Host traits, ownership behaviour and risk factors of SARS-CoV-2 infection in domestic pets in Mexico.

SARS-CoV-2 can infect pets under natural conditions, which raises questions about the risk factors related to the susceptibility of these animals to infection. The status of pet infection by SARS-CoV-2 in Mexico is not well-understood. We aimed to estimate the frequency of positive household cats and dogs to viral RNA and antibodies for SARS-CoV-2 during the second wave of human infections in Mexico, and to recognize the major risk factors related to host and pet ownership behaviour. We evaluated two study groups, cats and dogs from COVID-19-infected/-suspected households (n = 44) and those admitted for veterinary care for any reason at several veterinary hospitals in Puebla City, Mexico (n = 91). Using RT-PCR, we identified the presence of SARS-CoV-2 RNA in swabs of four dogs (18.18%) and zero cats in COVID-19-infected/-suspected households; within this group, 31.82% of dogs and 27.27% of cats were tested IgG ELISA-positive; and neutralizing antibodies were detected in one dog (4.55%) and two cats (9.09%). In the random group (pets evaluated at private clinics and veterinary teaching hospital), 25.00% of dogs and 43.59% of cats were ELISA-positive and only one cat showed neutralizing antibodies (2.56%). Older than 4-year-old, other pets at home, and daily cleaning of pet dish, were each associated with an increase in SARS-CoV-2 infection (p < 0.05). Allowing face lick, sharing bed/food with pets and owner tested positive or suspected COVID-19 were not significant risk factors, but more than 4 h the owner spent away from home during the lockdown for COVID-19 (OR = 0.37, p = 0.01), and outdoor pet food tray (OR = 0.32, p = 0.01) significantly decreased the risks of SARS-CoV-2 infection in pets, suggesting that time the owner spends with their pet is an important risk factor.

Stability of a tilted granular monolayer: How many spheres can we pick before the collapse?

The triggering of avalanches is investigated using discrete element simulations for a process of random extraction of spheres. A monolayer, formed by identical spheres in a hexagonal configuration, is placed on a tilted plane surrounded by a small fence that sustains the spheres, mimicking the disposal of fruits in the market. Then, a random continuous extraction process of spheres is imposed until the collapse. For this simple numerical experiment, a phase diagram was obtained to visualize the occurrence of avalanches triggered by vacancies as a function of the tilting angle, system size, and friction coefficient. More importantly, a subzone was found where we can predict the critical number of extractions until the avalanche takes place. The prediction is made from an evolution model of the average coordination number based on statistical considerations. The theoretical prediction also gives a constant critical void fraction of spheres, which implies the system collapses at a critical packing fraction.

Effect of methyl-ene versus ethyl-ene linkers on structural properties of tert-butyl and mesityl bis-(imidazolium) bromide salts.

The crystal structures of ligand precursor bis-(imidazolium) salts 1,1'-methyl-enebis(3-tert-butyl-imidazolium) dibromide monohydrate, C15H26N4 +·2Br-·H2O or [ tBuNHC2Me][Br]2·H2O, 1,1'-(ethane-1,2-di-yl)bis-(3-tert-butyl-imidazolium) dibromide dihydrate, C16H28N4 +·2Br-·2H2O or [ tBuNHC2Et][Br]2·2H2O, 1,1'-methyl-enebis[3-(2,4,6-tri-methyl-phen-yl)imidazolium] dibromide dihydrate, C25H30N4 2+·2Br-·2H2O or [MesNHC2Me][Br]2·2H2O, and 1,1'-(ethane-1,2-di-yl)bis-[3-(2,4,6-tri-methyl-phen-yl)imidazolium] dibromide tetra-hydrate, C26H32N4 2+·2Br-·4H2O or [MesNHC2Et][Br]2·4H2O, are reported. At 293 K, [ tBuNHC2Me][Br]2·H2O crystallizes in the P21/c space group, while [ tBuNHC2Et][Br]2·2H2O crystallizes in the P21/n space group at 100 K. At 112 K, [MesNHC2Me][Br]2·2H2O crystallizes in the ortho-rhom-bic space group Pccn while [MesNHC2Et][Br]2·4H2O crystallizes in the P21/c space group at 100 K. Bond distances and angles within the imidazolium rings are generally comparable among the four structures. All four bis-(imidazolium) salts co-crystallize with one to four mol-ecules of water.

Relevance of biometals during neuronal differentiation and myelination: in vitro and in vivo studies.

