Though the portrayal of African American mothers in cinema has been diverse, it has too often misrepresented the lived experiences of mothers and has contributed to negative stereotypes about African American motherhood. Existing analyses have not provided an Afrocentric examination of these specific depictions and their broader societal impact. This dissertation aims to address this gap by investigating the representation of African American mothers in film. Grounded in Afrocentric research, scholarship, and theories, the project seeks to develop a framework centered on African Matriarchy and the experiences of African American mothers. This paper introduces the Taylor Test, a comprehensive rubric informed by the Afrocentric paradigm, film theories, and feminist and womanist theories. Through the application of the Taylor Test, a content analysis was conducted on select films by renowned African American filmmaker Spike Lee, including Crooklyn (1994), She Hate Me (2004), and Chi-Raq (2015). The findings of this research contribute to the development of an Afrocentric film analysis framework, demonstrating the effectiveness of the Taylor Test. Additionally, it offers insights into fostering a "liberated maternal" identity by leveraging media, particularly film, to reshape narratives surrounding African American motherhood. / Africology and African American Studies

Abstract : Electroencephalography (EEG) is a non-invasive neuroimaging modality that was first introduced over 80 years ago. Surface EEG does not directly measure neuronal activity, and it is often assumed that it cannot provide indications on the underlying neuronal firing. However, recent studies based on invasive measurements in monkeys have shown that the coupling between two EEG frequency bands, namely the Gamma (25-45 Hz) and Delta (2-4 Hz) bands, is a good predictor of underlying mass-spiking activity. Specifically, when the Delta signal is in its trough and Gamma power is high, the probability of mass- firing of neurons is large. Here, we investigate this property in healthy human EEG acquired during resting-state. Using the interaction between Delta phase and Gamma power, we derived a modeled spike signal (MSS) from the recorded EEG. We found the power spectrum density (PSD) pattern of the MSS to be similar to that observed in animal studies. Specifically, between 1-10 Hz that the PSD deviates from a 1/[florin] trend and exhibits a small peak at about 2-3Hz. In addition, an inter-hemispheric correlation was found between the MSS of the different pairs of electrode in opposite hemispheres. Our results open the possibility of studying underlying neuronal output with non-invasive EEG. // Résumé : L'électroencéphalographie (EEG) est une modalité de neuro-imagerie non invasive qui a été introduite il y a plus de 80 ans. L’EEG de surface ne mesure pas directement l’activité neuronale et il est généralement supposé qu’elle ne donne pas d’indications sur la décharge neuronale sous-jacente. Cependant des études récentes ont montré à l’aide de mesures invasives que le couplage entre deux bandes de fréquences EEG, soit les bandes Gamma (25-45 Hz) et Delta (2-4 Hz), est un bon indicateur de l’activité neuronale de masse sous-jacente chez les singes. Plus précisément, lorsque le signal Delta est dans un creux (phase de π) et que la puissance dans le signal Gamma est élevée, la probabilité de décharge de masse des neurones est grande. Cette propriété est ici étudiée dans les signaux EEG d’humains sains en état de repos. En se basant sur l'interaction entre la phase du signal Delta et la puissance du signal Gamma, nous avons dérivé un modèle de l’activité neuronale de masse sous-jacente (modeled spike signal-MSS) obtenu à partir du signal l'EEG enregistrée. On trouve que la densité spectrale de puissance (power spectal density-PSD) du MSS est similaire à celle observée dans les études animales. Plus spécifiquement, entre 1-10 Hz la PSD s’écarte d’une tendance en 1 / [florin] et présente un pic de faible amplitude à environ 2-3Hz. En outre, une corrélation inter-hémisphérique a été observée entre les MSS de différentes paires d'électrodes positionnées sur les hémisphères opposés. Nos résultats ouvrent la possibilité d'étudier l’activité neuronale sous-jacente par EEG non-invasive.

Online monitoring applications requiring advanced pattern recognition capabilities implemented in resource-constrained wireless sensor systems are challenging to construct using standard digital computers. An interesting alternative solution is to use a low-power neuromorphic processor like the ROLLS, with subthreshold mixed analog/digital circuits and online learning capabilities that approximate the behavior of real neurons and synapses. This requires that the monitoring algorithm is implemented with spiking neural networks, which in principle are efficient computational models for tasks such as pattern recognition. In this work, I investigate how spiking neural networks can be used as a pre-processing and feature learning system in a condition monitoring application where the vibration of a machine with healthy and faulty rolling-element bearings is considered. Pattern recognition with spiking neural networks is investigated using simulations with Brian -- a Python-based open source toolbox -- and an implementation is developed for the ROLLS neuromorphic processor. I analyze the learned feature-response properties of individual neurons. When pre-processing the input signals with a neuromorphic cochlea known as the AER-EAR system, the ROLLS chip learns to classify the resulting spike patterns with a training error of less than 1 %, at a combined power consumption of approximately 30 mW. Thus, the neuromorphic hardware system can potentially be realized in a resource-constrained wireless sensor for online monitoring applications.However, further work is needed for testing and cross validation of the feature learning and pattern recognition networks.i

