Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Life Sciences (3550)
- Physical Sciences and Mathematics (2014)
- Social and Behavioral Sciences (1958)
- Medicine and Health Sciences (1792)
- Education (1223)
-
- Arts and Humanities (1125)
- Law (1099)
- Engineering (930)
- Biology (914)
- Environmental Sciences (718)
- Animal Sciences (579)
- Chemistry (486)
- Psychology (482)
- Higher Education (473)
- Ecology and Evolutionary Biology (449)
- Plant Sciences (448)
- Medical Sciences (417)
- Biochemistry, Biophysics, and Structural Biology (351)
- Sociology (291)
- Communication (287)
- Medical Specialties (277)
- History (272)
- American Studies (250)
- Public Health (213)
- Library and Information Science (210)
- Computer Sciences (204)
- Genetics and Genomics (199)
- Biomedical Engineering and Bioengineering (198)
- Business (185)
- Earth Sciences (181)
- Institution
-
- University of Nebraska - Lincoln (1463)
- University of South Florida (560)
- Brigham Young University (454)
- Louisiana State University (414)
- TÜBİTAK (376)
-
- California Polytechnic State University, San Luis Obispo (364)
- Utah State University (355)
- Southern Illinois University Carbondale (263)
- Washington University School of Medicine (257)
- University of Central Florida (256)
- Virginia Commonwealth University (253)
- Clemson University (239)
- University of New Hampshire (228)
- University of Alabama at Birmingham (227)
- University of New Mexico (226)
- University of Kentucky (213)
- Stony Brook University (208)
- University of Montana (201)
- University of Nevada, Las Vegas (200)
- University of Malaya (194)
- West Virginia University (193)
- Old Dominion University (176)
- Portland State University (175)
- Georgia Southern University (166)
- Technological University Dublin (158)
- Nova Southeastern University (155)
- Eastern Illinois University (154)
- Purdue University (150)
- Marquette University (146)
- Wayne State University (143)
- Keyword
-
- Newspaper (198)
- Biology (169)
- Humans (136)
- Animals (135)
- 2010 (132)
-
- Newsletter (93)
- Education (90)
- Genetics (89)
- Bowling Green State University (82)
- Research (80)
- Gender (79)
- Ecology (78)
- Climate change (75)
- Male (69)
- Female (68)
- Chemistry (65)
- EIU (65)
- History (65)
- Doctor of Philosophy (PhD) Heersink School of Medicine (64)
- Conservation (62)
- Student newspapers (62)
- UAB (61)
- Cancer (60)
- Eastern Illinois University (60)
- Mice (59)
- Student newspaper (59)
- B.G. News (58)
- BG News (58)
- Daily Eastern News (58)
- Higher education (56)
- Publication
-
- Theses and Dissertations (543)
- Faculty Publications (380)
- Electronic Theses and Dissertations (338)
- Open Access Publications (219)
- USF Tampa Graduate Theses and Dissertations (199)
-
- Dissertations (193)
- International Congress on Environmental Modelling and Software (182)
- Graduate Theses, Dissertations, and Problem Reports (ETD) (151)
- Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions) (150)
- Articles (139)
- Master's Theses (136)
- All ETDs from UAB (129)
- Theses (120)
- All Graduate Theses and Dissertations, Spring 1920 to Summer 2023 (114)
- Research Publications (2006 to 2010) (113)
- All Theses and Dissertations (ETDs) (109)
- Open Access Dissertations (108)
- Faculty Scholarship (107)
- LSU Doctoral Dissertations (106)
- LSU Master's Theses (104)
- Publications and Research (98)
- United States Department of Agriculture Wildlife Services: Staff Publications (89)
- All Theses (87)
- UNLV Theses, Dissertations, Professional Papers, and Capstones (86)
- Biological Sciences (83)
- Wayne State University Dissertations (82)
- Student Works (2010-2019) (80)
- Dissertations and Theses (Open Access) (79)
- All-Inclusive List of Electronic Theses and Dissertations (78)
