Estimating the total oxidant demand for in situ chemical oxidation design

Analytical techniques for designing of in situ chemical oxidation (ISCO) to treat organics in soil and groundwater are emerging. There are several issues that need to be resolved prior to adopting a standard analytical technique. Some of the more salient issues are discussed. In addition, currently practiced analytical techniques for estimating the oxidant demand for the oxidants permanganate and persulfate are provided. In the absence of analytical measurements, rules of thumb can be used with caution to estimate the overall oxidant demand. © 2003 Wiley Periodicals, Inc.     

Die Aleuronzellen des keimenden Getreides

Während der Vorbereitungen zu diesem Artikel war R. L. J. als Preisträger der Alexander-von-Humboldt-Stiftung in Göttingen tätig. Unsere Forschung auf diesem Gebiet wurde durch großzügige Hilfe der Deutschen Forschungsgemeinschaft und der National Science Foundation (USA) ermöglicht. Außerdem sind wir B. Raufeisen für die Herstellung der Zeichnungen sehr zu Dank verpflichtet.     

Classical foundations of the contemporary economic theory of non-renewable resources

There exists a formalized and well integrated neoclassical theory of the economics of non-renewable resources. While the classical economists did not deal with non-renewable resources as such, many of them did discuss the economics of the mining industry or of the mine. This paper reviews the theoretical aspects of the contemporary theory of the economics of non-renewable resources and contrasts them with the less formal treatment given by the classical economists. As well as affording a critical review of the classical literature this comparison indicates areas of the contemporary theory which need to be reassessed.     

Shoreline erosion in a reef-beach system

Beach erosion on Cinnamon Bay in the U.S. Virgin Islands results from storm waves in the North Atlantic. The net trend of erosion, however, is due to local environmental degradation. Reef die-back, initiated during the period of high sedimentation associated with 18th and 19th century sugar cane cropping, has reduced the rate of generation of new coral sands. Sand losses to deep water during periods of storm waves are not replenished. Engineering measures designed to check erosion at Cinnamon Bay have had little effect in this environment of low wave energies, but sand deficiency. The appropriate environmental focus for management of reef-beach systems is reef health and thus, water quality.     

New Proof-of-Concept in Viral Inactivation: Virucidal Efficacy of 405 nm Light Against Feline Calicivirus as a Model for Norovirus Decontamination

The requirement for novel decontamination technologies for use in hospitals is ever present. One such system uses 405 nm visible light to inactivate microorganisms via ROS-generated oxidative damage. Although effective for bacterial and fungal inactivation, little is known about the virucidal effects of 405 nm light. Norovirus (NoV) gastroenteritis outbreaks often occur in the clinical setting, and this study was designed to investigate potential inactivation effects of 405 nm light on the NoV surrogate, feline calicivirus (FCV). FCV was exposed to 405 nm light whilst suspended in minimal and organically-rich media to establish the virucidal efficacy and the effect biologically-relevant material may play in viral susceptibility. Antiviral activity was successfully demonstrated with a 4 Log₁₀ (99.99%) reduction in infectivity when suspended in minimal media evident after a dose of 2.8 kJ cm^?2. FCV exposed in artificial faeces, artificial saliva, blood plasma and other organically rich media exhibited an equivalent level of inactivation using between 50–85% less dose of the light, indicating enhanced inactivation when the virus is present in organically-rich biologically-relevant media. Further research in this area could aid in the development of 405 nm light technology for effective NoV decontamination within the hospital environment.     

Long-Term Changes in the Avifauna of Barro Colorado Island, Panama, a Tropical Forest Isolate

Since its isolation from the mainland more than 85 years ago, 65 bird species have disappeared from Barro Colorado Island, Panama. Because of these extinctions the island is often used as a model for the study of faunal relaxation, or loss of species through time. The most recent survey of the island's bird community was completed in 1970. Between June 1994 and May 1996 I surveyed the island and observed 218 species, including 5 species never before recorded. Three relatively sedentary species have experienced severe population declines since Willis's 1970 survey and may be on the brink of disappearing from the island. Willis estimated 500 Slate-colored Grosbeaks ( Pitylus grossus ), whereas I found only two pairs of this conspicuous midstory-dwelling finch. Two cotingas—Speckled Mourner ( Laniocera rufescens ) and Rufous Piha ( Lipaugus unirufus )—have declined by 85–95%. I did not locate any individuals of 36 other species that were present during the 1970s. Most (21) of these are uncommon aquatic or nocturnal species, which I may have missed during my surveys, or are rare to uncommon edge species that probably move frequently to and from the island. Seven species, however, are primarily inhabitants of second-growth forest and have been lost probably because of continuing successional maturation of the forest, including changes in land use around the laboratory clearing. Seven forest-dwelling species disappeared during the 1970s and have not recolonized. I detected only one sedentary forest-dwelling species, Great Currasow ( Crax rubra ), that previously had been reported as missing from the island. The nearly complete lack of recolonizations by such forest-interior species suggests that local extinction from tropical forest isolates may be extremely persistent. Tropical forest reserves as small as Barro Colorado Island (1600 ha) may not preserve high levels of regional avian diversity over long periods of time.     

Individual differences in foraging behavior and cortisol levels in recently emerged brook charr (Salvelinus fontinalis)

Recently emerged brook charr (Salvelinus fontinalis) foraging in still-water pools along the sides of streams tend to be either sedentary, feeding from the lower portion of the water column (a sit-and-wait tactic), or very active, feeding from the upper portion of the water column (an active search tactic). We tested whether the individual differences in foraging behavior were associated with baseline concentrations and responses of cortisol, a steroid hormone linked to personality differences in a variety of animals including fishes. We quantified the proportion of time spent on moving by focal charr in the field and then capturing them. Captured individuals were either (i) sacrificed immediately to quantify baseline cortisol concentrations, (ii) held in an unfamiliar field environment for 15 min and then sacrificed to quantify cortisol concentrations in response to handling and holding in a novel field environment, or (iii) held in an unfamiliar field environment with a white Plexiglas base (stressor) for 15 min to quantify cortisol concentrations in response to a novel object. Eleven statistical models relating cortisol concentrations to the proportion of time individuals spent on moving while searching for prey were compared using multi-model inferencing. Cortisol concentrations were higher for charr that spent a lower proportion of time on moving in the field than for charr that spent a higher proportion of time on moving. For a given proportion of time spent on moving, mean cortisol concentrations between baseline and experimental treatments, our measure of cortisol response, did not differ markedly. Our findings suggest that the foraging tactics displayed by wild brook charr in the field could reflect differences in how individuals perceive their environment.     

Modeled historical land use and land cover for the conterminous United States

The landscape of the conterminous United States has changed dramatically over the last 200 years, with agricultural land use, urban expansion, forestry, and other anthropogenic activities altering land cover across vast swaths of the country. While land use and land cover (LULC) models have been developed to model potential future LULC change, few efforts have focused on recreating historical landscapes. Researchers at the US Geological Survey have used a wide range of historical data sources and a spatially explicit modeling framework to model spatially explicit historical LULC change in the conterminous United States from 1992 back to 1938. Annual LULC maps were produced at 250-m resolution, with 14 LULC classes. Assessment of model results showed good agreement with trends and spatial patterns in historical data sources such as the Census of Agriculture and historical housing density data, although comparison with historical data is complicated by definitional and methodological differences. The completion of this dataset allows researchers to assess historical LULC impacts on a range of ecological processes.