Striatal neuroinflammation promotes parkinsonism in rats

The specific role of neuroinflammation in the pathogenesis of Parkinson's disease remains to be fully elucidated. By infusing lipopolysaccharide (LPS) into the striatum, we investigated the effect of neuroinflammation on the dopamine nigrostriatal pathway. Here, we report that LPS-induced neuroinflammation in the striatum causes progressive degeneration of the dopamine nigrostriatal system, which is accompanied by motor impairments resembling parkinsonism. Our results indicate that neurodegeneration is associated with defects in the mitochondrial respiratory chain related to extensive S-nitrosylation/nitration of mitochondrial proteins. Mitochondrial injury was prevented by treatment of L-N^6^-(l-iminoethyl)-lysine, an inducible nitric oxide synthase (iNOS) inhibitor, suggesting that iNOS-derived NO is responsible for mitochondrial dysfunction. Furthermore, the nigral dopamine neurons exhibited intracytoplasmic [alpha]-synuclein and ubiquitin accumulation. These results demonstrate that degeneration of nigral dopamine neurons by neuroinflammation is associated with mitochondrial malfunction induced by NO-mediated S-nitrosylation/nitration of mitochondrial proteins

A Motor Drive Electronics Assembly for Mars Curiosity Rover: An Example of Assembly Qualification for Extreme Environments

This paper describes the technology development and infusion of a motor drive electronics assembly for Mars Curiosity Rover under space extreme environments. The technology evaluation and qualification as well as space qualification of the assembly are detailed and summarized. Because of the uncertainty of the technologies operating under the extreme space environments and that a high level reliability was required for this assembly application, both component and assembly board level qualifications were performed

Australian vegetation classification and the International Vegetation Classification framework: an overview with case studies

Recent advances in conceptual frameworks in vegetation classifications, such as the EcoVeg approach that underpins the International Vegetation Classification (IVC) developed by NatureServe staff and colleagues, offer opportunities to enhance national classification initiatives. National level initiatives provide an important stepping-stone between international units and subnational units. Australia has a long history of developing various vegetation typologies at local to regional scales, but ecologists recognise the need for an Australia-wide, plot-based vegetation classification system that incorporates the principles of the EcoVeg approach, and thereby helps build an international classification system. Using two case studies, we provide a comparison of various structures and criteria for relevant Australian classifications in the context of the IVC, and exemplify how Australian classifications of forest, shrublands, grasslands, and deserts could potentially link into the IVC hierarchy to illustrate the capacity of the IVC to summarise the full range of Australian vegetation at a broad formation (biome) scale. We then discuss how the IVC might inform future work towards an Australian vegetation classification system and, vice versa, the implications of an Australian vegetation classification for IVC development

Universal Controller for Spacecraft Mechanisms

An electronic control unit has been fabricated and tested that can be replicated as a universal interface between the electronic infrastructure of a spacecraft and a brushless-motor (or other electromechanical actuator) driven mechanism that performs a specific mechanical function within the overall spacecraft system. The unit includes interfaces to a variety of spacecraft sensors, power outputs, and has selectable actuator control parameters making the assembly a mechanism controller. Several control topologies are selectable and reconfigurable at any time. This allows the same actuator to perform different functions during the mission life of the spacecraft. The unit includes complementary metal oxide/semiconductor electronic components on a circuit board of a type called rigid flex (signifying flexible printed wiring along with a rigid substrate). The rigid flex board is folded to make the unit fit into a housing on the back of a motor. The assembly has redundant critical interfaces, allowing the controller to perform time-critical operations when no human interface with the hardware is possible. The controller is designed to function over a wide temperature range without the need for thermal control, including withstanding significant thermal cycling, making it usable in nearly all environments that spacecraft or landers will endure. A prototype has withstood 1,500 thermal cycles between 120 and +85 C without significant deterioration of its packaging or electronic function. Because there is no need for thermal control and the unit is addressed through a serial bus interface, the cabling and other system hardware are substantially reduced in quantity and complexity, with corresponding reductions in overall spacecraft mass and cost

