Resumen Introducción. Los estudios de conocimientos, actitudes y prácticas (CAP) relacionados con la Covid-19 permiten establecer los conceptos erróneos y las prácticas inadecuadas en torno a esta enfermedad, información fundamental para diseñar estrategias eficaces y mejorar el cumplimiento de las medidas de prevención. Objetivo. Establecer los conocimientos, actitudes y prácticas relacionadas con la Covid-19 en pacientes venezolanos cribados en la carpa de triaje del Hospital Universitario de Caracas. Materiales y métodos. Se hizo un estudio transversal en 215 pacientes entre el 25 de abril y el 25 de mayo de 2020, mediante entrevistas personales y utilizando una encuesta sobre conocimientos, actitudes y prácticas. Resultados. La mayoría (53,5 %) de los pacientes encuestados se encontraba asintomática; los encuestados tenían un conocimiento adecuado sobre los síntomas y la transmisión de la enfermedad, sin distinción entre sintomáticos y asintomáticos. La mayoría de ellos indicó estar respetando las prácticas de cuarentena, lavado de manos frecuente y uso de tapabocas en público; sin embargo, el reemplazo diario de los tapabocas de tela fue más frecuente en el grupo de los asintomáticos, en tanto que el reemplazo cada tres días fue más común entre los sintomáticos. Por último, más de la mitad de los participantes admitió haber estado en lugares concurridos, siendo esta práctica más frecuente entre los sintomáticos que entre los asintomáticos. Conclusiones. Este es el primer estudio de conocimientos, actitudes y prácticas sobre la Covid-19 en Venezuela. El conocimiento y las prácticas de los venezolanos podrían mejorar mediante el fortalecimiento de los programas de educación y capacitación. Esta información, obtenida durante la fase inicial de la pandemia en Venezuela, podría contribuir al diseño de estrategias de promoción y prevención de la Covid-19.

Abstract Introduction: The studies on knowledge, attitudes, and practices (KAP) regarding COVID-19 help to identify erroneous concepts and inadequate practices related to the disease. This baseline information is essential to design effective strategies and improve adherence to prevention measures. Objective: To identify the COVID-19-related KAP in Venezuelan patients screened at the Hospital Universitario de Caracas triage tent. Materials and methods: We conducted a cross-sectional study among 215 patients between April 25th and May 25th, 2020, with in-person interviews using a KAP survey. Results: Most surveyed patients (53.5%) were asymptomatic. Most of them, both from the symptomatic and the asymptomatic groups, had adequate knowledge about the symptoms and transmission of the disease and the majority said they were practicing quarantine, frequent handwashing, and the use of face masks in public areas. However, the daily replacement of cloth face masks was more frequent in the asymptomatic group whereas replacement every three days was more frequent in the symptomatic group. Finally, more than half of the participants admitted having been in crowded places, a common practice among the symptomatic compared to the asymptomatic patients. Conclusions: This is the first KAP study in Venezuela about COVID-19. Knowledge and practices among Venezuelans could be improved by strengthening education and training programs. This information from the early phase of the pandemic in Venezuela may contribute to the design of COVID-19 promotion and prevention strategies.

In order to evaluate the storage effect of A. lebbeck seeds on the viability, germination and dormancy indicators, a completely randomized design with factorial arrangement (3 x 6) was used, in which the factors were determined by the study years and storage times. A variance analysis was performed, according to simple classification model in factorial arrangement. The multiple comparison Duncan test (1955) was applied and differences were declared as significant at P <0.05. The percentage of viable seeds slightly decreased, as the storage increased. The most marked decrease occurred in the range of 0 to 2 months of storage started (mss) for three years, with significant differences between both evaluations in each year. Germination had variable performance in each year. In each storage period, the highest percentage, although without differ each other, it was found at 0 mss. In each of the months there were no significant differences between years, except for the value reported at 7 mss for years 1 and 3.The first year (31.0%) was not different from year 2 (34.0%), and in turn the latter showed no differences with regard to year 3 (37.75%). At the start of storage (0 mss), the values of dormant and hard seeds were identical (52.85%), although, from this evaluation slight differences were observed, which only at 11 mss were 7% (51.0 vs 58.0% respectively). It is very probably that the germination percentage and longevity of A. lebbeck seeds depend on the time they spent in the store, indicating that the intrinsic factors may be the main responsible agent of viability loss

