RESUMO
Resumen Se ha propuesto, en la literatura de neurociencias, la hipótesis de que el cerebro funciona con base en redes glioneuronales, responsables de los procesos sensoriales, motores y cognitivos. La teoría de gráficas ofrece modelos matemáticos para describir estas redes complejas a partir de simples abstracciones: nodos y aristas. En este trabajo se plantea el uso de técnicas de procesamiento de señales para el análisis de la conectividad funcional entre ensambles neuronales a partir de medidas derivadas del EEG a través de la teoría de gráficas. Se describen los procedimientos para el análisis de la conectividad, desde el procesamiento y acondicionamiento de los registros, el cálculo de la densidad espectral en el EEG en banda ancha, la determinación de medidas de conectividad entre electrodos, y la estimación de parámetros de las redes complejas resultantes. Se analizó el EEG de 50 sujetos en intervalos de antes (Pre) y durante la fotoestimulación repetida (Rph). Con base en la significancia estadística de la respuesta durante Rph de desincronización/sincronización (D/S) en la banda alfa, y su extensión en las regiones corticales, los participantes se separaron en tres grupos: G1, G2 y G3. La pendiente de la regresión lineal D/S vs repetición en banda alfa, fue significativa en 16 de 16 regiones en G1, 12 de 16 en G2 y 5 de 16 en G3. La conectividad funcional siguió estos cambios mientras que en las bandas delta, theta y beta no se registraron modificaciones. D se relaciona con activación y la S con inhibición lo que apoya la hipótesis de la participación de alfa en el proceso cognitivo de habituación a la fotoestimulación.
Abstract The hypothesis that the brain works using glial-neuronal networks that are responsible for sensory, motor and cognitive processes has been proposed in the neuroscience literature. Graph theory offers mathematical models to describe these complex networks from simple abstractions such as nodes and connecting edges. In this work, usign signal processing techniques to the analysis of functional connectivity between neuronal emsembles derived from EEG measurements through theory graph. Procedures for the analysis of connectivity are described, from multichannel record processing and conditioning, computation of wideband power spectral density, determination of connectivity measures between electrodes, and parameter estimation of the resulting complex networks. EEG recordings from fifty subjects were analyzed in intervals before (pre) and during repeated photostimulation (Rph). Based on the statistical significance of the response during Rph, desynchronization/synchronization (D/S) in alfa band, and its wide distribution in corticals areas, the participants were divided into three groups: G1 , G2 and G3. The slope D/S in alfa band was significant in 16 of 16 regions (G1), 12 of 16 (G2) and 5 of 16 (G3). The functional connectivity depicted the same trend as these changes, whereas in the delta, theta and beta bands occurred no modifications. D is related to activation and S with inhibition, supporting the hypothesis of alfa-band's participation in the cognitive process of habituation to photostimulation.
RESUMO
Among its different activities the Mexican Health Ministry (SSA) promotes: 1) the specification of biological standards for the Mexican population; 2) mechanisms for early detection of physiopathological changes and 3) development of the appropriate technology as a basis for primary health care. As part of this program we studied a random sample of students at the "Colegio de Bachilleres" of Cuajimalpa a suburban area of Mexico City, situated at 2800 m above sea level, part of the equipment used was produced at the Center for Development and Technological Applications (CE-DAT), an agency of SSA. Height, weight, heart rate (HR), systolic and diastolic blood pressures (SBP/DBP) were measured at rest in sitting position, standing up and walking on a treadmill. The results show a population with similar physical characteristics to those described for other populations in Mexico, with HR values within a homogeneous distribution, except for three subjects with rates larger than 2 standard deviations (SD). At standing up, women showed an orthostatic reflex of 27 beats/min and men of 22 beats/min. At the beginning of the exercise, the HR curve becomes more homogeneous, showing a discrete ascending slope with a low correlation coefficient, suggesting low physical capacity of the studied population. As exercise continued, some subjects showed a low increment of HR, giving values differing by 2 SD. Five women and three men had resting SBP values lying 2 SD out of the mean values of the sample. During exercise, SBP increases 28 mmHg as average. Notwithstanding the low cardiac response, the time spent on the treadmill lies within the levels considered as good and, even, excellent, on the table of the National Institute of Cardiology. We discuss new procedures to analyze instantaneously the HR and the pressoreceptor reflex as well as their functional significance.
Assuntos
Altitude , Teste de Esforço , Adolescente , Adulto , Feminino , Humanos , MasculinoRESUMO
Both the altitude of Mexico City (D.F.) and the increase in atmospheric pollutants make it important to establish parameters of comparison for cardiovascular variables, such as heart rate (HR) and blood pressure (BP). The epidemiological transition occurring in Mexico is increasing the need for human and physical resources at the first level of health care in order to perform early diagnoses of cardiovascular disorders among the population. Heart rate, systolic and diastolic blood pressures (SBP, DBP) were recorded under diverse conditions (seated, standing, performing 30 sit-ups, and then standing and seated after the sit-ups) in 235 inhabitants of Milpa Alta (a suburb of Mexico City). The procedures and equipment used were designed and produced at the Center for Development and Technological Applications, Ministry of Health. The following results were found: HR decreases with age and body surface. Likewise, the HR increase due to exercise is lower with increasing age and larger body surface and its return to resting levels is slower. SBP and DBP magnitude is directly related to body surface. In women an increase of body weight was found to be significantly related to a higher SBP. The orthostatic reflex (OR) decreases with age and body surface. The descending slope is higher in women than in men. We propose that the study of OR could provide better information for predicting cardiovascular changes. The described procedures can be performed with the physical and human resources available at the Health Centers. The extension of this type of applied research to first level health care centers would allow the country to respond efficiently to the epidemiological transition.
