Thesis (M. Sc.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (leaves 35-40). Also available via the World Wide Web.

Bone Morphogenetic Protein 2 (BMP2) is a growth factor needed to initiate fracture repair and is involved in the differentiation of progenitor cells to the osteochondral lineage. Osteogenesis and angiogenesis are coupled processes, however the mechanism by which these processes are coupled and the role that BMP2 plays in coupling these processes is not well understood. In distraction osteogenesis, a bone regeneration model mediated by mechanical distraction of an osteotomy, BMP2 expression was primarily associated with blood vessels. Therefore, transgenic mice were used to conditionally delete BMP2 expression (BMP2-cKO) in smooth muscle cells during distraction osteogenesis to identify the role of BMP2 in osteogenesis and angiogenesis. Vessel formation was characterized by vascular perfusion of animals with a barium-gelatin solution, which was used as a radiographic contrast agent that allowed vessel formation to be quantified by micro-computer assisted tomography (µCT). Using the same transgenic mice to label those cells in which BMP2 had been deleted, histological analysis was performed to confirm the targeting specificity of the BMP2-cKO. µCT analysis showed less bone formation occurred in the BMP2-cKO animals compared to controls. The µCT analysis further showed vessel volume and thickness were decreased in BMP2-cKO animals at both day 17 and 31, suggesting that there is a relationship between BMP2 and vessel size. Vessel number was greater in controls than the BMP2-cKO animals at day 17, however the BMP2-cKO animals had a larger vessel number than the number by day 31. Histological analysis confirmed knockout of BMP2 expression in smooth muscle cells, as well as in skeletal muscle and chondrocytes. These results suggest the importance of BMP2, not only in bone formation, but also in vessel morphogenesis.

abstract: In 2013, 1.8 million US drivers were responsible for rear-end collisions with other vehicles (NHTSA 2014), for which driver distraction has been identified as the main factor (Campbell, Smith & Najm, 2003; Knipling, Mironer, Hendricks, Tijerina, Everson, Allen & Wilson 1993; Wang, Knipling & Goodman, 1996). The ubiquity of cell phones and their use behind the wheel has played a major role in distracting these drivers. To mitigate this, some manufacturers are equipping vehicles with forward collision warning (FCW) systems. Generally, warnings that are perceived as being urgent produce lower response times. One technique for increasing perceived urgency of a warning is called looming, where the signal increases in or more dimensions over time. Looming warning signals have been shown to produce low response times, likely because the recipient perceives the signal as a potential approaching threat, prompting defensive reactions (Graziano and Cooke, 2006). The present study evaluates the effect of veridical (intensity increases at the rate of closure with the lead vehicle) and high urgency (intensity increases at a rate of Time to Collision minus 0.5 seconds) looming FCW, as well as a static FCW, on drivers’ brake reaction times in the presence of a secondary texting task. Participants’ brake reaction times were recorded as they followed a lead car in a driving simulator, encountering multiple sudden-braking events across the five conditions (a control condition as well as four counterbalanced conditions using a secondary texting task). In the four conditions with a secondary task, participants received no FCW, static FCW, veridical FCW, and high-urgency FCW, respectively. Performance data was analyzed using a repeated measures ANOVA, and a series of pairwise comparisons were then made using Bonferroni corrected pairwise t-tests. The presence of a visually and manually distracting secondary task (texting) seems to diminish the performance of the looming signals as compared to previous studies that did not use a distraction component. While looming FCW do seem to effectively lower BRTs when the driver is distracted, it is recommended that further research investigate the relationship between secondary task types and their respective levels of distraction, and the effectiveness of auditory looming FCW. / Dissertation/Thesis / Masters Thesis Applied Psychology 2016

