Breaking in a new function for casein kinase 2

DNA damage response mechanisms help ensure the fidelity of chromosomal transmission, and the failure of such mechanisms might lead to premature aging and cancer. A new report has established that casein kinase 2 (CK2), a protein that functions in diverse cellular processes, controls the activity of the DNA repair protein XRCC1. These results indicate that CK2 is a key participant in the cellular response to DNA damage.     

Bear ye one another’s genetic burdens: the price of diversity and complexity

Genetic variability and diversity are the result of a mutation-selection balance that acts permanently within and between species. The presence of deleterious mutations is a necessary consequence of this process and thus “the price paid by a species for its capacity for further evolution” (Haldane 1937, Am Nat 71:337–349). Recent estimations of mutation rate in the human lineage has revived the debate as to whether the high number of deleterious mutations poses a severe problem for the future of mankind. Theoretical considerations allow a scenario in which the survival of the human race is maintained by truncation selection of deleterious mutations that removes as many mutations as appear anew in every generation. In this case our genetic burden is carried by those individuals that suffer a genetic death resulting from random distribution of deleterious alleles. Nevertheless, one has to ask whether the mutation rate may set absolute limits on the complexity of a species.     

Bayesian Estimation of Survival Functions under Stochastic Precedence

When estimating the distributions of two random variables, X and Y, investigators often have prior information that Y tends to be bigger than X. To formalize this prior belief, one could potentially assume stochastic ordering between X and Y, which implies Pr(X < or = z) > or = Pr(Y < or = z) for all z in the domain of X and Y. Stochastic ordering is quite restrictive, though, and this article focuses instead on Bayesian estimation of the distribution functions of X and Y under the weaker stochastic precedence constraint, Pr(X < or = Y) > or = 0.5. We consider the case where both X and Y are categorical variables with common support and develop a Gibbs sampling algorithm for posterior computation. The method is then generalized to the case where X and Y are survival times. The proposed approach is illustrated using data on survival after tumor removal for patients with malignant melanoma.     

Teacher-pupil interactions: a negotiation perspective*

L'analyse de l'interaction entre enseignant et élève dans une perspective de négociation augmenterait notre compréhension des processus par lesquels on arrive à des ententes collectives, si on y arrive dans ces situations. Ann de démontrer l'utilité de cette proposition, trois processus de négociation sont sélectionnés pour l'analyse de l'interaction entre enseignant et élève. Les processus sont les suivants: (1) les ambiguites et les désaccords autour desquels les négociations se déroulent, (2) les stratégies adoptées par les enseignants et par les élèves, (3) les aspects temporels de la négociation. Le texte conclut en indiquant des domaines de recherche que suggère cette perspective. It is proposed that analyses of teacher-pupil interactions from a negotiation perspective would increase our understanding of the processes whereby collective agreements are achieved, if at all, in these situations. To demonstrate the utility of this proposal this paper selects three processes of negotiation and analyses teacher-pupil interactions along these lines. The processes analysed are (1) the ambiguities and disagreements around which negotiations evolve, (2) the strategies employed by teachers and pupils, and (3) the temporal aspects of negotiation. Further areas of research suggested by this perspective are indicated.     

The McMaster Model of Family Functioning

The model of family functioning being presented is the product of over twenty years of research in clinical work with family units. A method of family therapy has been developed based upon this model and will be described in a future issue. The model utilizes a general systems theory approach in an attempt to describe the structure, organization, and transactional patterns of the family unit. It allows examination of families along the total spectrum ranging from healthy to severely pathological in their functioning. It is based upon a Judaeo-Christian value set, and allows attention to be paid to cultural differences and other issues of cultural relativity .     

DYSFUNCTIONAL MARITAL CONFLICT: AN INTEGRATIVE INTERPERSONAL-INTRAPSYCHIC MODEL*

An integrative interpersonal-intrapsychic model of dysfunctional marital conflict is presented and research support for the model is reviewed. The therapeutic applications of the model are discussed and illustrated with a clinical example.