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A significant increase in catastrophic wildfires in the interior West of the United States has left public land agencies scrambling to reduce dangerous fuel loads and manage forests according to an ecological understanding of fire and forest health. However, this has not translated into standardized on-the-ground fire and fuel management in public land agencies. Different on-the-ground management practices raise questions about the extent to which ecosystems management is being utilized and how well land agencies are adapting to their new responsibilities. This study employs an institutional analysis and development framework to examine how and why on-the-ground decisions and outcomes differ. Decisions and outcomes are discussed as a function of the multiple layers of institutions that guide and constrain the decision processes of line officers who are responsible for developing and executing fire and fuel management projects. [ABSTRACT FROM AUTHOR]

The Blue Ridge escarpment is a rugged landform situated within the ancient Appalachian orogen. While similar in some respects to the great escarpments along other passive margins, which have evolved by erosion following rifting, its youthful topographic expression has inspired proposals of Cenozoic tectonic rejuvenation in eastern North America. To better understand the post-orogenic and post-rift geomorphic evolution of passive margins, we have examined the origin of this landform using low-temperature thermochronometry and manipulation of topographic indices. Apatite (U–Th)/He and fission-track analyses along transects across the escarpment reveal a younging trend towards the coast. This pattern is consistent with other great escarpments and fits with an interpretation of having evolved by prolonged erosion, without the requirement of tectonic rejuvenation. Measured ages are also comparable specifically to those measured along other great escarpments that are as much as 100 Myr younger. This suggests that erosional mechanisms that maintain rugged escarpments in the early post-rift stages may remain active on ancient passive margins for prolonged periods. The precise erosional evolution of the escarpment is less clear, however, and several end-member models can explain the data. Our preferred model, which fits with all data, involves a significant degree of erosional escarpment retreat in the Cenozoic. Although this suggests that early onset of topographic stability is not required of passive margin evolution, more data are required to better constrain the details of the escarpment's development. [ABSTRACT FROM AUTHOR]

Carbon sequestration was estimated a northern mixed-grass prairie site and a sagebrush–steppe site in southeastern Wyoming using an approach that integrates remote sensing, CO2 flux measurements, and meteorological data. Net ecosystem exchange (NEE) of CO2 was measured using aircraft and ground flux techniques and was linearly related to absorbed photosynthetically active radiation (APAR). The slope of this relationship is the radiation use efficiency (ℇ = 0.51 g C/MJ APAR); there were no significant differences in the regression coefficients between the two sites. Furthermore, ecosystem chamber measurements of total respiration in 1998 and 1999 were used to develop a functional relationship with daily average temperature; the Q10 of the relationship was 2.2. Using the Advanced Very High Resolution radiometer. Normalized Difference Vegetation Index and meteorological data, annual gross primary production and respiration were calculated from 1995 to 1999 for the two sites. Overall, the sagebrush–steppe site was a net carbon sink, whereas the northern mixed-grass prairie site was in carbon balance. There was no significant relationship between NEE and APAR for a coniferous forest site, indicating this method for scaling up CO2 flux data may be only applicable to rangeland ecosystems. The combination of remote sensing with data from CO2 flux networks can be used to estimate carbon sequestration regionally in rangeland ecosystems. [ABSTRACT FROM AUTHOR]

The Washington Cascade Range is a complex, polygenetic mountain range that dominates the topographic, climatic, and cultural configurations of Washington State. Although it has been the locus of ongoing arc magmatism since the Eocene, most of the range is distinct from the southern part of the arc in Oregon and California in that bedrock uplift has produced high surface elevations and topographic relief, rather than volcanic burial or edifice construction. (U-Th)/He and fission-track ages of bedrock samples on the east flank of the range record relatively rapid cooling in the early Tertiary, but slow exhumarion rates (∼0.2 km/m.y.) through most of the Oligocene. Samples on the west flank suggest rapid cooling in the late Miocene (8-12 Ma), and age variations in vertical transects are consistent with a pulse of rapid exhumation (0.5-1.0 km/m.y.) at that time. Apatite He ages as young as 1-5 Ma in several areas suggest that high cooling and possibly exhumation rates persist locally. Accelerated exhumation rates ca. 10 Ma are also observed in the Coast Mountains of British Columbia and southeast Alaska, ∼ 1500 km to the north, suggesting a large-scale mechanism for the exhumation pulse at that time. [ABSTRACT FROM AUTHOR]

Focuses on the laramide exhumation of the Bighorn Mountains in Wyoming. Preservation of a pre-Laramide partial retention zone; Temperature at the Cambrian unconformity; Sequences of sedimentary rocks.

Presents a study which evaluated the invasion of annual brome grasses into a northern mixed grass prairie/ponderosa pine forest ecotone at Wind Cave National Park, South Dakota. Methods; Results and discussion.

Presents a study which erupted basaltic lavas from vents in the central Washington Cascades. Characteristics of arch basalts; Samples and methods; Results; Discussion; Conclusions.

Investigates the subsurface geology and origin of the Lihue basin in the Hawaiian island of Kauai. Indications of a gradual decrease in the extent of partial melting of mantle sources in time in the Koloa Volcanics; Indications of the Lihue basin formation by structural collapse; Deposits of debris flows which form large matrix-supported breccia throughout the basin.

Examines the pattern of changes in above-ground plant litter with altitude in the White Mountains of New Hampshire. Physical changes along the altitudinal gradient; Influence of temperature and evapotranspiration on litterfall.