- Dartmouth Scholarship (75)
- Publication Type
- File Type
Articles 12751 - 12780 of 18907
Full-Text Articles in Entire DC Network
An Inquiry Into Situational Interest In A Tenth Grade History Class: Lesson Design And Implementation From Berlyne And Bergin Perspectives, Christine Louise Morgan
An Inquiry Into Situational Interest In A Tenth Grade History Class: Lesson Design And Implementation From Berlyne And Bergin Perspectives, Christine Louise Morgan
Wayne State University Dissertations
No
A Natural History Study Of Bufo A. Americanus, The Eastern American Toad, And The Phenology Of Spring Breeders In Southwest West Virginia, Tomi Maria Bergstrom
A Natural History Study Of Bufo A. Americanus, The Eastern American Toad, And The Phenology Of Spring Breeders In Southwest West Virginia, Tomi Maria Bergstrom
Theses, Dissertations and Capstones
Natural history traits have not been thoroughly collected and analyzed on the "common hoptoad," Bufo a. americanus (eastern American toad) in West Virginia. Updating natural history information is important to understand the present population status (Jackson, 2001). I chose to have two study sites at opposing physiographic regions to constitute a better understanding of B. a. americanus natural history in WV. The study was initiated in spring 2008 at Beech Fork State Park and Green Bottom Swamp Wildlife Refuge (in Mason and Cabell counties) and in 2009 incorporated Canaan Valley of Tucker County. Ten natural history morphometrics and characters were …
Research & Innovation For 2009-2010, University Of Rhode Island
Research & Innovation For 2009-2010, University Of Rhode Island
Publications (Research and Economic Development)
The 2009-2010 issue of Research & Innovation, a periodical focused on research at the University of Rhode Island.
Against Feasibility Analysis, Jonathan Masur, Eric A. Posner
Against Feasibility Analysis, Jonathan Masur, Eric A. Posner
Articles
Feasibility analysis, a method of evaluating government regulations, has emerged as the major alternative to cost-benefit analysis. Although regulatory agencies have used feasibility analysis (in some contexts called "technology-based" analysis) longer than cost-benefit analysis, feasibility analysis has received far less attention in the scholarly literature. In recent years; however, critics of cost-benefit analysis have offered feasibility analysis as a superior alternative. We advance the debate by uncovering the analytic structure of feasibility analysis and its normative premises, and then criticizing them. Our account builds on two examples of feasibility analysis, one conducted by OSHA and the other by EPA. We …
Die Stellungnahme Der Europäischen Gruppe Für Ethik Der Naturwissenschaften Und Der Neuen Technologien (Ege) Zum Thema „Ethik Der Synthetischen Biologie, Hille Haker
Theology: Faculty Publications and Other Works
No abstract provided.
Adaptive Evolution And Inherent Tolerance To Extreme Thermal Environments, Jennifer Cox, Alyxandria Schubert, Michael Travisano, Catherine Putonti
Adaptive Evolution And Inherent Tolerance To Extreme Thermal Environments, Jennifer Cox, Alyxandria Schubert, Michael Travisano, Catherine Putonti
Bioinformatics Faculty Publications
Background
When introduced to novel environments, the ability for a species to survive and rapidly proliferate corresponds with its adaptive potential. Of the many factors that can yield an environment inhospitable to foreign species, phenotypic response to variation in the thermal climate has been observed within a wide variety of species. Experimental evolution studies using bacteriophage model systems have been able to elucidate mutations, which may correspond with the ability of phage to survive modest increases/decreases in the temperature of their environment.
