Background. Previous epidemiologic studies, including our own, have consistently linked long-term... more Background. Previous epidemiologic studies, including our own, have consistently linked long-term exposure to single-source polycyclic aromatic hydrocarbons (PAHs) to increased breast cancer incidence. It is unclear whether single sources, specific groups, or all PAH sources should be targeted for breast cancer risk reduction. This study considers the impact on breast cancer incidence from multiple PAH exposure sources in a single model, which better reflects exposure to these complex mixtures. Methods. In a population-based case-control study conducted on Long Island, New York (N=1,508 breast cancer cases/1,556 controls), a Bayesian hierarchical regression approach was used to estimate adjusted posterior means and credible intervals (CrI) for the adjusted odds ratios (ORs) for PAH exposure sources, considered singly and as groups: active smoking; residential environmental tobacco smoke (ETS); indoor and outdoor air pollution; and grilled/smoked meat intake. Results. Most women were...
Tobacco smoke, diet, and indoor and outdoor air pollution, all major sources of polycyclic aromat... more Tobacco smoke, diet, and indoor and outdoor air pollution, all major sources of polycyclic aromatic hydrocarbons (PAHs), have been associated with breast cancer incidence. Aberrant methylation may be an early event in carcinogenesis, but whether PAHs influence the epigenome is unclear. Few studies have evaluated whether PAHs are associated with methylation, particularly in breast tumors where methylation changes are particularly relevant. In a population-based case-control study, we measured promoter methylation of 13 breast cancer-related genes in breast tumor tissue (n=765-851 cases) and global methylation in peripheral blood (1,055 cases/1,101 controls). PAH sources (current active smoking, residential environmental tobacco smoke (ETS), vehicular traffic, synthetic log burning, and grilled/smoked meat intake) were evaluated separately. Logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). When comparing methylated versus unmethyla...
To explore the likely prevalence of false indications of dose-response nonlinearity in large epid... more To explore the likely prevalence of false indications of dose-response nonlinearity in large epidemiologic cancer radiation cohort studies (A-bomb survivors, INWORKS, Techa River). Reasons: Increasing numbers of tests of nonlinearity are being made in studies. Hypothesized nonlinear dose-response models have been justified to policy makers by analyses that rely in part on isolated findings that could be statistical fluctuations. After removing dose nonlinearity (linearization) by adjusting person-years of observation at each dose category, indications of nonlinearity, necessarily false, were counted in 5,000 randomized replications of six datasets. 1. The average frequency of any false positive for five indicators of nonlinearity tested against a linear null was roughly 25% in Monte Carlo simulations per study, consistent with binomial calculations, increasing to ∼50% within 6 studies assessed. 2. Comparable frequencies were found using Akaike's information criterion (AIC) for model selection or multi-model averaging. 3. False above-zero threshold doses were found more than 50% of the time, averaging to 0.05 Gy, consistent with findings in the 6 studies. Such bias, uncorrected, could distort meta-analyses of multiple studies, because meta-analyses can incorporate high P value findings. AIC-based correction for the extra threshold parameter lowered these false occurrences to 8 to 19%. Given the simulation rates, the possibility of false positives might be noted when isolated findings of nonlinearity are discussed in a regulatory context. When reporting a threshold dose with a P value > 0.05, it would be informative to note the expected high false prevalence rate due to bias.
