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At least 1,315 records · Page 73Linked to original sources

Sex-biased infections scale to population impacts for an emerging wildlife disease

Demographic factors are fundamental in shaping infectious disease dynamics. Aspects of populations that create structure, like age and sex, can affect patterns of transmission, infection intensity and population outcomes. However, studies rarely link these processes from individual to population-scale effects. Moreover, the mechanisms underlying demographic differences in disease are frequently unclear. Here, we explore sex-biased infections for a multi-host fungal disease of bats, white-nose syndrome, and link disease-associated mortality between sexes, the distortion of sex ratios and the potential mechanisms underlying sex differences in infection. We collected data on host traits, infection intensity and survival of five bat species at 42 sites across seven years. We found females were more infected than males for all five species. Females also had lower apparent survival over winter and accounted for a smaller proportion of populations over time. Notably, female-biased infections were evident by early hibernation and likely driven by sex-based differences in autumn mating behaviour. Male bats were more active during autumn which likely reduced replication of the cool-growing fungus. Higher disease impacts in female bats may have cascading effects on bat populations beyond the hibernation season by limiting recruitment and increasing the risk of Allee effects.

Proceedings of the Royal Society B: Biological Sci↗

Multiscale perspectives of fire, climate and humans in western North America and the Jemez Mountains, USA

Interannual climate variations have been important drivers of wildfire occurrence in ponderosa pine forests across western North America for at least 400 years, but at finer scales of mountain ranges and landscapes human land uses sometimes over-rode climate influences. We reconstruct and analyse effects of high human population densities in forests of the Jemez Mountains, New Mexico from ca 1300 CE to Present. Prior to the 1680 Pueblo Revolt, human land uses reduced the occurrence of widespread fires while simultaneously adding more ignitions resulting in many small-extent fires. During the 18th and 19th centuries, wet/dry oscillations and their effects on fuels dynamics controlled widespread fire occurrence. In the late 19th century, intensive livestock grazing disrupted fuels continuity and fire spread and then active fire suppression maintained the absence of widespread surface fires during most of the 20th century. The abundance and continuity of fuels is the most important controlling variable in fire regimes of these semi-arid forests. Reduction of widespread fires owing to reduction of fuel continuity emerges as a hallmark of extensive human impacts on past forests and fire regimes.

New Mexico↗

Overview of the Mars Pathfinder Mission and assessment of landing site predictions

Chemical analyses returned by Mars Pathfinder indicate that some rocks may be high in silica, implying differentiated parent materials. Rounded pebbles and cobbles and a possible conglomerate suggest fluvial processes that imply liquid water in equilibrium with the atmosphere and thus a warmer and wetter past. The moment of inertia indicates a central metallic core of 1300 to 2000 kilometers in radius. Composite airborne dust particles appear magnetized by freeze-dried maghemite stain or cement that may have been leached from crustal materials by an active hydrologic cycle. Remote-sensing data at a scale of generally greater than ∼1 kilometer and an Earth analog correctly predicted a rocky plain safe for landing and roving with a variety of rocks deposited by catastrophic floods that are relatively dust-free.

Science↗

Petrology and isotopic composition of Quaternary basanites dredged from the Bering Sea continental margin near Navarin Basin

Quaternary basanites were recovered from shallow water depth from the continental margin of the Bering Sea (58°39.0′N, 177°12.9′W) near Navarin Basin. The basanites are highly vesicular flow rock and hyaloclastites similar to other alkalic volcanic rocks erupted repeatedly during the late Cenozoic on islands in the Bering Sea region and in mainland Alaska. K–Ar ages for the basanites indicate at least two episodes of volcanism at about 1.1 and 0.4 Ma. Similar alkalic volcanism occurred sporadically at geographically widely separated centers in the Bering Sea region for at least the past 6 Ma. Chemically, these alkalic lavas are intraplate basalts similar to those erupted from oceanic islands and in some continental settings. Trace-element data indicate these alkalic lavas have been generated by small, but variable, amounts of partial melting of a meta-somatized lherzolite source. The relatively primitive compositions (MgO > 9%), presence of mantle-derived xenoliths in some alkalic lavas, and presence of forsteritic olivine with low CaO and high NiO suggest that magma rose rapidly from greath depth without spending time in large, long-lived magma chambers. Although lavas from different volcanic centers in the Bering Sea region are similar with respect to major elements and many trace-element ratios, isotopic compositions indicate heterogeneities in the source. The Navarin basanites have higher 87 Sr/ 86 Sr and lower 143 Nd/ 144 Nd values than any other lavas so far reported from this region. The 207 Pb/ 204 Pb isotopic ratios indicate involvement of a crustal component, which may have resulted from metasomatism associated with subduction-related magmatic activity during the Early Eocene in this region. Although some volcanic episodes appear to have occurred roughly synchronously at geographically widely separated centers, no large-scale regional extension nor presence of large mantle plumes are indicated. Instead, alkalic volcanism apparently resulted from upwelling and decompressional melting of small isolated mantle diapirs in response to local lithospheric attenuation associated with jostling of blocks during adjustment to regional stresses.

