Higher order elliptic operators on variable domains. Stability results and boundary oscillations for intermediate problems

We study the spectral behavior of higher order elliptic operators upon domain perturbation. We prove general spectral stability results for Dirichlet, Neumann and intermediate boundary conditions. Moreover, we consider the case of the bi-harmonic operator with those intermediate boundary conditions which ap-pears in the study of hinged plates. In this case, we analyze the spectral behavior when the boundary of the domain is subject to a periodic oscillatory perturbation. We will show that there is a critical oscillatory behavior and the limit problem depends on whether we are above, below or just sitting on this critical value. In particular, in the critical case we identify the strange term appearing in the limiting boundary conditions by using the unfolding method from homogenization theory

On a nonlocal moving frame approximation of traveling waves

Abstract The profiles of traveling wave solutions of a 1-d reaction-diffusion parabolic equation are transformed into equilibria of a nonlocal equation, by means of an appropriate nonlocal change of variables. In this new formulation both the profile and the propagation speed of the traveling waves emerge as asymptotic limits of solutions of a nonlocal reaction-diffusion problem when time goes to infinity. In this Note we make these results rigorous analyzing the well-posedness and the stability properties of the corresponding nonlocal Cauchy problem. We also analyze its truncation to a finite interval with consistent boundary conditions. For large enough intervals we show that there is an asymptotically stable equilibrium which approximates the profile of the traveling wave in R. This leads to efficient numerical algorithms for computing the traveling wave profile and velocity of propagation. Résumé Dans cette Note nous considérons le développement de méthodes permettant de préciser aussi bien les profils que la vitesse des ondes progressives pour deséquations de reaction-diffusion, modélisées par deséquations paraboliques semi-linéairesà une dimension d'espace. Moyennant un changement de variable non-local, les profils deviennent des solutions stationnaires d'un problème d'évolution non-local. Nous démontrons que, dans cette nouvelle formulaison, aussi bien les profils que les vitesses de propagation des ondes progressives deviennent desétats stationnaires asymptotiques stables lorsque le temps tend vers l'infini. On analyse aussi la troncature de ce nouveau problème non-local de Cauchy en espace,à un intervalle d'espace fini. Lorsque l'intervalle d'espace tronqué est assez grand on montre qu'il existe unétat stationnaire unique et que si l'intervalle tend vers la droite réelle entière, l'état stationnaire converge vers le profil de l'onde progressive. Ceci permet de développer des méthodes numériques efficaces de calcul des profils et vitesses de ces ondes progressives nonlinéaires

Sexual behavior, use of contraceptive methods and pregnancy in young people from a population affiliated in a health insurer company in Colombia 2018

Describe the average age of sexual life onset from young people and adolescents, the prevalence of contraceptive methods and explore determinants of pregnancy. A retrospective cohort (2014-2018) was followed by a health insurer of the subsidized regime in Colombia. The study sample consisted of 35,214 young people aged 10-24 years living in 21 municipalities of the Colombian Caribbean region. For the social determinants of pregnancy, a multivariate probit model was estimated using as explanatory variables, housing area, education, family functionality and sexual behavior. 10.3% of women and 14.1% of men had their first sexual encounter before age 14 and 43.5% of women and 37.4% of men began their sex life after age 17. From the young people who claimed to have started their sexual life, 70.9% of the men made use of the condom as a contraceptive method, while the women divided on average 27.2% for the pills and / or injections followed by 16 , 1% in the use of the subdermal implant. As determinants of pregnancy in young people under 20, it was found that variables such as suspending school years [Yes (β = 0.6, p = 0.006)], being planned with hormonal method [Yes (β = 0.5, p = 0.000)] or start sexual life [Between 10 to 14 years (β = 0.14, p = 0.000)], increase the likelihood of young women becoming pregnant at some time in their life. These results also showed that the schooling of the young [University (β = -0.4, p = 0.038)] and always use condoms in sexual intercourse [Yes (β = -0.5, p = 0.042)] help prevent the pregnancy event from occurring. The age of sexual onset establishes a basis on which decision makers should intervene for promote a safe sex life, from use of anticonceptives in young people and thus avoiding unplanned pregnancy

Perception, prevalence and factors associated to school bullying in young people from a population affiliated in a colombian health subsidized insurance company in 2018.

Describe the perception from young people about bullying, the prevalence of this event and explore the factors associated with being a victim. A retrospective cohort (2014-2018) was followed by a health insurer company of the subsidized regime in Colombia. The study sample consisted of 35,214 young people aged 10-24 years living in 21 municipalities of the Colombian Caribbean region. Means and standard deviation were expressed for continuous variables and frequencies for categorical variables. For the associated factors, a logistic model was estimated using as explanatory variables, sex, housing area, age range, family functionality, disability of the young person, disability of a family member and variables of psychological perception. 63.6% of young people answered that they have knowledge about what school bullying is, noting that as the schooling of the young person increases, the higher the proportion of positive response. The physical or verbal school bullying rate was 94 young people per 1,000. It was found that factors such as the youth feeling useless and guilty (OR = 3.14, p = 0.000), attending psychological counseling (OR = 1.78, p = 0.000), repeating years (OR = 1.49, p = 0.000), that the young person has a disability (OR = 1.33, p = 0.004), or a family member has a disability (OR = 1.27, p = 0.000), is associated with being a victim of bullying. Likewise, it was found that belonging to a highly functional family environment (OR = 0.57, p = 0.000) is a protective factor. School bullying is an event that needs attention and requires supervision of all those around young people, in order to avoid changes in behavior or suicide. Therefore, health systems must offer comprehensive care to prevent mental health risks related to bullying given their relationship with the presence of disability of the young person or a relativ