A Bronquite Infecciosa das Aves (BIG) é uma das doenças respiratórias aviárias de maior impacto na avicultura mundial. No Brasil, as estirpes BR-I (GI-11) e Massachusetts (GI-1) são as mais prevalentes nos planteis avícolas. O presente estudo teve como objetivos desenvolver reações de semi-nested PCR para o diagnóstico das estirpes BR-I e Mass, em amostras brasileiras obtidas durante o período de 2016 e 2017. Foram desenvolvidas duas reações de semi-nested PCR tendo como alvo a subunidade 1 do gene S, específicas para as estirpes BR-I e Mass. O limiar de detecção foi de 104 cópias de DNA/µL nas duas reações (3,76fg/µL na reação exclusiva de BR-I; e 5,58fg/µL e 5,57fg/µL na reação duplex de BR-I e Mass, respectivamente). Posteriormente, foram avaliados 572 pools de órgãos procedentes das 5 regiões do Brasil. Dentre estas amostras, 62,24% foram positivas para Coronavírus, sendo o alvo desta reação a região 3UTR. A reação de semi-nested PCR específica detectou a estirpe BR-I em 84,83% das amostras positivas para Coronavírus. A reação de semi-nested PCR duplex detectou 65,44% das amostras positivas para a estirpe BR-I; 7,35% positivas para a estirpe Mass e co-infecção da estirpe BR-I com Mass em 17,65% das amostras. Após a análise dos controles positivos (vacinas Mass e BR-I) no BLASTn, do resultado do sequenciamento dos produtos de PCR, da análise filogenética, da similaridade de nucleotídeos e a dedução em aminoácidos, foi confirmado o agrupamento esperado das sequências detectadas pelas reações PCR dirigidas para a estirpe BR-I ou Mass. Estes resultados confirmaram a presença predominante da estirpe BR-I, e em menor número, da estirpe Mass nos planteis avícolas do Brasil. As reações desenvolvidas no presente estudo serão valiosas no diagnóstico e na monitoria da doença. / Avian Infectious Bronchitis (IB) is one of the avian respiratory diseases with the greatest impact on poultry farming worldwide. In Brazil, strains BR-I (GI-11) and Massachusetts (GI-1) are the most prevalent in poultry flocks. The present study aimed to develop semi-nested PCR reactions for the diagnosis of IBV BR-I and Mass strains, in Brazilian samples obtained during the period of 2016 and 2017. Two semi-nested PCR reactions targeting the 1 subunit of the S gene were developed, specific for BR-I and Mass strains. The detection threshold was 104 copies of DNA/µL in both reactions (3,76fg/µL in the exclusive BR-I reaction; and 5,58fg/µL and 5,57fg/µL in the duplex reaction of BR-I and Mass, respectively). Subsequently, 572 organ pools from the 5 regions of Brazil were evaluated. Among these samples, 62,24% were positive for Coronavirus, being the target of this reaction the 3UTR region. The specific semi-nested PCR reaction detected the BR-I strain in 84,83% of the Coronavirus positive samples. The duplex semi-nested PCR reaction detected 65,44% of the samples positive for the BR-I strain, 7,35% positive for Mass strain, and co-infection of the BR-I and Mass strain in 17,65% of the samples. After the analysis of the positive controls (Mass and BR-I vaccines) in BLASTn, the result of the sequencing of the PCR products, phylogenetic analysis, nucleotide similarity and amino acid deduction, was confirmed the expected clustering of the sequences detected by the PCR reactions directed to BR-I and Mass strains. These results confirm the predominant presence of the BR-I strain, and to a lesser extent, the Mass strain in Brazilian poultry flocks. The reactions developed in the present study will be valuabe in the diagnosis and monitoring of the disease.

