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Full-Text Articles in Life Sciences

Collection Techniques For The Analyses Of Pathogens In Crustaceans, Jeffrey D. Shields Nov 2017

Collection Techniques For The Analyses Of Pathogens In Crustaceans, Jeffrey D. Shields

VIMS Articles

Outbreaks of diseases have been reported from a number of ecologically or commercially important crustaceans in tropical, temperature, and boreal waters. The etiology of a disease is often unknown prior to these outbreaks and the effect of the pathogen on the host population is poorly understood. Various techniques can be used to collect, identify, and monitor host populations for pathogens. These include classical methods, such as visual or histological assessment, to more refined techniques, such as simple and quantitative polymerase chain reaction assays. The strengths and weaknesses of the different methods are presented as well as some general guidelines for …


Impact Of Disease On The Survival Of Three Commercially Fished Species, John M. Hoenig, Maya L. Groner, Matthew W. Smith, Wolfgang K. Vogelbein, David M. Taylor, Donald F. Landers, John T. Swenarton, David T. Gauthier, Philip W. Sadler, Mark A. Matsche, Ashley N. Haines, Hamish J. Small, Roger Pradel, Remi Choquet, Jeffrey D. Shields Oct 2017

Impact Of Disease On The Survival Of Three Commercially Fished Species, John M. Hoenig, Maya L. Groner, Matthew W. Smith, Wolfgang K. Vogelbein, David M. Taylor, Donald F. Landers, John T. Swenarton, David T. Gauthier, Philip W. Sadler, Mark A. Matsche, Ashley N. Haines, Hamish J. Small, Roger Pradel, Remi Choquet, Jeffrey D. Shields

VIMS Articles

Recent increases in emergent infectious diseases have raised concerns about the sustainability of some marine species. The complexity and expense of studying diseases in marine systems often dictate that conservation and management decisions are made without quantitative data on population-level impacts of disease. Mark-recapture is a powerful, underutilized, tool for calculating impacts of disease on population size and structure, even in the absence of etiological information. We applied logistic regression models to mark-recapture data to obtain estimates of disease-associated mortality rates in three commercially important marine species: snow crab (Chionoecetes opilio) in Newfoundland, Canada, that experience sporadic epizootics of bitter …


New Insight Into The Transmission Dynamics Of The Crustacean Pathogen Hematodinium Perezi (Dinoflagellata) Using A Novel Sentinel Methodology, Jeffrey D. Shields, Juan Pablo Huchin-Mian Huchin-Mian, Pattie A. O’Leary, Hamish J. Small Jun 2017

New Insight Into The Transmission Dynamics Of The Crustacean Pathogen Hematodinium Perezi (Dinoflagellata) Using A Novel Sentinel Methodology, Jeffrey D. Shields, Juan Pablo Huchin-Mian Huchin-Mian, Pattie A. O’Leary, Hamish J. Small

VIMS Articles

Hematodinium perezi causes disease and mortality in several decapod crustaceans along the eastern seaboard and Gulf coast of the USA. The route of transmission of the parasite is unknown, but infections exhibit a sharp seasonal cycle in its primary host, the blue crab Callinectes sapidus, that indicates the possibility of a short transmission period in its life cycle. We developed a sentinel methodology based on the use of naïve, uninfected, early benthic juvenile crabs (instars C1 to C10) to investigate the transmission of H. perezi. Crabs were collected from a non-endemic site, held for a short period for evaluation, and …


Vaccine Effects On Heterogeneity In Susceptibility And Implications For Population Health Management, Ke Langwig, Ar Wargo, Dr Jones, Jr Viss, Bj Rutan, Et Al. Jan 2017

Vaccine Effects On Heterogeneity In Susceptibility And Implications For Population Health Management, Ke Langwig, Ar Wargo, Dr Jones, Jr Viss, Bj Rutan, Et Al.

VIMS Articles

Heterogeneity in host susceptibility is a key determinant of infectious disease dynamics but is rarely accounted for in assessment of disease control measures. Understanding how susceptibility is distributed in populations, and how control measures change this distribution, is integral to predicting the course of epidemics with and without interventions. Using multiple experimental and modeling approaches, we show that rainbow trout have relatively homogeneous susceptibility to infection with infectious hematopoietic necrosis virus and that vaccination increases heterogeneity in susceptibility in a nearly all-or-nothing fashion. In a simple transmission model with an R-0 of 2, the highly heterogeneous vaccine protection would cause …