Evaluates the deductibility of restitutionary payments under section 165 of the Internal Revenue Code in the United States. Scrutiny on the standard of restitutionary payments in accordance to national and state policies; Interpretation of the public policy exception to deductibility under section 165 by the Tax Court; Consequences of the criminal activities of taxpayers.

Past studies of tectonically active mountain ranges have suggested strong coupling and feedbacks between climate, tectonics and topography. For example, rock uplift generates topographic relief, thereby enhancing precipitation, which focuses erosion and in turn influences rates and spatial patterns of further rock uplift. Although theoretical links between climate, erosion and uplift have received much attention, few studies have shown convincing correlations between observable indices of these processes on mountain-range scales. Here we show that strongly varying long-term (>106-107?yr) erosion rates inferred from apatite (U-Th)/He cooling ages across the Cascades mountains of Washington state closely track modern mean annual precipitation rates. Erosion and precipitation rates vary over an order of magnitude across the range with maxima of 0.33?mm?yr-1 and 3.5?m?yr-1, respectively, with both maxima located 50?km west (windward) of the topographic crest of the range. These data demonstrate a strong coupling between precipitation and long-term erosion rates on the mountain-range scale. If the range is currently in topographic steady state, rock uplift on the west flank is three to ten times faster than elsewhere in the range, possibly in response to climatically focused erosion. [ABSTRACT FROM AUTHOR]

The article focuses on a study conducted by R. M. Tuttle and colleagues regarding the staging, treatment and follow-up of differentiated thyroid carcinoma (DTC). An overview of the situation involving the aftercare of patients with DTC is provided including the absence of a scoring system to predict the risk of recurrence. The problem in using the American Thyroid Association (ATA) staging system is discussed in relation to recurrences that indicated unsuccessful ablation of postoperative thyroid remnant tissue.

View quality rating is an important component of land management that is still undergoing parameter definition and technical development.Methods enabling the efficient and accurate quantification of viewshed properties over large viewsheds using readily available data are particularly needed. This paper describes a procedure for measuring a suite of visual properties known to influence viewer preferences for hundreds of observation points in extensive Wyoming landscapes. Planimetric and panoramic simulations were used for quantifying appropriate viewshed parameters. These simulations were created in ArcInfo using USGS digital elevation data and satellite-derived landcover. The planimetric simulation was ideal for quantifying the dimensions of views (areal extent, depth, relief), but not adequate for quantifying thecomposition of views (landcover, diversity, and edge of landcover). Instead, a high correlation existed between panoramic estimates of landcover and equivalent images captured in the field (r2=0.97). The viewsheds examined in this study had large areal extents, large relief, extended depth, and naturalness, and may extend beyond the spatial scales for which view-quality concepts and preference relationships were developed. [ABSTRACT FROM AUTHOR]

Synconvergent extension within orogenic systems is often interpreted as gravitational spreading of thickened crust or as a response to thrust belt dynamics. However, the processes that spatially localize extension during orogenesis are not fully understood. Here, a case study from the United States Cordillera demonstrates that localized upper-crustal thickening can exert a first-order control on the spatial location of synorogenic extension. The Eureka culmination, a 20-km-wide, north-trending anticline with 4.5 km of structural relief in the hinterland plateau of the Sevier orogenic belt (or "Nevadaplano") in eastern Nevada was deformed by two sets of north-striking normal faults that pre-date late Eocene volcanism. (U-Th)/He and fission-track thermochronology data collected from Paleozoic quartzite in the footwalls of two normal faults demonstrate rapid (10 °C/m.y.), Late Cretaceous to Paleocene (75-60 Ma) cooling, which we interpret as tectonic exhumation during extension, and which was concurrent with late-stage shortening in the frontal Sevier thrust belt. This example illustrates that structural and topographic relief generated within zones of localized upper-crustal thickening can spatially focus extension during orogenesis, and adds to a growing body of evidence that Late Cretaceous-Paleocene extension in the Nevadaplano occurred at both mid- and upper-crustal levels. [ABSTRACT FROM AUTHOR]

Abstract: As part of a larger research project initiated by the Geospatial Determinants of Health Outcomes Consortium (GeoDHOC), an air quality study was conducted in an international airshed encompassing Detroit, Michigan, USA, and Windsor, Ontario, Canada. Active and passive samplers were used to measure nitrogen dioxide (NO2), sulfur dioxide (SO2), 26 volatile organic compounds (VOCs), 23 polycyclic aromatic hydrocarbons (PAHs) and pesticides, and three size fractions of particulate matter (PM) over a two-week period in September, 2008. Measurements of NO2 and 14 VOCs were found to be acceptable at 98 out of 100 passive monitoring sites. PAH and PM measurements were acceptable at 38 out of 50 active sites. Mean concentrations for all analytes except for PM2.5–10 were higher in Detroit than Windsor by a factor of up to 1.8. Strong statistical correlations were found among benzene, toluene, ethylbenzene, and xylene (BTEX), as well as between NO2 and PM in Detroit. In Windsor, the strongest correlations were between NO2 and total VOCs, as well as total PAHs and total VOCs. Differences in the degree of correlation observed in Detroit and Windsor are attributable to differences in the volume and composition of emissions within the two cities. Spatial variability was evaluated using a combination of statistical (coefficient of variation) and geostatistical (standardized variogram slope) metrics together with concentration maps. Greater spatial variability was observed for total VOCs and total BTEX in Detroit, while greater variability of NO2, total PAHs, and PM was found in Windsor. Results of this study suggest that statistical correlations between NO2 and other contaminants may not provide sufficient justification for the indiscriminant use of NO2 as a proxy for those contaminants if smaller scale features are to be reproduced. [Copyright &y& Elsevier]