Non-Universal Critical Behaviour of Two-Dimensional Ising Systems

Two conditions are derived for Ising models to show non-universal critical behaviour, namely conditions concerning 1) logarithmic singularity of the specific heat and 2) degeneracy of the ground state. These conditions are satisfied with the eight-vertex model, the Ashkin-Teller model, some Ising models with short- or long-range interactions and even Ising systems without the translational or the rotational invariance.Comment: 17 page

The Lunar Lander Neutron & Dosimetry (LND) Experiment on Chang’E4

Introduction: Chang'E 4 is the next Chinese mission to the Moon and is planned to land on the far side of the Moon in the South Pole Aitken Basin. The mission consists of a lander, a rover, and a communication relay. Here we describe the Lunar Lander Neutrons & Dosimetry experiment (LND) which will be placed on the lander. It consists of a stack of 10 segmented Si solid-state detectors (SSDs) which forms a particle telescope to measure charged particles (electrons 150-500 keV, protons 12-30 MeV, and heavier nuclei 15-30 MeV/nuc). A special geometrical arrangement allows observations of fast neutrons (and γ-rays) which are also important for dosimetry and cosmic-ray exposure of lunar soils. Thermal neutrons are measured using a very thin Gd conversion foil which is sandwiched between two SSDs. Thermal neutrons are sensitive to subsurface water and important to understand lunar surface mixing processes

Cloning and expression of the human transient receptor potential 4 (TRP4) gene: localization and functional expression of human TRP4 and TRP3.

Mammalian homologues of the Drosophila transient receptor potential (TRP) protein have been proposed to function as ion channels, and in some cases as store-operated or capacitative calcium entry channels. However, for each of the mammalian TRP proteins, different laboratories have reported distinct modes of cellular regulation. In the present study we describe the cloning and functional expression of the human form of TRP4 (hTRP4), and compare its activity with another well studied protein, hTRP3. When hTRP4 was transiently expressed in human embryonic kidney (HEK)-293 cells, basal bivalent cation permeability (barium) was increased. Whole-cell patch-clamp studies of hTRP4 expressed in Chinese hamster ovary cells revealed a constitutively active non-selective cation current which probably underlies the increased bivalent cation entry. Barium entry into hTRP4-transfected HEK-293 cells was not further increased by phospholipase C (PLC)-linked receptor activation, by intracellular calcium store depletion with thapsigargin, or by a synthetic diacylglycerol, 1-oleoyl-2-acetyl-sn-glycerol (OAG). In contrast, transient expression of hTRP3 resulted in a bivalent cation influx that was markedly increased by PLC-linked receptor activation and by OAG, but not by thapsigargin. Despite the apparent differences in regulation of these two putative channel proteins, green fluorescent protein fusions of both molecules localized similarly to the plasma-membrane, notably in discrete punctate regions suggestive of specialized signalling complexes. Our findings indicate that while both hTRP4 and hTRP3 can apparently function as cation channels, their putative roles as components of capacitative calcium entry channels are not readily demonstrable by examining their behaviour when exogenously expressed in cells