Brian Gray, PhD
Brian Gray
Education and Certifications
Ph.D., Biostatistics, University of South Carolina, 2001
M.S., Biology, University of Kentucky, 1993
Diploma in Natural Resources, Lincoln University, 1982
B.Sc., Botany, University of Auckland, 1981
Science and Products
Filter Total Items: 50
Effects of egg order on organic and inorganic element concentrations and egg characteristics in tree swallows, tachycineta bicolor
The laying order of tree swallow eggs was identified from the Housatonic River, Berkshire County, Massachusetts, USA, and eggs were chemically analyzed individually to document possible effects of laying order on organic contaminant and inorganic element concentrations. Effects of laying order on other parameters such as egg weight, size, and lipid and moisture content also were assessed. Some eff
Authors
Christine M. Custer, Brian R. Gray, Thomas W. Custer
A finite population Bayes procedure for censored categorical abundance data
No abstract available.
Authors
Mark D. Holland, Glen Meeden, Brian R. Gray
Polychlorinated biphenyls, dioxins, furans, and organochlorine pesticides in belted kingfisher eggs from the upper Hudson River basin, New York, USA
Nesting belted kingfishers (hereafter kingfishers, Ceryle alcyon) were studied on the Hudson River near Fort Edward south to New Baltimore (NY, USA) and three nearby river drainages in 2004. Concentrations of 28 organochlorine pesticides, 160 polychlorinated biphenyl (PCB) congeners, and 17 dioxin and furan (PCDD‐F) congeners were quantified in kingfisher eggs. The pattern of organochlorine pestic
Authors
Thomas W. Custer, Christine M. Custer, Brian R. Gray
Associations between land use and Perkinsus marinus infection of eastern oysters in a high salinity, partially urbanized estuary
Infection levels of eastern oysters by the unicellular pathogen Perkinsus marinus have been associated with anthropogenic influences in laboratory studies. However, these relationships have been difficult to investigate in the field because anthropogenic inputs are often associated with natural influences such as freshwater inflow, which can also affect infection levels. We addressed P. marinus-la
Authors
Brian R. Gray, David Bushek, J. Wanzer Drane, Dwayne Porter
An empirical study of statistical properties of variance partition coefficients for multi-level logistic regression models
Partitioning the variance of a response by design levels is challenging for binomial and other discrete outcomes. Goldstein (2003) proposed four definitions for variance partitioning coefficients (VPC) under a two-level logistic regression model. In this study, we explicitly derived formulae for multi-level logistic regression model and subsequently studied the distributional properties of the cal
Authors
Ji Li, B. R. Gray, D.M. Bates
Breeding bird territory placement in riparian wet meadows in relation to invasive reed canary grass, Phalaris arundinacea
Invasive plants are a growing concern worldwide for conservation of native habitats. In endangered wet meadow habitat in the Upper Midwestern United States, reed canary grass (Phalaris arundinacea) is a recognized problem and its prevalence is more widespread than the better-known invasive wetland plant purple loosestrife (Lythrum salicaria). Although resource managers are concerned about the effe
Authors
E.M. Kirsch, B. R. Gray, T.J. Fox, W.E. Thogmartin
Estimating trend precision and power to detect trends across grouped count data
Ecologists commonly use grouped or clustered count data to estimate temporal trends in counts, abundance indices, or abundance. For example, the U.S. Breeding Bird Survey data represent multiple counts of birds from within each of multiple, spatially defined routes. Despite a reliance on grouped counts, analytical methods for prospectively estimating precision of trend estimates or statistical pow
Authors
B. R. Gray, M.M. Burlew
Effects of methylmercury exposure on the immune function of juvenile common loons (Gavia immer)
We conducted a dose-response laboratory study to quantify the level of exposure to dietary Hg, delivered as methylmercury chloride (CH3HgCl), that is associated with suppressed immune function in captive-reared common loon (Gavia immer) chicks. We used the phytohemagglutinin (PHA) skin test to assess T-lymphocyte function and the sheep red blood cell (SRBC) hemagglutination test to measure antibod
Authors
K.P. Kenow, K.A. Grasman, R. K. Hines, M.W. Meyer, A. Gendron-Fitzpatrick, M. G. Spalding, B. R. Gray
