Use of remote sensing techniques for geological hazard surveys in vegetated urban regions

The feasibility of using aerial photography for lithologic differentiation in a heavily vegetated region is investigated using multispectral imagery obtained from LANDSAT satellite and aircraft-borne photography. Delineating and mapping of localized vegetal zones can be accomplished by the use of remote sensing because a difference in morphology and physiology results in different natural reflectances or signatures. An investigation was made to show that these local plant zones are affected by altitude, topography, weathering, and gullying; but are controlled by lithology. Therefore, maps outlining local plant zones were used as a basis for lithologic map construction

Upstream-binding factor is sequestered into herpes simplex virus type 1 replication compartments

Previous reports have shown that adenovirus recruits nucleolar protein upstream-binding factor (UBF) into adenovirus DNA replication centres. Here, we report that despite having a different mode of viral DNA replication, herpes simplex virus type 1 (HSV-1) also recruits UBF into viral DNA replication centres. Moreover, as with adenovirus, enhanced green fluorescent protein-tagged fusion proteins of UBF inhibit viral DNA replication. We propose that UBF is recruited to the replication compartments to aid replication of HSV-1 DNA. In addition, this is a further example of the role of nucleolar components in viral life cycle

Impact of Molecular Architecture and Adsorption Density on Adhesion of Mussel-Inspired Surface Primers with Catechol-Cation Synergy.

Marine mussels secrete proteins rich in residues containing catechols and cationic amines that displace hydration layers and adhere to charged surfaces under water via a cooperative binding effect known as catechol-cation synergy. Mussel-inspired adhesives containing paired catechol and cationic functionalities are a promising class of materials for biomedical applications, but few studies address the molecular adhesion mechanism(s) of these materials. To determine whether intramolecular adjacency of these functionalities is necessary for robust adhesion, a suite of siderophore analog surface primers was synthesized with systematic variations in intramolecular spacing between catechol and cationic functionalities. Adhesion measurements conducted with a surface forces apparatus (SFA) allow adhesive failure to be distinguished from cohesive failure and show that the failure mode depends critically on the siderophore analog adsorption density. The adhesion of these molecules to muscovite mica in an aqueous electrolyte solution demonstrates that direct intramolecular adjacency of catechol and cationic functionalities is not necessary for synergistic binding. However, we show that increasing the catechol-cation spacing by incorporating nonbinding domains results in decreased adhesion, which we attribute to a decrease in the density of catechol functionalities. A mechanism for catechol-cation synergy is proposed based on electrostatically driven adsorption and subsequent binding of catechol functionalities. This work should guide the design of new adhesives for binding to charged surfaces in saline environments

Electrostatics in wind-blown sand

Wind-blown sand, or "saltation," is an important geological process, and the primary source of atmospheric dust aerosols. Significant discrepancies exist between classical saltation theory and measurements. We show here that these discrepancies can be resolved by the inclusion of sand electrification in a physically based saltation model. Indeed, we find that electric forces enhance the concentration of saltating particles and cause them to travel closer to the surface, in agreement with measurements. Our results thus indicate that sand electrification plays an important role in saltation.Comment: 4 journal pages, 5 figures, and supplementary material. Article is in press at PR

VEGETATION FIRE FUELS MAPPING IN THE SAN DIEGO CITY CANYONS – A METHOD COMPARISON

Fire risk is a major threat to life, property and natural resources in southern California. Recent fire disasters occurred in autumn 2003 and 2007. Fire risk management deals with these hazards, input data are collected, analyzed and evaluated. One of the most important input data is the vegetation density in the endangered areas. Here we describe methods to map vegetation density forming five hazard classes. The main objective of this study is to explore the benefits of using remote sensed data for the accurate classification of vegetation in San Diego city canyons. Three very high resolution remote sensing data sets (< 1 m) were used in comparison: scanned color infrared film (CIR) airborne, digital multi-spectral airborne (ADS40) and digital multi-spectral satellite imagery (QuickBird). Different classification approaches (e.g. pixel-based, segment-based and knowledge-based) were tested and analyzed to separate the vegetation into five hazard classes. Accuracy assessment indicated low overall accuracies of 58 % on average. With regard to an optimized classification result in particular unsupervised and segment-based classification can be recommended. The overall accuracy for these two methods reached around 62 %. The use of specially selected reference areas for validation helped to increase the accuracies up to 81 %. Also a separating between three instead of five different hazard classes resulted in accuracies around 80 %. Furthermore it could be shown that all three data sets can be used for successful classification procedures. The resulting fire risk maps can help to reduce or prevent fire hazards. The maps are a basis for the brush management of the Fir

Drop Splashing on a Dry Smooth Surface

The corona splash due to the impact of a liquid drop on a smooth dry substrate is investigated with high speed photography. A striking phenomenon is observed: splashing can be completely suppressed by decreasing the pressure of the surrounding gas. The threshold pressure where a splash first occurs is measured as a function of the impact velocity and found to scale with the molecular weight of the gas and the viscosity of the liquid. Both experimental scaling relations support a model in which compressible effects in the gas are responsible for splashing in liquid solid impacts.Comment: 11 pages, 4 figure

Subsurface disposal of liquid low-level radioactive wastes at Oak Ridge, Tennessee

