Genetic and Environmental Influences on Self-Control: Assessing Self-Control with the ASEBA Self-Control Scale

This study used a theoretically-derived set of items of the Achenbach System of Empirically Based Assessment to develop the Achenbach Self-Control Scale (ASCS) for 7–16 year olds. Using a large dataset of over 20,000 children, who are enrolled in the Netherlands Twin Register, we demonstrated the psychometric properties of the ASCS for parent-, self- and teacher-report by examining internal and criterion validity, and inter-rater and test–retest reliability. We found associations between the ASCS and measures of well-being, educational achievement, and substance use. Next, we applied the classical twin design to estimate the genetic and environmental contributions to self-control. Genetic influences accounted for 64–75% of the variance in self-control based on parent- and teacher-report (age 7–12), and for 47–49% of the variance in self-control based on self-report (age 12–16), with the remaining variance accounted by non-shared environmental influences. In conclusion, we developed a validated and accessible self-control scale, and show that genetic influences explain a majority of the individual differences in self-control across youth aged 7–16 years.     

Foot and leg problems are important determinants of functional status in community dwelling older people

Purpose.?To determine whether foot and leg problems are independently associated with functional status in a community sample of older people after adjusting for the influence of socio-demographic, physical and medical factors.

Method.?Data were analysed from the Health Status of Older People project, a population-based study involving a random sample of 1000 community-dwelling people aged 65?–?94 years (533 females, 467 males, mean age 73.4 years?±?5.87). A structured interview and brief physical examination were used to investigate the associations between self-reported foot and leg problems and functional status. Functional status was assessed using: (i) timed ‘Up & Go’ test, (ii) self-reported difficulty climbing stairs, (iii) self-reported difficulty walking one kilometer, (iv) self-reported difficulty performing instrumental activities of daily living (IADLs), and (v) self-reported history of one or more falls in the previous 12 months. These associations were then explored after adjusting for socio-demographic, physical and medical factors.

Results.?Thirty-six percent of the sample reported having foot or leg problems. Univariate analyses revealed that people with foot and leg problems were significantly more likely to exhibit poorer functional status in all parameters measured. After adjusting for socio-demographic, physical and medical factors, foot and leg problems remained significantly associated with impaired timed ‘Up & Go’ performance (OR?=?2.15, 95%CI 1.55?–?2.97), difficulty climbing stairs (OR?=?3.33, 95%CI 1.98?–?5.61), difficulty walking one kilometer (OR?=?3.13, 95%CI 2.09?–?4.69), and history of falling (OR?=?1.73, 95%CI 1.26?–?2.37).

Conclusions.?Foot and leg problems are reported by one in three community-dwelling people aged 65 years and older. Independent of the influence of age, gender, common medical conditions and other socio-demographic factors, foot and leg problems have a significant impact on the ability to perform functional tasks integral to independent living.     

Pseudoepidemic of Aspergillus niger infections traced to specimen contamination in the microbiology laboratory

We report a pseudo-outbreak of Aspergillus niger that followed building construction in our clinical microbiology laboratory. Because outbreaks of invasive aspergillosis have been linked to hospital construction, strategies to minimize dust in patient care areas are common practice. We illustrate that the impact of false-positive cultures on patient care should compel laboratories to prevent specimen contamination during construction.     

Beta-chemokines inhibit activation-induced death of lymphocytes from HIV-infected individuals

The present study investigates the role of the HIV-suppressive beta-chemokines macrophage inflammatory protein (MIP)-1alpha, MIP-1 and RANTES in activation-induced cell death (AICD). A pool of these beta-chemokines reduced anti-CD3-induced apoptosis of T cell blasts from healthy blood donors in a dose-dependent manner. Although the pooled beta-chemokines were more effective, the inhibitory effect could also be mediated by each of the individual chemokines and was blocked by neutralizing anti-chemokine antibodies. The beta-chemokines also inhibited pokeweed mitogen/staphylococcal enterotoxin B-induced T lymphocyte apoptosis in 33/49 HIV-infected (HIV+) individuals. This anti-apoptotic effect was not correlated with the patients' CD4 T cell counts. beta-chemokines did not lead to altered secretion of IL-2, IL-4, IFN-gamma or IL-10 in response to activation stimuli in either normal T cell blasts or peripheral blood mononuclear cells from HIV+ individuals. Co-incubation with beta-chemokines did not inhibit anti-CD3-induced expression of cell surface Fas ligand, nor did it alter levels of the death receptor Fas or Bcl-2 in T cell blasts, suggesting that the beta-chemokines are blocking AICD downstream of Fas. These observations indicate that beta-chemokines may play a novel role as modulators of AICD, in addition to their known role as chemoattractants and inhibitors of HIV replication.     

BOLD repetition decreases in object-responsive ventral visual areas depend on spatial attention

Functional imaging studies of priming-related repetition phenomena have become widely used to study neural object representation. Although blood oxygenation level-dependent (BOLD) repetition decreases can sometimes be observed without awareness of repetition, any role for spatial attention in BOLD repetition effects remains largely unknown. We used fMRI in 13 healthy subjects to test whether BOLD repetition decreases for repeated objects in ventral visual cortices depend on allocation of spatial attention to the prime. Subjects performed a size-judgment task on a probe object that had been attended or ignored in a preceding prime display of 2 lateralized objects. Reaction times showed faster responses when the probe was the same object as the attended prime, independent of the view tested (identical vs. mirror image). No behavioral effect was evident from unattended primes. BOLD repetition decreases for attended primes were found in lateral occipital and fusiform regions bilaterally, which generalized across identical and mirror-image repeats. No repetition decreases were observed for ignored primes. Our results suggest a critical role for attention in achieving visual representations of objects that lead to both BOLD signal decreases and behavioral priming on repeated presentation.