Erratum: Ratchet universality in the bidirectional escape from a symmetric potential well [Phys. Rev. E 103, 022203 (2021)].

This corrects the article DOI: 10.1103/PhysRevE.103.022203.

Long-term commuting times and air quality relationship to COVID-19 in São Paulo.

The Coronavirus Disease 2019 (COVID-19) epidemic is an unprecedented global health crisis and the effects may be related to environmental and socio-economic factors. In São Paulo, Brazil, the first death occurred in March 2020 and since then the numbers have grown to 175 new deaths per day in April 2021, positioning the city as the epicenter of the number of cases and deaths in Brazil. São Paulo is one of the largest cities in the world with more than 12 million inhabitants, a fleet of about 8 million vehicles and frequent pollutant concentrations above recommended values. Social inequalities are evident in the municipality, similarly to other cities in the world. This paper focuses on transportation activities related to air pollution and associated with cardiovascular and respiratory diseases especially on people who developed comorbidities during their whole life. This study relates travel trip data to air quality analysis and expanded to COVID-19 disease. This work studied the relationship of deaths in São Paulo due to COVID-19 with demographic density, with family income, with the use of public transport and with atmospheric pollution for the period between March 17th, 2020 and April 29th, 2021. The main results showed that generally passenger kilometers traveled, commuting times and air quality related diseases increase with residential distance from the city center, and thus, with decreasing residential density. PM2.5 concentrations are positively correlated with COVID-19 deaths, regions with high urban densities have higher numbers of deaths and long-distance frequent trips can contribute to spread of the disease.

Ratchet universality in the bidirectional escape from a symmetric potential well.

The present work discusses symmetry-breaking-induced bidirectional escape from a symmetric metastable potential well by the application of zero-average periodic forces in the presence of dissipation. We characterized the interplay between heteroclinic instabilities leading to chaotic escape and breaking of a generalized parity symmetry leading to directed ratchet escape to an attractor either at ∞ or at -∞. Optimal enhancement of directed ratchet escape is found to occur when the wave form of the zero-average periodic force acting on the damped driven oscillator matches as closely as possible to a universal wave form, as predicted by the theory of ratchet universality. Specifically, the optimal approximation to the universal force triggers the almost complete destruction of the nonescaping basin for driving amplitudes which are systematically lower than those corresponding to a symmetric periodic force having the same period. We expect that this work could be potentially useful in the control of elementary dynamic processes characterized by multidirectional escape from a potential well, such as forced chaotic scattering and laser-induced dissociation of molecular systems, among others.

Accuracy of cotinine serum test to detect the smoking habit and its association with periodontal disease in a multicenter study.

BACKGROUND: The validity of the surveys on self-reported smoking status is often questioned because smokers underestimate cigarette use and deny the habit. It has been suggested that self-report should be accompanied by cotinine test. This report evaluates the usefulness of serum cotinine test to assess the association between smoking and periodontal status in a study with a large sample population to be used in studies with other serum markers in epidemiologic and periodontal medicine researches. MATERIAL AND METHODS: 578 patients who were part of a multicenter study on blood biomarkers were evaluated about smoking and its relation to periodontal disease. Severity of periodontal disease was determinate using clinical attachment loss (CAL). Smoking was assessed by a questionnaire and a blood sample drawn for serum cotinine determination. RESULTS: The optimal cut-off point for serum cotinine was 10 ng/ml. Serum cotinine showed greater association with severity of CAL than self-report for mild-moderate CAL [OR 2.03 (CI95% 1.16-3.53) vs. OR 1.08 (CI95% 0.62-1.87) ] advanced periodontitis [OR 2.36 (CI95% 1.30- 4.31) vs. OR 2.06 (CI95% 0.97-4.38) ] and extension of CAL > 3 mm [ OR 1.78 (CI95% 1.16-1.71) vs. 1.37 (CI95% 0.89-2.11)]. When the two tests were evaluated together were not shown to be better than serum cotinine test. CONCLUSIONS: Self-reported smoking and serum cotinine test ≥ 10ng/ml are accurate ,complementary and more reliable methods to assess the patient's smoking status and could be used in studies evaluating serum samples in large population and multicenter studies. CLINICAL RELEVANCE: The serum cotinine level is more reliable to make associations with the patient's periodontal status than self-report questionnaire and could be used in multicenter and periodontal medicine studies.