At Oak Ridge National Laboratory (ORNL) subsurface injection has been used to dispose of low-level liquid nuclear waste for the last two decades. The process consists of mixing liquid waste with cement and other additives to form a slurry that is injected under pressure through a cased well into a low-permeability shale at a depth of 300 m (1000 ft). The slurry spreads from the injection well along bedding plane fractures and forms solid grout sheets of up to 200 m (660 ft) in radius. Using this process, ORNL has disposed of over 1.5 x 10/sup 6/ Ci of activity; the principal nuclides are /sup 90/Sr and /sup 137/Cs. In 1982, a new injection facility was put into operation. Each injection, which lasts some two days, results in the emplacement of approximately 750,000 l (180,000 gal) of slurry. Disposal cost per liter is approximately $0.30, including capital costs of the facility. This subsurface disposal process is fundamentally different from other operations. Wastes are injected into a low-permeability aquitard, and the process is designed to isolate nuclides, preventing dispersion in groundwaters. The porosity into which wastes are injected is created by hydraulically fracturing the host formation along bedding planes. The site is in the structurally complex Valley and Ridge Province. The stratigraphy consists of lower Paleozoic rocks. Investigations are under way to determine the long-term hydrologic isolation of the injection zone and the geochemical impact of saline groundwater on nuclide mobility. Injections are monitored by gamma-ray logging of cased observation wells to determine grout sheet orientation after an injection. Recent monitoring work has involved the use of tiltmeters, surface uplift surveys, and seismic arrays. 26 refs., 7 figs

Status of the Oak Ridge National Laboratory new hydrofracture facility: Implications for the disposal of liquid low-level radioactive wastes by underground injection

From 1982 to 1984, Oak Ridge National Laboratory (ORNL) disposed of approximately 2.8 x 10/sup 16/ Bq (7.5 x 10/sup 5/ Ci) of liquid low-level radioactive wastes by underground injection at its new hydrofracture facility. This paper summarizes the regulatory and operational status of that ORNL facility and discusses its future outlook. Operational developments and regulatory changes that have raised major questions about the continued operation of the new hydrofracture facility include: (1) significant /sup 90/Sr contamination of some groundwater in the injection formation; (2) questions about the design of the injection well, completed prior to the application of the underground injection control (UIC) regulations to the ORNL facility; (3) questions about the integrity of the reconfigured injection well put into service following the loss of the initial injection well; and (4) implementation of UIC regulations. Ultimately, consideration of the regulatory and operational factors led to the decision in early 1986 not to proceed with a UIC permit application for the ORNL facility. Subsequent to the decision not to proceed with a UIC permit application, closure activities were initiated for the ORNL hydrofracture facility. Closure of the facility will occur under both state of Tennessee and federal UIC regulations. The facility also falls under the provisions of part 3004(u) of the Resource Conservation and Recovery Act pertaining to corrective actions. Nationally, there is an uncertain outlook for the disposal of wastes by underground injection. All wells used for the injection of hazardous wastes (Class I wells) are being reviewed. 8 refs., 4 figs., 2 tabs

Waste disposal by hydrofracture and application of the technology to the management of hazardous wastes

A unique disposal method, involving hydrofracturing, has been used for management of liquid low-level radioactive wastes at Oak Ridge National Laboratory (ORNL). Wastes are mixed with cement and other solids and injected along bedding plane fractures into highly impermeable shale at a depth of 300 m forming a grout sheet. The process has operated successfully for 20 years and may be applicable to disposal of hazardous wastes. The cement grout represents the primary barrier for immobilization of the wastes; the hydrologically isolated injection horizon represents a secondary barrier. At ORNL work has been conducted to characterize the geology of the disposal site and to determine its relationship to the injection process. The site is structurally quite complex. Research has also been conducted on the development of methods for monitoring the extent and orientation of the grout sheets; these methods include gamma-ray logging of cased observation wells, leveling surveys of benchmarks, tiltmeter surveys, and microseismic arrays. These methods, some of which need further development, offer promise for real-time and post-injection monitoring. Initial suggestions are offered for possible application of the technology to hazardous waste management and technical and regulatory areas needing attention are addressed. 11 refs., 1 fig

A study of wrist-worn activity measurement as a potential real-world biomarker for late-life depression.

BACKGROUND: Late-life depression (LLD) is associated with a decline in physical activity. Typically this is assessed by self-report questionnaires and, more recently, with actigraphy. We sought to explore the utility of a bespoke activity monitor to characterize activity profiles in LLD more precisely. METHOD: The activity monitor was worn for 7 days by 29 adults with LLD and 30 healthy controls. Subjects underwent neuropsychological assessment and quality of life (QoL) (36-item Short-Form Health Survey) and activities of daily living (ADL) scales (Instrumental Activities of Daily Living Scale) were administered. RESULTS: Physical activity was significantly reduced in LLD compared with controls (t = 3.63, p < 0.001), primarily in the morning. LLD subjects showed slower fine motor movements (t = 3.49, p < 0.001). In LLD patients, activity reductions were related to reduced ADL (r = 0.61, p < 0.001), lower QoL (r = 0.65, p < 0.001), associative learning (r = 0.40, p = 0.036), and higher Montgomery-Åsberg Depression Rating Scale score (r = -0.37, p < 0.05). CONCLUSIONS: Patients with LLD had a significant reduction in general physical activity compared with healthy controls. Assessment of specific activity parameters further revealed the correlates of impairments associated with LLD. Our study suggests that novel wearable technology has the potential to provide an objective way of monitoring real-world function.This study was funded by an award from the UK Medical Research Council (G1001828/1)