Modeling Migration and Citizen-Science Data to Estimate Golden Eagle Abundance in Eastern North America

Understanding animal movements is fundamental to ecology and conservation, yet direct measurement of movements of birds is both challenging and costly. Raptor populations are especially difficult to monitor, but movement models can provide information toward this goal. The golden eagle (Aquila chrysaetos canadensis) in eastern North America is a species of regional conservation concern, and little is known about its population ecology, movements, or behavior. Because of their rarity and role as apex predators, improving monitoring of this small population is of great importance. Similar to using movement models to help improve monitoring, developing new methods to estimate the size of wildlife populations is also important to ecology and conservation.;In my first chapter, I simulated autumn migration of golden eagles in Pennsylvania, USA based on regional topography, eagle flight behaviors, estimated uplift, and a principal axis of migration. In total, I modeled 6,094 flight routes, averaging 2,191 (+/- 1,281; +/- SD; range: 3 - 5,373) moves. I found that 71% of my simulations intersected the Ridge and Valley physiographic province of the central Appalachians. Simulations were spatially comparable to historic, flight route data collected via telemetry. In my model, orographic uplift was significantly stronger and more frequently occurring than thermal uplift (Welch\u27s two-sample t = -560.13, df = 43,059,702, p \u3c 0.0001), and uplift values were not correlated with the number of simulated movements (orographic, Pearson\u27s r = -0.015 and thermal, r = 0.003). I used output from my simulations to select sites and collect field data in new areas concentrating golden eagles on migration. This not only preliminarily verified my modeled predictions, but it also allowed me to locate new, potential monitoring sites for migrant golden eagles. I also compared output from my migration model to that of another model, to evaluate the influence of topography, spatial relationships with hawk-count sites, and role of scale in modeling migration.;In my second chapter, I evaluated the utility of hawk-count data for population size estimation of golden eagles migrating in eastern North America. I used my computer model from the first chapter to simulate migratory flights of eagles to assess what proportion of the population is available to be counted at hawk-counts in Pennsylvania, USA. I then conducted a mark-recapture analysis to estimate mean detectability of migrating eagles and mean local abundance along an important migration corridor. Finally, I used estimates of availability and detectability to adjust data from hawk-count sites to derive regional estimates of population size. Mean (+/- SD) availability of golden eagles to hawk-count sites was 0.240 (+/- 0.140; range: 0.040 - 0.440). I estimated mean detectability as 0.073 (+/- 0.010; range: 0.048 - 0.109). Previous estimates of population size for golden eagles in eastern North America were 1000 - 5000.;All of my population estimates far exceeded that of previous approximations. When using detection rates from recent literature, only then were my estimates \u3c 5,000 individuals. Using my estimates of availability and detectability, mean population size was more than five times larger than the maximum previous estimate. My smallest estimate was three times larger than the previous maximum estimate. Larger estimates were driven by the low availability and detectability of birds passing by hawk-counts. Overall, this work suggests that (a) detection estimates need to be improved, (b) the majority of migrating golden eagles in eastern North America are not counted at hawk-count sites, and (c) previous population estimates for this species are likely low--possibly, greatly so. This exercise demonstrates the utility of using citizen-science data in concert with movement models to address a pressing conservation goal: estimating population size for species of regional concern. My research contributes to current scientific knowledge through development of a novel, cost-effective method for modeling migration patterns and abundance of a rare, low-density raptor species. (Abstract shortened by UMI.)

No-go theorem for false vacuum black holes

We study the possibility of non-singular black hole solutions in the theory of general relativity coupled to a non-linear scalar field with a positive potential possessing two minima: a `false vacuum' with positive energy and a `true vacuum' with zero energy. Assuming that the scalar field starts at the false vacuum at the origin and comes to the true vacuum at spatial infinity, we prove a no-go theorem by extending a no-hair theorem to the black hole interior: no smooth solutions exist which interpolate between the local de Sitter solution near the origin and the asymptotic Schwarzschild solution through a regular event horizon or several horizons.Comment: 16 pages, 1 figure, Latex, some references added, to appear in Classical and Quantum Gravit

Perception of High Alcohol Use of Peers Is Associated With High Personal Alcohol Use in First-Year University Students in Three Central and Eastern European Countries

Objectives: The objectives of this study were to assess discrepancies between estimated peer and personal drinking behavior and to determine associations between perceptions of peer and personal drinking behavior among university students from Hungary (HU), Lithuania (LT), and the Slovak Republic (SK). Methods: 2,554 freshman university students completed an online questionnaire on the frequency of their personal alcohol use, the number of heavy drinking occasions and on their perception concerning the corresponding drinking behavior of a typical student. Associations between perceived peer and personal use were analyzed by means of logistic regression, adjusting for sex. Results: The majority of students across all countries thought their peers drink more frequently and are more often involved in heavy drinking occasions than themselves. Students who perceived the frequency of peer alcohol use to be higher were more likely to drink alcohol twice a week or more often (SR: OR = 3.81, 95% CI = 2.51–5.79; LT: OR = 3.16, 95% CI = 2.11–4.75; HU: OR = 2.10, 95% CI = 1.53–2.87) compared with students who drink alcohol monthly or less. Those who perceived the number of peer heavy drinking occasions as high were more likely to report heavy drinking weekly or more often (SR: OR = 3.16, 95% CI = 1.92–5.20; LT:OR = 3.56, 95% CI = 2.14–5.94; HU:OR = 1.41, 95% CI = 0.79–2.51) compared with students who report heavy drinking less than monthly. Conclusions/Importance: University students perceived peer alcohol use to be higher than their personal use. Given the association between perceptions and personal alcohol use, future research should investigate if targeting perceptions in the surveyed countries may have an impact on alcohol use

