Alumni Dissertations and Theses

 
 

Alumni Dissertations and Theses

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  • The Vocal Behaviors of Captive North American River Otters (Lontra canadensis) Individual differences and shared repertoires

    Author:
    Carla Almonte
    Year of Dissertation:
    2011
    Program:
    Biology
    Advisor:
    Richard Veit
    Abstract:

    The current information on the vocal repertoire of the North American River Otter is very limited. To date there have been no direct studies conducted on their repertories. In this study, I examined the vocal behavior of 12 captive river otters. The discriminant function analysis suggests that river otters have 4 distinct call types with 7 sub-call types and one call the whistle is unique to one group of pups. The results of the Kruskal-Wallis comparing acoustical structures shows strong evidence for the presence of individuality with some individuals showing greater differences in comparison to the others. I also examined the differences in sexes and age groups, and the results show that unique calls are present, and there are significant differences across groups when comparing acoustical structures. Finally, I examined the uses of vocalizations, and the results show a positive correlation between the duration, max frequency, and max power of the call and the arousal state of the individual producing the call. Specific call types also showed tendencies to be produced when the individual was in a particular interaction (asocial or social) and when in a particular arousal state.

  • ROUTING PROTOCOLS ENHANCEMENT FOR DELAY TOLERANT NETWORKS

    Author:
    Fuad Alnajjar
    Year of Dissertation:
    2010
    Program:
    Engineering
    Advisor:
    Tarek Saadawi
    Abstract:

    Routing in Delay/Disruption Tolerant Networks (DTN) is active area of research and acquires the attention of researchers as being the most adequate solution for the problem of intermittently connection in Mobile Ad hoc Networks (MANET). The challenge is to find a routing algorithm that can deal with dynamic environment causing networks to split and merge, considering nodes mobility. In this dissertation we enhance the performance of DTN routing protocols in Delay Tolerant Mobile Ad Hoc Networks by accomplishing the following goals to address the routing challenges: * Design a new probabilistic routing protocol based on history of encountered nodes. * Determination of strength and weakness of DTN routing protocols by comparison. * Enhancing DTN routing protocols by inclusion of study of the impact of link availability on performance of the DTN-based protocols * A Cross Layer Design (CLD) to enhance service quality of some common MANET-based routing protocols. v We have designed a DTN-based probabilistic routing algorithm using the concept of History of Encounters, HEPRA. Our routing protocol relies on the knowledge of the mobility of nodes and uses the history of encountered nodes to predict its future suitability to deliver messages to next node toward destination. The probabilistic routing approach is built on a store-carry-forward network to deliver messages to final destination in MANET environment. We evaluate the performance of HEPRA in various network environment behaviors. We present an evaluation and analysis of performances of some common DTN routing protocols including HEPRA in terms of different parameters in MANET environment. We illustrate the behaviors of the DTN routing protocols in terms of various parameters and variables. This evaluation presents the strengths and weakness of selected protocols. We study the impact of link availability as a parameter of the physical layer environment on the performance of DTN routing protocols. This study is the first research analysis of the impact of physical layer parameters on the performance of DTN routing protocols. We demonstrate through the simulation how those protocols act against changes in network environment. We propose a CLD to attain a reliable data transmission in MANET. We present a model that allows the network layer to adjust its routing protocol dynamically based on Signal Noise Ratio (SNR) and Received Power (RP) along the end-to-end routing path for each transmission link to improve the end-to-end routing performance in MANET environment. In this dissertation, we present the design basis for those contributions, illustrate and evaluate our design efforts, and discuss the advantages of our models.

