5,865 research outputs found

    A Role for Intraflagellar Transport Proteins in Mitosis: A Dissertation

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    Disruption of cilia proteins results in a range of disorders called ciliopathies. However, the mechanism by which cilia dysfunction contributes to disease is not well understood. Intraflagellar transport (IFT) proteins are required for ciliogenesis. They carry ciliary cargo along the microtubule axoneme while riding microtubule motors. Interestingly, IFT proteins localize to spindle poles in non-ciliated, mitotic cells, suggesting a mitotic function for IFT proteins. Based on their role in cilia, we hypothesized that IFT proteins regulate microtubule-based transport during mitotic spindle assembly. Biochemical investigation revealed that in mitotic cells IFT88, IFT57, IFT52, and IFT20 interact with dynein1, a microtubule motor required for spindle pole maturation. Furthermore, IFT88 co-localizes with dynein1 and its mitotic cargo during spindle assembly, suggesting a role for IFT88 in regulating dynein-mediated transport to spindle poles. Based on these results we analyzed spindle poles after IFT protein depletion and found that IFT88 depletion disrupted EB1, Îł-tubulin, and astral microtubule arrays at spindle poles. Unlike IFT88, depletion of IFT57, IFT52, or IFT20 did not disrupt spindle poles. Strikingly, the simultaneous depletion of IFT88 and IFT20 rescued the spindle pole disruption caused by IFT88 depletion alone, suggesting a model in which IFT88 negatively regulates IFT20, and IFT20 negatively regulates microtubulebased transport during mitosis. Our work demonstrates for the first time that IFT proteins function with dynein1 in mitosis, and it also raises the important possibility that mitotic defects caused by IFT protein disruption could contribute to the phenotypes associated with ciliopathies

    Applying series braking resistors to improve the stability of low inertia synchronous generators

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    Widely held concerns over the environmental impact of emissions from large fossil fuelled generating plants are serving to promote the connection of renewable or sustainable generation onto distribution networks. Many such generators are synchronous machines with low values of inertia, and thus possess short critical clearance times to avoid the onset of transient instability. With fault clearance times of up to 1s occurring in distribution networks, there is the potential for a growing problem as distributed generation makes up a larger proportion of installed capacity. This paper proposes the use of series braking resistors that are switched into circuit at the generator terminals as a means of improving transient stability, and thus avoid, or at least defer major upgrades to distribution system protectio

    The education and training of accounting technicians in the Sultanate of Oman : The accounting diploma program at Sultan Qaboos University

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    The discovery and subsequent commercial exploitation of oil in the Arabian Gulf region has brought profound and far-reaching change to the peoples of the area. What has happened has been nothing short of a transformation from desert sheikdoms into modem nation states;The Sultanate of Oman is one of those states. Although Oman is not a major oil producer in world terms, it has been able to use its oil revenues over the past three decades to finance the establishment of a modem infrastructure and to develop its social and economic systems. Notwithstanding the success of Oman\u27s national development efforts thus far, significant challenges lie ahead

    Towards a Common Center: Locating Common Characteristics of African Centeredness in an Independent African Centered Learning Environment

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    As a culturally relevant alternative to traditional public school environments, Independent African Centered schools feature a particular type of culturally relevant pedagogy. This study explored the teachers’ and administrator’s perceptions and applications of African Centered pedagogy in an African Centered school. Interviews, observations and a document review served as the source of data for this study. This basic interpretive study utilized a qualitative research design to explore the perceptions and application of African Centeredness among the participants. An analysis of the data revealed categories and themes related to the school’s mission and the participants’ perceptions and performance of African-centered pedagogy. Three general conclusions were drawn from the findings. Implications for theory, study limitations and recommendations for future research are provided

    Performance evaluation of two degree of freedom conventional controller adopting the smith principle for first order process with dead time

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    The Proportional Integral Derivative Controller is a typical controller implemented frequently in many services and integrating the Smith predictor is an extremely useful control system structure for processes with dead time. This paper has evaluated two control schemes with the modified structures of the Smith predictor incorporating dead time compensators and conventional controllers for first order process with dead time. The disturbance response and the set point response for both the control schemes were decoupled from each other. Therefore two degrees of freedom control design was formulated, and hence the responses could be designed separately. The two control schemes have mainly two variables to be adjusted that decide the robustness and closed-loop behaviour. This paper also contains the calculation of various parameters that were used in each scheme. A comparison of the two control schemes along with the general Smith predictor control scheme was made using Simulink/Matlab. The conclusion is the second control scheme gave better response overall for the processes with dead time having dead time uncertainty and for the processes with dead time without dead time uncertainty

    Caribbean Chronicle

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    A trip to Jamaica and Cuba offers Furman faculty an absorbing look at the sights, sounds and societal changes in two of the most exotic locales in the Western Hemisphere

    Discourse and identity in a corpus of lesbian erotica

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    This article uses corpus linguistic methodologies to explore representations of lesbian desires and identities in a corpus of lesbian erotica from the 1980s and 1990s. We provide a critical examination of the ways in which “lesbian gender,” power, and desire are represented, (re-)produced, and enacted, often in ways that challenge hegemonic discourses of gender and sexuality. By examining word frequencies and collocations, we critically analyze some of the themes, processes, and patterns of representation in the texts. Although rooted in linguistics, we hope this article provides an accessible, interdisciplinary, and timely contribution toward developing understandings of discursive practices surrounding gender and sexuality

    EXPRESS: Trajectories of verbal fluency and executive functions in multilingual and monolingual children and adults: A cross-sectional study

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    The development of verbal fluency is associated with the maturation of executive function skills, such as the ability to inhibit irrelevant information, shift between tasks and hold information in working memory. Some evidence suggests that multilinguistic upbringing may underpin disadvantages in verbal fluency and lexical retrieval, but can also afford executive function advantages beyond the language system including possible beneficial effects in older age. This study examined the relationship between verbal fluency and executive function in 324 individuals across the lifespan by assessing the developmental trajectories of English monolingual and multilingual children aged 7 to 15 years (N=154) and adults from 18 to 80 years old (N=170). The childhood data indicated patterns of improvement in verbal fluency and executive function skills as a function of age. Multilingual and monolingual children had comparable developmental trajectories in all linguistic and non-linguistic measures used in the study with the exception of planning, for which monolingual children showed a steeper improvement over the studied age range relative to multilingual children. For adults, monolinguals and multilingual participants had comparable performance on all measures with the exception of non-verbal inhibitory control and response times on the Tower of London task: monolinguals showed a steeper decline associated with age. Exploratory factor analysis indicated that verbal fluency was associated with working memory and fluid intelligence in monolingual participants but not in multilinguals. These findings raise the possibility that early acquisition of an additional language may impact on the development of the functional architecture serving high-level human cognition
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