Further SEASAT SAR coastal ocean wave analysis

Analysis techniques used to exploit SEASAT synthetic aperture radar (SAR) data of gravity waves are discussed and the SEASAT SAR's ability to monitor large scale variations in gravity wave fields in both deep and shallow water is evaluated. The SAR analysis techniques investigated included motion compensation adjustments and the semicausal model for spectral analysis of SAR wave data. It was determined that spectra generated from fast Fourier transform analysis (FFT) of SAR wave data were not significantly altered when either range telerotation adjustments or azimuth focus shifts were used during processing of the SAR signal histories, indicating that SEASAT imagery of gravity waves is not significantly improved or degraded by motion compensation adjustments. Evaluation of the semicausal (SC) model using SEASAT SAR data from Rev. 974 indicates that the SC spectral estimates were not significantly better than the FFT results

NbSe3: Effect of Uniaxial Stress on the Threshold Field and Fermiology

We have measured the effect of uniaxial stress on the threshold field ET for the motion of the upper CDW in NbSe3. ET exhibits a critical behavior, ET ~ (1 - e/ec)^g, wher e is the strain, and ec is about 2.6% and g ~ 1.2. This ecpression remains valid over more than two decades of ET, up to the highest fields of about 1.5keV/m. Neither g nor ec is very sensitive to the impurity concentraction. The CDW transition temperature Tp decreases linearly with e at a rate dTp/de = -10K/%, and it does not show any anomaly near ec. Shubnikov de-Haas measurements show that the extremal area of the Fermi surface decreases with increasing strain. The results suggest that there is an intimate relationship between pinning of the upper CDW and the Fermiology of NbSe3.Comment: 4 pages, 5 figure

Hereditary Character of Photonics Structure in Pachyrhynchus sarcitis Weevils: Color Changes via One Generation Hybridization

Pachyrhynchus sarcitis weevils are flightless weevils characterized by colored patches of scales on their dark elytra. The vivid colors of such patches result from the reflection of differently oriented three-dimensional photonic crystals within their scales. Our results show that hybrid P. sarcitis, the first filial generation of two P. sarcitis populations from Lanyu Island (Taiwan) and Babuyan Island (Philippines), mixes the color of its ancestors by tuning the photonic structure in its scales. A careful spectroscopical and anatomical analysis of the weevils in the phylogeny reveals the hereditary characteristics of the photonic crystals within their scales in terms of lattice constant, orientation and domain size. Monitoring how structural coloration is inherited by offspring highlights the versatility of photonic structures to completely redesign the optical response of living organisms. Such finding shed light onto the evolution and development mechanisms of structural coloration in Pachyrhynchus weevils and provides inspiration for the design of visual appearance in artificial photonic materials.NanoBio-ICMG platform (FR 2607) Cambridge Trus

Wavelet Analysis of SAR Images for Coastal Monitoring

The mapping of mesoscale ocean features in the coastal zone is a major potential application for satellite data. The evolution of mesoscale features such as oil slicks, fronts, eddies, and ice edge can be tracked by the wavelet analysis using satellite data from repeating paths. The wavelet transform has been applied to satellite images, such as those from Synthetic Aperture Radar (SAR), Advanced Very High-Resolution Radiometer (AVHRR), and ocean color sensor for feature extraction. In this paper, algorithms and techniques for automated detection and tracking of mesoscale features from satellite SAR imagery employing wavelet analysis have been developed. Case studies on two major coastal oil spills have been investigated using wavelet analysis for tracking along the coast of Uruguay (February 1997), and near Point Barrow, Alaska (November 1997). Comparison of SAR images with SeaWiFS (Sea-viewing Wide Field-of-view Sensor) data for coccolithophore bloom in the East Bering Sea during the fall of 1997 shows a good match on bloom boundary. This paper demonstrates that this technique is a useful and promising tool for monitoring of coastal waters

α-Actinin and Filamin Cooperatively Enhance the Stiffness of Actin Filament Networks