Dissipative dynamics of a particle in a vibrating periodic potential: Chaos and control.

The dissipative chaotic dynamics of a particle subjected to a horizontally vibrating periodic potential is characterized theoretically and confirmed numerically in the case of an external chaos-controlling periodic excitation also acting on the particle. Theoretical predictions concerning the chaotic threshold in parameter space are deduced from the application of Melnikov's method that fully determine the chaos-control scenario. Also, the structure of diverse regularization regions in parameter space is explained theoretically with the aid of an energy analysis. It was found that the phase difference between the two periodic excitations involved plays a crucial role in the chaos-control scenario, with the particular feature that its optimal value depends upon the ratio between the damping coefficient and the excitation frequency. This constitutes a genuine feature of the chaos-control scenario associated with nonsteady potentials which is in contrast to the case of steady potentials. Additionally, we demonstrate the robustness of the chaos-control scenario against the presence of low-intensity Gaussian noise and reshaping of chaos-suppressing excitations.

Motivos de elección de una asignatura por parte de los alumnos / Some reasons which could induce to the students to choose an academic subject

El motivo de elección de una determinada asignatura por parte de los alumnos, ha sidofrecuentemente interpretado bajo diferentes puntos de vista. En esta comunicación nuestro objetivo hasido analizar los motivos de elección en distintos tipos de asignaturas con características peculiarescada una de ellas, concretamente dos de ellas son de libre configuración, siendo una de impartición enel campus andaluz virtual –Fotoprotección- y la otra en el campus virtual de la Universidad deGranada –Aplicación de la Tecnología Farmacéutica en el tratamiento del cáncer y del dolor-. Latercera asignatura seleccionada es una optativa -Farmacia Práctica- que se imparte actualmente en laLicenciatura en Farmacia. Se ha realizado un análisis de los diferentes motivos que impulsan a unalumno a la elección de una disciplina frente a otra, para ello se ha utilizado una de las herramientas demayor uso, la encuesta anónima a todos aquellos que estaban matriculados. Las conclusiones de esteestudio son diversas pero ante todo cabe señalar en el caso de las virtuales la facilidad de acceso yrealización de las asignaturas virtuales, y destacar también que un título atractivo es fundamental en suelección. En el caso de la optativa el motivo fundamental ha sido aprender algo nuevo relacionado consu licenciatura y seguido muy de cerca por la facilidad de horario. Por tanto como conclusióndefinitiva es interesante destacar que tanto en un caso como en otro el alumno desea aprender algoatractivo y que se acomode fácilmente a su horario de estudio(AU)

The reason why a specific subject is chosen by the students has been frequently interpretedfrom several points of view. The aim of this study is to analyze the reasons why different types ofsubjects with particular characteristics are chosen. Specifically, two of these subjects are freeelectives: one of them –Fotoprotección- is imparted through the Andalusian Virtual Campus, and theother one –Aplicación de la Tecnología Farmacéutica en el tratamiento del cáncer y del dolorthroughthe virtual campus of the University of Granada. The third subject chosen is optional -Farmacia Práctica- and it is at present imparted within the Degree in Pharmacy. The different reasonswhy a student chooses one subject against other have been analyzed using one of the most used tools:an anonymous survey to all the students enrolled. The conclusions of this study are diverse, but it ismainly to be remarked in the case of the virtual subjects their accessibility and easy implementation aswell as the importance of an attractive title for the selection of a subject. The main reason in the caseof the optional subject is to learn something new in relation to their Degree, followed very closely byits timetable. Therefore, as final conclusion, it is interesting to remark that the students want in bothcases to learn something attractive that can be easily adapted to their study schedule(AU)

Creación de un espacio virtual para el apoyo de la docencia en Química Física (Farmacia) / Creation of a virtual environment for supporting the teaching in Physical-Chemistry (Pharmacy)

