SEARCH · USGS Science

Results for “Electronics”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,441 records · Page 80Linked to original sources

USGS2021

A new analysis of caldera unrest through the integration of geophysical data and FEM modeling: The Long Valley caldera case study

The Long Valley Caldera, located at the eastern edge of the Sierra Nevada range in California, has been in a state of unrest since the late 1970s. Seismic, gravity and geodetic data strongly suggest that the source of unrest is an intrusion beneath the caldera resurgent dome. However, it is not clear yet if the main contribution to the deformation comes from pulses of ascending high-pressure hydrothermal fluids or low viscosity magmatic melts. To characterize the nature of the intrusion, we developed a 3D finite element model which includes topography and crust heterogeneities. We first performed joint numerical inversions of uplift and Electronic Distance Measurement baseline length change data, collected during the period 1985–1999, to infer the deformation-source size, position, and overpressure. Successively, we used this information to refine the source overpressure estimation, compute the gravity potential and infer the intrusion density from the inversion of deformation and gravity data collected in 1982–1998. The deformation source is located beneath the resurgent dome, at a depth of 7.5 ± 0.5 km and a volume change of 0.21 ± 0.04 km 3 . We assumed a rhyolite compressibility of 0.026 ± 0.0011 GPa −1 (volume fraction of water between 0% and 30%) and estimated a reservoir compressibility of 0.147 ± 0.037 GPa −1 . We obtained a density of 1856 ± 72 kg/m 3 . This density is consistent with a rhyolite melt, with 20% to 30% of dissolved hydrothermal fluids.

California↗

USGS2024

Discovery and genomic characterization of a novel hepadnavirus from asymptomatic anadromous alewife (Alosa pseudoharengus)

The alewife ( Alosa pseudoharengus) is an anadromous herring that inhabits waters of northeastern North America. This prey species is a critical forage for piscivorous birds, mammals, and fishes in estuarine and oceanic ecosystems. During a discovery project tailored to identify potentially emerging pathogens of this species, we obtained the full genome of a novel hepadnavirus (ApHBV) from clinically normal alewives collected from the Maurice River, Great Egg Harbor River, and Delaware River in New Jersey, USA during 2015–2018. This previously undescribed hepadnavirus contained a circular DNA genome of 3146 nucleotides. Phylogenetic analysis of the polymerase protein placed this virus in the clade of metahepadnaviruses (family: Hepadnaviridae ; genus: Metahepadnavirus ). There was no evidence of pathology in the internal organs of infected fish and virions were not observed in liver tissues by electron microscopy. We developed a Taqman-based quantitative (qPCR) assay and screened 182 individuals collected between 2015 and 2018 and detected additional qPCR positives (n = 6). An additional complete genome was obtained in 2018 and it has 99.4% genome nucleotide identity to the first virus. Single-nucleotide polymorphisms were observed between the two genomes, including 7/9 and 12/8 synonymous vs nonsynonymous mutations across the polymerase and surface proteins, respectively. While there was no evidence that this virus was associated with disease in this species, alewives are migratory interjurisdictional fishes of management concern. Identification of microbial agents using de novo sequencing and other advanced technologies is a critical aspect of understanding disease ecology for informed population management.

New Jersey↗

USGS2008

Mineral chemistry and shrimp U-Pb Geochronology of mesoproterozoic polycrase-titanite veins in the sullivan Pb-Zn-Ag Deposit, British Columbia

