Role of the fission yeast Taz1p in promoting genomic stability

Telomeres define the ends of eukaryotic chromosomes and comprise multiprotein complexes bound to terminal DNA sequence repeats. An intrinsic role of telomeres is to protect chromosomal termini from being processed as damaged-induced DNA breaks; this role is critical for maintaining genomic integrity. The fission yeast Taz1 protein regulates telomere functions throughout the mitotic and meiotic cell cycles. In this study, we employed biochemical, molecular and genetic analysis to dissect the regulation and role that taz1+ and other telomere proteins play in promoting genomic stability. We find during growth at low temperatures, loss of taz1+ results in decreased viability, chromosome missegregation and DNA damage checkpoint activation. Strikingly, these cells exhibit entangled chromosomes and a pronounced de novo accumulation of DNA double strand breaks (DSBs). These defects are suppressed by altered topoisomerase II function, implicating unprotected telomeres as substrates for Top2p. Furthermore, taz1δ cells are sensitive to treatments that induce DSBs suggesting a role for Taz1p in general DSB repair. Recent data obtained from 2-D DNA gel electrophoresis suggests that Taz1 is specifically required for telomere replication and that loss of Taz1 results in perturbed fork progression through both telomere and telomere associated sequences. These data suggest a model whereby aberrant replication in taz1δ cells results in entangled chromosomes, leading to a requirement for altered Top2 activity and homologous recombination. These phenotypes are specific to taz1δ cells and not other telomere mutants suggesting that Taz1 plays a central role in promoting genomic stability that is separable from its interacting partners

Using Active Shape Modeling Based on MRI to Study Morphologic and Pitch-Related Functional Changes Affecting Vocal Structures and the Airway

Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.Peer reviewedPostprin

Relationships Between Vocal Structures, the Airway, and Craniocervical Posture Investigated Using Magnetic Resonance Imaging

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The Effects of Humming and Pitch on Craniofacial and Craniocervical Morphology Measured Using MRI

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Political Parties and Primaries in Kentucky

This is a study of Kentucky political parties: how they are organized and how they nominate and elect candidates. Because state politics in Kentucky is dominated by the Democratic Party, a major portion of the study is devoted to the Democratic primary candidates, campaign techniques, funding, of elections, and voting patterns. As in other states, campaign techniques in Kentucky are changing. During the 1950s and 1960s the Democratic Party had two dominant factions, and candidates for statewide office sought factional allies among local party organizations. Now factional alignments have disappeared, and candidates for statewide office build campaign organizations from thousands of active party workers. The characteristics, motivations, and allegiances of these party activists form one major focus of this book. Another focus is television, which has assumed ever greater importance in statewide primary campaigns. Because it is expensive, candidates who are wealthy or can raise large sums for television advertising enter the primaries with a substantial advantage, and those who use that medium most effectively are most likely to win. Two wealthy candidates who proved to be talented campaigners in person and on television were nominated by the Democrats in 1987: Wallace Wilkinson in the gubernatorial race and Brereton Jones in the race for lieutenant governor. The book features case studies of these two campaigns, which in many ways typify modern primary elections in Kentucky. Finally, since the 1950s, the Republican Party has been highly successful in campaigns for national office in Kentucky but has been unable to elect a governor since 1967. This study provides some answers to two questions: What is wrong with the Republican Party in Kentucky? And why are so many Kentuckians voting Republican in national races and Democratic in state races? Penny M. Miller is assistant professor of political science at Temple University. Malcolm E. Jewell is professor of political science at the University of Kentucky.https://uknowledge.uky.edu/upk_political_science_american_politics/1021/thumbnail.jp

The Shapiro Conjecture: Prompt or Delayed Collapse in the head-on collision of neutron stars?

We study the question of prompt vs. delayed collapse in the head-on collision of two neutron stars. We show that the prompt formation of a black hole is possible, contrary to a conjecture of Shapiro which claims that collapse is delayed until after neutrino cooling. We discuss the insight provided by Shapiro's conjecture and its limitation. An understanding of the limitation of the conjecture is provided in terms of the many time scales involved in the problem. General relativistic simulations in the Einstein theory with the full set of Einstein equations coupled to the general relativistic hydrodynamic equations are carried out in our study.Comment: 4 pages, 7 figure

Applications of responsive small satellites with MIT TILE electrospray propulsion

Responsive, manoeuvrable small satellites are an enabling technology for affordable, flexible and agile space missions with possible applications as wide-reaching as military reconnaissance, disaster response, and even wildlife tracking. This paper presents an analysis of some of these applications and is the outcome of a four month collaborative research visit at the Space Propulsion Laboratory of the Massachusetts Institute of Technology. This work builds upon the analytical satellite manoeuvring strategy previously developed by the author, and analyses the potential capabilities and applications of small satellites equipped with the MIT TILE electrospray thruster. This previously developed analytical method enables the rapid investigation of the manoeuvres of a constellation of small satellites, with the goal of targeting a particular region on the Earth. A full overview of the solution space can be rapidly generated, allowing for the mission designer or operator to trade off all possible manoeuvres and select the best solution for their specific purpose. The MIT TILE is a modular, miniaturised MEMS based propulsion system for nanosatellites capable of producing 350μN nominal thrust for up to 200hrs operation. A standard TILE system weighs <450g and is sized to fit in 0.5U of a CubeSat. Three case studies are presented which demonstrate the effectiveness of responsive satellites in disaster response missions. The first case study considers a rapid flyover of Los Angeles following an earthquake. The results show a reduction in flyover time of almost 9 days using 21m/s Δ퐕 when compared with a non-manoeuvring satellite. A second case study considers a fire detection constellation of 24 satellites, which can manoeuvre to provide targeted coverage of a given region as required. Selecting the Cairngorms National Park in Scotland, UK as the region of interest, the results show that by manoeuvring the constellation to directly target the region, an increase in coverage is achievable over the entire target area, with total coverage times of some areas more than doubled from 3.4 minutes coverage in a week to 8.4 minutes. The final case study considers providing communication services to helicopters at a range of locations from the UK to Svalbard, Norway. The manoeuvring capabilities of the satellites are used to follow the helicopters over an eight week period. Results show that a single satellite using <150m/s ΔV can achieve 50 flyovers of the helicopters during the journey, compared with 24 flyovers if a static satellite is used. These missions are all shown to be possible with existing technologies, and they exemplify the dramatic improvement in performance that can be achieved by using manoeuvrable satellites