Un aspecto importante de la práctica docente en el EEES es su interés en el trabajo global del alumno a partir del cual se establece el sistema ECTS de créditos curriculares. Este enfoque requiere una revisión de la metodología docente.Es reconocido que la irrupción de las TIC en todos los sectores sociales, ha tenido una repercusión directa en el sistema educativo. En este contexto, Internet ha demostrado no sólo su importancia como canal de transmisión de contenidos sino su potencial como herramienta docente ya que incorpora interactividad, permite la personalización en la utilización de recursos, se adapta a necesidades particulares en el proceso formativo y permite combinar diferentes tipos de recursos.La aplicación de las TIC en la educación superior es cada día más palpable. Con las limitaciones que imponen los grupos numerosos de alumnos, es clara la tendencia hacia la creación de entornos virtuales como apoyo de la docencia presencial con una integración lo más completa posible en la programación didáctica.La presente comunicación analiza estas cuestiones desde la experiencia acumulada en el desarrollo de diversos recursos docentes y la creación de un entorno específico para algunos grupos de alumnos del curso primero adscritos a las enseñanzas impartidas por el Departamento de Química Física en su sección de Farmacia.El entorno virtual se propone como a) un espacio diseñado no como acumulación de páginas HTML, sino como estructurado de una forma flexible de manera que permita ser actualizado por aportaciones múltiples; b) un espacio interactivo que facilite tanto los intercambios más habituales: profesor-alumnos, como los intercambios transversales entre los alumnos; c) una referencia para alojar recursos que complementen la actividad presencial y d) un lugar de integración de diversas herramientas de aplicación docente(AU)

A important issue regarding the educational practice in the EEES, is the interest in the students’ global work from which curricular ECST system has been established. This particular approach requires a revision of the methodology applied in teaching.It is well known that the Information and Communication Technologies (ICT) have been extended to all social sectors and have produced a special impact on the educational system. In this context, Internet has proved to be not only important as a channel for the transmission of contents but also as a potential educational tool since incorporates interactivity, allows a personalized use of multiple resources, is adaptable to particular needs in the formative process and allows to combine different kinds of resources.The application of ICT in the University studies is more extended every day. In spite of the limitations imposed by the existence of groups formed by a high number of students, a clear trend seems to consolidate nowadays: the creation of virtual environments supporting on-site teaching and which are integrated as much as possible in the study schedules.The present communication focuses on these general aspects in relation with the experience accumulated in the development of several educational resources and the creation of a specific virtual environment for students which enrolled in Physical- Chemistry (Pharmacy section) during the past academic years.The virtual environment developed is a) a designed space not for accumulating static HTML pages but structured for allowing to update it with periodical contributions; b) an interactive space where the usual communicative exchange between students and teacher as well as between students is facilitated; c) a reference in which to incorporate complementary resources in order to support 'on site' teaching; and d) a place to integrate different tools with application in educational matters(AU)

Contribución de la etapa de secado a la maduración de la longaniza crudo-curada fermentada / Contribution of drying stage to the ripening of dry-cured fermented Longaniza

El objetivo fue estudiar el grado de maduración alcanzado por una Longaniza crudo-curada fermentada,elaborada con carne de cerdo en tripa natural y sometida a un secado industrial estándar (12 días a 15ºC/85-65%HR). Se determinaron diversos parámetros (composición, mermas, actividad de agua, pH, acidez total, colorCIELab, proteolisis, lipolisis, TBARS y ácidos grasos) y atributos sensoriales (enrojecimiento, olor y sabor,acidez, fi rmeza) en Longaniza cruda y curada. El tratamiento de secado produjo una merma de peso del 30%por unidad de embutido y permitió alcanzar un adecuado grado de deshidratación, acidifi cación y enrojecimiento,auxiliado por la adición de cultivos iniciadores y de colorante Rojo. Se obtuvo una Longaniza fi rme al corte.Se alcanzaron poblaciones efectivas de micrococáeas y bacterias ácido-lácticas, que proporcionaron seguridadmicrobiológica y una apreciable acidez. Sin embargo, la trasformación de lípidos y proteínas no tuvo magnitudsufi ciente para desarrollar un marcado aroma y sabor a carne crudo-curada, no apreciándose matices aromáticospropios de la oxidación de la grasa, debido en parte a la adición de antioxidantes. La calidad sensorial de Longanizaseco-curada estaría limitada por el lento desarrollo del aroma y sabor durante la etapa de secado(AU)

