Entropy production in the early-cosmology pionic phase

We point out that in the early universe, for temperatures in the approximate interval 175-80 MeV (after the quark-gluon plasma), pions carried a large share of the entropy and supported the largest inhomogeneities. Thus, we examine the production of entropy in a pion gas, particularizing to inhomogeneities of the temperature, for which we benefit from the known thermal conductivity. We finally put that entropy produced in relaxing such thermal inhomogeneities in the broad context of this relatively unexplored phase of early-universe cosmology.Comment: 10 pages, 10 figures

Spontaneous mass generation and the small dimensions of the Standard Model gauge groups U(1), SU(2) and SU(3)

The gauge symmetry of the Standard Model is SU(3)_c x SU(2)_L x U(1)_Y for unknown reasons. One aspect that can be addressed is the low dimensionality of all its subgroups. Why not much larger groups like SU(7), or for that matter, SP(38) or E7? We observe that fermions charged under large groups acquire much bigger dynamical masses, all things being equal at a high e.g. GUT scale, than ordinary quarks. Should such multicharged fermions exist, they are too heavy to be observed today and have either decayed early on (if they couple to the rest of the Standard Model) or become reliquial dark matter (if they don't). The result follows from strong antiscreening of the running coupling for those larger groups (with an appropriately small number of flavors) together with scaling properties of the Dyson-Schwinger equation for the fermion mass.Comment: 15 pages, 17 plots. This version incorporates community as well as referee comments. Accepted for publication in Nuclear Physics

The ratio of viscosity to entropy density in a pion gas satisfies the KSS holographic bound

We evaluate the ratio of shear viscosity to entropy density in a pion gas employing the Uehling-Uehlenbeck equation and experimental phase-shifts parameterized by means of the SU(2) Inverse Amplitude Method. We find that the ratio for this monocomponent gas stays well above the KSS 1/(4 pi) bound. We find similar results with other sets of phase shifts and conclude the bound is nowhere violated.Comment: 2 page text, three figures. V2: short comment and graph added to assert that a minimum of eta/s is not discarded from the hadron, low T side in a heavy-ion collisio

Bulk viscosity of low-temperature strongly interacting matter

We study the bulk viscosity of a pion gas in unitarized Chiral Perturbation Theory at low and moderate temperatures, below any phase transition to a quark-gluon plasma phase. We argue that inelastic processes are irrelevant and exponentially suppressed at low temperatures. Since the system falls out of chemical equilibrium upon expansion,a pion chemical potential must be introduced, so we extend the existing theory to include it. We control the zero modes of the collision operator and Landau's conditions of fit when solving the Boltzmann equation with the elastic collision kernel. The dependence of the bulk viscosity with temperature is reminiscent of the findings of Fernandez-Fraile and Gomez Nicola, while the numerical value is closer to that of Davesne. In the zero-temperature limit we correctly recover the vanishing viscosity associated to a non-relativistic monoatomic gas.Comment: 8 pages, 8 figure

Locus of Control in Mexican University Students Comparisons by Gender

The aim of this research was to compare the profiles of locus of control in Mexican university students. The total sample was of 1537 subjects; 820 women and 717 men, with a mean age of 20.38 years (SD = 1.81) and 20.78 years (SD = 1.94) respectively. The approach adopted in the research is framed within a quantitative approach with a survey descriptive design. The results of the multivariate analysis of variance, followed by the univariate variance analyzes, are the ones who show higher levels of external locus of control in the factors of luck, political power, destiny and interpersonal relationships, while men report higher levels of locus as luck external control, political power, destination and interpersonal relationships. The differences found between men and women regarding the locus of control, suggest that when designing any intervention that aims to strengthen the internal locus of control will have to take into account the gender variable

Psychiatric disorders as debut of acute intermittent porphyria in a patient with no family history