Para evaluar el efecto del almacenamiento de las semillas de A. lebbeck en los indicadores viabilidad, germinación y dormancia, se utilizó un diseño completamente aleatorizado con arreglo factorial (3 x 6), en el que los factores estuvieron determinados por los años de estudio y los tiempos de almacenamiento. Se realizó análisis de varianza, según modelo de clasificación simple en arreglo factorial. Se aplicó la dócima de comparación múltiple de Duncan (1955) y las diferencias se declararon como significativas en valores de P < 0.05. El porcentaje de semillas viables disminuyó ligeramente, en la medida que aumentó el almacenaje. El descenso más marcado se presentó en el intervalo de 0 a 2 meses de iniciado el almacenamiento (mdia) para los tres años, con diferencias significativas entre ambas evaluaciones en cada año. La germinación tuvo comportamiento variable en cada año. En cada período de almacenamiento, el porcentaje más alto, aunque sin diferir entre sí, se constató a 0 mdia. En cada uno de los meses no se encontraron diferencias significativas entre los años, a excepción del valor informado a los 7 mdia para los años 1 y 3. El año 1 (31.0 %) no difirió del 2 (34.0 %), y a su vez este último no mostró diferencias con respecto al 3 (37.75 %). Al inicio del almacenamiento (0 mdia), los valores de semillas dormantes y duras fueron idénticos (52.85 %), aunque, a partir de esta evaluación se observaron ligeras diferencias, que solo a 11 mdia fueron de 7 % (51.0 vs 58.0 %, respectivamente). Es muy probable que el porcentaje de germinación y la longevidad de las semillas de A. lebbeck dependan del tiempo que permanecen en el almacén, lo que indica que los factores intrínsecos pueden constituir el principal agente causante de la pérdida de viabilidad

To evaluate the Sorbial probiotic as additive for dairy goats in grazing under tropic conditions, 180 dairy goats were evaluated (90 Saanen and 90 Alpina), with 41.3 ± 0.4 kg of live weight, 23.6 days of lactation and 2.1parturition as average. The study lasted 245 days. Goats grazing (start grass and natural grass mixing) and were supplemented with 0.46 kg of concentrate animal-1 d-1. They were randomly distributed in 2 treatments: A.10g of probiotic in post parturition, until 100 days of lactation, and B. 0g of probiotic post parturition probiotic. The results of milk production showed that goats that consumed the probiotic, in both breeds, produced 3.9% more milk (P < 0.05) than those that did not consume it. Although, the Saanen goats produced 2.4% more milk (P < 0.05) than the Alpinas. With the probiotic usage, milk quality improved (P < 0.05) in 6.9 and 7.8% for the fat percentage and non fat solids. The costs of the milk liter, per supplement concepts, decreased (P < 0.05) in 0.012 and 0.007 Cuban pesos due to the probiotic inclusion, for Saanen and Alpine breeds, respectively. In this study conditions, the use of the probiotic during the first 100 lactation days, decreased costs per supplement concepts

