Geometry-induced fluctuations of olfactory searches in bounded domains

In olfactory search an immobile target emits chemical molecules at constant rate. The molecules are transported by the medium which is assumed to be turbulent. Considering a searcher able to detect such chemical signals and whose motion follows the infotaxis strategy, we study the statistics of the first-passage time to the target when the searcher moves on a finite two-dimensional lattice of different geometries. Far from the target, where the concentration of chemicals is low the direction of the searcher's first movement is determined by the geometry of the domain and the topology of the lattice, inducing strong fluctuations on the average search time with respect to the initial position of the searcher. The domain is partitioned in well defined regions characterized by the direction of the first movement. If the search starts over the interface between two different regions, large fluctuations in the search time are observed.Comment: 7 pages, 8 figures, typed in revte

Proyecto de comparación del Modelo de Evaluación de Desempeño de la Empresa Bancoomeva S.A., Regional Palmira con un esquema cimentado en la Metodología de 360°

En este proyecto se analiza el modelo de evaluación de desempeño implementado y formalizado en Bancoomeva S.A. Regional Palmira. Se parte de desintegrar dicho modelo para establecer a qué metodología hace referencia, dentro de los modelos de evaluación de desempeño aceptados y académicamente desarrollados por el área de la Administración de Empresas. Una vez entendido el modelo organizacional oficial, se analiza uno que está a la vanguardia en la academia, el modelo de 360°, el cual se explica y se fundamenta para determinar cuáles son sus bondades más relevantes y sus carencias más significativas, a fin de establecer puntos de referencia y pasar al componente comparativo. Por último, y para poder establecer herramientas de comparación, se realiza un trabajo de campo explicando a los empleados de la organización cuáles son los dos modelos, el que tienen en su organización y el modelo de 360°. Así, a través de una encuesta se realiza la comparación y establece en suma cuál de los dos modelos, y en qué situación, puede ser mejor implementar

Desing and development of a robotic platform for the evaluation of search algorithms

Plant diseases represent a major economic and environmental problem in agriculture and forestry. Upon infection, a plant develops symptoms that affect different parts of the plant causing a significant agronomic impact. As many such diseases spread in time over the whole crop, a system for early disease detection can aid to mitigate the losses produced by the plant diseases and can further prevent their spread [1]. In recent years, several mathematical algorithms of search have been proposed [2,3] that could be used as a non-invasive, fast, reliable and cost-effective methods to localize in space infectious focus by detecting changes in the profile of volatile organic compounds. Tracking scents and locating odor sources is a major challenge in robotics, on one hand because odour plumes consists of non-uniform intermittent odour patches dispersed by the wind and on the other hand because of the lack of precise and reliable odour sensors. Notwithstanding, we have develop a simple robotic platform to study the robustness and effectiveness of different search algorithms [4], with respect to specific problems to be found in their further application in agriculture, namely errors committed in the motion and sensing and to the existence of spatial constraints due to land topology or the presence of obstacles

Search strategies and the automated control of plant diseases

We propose the use of the "infotaxis" search strategy as the navigation system of a robotic platform, able to search and localize infectious foci by detecting the changes in the profile of volatile organic compounds emitted by and infected plant. We builded a simple and cost effective robot platform that substitutes odour sensors in favour of light sensors and study their robustness and performance under non ideal conditions such as the exitence of obstacles due to land topology or weeds

Prevalence of antinuclear antibodies in inflammatory bowel disease and seroconversion after biological therapy

