El ojo seco está relacionado con un aumento intrasujeto de la variabilidad de osmolaridad lagrimal confirmado por tecnología de aprendizaje de máquinas / Dry eye is matched by increased intrasubject variability in tear osmolarity as confirmed by machine learning approach

Objetivo: La medición de la osmolaridad lagrimal en pacientes con ojo seco ha sido cuestionada debido a su alta variabilidad. El entendimiento del origen de dicha variabilidad ayudaría a la interpretación clínica de los valores obtenidos. Esta investigación evalúa la medición de la variabilidad lagrimal en la práctica clínica. Material y métodos: Veinte pacientes con ojo seco y 20 controles fueron evaluados. Fueron realizadas 3 mediciones consecutivas de osmolaridad a intervalos de 5min. La variabilidad fue definida como la diferencia entre las mediciones más extremas obtenidas en cada ojo. Se utilizaron técnicas de aprendizaje de máquinas para evaluar la capacidad discriminadora de la osmolaridad lagrimal. Resultados: La osmolaridad promedio en el grupo control y ojo seco fueron 295,1 ± 7,3 mOsm/L y 300,6 ± 11,2 mOsm/L, respectivamente (p = 0,004). La variabilidad de la osmolaridad lagrimal fue 7,5 ± 3,6 mOsm/L en el grupo control y 16,7 ± 11,9 mOsm/L en los pacientes con ojo seco (p < 0,001). Basado en la osmolaridad, un clasificador logístico obtuvo un 85% de precisión. Conclusiones: La osmolaridad promedio y la variabilidad fueron significativamente más altas en pacientes con ojo seco. Por otra parte, las técnicas de aprendizaje de máquina demostraron buena precisión para clasificar a los pacientes. Por tanto, la alta variabilidad parece ser característica propia de la enfermedad de ojo seco

Objective: Because of high variability, tear film osmolarity measures have been questioned in dry eye assessment. Understanding the origin of such variability would aid data interpretation. This study aims to evaluate osmolarity variability in a clinical setting. Material and methods: Twenty dry eyes and 20 control patients were evaluated. Three consecutive osmolarity measurements per eye at 5min intervals were obtained. Variability was represented by the difference between both extreme readings per eye. Machine learning techniques were used to quantify discrimination capacity of tear osmolarity for dry eye. Results: Mean osmolarities in the control and dry eye groups were 295.1 ± 7.3 mOsm/L and 300.6 ± 11.2 mOsm/L, respectively (P=.004). Osmolarity variabilities were 7.5 ± 3.6 mOsm/L and 16.7 ± 11.9 mOsm/L, for the control and dry eye groups, respectively (P < .001). Based on osmolarity, a logistic classifier showed an 85% classification accuracy. Conclusions: In the clinical setting, both mean osmolarity and osmolarity variability in the dry eye group were significantly higher than in the control group. Machine learning techniques showed good classification accuracy. It is concluded that higher variability of tear osmolarity is a dry eye feature

Dry eye is matched by increased intrasubject variability in tear osmolarity as confirmed by machine learning approach. / El ojo seco está relacionado con un aumento intrasujeto de la variabilidad de osmolaridad lagrimal confirmado por tecnología de aprendizaje de máquinas.

OBJECTIVE: Because of high variability, tear film osmolarity measures have been questioned in dry eye assessment. Understanding the origin of such variability would aid data interpretation. This study aims to evaluate osmolarity variability in a clinical setting. MATERIAL AND METHODS: Twenty dry eyes and 20 control patients were evaluated. Three consecutive osmolarity measurements per eye at 5min intervals were obtained. Variability was represented by the difference between both extreme readings per eye. Machine learning techniques were used to quantify discrimination capacity of tear osmolarity for dry eye. RESULTS: Mean osmolarities in the control and dry eye groups were 295.1±7.3mOsm/L and 300.6±11.2mOsm/L, respectively (P=.004). Osmolarity variabilities were 7.5±3.6mOsm/L and 16.7±11.9mOsm/L, for the control and dry eye groups, respectively (P<.001). Based on osmolarity, a logistic classifier showed an 85% classification accuracy. CONCLUSIONS: In the clinical setting, both mean osmolarity and osmolarity variability in the dry eye group were significantly higher than in the control group. Machine learning techniques showed good classification accuracy. It is concluded that higher variability of tear osmolarity is a dry eye feature.

Hijos adultos mayores al cuidado de sus padres, un fenómeno reciente / Elderly children in care of their parents, a recent phenomenon

Es un hecho inédito en la historia de la humanidad que hijos que han llegado a la ancianidad cuiden de sus padres. Se mostrarán las particulares vicisitudes y desafíos que se plantean en el seno de la familia extensa cuando se trata de hijos adultos mayores quienes asumen la tarea de cuidar a sus padres, ya que éstas difieren de aquellas que se formulan cuando los hijos se encuentran en la adultez media. Si bien muchas familias se adaptan sin grandes sobresaltos a esta transición biográfica, otras se enfrentan a auténticas crisis. Distinguirlas puede ayudar a los profesionales de salud a manejar de mejor modo a sus pacientes y también ayudar a quienes se encuentran abocados a esta tarea.

