Christine Densmore (Former Employee)
Science and Products
Filter Total Items: 26
Mycobacterial infection in Northern snakehead (Channa argus) from the Potomac River catchment
The Northern snakehead, Channa argus (Cantor), is a non-native predatory fish that has become established regionally in some temperate freshwater habitats within the United States. Over the past decade, Northern snakehead populations have developed within aquatic ecosystems throughout the eastern USA, including the Potomac River system within Virginia, Maryland and Washington, D.C. Since this spec
Authors
Christine L. Densmore, Luke R. Iwanowicz, Anne Henderson, Deborah D. Iwanowicz, J.S. Odenkirk
In vitro immune functions in thiamine-replete and -depleted lake trout (Salvelinus namaycush)
In this study we examined the impacts of in vivo thiamine deficiency on lake trout leukocyte function measured in vitro. When compared outside the context of individual-specific thiamine concentrations no significant differences were observed in leukocyte bactericidal activity or in concanavalin A (Con A), and phytohemagglutinin-P (PHA-P) stimulated leukocyte proliferation. Placing immune function
Authors
Christopher A. Ottinger, Dale C. Honeyfield, Christine L. Densmore, Luke R. Iwanowicz
Suppressing bullfrog larvae with carbon dioxide
Current management strategies for the control and suppression of the American Bullfrog (Lithobates catesbeianus = Rana catesbeiana Shaw) and other invasive amphibians have had minimal effect on their abundance and distribution. This study evaluates the effects of carbon dioxide (CO2) on pre- and prometamorphic Bullfrog larvae. Bullfrogs are a model organism for evaluating potential suppression age
Authors
Mark Abbey-Lambert, Andrew Ray, Megan J. Layhee, Christine L. Densmore, Adam Sepulveda, Jackson A. Gross, Barnaby J. Watten
Identification of largemouth bass virus in the introduced Northern snakehead inhabiting the Cheasapeake Bay watershed
The Northern Snakehead Channa argus is an introduced species that now inhabits the Chesapeake Bay. During a preliminary survey for introduced pathogens possibly harbored by these fish in Virginia waters, a filterable agent was isolated from five specimens that produced cytopathic effects in BF-2 cells. Based on PCR amplification and partial sequencing of the major capsid protein (MCP), DNA polymer
Authors
Luke R. Iwanowicz, Christine L. Densmore, Cassidy M. Hahn, Phillip McAllister, John Odenkirk
Effects of depletion sampling by standard three-pass pulsed DC electrofishing on blood chemistry parameters of fishes from Appalachian streams
Adverse effects on fishes captured by electrofishing techniques have long been recognized, although the extent of associated physical injury and behavioral alterations are highly variable and dependent on a number of factors. We examined the effects of three-pass pulsed DC (PDC) electrofishing on two salmonid species (Rainbow Trout Oncorhynchus mykiss and Brook Trout Salvelinus fontinalis) and fiv
Authors
Christine L. Densmore, Frank M. Panek
Frequency and Severity of Trauma in Fishes Subjected to Multiple-pass Depletion Electrofishing
The incidence and severity of trauma associated with multiple-pass electrofishing and the effects on short-term (30-d) survival and growth of Rainbow Trout Oncorhynchus mykiss, Brook Trout Salvelinus fontinalis, and five representative co-inhabiting nontarget or bycatch species were examined. Fish were held in four rectangular fiberglass tanks (190 × 66 cm) equipped with electrodes, a gravel–cobbl
Authors
Frank Panek, Christine L. Densmore
Impact of thiamine deficiency on T-cell dependent and T-cell independent antibody production in lake trout
Lake trout Salvelinus namaycush on thiamine-replete and thiamine-depleted diets were evaluated for the effects of thiamine status on in vivo responses to the T-dependent antigen trinitophenol (TNP)-keyhole limpet hemocyanin (TNP-KLH), the T-independent antigen trinitrophenol-lipolysaccaharide (TNP-LPS), or Dulbecco's phosphate-buffered saline (DPBS; negative control fish). Plasma antibody concentr
Authors
Christopher A. Ottinger, Dale C. Honeyfield, Christine L. Densmore, Luke R. Iwanowicz
Global amphibian declines: perspectives from the United States and beyond
Over recent decades, amphibians have experienced population declines, extirpations and species-level extinctions at an alarming rate. Numerous potential etiologies for amphibian declines have been postulated including climate and habitat degradation. Other potential anthropogenic causes including overexploitation and the frequent introductions of invasive predatory species have also been blamed fo