BACKGROUND: The close subcellular proximity of different actin filament crosslinking proteins suggests that these proteins may cooperate to organize F-actin structures to drive complex cellular functions during cell adhesion, motility and division. Here we hypothesize that alpha-actinin and filamin, two major F-actin crosslinking proteins that are both present in the lamella of adherent cells, display synergistic mechanical functions. METHODOLOGY/PRINCIPAL FINDINGS: Using quantitative rheology, we find that combining alpha-actinin and filamin is much more effective at producing elastic, solid-like actin filament networks than alpha-actinin and filamin separately. Moreover, F-actin networks assembled in the presence of alpha-actinin and filamin strain-harden more readily than networks in the presence of either alpha-actinin or filamin. SIGNIFICANCE: These results suggest that cells combine auxiliary proteins with similar ability to crosslink filaments to generate stiff cytoskeletal structures, which are required for the production of internal propulsive forces for cell migration, and that these proteins do not have redundant mechanical functions

A pilot study into the perception of unreliability of travel times using in-depth interviews

AbstractTransport investments normally reduce travel times, but may also reduce unreliability. Conventional time gains can be evaluated in cost benefit analysis using standard values of time. For valuing reliability gains, however, no standard measures are readily available. The Dutch Ministry of Transport has commissioned a project to design a Stated Preference methodology. Reliability is a complex “academic” concept and it may be difficult to present and explain it to respondents. Therefore, a pilot study using in-depth face-to-face interviews has been carried out, in which various SP choice designs have been presented to the participants to test their understanding of the questions. In the end, we found a “best” design. But still, much care is needed for an acceptable response rate and to prevent illogical and inconsistent responses

Inhibition of dengue virus replication by novel inhibitors of RNA-dependent RNA polymerase and protease activities

Dengue virus (DENV) is the leading mosquito-transmitted viral infection in the world. With more than 390 million new infections annually, and up to 1 million clinical cases with severe disease manifestations, there continues to be a need to develop new antiviral agents against dengue infection. In addition, there is no approved anti-DENV agents for treating DENV-infected patients. In the present study, we identified new compounds with anti-DENV replication activity by targeting viral replication enzymes – NS5, RNA-dependent RNA polymerase (RdRp) and NS3 protease, using cell-based reporter assay. Subsequently, we performed an enzyme-based assay to clarify the action of these compounds against DENV RdRp or NS3 protease activity. Moreover, these compounds exhibited anti-DENV activity in vivo in the ICR-suckling DENV-infected mouse model. Combination drug treatment exhibited a synergistic inhibition of DENV replication. These results describe novel prototypical small anti-DENV molecules for further development through compound modification and provide potential antivirals for treating DENV infection and DENV-related diseases

Topical application of hyaluronic acid-RGD peptide-coated gelatin/epigallocatechin-3 gallate (EGCG) nanoparticles inhibits corneal neovascularization via inhibition of VEGF production

Neovascularization (NV) of the cornea disrupts vision which leads to blindness. Investigation of antiangiogenic, slow-release and biocompatible approaches for treating corneal NV is of great importance. We designed an eye drop formulation containing gelatin/epigallocatechin-3-gallate (EGCG) nanoparticles (NPs) for targeted therapy in corneal NV. Gelatin-EGCG self-assembled NPs with hyaluronic acid (HA) coating on its surface (named GEH) and hyaluronic acid conjugated with arginine-glycine-aspartic acid (RGD) (GEH-RGD) were synthesized. Human umbilical vein endothelial cells (HUVECs) were used to evaluate the antiangiogenic effect of GEH-RGD NPs in vitro. Moreover, a mouse model of chemical corneal cauterization was employed to evaluate the antiangiogenic effects of GEH-RGD NPs in vivo. GEH-RGD NP treatment significantly reduced endothelial cell tube formation and inhibited metalloproteinase (MMP)-2 and MMP-9 activity in HUVECs in vitro. Topical application of GEH-RGD NPs (once daily for a week) significantly attenuated the formation of pathological vessels in the mouse cornea after chemical cauterization. Reduction in both vascular endothelial growth factor (VEGF) and MMP-9 protein in the GEH-RGD NP-treated cauterized corneas was observed. These results confirm the molecular mechanism of the antiangiogenic effect of GEH-RGD NPs in suppressing pathological corneal NV