Alaska↗

Hydrologic conditions in Kansas, water year 2019

The U.S. Geological Survey Kansas Water Science Center, in cooperation with Federal, State, and local agencies, maintains a long-term network of hydrologic monitoring stations in the State of Kansas. These include a network of 217 real-time streamgages and 12 real-time reservoir-level monitoring stations in water year 2019. The data and associated analyses from the streamgages and monitoring stations provide a unique overview of hydrologic conditions and help improve the understanding of Kansas’ water resources. Annual assessments of hydrologic conditions are made by comparing statistical analyses of current and past water year data for the period of record. Long-term monitoring of hydrologic conditions in Kansas provides imperative information for many uses including managing water resources and protecting human life and property and promoting agricultural practices, industrial activities, operation of reservoirs , development of infrastructure, ecological assessments, and recreational purposes.

Kansas↗

Radar study of seabirds and bats on windward Hawai'i

Modified marine surveillance radar was used to study the presence/ absence, abundance, and flight activity of four nocturnal species: Hawaiian darkrumped petrel [ Pterodroma phaeopygia sandwichensis (Ridgeway)], Newell's shearwater [ Puffinus auricularis newelli (Henshaw)], Band-rumped storm-petrel [ Oceanodroma castro (Harcourt)], and Hawaiian hoary bat ( Lasiurus cinereus semotus Sanborn & Crespo). Hawaiian seabirds were recorded flying to or from inland nesting colonies at seven sampling sites on the windward side of the island of Hawai'i. In total, 527 radar "targets" identified as petrel or shearwater-type on the basis of speed, flight behavior, and radar signal strength were observed during eight nights of sampling. Mean movement rates (targets per minute) for seabird targets were 0.1, 0.1, 0.3, 3.8, 0.9, and 2.2 for surveys at Kahakai, Kapoho, Mauna Loa, Pali Uli, Pu'ulena Crater, and Waipi'o Valley, respectively. Two percent of the petrel and shearwater-type targets detected on radar were confirmed visually or aurally. Flight paths for seabird targets showed strong directionality at six sampling sites. Mean flight speed for seabird targets (n = 524) was 61 km/hr for all survey areas. Peak detection times for seabirds were from 0430 to 0530 hours for birds flying to sea and 2000 to 2150 hours for birds returning to colonies. Most inland, low-elevation sampling sites could not be surveyed reliably for seabirds during the evening activity periods because of radar interference from insects and rapidly flying bats. At those inland sites predawn sampling was the best time for using radar to detect Hawaiian seabirds moving seaward. Hawaiian hoary bats were recorded at eight sampling sites. Eighty-six to 89 radar targets that exhibited erratic flight behavior were identified as "batlike" targets; 17% of these batlike radar targets were confirmed visually. Band-rumped storm-petrels were not identified during our surveys.

Pacific Science↗

Disease in Central Valley salmon: Status and lessons from other systems

Chinook Salmon ( Oncorhynchus tshawytscha ) are increasingly vulnerable to anthropogenic activities and climate change, especially at their most southern species range in California’s Central Valley. There is considerable interest in understanding stressors that contribute to population decline and in identifying management actions that reduce the impacts of those stressors. Along the west coast of North America, disease has been linked to declining numbers of salmonids and identified as a key stressor resulting in mortality. In the Central Valley, targeted studies have revealed extremely high prevalence of infectious agents and disease. However, there has been insufficient monitoring to understand the effect that disease may have on salmon populations. In order to inform future research, monitoring, and management efforts, a two-day workshop on salmon disease was held at UC Davis on March 14-15, 2018. This paper summarizes the science presented at this workshop, including the current state of knowledge of salmonid disease in the Central Valley and current and emerging tools to better understand its impacts on salmon. We highlight case studies from other systems where successful monitoring programs have been implemented. First, in the Klamath River where the integration of several data collection and modeling approaches led to the development of successful management actions, and second in British Columbia where investment in researching novel technologies led to breakthroughs in the understanding of salmon disease dynamics. Finally, we identify key information and knowledge gaps necessary to guide research and management of disease in Central Valley salmon populations.