Para evaluar el probiótico Sorbial como aditivo para cabras lecheras en pastoreo de gramíneas en las condiciones del trópico, se evaluaron 180 cabras lecheras (90 Saanen y 90 Alpina), con 41.3 ± 0.4 kg de peso vivo, 23.6 d de lactancia y 2.1 partos como promedio. La duración del estudio fue de 245 d. Las cabras pastaron gramíneas (mezcla de pasto estrella y pasto natural) y se suplementaron con 0.46 kg de concentrado animal-1 d-1. Se distribuyeron aleatoriamente en dos tratamientos: A. 10 g de probiótico en el post-parto, hasta los 100 d de lactancia, y B.0 g de probiótico post-parto. Los resultados de la producción de leche indicaron que las cabras que consumieron el probiótico, en ambas razas, produjeron 3.9 % más de leche (P < 0.05) que las que no lo consumieron. Sin embargo, las cabras Saanen produjeron 2.4 % más de leche (P < 0.05) que las Alpinas. Con la utilización del probiótico, la calidad de la leche mejoró (P < 0.05) en 6.9 y 7.8 % para el porcentaje de grasa y sólidos no grasos. Los costos del litro de leche, por concepto de suplementos, disminuyeron (P < 0.05) en 0.012 y 0.007 pesos cubanos por la inclusión del probiótico, para las razas Saanen y Alpinas, respectivamente. En las condiciones de este estudio, la utilización del probiótico durante los primeros 100 d de lactancia, mejoró la producción y calidad láctea, y disminuyó los costos por concepto de suplementos

Foram coletados 100 suabes retais e 100 suabes de carcaças bovinas em matadouros do estado de São Paulo, e um total de 326 estirpes de E. coli foram identificadas, sendo 163 de amostras retais e 163 de amostras de carcaça. Todos os isolados submetidos à PCR para detecção dos genes das toxinas Stx1 e Stx2 foram identificados como não-O157 e fenotipados pelo teste da citotoxicidade em células Vero. Das 26 estirpes que apresentaram apenas o gene stx1, das 56 que apresentaram apenas o gene stx2 e das 30 estirpes que apresentaram ambos os genes, 17 (65,4%), 42 (75%) e 22 (73,3%), respectivamente, foram positivas ao teste de citotoxicidade. Não houve diferença estatística entre os três perfis genéticos e na positividade ao teste de citotoxicidade. Os resultados mostram a alta frequência de expressão dos fatores de virulência das STEC de bovinos.

In the present study 100 rectal and 100 carcass swabs were collected from bovines at slaughterhouses in São Paulo state, and the total of 326 E. coli strains were identified (163 from rectal samples and 163 from carcass samples). All the isolates were submitted to PCR for Stx1 and Stx2 toxin gene detection and all strains were identified as non-O157 and phenotyped by the citotoxicity test in Vero cells. Out of 26 strains that presented only the stx1 gene, 56 that presented only the stx2 gene and 30 that presented both genes, 17 (65.4%), 42 (75%) and 22 (73.3%), respectively, were positive for the citotoxicity test. There was no statistically significant difference among these three toxinotyping profiles and positivity in the citotoxicity test, but the results show high frequency of virulence factor expression of bovine.

The application of different scarification methods to favour seedling emergence from A. lebbeck seeds stored under ambient conditions was evaluated, for which a completely randomized design was used with 4 x 13 and 3 x 13 factorial arrangement for moist and dry scarification, respectively. Significant interaction was found among the factors for moist scarification (P<0,001). The best values for the acid, hot water and soaking were found at 4 mos; they were lower than the control and among them only water and soaking and water and control were statistically different. The contrast between the values at 6 mos for the acid (6,3%) and the control (40,1%) stands out; in this last evaluation the highest emergence for moist scarification was achieved. In dry scarification, the highest percentage was obtained in the treatment based on the coat cut and 3 mos (71,0%), and differed statistically from the rest. In the cutting method all the emergence records were higher than the control. For the cut and puncture, statistical differences were detected only between 2 and 3 mos; in both the prevailing value was that of the cutting method. The emergence results allow to evaluate the coat cut as an appropriate method for A. lebbeck seeds, without obviating that soaking also constitutes an alternative for scarification.

