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1.
Hugo R. Permingeat Maria V. Romagnoli Juliana I. Sesma Ruben H. Vallejos 《Plant Molecular Biology Reporter》1998,16(1):89-89
An easy, reproducible and fast procedure to isolate DNA from cotton leaves is described. The addition of 0.5 M glucose in the extraction buffer avoids browning by polyphenolic compounds and improves the quality of DNA for molecular analysis. The DNA yield ranged between 150–400 mg per gram of fresh tissue. The DNA was suitable for digestion by restriction enzymes and amplificatiion by Taq DNA polymerase. 相似文献
2.
Pablo Manrique-Saide Sergio Ibáñez-Bernal Hugo Delfín-González Victor Parra Tabla 《Medical and veterinary entomology》1998,12(4):386-390
Abstract .The effect of the introduction of the entomophagous copepod Mesocyclops longisetus (Acuacultura F.C.B. strain) on the survival of Aedes aegypti immature stages in car tyres was evaluated under semi-natural conditions in the municipality of Merida, Yucatan, Mexico. Life tables were constructed for the immature stages of the mosquito in the presence and absence of M. longisetus , and the survival data were compared using log–linear models. The data set was adjusted using the GLIM statistical package and the quality of adjustment was evaluated with a chi-squared test . Survivorship curves were constructed for each treatment.
In the absence of M. longisetus , the survivorship of Ae. aegypti immature stages averaged 9%. The highest mortality rate was observed during the fourth larval instar (54%) and the resulting survival pattern corresponded to a type II survivorship curve. The mortality rate of Ae. aegypti first-instar larvae (fifty per tyre) increased more than 200-fold in the presence of M. longisetus (twenty per tyre) and the highest mortality was during the first two larval instars, where it reached 98.9%, with a resulting survivorship of 0.2%. Overall mortality was sixfold greater in the presence of the copepod than in its absence. The survival pattern of immature stages of Ae. aegypti in the presence of the copepod corresponded to a type III survivorship curve. As M. longisetus was so effective against Ae. aegypti immature stages in tyres under semi-natural conditions, its long-term effectiveness should be evaluated under socially and ecologically realistic field conditions in Mexico. 相似文献
In the absence of M. longisetus , the survivorship of Ae. aegypti immature stages averaged 9%. The highest mortality rate was observed during the fourth larval instar (54%) and the resulting survival pattern corresponded to a type II survivorship curve. The mortality rate of Ae. aegypti first-instar larvae (fifty per tyre) increased more than 200-fold in the presence of M. longisetus (twenty per tyre) and the highest mortality was during the first two larval instars, where it reached 98.9%, with a resulting survivorship of 0.2%. Overall mortality was sixfold greater in the presence of the copepod than in its absence. The survival pattern of immature stages of Ae. aegypti in the presence of the copepod corresponded to a type III survivorship curve. As M. longisetus was so effective against Ae. aegypti immature stages in tyres under semi-natural conditions, its long-term effectiveness should be evaluated under socially and ecologically realistic field conditions in Mexico. 相似文献
3.
Pascal Griesmar Clément Sanchez Germain Puccetti Isabelle Ledoux Joseph Zyss 《Molecular Engineering》1991,1(3):205-220
Orientation of optically nonlinear organic molecules inside sol-gel matrices upon application of an external D.C. electrical field is demonstrated for the first time. The quadratic nonlinear response of silicon oxide or transition metal oxide based gels containing organic molecules has been determined from Electric Field Induced Second Harmonic (EFISH) measurements. Large concentrations of Optically Nonlinear Organic Molecules (ONOM) have been either incorporated inside the macromolecular network or chemically bonded to the oxide backbone of the gels. These results demonstrate the feasibility of permanently poled doped sol-gel matrices. Moreover, EFISH measurements performed on organic molecules appear to be a useful tool for monitoring the changes occurring during sol-gel transformations. 相似文献
4.
Eighty-five catalase- and oxidase-positive Gram-negative rods and cocci susceptible to penicillin G were isolated from a variety of food sources. The phenotypic relationships of these isolates with reference cultures of Bergeyella -like, Chryseobacterium, Empedobacter, Myroides , Moraxella , Sphingobacterium and Weeksella -like strains were examined by numerical taxonomy. Seventy-three isolates were recovered in five groups; 80% of the isolates clustered in groups 1, 2 and 3 and produced indole, bearing a strong resemblance to Weeksella and Bergeyella . They could not, however, be regarded as belonging to the known species of W. virosa and B. zoohelcum . It is suggested that three species may be necessary to accommodate the environmental Weeksella - or Bergeyella -like bacteria. The isolates in groups 4 and 5 had white colonies and were unable to produce indole, in this way resembling the Moraxella genus. 相似文献
5.