The objective was to study ripening of dry-cured fermented Longaniza, a small calibre Salami manufacturedwith pork, stuffed into natural casing and dried following a standard industrial process (12 days at 15 º C/85-65% RH). Several parameters (composition, shrinkage, water activity, pH, total acidity, CIELab colour,proteolysis, lipolysis, TBARS and fatty acids) and sensory attributes (redness, odour and fl avour, acidity, fi rmness) were determined in raw and cured samples. The drying process produced weight loss of 30% perunit of sausage and allowed to achieve an adequate degree of dehydration, acidifi cation and reddening, aidedby the addition of starter cultures and artifi cial red colouring. Longaniza presented suffi cient strength to besliced. Effective populations of Micrococaeae and lactic-acid bacteria were achieved, providing signifi cantmicrobiological safety and acidity. However, the transformation of lipids and proteins was not intense enough todevelop a pronounced dry-cured meat aroma and taste, since no fat-oxidation aromatic traits were found. Thismay be partly due to the addition of antioxidants. Sensory quality of Longaniza would be limited by the slowdevelopment of aroma and fl avor during the drying stage(AU)

Mode-locking of mobile discrete breathers.

We study numerically synchronization phenomena of mobile discrete breathers in dissipative nonlinear lattices periodically forced. When varying the driving intensity, the breather velocity generically locks at rational multiples of the driving frequency. In most cases, the locking plateau coincides with the linear stability domain of the resonant mobile breather and desynchronization occurs by the regular appearance of type-I intermittencies. However, some plateaus also show chaotic mobile breathers with locked velocity in the locking region. The addition of a small subharmonic driving tames the locked chaotic solution and enhances the stability of resonant mobile breathers.

Dissipative discrete breathers: periodic, quasiperiodic, chaotic, and mobile.

The properties of discrete breathers in dissipative one-dimensional lattices of nonlinear oscillators subject to periodic driving forces are reviewed. We focus on oscillobreathers in the Frenkel-Kontorova chain and rotobreathers in a ladder of Josephson junctions. Both types of exponentially localized solutions are easily obtained numerically using adiabatic continuation from the anticontinuous limit. Linear stability (Floquet) analysis allows the characterization of different types of bifurcations experienced by periodic discrete breathers. Some of these bifurcations produce nonperiodic localized solutions, namely, quasiperiodic and chaotic discrete breathers, which are generally impossible as exact solutions in Hamiltonian systems. Within a certain range of parameters, propagating breathers occur as attractors of the dissipative dynamics. General features of these excitations are discussed and the Peierls-Nabarro barrier is addressed. Numerical scattering experiments with mobile breathers reveal the existence of two-breather bound states and allow a first glimpse at the intricate phenomenology of these special multibreather configurations.

Estudio cinético de la desdiazoación en medio acuoso del tetrafluorborato de bencenodiazonio / The kinetic study of dediazoniation in an aqueous medium of benzenediazonium tetraflourborate

Los análisis cinéticos realizados a diferentes temperaturas (20º C - 40º C) indican que el proceso de desdiazoación del ion bencenodiazonio (BZ) es de orden uno respecto a BZ siendo A = 2,3.1015 s-1 y Ea = 112,5 kJ.mol-1 en la ecuación de Arrhenius así como A H = 110,0 kJ.mol-1 y AS = 40,7 J.K-1.mol-1 para la ecuación de Eyring. Los resultados cromatográficos revelan que BZ se descompone por un proceso heterolítico mediado por el catión arilo. La presencia de sales Cu(I) o de Cu(II) y ácido ascórbico produce un cambio del mecanismo de reacción. Los compuestos intermedios originados en estas condiciones son especies estables que pueden ser transportadas en la sangre. El modelo estudiado sugiere una posible explicación para la localización descrita en la literatura para los tumores producidos por la administración de BZ a ratas (AU)

Characterization of the signal transduction pathways mediating morphine withdrawal-stimulated c-fos expression in hypothalamic nuclei.