Small polycrase-titanite veins 0.1-2 mm thick cut the tourmalinite feeder zone in the deep footwall of the Sullivan Pb-Zn-Ag deposit, southeastern British Columbia. Unaltered, euhedral crystals of polycrase and titanite 50-100 ??m in diameter are variably replaced by a finer-grained alteration-induced assemblage composed of anhedral polycrase and titanite with local calcite, albite, epidote, allanite, and thorite or uranothorite (or both). Average compositions of the unaltered and altered polycrase, as determined by electron-microprobe analysis, are (Y0.38 REE0.49 Th0.10 Ca0.04 Pb0.03 Fe0.01U0.01) (Ti1.48 Nb0.54 W0.04 Ta0.02)O6 and (Y0.42 REE0.32 Th0.15 U0.06 Ca0.04 Pb0.01 Fe0.01) (Ti1.57 Nb0.44 W0.04 Ta0.02)O6, respectively. The unaltered titanite has, in some areas, appreciable F (to 0.15 apfu), Y (to 0.40 apfu), and Nb (to 0.13 apfu). SHRIMP U-Pb geochronology of eight grains of unaltered polycrase yields a weighted 207Pb/206Pb age of 1413 ?? 4 Ma (2??) that is interpreted to be the age of vein formation. This age is 50-60 m.y. younger than the ca. 1470 Ma age of synsedimentary Pb-Zn-Ag mineralization in the Sullivan deposit, which is based on combined geological and geochronological data. SHRIMP ages for altered polycrase and titanite suggest later growth of minerals during the ???1370-1320 Ma East Kootenay and ???1150-1050 Ma Grenvillian orogenies. The 1413 ?? 4 Ma age for the unaltered polycrase in the veins records a previously unrecognized post-ore (<1470 Ma) and premetamorphic (>1370 Ma) mineralizing event in the Sullivan deposit and vicinity. The SHRIMP U-Pb age of the polycrase and high concentrations of REE, Y, Ti, Nb, and Th in the veins, together with elevated F in titanite and the absence of associated sulfides, suggest transport of these high-field-strength elements (HFSE) by F-rich and S-poor hydrothermal fluids unrelated to the fluids that formed the older Fe-Pb-Zn-Ag sulfide ores of the Sullivan deposit. Fluids containing abundant REE, HFSE, and F may have been derived from a geochemically specialized magma such as those that form alkaline granites, pegmatites, or carbonatites. In an alternative model. preferred here, these fluids were associated with a rift-related, crustal metasomatic event in the region. Determination of a Mesoproterozoic age for the polycrase-titanite veins establishes the first known occurrence of pre-Grenvillian REE-rich mineralization in the Belt-Purcell basin.

Canadian Mineralogist↗

USGS2012

A simple method for in situ monitoring of water temperature in substrates used by spawning salmonids

Interstitial water temperature within spawning habitats of salmonids may differ from surface-water temperature depending on intragravel flow paths, geomorphic setting, or presence of groundwater. Because survival and developmental timing of salmon are partly controlled by temperature, monitoring temperature within gravels used by spawning salmonids is required to adequately describe the environment experienced by incubating eggs and embryos. Here we describe a simple method of deploying electronic data loggers within gravel substrates with minimal alteration of the natural gravel structure and composition. Using data collected in spawning sites used by summer and fall chum salmon Oncorhynchus keta from two streams within the Yukon River watershed, we compare contrasting thermal regimes to demonstrate the utility of this method.

Journal of Fish and Wildlife Management↗

USGS2015

Green turtles ( Chelonia mydas ) have novel asymmetrical antibodies

Igs in vertebrates comprise equally sized H and L chains, with exceptions such as H chain–only Abs in camels or natural Ag receptors in sharks. In Reptilia, Igs are known as IgYs. Using immunoassays with isotype-specific mAbs, in this study we show that green turtles ( Chelonia mydas ) have a 5.7S 120-kDa IgY comprising two equally sized H/L chains with truncated Fc and a 7S 200-kDa IgY comprised of two differently sized H chains bound to L chains and apparently often noncovalently associated with an antigenically related 90-kDa moiety. Both the 200- and 90-kDa 7S molecules are made in response to specific Ag, although the 90-kDa molecule appears more prominent after chronic Ag stimulation. Despite no molecular evidence of a hinge, electron microscopy reveals marked flexibility of Fab arms of 7S and 5.7S IgY. Both IgY can be captured with protein G or melon gel, but less so with protein A. Thus, turtle IgY share some characteristics with mammalian IgG. However, the asymmetrical structure of some turtle Ig and the discovery of an Ig class indicative of chronic antigenic stimulation represent striking advances in our understanding of immunology.

