Examining relations between performance on non-verbal executive function and verbal self-regulation tasks in demographically-diverse populations.

Self-regulation is a widely studied construct, generally assumed to be cognitively supported by executive functions (EFs). There is a lack of clarity and consensus over the roles of specific components of EFs in self-regulation. The current study examines the relations between performance on (a) a self-regulation task (Heads, Toes, Knees Shoulders Task) and (b) two EF tasks (Knox Cube and Beads Tasks) that measure different components of updating: working memory and short-term memory, respectively.

Differential toxicity of silver and titanium dioxide nanoparticles on Drosophila melanogaster development, reproductive effort, and viability: size, coatings and antioxidants matter.

Silver and titanium dioxide nanoparticles are known to induce oxidative stress in vitro and in vivo. Here we test if they impact development, mating success, and survivorship in Drosophila melanogaster, and if so, if these effects are reversible by antioxidants. Ingestion of nanotitanium dioxide during the larval stage of the life cycle showed no effects on development or survivorship, up to doses of 200 μg mL(-1).

Tubulin evolution in insects: gene duplication and subfunctionalization provide specialized isoforms in a functionally constrained gene family.

Background: The completion of 19 insect genome sequencing projects spanning six insect orders provides the opportunity to investigate the evolution of important gene families, here tubulins. Tubulins are a family of eukaryotic structural genes that form microtubules, fundamental components of the cytoskeleton that mediate cell division, shape, motility, and intracellular trafficking. Previous in vivo studies in Drosophila find a stringent relationship between tubulin structure and function; small, biochemically similar changes in the major alpha 1 or testis-specific beta 2 tubulin protein render each unable to generate a motile spermtail axoneme.

Inhalation method for delivery of nanoparticles to the Drosophila respiratory system for toxicity testing.

The growth of the nanotechnology industry and subsequent proliferation of nanoparticle types present the need to rapidly assess nanoparticle toxicity. We present a novel, simple and cost-effective nebulizer-based method to deliver nanoparticles to the Drosophila melanogaster respiratory system, for the purpose of toxicity testing. FluoSpheres, silver, and CdSe/ZnS nanoparticles of different sizes were effectively aerosolized, showing the system is capable of functioning with a wide range of nanoparticle types and sizes.

Functional constraint underlies 60 million year stasis of Dipteran testis-specific beta-tubulin.

How do proteins evolve while maintaining their function? Previous studies find a highly stringent structure/function relationship between the Drosophila melanogaster testis-specific tubulin beta2 and the spermtail axoneme, such that small changes in the beta2 protein render it unable to generate a motile axoneme. This raises the question, how does beta2 evolve while maintaining its function? To address this question we cloned full- and partial-length beta2 sequences from 17 species of Drosophila and Hirtodrosophila flies spanning 60 Myr of evolution. Not a single amino acid difference is coded among them-beta2 maintains its function by not evolving.

The best of all worlds or the best possible world? Developmental constraint in the evolution of beta-tubulin and the sperm tail axoneme.

Through evolutionary history, some features of the phenotype show little variation. Stabilizing selection could produce this result, but the possibility also exists that a feature is conserved because it is developmentally constrained--only one or a few developmental mechanisms can produce that feature. We present experimental data documenting developmental constraint in the assembly of the motile sperm tail axoneme.