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91.
K Holzmann B Klump F Borchard CJ Hsieh A Kühn V Gaco M Gregor R Porschen 《Canadian Metallurgical Quarterly》1998,76(1):1-6
CYP2C19 (S-mephenytoin hydroxylase) is a polymorphically expressed enzyme. Currently, two defective alleles are known--CYP2C19*2 and CYP2C19*3. The authors have developed an oligonucleotide ligation assay to detect these two alleles. This assay combines the hybridization of one common, biotinylated capture probe and two allele-specific probes to the target DNA, with the ability of a DNA ligase to distinguish mismatched nucleotides. The probes are only ligated if they are base paired correctly to the target strand. The biotin is bound to streptavidin, and all DNA not covalently bound to the biotin-labeled capture probe, is removed in a washing procedure. The allele-specific probes are labeled with either europium or samarium, and their emission can be measured simultaneously. The ratio between the emission separates the genotypes. This method was applied on DNA from 19 whites and 21 Vietnamese living in Denmark. All genotypes determined by the assay were consistent with the results from restriction enzyme cleavage. There were 12 poor metabolizers; 10 homozygous CYP2C19*2/CYP2C19*2, one heterozygous CYP2C19*2/CYP2C19*3, and one heterozygous CYP2C19*1/CYP2C19*2. The authors conclude that this assay is well-suited for a high throughput of samples in a routine laboratory. The finding of an apparently heterozygous CYP2C19*1/CYP2C19*2 poor metabolizer, confirms that there are still unknown mutations in CYP2C19. 相似文献
92.
93.
Pigeons were trained on a psychophysical choice task to discriminate between 2 fixed ratios and tested with probe ratios intermediate to the training requirements. Absolute and relative ratio size were varied over conditions. In a final condition, Ss were transferred from the number-based discrimination to a time-based discrimination. The times taken to emit the ratios were recorded, and ratio value and ratio time were used to predict choice in a multiple regression analysis. Psychophysical analyses of the response number dimension suggested a scalar counting principle of numerosity discrimination, similar to that found with temporal dimensions. The multiple regression analysis indicated that both number and time contributed to the discrimination of ratio value. The results of the transfer test indicated individual differences in the degree to which responding was controlled by temporal vs numerical factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
94.
Animal reaming research has increasingly used complex stimuli that approximate natural objects, events, and locations, a trend that has accompanied a resurgence of interest in the role of cognitive factors in reaming. Accounts of complex stimulus control have focused mainly on cognitive mechanisms and largely ignored the contribution of stimulus information to perception and memory for complex events. It is argued here that research on animal reaming stands to benefit from a more detailed consideration of the stimulus and that James Gibson's stimulus-centered theory of perception serves as a useful framework for analyses of complex stimuli. Several issues in the field of animal reaming and cognition are considered from the Gibsonian perspective on stimuli, including the fundamental problem of defining the effective stimulus. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
95.
Gregor Snelting 《Informatik-Spektrum》1998,21(5):273-276
Zusammenfassung Der folgende Beitrag ist ein Pl?doyer für st?rkere methodische Standards in der Softwaretechnologie. Nicht immer werden
wissenschaftstheoretischen Grunds?tze beachtet wie das Prinzip, da? Aussagen falsifizierbar sein sollten. Dies scheint die
These der sog. Konstruktivisten zu best?tigen, da? n?mlich „objektive Wahrheiten“ in Wirklichkeit soziale Konstrukte seien.
Der Beitrag pl?diert deshalb für eine st?rkere empirische Fundierung der Softwaretechnologie.
Eingegangen in überarbeiteter Form am 07.09.1998 相似文献
96.
One thousand black African and 380 white Caucasian patients over the age of 50 were examined for evidence of age-related macular changes, namely, drusen, pigment epithelial atrophy, and disciform macular degeneration. Drusen and pigment epithelial changes were found to occur twice as commonly in Caucasians as in Africans; there was a much greater difference in the prevalence of disciform macular degeneration between the 2 groups. The cause of the differences remains unexplained. 相似文献
97.
98.
Alternately isolated and crowded 2 groups of 12 male Long-Evans rats. Order of housing and familiarity of the Ss with the test apparatus were also varied systematically. Ss were deprived of food, trained to bar press, and allowed to compete in pairs for sugar water in a Skinner box. Isolated pairs produced more agonistic and contact behaviors and fewer bar presses than did crowded pairs. Weight was found to increase more rapidly during free feeding when animals were isolated. Familiarity of only 1 isolate with the testing environment led to the display of less aggression than was observed in other isolate conditions. (20 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
99.
European Food Research and Technology - Red pepper is a very important Hungarian spice which is widely used for seasoning food at home as well as abroad. During its production there is a... 相似文献
100.
Using mass, momentum and energy balances, a theory is developed which permits the calculation of the viscous and thermal attenuation of sonic waves in gas—solid suspensions. Equations are obtained giving the viscous and thermal attenuation coefficients as explicit functions of the solid particle diameter, the porosity, the gas viscosity, the specific heat of the solid material, the temperature of the suspension, the densities and heat conductivities of gas and solid, and the sound frequency. Experimental results agree well with the theory. 相似文献