Environmental dependence of 8 μm luminosity functions of galaxies at z ~ 0.8: Comparison between RXJ1716.4+6708 and the AKARI NEP-deep field

Aims. We aim to reveal environmental dependence of infrared luminosity functions (IR LFs) of galaxies at z ~ 0.8 using the AKARI satellite. AKARI’s wide field of view and unique mid-IR filters help us to construct restframe 8 μm LFs directly without relying on SED models. Methods. We construct restframe 8 μm IR LFs in the cluster region RXJ1716.4+6708 at z = 0.81, and compare them with a blank field using the AKARI north ecliptic pole deep field data at the same redshift. AKARI’s wide field of view (10' × 10') is suitable to investigate wide range of galaxy environments. AKARI’s 15 μm filter is advantageous here since it directly probes restframe 8 μm at z ~ 0.8, without relying on a large extrapolation based on a SED fit, which was the largest uncertainty in previous work. Results. We have found that cluster IR LFs at restframe 8 μm have a factor of 2.4 smaller L^∗ and a steeper faint-end slope than that of the field. Confirming this trend, we also found that faint-end slopes of the cluster LFs becomes flatter and flatter with decreasing local galaxy density. These changes in LFs cannot be explained by a simple infall of field galaxy population into a cluster. Physics that can preferentially suppress IR luminous galaxies in high density regions is required to explain the observed results

A Bose-Einstein condensation model for high-temperature superconductivity

I propose that a dopant charge singlet bonding state may arise from the hybridization of molecular orbitals in a cluster containing 13 Cu atoms in the CuO2 plane of the superconducting cuprates. This singlet state forms a pre-formed pair with low binding energy that is spatially bounded and weakly interacting, and that can undergo Bose-Einstein condensation. I show that this model is able to account, in a quantitative and natural way, for many of the thermodynamic and electronic characteristics of the superconducting cuprates, including many of the key experimental ARPES, muSR and microwave results on the temperature and doping dependencies of both the superfluid density and the pairing strengths (superconducting gap, leading-edge-midpoint and psuedogap) in these high-temperature superconductors.Comment: 28 pages, 9 figures, submitted to Phys. Rev.

Quantum Critical Point, Scaling, and Universality in High Tc [CaxLa(1-x)][Ba(2-c-x)La(c+x)]Cu3Oy

Using charge transport observations on sintered ceramic samples of CLBLCO, we failed to observe the Quantum Critical Point (QCP) where it is expected. Experimental data relating Cooper pair density, electrical conductivity, and superconductivity critical temperature suggest that Homes' relation might need a more specific definition of 'sigma'. Transport observations on YBCO single crystals will resolve this question.Comment: 5 pages, 3 figure

Modelling the Pan-Spectral Energy Distribution of Starburst Galaxies: IV The Controlling Parameters of the Starburst SED

We combine the the stellar spectral synthesis code Starburst99, the nebular modelling code MAPPINGSIII, and a 1-D dynamical evolution model of HII regions around massive clusters of young stars to generate improved models of the spectral energy distribution (SED) of starburst galaxies. We introduce a compactness parameter, C, which characterizes the specific intensity of the radiation field at ionization fronts in HII regions, and which controls the shape of the far-IR dust re-emission, often referred to loosely as the dust ``temperature''. We also investigate the effect of metallicity on the overall SED and in particular, on the strength of the PAH features. We provide templates for the mean emission produced by the young compact HII regions, the older (10 - 100 Myr) stars and for the wavelength-dependent attenuation produced by a foreground screen of the dust used in our model. We demonstrate that these components may be combined to produce a excellent fit to the observed SEDs of star formation dominated galaxies which are often used as templates (Arp 220 and NGC 6240). This fit extends from the Lyman Limit to wavelengths of about one mm. The methods presented in both this paper and in the previous papers of this series allow the extraction of the physical parameters of the starburst region (star formation rates, star formation rate history, mean cluster mass, metallicity, dust attenuation and pressure) from the analysis of the pan-spectral SED.Comment: 35 pages, 21 figures, accepted for publication in ApJS full-res available at http://www.strw.leidenuniv.nl/~brent/publications/SEDIV.pd

Developmental expression of the cucumber <i>Cs-XTH1</i> and <i>Cs-XTH3</i> genes, encoding xyloglucan endotransglucosylase/hydrolases, can be influenced by mechanical stimuli

The expression of two genes encoding xyloglucan endotransglucosylase/hydrolases (XTHs), Cs-XTH1 and Cs-XTH3, was upregulated during the onset of cucumber somatic embryogenesis. As a means of characterising the developmental regulation of these genes, the activity of the respective upstream regulatory regions was investigated in seedlings and somatic embryos of Arabidopsis thaliana and Cucumis sativus. GUS assays revealed that both genes are under developmental control. In addition, elevated promoter activity was found in the tension-bearing regions of the plant and in response to touch and wounding, which is consistent with the existence of numerous stress-related cis elements in the 5′-regulatory regions. In vivo xyloglucan endotransglucosylase (XET) action assays were performed to gain an overview on the role of XTHs during somatic embryogenesis. The highest XET action was observed in the external cell layers of somatic embryos in the cotyledonary region and in the presumptive region of peg formation. Based on the results, we propose a dual mechanism (one developmental and the second adaptive) for the regulation of Cs-XTH1 and Cs-XTH3 activity wherein the developmental pattern can be modified by mechanical stimuli

Controlling posture using a plantar pressure-based, tongue-placed tactile biofeedback system

The present paper introduces an original biofeedback system for improving human balance control, whose underlying principle consists in providing additional sensory information related to foot sole pressure distribution to the user through a tongue-placed tactile output device. To assess the effect of this biofeedback system on postural control during quiet standing, ten young healthy adults were asked to stand as immobile as possible with their eyes closed in two conditions of No-biofeedback and Biofeedback. Centre of foot pressure (CoP) displacements were recorded using a force platform. Results showed reduced CoP displacements in the Biofeedback relative to the No-biofeedback condition. The present findings evidenced the ability of the central nervous system to efficiently integrate an artificial plantar-based, tongue-placed tactile biofeedback for controlling control posture during quiet standing