Teamwork and well-being:the role of social support

This thesis explores, in a team context, using the Michigan Model, the relationship between social support, stress and well-being outcomes. The studies reported were carried out in Post Office Ltd. Study one examines differences in social support source and type for employees working in teams and quasi teams. Analysis was carried out at the individual level. The results supported previous work on well-being in teams: individuals working in teams report significantly higher levels of well-being, job satisfaction and organisational commitment than those individuals in quasi teams. Members of teams reported greater satisfaction with support from their manager and colleagues, and all types of support compared to members of quasi teams. Manager support and specific types of support mediated the relationship between team working and well-being outcomes. In terms of stressors, satisfaction with manager support and emotional challenge predicted greater influence which was positively related to the well-being outcomes. Study two conducted at the team level builds on relationships established in study one. Stage one explored teamness, the extent to which, along a continuum the team was well-defined. Stage two explored teamness agreement, the extent to which the team agreed on their teamness. The extent to which the Branch Office were a well-defined team had a positive effect on team functioning; participation, innovation and commitment to task excellence. Team functioning was associated with higher levels of satisfaction with manager and team support and all types of support. Working in a well-defined team was associated with job satisfaction, mediated by positive team functioning and social support. Teamness agreement predicted team well-being, clarity of objectives, work demands and satisfaction with reality check. Working in a team was not associated with performance. This thesis advances understanding in the area of team working and processes within teams, advancing understanding of the specifics of social support from different so urces and types of support. The studies reveal the key role of team functional characteri stics in creating the vehicle through which supportive interactions take place. which contribute to positive outcomes associated with working in a well-defined team

Supermassive black holes as the regulators of star formation in central galaxies

We present a relationship between the black hole mass, stellar mass, and star formation rate of a diverse group of 91 galaxies with dynamically-measured black hole masses. For our sample of galaxies with a variety of morphologies and other galactic properties, we find that the specific star formation rate is a smoothly decreasing function of the ratio between black hole mass and stellar mass, or what we call the specific black hole mass. In order to explain this relation, we propose a physical framework where the gradual suppression of a galaxy's star formation activity results from the adjustment to an increase in specific black hole mass and, accordingly, an increase in the amount of heating. From this framework, it follows that at least some galaxies with intermediate specific black hole masses are in a steady state of partial quiescence with intermediate specific star formation rates, implying that both transitioning and steady-state galaxies live within this region known as the "green valley." With respect to galaxy formation models, our results present an important diagnostic with which to test various prescriptions of black hole feedback and its effects on star formation activity.Comment: 15 pages, 4 figures, 2 tables. Accepted for publication in The Astrophysical Journa

Remédiation cognitive et thérapie occupationnelle dans le traitement ambulatoire du patient souffrant de schizophrénie

Dans cet article, les auteurs décrivent un programme de réhabilitation comportementale pour patients souffrant de schizophrénie. Le programme combine la réhabilitation occupationnelle à l’entraînement cognitif, s’attaquant ainsi à deux des déficiences marquantes de ce trouble chronique. En plus de cibler ces deux types de déficiences, les auteurs ont aussi examiné l’impact de l’une sur l’autre. En effet, des recherches suggéraient que les déficiences cognitives peuvent indiquer une limite à la réhabilitation psychosociale de ces patients. L’intention des auteurs était d’examiner si le fait de remédier spécifiquement à ces déficits cognitifs mènerait la réhabilitation occupationnelle à des résultats supérieurs. Après une description détaillée du programme, ils présentent des données à l’appui de l’efficacité de ce type d’approche, à la fois pour améliorer les fonctions cognitives et mener à de meilleurs résultats fonctionnels.In the present paper, we describe a behavioral rehabilitation program for patients with schizophrenia. The program combines vocational rehabilitation with cognitive training, thereby addressing two of the hallmark impairments of this chronic disorder. In addition to targeting these two types of impairments, we also wished to investigate the impact of one on the other. Specifically, previous research has suggested that cognitive impairments may serve as rate-limiters in the psychosocial rehabilitation of patients with schizophrenia. Our intent was to investigate whether specifically addressing and remediating these cognitive deficits would in turn lead to superior outcomes in vocational rehabilitation. Following a detailed description of our program, we offer initial support for the efficacy of this type of approach in both improving cognitive function as well as leading to better functional outcomes.En este artículo, los autores describen un programa de rehabilitación comportamental para los pacientes que sufren de esquizofrenia. El programa combina la rehabilitación ocupacional con el entrenamiento cognitivo, enfrentándose así a dos deficiencias que marcan este trastorno crónico. Además de enfocarse en estos dos tipos de deficiencias, los autores también examinan el impacto de una en la otra. De hecho, los estudios sugieren que las deficiencias cognitivas pueden indicar un límite en la rehabilitación psicosocial de estos pacientes. La intención de los autores fue examinar si el hecho de remediar específicamente estos déficits cognitivos lleva a la rehabilitación ocupacional a resultados superiores. Después de una descripción detallada del programa, presentan datos que apoyan la eficacia de este tipo de enfoque para mejorar las funciones cognitivas y, al mismo tiempo, conducir a mejores resultados funcionales.Neste artigo, os autores descrevem um programa de reabilitação comportamental para pacientes que sofrem de esquizofrenia. O programa associa a reabilitação ocupacional ao treinamento cognitivo, combatendo, assim, duas das deficiências marcantes deste transtorno crônico. Além de tratar destes dois tipos de deficiências, os autores examinaram também o impacto de uma sobre a outra. De fato, as pesquisas salientaram que as deficiências cognitivas podem indicar um limite na reabilitação psicossocial destes pacientes. A intenção dos autores era examinar se o fato de remediar especificamente estes déficits cognitivos levaria a reabilitação ocupacional a resultados superiores. Após uma descrição detalhada do programa, eles apresentam dados para apoiar a eficácia deste tipo de abordagem para melhorar as funções cognitivas e ao mesmo tempo levar a melhores resultados funcionais

