Chemical communication in the Mozambique tilapia: a role for amino acids

The Mozambique tilapia (Oreochromis mossambicus) is a maternal mouthbrooding cichlid from the southern Africa. The olfactory sensitivity of the species to 20 amino acids was assessed using the electro-olfactogram (EOG). We estimated whether the olfactory potency of the polar fraction of male urine can be explained by the presence of identified amino acids. In addition, filtrate and amino acid mixture of the urine of Nile tilapia were used to estimate their olfactory potency for O.mossambicus. Finally, concentrations of the main amino acids were measured in the urine of males of different social status and the correlations between amino acid concentration and hierarchical status were explored. L-cysteine, L-glutamine and L-threonine were the most potent stimuli at M while L-proline and L-aspartate were the least potent. Four groups of amino acids were identified according to their thresholds of detection and three groups – according to the similarity of their ɣ-factors. The estimated threshold of detection for O.mossambicus mixture was higher than that for the filtrate. On the contrary, the threshold of detection for the mixture of Nile tilapia was lower than that for the filtrate The concentration of L-arginine in the urine was positively correlated with fish dominance index. Both L-arginine and L-glutamic acid concentrations had much greater variability in dominant males (DI˃0.5) than in subordinate males (DI˂0.5). The urinary concentrations of L-phenylalanine had similar variability in dominant and subordinate groups. The Mozambique tilapia has olfactory sensitivity to all twenty amino acids tested. The fish showed more acute sensitivity to conspecific urine filtrate than to the heterospecific. Olfactory potency of O.mossambicus filtrate can be largely but not fully explained by the presence of L-arginine, L-glutamic acid and L-phenylalanine. Larginine and L-glutamic acid may indicate the dominance status of the fish and, possibly, individual identity.

Joint compensation of IQ-imbalance and carrier phase sychronization errors in communication receivers

This work addresses the joint compensation of IQimbalances and carrier phase synchronization errors of zero- IF receivers. The compensation scheme based on blind-source separation which provides simple yet potent means to jointly compensate for these errors independent of modulation format and constellation size used. The low-complexity of the algorithm makes it a suitable option for real-time deployment as well as practical for integration into monolithic receiver designs.

Miniaturization and Integration of Optoelectronics for Contact Lens Embedded Display and Wireless Communication

Thesis (Ph.D.)--University of Washington, 2013

Living and dealing with RF impairments in communication transceivers

This paper provides an overview of the sources and effects of the RF impairments limiting and rendering the performance of the future wireless communication transceivers costly as well as hindering their wide-spread use in commercial products. As transmission bandwidths and carrier frequencies increase effect of these impairments worsen. This paper studies and presents analytical evaluations of the performance degradation due to the RF impairments in terms of bit-error-rate and image rejection ratio. The paper also give highlights of the various aspects of the research carried out in mitigating the effects of these impairments primarily in the digital signal processing domain at the baseband as well as providing low-complexity hardware implementations of such algorithms incorporating a number of power and area saving techniques.

World Cultures in English(es) at the School of Arts and Humanities Library, University of Lisbon: the Communication Platform Architecture and Its Critical Analysis

We will consider the architecture of the communication platform prototype, "World Cultures in English(es)" (WCE), in relation to the interaction among different types of media and audiences. Such an architecture has emphasized the need for an interdisciplinary team of scholars, librarians, and Information Technology experts who have conceived the prototype. This prototype was developed using PHP and MySQL, and is based on the University of Lisbon server. The "World Cultures in English(es)" is an Open Access platform bringing together different types of documents—written, audio, visual, multimedia, and electronic—and aims at educational, cultural, social, and economic inclusiveness, namely in terms of users with special needs. The WCE platform strongly implies social commitment through reliable information and forms of communication adequate to different kinds of audiences. The "World Cultures in English(es)" prototype will be tested by different audiences from different schools and universities, leading to the necessary adjustments.

Hierarchical structures: conducive or barrier to knowledge management?

This study examines managers‟ perceptions of Knowledge Management (KM) prior to implementation of KM-systems in a global insurance company and investigates whether Hierarchical structures are conducive to KM. Mixed methods are used, combining large scale surveying and case study using content analysis to organize the data into themes that provide the basis for arguments. Evidence suggests that managers strongly align their perception of KM with communication. Despite a multi-layered, hierarchical structure and strong middle management presence, organizational structure was not viewed as an issue. These factors are usually barriers to communication and organizational flexibility, yet managers believe that they may not inhibit KM becoming fully embedded. This evidence is contradicted by the results of a global KM study where silos, stovepipe and hierarchical structures were commonly cited as barriers. This contributes to the understanding of managerial mis-conceptions of knowledge as opposed to communication, and how organizations effectively share knowledge.

Locally Periodic Signal Estimation and Pitch Detection, and Acoustic Communication in American and Northwestern Crows

Thesis (Ph.D.)--University of Washington, 2016-03

Nonlinear distortion evaluation of reconfigurable RF circuits in wireless communication systems

A compact highly linear microstrip dual - mode optically switchable filter and a reconfigurable power amplifier are presented. The key characteristics of the dual - mode switchable filter are investigated and described. A second order filter design procedure is outlined to facilitate the realisation of Butterworth and Chebyshev functions. The proposed filter was built and tested with an optical switch, which comprised of a silicon dice acti vated using near infrared light. The measured and simulated results are in good agreement. The measured insertion loss in the ON state was 3.0 dB the isolation in the OFF state was 45 dB at the centre frequency. An evaluation of filter distortion is presen ted for digitally modulated M - QAM and M - QAM OFDM singals.

Academics across borders: narratives of linguistic capital, language competence, and communication strategies

This article reports on a study that examined the personal employment paths of six international academics at a British university. To complement previous accounts of difficult migration, it focuses on the successful experiences of such academics, in particular how proficiency in English facilitated their move into employment in higher education (HE), and the linguistic competences and communication strategies they deploy in their daily activities. The article identifies key factors that have facilitated to their academic achievements and contributes to the understanding of the benefits and consequences of skilled migration. In conclusion, it suggests workplace pedagogy and policy responses that could facilitate other international academics' successful experiences in the UK HE sector.