Promoção do desenvolvimento de nogueira-macadâmia com reguladores vegetais visando enxertia precoce

O experimento, realizado no Horto Experimental do Departamento de Botânica da Escola Superior de Agricultura "Luiz de Queiroz", teve por finalidade promover o desenvolvimento precoce de porta-enxertos de Macadamia integrifolia visando abreviar a produção de mudas. As plantas de nogueira-macadâmia com 4 meses de idade (120 D.A.S.) foram pulverizadas com ácido giberélico 50, 100, 250 e 500 ppm, ácido naftalenacético 50, 100, 250 e 500 ppm, ácido giberélico 100 ppm + ácido naftalenacético 100 ppm, além do contro-le. Esses tratamentos foram repetidos aos 181 D.A.S. Determinações periódicas da altura da planta e do diâmetro do caule mostraram que ácido giberélico 500 ppm aplicado 120 D.A.S. promoveu o maior crescimento em altura dos porta-enxertos de nogueira-macadâmia; sendo que ácido giberélico 50 ppm, aplicado 120 e 181 D.A.S. também se mostrou eficiente. Pulveriza-ção com ácido giberélico 500 ppm ou ácido giberélico 100 ppm + ácido naftalenacético 100 ppm, 120 D.A.S. promoveram o maior aumento precoce no diâmetro do caule das mudas de Macadamia; sendo que ácido giberélico 50 e 250 ppm, aplicado 120 e 181 D.A.S. também se revelaram eficientes.

Atividade moluscicida de princípios ativos de folhas de Lycopersicon esculentum (Solanales, Solanaceae) em Biomphalaria glabrata (Gastropoda, Planorbidae)

Foram obtidos extratos aquosos e alcoólicos a partir de pó de folhas secas de tomateiro (Lycopersicon esculentum, Mill.) c.v. Cereja. Por extração metanólica e precipitação alcalina, foi obtido um produto que denominamos "glicoalcalóide esteroidal bruto" (GEb), no qual foi caracterizada a presença de tomatina. Em ensaios laboratoriais, os extratos aquosos, alcoólicos e o GEb apresentaram atividade moluscicida em Biomphalaria glabrata (Say, 1818). O "glicoalcalóide esteroidal bruto" apresentou alta atividade moluscicida (CL50 = 8,01 ppm e CL90 = 13,17 ppm), comparável à atividade da tomatina. Desovas de B. glabrata mostraram-se resistentes aos extratos testados. Os níveis de atividade moluscicida apresentados pelos diversos extratos e o GEb, apontam apenas o GEb como candidato para a continuação dos estudos visando a sua possível utilização em campo.

Hatching and larval export of the intertidal crab Neohelice granulata in Mar Chiquita coastal lagoon, Argentina

Synchronization in the events of the reproductive cycle in female Neohelice granulata Dana, 1851 were studied from samples taken weekly and biweekly from September to December 2006 in the Laguna Mar Chiquita. The timing and larval hatching and synchronicity were inferred from numbers of ovigerous females and observing the stages of embryonic development. Synchronization in larval hatching also was observed in females in experiments in dark for a period of 48 hours, at three different salinities (10, 23 and 33 ppm). In addition plankton sampling were performed in order to study larval exportation at the field and its link to the tidal and light/dark cycles. We found that ovigerous females of N. granulata have a marked synchronization in embryonic development which results in that most of berried females are close to hatching within a period of maximum tidal range (days). Within this period, there is a synchronization of hatching at a time scale of hours, governed by environmental conditions. The salinity range used in this study (10-32‰) did not affect hatching synchronicity neither time to hatch. Hatching was synchronized according to endogenous rhythms governed mainly by the tidal cycle and secondarily by the breadth of it. It is also conditioned by the light-dark cycle through an exogenous cycle, so that the hatchings would occur mostly at night high tides.

Comportamento de Biomphalaria glabrata (Say, 1818) como critério de toxicidade em ensaios biológicos com moluscicidas