Este trabalho descreve as pesquisas e desenvolvimentos em instrumentação eletrônica computacional, realizados para viabilizar experiências na área de neurobiofísica, tendo como objetivos principais a geração de estímulos visuais para invertebrados e a captação de sinais eletrofisiológicos gerados por sistemas biológicos sensoriais submetidos a estímulos. Trata-se de um conjunto de equipamentos que, operando de maneira integrada, são capazes de fornecer e sincronizar estímulos, realizar a aquisição dos dados de sinais neurais a serem utilizados para controle e análise em experiências in vivo\" nos estudos da visão de invertebrados no Laboratório de Neurobiofísica - DipteraLab do IFSC. A integração desta instrumentação eletrônica visa facilitar a sua utilização durante os experimentos, permitindo o acompanhamento das aquisições de dados neurais, viabilizando a realização de experimentos com alterações dos estímulos através de realimentação em tempo real. / This work describes the research and development of computational instrumentation to be used in experimental neurobiophysics. The developed electronic modules operate in an integrated manner and are used to generate visual stimuli for invertebrates and capture electrophysiological signals generated by biological systems subjected to sensory stimuli. They are able to provide synchronized stimuli and perform data acquisition of neural signals events to be used for control and analysis of vision experiments with invertebrates at the Laboratory of Neurobiophysics Dipteralab Laboratory, at the IFSC. The integration of electronic instrumentation facilitate its use during experiments allowing, through its monitoring capabilities of the neural data acquisition, the realization of experiments with real time stimuli changes through feedback. The possibility to perform pre-analyses of neural responses in behavioral closed loop experiments is also implemented.

Das Neuron ist das zentrale Element in der Informationsverarbeitung im Nervensystem. In dieser Arbeit werden verschiedene Aspekte der Spikegenerierung sowohl theoretisch als auch experimentell untersucht. Phasen-Rotatoren verschiedener Komplexität werden zur Vorhersage von Spikezeitpunkten vorgestellt. Die Kennlinie eines Neurons wird dabei als wichtiger Parameter für diese Modelle verwendet, damit diese leicht auf echte Neurone anwendbar sind. Die Phasenantwortkurve als ein zweiter wichtiger Aspekt der Spikedynamik wird zur Erweiterung der Modelle verwendet. Solange ein Neuron in seinem überschwelligen Bereich gereizt wird, erweisen sich die Phasenrotatoren als gute Beschreibung des Spikeverhaltens. Es wird jedoch gezeigt, daß bei einer Stimulierung mit Strömen, die um die Schwelle des Neurons herum fluktuieren, diese Modelle, genauso wie alle anderen eindimensionalen Modelle einschließlich des Intergrate-and-fire Neurons, versagen. Feuerraten Adaptation kann in vielen Neuronen beobachtet werden. Es wird ein allgemeines phänomenologisches Modell für die Feuerrate adaptierender Neurone aus den Eigenschaften verschiedene Ionenströme, die Adaptation verursachen, hergeleitet. Dieses Modell ist durch die Kennlinien und einer Adaptations-Zeitkonstanten vollständig definiert. Mit Hilfe des Modells können die Eigenschaften der Adaptation als Hochpassfilter quantifiziert werden. Weiterhin wird die Rolle der Adaptation bei der Unterdrückung von Hintergrundrauschen diskutiert. Sowohl die Phasenrotatoren als auch das Adaptationsmodell werden an auditorischen Rezeptorzellen der Wanderheuschrecke und dem AN1, ein primäres auditorisches Interneuron der Grille {Teleogryllus oceanicus}, getestet. In beiden Fällen stimmen die Modelle gut mit den experimentelle Daten überein. Es wird mit Hilfe der Modelle gezeigt, daß Adaptation in den Rezeptorzellen durch Ionenströme des Spikegenerators verursacht wird, während in dem Interneuron der Eingang schon adaptatiert. Zusätzlich wird der Einfluß der Feuerraten-Adaptation auf die Gesangserkennung analysiert. / The single neuron is the basic element of information processing in nervous systems. In this thesis several properties of the dynamics of the generation of spikes are investigated theoretically as well as experimentally. Phase oscillators of different complexity are introduced as models to predict the timing of spikes. The neuron's intensity-response curve is used as a basic parameter in these models to make them easily applicable to real neurons. As a second important aspect of the spiking dynamics, the neuron's phase-resetting curve is used to extend the models. The phase oscillators turn out to be a good approximation of the spiking behavior of a neuron as long as it is stimulated in its super-threshold regime. However, it is shown by comparison with conductance-based models that these models, as well as all other one-dimensional models including the common integrate-and-fire model, fail, if the neuron is stimulated with currents fluctuating around its threshold. Spike-frequency adaptation is a common feature of many neurons. For various ionic currents, as a possible reason for adaptation, a general phenomenological model for the firing rate of adapting neurons is derived from their biophysical properties. This model is defined by the neuron's intensity-response curves and an adaptation time-constant. By means of this model the high-pass properties of spike-frequency adaptation can be quantified. Also the role of adaptation in supression of background noise is discussed. Both the phase oscillators and the adaptation-model are tested on auditory receptor neurons of locusts and the AN1, a primary auditory interneuron of the cricket {Teleogryllus oceanicus}. In both cases the models are in good agreement with the experimental data. By means of the models it is shown that adaptation in the receptor neurons is caused by ionic currents of the spike generator while in the interneuron it is the input which is already adapting. In addition, the influence of spike-frequency adaptation on the recognition of courtship songs is analysed.