  • ROUTING PROTOCOLS ENHANCEMENT FOR DELAY TOLERANT NETWORKS

    Author:
    Fuad Alnajjar
    Year of Dissertation:
    2010
    Program:
    Engineering
    Advisor:
    Tarek Saadawi
    Abstract:

    Routing in Delay/Disruption Tolerant Networks (DTN) is active area of research and acquires the attention of researchers as being the most adequate solution for the problem of intermittently connection in Mobile Ad hoc Networks (MANET). The challenge is to find a routing algorithm that can deal with dynamic environment causing networks to split and merge, considering nodes mobility. In this dissertation we enhance the performance of DTN routing protocols in Delay Tolerant Mobile Ad Hoc Networks by accomplishing the following goals to address the routing challenges: * Design a new probabilistic routing protocol based on history of encountered nodes. * Determination of strength and weakness of DTN routing protocols by comparison. * Enhancing DTN routing protocols by inclusion of study of the impact of link availability on performance of the DTN-based protocols * A Cross Layer Design (CLD) to enhance service quality of some common MANET-based routing protocols. v We have designed a DTN-based probabilistic routing algorithm using the concept of History of Encounters, HEPRA. Our routing protocol relies on the knowledge of the mobility of nodes and uses the history of encountered nodes to predict its future suitability to deliver messages to next node toward destination. The probabilistic routing approach is built on a store-carry-forward network to deliver messages to final destination in MANET environment. We evaluate the performance of HEPRA in various network environment behaviors. We present an evaluation and analysis of performances of some common DTN routing protocols including HEPRA in terms of different parameters in MANET environment. We illustrate the behaviors of the DTN routing protocols in terms of various parameters and variables. This evaluation presents the strengths and weakness of selected protocols. We study the impact of link availability as a parameter of the physical layer environment on the performance of DTN routing protocols. This study is the first research analysis of the impact of physical layer parameters on the performance of DTN routing protocols. We demonstrate through the simulation how those protocols act against changes in network environment. We propose a CLD to attain a reliable data transmission in MANET. We present a model that allows the network layer to adjust its routing protocol dynamically based on Signal Noise Ratio (SNR) and Received Power (RP) along the end-to-end routing path for each transmission link to improve the end-to-end routing performance in MANET environment. In this dissertation, we present the design basis for those contributions, illustrate and evaluate our design efforts, and discuss the advantages of our models.

  • Hispanic Catholic Women Converting to Islam/Latinas Converting to Islam in New York

    Author:
    Amalia Alonzo
    Year of Dissertation:
    2014
    Program:
    Middle Eastern Studies
    Advisor:
    Bryan Turner
    Abstract:

    This paper explores the topic of religious conversion in relation to Pierre Bourdieu's theory of habitus, with a focus on Catholic Latina converts to Sunni Islam. Bourdieu suggests that these types of religious choices are not choices at all, but predetermined by an individual's history, culture, and setting. That is, an individual already has dispositions that are taken for granted. While this study's participants report that Islam is a new religion for them and not a continuation of their Catholic faith (as habitus would suggest,) this study shows that these converts retain dispositions that are consistent with their previous religious identity. However, there are limits to the theory of habitus when analyzing complex, patterns of behavior including religious conversion. Therefore, a theory of reflexive-identity formation is also considered. I argue that these Latina converts are breaking down traditional religious boundaries and, in doing so, they embody the complexity of a modern identity.

  • Molecular Dynamics of Shock Wave Interaction with Nanoscale Structured Materials

    Author:
    Ahmad AL-QANANWAH
    Year of Dissertation:
    2012
    Program:
    Engineering
    Advisor:
    Yiannis Andreopoulos
    Abstract:

    Typical theoretical treatments of shock wave interactions are based on a continuum approach, which cannot resolve the spatial variations in solids with nano-scale porous structure. Nano-structured materials have the potential to attenuate the strength of traveling shock waves because of their high surface-to-volume ratio. To investigate such interactions we have developed a molecular dynamics simulation model, based on Short Range Attractive interactions. A piston, modeled as a uni-directional repulsive force field translating at a prescribed velocity, impinges on a region of gas which is compressed to form a shock, which in turn is driven against an atomistic solid wall. Periodic boundary conditions are used in the directions orthogonal to the piston motion, and we have considered solids based on either embedded atom potentials (target structure) or tethered potential (rigid piston, holding wall). Velocity, temperature and stress fields are computed locally in both gas and solid regions, and displacements within the solid are interpreted in terms of its elastic constants. In this work we present results of the elastic behavior of solid structures subjected to shock wave impact and analysis of energy transport and absorption in porous materials. The results indicated that the presence of nano-porous material layers in front of a target wall reduced the stress magnitude detected inside and the energy deposited there by about 30 percent while, at the same time, its loading rate was decreased substantially

