Phenotypic plasticity affects the response of a sexually selected trait to anthropogenic noise

Sexually selected traits are shaped by an interaction between sexual selection and other natural selection pressures in the environment. However, there is little understanding of how recent anthropogenic environmental change affects the elaboration of sexually selected traits. Most sexually selected traits are complex displays comprising multiple components that interact in a functional way, thereby affecting overall trait expression. To understand how environmental change may shape the expression of sexually selected traits, we have to consider not only (i) the phenotypic plasticity of individual components of traits but also their (ii) phenotypic integration, that is, the correlations among trait components, as well as (iii) plasticity integration, that is, the correlations among the plasticities of trait components. Here, we show that background noise is a considerable pressure in shaping a sexually selected multicomponent acoustic signal, bird song. We compared singing behavior of European robins (Erithacus rubecula) in territories that differed in levels of anthropogenic noise and conducted noise-exposure experiments to test if behavioral plasticity caused immediate changes in song components, for example, minimum frequency, song complexity, and song length. We found that song components differed in their plasticity to background noise and that plasticity integration between components may further restrict the elaboration of song. Thus, the altered expression of song components under noise exposure leads to increased phenotypic integration, which is linked with reduced song complexity. Our findings demonstrate that plasticity integration restricts the elaboration of a sexually selected trait, which raises the question of how changing environments may modify sexual selection.

Expression of the 67 kDa laminin receptor (67LR) during retinal development: correlations with angiogenesis

Interaction of vascular cells with the laminin component of basement membranes is important for normal cell function. Likewise, abnormal interactions may have a critical role in vascular pathology. It has been previously demonstrated that the 67 kDa laminin receptor (67LR) is expressed at high levels during proliferative retinopathy in a mouse model and in the current study we have examined 67LR in the neonatal mouse to determine if this receptor plays a role in aspects of developmental angiogenesis in the developing murine retina. Groups of C57/BL6 mice were killed at postnatal day P1, P3, P5, P7, P9 and P11 to assess the retinal vasculature. A number of mice were perfused with FITC-dextran and the eyes removed, fixed in 4% paraformaldehyde (PFA) and flat-mounted for confocal scanning laser microscopy. The eyes from the remaining mice were either placed in 4% PFA and embedded in paraffin-wax, or had the neural retina dissected off and total RNA or protein extracted. Immunofluorescence, in situ hybridization, quantitative reverse transcriptase polymerase chain reaction and Western blotting analysis were employed to locate and determine expression levels of 67LR. Both 67LR mRNA and protein expression showed a characteristic bi-phasic expression pattern which correlated with key stages of retinal vascular development in the murine retina. 67LR showed high expression levels at P1 (P < 0.05) (correlating with superficial vascular plexus formation) and at P7 (P < 0.05) (correlating with deep vascular plexus formation). Conversely, 67LR expression was decreased when active angiogenic activity was lowest. Significantly, optical sectioning of retinal flat-mounts revealed high levels of 67LR expression in developing segments of both superficial and deep capillary plexi, a pattern which co-localized strongly with laminin. 67LR is regulated during post-natal development of the retinal vasculature. High levels of 67LR during the two well-defined phases of retinal capillary plexus formation suggests that this receptor may play an important role in retinal angiogenesis.

Pullout test correlations and in-place strength assessment - the European Concrete Frame Building Project

A full-scale, seven-story, reinforced concrete building frame was constructed in-place at the Building Research Establishment's Cardington Laboratory, which encompassed a range of different concrete mixtures and advanced construction techniques. This provided an opportunity to assess in-place nondestructive test methods, namely the pullout test, and more specifically the Danish version, which has been known as the Lok test, on a systematic basis during the construction of the building. It was used in conjunction with both standard and temperature-matched cube specimens to assess its practicality and accuracy under site conditions. Strength correlations were determined using linear and power function regression analysis. Strength predictions from these were found to be in very good agreement with the compressive strengths of temperature-matched cube specimens. When a general correlation is used, however, estimates for compressive strength are likely to have 95% confidence limits of around '20% of the mean value of four results.

Phenotypic diversity amongst strains of Pleurotus sajor-caju: implications for cultivation in and environments

In arid regions, biodiversity and biomass are limited by water availability, and this problem has been compounded by desertification associated with global climate change. The saprotrophic macrofungi that are indigenous to hot subtropical and tropical regions, such as Pleurotus spp., can play key roles in water sequestration, nutrient cycling, human nutrition, and bioremediation of waste materials. We studied 15 strains of Pleurotus sajor-caju, a widespread and phenotypically-diverse species, to establish variability in growth response and primordium development over a range of stress parameters: osmotic potential (-0.5 to -5 MPa), temperature (5-40 degrees C) and pH (2-12). The initiation of primordia precedes basidiome production and therefore represents a key stage in bioremediation strategies and fungi-driven nutrient cycles. Primordia were produced at low pH (4-6), at suboptimal growth temperatures (<or =25 degrees C), and under moderate water stress (-0.5 to -3.5 MPa). Although the growth windows for different strains were similar, their maximum growth rates and the optimum conditions for growth varied. We discuss the phenotypic diversity of Pleurotus strains and discuss their potential for cultivation, bioremediation and ecological regeneration.

Measurement of Short-Range Correlations in Shock-Compressed Plastic by Short-Pulse X-Ray Scattering

We have performed short-pulse x-ray scattering measurements on laser-driven shock-compressed plastic samples in the warm dense matter regime, providing instantaneous snapshots of the system evolution. Time-resolved and angularly resolved scattered spectra sensitive to the correlation effects in the plasma show the appearance of short-range order within a few interionic separations. Comparison with radiation-hydrodynamic simulations indicates that the shocked plastic is compressed with a temperature of a few electron volts. These results are important for the understanding of the thermodynamic behavior of strongly correlated matter for conditions relevant to both laboratory astrophysics and inertial confinement fusion research.