O conhecimento da flutuação populacional e distribuição espacial de pragas são fundamentais para o estabelecimento de uma metodologia de controle adequada. A flutuação populacional e distribuição espacial de Alphitobius -diaperinus em aviário de corte, localizado em Cascavel, Paraná foi avaliada no período entre outubro/2001 e Outubro/2002. Larvas e adultos do cascudinho foram coletados semanalmente com armadilhas de Arends (n = 22) em seis lotes de frangos, consecutivamente. A temperatura da cama foi medida nos locais onde as armadilhas foram expostas, bem como a temperatura no interior do galpão do aviário. O número de besouros aumentou continuamente em todas as áreas do aviário no decorrer das semanas de coleta (média de 5.137, na primeira semana, e de 18.494 insetos, na sexta semana). O número de larvas coletadas foi significantemente maior que o número de adultos (de 1 a 20 vezes em 95% do total de coletas realizadas). Não houve correlação entre as variações de temperatura do galpão e da cama e o número de insetos coletados, não sendo, portanto, observada flutuação populacional ao longo do período de avaliação. O crescimento da população esteve relacionado ao acúmulo de camas, observando-se temperaturas mais altas em locais onde a cama era mais profunda. A distribuição espacial de larvas e adultos no galpão foi desuniforme com relação aos locais de coleta. Com base nos resultados obtidos, sugere-se que há necessidade de monitoramento dos aviários individualmente antes do emprego de qualquer medida de controle, devido à grande variabilidade na distribuição dos insetos em um único galpão de criação.

Knowledge of the population fluctuation and spatial distribution of pests is fundamental for establishing an appropriate control method. The population fluctuation and spatial distribution of the Alphitobius diaperinus in a poultry house in Cascavel, in the state of Parana, Brazil, was studied between October, 2001 and October 2002. Larvae and adults of the lesser mealworm were sampled weekly using Arends tube traps (n = 22) for six consecutive flock grow-outs. The temperature of the litter and of the poultry house was measured at the same locations of the tube traps. Beetle numbers increased continuously throughout all the sampling dates (average 5,137 in the first week and 18,494 insects on the sixth week). Significantly greater numbers of larvae were collected than adults (1 to 20 times in 95% of the sampling points). There was no correlation between temperature and the number of larvae and adults collected, therefore no fluctuation was observed during the sampling period. The population growth was correlated to litter re-use. The highest temperatures were observed in deep litter. The spatial distribution of larvae and adults in the poultry house was heterogeneous during the whole period of evaluation. Results suggest that monitoring in poultry houses is necessary prior to adopting and evaluating control measures due to the great variability of the insect distribution in the poultry house.

A series of PbTe/PbEuTe double barrier samples with different barrier widths were successfully grown on BaF2 substrates by molecular beam epitaxy. The electron concentration of PbTe spacer and well layers was controlled by the deviation from stoichiometry, while the buffer and cap layers were intentionally doped with bismuth to obtain low-resistivity layers to be used as top and bottom contacts. Assuming 50% of band offset, a barrier height of 150 meV was determined by infrared transmission measurements, corresponding to a PbEuTe barrier with 5% of europium content. The structural parameters of the samples were accurately determined by combining the measurement in a high-resolution x-ray diffractometer in the triple-axis configuration with a simulation within the framework of dynamical theory of diffraction.

Galactomannans (GMs) extracted from seeds of a native Brazilian specie designated Cassia fastuosa (cassia) and from Cyamopsis tetragonolobus (guar gum - a commercial GM) were mixed with agar, in the proportion of 3/3 g.L¹ (w/w), and used as a gelling agent in Marubakaido apple rootstock (Malus prunifolia Borkh) micropropagation. The rheological measurements of the gels showed a good interaction between both hidrocolloids. The micropropagation results on these media were compared with behaviour of standard medium containing agar only (6 g.L-1). Results from in vitro experiments indicated enhanced proliferation of apple shoots and also the occurrence of hyperhydric shoots was lower in the modified gel-medium.

A lixiviação de nitratos e dos metais K, Ca, Mg, Cd, Cu, Cr, Ni, Pb e Zn, em solos repetidamente tratados com biossólido, foi avaliada num experimento em vasos, segundo um delineamento em blocos ao acaso, com quatro tratamentos e quatro repetições, subdividindo as parcelas em aplicações. A adição de biossólidos foi feita aos vasos com capacidade para 0,5 m³ de terra, que continham Latossolo Amarelo distrófico (LAd) e Latossolo Vermelho distrófico (LVd), a cada dois meses, num total de 388 Mg ha-1. Após a aplicação do resíduo, foi feita sua incorporação na camada de 0-0,20 m do solo contido nos vasos. As aplicações de biossólidos foram sempre precedidas de amostragem de solo. Toda a água drenada através dos vasos, oriunda da precipitação atmosférica, num período de 12 meses, foi quantificada e amostrada para determinação do teor dos metais presentes, enquanto o teor de NO3- foi determinado apenas nas amostras coletadas após a primeira e a última aplicação do biossólido. As repetidas aplicações de biossólidos, em doses médias de 78 Mg ha-1, proporcionaram aumento da condutividade elétrica dos solos e das quantidades lixiviadas, pela ordem, de K > Mg > Ca. A quantidade de N-NO3- lixiviada atingiu valores de até 96 mg L-1, o que indica que a quantidade de biossólido a ser aplicada no solo agrícola depende do teor de N contido no resíduo. Não foi observada lixiviação de metais pesados, o que demonstra o poder de acumulação desses metais nos Latossolos utilizados.

The leaching of nitrates and the metals K, Ca, Mg, Cd, Cu, Cr, Ni, Pb and Zn were evaluated in an experiment using biosolids amended soils. The experiment was arranged in a completely randomized block design with four treatments: Typic Hapludox with and without biosolids (LA and LA + sludge) and Rhodic Hapludox with and without biosolids (LV and LV + sludge) and four replications. Biosolids were applied to soils every two months in an average rate corresponding to 78 Mg ha-1 (dry weight basis), during 11 months totalizing 5 additions and a total of 388 Mg ha-1. Control treatments consisted of soil only. Soil sampling was taken before each biosolid application. Leachate was collected, sampled and analyzed. Rainfall during this period was measured. The results showed that the rate and frequency of biosolid application caused an increase on soil electric conductivity, particularly in the clayey soil. Increased leaching of K, Mg and Ca, in the order K > Mg > Ca was also observed. There was an increase on nitrate leaching caused by the biosolid addition to soil, with values as high as 96 mg L-1 in the leachate. No presence of heavy metals was observed in the leachate, which shows the soil's heavy metal retention capacity. The possibility of N-NO3- leaching to groundwater makes the biosolids application to soil dependent on the biosolids content of N.