Search Results

Chemometric analyses of geochemical data for 165 crude oil samples from the San Joaquin Basin identify genetically distinct oil families and their inferred source rocks and provide insight into migration pathways, reservoir compartments, and filling histories. In the first part of the study, 17 source-related biomarker and stable carbon-isotope ratios...

The ecology of mosquito vectors and malaria parasites affect the incidence, seasonal transmission and geographical range of malaria. Most malaria models to date assume constant or linear responses of mosquito and parasite life-history traits to temperature, predicting optimal transmission at 31 °C. These models are at odds with field observations...

Herbivory has played a major role in dictating vegetation abundance and species composition at Kingman Marsh in Anacostia Park, Washington, D.C., since restoration of this tidal freshwater wetland was initiated in 2000. The diverse and robust vegetative cover that developed in the first year post-reconstruction experienced significant decimation in...

The Southern Oregon-Northeastern California (SONEC) region is an important migration and breeding area for Pacific Flyway waterfowl. Through a Conservation Effects Assessment Project (CEAP) partnership, the Intermountain West Joint Venture conducted a preliminary analysis of the contribution of SONEC Wetlands Reserve Program (WRP) enrollments in meeting recently established spring migrating waterfowl...

No abstract available....

As part of the assessment of undiscovered oil and gas resources in Jurassic and Cretaceous strata of the U.S. Gulf Coast in 2010, the U.S. Geological Survey assessed carbonate rocks of the Fredericksburg and Washita groups and their equivalent units underlying onshore lands and State waters. One conventional assessment unit...

In 1995, U.S. Geological Survey made the first systematic assessment of the volume of natural gas stored in the hydrate accumulations of the United States. That study, along with numerous other studies, has shown that the amount of gas stored as methane hydrates in the world greatly exceeds the volume...

The invasive yellow bluestem (Bothriochloa ischaemum [L.] Keng) threatens native biodiversity, and its control is of interest to land managers involved in restoration of invaded grasslands. We used single, double, and triple applications of glyphosate (2.125 kg ai.ha-1.application-1) over the course of one growing season in combinations at different timings...

We investigated the influence of Old World bluestem (Bothriochloa ischaemum; OWB) monocultures on grassland bird abundance through analysis of vegetation structure and food availability. We compared breeding bird density, vegetation structure and composition, and arthropod biomass between six native grass and six OWB fields in the southern Great Plains. The...

The International Seismological Centre–Global Earthquake Model (ISC–GEM) Global Instrumental Earthquake Catalogue (1900–2009) is the result of a special effort to substantially extend and improve currently existing global catalogs to serve the requirements of specific user groups who assess and model seismic hazard and risk. The data from the ISC–GEM Catalogue...

Managers in southern Nevada are challenge with determining appropriate goals and objectives and developing viable approaches for maintaining and restoring sustainable ecosystems in a time of rapid socio-ecological and environmental change. Sustainable or "healthy" ecosystems supply clean air, water and habitat for a diverse array of plants and animals. As...

This document describes progress to date on the development of a harvest‐management strategy for maintaining pink‐footed goose abundance near their target level by providing for sustainable harvests in Norway and Denmark. Many goose populations in western Europe have increased dramatically in recent decades. The Svalbard population of pink‐footed geese (Anser brachyrhynchus) is a good...

In most areas, rocks in the subsurface are saturated with water at relatively shallow depths. The top of the saturated zone—the water table—typically occurs anywhere from just below land surface to hundreds of feet below the land surface. Groundwater generally fills all pore spaces below the water table and is...

Dissolved organic carbon (DOC) flux from the Penobscot River and its major tributaries in Maine was determined using continuous discharge measurements, discrete water sampling, and the LOADEST regression software. The average daily flux during 2004–2007 was 71 kg C ha−1 yr−1 (392 Mt C d−1), an amount larger than measured...

A five-day odyssey, spanning 58 hours without decent sleep or meals, taught these researchers one thing-how not to find a wolf den....

Herein we provide excerpts of the reviewers' comments and our response. We did not duplicate the portion of the reviewers' comments in which they summarized our findings....

The economic vitality and quality of life of many northern Wisconsin communities is closely associated with the ecological condition of the abundant water resources in the region. Climate change models predict warmer temperatures, changes to precipitation patterns, and increased evapotranspiration in the Great Lakes region. Recently (1950-2006), many regions of...

Habitat connectivity is vital to the persistence of migratory fishes. Native tropical island stream fish assemblages composed of diadromous species require intact corridors between ocean and riverine habitats. High dams block fish migration, but low-head artificial barriers are more widespread and are rarely assessed for impacts. Among all 46 drainages...

Using classical molecular dynamics simulations, the 2D infrared (IR) spectroscopy of CN− solvated in D2O is investigated. Depending on the force field parametrizations, most of which are based on multipolar interactions for the CN− molecule, the frequency-frequency correlation function and observables computed from it differ. Most notably, models based on...

Species conservation has traditionally been based on individual species within the context of their requisite habitat, which is generally defined as the communities and ecosystems deemed necessary for their presence. Conservation decisions are hampered by the fact that environmental stressors that poetically threaten the persistence of species can operate at...

No abstract available....

To better understand the future spread of chronic wasting disease, we conducted a genetic assessment of mule deer Odocoileus hemionus population structure across the state of Montana, USA. Individual based analyses were used to test for population structure in the absence of a priori designations of population membership across the sampling area. Samples from...

Hydrologic connectivity can be an important driver of aquatic macroinvertebrate assemblages. Its effects on aquatic macroinvertebrate assemblages in coastal marshes, however, are relatively poorly studied. We evaluated the effects of lateral hydrologic connectivity (permanently connected ponds: PCPs; temporary connected ponds: TCPs), and other environmental variables on aquatic macroinvertebrate assemblages and...

The Hawaiian islands are home to a diverse array of plants and animals found nowhere else on Earth. Among the most famous of these are the spectacular Hawaiian honeycreepers, a group that evolved from a single flock of ancestral finches into at least 54 unique species. Unfortunately, the same isolation...

We find subdivisions within the Mojave Block using cluster analysis to identify groupings in the velocities observed at GPS stations there. The clusters are represented on a fault map by symbols located at the positions of the GPS stations, each symbol representing the cluster to which the velocity of that...