  • Making Conversation: The Poetics of Voice in Modernist Fiction

    Author:
    Elizabeth Alsop
    Year of Dissertation:
    2012
    Program:
    Comparative Literature
    Advisor:
    John Brenkman
    Abstract:

    This dissertation examines the function of dialogue within modernist fiction, and argues that it can be seen to assume a substantially expanded and diversified role in early twentieth-century narrative texts. While existing accounts of fictional speech stress its capacity to develop character or advance plot, I contend that modernist authors began using speech differently than it had historically been used in the novel: less for characterizing and plot-advancing purposes, than for rhetorical and poetic ones. My primary case studies include a cross-section of British and American modernist texts - including Henry James's The Ambassadors, Ernest Hemingway's The Sun Also Rises, James Joyce's "The Dead," Virginia Woolf's The Waves, and William Faulkner's The Sound and the Fury and Absalom, Absalom! - as well as examples from post-War Italian narrative, which reflect the influence of Anglophone modernism. Through close, comparative analyses of how fictional voice is deployed in these texts, and by drawing on a range of literary and narrative theory (by Mikhail Bakhtin, Franco Moretti, and Sharon Cameron among others) I demonstrate that these writers frequently "make" conversation less to express character, than to communicate ideas or affects that exceed character. In particular, I disclose the tendency for discourse within these fictional environments to belong to more than one speaker - or conversely, to none. By challenging the attributive logic used to make sense of represented speech, these texts encourage us to refocus our critical attention away from discrete utterances, and toward the larger system of utterances that emerges in a given work. In this way, I argue, modernist fiction seems to demand (and reward) a new mode of reading and interpreting fictional dialogue: one which takes into account how characters say, as well as what they say, and which treats dialogue's form as at least as rich a source of meaning as its content.

  • FACIAL EMOTIONAL EXPRESSION FOLLOWING VOICE TREATMENTS IN INDIVIDUALS WITH PARKINSON'S DISEASE

    Author:
    Karin Alterescu
    Year of Dissertation:
    2012
    Program:
    Psychology
    Advisor:
    Joan Borod
    Abstract:

    A growing body of work has documented impairments in emotional facial expression (i.e., masked facies) in individuals with Parkinson's disease (PD). These impairments negatively impact patients' social interactions and functioning in daily life. However, little attention has been given to remediating facial emotional expression deficits in PD. Preliminary research has demonstrated that the treatment of voice using the Lee Silverman Voice Treatment (LSVT®; Ramig et al., 1995) has beneficial effects on limited aspects of facial expression in PD (Spielman et al., 2003). The present study extends the literature by examining the effects of two voice treatments on facial expression in PD in a comprehensive way, including facial mobility (FM) and three aspects of facial emotional expressivity (i.e., frequency [EF], variability [EV] and intensity [EI]). Participants included 56 posers, individuals who produced emotional and non-emotional monologues, and 18 raters, individuals who rated posers' facial expressions from video-recorded monologues. Ratings were made on a 7-point Likert scale for the four aspects of facial expression. Raters were trained to criterion, and reliability was high for each emotional expression variable (Intraclass Correlation Coefficient range .85 to .90). The study included four poser groups: 3 PD groups whose posers were randomly assigned into an LSVT, Articulation Voice Treatment (ARTIC), or a no treatment control group, and a demographically matched healthy control group (NC). Findings revealed that PD male posers displayed impaired facial expression at baseline compared to NCs on all variables examined, although PD women did not differ from NCs for any aspect of facial expression. Treatment findings showed that patients who received LSVT were rated as having higher FM, EF, EV, and EI after treatment, four weeks later, than at baseline. This increase was not observed for the 3 other poser groups. It is speculated that LSVT improves facial expression because facial and vocal expression are emotional communication channels that exist within a larger network of emotional processing. Facial and vocal emotional expression are linked at several levels of neural organization: cortical, subcortical, and cranial nerve. The broader clinical implications of our findings are that masked facies can be remediated using LSVT.