Made available in DSpace on 2014-06-11T19:27:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-07-06Bitstream added on 2014-06-13T20:57:09Z : No. of bitstreams: 1 oliveira_ca_me_arafo.pdf: 995320 bytes, checksum: fe65fd0d87c661122e78f571d2bfe20f (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo deste trabalho foi avaliar, por meio de modelos de estudo, os efeitos da Distração Osteogênica Médio-Sagital da Mandíbula (DOMM) no arco mandibular de pacientes que utilizaram aparelhos dento-suportados. A amostra consistiu de 14 pacientes (5 do gênero masculino e 9 do gênero feminino) com idades variando de 13 a 19 anos e média de idade de 15,74 ± 1,89 anos no início do tratamento. Modelos de estudo foram obtidos de cada paciente no início do tratamento (T1), três meses após a DOMM (T2) e no momento da remoção dos aparelhos fixos (T3). Os dados foram submetidos à Análise de Variância e teste complementar de Duncan e demonstraram que todas as dimensões transversais aumentaram com a DOMM, o comprimento do arco não sofreu alteração estatisticamente significante, o perímetro do arco aumentou e o Índice de Irregularidade diminuiu consideravelmente, refletindo a correção do apinhamento ântero-inferior. Os dentes posteriores apresentaram maior expansão das cúspides do que das cervicais, indicando uma possível inclinação causada pelo uso de aparelho dento-suportado. Todas a medidas mostraram algum grau de recidiva, que variou de 2,8% a 8,84%. Os achados desta pesquisa permitiram concluir que a DOMM é uma alternativa eficaz para o tratamento do apinhamento associado à deficiência transversal de mandíbula. / The purpose of this study was to evaluate the effects of Mandibular Symphyseal Distraction Osteogenesis (MSDO) with a tooth-borne distraction device, analysed in dental casts. The sample included 14 patients (5 males and 9 females) between 13 and 19 years of age, with a mean age of 15,74 ± 1,89 years at the start of treatment. Dental casts were obtained at the start of treatment (T1), three months after distraction (T2) and at the end of treatment, when fixed appliances were removed (T3). The data were analysed statistically using ANOVA and Duncan’s test and showed that all transverse widths increased, arch length was maintained, arch perimeter increased significantly and Irregularity Index decreased, showing the correction of crowding. Molars and premolars had a disproportionate pattern of distraction, characterized by greater cusps expansion than cervical one. This pattern might be caused by the use of a tooth-borne distraction device. All the measurements demonstrated evidence of relapse, that varied from 2,8% to 8,84%. The findings of this study indicate that MSDO is an efficient treatment alternative for dental crowding and mandibular transverse deficiency.

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This thesis investigates the level of distraction while driving. The first part of the thesis is focused on the literature review in the field of distraction while driving. Several methods of measuring distraction while driving are being addressed here. The analytical part of the thesis draws on the video recordings of driving tests which were provided specifically for the purpose of this thesis. The resulting data were evaluated with goal to determine the time of visual fixation on traffic signs and advertising equipment in the urban area/non-urban area during the day/night and subsequent comparison of the visual perception of traffic signs and advertising equipment.

