Doctor of Philosophy

dissertationThe research detailed within this dissertation investigates the neurobiological changes associated with emotional processing of backward masked emotional faces in veterans with and without posttraumatic stress disorder (PTSD). PTSD affects millions of Americans, including approximately 20% of veterans, and is associated with a number of negative symptoms, including hyperarousal, avoidance, and flashbacks. In this dissertation, we examined a group of 15 veterans with PTSD and a group of 12 veterans without PTSD using both functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). Using fMRI, the blood oxygen level dependent (BOLD) signal of the amygdala and extrastriate cortex was measured, and using EEG, the P1 event-related potential (ERP) was recorded in response to masked affect. The veteran group with PTSD exhibited increased extrastriate BOLD signal but decreased P1 ERP amplitude in the right hemisphere. This was evidence of a right hemisphere specific visuosensory modulation in veterans with PTSD, which is most evident using EEG. Unexpectedly, the P1 ERP and extrastriate BOLD signal did not display a significant linear relationship in either veteran group, which indicates that although activity was measured from similar regions, the two methodologies provided distinct information regarding neuronal activity in this study. In addition, a relationship was observed between the BOLD signal of the amygdala and extrastriate cortex and the degree of combat exposure, based on the Combat Exposure Scale (CES). A veteran group without PTSD displayed a negative correlation between the extent of combat exposure and amygdalar BOLD activity. This was not the case for a veteran group with PTSD, who instead exhibited a negative correlation between the degree of combat exposure and extrastriate BOLD activity. When the total score of the CES was used as a covariate, the veteran group with PTSD displayed significantly increased amygdalar BOLD and extrastriate BOLD activity, compared to the veteran group without PTSD. This research highlights the importance of multimodal research, as differences between the two groups were observed using both methodologies. Our results suggest a relationship between the degree of combat exposure and the processing of masked emotional stimuli, even in veterans without PTSD

Spare Parts Supply Chain Shipment Decision Making in a Deterministic Environment

Determining the optimal lot size is a well discussed problem across many industries. This paper suggests a deterministic approach to shipment decision taking in a deterministic environment of spare parts supply chain. The model considered a deterministic forecast for the incoming faulty units. An objective function was modeled by taking in consideration three main elements: the number of malfunctioned units, the shipping cost and the storage cost. A deterministic forecast allowed calculating the cost effective schedule of shipments and its lot sizes. The purpose of this paper it to study the reverse logistics supply chain of a typical telecom devices company (that offers warranty/repairing services) and try to reduce its transportation and handling costs in order to bring added-value to the customer and by doing so, expand the competitive advantage of the company

Semi-simple Lie algebras are determined by their Iwasawa subalgebras

Using tools from the geometry of Einstein solvmanifolds, we give a geometric argument that a semi-simple Lie algebra (of non-compact type) is completely determined by its Iwasawa subalgebra. Furthermore, we produce an algebraic procedure for recovering the semi-simple (of non-compact type) from its Iwasawa subalgebra.Comment: 7 pages, main theorem improved in new versio

Designing graduate training programs in conservation medicine-producing the right professionals with the right tools.

New challenges to human, animal, and ecosystem health demand novel solutions: New diseases are emerging from new configurations of humans, their domestic animals and wildlife; new pressures on once robust and resilient ecosystems are compromising their integrity; synthetic compounds and engineered organisms, new to the natural world, are spreading unpredictably around the globe. Globalization provides opportunities for infectious organisms to gain access to new hosts, changing in distribution and virulence. What type of training should be developed to provide professionals with the right tools to meet these challenges? In this article, we offer recommendations for developing academic programs in conservation medicine. We discuss the need for, and the advantages to, using a conservation medicine approach to address real world situations and present illustrations of how this is applied today. We suggest a core set of skills that are needed in a conservation medicine practitioner, and recommend key considerations for designing new conservation medicine training programs. We review existing programs that offer conservation medicine content, and provide examples of where opportunities exist for those interested in pursuing a conservation medicine career

A mathematician’s deliberation in reaching the formal world and students’ world views of the eigentheory

International audienceIn this paper we analyzed a mathematician’s journals of 5-day teaching episodes on eigenvalues and eigenvectors in a first-year linear algebra course, as well as his students’ responses to a survey. We employed Tall’s (2013) three world model, to follow the mathematician’s and his students’ movements between the three worlds. The study revealed that despite the mathematician’s efforts in demonstrating a more holistic view of the concepts, many students found linear algebra very abstract and gravitated more toward symbolic thinking

Pursuing Cardiac Progenitors: Regeneration Redux

Recent studies have questioned the accepted dogma that the regenerative capacity of the heart following injury is limited. Several apparently distinct populations of resident cardiac progenitor cells may have the potential to regenerate functional heart muscle. Despite this progress, the physiologic role and therapeutic potential of cardiac resident progenitor cells remain unclear

Civic Meanings Reconsidered: A Response to “Civic Meanings: Understanding the Constellations of Democratic and Civic Beliefs of Educators”

In this response, we argue for the importance of understanding teachers\u27 and administrators\u27 beliefs about civic education, as well as how those beliefs may influence teachers\u27 practices. We commend the authors for examining the beliefs of principals and school board members—groups rarely surveyed—but question how their beliefs may affect the teaching and learning of citizenship in schools

An Ecological and Conservation Perspective on Advances in the Applied Virology of Zoonoses

The aim of this manuscript is to describe how modern advances in our knowledge of viruses and viral evolution can be applied to the fields of disease ecology and conservation. We review recent progress in virology and provide examples of how it is informing both empirical research in field ecology and applied conservation. We include a discussion of needed breakthroughs and ways to bridge communication gaps between the field and the lab. In an effort to foster this interdisciplinary effort, we have also included a table that lists the definitions of key terms. The importance of understanding the dynamics of zoonotic pathogens in their reservoir hosts is emphasized as a tool to both assess risk factors for spillover and to test hypotheses related to treatment and/or intervention strategies. In conclusion, we highlight the need for smart surveillance, viral discovery efforts and predictive modeling. A shift towards a predictive approach is necessary in today’s globalized society because, as the 2009 H1N1 pandemic demonstrated, identification post-emergence is often too late to prevent global spread. Integrating molecular virology and ecological techniques will allow for earlier recognition of potentially dangerous pathogens, ideally before they jump from wildlife reservoirs into human or livestock populations and cause serious public health or conservation issues