Biometals are essential during the development of the central nervous system (CNS) since they participate in the organization and regulation of multiple processes related with the proper organization and functioning of brain structures. Neuronal differentiation is a specialized and complex process that occurs actively from embryonic development to the first years of life and is even maintained in specific areas of the mammalian adult brain. In this review, we focus on describing the cellular and molecular mechanisms of trace biometals such as iron (Fe), zinc (Zn), copper (Cu), and manganese (Mn) on neuronal specialization, comprising from brain uptake to effects on synaptogenesis, axonal outgrowth, myelination, and cellular and neurochemical phenotype determination. We highlight the relevance of biometals in the proper brain functioning by discussing some of the potentially detrimental effects when biometal dyshomeostasis occurs in the brain. Finally, future directions are proposed for exploring the relevance of biometals in brain function using pharmacological, molecular, and analytical approaches.

Nonlinear amplification of adhesion forces in interleaved books.

It is nearly impossible to separate two interleaved phonebooks by pulling their spines. The very slight force exerted by the outer sheets of the assembly is amplified as the exponential of the square of the number of sheets, meaning that even a small number of sheets can create a highly resistant system. We present a systematic and detailed study of the influences of the normal external force and the geometrical parameters of the booklets on the assembly strength. We conclude that the paper-paper adhesion force between the two outer sheets, on the order of a few [Formula: see text],  is the one amplified by the interleaved-book system. The two-phonebook experiment-which has attracted the attention of students and the non-scientific public all around the world as an outstanding demonstration of the strength of friction-appears to also be a spectacular macroscopic manifestation of the microscopic coupling of friction and adhesion.

Faraday-Wave Contact-Line Shear Gradient Induces Streaming and Tracer Self-Organization: From Vortical to Hedgehoglike Patterns.

In this Letter, we experimentally demonstrate self-organization of small tracers under the action of longitudinal Faraday waves in a narrow container. We observe a steady current formation dividing the interface in small cells given by Faraday-wave symmetries. These streaming currents rotate in each cell, and their circulation increases with wave amplitude. This streaming flow drives the tracers to form patterns, whose shapes depend on the Faraday-wave amplitude: From low to high amplitudes, we find tracers dispersed on vortices, narrow rotating rings, and a hedgehoglike pattern. We first describe the main pattern features and characterize the wave and tracers' motion. We then show experimentally that the main source of the streaming flow is the spatiotemporal-dependent shear at the wall contact line created by the Faraday wave itself. We end by presenting a 2D compressible advection model that considers the minimal ingredients present in the Faraday experiment, namely, the stationary circulation, the stretching component due to the oscillatory wave, and a steady converging field, which combined produce the observed self-organized patterns.

Patterning of a cohesionless granular layer under pure shear.

The response of a thin layer of granular material to an external pure shear imposed at its base is investigated. The experiments show that, even for noncohesive materials, the resulting deformation of the material is inhomogeneous. Indeed, a novel smooth pattern, consisting of a periodic modulation of the shear deformation of the free surface, is revealed by an image-correlation technique. These observations are in contrast with the previous observation of the fracture pattern in cohesive granular materials subjected to stretching. For cohesive materials, the instability is due to the weakening of the material which results from the rupture of capillary bridges that bond the grains to one another. For noncohesive materials, the rupture of the capillary bridges cannot be invoked anymore. We show that the instability results from the decrease of friction on shearing. PACS: 89.75.Kd: Pattern formation in complex systems; 83.60.Uv: Rheology: fracture; 45.70.Qj: Pattern formation in granular matter.

Self-Amplification of Solid Friction in Interleaved Assemblies.

It is nearly impossible to separate two interleaved phone books when held by their spines. A full understanding of this astonishing demonstration of solid friction in complex assemblies remains elusive. In this Letter, we report on experiments with controlled booklets and show that the force required increases sharply with the number of sheets. A model captures the effect of the number of sheets, their thickness, and the overlapping distance. Furthermore, the data collapse onto a self-similar master curve with one dimensionless amplification parameter. In addition to solving a long-standing familiar enigma, this model system provides a framework with which one can accurately measure friction forces and coefficients at low loads, and that has relevance to complex assemblies from the macro- to the nanoscale.

