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M W Davidson

Publications and source records attributed to M W Davidson.

25 records · Page 2Linked to original sources
PubMed1977

The interaction of plant alkaloids with DNA. II. Berberinium chloride.

The interaction of berberinium chloride with DNA has been investigated using spectrophotometry, viscometric titrations with sonicated and closed circular superhelical DNA, and flow polarized fluorescence. The binding results for berberinium were found to fit the neighbor exclusion model. The two viscometric titrations and flow polarized fluorescence results exclusion model. The two viscometric titrations and flow polarized fluorescence results also indicated that berberinium binds to DNA by intercalation. Titration of sonicated DNA with berberinium produced viscosity increases which were less than those obtained with quinacrine and the titration of superhelical DNA indicated a significantly smaller unwinding angle for intercalation of berberinium than for quinacrine. These results can be interpreted in terms of a model in which (i) berberinium is partially intercalated into the double helix, or (ii) the alkaloid is more completely intercalated into the double helix, but causes bending of the helix due to the slight nonplanarity of the berberinium ring system, or (iii) a combination of (i) and (22).

Berberine↗
PubMedDate not supplied

Are teachers of children and young adolescents responsive to suicide prevention training modules? Yes.

Both before and after a 1-hour suicide prevention training module, 75 elementary teachers-in-training read a 4-sentence vignette about a suicidal student ("Pat"), then completed 8 questions about their responses. Compared with pretraining, at post-training these teachers were more likely to say that they would send or escort Pat to the counselor's office, use written or verbal no-suicide agreements, call Pat's parents, believe Pat to be serious rather than simply seeking attention, and feel comfortable handling a similar situation. Increased proactive attitudes after one hour of training imply that teachers would benefit from periodic suicide awareness and prevention training modules.

Adolescent↗