The transcription factor, Fos, is considered as a functional marker of activated neurons. We have shown previously that acute administration of morphine induces the expression of Fos in hypothalamic nuclei associated with control of the hypothalamus-pituitary-adrenocortex axis, such as the paraventricular nucleus and the supraoptic nucleus. In the current study, we examined the role of protein kinase A, protein kinase C and Ca2+ entry through L-type Ca2+ channels in naloxone-precipitated Fos expression in the paraventricular and supraoptic nuclei. After 7 days of morphine treatment, we did not observe any modification in Fos production. However, when opioid withdrawal was precipitated with naloxone a dramatic increase in Fos immunoreactivity was observed in the parvocellular division of the paraventricular nucleus and in the supraoptic nucleus. Chronic co-administration of chelerythrine (a selective protein kinase C inhibitor acting at its catalytic domain) with morphine did not affect the increase in Fos expression observed in nuclei from morphine withdrawn rats. In addition, infusion of calphostin C (another protein kinase C inhibitor, which interacts with its regulatory domain) did not modify the morphine withdrawal-induced expression of Fos. In contrast, when the selective protein kinase A inhibitor, N-(2'guanidinoethyl)-5-isoquinolinesulfonamide (HA-1004), was infused it greatly diminished the increased Fos production observed in morphine-withdrawn rats. Furthermore, chronic infusion of the selective L-type Ca2+ channel antagonist, nimodipine, significantly inhibited the enhancement of Fos induction in the paraventricular and supraoptic nuclei from morphine-withdrawn animals. Taken together, these data might indicate that protein kinase A activity is necessary for the expression of Fos during morphine withdrawal and that an up-regulated Ca2+ system might contribute to the activation of Fos. The present findings suggest that protein kinase A and Ca2+ influx through L-type Ca2+ channels might contribute to the activation of neuroendocrine cells in the paraventricular and supraoptic nuclei.

Discrete breathers in dissipative lattices.

We study the properties of discrete breathers, also known as intrinsic localized modes, in the one-dimensional Frenkel-Kontorova lattice of oscillators subject to damping and external force. The system is studied in the whole range of values of the coupling parameter, from C=0 (uncoupled limit) up to values close to the continuum limit (forced and damped sine-Gordon model). As this parameter is varied, the existence of different bifurcations is investigated numerically. Using Floquet spectral analysis, we give a complete characterization of the most relevant bifurcations, and we find (spatial) symmetry-breaking bifurcations that are linked to breather mobility, just as it was found in Hamiltonian systems by other authors. In this way moving breathers are shown to exist even at remarkably high levels of discreteness. We study mobile breathers and characterize them in terms of the phonon radiation they emit, which explains successfully the way in which they interact. For instance, it is possible to form "bound states" of moving breathers, through the interaction of their phonon tails. Over all, both stationary and moving breathers are found to be generic localized states over large values of C, and they are shown to be robust against low temperature fluctuations.

[Perioperative monitoring using transesophageal echocardiography in a case of endocarditis-related tricuspid valve disease]. / Monitorización perioperatoria con ecocardiografía transesofágica en un caso de valvulopatía tricuspídea por endocarditis.

The risk of infectious endocarditis is higher for intravenous drug users than for patients with either rheumatic disease or valve prostheses. We report the case of a 33-year-old woman who self-administered opioid drugs parenterally and who developed a clinical picture of infectious endocarditis. Serious involvement of the tricuspid valve developed in the form of vegetation requiring surgical repair, during which transesophageal echocardiography was used for perioperative monitoring.

