Nancy S. Brodsky

Modeling the Potential Effects of New Tobacco Products and Policies. A Dynamic Population Model for Multiple Product Use and Harm

Background Recent declines in US cigarette smoking prevalence have coincided with increases in use of other tobacco products. Multiple product tobacco models can help assess the population health impacts associated with use of a wide range of tobacco products. Methods and Findings We present a multi-state, dynamical systems population structure model that can be used to assess the effects of tobacco product use behaviors on population health. The model incorporates transition behaviors, such as initiation, cessation, switching, and dual use, related to the use of multiple products. The model tracks product use prevalence and mortality attributable to tobacco use for the overall population and by sex and age group. The model can also be used to estimate differences in these outcomes between scenarios by varying input parameter values. We demonstrate model capabilities by projecting future cigarette smoking prevalence and smoking-attributable mortality and then simulating the effects of introduction of a hypothetical new lower-risk tobacco product under a variety of assumptions about product use. Sensitivity analyses were conducted to examine the range of population impacts that could occur due to differences in input values for product use and risk. We demonstrate that potential benefits from cigarette smokers switching to the lower-risk product can be offset over time through increased initiation of this product. Model results show that population health benefits are particularly sensitive to product risks and initiation, switching, and dual use behaviors. Conclusion Our model incorporates the variety of tobacco use behaviors and risks that occur with multiple products. As such, it can evaluate the population health impacts associated with the introduction of new tobacco products or policies that may result in product switching or dual use. Further model development will include refinement of data inputs for non-cigarette tobacco products and inclusion of health outcomes such as morbidity and disability.

Potential Public Health Effects of Reducing Nicotine Levels in Cigarettes in the United States

Potential Health Effects of Reducing Nicotine Using a simulation model, the FDA has estimated that lowering the nicotine content in cigarettes to a minimally addictive level could substantially reduce tobacco-related mortality.

Thermal expansion, thermal conductivity, and heat capacity measurements at Yucca Mountain, Nevada

Abstract A very extensive database for thermal properties of Yucca Mountain tuffs has been collected to characterize the Yucca Mountain, NV site. Cores from boreholes UE25 NRG-4, UE25 NRG-5, USW NRG-6, and USW NRG-7/7A, all drilled near the North Ramp of the Exploratory Studies Facility, were tested to determine thermal conductivity, thermal expansion, and specific heat. Specimens were tested from four thermal-mechanical units (TCw, PTn, TSw1, and TSw2) that included welded devitrified (TCw, TSw1, TSw2) and nonwelded vitric (PTn) tuff. The effects of moisture content, temperature, and composition were assessed. Petrologic data were obtained from 97 samples, all from USW NRG-6, to assess relationships between measured thermal properties and composition.

Experimental determination of the relationship between permeability and microfracture-induced damage in bedded salt

The development of deep underground structures (e.g., shafts, mines, storage and disposal caverns) significantly alters the stress state in the rock near the structure or opening. The effect of such an opening is to concentrate the far-field stress near the free surface. For soft rock such as salt, the concentrating effect of the opening induces deviatoric stresses in the salt that may be large enough to initiate microcracks which then propagate with time. The volume of rock susceptible to damage by microfracturing is often referred to as the disturbed rock zone and, by its nature, is expected to exhibit high permeability relative to that of the native, far-field rock. This paper presents laboratory data that characterize microfracture-induced damage and the effect this damage has on permeability for bedded salt from the Waste Isolation Pilot Plant located in southeastern New Mexico. Damage is induced in the salt through a series of tertiary creep experiments and quantified in terms of dilatant volumetric strain. The permeability of damaged specimens is then measured using nitrogen gas as the permeant. The range in damage investigated included dilatant volumetric strains from less than 0.03 percent to nearly 4.0 percent. Permeability values corresponding to these damage levels ranged from 1 {times} 10{sup {minus}18} m{sup 2} to 1 {times} 10{sup {minus}12} m{sup 2}. Two simple models were fitted to the data for use in predicting permeability from dilatant volumetric strain.

Earthquake warning system for infrastructures : a scoping analysis.

This report provides the results of a scoping study evaluating the potential risk reduction value of a hypothetical, earthquake early-warning system. The study was based on an analysis of the actions that could be taken to reduce risks to population and infrastructures, how much time would be required to take each action and the potential consequences of false alarms given the nature of the action. The results of the scoping analysis indicate that risks could be reduced through improving existing event notification systems and individual responses to the notification; and production and utilization of more detailed risk maps for local planning. Detailed maps and training programs, based on existing knowledge of geologic conditions and processes, would reduce uncertainty in the consequence portion of the risk analysis. Uncertainties in the timing, magnitude and location of earthquakes and the potential impacts of false alarms will present major challenges to the value of an early-warning system.

Phoenix : Complex Adaptive System of Systems (CASoS) engineering version 1.0.

Complex Adaptive Systems of Systems, or CASoS, are vastly complex ecological, sociological, economic and/or technical systems which we must understand to design a secure future for the nation and the world. Perturbations/disruptions in CASoS have the potential for far-reaching effects due to pervasive interdependencies and attendant vulnerabilities to cascades in associated systems. Phoenix was initiated to address this high-impact problem space as engineers. Our overarching goals are maximizing security, maximizing health, and minimizing risk. We design interventions, or problem solutions, that influence CASoS to achieve specific aspirations. Through application to real-world problems, Phoenix is evolving the principles and discipline of CASoS Engineering while growing a community of practice and the CASoS engineers to populate it. Both grounded in reality and working to extend our understanding and control of that reality, Phoenix is at the same time a solution within a CASoS and a CASoS itself.