Simulating prehistoric population dynamics and adaptive behavioral responses to the environment in Long House Valley and Black Mesa, Arizona

Dr. Lisa Sattenspiel, Dissertation Supervisor.Field of study: Anthropology."May 2018."This project contributes to our understanding of human adaptability to environmental stress and climate change in Long House Valley and Black Mesa, Arizona from AD 800-1350. This was accomplished through the development of a series of agentbased archaeological models. The first stage, Disaggregation, created a model that simulated individual persons within the Long House Valley landscape, a departure from the household-level models common in archaeological modeling. The second stage, Demography, applied empirically derived fertility and mortality rates to these human populations to provide insight into the effects of such rates on population patterns. The final stage expanded the modeled environment to include Black Mesa and allowed for the migration of individuals and households between the two areas in response to varying environmental and demographic pressures throughout the study period. The results of this project indicate that the introduction of biological and ethnographic realism to a model can produce unexpected results, including those that deviate from the population patterns observed archaeologically. Despite these unexpected interactions, the results support the importance of variations in agricultural productivity in driving human migrations in the region. Future archaeological models should consider further exploration small-scale, local population movements and the effects of dynamically changing fertility and mortality rates.Includes bibliographical references (pages 145-156)

Impact of Yoga on Low Back Pain and Function: A Systematic Review and Meta-Analysis

An estimated 70% of people will experience low back pain at some point in their lives, and recurrence rates can be as high as 85%. Recent studies suggest that yoga – a widely practiced physical/mental discipline – may relieve back pain and reduce functional disability. The objective of this study was to conduct a systematic review and meta-analysis of the existing research on the effects of yoga on chronic low back pain and function. Our literature search began April 2011 and continued through October 2011. Cochrane, PubMed, CINAHL, Embase, ProQuest Dissertations and Theses, Google Scholar, and Clinicaltrials.gov databases were searched electronically. The search terms used were: yoga AND back pain. A total of 58 relevant studies were originally identified through the database searches. Of those, 45 were excluded on the basis of the title and/or review of the abstract. The 13 remaining studies were fully evaluated via a careful review of the full text. On the basis of the inclusion and exclusion criteria, 6 studies were excluded, leaving a total of 7 studies to be included in the meta-analyses of the impact of yoga on low back pain and function. Effect sizes were calculated as the standardized mean difference and meta-analyses were completed using a random-effects model. Overall, yoga was found to result in a medium, beneficial effect on chronic low back pain [overall effect size (ES) = 0.58, p\u3c0.001], indicating that subjects practicing yoga reported significantly less pain than control subjects. Yoga subjects also reported significantly less functional disability after the intervention (overall ES = 0.53, p\u3c0.001). Moreover, the improvements in pain and function for yoga subjects remained statistically significant 12-24 weeks after the end of the intervention (overall ES = 0.44-0.54, p≤0.002). In conclusion, yoga practice can significantly reduce pain and increase functional ability in chronic low back pain patients

Modeling X-ray Loops and EUV "Moss" in an Active Region Core

The Soft X-ray intensity of loops in active region cores and corresponding footpoint, or moss, intensity observed in the EUV remain steady for several hours of observation. The steadiness of the emission has prompted many to suggest that the heating in these loops must also be steady, though no direct comparison between the observed X-ray and EUV intensities and the steady heating solutions of the hydrodynamic equations has yet been made. In this paper, we perform these simulations and simultaneously model the X-Ray and EUV moss intensities in one active regioncore with steady uniform heating. To perform this task, we introduce a new technique to constrain the model parameters using the measured EUV footpoint intensity to infer a heating rate. We find that a filling factor of 8% and loops that expand with height provides the best agreement with the intensity in two X-ray filters, though the simulated SXT Al12 intensity is 147% the observed intensity and the SXT AlMg intensity is 80% the observed intensity. From this solution, we determine the required heating rate scales as ${\bar{B}}^{0.29} L^{-0.95}$. Finally we discuss the future potential of this type of modeling, such as the ability to use density measurements to fully constrain filling factor, and its shortcomings, such as the requirement to use potential field extrapolations to approximate the coronal field.Comment: 17 pages, 6 figurs, accepted to Ap

Using a Differential Emission Measure and Density Measurements in an Active Region Core to Test a Steady Heating Model

