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At least 1,387 records · Page 77Linked to original sources
USGS2010

The mobilization of aluminum in a natural soil system: Effects of hydrologic pathways

A two-component soil water flow model was used in conjunction with an equilibrium speciation model WATEQF to study aluminum mobility in soils of a forested watershed, White Oak Run, in the Shenandoah National Park, Virginia. Soil solution samples, taken from the O, E, B, C 1 , and C 2 horizons, were collected from zero-tension lysimeters designed to collect faster gravitational macropore flow and tension lysimeters designed to collect slower capillary micropore flow. Dissolved aluminum was fractionated into acid-soluble, inorganic monomeric, and organic monomeric aluminum. Soil water aluminum concentrations decreased with depth indicating that the deep soil is a sink for aluminum. All waters contained significant concentrations of acid-soluble aluminum and exhibited a negative correlation between p H and the inorganic monomeric aluminum concentrations. Water in the shallow soil showed distinctly different chemical compositions for the two flow types, while C horizon micropore and macropore waters were more similar. Because of its shorter residence time, water flowing in deep soil macropores underwent less extensive neutralization and immobilization of aqueous aluminum than micropore water. The O horizon macropore waters were undersaturated for all hydroxide, silicate, and sulfate mineral phases considered. The C horizon samples from both flow types were near equilibrium with respect to kaolinite and synthetic gibbsite, indicating that mineral solubility controls water chemistry in the deep soil, while organic substances are the key control in the shallow macropore waters.

Water Resources Research↗
USGS2003

Sulfur geochemistry of hydrothermal waters in Yellowstone National Park, Wyoming, USA. III. An anion-exchange resin technique for sampling and preservation of sulfoxyanions in natural waters

A sampling protocol for the retention, extraction, and analysis of sulfoxyanions in hydrothermal waters has been developed in the laboratory and tested at Yellowstone National Park and Green Lake, NY. Initial laboratory testing of the anion-exchange resin Bio-Rad??? AG1-X8 indicated that the resin was well suited for the sampling, preservation, and extraction of sulfate and thiosulfate. Synthetic solutions containing sulfate and thiosulfate were passed through AG1-X8 resin columns and eluted with 1 and 3 M KCl, respectively. Recovery ranged from 89 to 100%. Comparison of results for water samples collected from five pools in Yellowstone National Park between on-site IC analysis (U.S. Geological Survey mobile lab) and IC analysis of resin-stored sample at SUNY-Stony Brook indicates 96 to 100% agreement for three pools (Cinder, Cistern, and an unnamed pool near Cistern) and 76 and 63% agreement for two pools (Sulfur Dust and Frying Pan). Attempts to extract polythionates from the AG1-X8 resin were made using HCl solutions, but were unsuccessful. Bio-Rad??? AG2-X8, an anion-exchange resin with weaker binding sites than the AG1-X8 resin, is better suited for polythionate extraction. Sulfate and thiosulfate extraction with this resin has been accomplished with KCl solutions of 0.1 and 0.5 M, respectively. Trithionate and tetrathionate can be extracted with 4 M KCl. Higher polythionates can be extracted with 9 M hydrochloric acid. Polythionate concentrations can then be determined directly using ion chromatographic methods, and laboratory results indicate recovery of up to 90% for synthetic polythionate solutions using AG2-X8 resin columns. ?? The Royal Society of Chemistry and the Division of Geochemistry of the American Chemical Society 2003.

Geochemical Transactions↗
USGS2010

Discussion of "Natural hydrograph of the Missouri River near Sioux City and the least tern and piping plover" by Donald G. Jorgensen

The author analyzed stream-flow data from a single gauging station to predict preengineering flooding frequency for "sandbar islands adjacent to stream gauge on the Missouri River at Sioux City." He predicted dates that sandbars would be exposed and discussed his results relative to reproduction by least terns (Sternula antillarum) and piping plovers (Charadrius melodus). His analysis predicted sandbar inundation during nesting and concluded that "successful migrations of age-zero juveniles leading to recruitment would not have resulted from the use of the sandbar islands for attempted reproduction most years in the Sioux City area." We argue that the author (1) overlooked published historical records of breeding terns and plovers on the Missouri River and nearby systems, (2) inaccurately portrayed inundation for Missouri River sandbars and the importance of high flows for forming sandbars, and (3) underestimated these species' ability to withstand periodic reproductive failures. We conclude that the data do not support the author's contention that the preengineered Missouri River was "unfriendly" to terns and plovers.