Power to detect trend in short-term time series of bird abundance
Avian point counts for population monitoring are often collected over a short timespan (e.g., 3-5 years). We examined whether power was adequate (power ???0.80) in short-duration studies to warrant the calculation of trend estimates. We modeled power to detect trends in abundance indices of eight bird species occurring across three floodplain habitats (wet prairie, early successional forest, and m
Authors
W.E. Thogmartin, B. R. Gray, M. Gallagher, N. Young, J.J. Rohweder, M. G. Knutson
Chlorophyll a and inorganic suspended solids in backwaters of the upper Mississippi River system: Backwater lake effects and their associations with selected environmental predictors
The Long Term Resource Monitoring Program (LTRMP) uses a stratified random sampling design to obtain water quality statistics within selected study reaches of the Upper Mississippi River System (UMRS). LTRMP sampling strata are based on aquatic area types generally found in large rivers (e.g., main channel, side channel, backwater, and impounded areas). For hydrologically well-mixed strata (i.e.,
Authors
James T. Rogala, Brian R. Gray
Selecting a distributional assumption for modelling relative densities of benthic macroinvertebrates
The selection of a distributional assumption suitable for modelling macroinvertebrate density data is typically challenging. Macroinvertebrate data often exhibit substantially larger variances than expected under a standard count assumption, that of the Poisson distribution. Such overdispersion may derive from multiple sources, including heterogeneity of habitat (historically and spatially), diffe
Authors
B. R. Gray
Modelling habitat associations with fingernail clam (Family: Sphaeriidae) counts at multiple spatial scales using hierarchical count models
1. Macroinvertebrate count data often exhibit nested or hierarchical structure. Examples include multiple measurements along each of a set of streams, and multiple synoptic measurements from each of a set of ponds. With data exhibiting hierarchical structure, outcomes at both sampling (e.g. within stream) and aggregated (e.g. stream) scales are often of interest. Unfortunately, methods for modelli
Authors
Brian R. Gray, Roger J. Haro, James T. Rogala, Jennifer S. Sauer
Science and Products
Filter Total Items: 50
Effects of egg order on organic and inorganic element concentrations and egg characteristics in tree swallows, tachycineta bicolor
The laying order of tree swallow eggs was identified from the Housatonic River, Berkshire County, Massachusetts, USA, and eggs were chemically analyzed individually to document possible effects of laying order on organic contaminant and inorganic element concentrations. Effects of laying order on other parameters such as egg weight, size, and lipid and moisture content also were assessed. Some eff
Authors
Christine M. Custer, Brian R. Gray, Thomas W. Custer
A finite population Bayes procedure for censored categorical abundance data
No abstract available.
Authors
Mark D. Holland, Glen Meeden, Brian R. Gray
Polychlorinated biphenyls, dioxins, furans, and organochlorine pesticides in belted kingfisher eggs from the upper Hudson River basin, New York, USA
Nesting belted kingfishers (hereafter kingfishers, Ceryle alcyon) were studied on the Hudson River near Fort Edward south to New Baltimore (NY, USA) and three nearby river drainages in 2004. Concentrations of 28 organochlorine pesticides, 160 polychlorinated biphenyl (PCB) congeners, and 17 dioxin and furan (PCDD‐F) congeners were quantified in kingfisher eggs. The pattern of organochlorine pestic
Authors
Thomas W. Custer, Christine M. Custer, Brian R. Gray
Associations between land use and Perkinsus marinus infection of eastern oysters in a high salinity, partially urbanized estuary
Infection levels of eastern oysters by the unicellular pathogen Perkinsus marinus have been associated with anthropogenic influences in laboratory studies. However, these relationships have been difficult to investigate in the field because anthropogenic inputs are often associated with natural influences such as freshwater inflow, which can also affect infection levels. We addressed P. marinus-la
Authors
Brian R. Gray, David Bushek, J. Wanzer Drane, Dwayne Porter
An empirical study of statistical properties of variance partition coefficients for multi-level logistic regression models