Se evaluó la aplicación de diferentes métodos de escarificación para favorecer la emergencia de plántulas a partir de semillas de A. lebbeck almacenadas al ambiente, para lo cual se empleó un diseño completamente aleatorizado con arreglo factorial 4 x 13 y 3 x 13 para la escarificación húmeda y la seca, respectivamente. Se encontró interacción significativa entre los factores para la escarificación húmeda (P<0,001). Los mejores valores para el ácido, el agua caliente y el remojo se presentaron a los 4 mdia; estos fueron inferiores a lo ocurrido en el control y entre ellos sólo fueron estadísticamente diferentes el agua y el remojo, y el agua y el control. Se destaca el contraste entre los valores a 6 mdia para el ácido (6,3%) y el control (40,1%); en esta última evaluación se logró la mayor emergencia para la escarificación húmeda. En la escarificación seca, se obtuvo el mayor porcentaje en el tratamiento basado en el corte de cubierta y 3 mdia (71,0%), y difirió estadísticamente del resto. En el método del corte todos los registros de la emergencia fueron superiores a los del control. Para el corte y el pinchazo, sólo se detectaron diferencias estadísticas entre 2 y 3 mdia; en ambos el valor dominante fue el del método del corte. Los resultados de la emergencia permiten valorar el corte de cubierta como un método apropiado para las semillas de albizia, sin dejar de mencionar que el remojo también constituye otra alternativa para la escarificación.

With the objective of favoring germination in A. lebbeck seeds stored under ambient conditions, different pre-planting methods were evaluated by means of a completely randomized design with 4 x 13 and 3 x 13 factorial arrangement for moist and dry scarification, respectively. In moist scarification significant interaction was found among the studied factors (P<0,001). No statistical differences were observed between the acid and the hot water, in the seeds evaluated at 1, 3, 6 and 7 mos; while the same evaluations were statistically different from the control and in all cases the values were lower than the latter. All the soaking and control evaluations were not significant among themselves, while they differed from the hot water and the acid. In the dry scarification the germination capacity showed significant interaction (P<0,001). The highest values were reported in 1, 2 and 3 mos in seeds with one cut; these percentages did not differ among themselves but they did differ from the others. When comparing the cut with the puncture, a statistically different behavior was observed; in all the evaluations the lowest values were those of the puncture. It is necessary to emphasize the efficacy of the seed coat cut and the soaking for 24 hours in water at ambient temperature as dry and moist scarification treatments, respectively, in spite of the acceptable results shown by the control.

Con el objetivo de favorecer la germinación en semillas de A. lebbeck almacenadas en condiciones ambientales, se evaluaron diferentes métodos presiembra mediante un diseño completamente aleatorizado con arreglo factorial 4 x 13 y 3 x 13 para la escarificación húmeda y la seca, respectivamente. En la escarificación húmeda se halló interacción significativa entre los factores estudiados (P<0,001). No se encontraron diferencias estadísticas entre el ácido y el agua caliente, en las semillas evaluadas a 1, 3, 6 y 7 mdia; mientras que estas mismas evaluaciones fueron estadísticamente diferentes al control y en todos los casos los valores resultaron inferiores a este último. La totalidad de las evaluaciones del remojo y el control no fueron significativas entre sí, mientras que difirieron del agua caliente y el ácido. En la escarificación seca la capacidad germinativa mostró interacción significativa (P<0,001). Los valores más altos se reportaron en 1, 2 y 3 mdia en semillas con un corte; estos porcentajes no difirieron entre ellos, pero sí del resto. Al comparar el corte con el pinchazo, se presentó un comportamiento estadísticamente diferente; en todas las evaluaciones los valores inferiores fueron los del pinchazo. Es necesario resaltar la eficacia del corte de cubierta y el remojo durante 24 horas en agua a temperatura ambiente como tratamientos de escarificación seca y húmeda, respectivamente, a pesar de los resultados aceptables mostrados por el control.