Visando à aplicação sistemática de parâmetros comportamentais como indicadores da ação tóxica de moluscicidas empregados no combate aos hospedeiros intermediários do Schistosoma mansoni, um procedimento para avaliação quantitativa do efeito de dose sobre o comprotamento de Biomphalaria glabrata foi desenvolvido, com base no paradigma recomendado pela O.M.S. para ensaios biológicos e envolvendo registro comportamental por cenematografia ocm lapso de tempo: caramujos com 5 7/8 ± 1/8 giros eram subemtidos a diferentes concentrações subletais de sulfato de cobre durante 24 horas e em seguida transferidos para recuperação em água destilada desionizada; a partir da análise dos registros foram computados (a) a freqüência total de subidas à superfície por indivíduo, (b) a frqüência total de saídas da água por indivíduo e (c) a proporção média de indivíduos no terço superior do recipiente de teste. O método Litchfield-Wilcoxon foi empregaod para determinação de índices de referência (denominados "concentrações de efieto comportamental de 50%" ou CEC50) em relação a cada parâmetro, e os valores obtidos - (a) 0,010, (b) 0,006 e (c) 0,029 ppm de cobre - não só evidenciaram a exeqüibilidade da aplicação sistemática de critérios comportamentais de toxidade, como se revelaram capazes de detectar o efieto tóxico do produto em concentrações muito infereiores às obtidas nas determinações convencionais de letalidade. Os dados também mostraram alterações na atividade dos caramujos em decorrência do ciclo de iluminação dia-noite. Embora o esclarecimento dos aspectos etológicos envolvidos no problema do controle químico do vetor dependa da análise das relações entre o indivíduo e seu ambiente natural, estudos de laboratório com mensurações acuradas de parâmetros relacionados a comportamentos de proteção podem fornecer subsídios relevantes a respeito.

Effects of a nursery CO2 enriched atmosphere on the germination and seedling morphology of two Mediterranean oaks with contrasting leaf habit

Abstract: The use of an enriched CO2 atmosphere in tree nurseries has been envisaged as a promising technique to increase productivity and to obtain seedlings with a higher root/shoot ratio, an essential trait to respond to water stress in Mediterranean-type ecosystems. In that framework, we have analyzed the effects of three levels of atmospheric CO2 concentration (350, 500 and 700 ppm) on the germination rate, growth and morphology of seedlings of two Mediterranean oaks used in reforestation programs: the evergreen Quercus ilex L. and the deciduous Quercus cerrioides Wilk. et Costa. CO2 enrichment increased the germination rate of Q. cerrioides (from 70±7 to 81±3 %) while it decreased that of Q. ilex (from 71±10 to 41±12 %). Seedlings of both species increased approximately 60% their total biomass in response to CO2 enrichment but at two different CO2 concentrations: 500 ppm for Q. cerrioides and 700 ppm for Q. ilex. This increase in seedlings biomass was entirely due to an augmentation of root biomass. Considering germination and biomass partitioning, an enriched CO2 atmosphere might not be appropriate for growing Mediterranean evergreen oaks, such as Q. ilex, since it reduces acorn germination and the only gains in root biomass occur at a high concentration (700 ppm). On the other hand, a moderate CO2 enrichment (500 ppm) appears as a promising nursery technique to stimulate the germination, growth and root/shoot ratio of deciduous oaks, such as Q. cerrioides. Resumen: El uso de una atmósfera enriquecida en CO2 durante la fase de vivero puede contribuir a aumentar la producción viverística, a la vez que ayudar a conseguir plántulas con una mayor relación biomasa subterránea/biomasa aérea, más adecuadas para hacer frente al severo estrés hídrico que generalmente limita el éxito de las repoblaciones en el clima Mediterráneo. En este estudio hemos analizado el efecto de tres niveles de abonado carbónico atmosférico (350, 500 y 750 ppm) en la germinación y morfología de plántulas de encina (Quercus ilex) y roble cerrioide (Quercus cerrioides). Una atmósfera enriquecida en CO2 incrementó la germinación de Q. cerrioides (de 70±7 a 81±3 %) mientras que disminuyó la de Q. ilex (de 71±10 a 41±12 %). Las plántulas de ambas especies incrementaron aproximadamente un 60% su biomasa en respuesta a una mayor concentración de CO2, aunque esta respuesta se produjo a diferentes dosis: 500 ppm en Q. cerrioides y 700 ppm en Q. ilex. El aumento en la biomasa total de las plántulas se debió enteramente a un mayor desarrollo de su sistema radical, Considerando tanto la germinación como los efectos sobre la relación biomasa subterránea/biomasa aérea, una atmósfera enriquecida en CO2 no parece ser un tratamiento adecuado para la producción en vivero de plántulas de Q.ilex, puesto que diminuye su germinación y solo aumenta su sistema radicular a dosis muy elevadas (700 ppm). Por el contrario, un aumento moderado en la concentración de CO2 (500 ppm) aparece como una técnica interesante para estimular el crecimiento y obtener plántulas de Q. cerrioides con un sistema radical más desarrollado.

