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Variable Helper Effects, Ecological Conditions, And The Evolution Of Cooperative Breeding In The Acorn Woodpecker, Walter D. Koenig, Eric L. Walters, Joseph Haydock

Biological Sciences Faculty Publications

The ecological conditions leading to delayed dispersal and helping behavior are generally thought to follow one of two contrasting scenarios: that conditions are stable and predictable, resulting in young being ecologically forced to remain as helpers (extrinsic constraints and the habitat saturation hypothesis), or that conditions are highly variable and unpredictable, leading to the need for helpers to raise young, at least when conditions are poor (intrinsic constraints and the hard life hypothesis). We investigated how variability in ecological conditions influences the degree to which helpers augment breeder fitness in the cooperatively breeding acorn woodpecker (Melanerpes formicivorus), a …

Biological Condition Of Money Pont Benthic Communities, Southern Branch Of The Elizabeth River (2010), Daniel M. Dauer

Elizabeth River Reports

Executive Summary

The subtidal macrobenthic communities off Money Point in the Southern Branch of the Elizabeth River were quantitatively sampled in summer 2011. The designated Money Point study area will be a part of a sediment contaminant remediation effort. The primary objectives of this study were to: (1) characterize the biological health of the benthos of Money Point and (2) produce an historical data base that will allow an assessment of the effectiveness of the proposed sediment contamination remediation efforts with respect to Money Point benthos.

The most quantitative characterization of the benthos of the Elizabeth River watershed was the …

Application Of A Gene-Based Population Dynamics Model To The Optimal Egg Size Problem: Why Do Bivalve Planktotrophic Eggs Vary In Size?, Eric N. Powell, Jason Morson, John M. Klinck

CCPO Publications

The presumption is that egg quality influences larval survival and that egg size influences egg quality. Thus, larger eggs should be favored by selection. Counterweighing the tendency for egg size to increase is the number of eggs that can be produced if egg size remains small. We examine how egg size and egg number counterbalance in Crassostrea oysters, resulting in an average egg size near 50 mu m. Simulations imposing a diversity of ranges in larval survivorship-from little advantage for large eggs relative to small eggs to a great advantage-yield some anticipated outcomes in which genotypes generating larger eggs are …

Stability Analysis And Application Of A Mathematical Cholera Model, Shu Liao, Jim Wang

Mathematics & Statistics Faculty Publications

In this paper, we conduct a dynamical analysis of the deterministic cholera model proposed in [9]. We study the stability of both the disease-free and endemic equilibria so as to explore the complex epidemic and endemic dynamics of the disease. We demonstrate a real-world application of this model by investigating the recent cholera outbreak in Zimbabwe. Meanwhile, we present numerical simulation results to verify the analytical predictions.

Conditions For Empathy In Medicine: A Grounded Theory Study, Hannah Barnhill Bayne

Counseling & Human Services Theses & Dissertations

Previous research in the medical setting has credited empathy with improving treatment outcomes and patient satisfaction, though operational definitions of the concept are widely varied and indicate inconsistencies in conceptualization and subsequent assessment. The purpose of this grounded theory study was to examine the role of empathy in the medical setting. A model of conditions for empathy in medicine was developed through in-depth interviews with 21 healthcare professionals, utilizing their professional experiences and perspectives to structure the multi-level model. The seven levels of the model indicate the layers of complexity inherent in facilitating optimal empathy in medicine and add to …

Treating Trauma Survivors With Neurofeedback: A Grounded Theory Study Based On The Practices Of Experienced Mental Health Professionals, Christine L. Currie

Counseling & Human Services Theses & Dissertations

Neuroscience, the mental health field, and the concept of trauma as an underlying factor in mental and physical disorders have been inextricably linked since the inception of the mental health professions. Numerous quantitative studies have indicated that neurofeedback may be effective in ameliorating trauma symptoms; however, there is a paucity of research exploring the factors that produce those positive outcomes. The purpose of this qualitative grounded theory study was to explore the factors and processes that influence treatment outcomes when neurofeedback is used with trauma survivors. Thirty interviews were completed with ten experienced mental health and neurofeedback professionals identified through …

The Relationship Of Cognitive Development Level, Supervision, And Counselor Skills In Preparing Counselors, Margaret Jean Jensen

