George Eliot's fiction is filled with mentoring relationships which generally consist of a wise male mentor and a foolish, egotistic female mentee. The mentoring narratives relate the conversion of the mentee from narcissism to selfless devotion to the community. By retaining the Christian value of self-abnegation and the Christian tendency to devalue nature, Eliot, nominally a secular humanist who abandoned Christianity, reveals herself still to be a covert Christian. In Chapter 1 I introduce the moral mentoring theme and provide background material. Chapter 2 consists of an examination of Felix Holt, which clearly displays Eliot's crucial dichotomy: the moral is superior to the natural. In Chapter 3 I present a Freudian analysis of Gwendolen Harleth, the mentee most fully developed. In Chapter 4 I examine two early mentees, who differ from later mentees primarily in that they are not egotists and can be treated with sympathy. Chapter 5 covers three gender-modified relationships. These relationships show contrasting views of nature: in the Dinah Morris-Hetty Sorrel narrative, like most of the others, Eliot privileges the transcendence of nature. The other two, Mary Garth-Fred Vincy and Dolly Winthrop-Silas Marner, are exceptions as Eliot portrays in them a Wordsworthian reconciliation with nature. In Chapter 6 I focus on Maggie Tulliver, a mentee with three failed mentors and two antimentors. Maggie chooses regression over growth as symbolized by her drowning death in her brother's arms. In Chapter 7 I examine Middlemarch, whose lack of a successful standard mentoring relationship contributes to its dark vision. Chapter 8 contains a reading of Romola which interprets Romola, the only mentee whose story takes place outside nineteenth-century England, as a feminist fantasy for Eliot. Chapter 9 concludes the discussion, focusing primarily on the question why the mentoring theme was so compelling for George Eliot. In the Appendix I examine the relationships in Eliot's life in which she herself was a mentee or a mentor.

Foi investigado o curso temporal da orientação da atenção numa tarefa de orientação encoberta adaptada para ratos. A tarefa envolveu a avaliação do efeito de pistas auditivas centrais e periféricas, preditivas ou não preditivas, sob o tempo de reação a alvos visuais apresentados à direita ou à esquerda do campo visual. Foram utilizados tempos entre pista e alvo (SOAs) entre 50 a 1200 ms. Pistas centrais consistiram em bipes de 5 ou 8 kHz reproduzidos em ambos ouvidos concomitantemente. Neste caso a frequência do bipe indicava o lado para o qual a atenção deveria ser orientada. Pistas periféricas constituíram-se de bipes de 5 ou 8 kHz, apresentados individualmente no ouvido esquerdo ou direito. Neste caso o lado da apresentação do estímulo indicava a direção para a qual o animal deveria orientar a atenção. Esses estímulos foram apresentados de forma preditiva - em 80% das tentativas as pistas indicavam corretamente a localização do alvo (tentativas válidas) e em 20% o indicavam incorretamente (tentativas inválidas) - ou não preditiva - 50% de tentativas válidas e 20% de tentativas inválidas - a depender do grupo. Vinte e quatro ratos Wistar machos, com 3 meses no início dos experimentos, divididos em quatro grupos experimentais independentes - Central Preditivo (CP), Central Não Preditivo (CNP), Periférico Preditivo (PP) e Periférico Não Preditivo (PNP) - foram empregados. Os resultados mostram que animais dos grupos preditivos (CP e PP) respondem mais rapidamente e de forma mais precisa em tentativas válidas do que em tentativas inválidas, ao passo que animais em grupos não preditivos (CNP e PNP) respondem da mesma maneira em tentativas válidas ou inválidas. Esses resultados indicam de estes animais foram capazes de orientar a atenção de forma endógena, de forma análoga a seres humanos, sugerindo que ratos podem ser empregados amplamente como modelo animal na avaliação das orientações endógena e exógena da atenção / Orienting of visual attention was investigated in rats using a 3-hole nose-poke task analogous to the covert attention task for humans. The task involved evaluation of the effects of either central or peripheral auditory cues, presented either predictively or non-predictively on reaction times to a visual target presented either to the left or to the right sides of the visual field; stimuli-onset asynchronies (SOAs) varied from 50 to 1200 ms. Central cues were either 5 or 8 KHz auditory stimuli, released on both ears concomitantly. In this case, the frequency indicated the side to which attention should be oriented to. Peripheral cues were 5 and 8 KHz auditory stimuli presented individually either to the left or to the right ears. In this case, the sound source indicated to which side attention should be oriented to. These stimuli were presented either predictively - 80% of cues predicted the target\'s location correctly (valid trials) and 20% of cues predicted it incorrectly (invalid trials) - or non-predictively - 50% of valid trials and 50% invalid trials - depending on the group. Twenty-four male Wistar rats, 3 month-old at the beginning of the experiment, divided in four independent groups - Central Predictive (CP), Central Non-Predictive (CNP), Peripheral Predictive (PP) and Peripheral Non-Predictive (PNP) - were employed. Animals on predictive groups (CP and PP) showed faster and more accurate responses on valid trials than on invalid trials, while non-predictive groups (CNP and PNP) didn\'t show any differences on reaction times and accuracy in valid as compared to invalid trials. These results indicate that rats do orient attention endogenously, analogously to humans. This suggests that these animals may be employed as animal model to the study of endogenous and exogenous orienting of attention