Monitorización perioperatoria con ecocardiografía transesofágica en un caso de valvulopatía tricuspídea por endocarditis / Perioperative monitoring with transesophageal echocardiography in a case of tricuspid valve disease due to endocarditis

El riesgo de endocarditis infecciosa entre los consumidores de drogas por vía intravenosa es superior al que pudieran presentar los pacientes afectados de enfermedad reumática o prótesis valvulares. Presentamos el caso de una mujer de 33 años de edad, consumidora de opiáceos por vía parenteral, que presentó cuadro de endocarditis infecciosa con importante afección de la válvula tricúspide en forma de gran vegetación que requirió tratamiento quirúrgico reparador, durante el cual se realizó monitorización perioperatoria mediante ecocardiografía transesofágica (AU)

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Activation of c-fos expression in hypothalamic nuclei by mu- and kappa-receptor agonists: correlation with catecholaminergic activity in the hypothalamic paraventricular nucleus.

Administration of the preferential mu-opioid receptor agonist, morphine, and selective K-opioid receptor agonists elicits activation of the hypothalamus-pituitary-adrenocortical axis, although the site or the molecular mechanisms for these effects have not been determined. The expression ofFos, the protein product of the c-fos protooncogene, has been widely used as an anatomical marker of monitoring neuronal activity. In the present study we evaluated 1) the effects of the mu-opioid receptor agonist, morphine, and those of the selective K-opioid receptor agonist, trans-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl-]benzeneacet amide methane sulfonate (U-50,488H), administration on the expression of Fos in hypothalamic nuclei; and 2) the possible modification of the activity of noradrenergic neurons known to send afferent projections to the paraventricular nucleus (PVN), the site of CRF neurons involved in initiating ACTH secretion. Using immunohistochemical staining of Fos, the present results indicate that acute treatment with either morphine or U-50,488H induces marked Fos immunoreactivity within the hypothalamus, including the medial parvicellular PVN and supraoptic and suprachiasmatic nuclei. Pretreatment with naloxone attenuated the effect of morphine, whereas nor-binaltorphimine, a selective kappa-opioid receptor antagonist, abolished the effect of U-50,488H on Fos induction. Correspondingly, morphine and U-50,488H injection increased the production of the cerebral noradrenaline metabolite 3-methoxy-4-hydroxyphenylethylene glycol as well as noradrenaline turnover in the PVN. These effects were antagonized by naloxone and nor-bin-altorphimine, respectively. All of these findings are discussed in terms of specific events that couple opioid-induced activation of the hypothalamus-pituitary-adrenocortical axis and noradrenergic activity with changes in gene expression in selective hypothalamic nuclei.

Effects of a vasorelaxing factor liberated by the rat isolated atria on rat aortic rings with and without endothelium.

In 1993, Illanes et al. described a vasoactive factor, the auricular vasorelaxing factor (AVF), by controlled distension of rat isolated atria. This factor produces vasodilation, antagonizing the vasoconstrictor action of phenylephrine. We now report assays by using isolated rat aortic rings and norepinephrine as a vasoconstrictor. Isolated thoraxic aortic rings were mechanically deprived of endothelium and subjected to the effects of increasing, cumulative concentrations of 6.6 x 10(-11) M to 6.6 x 10(-7) M norepinephrine. AVF significantly decreases the constrictor effect of norepinephrine assayed afterward, shifting the vasoconstrictor dose-response relation to the right. The effect was the same in rat aortic rings with or without endothelium. Subjecting aortic rings to control vehicle samples did not alter the dose-response curve to norepinephrine. We conclude that AVF antagonizes the norepinephrine vasoconstrictor effect in rat isolated aortic rings and that the mechanism of this vasorelaxing effect is independent of any contribution from the endothelial cells.

Study of the reaction of complexation of penicillin V with cobalt(II) in methanolic medium.

As shown by spectrophotometry, two specific complexes with stoichiometry 1:1 and 2:1 are formed when penicillin V reacts with cobalt(II) in a methanolic medium. Stability constants are determined at 20 degrees , as well as the molar absorptivities at 510 nm. The results obtained are: log beta(1:1) = 1.67 +/- 0.01 l.mole(-1) and log beta(2:1) = 5.76 +/- 1.01 l(2).mole(-2), (1:1) = 13.62 +/- 0.73 and (2:1) = 12.95 +/- 0.61 l.mole(-1).cm(-1).