Evidence-based Kernels: Fundamental Units of Behavioral Influence

This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behavior–influence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior

Resistance of dicot weeds to acetolactate synthase (ALS)-inhibiting herbicides in Australia

A biotype of Sonchus oleraceus L. and two bio types of Sisymbrium orientate Torn., SSO 3 and NSO 1, are the first dicot weeds in Australia to develop resistance to ALS‐inhibiting herbicides. The resistant biotypes had been exposed to va rying periods of selection with sulfonylurea her bicides. All three biotypes are resistant to a range of sulfonylurea and imidazolinone herbicides. The S. orientale biotypes are also resistant to the triazolopyrimidine herbicide, flumetsulam. LD50 ratios of resistant Sonchus oleraceus for sulfony lurea and imidazolinone herbicides are greater than 64‐fold and 4.5‐fold, respectively. GR50 ratios are greater than 9 for sulfonylureas and 7.4 for imazapyr. The LD50 ratios for both S. orien tale biotypes for chlorsulfuron, sulfometuron methyl, metsulfuron‐methyl, flumetsulam and imazethapyr are greater than 110‐, 15‐, 7‐, 24‐ and 29‐fold, respectively. All resistant biotypes are susceptible to MCPA, diuron and diflufenican, herbicides which do not inhibit ALS. Copyright © 1995, Wiley Blackwell. All rights reserve

Inheritance and mechanisms of resistance to herbicides inhibiting acetolacate synthase in Sonchus oleraceus L.

A biotype of Sonchus oleraceus L. (Compositae) has developed resistance to herbicides inhibiting acetolactate synthase (ALS) following field selection with chlorsulfuron for 8 consecutive years. The aim of this study was to determine the inheritance and mechanism of resistance in this biotype. Determination of ALS activity and inhibition kinetics revealed that Km and Vmax did not vary greatly between the resistant and susceptible biotypes. ALS extracted from the resistant biotype was resistant to five ALS-inhibiting herbicides in an in vitro assay. ALS activity from the resistant biotype was 14 19, 2, 3 and 3 times more resistant to inhibition by chlorsulfuron, sulfometuron, imazethapyr, imazapyr and flumetsulam, respectively, than the susceptible biotype. Hybrids between the resistant and a susceptible biotype were produced, and inheritance was followed through the F1, F2 and F3 generations. F1 hybrids displayed a uniform intermediate level of resistance between resistant and susceptible parents. Three distinct phenotypes, resistant, intermediate and susceptible, were identified in the F2 generation following chlorsulfuron application. A segregation ratio of 1:2:1 was observed, indicative of the action of a single, nuclear, incompletely dominant gene. F3 families, derived from intermediate F2 individuals, segregated in a similar manner. Resistance to herbicides inhibiting ALS in this biotype of S. oleraceus is due to the effect of a single gene coding for a resistant form of the target enzyme, ALS. © 1995 Springer-Verlag.P. Boutsalis, S. B. Powle

Comparison of cementing techniques of the tibial component in total knee replacement

A few studies have shown that cementing the stem enhances fixation of the tibial baseplate in total knee replacement (TKR). Even the horizontal technique has been shown to provide good fixation. We used radiostereometry to study migration of the tibial component in 30 knees operated with Profix TKR. The knees were randomised for either complete (both under the baseplate and around the stem) or horizontal (only under the baseplate) cementing of the tibial component. At two years the tibial baseplate rotated externally a median of 0.18° in the uncemented stem group and internally a median of 0.23° in the cemented stem group. The tibial baseplate subsided 0.14 mm in the cemented stem group, and no translation was seen in the uncemented stem group. The differences in migration were small and probably without clinical significance. The findings do not favour either of the cementing techniques in TKR