INTRODUCTION: ecological studies were carried out on mollusk populations of medical and veterinary importance with emphasis on Fasciola hepatica intermediary hosts species. OBJECTIVES: to determine the relative abundance of populations and the possible use of some species as biological control agents against F. hepatica intermediary hosts. METHODS: a total of 13 freshwater bodies were sampled during March and November, 2008 using Capture by effort unit method to capture the mollusks RESULTS: thirteen mollusk species (12 gastropods and 1 bivalve) were found after sampling. The relative abundance of species varied in different types of habitat. The intermediary host species of fascioliasis were dominant in two sites. Fossaria cubensis was dominant in Canal de la Entrada despite the presence of Melanoides tuberculata. The specie Pseudosuccinea columella was more abundant in Los Mangos. In La Presa del Matadero y Las Palmas despite the presence of these species, the prevailing ones were Physa acuta and some planorbids. CONCLUSIONS: the sites where intermediary hosts of Fasciola hepatica predominated were identified through data on the distribution and relative abundance. In some sites Melanoides tuberculata was present and acted as a biological control agent but it did not in others. Therefore, an evaluation on using a different thiarid would be useful to control these species.

INTRODUCCIÓN: se realizaron estudios ecológicos sobre las poblaciones de moluscos de importancia médico-veterinaria con énfasis en las especies hospederas de Fasciola hepatica. OBJETIVOS: determinar la abundancia relativa de las poblaciones, así como el posible uso de algunas especies competidoras en el control biológico de hospederos intermediarios de Fasciola hepatica. MÉTODOS: se muestrearon 13 cuerpos de agua dulce durante el período marzo-noviembre de 2008 utilizando el método de captura por unidad de esfuerzo para la colecta de los moluscos. RESULTADOS: por medio de los muestreos se identificaron 13 especies de moluscos dulceacuícolas pertenecientes a las clases Gastropoda (12) y Bilvalvia (1). Las abundancias relativas de las especies presentaron variaciones según el tipo de hábitat. Las especies hospederas intermediarias de fasciolosis predominaron en 2 de los sitios de muestreo. Fossaria cubensis fue dominante en la localidad del Canal de la Entrada, a pesar de estar presente Melanoides tuberculata, posible control biológico. Pseudosuccinea columella fue más abundante en la localidad de Los Mangos. En La Presa del Matadero y Las Palmas, a pesar de estar presente estas especies, las que predominaron fueron Physa acuta y algunos planórbidos. CONCLUSIONES: se identificaron los sitios donde están presentes los hospederos de Fasciola hepatica, con datos de su distribución y abundancia relativa. En algunos sitios Melanoides tuberculata actúa como control biológico y en otros no, por lo que habría que evaluar el uso de otros tiáridos para poder controlar estas especies.

Background: Field studies have previously demonstrated that freshwater mollusk populations did not exist in the ecological and natural environment of pine trees, which led to study pine resin, colophony, as a controlling agent for Biomphalaria havanensis mollusk, an intermediate host of Schistosoma mansoni. Objective: to determine the molluscicidical action of colophony as possible use as a controlling agent for Biomphalaria havanensis. Methods: Seven different concentrations were used to determinate the lethal doses. Data were analyzed by probit-log program. Results: The lethal doses found were as follows: LD50 = 443.3 mg/L and LD90 = 1417.6 mg/L. Conclusions: These experiments showed the molluscicidical activity of the two Cuban pinaceas, through the colophony resin, on Biomphalaria havanensis.

Introducción: la ausencia de poblaciones de moluscos en el entorno ecológico y natural de las pináceas, observada en estudios de campo, conllevó a estudiar la resina de pino, colofonia, como control del molusco Biomphalaria havanensis, hospedero intermediario de Schistosoma mansoni. Objetivo: determinar la acción molusquicida de la colofonia para su posible utilización en el control de Biomphalaria havanensis. Métodos: se utilizaron 7 concentraciones diferentes para determinar las dosis letales y los datos fueron analizados por un probit-log. Resultados: las dosis letales encontradas fueron: DL50= 44,33 mg/L y DL90= 141,76 mg/L. Conclusiones: con estos resultados se demostró el poder molusquicida de 2 de las pináceas cubanas, a través de la resina de colofonia, sobre Biomphalaria havanensis.