The growing aging population has given rise to unprecedented event in human history: elderly children in care of their parents. The work will show the particular vicissitudes and challenges within the extended family when it comes to elderly children who assume the task of caring for their parents because they differ from those that are made when children are in the middle adulthood. While many families adapt without major surprises to this biographical transition, others face a real crisis. Distinguishing between both, could help health professionals to best manage their patients and also help those who are working on this task.

La escala de autoestima de Rosenberg: Validación para Chile en una muestra de jóvenes adultos, adultos y adultos mayores / Rosenberg self-esteem scale: Validation in a representative sample of Chilean adults

Background: Self-esteem is positively associated to the well being of people and could be a good mental health indicator. Aim: To determine the reliability and validity of the Rosenberg Self-esteem Scale in a Chilean adult sample. Material and methods: The instrument was applied to 473 subjects living in the Metropolitan Region of Santiago, evenly distributed according to gender, age, educational level and income. The Neugarten Life Satisfaction index (LSI-A) was also applied to the sample. Results: Cronbach's alpha for reliability of the scale was 0.754. There was no gender bias and factor analysis grouped items into two factors (5positive and 5 negative). The instrument had a correlation of 0.455 with the LSI-A. Conclusions: The Rosenberg Self-esteem Scale meets the criteria for validity and reliability of a quality instrument to measure self-esteem in Chile.

Trajectory generation and modulation using dynamic neural networks.

Generation of desired trajectory behavior using neural networks involves a particularly challenging spatio-temporal learning problem. This paper introduces a novel solution, i.e., designing a dynamic system whose terminal behavior emulates a prespecified spatio-temporal pattern independently of its initial conditions. The proposed solution uses a dynamic neural network (DNN), a hybrid architecture that employs a recurrent neural network (RNN) in cascade with a nonrecurrent neural network (NRNN). The RNN generates a simple limit cycle, which the NRNN reshapes into the desired trajectory. This architecture is simple to train. A systematic synthesis procedure based on the design of relay control systems is developed for configuring an RNN that can produce a limit cycle of elementary complexity. It is further shown that a cascade arrangement of this RNN and an appropriately trained NRNN can emulate any desired trajectory behavior irrespective of its complexity. An interesting solution to the trajectory modulation problem, i.e., online modulation of the generated trajectories using external inputs, is also presented. Results of several experiments are included to demonstrate the capabilities and performance of the DNN in handling trajectory generation and modulation problems.

Second-Look Microlaparoscopy

Second-look laparoscopy performed a short time after corrective surgery to determine reproductive function has always been controversial. The need for general anesthesia and additional abdominal wall trauma make it unpopular. However, postponing pelvic evaluation after the original surgery results in a large proportion of women attempting pregnancy with deformed anatomy as the result of reformation of pelvic adhesions. Since November 1995 we performed microlaparoscopy for a second look in 20 patients. Original procedures were performed for endometriosis, salpingo-oophorolysis, tubal repair, and complicated ectopic pregnancy. Six of the women had adhesions that interfered with fertility and were referred to an assisted reproduction technology (ART) program. Procedures lasted 14 minutes (range 10-17 min). We encountered no complications. Patients were discharged after 2 hours of recovery and resumed normal activity. Second-look microlaparoscopy can be an important tool in assessing the efficacy of reconstructive reproductive surgery, and in accelerating referral to ART programs in women with poor results.

Ulcera péptica y sintomatologia psiquiátrica: un estudio descriptivo / Peptic ulcer and psychiatric symptomatology: a descriptive study

Este trabajo describe clínica y biográficamente tres casos típicos de pacientes ulcerosos pépticos, provenientes de una muestra secuencial de 40 casos estudiados desde el punto de vista psicosocial por los autores. Estos 40 casos provienen de los diagnósticoss endoscópicos realizados en el Departamento de Gastroenterología del Hospital del Salvador. Llama la atención la prevalencia de sintomatología ansiosa, que predomine entre los ulcerosos, duodenales, mientras que entre los gástricos las estructuras depresivas son más frecuentes. Los problemas familiares (alcoholismo paterno, muerte o abandono por parte de los hijos) representan eventos generadores de stress especialmente frecuentes en estos pacientes

Inhibition of IAA-induced elongation in Avena coleoptile segments by lead: a physiological and an electron microscopic study.

A high resolution growth measuring apparatus was used to demonstrate the inhibition of auxin-induced cell elongation in oat coleoptile segments (Avena sativa L. var Holden) by lead at concentrations ranging from 2 x 10-6 M to 2 x 10-3 M. The inhibition was immediate, having no measurable lag period. Electron micrographs of lead-treated and control segments revealed that in the treated material, lead became localized as electron-dense granules in the cell walls and in vesicles associated with dictyosomes. These granules were found to be lead hydroxide phosphate by electron diffraction techniques. The possible significance of this localization and identification with regard to phosphatase activity is discussed.