Evolution of sarcoma 180 in mice treated with hyperchlorinated water

Mice treated with hyperchlorinated water (50 ppm of chlorine) and control mice, drinking tap water (1-3 ppm of chlorine) were inoculated with 2.5 x 10 [raised to the power of 6] sarcoma 180 cells, by intraperitoneal route. Tumor evolution was measured by enumeration of tumor cells in peritoneal cavity and by evaluation of weight gain at different time intervals after tumor implantation. In mice treated with excessive amounts of chlorine there was enhancement of tumor growth demonstrated by: (a) shorter incubation period and increased weight gain (ascites formation) after tumor implantation; (b) increased number of tumor cells in the peritoneal cavity 2, 3 and 4 days after tumor challenge. The number of peritoneal cells exsudated after tumor implantation was lower in mice treated with hyperchlorinated water than in controls. The tumor enhancement observed after excessive chlorine ingestion would be due to: (a) reduction of the number of peritoneal macrophages that migrate to the peritoneal cavity and (b) reduction of the tumoricidal capacity of peritonela macrophages induced by the direct effect of chlorine or by the reduction of the amount of endogenous endotoxins due to the bactericidal effect of chlorine.

Molluscicide activity of the "Avelós" plant (Euphorbia tirucalli, L. ) on Biomphalaria glabrata, the mollusc vector of schistosomiasis

An aqueous solution of the latex of Euphorbia tirucalli collected at sites receiving large amounts of sunlight showed molluscicide action on Biomphalaria glabrata, with LD50 obtained at the concentration of 28,0 ppm and LD90 at the concentration of 85,0 ppm. The toxicity of the product for fish was similar to that of Bayluscide and of copper sulfate used for comparison. However, the wide distribution of the plant, its easy propagation and the simple procedure for extraction of the active substance, which is biodegradable, favor "avelós" as a promising agent in the control of schistosomiasis.

GenRegion: aplicatiu de generació de màscares per a la codificació d'imatges amb regions d'interès

En aquest projecte, titulat "GenRegion: aplicatiu de generació de màscares per a la codificació d'imatges amb regions d'interès", presentem una aplicació multiplataforma que visualitza imatges PGM i PPM amb un mínim cost de memòria i sobre les quals podrem dibuixar regions d'interès. L'aplicació carregarà només la part de la imatge que podem visualitzar a la pantalla de treball permetent treballar amb imatges de gran tamany. Les regions definides seran accessibles en tot moment, podent modificar-les i esborrar-les. Finalment podrem generar ja sigui una màscara de la imatge actual amb les regions definides o bé una imatge idèntica a l'original però on es visualitzaran les regions definides.

Latex of "Coroa de Cristo" (Euphorbia Splendens): an effective molluscicide

An aqueous solution of the latex of "coroa de cristo" (Euphorbia splendens var. hislopii) showed molluscicide action (LD90) at a concentration lower than 0.5 ppm on Biomphalaria glabrata and B. tenagophila reared in laboratory and at a concentration lower than 4.0 ppm for field B. tenagophila.

Atividade moluscicida do extrato butílico de Phytolaca dodecandra (Endod) sobre Biomphalaria glabrata

O extrato butílico da Phytolacca dodecandra (tipo 44) obtido de frutos procedentes da Etiópia, foi testado como moluscicida em nosso laboratório e no campo. As concentrações letais, CL90, com 24 horas de exposição, para Biomphalaria glabrata adulta, recém-eclodidas e desovadas foram de 4,5, 23,0 e 102,0 ppm, respectivamente. Para peixes, Lebistes reticulatus, a CL90 foi de 2,0 ppm. Esses resultados foram semelhantes aos obtidos por Lemma em 1984, na Etiópia. Em dois criadouros com água parada, tratados com 10ppm de estrato butílico e 3ppm de niclosamida, ocorreu 84,0 e 100,0% de mortalidade B. glabrata, respectivamente. Os dois produtos foram tóxicos para peixes (L. reticulatus) no campo. É discutida a possibilidade do uso de moluscidas de origem vegetal, como alternativa para o combate a focos de esquistossomose no Brasil.