Journal of Immunology↗

USGS2014

Focused campaign increases activity among participants in Nature's Notebook , a citizen science project

Citizen science projects, which engage non-professional scientists in one or more stages of scientific research, have been gaining popularity; yet maintaining participants’ activity level over time remains a challenge. The objective of this study was to evaluate the potential for a short-term, focused campaign to increase participant activity in a national-scale citizen science program. The campaign that we implemented was designed to answer a compelling scientific question. We invited participants in the phenology-observing program, Nature’s Notebook, to track trees throughout the spring of 2012, to ascertain whether the season arrived as early as the anomalous spring of 2010. Consisting of a series of six electronic newsletters and costing our office slightly more than 1 week of staff resources, our effort was successful; compared with previous years, the number of observations collected in the region where the campaign was run increased by 184%, the number of participants submitting observations increased by 116%, and the number of trees registered increased by 110%. In comparison, these respective metrics grew by 25, 55, and 44%, over previous years, in the southeastern quadrant of the United States, where no such campaign was carried out. The campaign approach we describe here is a model that could be adapted by a wide variety of programs to increase engagement and thereby positively influence participant retention.

Natural Sciences Education↗

USGS2003

Big Soda Lake (Nevada). 2. Pelagic sulfate reduction

The epilimnion of hypersaline, alkaline, meromictic Big Soda Lake contains an average 58 mmol sulfate liter −1 and 0.4 µ mol dissolved iron liter −1 . The monimolimnion, which is permanently anoxic, has a sulfide concentration ranging seasonally from 4 to 7 mmol liter −1 . Depth profiles of sulfate reduction in the monimolimnion, assayed with a 35 S tracer technique and in situ incubations, demonstrated that sulfate reduction occurs within the water column of this extreme environment. The average rate of reduction in the monimolimnion was 3 µ mol sulfate liter −1 d −1 in May compared to 0.9 in October. These values are comparable to rates of sulfate reduction reported for anoxic waters of more moderate environments. Sulfate reduction also occurred in the anoxic zone of the mixolimnion, though at significantly lower rates (0.025–0.090 µ mol liter −1 d −1 at 25 m). Additions of FeS (1.0 mmol liter −1 ) doubled the endogenous rate of sulfate reduction in the monimolimnion, while MnS and kaolinite had no effect. These results suggest that sulfate reduction in Big Soda Lake is iron limited and controlled by seasonal variables other than temperature. Estimates of the organic carbon mineralized by sulfate reduction exceed measured fluxes of particulate organic carbon sinking from the mixolimnion. Thus, additional sources of electron donors (other than those derived from the sinking of pelagic autotrophs) may also fuel monimolimnetic sulfate reduction in the lake.

Nevada↗

USGS2003

Exopolymer microenvironments of microbial flora: Multiple and interactive effects on trophic relationships

Microbial cells in natural environments are often encased in different types of exopolymer secretions (EPS), ranging from tight capsules surrounding individual cells to the looser slime matrices of biofilms. The different physical and chemical properties of exopolymers could have secondary effects on trophic interactions between microbial cells and consumer animals. Laboratory studies showed that capsule EPS is significantly less digestible to consumers than slime EPS, even when extracted from the same bacterial strain. Bacterial cells with EPS capsules are less efficiently digested than noncapsuled cells, suggesting that capsules protect against digestion. Follow-up experiments determined that polysaccharide-rich fractions of slime EPS are absorbed with very high efficiencies while protein portions, which are more abundant in capsular polymers, are absorbed relatively poorly. Another series of experiments showed that dissolved organic matter (DOM), when adsorbed directly to the mineralogical portions of sediment particles, is available to deposit feeders. However, the further presence of an exopolymer coating on sediments more than doubled the bioavailability of adsorbed DOM to the consumer. Observations using cold-stage scanning electron microscopy indicated that exopolymer microenvironments are a common feature of natural marine sediments. Microbial exopolymers range from easily digestible carbon sources to relatively refractory ones that effectively protect some microbial cells from consumer digestion. Exopolymer microenvironments may also make recently adsorbed DOM highly accessible to particle-ingesting animals.