Synthesis of Chromen[4,3-b]pyrrolidines by Intramolecular 1,3-Dipolar Cycloadditions of Azomethine Ylides: An Experimental and Computational Assessment of the Origin of Stereocontrol

Azomethine ylides, generated from imine-derived O-cinnamyl or O-crotonyl salicylaldeyde and α-amino acids, undergo intramolecular 1,3-dipolar cycloaddition, leading to chromene[4,3-b]pyrrolidines. Two reaction conditions are used: (a) microwave-assisted heating (200 W, 185 °C) of a neat mixture of reagents, and (b) conventional heating (170 °C) in PEG-400 as solvent. In both cases, a mixture of two epimers at the α-position of the nitrogen atom in the pyrrolidine nucleus was formed through the less energetic endo-approach (B/C ring fusion). In many cases, the formation of the stereoisomer bearing a trans-arrangement into the B/C ring fusion was observed in high proportions. Comprehensive computational and kinetic simulation studies are detailed. An analysis of the stability of transient 1,3-dipoles, followed by an assessment of the intramolecular pathways and kinetics are also reported.Financial support was provided by the Brasilian Universiade Federal do Rio de Janeiro (UFRJ), the Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), by the Spanish Ministerio de Ciencia e Innovación (MICINN) (projects CTQ2010-20387, Consolider Ingenio 2010, CSD2007-00006), the Spanish Ministerio de Economía y Competitividad (MINECO) (projects CTQ2013-43446-P, CTQ2014-51912-REDC, and CTQ2013-45415-P), the Fondos Europeos para el Desarrollo Regional (FEDER), the Generalitat Valenciana (PROMETEO 2009/039 and PROMETEOII/2014/017), the Basque Government (GV/EJ, grant IT-324-07), and the Universities of Alicante and of the Basque Country (UPV/EHU) (UFI11/22 QOSYC)

Evaluación de métodos para medir la actividad inhibitoria de extractos vegetales nativos del departamento de sucre sobre bacterias y levadura patógenas

The objective of this study was to evaluate the efficiency of two methods for measuring inhibitory activity of native ethanolic extracts plant of the Department of Sucre on bacteria and yeast human pathogenic. Sampling was conducted in the municipalities of Morroa and Sincelejo. The leaves of the plants Melia azederach, Sapium sp, Jatropha gossypilia, Psidium guajava, Origanum vulgare, Melissa officinalis, Eucalyptus sp and Cymbopogon citratus were processed using the methods of percolation and Soxhlet for the extraction of the extract. Methods were tested on agar hole method (Method 1) and the sensitive disk method (method 2) to measure the inhibitory effect on Pseudomonas aeruginosa, Klebsiella oxytoca, Enterococcus faecalis, Escherichia coli, and Bulkolderia glumaea Zygosaccharomyces microellipsoides. The results demonstrate that the method 2 allows greater efficiency and interpretation of results with regard to method 1 where there was diffusion of the extracts in the hole, which creates interference in the measurement. This is the first work in the department of Sucre where two methods are evaluated to determine inhibitory activity of a large group of native plants on pathogenic bacteria and yeast.El objetivo del presente trabajo fue evaluar la eficiencia de dos métodos para medir actividad inhibitoria de extractos vegetales etanólicos nativos del Departamento de Sucre sobre bacterias y levadura patógenas de humanos y plantas. Los muestreos se realizaron en los municipios de Morroa y Sincelejo. Las hojas de las plantas Melia Azederach, Sapium sp, Jatropha gossypilia, Psidium guajava, Origanum vulgare Melissa officinalis, Eucalyptus sp y Cymbopogon citratus fueron procesadas utilizando los métodos de percolación y de soxhlet para la extracción de los extractos. Se evaluaron los métodos de orificio sobre agar (método 1) y el método de disco sensitivos (método 2) para medir el efecto inhibitorio sobre Pseudomonas aeruginosa, Klebsiella oxytoca, Enterococcus faecalis, Escherichia coli, Bulkolderia glumaea y Zygosaccharomyces microellipsoides. Los resultados obtenidos demuestran que el método 2 permite una mayor eficacia e interpretación de los resultados con relación al método 1 donde se observó difusión de los extractos en el orificio, lo cual crea interferencia en la medición. Este es el primer trabajo en el departamento de Sucre donde se evalúan dos métodos para determinar actividad inhibitoria de un grupo amplio de plantas nativas sobre bacterias y levadura patógenas

Design, synthesis and biological evaluation of new embelin derivatives as CK2 Inhibitors

A new series of furan embelin derivatives was synthesized and characterized as ATPcompetitive CK2 inhibitors. The new compounds were efficiently synthesized using a multicomponent approach from embelin (1), aldehydes and isonitriles through a Knoevenagel condensation/ Michael addition/ heterocyclization. Several compounds with inhibitory activities in the low micromolar or even submicromolar were identified. The most active derivative was compound 4l (2-(tert-butylamino)-3-(furan-3-yl)-5- hydroxy-6-undecylbenzofuran-4,7-dione) with an IC50 value of 0.63 μM. It turned out to be an ATP competitive CK2 inhibitor with a Ki value determined to be 0.48 μM. Docking studies allowed the identification of key ligand-CK2 interactions, which could help to further optimize this family of compounds as CK2 inhibitor