  • Synthesis of Biologically Important C-glycosides from Simple C-glycosyl Alkenes

    Author:
    Ahmad Altiti
    Year of Dissertation:
    2014
    Program:
    Chemistry
    Advisor:
    David Mootoo
    Abstract:

    Abstract Synthesis of Biologically Important C-glycosides from Simple C-glycosyl Alkenes by Ahmad Altiti Adviser: Professor David Mootoo C-Glycosides are carbohydrate analogues in which the glycosidic oxygen is replaced with a methylene substituent. Because of their stability under acidic hydrolysis or enzymatic cleavage, they are widely used as mimetics of their parent O-glycosides in medicinal chemistry. This thesis describes the development of new synthetic methods for C-glycosides, which center on the use of readily available, simple C-allyl glycosides as precursors. C- glycosides of three structurally distinct and pharmacologically interesting carbohydrates, the immunostimulatory glycolipid C-KRN700, the insulin mimetic glycoinositol β-galactosamine-(1→4)-3-O-methyl-D-chiro-inositiol (INS-2), and α-mannose-(1→6)-D-myo-inositiol, a subunit of the cell wall in Mycobacterium tuberculosis, will be used as test cases for these methodologies. Chapter I and II α-Galactosylceramide (α-GalCer) also called KRN7000 is a potent stimulant of invariant natural killer T (iNKT) cells. The C-glycoside of KRN7000 shows higher activity than its parent O-glycoside against malaria and melanoma in mice models. The high activity of C-KRN7000 could be due to its hydrolytic stability or the way in which it interacts with receptors in the immunological pathway. New analogues of C-KRN7000 are needed to elucidate this picture. Two robust synthetic methodologies that can provide structurally diverse structures in the polar head region were developed. Chapter 1 describes the first approach, which entails: (i) the convergent union of relatively simple and readily accessible carbohydrate and lipid precursors to give a homoallylic alcohol, (ii) introduction of the amino group in the target via an iodocyclization reaction on derived homoallylic trichloroacetimidates and carboimidothioates. The cyclization reactions were evaluated for both E and Z alkene substrates. The E and Z trichloroacetimidates showed opposite facial selectivities, with the Z isomer providing the desired result for C-KRN7000. This stereochemical result is as expected for related electrophilic cyclizations. In contrast both E and Z carboimidothioates showed the same facial selectivity, in favor of the desired product. The iodo-carbamate products that were obtained from the reactions of the E and Z carboimidothioates were both processed to C-KRN7000 via established and straightforward deiodination and alcohol protecting group procedures. However, the elaboration of the iodo-oxazine products from the tricholoroacetimidate reactions was problematic. Chapter II describes the second method, which centers on the Lewis acid mediated crotylation reaction of a C-glycoside crotylstannane on a simple α-alkoxy aldehyde to give diastereomeric homoallylic products. These products can be transformed to different diastereomers of C-KRN7000, and homologated and reverse amide analogues thereof. The diasteroselectivity of the crotylation reaction was examined and found to vary with the Lewis acid or the protecting group on the aldehyde. The key step in the processing of the crotylation products to C-glycosides of C-KRN700 was a Curtius rearrangement on the acyl azide derived from the terminal alkene in the crotylation product. This chemistry was applied to C-KRN7000, its amide epimer, and an analogue of C-KRN7000 with a fluorine atom at the pseudoanomeric position. Chapter III As an extension to the crotylation chemistry in Chapter II, we developed a new approach to the synthesis of C-glycoinositols, which pivots on late stage construction of the inositol ring. The strategy uses easily accessed 3,4-dialkoxy-4-enals as aldehyde partners for C-linked crotyltins. A ring closing metathesis (RCM) on the crotylation product gives a C-linked dioxygenated cyclohexene that can be converted to a fully oxygenated C-glycoinositol by a dihydroxylation reaction. Different alkene functionalization reactions on the RCM product leads to inositol with different functional groups. Using different combinations of crotylstannane and aldehydes can further increase analogue diversity. For a given crotylstannane the diastereoselectivity of crotylation reaction was found to vary with choice of Lewis acid and the stereochemistry of the aldehyde partner. This methodology was applied to the C-glycosides of INS-2 and α-mannose-(1→6)-D-myo-inositiol. The results in Chapters II and II illustrate the attributes of the C-glycoside crotyltin methodology: (i) easy availability of the crotyltin and aldehyde precursors; (ii) the compatibility of the key segment coupling reaction with a variety of different functional groups; (iii) the synthetic versatility of the reaction products, which allows for a high throughput of complex and diverse glycomimetic libraries.