Results
Phage ΦX174 was subjected to both elevated (50°C) and extreme (70°C+) temperatures for anywhere from a few …
Mechanisms Responsible For A Φx174 Mutant's Ability To Infect Escherichia Coli By Phosphorylation, Jennifer Cox, Catherine Putonti
Mechanisms Responsible For A Φx174 Mutant's Ability To Infect Escherichia Coli By Phosphorylation, Jennifer Cox, Catherine Putonti
Bioinformatics Faculty Publications
The ability for a virus to expand its host range is dependent upon a successful mode of viral entry. As such, the host range of the well-studied ΦX174 bacteriophage is dictated by the presence of a particular lipopolysaccharide (LPS) on the bacterial surface. The mutant ΦX174 strain JACS-K, unlike its ancestor, is capable of infecting both its native host Escherichia coli C and E. coli K-12, which does not have the necessary LPS. The conversion of an alanine to a very reactive threonine on its virion surface was found to be responsible for the strain's expanded host range.
Evolution Of The Sequence Composition Of Flaviviruses, Alyxandria M. Schubert, Catherine Putonti
Evolution Of The Sequence Composition Of Flaviviruses, Alyxandria M. Schubert, Catherine Putonti
Bioinformatics Faculty Publications
The adaption of pathogens to their host(s) is a major factor in the emergence of infectious disease and the persistent survival of many of the infectious diseases within the population. Since many of the smaller viral pathogens are entirely dependent upon host machinery, it has been postulated that they are under selection for a composition similar to that of their host. Analyses of sequence composition have been conducted for numerous small viral species including the Flavivirus genus. Examination of the species within this particular genus that infect vertebrate hosts revealed that sequence composition proclivities do not correspond with vector transmission …
Late Pragmatism, Logical Positivism, And Their Aftermath, David Ingram
Late Pragmatism, Logical Positivism, And Their Aftermath, David Ingram
Philosophy: Faculty Publications and Other Works
Developments in Anglo-American philosophy during the first half of the 20th Century closely tracked developments that were occurring in continental philosophy during this period. This should not surprise us. Aside from the fertile communication between these ostensibly separate traditions, both were responding to problems associated with the rise of mass society. Rabid nationalism, corporate statism, and totalitarianism (Left and Right) posed a profound challenge to the idealistic rationalism of neo-Kantian and neo-Hegelian philosophies. The decline of the individual – classically conceived by the 18th-century Enlightenment as a self-determining agent – provoked strong reactions. While some philosophical tendencies sought to …
Contents, Inquiry Editors
Contents, Inquiry Editors
Inquiry: The University of Arkansas Undergraduate Research Journal
No abstract provided.
Resilience & Recovery After War: Refugee Children And Families In The United States, Katherine Porterfield, Adeyinka M. Akinsulure-Smith, Molly A. Benson, Theresa Betancourt, B. Heidi Ellis, Maryam Kia-Keating, Kenneth Miller
Resilience & Recovery After War: Refugee Children And Families In The United States, Katherine Porterfield, Adeyinka M. Akinsulure-Smith, Molly A. Benson, Theresa Betancourt, B. Heidi Ellis, Maryam Kia-Keating, Kenneth Miller
Publications and Research
No abstract provided.
Evidence For A Sauropod−Like Metacarpal Configuration In Ankylosaurian Dinosaurs, Philip J. Senter
Evidence For A Sauropod−Like Metacarpal Configuration In Ankylosaurian Dinosaurs, Philip J. Senter
Biological Science Faculty Working Papers
Ankylosaurian dinosaurs are armored, quadrupedal members of the ornithischian clade Thyreophora. Ankylosaurs are typically portrayed with the metacarpals slanted and distally divergent, with their proximal ends arranged in a shallow arc, both in the literature (Matthew 1922; Gaston et al. 2001; McCrea et al. 2001; Vickaryous et al. 2004) and in museum mounts (Fig. 1). In contrast, Carpenter (1984) illustrated the metacarpals of the ankylosaur Sauropelta edwardsorum Ostrom, 1970, from the Lower Cretaceous Cloverly Formation of Wyoming and Montana, with their proximal ends arranged in a tight, semicircular arc, but even in that depiction themetacarpals were slanted and distally divergent. …
The Plenary Power Of States To Protect Citizens From Environmental Hazards: Who's Failing? New York State: A Case In Point, Tonya R. Lewis
The Plenary Power Of States To Protect Citizens From Environmental Hazards: Who's Failing? New York State: A Case In Point, Tonya R. Lewis
Buffalo Environmental Law Journal
No abstract provided.
