Romantic relationship involvement has repeatedly been associated with the incidence of externalizing behavior problems, but little is known about the nature and developmental significance of this relation. The current study extends previous research by investigating whether and through what processes romantic relationships distinctively predict…

There are several self-report measures of psychopathy, most of which use a two-factor structure. There is debate regarding the convergence of these factors, particularly with regard to Factor 1 (F1), which is related to the interpersonal and affective aspects of psychopathy; Factor 2 (F2) is related to the social deviance associated with…

Background: The parent-child relationship is considered important for children's future conscience, and conscience is seen as protecting them from disruptive behavior problems, but specific mechanisms of this developmental process are rarely studied. Methods: This multi-trait multi-method study examined, in a longitudinal design, paths linking…

Background: Inverse associations of fetal growth with behavioural problems in childhood have been repeatedly reported, suggesting long-term effects of the prenatal developmental environment on behaviour later in life. However, no study so far has examined effects on temperament and potential developmental pathways. Temperamental traits may be…

A model of treatment acceptability is proposed that distributes overall treatment acceptability into three separate categories of influence. The categories are comprised of societal influences, consultant influences, and influences associated with consumers of treatments. Each of these categories are defined and their inter-relationships within…

In order to determine the nature of naturalistic learners' difficulty with grammatical gender in a complex morphological system, the longitudinal production data of an early naturalistic L1-Italian and L1-Turkish learner who are acquiring German are examined in light of current theories of gender within Chomsky's (1995) Minimalist Program. After…

It is generally believed that students should use multiple representations in solving certain physics problems, and earlier work in PER has begun to outline how experts and novices differ in their use of multiple representations. In this study, we build on this foundation by interviewing expert and novice physicists as they solve two types of…

This study used latent profile modeling (LPA) with a community sample that included an enriched sampling of children (aged 6-11) diagnosed with attention deficit/hyperactivity disorder (ADHD) (N = 271). Six classes of ADHD emerged from our LPA; only 17% of children fell into a class without significant co-occurring symptoms. In addition, nearly…

Relativistic hydrodynamics is essential to our current understanding of nucleus-nucleus collisions at ultrarelativistic energies (current experiments at the Relativistic Heavy Ion Collider, forthcoming experiments at the CERN Large Hadron Collider). This is an introduction to relativistic hydrodynamics for graduate students. It includes a detailed…

This article describes the design and evaluation approaches to address the complexity posed by systems change initiatives. The role of evaluations in addressing the following issues is briefly reviewed: moving from strategic planning to implementation, impacts on system-level coordination, anticipated timeline of impact, and individual level…

We present a study of the ascending vertical motion of a self-propelled body under a uniform gravitational field suffering the action of two different types of air friction forces: linear on the velocity, which is valid for slowly moving bodies, and quadratic on the velocity. We study the special case where the thrust force is a decreasing…

This study investigated sleep of children with autism and developmental regression and the possible relationship with epilepsy and epileptiform abnormalities. Participants were 104 children with autism (70 non-regressed, 34 regressed) and 162 typically developing children (TD). Results suggested that the regressed group had higher incidence of…

We solve for the motion of an object with initial velocity v[subscript 0] and subject only to the combined drag of forces linear and quadratic in the velocity. This problem was treated briefly by Newton, after he developed a theoretical argument for the quadratic term, which we now know is characteristic of turbulent flow. Linear drag introduces a…

This study investigated quantitative and qualitative changes in mental rotation performance and solution strategies with a focus on sex differences. German children (N = 519) completed the Mental Rotations Test (MRT) in the 5th and 6th grades (interval: one year; age range at time 1: 10-11 years). Boys on average outperformed girls on both…

It is interesting to note how technology has changed the way that people communicate with one another. Several of the major historical developments of communication are: (1) language; (2) alphabet; and (3) writing. These early forms of communication enabled humans to go beyond verbal and symbolic communication and on to such technologies as the…