  • National Physiology: Literature, Medicine, and the Invention of the American Body, 1789-1860

    Author:
    Sari Altschuler
    Year of Dissertation:
    2012
    Program:
    English
    Advisor:
    David Reynolds
    Abstract:

    "National Physiology" investigates the intertwined discourses of literature and medicine in the proto-disciplinary early American world. It makes three interventions. First, in contrast to existing scholarship that has actively neglected it, I bring to light an important history of early American medicine. Second, I show how American writers produced medical models of their own. Literary figures did not simply reflect medicine in their texts, but used fiction to craft medical philosophies, which they believed directly promoted the health of the nation. Finally, I argue these histories were not separate, but intimately connected: doctors and writers worked together to craft an American body that was metonymically linked to the healthy nation. In mining the relationship between medicine and literature in the early republic, my project is the first to offer a genealogy of the Medical Humanities in America; it also suggests that by looking at this history, we will find promising new models for interdisciplinary scholarship. The writings of prominent doctors and writers who were friends, teachers, and colleagues in the early U.S. political and medical capital anchor this study. My dissertation traces the development of a "national physiology" that understood the body and nation always to be, in founding father Benjamin Rush's words "tremendous, oscillatory mass[es] of matter," systems defined by motion and flux. National physiology was based in the connected mechanisms of circulation and sympathy that were always simultaneously physiological, philosophical, and political. I demonstrate how American medical philosophy broke with European models and developed dynamic notions that offered non-hierarchical alternatives. There was an American school of medicine, and this school used literary forms as central rhetorical tools to promote health. Rather than be surprised by the prevalence of doctor-writers, I suggest such figures reveal the generic fluidity of early American discourse. Tracing a literary history from Charles Brockden Brown to Weir Mitchell, my project illuminates the medical and political work of early American fiction. Turning to periods when disciplinary boundaries were not fully formed offers exciting possibilities both for future Medical Humanities, with its investments in unraveling disciplinary distinctions, and for providing insight into (inter)disciplinary work more broadly.

  • The developmental trajectory of contour integration in autism spectrum disorders

    Author:
    Ted Altschuler
    Year of Dissertation:
    2014
    Program:
    Psychology
    Advisor:
    John Foxe
    Abstract:

    Sensory input is inherently ambiguous and complex, so perception is believed to be achieved by combining incoming sensory information with prior knowledge. One model envisions the grouping of sensory features (the local dimensions of stimuli) to be the outcome of a predictive process relying on prior experience (the global dimension of stimuli) to disambiguate possible configurations those elements could take. Contour integration, the linking of aligned but separate visual elements, is one example of perceptual grouping. Kanizsa-type illusory contour (IC) stimuli have been widely used to explore contour integration processing. Consisting of two conditions which differ only in the alignment of their inducing elements, one induces the experience of a shape apparently defined by a contour and the second does not. This contour has no counterpart in actual visual space - it is the visual system that fills-in the gap between inducing elements. A well-tested electrophysiological index associated with this process (the IC-effect) provided us with a metric of the visual system's contribution to contour integration. Using visually evoked potentials (VEP), we began by probing the limits of this metric to three manipulations of contour parameters previously shown to impact subjective experience of illusion strength. Next we detailed the developmental trajectory of contour integration processes over childhood and adolescence. Finally, because persons with autism spectrum disorders (ASDs) have demonstrated an altered balance of global and local processing, we hypothesized that contour integration may be atypical. We compared typical development to development in persons with ASDs to reveal possible mechanisms underlying this processing difference. Our manipulations resulted in no differences in the strength of the IC-effect in adults or children in either group. However, timing of the IC-effect was delayed in two instances: 1) peak latency was delayed by increasing the extent of contour to be filled-in relative to overall IC size and 2) onset latency was delayed in participants with ASDs relative to their neurotypical counterparts.