Sound communication inNezara viridula (L.) (Heteroptera: Pentatomidae): Further evidence that signal transmission is substrate-borne

We investigated the sound communication associated with mating inNezara viridula (L.) to clarify conflicting reports on the medium through which acoustic signals are borne. Recordings made from virgin pairs ofN. viridula during precopulatory and compulatory behaviour have revealed that signals transmitted as vibrations through the substrate are a more likely means of communication than signals transmitted by a radiation of sound pressure waves through the air (at least in Australian populations). We present evidence (additional to that already in the literature) that air-borne acoustics are an unlikely mechanism of sexual communication in this species. Specifically, the recorded pulse train patterns showed no consistency or repeatability in relation to different stages of mating behaviour. In contrast, frequency spectrograms of substrate-borne signals reveal repeatable patterns that do correspond with the stage of mating behaviour.     

Nanoparticle-based drug delivery: case studies for cancer and cardiovascular applications

Nanoparticles (NPs) comprised of nanoengineered complexes are providing new opportunities for enabling targeted delivery of a range of therapeutics and combinations. A range of functionalities can be included within a nanoparticle complex, including surface chemistry that allows attachment of cell-specific ligands for targeted delivery, surface coatings to increase circulation times for enhanced bioavailability, specific materials on the surface or in the nanoparticle core that enable storage of a therapeutic cargo until the target site is reached, and materials sensitive to local or remote actuation cues that allow controlled delivery of therapeutics to the target cells. However, despite the potential benefits of NPs as smart drug delivery and diagnostic systems, much research is still required to evaluate potential toxicity issues related to the chemical properties of NP materials, as well as their size and shape. The need to validate each NP for safety and efficacy with each therapeutic compound or combination of therapeutics is an enormous challenge, which forces industry to focus mainly on those nanoparticle materials where data on safety and efficacy already exists, i.e., predominantly polymer NPs. However, the enhanced functionality affordable by inclusion of metallic materials as part of nanoengineered particles provides a wealth of new opportunity for innovation and new, more effective, and safer therapeutics for applications such as cancer and cardiovascular diseases, which require selective targeting of the therapeutic to maximize effectiveness while avoiding adverse effects on non-target tissues.     

Common variants at TRAF3IP2 are associated with susceptibility to psoriatic arthritis and psoriasis

Psoriatic arthritis (PsA) is an inflammatory joint disease that is distinct from other chronic arthritides and which is frequently accompanied by psoriasis vulgaris (PsV) and seronegativity for rheumatoid factor. We conducted a genome-wide association study in 609 German individuals with PsA (cases) and 990 controls with replication in 6 European cohorts including a total of 5,488 individuals. We replicated PsA associations at HLA-C and IL12B and identified a new association at TRAF3IP2 (rs13190932, P = 8.56 × 10?1?). TRAF3IP2 was also associated with PsV in a German cohort including 2,040 individuals (rs13190932, P = 1.95 × 10?3). Sequencing of the exons of TRAF3IP2 identified a coding variant (p.Asp10Asn, rs33980500) as the most significantly associated SNP (P = 1.13 × 10?2?, odds ratio = 1.95). Functional assays showed reduced binding of this TRAF3IP2 variant to TRAF6, suggesting altered modulation of immunoregulatory signals through altered TRAF interactions as a new and shared pathway for PsA and PsV.     

The binary progenitor of Tycho Brahe's 1572 supernova

The brightness of type Ia supernovae, and their homogeneity as a class, makes them powerful tools in cosmology, yet little is known about the progenitor systems of these explosions. They are thought to arise when a white dwarf accretes matter from a companion star, is compressed and undergoes a thermonuclear explosion. Unless the companion star is another white dwarf (in which case it should be destroyed by the mass-transfer process itself), it should survive and show distinguishing properties. Tycho's supernova is one of only two type Ia supernovae observed in our Galaxy, and so provides an opportunity to address observationally the identification of the surviving companion. Here we report a survey of the central region of its remnant, around the position of the explosion, which excludes red giants as the mass donor of the exploding white dwarf. We found a type G0-G2 star, similar to our Sun in surface temperature and luminosity (but lower surface gravity), moving at more than three times the mean velocity of the stars at that distance, which appears to be the surviving companion of the supernova.     

Duplicate genes increase gene expression diversity within and between species

Using microarray gene expression data from several Drosophila species and strains, we show that duplicated genes, compared with single-copy genes, significantly increase gene expression diversity during development. We show further that duplicate genes tend to cause expression divergences between Drosophila species (or strains) to evolve faster than do single-copy genes. This conclusion is also supported by data from different yeast strains.     

Electronic connection to the interior of a mesoporous insulator with nanowires of crystalline RuO2

Highly porous materials such as mesoporous oxides are of technological interest for catalytic, sensing and remediation applications: the mesopores (of size 2-50 nm) permit ingress by molecules and guests that are physically excluded from microporous materials. Connecting the interior of porous materials with a nanoscale or 'molecular' wire would allow the direct electronic control (and monitoring) of chemical reactions and the creation of nanostructures for high-density electronic materials. The challenge is to create an electronic pathway (that is, a wire) within a mesoporous platform without greatly occluding its free volume and reactive surface area. Here we report the synthesis of an electronically conductive mesoporous composite--by the cryogenic decomposition of RuO4--on the nanoscale network of a partially densified silica aerogel. The composite consists of a three-dimensional web of interconnected (approximately 4-nm in diameter) crystallites of RuO2, supported conformally on the nanoscopic silica network. The resulting monolithic (RuO2//SiO2) composite retains the free volume of the aerogel and exhibits pure electronic conductivity. In addition to acting as a wired mesoporous platform, the RuO2-wired silica aerogel behaves as a porous catalytic electrode for the oxidation of chloride to molecular chlorine.     

Nesting ecology of Yellow Warblers ( Dendroica petechia ) in montane chaparral habitat in the northern Sierra Nevada

The Yellow Warbler ( Dendroica petechia ) is considered a riparian specialist in much of western North America, but in California it also breeds in a second habitat type: montane chaparral of the Sierra Nevada and southern Cascades. We monitored Yellow Warbler nests in montane chaparral and assessed their poorly known nesting ecology in this habitat. We also conducted point counts in upland habitat throughout the region. We determined habitat associations for Yellow Warblers based on nest site and point-count vegetation data; nests were predominantly in bush chinquapin ( Chrysolepis sempervirens ) and greenleaf manzanita ( Arctostaphylos patula ), and point-count abundance was most strongly associated with high overall shrub cover. The importance of montane chaparral for a number of shrub-dependent Sierran birds is well documented, yet the chaparral is threatened by various practices including fire suppression, closed-canopy-focused forest management, and understory fuels-reduction treatments. Although Yellow Warblers are far more abundant in wet mountain meadow riparian habitat in the region, we recommend that management of montane chaparral habitat consider this species and the requirements of other shrub-nesting birds.