Limnology and Oceanography↗

USGS2012

Introduction

elemetry provides a powerful and flexible tool for studying aquatic animals, making it possible to repeatedly locate and identify individuals in remote or inaccessible settings—a task that would be difficult (if not impossible) to accomplish using other methods. The use of telemetry has increased dramatically in recent years, and its application is limited only by the capabilities of the equipment and the researcher’s imagination. In spite of these advantages, telemetry is equipment-intensive and generally requires more specialized knowledge and training than many other field techniques. The electronic equipment associated with its use can often dazzle, intimidate, and confuse those just starting out. Even experienced users are often hard-pressed to keep up with the technological advances. Answers to such basic questions as “what equipment do I need?” or “how do I get started?” are not always evident or straightforward. These are valid concerns, since the equipment and methods used can affect the success of the study and the quality of information collected. The purpose of this book is to provide a guide for using telemetry to study aquatic animals—call it a user’s manual or Telemetry 101. Our principal intent is to provide the basic information to plan, implement, and conduct telemetry studies under field conditions. Considerations related to data collection and interpretations are also discussed. As with any scientific procedure, collecting usable information and accurately interpreting study results depends on an understanding of the underlying principles of the methods used. A wide range of telemetry equipment and field techniques are available. Clearly defined research objectives and knowledge of the various options, capabilities, and limitations of the equipment and methods is essential for developing projects that effectively address the research or management questions being asked. Telemetry is a tool, and like any tool it will only function effectively when used properly.

Book chapter↗

USGS2012

Bias from false-positive detections and strategies for their removal in studies using telemetry

The use of radio and acoustic telemetry to study aquatic animals has flourished since the 1950s and 1960s (see Section 1). Electronic data-logging receivers are commonly used in both types of active telemetry to record the presence of transmitters in the detection field formed by one or more antennas or hydrophones. As described in Sections 5.1 and 7.1, the path of a transmitter signal to a telemetry receiver can be influenced by many factors and the received signal is not always detected or correctly assigned. It should be of no surprise to users of active telemetry systems that not all records in telemetry receivers are from tagged fish and not all tagged fish are recorded when present. Four types of observations are possible in data from telemetry receiving systems based on the binary nature of presence and absence (Table 1). True positives and true negatives are what one ideally expects from telemetry systems, but in most studies they are accompanied by false negatives (not recorded when present) and false positives (recorded when absent). False negatives arise due to a variety of causes, including insufficient detection area relative to transmitter pulse rate and fish travel speed, collisions between transmitters in the detection area, interference from ambient noise, or a received signal too weak to be recorded (see Sections 3, 5, and 7). The probability of false negatives can be calculated as (1–detection probability) and can be estimated with proper study design and incorporated into estimates of fish presence (see Sections 7.2 and 9.2).

Book chapter↗

USGS2009

Response of Halimeda to ocean acidification: Field and laboratory evidence

Rising atmospheric pCO 2 levels are changing ocean chemistry more dramatically now than in the last 20 million years. In fact, pHvalues of the open ocean have decreased by 0.1 since the 1800s and are predicted to decrease 0.1-0.4 globally in the next 90 years. Ocean acidification will affect fundamental geochemical and biological processes including calcification and carbonate sediment production. The west Florida shelf is a natural laboratory to examine the effects of ocean acidification on aragonite production by calcareous green algae. Scanning electron microscopy (SEM) of crystal morphology of calcifying organisms reveals ultrastructural details of calcification that occurred at different saturation states. Comparison of archived and recent specimens of calcareous green alga Halimeda spp. from the west Florida shelf, demonstrates crystal changes in shape and abundance over a 40+ year time span. Halimeda crystal data from apical sections indicate that increases in crystal concentration and decreases in crystal width occurred over the last 40+ years. Laboratory experiments using living specimens of Halimeda grown in environments with known pH values were used to constrain historical observations. Percentages of organic and inorganic carbon per sample weight of pooled species did not significantly change. However, individual species showed decreased inorganic carbon and increased organic carbon in more recent samples, although the sample sizes were limited. These results indicate that the effect of increased pCO 2 and decreased pH on calcification is reflected in the crystal morphology of this organism. More data are needed to confirm the observed changes in mass of crystal and organic carbon. ?? Author(s) 2009.