There are an increasing number of studies that are now focussing on the influence of climate change on species’ distributions. However, access to predictive climatic datasets for future scenarios is difficult due to their specific formats and/or the need to be geographically downscaled. The TYN dataset is freely available to users and provides a synthetic format with several climatic models and IPCC future climate scenarios. Moreover, the CRU historical dataset (1901–2000) is also available which allows users to create baseline models for current climatic variables. E‐clic is a free, user‐friendly software package that offers three different ways to convert these two datasets into a spatially explicit raster format which is compatible with the most common geographic information systems and usable on different platforms. 相似文献
6.
A. Doisy S. Paillasson P. Tracqui F. Germain F. Leitner M. Robert-Nicoud X. Ronot 《Cell biology and toxicology》1996,12(4-6):363-366
The organization of eukaryotic chromatin is not static but changes as a function of cell status during processes such as proliferation, differentiation, and migration. DNA quantification has not been used extensively to investigate chromatin dynamics in combination with cellular migration. In this context, an optimized DNA-specific, nonperturbant method has been developed for studying chromatin organization, using the fluorescent vital bisbenzimidazole probe Hoechst 33342: this property has been described by Hamori et al. (1980). Computer-assisted image analysis was used to follow migratory activity and chromatin organization of L929 fibroblasts during in vitro wound healing. Cell movements were analyzed using an optical flow technique, which consists in the calculation of the velocity field of cells and nuclear movements in the frame. This system allows the correlation of cell migration and position in the cell cycle. It makes it possible to study chromatin dynamics using a quantitative analysis of nuclear differentiation reorganization (nuclear texture) and to correlate this with migration characteristics. The present system would be of interest for studying cell-extracellular matrix interactions using differing substrates, and also the migratory response to chemotactic factors. Such a model is a prerequisite for gaining better understanding of drug action. 相似文献
7.
8.
I C Dormehl H Bosman N Hugo M Maree C van Vuuren C van Zandwyk A van Aswegen L Paterson 《Journal of medical primatology》1987,16(3):139-150
Thermodilution cardiac output determinations and multigated equilibrium blood-pool scintigraphy were performed in ten healthy chacma baboons (Papio ursinus). The correlation was moderately good between both the radionuclide and thermodilution stroke volume (r = 0.58, SEE = 3 ml; SVth = 0.78SVr + 15.6 ml) as well as the cardiac output (r = 0.72, SEE = 0.2 liter/min; COth = 0.56 Cor + 2.1 liter/min). The attenuation depth dr as determined by radionuclide techniques was found to correlate well with the radiologically determined values dx (r = 0.8, SEE = 0.4 cm; dx = 0.87dr + 0.72 cm) which validated the depth values used in the calculations. 相似文献
9.
Ahmed Lebrihi Pierre Germain Gérard Lefebvre 《Applied microbiology and biotechnology》1987,26(2):130-135
Summary Production of cephamycin and clavulanic acid by Streptomyces clavuligerus is controlled by the phosphate concentration. Phosphate represses the biosynthesis of cephamycin synthetase, expandase and clavulanic acid synthetase. In the presence of 2 mM phosphate, the specific activities of expandase, cephamycin synthetase and clavulanic acid synthetase were higher than in the presence of 75 mM phosphate. The specific activity of cephamycin synthetase is maximal with an initial phosphate concentration of 10 mM, whereas the specific activity of expandase is maximal with 1 mM phosphate. A correlation between cephamycin synthetase specific activity and expandase specific activity was established at phosphate concentrations higher than 10 mM. This shows that the expandase is an important enzyme in the mechanism by which the phosphate concentration affects the biosynthesis of cephamycin. 相似文献
10.
M J Bosc G Germain A Nicolle M Mouren D Philibert E E Baulieu 《Journal of reproduction and fertility》1987,79(1):1-8
Rats, isolated at mating (Day 1 of pregnancy), were submitted to either 8 h (8L:16D, Exp. I) or 14 h (14L:10D, Exp. II) of light daily with lights on from 12:00 h to 20:00 h and from 06:00 to 20:00 h respectively. In Exp. I, a single dose of RU 486 (10 mg in 0.2 ml ethanol) was given cutaneously at 08:00 h (Group A1), 12:00 h (Group B1), 19:00 h (Group C1) on Day 21 and at 08:00 h (Group D1) and 12:00 h (Group E1) on Day 22. In Exp. II, the same dose of RU 486 was given at 08:00 h (Group A2), 12:00 h (Group B2) and 19:00 h (Group C2) on Day 21. The solvent was given once at each of the preceding times to the control groups (T1 and T2) in both experiments. Groups T1 and T2 gave birth at two periods, the first on Day 22, the second on Day 23; the proportion of births during each of these periods depended on the light regimen (66.3% in 8L:16D; 50% in 14L:10D on Day 22). The distribution of births in Groups D1 and E1 treated on Day 22 were similar to their controls (T1). Rats treated on Day 21 (Groups A1, A2, B1, B2, C1, C2) gave birth over single periods on Day 22 after an interval correlated with the time of RU 486 administration. The earlier the treatment was given, the higher was the number of dead young and the lower the weight of live young 1 day after birth. These effects of prematurity did not impair further survival rates or weight at weaning.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献