Assuntos
Pressão Sanguínea , Frequência Cardíaca , Adolescente , Adulto , Fatores Etários , Idoso , Peso Corporal , Criança , Pré-Escolar , Feminino , Humanos , Masculino , México , Pessoa de Meia-Idade , Esforço Físico , Postura , Fatores Sexuais , População UrbanaRESUMO
With a view to evaluating a small-scale water disinfection system based on production and application of oxidizing gases, the level of equivalent residual chlorine and the degree of contamination by fecal and total coliform bacteria was assessed at various points in the drinking water system of a Mexico City hospital before and after installation of the disinfection equipment. Tests done in May and June 1989, prior to installation of the equipment, showed that residual chlorine concentrations were lower than the national standard in most of the samples and that a sizable portion of these samples were also contaminated with fecal and total coliform concentrations exceeding national standards. After installation of the disinfection system at the main inflow to the hospital's drinking water supply in August 1989, the equivalent residual chlorine concentrations were found adequate and no coliform bacteria were detected. These results indicate that the oxidant mixture generated by the newly installed system was effectively disinfecting the water.
Assuntos
Desinfecção/normas , Hospitais Urbanos , Microbiologia da Água , Desinfecção/instrumentação , Desinfecção/métodos , Monitoramento Ambiental , Humanos , México , Avaliação de Programas e Projetos de SaúdeRESUMO
Para mejorar los procedimientos de atención de la salud cardiovascular en México es indispensable que en los centros de salud puedan hacer mediciones precisas con aparatos adecuados y se cuente con valores estándar de la población. Se analizaron en 102 personas la frecuencia cardiaca (FC), presión arterial sistólica (PAS) y presión arterial diastólica (PAD) en situasión de reposo sentados, parados, haciendo 30 sentadillas y nuevamente en reposo, parados y sentados. Se encontró una relación directa entre la magnitud de FC y PA con la supérficie corporal y con la edad cronológica. El reflejo ortostático va disminuyendo en relación con el incremento de años de vida. El ejercicio físico incrementó la FC, PAS y PAD que vuelve a disminuir en los siguientes cuatro a ocho minutos consecutivos al ejercicio en las personas en las tres primeras décadas de vida, mientras que en las otras dos no regresa, dentro de este tiempo, a los valores previos. Este decremento de RO es más pronunciado en los hombres que en las mujeres, aunque las cifras de PA son mayores en mujeres en las dos últimas décadas estudiadas. La distribución de los datos parece seguir la curva de distribución normal y queda dentro de lo descrito para altitudes sobre el nivel del mar menores que la ciudad de México. Al implantar los sistemas de medición que se describen en este trabajo, se podrán detectar al inicio los procesos patológicos que afecten la actividad cardiaca y la presión arterial, en situasiones de alteración del ambiente
To improve theprocedures for cardiovascular health care in Mexico it is necessary to be able to perform accurate measurements of the cardiovascular parameters with appropriate equipment and to count with standard values for the Mexican population at the primary health level. Cardiac frequency (CF), systolic arterial pressure (DAP) and diastolic arterial pressure (DAP) were analyzed in 02 consenting volunteers under resting (seated) and standing conditions as well as during excercise (30 sitting), and again after excercise under resurge conditions. A direct relation was found between CF, SAP and DAP with body surface and age. The orthostatic reflex (OR) diminished with age. Excercise increased FC, PAS and PAD, which decreased four-eight minutes after completing the excercise in those subjetcs under 30 years of age, where as in those aged 30 to 50 years these parameters did not return to their previous values. The RO decrement is more pronounced in men, although arterial pressure values ar higher in women aged 30 to 50 years. Data followed normal distribution curve, agreeing with the data re ported for altitudes lower than that of Mexico City. Implementing the measurement systems described in thi paper will allow early detection of pathology that migh affect cardiac activity and arterial pressure that could b, related to environmental pollution at the first level o medical attention.
Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Frequência Cardíaca , Hipertensão , Pressão Sanguínea , Equipe de Assistência ao PacienteRESUMO
To improve the procedures for cardiovascular health care in Mexico it is necessary to be able to perform accurate measurements of the cardiovascular parameters with appropriate equipment and to count with standard values for the Mexican population at the primary health level. Cardiac frequency (CF), systolic arterial pressure (SAP) and diastolic arterial pressure (DAP) were analyzed in O2 consenting volunteers under resting (seated) and standing conditions as well as during exercise (30 sitting), and again after exercise under resurge conditions. A direct relation was found between CF, SAP and DAP with body surface and age. The orthostatic reflex (OR) diminished with age. Exercise increased FC, PAS and PAD, which decreased four-eight minutes after completing the exercise in those subjects under 30 years of age, where as in those aged 30 to 50 years these parameters did not return to their previous values. The RO decrement is more pronounced in men, although arterial pressure values are higher in women aged 30 to 50 years. Data followed a normal distribution curve, agreeing with the data reported for altitudes lower than that of Mexico City. Implementing the measurement systems described in this paper will allow early detection of pathology that might affect cardiac activity and arterial pressure that could be related to environmental pollution at the first level of medical attention.