The Azadirachtins: potent insect growth inhibitors

In the course of their coevolution with insects, plants have learnt to protect themselves by chemical means. Semiochemical act as antifeedants or deterrents, others by disrupting growth and development. By use of the Epilachna varivestis bioassay we isolated from Azadirachta indica seed a group of triterpenoids which interfee with larval growth and development in ppm range. Main components are the azadirachtins A and B with identical biological activity. Various other azadirachtins were obtained, either as minor seed components or by chemical modification of the naturally occuring compounds. Structure vs. activity relation studies enabled us to postulate a basic structural element that should still be biologically active and with much simpler chemical structure than natural compounds. What underlies the biological activity of these insect growth inhibitors? Their interference with the hormonal regulation of development and reproduction has been studied in Locusta migratoria and Rhodnius prolixus. In addition, tritiated dihydroazadirachtin A was used. With this approach, a precise correlation between administered dose, resulting effects, and retention of the compound was established. The azadirachtins either interrupt, delay, or deviate whole developmental programs. Results from these studies provide another chemical probe for studies in insect endocrinology and physiology.

Effects of Laurus nobilis (Lauraceae) on Biomphalaria glabrata (Say, 1818)

Experiments were carried out using aqueous extracts from leaves and flowers of Laurus nobilis on Biomphalaria glabrata. Treatments were performed on blastula stage (± 15 h after first cleavage) and on adult snails (11-18 mm). In both instances they were exposed for 24 h to different concentrations of the extracts on snails (200 to 2500 ppm) and embryos (20 to 300 ppm) at 25 ± 1ºC. The embryos were observed for a period of 20 days after treatment and the snails for 10 days. Results obtained with leaf aqueous extracts have shown a degree of toxicity on embryos starting at a concentration of 125 ppm, the flower extract being effective at 35 ppm. The malformation obtained with the different concentrations falls into the unespecific type category, however some cephalic and shell malformations were found in embryos treated with concentrations over 50 ppm (leaves) and 25 ppm (flowers). The LD90 on adult snails obtained by treatments with flower and leaf extract was observed at concentrations of 340 ppm and 1900 ppm respectively.

Estudo da ação do moluscocida (Bayluscide-SRB) da Dynatech R/D Company em lagos do nordeste brasileiro - Sergipe, Brasil

To study the action of molluscicide nine ponds were selected: 3 of them lying in Maruim municipality, 29 km far from north Aracaju, the State capital, and 6 ponds in Itabaianinha municipality, 118 km far from south Aracaju. This study was carried out for 16 months. Environmental parameters observed were those thought to have any influence on the planorbids and/or the molluscicide: water temperature, transparence, salinity, pH, dissolved oxygen, CO2, and the nutrients-phosphorus, nitrogen, potassium and calcium. Plancton microorganisms were also considered to observe Bayluscide action on them. SRB was used in a concentration of 6.25 kg per 1.000 [cubic metres] water, to achieve 1.0 ppm Bayluscide concentration according to the producer's instruction in Massachussett-USA.

Influência de diversos derivados de vegetais na sobrevida das larvas de Aedes fluviatilis(Lutz) (Diptera: Culicidade) em laboratorio

As propriedades larvicidas de 34 extratos, provenientes de 29 vegetais, foram testados em larvas de Aedes fluviatilis (Lutz) (Diptera: Culicidae) nas concentrações de 100, 10 e 1 ppm. 26,5% dos exames utilizados, reduziram significamente a sobrevida larvária (alfa = 0,05), quando empregados na concentração de 100 ppm (Anacardium occidentale, Agave americana, Allium sativum, Coriandrum sativum, Nerium oleander, Spatodea campanulata, Tibouchina scrobiculata e Vernonia salzmanni). O ácido anacárdio (A. occidentale) mostrou-se larvicida na concentração de 10 ppm e o extrato bruto de A. sativum foi eficaz contra as larvas na concentração de 1 ppm.

Podoconiosis in the Ethiopian Rift Valley - Role of beryllium and zirconium

A geogenic origin has been proposed in the aetiology of non-filarial elephantiasis of the feet and legs, recently renamed podoconiosis. Soil collected in an area of the Ethiopian Rift Valley, the borough of Ocholo, known for its high prevalence of podoconiosis (5.06%), has been submitted to mineral analysis. High values of sulphur (S), cerium (Ce), lanthanum (La) and neodymium (Nd), typical for basaltic bedrocks, were found. Of special interest were the values for zirconium (Zr) and beryllium (Be), 618 +/- 87 ppm and 4.6 +/- 0.5 ppm respectively, twice as high as those recorded for soils sampled in neighbouring areas where the prevalence of podoconiosis is low. To be noted also, a high content in vanadium, above 250 ppm, in half of the soil samples collected in this region. Year-long exposure of unprotected feet to Zr and Be, known for their ability to induce granuloma formation in the lymphoid tissue of man, and present in a clay rich in colloidal silica particle, highly abrasive to skin, is doubtlessly a factor involved in the development of lymph node sclerosis leading to elephantiasis.