Este experimento objetivou a obtenção de sementes de milho (Zea mays) portadoras de Acremonium strictum, utilizando-se técnica de restrição hídrica e visando sua utilização posterior em estudos sobre a interação patógeno - hospedeiro. O trabalho constou de avaliações de efeitos da adição de manitol, NaCl e KCl nos potenciais de -0,48; -0,6; -0,8; -1,0; -1,2 e -1,4 MPa ao meio extrato de malte-ágar (MEA) sobre o crescimento micelial, textura de micélio, forma marginal da colônia, pigmentação e esporulação in vitro de colônias de A. strictum, bem como sobre o percentual de protrusão de radículas de sementes de milho. Foi avaliada também a correlação entre diferentes períodos de exposição das sementes à colônia do fungo e sua incidência em sementes desinfestadas ou não com NaClO 1% por 2 min. A taxa de crescimento micelial de A. strictum foi estimulada em meio MEA + manitol (-0,6 a -1,4 MPa) e a morfologia típica de colônias do patógeno em meio MEA acrescido com manitol, NaCl e KCl diferiu dos padrões apresentados no controle (-0,48 MPa). A esporulação do fungo foi estimulada pelo manitol nos potenciais -0,8 a -1,4 MPa, aplicados ao meio de cultivo padrão. As menores percentagens de protrusão radicular em sementes de milho incubadas por até cinco dias foram observadas em MEA + manitol (-1,4 MPa) e MEA + NaCl (-1,2 e -1,4 MPa). No entanto, verificou-se efeito fitotóxico do NaCl sobre a germinação das sementes. Por meio da técnica de restrição hídrica foi possível obter até 36% de sementes de milho infetadas por A. strictum.

This work was carried out to obtain maize (Zea mays) seeds with Acremonium strictum, by means of an adapted water restriction technique, in order to use them in pathogen-host studies. An evaluation was made of the effects of mannitol, NaCl and KCl at potentials of -0.48; -0.6; -0.8; -1.0; -1.2 and -1.4 MPa in malt extract agar medium (MEA) on the colony morphology and sporulation of A. strictum, and on radicle protrusion of maize seeds. Also evaluated was the correlation between different exposition periods of the seeds to the fungal colony and its incidence on disinfested and non-disinfested seeds with NaClO 1% (2 min). The micelial growth of A. strictum was stimulated in MEA + mannitol medium at potentials of -0.6 to -1.4 MPa. The morphology of A. strictum colonies in MEA medium for all the solutes used differed from the colonies in the control treatment (-0.48 MPa). Fungal sporulation was stimulated by mannitol on potentials -0.8 to -1.4 MPa in MEA. The lowest percentages of radicle protrusion in maize seeds were observed in cases when seeds were exposed to water restriction induced by MEA + mannitol at potential of -1,4 MPa; MEA + NaCl at -1,2 and -1,4 MPa. The NaCl, however, was verified to cause toxic effects in seed germination. This work shows that it is possible to obtain A. strictum infection in 36% of maize seeds infected by means of water restriction.

Durante 1998 e 2000, a incidência de murcha bacteriana causada por Ralstonia solanacearum foi registrada em 25 municípios do estado do Amazonas. A bactéria foi encontrada nas seguintes espécies vegetais: Capsicum annuum, C. chinense, C. frutescens, Cucumis sativus, Heliconia sp., Lycopersicon esculentum, Melanthera discoidea, Moringa oleifera, Musa sp., Solanum melongena, S. gilo, e S. nigrum. Em tomateiros (Lycopersicon esculentum), a murcha bacteriana estava presente em todos os plantios. Em bananeiras (Musa spp.), a incidência do Moko foi menor nas várzeas dos rios Madeira e Negro do que nas dos rios Solimões e Amazonas. Caracterizaram-se 320 isolados de R. solanacearum, obtidos no levantamento, com relação a raça e a biovar. A biovar 1 predominou em todos os hospedeiros, com exceção de C. annuum e C. chinense, onde estirpes da biovar 3 foram maioria. Apenas 7,8% das estirpes foram da biovar N2. A sensibilidade de 56 estirpes da raça 1 a 23 bacteriocinas foi avaliada. As estirpes da biovar 3 apresentaram uma menor variabilidade, na sensibilidade a bacteriocinas do que as estirpes das biovares 1 e N2.