A Comparison Of Ground Cover And Frequency Estimation Methods For Post-Harvest Soil Monitoring, Curtis David Kvamme
A Comparison Of Ground Cover And Frequency Estimation Methods For Post-Harvest Soil Monitoring, Curtis David Kvamme
Dissertations, Master's Theses and Master's Reports - Open
The amount and type of ground cover is an important characteristic to measure when collecting soil disturbance monitoring data after a timber harvest. Estimates of ground cover and bare soil can be used for tracking changes in invasive species, plant growth and regeneration, woody debris loadings, and the risk of surface water runoff and soil erosion. A new method of assessing ground cover and soil disturbance was recently published by the U.S. Forest Service, the Forest Soil Disturbance Monitoring Protocol (FSDMP). This protocol uses the frequency of cover types in small circular (15cm) plots to compare ground surface in pre- …
Faculty Senate Minutes, 2010 Meetings, Clemson University
Faculty Senate Minutes, 2010 Meetings, Clemson University
Faculty Senate Minutes
No abstract provided.
Long-Term Core Site Grasshopper Dynamics For The Sevilleta National Wildlife Refuge, New Mexico (1992-2013), David Lightfoot
Long-Term Core Site Grasshopper Dynamics For The Sevilleta National Wildlife Refuge, New Mexico (1992-2013), David Lightfoot
Sevilleta LTER Program Data
Grasshoppers are important animals in semi-arid environments, both as herbivores and as food resources for higher level consumer animals. Grasshoppers tend to be numerous and represented by many species in semi-arid environments, especially in desert grasslands. Grasshopper species range from environmental specialists, to environmental generalists. Grasshopper populations tend to change considerably from year to year, often in response to annual variation in rainfall and plant production. The purpose of this study was to monitor grasshopper species composition and abundance over a period of many years from black grama grassland, blue grama grassland, creosotebush shrubland, and pinyon/juniper woodland environments at the …
Early Life Characteristics, Psychiatric History, And Cognition Trajectories In Later Life, Maria Teresa Brown
Early Life Characteristics, Psychiatric History, And Cognition Trajectories In Later Life, Maria Teresa Brown
Falk College Research Center
Purpose of the Study: Although considerable attention has been paid to the relationship between later-life depression and cognitive function, the relationship between a history of psychiatric problems and cognitive function is not very well documented. Few studies of relationships between childhood health, childhood disadvantage, and cognitive function in later life consider both childhood health and disadvantage, include measures for psychiatric history, or use nationally representative longitudinal data. Design and Methods: This study uses growth curve models to analyze the relationships between childhood health and disadvantage, psychiatric history, and cognitive function using 6 waves of the Health and Retirement Study, controlling …
2010 Self-Study Report: Explore, Renew, Sustain, Lead, University Of Minnesota, Morris
2010 Self-Study Report: Explore, Renew, Sustain, Lead, University Of Minnesota, Morris
Miscellaneous Campus Publications
No abstract provided.