Embeddings for DNN speaker adaptive training

In this work, we investigate the use of embeddings for speaker-adaptive training of DNNs (DNN-SAT) focusing on a small amount of adaptation data per speaker. DNN-SAT can be viewed as learning a mapping from each embedding to transformation parameters that are applied to the shared parameters of the DNN. We investigate different approaches to applying these transformations, and find that with a good training strategy, a multi-layer adaptation network applied to all hidden layers is no more effective than a single linear layer acting on the embeddings to transform the input features. In the second part of our work, we evaluate different embeddings (i-vectors, x-vectors and deep CNN embeddings) in an additional speaker recognition task in order to gain insight into what should characterize an embedding for DNN-SAT. We find the performance for speaker recognition of a given representation is not correlated with its ASR performance; in fact, ability to capture more speech attributes than just speaker identity was the most important characteristic of the embeddings for efficient DNN-SAT ASR. Our best models achieved relative WER gains of 4% and 9% over DNN baselines using speaker-level cepstral mean normalisation (CMN), and a fully speaker-independent model, respectively.Comment: Accepted at ASRU 201

Multi-Scale Octave Convolutions for Robust Speech Recognition

We propose a multi-scale octave convolution layer to learn robust speech representations efficiently. Octave convolutions were introduced by Chen et al [1] in the computer vision field to reduce the spatial redundancy of the feature maps by decomposing the output of a convolutional layer into feature maps at two different spatial resolutions, one octave apart. This approach improved the efficiency as well as the accuracy of the CNN models. The accuracy gain was attributed to the enlargement of the receptive field in the original input space. We argue that octave convolutions likewise improve the robustness of learned representations due to the use of average pooling in the lower resolution group, acting as a low-pass filter. We test this hypothesis by evaluating on two noisy speech corpora - Aurora-4 and AMI. We extend the octave convolution concept to multiple resolution groups and multiple octaves. To evaluate the robustness of the inferred representations, we report the similarity between clean and noisy encodings using an affine projection loss as a proxy robustness measure. The results show that proposed method reduces the WER by up to 6.6% relative for Aurora-4 and 3.6% for AMI, while improving the computational efficiency of the CNN acoustic models.Comment: submitted to ICASSP202

Mismatch repair in DNA recombination and antigenic variation in Trypanosoma brucei

African trypanosomes evade the mammalian host immune system for prolonged periods by periodically switching the protective Variant Surface Glycoprotein (VSG) coat expressed on their cell surface. Recombination reactions, which introduce novel VSG gene copies into specialised expression sites, constitute the principal mechanism of this antigenic variation process. Since VSG genes occupy cassettes with common upstream and downstream sequences it is hypothesised that VSG switching reactions occur primarily by homologous recombination. It has previously been shown that at least some of the VSG switching reactions are either catalysed or regulated by RAD51, a fundamental component of the homologous recombination machinery in eukaryotes. In order to investigate further the factors regulating antigenic variation we have characterised several components of the highly conserved post-replicative mismatch repair (MMR) system in T. brucei. The nuclear MMR system recognises mispaired bases in heteroduplex recombination intermediates preventing recombination between divergent DNA molecules, and thereby confining such reactions to highly homologous sequences. In yeast and mammals this system is composed of three homologues of the bacterial MutS enzyme and three bacterial MutL-related enzymes. We have identified five single-copy genes putatively encoding three MutS homologues and two MutL homologues, suggesting that most of the components of eukaryotic MMR are conserved in trypanosomes. Knockout mutants have been generated in two of the genes, MSH2 and MLH1, to investigate the activities of MMR in this organism. Both MSH2-deficient and MLH1- deficient trypanosomes exhibit microsatellite instability, a mutator phenotype, and tolerance to the methylating agent MNNG, demonstrating that these genes encode components of an active MMR system in T. brucei. Moreover, deletion of MSH2 increases the frequency of recombination between 3% divergent sequences, revealing that MMR is also involved in the regulation of recombination in this organism. Despite this, no effect on the frequency or mechanisms used in antigenic variation was observed in either MSH2 or MLH1 mutants, suggesting that MMR has little or no influence on this process, and that perhaps the homologous recombination reactions underlying antigenic variation proceed by a mechanism distinct from general recombination