Die Eigenschaften einzelner Nervenzellen sind von grundlegender Bedeutung für die Verarbeitung von Informationen im Nervensystem. Neuronen antworten auf Eingangsreize durch Veränderung der elektrischen Spannung über die Zellmembran. Die Spannungsantwort wird dabei durch die Dynamik der Ionenkanäle in der Zellmembran bestimmt. In dieser Arbeit untersuche ich anhand von leitfähigkeits-basierten Modellneuronen den Einfluss von Ionenkanälen auf zwei Aspekte der Signalverarbeitung: die Frequenz-Selektivität sowie die Zuverlässigkeit und zeitliche Präzision von Aktionspotentialen. Zunächst werden die zell-intrinsischen Mechanismen identifiziert, welche the Frequenz-Selektivität und die Zuverlässigkeit bestimmen. Weiterhin wird untersucht, wie Ionenkanäle diese Mechanismen modulieren können, um die Integration von Signalen zu optimieren. Im ersten Teil der Arbeit wird demonstriert, dass der Mechanismus der unterschwelligen Resonanz, so wie er bisher für periodische Signale beobachtet wurde, auch auf nicht-periodische Signale anwendbar ist und sich ebenfalls in den Feuerraten niederschlägt. Im zweiten Teil wird gezeigt, dass zeitliche Präzision und Zuverlässigkeit von Aktionspotentialen mit der Stimulusfrequenz variieren und dass, in Abhängigkeit davon, ob das Stimulusmittel über- oder unterhalb der Feuerschwelle liegt, zwei Stimulusregime unterschieden werden müssen. In beiden Regimen existiert eine bevorzugte Stimulusfrequenz, welche durch die Gesamtleitfähigkeit und die Dynamik spezifischer Ionenkanäle moduliert werden kann. Im dritten Teil wird belegt, dass Ionenkanäle die Zuverlässigkeit auch direkt über eine Veränderung der Sensitivität einer Zelle gegenüber neuronalem Rauschen bestimmen können. Die Ergebnisse der Arbeit lassen auf eine wichtige Rolle der dynamischen Regulierung der Ionenkanäle für die Frequenz-Selektivität und die zeitliche Präzision und Zuverlässigkeit der Spannungsantworten schließen. / The properties of individual neurons are of fundamental importance for the processing of information in the nervous system. The generation of voltage responses to input signals, in particular, depends on the properties of ion channels in the cell membrane. Within this thesis, I employ conductance-based model neurons to investigate the effect of ionic conductances and their dynamics on two aspects of signal processing: frequency-selectivity and temporal precision and reliability of spikes. First, the cell-intrinsic mechanisms that determine frequency selectivity and spike timing reliability are identified on the basis of conductance-based model neurons. Second, it is analyzed how ionic conductances can serve to modulate these mechanisms in order to optimize signal integration. In the first part, the frequency selectivity of subthreshold response amplitudes previously observed for periodic stimuli is proven to extend to nonperiodic stimuli and to translate into firing rates. In the second part, it is demonstrated that spike timing reliability is frequency-selective and that two different stimulus regimes have to be distinguished, depending on whether the stimulus mean is below or above threshold. In both cases, resonance effects determine the most reliable stimulus frequency. It is shown that this frequency preference can be modulated by the peak conductance and dynamics of specific ion channels. In the third part, evidence is provided that ionic conductances determine spike timing reliability beyond changes in the preferred frequency. It is demonstrated that ionic conductances also exert a direct influence on the sensitivity of the timing of spikes to neuronal noise. The findings suggest an important role for dynamic neuromodulation of ion channels with regard to frequency selectivity and spike timing reliability.