California↗

U.S. Geological Survey Earthquake Science Center

The mission of the U.S. Geological Survey (USGS) Earthquake Science Center is to collect a wide range of data on earthquakes, faults, and crustal deformation; conduct research to increase our understanding of earthquake source processes, occurrence, and effects; and synthesize this knowledge into probabilistic seismic hazard assessments, aftershock forecasts, and ground-shaking scenarios for anticipated major earthquakes. We disseminate these data products, hazard assessments, and research discoveries to scientists, engineers, emergency managers, and the public. With university and State partners, we operate the California Integrated Seismic Network and the Pacific Northwest Seismic Network, as well as geodetic networks throughout the western United States. We also lead the National Strong Motion Project and the ShakeAlert earthquake early warning (EEW) system; house renowned rock mechanics laboratories and deep borehole geophysics facilities; and conduct extensive geophysical, geologic, and paleoseismic investigations along active faults. We are funded primarily by the USGS Earthquake Hazards Program, with additional support from the USGS Volcano Hazards and Energy Resources Programs, other Federal and State agencies, private foundations, and public and private utilities and corporations.

California↗

Overview and progress of the pallid sturgeon assessment framework redesign process

The Pallid Sturgeon Population Assessment Program (PSPAP) was initiated in 2003, and full implementation began in 2006, to monitor the trend of Scaphirhynchus albus (pallid sturgeon) and native fish communities in the Upper and Lower Missouri River Basins. The original PSPAP (v. 1.0) was a catch-effort based monitoring program where population abundance and trend were monitored using a relative index, catch per unit effort. In 2013, the Missouri River Recovery Program (MRRP), led by the U.S. Army Corps of Engineers (USACE) and the U.S. Fish and Wildlife Service (USFWS), began a reassessment of science and monitoring approaches to support a new river management plan. The need to redesign the PSPAP was triggered by the recognition that the PSPAP v. 1.0 would not be optimally effective in contributing information needed to make decisions about the pallid sturgeon fundamental management objective—to avoid jeopardizing the continued existence of the pallid sturgeon from USACE actions in the Missouri River—identified in the Missouri River Science and Adaptive Management Plan. The fundamental management objective includes two management subobjectives: (1) increase pallid sturgeon recruitment to age 1 and (2) maintain or increase numbers of pallid sturgeon as an interim measure until sufficient and sustained natural recruitment occurs. These two management subobjectives motivated the development of two fundamental information objectives for PSPAP v. 2.0: (1) to provide information needed to quantify recruitment to age 1 and (2) to quantify pallid sturgeon population abundance and trend. The charge to the authors of this report was to develop an approach to monitoring the pallid sturgeon population in the Missouri River that would contribute information toward gauging overall performance of management actions to achieve the fundamental objectives of the MRRP and to potentially improve understanding of linkages from the management activities to population responses. We used transparent and robust processes to identify alternative monitoring designs that meet the fundamental objectives for managing pallid sturgeon in the MRRP, with a focus on simulation models to evaluate the performance of varying monitoring. This report documents the process of comparing potential alternative monitoring design abilities to provide decision-relevant information for management of the species. The process includes evaluation of information content and attendant uncertainties and considers tradeoffs in types of information valued by stakeholders. The anticipated end product of this process will be synthesized in a decision-support tool that can be used to facilitate learning and iterative revisions of the monitoring roadmap.

Open-File Report↗

Predictive analysis using chemical-gene interaction networks consistent with observed endocrine activity and mutagenicity of U.S. streams

