Seasonal variation of biomass and productivity of the periphytic community on artificial substrata in the Jurumirim Reservoir (S��o Paulo, Brazil)

The seasonal variation of the periphytic community attached to an artificial substratum (glass tubes) was studied during two different periods in a lagoon connected to the Paranapanema River, the main tributary of the Jurumirim Reservoir (S��o Paulo-Brazil). An analysis of dry weight, ash free dry weight, chlorophyll a, phaeophytin and primary productivity of periphyton was carried out. The first experiment lasted from August to December 1993, the second from February to June 1994. Tubes were removed after 7, 14, 21, 28, 60, 90 and 119 days of incubation. In the 1st experiment, the periphytic community reached a higher biomass after the 4th week of colonization (28th day), in the 2nd experiment after the 2nd week (14th day). This discrepancy is related to seasonal differences in environmental factors (water temperature, nutrients concentrations and water discharge) that determine initial colonization. After the first stages of colonization, the biomass and primary productivity of periphyton reached their maximum values after the 60th day of incubation. In both experiments, three developmental phases could be discerned. In the initial phase, an exponential growth was observed. In the second phase, the bioderm reached its maximum biomass and productivity. In the third phase, a decrease of biomass and productivity occurred.

Coloniza����o por macroinvertebrados bent��nicos em substrato artificial e natural em um riacho da serra de Itatinga, S��o Paulo, Brasil

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Morphological modifications induced by an artificial diet on the hypopharyngeal glands of Apis mellifera (Hymenoptera, apidae) during their degenerative process

The morphological aspects of the hypopharyngeal glands were analyzed in worker bees of Apis mellifera of 15 and 30 days of age. The individuals were kept in a room with controlled temperature at 32degreesC where they received water and either a protein or a high energy food. Nurse and foraging workers were used as a control for the experiment. The morphological results showed that the different diets modified the cell death characteristics and intensified its occurrence. Both diets caused precocious glandular degeneration. However, this anticipation of cell death was more pronounced in the glandular tissue of the workers who received the high energy diet when compared to the glands of the bees fed with the protein meal.The degenerative signs observed were an intense cytoplasmic vacuolization, with a loss of cytoplasm and of the cell boundaries, dilation or condensation of the cells and nuclei, and nuclear fragmentation. At the end of the degenerative process, we observed the extrusion of nuclei and, finally, the dissolution of the glands. The hypopharyngeal glands' remains were found in the haemolymph.

Artificial neural networks: A novel approach to analysing the nutritional ecology of a blowfly species, Chrysomya megacephala

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Reproduction of Cichla kelberi Kullander and Ferreira, 2006 introduced into an artificial lake in southeastern Brazil

O objetivo do estudo foi caracterizar a reprodu����o de Cichla kelberi em um lago artificial no munic��pio de Leme, Estado de S��o Paulo, Brasil. A ��poca reprodutiva ocorreu na primavera e ver��o. O L50 e o L100 desta esp��cie foram de 192 e 235 mm (L50) para machos e f��meas, respectivamente e 290 mm (L100) para ambos os sexos. A desova foi do tipo parcelado. O tamanho dos ov��citos maduros foi de 428,4 ��m, atingindo o m��ximo em 2.203,2 ��m. A m��dia da fecundidade foi de 12.129,2 ov��citos com m��dia de cada desova de 4.897,7 ov��citos. Esta esp��cie adequou-se �� defini����o de peixes com fecunda����o externa, n��o migradoras e com cuidado parental da prole. Os atributos para a introdu����o dos tucunar��s podem ser tentadores. Por��m, suas caracter��sticas reprodutivas e alimentares fazem com que n��o existam competidores ou predadores naturais e, assim, a sua expans��o populacional seja de dif��cil controle e erradica����o.

Growth and mortality of Cichla spp. (Perciformes, Cichlidae) introduced in Volta Grande Reservoir (Grande River) and in a small artificial lake in Southeastern Brazil

Os par��metros de crescimento e mortalidade foram estimados indiretamente pelas distribui����es das frequ��ncias de comprimento para esp��cies de Cichla spp. introduzidas em um lago em Leme (SP) e no reservat��rio de Volta Grande (SP-MG). em Leme, Cichla kelberi apresentou maior frequ��ncia nas classes de comprimentos inferiores, maior taxa instant��nea de mortalidade natural e menor n��mero de coortes do que C. kelberi e C. piquiti em Volta Grande. Os valores de performance de crescimento obtidos para as esp��cies foram pr��ximos, corroborando a validade dos par��metros estimados de crescimento e de mortalidade. A press��o em crescer rapidamente, devido �� preda����o, aumenta quanto menor e menos diverso for o ambiente. O g��nero Cichla adapta-se bem nos locais em que �� introduzido, entretanto essa adapta����o mostra-se fortemente ajustada a cada ambiente em particular, determinando com isso grande plasticidade e capacidade de estabelecimento.