A survey for bacterial wilt caused by Ralstonia solanacearum was conducted in 25 counties in the state of Amazonas during the years 1998 and 2000. Ralstonia solanacearum was found in the following species: Capsicum annuum, C. chinense, C. frutescens, Cucumis sativus, Heliconia sp., Lycopersicon esculentum, Melanthera discoidea, Moringa oleifera, Musa sp., Solanum melongena, S. gilo, and S. nigrum. In tomatoes (Lycopersicon esculentum), bacterial wilt was present in all fields. In banana (Musa spp.), the incidence of Moko disease was lower in the flooded areas of the Madeira and Negro Rivers than in the Solimões and Amazonas Rivers. In this survey the race and biovar of 320 R. solanacearum isolates was determined. The biovar 1 strains predominate in almost all hosts. In C. annuum and C. chinense, however, biovar 3 was more common. Only 7.8% of the strains were biovar N2. Fifty-six race 1 strains originating from different hosts and counties were evaluated with regard to sensitivity to 23 bacteriocins. Strains from biovars 1 and N2 showed more variability regarding bacteriocin sensitivity than biovar 3 strains.

A variabilidade de isolados de Ralstonia solanacearum, provenientes de tomateiros (Lycopersicon esculentum) do Estado do Amazonas, foi estudada com relação à agressividade, à sensibilidade a bacteriocinas e às características bioquímicas. Três experimentos foram estabelecidos em áreas naturalmente infestadas com R. solanacearum sendo um em terra firme, em 1998, e dois em uma mesma área de várzea, em 1998 e em 2000. Em cada experimento, 200 mudas de tomateiros da cv Yoshimatsu (resistente) e 200 da cv. Santa Cruz Kada (suscetível) foram plantadas alternadas em um espaçamento de 1 m entre fileiras e 0,5 m entre plantas. Semanalmente, isolou-se a bactéria, a partir de plantas apresentando sintomas de murcha. Obtiveram-se, nos três experimentos, 267 isolados pertencentes aos biovares 1 (67,8%) e 3 (32,2%). Em terra firme, 80,4% dos isolados obtidos eram do biovar 1 enquanto que em várzea, os isolados do biovar 1 foram 37,4 e 87,8%, nos ensaios de 1998 e de 2000, respectivamente. Com base na sensibilidade a bacteriocinas os isolados foram divididos em sete grupos, sendo que dois deles englobaram 80,5% do total dos isolados. Através da reação apresentada por 15 plantas de tomate, de berinjela (Solanum melongena) e de pimentão (Capsicum annuum) , inoculadas um mês após a semeadura, a agressividade de isolados selecionados foi avaliada. Os isolados do biovar 1 foram mais agressivos sobre tomateiros que os do biovar 3. Estes últimos, no entanto, foram mais agressivos sobre pimentão e berinjela. Em várzea, as plantas da cv. Yoshimatsu tiveram 50,5% de mortalidade contra 22,5%, em terra firme, comprovando a importância do fator ambiente na ocorrência da doença.

The variability of Ralstonia solanacearum isolates obtained from tomato (Lycopersicon esculentum) plants in the Amazonas State was studied for pathogen aggressiveness, bacteriocin sensitivity and for biochemical characteristics. Three experiments were established in areas naturally infested with R. solanacearum. These were: (i) in a non-flooded area of a field in 1998, (ii) in an periodically-flooded area, in 1998, and (iii) in the same periodically-flooded area in 2000. In each experiment there were 200 resistant tomato plants (cv. Yoshimatsu) and 200 susceptible (cv. Santa Cruz Kada) planted by alternating resistant and susceptible cultivars. From the 267 isolates obtained from plants exhibiting wilt symptoms, 67.8% belonged to biovar 1 and 32.2% to biovar 3. In the non-flooded soil, 80.4% of he isolates collected were found to be biovar 1, whereas in fields periodically-flooded, the percentage of biovar 1 isolates was 37.4 and 87.8% for the 1998 and 2000 experiments, respectively. Based on bacteriocin sensitivity classification, isolates were divided into seven groups and two of these groups accounted for 80.5% of the isolates. The aggressiveness of selected isolates was evaluated in tomato, eggplant (Solanum melongena) and sweet pepper (Capsicum annuum) plants. Biovar 1 isolates were more aggressive on tomato than biovar 3 isolates. Biovar 3, however, was more aggressive on sweet pepper and eggplant than biovar 1. In fields subject to periodic flooding, cv. Yoshimatsu had 50.5% mortality versus 22.5% mortality in the non-flooded field. This indicates the importance of this environmental factor on disease occurrence.