In a recent U.S. Geological Survey/U.S. Environmental Protection Agency study assessing >700 organic compounds in 38 streams, in vitro assays indicated generally low estrogen, androgen, and glucocorticoid receptor activities, but identified 13 surface waters with 17β estradiol equivalent (E2Eq) activities greater than the 1 ng/L level of concern for feminization of male fish. Among the 36 samples assayed for mutagenicity in the Salmonella bioassay (reported here), 25% were considered mutagenic (statistically significant slope and at least a two-fold increase in revertants/plate). Endocrine and mutagenic activities of the water samples were well correlated with each other and with the total number and cumulative concentrations of detected chemical contaminants. To test the predictive utility of knowledgebase-leveraging approaches, site-specific predicted chemical-gene (pCGA) and predicted analogous pathway-linked (pPLA) association networks identified in the Comparative Toxicogenomics Database were compared with observed endocrine/mutagenic bioactivities. We evaluated pCGA/pPLA patterns among sites by cluster analysis and principal component analysis and grouped the pPLA into broad mode-of-action classes. Measured E2Eq and mutagenic activities correlated well with predicted pathways. The pPLA analysis also revealed correlations with signaling, metabolic, and regulatory groups, suggesting that other effects pathways may be associated with chemical contaminants in these waters and indicating the need for broader bioassay coverage to assess potential adverse impacts.

Environmental Science & Technology↗

Radiocarbon determinations for estimating groundwater flow velocities in central Florida

Carbon-14 activity was determined from HCO 3 - in samples of groundwater obtained from the principal artesian aquifer in Florida. From these data the "age" of water obtained from a series of wells, each progressively farther down gradient on the piezometric surface, was established. Relative carbon-14 ages indicated a velocity of groundwater movement of 23 feet (7 meters) per year for about 85 miles (137 kilometers) of travel. A velocity of 23 feet per year was calculated independently from Darcy's law.

Florida↗

Translocation as a species conservation tool: Status and strategy

Surveys of recent (1973 to 1986) intentional releases of native birds and mammals to the wild in Australia, Canada, Hawaii, New Zealand, and the United States were conducted to document current activities, identify factors associated with success, and suggest guidelines for enhancing future work. Nearly 700 translocations were conducted each year. Native game species constituted 90 percent of translocations and were more successful (86 percent) than were translocations of threatened, endangered, or sensitive species (46 percent). Knowledge of habitat quality, location of release area within the species range, number of animals released, program length, and reproductive traits allowed correct classification of 81 percent of observed translocations as successful or not.

Science↗

Cryovolcanism on Ceres

Volcanic edifices are abundant on rocky bodies of the inner solar system. In the cold outer solar system, volcanism can occur on solid bodies with a water-ice shell, but derived cryovolcanic constructs have proved elusive. We report the discovery using Dawn Framing Camera images of a landform on dwarf planet Ceres, which we argue represents a viscous cryovolcanic dome. Parent material of the cryomagma is a mixture of secondary minerals, including salts and water ice. Absolute model ages from impact craters reveal that extrusion of the dome has occurred recently. Ceres’ evolution must have been able to sustain recent interior activity and associated surface expressions. We propose salts with low eutectic temperatures and thermal conductivities as key drivers for Ceres’ long-term internal evolution.

Science↗

Inventory of montane-nesting birds in the Arctic Network of National Parks, Alaska

The Alaska Science Center of the U.S. Geological Survey conducted an inventory of birds in montane areas of the four northern parks in the Arctic Network of National Parks, Alaska. This effort represents the first comprehensive assessment of breeding range and habitat associations for the majority of avian species in the Arctic Network. Ultimately, these data provide a framework upon which to design future monitoring programs. A stratified random sampling design was used to select sample plots (n = 73 plots) that were allocated in proportion to the availability of ecological subsections. Point counts (n = 1,652) were conducted to quantify abundance, distribution, and habitat associations of birds. Field work occurred over three years (2001 to 2003) during two-week-long sessions in late May through early June that coincided with peak courtship activity of breeding birds. Totals of 53 species were recorded in Cape Krusenstern National Monument, 91 in Noatak National Preserve, 57 in Kobuk Valley National Park, and 96 in Gates of the Arctic National Park and Preserve. Substantial proportions of species in individual parks are considered species of conservation concern (18 to 26%) or species of stewardship responsibility of the land managers in the region (8 to 18%). The most commonly detected passerines on point counts included Redpoll spp. ( Carduelis flammea and C. hornemanni ), Savannah Sparrow ( Passerculus sandwichensis ), and American Tree Sparrow ( Spizella arborea ). The most numerous shorebirds were American Golden-Plover ( Pluvialis dominica ), Wilson’s Snipe ( Gallinago delicata ), and Whimbrel ( Numenius phaeopus ). Most species were detected at low rates, reflecting the low breeding densities (and/or low detectabilities) of birds in the montane Arctic. Suites of species were associated with particular ranges of elevation and showed strong associations with particular habitat types.