Seasonal and ontogenetic variations in the diet of Cichla kelberi Kullander and Ferreira, 2006 introduced in an artificial lake in southeastern Brazil

A dieta de Cichla kelberi introduzido em um lago artificial em Leme-SP foi composta predominantemente pelas esp��cies de peixes mais comuns nesse lago (Oreochromis niloticus e o pr��prio C. kelberi). Na primavera e no ver��o, o item mais consumido foi O. niloticus. Por��m, o canibalismo foi muito comum para esta esp��cie. As altas frequ��ncias de O. niloticus e de C. kelberi revelam que a esp��cie apresenta um ciclo sazonal, se alimentando das presas mais comuns em cada per��odo do ano, com uma redu����o da sua atividade alimentar durante o inverno. As dietas foram diferentes entre os exemplares imaturos e maduros, sugerindo que existem diferen��as ontogen��ticas, principalmente relacionadas ao tipo de presa, como: Ephemeroptera, consumidos pelos tucunar��s imaturos e peixes, pelos maduros, al��m do tamanho das presas.

Feeding dynamics of Cichla kelberi Kullander & Ferreira, 2006 introduced into an artificial lake in southeastern Brazil

O objetivo desse estudo foi caracterizar sazonalmente a dieta de Cichla kelberi em um lago artificial em Leme-SP, determinando os itens alimentares e as rela����es com os sexos e com a matura����o gonadal dos exemplares amostrados. A dieta de C. kelberi apresenta uma din��mica em tr��s diferentes per��odos: os meses de inverno foram caracterizados por baixa atividade alimentar e alta concentra����o de peixes indeterminados, durante a primavera ocorreu um aumento na atividade alimentar, sendo Tilapia sp. o item alimentar dominante e durante o ver��o e in��cio do outono foi evidenciada alta taxa de canibalismo. A plasticidade na composi����o da dieta foi marcada pela quantidade de presas dispon��veis durante os per��odos do ano e pelo per��odo reprodutivo.

The use of artificial neural networks in analysing the nutritional ecology of Chrysomya megacephala (F.) (Diptera: Calliphoridae), compared with a statistical model

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Influ��ncia de variedades de cana-de-a����car, incorporadas em dieta artificial, no desenvolvimento de Diatraea saccharalis (Fabr.) e no seu parasitismo por Cotesia flavipes (Cam.)

Verificou-se a influ��ncia de duas variedades de cana-de-a����car (Saccharum spp.), incorparados em dieta artificial, na forma de colmos triturados, no desenvolvimento de Diatraea saccharalis (Fabr.) e no parasitismo de Cotesia flavipes (Cam.). A variedade SP71-1081 foi menos adequada ao desenvolvimento de D. saccharalis comparada �� SP71-3146, aumentando os per��odos larval e pupal (dias) e, diminuindo o peso larval; n��o houve diferen��as para as viabilidades larval e pupal e peso de pupa. Lagartas oriundas das dietas artificiais e lagartas alojadas no interior dos toletes das variedades de cana, foram igualmente parasitadas por C. flavipes. Lagartas criadas em dieta artificial contendo colmos triturados das variedades testadas, promoveram desenvolvimento semelhante de C. flavipes. A percentagem de parasitismo foi semelhante nas larvas criadas em dietas artificiais contendo colmos das variedades SP 71 - 1081 (84,0%) e SP 71-3146 (81,3%).

Trait-mediated effects on flowers: Artificial spiders deceive pollinators and decrease plant fitness

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Effects of artificial substratum types and exposure time on macroalgal colonization in a tropical stream

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Influence of artificial saliva in biofilm formation of Candida albicans in vitro

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Artificial immune systems for classification of petroleum well drilling operations

This paper presents two approaches of Artificial Immune System for Pattern Recognition (CLONALG and Parallel AIRS2) to classify automatically the well drilling operation stages. The classification is carried out through the analysis of some mud-logging parameters. In order to validate the performance of AIS techniques, the results were compared with others classification methods: neural network, support vector machine and lazy learning.

Petroleum well drilling monitoring through cutting image analysis and artificial intelligence techniques

Petroleum well drilling monitoring has become an important tool for detecting and preventing problems during the well drilling process. In this paper, we propose to assist the drilling process by analyzing the cutting images at the vibrating shake shaker, in which different concentrations of cuttings can indicate possible problems, such as the collapse of the well borehole walls. In such a way, we present here an innovative computer vision system composed by a real time cutting volume estimator addressed by support vector regression. As far we know, we are the first to propose the petroleum well drilling monitoring by cutting image analysis. We also applied a collection of supervised classifiers for cutting volume classification. (C) 2010 Elsevier Ltd. All rights reserved.