The frequency of heating events in the corona is an important constraint on the coronal heating mechanisms. Observations indicate that the intensities and velocities measured in active region cores are effectively steady, suggesting that heating events occur rapidly enough to keep high temperature active region loops close to equilibrium. In this paper, we couple observations of Active Region 10955 made with XRT and EIS on \textit{Hinode} to test a simple steady heating model. First we calculate the differential emission measure of the apex region of the loops in the active region core. We find the DEM to be broad and peaked around 3\,MK. We then determine the densities in the corresponding footpoint regions. Using potential field extrapolations to approximate the loop lengths and the density-sensitive line ratios to infer the magnitude of the heating, we build a steady heating model for the active region core and find that we can match the general properties of the observed DEM for the temperature range of 6.3 $<$ Log T $<$ 6.7. This model, for the first time, accounts for the base pressure, loop length, and distribution of apex temperatures of the core loops. We find that the density-sensitive spectral line intensities and the bulk of the hot emission in the active region core are consistent with steady heating. We also find, however, that the steady heating model cannot address the emission observed at lower temperatures. This emission may be due to foreground or background structures, or may indicate that the heating in the core is more complicated. Different heating scenarios must be tested to determine if they have the same level of agreement.Comment: 16 pages, 9 figures, accepted to Ap

Spatially modelling the association between access to recreational facilities and exercise: the ‘Multi-ethnic study of atherosclerosis’

Numerous studies have investigated the relationship between the built environment and physical activity. However these studies assume that these relationships are invariant over space. In this study, we introduce a novel method to analyze the association between access to recreational facilities and exercise allowing for spatial heterogeneity. In addition, this association is studied before and after controlling for crime, a variable that could explain spatial heterogeneity of associations. We use data from the Chicago site of the Multi-Ethnic Study of Atherosclerosis of 781 adults aged 46 years and over. A spatially varying coefficient Tobit regression model is implemented in the Bayesian setting to allow for the association of interest to vary over space. The relationship is shown to vary over Chicago, being positive in the south but negative or null in the north. Controlling for crime weakens the association in the south with little change observed in northern Chicago. The results of this study indicate that spatial heterogeneity in associations of environmental factors with health may vary over space and deserve further exploration

Covalent bond shortening and distortion induced by pressurization of thorium, uranium, and neptunium tetrakis aryloxides

Covalency involving the 5f orbitals is regularly invoked to explain the reactivity, structure and spectroscopic properties of the actinides, but the ionic versus covalent nature of metal-ligand bonding in actinide complexes remains controversial. The tetrakis 2,6-di-tert-butylphenoxide complexes of Th, U and Np form an isostructural series of crystal structures containing approximately tetrahedral MO(4) cores. We show that up to 3 GPa the Th and U crystal structures show negative linear compressibility as the OMO angles distort. At 3 GPa the angles snap back to their original values, reverting to a tetrahedral geometry with an abrupt shortening of the M-O distances by up to 0.1 Å. The Np complex shows similar but smaller effects, transforming above 2.4 GPa. Electronic structure calculations associate the M-O bond shortening with a change in covalency resulting from increased contributions to the M-O bonding by the metal 6d and 5f orbitals, the combination promoting MO(4) flexibility at little cost in energy

Critical comments on the WHO-UNEP State of the Science of Endocrine Disrupting Chemicals – 2012

AbstractEarly in 2013, the World Health Organization (WHO) released a 2012 update to the 2002 State of the Science of Endocrine Disrupting Chemicals. Several significant concerns have been identified that raise questions about conclusions reached in this report regarding endocrine disruption. First, the report is not a state-of-the-science review and does not follow the 2002 WHO recommended weight-of-evidence approach. Second, endocrine disruption is often presumed to occur based on exposure or a potential mechanism despite a lack of evidence to show that chemicals are causally established as endocrine disruptors. Additionally, causation is often inferred by the presentation of a series of unrelated facts, which collectively do not demonstrate causation. Third, trends in disease incidence or prevalence are discussed without regard to known causes or risk factors; endocrine disruption is implicated as the reason for such trends in the absence of evidence. Fourth, dose and potency are ignored for most chemicals discussed. Finally, controversial topics (i.e., low dose effects, non-monotonic dose response) are presented in a one-sided manner and these topics are important to understanding endocrine disruption. Overall, the 2012 report does not provide a balanced perspective, nor does it accurately reflect the state of the science on endocrine disruption

The Fundamental Structure of Coronal Loops

During the past ten years, solar physicists have attempted to infer the coronal heating mechanism by comparing observations of coronal loops with hydrodynamic model predictions. These comparisons often used the addition of sub ]resolution strands to explain the observed loop properties. On July 11, 2012, the High Resolution Coronal Imager (Hi ]C) was launched on a sounding rocket. This instrument obtained images of the solar corona was 0.2 ]0.3'' resolution in a narrowband EUV filter centered around 193 Angstroms. In this talk, we will compare these high resolution images to simultaneous density measurements obtained with the Extreme Ultraviolet Imaging Spectrograph (EIS) on Hinode to determine whether the structures observed with Hi ]C are resolved