Vision antropologica de la descentralizacion del sistema de salud en Mexico

OBJETIVO: Analizar cambios organizacionales, políticos y económicos resultantes de la descentralización del sistema de salud en la población sin seguridad social en México. METODOS: Se visitaron tres estados del país seleccionados por el número de habitantes en condición de pobreza, el partido político en el poder y la etapa de implementación de la descentralización (la primera fue en 1984 y la segunda en 1997). Se realizaron entrevistas durante 2007 con informantes clave de los servicios de salud de los gobiernos estatales, personas que acudieron a consulta en los servicios estatales de salud y líderes comunitarios. Los datos fueron analizados desde una perspectiva antropológica y económica. RESULTADOS: La descentralización ocurrió de forma heterogénea en cada estado, observándose una transferencia de responsabilidades de la federación a los estados, más no así una ruptura con la dependencia del nivel central - federal. Las reformas impulsadas desde el nivel federal para crear un esquema fundamentado en principios de subsidiaridad financiera y democratización en salud enfrentan retos políticos y organizacionales para su consolidación. CONCLUSIONES: El enfoque antropológico muestra la relevancia de considerar factores organizacionales, políticos y económicos como parte del proceso de descentralización.

Causes of low vision and use of optical aids in the elderly

PURPOSE: To determine the causes of low vision in an elderly population attended by a university visual rehabilitation service and to check for the use of prescribed optical aids. METHOD: A cross-sectional study was carried out on patients aged 60 years or over attending for the first time a university low vision service in 2001. Ophthalmic reevaluation and interview were performed by means of a structured questionnaire in 2002. RESULTS: The sample comprised 50 subjects aged between 60 and 90 years. Severe low vision (<20/200) was present in 68.0% of patients. The main cause of low vision was age-related macular degeneration (44.0%). Regarding literacy, 16.0% were illiterate and 72.0% had completed fundamental schooling. Thirty-one patients (62.0%) had been prescribed optical aids; 54.8% of these patients stated that they use them. A majority (70.6%) held a favorable opinion of these aids. CONCLUSIONS: The main cause of low vision was age-related macular degeneration. Approximately half of those receiving prescriptions reported actually using the aids in their daily activities. Making best use of residual vision in the elderly population with visual impairment is a priority, given the social context, if the independence necessary for enhanced quality of life is to be achieved.

Efficiency of distinct data mining algorithms for classifying stress level in piglets from their vocalization

Among the challenges of pig farming in today's competitive market, there is factor of the product traceability that ensures, among many points, animal welfare. Vocalization is a valuable tool to identify situations of stress in pigs, and it can be used in welfare records for traceability. The objective of this work was to identify stress in piglets using vocalization, calling this stress on three levels: no stress, moderate stress, and acute stress. An experiment was conducted on a commercial farm in the municipality of Holambra, São Paulo State , where vocalizations of twenty piglets were recorded during the castration procedure, and separated into two groups: without anesthesia and local anesthesia with lidocaine base. For the recording of acoustic signals, a unidirectional microphone was connected to a digital recorder, in which signals were digitized at a frequency of 44,100 Hz. For evaluation of sound signals, Praat® software was used, and different data mining algorithms were applied using Weka® software. The selection of attributes improved model accuracy, and the best attribute selection was used by applying Wrapper method, while the best classification algorithms were the k-NN and Naive Bayes. According to the results, it was possible to classify the level of stress in pigs through their vocalization.

Experimental validation of a 3-D vision-based measurement system applied to robot calibration

One of the problems that slows the development of off-line programming is the low static and dynamic positioning accuracy of robots. Robot calibration improves the positioning accuracy and can also be used as a diagnostic tool in robot production and maintenance. A large number of robot measurement systems are now available commercially. Yet, there is a dearth of systems that are portable, accurate and low cost. In this work a measurement system that can fill this gap in local calibration is presented. The measurement system consists of a single CCD camera mounted on the robot tool flange with a wide angle lens, and uses space resection models to measure the end-effector pose relative to a world coordinate system, considering radial distortions. Scale factors and image center are obtained with innovative techniques, making use of a multiview approach. The target plate consists of a grid of white dots impressed on a black photographic paper, and mounted on the sides of a 90-degree angle plate. Results show that the achieved average accuracy varies from 0.2mm to 0.4mm, at distances from the target from 600mm to 1000mm respectively, with different camera orientations.

Performance evaluation of 3D computer vision techniques

This work presents the implementation and comparison of three different techniques of three-dimensional computer vision as follows: • Stereo vision - correlation between two 2D images • Sensorial fusion - use of different sensors: camera 2D + ultrasound sensor (1D); • Structured light The computer vision techniques herein presented took into consideration the following characteristics: • Computational effort ( elapsed time for obtain the 3D information); • Influence of environmental conditions (noise due to a non uniform lighting, overlighting and shades); • The cost of the infrastructure for each technique; • Analysis of uncertainties, precision and accuracy. The option of using the Matlab software, version 5.1, for algorithm implementation of the three techniques was due to the simplicity of their commands, programming and debugging. Besides, this software is well known and used by the academic community, allowing the results of this work to be obtained and verified. Examples of three-dimensional vision applied to robotic assembling tasks ("pick-and-place") are presented.

