A dual-mode engine has been developed where in one mode all engine cylinders fire normally, providing locomotion for the vehicle. In the other mode, one cylinder of the engine is used to compress low pressure residential natural gas (NG), in multiple stages, to a standard U.S. compressed natural gas (CNG)...
This work experimentally assesses the thermodynamic performance of the only single kWe, variable-output continuous duty, internal combustion engine driven, residential micro-combined heat and power (mCHP generator (Marathon Engine Systems ecopower) available in the United States. The system underwent steady state testing over its full operating range, and first (energy) and...
The use of antioxidants is now often used as a pharmacological adjunct to limit infertility. Indeed, the lay public rightly perceives oxidative stress and, thus, antioxidant treatment as important modulators of infertility. While the direct effects of antioxidant treatment on the quality of semen and oocytes are still under investigation,...
Mortality due to infectious diseases is seldom reported in the Greater Sage-Grouse (Centrocercus urophasianus). A case of necrotic enteritis associated with Clostridium perfringens type A is described in a free-ranging adult male sage-grouse in eastern Oregon. Clostridial enteritis is known to cause outbreaks of mortality in various domestic and wild...
Water scarcity in semiarid environments provides a model system to evaluate the role of mesic resources in structuring the distribution and abundance of wildlife. We used remote sensing and point process analyses to evaluate spatio–temporal variability in limited mesic resources in relation to greater sage-grouse (Centrocercus urophasianus) distributions in Oregon,...
The primary objective of Leg 138 was to provide detailed information about the ocean's response to global climate change
during the Neogene. Two north south transects were drilled (95° and 110°W) within the region of equatorial divergence driven
upwelling (and thus high accumulation rates and resolution) and spanning the major...
The distribution and range of lesser prairie-chicken (Tympanuchus pallidicinctus) has been reduced by >90% since European settlement of the Great Plains of North America. Currently, lesser prairie-chickens occupy 3 general vegetation communities: sand sagebrush (Artemisia filifolia), sand shinnery oak (Quercus havardii), and mixed-grass prairies juxtaposed with Conservation Reserve Program grasslands....
Greater sage-grouse (Centrocercus urophasianus) have been subject to long-term and continuing declines in population and habitat since European settlement of western North America. Increased wildfire activity constitutes a primary threat to the species in western portions of their range, with documented declines in wildfire-affected populations. Following a 187,000-ha wildfire in...
The distribution and range of the greater sage-grouse Centrocercus urophasianus have been reduced by 56% since the European settlement of western North America. Although there is an unprecedented effort to conserve the species, there is still considerable debate about the vegetation composition and structure required for nesting and brood-rearing habitat....
We conducted this 2-year study to determine if lesser prairie-chickens Tympanuchus pallidicinctus and ring-necked pheasants Phasianus colchicus used the same habitats where their ranges overlapped in southwestern Kansas. Telemetry locations of 50 transmitter-equipped lesser prairie-chickens and 28 pheasants were used to monitor habitat use by the two species. Additionally, vegetation...
Invertebrates are an important food source for grouse chicks, especially within the first 2 weeks of life. Invertebrate abundance is highly patchy and dependent upon herbaceous cover and vegetation structure. We examined the relationship between invertebrate biomass (from sweepnet samples) and habitat structure at lesser prairie-chicken (Tympanuchus pallidicinctus) brood-use and...
We used mark-recapture methods to estimate age-specific apparent survival rates for male Lesser Prairie-Chickens (Tympanuchus pallidicinctus), a gamebird of conservation concern. A total of 311 male prairie-chickens (135 yearlings, 176 adults) were captured and banded during a 5-year study in southwest Kansas. Time-since-marking models were used to estimate apparent survival...
The ability to ascertain gender and age of juvenile grouse is essential for determining gender-specific population age structure and studying timing of reproductive events, respectively. We examined outer rectrix feathers from juvenile Lesser Prairie-Chickens (Tympanuchus pallidicinctus) captured at 30–40 and 50–60 days post-hatching. Blood samples were collected from most chicks...
The distribution and geographic range of Greater Sage-Grouse (Centrocercus urophasianus) have been reduced by 56% since European settlement. Although loss and fragmentation of sagebrush (Artemisia spp.) habitats have been cited as the primary causes for the decline of the species, degradation of existing habitat also has been considered an important...
The distribution and geographic range of Greater Sage-Grouse (Centrocercus urophasianus) have been reduced by 56% since European settlement. Although loss and fragmentation of sagebrush (Artemisia spp.) habitats have been cited as the primary causes for the decline of the species, degradation of existing habitat also has been considered an important...
An exact integral solution for the moisture profile in growing fingers in sandy soil is derived from Richards' equation. The solution provides moisture content along a finger as a function of position and time and provides applicable results, including the calculation of the asymptotic matric potential of a growing finger...
Sediments from five Leg 167 drill sites and three piston cores were analyzed for C[subscript ORG] and CaCO₃. Oxygen isotope stratigraphy on benthic foraminifers was used to assign age models to these sedimentary records. We find that the northern and central California margin is characterized by k.y.-scale events that can...
