Global features of the disturbance winds during storm time deduced from CHAMP observations

A wind-driven disturbance dynamo has been postulated many decades ago. But due to the sparseness of thermospheric wind measurements, details of the phenomena could not be investigated. In this study we use the CHAMP zonal wind observations from 2001 to 2005 to investigate the global features of the disturbance winds during magnetically disturbed periods. The disturbance zonal wind is mainly westward, which increases with magnetic activity and latitude. At subauroral region, the westward zonal wind is strongly enhanced in the magnetic local time (MLT) sector from afternoon to midnight, which we relate to the plasma drift within the subauroral polarization streams. At middle and low latitudes, the disturbance zonal wind is largely independent of season. Peak values of the disturbance zonal wind occur at different MLTs for different latitudes. That is around 1800MLT at subauroal region, with average values of about 200m/s; around 2300 MLT at middle latitudes, with average values of about 80m/s; and around 0300MLT at low latitudes, with average values up to 50m/s. The shift of the peak values of the westward disturbance zonal wind in local time at different latitudes could be considered as a response of the disturbance wind when it propagates from high to low latitudes. Further by applying for the first time a superposed epoch analysis, we show that the disturbance zonal wind responds with a delay to the sudden changes of solar wind input, which is different for the various latitudinal ranges. The propagation time of disturbance wind from the auroral region to the equator is about 3-4h. This is consistent with the speed of traveling atmospheric disturbances. Based on CHAMP observations, we try to illustrate the whole chain of processes from the solar wind driving to the ionospheric effects at lower latitudes. ©2015. American Geophysical Union. All Rights Reserved

Demonstrating the Benefits of Green Streets for Active Aging: Initial Findings

This project will help demonstrate how sustainable ( green ) streets contribute to the well-being of a community, including the physical and mental health of older and younger adults, along with the environment and economy. The project will collect data in Portland, OR neighborhoods to answer the following research questions: Are residents living near sustainable streets more physically active in their neighborhood? Do residents living near sustainable streets interact with neighbors more and demonstrate higher levels of neighborhood social capital? What are residents’ opinions of sustainable streets? Are there variations in responses to sustainable streets by age or other demographics? In particular, how to older adults differ from younger adults? Does the implementation process and design affect green street outcomes? Do sustainable streets affect home values? How do green streets affect stormwater flows, urban heat island, and carbon sequestration in Portland neighborhoods? The project includes a survey of residents in two neighborhoods with green street features and two control neighborhoods; an environmental assessment of the green street treatments; and an analysis of housing values using a hedonic modeling approach. The project will be guided by an Advisory council of members of various stakeholder organizations and representing different types of expertise. Members will include representatives of the city of Portland’s Bureau of the Environmental Services and Office of Transportation, Multnomah County Aging and Disability Services (the local area agency on aging), Elders in Action, (a statewide advocacy group for elders), AARP Oregon, and the neighborhood associations of the four study neighborhoods

Upper crustal structure of central Java, Indonesia, from transdimensional seismic ambient noise tomography

Delineating the crustal structure of central Java is crucial for understanding its complex tectonic setting. However, seismic imaging of the strong heterogeneity typical of such a tectonically active region can be challenging, particularly in the upper crust where velocity contrasts are strongest and steep bodywave ray paths provide poor resolution. To overcome these difficulties, we apply the technique of ambient noise tomography (ANT) to data collected during the Merapi Amphibious Experiment (MERAMEX), which covered central Java with a temporary deployment of over 120 seismometers during 2004 May-October. More than 5000 Rayleigh wave Green's functions were extracted by cross-correlating the noise simultaneously recorded at available station pairs. We applied a fully non-linear 2-D Bayesian probabilistic inversion technique to the retrieved traveltimes. Features in the derived tomographic images correlate well with previous studies, and some shallow structures that were not evident in previous studies are clearly imaged with ANT. The Kendeng Basin and several active volcanoes appear with very low group velocities, and anomalies with relatively high velocities can be interpreted in terms of crustal sutures and/or surface geological features

Monitoring SO2 emission at the Soufriere Hills Volcano: implications for changes in erruptive conditions

FLWINinfo:eu-repo/semantics/publishe

Geotail Measurements Compared with the Motions of High-Latitude Auroral Boundaries during Two Substorms