Most developmental work on biomass crops has involved extensive monocultures of genetically unifo... more Most developmental work on biomass crops has involved extensive monocultures of genetically uniform crops. We review the relevant ecology of agricultural monocultures, and some consequences of monocultural methods for the biomass industry. Monocultures can have very high primary productivity; indeed biomass crops are selected for high productivity. The seasonal tempo of productivity is often more punctuated in monocultures than in multispecies system, leaving temporal productivity gaps. In turn, folivorous insect diversity and abundance tends to track the foliage productivity. The productivity gaps may produce bottlenecks in herbivore abundance and diversity. Herbivore population dynamics tend to be less stable in monocultures, driving fluctuations in predator abundance and diversity. These bottlenecks and fluctuations can increase the frequency and severity of pest problems, for herbivorous insects usually respond to productivity increases faster than their predators. The spatial scaling of structural complexity is also critical to habitat value, particularly for vertebrates. At micro scales structural complexity is a function of plant structure. At meso scales, agricultural monocultures tend to be very uniform, compared to multispecies systems, and provide poorer habitat for species needing meso-scale diversity. We suggest three strategies to enhance or restore biodiversity while developing biomass crops. First, tailor the scale of plantingsmore » to the needs of wildlife in the system. Second, manage the deployment of the biomass plantings to be complementary to other landscape features. For example, concentrate biomass plantings on the most favorable sites in the landscape, and develop complementary habitat inclusions on poorer microsites. Third, develop crops and crop combinations to benefit wildlife as well as to provide high yields. Select and deploy crops and clones to bridge productivity gaps.« less
ABSTRACT The major theme underlying "Beyond Oil" is that traditional economists... more ABSTRACT The major theme underlying "Beyond Oil" is that traditional economists don't know what they're talking about when they treat price, capital, and labor as key factors in the economy. Energy, according to the book's authors, is the major driving force behind the gross national product. Such a doctrine will have great appeal to those of us who are physical scientists and engineers, because most of us have secretly held negative views about economists for years and would love to believe that thermodynamics can explain the behavior of national economies. Unfortunately, the authors, all four of whom are (or were when the book was being written) with the University of New Hampshire's Complex Systems Research Center, fail to prove their case. We are going to have to await additional research before we can demonstrate to our economics-oriented friends that they are fools. However, we can certainly have some fun with them in the meantime by suggesting ...
... Study stands were lo-cated in five counties (Monroe, Pike, Susquehanna, Wayne, and Wyoming) i... more ... Study stands were lo-cated in five counties (Monroe, Pike, Susquehanna, Wayne, and Wyoming) in northeastern Pennsylvania (fig. ... Northern hardwood stands had a much larger ange of re-maining basal area (zero to 160 square feet per acre) compared with oak-h,ck-ory ...
The objective of this paper is to compare post-2007 epidemiological results for plutonium workers... more The objective of this paper is to compare post-2007 epidemiological results for plutonium workers to risk predicted by the software program NIOSH-IREP (IREP for short), which is used to determine the lowest dose for a US veteran to obtain cancer compensation. IREP output and methodology were used to predict excess relative risk per Gy (ERR Gy −1) for lung cancer at the 99 th credibility percentile, which is used for compensation decisions. Also estimated were relative biological effectiveness factors (RBE) predicted for workers using IREP methodology. IREP predictions were compared to results for Mayak and Sellafield plutonium workers, separately and pooled. Indications that IREP might underpredict 99 th-percentile lung cancer plutonium risk came from (1) comparison of worker RBEs and (2) from comparison of Sellafield results separately. When Sellafield and Mayak data were pooled, ERR Gy −1 comparisons at the 99 th percentile roughly matched epidemiological data with regression dose range restricted to < 0.05 Gy, the most relevant region to veterans, but overpredicted for the full dose range. When four plausible distributions for lung cancer risk, including both new and old data, were combined using illustrative weighting factors, compensation cutoff dose for lung cancer matched current IREP values unless regression results below 0.05 were chosen for Sellafield, producing a twofold reduction. A 1997 claim of a dose threshold in lung cancer dose response was not confirmed in later literature. The benefit of the doubt is given to claimants when the science is unclear. The challenge for NIOSH-IREP custodians is dealing with the Sellafield results, which might best match US claimants.
The relative abundance and species richness of herpetofauna was investigated to assess the impact... more The relative abundance and species richness of herpetofauna was investigated to assess the impact of recent logging operations in 47 forest stands in northeastern Pennsylvania during 1996 and 1997. Stands including nonindustrial private forestlands and public lands that have received some type of harvesting within the last 8 yr ranged from near complete overstory tree cover to complete removal of overstory cover. Stands included the two dominant forest types in the region: northern hardwood (Betula, Fagus, Prunus, Acer, and Tsuga spp.) and oak-hickory (Quercus and Carya spp.). A total of 8,181 individuals of 26 species (12 salamander, 7 snake, 6 frog, and 1 toad species) were observed in the study stands. The relative abundance and species richness of salamanders increased significantly with increasing retention of tree basal area. Forest stands containing> 15 m 2 /ha live tree basal area appeared to be a threshold level for high salamander abundance. Snake species abundance and ...
