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L Kruse

Publications and source records attributed to L Kruse.

15 recordsLinked to original sources
PubMed1997

Detection of a single base exchange in PCR-amplified DNA fragments using agarose gel electrophoresis containing bisbenzimide-PEG.

Using PCR fragments of known sequences derived from isolates of two related fungal species, simple submarine electrophoresis in agarose gels containing a bisbenzimide-PEG conjugate (H.A.-Yellow) has been shown to be capable of distinguishing DNA fragments 567 bp long which differ by as little as a single base change. However, only changes affecting bisbenzimide binding sites (which consist of at least four consecutive A/T bases) alter mobility; other changes are ineffective. A second ligand (H.A.-Red) with high G/C specificity is suggested which may be as effective in detecting other sequence changes.

Bisbenzimidazole↗
PubMed1995

Improving food frequency questionnaires: a qualitative approach using cognitive interviewing.

In an attempt to improve data quality and ease of administration of standard self-administered food frequency questionnaires, various alternative approaches were tried for inquiring about frequency of consumption, portion size, seasonal intake, and food preparation. Evaluation consisted of a cognitive interviewing method in which respondents verbalize their thought process while completing several variations of a questionnaire. Interviewers observed and asked follow-up probe questions to evaluate problems or inconsistencies verbalized by respondents. Consensus and judgment by interviewers and observers suggested several problematic features of food frequency questionnaires: formatting of questions about frequency and portion size; computing average frequencies for aggregated food items or for foods eaten seasonally; comprehension of many items; and ordering of foods. These findings led to cognitive refinement and innovations, which included detailed questions regarding preparation or use of low-fat varieties or other alternatives to help better describe specifics of intake for some foods; questions on seasonal intake for several foods; inclusion of portion size ranges; and additional response categories for frequency of intake. Cognitive interviewing is an important step in pinpointing cognitive problems in dietary questionnaires.

Aged↗
PubMed1994

Memory through metamorphosis in normal and mutant Drosophila.

To establish that a stable, long-lasting form of memory exists in Drosophila, we trained third-instar larvae by electroshocking them in the presence of a specific odor using a Pavlovian conditioning procedure. We show that conditioned odor avoidance produced in larvae still was present in adults 8 d later. Such memory through metamorphosis was specific to the temporal pairing of odor and shock; presentations of odors alone or shock alone did not produce a change. Thus, the memory involved associative processes. We also show that similar training of the single-gene memory mutants dunce and amnesiac did not yield any detectable learning in larvae or memory retention in adults, suggesting that these mutations interfere with long-term memory (LTM) formation even if LTM is induced independently of earlier memory retention processes.

Animals↗
PubMed1993

A highly conserved repetitive sequence from Physarum polycephalum contains nucleotide arrangements similar to replicator sequences.

An interspersed repetitive sequence from Physarum polycephalum has been cloned and analysed. The 394 bp sequence is highly conserved and contains several homopolymeric (dA)-(dT) tracts capable of forming bent DNA structures and a 10/11 match to the yeast-ARS-consensus sequence. The repetition frequency of the described sequence is about 3000 to 7000, a number that would fit with the distribution of replicator segments in Physarum.

Animals↗
PubMed1983

[Doppler sonography of the extracranial cerebral arteries: primarily a didactic problem].

Three graduate students were systematically trained to apply continuous wave Doppler sonography for non-invasive screening of the extracranial brain-supplying arteries. The method described by Büdingen et al. (1982) was used. Each student was trained on 100 patients by means of instruction and supervision. 50% of the patients had vascular lesions. In the course of the training period the students were individually tested on fourty-eight (4 x 12) selected patients having vascular lesions of varying site and degree. The students' diagnostic progress was compared with the author's own performance on initial self-training used cerebral angiography as a reference. All measurable parameters of the students' performance considerably improved during the training period. At the end of the course the trainees were accurate in the diagnosis of carotid lesions but still had considerable difficulties in assessing the degree of stenoses as well as in recognizing multiple lesions, and in particular lesions within the subclavian-vertebral circulation. It is concluded that training on only 100 patients is insufficient. Nevertheless the study clearly demonstrated the value of instruction through an experienced examiner, including immediate feed-back on the performance in any individual case examined. This kind of training has proved to be definitely superior to, and more efficient than self-training as exclusively based on checking the diagnosis by angiography.

Adult↗