We examined childhood social withdrawal and aggression as predictive of adolescent maladaption, comparing and contrasting social and emotional outcomes associated with aggression and social withdrawal. We also focused on childhood social competence as a predictor of adolescent adaptation. The sample comprised 60 children for whom a complete data set was available at both ages 7 and 14 years. The predictors were aggregated measures of social withdrawal, aggression, and social competence derived from three sourcesbehavioral observations, peer assessments, and teacher ratings. The outcomes focused primarily on markers of internalizing and externalizing problems. The results indicated that childhood social withdrawal uniquely and significantly contributed to the prediction of adolescent loneliness, felt insecurity, and negative self-regard. Aggression predicted adolescent delinquent activity; social competence predicted felt security in the peer group and substance use in adolescence.

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ABSTRACI?Different organs of maize seedlings are known to contain different complements of NADH and NAD(P)H nitrate reductase (NR) activity.The study of the genetic programming that gives rise to such differences can be initiated by looking for genetic variants exhibiting different patterns of distribution of the above enzymes. We demonstrate in this work that scutella of very young maize seedlings contain NADH NR almost exclusively and that this activity is gradually replaced, as the seedling ages, with NAD(P)H NR. Leaves in the seedlings contain exclusively the NADH NR activity. A genetic variant is described that contains much reduced levels of NAD(P)H NR activity but not of NADH NR activity in the scutellum. This same variant exhibits a relatively low level of NAD(P)H NR but normal NADH NR activity in seedling root tips. These observations suggest that the genetic program used to specify the scutellar complement of NR activity shares some common components with the genetic program used to determine the young root tip complement of NR activities. Parts of regenerating callus at different stages of differentiation were examined to determine when the differences in NR complement begin to appear. The same pattern of NADH NR and NAD(P)H NR activities was found in unorganized as well as in organized callus, in recognizable root-like and even in green shoot-like material, both activities being present in all these tissues. An examination of the NR complement in different organs of a number of siblings originating from a cross involving transposon Mu-containing parents and having different levels of leaf NADH NR activity shows that the leaf NADH NR activity content and the scutellum NAD(P)H NR activity content are relatively independent of each other, indicating that the genetic programs specifying the NR content of these organs are not tightly coupled, if at all.(1) found that scutella contained both NADH and NAD(P)H activities, the latter using NADPH preferentially as electron donor, whereas leaves had no NAD(P)H NR activity. Redinbaugh and Campbell (7) examined young maize roots and found both NADH and NAD(P)H NR activities. On the basis of similarities in electron donor specificity, pH optimum, Stoke's radius, and Km for nitrate, these investigators concluded that the root NADH activity was identical with the leaf activity. Comparisons with NR activities in the scutellum were incomplete and revealed differences that were hard to interpret.Wells and Hageman (12) pointed out that phosphatases can complicate studies on the pyridine nucleotide specificity of NR because they can catalyze the conversion of NADPH to NADH. When studying NADH and NAD(P)H NR it is therefore necessary either to separate the enzymes physically, purify them away from contaminating phosphatases, inactivate the phosphatases, or continuously eliminate NADH from a NADPH dependent assay, in order to interpret the results in terms of the NADH or the NAD(P)H specific enzyme activity.In this study we show that scutella in very young maize seedlings ...

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The complicated current-voltage (flux flow) curves obtained from type 11 superconductors which show the peak effect are compared to the stress-strain curves of crystalline materials in which plastic flow a t low stresses is prevented by pinning of dislocations. It is suggested that the unstable step in the current-voltage characteristic is the result of "yield" and subsequent shearing of the fluxon lattice by dislocation motion.Die komplizierten Strom-Spannungs-(StromfluB-)Kurven, die an Typ-11-Supraleitern erhalten wurden, die den Peakeffekt zeigen, werden mit Spannungs-Dehnungskurven von kristallinem Material verglichen, in dem plastisches FlieBen bei niedrigen Spannungen durch festgehaltene Versetzungen verhindert wird. Es wird vorgeschlagen, daB die unstabile Stufe in der Strorn-Spannungskennlinie das Ergebnis des Nachgebens und der folgenden Scherung des FluBgitters durch Versetzungsbewegung ist.