Coronavírus bovino (BCoV) é o agente causador de doença, tanto entérica como respiratória em bovinos, mas até agora existem controvérsias sobre a relação genealógica entre as amostras de BCoV em diferentes tecidos. Neste estudo, amostras de fezes e secreções nasais de 14 vacas de um mesmo rebanho apresentando simultaneamente disenteria epizoótica e doença respiratória foram estudados quanto a presença de BCoV. As amostras virais detectadas tiveram tanto o gene de espícula (S) como o gene hemaglutinina-esterase (HE) parcialmente sequenciados. Para o gene HE, foram obtidas 12 sequências de secreções nasais e 12 de amostras de fezes e para o gene S, foram obtidas 14 sequências de secreções nasais e 12 de amostras de fezes, com 100% de identidade nucleotídica para cada gene para as amostras deste estudo. Estes resultados apresentam algumas divergências com estudos anteriores os quais relatam que linhagens diferentes de BCoV podem ser esperados em casos de disenteria e doença respiratória em vacas, pois linhagens com sequências idênticas dos genes S e HE podem não mostrar diferenças em relação tropismo pelos diferentes tecidos. Sequências completas de duas amostras brasileiras de BCoV mostram que o já descrito padrão filogeográfico baseado no sequenciamento do gene S parcial foi mantido, foram encontradas substituições de aminoácidos específicos. / Bovine coronavirus (BCoV) is the causative agent of both enteric and respiratory disease in cattle, but hitherto there were some controversy on the genealogic relationship amongst strains from these different tissues. In this study, samples of feces and nasal secretions of 14 cows from a same herd simultaneously presenting epizootic dysentery and respiratory disease were screened for BCoV and the strains detected had both the spike (S) and hemagglutinin-esterase (HE) genes partially sequenced. For HE gene, 12 sequences from nasal secretions and 12 from fecal samples were obtained and for S gene, 14 sequences from nasal secretions and 12 from fecal samples were obtained, with 100% nucleotide identities for each gene for the strains of this study. These results have some disagreements with previous reports which try to put forward that divergent BCoV strain should be expected in cases of dysentery and respiratory disease in cows, showing that strain with identical S and HE sequences might show no differences in tropisms. Complete S gene sequences of two Brazilian BCoV strains show that the already described phylogeographic pattern based on partial S gene is sustained, though specific amino acids subtitutions are found.

Music video is an intriguing genre of television due to the fact that music drives the images and ideas found in numerous and varied examples of the form. Pre-recorded pieces of pop music are visually written upon in a palimpsest manner, resulting in an immediate and entertaining synchronisation of sound and vision. Ever since the popularity of MTV in the early 1980s, music video has been a persistent fixture in academic discussion, most notably in the work of writers like E. Ann Kaplan, Simon Frith and Andrew Goodwin. What has been of major interest to such cultural scholars is the fact that music video was designed as a promotional tool in their inception, supporting album sales and increasing the stardom of the featured recording artists. Authorship in music video studies has been traditionally kept to the representation of music stars, how they incorporate post-modern references and touch upon wider cultural themes (the Marilyn Monroe pastiche for the Madonna video, Material Girl (1985) for instance). What has not been greatly discussed is the contribution of music video directors, and the reason for that is the target audience for music videos are teenagers, who respond more to the presence of the singer or the band than the unknown figure of the director, a view that is also adhered to by music television channels like MTV.

Le processus de certification de logiciels est dans la plupart des<br /> cas une tâche laborieuse et coûteuse qui nécessite aussi bien des<br /> méthodes mathématiques, pour exprimer sans ambiguïté et de façon<br /> structurée le comportement attendu du logiciel, que des outils<br /> automatiques pour vérifier ses propriétés. Parmi les techniques de<br /> preuve, la récurrence est parfaitement adaptée pour raisonner sur<br /> des structures de données infinies, comme les entiers et les<br /> listes, ou des systèmes paramétrés.<br /> <br /> Cette thèse comprend deux parties, l'une théorique, l'autre<br /> applicative. La première partie est centrée autour d'un nouveau<br /> concept, l'\emph(ensemble couvrant contextuel) (ECC). Le principe<br /> de preuve par récurrence avec ECC est exprimé par un système<br /> d'inférence abstrait qui introduit des conditions suffisantes pour<br /> son application correcte. La conception modulaire de règles<br /> d'inférence concrètes est un avantage de cette approche. Comme<br /> étude de cas, nous spécifions le système d'inférence du<br /> démonstrateur SPIKE en tant qu'instance de ce système.<br /> <br /> Dans la deuxième partie, nous analysons tout d'abord le problème<br /> d'interactions de services téléphoniques. Nous proposons une<br /> méthodologie pour les détecter et les résoudre, reposant sur des<br /> techniques basées sur la réécriture conditionnelle et la<br /> récurrence. Dans une autre application, nous obtenons, à l'aide<br /> du démonstrateur PVS, la première preuve formelle de l'équivalence<br /> entre deux algorithmes de conformité du protocole ABR. Puis,<br /> nous utilisons SPIKE pour vérifier complètement automatiquement<br /> la majorité des 80 lemmes de cette preuve.