A study considered as epidemiological for its dimension and as explicative (quasiexperimental) for their type was conducted among 8th-and 9th-grade students from the "Julio A. Mella" Secondary School in the Countryside, in the city of Placetas, from 1996 to 1997 aimed at knowing some aspects connected with sexual education by a system of anonymous formularies and by an experimental design of minimum control. Variables such as age, sex, family dynamics, sexual relation pattern and aspects that contribute to the knowledge on this subject were investigated by using a qualitative sampling of maximum variability. The data obtained were computerized at the "Joven Club" center in this city. The results were compared with those of the population census as regards proportions by means of the test of independence of variables with distribution of X² . It was proved that the level of knowledge on sexual education is deficient according to the "ANTES" (BEFORE) model. Once more it was demonstrated the unsubstitutable function of the educative work on improving the level of knowledge according to the "DESPUES" (AFTER) model. Cooperative tasks should urgently be undertaken by the Ministry of Education and the Ministry of Public Health in order to improve the knowledge and wrong practices of the students in this sense, as well as the extreme precocity of the first sexual relation

Se realizó un estudio, por su dimensión, epidemiológico, y por su tipo, explicativo (cuasiexperimental) con los estudiantes de 9no. y 8vo. grados de la ESBU "Julio A. Mella" de la ciudad de Placetas en el curso 1996-1997; para conocer aspectos relacionados con la educación sexual por un sistema de formularios anónimos y mediante un diseño experimental de control mínimo. Se investigaron variables como edad, sexo, dinámica familiar, patrón de relación sexual y aspectos que estructuran conocimientos sobre la materia con el empleo de un muestreo cualitativo de máxima variabilidad. Los datos obtenidos fueron computadorizados en el centro "Joven Club" de esta ciudad, y los resultados comparados con el censo de población en proporciones y por medio de la prueba de independencia de variables con distribución de x². Se comprobó que el nivel de conocimientos sobre educación sexual es deficiente según el modelo "ANTES", se evidencia una vez más la función insustituible que ejerce la labor educativa al mejorar el nivel de conocimientos según el modelo "DESPUÉS". Urgen tareas cooperativas MINED-MINSAP que mejoren conocimientos y prácticas erróneas en el alumnado en este sentido como la extrema precocidad de la primera relación sexual

The catalytic performance of solids with basic properties, such as CaO, MgO and hydrotalcites, was evaluated in the aldol condensation of citral and acetone, the first step in the synthesis of ionones from citral. The best results were obtained with CaO and hydrotalcite with high conversions (98%) and selectivities (close to 70% for the main product) observed for both of the catalyst. Such pseudoionone yields were greater than those reported in the literature for the homogeneous reaction.

Resumo Um levantamento preliminar de viroses de plantas cultivadas nos arredores de Manaus foi feito em março de 1977. Diversas propriedades particulares e campos experimentais foram inspecionados, anotando-se as plantas exibindo sintomatologia suspeita. A verificação da sua possível etiologia viral foi feita através de testes de transmissão, serologia e exames electrono microscópicos. Foram constatadas diversas viroses em tomateiro, pimentão, quiabeiro, feijoeiro, cucurbitáceas, soja, feijão-de-asa, milho. etc. Como regra geral, ao contrário do que sucede no Sul do País, as viroses transmitidas por afídeos foram de ocorrência rara, presumivelmente porque as condições climáticas da região seriam desfavoráveis à biologia desses insetos.