Alaska↗

U.S. Geological Survey activities in New York, 1979

This report describes the work of the U.S. Geological Survey and summarizes projects conducted in New York during 1979. Many of these projects are continuing into the 1980's. The major programs provide basic scientific information concerning water, land, and mineral resources. The Survey also supervises the exploration for mineral fuels on leased outer continental shelf lands. The programs are: (1) Water resources investigations--These encompass (a) statewide networks of measurement stations that provide continuous records of streamflow, groundwater levels, water quality, and sediment discharge, and (b) projects to study local or regional water problems as well as critical water problems of national scope or interest. (2) Geologic and mineral resource surveys and mapping--These studies focus on geologic, mineral, and energy-resources investigations both on land and offshore. (3) Conservation of lands and mineral resources--These studies include the classification and evaluation of mineral resources on the outer continental shelf. (4) Topographic surveys and mapping--These studies include quadrangle, small-scale, and special mapping. (5) Land information and analysis--These studies focus on the interpretation and application of earth-science and related information to multi-disciplinary land-resource and environmental-impact problems. (USGS)

Open-File Report↗

Magnetic storms and induction hazards

Magnetic storms are potentially hazardous to the activities and technological infrastructure of modern civilization. This reality was dramatically demonstrated during the great magnetic storm of March 1989, when surface geoelectric fields, produced by the interaction of the time-varying geomagnetic field with the Earth's electrically conducting interior, coupled onto the overlying Hydro-Québec electric power grid in Canada. Protective relays were tripped, the grid collapsed, and about 9 million people were temporarily left without electricity [ Bolduc , 2002].

Eos, Earth and Space Science News↗

Role of a polymorphism in a Hox/Pax-responsive enhancer in the evolution of the vertebrate spine

Patterning of the vertebrate skeleton requires the coordinated activity of Hox genes. In particular, Hox10 proteins are essential to set the transition from thoracic to lumbar vertebrae because of their rib-repressing activity. In snakes, however, the thoracic region extends well into Hox10-expressing areas of the embryo, suggesting that these proteins are unable to block rib formation. Here, we show that this is not a result of the loss of rib-repressing properties by the snake proteins, but rather to a single base pair change in a Hox/Paired box (Pax)-responsive enhancer, which prevents the binding of Hox proteins. This polymorphism is also found in Paenungulata, such as elephants and manatees, which have extended rib cages. In vivo, this modified enhancer failed to respond to Hox10 activity, supporting its role in the extension of rib cages. In contrast, the enhancer could still interact with Hoxb6 and Pax3 to promote rib formation. These results suggest that a polymorphism in the Hox/Pax-responsive enhancer may have played a role in the evolution of the vertebrate spine by differently modulating its response to rib-suppressing and rib-promoting Hox proteins.

Proceedings of the National Academy of Sciences↗

Early chromite mining and agricultural clearance: Opportunities for the investigation of agricultural sediment dynamics in the Eastern Piedmont (USA)

Many flood plains in the Eastern Piedmont (USA) are buried under deposits of sediment resulting from European agricultural clearance. Classic radioisotopic dating techniques cover temporal periods too short (137Cs, 210Pb) or too long (14C) to reliably date sediments deposited during periods of local European activity (1660-1900). Moreover, many potential biomarkers, such as pollen, degrade in oxic flood plain sediments. In the Baltimore, Maryland (USA) region, early chromite mining (1820 - 1880) occurred during periods of rapid agricultural clearance. Use of chromium (Cr) chemostratigraphic profiles in flood plain sediments tied to historical mining activity can provide improved precision in overbank accumulation rates and timing. Sediment cores were collected from the Red Run basin, which is part of the Baltimore Ecosystem Study, an urban Long-Term Ecological Research site. Trace metal chemostratigraphic profiles were measured and peaks in Cr concentration tied to historic mining activity. Dates from Cr chemostratigraphic profiles were combined with 137Cs dating to reconstruct flood plain sedimentation rates. Red Run early sedimentation rates (1820 - 1880) were higher (0.45 - 1.19 cm/yr) than more recent (1880 - 1963) rates (0.08 - 0.46 cm/yr). This indicates that Piedmont flood plain vertical sediment accumulation might have peaked before the peak in agricultural clearance, earlier than assumed by regional models. The Cr chemostratigraphy is applicable to a wider region including much of the Maryland and Pennsylvania (USA) Piedmont.

American Journal of Science↗