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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse more than 65,000 articles authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.
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A phylogeny based on cytochrome-c oxidase gene sequences identifies sympatric Ichthyophonus genotypes in the NE Pacific Ocean A phylogeny based on cytochrome-c oxidase gene sequences identifies sympatric Ichthyophonus genotypes in the NE Pacific Ocean
ABSTRACT: In recent decades, evidence has accumulated to suggest that the widespread and highly variable parasite Ichthyophonus hoferi is actually a species complex. Highly plastic morphology and a general lack of defining structures has contributed to the likely underestimate of biodiversity within this group. Molecular methods are a logical next step in the description of these...
Authors
Jacob L. Gregg, Paul Hershberger, Abigail S. Neat, Hiruni T. Jayasekera, Jayde A. Ferguson, Rachel L. Powers, Maureen K. Purcell
Ten-year ecological responses to fuel treatments within semiarid Wyoming big sagebrush ecosystems Ten-year ecological responses to fuel treatments within semiarid Wyoming big sagebrush ecosystems
Sagebrush ecosystems of western North America are threatened by invasive annual grasses and wildfires that can remove fire-intolerant shrubs for decades. Fuel reduction treatments are used ostensibly to aid in fire suppression, conserve wildlife habitat, and restore historical fire regimes, but long-term ecological impacts of these treatments are not clear. In 2006, we initiated fuel...
Authors
David A. Pyke, Scott E. Shaff, Jeanne C. Chambers, Eugene W. Schupp, Beth A. Newingham, Margaret L Gray, Lisa M. Ellsworth
Fibropapillomatosis dynamics in green sea turtles Chelonia mydas over 15 years of monitoring in Akumal Bay, Quintana Roo, Mexico Fibropapillomatosis dynamics in green sea turtles Chelonia mydas over 15 years of monitoring in Akumal Bay, Quintana Roo, Mexico
ABSTRACT: Fibropapillomatosis (FP) is a tumor disease that affects all sea turtle species but is mainly seen in green turtles Chelonia mydas. The pathology of FP has been described extensively, but its dynamics in populations over time have been less studied. We analyzed the dynamics of FP in a population of green turtles in Akumal Bay on the central coast of the Mexican Caribbean. A...
Authors
Fernando A. Munoz Teneria, Vanessa Labrada-Martagon, Roberto Herrera-Pavon, Thierry M. Work, Erik Gonzalez Ballesteros, Ana Negrete-Philippe, Gisela Maldonado-Saldana
Prioritizing pharmaceutical contaminants in Great Lakes tributaries using risk-based screening techniques Prioritizing pharmaceutical contaminants in Great Lakes tributaries using risk-based screening techniques
In a study of 44 diverse sampling sites across 16 Great Lakes tributaries, 110 pharmaceuticals were detected of 257 monitored. The present study evaluated the ecological relevance of detected chemicals and identified heavily impacted areas to help inform resource managers and guide future investigations. Ten pharmaceuticals (caffeine, nicotine, albuterol, sulfamethoxazole, venlafaxine
Authors
Matthew A. Pronschinske, Steven R. Corsi, Laura A. DeCicco, Edward Furlong, Gerald T. Ankley, Brett R. Blackwell, Daniel L. Villeneuve, Peter L. Lenaker, Michelle A. Nott
Divergent successional trajectories of soil seed bank and post-fire vegetation in a semiarid oak forest: Implications for post-fire ecological restoration Divergent successional trajectories of soil seed bank and post-fire vegetation in a semiarid oak forest: Implications for post-fire ecological restoration
Wildfires are a major disturbance in forest ecosystems around the world and may lead to changes in vegetation succession trajectories. This study examined the impact of time since wildfires on the successional gradients of the degraded Zagros semi-arid oak forest in Iran. Here, we investigated the role of soil seed bank in postfire understory vegetation successional trajectories after...
Authors
Sina Attar Roshan, Mehdi Heydari, Alexander Wait, S.M. Mijan Uddin, Manuel Esteban Lucas-Borja, Jon Keeley
Root-mean-square error (RMSE) or mean absolute error (MAE): When to use them or not Root-mean-square error (RMSE) or mean absolute error (MAE): When to use them or not
The root-mean-squared error (RMSE) and mean absolute error (MAE) are widely used metrics for evaluating models. Yet, there remains enduring confusion over their use, such that a standard practice is to present both, leaving it to the reader to decide which is more relevant. In a recent reprise to the 200-year debate over their use, Willmott and Matsuura (2005) and Chai and Draxler (2014)...
Authors
Timothy O. Hodson
Thermophysical and compositional properties of paleobedforms on Mars Thermophysical and compositional properties of paleobedforms on Mars
Bedforms on Earth and Mars are often preserved in the rock record in the form of sedimentary rock with distinct cross-bedding. On rare occasions, the full-surface geometry of a bedform can be preserved through burial and lithification. These features, known as paleobedforms, are found in a variety of geographic locations on Mars. Evidence in the morphology of paleobedforms, such as the...