Prion Genotypes Of Scrapie-Infected Canadian Sheep 1998–2008, Noel P. Harrington, Katherine I. O'Rourke, Yuquin Feng, Jasmine Rendulich, Cathleen Difruscio, Aru Balachandran
Prion Genotypes Of Scrapie-Infected Canadian Sheep 1998–2008, Noel P. Harrington, Katherine I. O'Rourke, Yuquin Feng, Jasmine Rendulich, Cathleen Difruscio, Aru Balachandran
Zoonotics and Wildlife Disease: Publications
This report describes the genetics of the prion protein gene (PRNP) at codons 136, 154, and 171 for sheep diagnosed with naturally acquired classical scrapie in Canada between 1998 and 2008. Genotyping analysis was performed on 249 sheep with confirmed classical scrapie infection representing 98 flocks from 6 provinces. A further case-control analysis of 3 of these flocks compared the genotypes between infected sheep (n = 72) and those of their healthy flockmates (n = 1990). The incidence of classical scrapie in the Canadian sheep population was highly associated with the ARQ haplotype (91.8%) and the …
Increased Risk Of Chronic Wasting Disease In Rocky Mountain Elk Associated With Decreased Magnesium And Increased Manganese In Brain Tissue, Stephen N. White, Katherine I. O'Rourke, Thomas Gidlewski, Kurt C. Vercauteren, Michelle R. Mousel, Gregory E. Phillips, Terry R. Spraker
Increased Risk Of Chronic Wasting Disease In Rocky Mountain Elk Associated With Decreased Magnesium And Increased Manganese In Brain Tissue, Stephen N. White, Katherine I. O'Rourke, Thomas Gidlewski, Kurt C. Vercauteren, Michelle R. Mousel, Gregory E. Phillips, Terry R. Spraker
Zoonotics and Wildlife Disease: Publications
Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) of Rocky Mountain elk in North America. Recent studies suggest that tissue and blood mineral levels may be valuable in assessing TSE infection in sheep and cattle. The objectives of this study were to examine baseline levels of copper, manganese, magnesium, zinc, selenium, and molybdenum in the brains of Rocky Mountain elk with differing prion genotypes and to assess the association of mineral levels with CWD infection. Elk with leucine at prion position 132 had significantly lower magnesium levels than elk with 2 copies of methionine. Chronic wasting disease-positive elk …
Human-Animal Medicine: Clinical Approaches To Zoonoses, Toxicants And Other Shared Health Risks, Katie Portacci Dvm, Mph, Dacvpm
Human-Animal Medicine: Clinical Approaches To Zoonoses, Toxicants And Other Shared Health Risks, Katie Portacci Dvm, Mph, Dacvpm
Zoonotics and Wildlife Disease: Publications
Oftentimes, the wide breadth of literature available on zoonotic diseases can be difficult to obtain in a clinical setting, yet veterinarians are looked on as a primary source of information for zoonotic diseases. Human- Animal Medicine: Clinical Approaches to Zoonoses, Toxicants and Other Shared Health Risks serves as a consolidated resource for a number of zoonotic and other disease risks that may be shared between humans and other animals. The book highlights the role of veterinarians in the detection of diseases that may have an impact on human, wildlife, or pet health. It also serves as a reminder that veterinarians …
2010 Community Benefit Annual Report: Redefining Pediatric Medicine One Child At A Time, Children's Mercy Hospital
2010 Community Benefit Annual Report: Redefining Pediatric Medicine One Child At A Time, Children's Mercy Hospital
Community Benefits
Fiscal year report on the community benefits provided by Children's Mercy Kansas City to the communities in the Kansas City region.
Microbial And Mineralogical Characterizations Of Soils Collected From The Deep Biosphere Of The Former Homestake Gold Mine, South Dakota, Gurdeep Rastogi, Shariff Osman, Ravi K. Kukkadapu, Mark Engelhard, Parag A. Vaishampayan, Gary L. Andersen, Rajesh K. Sani
Microbial And Mineralogical Characterizations Of Soils Collected From The Deep Biosphere Of The Former Homestake Gold Mine, South Dakota, Gurdeep Rastogi, Shariff Osman, Ravi K. Kukkadapu, Mark Engelhard, Parag A. Vaishampayan, Gary L. Andersen, Rajesh K. Sani
United States Department of Energy: Publications