Assuntos
Determinação da Pressão Arterial , Frequência Cardíaca , Adolescente , Adulto , Determinação da Pressão Arterial/instrumentação , Estatura , Peso Corporal , Criança , Eletrocardiografia/instrumentação , Feminino , Humanos , Masculino , México , Microcomputadores , Pessoa de Meia-Idade , Caracteres SexuaisAssuntos
Ciência de Laboratório Médico , Países em Desenvolvimento/economia , Economia Médica , Órgãos Governamentais , Prioridades em Saúde , Recursos em Saúde , Projeto Genoma Humano , Humanos , Serviços de Informação , Ciência de Laboratório Médico/economia , Ciência de Laboratório Médico/tendências , México , Tecnologia de Alto Custo , Estados UnidosRESUMO
The Mexican Health Office (SSA) promotes the use and progeny of the appropriate technology for the bacteriological quality evaluation and disinfect the water by means of the in situ progeny of the clorus and ozonus gases when needed, for the human consumption in suburban and rural communities. The clorus water disinfecting conventional methods by many reasons are useless, even in urbanized cities. CEDAT has built and design a group of apparatus, called: "Water treatment whole equipment for small communities", and it's build up by: Membrane Filter, Double Chamber Incubator, ultraviolet Light Sterilizer and a clorus and ozonus progenic gas electrolytic cell with CA and CD power box and a Venturi Tube. The electrolytic cell raw material is the sodium chlorine (salt) water mixed. The evaluation of these equipment was made at the Manuel Gea González Medical Doctor General Hospital. During 38 days there was a daily measure of chlorine sewage in six different parts of the hospital. It was used the cellulose membrane filter technic with a 0.45 mm porus and a sowing in M-Endo and M-FC Broth cultivation was in a 37 and 44 centigrade incubation. The first 10 days chlorine sewage was found, the last 28 weren't measurable. Total coliforms in 23 of 42, 7 days samples and excrement coliforms in 5 of 18, 3 days samples, were developed during the 38 days period. The electrolytic cell was settled for the water gas measure up in its way to the reservoir. Afterwards chlorine sewage was measured from 0.2 mg/l to 1 mg/l in all the sample parts. No germ kind was discovered during the 10 days sampling.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Hospitais Gerais/normas , Serviço Hospitalar de Engenharia e Manutenção/normas , Engenharia Sanitária/instrumentação , Abastecimento de Água/normas , Estudos de Avaliação como Assunto , México , Engenharia Sanitária/normas , Esterilização/instrumentação , Microbiologia da ÁguaRESUMO
This paper presents the results of an intradomiciliary procedure for arsenic removal from water, by means of flocculation with ferric sulphate. The reaction was carried out in a specifically designed tank with a manual agitator (reactor) installed in a vertical support. The salts to flocculate were handed in two small envelopes, whose contents were added independently, agitating the water and letting it settle for two to three hours. Water is decanted by opening a faucet connected to the inferior part of the recipient. Ten families of the states of Durango and Coahuila (the Comarca Lagunera) were selected. Samples of water were taken before and after the treatment. In 70 percent of these samples the arsenic removal was total, and in the remaining 30 percent the removal was superior to 93 percent. The arsenic removal of water in the domicile was very effective, for which it is suggested as a palliative method for those groups with higher levels of exposition.
Assuntos
Arsênio , Utensílios Domésticos , Poluentes Químicos da Água , Poluentes da Água , Abastecimento de Água/análise , Hidróxido de Cálcio , Precipitação Química , Compostos Férricos , Humanos , Saúde da População RuralRESUMO
Based on the fact that drinking-water is of great significance in the transmission of infectious diseases, the incidence of diarrheal disorders was examined in two cities similar in their demographic composition and in their use of health services, but not in the quality of the drinking-water supply. In Navojoa, a city with high incidence of diarrheal diseases (116/1000 pop. in 1985), high rates of drinking-water contamination with fecal coliforms were found (43% of water samples); on the contrary, in Ciudad Obregón, a city with lower rates of diarrheal diseases (49/1000 pop. in 1985), drinking-water contamination with fecal coliforms was also comparatively lower (only 6% of water samples). These data illustrate the need to promote the implementation of drinking-water treatment in those places with signs of fecal contamination and high incidence of diarrheal diseases. To this regard, the General Direction for Research and Technological Development of the Ministry of Health has promoted the development of a chlorination equipment, useful mainly in rural areas, where biological contamination is usually high. These and similar procedures for water treatment should be considered as effective means to decrease the incidence of diarrheal diseases.