Counseling & Human Services Theses & Dissertations

The focus of this study was the exploration of specific developmental dimensions that may have an impact on the counselor training process, which ultimately will affect the quality of care offered by counselors to clients. Specifically, the relationship of cognitive developmental level and counseling competency skills was examined to determine if a relationship exists between the two dimensions and if so, can a counselor trainee's developmental level predict his or her level of counseling skills. Thirty master level counseling students (trainees) participated in this study during practicum or internship. The trainees were rated by their supervisors on both a measure …

A Mixed Methodological Analysis Of The Role Of Culture And Diagnostic Variance Among Counselors And Counselor Trainees, Elizabeth A. Prosek

Counseling & Human Services Theses & Dissertations

As the U.S. population continues to diversify, counselors are challenged to respond to the interface of culture and mental health concerns of clients (Gushue, Constantine, & Sciarra, 2008). It is important for counselors when making clinical decisions to reflect on the diverse needs of clients as well as the potential impact of cultural factors on mental health (Sue & Sue, 2008). Accordingly, this study sought to investigate the clinical decision-making process among counselors and counselor trainees and how, if at all, cultural factors influence the case conceptualization of clients. The study also investigated how counselors and counselor trainees collect and …

Statistical Optimizations Of Muscle Action Potentials Based On Modeling And Analysis Of Ion Channel Dynamics, Gyutae Kim

Electrical & Computer Engineering Theses & Dissertations

An Electromyogram (EMG) is an electrical signal, which is measured from a skeletal muscle during voluntary and involuntary contractions. EMGs are useful in interpreting pathological states of the musculoskeletal system. In particular, EMGs offer valuable information concerning the timing of muscular activity and its relative intensity. Various EMG models have developed with many different purposes from a pure mathematical model to a pattern structure model [17,46]. Sophisticated EMG models are necessary to examine the effects of small changes in muscular morphology and activities [46]. Due to the crucial importance of EMG models, all factors in the model should be precise …

The Effect Of Improvisations And Observations On Standardized Patient Encounters, Subjective Workload And Stress, Elizabeth T. Newlin-Canzone

Psychology Theses & Dissertations

Standardized patients (SPs) are people trained to present a medical case for teaching and assessing medical students and they simultaneously perform several demanding tasks including portraying the patient, assessing the learner, and providing feedback. This study investigated the effect of improvisations and multiple task performance on the ability to observe another's nonverbal (NV) behaviors and rate their communication skills. Subjective reports of mental workload and stress were also obtained. The first study involved undergraduates interviewing for a job. Type of interview (rote and improvisational) and type of observation (passive and active) were manipulated within groups. Based on theories of attention …

The Nature, Origin And Preservation Of Amide Organic Nitrogen In Organic Matter, Georgina Anne Mckee

Chemistry & Biochemistry Theses & Dissertations

Past studies have found much of nonliving sedimentary/aqueous nitrogen-containing organic matter (NCOM) is composed of amides, assumed to be peptides/proteins. Their lability calls into question their survival, and several hypotheses have been suggested to explain this. Using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and nuclear magnetic resonance (NMR) spectroscopy I investigated the molecular amide composition in sedimentary/aqueous systems while reassessing their preservation and formation routes.

Development of a suitable methodology is essential for successful NCOM study due to electrospray ionisation source requirements: sediment samples need to be rendered into solution. Based on NMR and FT-ICR-MS analysis, I determined …

Controls On The Formation Of Algal Blooms In The Lower Chesapeake Bay And Its Tributaries, Ryan Eric Morse

OES Theses and Dissertations

Algal blooms occur seasonally in the Chesapeake Bay and its tributaries, and while the consequences of algal blooms have been qualitatively and quantitatively assessed, the causes of algal blooms and mechanisms of bloom initiation are still not well understood despite decades of research. In order to understand nutrient dynamics and other factors that promote the initiation of algal blooms, the Lafayette River, a tidal sub-estuary of Chesapeake Bay that experiences seasonal algal blooms, was sampled daily in the fall of 2005. Three phytoplankton blooms (Chlorophyll a concentrations exceeding twice the average of monthly measurements from 2000-2009) occurred during this period, …

The Effects Of Rumination, Hostility, And Distraction On Cardiovascular Reactivity And Recovery From Anger Recall In Healthy Women, Meghan K. Mclain

