O objetivo do presente estudo foi analisar a influência do volume de calda e da altura de voo na deposição em aplicações aéreas de herbicidas em áreas de pastagens. Para a montagem das parcelas experimentais, foi escolhida uma área com pastagens no município de Porto Esperidião-MT. Em todos os tratamentos, as aplicações foram realizadas utilizando os herbicidas aminopiralide e fluroxipir (Dominum) na dose de 2,5 L p.c. ha-1, incluindo o adjuvante óleo mineral (Joint Oil) na dose de 1,0 Lha-1 e um traçante para determinação da deposição por cromatografia HPLC (rodamina, na concentração de 0,6%). O ensaio considerou nove tratamentos que consistiram nas combinações de três volumes de calda (20, 30 e 50Lha-1) e três alturas de voo (10, 30 e 40 m). Os resultados mostraram que, em média, houve tendência de maiores depósitos para as menores alturas de voo, com diferença significativa entre 10 e 40 m de altura. Não houve diferença significativa entre os depósitos obtidos com os diferentes volumes de calda.

The objective of the present study was to analyze the influence of spray mixture volume and flight height on herbicide deposition in aerial applications on pastures. The experimental plots were arranged in a pasture area in the district of Porto Esperidião (Mato Grosso, Brazil). In all of the treatments, the applications contained the herbicides aminopyralid and fluroxypyr (Dominum) at the dose of 2.5 L c.p. ha-1, including the adjuvant mineral oil (Joint Oil) at the dose of 1.0 L and a tracer to determine the deposition by high-performance liquid chromatography (HPLC) (rhodamine at a concentration of 0.6%). The experiment consisted of nine treatments that comprised the combinations of three spray volumes (20, 30 and 50 L ha-1) and three flight heights (10, 30 and 40 m). The results showed that, on average, there was a tendency for larger deposits for the smallest flight heights, with a significant difference between the heights of 10 and 40 m. There was no significant difference among the deposits obtained with the different spray mixture volumes.

RESUMO Pesquisas sobre patogenicidade necessitam de conhecimentos básicos em biologia e ecologia dos organismos envolvidos no estudo. O presente trabalho descreve uma técnica de manutenção do cupim Nasutitermes coxipoensis em condições de laboratório a fim de realização de testes com fungos entomopatogênicos. Os cupins foram mantidos em caixas plásticas contendo pedaço de ninho (20 g) e substratos alimentares diferentes: madeira em decomposição, madeira seca, colmo de cana-de-açúcar e papel madeira. Utilizou-se a função de sobrevivência S(t) com o objetivo de verificar a probabilidade de vida dos insetos até um tempo t (18 dias), a fim de mantê-los em condições de laboratório. Os resultados indicaram que o substrato que possibilitou maior tempo de sobrevivência foi cana-de-açúcar, seguido de papel madeira picado. Tais informações possibilitarão a realização de testes diversos com cupins, em condições de laboratório.

ABSTRACT Investigations concerning pathogenicity require basic knowledge in the biology and ecology of the target species involved in the study. The present work describes a technique to maintain the termite Nasutitermes coxipoensis under laboratory conditions to conduct tests with entomopathogenic fungi. The termites were maintained in plastic boxes with a piece of the original nest (20 g) and different food substrates: rotting wood, dry wood, sugarcane pulp, and wood paper. The survival function S(t) was applied to determine the best substrate for maintaining the termites under laboratory conditions, considering an ending time for the experiment of 18 days (t). The results indicated the sugarcane pulp, followed by wood paper as the best substrates for maintaining N. coxipoensis. This information will open opportunities for studies with termites under laboratory conditions.

RESUMO A pesquisa objetivou analisar, morfológica e quantitativamente, os tipos de hemócitos em lagartas do terceiro ínstar de Diatraea saccharalis F., desafiadas imunologicamente por Metarhizium anisopliae (Metsch.) Sorok. e Beauveria bassiana (Bals.) Vuill., nas concentrações 103, 105 e 107 conídios mL-1, em comparação a lagartas não tratadas. Foram coletados 10 µL de hemolinfa de cinco lagartas por tratamento, nos intervalos de 24, 36, 48, e 60 horas pós-inoculação, sendo contadas 300 células em campos aleatórios da lâmina, utilizando-se a objetiva de imersão (100X). Os hemócitos mais freqüentes foram os esferulócitos (34,8%), plasmatócitos (29,7%) e granulócitos (22,2%), enquanto os menos freqüentes foram os prohemócitos (8,3%), adipohemócitos (2,6%) e oenocitóides (2,4%). B. bassiana promoveu interferência efetiva na população de granulócitos na concentração de 107 conídios mL-1 (24 e 36h) e plasmatócitos nas concentrações 103 conídios mL-1 (60h) e 107 conídios mL-1 (24 e 36h), onde ocorreu aumento do número de granulócitos e redução do número de plasmatócitos na maior concentração e, ainda, o aumento do número de plasmatócitos na concentração 103 conídios mL-1. M. anisopliae não interferiu quantitativamente nos granulócitos e plasmatócitos. No que se refere aos esferulócitos, verificou-se maior tendência de redução do número dessas células no intervalo de 36h para ambos os fungos, porém, diferença significativa só ocorreu na concentração de 105 conídios mL-1 no intervalo de 60h, apresentando a menor média. Conclui-se que B. bassiana tem ação mais efetiva sobre a dinâmica populacional dos granulócitos e plasmatócitos em lagartas de D. saccharalis em relação ao M. anisopliae.