Partitioning the variance of a response by design levels is challenging for binomial and other discrete outcomes. Goldstein (2003) proposed four definitions for variance partitioning coefficients (VPC) under a two-level logistic regression model. In this study, we explicitly derived formulae for multi-level logistic regression model and subsequently studied the distributional properties of the cal
Authors
Ji Li, B. R. Gray, D.M. Bates
Breeding bird territory placement in riparian wet meadows in relation to invasive reed canary grass, Phalaris arundinacea
Invasive plants are a growing concern worldwide for conservation of native habitats. In endangered wet meadow habitat in the Upper Midwestern United States, reed canary grass (Phalaris arundinacea) is a recognized problem and its prevalence is more widespread than the better-known invasive wetland plant purple loosestrife (Lythrum salicaria). Although resource managers are concerned about the effe
Authors
E.M. Kirsch, B. R. Gray, T.J. Fox, W.E. Thogmartin
Estimating trend precision and power to detect trends across grouped count data
Ecologists commonly use grouped or clustered count data to estimate temporal trends in counts, abundance indices, or abundance. For example, the U.S. Breeding Bird Survey data represent multiple counts of birds from within each of multiple, spatially defined routes. Despite a reliance on grouped counts, analytical methods for prospectively estimating precision of trend estimates or statistical pow
Authors
B. R. Gray, M.M. Burlew
Effects of methylmercury exposure on the immune function of juvenile common loons (Gavia immer)
We conducted a dose-response laboratory study to quantify the level of exposure to dietary Hg, delivered as methylmercury chloride (CH3HgCl), that is associated with suppressed immune function in captive-reared common loon (Gavia immer) chicks. We used the phytohemagglutinin (PHA) skin test to assess T-lymphocyte function and the sheep red blood cell (SRBC) hemagglutination test to measure antibod
Authors
K.P. Kenow, K.A. Grasman, R. K. Hines, M.W. Meyer, A. Gendron-Fitzpatrick, M. G. Spalding, B. R. Gray
Power to detect trend in short-term time series of bird abundance
Avian point counts for population monitoring are often collected over a short timespan (e.g., 3-5 years). We examined whether power was adequate (power ???0.80) in short-duration studies to warrant the calculation of trend estimates. We modeled power to detect trends in abundance indices of eight bird species occurring across three floodplain habitats (wet prairie, early successional forest, and m
Authors
W.E. Thogmartin, B. R. Gray, M. Gallagher, N. Young, J.J. Rohweder, M. G. Knutson
Chlorophyll a and inorganic suspended solids in backwaters of the upper Mississippi River system: Backwater lake effects and their associations with selected environmental predictors
The Long Term Resource Monitoring Program (LTRMP) uses a stratified random sampling design to obtain water quality statistics within selected study reaches of the Upper Mississippi River System (UMRS). LTRMP sampling strata are based on aquatic area types generally found in large rivers (e.g., main channel, side channel, backwater, and impounded areas). For hydrologically well-mixed strata (i.e.,
Authors
James T. Rogala, Brian R. Gray
Selecting a distributional assumption for modelling relative densities of benthic macroinvertebrates
The selection of a distributional assumption suitable for modelling macroinvertebrate density data is typically challenging. Macroinvertebrate data often exhibit substantially larger variances than expected under a standard count assumption, that of the Poisson distribution. Such overdispersion may derive from multiple sources, including heterogeneity of habitat (historically and spatially), diffe
Authors
B. R. Gray
Modelling habitat associations with fingernail clam (Family: Sphaeriidae) counts at multiple spatial scales using hierarchical count models
1. Macroinvertebrate count data often exhibit nested or hierarchical structure. Examples include multiple measurements along each of a set of streams, and multiple synoptic measurements from each of a set of ponds. With data exhibiting hierarchical structure, outcomes at both sampling (e.g. within stream) and aggregated (e.g. stream) scales are often of interest. Unfortunately, methods for modelli
Authors
Brian R. Gray, Roger J. Haro, James T. Rogala, Jennifer S. Sauer