PubMed Health⌕ Search

Biomedical subjects

L Nicholas

Publications and source records attributed to L Nicholas.

At least 19 recordsLinked to original sources
PubMed1986

Allele frequency distribution of two highly polymorphic DNA sequences in three ethnic groups and its application to the determination of paternity.

The allele frequency distribution of two highly polymorphic DNA sequences has been determined in three ethnic groups (American blacks, Caucasoids, and Hispanics) from the New York metropolitan area. The two loci examined were D14S1 and the flanking region of HRAS-1. The former was analyzed in EcoRI-digested DNA and the latter in TaqI-digested DNA. Approximately 700 DNA samples from unrelated individuals were digested with each of these enzymes and hybridized with the appropriate recombinant DNA probes. The size range of the DNA fragments detected for the D14S1 polymorphism varied from 14.3 to 32.5 kilobase pairs (kbp). The number of alleles identified under the experimental conditions used in this study was more than 40. For the HRAS-1 polymorphism, we have detected 18 different alleles varying in size from 1.85 to 4.5 kbp. Although the number of alleles observed in the different ethnic groups examined was very similar, the relative frequency of them varied significantly. The results presented here can be used as the basis for the utilization of DNA RFLP for the purpose of identity, such as paternity determinations or the analysis of forensic material. As an example, we have compared the results of paternity cases analyzed by HLA typing with those obtained with these two DNA polymorphisms. The values of paternity index and power of exclusion were similar by both procedures.

Alleles↗
PubMed1979

Effects of clinician behaviors on acceptability of patients' responses in aphasia treatment sessions.

Records of the content of 40 videotaped samples of aphasia treatment sessions were prepared. These records were analyzed to determine (a) whether certain clinician behaviors and task characteristics are related to the occurrence of patient error responses in speech and language treatment sessions for aphasic individuals, and (b) whether "errors generate errors"; that is, whether error responses tend to occur in clusters rather than being distributed uniformly throughout the treatment session. The results of these analyses indicated that a number of event categories were significantly related to the occurrence of unacceptable patient responses. These results suggest that certain clinician behaviors generate patient error responses and also that clinicians tend to response to patient errors in characteristic ways. An analysis of these results also confirmed that unacceptable patient responses tended to occur in clusters.

Aphasia↗