Background: Estimates of detectable antinuclear antibodies (ANA) prevalence vary widely, from 6% in healthy populations to 50-80% in patients with autoimmune disease. However, there is a lack of evidence about the overall prevalence in inflammatory bowel disease (IBD) and ANA seroconversion after the beginning of biological therapy. Objectives: The aim of the study was to investigate the overall prevalence of ANA in IBD patients, their relationship with different treatments, clinical outcomes and the seroconversion rate of ANA in patients treated with biological therapy. Methods: Ambispective observational study including all consecutive IBD patients was carried out. Information about the presence of ANA, disease phenotype, duration, activity, complications, and past and current treatments were transversally collected. Retrospectively, in patients with detectable ANA, data regarding previous ANA detection and the diagnosis of lupus-like syndrome (LLS) was gathered. Results: A total of 879 IBD patients were included. We observed a detectable ANA prevalence of 13.6%. The presence of ANA was frequently associated with biological therapy (36/118) and decreased when immunomodulators were combined to this therapy (7/32). Of 78 patients with ANA prior to the beginning of biological therapy, a seroconversion rate of 28.8% was observed after a mean of 3.14 years. Only 1 patient suffered LLS. Conclusion: Our study showed a prevalence of detectable ANA higher than the expected in healthy population. The presence of ANA was lower when immunomodulator therapy is associated. The ANA seroconversion rate is relevant after the initiation of biological treatment nevertheless, the risk of LLS appeared to be marginal.Funding: The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors report funding support from the Spanish Instituto de Salud Carlos III Grant (FIS–PI18/01304) related to this article

Células troncales mesenquimales de la papila apical y su papel prometedor en la biología radicular

OBJETIVO: En la actualidad, la práctica odontológica ha centrado su atención en terapias regenerativas. Una nueva fuente de células troncales dentales ha sido hallada en la papila apical de dientes permanentes inmaduros humanos, sin embargo, no hay ningún estudio de revisión bibliográfica de esta nueva población celular y su papel prometedor en la biología radicular para posterior aplicación en endodoncia regenerativa. METODOLOGÍA: Se realizó una revisión en la literatura usando bases de datos como PubMed, MEDLINE, Science Direct, entre otras. Se utilizó el algoritmo de búsqueda: (Stem Cells OR Cell, Stem OR Cells, Stem OR Stem Cell OR Progenitor Cells OR Cell, Progenitor OR Cells, Progenitor OR Progenitor Cell OR Mother Cells OR Cell, Mother OR Cells, Mother OR Mother Cell OR Dental Papilla OR Papillae, Dental OR Dental Papillae OR Papilla, Dental) OR Papilla Apical AND Cell Proliferation OR Proliferation, Cell OR Cellular Proliferation OR Proliferation. No hubo restricción de lenguaje ni de sexo. Se buscaron estudios en humanos, y artículos de revisión en los últimos 5 años. RESULTADOS: La búsqueda arrojó 50 artículos de los cuales fueron seleccionados 30 basados en su abstract. CONCLUSIÓN: Es posible obtener y expandir células de la papila apical de dientes permanentes inmaduros con fenotipo de células troncales mesenquimales. Estas células pueden ser viables y son posibles candidatas estándar para ser usadas en terapias en regeneración de tejidos dentales.

Canal endémico de la Enfermedad Diarreica Aguda en menores de 5 años, Cali - Colombia, 2012-2016