Background Meetings are important for organisational functioning and the co-ordination of people, tasks and processes, and an everyday reality of organisational life. As mobile communication technology, such as smart phones, tablets and laptops gets smaller and more powerful, these devices have become more pervasive in every aspect of personal and work life. Increasingly, organisations allow mobile devices to be used during meetings in an effort to be more efficient and save time. However, for a meeting to achieve the desired meeting outcomes, those that participate in the meeting need be actively engaged and focused. It is widely accepted though that mobile communication technology is distracting and can easily draw away one’s focus. This begs the question then as to whether employees should in fact be able to use mobile devices in meetings, or not. Rationale for the research study Research into the effect of mobile communication technology as a source of digital distraction on meeting performance, given individual differences in cognitive processing, is limited. Moreover, no experimental studies could be found that have investigated these relationships. It is hoped that the results of the present study will address the gap that was identified in the literature, as well as provide a useful practical contribution for organisations. The findings of the present study may further be used to inform organisation policy and practice concerning the use of mobile communication technology in meetings. Aim of the research study The aim of the present study was to investigate if the presence of digital distraction in meetings, i.e. the presence of mobile communication technology or mobile devices significantly negatively influences selected cognitive processes (i.e. cognitive load and attention conflict) and ultimately meeting performance (assessed as the time it takes to make a decision; as well as the number and quality of decisions made). Research design and method A two-group post-test only, quasi-experimental research method was utilised to investigate the causal effect of the presence of digital distraction on selected aspects of cognitive processing and meeting performance. For an experiment to be valid, no systematic bias should exist in the comparison groups before the manipulation or intervention, otherwise, one would not be able to deduce that any difference that is observed after the manipulation or intervention was due to the manipulation or intervention. Therefore, to ensure that two equivalent treatment groups were available, individuals were randomly assigned to two meetings. The composition of the two groups was then assessed using the demographic variables that were collected and were not found to be significantly different from one another. The average level concentration performance or attentiveness was also measured and not found to be significantly different. This suggests that the average level of distractibility was the same for the two groups. Two equivalent meetings were held with only the availability of mobile communication technology being different between the meetings (i.e. mobile devices were present and used during the meeting or not). After the meetings were concluded, respondents were asked to complete an online questionnaire that consisted of closed- and openended questions designed to measure the concentration performance, cognitive load and attention conflict constructs. Meeting performance was further evaluated by two independent subject matter experts using a decision-rating scale. Sampling and sample As meetings in organisations was the focus, the study targeted employed individuals, a convenient sample of employees were obtained (n=15) that were randomly assigned to one of two participant groups in two separate meetings. Results The inferential data analyses revealed that cognitive load and attention conflict were both statistically significantly higher in the meeting in which the use of mobile devices were available and used, compared to the meeting in which mobile devices were not present. Moreover, it was found that meeting performance was lower in the meetingwhere mobile communication technology was present. The members of the two meetings made a similar number of decisions, which the independent assessors rated as being of similar quality, however, the group in which mobile communication technology was available took 30 per cent longer (120 versus 90 mins) to come to a similar outcome. Findings The results of the present research study suggest that the presence of digital distraction placed significant (additional) demands on the cognitive processing of individuals, who in meetings are required to fulfil cognitive decision-making tasks. As a direct or indirect result, the presence of digital distractions had a marked negative impact on meeting performance and productivity. Based on the findings, it is argued that restricting digital distractions in meetings can greatly reduce the time spent in meetings, while still achieving desired meetings outcomes. Meetings are essential to effective organisational management and coordination but are also resource intensive with managers spending substantial amounts of their available work time in meetings. Organisations operating in resource constrained environments need to be increasingly efficient in their use of scarce resources and, arguably, time is the most precious resource of all. Managerial Implications Based on the findings of the present study, it is recommended that unless mobile communication devices are required to achieve meeting outcomes, managers should declare meetings as technology free zones. Doing so may lead to shorter more productive meetings giving those that often attend meetings more time to attend to other matters.

This study examined how different background noise conditions affected the spoken language production of young (18-25) and older (60-85) adults when performing a story retell task. Participants included 10 female and 10 male young adult (YA) participants, as well as 10 female and 10 male older adult (OA) participants. Participants retold stories in a silent baseline and five background noise conditions (conversation, monologue, phone call, cocktail, pink noise). Speech fluency and language production measures (cohesive and coherent utterances, lexical-phonological errors, grammatically correct words, Moving Average Type Token Ratio (MATTR), speech rate, and disfluent words) were compared between groups and across conditions. Results reveal that background noise led to an increase in speech rate for the OA compared to the YA group. A main effect was also found for disfluent words, specifically between the phone call and conversation condition, as well as the pink noise and phone call conditions. The OA also experience background noise benefits in relation to speech fluency (conversation and phone call conditions) and lexical production (conversation condition). The YA group experience background noise costs in relation to speech rate in the phone call condition. These findings suggest that background noise benefits discourse more for OA and interferes more for YA.

The struggle to regulate one's emotions can sometimes be difficult. Two emotion regulation strategies are to reappraise an emotional stimulus or to distract oneself from the stimulus. While there have been many investigations of both strategies, previous research suffers from methodological problems. Reappraisal conditions might be confounded by non-reappraisal-related cognitive processes, resulting in effects of distraction rather than reappraisal. In the current exploratory within-subjects study, participants completed an online survey where the conditions were held as equal as possible to avoid any differences in non-task-related cognitive processes. I measured variables that have been associated with an electrophysiological response correlated to the intensity level of emotions: the late positive potential. First, participants watched emotionally negative film clips in a reappraisal, distraction, and control condition, followed by ratings of experienced feeling. Second, participants rated the threat level of angry and neutral faces. It was hypothesized that applying ER during emotion induction compared to no ER should result in more positive ratings of experienced feeling after induction and lower threat-ratings of angry faces due to a more positive emotional state. The results showed no significant differences between conditions, most likely due to either methodological limitations or an actual lack of emotion regulation effects. I discuss future directions and improvements of the method.

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