Human Indoor Exposure To Airborne Halogenated Flame Retardants: Influence Of Airborne Particle Size, M. J. La Guardia, Erika D. Schreder, Nancy Uding, Robert C. Hale Jan 2017

Human Indoor Exposure To Airborne Halogenated Flame Retardants: Influence Of Airborne Particle Size, M. J. La Guardia, Erika D. Schreder, Nancy Uding, Robert C. Hale

VIMS Articles

Inhalation of halogenated flame-retardants (HFRs) released from consumer products is an important route of exposure. However, not all airborne HFRs are respirable, and thus interact with vascular membranes within the gas exchange (alveolar) region of the lung. HFRs associated with large (> 4 mu m), inhalable airborne particulates are trapped on the mucosal lining of the respiratory tract and then are expelled or swallowed. The latter may contribute to internal exposure via desorption from particles in the digestive tract. Exposures may also be underestimated if personal activities that re-suspend particles into the breathing zone are not taken into account. Here, …


Behavioral Analysis Of Microphallus Turgidus Cercariae In Relation To Microhabitat Of Two Host Grass Shrimp Species (Palaemonetes Spp.), Pa O'Leary, Oj Pung Jan 2017

Behavioral Analysis Of Microphallus Turgidus Cercariae In Relation To Microhabitat Of Two Host Grass Shrimp Species (Palaemonetes Spp.), Pa O'Leary, Oj Pung

VIMS Articles

The behavior of Microphallus turgidus cercariae was examined and compared to microhabitat selection of the second intermediate hosts of the parasite, Palaemonetes spp. grass shrimp. Cercariae were tested for photokinetic and geotactic responses, and a behavioral ethogram was established for cercariae in control and grass shrimp-conditioned brackish water. Photo kinesis trials were performed using a half-covered Petri dish, and geotaxis trials used a graduated cylinder. Both photokinesis and geotaxis trials were performed in lighted and unlighted conditions. In 9 of 10 photokinesis experiments, over half of the cercariae swam horizontally under the covered half of a Petri dish in both …


Transmission Routes Maintaining A Viral Pathogen Of Steelhead Trout Within A Complex Multi-Host Assemblage, Rachel Breyta, Ilana Brito, Paige Ferguson, Gael Kurath, Kerry Naish, Maureen Purcell, Ar Wargo, Shannon Ladeau Jan 2017

Transmission Routes Maintaining A Viral Pathogen Of Steelhead Trout Within A Complex Multi-Host Assemblage, Rachel Breyta, Ilana Brito, Paige Ferguson, Gael Kurath, Kerry Naish, Maureen Purcell, Ar Wargo, Shannon Ladeau

VIMS Articles

This is the first comprehensive region wide, spatially explicit epidemiologic analysis of surveillance data of the aquatic viral pathogen infectious hematopoietic necrosis virus (IHNV) infecting native salmonid fish. The pathogen has been documented in the freshwater ecosystem of the Pacific Northwest of North America since the 1950s, and the current report describes the disease ecology of IHNV during 2000-2012. Prevalence of IHNV infection in monitored salmonid host cohorts ranged from 8% to 30%, with the highest levels observed in juvenile steelhead trout. The spatial distribution of all IHNV-infected cohorts was concentrated in two sub-regions of the study area, where historic …


Honored Life Member Eugene M. Burreson March 25, 2009, Ryan Carnegie, Cf Dungan, A Villalba, Kimberly S. Reece Jan 2017

Honored Life Member Eugene M. Burreson March 25, 2009, Ryan Carnegie, Cf Dungan, A Villalba, Kimberly S. Reece

VIMS Articles

No abstract provided.


Replication And Shedding Kinetics Of Infectious Hematopoietic Necrosis Virus In Juvenile Rainbow Trout, Ar Wargo, Rj Scott, B Kerr, G Kurath Jan 2017

Replication And Shedding Kinetics Of Infectious Hematopoietic Necrosis Virus In Juvenile Rainbow Trout, Ar Wargo, Rj Scott, B Kerr, G Kurath

VIMS Articles

Viral replication and shedding are key components of transmission and fitness, the kinetics of which are heavily dependent on virus, host, and environmental factors. To date, no studies have quantified the shedding kinetics of infectious hematopoietic necrosis virus (IHNV) in rainbow trout (Oncorhynchus mykiss), or how they are associated with replication, making it difficult to ascertain the transmission dynamics of this pathogen of high agricultural and conservation importance. Here, the replication and shedding kinetics of two M genogroup IHNV genotypes were examined in their naturally co-evolved rainbow trout host. Within host virus replication began rapidly, approaching maximum values by day …