Weed mapping using a machine vision system

Weed mapping is a useful tool for site-specific herbicide applications. The objectives of this study were (1) to determine the percentage of land area covered by weeds in no-till and conventionally tilled fields of common bean using digital image processing and geostatistics, and (2) to compare two types of cameras. Two digital cameras (color and infrared) and a differential GPS were affixed to a center pivot structure for image acquisition. Sample field images were acquired in a regular grid pattern, and the images were processed to estimate the percentage of weed cover. After calculating the georeferenced weed percentage values, maps were constructed using geostatistical techniques. Based on the results, color images are recommended for mapping the percentage of weed cover in no-till systems, while infrared images are recommended for weed mapping in conventional tillage systems.

Long-term loss of color vision after exposure to mercury vapor

We evaluated the color vision of 24 subjects (41.6 ± 6.5 years; 6 females) who worked in fluorescent lamp industries. They had been occupationally exposed to mercury vapor (10.6 ± 5.2 years) and had been away from the source of exposure for 6.4 ± 4.04 years. Mean urinary concentration of mercury was 40.6 ± 36.4 µg/g creatinine during or up to 1 year after exposure and 2.71 ± 1.19 µg/g creatinine at the time of color vision testing or up to 1 year thereafter. All patients were diagnosed with chronic mercury intoxication, characterized by clinical symptoms and neuropsychological alterations. A control group (N = 36, 48.6 ± 11.9 years, 10 females, 1.5 ± 0.47 µg mercury/g creatinine) was subjected to the same tests. Inclusion criteria for both groups were Snellen VA 20/30 or better and absence of known ophthalmologic pathologies. Color discrimination was assessed with the Farnsworth D-15 test (D-15) and with the Lanthony D-15d test (D-15d). Significant differences were found between the two eyes of the patients (P < 0.001) in both tests. Results for the worst eye were also different from controls for both tests: P = 0.014 for D-15 and P < 0.001 for D-15d. As shown in previous studies, the D-15d proved to be more sensitive than the D-15 for the screening and diagnosis of the color discrimination losses. Since color discrimination losses were still present many years after the end of exposure, they may be considered to be irreversible, at least under the conditions of the present study.

Cost-effective analysis of different algorithms for the diagnosis of hepatitis C virus infection

We compared the cost-benefit of two algorithms, recently proposed by the Centers for Disease Control and Prevention, USA, with the conventional one, the most appropriate for the diagnosis of hepatitis C virus (HCV) infection in the Brazilian population. Serum samples were obtained from 517 ELISA-positive or -inconclusive blood donors who had returned to Fundação Pró-Sangue/Hemocentro de São Paulo to confirm previous results. Algorithm A was based on signal-to-cut-off (s/co) ratio of ELISA anti-HCV samples that show s/co ratio ³95% concordance with immunoblot (IB) positivity. For algorithm B, reflex nucleic acid amplification testing by PCR was required for ELISA-positive or -inconclusive samples and IB for PCR-negative samples. For algorithm C, all positive or inconclusive ELISA samples were submitted to IB. We observed a similar rate of positive results with the three algorithms: 287, 287, and 285 for A, B, and C, respectively, and 283 were concordant with one another. Indeterminate results from algorithms A and C were elucidated by PCR (expanded algorithm) which detected two more positive samples. The estimated cost of algorithms A and B was US$21,299.39 and US$32,397.40, respectively, which were 43.5 and 14.0% more economic than C (US$37,673.79). The cost can vary according to the technique used. We conclude that both algorithms A and B are suitable for diagnosing HCV infection in the Brazilian population. Furthermore, algorithm A is the more practical and economical one since it requires supplemental tests for only 54% of the samples. Algorithm B provides early information about the presence of viremia.

Differentiating origins of outflow tract ventricular arrhythmias: a comparison of three different electrocardiographic algorithms

Our objective is to evaluate the accuracy of three algorithms in differentiating the origins of outflow tract ventricular arrhythmias (OTVAs). This study involved 110 consecutive patients with OTVAs for whom a standard 12-lead surface electrocardiogram (ECG) showed typical left bundle branch block morphology with an inferior axis. All the ECG tracings were retrospectively analyzed using the following three recently published ECG algorithms: 1) the transitional zone (TZ) index, 2) the V2 transition ratio, and 3) V2 R wave duration and R/S wave amplitude indices. Considering all patients, the V2 transition ratio had the highest sensitivity (92.3%), while the R wave duration and R/S wave amplitude indices in V2 had the highest specificity (93.9%). The latter finding had a maximal area under the ROC curve of 0.925. In patients with left ventricular (LV) rotation, the V2 transition ratio had the highest sensitivity (94.1%), while the R wave duration and R/S wave amplitude indices in V2 had the highest specificity (87.5%). The former finding had a maximal area under the ROC curve of 0.892. All three published ECG algorithms are effective in differentiating the origin of OTVAs, while the V2 transition ratio, and the V2 R wave duration and R/S wave amplitude indices are the most sensitive and specific algorithms, respectively. Amongst all of the patients, the V2 R wave duration and R/S wave amplitude algorithm had the maximal area under the ROC curve, but in patients with LV rotation the V2 transition ratio algorithm had the maximum area under the ROC curve.