Geotail plasma and field measurements at -95 R(sub E) are compared with extensive ground-based, near-Earth, and geosynchronous measurements to study relationships between auroral activity and magnetotail dynamics during the expansion phases of two substorms. The studied intervals are representative of intermittent, moderate activity. The behavior of the aurora and the observed effects at Geotail for both events are harmonized by the concept of the activation of near-Earth X lines (NEXL) after substorm onsets, with subsequent discharges of one or more plasmoids down the magnetotail. The plasmoids must be viewed as three-dimensional structures which are spatially limited in the dawn-dusk direction. Also, reconnection at the NEXL must proceed at variable rates on closed magnetic field lines for significant times before beginning to reconnect lobe flux. This implies that the plasma sheet in the near-Earth magnetotail is relatively thick in comparison with an embedded current sheet and that both the NEXL and distant X line can be active simultaneously. Until reconnection at the NEXL engages lobe flux, the distant X line maintains control of the poleward auroral boundary. If the NEXL remains active after reaching the lobe, the auroral boundary can move poleward explosively. The dynamics of high-latitude aurora in the midnight region thus provides a means for monitoring these processes and indicating when significant lobe flux reconnects at the NEXL

Inhibition of cholesterol recycling impairs cellular PrPSc propagation

The infectious agent in prion diseases consists of an aberrantly folded isoform of the cellular prion protein (PrPc), termed PrPSc, which accumulates in brains of affected individuals. Studies on prion-infected cultured cells indicate that cellular cholesterol homeostasis influences PrPSc propagation. Here, we demonstrate that the cellular PrPSc content decreases upon accumulation of cholesterol in late endosomes, as induced by NPC-1 knock-down or treatment with U18666A. PrPc trafficking, lipid raft association, and membrane turnover are not significantly altered by such treatments. Cellular PrPSc formation is not impaired, suggesting that PrPSc degradation is increased by intracellular cholesterol accumulation. Interestingly, PrPSc propagation in U18666A-treated cells was partially restored by overexpression of rab 9, which causes redistribution of cholesterol and possibly of PrPSc to the trans-Golgi network. Surprisingly, rab 9 overexpression itself reduced cellular PrPSc content, indicating that PrPSc production is highly sensitive to alterations in dynamics of vesicle trafficking

The Calcitonin Receptor Gene Is a Candidate for Regulation of Susceptibility to Herpes simplex Type 1 Neuronal Infection Leading to Encephalitis in Rat

Herpes simplex encephalitis (HSE) is a fatal infection of the central nervous system (CNS) predominantly caused by Herpes simplex virus type 1. Factors regulating the susceptibility to HSE are still largely unknown. To identify host gene(s) regulating HSE susceptibility we performed a genome-wide linkage scan in an intercross between the susceptible DA and the resistant PVG rat. We found one major quantitative trait locus (QTL), Hse1, on rat chromosome 4 (confidence interval 24.3–31 Mb; LOD score 29.5) governing disease susceptibility. Fine mapping of Hse1 using recombinants, haplotype mapping and sequencing, as well as expression analysis of all genes in the interval identified the calcitonin receptor gene (Calcr) as the main candidate, which also is supported by functional studies. Thus, using unbiased genetic approach variability in Calcr was identified as potentially critical for infection and viral spread to the CNS and subsequent HSE development

Dissociation of Infectivity from Seeding Ability in Prions with Alternate Docking Mechanism

Previous studies identified two mammalian prion protein (PrP) polybasic domains that bind the disease-associated conformer PrPSc, suggesting that these domains of cellular prion protein (PrPC) serve as docking sites for PrPSc during prion propagation. To examine the role of polybasic domains in the context of full-length PrPC, we used prion proteins lacking one or both polybasic domains expressed from Chinese hamster ovary (CHO) cells as substrates in serial protein misfolding cyclic amplification (sPMCA) reactions. After ∼5 rounds of sPMCA, PrPSc molecules lacking the central polybasic domain (ΔC) were formed. Surprisingly, in contrast to wild-type prions, ΔC-PrPSc prions could bind to and induce quantitative conversion of all the polybasic domain mutant substrates into PrPSc molecules. Remarkably, ΔC-PrPSc and other polybasic domain PrPSc molecules displayed diminished or absent biological infectivity relative to wild-type PrPSc, despite their ability to seed sPMCA reactions of normal mouse brain homogenate. Thus, ΔC-PrPSc prions interact with PrPC molecules through a novel interaction mechanism, yielding an expanded substrate range and highly efficient PrPSc propagation. Furthermore, polybasic domain deficient PrPSc molecules provide the first example of dissociation between normal brain homogenate sPMCA seeding ability from biological prion infectivity. These results suggest that the propagation of PrPSc molecules may not depend on a single stereotypic mechanism, but that normal PrPC/PrPSc interaction through polybasic domains may be required to generate prion infectivity