Psychology Theses & Dissertations

Cardiovascular reactivity and recovery following an emotional stressor may play a crucial role in mediating the relation between psychosocial factors (e.g. hostility and anger) and cardiovascular disease. Hostility has been associated with trait rumination. Trait rumination, a tendency to focus attention on negative thoughts and emotions and be prone to feelings of revenge, is not adequately captured in current measures of hostility. The current study examined whether trait rumination, indexed by the Dissipation-Rumination Scale, has an independent effect of increasing cardiovascular reactivity and prolonging cardiovascular recovery from angry events above and beyond hostility as measured by the Cook-Medley Hostility Scale. …

Nanosecond Pulsed Electric Field Induction Of Programmed Cell Death Is Cell Type Dependent: An In Vitro Study, Wei Ren

Theses and Dissertations in Biomedical Sciences

Nanosecond pulsed electric fields (nsPEFs) present a novel and effective method for cancer ablation by eradicating the ubiquitous cancer hallmark of apoptosis evasion and enforcing cancer programmed cell death. To develop nsPEFs as an anticancer method, a comprehensive understanding of cell death mechanisms is required. The overall objective of this dissertation is to elucidate molecular mechanisms underlying effects of nsPEFs on E4 murine squamous cell carcinoma and human T-cell Jurkat clones that are wildtype, deficient in FADD (ΔFADD) and deficient in caspase-8 (ACas-8). The overall hypothesis is that nsPEFs eliminate cancer cells through activating caspase-dependent and caspase-independent programmed cell death …

The Tracking Performance Of Distributed Recoverable Flight Control Systems Subject To High Intensity Radiated Fields, Rui Wang

Electrical & Computer Engineering Theses & Dissertations

It is known that high intensity radiated fields (HIRF) can produce upsets in digital electronics, and thereby degrade the performance of digital flight control systems. Such upsets, either from natural or man-made sources, can change data values on digital buses and memory and affect CPU instruction execution. HIRF environments are also known to trigger common-mode faults, affecting nearly-simultaneously multiple fault containment regions, and hence reducing the benefits of n-modular redundancy and other fault-tolerant computing techniques. Thus, it is important to develop models which describe the integration of the embedded digital system, where the control law is implemented, as well …

Patterns Of Transience, Sex Bias, And Body Mass In Open-Habitat Rodent Populations, Stephen Edward Rice

Biological Sciences Theses & Dissertations

Rodents are assumed to live their lives in circumscribed (natal) areas with males being more prone to disperse than females and juveniles more prone to disperse than adults. To test these assumptions we examined the initial captures of geographic populations of hispid cotton rat, meadow vole, prairie vole, and marsh rice rat obtained through capture-mark-recapture methods. Capture records were obtained from Kansas and Illinois from long-term studies, and through live-trapping in Chesapeake, Virginia. I evaluated proportions of residents and transients, adults and juveniles, and males and females for significant differences among seasons, years, and geographic locations. The overall body masses …

Effects Of 11 Years Of Co2 Enrichment On Root Biomass And Spatial Distribution In A Florida Scrub-Oak Ecosystem, Rachel Eilenfield Schroeder

Biological Sciences Theses & Dissertations

A Florida (USA) scrub-oak ecosystem was exposed to elevated atmospheric CO₂ in open-top chambers from 1996-2007. Minirhizotrons and ground-penetrating radar (GPR) were used to measure fine root (< 2 mm diameter) and coarse root (> 5 mm diameter) biomass, respectively. After 11 years of CO₂ enrichment, there was a trend of greater total root biomass under elevated CO₂. Fine root biomass exhibited a pattern of recovery and steady state throughout the study, with significant CO₂ stimulation observed only after disturbance. Greater root biomass under elevated CO₂ during recovery periods could result in greater carbon inputs belowground, alteration of the soil carbon …

Altering Nitric Oxide Bioavailability And Lipid Profiles In Endothelial Cells By Polycyclic Aromatic Hydrocarbons In Particulate Matter, Liang Yu

Theses and Dissertations in Biomedical Sciences

Epidemiologic studies have demonstrated a significant association between exposure to particulate matter (PM) and atherosclerosis. Polycyclic aromatic hydrocarbons (PAHs) present in particulate matter, are well known to induce oxidative stress and lipid peroxidation via generation of reactive oxygen species (ROS). Lipid peroxidation involves regulating endothelial nitric oxide synthase via inhibition of its activity, and as a result, mediates dilation of coronary arterioles is involved with the pathogenesis of atherosclerosis. However, data on assessment of oxidized lipid formation is limited due to low resolution of mass spectrometer methods. Taking the advantage of a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FT-ICR-MS) …