Authors
Aaron R. Weintraub, Christopher S. Edwards, Matthew Chojnacki, Lauren A. Edgar, Lori K. Fenton, Sylvain Piqueux, Amber L. Gullikson
Using piecewise regression to identify biological phenomena in biotelemetry datasets Using piecewise regression to identify biological phenomena in biotelemetry datasets
1. Technological advances in the field of animal tracking have greatly expanded the potential to remotely monitor animals, opening the door to exploring how animals shift their behavior over time or respond to external stimuli. A wide variety of animal-borne sensors can provide information on an animal’s location, movement characteristics, external environmental conditions, and internal
Authors
David W. Wolfson, David E. Andersen, John R. Fieberg
Expert perspectives on global biodiversity loss and its drivers and impacts on people Expert perspectives on global biodiversity loss and its drivers and impacts on people
Despite substantial progress in understanding global biodiversity loss, major taxonomic and geographic knowledge gaps remain. Decision makers often rely on expert judgement to fill knowledge gaps, but are rarely able to engage with sufficiently large and diverse groups of specialists. To improve understanding of the perspectives of thousands of biodiversity experts worldwide, we...
Authors
Forest Isbell, Patricia Balvanera, Akira S. Mori, Jin-Sheng He, James M. Bullock, Ganga Ram Regmi, Eric W. Seabloom, Simon Ferrier, Osvaldo E. Sala, Nathaly R. Guerrero-Ramirez, Julia Tavella, Daniel J. Larkin, Bernhard Schmid, Charlotte L. Outhwaite, Pairot Pramua, Elizabeth T. Borer, Michel Loreau, Taiwo Crossby Omotoriogun, David O. Obura, Maggie Anderson, Cristina Portales-Reyes, Kevin Kirkman, Pablo M Vergara, Adam Thomas Clark, Kimberly J Komatsu, Owen L. Petchey, Sarah R. Weiskopf, Laura J. Williams, Scott L. Collins, Nico Eisenhauer, Christopher H Trisos, Delphine Renard, Alexandra J. Wright, Poonam Tripathi, Jane Cowles, Jarrett E. K. Byrnes, Peter B. Reich, Andy Purvis, Zati Sharip, Mary I. O’Connor, Clare E. Kazanski, Nick M. Haddad, Eulogio H. Soto, Laura E. Dee, Sandra Díaz, Chad R. Zirbel, Meghan L. Avolio, Shaopeng Wang, Zhiyuan Ma, Jingjing Liang, Hanan C. Farah, Justin Andrew Johnson, Brian W. Miller, Yann Hautier, Melinda D. Smith, Johannes M. H. Knops, Bonnie Myers, Zuzana Harmáčková, Jorge Cortes, Mike Harfoot, Andrew Gonzalez, Tim Newbold, Jacqueline Oehri, Marina Mazon, Cynnamon Dobbs, Meredith S. Palmer
Testing whether adrenal steroids mediate phenotypic and physiologic effects of elevated salinity on larval tiger salamanders Testing whether adrenal steroids mediate phenotypic and physiologic effects of elevated salinity on larval tiger salamanders
Salinity (sodium chloride, NaCl) from anthropogenic sources is a persistent contaminant that negatively affects freshwater taxa. Amphibians can be susceptible to salinity, but some species are innately or adaptively tolerant. Physiological mechanisms mediating tolerance to salinity are still unclear, but changes in osmoregulatory hormones such as corticosterone (CORT) and aldosterone...
Authors
Brian J. Tornabene, Creagh W Breuner, Erica J Crespi, Blake R. Hossack
Tephrochronology of the Miocene Monterey and Modelo Formations, California Tephrochronology of the Miocene Monterey and Modelo Formations, California
Tuff beds have been known in the Miocene Monterey and Modelo Formations since the initial descriptions; however, age control and correlation is predominantly biostratigraphy. Here we combine tephrochronology and biostratigraphy in order to provide numerical age control for eight sedimentary sequences of the Monterey and Modelo Formations from Monterey, California to Orange County...
Authors
Jeffrey R. Knott, Andrei M. Sarna-Wojcicki, John A. Barron, Elmira Wan, Nancy Heizler, Priscilla Martinez
The effects of earthquake experience on intentions to respond to Earthquake Early Warnings The effects of earthquake experience on intentions to respond to Earthquake Early Warnings
Warning systems are essential for providing people with information so they can take protective action in response to perils. Systems need to be human-centered, which requires an understanding of the context within which humans operate. Therefore, our research sought to understand the human context for Earthquake Early Warning (EEW) in Aotearoa New Zealand, a location where no...
Authors
Julia S. Becker, Lauren Vinnell, Sara K. McBride, K. Nakayachi, Emma Doyle, Sally H. Potter, Ann Bostrom