Utilidad farmacoclínica de los antidepresivos ISRS en la impulsividad y la agresividad / Utility of SSRI antidepressants in the treatment of impulsivity and aggression

Introducción: Estudios preliminares sobre neurobiología de la agresividad impulsiva destacaron el papel de la serotonina para inhibir la conducta violenta que se relacionaría con la impulsividad, pero no con la agresividad. En el ámbito carcelario las conductas agresivas e impulsivas presentan una alta prevalencia y requieren su abordaje por el equipo interdisciplinario de Salud Mental. Objetivos: Determinar la utilidad farmacoclínica de antidepresivos ISRS en el tratamiento de la impulsividad y la agresividad, y sus especificidades clínicas y poblacionales. Material y Método: Estudio observacional y transversal mediante evaluación de historias clínicas de 104 masculinos con pena privativa de la libertad. Se evaluaron psicopatológicamente y se valoraron los resultados obtenidos en 4 escalas de seguimiento clínico para impulsividad y agresividad. Al subgrupo con resultado positivo en al menos 2 escalas y en la evaluación clínica (n=30) se les indicó un ISRS (paroxetina o sertralina) a su plan farmacológico y se los reevaluaron en 2 tiempos posteriores. Se aplicaron parámetros estadísticos y se cumplimentó con requisitos ético-legales. Resultados: Al analizar las subescalas de la ABS hallamos que el parámetro de agresividad y el de desinhibición fueron los que más respondieron de forma significativa (25.96%, 21.43%; p<0.01). El análisis de la escala IRS arrojó que las subescalas de tiempo para toma de decisiones y de capacidad para diferir disminuyeron significativamente (p<0.01), mientras que la de agresividad y de paciencia/impaciencia tuvieron menor significación estadística (p<0.05). Conclusiones: Los inhibidores selectivos de recaptación de serotonina tienen eficacia y utilidad clínica en el tratamiento de pacientes con comportamientos impulsivo-agresivos con particularidades asociadas a otros fármacos, diagnóstico psicopatológico y tipo de agresividad.

Introduction: Preliminary Studies on neurobiology of impulsive aggression highlighted the role of serotonin to inhibit violent behavior that would be related to impulsivity, but not aggressive. In prisons, aggressive and impulsive behaviors have a high prevalence and require interdisciplinary team approach for Mental Health. Objectives: To determine the utility of SSRI antidepressants in the treatment of impulsivity and aggression, and its clinical and population specific. Material and method: Observational and transversal study through evaluation of medical records of 104 men in prision. Psychiatrically evaluated and the results obtained in four scales for clinical follow-up were evaluated impulsivity and aggressiveness. The subgroup with a positive result in at least 2 scales and clinical evaluation (n = 30) were prescribed an SSRI (paroxetine or ser traline) to your drug plan and the re-evaluated in two later times. Statistical parameters were applied and complied with ethical and legal requirements. Results: to analyze ABS ́s subscales we found that aggressiveness and disinhibition settings were the ones that responded significantly (25.96%, 21.43%; p<0.01). The analysis of the IRS scale showed that time for decision making scale and ability to differ subscales decreased significantly (p<0.01), while aggressiveness and patience/impatience ones had less statistical significance. Conclusions: Selective serotonin reuptake inhibitors have clinical utility and effectiveness in the treatment of patients with impulsive-aggressive behavior associated with drugs other particularities, psychopathological diagnosis and aggressive type

Effect of cohesion and shear modulus on the stability of a stretched granular layer.

The main mechanism of the cellular pattern which forms at the surface of a thin layer of a cohesive granular material submitted to in-plane stretching has been identified as the "strain softening" arising from the features of grain-grain interactions. We perform measurements of the strain field associated with such structures by using a correlation image technique and additionally characterize the cohesion and shear modulus of the samples. We show that for high cohesion, the layer is fragile and the surface deformation is highly nonlinear, whereas at low cohesion, a smooth and linearly growing structure is observed as a function of external stretching. Analysis of the wavelength as a function of cohesion along with independent measurement of the shear modulus indicate that a simple model of strain softening is acceptable if a mechanism of cluster formation due to cohesion is taking place.

Softening induced instability of a stretched cohesive granular layer.

We report on a cellular pattern which spontaneously forms at the surface of a thin layer of a cohesive granular material submitted to in-plane stretching. We present a simple model in which the mechanism responsible of the instability is the "strain softening" exhibited by humid granular materials above a typical strain. Our analysis indicates that such a type of instability should be observed in any system presenting a negative stress sensitivity to strain perturbations.