A cluster randomised controlled trial of an intervention based on the Health Action Process Approach for increasing fruit and vegetable consumption in Iranian adolescents

Objective: To evaluate an intervention programme based on the Health Action Process Approach and designed to increase the intake of fruit and vegetables (F&V) among Iranian adolescents aged 13 to 18.

Design: A randomised controlled trial with three arms examined the short- (1 month) and long-term (6 months) effects of the intervention. There were two intervention groups (one included adolescents only [A group; n = 510]; the second included mothers and adolescents [M + A group; n = 462]) and a control group (n = 483). All participants were recruited from schools.

Main outcome measures: Social cognitions, self-regulatory processes and F&V intake.

Results: The intervention led to an increase in F&V intake for adolescents in the short and long terms. Adolescents in the M + A group increased their F& V intake more than adolescents in the A group. Outcome expectancies, self-monitoring, intentions, action and coping planning, perceived social support and behavioural automaticity mediated the effect of the intervention on F&V intake.

Conclusion: The theory-based intervention led to an increase in F&V intake and promoted more positive social cognitions and self-regulatory processes among Iranian adolescents. The findings also provide evidence that involving mothers in an intervention can confer additional benefit.     

THE EFFECTS OF A GOOD-BEHAVIOR CONTRACT ON THE CLASSROOM BEHAVIORS OF SIXTH-GRADE STUDENTS1

The effects of a good-behavior contract on the on-task behavior, disruptive behavior, daily assignment completion, and weekly grades of four sixth-grade students were examined in a public school classroom. The contract consisted of presenting the students with a list of good conduct and assignment completion goals and a list of disruptive behaviors coupled with a list of rewards and penalties that could be earned. The rewards and penalties made use of existing facilities and classroom privileges. At the beginning of each morning work period, the teacher negotiated the good-behavior contract with each experimental subject. During the negotiations, the teacher emphasized student self-management and encouraged each student to earn a reward by achieving the good-conduct goals and completing the contract assignments. An isolated work area was provided to allow students the opportunity to remove themselves from their desks for a fixed period of 15 min. At the end of the work period, the teacher determined whether each student earned a choice of reward or penalty dependent on assignment completion and whether the teacher had observed disruptive behaviors. Thus, the contract permitted the student to negotiate the goal behaviors and contingencies with the teacher. Throughout the study, the students were in agreement with the teacher on whether a choice of reward or penalty had been earned. The contract was introduced for different children at different times, constituting a multiple-baseline analysis. On-task behavior and daily assignment completion increased, weekly grades were higher, and disruptive behavior decreased when the contract was in effect. Three contrast subjects were selected from the class as model students who consistently produced acceptable assignments and who did not engage in high rates of disruptive and/or off-task behaviors. When the contract was in effect for the experimental subjects, their performance compared favorably with the contrast subjects, who never received the daily contract. The results demonstrated that the contract was effective within the confines of the facilities and contingencies readily available in a public school classroom setting.     

Egocentric search for disappearing objects in domestic dogs: evidence for a geometric hypothesis of direction

In several species, the ability to locate a disappearing object is an adaptive component of predatory and social behaviour. In domestic dogs, spatial memory for hidden objects is primarily based on an egocentric frame of reference. We investigated the geometric components of egocentric spatial information used by domestic dogs to locate an object they saw move and disappear. In experiment 1, the distance and the direction between the position of the animal and the hiding location were put in conflict. Results showed that the dogs primarily used the directional information between their own spatial coordinates and the target position. In experiment 2, the accuracy of the dogs in finding a hidden object by using directional information was estimated by manipulating the angular deviation between adjacent hiding locations and the position of the animal. Four angular deviations were tested: 5, 7.5, 10 and 15°. Results showed that the performance of the dogs decreased as a function of the angular deviations but it clearly remained well above chance, revealing that the representation of the dogs for direction is precise. In the discussion, we examine how and why domestic dogs determine the direction in which they saw an object disappear.     

Effectiveness of dialectical behaviour therapy for borderline personality disorder in an inpatient setting

This study evaluates the effectiveness of dialectical behaviour therapy (DBT) for borderline personality disorder (BPD) in an unselected, comorbid population seeking 3-month inpatient treatment. We studied 50 consecutively admitted individuals (44 women, six men) with BPD as defined by DSM-IV at three time points (at admission, at discharge, and at the 15-month follow-up). For the clinical diagnoses, we used the Structured Clinical Interview for DSM-IV (SCID) and compared the frequencies of comorbid axis I and axis II disorders at admission and at the 15-month follow-up. Overall, participants showed a high degree of comorbidity. Psychopathology was significantly reduced at post-treatment and at follow-up. Effect sizes for outcome measures were within the range of those of previous studies. Our findings support the notion that the results of the DBT efficacy research can be generalized to an inpatient setting and to patients with BPD disorder with high comorbidity.     

Before they're victims: Rethinking youth‐targeted relationship abuse prevention in Australia

Intimate partner abuse (or relationship abuse) against women is recognised as a major public health issue. A number of relationship abuse prevention programs targeted at youth have been developed in Australia. These programs are generally aimed at changing attitudes, and take the stance that girls should not be viewed as being responsible for protecting themselves against violence. In this paper it is argued that the current, dominant focus on physical violence, over other forms of relationship abuse, limits the potential effectiveness of programs that might otherwise help young people to resist the development of abusive dynamics. It is also argued that programs that presume a victim status for girls and a perpetrator status for boys are both inconsistent with contemporary evidence and unlikely to empower young people at risk of chronic perpetration and/or victimisation to avoid such outcomes. A dyadic slippery slope model of chronic relationship abuse is proposed and new directions for prevention research in this area are suggested.     

Self-assembly-assisted growth of two-dimensional Penrose tiling

An algorithm for the growth of two-dimensional Penrose tiling, based on symmetry operations on a seed rhombus, is discussed and demonstrated. Independent of empirical matching rules, as suggested by Penrose [Bull. Inst. Math. Appl. 10 266 (1974)], and also overcoming the scaling-down operation, as proposed by Ramachandrarao et al. (Acta Crystallogr. A 47 210 (1991)], the present algorithm follows a mechanism akin to self-assembly and can be continued ad infinitum.