Introducción: las porfirias agudas comprenden un grupo de trastornos genéticos en la síntesis del grupo hemo, que pueden comprometer la vida y cuyas manifestaciones clínicas simulan otras enfermedades como: abdomen agudo, neuropatía periférica, trastornos psiquiátricos primarios, entre otras. La demora en el diagnóstico, el que se confirma al demostrar niveles elevados de porfirinas totales en sangre y orina, retarda el inicio del tratamiento específico incrementando la morbimortalidad.Reporte de caso: se reporta una paciente cuyas manifestaciones clínicas motivaron el planteamiento de varios diagnósticos erróneos, privándola de la terapéutica adecuada y oportuna. Se analizan la clínica, la orientación diagnóstica y terapéutica.Conclusiones: la porfiria aguda intermitente es poco frecuente pero grave, y debe considerarse en mujeres jóvenes con dolor abdominal agudo no atribuible a otras causas.Introduction: acute porphyrias comprise a group of genetic disorders in the synthesis of the heme group, which can compromise life and whose clinical manifestations simulate other diseases such as: acute abdomen, peripheral neuropathy, primary psychiatric disorders, among others.Case presentation: the delay in diagnosis, which is confirmed by demonstrating elevated levels of total porphyrins in blood and urine, delays the initiation of specific treatment, increasing morbimortality. We report a patient whose clinical manifestations led to several erroneous diagnoses, depriving her of adequate and timely treatment.Conclusions: the clinical, diagnostic and therapeutic orientation are analyzed.  Acute intermittent porphyria is rare but serious, and should be considered in young women with acute abdominal pain not attributable to other causes

Experiences of artificial intelligence application at international level

Informatics and communications have revolutionized different sectors the energy is one of them through the application using the smart grid in the research exposes its importance in the new vision of the transmission and distribution of electric energy according to the implementation of Distributed Generation with the contributions of different energy sources from different points close to the consumer. The support of this new approach based on current technological advances, with intelligent instrumentation that supports these working methods, has taken into account the incorporation of these techniques as a fundamental tool for the successful decision making. Provides security, security of supply, reliability and energy savings, which translates into the achievement of energy efficiency in the grid system

Bulk viscosity and energy-momentum correlations in high energy hadron collisions

We show how the measurement of appropriately constructed particle-energy/momentum correlations allows access to the bulk viscosity of strongly interacting hadron matter in heavy ion collisions. This measurement can be performed by the LHC and RHIC experiments in events with high-particle multiplicity, following up on existing estimates of the shear viscosity based on elliptic flow.Comment: 7 pages, no figure

Occupational exposure to pesticides and endometrial cancer in the Screenwide case-control study

Background: Endometrial cancer is the most common gynaecological tumour in developed countries and disease burden is expected to increase over the years. Identifying modifiable risk factors may help developing strategies to reduce the expected increasing incidence of these neoplasms. Objective: This study evaluates the association between occupational exposure to pesticides and endometrial cancer using data from a recent case-control study in Spain. Methods: The analyses included data from 174 consecutive incident endometrial cancer cases and 216 hospital controls frequency-matched by age. Data were collected through structured epidemiological questionnaires and exposure to pesticides was assessed using a Spanish job-exposure matrix (MatEmESp). Results: Overall, 12% of controls and 18% of cases were occupationally exposed to pesticides. We observed a positive association between occupational exposure to pesticides and endometrial cancer (OR = 2.08; 95% CI = 1.13-3.88 compared to non-exposed). In general, exposures that occurred farther in the past were significantly associated with endometrial cancer. Exposure to insecticides, fungicides and herbicides were positively associated with endometrial cancer (OR = 2.08; 95% CI = 1.13-3.88, OR = 4.40; 95% CI = 1.65-13.33, and OR = 5.25; 95% CI = 1.84-17.67, respectively). The agricultural, poultry and livestock activities scenario was associated with endometrial cancer (OR = 4.16; 95% CI = 1.59-12.32), while the cleaning exposure scenario was not (OR = 1.22; 95% CI = 0.55-2.67). Conclusions: Assessment of occupational exposure to pesticides assessed using a Spanish job-exposure matrix revealed a positive association with endometrial cancer. The elucidation of the role of pesticide compounds on endometrial cancer should shed a light on the aetiology of this tumour