Introduction: In Colombia, Acute Diarrheal Disease (ADD) occupies the second place of morbidity and mortality in the population under five years of age, knowing its behavior during the year is relevant for decision making. Objective: To elaborate an endemic channel for notified cases of EDA between 2012 and 2016 in the municipality of Cali. Methods: A retrospective descriptive study was carried out. The behavior during the years 2012 to 2016 of the ADD is presented in children under 5 years notified to the Public Health Surveillance System of the municipal health secretariat of Cali. An endemic channel was prepared per epidemiological week. The data processing was done in Excel and the statistical software R.5.0 was used. Results: It is observed that the tendency of the ADD in the municipality of Cali is positive, which indicates that in recent years there has been an increase in the number of cases reported to SIVIGILA (Public Health Surveillance System) in comparison with those referring to the endemic channel. Discussion: The development of the endemic channel of the EDA in Cali, showed the importance of applying these surveillance methodologies in situations of public health interest. As noted in the results, it is necessary to have a monitoring tool like the endemic channel.Introducción: En Colombia, la Enfermedad Diarreica Aguda (EDA) ocupa el segundo lugar de morbi-mortalidad en la población menor de cinco años, conocer su comportamiento durante el año es relevante para la toma de decisiones. Objetivo: Elaborar un canal endémico para los casos notificados de EDA entre los años 2012 y 2016 en el municipio de Cali. Métodos: Se realizó un estudio descriptivo retrospectivo. Se presenta el comportamiento durante los años 2012 a 2016 de la EDA en menores de 5 años notificados al Sistema de Vigilancia en Salud Pública de la secretaría de salud municipal de Cali. Se elaboró un canal endémico por semana epidemiológica. El procesamiento de datos se realizó en Excel y se utilizó el software estadístico R.5.0. Resultados: Se observa que la tendencia de la EDA en el municipio de Cali es positiva, lo que indica que en los últimos años se ha incrementado el número de casos notificados al SIVIGILA (Sistema de Vigilancia en Salud Pública) en comparación con los referentes para el canal endémico. Discusión: La elaboración del canal endémico de la EDA en el Cali, evidenció la importancia de aplicar estas metodologías de vigilancia en situaciones de interés en salud pública. Como se observó en los resultados, es necesario contar con una herramienta de monitoreo como el canal endémico

Terapia con pregabalina versus bloqueos intervencionistas en dolor neuropático: Un estudio de cohorte

Objective: tcompare the decrease in pain in patients with pregabalin therapy versus interventional blocks. Materials and methods: retrospective cohort study that included patients older than 18 years diagnosed with neuropathic pain from a reference center in Pereira, Colombia, between the years 2010-2016. The outcome was assessed at three months in each cohort and was defined as the change in pain intensity according to the visual analog pain scale. The comparison between cohorts and the effectiveness of the intervention was evaluated through repeated measures analysis with the generalized estimating equation. Results: a total of 1451 patients with pain were selected, of these, only 94 met the inclusion criteria. Sixty-two (66%) patients received a pharmacological scheme with pregabalin, and 32 patients (34%) underwent blockages. The pain intensity prior to pregabalin treatment was 7.3 ± 1.8 and 8.9 ± 1.2 in the group with blocks, p = 0.005. The intensity of posterior pain in the group with pregabalin was 3.5 ± 2.4, with an average improvement of 53.9%, while in the group with blocks, it was 2.5 ± 2 with an average improvement of 70.7%. Interventional management reduces pain 2.09 times more compared to pregabalin therapy (p <0.001). Conclusions: the use of interventional blocks in the treatment of neuropathic pain should be considered in patients with moderate to severe neuropathic pain.Objetivo: comparar la disminución en el dolor en pacientes con terapia con pregabalina frente a bloqueos intervencionistas. Materiales y métodos: estudio de cohorte retrospectiva, se reclutó pacientes mayores de 18 años diagnosticados con dolor de tipo neuropático de centro de referencia de la ciudad de Pereira, Colombia, entre los años 2010 a 2016. Se evaluó la variación en la intensidad del dolor. La comparación entre cohortes y la efectividad de la intervención se evaluó a través del análisis de medias repetidas con la ecuación de estimación generalizada. Resultados: se incluyeron 94 pacientes con dolor neuropático. A 62 (66%) pacientes se les formuló un esquema farmacológico con pregabalina y a 32 (34%) pacientes se les realizó bloqueos. La intensidad del dolor previa al tratamiento con pregabalina fue de 7,3 ± 1,8 y de 8,9 ± 1,2 en el grupo con bloqueos, p=0,005. La intensidad del dolor posterior en el grupo con pregabalina fue de 3,5 ± 2,4, con una mejoría media de 53,9%, mientras que en el grupo con bloqueos fue del 2,5 ± 2 con una mejoría media de 70,7%. El manejo intervencionista logró una reducción 2,09 veces mayor comparada con la pregabalina (p<0,001). Conclusiones: el empleo de bloqueos intervencionistas en el tratamiento del dolor neuropático debe ser considerado en pacientes con dolor neuropático moderado a severo