Low-temperature combustion (LTC) engine concepts such as homogeneous charge compression ignition (HCCI) offer the potential of improved efficiency and reduced emissions of NOₓ and particulates. However, engines can only successfully operate in HCCI mode for limited operating ranges that vary depending on the fuel composition. Unfortunately, traditional ratings such as...
Greater sage-grouse (Centrocercus urophasianus; sage-grouse) are highly susceptible to infection with West Nile virus (WNV), with substantial mortality reported in wild populations and in experimentally infected birds. Although sage-grouse are hunted throughout much of their range, they have also recently been considered for protection under the Endangered Species Act. We...
Broadband absorption spectroscopy, by way of FTIR, was used to investigate the vapor cloud of a single millimeter sized liquid droplet suspended by a syringe as it evaporates at standard conditions. Single beam data were collected every 8 seconds resulting in a time-resolved record. Species concentrations were tracked using their...
A new metric for ranking the suitability of fuels in LTC engines was recently introduced, based on the fraction of potential fuel savings achieved in the FTP-75 light-duty vehicle driving cycle. In the current study, this LTC fuel performance index was calculated computationally and analyzed for a number of fuel...
Liquid transportation fuels require costly and time-consuming tests to characterize metrics, such as Research Octane Number (RON) for gasoline. If fuel sale restrictions requiring use of standard Cooperative Fuel Research (CFR) testing procedures do not apply, these tests may be avoided by using multivariate statistical models to predict RON and...
A stable-isotope stratigraphy at Site 846 (tropical Pacific, 3°06'S, 90°49'W, 3307 m water depth), based on the benthic
foraminifers Cibicides wuellerstorfi and Uvigerina peregrina, yields a high-resolution record of deep-sea δ¹⁸O and δ¹³C over the
past 1.8 Ma, with an average sampling interval of 3 k.y. Variance in the δ¹⁸O...
The data presented in this report demonstrate significant improvements
in the ability to constrain trace element and Sr isotopic
concentrations in sediments overlying ridge-flank hydrothermal
systems. Improved sampling methods orchestrated by the Integrated
Ocean Drilling Program (i.e., advanced piston coring and
anoxic sample processing) enabled the collection of reactive pore...
High resolution, continuous records of GRAPE wet bulk density (a carbonate proxy) from Ocean Drilling Program Leg 138
provide one the opportunity for a detailed study of eastern equatorial Pacific Ocean carbonate sedimentation during the last 6 m.y.
The transect of sites drilled spans both latitude and longitude in the...
Establishing true depths of recovered sediments is critical to determining sedimentation rates for high-resolution paleoclimatic
studies. We have corrected the composite depth scale, which accounts for the entire continuous sedimentary sequence, so that sediment
depths are consistent with logging depths, or "true" depths. We accomplished this by taking advantage of...
The distribution of the Lesser Prairie-Chicken (Tympanuchus pallidicinctus) has been markedly reduced due to loss and fragmentation of habitat. Portions of the historical range, however, have been recolonized and even expanded due to planting of conservation reserve program (CRP) fields that provide favorable vegetation structure for Lesser Prairie-Chickens. The source...
Design of a small scale rotating fluidized bed (RFB) with diameter of 4-6 cm to fluidize 40-80 mu m diameter particles was investigated using computational fluid dynamics (CFD). Simulations explored the impact of the following components on pressure drop and fluidized behavior of the device: particle size, particle density, outer...
Ocean Drilling Program (ODP) Leg 202 has opened a new window
into understanding late Paleogene and Neogene global environmental
change by providing high-quality sediment sequences from a previously
unsampled region, the eastern South Pacific. Eleven sites (1232–
1242) that record variations on timescales ranging from decades to tens
of millions...
We analyzed the unsaturation ratio (U k/37 ) of long-chain ketones—a molecular sea-surface temperature (SST) indicator—concentrations of carbonate and organic carbon in sediments from Site 846 in the eastern equatorial Pacific Ocean. Based on an isotopic age model for the composite depth section of 0-46 m below seafloor and on...
Livestock fences have been hypothesized to significantly contribute to mortality of lesser prairie-chickens (Tympanuchus pallidicinctus); however, quantification of mortality due to fence collisions is lacking across their current distribution. Variation in fence density, landscape composition and configuration, and land use could influence collision risk of lesser prairie-chickens. We monitored fences...
Pollen analyses of sediments from Holes 1019C, 1019E, 1020C, and 1020D as well as piston Core EW9504-17 provide
continuous, chronostratigraphically controlled proxy vegetation and climate data for coastal northwest North America for the
last ~500 k.y. Systematic changes in the representation of the diagnostic components of northern California plant assemblages...
We conducted a 3-year study of helminth parasites to assess their effect on the lesser prairie-chicken Tympanuchus pallidicinctus. Helminth parasites were found in most of the examined wild prairie chicken carcasses: 95% had eye worm Oxyspirura petrowi, 92% had stomach worm Tetrameres sp., and 59% had caecal worm Subulura sp....
