10 research outputs found

    Innate and learned predator recognition in four strains of captive-bred atlantic salmon, Salmo salar

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    Innate and learned anti-predator responses can be important determinants of survival in natural environments. However, few studies have examined population differences in these anti-predator responses. My study measured innate and learned anti-predator responses in four strains of Atlantic salmon, Salmo salar, which had varying captive breeding histories. All four strains of salmon tested had an innate anti-predator response to alarm cue and no response to a visual predator cue. Following training in which the alarm cue and predator cue were paired, I found that one of the four strains (Sebago), developed a learned anti-predator responses as indicated by reduced activity in response to the predator cue. The duration of captive breeding could not explain why only the Sebago strain showed an ability to learn, suggesting that other factors affect the evolution of learned anti-predator responses. Understanding population variability in learning ability may be important when selecting populations for reintroduction efforts

    A Platform for Storing, Visualizing, and Interpreting Collections of Noisy Documents

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    International audienceThe goal of document image analysis is to produce interpretations that match those of a fluent and knowledgeable human when viewing the same input. Because computer vision techniques are not perfect, the text that results when processing scanned pages is frequently noisy. Building on previous work, we propose a new paradigm for handling the inevitable incomplete, partial, erroneous, or slightly orthogonal interpretations that commonly arise in document datasets. Starting from the observation that interpretations are dependent on application context or user viewpoint, we describe a platform now under development that is capable of managing multiple interpretations for a document and offers an unprecedented level of interaction so that users can freely build upon, extend, or correct existing interpretations. In this way, the system supports the creation of a continuously expanding and improving document analysis repository which can be used to support research in the field

    Doctor of Philosophy

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    dissertationNanopore technology has been at the center of attention during the past decade as one of the most promising methods for next-generation DNA sequencing. It proceeds by electrically drawing an individual single-stranded DNA (ssDNA) strand through a nanoscale pore, leading to detectable changes in the electrical current. Chief advantages of this technology are the minimal requirements of expensive reagents and data storage and handling equipment. The bacterial protein a-hemolysin is the most commonly used biological nanopore for this platform, due to its excellent stability, reproducibility and precise tuning properties by site-directed mutagenesis. One of the most difficult challenges of this technology arises from the low current amplitude resolution between the DNA nucleotides. The first work presented here approaches these problems by DNA site-specific chemistry to attach detectable labels to one of the most commonly occurring lesions in cells, DNA abasic (AP) sites. Several amines were used to attach to AP site, which showed detectable current changes when the ssDNA was immobilized inside of the nanopore. However, only the 18-crown-6 (18c6) moiety produced distinct current signatures during translocation, when bound to Na+. The bulky adduct also slowed down the DNA motion to more easily recordable levels, achieving the detection of individual AP sites at a single-molecule level. 18c6 can form different shapes of complexes, dictated by the surrounding ions, which was used to precisely manipulate its electrical behaviors. Secondly, the nanocavity of this protein was used to provide insights into secondary structures of the human telomeric G-quadruplexes at a single-molecule level. The folding of the repeat sequence at the end of the chromosome was shown to have significance to genome protection, and depending on the surrounding ions, it could form various quadruplexes. The interactions of these structures and the a-HL were correlated to different current patterns when the DNA was encapsulated inside of the channel, providing better understanding into the polymorphism of the human telomere sequence. Lastly, combining the above two findings, the 18c6 label was used to detect the oxidative damage of the G-quadruplexes, and the effect on the stability of these structures were also evaluated

    The eyes have it

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    Complete Proceedings - Armistice & Aftermath: A World War One Symposium

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    View the PDF of the complete proceedings for Armistice & Aftermath: A World War I Symposium. We are pleased to bring together many of the papers presented at the Michigan Tech World War I symposium, Armistice & Aftermath. They provide various examples of how WWI affected the heartland, both during and after the war – a topic often missed in general histories, at least in the United States. American stories of WWI are relatively scarce in relation to general American military history, where the Civil War and WWII dominate, and in relation to WWI histories, which are dominated by the European combat experience