A microbial census on deep biosphere (1.34 km depth) microbial communities was performed in two soil samples collected from the Ross and number 6Winze sites of the former Homestake gold mine, Lead, South Dakota using high-density 16S microarrays (PhyloChip). Soil mineralogical characterization was carried out using X-ray diffraction, X-ray photoelectron, and Mössbauer spectroscopic techniques which demonstrated silicates and iron minerals (phyllosilicates and clays) in both samples. Microarray data revealed extensive bacterial diversity in soils and detected the largest number of taxa in Proteobacteria phylum followed by Firmicutes and Actinobacteria. The archael communities in the deep gold mine environments were …
Microbial Reduction Of Uranium Under Iron- And Sulfate-Reducing Conditions: Effect Of Amended Goethite On Microbial Community Composition And Dynamics, H.S. Moon, L. Mcguinness, Ravi K. Kukkadapu, A.D. Peacock, John Komlos, L.J. Kerkhof, P.E. Long, Peter R. Jaffe
Microbial Reduction Of Uranium Under Iron- And Sulfate-Reducing Conditions: Effect Of Amended Goethite On Microbial Community Composition And Dynamics, H.S. Moon, L. Mcguinness, Ravi K. Kukkadapu, A.D. Peacock, John Komlos, L.J. Kerkhof, P.E. Long, Peter R. Jaffe
United States Department of Energy: Publications
There is a growing need for a better understanding of the biogeochemical dynamics involved in microbial U(VI) reduction due to an increasing interest in using biostimulation via electron donor addition as a means to remediate uranium contaminated sites. U (VI) reduction has been observed to be maximized during iron-reducing conditions and to decrease upon commencement of sulfate-reducing conditions. There are many unknowns regarding the impact of iron/sulfate biogeochemistry on U(VI) reduction. This includes Fe(III) availability as well as the microbial community changes, including the activity of iron-reducers during the uranium biostimulation period even after sulfate reduction becomes dominant. Column experiments …
Spatial-Temporal Stratifications In Natural Populations And How They Affect Understanding And Estimation Of Effective Population Size, Robin Waples
United States Department of Commerce: Staff Publications
The concept of effective population size (Ne) is based on an elegantly simple idea which, however, rapidly becomes very complex when applied to most real-world situations. In natural populations, spatial and temporal stratifications create different classes of individuals with different vital rates, and this in turn affects (generally reduces) Ne in complex ways. I consider how these natural stratifications influence our understanding of effective size and how to estimate it, and what the consequences are for conservation and management of natural populations. Important points that emerge include the following:
1. The relative influences of local vs. …
Complete Mitochondrial Genome Phylogeographic Analysis Of Killer Whales (Orcinus Orca) Indicates Multiple Species, Phillip A. Morin, Frederick I. Archer, Andrew D. Foote, Julia Vilstrup, Eric E. Allen, Paul Wade, John Durban, Kim Parsons, Robert Pitman, Lewyn Li, Pascal Bouffard, Sandra C. Abel Nielsen, Morten Rasmussen, Eske Willerslev, M. Thomas P. Gilbert, Timothy Harkins
Complete Mitochondrial Genome Phylogeographic Analysis Of Killer Whales (Orcinus Orca) Indicates Multiple Species, Phillip A. Morin, Frederick I. Archer, Andrew D. Foote, Julia Vilstrup, Eric E. Allen, Paul Wade, John Durban, Kim Parsons, Robert Pitman, Lewyn Li, Pascal Bouffard, Sandra C. Abel Nielsen, Morten Rasmussen, Eske Willerslev, M. Thomas P. Gilbert, Timothy Harkins
United States Department of Commerce: Staff Publications
Killer whales (Orcinus orca) currently comprise a single, cosmopolitan species with a diverse diet. However, studies over the last 30 yr have revealed populations of sympatric ‘‘ecotypes’’ with discrete prey preferences, morphology, and behaviors. Although these ecotypes avoid social interactions and are not known to interbreed, genetic studies to date have found extremely low levels of diversity in the mitochondrial control region, and few clear phylogeographic patterns worldwide. This low level of diversity is likely due to low mitochondrial mutation rates that are common to cetaceans. Using killer whales as a case study, we have developed a method …
Highly Discordant Nuclear And Mitochondrial Dna Diversities In Atka Mackerel, M. F. Canino, I. B. Spies, S. A. Lowe, W. S. Grant
Highly Discordant Nuclear And Mitochondrial Dna Diversities In Atka Mackerel, M. F. Canino, I. B. Spies, S. A. Lowe, W. S. Grant