Iowa↗
USGS2022

Preliminary national-scale seismic risk assessment of natural gas pipelines in the United States

Although the gas pipeline infrastructure in the United States is vulnerable to the seismic hazards of (i) strong ground shaking, and (ii) ground failures induced by surface faulting, liquefaction, or landslides, limited national guidance exists for operators to consistently evaluate the earthquake response of their pipelines. To provide additional information for stakeholders and establish more consistency at a national scale, we attempt to quantify seismic risk for gas transmission pipelines in the conterminous United States using a metric such as average annual loss, which helps readily distinguish geographic areas of high and low relative risk. Specifically, we integrate the 2018 National Pipeline Mapping System, the 2018 National Seismic Hazard Model, and several candidate models from the literature for estimating pipeline damage. Through this effort, we highlight major research needs for ultimately reducing the many uncertainties associated with a comprehensive seismic risk assessment of gas pipelines.

conterminous United States↗
USGS1991

Zoned garnets in metapelites in western Fiordland, southwest New Zealand: polychronic crystallisation and insight into the nature and extent of early Cretaceous regional metamorphism

Two distinct types of compositional zoning are recognised in idioblastic to subidioblastic garnets in amphibolite facies metapelites in western Fiordland. One type occurs in kyanite (?? sillimanite)-bearing rocks and is characterised by a core to rim increase in CaO content, and a sympathetic decrease in FeO and MgO, with MnO remaining essentially constant, or decreasing slightly near the rim. This zoning pattern formed during garnet growth, and records adjustment of mineral equilibria under conditions of increasing load pressure. A much less common type of zoned garnet occurs in sillimanite + K-feldspar-bearing metapelites and is characterised by a core to rim decrease in CaO and MgO contents and a sympathetic increase in FeO and MnO near the rim. This zoning pattern is interpreted to result from post-growth volume diffusion, and records metamorphism at significantly lower pressures. -from Author

New Zealand Journal of Geology and Geophysics↗
USGS1993

Nature of migrabitumen and their relation to regional thermal maturity, Ouachita Mountains, Oklahoma

Two grahamite and three impsonite localities are within an 82-km-long segment of the Ouachita Mountains of southeastern Oklahoma. Grab samples were collected to study the petrographic and geochemical characteristics of the migrabitumen at the grahamite-impsonite transition and the relation of the migrabitumen to the regional thermal maturity pattern. Maximum and random bitumen reflectance values increased from 0·75 to 1·80% from west to east, consistent with the regional thermal maturation trend. Mean bireflectance values increased from 0·04 to 0·38%. The two grahamite samples are classified at the grahamite-impsonite boundary with conflicting petrographic (bitumen reflectance) and bulk chemical (volatile matter) maturity indicators. The regional maturation trend, based on vitrinite reflectance and bitumen reflectance values, was confirmed by a detailed geochemical investigation of bitumen extracts. Although biomarker analyses were influenced by extensive biodegradation effects, molecular parameters based on the phenanthrenes, dibenzothiophenes, and tricyclic terpanes were identified as useful maturity indicators.

Oklahoma↗
USGS1999

Ozone-induced changes in natural organic matter (NOM) structure

Hydrophobic organic acids (combined humic and fulvic acids), obtained from an Antarctic Lake with predominantly microbially derived organic carbon sources and two US river systems with terrestrial organic carbon sources, were ozonated. Several analyses, including 13 C‐NMR, UV absorbance, fluorescence, hydrophobic/transphilic classification, and potentiometric titrations, were performed before and after ozonation. Ozonation reduced aromatic carbon content, selectively reducing phenolic carbon content. Ozonation of the samples resulted in increased aliphatic, carboxyl, plus acetal and ketal anomeric carbon content and shifted towards less hydrophobic compounds.

Ozone: Science and Engineering↗
USGS2007

Microcystin distribution in physical size class separations of natural plankton communities