Authors
Christine L. Densmore
Diseases of amphibians
The development and refinement of amphibian medicine comprise an ongoing science that reflects the unique life history of these animals and our growing knowledge of amphibian diseases. Amphibians are notoriously fastidious in terms of captive care requirements, and the majority of diseases of amphibians maintained in captivity will relate directly or indirectly to husbandry and management. Investi
Authors
Christine L. Densmore, David E. Green
Synthesis of U.S. Geological Survey science for the Chesapeake Bay ecosystem and implications for environmental management
The purpose of this report is to present a synthesis of the USGS Chesapeake Bay science related to the 2001-06 goals and provide implications for environmental management. The report provides USGS findings that address the science needs of the Chesapeake Bay Program (CBP) restoration goals and includes summaries of 1. land-use change; 2. water quality in the watershed, including nutrients, sedimen
Authors
Scott W. Ator, Vicki S. Blazer, John W. Brakebill, Donald R. Cahoon, Peter R. Claggett, Thomas M. Cronin, Judith M. Denver, Christine L. Densmore, Allen C. Gellis, Cliff R. Hupp, Jurate M. Landwehr, Michael J. Langland, Christopher A. Ottinger, Milan J. Pavich, Matthew C. Perry, Scott W. Phillips, Stephen D. Preston, Jeff P. Raffensperger, Barnett A. Rattner, Nancy B. Rybicki, Debra A. Willard
Mycobacteriosis in Chesapeake Bay Striped Bass (Morone saxatilis)
No abstract available.
Authors
Christopher A. Ottinger, Vicki S. Blazer, Christine L. Densmore, David T. Gauthier, H. Kator, F. M. Panek, M. W. Rhodes, W. Vogelbein
Calcein AM release-based cytotoxic cell assay for fish leucocytes
A non-specific cytotoxic cell assay for fish is presented that is based on the release of the activated fluorochrome calcein AM from lysed carp epithelioma papulosum cyprini (EPC) cells. To establish the suitability of treating EPC cells with calcein AM the uptake and spontaneous release of the calcein AM by the EPC cells was evaluated. Incubation of 5 μM calcein AM in culture medium with 1×105EPC
Authors
Luke R. Iwanowicz, Christine L. Densmore, Christopher A. Ottinger
Science and Products
Filter Total Items: 26
Mycobacterial infection in Northern snakehead (Channa argus) from the Potomac River catchment
The Northern snakehead, Channa argus (Cantor), is a non-native predatory fish that has become established regionally in some temperate freshwater habitats within the United States. Over the past decade, Northern snakehead populations have developed within aquatic ecosystems throughout the eastern USA, including the Potomac River system within Virginia, Maryland and Washington, D.C. Since this spec
Authors
Christine L. Densmore, Luke R. Iwanowicz, Anne Henderson, Deborah D. Iwanowicz, J.S. Odenkirk
In vitro immune functions in thiamine-replete and -depleted lake trout (Salvelinus namaycush)
In this study we examined the impacts of in vivo thiamine deficiency on lake trout leukocyte function measured in vitro. When compared outside the context of individual-specific thiamine concentrations no significant differences were observed in leukocyte bactericidal activity or in concanavalin A (Con A), and phytohemagglutinin-P (PHA-P) stimulated leukocyte proliferation. Placing immune function
Authors
Christopher A. Ottinger, Dale C. Honeyfield, Christine L. Densmore, Luke R. Iwanowicz
Suppressing bullfrog larvae with carbon dioxide
Current management strategies for the control and suppression of the American Bullfrog (Lithobates catesbeianus = Rana catesbeiana Shaw) and other invasive amphibians have had minimal effect on their abundance and distribution. This study evaluates the effects of carbon dioxide (CO2) on pre- and prometamorphic Bullfrog larvae. Bullfrogs are a model organism for evaluating potential suppression age
Authors
Mark Abbey-Lambert, Andrew Ray, Megan J. Layhee, Christine L. Densmore, Adam Sepulveda, Jackson A. Gross, Barnaby J. Watten
Identification of largemouth bass virus in the introduced Northern snakehead inhabiting the Cheasapeake Bay watershed
The Northern Snakehead Channa argus is an introduced species that now inhabits the Chesapeake Bay. During a preliminary survey for introduced pathogens possibly harbored by these fish in Virginia waters, a filterable agent was isolated from five specimens that produced cytopathic effects in BF-2 cells. Based on PCR amplification and partial sequencing of the major capsid protein (MCP), DNA polymer