Mapping bedrock beneath glacial till using CDP seismic reflection methods

This is the published version, also available here, http://dx.doi.org/10.1029/94GL00051.This paper is a case history demonstrating the applicability of the common depth point (CDP) seismic reflection method to image bedrock beneath glacial till in northwestern Iowa. Reflections from the base of the 40-m thick glacial till are clearly observable on field files at around 45 to 50 ms two-way traveltime and possess a dominant frequency of around 100 Hz. The bedrock reflection is confirmed by drill data. The seismic data are of sufficient quality to detect local bedrock topographic changes and to interpret discontinuities along the till-bedrock interface. Finite-difference synthetic seismograms substantiate the interpreted reflections and the diffraction signatures from faults observed on the field files. At some locations along the seismic line, intra-till reflections are apparent on the field files. These Intra-till features are on the order of tens of meters in length along the line traverse and reflections from them are not enhanced by common depth point processing. Intra-till reflections could be indicative of gravels or other alluvial materials that may serve as local aquifers

Shallow seismic reflection profile of the Meers fault, Comanche County, Oklahoma

This is the publisher's version, also available electronically from “http://onlinelibrary.wiley.com”.A high-resolution seismic-reflection survey was conducted across the Meers fault in Comanche County, Oklahoma, in an attempt to determine the shallow structure associated with the fault zone. A downhole .50-caliber rifle was used as the seismic-energy source. Two 100-Hz geophones were connected in series at each receiver station. A 1.22-m station spacing was used for both source and receiver. Field recording parameters were set to optimize seismic reflections in the 40–150 millisecond range. A pre-analog-to-digital low-cut filter (24 dB/octave rolloff with −3 dB point of 220 Hz) resulted in dominant frequencies in excess of 150 Hz. Several interpretable reflection events between 40 and 120 msec on the processed seismic section provide a clear picture of the shallow structure. Reverse faulting is evident not only at the scarp itself but also on both the upthrown (north) and downthrown (south) portions of the line. This suggests the fault zone extends at least 180 m in both directions (north and south) from the scarp itself. Recent movement appears only to have occurred along the major fault associated with the scarp. The northern portion of the seismic line is characterized by gentle folding, which is not present on the southern portion

Reservoir-host amplification of disease impact in an endangered amphibian

Emerging wildlife pathogens are an increasing threat to biodiversity. One of the most serious wildlife diseases is chytridiomycosis, caused by the fungal pathogen, Batrachochytrium dendrobatidis (Bd), which has been documented in over 500 amphibian species. Amphibians vary greatly in their susceptibility to Bd; some species tolerate infection, whereas others experience rapid mortality. Reservoir hosts-species that carry infection while maintaining high abundance but are rarely killed by disease-can increase extinction risk in highly susceptible, sympatric species. However, whether reservoir hosts amplify Bd in declining amphibian species has not been examined. We investigated the role of reservoir hosts in the decline of the threatened northern corroboree frog (Pseudophryne pengilleyi) in an amphibian community in southeastern Australia. In the laboratory, we characterized the response of a potential reservoir host, the (nondeclining) common eastern froglet (Crinia signifera), to Bd infection. In the field, we conducted frog abundance surveys and Bd sampling for both P. pengilleyi and C. signifera. We built multinomial logistic regression models to test whether Crinia signifera and environmental factors were associated with P. pengilleyi decline. C. signifera was a reservoir host for Bd. In the laboratory, many individuals maintained intense infections (>1000 zoospore equivalents) over 12 weeks without mortality, and 79% of individuals sampled in the wild also carried infections. The presence of C. signifera at a site was strongly associated with increased Bd prevalence in sympatric P. pengilleyi. Consistent with disease amplification by a reservoir host, P. pengilleyi declined at sites with high C. signifera abundance. Our results suggest that when reservoir hosts are present, population declines of susceptible species may continue long after the initial emergence of Bd, highlighting an urgent need to assess extinction risk in remnant populations of other declined amphibian species.Funding was provided by the Australian Academy of Science and a Taronga Zoo Field Conservation Grant. B. Scheele was supported by Australian Research Council grant LP110200240 during the revisions of this manuscript