United States Department of Commerce: Staff Publications
Levels of neutral genetic diversity largely reflect effective population size (Ne), which is influenced by physical and biological environmental variables. While large populations of marine fishes generally harbor higher diversities than freshwater species, historical demography or the effects of natural selection may significantly reduce Ne and differentially affect genomic diversities. Here, we surveyed levels of genetic diversity and examined genetic structure among populations of the Atka mackerel Pleurogrammus monopterygius across most of its geographic range by screening variation at nine nuclear microsatellite DNA markers (n = 745) and in a 468-base-pair segment of the mitochondrial …
Genetic Assessment Of The Mating System And Patterns Of Egg Cannibalism In Atka Mackerel, M. F. Canino, I. B. Spies, J. L. Guthridge, M. M. Hollowed
Genetic Assessment Of The Mating System And Patterns Of Egg Cannibalism In Atka Mackerel, M. F. Canino, I. B. Spies, J. L. Guthridge, M. M. Hollowed
United States Department of Commerce: Staff Publications
The mating system and patterns of gender-specific egg cannibalism in Atka mackerel Pleurogrammus monopterygius were examined through genetic parentage analysis of embryos in egg clutches produced in captive and wild populations. Like other hexagrammid fishes, Atka mackerel exhibit polygynandry, which is characterized by serial matings by both genders within a breeding season. Most matings in captivity were pairings of females with nest-attendant males, although parentage analysis of clutches produced in a small tank with limited nesting substrate revealed that 31% contained contributions by non–nest-guarding males. In contrast, all egg clutches produced in a large exhibit tank were sired by guardian …
Effects From Filtration, Capping Agents, And Presence/Absence Of Food On The Toxicity Of Silver Nanoparticles To Daphnia Magna, H. Joel Allen, Christopher A. Impellitteri, Dana A. Macke, J. Lee Heckman, Helen C. Poynton, James M. Lazorchak, Shekar Govindaswamy, Deborah L. Roose, Mallikarjuna N. Nadagouda
Effects From Filtration, Capping Agents, And Presence/Absence Of Food On The Toxicity Of Silver Nanoparticles To Daphnia Magna, H. Joel Allen, Christopher A. Impellitteri, Dana A. Macke, J. Lee Heckman, Helen C. Poynton, James M. Lazorchak, Shekar Govindaswamy, Deborah L. Roose, Mallikarjuna N. Nadagouda
United States Environmental Protection Agency: Publications
Relatively little is known about the behavior and toxicity of nanoparticles in the environment. Objectives of work presented here include establishing the toxicity of a variety of silver nanoparticles (AgNPs) to Daphnia magna neonates, assessing the applicability of a commonly used bioassay for testing AgNPs, and determining the advantages and disadvantages of multiple characterization techniques for AgNPs in simple aquatic systems. Daphnia magna were exposed to a silver nitrate solution and AgNPs suspensions including commercially available AgNPs (uncoated and coated), and laboratory-synthesized AgNPs (coated with coffee or citrate). The nanoparticle suspensions were analyzed for silver concentration (microwave acid digestions), size …
Assessing The Effects Of Exposure Timing On Biomarker Expression Using Β-Estradiol, K. M. Hyndman, A. Biales, S. E. Bartell, H. L. Schoenfuss
Assessing The Effects Of Exposure Timing On Biomarker Expression Using Β-Estradiol, K. M. Hyndman, A. Biales, S. E. Bartell, H. L. Schoenfuss
United States Environmental Protection Agency: Publications
Temporal and spatial variability in estrogenicity has been documented formanytreated wastewater effluents with the consequences of this variability on the expression of biomarkers of endocrine disruption being largely unknown. Laboratory exposure studies usually utilize constant exposure concentrations which may produce biological effects that differ from those observed in organisms exposed in natural environments. In this study, we investigated the effects of differential timing of exposures with 17β - estradiol (E2) on a range of fathead minnow biomarkers to simulate diverse environmentally relevant exposure profiles. Two 21-day, replicate experiments were performed exposing mature male fathead minnows to E2 at time-weighted mean …