Background. Previous epidemiologic studies, including our own, have consistently linked long-term... more Background. Previous epidemiologic studies, including our own, have consistently linked long-term exposure to single-source polycyclic aromatic hydrocarbons (PAHs) to increased breast cancer incidence. It is unclear whether single sources, specific groups, or all PAH sources should be targeted for breast cancer risk reduction. This study considers the impact on breast cancer incidence from multiple PAH exposure sources in a single model, which better reflects exposure to these complex mixtures. Methods. In a population-based case-control study conducted on Long Island, New York (N=1,508 breast cancer cases/1,556 controls), a Bayesian hierarchical regression approach was used to estimate adjusted posterior means and credible intervals (CrI) for the adjusted odds ratios (ORs) for PAH exposure sources, considered singly and as groups: active smoking; residential environmental tobacco smoke (ETS); indoor and outdoor air pollution; and grilled/smoked meat intake. Results. Most women were...
Tobacco smoke, diet, and indoor and outdoor air pollution, all major sources of polycyclic aromat... more Tobacco smoke, diet, and indoor and outdoor air pollution, all major sources of polycyclic aromatic hydrocarbons (PAHs), have been associated with breast cancer incidence. Aberrant methylation may be an early event in carcinogenesis, but whether PAHs influence the epigenome is unclear. Few studies have evaluated whether PAHs are associated with methylation, particularly in breast tumors where methylation changes are particularly relevant. In a population-based case-control study, we measured promoter methylation of 13 breast cancer-related genes in breast tumor tissue (n=765-851 cases) and global methylation in peripheral blood (1,055 cases/1,101 controls). PAH sources (current active smoking, residential environmental tobacco smoke (ETS), vehicular traffic, synthetic log burning, and grilled/smoked meat intake) were evaluated separately. Logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). When comparing methylated versus unmethyla...
To explore the likely prevalence of false indications of dose-response nonlinearity in large epid... more To explore the likely prevalence of false indications of dose-response nonlinearity in large epidemiologic cancer radiation cohort studies (A-bomb survivors, INWORKS, Techa River). Reasons: Increasing numbers of tests of nonlinearity are being made in studies. Hypothesized nonlinear dose-response models have been justified to policy makers by analyses that rely in part on isolated findings that could be statistical fluctuations. After removing dose nonlinearity (linearization) by adjusting person-years of observation at each dose category, indications of nonlinearity, necessarily false, were counted in 5,000 randomized replications of six datasets. 1. The average frequency of any false positive for five indicators of nonlinearity tested against a linear null was roughly 25% in Monte Carlo simulations per study, consistent with binomial calculations, increasing to ∼50% within 6 studies assessed. 2. Comparable frequencies were found using Akaike's information criterion (AIC) for model selection or multi-model averaging. 3. False above-zero threshold doses were found more than 50% of the time, averaging to 0.05 Gy, consistent with findings in the 6 studies. Such bias, uncorrected, could distort meta-analyses of multiple studies, because meta-analyses can incorporate high P value findings. AIC-based correction for the extra threshold parameter lowered these false occurrences to 8 to 19%. Given the simulation rates, the possibility of false positives might be noted when isolated findings of nonlinearity are discussed in a regulatory context. When reporting a threshold dose with a P value > 0.05, it would be informative to note the expected high false prevalence rate due to bias.