Biogeosciences Discussions↗

USGS2026

Proposing sources for discrete groundwater discharges to patterned pools in three regional raised northern peat bogs

Raised northern peat bogs are generally assumed to be entirely precipitation-fed (ombrogenous), suggesting they are void of groundwater (minerogenous) inflow from underlying sediments. Patterned pools in raised bogs have often been attributed to surficial flow filling depressions along the peat surface that produces subtle differences in peat pore-water chemistry. However, we present evidence that certain patterned pools may be partially fed by localized upwelling of minerogenous groundwater from underlying glacial sediments in three northern peat bogs of Maine, USA. Underlying permeable glacial deposits, embedded in hydraulically confining glacio-marine clay deposits, were delineated using ground-penetrating radar and transient electromagnetic surveys. Paired point measurements of temperature and specific conductance (SpC) were surveyed around pools, and statistical relationships indicative of groundwater upwelling were established. Uncrewed aerial systems (UAS) thermal infrared (TIR) mapping was conducted, augmented by handheld TIR imaging, to examine characteristic groundwater temperatures in cold and warm seasons across pool surfaces. Surface water samples were acquired to assess the relationship between SpC / temperature signals and elevated iron and manganese concentrations that could be indicative of glacial aquifer sources. The combined datasets present evidence for localized upwelling in pools underlain by glacial structures, and the possibility of minerogenous groundwater contributions. Upwelling through the peat matrix is possibly partially facilitated by macropore, “peat pipe” features that serve as preferential flowpaths of varying lengths to the surface. Such upwelling could drive a positive feedback loop where elevated concentrations of ionic constituents repeatedly dilate the peat matrix and/or terminal electron acceptors enhance anaerobic respiration and microbial activity, accelerating the humification of peat around patterned pools and potentially magnifying carbon loss.

Maine↗

USGS2016

Lithium brines: A global perspective

Lithium is a critical and technologically important element that has widespread use, particularly in batteries for hybrid cars and portable electronic devices. Global demand for lithium has been on the rise since the mid-1900s and is projected to continue to increase. Lithium is found in three main deposit types: (1) pegmatites, (2) continental brines, and (3) hydrothermally altered clays. Continental brines provide approximately three-fourths of the world’s Li production due to their relatively low production cost. The Li-rich brine systems addressed here share six common characteristics that provide clues to deposit genesis while also serving as exploration guidelines. These are as follows: (1) arid climate; (2) closed basin containing a salar (salt crust), a salt lake, or both; (3) associated igneous and/or geothermal activity; (4) tectonically driven subsidence; (5) suitable lithium sources; and (6) sufficient time to concentrate brine. Two detailed case studies of Li-rich brines are presented; one on the longest produced lithium brine at Clayton Valley, Nevada, and the other on the world’s largest producing lithium brine at the Salar de Atacama, Chile.

Book chapter↗

USGS2012

Catalog of type specimens of recent mammals: Rodentia (Sciuromorpha and Castorimorpha) in the National Museum of Natural History, Smithsonian Institution

The type collection of Recent mammals in the Division of Mammals, National Museum of Natural History, Smithsonian Institution, contains 843 specimens bearing names of 820 species group taxa of Rodentia (Sciuromorpha and Castorimorpha) as of July 2011. This catalog presents a list of these holdings, which comprise 798 holotypes, 14 lectotypes, seven syntypes (30 specimens), and one neotype. In addition, we include three holotypes and 10 specimens that are part of syntype series that should be in the collection but cannot be found and three syntypes that were originally in this collection but are now known to be in other collections. One specimen that no longer has name-bearing status is included for the record. Forty-one of the names are new since the last type catalog. One new lectotype is designated. Suborders and families are listed as in Wilson and Reeder. Within families, currently recognized genera are arranged alphabetically. Within each currently recognized genus, accounts are arranged alphabetically by original published name. Information in each account includes original name and abbreviated citation thereto, current name if other than original, citation for first use of current name combination for the taxon (or new name combination if used herein for the first time), type designation, U.S. National Museum catalog number(s), preparation, age and sex, type locality, date of collection and name of collector, collector’s original number, and comments or additional information as appropriate. Digital photographs of each specimen serve as a condition report and will be linked to each electronic specimen record.