A Systemic Approach To Next Generation Infrastructure Data Elicitation And Planning Using Serious Gaming Methods, Ersin Ancel

Engineering Management & Systems Engineering Theses & Dissertations

Infrastructure systems are vital to the functioning of our society and economy. However, these systems are increasingly complex and are more interdependent than ever, making them difficult to manage. In order to respond to increasing demand, environmental concerns, and natural and man-made threats, infrastructure systems have to adapt and transform. Traditional engineering design approaches and planning tools have proven to be inadequate when planning and managing these complex socio-technical system transitions. The design and implementation of next generation infrastructure systems require holistic methodologies, encompassing organizational and societal aspects in addition to technical factors. In order to do so, a serious …

Faculty And Student Perceptions Of Students' Sense Of Community In Online Courses, William C. Fiege

Educational Leadership & Workforce Development Theses & Dissertations

The Classroom Community Scale (Rovai, 2002b) was used to examine faculty and student perceptions of students' sense of community at two points during an academic semester. The study also examined the relationship between student sense of community scores and their final course grades. A non-experimental research design was used by the researcher to analyze pre-survey to post-survey score means of students' sense of community as perceived by students and faculty. Two hundred sixty-nine (269) students and 48 faculty members representing 56 online arts and science courses at a community college in Virginia completed the pre-survey and post-survey surveys.

Students' perceptions …

Model-Based Analyses Of Nitrogen On The Mid-Atlantic Bight Continental Shelf, Tian Tian

OES Theses and Dissertations

The biogeochemistry of continental shelf systems is an important, but poorly quantified, component of the global cycling of nitrogen and carbon. In this study, simulations obtained from a one-dimensional (ID) biogeochemical model developed for the Middle Atlantic Bight (MAB) portion of the U.S. eastern continental shelf were analyzed to investigate nitrogen cycling processes. The 1D model included lower trophic level interactions and was forced by advective fields obtained from a corresponding three-dimensional biogeochemical model. Taylor and target diagram analyses, which compared in situ measurements of sea surface temperature (SST) and salinity, and chlorophyll and particulate organic carbon (POC) derived from …

Rats As Forest Pests In Southeastern Virginia: Girdling By The Hispid Cotton Rat Sigmodon Hispidus As A Significant Source Of Mortality Of Loblolly Pines (Pinus Taeda) In A Successional Pine Forest, Robyn M. Nadolny

Biological Sciences Theses & Dissertations

The hispid cotton rat (Sigmodon hispidus) is a common field rodent throughout the southeastern US, where volunteer loblolly pine trees (Pinus taeda) invade open space and begin the process of ecological succession from field to pine forest. Recent analysis of the diet of S. hispidus indicates that loblolly pine bark is stripped and eaten during the winter months. In this study, we explored the extent of rodent girdling on a 1.23 ha grid in a successional pine forest in southeastern Virginia. During the winter of 2005 we observed damage to 65% of trees in our study area, with 98% …

Automatic High-Fidelity 3d Road Network Modeling, Jie Wang

Computational Modeling & Simulation Engineering Theses & Dissertations

Many computer applications such as racing games and driving simulations frequently make use of 3D high-fidelity road network models for a variety of purposes. However, there are very few existing methods for automatic generation of 3D realistic road networks, especially for those in the real world. On the other hand, vast road network GIS data have been collected in the past and used by a wide range of applications, such as navigation and evaluation. A method that can automatically produce 3D high-fidelity road network models from 2D real road GIS data will significantly reduce both the labor and time needed …

Age-Related Hamster Mitochondrial Changes And Oocyte Changes Following Autologous Platelet Mitochondrial Microinjection, Fang Li

Theses and Dissertations in Biomedical Sciences

This study's objective was to verify age-related mitochondrial changes in oocytes from old hamsters compared with those from young hamsters. We used autologous platelet mitochondrial microinjection to improve the mitochondrial quality and quantity of aged oocytes to improve their pregnancy potential. Metaphase II oocytes were collected from super-ovulated female hamsters and prepared for biochemical and morphological analysis. Adenosine triphosphate (ATP) levels, mitochondrial DNA (mtDNA) number, reactive oxygen species (ROS) level and mitochondrial membrane potential (MMP) were determined in individual oocytes from young and old hamsters. Transmission electron microscopy (TEM) allowed evaluation of oocyte ultra-structure. In oocytes from old hamsters, ATP …

Looking Beyond The Medical Model Of Sexuality: Social Factors In Women's Sexual Satisfaction, Cristalle Rae Pronier

Sociology & Criminal Justice Theses & Dissertations

Since the explosive profit of Viagra in 1998, the pharmaceutical giants have been scrambling to develop a similar drug to treat Sexual Dysfunction in women. Female Sexual Dysfunction became an official disorder in 1999 shortly after the release of Viagra. This relatively new disorder has emerged as a prominent example of the medicalization of female sexuality whereby problems are defined, conceptualized, and solved in medical terms.

