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Transient receptor potential channel vanilloid type 6 (TRPV6) is a non-selective cation channel with high permeability for Ca 2 + ions. So far, the role of TRPV6 in pancreatic beta cells is unknown. In the present study, we characterized the role of TRPV6 in controlling calcium signaling, cell proliferation as well as insulin expression, and secretion in experimental INS-1E beta cell model. TRPV6 protein production was downregulated using siRNA by approx. 70%, as detected by Western blot. Intracellular free Ca 2 + ([Ca 2 + ] i ) was measured by fluorescence Ca 2 + imaging using fura-2. Calcineurin/NFAT signaling was analyzed using a NFAT reporter assay as well as a calcineurin activity assay. TRPV6 downregulation resulted in impaired cellular calcium influx. Its downregulation also reduced cell proliferation and decreased insulin mRNA expression. These changes were companied by the inhibition of the calcineurin/NFAT signaling. In contrast, insulin exocytosis was not affected by TRPV6 downregulation. In conclusion, this study demonstrates for the first time the expression of TRPV6 in INS-1E cells and rat pancreatic beta cells and describes its role in modulating calcium signaling, beta cell proliferation and insulin mRNA expression. In contrast, TRPV6 fails to influence insulin secretion. [ABSTRACT FROM AUTHOR]

This paper presents narrow-band bandpass filters with wide stopband for WLAN and WiMAX systems. First, open-stub and T-shaped resonators were used to design a filter (F1) with the center frequency 2.4 GHz. In order to examine the architectures of the proposed resonators, their frequency responses were compared to the response of an LC model. Next, Defected Ground Structure (DGS) was utilized to achieve a wide stopband within the frequency response of F1. Then, the structure of F1 (without using DGS) only with some changes in the dimensions of the resonators was employed to design the narrow-band filters F² and F3 with the center frequencies 3.7 GHz and 5.1 GHz, respectively. Advantages of these filters include simplicity, architectural symmetry, tenability for applications at other frequency, and proper bandwidth. The filters also provide optimal return loss and insertion loss. [ABSTRACT FROM AUTHOR]

An analysis of boulders displaced during the September 2010 MW 7.1 Darfield (Canterbury) earthquake provides non-instrumental constraints on the variability, distribution and origin of strong ground motion during major earthquakes. Boulders ranging in mass from 10 to 5000 kg were displaced 8–970 cm laterally from hosting soil sockets of <1 cm to 50 cm depth at several sites in the Port Hills, roughly 35 km southeast of the earthquake epicentre. Boulder displacement was observed on N-striking (000–015°) ridges above c. 400 m elevation but not on NE-, NW- and SE-striking ridges. The prevailing boulder horizontal displacement azimuth of 250±20° is subparallel with the direction of instrumentally recorded transient peak ground horizontal displacements. Boulder displacement distance has no correlation with displacement azimuth, boulder mass or soil socket depth and has a partial correlation with slope angle. The lateral displacement of many boulders from low slope (<10°) ground surfaces on ridge crests exceeds nearby instrumentally recorded peak ground displacements at lower elevations by up to an order of magnitude, implying that seismic waves were amplified at the study sites. Preliminary 2-D FLAC modelling suggests that topographic amplification may explain this observation. The co-existence of displaced and non-displaced boulders at proximal (<1 m spacing) sites also suggests small-scale ground motion variability and/or varying boulder-ground dynamic interactions relating to shallow phenomena such as variability in soil depth, bedrock fracture density and/or microtopography on the bedrock–soil interface. Remapping of boulders following the February 2011 MW 6.2 Christchurch earthquake reveals no subsequent relocation despite locally recorded horizontal and vertical ground accelerations well in excess of the Darfield earthquake and pervasive rockfalls and landslides elsewhere. This study successfully identifies some of the major controls on spatial ground motion variability at non-instrumented locations and highlights the complexity of ground response at different spatial scales and for different earthquake characteristics. [ABSTRACT FROM AUTHOR]

Abstract: Kilometre-wide airborne light detection and ranging (LiDAR) surveys were collected along portions of the Alpine and Hope faults in New Zealand to assess the potential for generating sub 5-m bare earth digital elevation models (DEMs) from ground return data in areas of dense rainforest (bush) cover as an aid to mapping these faults. The 34-km long Franz-Whataroa LiDAR survey was flown along the densely-vegetated central-most portion of the transpressive Alpine Fault. Six closely spaced flight lines (200 m apart) yielded survey coverage with double overlap of swath collection, which was considered necessary due to the low density of ground returns (0.16 m−2 or a point every 6 m2) under mature West Coast podocarp-broadleaf rainforest. This average point spacing (∼2.5 m) allowed for the generation of a robust, high quality 3-m bare earth DEM. The DEM confirmed the zigzagged form of the surface trace of the Alpine Fault in this area, originally recognised by Norris and Cooper (1995, 1997) and highlights that the surface strike variations are more variant than previously mapped. The 29-km long Hurunui-Hope LiDAR survey was flown east of the Main Divide of the Southern Alps along the dextral-slip Hope Fault, where the terrain is characterised by lower rainfall and more open beech forest. Flight line spacings of ∼275 m were used to generate a DEM from the ground return data. The average ground return values under beech forest were 0.27 m−2 and yielded an estimated cell size suitable for a 2-m DEM. In both cases the LiDAR revealed unprecedented views of the surface geomorphology of these active faults. Lessons learned from our survey methodologies can be employed to plan cost-effective, high-gain airborne surveys to yield bare earth DEMs underneath vegetated terrain and multi-storeyed canopies from densely forested environments across New Zealand and worldwide. [Copyright &y& Elsevier]

Highlights: [•] TRPV4 is expressed in pancreatic INS-1E beta cells. [•] Thermal, osmotic and pharmacological stimulation of TRPV4 increases [Ca2+]i. [•] TRPV4 activation leads to enhanced glucose-induced insulin secretion. [ABSTRACT FROM AUTHOR]