Efficacy of Duddingtonia flagrans and Arthrobotrys robusta in controlling sheep parasitic gastroenteritis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Eficácia dos fungos nematófagos Duddingtonia flagrans e Arthrootrys robusta na profilaxa das infecções naturais por nematódeos gastrointestinais em ovinos

Pós-graduação em Medicina Veterinária - FMVZ

Estabelecimento de fungos nematófagos aplicados no campo para o controle dos nematoides-chaves dos citros no Brasil

Monitoring the survival of nematophagous fungi is needed to establish periods of reapplication of formulations of nematophagous fungi to control the citrus nematode in the field. We monitored the survival of fungi: Arthrobotrys robusta, A. oligospora, A. musiformis Dactylella leptospora and Monacrosporium eudermatum in plots treated with 1, 2, 4, 6 liters of the formulation of fungi/plant or witness without the application, during the period of nine months with the first assessment six months after application and the other with intervals of three months after the first evaluation. The fungus D. leptospora was found only in the evaluation of 6 months after treatment application, indicated a short survival time in the soil. However, the isolated A. robusta, A. musiformis and A. oligospora were recovered in all evaluations and especially in plots treated with higher doses of the formulation and witness. Monacrosporium eudermatum was recovered in all experimental periods and even in assessing the witness portion of nine months after application. The fact of the presence of species of Arthrobotrys and M. eudermatum in control plots indicates that native species that were already orchard.

Estudo do controle biológico dos nematóides dos citros no Estado de São Paulo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of artificial shade on attack by the mahogany shoot borer, Hypsipyla robusta (Moore)

Swietenia macrophylla King (Meliaceae: Swietenioideae) provides one of the premier timbers of the world. The mahogany shoot borer Hypsipyla robusta Moore (Lepidoptera: Pyralidae) is an economically important pest of S. macrophylla throughout Asia, Africa and the Pacific. No viable method of controlling this pest is known. Previous observations have suggested that the presence of overhead shade may reduce attack by H. robusta, but this has not been investigated experimentally. This research was therefore designed to assess the influence of light availability on shoot-borer attack on S. macrophylla, by establishing seedlings under three different artificial shade regimes, then using these seedlings to test oviposition preference of adult moths, neonate larval survival and growth and development of shoot borer larvae. Oviposition preference of shoot borer moths was tested on leaves from seedlings grown under artificial shade for 63 weeks. A significant difference in choice was recorded between treatments, with 27.4 ± 1.5 eggs laid under high shade and 87.1 ± 1.8 under low shade. Neonate larval survival on early flushing leaflets of S. macrophylla did not differ significantly between shade treatments. Larval growth rate, estimated by measuring daily frass width, was significantly higher for those larvae fed on seedlings from the high and medium shade treatments (0.1 mm/day), than the low shade treatment (0.06 mm/day). In laboratory-reared larvae, the total mass of frass produced was significantly higher in the high shade treatment (0.4 g) than under the low shade treatment (0.2 g). Longer tunnel lengths were bored by larvae in plants grown under high shade (12.0 ± 2.4 cm) than under low shade (7.07 ± 1.9 cm). However, pupal mass under low shade was 48% higher than that under the high shade treatment, suggesting that plants grown under high shade were of lower nutritional quality for shoot borer larvae. These results indicate that shading of mahogany seedlings may reduce the incidence of shoot borer attack, by influencing both oviposition and larval development. The establishment of mahogany under suitable shade regimes may therefore provide a basis for controlling shoot borer attack using silvicultural approaches.

An investigation of migration and possible stock structuring by the stout whiting, Sillago robusta, in southern Queensland waters, and its impact on managing the fishery. Final Report on the Pilot Program

A highly polymorphic genetic locus of Stout Whiting was examined for evidence of geographical subdivision amongst samples collected from three locales in southern Queensland waters. Statistical indicators of subdivision were not significantly different from zero, suggesting that it is unlikely that the Stout Whiting resource in southern Queensland is genetically subdivided into separate stocks. It is recommended that the full-scale genetic program not proceed and that the resource be managed as a single stock.