    Medicinal chemistry and molecular pharmacology of orphan human Mas-related G protein-coupled receptors X2 and X4 (MRGPRX2 and MRGPRX4)

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    The MRGPRX protein subfamily comprise rhodopsin-like orphan GPCRs, whose endogenous agonists have not been identified yet. They are exclusively expressed in primates, including humans. All Mas-related GPCRs (MRGPRs) were first detected in dorsal root ganglia (DRGs) and trigeminal ganglia (TGs), suggesting a role in pain and itch. The MRGPRX2 subtype and its postulated mouse orthologue MRGPRB2 exhibit unique features being activated by various endogenous and exogenous agonists and due to their predominant expression in mast cells (MCs). Both MRGPRX2 and MRGPRB2 are associated with pseudoallergic reactions, such as asthma, chronic urticaria and skin inflammation. Due to its activation by bile acids and bilirubin, MRGPRX4 has been proposed to the target of high concentrations of these molecules released in cholestasis and being responsible for their provoking of itch. MRGPRX2 and MRGPRX4 represent fundamentally new drug targets. Therefore, the development of potent and selective agonists and antagonists is essential to reveal the (patho)physiological functions of these GPCRs, and validating them as novel drug targets, performing preclinical studies and eventually advance them towards clinical development. In view of the need of new drugs to treat and prevent chronic itch and pain, the design of MRGPRX2, MRGPRB2 and MRGPRX4 ligands represents a crucial step. In this PhD thesis, MRGPRX2, its proposed mouse orthologue MRGPRB2, as well as MRGPRX4 were pharmacologically investigated. Tricyclic benzimidazole derivatives have been identified before as potent MRGPRX2 antagonists, and polar xanthine derivatives as MRGPRX4 agonists with high potency. Structure-activity relationships (SARs) at both GPCRs have been intensively investigated in this study as well as their chemical optimization. This approach resulted in finding the most potent ligands for these GPCRs so far: whereas the MRGPRX2 antagonist CB70 displayed a potency in the nanomolar range (IC50 0.0225 µM in β-arrestin assays), the determined agonistic potency of the MRGPRX4 agonist DM288 was in the high picomolar range (EC50 0.000296 µM in β-arrestin assays). Additionally, tricyclic benzimidazole derivatives were evaluated for their additional antagonism at MRGPRB2 in calcium assays and SAR analysis allowed the identification of the most potent MRGPRB2 antagonist to date (CB70, IC50 0.00169 µM in calcium assays). In order to further characterize CB70, the compound was analyzed for its inhibition mode at MRGPRX2. Several antagonistic hit compounds for MRGPRX4 were evaluated for their potency and selectivity. During the development of calcium and β-arrestin assays for MRGPRX4, a single nucleotide polymorphism (S83L) has been identified in the MRGPRX4 gene that altered the GPCR function and impacted the potency of the investigated MRGPRX4 ligands. Lastly, optimized ligands were tested for their inhibition of mast cell degranulation as well as for their induction of intracellular calcium concentration in stem cell-derived mature human dorsal root ganglia neurons. The successful development of new potent and selective MRGPRX2 and MRGPRX4 ligands will help to further characterize the physiological role of these GPCRs

    An Exploration of RPL (Recognition of Prior Learning) in Companies and Organisations in Ireland Valorisation, Return on Investment, and Emerging Trends

