients of the trapping potential are absent. Across the whole crossover, we determine all the coefficient functions at the one-loop level, taking into account the dependence of the gap parameter on the chemical potential in the mean-field approximation. These results are analytically expressed in terms of elliptic integrals of the first and second kind. We discuss the form of these coefficients in the extreme BCS and BEC regimes and around the unitary limit, and compare with recent work by other authors.Comment: 27 pages. 4 references added, typos corrected, expanded Section III

Usos tradicionales de la vid silvestre euroasiática en la Península Ibérica

The Iberian Peninsula constitutes the Western limit of the dioecious Eurasian wild grapevine (Vitis vinifera L. subsp. sylvestris). At present, it is a threatened plant, due to human impacts. This liana has had different uses in this territory from the Paleolithic until the end of the last century, including several medicinal applications, inherited from the classical Greek culture. In order to retrieve the available written information, we carried out an exhaustive bibliographic search of the pharmacopoeia linked to this Vitaceae, from the 16th century to the present day. Current references on chemical composition of different parts of grapevine and their medicinal uses were also covered. In parallel, we conducted research in several archives and made inquiries to historians, anthropologists, and sanitary personnel. We also interviewed elderly people from rural areas of Spain and Portugal where some relic populations of wild grapevine are still conserved. Among the written and oral medicinal uses compiled, the main ones are: the use of the grapevine bleeding water to alleviate eczema and skin eruptions and to combat conjunctivitis and keratitis; the use of must from unripe berries (agua de agraz in Spanish) as liver tonic and to treat digestive diseases; the leaves were used to reduce edema, as antihemorrhoidal, and for menopausal disorders; and finally, the vinegar was used to clean and disinfect wounds both on humans and animals. This paper highlights the tremendous erosion of the traditional knowledge about this relevant plant genetic resource.La Península Ibérica constituye el límite occidental de la euroasiática y dioica vid silvestre (Vitis vinifera L. subsp. sylvestris). Actualmente la vid silvestre se encuentra amenazada debido al impacto humano. Esta liana tuvo diferentes usos en la península desde el Paleolítico hasta finales del siglo pasado. Entre ellos, como herencia de la cultura griega clásica, aparecen diferentes usos médicos. Para recuperar la información escrita existente, hemos llevado a cabo una búsqueda bibliográfica exhaustiva sobre la farmacopea vinculada a esta Vitaceae, desde el siglo XVI hasta el presente. Incluimos también referencias sobre la composición química de diferentes partes de la vid y sus usos medicinales. Paralelamente, hemos investigado en los archivos de diferentes localidades y realizado consultas a historiadores, antropólogos y personal sanitario. Asimismo, hemos realizado entrevistas a ancianos de diferentes regiones de España y Portugal donde todavía se conservan algunas poblaciones relictas de vid silvestre. Entre la información escrita y oral de los usos medicinales recopilados, mencionaremos el uso del “agua de lloro” de la vid para aliviar eczemas y erupciones cutáneas; para combatir la conjuntivitis y la queratitis; el mosto o “agua de agraz”, como tónico para el hígado y para tratar afecciones digestivas; las hojas para reducir el edema, como antihemorroidales y para trastornos de la menopausia; y por último, el vinagre para limpiar y desinfectar heridas de personas y animales. Este trabajo destaca la tremenda erosión del conocimiento tradicional sobre este recurso fitogenético tan relevante