The inherent problem in medicalization is the denial of social, cultural, and psychological factors in women's sexual issues and concerns. To address this disconnect between the medical and social models of sexuality this study …

Evaluation Of Delivery Conditions For Cutaneous Plasmid Electrotransfer Using A Multielectrode Array, Bernadette Ferraro, Loree C. Heller, Yolmari L. Cruz, Siqi Guo, Amy Donate, Richard Heller

Bioelectrics Publications

Electroporation (EP) is a simple in vivo method to deliver normally impermeable molecules, such as plasmid DNA, to a variety of tissues. Delivery of plasmid DNA by EP to a large surface area is not practical because the distance between the electrode pairs, and therefore the applied voltage, must be increased to effectively permeabilize the cell membrane. The design of the multielectrode array (MEA) incorporates multiple electrode pairs at a fixed distance to allow for delivery of plasmid DNA to the skin, potentially reducing the sensation associated with in vivo EP. In this report, we evaluate the effects of field …

Rickettsia Parkeri In Gulf Coast Ticks, Southeastern Virginia, Usa, Chelsea L. Wright, Robyn M. Nadolny, Ju Jiang, Allen L. Richards, Daniel E. Sonenshine, Holly D. Gaff, Wayne L. Hynes

Biological Sciences Faculty Publications

We report evidence that Amblyomma maculatum tick populations are well established in southeastern Virginia. We found that 43.1% of the adult Gulf Coast ticks collected in the summer of 2010 carried Rickettsia parkeri, suggesting that persons living in or visiting southeastern Virginia are at risk for infection with this pathogen.

Effects Of Gypsy Moth Outbreaks On North American Woodpeckers, Walter D. Koenig, Eric L. Walters, Andrew M. Liebhold

Biological Sciences Faculty Publications

We examined the effects of the introduced gypsy moth (Lymantria dispar) on seven species of North American woodpeckers by matching spatially explicit data on gypsy moth outbreaks with data on breeding and wintering populations. In general, we detected modest effects during outbreaks: during the breeding season one species, the Red-headed Woodpecker (Melanerpes erythrocephalus), increased over pre-outbreak levels, while during the winter one species, the Yellow-bellied Sapsucker (Sphyrapicus varius), increased and one, the Downy Woodpecker (Picoides pubescens), decreased from pre-outbreak levels. Responses following outbreaks were similarly variable, and in general we were unsuccessful …

Examining The Association Between Attachment And Relationship Satisfaction Through The Use Of The Couples Drawing And The Bird’S Nest Drawing, Jessica Furiness

EVMS School of Health Professions Theses & Dissertations

The purpose of this thesis was to determine if there is a positive statistical correlation between relationship satisfaction and attachment and whether or not these two factors can be accurately assessed through a single drawing. The proposed study will use a quantitative approach to examine the association between attachment and relationship satisfaction, as determined by scores on the Adult Attachment Scale and the Relationship Assessment Scale. A qualitative approach will be used to examine graphic elements within the Bird’s Nest Drawing, and the Couples Drawing to determine which elements are associated with relationship satisfaction, attachment, or both. A sample size …

A Cross-Cultural Study Of Korean And American Children’S Human Figure Drawings, Suhyun Tess Lee

EVMS School of Health Professions Theses & Dissertations

Children’s human figure drawings (HFDs), known as one of the most widely used drawing assessment techniques, reflect various aspects of understanding children and some studies indicate that children’s HFDs are affected by cultural and environmental factors. Yet, the data collected are out of date or the studies predominantly included children from Western cultures. The purpose of this study was to explore the cultural impact on children’s HFDs from a non-western culture to promote a cross-cultural perspective in the field of art therapy.

In this quantitative study, 23 HFDs were collected in an elementary school setting in South Korea. Drawings were …