Characterization of a Large Group of Individuals with Huntington Disease and Their Relatives Enrolled in the COHORT Study

Careful characterization of the phenotype and genotype of Huntington disease (HD) can foster better understanding of the condition.We conducted a cohort study in the United States, Canada, and Australia of members of families affected by HD. We collected demographic and clinical data, conducted the Unified Huntington's Disease Rating Scale and Mini-Mental State Examination, and determined Huntingtin trinucleotide CAG repeat length. We report primarily on cross-sectional baseline data from this recently completed prospective, longitudinal, observational study.As of December 31, 2009, 2,318 individuals enrolled; of these, 1,985 (85.6%) were classified into six analysis groups. Three groups had expanded CAG alleles (36 repeats or more): individuals with clinically diagnosed HD [n = 930], and clinically unaffected first-degree relatives who had previously pursued [n = 248] or not pursued [n = 112] predictive DNA testing. Three groups lacked expanded alleles: first-degree relatives who had previously pursued [n = 41] or not pursued [n = 224] genetic testing, and spouses and caregivers [n = 430]. Baseline mean performance differed across groups in all motor, behavioral, cognitive, and functional measures (p<0.001). Clinically unaffected individuals with expanded alleles weighed less (76.0 vs. 79.6 kg; p = 0.01) and had lower cognitive scores (28.5 vs. 29.1 on the Mini Mental State Examination; p = 0.008) than individuals without expanded alleles. The frequency of "high normal" repeat lengths (27 to 35) was 2.5% and repeat lengths associated with reduced penetrance (36 to 39) was 2.7%.Baseline analysis of COHORT study participants revealed differences that emerge prior to clinical diagnosis. Longitudinal investigation of this cohort will further characterize the natural history of HD and genetic and biological modifiers.Clinicaltrials.gov NCT00313495

Species identification by experts and non-experts: comparing images from field guides

Accurate species identification is fundamental when recording ecological data. However, the ability to correctly identify organisms visually is rarely questioned. We investigated how experts and non-experts compared in the identification of bumblebees, a group of insects of considerable conservation concern. Experts and non-experts were asked whether two concurrent bumblebee images depicted the same or two different species. Overall accuracy was below 60% and comparable for experts and non-experts. However, experts were more consistent in their answers when the same images were repeated, and more cautious in committing to a definitive answer. Our findings demonstrate the difficulty of correctly identifying bumblebees using images from field guides. Such error rates need to be accounted for when interpreting species data, whether or not they have been collected by experts. We suggest that investigation of how experts and non-experts make observations should be incorporated into study design, and could be used to improve training in species identification

On the stability of scalar-vacuum space-times

We study the stability of static, spherically symmetric solutions to the Einstein equations with a scalar field as the source. We describe a general methodology of studying small radial perturbations of scalar-vacuum configurations with arbitrary potentials V(\phi), and in particular space-times with throats (including wormholes), which are possible if the scalar is phantom. At such a throat, the effective potential for perturbations V_eff has a positive pole (a potential wall) that prevents a complete perturbation analysis. We show that, generically, (i) V_eff has precisely the form required for regularization by the known S-deformation method, and (ii) a solution with the regularized potential leads to regular scalar field and metric perturbations of the initial configuration. The well-known conformal mappings make these results also applicable to scalar-tensor and f(R) theories of gravity. As a particular example, we prove the instability of all static solutions with both normal and phantom scalars and V(\phi) = 0 under spherical perturbations. We thus confirm the previous results on the unstable nature of anti-Fisher wormholes and Fisher's singular solution and prove the instability of other branches of these solutions including the anti-Fisher "cold black holes".Comment: 18 pages, 5 figures. A few comments and references added. Final version accepted at EPJ

Huntington disease in a nonagenarian mistakenly diagnosed as normal pressure hydrocephalus

In the absence of family history or overt chorea, the protean manifestations (cognitive, motor and behavioral) of Huntington disease (HD) may suggest alternative disease processes, particularly in elderly patients. Herein, we report on a nonagenarian with HD who did not manifest overt chorea until 91 years of age and was mistakenly diagnosed with normal pressure hydrocephalus at 89 years of age. The gait abnormalities seen in early HD should be readily distinguished from those of normal pressure hydrocephalus. © 2010 Elsevier Ltd. All rights reserved

A behavioral economic analysis of the effect of next-day responsibilities on drinking

Approximately 37% of college students report heavy episodic drinking (5 or more drinks in an occasion for men and 4 or more for women) in the past month. This pattern of drinking is often associated with high blood alcohol levels, accidents, injuries, and negative social and academic outcomes. There is a need for novel theoretical approaches to guide prevention efforts. Behavioral economics emphasizes the role of contextual determinants, such as drink price and the presence and amount of alternative reinforcement as determinants of drinking levels and has received strong empirical support in basic laboratory research. This translational research study used a hypothetical behavioral economic measure to investigate the impact of a variety of next-day responsibilities on night-before drinking intentions in a sample of first-year college students (N = 80; 50% female) who reported recent heavy episodic drinking. Drinking estimates were significantly lower in all of the responsibility conditions relative to the no-responsibility condition; internships were associated with the greatest reduction (drm = 1.72), and earlier class times were associated with greater reductions in drinking intentions (drm range = 1.22-1.35) than later class times (drm range = 0.83-1.00). These results suggest that increasing morning responsibilities should be further investigated as a potential strategy to reduce drinking in college students