ABSTRACT This study was aimed to morphologically and quantitatively analyze the types of hemocytes in Diatraea saccharalis F. thirdinstar caterpillar immunologicaly challenged by Metarhizium anisopliae (Metsch.) Sorok. and Beauveria bassiana (Bals.) Vuill. in concentrations of 103, 105 and 107 conidia mL-1, compared to nontreated specimens. A 10µL-sample of hemolymphs from five caterpillars for each treatment, in the intervals of 24, 36, 48 and 60h; 300 cells were counted in random fields of the lamina, using the immersion objective (100X). The most frequent hemocytes were the spherulocytes (34.8%), plasmatocytes (29.7%) and granulocytes (22.2%), while the least frequent were the prohemocytes (8.3%), the adipohemocytes (2.6%) and the oenocytoids (2.4%). B. bassiana promoted effective interference in the population of granulocytes at the concentration of 107 conidia mL-1 (24 and 36h) and of plasmatocytes at the concentrations of 103 conidia mL-1 (60h) and 107 conidia mL-1 (24 and 36h); there occurred an increase of the number of the granulocytes and a decrease of the number of plasmotocytes at the highest concentration, and an increase in the number of plasmatocytes at the concentration of 103 conidia mL-1. M. anisopliae do not interfere quantitatively in the granulocytes and plasmatocytes. Regarding the spherulocytes, there was observed a higher tendency of reduction in the number of these cells in the interval of 24 and 36h for both fungi, but a meaningful difference only occurred at the concentration of 105 conidia mL-1 in the 60h interval, presenting the smallest average. It was possible to conclude that B. bassiana has a more effective action over the populational dynamics of the granulocytes and plasmatocytes of D. saccharalis caterpillars in association with M. anisopliae.

Probiotics are formulations containing live microorganisms or microbial stimulants that have some beneficial influence on the maintenance of a balanced intestinal microbiota and on the resistance to infections. The search for probiotics to be used in prevention or treatment of enteric infections, as an alternative to antibiotic therapy, has gained significant impulse in the last few years. Several studies have demonstrated the beneficial effects of lactic acid bacteria in controlling infection by intestinal pathogens and in boosting the host's nonspecific immune response. Here, we studied the use of Lactobacillus acidophilus UFV-H2b20, a lactic acid bacterium isolated from a human newborn from Viçosa, Minas Gerais, Brazil, as a probiotic. A suspension containing 108 cells of Lactobacillus acidophilus UFV-H2b20 was inoculated into groups of at least five conventional and germfree Swiss mice to determine its capacity to stimulate the host mononuclear phagocytic activity. We demonstrate that this strain can survive the stressing conditions of the intestinal tract in vivo. Moreover, the monoassociation of germfree mice with this strain for seven days improved the host's macrophage phagocytic capacity, as demonstrated by the clearance of a Gram-negative bacterium inoculated intravenously. Monoassociated mice showed an undetectable number of circulating E. coli, while 0.1% of the original inoculum was still present in germfree animals. Mice treated with viable or heat-killed Lactobacillus acidophilus UFV-H2b20 presented similarly improved clearance capacity when compared with germfree controls. In addition, monoassociated mice had twice the amount of Kupffer cells, which are responsible for the clearance of circulating bacteria, compared to germfree controls. These results suggest that the L. acidophilus strain used here stimulates a nonspecific immune response and is a strong candidate to be used as a probiotic.

Toxoplasma gondii and Trypanosoma cruzi are intracellular parasites which, as part of their life cycle, induce a potent cell-mediated immunity (CMI) maintained by Th1 lymphocytes and IFN-<FONT FACE="Symbol">g</font>. In both cases, induction of a strong CMI is thought to protect the host against rapid parasite multiplication and consequent pathology and lethality during the acute phase of infection. However, the parasitic infection is not eliminated by the immune system and the vertebrate host serves as a parasite reservoir. In contrast, Leishmania sp, which is a slow growing parasite, appears to evade induction of CMI during early stages of infection as a strategy for surviving in a hostile environment (i.e., inside the macrophages which are their obligatory niche in the vertebrate host). Recent reports show that the initiation of IL-12 synthesis by macrophages during these parasitic infections is a key event in regulating CMI and disease outcome. The studies reviewed here indicate that activation/inhibition of distinct signaling pathways and certain macrophage functions by intracellular protozoa are important events in inducing/modulating the immune response of their vertebrate hosts, allowing parasite and host survival and therefore maintaining parasite life cycles.