Most developmental work on biomass crops has involved extensive monocultures of genetically unifo... more Most developmental work on biomass crops has involved extensive monocultures of genetically uniform crops. We review the relevant ecology of agricultural monocultures, and some consequences of monocultural methods for the biomass industry. Monocultures can have very high primary productivity; indeed biomass crops are selected for high productivity. The seasonal tempo of productivity is often more punctuated in monocultures than in multispecies system, leaving temporal productivity gaps. In turn, folivorous insect diversity and abundance tends to track the foliage productivity. The productivity gaps may produce bottlenecks in herbivore abundance and diversity. Herbivore population dynamics tend to be less stable in monocultures, driving fluctuations in predator abundance and diversity. These bottlenecks and fluctuations can increase the frequency and severity of pest problems, for herbivorous insects usually respond to productivity increases faster than their predators. The spatial scaling of structural complexity is also critical to habitat value, particularly for vertebrates. At micro scales structural complexity is a function of plant structure. At meso scales, agricultural monocultures tend to be very uniform, compared to multispecies systems, and provide poorer habitat for species needing meso-scale diversity. We suggest three strategies to enhance or restore biodiversity while developing biomass crops. First, tailor the scale of plantingsmore » to the needs of wildlife in the system. Second, manage the deployment of the biomass plantings to be complementary to other landscape features. For example, concentrate biomass plantings on the most favorable sites in the landscape, and develop complementary habitat inclusions on poorer microsites. Third, develop crops and crop combinations to benefit wildlife as well as to provide high yields. Select and deploy crops and clones to bridge productivity gaps.« less
ABSTRACT The major theme underlying "Beyond Oil" is that traditional economists... more ABSTRACT The major theme underlying "Beyond Oil" is that traditional economists don't know what they're talking about when they treat price, capital, and labor as key factors in the economy. Energy, according to the book's authors, is the major driving force behind the gross national product. Such a doctrine will have great appeal to those of us who are physical scientists and engineers, because most of us have secretly held negative views about economists for years and would love to believe that thermodynamics can explain the behavior of national economies. Unfortunately, the authors, all four of whom are (or were when the book was being written) with the University of New Hampshire's Complex Systems Research Center, fail to prove their case. We are going to have to await additional research before we can demonstrate to our economics-oriented friends that they are fools. However, we can certainly have some fun with them in the meantime by suggesting ...
... Study stands were lo-cated in five counties (Monroe, Pike, Susquehanna, Wayne, and Wyoming) i... more ... Study stands were lo-cated in five counties (Monroe, Pike, Susquehanna, Wayne, and Wyoming) in northeastern Pennsylvania (fig. ... Northern hardwood stands had a much larger ange of re-maining basal area (zero to 160 square feet per acre) compared with oak-h,ck-ory ...
The objective of this paper is to compare post-2007 epidemiological results for plutonium workers... more The objective of this paper is to compare post-2007 epidemiological results for plutonium workers to risk predicted by the software program NIOSH-IREP (IREP for short), which is used to determine the lowest dose for a US veteran to obtain cancer compensation. IREP output and methodology were used to predict excess relative risk per Gy (ERR Gy −1) for lung cancer at the 99 th credibility percentile, which is used for compensation decisions. Also estimated were relative biological effectiveness factors (RBE) predicted for workers using IREP methodology. IREP predictions were compared to results for Mayak and Sellafield plutonium workers, separately and pooled. Indications that IREP might underpredict 99 th-percentile lung cancer plutonium risk came from (1) comparison of worker RBEs and (2) from comparison of Sellafield results separately. When Sellafield and Mayak data were pooled, ERR Gy −1 comparisons at the 99 th percentile roughly matched epidemiological data with regression dose range restricted to < 0.05 Gy, the most relevant region to veterans, but overpredicted for the full dose range. When four plausible distributions for lung cancer risk, including both new and old data, were combined using illustrative weighting factors, compensation cutoff dose for lung cancer matched current IREP values unless regression results below 0.05 were chosen for Sellafield, producing a twofold reduction. A 1997 claim of a dose threshold in lung cancer dose response was not confirmed in later literature. The benefit of the doubt is given to claimants when the science is unclear. The challenge for NIOSH-IREP custodians is dealing with the Sellafield results, which might best match US claimants.
The relative abundance and species richness of herpetofauna was investigated to assess the impact... more The relative abundance and species richness of herpetofauna was investigated to assess the impact of recent logging operations in 47 forest stands in northeastern Pennsylvania during 1996 and 1997. Stands including nonindustrial private forestlands and public lands that have received some type of harvesting within the last 8 yr ranged from near complete overstory tree cover to complete removal of overstory cover. Stands included the two dominant forest types in the region: northern hardwood (Betula, Fagus, Prunus, Acer, and Tsuga spp.) and oak-hickory (Quercus and Carya spp.). A total of 8,181 individuals of 26 species (12 salamander, 7 snake, 6 frog, and 1 toad species) were observed in the study stands. The relative abundance and species richness of salamanders increased significantly with increasing retention of tree basal area. Forest stands containing> 15 m 2 /ha live tree basal area appeared to be a threshold level for high salamander abundance. Snake species abundance and ...
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