Smithsonian Contributions to Zoology↗

USGS2015

Catalog of type specimens of recent mammals: orders Didelphimorpha through Chiroptera (Excluding Rodentia) in the National Museum of Natural History, Smithsonian Institution

The type collection of Recent Mammals in the Division of Mammals, National Museum of Natural History, Smithsonian Institution, contains 820 specimens bearing names of 809 species-group taxa of Didelphimorphia through Chiroptera, excluding Rodentia, as of June 2014. This catalog presents an annotated list of these holdings comprised of 788 holotypes, 26 lectotypes, 11 syntypes (22 specimens), and 4 neotypes. Included are several specimens that should be in the collection but cannot be found or are now known to be in other collections. One hundred and twenty-seven of the names are new since the last type catalog covering these orders, Poole and Schantz (1942). Five specimens reported in Poole and Schantz (1942) were subsequently sent to the Vertebrate Paleontology collection and are not included here. Orders and families are ordered as in Wilson and Reeder (2005); within families, currently recognized genera are arranged alphabetically; within each currently recognized genus, accounts are arranged alphabetically by original published name. Information in each account includes original name and abbreviated citation thereto, current name if other than original, citation for first use of current name combination for the taxon (or new name combination if used herein for the first time), type designation, U.S. National Museum catalog number(s), preparation, age and sex, date of collection and collector, original collector number, type locality, and remarks as appropriate. Digital photographs of each specimen will serve as a condition report and will be attached to each electronic specimen record.

Book↗

USGS2016

Forward

No abstract available.

Book chapter↗

USGS2023

Characterizing lung particulates using quantitative microscopy in coal miners with severe pneumoconiosis

Context.— Current approaches for characterizing retained lung dust using pathologists' qualitative assessment or scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS) have limitations. Objective.— To explore polarized light microscopy coupled with image-processing software, termed quantitative microscopy–particulate matter (QM-PM), as a tool to characterize in situ dust in lung tissue of US coal miners with progressive massive fibrosis. Design.— We developed a standardized protocol using microscopy images to characterize the in situ burden of birefringent crystalline silica/silicate particles (mineral density) and carbonaceous particles (pigment fraction). Mineral density and pigment fraction were compared with pathologists' qualitative assessments and SEM/EDS analyses. Particle features were compared between historical (born before 1930) and contemporary coal miners, who likely had different exposures following changes in mining technology. Results.— Lung tissue samples from 85 coal miners (62 historical and 23 contemporary) and 10 healthy controls were analyzed using QM-PM. Mineral density and pigment fraction measurements with QM-PM were comparable to consensus pathologists' scoring and SEM/EDS analyses. Contemporary miners had greater mineral density than historical miners (186 456 versus 63 727/mm 3 ; P = .02) and controls (4542/mm 3 ), consistent with higher amounts of silica/silicate dust. Contemporary and historical miners had similar particle sizes (median area, 1.00 versus 1.14 μm 2 ; P = .46) and birefringence under polarized light (median grayscale brightness: 80.9 versus 87.6; P = .29). Conclusions.— QM-PM reliably characterizes in situ silica/silicate and carbonaceous particles in a reproducible, automated, accessible, and time/cost/labor-efficient manner, and shows promise as a tool for understanding occupational lung pathology and targeting exposure controls.

Archives of Pathology and Laboratory Medicine↗

USGS1975

Fatal pox infection in a rough-legged hawk

Natural pox infection occurred in a free-living rough-legged hawk ( Buteo lagopus ) in northeastern North Dakota. Gross, histological and electron microscopic findings were typical of pox infection, and characteristic lesions developed in red-tailed hawks ( Buteo jamaicensis ) but not in great horned owls ( Bubo virginianus ) following inoculation with case material. Death of the rough-legged hawk was attributed to starvation resulting from inability to capture prey and to blood loss from foot lesions.

Journal of Wildlife Diseases↗