Children who receive cochlear implants (CIs) demonstrate considerable variability in speech sound production. Investigations focused on speech sound development in children with CIs have shown initial accelerated growth, followed by a plateau where consonant order of acquisition generally mirrors that of NH children, but is slower (Blamey, Barry, & Pascale, 2001; Serry & Blamey, 1999; Spencer & Guo, 2013). A notable exception to this pattern, /t/, has been shown to be acquired later-than normal in several investigations (Blamey et al., 2001; Chin, 2003; Ertmer, True Kloiber, Jongmin, Connell Kirleis, & Bradford, 2012). The primary purpose of this investigation was to 1) examine the accuracy of /t/ productions in children with CIs and 2) quantify subtle phonetic differences in correctly produced consonants and substituted consonants (or covert contrast). Two groups of children who had participated in a larger study that examined the influence of speech production abilities on speech perception scores of children with CI (Gonzalez, 2013) provided the speech stimuli for this investigation. The experimental group included nine congenitally deafened children with CI, ranging in age from 2;11 to 6;4 years (M=4;9), who were implanted by 3 years of age, had at least 12 months of device experience, and only used an oral mode of communication. These children were matched to typically developing children by articulation ability and gender. Recordings of the verbal responses on the OlimSpac were obtained from the Gonzalez (2013) study. Thirty-three graduate students in speech-language pathology rated the phonetic accuracy of /t/ and the phonemes that were found to be most often substituted for it, /d/ and /ʧ/ on a 7 point equal-appearing interval scale. A three-way ANOVA was performed to determine the differences in perceived consonant accuracy across: group, transcription category, and phoneme substitution. The significant interaction between group and transcription category was of particular interest. Results indicated that children with CIs did not show an unusually delayed development of /t/. When a confusion matrix was generated to depict overall OlimSpac performance, the NH group was noted to outperform the CI group across all phonemes. This would suggest that /t/ was not uniquely poorer in the CI group, but instead these children evidenced poorer phoneme accuracy in general. Finally, group differences also were apparent in substitutions of [t] for target /d/ and /ʧ/ productions (i.e., covert contrast). The clinical applications are described.

Current models of visual spatial attention are based on the extent to which attention can be allocated in 2-dimensional displays. The distribution of attention in 3-dimensional space has received little consideration. A series of experiments were devised to explore the apparent inconsistencies in the literature pertaining to the allocation of spatial attention in the third dimension. A review of the literature attributed these inconsistencies to differences and limitations in the various methodologies employed, in addition to the use of differing attentional paradigms. An initial aim of this thesis was to develop a highly controlled novel adaptation of the conventional robust covert orienting of visual attention task (COVAT) in depth defined by either binocular (stereoscopic) or monocular cues. The results indicated that attentional selection in the COVAT is not allocated within a 3-dimensional representation of space. Consequently, an alternative measure of spatial attention in depth, the overlay interference task, was successfully validated in a different stereoscopic depth environment and then manipulated to further examine the allocation of attention in depth. Findings from the overlay interference experiments indicated that attentional selection is based on a representation that includes depth information, but only when an additional feature can aid 3D selection. Collectively, the results suggest a dissociation between two paradigms that are both purported to be measures of spatial attention. There appears to be a further dissociation between 2-dimensional and 3-dimensional attentional selection in both paradigms for different reasons. These behavioural results, combined with recent electrophysiological evidence suggest that the temporal constraints of the 3D COVAT paradigm result in early selection based predominantly on retinotopic spatial coordinates prior to the complete construction of a 3-dimensional representation. Task requirements of the 3D overlay interference paradigm, on the other hand, while not being restricted by temporal constraints, demand that attentional selection occurs later, after the construction of a 3-dimensional representation, but only with the guidance of a secondary feature. Regardless of whether attentional selection occurs early or late, however, some component of selection appears to be based on viewer-centred spatial coordinates.

Covert communication refers to the process of communicating data through a channel that is neither designed, nor intended to transfer information. Traditionally, covert channels are considered as security threats in computer systems and a great deal of attention has been given to countermeasures for covert communication schemes. The evolution of computer networks led the communication community to revisit the concept of covert communication not only as a security threat but also as an alternative way of providing security and privacy to communication networks. In fact, the heterogeneous structure of computer networks and the diversity of communication protocols provide an appealing setting for covert channels. This dissertation is an exploration on a novel design methodology for undetectable and robust covert channels in communication networks. Our new design methodology is based on the concept of behavioral mimicry in computer systems. The objective is to design a covert transmitter that has enough degrees of freedom to behave like an ordinary transmitter and react normally to unpredictable network events, yet it has the ability to modulate a covert message over its behavioral fingerprints in the network. To this end, we argue that the inherent randomness in communication protocols and network environments is the key in finding the proper medium for network covert channels. We present a few examples on how random behaviors in communication protocols lead to discovery of suitable shared resources for covert channels. The proposed design methodology is tested on two new covert communication schemes, one is designed for wireless networks and the other one is optimized for public communication networks (e.g., Internet). Each design is accompanied by a comprehensive analysis from undetectability, achievable covert rate and reliability perspectives. In particular, we introduced turbo covert channels, a family of extremely robust model-based timing covert channels that achieve provable polynomial undetectability in public communication networks. This means that the covert channel is undetectable against any polynomial-time statistical test that analyzes samples of the covert traffic and the legitimate traffic of the network. Target applications for the proposed covert communication schemes are discussed including detailed practical scenarios in which the proposed channels can be implemented.