Authors
Luke R. Iwanowicz, Christine L. Densmore, Cassidy M. Hahn, Phillip McAllister, John Odenkirk
Effects of depletion sampling by standard three-pass pulsed DC electrofishing on blood chemistry parameters of fishes from Appalachian streams
Adverse effects on fishes captured by electrofishing techniques have long been recognized, although the extent of associated physical injury and behavioral alterations are highly variable and dependent on a number of factors. We examined the effects of three-pass pulsed DC (PDC) electrofishing on two salmonid species (Rainbow Trout Oncorhynchus mykiss and Brook Trout Salvelinus fontinalis) and fiv
Authors
Christine L. Densmore, Frank M. Panek
Frequency and Severity of Trauma in Fishes Subjected to Multiple-pass Depletion Electrofishing
The incidence and severity of trauma associated with multiple-pass electrofishing and the effects on short-term (30-d) survival and growth of Rainbow Trout Oncorhynchus mykiss, Brook Trout Salvelinus fontinalis, and five representative co-inhabiting nontarget or bycatch species were examined. Fish were held in four rectangular fiberglass tanks (190 × 66 cm) equipped with electrodes, a gravel–cobbl
Authors
Frank Panek, Christine L. Densmore
Impact of thiamine deficiency on T-cell dependent and T-cell independent antibody production in lake trout
Lake trout Salvelinus namaycush on thiamine-replete and thiamine-depleted diets were evaluated for the effects of thiamine status on in vivo responses to the T-dependent antigen trinitophenol (TNP)-keyhole limpet hemocyanin (TNP-KLH), the T-independent antigen trinitrophenol-lipolysaccaharide (TNP-LPS), or Dulbecco's phosphate-buffered saline (DPBS; negative control fish). Plasma antibody concentr
Authors
Christopher A. Ottinger, Dale C. Honeyfield, Christine L. Densmore, Luke R. Iwanowicz
Global amphibian declines: perspectives from the United States and beyond
Over recent decades, amphibians have experienced population declines, extirpations and species-level extinctions at an alarming rate. Numerous potential etiologies for amphibian declines have been postulated including climate and habitat degradation. Other potential anthropogenic causes including overexploitation and the frequent introductions of invasive predatory species have also been blamed fo
Authors
Christine L. Densmore
Diseases of amphibians
The development and refinement of amphibian medicine comprise an ongoing science that reflects the unique life history of these animals and our growing knowledge of amphibian diseases. Amphibians are notoriously fastidious in terms of captive care requirements, and the majority of diseases of amphibians maintained in captivity will relate directly or indirectly to husbandry and management. Investi
Authors
Christine L. Densmore, David E. Green
Synthesis of U.S. Geological Survey science for the Chesapeake Bay ecosystem and implications for environmental management
The purpose of this report is to present a synthesis of the USGS Chesapeake Bay science related to the 2001-06 goals and provide implications for environmental management. The report provides USGS findings that address the science needs of the Chesapeake Bay Program (CBP) restoration goals and includes summaries of 1. land-use change; 2. water quality in the watershed, including nutrients, sedimen
Authors
Scott W. Ator, Vicki S. Blazer, John W. Brakebill, Donald R. Cahoon, Peter R. Claggett, Thomas M. Cronin, Judith M. Denver, Christine L. Densmore, Allen C. Gellis, Cliff R. Hupp, Jurate M. Landwehr, Michael J. Langland, Christopher A. Ottinger, Milan J. Pavich, Matthew C. Perry, Scott W. Phillips, Stephen D. Preston, Jeff P. Raffensperger, Barnett A. Rattner, Nancy B. Rybicki, Debra A. Willard
Mycobacteriosis in Chesapeake Bay Striped Bass (Morone saxatilis)
No abstract available.
Authors
Christopher A. Ottinger, Vicki S. Blazer, Christine L. Densmore, David T. Gauthier, H. Kator, F. M. Panek, M. W. Rhodes, W. Vogelbein
Calcein AM release-based cytotoxic cell assay for fish leucocytes
A non-specific cytotoxic cell assay for fish is presented that is based on the release of the activated fluorochrome calcein AM from lysed carp epithelioma papulosum cyprini (EPC) cells. To establish the suitability of treating EPC cells with calcein AM the uptake and spontaneous release of the calcein AM by the EPC cells was evaluated. Incubation of 5 μM calcein AM in culture medium with 1×105EPC
Authors
Luke R. Iwanowicz, Christine L. Densmore, Christopher A. Ottinger
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government