Phytoplankton communities in 30 northern Missouri and Iowa lakes were physically separated into 5 size classes (>100 µm, 53-100 µm, 35-53 µm, 10-35 µm, 1-10 µm) during 15-21 August 2004 to determine the distribution of microcystin (MC) in size fractionated lake samples and assess how net collections influence estimates of MC concentration. MC was detected in whole water (total) from 83% of lakes sampled, and total MC values ranged from 0.1-7.0 µg/L (mean = 0.8 µg/L). On average, MC in the >100 µm size class comprised ~40% of total MC, while other individual size classes contributed 9-20% to total MC. MC values decreased with size class and were significantly greater in the >100 µm size class (mean = 0.5 µg/L) than the 35-53 µm (mean = 0.1 µg/L), 10-35 µm (mean = 0.0µg/L), and 1-10 µm (mean = 0.0 µg/L) size classes (p < 0.01). MC values in nets with 100-µm, 53-µm, 35-µm, and 10-µm mesh were cumulatively summed to simulate the potential bias of measuring MC with various size plankton nets. On average, a 100-µm net underestimated total MC by 51%, compared to 37% for a 53-µm net, 28% for a 35-µm net, and 17% for a 10-µm net. While plankton nets consistently underestimated total MC, concentration of algae with net sieves allowed detection of MC at low levels (≤0.01 µg/L); 93% of lakes had detectable levels of MC in concentrated samples. Thus, small mesh plankton nets are an option for documenting MC occurrence, but whole water samples should be collected to characterize total MC concentrations.

Iowa, Missouri↗
USGS1997

Episodic nature of earthquake activity in stable continental regions revealed by palaeoseismicity studies of Australian and North American Quaternary faults

Palaeoseismic investigations of recent faulting in stable continental regions of Australia, North America and India show that these faults typically have a long-term behaviour characterised by episodes of activity separated by quiescent intervals of at least 10 000 and commonly 100 000 years or more. Long recurrence intervals such as these are well documented by detailed studies of the faults that ruptured during the 1986 Marryat Creek, South Australia and 1988 Tennant Creek, Northern Territory earthquakes. Thus, neotectonic features associated with stable continental region faults such as scarps and grabens commonly have subtle geomorphic expression and may be poorly preserved. Many potentially hazardous faults in stable continental regions are aseismic, which is one reason why the inventory of these faults is incomplete. Although they may be currently aseismic, faults in stable continental regions that are favourably oriented for movement in the current stress field could produce damaging earthquakes, often in unexpected places. Comprehensive palaeoseismic investigations of modern and prehistoric faulting events in stable continental regions are needed to understand the long-term behaviour of these faults, and thereby, improve seismic-hazard assessments.

Australian Journal of Earth Sciences↗
USGS2008

Conveying multiple, complex themes and classes for natural resource assessments

Two methods were used to convey the spatial association between a classified forested landscape, the distribution of a hurricane impact, and the subsequent recovery of the habitat from the storm. The first method used a constant hue matrix with varying intensity to visually represent combinations of impact and recovery magnitudes. The second combined two colors of constant hue to represent the impact and recovery succession. Maps produced using either method generally simulated known impact and recovery spatial distributions. In the constant hue representation with varying intensity, the combination of impact and recovery could not be uniquely represented in all cases and the relationship was confused between the map and legend color. In the two color representation, however, a definite link existed between the map and legend color and the impact and recovery magnitudes. A drawback to this approach over the constant hue approach was that a separate map had to be used to represent each forest type and its associated impact and recovery covariation. The two color combination, however, provided improved contrast and uniquely defined the link between map and legend colors, and ultimately, a unique impact and recovery combination. In addition, the two color combination produced the highest conveyance of spatial information related to the covariation of forest type, impact, and recovery.

Louisiana↗
USGS2001

Pathogenicity, serological responses, and diagnosis of experimental and natural malarial infections in native Hawaiian thrushes

Omao ( Myadestes obscurus ) from the Hawaiian Islands typically have very low prevalences of infection with avian malaria ( Plasmodium relictum ) and it is not clear whether they share the same high susceptibility to this parasite that has been documented in native Hawaiian honeycreepers. We exposed four captive Omao to single infective mosquito bites and measured parasitemia, serological responses, and mortality over time. All four birds experienced transient infections with low parasitemias and were immune when rechallenged with multiple infective mosquito bites. By contrast, three of four honeycreepers (Maui Alauahio, Paroreomyza montana ) that were exposed to the same dose and parasite isolate succumbed to infection. All four Omao developed antibodies to a common suite of malarial antigens that were detectable on immunoblots of a crude red blood cell extract of P. relictum. We used this technique to screen plasma samples from wild Omao and endangered Puaiohi ( Myadestes palmeri ) that were captured at elevations between 900 and 1300 m on the islands of Hawaii and Kauai. We found that the true prevalence of infection at elevations where active malaria transmission occurs is much higher than estimates based on blood smears alone. Hawaiian thrushes appear to have a high tolerance for malaria, with most individuals developing chronic, low-level infections after exposure that cannot be diagnosed accurately by blood smears.