Calcium carbonate percentages at five Ceara Rise sites were estimated at 1- to 2-k.y. intervals over the past 5 m.y., using
reflectance spectroscopy and magnetic susceptibility proxies. From these estimates and detailed correlations between sites, gradients
of calcite and terrigenous sediment accumulation rates in a depth transect of sites reveal...
Sediment spectral reflectance measurements were generated aboard the JOIDES Resolution during Ocean Drilling Program Leg 162 shipboard operations. The large size of the raw data set (over 1.3 gigabytes) and limited computer hard disk storage space precluded detailed analysis of the data at sea, although broad band averages were used...
Conservation of wildlife depends on an understanding of the interactions between animal movements and key landscape factors. Habitat requirements of wide-ranging species often vary spatially, but quantitative assessment of variation among replicated studies at multiple sites is rare. We investigated patterns of space use for 10 populations of two closely...
Cumulative loss of habitat and long-term decline in the populations of the Lesser Prairie-Chicken (Tympanuchus pallidicinctus) have led to concerns for the species’ viability throughout its range in the southern Great Plains. For more efficient conservation past and present distributions of genetic variation need to be understood. We examined the...
This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
Grasslands account for a large proportion of global terrestrial productivity and play a critical role in carbon and water
cycling. Within grasslands, photosynthetic pathway is an important functional trait yielding different rates of productivity
along environmental gradients. Recently, C₃-C₄ sorting along spatial environmental gradients has been reassessed by
controlling for...
During ODP Leg 138, we tested a prototype instrument, developed
at Oregon State University, for measuring light reflectance in 511
channels of the visible and near-infrared bands. The technique of
reflectance spectroscopy has been used for some time in chemistry
and mineralogy (e.g., Hunt, 1977; Gaffey, 1986) and has found...
Ocean Drilling Program (ODP) Leg 138 was designed to study the late Neogene paleoceanography of the equatorial Pacific Ocean at time scales of thousands to millions of years. Crucial to this objective was the acquisition of continuous, high-resolution sedimentary records. It is well known that between successive advanced piston corer...
To facilitate the selection of drill sites for Leg 138, a site survey
program was conducted on board the Scripps Institution of
Oceanography's research vessel Thomas Washington (Cruise Venture
1). During this cruise, which departed San Diego on 30 August 1989
and arrived in Manzanillo, Mexico, on 4 October 1989,...
The shallow sections of most holes drilled during Ocean Drilling Program Leg 139 contain alkenones derived from prymnesiophyte algae. The alkenones indicate a paleotemperature of the photic zone in the upper ocean during primary carbon fixation of 7°-15°C, with an average of 10.7°C. Based on laboratory hydrous pyrolyses these alkenones...
The sorbed gases at all four Ocean Drilling Program Leg 139 sites (855, 856, 857, and 858) showed the unmistakable presence of thermogenic hydrocarbons. No indication of abiogenic gas was found. The evidence for the thermogenic hydrocarbons includes elevated contents of higher hydrocarbons (i.e., C₁/[C₂ + C₃] ca. 2-20), δ¹³CCH₄...
We present benthic isotope stratigraphies for Sites 1236, 1237, 1239, and 1241 that span the late Miocene–Pliocene time interval from 6 to 2.4 Ma. Orbitally tuned timescales were generated for Sites 1237 and 1241 by correlating the high-frequency variations in gamma ray attenuation density, percent sand of the carbonate fraction,...
Coring at ODP Sites 859, 860, and 861 near the Chile Triple Junction failed to recover anticipated gas hydrate that was inferred
to be present from two lines of geophysical evidence: pre-cruise observation of a weak to strong bottom simulating reflector (BSR)
marking the predicted base of the gas-hydrate stability...
The placement of ‘Pseudomonas butanovora’ in the genus Thauera was proposed previously, based on 16S rRNA gene sequence analysis, upon further studies of taxonomical characteristics. In this study, physiological characteristics and DNA–DNA reassociation data are presented and the transfer of ‘P. butanovora’ to the genus Thauera is proposed. The original...
Extensive first-pass metabolism of ingested bisphenol A (BPA) in the gastro-intestinal tract and liver restricts blood concentrations of bioactive BPA to < 1% of total BPA in humans and non-human primates. Absorption of ingested BPA through non-metabolizing tissues of the oral cavity, recently demonstrated in dogs, could lead to the...
AIM: C₄ photosynthesis is an adaptation that maintains efficient carbon assimilation in warm and low-CO₂ conditions. Due to the importance of C₄ grasses for carbon and surface energy fluxes numerous models have been proposed to describe their spatial distribution and forecast responses to climate change. These models often rely on...
Research progress to understand the role of vitamin C (ascorbic acid) in human health has been slow in coming. This is predominantly the result of several flawed approaches to study design, often lacking a full appreciation of the redox chemistry and biology of ascorbic acid. In this review, we summarize...