磷微蠕蚓(Microscolex phosphoreus)和壮伟环毛蚓(Pheretima robusta)体腔细胞的超微结构研究

发光蚯蚓在世界范围内广泛分布。大多数发光蚯蚓的发光体系包含于蚯蚓体腔液内充满颗粒的细胞内。早期对不同种发光蚯蚓的生理学及生物化学方面的对比研究表明大多数发光蚯蚓的发光体系是类似的，但最近对线蚓科的两个种的研究发现它们不仅发光源的定位特殊，发光反应所需要的成分也明显不同于其他种类，而且它们两者之间也互不相同。本文对发光蚯蚓的发光器官和发光体系的研究现状及其进展进行了综述，并将有代表性的发光蚯蚓的发光体系进行了对比总结。 应用光学显微镜、扫描电镜和透射电镜对发光性蚯蚓——磷微蠕蚓(Microscolex phosphoreus)的体腔细胞进行观察，基于各种细胞的形态特征、胞质内细胞器和颗粒组成、伪足形状和行为特征等将其归纳为三类：黄色细胞、阿米巴样细胞、粒细胞。从外观上看，黄色细胞由几个个体较大的黄色细胞体组成，其细胞质内缺少细胞器；阿米巴样细胞呈明显的球形或椭圆形的花朵状，经常可见几个至十几个细胞形成聚合体，胞质内细胞器丰富；粒细胞的胞质内具有颗粒是其主要特征，其星状伪足常处于细胞一端，细胞质内细胞器含量中等。将磷微蠕蚓的三类细胞与前人研究过的几种蚯蚓中相关体腔细胞的形态和超微结构进行了异同比较。 应用光学显微镜，扫描电子显微镜和透射电子显微镜对非发光种——壮伟环毛蚓(Pheretima robusta)的体腔细胞进行了分类和超微结构观察。结果显示壮伟环毛蚓的体腔细胞主要可分为三种类型：黄色细胞、Ⅰ型阿米巴样细胞、Ⅱ型阿米巴样细胞。黄色细胞外观看上去由大量的小颗粒组成，在透射电镜下发现其胞质内含有许多黄色细胞体和过氧化物酶体，细胞质内缺少细胞器。Ⅰ型阿米巴样细胞表面具有许多明显的褶皱和不规则的突起，大多数形态是不规则的。胞质内含有丰富的线粒体和游离的核糖体。Ⅱ型阿米巴样细胞表面有一些较小的凹陷和突起，细胞外质含有大量大小不等形态多样的空泡。细胞质内可见圆形或椭圆形的线粒体及粗面内质网。胞质内含有大量的核糖体颗粒。将壮伟环毛蚓(Pheretima robusta)与前人研究过的几种蚯蚓及磷微蠕蚓(Microscolex phosphoreus)的体腔细胞的结构进行了比较。

GREVILEA robusta.

2002

Excentricidade da medula em Grevilea robusta e Corymbia citriodora cultivados em sistema silvipastoril.

2010

ZONEAMENTO climático para a grevílea no Estado do Paraná: Grevillea robusta.

2010

Estimação robusta em modelos lineares de equações simultâneas

Os Modelos de Equações Simultâneas (SEM) são modelos estatísticos com muita tradição em estudos de Econometria, uma vez que permitem representar e estudar uma vasta gama de processos económicos. Os estimadores mais usados em SEM resultam da aplicação do Método dos Mínimos Quadrados ou do Método da Máxima Verosimilhança, os quais não são robustos. Em Maronna e Yohai (1997), os autores propõem formas de “robustificar” esses estimadores. Um outro método de estimação com interesse nestes modelos é o Método dos Momentos Generalizado (GMM), o qual também conduz a estimadores não robustos. Estimadores que sofrem de falta de robustez são muito inconvenientes uma vez que podem conduzir a resultados enganadores quando são violadas as hipóteses subjacentes ao modelo assumido. Os estimadores robustos são de grande valor, em particular quando os modelos em estudo são complexos, como é o caso dos SEM. O principal objectivo desta investigação foi o de procurar tais estimadores tendo-se construído um estimador robusto a que se deu o nome de GMMOGK. Trata-se de uma versão robusta do estimador GMM. Para avaliar o desempenho do novo estimador foi feito um adequado estudo de simulação e foi também feita a aplicação do estimador a um conjunto de dados reais. O estimador robusto tem um bom desempenho nos modelos heterocedásticos considerados e, nessas condições, comporta-se melhor do que os estimadores não robustos usados no estudo. Contudo, quando a análise é feita em cada equação separadamente, a especificidade de cada equação individual e a estrutura de dependência do sistema são dois aspectos que influenciam o desempenho do estimador, tal como acontece com os estimadores usuais. Para enquadrar a investigação, o texto inclui uma revisão de aspectos essenciais dos SEM, o seu papel em Econometria, os principais métodos de estimação, com particular ênfase no GMM, e uma curta introdução à estimação robusta.