Hawaii↗
USGS1963

The atomic ratios of natural ferruginous biotites with reference to 'the stability relations of the ferruginous biotite, annite'

The atomic ratios given by Eugster and Wones (1962) for analyses of high FeO-low MgO micas cited by Foster (1960) are in error. The recalculated atomic ratios herein presented show that only three of the thirteen have low (OH+F), and only one has characteristics that may possibly be due to loss of water during determination. None of the analyses exhibit characteristics suggestive of oxidation of iron and loss of H, as in progression towards oxyannite. The average recalculated octahedral occupancy is 2.69, not 2.91 as in the previous calculation. The differences between atomic ratios calculated on the basis ot determined H 2 O + and F and those calculated on the basis of the theoretical O 10 (OH) 2 content are not great enough to change the essential compositional character of these micas as interpreted by Foster (1960). However, they do affect significantly the calculated octahedral occupancy.

Journal of Petrology↗
USGS2024

A meta-analysis highlights the idiosyncratic nature of tradeoffs in laboratory models of virus evolution

Different theoretical frameworks have been invoked to guide the study of virus evolution. Three of the more prominent ones are (i) the evolution of virulence, (ii) life history theory, and (iii) the generalism–specialism dichotomy. All involve purported tradeoffs between traits that define the evolvability and constraint of virus-associated phenotypes. However, as popular as these frameworks are, there is a surprising paucity of direct laboratory tests of the frameworks that support their utility as broadly applicable theoretical pillars that can guide our understanding of disease evolution. In this study, we conduct a meta-analysis of direct experimental evidence for these three frameworks across several widely studied virus–host systems: plant viruses, fungal viruses, animal viruses, and bacteriophages. We extracted 60 datasets from 28 studies and found a range of relationships between traits in different analysis categories (e.g., frameworks, virus–host systems). Our work demonstrates that direct evidence for relationships between traits is highly idiosyncratic and specific to the host–virus system and theoretical framework. Consequently, scientists researching viral pathogens from different taxonomic groups might reconsider their allegiance to these canons as the basis for expectation, explanation, or prediction. Future efforts could benefit from consistent definitions, and from developing frameworks that are compatible with the evidence and apply to particular biological and ecological contexts.

Virus Evolution↗
USGS2005

The effects of urgency to reach agreement on the process and outcome of multi-party natural resource negotiations

We studied seven hydropower license consultations to examine the role of a sense of urgency to reach agreement. Hydropower licensing consultations were studied because the statutory requirement for consultation encourages negotiation, all such consultations are similar, and a negotiated settlement is not a foregone result. Cases selected for analysis met screening criteria. Structured interviews were conducted with participants after the negotiations had been concluded. Respondent recollections were checked against the documentary record. A sense of urgency to reach agreement was a significant factor in the completion of these negotiations; where there was no shared sense of urgency, purposeful delay adversely affected the negotiations. Although a sense of urgency was experienced by at least one party in each case, only a shared sense of urgency at the end of the process proved significant. Delay did not prevent ultimate agreement but a shared sense of urgency brought speedier agreement and greater satisfaction with the negotiation.

International Journal of Organizational Theory and↗
USGS2025

Integrating the resist–accept–direct framework into natural resource decision-making processes for climate adaptation

The resist–accept–direct (RAD) framework for climate adaptation is a useful tool, particularly when conservation practitioners know they need to address climate change but do not know where to start or when they struggle to implement conservation actions that are outside the status quo. Some conservation practitioners may view RAD as a decision process that will lead them through selecting climate adaptation actions to meet their objectives; however, RAD may be better suited for use with existing decision processes. RAD can improve adaptation planning processes by helping conservation practitioners examine a broader portfolio of climate adaptation actions. Choosing the actions that meet organizational objectives and long-term goals relies on a sound decision process through which to select RAD-generated actions to implement across space and time. The good news for conservation practitioners is that RAD can easily be integrated into the decision processes they are already using—that is, a new decision process for RAD is not necessary. We examined 6 commonly used decision frameworks in the context of RAD for climate adaptation: structured decision-making, adaptive management, conservation standards, climate-smart conservation, strategic habitat conservation, and scenario planning. Each decision framework can easily incorporate RAD methodologies to create climate adaptation menus and portfolios within existing structures, allowing conservation practitioners to continue to utilize existing frameworks for their valuable decision-making tools. Integrating the RAD framework can enhance them by explicitly considering future uncertainties and providing a menu of climate adaptation actions for navigating changing ecosystems.

Conservation Biology↗