Resumen: En este documento se realizará un análisis del marco teórico que rige SFRA y se ilustrará su metodología, a través de documentos técnicos relacionados exclusivamente con la ejecución e interpretación del ensayo. Posteriormente, a través de equipos de medición con certificaciones internacionales y que aseguran el cumplimiento de parámetros detallados en normas IEC e IEEE, se ejecutara el ensayo de diagnóstico en 3 transformadores de distribución, para luego dar paso al diagnóstico de estos equipos, tomando como guía la norma IEEE C57.149. Ensayos como el Análisis de Respuesta en Frecuencia (SFRA), garantizan la detección de mínimos daños en la estructura del equipo, asegurando un correcto diagnóstico del transformador y por ende generando a su vez mantenimientos programados de tiempos y costos menores.

Abstract: In this document which made an analysis of the SFRA theoretical framework explain the methodology of the test, it uses technical documents about the execution and interpretation of SRFA. Subsequently, three distribution transformers will be diagnosed with the frequency sweep method. An operator, who implement this test, must use measuring equipment with international certifications and should utilize the IEEE C57.149 standard as a guide because SFRA is a relatively new test in the country. Essays like the SFRA, guarantee the detection of minimal damage in the equipment, ensuring a correct diagnostic of the transformer and thus generating scheduled maintenances of times and lower cost.

El objetivo del presente trabajo fue estimar los efectos genéticos para peso al momento de sexaje, crecimiento y sobrevivencia hasta cosecha, y proporción de mancha (área de mancha y presencia/ausencia de mancha) durante la fase comercial en un grupo de 86 familias de hermanos enteros y 31 familias de hermanos medios de tilapia roja (tilapia sp). La media de peso durante la fase de crecimiento comercial fue de 181,4 g (184 g para machos y 178 g para hembras), los machos significativamente más grandes que las hembras (P < 0,001). Las variables de sobrevivencia, área de mancha y ausencia de mancha no presentaron diferencias entre los sexos. Las heredabilidades estimadas (h²±E.S) para crecimiento comercial y sobrevivencia fueron 0,23±0,02 y 0,05±0,03, respectivamente. El porcentaje de mancha y la ausencia y presencia de la misma mostraron heredabilidades cercanas a cero, lo cual indica que estos dos caracteres están relacionados más con efectos ambientales que con efectos genéticos aditivos. Se encontró una correlación favorable y significativa entre sobrevivencia y crecimiento comercial (0,24; P < 0,05). Los resultados de este trabajo indican que mediante la explotación de la genética aditiva es posible mejorar el desempeño de los animales para crecimiento comercial y sobrevivencia en la tilapia roja, mientras que poco progreso se puede esperar por medio de la selección para variables relacionadas con el manchado corporal en la población evaluada.

The aim of this study was to quantify the genetic effects for commercial weight as, pond survival and degree of black spot for red tilapia (Tilapia ssp). A total of 86 families were evaluated, the average weight at commercial size was 181.4 g with males being significantly heavier than females. Pond survival, spotted area and presence/absence of black spots did not differ between sexes. The estimated heritabilities (h²±S.E.) for harvest weight and pond survival were 0.23±0.02 0.05±0.03, respectively. No heritability was found for spotted area and for presence/absence of black spots indicating that these traits are more affected by environmental conditions rather than by additive genes. We found a significant positive favorable correlation between harvest weight and survival (0.26; P < 0.05). The results of this study show that through selective breeding is possible to improve the performance of red tilapia for commercial growth and survival. While selection to reduce black spots in the studied population should show little progress.

In this publication we are reporting for the first time on examples of the redox behavior of enamines and complexes derived from 1-alkylpyrazolones. Cyclic voltammetry experiment was performed on three enamines derived from 4-acyl-1-(n-hexyl)-3-methylpyrazol-5-ol and their chloromanganese(III) and nitridomanganese(V) complexes. The ligands have an irreversible oxidation potential of 1.1 V. Chloromanganese(III) complexes are quasi-reversible with an E1/2 of 0.1 V. Nitridomanganese(V) complexes are also quasi-reversible, with E1/2 potentials of 0.95 V. However, for nitridomanganese(V) complexes reversibility increases as the scan speed raises from 100 to 3000 mV·s-1

Oxopolimetalatos organicamente modificados do "tipo Keggin"de formula [R]4[SiW11O40(SiR')2], (R=Bu4N+, R' = -C2H5, -C10H21, -CH=CH2, -CH2CH=CH2, -OH, -C6H5, -C10H7, -C6H4NH2 (o, p), -C6H4NMe2 (p), -C6H4CH=CH2, -C6H4CF3, -C6H4CH=CHC6H5) foram sintetizados. O núcleo óxido apresentou propriedades redox reversíveis que foram sintonizadas, escolhendo-se o modificador orgânico. As variações nos deslocamentos químicos na RMN de 183W, induzidas pelos modificadores, foram também medidas e ambos os efeitos correlacionados com as propriedades de doação-aceitação eletrônica do radical orgânico. As magnitudes destes efeitos foram comparadas com aqueles causados pelo eletrólito.

Keggin-type" organically modified oxopolymetalates of formula [R]4[SiW11O40(SiR')2], (R=Bu4N+, R' = -C2H5, -C10H21, -CH=CH2, -CH2CH=CH2, -OH, -C6H5, -C10H7, -C6H4NH2 (o, p), -C6H4NMe2 (p), -C6H4CH=CH2, -C6H4CF3, -C6H4CH=CHC6H5) were synthesized. The oxide core presented reversible redox properties which were tuned by the choice of the organic modifier. Parallel variations of the 183W NMR chemical shifts were measured and both effects might be related to the electronic donor-acceptor properties of the organic radical. The magnitudes of these effects are compared with those coming from the electrolyte itself.

