High Activity Argon-39 Measurements

<p>This presentation was used for the Low-Radioactivity Underground Argon Workshop held at Pacific Northwest National Laboratory in Richland, Washington on March 19 - 20, 2018.</p

Feasibility of Carbon Dioxide Storage Resource Use within Climate Change Mitigation Scenarios for the United States

To progress decarbonization in the United States, numerous techno-economic models that project CO2 storage deployment at annual injection rates of 0.3–1.7 Gt year–1 by 2050 have been built. However, these models do not consider many geological, technical, or socio-economic factors that could impede the growth of geological storage resource use, and there is uncertainty about the feasibility of the resulting projections. Here, we evaluate storage scenarios across four major modeling efforts. We apply a growth modeling framework using logistic curves to analyze the feasibility of growth trajectories under constraints imposed by the associated storage resource availability. We show that storage resources are abundant, and resources of the Gulf Coast alone would be sufficient to meet national demand were it not for transport limitations. On the contrary, deployment trajectories require sustained average annual (exponential) growth at rates of >10% nationally for two of the three reports and between 3% and 20% regionally across four storage hubs projected in both reports with regional resolution. These rates are high relative to historical rates of growth in analogous large scale energy infrastructure in the United States. Projections for California appear to be particularly infeasible. Future modeling efforts should be constrained to more realistic deployment trajectories, which could be done with simple constraints from the type of modeling framework presented here

Feasibility of Carbon Dioxide Storage Resource Use within Climate Change Mitigation Scenarios for the United States

To progress decarbonization in the United States, numerous techno-economic models that project CO2 storage deployment at annual injection rates of 0.3–1.7 Gt year–1 by 2050 have been built. However, these models do not consider many geological, technical, or socio-economic factors that could impede the growth of geological storage resource use, and there is uncertainty about the feasibility of the resulting projections. Here, we evaluate storage scenarios across four major modeling efforts. We apply a growth modeling framework using logistic curves to analyze the feasibility of growth trajectories under constraints imposed by the associated storage resource availability. We show that storage resources are abundant, and resources of the Gulf Coast alone would be sufficient to meet national demand were it not for transport limitations. On the contrary, deployment trajectories require sustained average annual (exponential) growth at rates of >10% nationally for two of the three reports and between 3% and 20% regionally across four storage hubs projected in both reports with regional resolution. These rates are high relative to historical rates of growth in analogous large scale energy infrastructure in the United States. Projections for California appear to be particularly infeasible. Future modeling efforts should be constrained to more realistic deployment trajectories, which could be done with simple constraints from the type of modeling framework presented here

Natural History of Anal Dysplasia in an HIV-Infected Clinical Care Cohort: Estimates Using Multi-State Markov Modeling

<div><p>Objectives</p><p>(1) To model the natural history of anal neoplasia in HIV-infected patients using a 3-state Markov model of anal cancer pathogenesis, adjusting for cytology misclassification; and (2) to estimate the effects of selected time-varying covariates on transition probabilities.</p><p>Design</p><p>A retrospective cytology-based inception screening cohort of HIV-infected adults was analyzed using a 3-state Markov model of clinical pathogenesis of anal neoplasia.</p><p>Methods</p><p>Longitudinally ascertained cytology categories were adjusted for misclassification using estimates of cytology accuracy derived from the study cohort. Time-varying covariate effects were estimated as hazard ratios.</p><p>Results</p><p>(1) There was a moderate to high probability of regression of the high grade squamous intraepithelial lesion (HSIL) state (27–62%) at 2 years after initial cytology screening; (2) the probability of developing invasive anal cancer (IAC) during the first 2 years after a baseline HSIL cytology is low (1.9–2.8%); (3) infrared coagulation (IRC) ablation of HSIL lesions is associated with a 2.2–4.2 fold increased probability of regression to 3 are each associated with reduced probability of progression from </p><p>Conclusions</p><p>The finding of moderate to high rates of regression of the HSIL state accompanied by low rates of progression to IAC should inform both screening and precursor treatment guideline development. There appears to be a consistent and robust beneficial effect of antiretroviral therapy, suppressed viral load, and higher CD4 on the transition from the </p></div

Estimated 2 and 5 Year Transition Probabilities (95% C.I) for Progression and Regression in 3-State Hidden Markov Model Adjusted for Cytology Misclassification Assumptions, by IAC-Exclusion Window (≤180 vs.≤30 days)₁.

1.<p>Model estimates fit with time-updated infrared coagulation (IRC) indicator and standardized to reflect transition probabilities for those who never underwent IRC. Thus, these transition probabilities estimate the untreated natural history of AIN.</p>2.<p>IAC exclusion window: Cases of invasive anal carcinoma (IAC) diagnosed within 180 or 30 days of the first cytology result, respectively, were considered prevalent cases and were therefore excluded from analysis.</p>3.<p>Transition from HSIL: HSIL: high grade squamous intraepithelial lesion; IAC: invasive anal carcinoma.</p

Estimated Unadjusted Hazard Ratios (95% CI) of Time-Updated Covariate Effects on State Transitions, by Misclassification Assumptions and by IAC-Exclusion Window (≤180 vs.≤30 days).

1.<p>IRC: infrared coagulation.</p>2.<p>IAC exclusion window: Cases of invasive anal carcinoma (IAC) diagnosed within 180 or 30 days of the first cytology result, respectively, were considered prevalent cases and were therefore excluded from analysis.</p>3.<p>State Transitions: HSIL: high grade squamous intraepithelial lesion; IAC: invasive anal carcinoma.</p>4.<p>ART: antiretroviral therapy.</p

Estimates of State Transition Rate (per person-year) adjusted for Cytology Misclassification Assumptions, by IAC-Exclusion Window (≤180 vs. ≤30 days)₁.

1.<p>Model estimates fit with time-updated infrared coagulation (IRC) indicator and standardized to reflect transition rates for those who never underwent IRC. Thus, these rates estimate the untreated natural history of AIN if the rates remain constant over time and if the Markov assumption is valid.</p>2.<p>IAC exclusion window: Cases of invasive anal carcinoma (IAC) diagnosed within 180 or 30 days of the first cytology result, respectively, were considered prevalent cases and were therefore excluded from analysis.</p>3.<p>State Transitions: HSIL: high grade squamous intraepithelial lesion; IAC: invasive anal carcinoma.</p

Study Participant Characteristics (n = 2804).

1.<p>MSM: men having sex with men.</p>2.<p>IDU: injection drug use.</p>3.<p>NAMC: no atypical or malignant cells; ASCUS: atypical squamous cells of uncertain significance; LSIL: low grade squamous intraepithelial lesion; ASC-H: atypical squamous cells, can't exclude high grade; HSIL: high grade squamous intraepithelial lesion.</p>4.<p>IRC: infrared coagulation.</p

Three State Markov Model of Clinical Pathogenesis of Anal Neoplasia.

<p>Three State Markov Model of Clinical Pathogenesis of Anal Neoplasia.</p

Baseline characteristics of the whole population aged 40–45 years and those who go on to participate in the health check programme.

<p>Baseline characteristics of the whole population aged 40–45 years and those who go on to participate in the health check programme.</p