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    This thesis explored the topic of recognition of prior learning (RPL) in companies and organisations in Ireland against a backdrop of global, European, and national policy initiatives on the recognition of all forms of formal, non-formal and informal learning. The immediate context was coloured by shifts in employment, in labour markets, and in education and training policies because of increasing economic difficulties globally, and the greater levels of attention being paid to the role of education and training in the economic and social development of a country. The primary research question for the thesis was: Is there a return on investment from the recognition of prior learning (RPL) to companies and organisations that use RPL in their learning and development strategies? Return on investment in this research was conceived as achievement of impact at a societal, organisational, and individual level. The research approach was broadly social constructionist and interpretative. It took a multiperspective approach to explore past, current, and future perspectives of RPL in companies and organisations. There were three methodological strands of inquiry employed in the thesis. The first was an historical study to analyse previous RPL projects using a framework of valorisation. The second was a comparative analysis of RPL case studies in sixteen companies, professional bodies, training bodies, and community organisations. The third and final was a Delphi Future-Oriented Survey with experts in the areas of higher education, further education, workplace learning, vocational education, educational policy, and industry. The research findings indicated that initially RPL suffered from efforts to reconcile perceptions of ‘traditional’ learning as the sole route to achieve a qualification with the RPL route. In current practice RPL in companies and organisations is concerned with engaging with, rewarding and recognising the services of its employees. RPL is also considered a means to address continuing professional development needs without recourse to ‘training’. Finally, RPL is a means to link national, sectoral, and organisational training and qualifications systems to validate and professionalise company training and provide the potential for occupational mobility. From a policy perspective return on investment from RPL is concerned with labour mobility, social inclusion, improved individual career prospects, employee morale, and alternate pathways to qualifications. In practice labour mobility and social inclusion were not high on company or organisational agendas. This thesis finds that drives for economic competitiveness and up-skilling of the labour force in conjunction with economic difficulties have prioritised accredited employee development initiatives which are tied to national and sectoral qualifications frameworks. RPL development in companies and organisations is linked to these drives particularly as a means of employee engagement within the context of continuing professional development (CPD) rather than the annual evaluation process. It is therefore suggested, on the basis of the research findings, that companies and organisations should consider re-conceptualising CPD using RPL to achieve employee engagement

    Plataforma embarcada de reconhecimento autom?tico da fala para o aux?lio de pessoas com mobilidade reduzida

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    A busca por maior independ?ncia e autonomia para as pessoas com defici?ncia tem se apresentado como um fator decisivo ao proporcionar uma melhoria na qualidade de vida desses indiv?duos atrav?s do uso de tecnologias assistivas. A fala se constitui na mais b?sica, comum e eficiente forma de comunica??o entre os seres humanos, de modo que a entrada de comandos por voz pode ser uma alternativa para que pessoas com mobilidade reduzida, e que tenham preservada boa capacidade das habilidades da fala, realizem o controle do computador ou outros dispositivos. O objetivo deste trabalho consiste no desenvolvimento de uma interface de comandos por voz, atrav?s do reconhecimento autom?tico da fala, que seja facilmente adaptada e incorporada a sistemas e ferramentas de aux?lio ao controle do ambiente dom?stico (dom?tica). Com esse intuito, foram executadas duas abordagens de desenvolvimento. A primeira consistiu de um experimento piloto realizado com o intuito de formar uma base inicial de conhecimento no desenvolvimento de aplica??es utilizando o reconhecimento de comandos por voz. Esta etapa baseou-se na utiliza??o de um m?dulo de hardware espec?fico, que recebe os comando de voz diretamente atrav?s de um microfone, constituindo-se de um sistema dependente de locutor capaz de reconhecer comandos de palavras isoladas para o controle das luzes de umLED RGB. J? a segunda abordagem, integra componentes de hardware aberto e software livre e de c?digo aberto, sendo os comandos de voz fornecidos ao sistema atrav?s de um smartphone configurado com softphone VoIP (Voz sobre IP). Nesse ?ltimo caso, o softphone, ent?o, se registra no servidor de comunica??o Asterisk, que implementa uma central telef?nica com unidade de resposta aud?vel (URA). Integrada ao servidor, est? a ferramenta de reconhecimento da fala, Julius. Esses componentes est?o embarcados na plataforma Beaglebone Black, de baixo custo. O sistema ? dependente de locutor e capaz de reconhecer frases com tr?s palavras para o controle da ilumina??o, televis?o e acesso a portas de umambiente dom?stico hipot?tico constitu?do de sala, cozinha, quarto, banheiro e ?rea externa. Os resultados obtidos a partir dos testes realizados indicam taxas de acerto de 95,9% e 94,77% para as interfaces desenvolvidas na primeira e segunda abordagens, respectivamente. Esses ?ndices sugeremque ? vi?vel o emprego dos m?dulos de reconhecimento desenvolvidos na implementa??o de solu??es de tecnologias assistivas
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