In order to determine the effort performed by crossbred draught horses in agricultural work, the biochemical and physiological response of five horses was evaluated after performing five hours of work (3 in the morning and 2 in the afternoon) with a 90 minutes break between the periods. Blood samples were obtained from the jugular vein with a vacutainer. The haemoglobin concentration and globular volume were determined in whole blood. Lactic acid was determined in deproteinised blood, while cortisol and enzymatic activities were determined in plasma. Cardiac and respiratory frequencies increased significantly with the work. These physiological variables were recovered 30 minutes post exercise. Haemoglobin, globular volume, plasmatic cortisol and enzymatic activities of creatine kinases and aspartate aminotransferase increased significantly during the exercise, but lactic dehidrogenase and lactic acid presented no significant changes. The results showed that the muscular effort performed by the horses was very intense, but this exercise did not produce any evident injury or muscular fatigue on the animals

El objetivo del presente trabajo fue estudiar la adaptación fisiológica y bioquímica del caballo mestizo de tiro al realizar trabajos de labranza en suelos arroceros. Se utilizaron 5 caballos mestizos de tiro, clínicamente sanos, durante una jornada de 5 horas, dividida en 3 horas en la mañana y 2 horas en la tarde, con un descanso de una hora y media entre ambos períodos. Se registró la frecuencia cardíaca y respiratoria y la temperatura rectal. Muestras de sangre fueron extraídas desde la vena yugular, en las que se determinó el volumen globular, las concentraciones de hemoglobina, de cortisol y de ácido láctico y las actividades de creatinquinasa, aspartato amino- transferasa y láctico deshidrogenasa. La frecuencia cardíaca en reposo fue de 38 ± 3 lat/min alcanzando promedios máximos de 129 ± 4 lat/min durante el trabajo de la mañana y de 137 ± 8 lat/min en la tarde. La frecuencia respiratoria aumentó desde valores de reposo de 24.8 ± 3.5 resp/min en la mañana y 30.4 ± 4.1 resp/min en la tarde, a valores de 90.8 ± 8.9 resp/min en la mañana y de 111.8 ± 16.3 resp/min en la tarde. La recuperación de las frecuencias respiratoria y cardíaca se logró después de 30 minutos de haber finalizado el trabajo. Durante el ejercicio la temperatura rectal aumentó un promedio de 2.2 ± 0.2° C tanto en la mañana como en la tarde. La concentración de hemoglobina, el volumen globular, la concentración plasmática de cortisol y las actividades plasmáticas de creatinquinasa y transaminasa, aumentaron significativamente durante la jornada de trabajo con respecto al reposo. La actividad láctico deshidrogenasa y la concentración de ácido láctico no mostraron cambios significativos en el período de trabajo comparada con las determinadas en reposo.

Two syndromatic forms of Creutzfeldt-Jakob disease are illustrated with data from two cases confirmed by necropsy and studied by means of electroencephalogram, evoked potential recording and neuropathological techniques. One of the cases presented the typical hypersynchronous periodic discharges thougth to be characteristic of this disease. The other did not exhibit epileptiform diischarges, showing an evolution in which progressive diffuse slowing was the prominent feature. Cortical spongyosis, gliosis, and neuronal lose were intense in the case showing spikes, and moderate in the one without spikes. Subcortical involvement was similar in both cases. This different topography of pathological involvement might explain, in addition to electroencephalographic findings, the different behavior of somatosensory evoked potentials, which were of larger amplitude in the case showing epileptiform discharges, although in both cases deterioration of clinical state was accompanied by a progressive amplitude decrement in the evoked potential. Sleep induced by barbiturates was disrupted in the case with spikes, its pattern being closer to normal in the case with less severe cortical involvement. A Wada test demostrated that discharges in the hemispheres were independent. Spike periodicity is discussed. It is postulated that the heavier involvement of cortical layers II to IV deprive the remaining pyramidal cells of inhibitory influences, a condition which might explain the generation of periodic spike discharges.

Se estudian dos casos de enfermedad de Creutzfeldt-Jakob comprobados por examen necrópsico. Uno de ellos presentaba típicas descargas hipersincrónicas, periódicas en el electroencefalograma; el otro caso no mostraba estas descargas epileptiformes y evolucionó con una lentitud difusa progresiva. La espongiosis, gliosis y pérdida neuronal fué intensa en la corteza del caso con espigas y muy moderada en el caso sin espigas. El compromiso subcortical era similar en ambos casos. Se postula que la diferente expresión topográfica de su histopatología explicaria tambien la diferencia en el comportamiento de los potenciales evocados somatosensoriales y el diferente modelo electroencefalográfico del sueno penthotálico. La independencia de las descargas epileptiformes en cada hemisferio se prueba con el test de Wada. Se discute el origen de las espigas y su periodicidad. Se postula teóricamente que el predominio de las lesiones de las capas II a IV privaria a las células piramidales remanentes, de influencias inhibitorias, lo que explicaria la génesis de las espigas.

Foi estudado o efeito das carências combinadas de alguns macronutrientes no crescimento, aspecto e composição mineral do algodoeiro, Gossypium hirsutum L., var. IAC RMB. O trabalho regstra: sintomas foliares dos macronutrientes estudados nas folhas superiores e inferiores das plantas.

Symptoms of deficiencies of several macronutrients and binary combinations thereof were induced in the cotton plant. It was found that depending upon the particular combination the following picture developed: (a) individual symptoms are present according to the general pattern; (b) individual symptoms are present with a reversal of the general pattern with respect of distribution; (c) a combination of the individual symptoms shows up; (d) an individual symptom masks the other; (e) a different symptom develops. Chemical analysis of both upper and lower leaves has shown single and multiple effects depending upon the treatment considered.