927 resultados para Types of discourse. Writing production situations. Didactic collections


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background: The insecticides dichlorvos, paradichlorobenzene and naphthalene have been commonly used to eradicate pest insects from natural history collections. However, it is not known how these chemicals affect the DNA of the specimens in the collections. We thus tested the effect of dichlorvos, paradichlorobenzene and naphthalene on DNA of insects (Musca domestica) by extracting and amplifying DNA from specimens exposed to insecticides in two different concentrations over increasing time intervals. Results: The results clearly show that dichlorvos impedes both extraction and amplification of mitochondrial and nuclear DNA after relatively short time, whereas paradichlorobenzene and naphthalene do not. Conclusion: Collections treated with paradichlorobenzene and naphthalene, are better preserved concerning DNA, than those treated with dichlorvos. Non toxic pest control methods should, however, be preferred due to physical damage of specimens and putative health risks by chemicals.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

http://digitalcommons.colby.edu/atlasofmaine2006/1009/thumbnail.jpg

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Accumulating evidence points to relationships between increased production of reactive oxygen or decreased antioxidant protection in schizophrenic patients. Chlorpromazine (CPZ), which remains a benchmark treatment for people with schizophrenia, has been described as a pro-oxidant compound. Because the antioxidant compound melatonin exerts protective effects against CPZ-induced liver disease in rats, in this investigation, our main objective was to study the effect of CPZ as a co-catalyst of peroxidase-mediated oxidation of melatonin. We found that melatonin was an excellent reductor agent of preformed CPZ cation radical (CPZ(center dot+)). The addition of CPZ during the horseradish peroxidase (HRP)-catalyzed oxidation of melatonin provoked a significant increase in the rate of oxidation and production of N-1-acetyl-N-2-formyl-5-methoxykynuramine (AFMK). Similar results were obtained using myeloperoxidase. The effect of CPZ on melatonin oxidation was rather higher at alkaline pH. At pH 9.0, the efficiency of oxidation of melatonin was 15 times higher and the production of AFMK was 30 times higher as compared with the assays in the absence of CPZ. We suggest that CPZ is able to exacerbate the rate of oxidation of melatonin by an electron transfer mechanism where CPZ(center dot+), generated during the peroxidase-catalyzed oxidation, is able to efficiently oxidize melatonin.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dentre os materiais de construção utilizados nas instalações rurais, merecem destaque as coberturas, pois são grandes responsáveis pelo conforto térmico, influenciando no balanço térmico no interior das instalações. Este trabalho objetivou avaliar a influência das coberturas sobre a entalpia (H), Carga Térmica Radiante (CTR) e no Índice de Temperatura de Globo Negro e Umidade (ITGU), em abrigos individuais para bezerros leiteiros. O delineamento foi o inteiramente casualizado com três tratamentos: Z - telha de zinco; CA - telha de cimento amianto, e CAB - telha de cimento amianto pintada de branco na face superior. As médias foram comparadas pelo teste de Scott Knott, a 1% de probabilidade. Os resultados mostraram que não houve diferença estatística entre os tratamentos (P<0,01) e o ambiente externo, para a H. Para a CTR, houve diferença estatística entre todos os tratamentos, em que CAB demonstrou menor CTR, 489,28 W m-², seguido do tratamento CA, 506,72 W m-², e Z com maior valor de CTR, 523,55 W m-². Para o ITGU, observaram-se menores valores para CAB (76,8) e CA (77,4), diferindo-se, significativamente do Z, que obteve maior valor (81,6). As telhas com pintura branca em sua face superior promoveram menor CTR e menor ITGU, favorecendo o ambiente térmico da instalação.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Cells of Mikania glomerata, Cephaelis ipecacuanha and Maytenus aquifolia were co-cultured in a two-phase system using filter paper as a solid support. The species were co-cultured in all possible paired combinations. Interaction between Mikania and Maytenus cells resulted in increased biomass production of Maytenus cells, but the friedelin content was reduced. Co-cultivation of Cephaelis and Mikania cells enhanced coumarin content, but inhibited the growth of Mikania cells. However, yield of emetine as well as Cephaelis biomass accumulation were positively stimulated by the co-cultivation. Results indicate a possible occurrence of allelopathy in such a system.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The effect of application with different nozzle types and volume rates on spray deposition in the V3 stage of two soybean cultivars was evaluated. The experiments were conducted in the Facultad de Ciencias Agronomicas of the UNESP-Botucatu/SP. The nozzles evaluated were an air induced flat fan nozzle (Al 11015 at 150 L ha(-1), Al 11002 at 200 and 250 L ha(-1)), a twin flat fan nozzle (TJ 60 11002 at 150, 200 and 250 L ha(-1)), and a cone nozzle (TX 6 at 150 L ha(-1), TX 8 at 150 L ha(-1) and TX 10 at 250 L ha(-1)). To evaluate spray deposition on the plants, a tracer (Brilliant Blue FD&C-1) was added. The experimental design was random blocks with four replications. Deposition on plants was determined by absorbancy reading in 630 nm wavelength. The data were adjusted to a calibration curve and transformed into deposited spray volume in mL. The relationship deposition per unit of dry matter was adjusted to a regression curve (Gompertz model). In cultivar CD 208, the highest deposit was for the larger volumes and for the treatment TX 8 200 L ha(-1). The most uniform treatments were all the nozzles with the volume 150 L ha(-1) and the TJ60 nozzle for 200 1, ha(-1). In cultivar CD 216, the greatest spray depositions were achieved with the treatments Al at 200 and 250 L ha(-1) and TJ 60 at 250 L ha(-1), and the most uniform treatments were the TX 6 and TJ60 nozzles for the volume150 L ha(-1).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This note clarifies the design of proportional derivative (PD) controllers for the magnetic levitation systems of micro PM motors proposed in the above paper. It is shown that the PD controllers cannot stabilize the described levited micro motors because it is necessary to use other values of parameters for these controllers. We present necessary and sufficient conditions for the stability of the controlled systems described in the paper.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

O objetivo da presente investigação experimental foi avaliar o perfil mecânico de três tipos de técnicas de sutura entre tendões de dimensões diferentes. Foram utilizados 21 cães sem raça definida (11machos/10 fêmeas), dos quais foram obtidos os tendões flexor comum dos dedos - t.c. (maior dimensão) e tibial cranial - t.cr. (menor dimensão), de ambos os membros pélvicos. Logo após a obtenção das peças foi realizada sutura, segundo cada tipo de técnica, porém sempre com o mesmo número de pontos. Os tendões utilizados para sutura foram sempre do lado direito e o controle do lado esquerdo (t.cr.). Após a sutura, os corpos de prova foram fixados em garras especialmente desenvolvidas e submetidos a ensaio de tração axial à velocidade de 30mm/minuto. Após o ensaio o programa da máquina forneceu os valores da carga máxima ( na ruptura) e deformação absoluta (mm) e relativa (%), além do diagrama carga-deformação. Os resultados foram submetidos a estudo estatístico pela análise de medidas repetidas no nível de 5% de significância. Não foi constatada diferença estatisticamente significativa nos parâmetros mecânicos avaliados nos três grupos de técnicas de suturas. em relação ao controle (tendão de menos diâmetro contra-lateral), observou-se que a sutura apresenta resistência máxima a tração significativamente menor que o controle e maior deformação.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)