We propose a simple, passive and deployable approach for fingerprinting traffic on the wired side as a solution for three critical stealth attacks in wireless networks. We focus on extracting traces of the 802.11 medium access control (MAC) protocol from the temporal arrival patterns of incoming traffic streams as seen on the wired side, to identify attacker behavior. Attacks addressed include unauthorized access points, selfish behavior at the MAC layer and MAC layer covert timing channels. We employ the Bayesian binning technique as a means of classifying between delay distributions. The scheme requires no change to the 802.11 nodes or protocol, exhibits minimal computational overhead and offers a single point of discovery. We evaluate our model using experiments and simulations.

We present a covert side channel that uses the 802.11 MAC rate switching protocol. The covert channel provides a general method to hide communications in an 802.11 LAN. The technique uses a one-time password algorithm to ensure high-entropy randomness of the covert messages. We investigate how the covert side channel affects node throughput in mobile and non-mobile scenarios. We also investigate the covertness of the covert side channel using standardized entropy. The results show that the performance impact is minimal and increases slightly as the covert channel bandwidth increases. We further show that the channel has 100% accuracy with minimal impact on rate switching entropy. Finally, we present two applications for the covert channel: covert authentication and covert WiFi botnets.

Text messaging is a new form of writing, brought about by technological development in the last couple of decades. Mobile phone usage has increased rapidly worldwide and texting is now part of many people's everyday communcation. A large number of users send or receive texts which include some abbreviations and shortenings, commonly referred to as textspeak. This novel linguistic phenomenon is perceived by some with indifference and by others with aggravation. The following study examines attitudes towards this linguistic change from a gender and age perspective. The comparison between two groups show that the most conservative and least positive to change are young women. The analysis and discussion around this focuses on power, prestige and patterns.

A covert communications network (CCN) is a connected, overlay peer-to-peer network used to support communications within a group in which the survival of the group depends on the confidentiality and anonymity of communications, on concealment of participation in the network to both other members of the group and external eavesdroppers, and finally on resilience against disconnection. In this dissertation, we describe the challenges and requirements for such a system. We consider the topologies of resilient covert communications networks that: (1) minimize the impact on the network in the event of a subverted node; and (2) maximize the connectivity of the survivor network with the removal of the subverted node and its closed neighborhood. We analyze the properties of resilient covert networks, propose measurements for determining the suitability of a topology for use in a covert communication network, and determine the properties of an optimal covert network topology. We analyze multiple topologies and identify two constructions that are capable of generating optimal topologies. We then extend these constructions to produce near-optimal topologies that can “grow” as new nodes join the network. We also address protocols for membership management and routing. Finally, we describe the architecture of a prototype system for instantiating a CCN.

Covert communication refers to the process of communicating data through a channel that is neither designed, nor intended to transfer information. Traditionally, covert channels are considered as security threats in computer systems and a great deal of attention has been given to countermeasures for covert communication schemes. The evolution of computer networks led the communication community to revisit the concept of covert communication not only as a security threat but also as an alternative way of providing security and privacy to communication networks. In fact, the heterogeneous structure of computer networks and the diversity of communication protocols provide an appealing setting for covert channels. This dissertation is an exploration on a novel design methodology for undetectable and robust covert channels in communication networks. Our new design methodology is based on the concept of behavioral mimicry in computer systems. The objective is to design a covert transmitter that has enough degrees of freedom to behave like an ordinary transmitter and react normally to unpredictable network events, yet it has the ability to modulate a covert message over its behavioral fingerprints in the network. To this end, we argue that the inherent randomness in communication protocols and network environments is the key in finding the proper medium for network covert channels. We present a few examples on how random behaviors in communication protocols lead to discovery of suitable shared resources for covert channels. The proposed design methodology is tested on two new covert communication schemes, one is designed for wireless networks and the other one is optimized for public communication networks (e.g., Internet). Each design is accompanied by a comprehensive analysis from undetectability, achievable covert rate and reliability perspectives. In particular, we introduced turbo covert channels, a family of extremely robust model-based timing covert channels that achieve provable polynomial undetectability in public communication networks. This means that the covert channel is undetectable against any polynomial-time statistical test that analyzes samples of the covert traffic and the legitimate traffic of the network. Target applications for the proposed covert communication schemes are discussed including detailed practical scenarios in which the proposed channels can be implemented.