Mathematical abilities were tested in people with Prader-Willi syndrome (PWS), using a series of basic mathematical tasks for which normative data are available. The difference between the deletion and the disomy variants of this condition was explored. While a wide phenotypic variation was found, some basic findings emerge clearly. As expected…

Mutations in the human X-linked cyclin-dependent kinase-like 5 ("CDKL5") gene have been shown to cause infantile spasms as well as Rett syndrome (RTT)-like phenotype. To date, less than 25 different mutations have been reported. So far, there are still little data on the key clinical diagnosis criteria and on the natural history of…

Recently, there has been growing emphasis on supporting robust learning within intelligent tutoring systems, assessed by measures such as transfer to related skills, preparation for future learning, and longer term retention. It has been shown that different pedagogical strategies promote robust learning to different degrees. However, the student…

There is limited evidence surrounding the ability of families of children with autism spectrum disorders to access and implement recommended interventions following diagnosis. The distress a family may encounter with regard to inability to access recommended services is also poorly understood. In this study, we present preliminary data regarding…

Background: Attention-deficit/hyperactivity disorder (ADHD) symptoms and mathematics ability are associated, but little is known about the genetic and environmental influences underlying this association. Methods: Data came from more than 6,000 twelve-year-old twin pairs from the UK population-representative Twins Early Development Study. Parents…

Background: Presence of an autism spectrum disorder is a risk factor for development of self-injurious behaviour (SIB) exhibited by individuals with developmental disorders. The most salient SIB risk factors historically studied within developmental disorders are level of intellectual disability, communication deficits and presence of specific…

Science teachers frequently select science news articles as supplementary teaching materials; however, the literature indicates that students encounter difficulties in examining and evaluating the news content and textual elements. This paper reports an instructional strategy of utilizing science news articles and investigates its effectiveness in…

Purpose: The purpose of this study was to examine the association of speech-sound disorders (SSD) with symptoms of attention-deficit/hyperactivity disorder (ADHD) by the severity of the SSD and the mode of transmission of SSD within the pedigrees of children with SSD. Participants and Methods: The participants were 412 children who were enrolled…

The goal of this study was to examine how different types of social experiences in kindergarten relate to Grade 1 academic achievement, while controlling for possible genetic and shared environmental influences through the use of the monozygotic (MZ) twin difference method. Social experiences in kindergarten included relationship quality with the…

Bipolar disorder is frequently clinically diagnosed in youths who do not actually satisfy Diagnostic and Statistical Manual of Mental Disorders (4th ed., text revision; DSM-IV-TR; American Psychiatric Association, 1994) criteria, yet cases that would satisfy full DSM-IV-TR criteria are often undetected clinically. Evidence-based assessment methods…

We present one of the first behavior-genetic studies of individual differences in school students' levels of achievement in instructed second language acquisition (ISLA). We assessed these language abilities in Australian twin pairs (maximum N pairs = 251) by means of teacher ratings, class rankings, and self-ratings of proficiency, and used the…

Self-injurious behavior (SIB) is a devastating condition associated with intellectual and developmental disabilities (IDD). Efforts to understand its development are focused on early childhood when the behavior first emerges. Limited prevalence data on SIB during early childhood are currently available. The purpose of this study was to determine…

Background: Attention deficit hyperactivity disorder (ADHD) and reading disability commonly co-occur because of shared genetic risk factors. However, the stability and change of these genetic influences and the predictive relationships underlying this association longitudinally remain unclear. Methods: ADHD symptoms and reading were assessed as…

Mating between closely related individuals often causes reduced fitness, which is termed "inbreeding depression". Inbreeding is, therefore, a threat towards the persistence of animal and plant populations. Here we present methods and results from a practical for high-school and first-year university students and discuss learning outcomes…

RNA hypermodifications near the anticodon of tRNA are fundamental for the efficiency and fidelity of protein synthesis. Dimethylallyltransferase (DMATase) catalyzes transfer of a dimethylallyl moiety from dimethylallyl pyrophosphate to N6 of A37 in certain tRNAs. We first determined the crystal structures of "Pseudomonas aeruginosa" DMATase.…