Plenary: The History of Right to Work from the First Gilded Age to Janus

From Fighting the Dangerous Classes to “Protecting” the Common Peopl

Plenary: The History of Right to Work from the First Gilded Age to Janus

From Fighting the Dangerous Classes to Protecting the Common Peopl

HPV 20 Composite Disc Wheel Design and Production Senior Project

This project report will serve to describe the goals, objectives, and overall process of the Cal Poly Mechanical Engineering senior project team, PolyWheel, in the design and fabrication of a complete set of 20” composite disc wheels for use on a high-efficiency human powered vehicle (HPV). The project will include the manufacturing of durable and reusable molds to build the wheels in order for multiple wheel sets to be made in the future. The wheels will be designed and built to be compatible with the Cal Poly HPV Team’s 2012 race bike and by other streamlined recumbent bicycles requiring a 20” wheel. The wheels need to optimize weight, rigidity, crash survivability, and aerodynamics. Design requirements for the wheel sets are being provided by the Cal Poly HPV Team and George Leone. Funding for the materials is being provided by John Neilson

Correlation of Cortisol with Non-Invasive Physiological Measures in Response to Exercise

The present study attempted to find alternative methods to measure training stress when cortisol blood analysis is not available. The relationships during exercise between cortisol and six non-invasive physiological measures (heart rate, lactate, lactate:RPE ratios, oxygen uptake, oxygen pulse, and ratings of perceived exertion) were assessed. Subjects (n = 18) participated in four experimental sessions (40%, 60%, and 80% VO2max, and control). Blood samples were taken pre- and post-exercise along with non-invasive measures being recorded throughout the exercise session. All correlations between cortisol and the non-invasive measures were significant. However, the small variance accounted for between each non-invasive measure and cortisol lead to low predictability. Individually, non-invasive measures are not viable indicators of training stress. However, exploratory step-wise multiple regression analysis revealed that when combined, blood lactate and lactate:RPE ratio are highly predictive of cortisol, suggesting that in combination they may be a plausible alternative to assess training stress

Stable Kinetochore-Microtubule Attachment Constrains Centromere Positioning in Metaphase

With a single microtubule attachment, budding-yeast kinetochores provide an excellent system for understanding the coordinated linkage to dynamic microtubule plus ends for chromosome oscillation and positioning. Fluorescent tagging of kinetochore proteins indicates that, on average, all centromeres are clustered, distinctly separated from their sisters, and positioned equidistant from their respective spindle poles during metaphase. However, individual fluorescent chromosome markers near the centromere transiently reassociate with their sisters and oscillate from one spindle half to the other. To reconcile the apparent disparity between the average centromere position and individual centromere proximal markers, we utilized fluorescence recovery after photobleaching to measure stability of the histone-H3 variant Cse4p/CENP-A. Newly synthesized Cse4p replaces old protein during DNA replication. Once assembled, Cse4-GFP is a physically stable component of centromeres during mitosis. This allowed us to follow centromere dynamics within each spindle half. Kinetochores remain stably attached to dynamic microtubules and exhibit a low incidence of switching orientation or position between the spindle halves. Switching of sister chromatid attachment may be contemporaneous with Cse4p exchange and early kinetochore assembly during S phase; this would promote mixing of chromosome attachment to each spindle pole. Once biorientation is attained, centromeres rarely make excursions beyond their proximal half spindle

Chemical Genetics Reveals a Role for Mps1 Kinase in Kinetochore Attachment during Mitosis

Accurate chromosome segregation depends on proper assembly and function of the kinetochore and the mitotic spindle. In the budding yeast, Saccharomyces cerevisiae, the highly conserved protein kinase Mps1 has well-characterized roles in spindle pole body (SPB, yeast centrosome equivalent) duplication and the mitotic checkpoint [1]. However, an additional role for Mps1 is suggested by phenotypes of MPS1 mutations that include genetic interactions with kinetochore mutations and meiotic chromosome segregation defects [1] and also by the localization of Mps1 at the kinetochore, the latter being independent of checkpoint activation [2]. We have developed a new MPS1 allele, mps1-as1, that renders the kinase specifically sensitive to a cell-permeable ATP analog inhibitor, allowing us to perform high-resolution execution point experiments that identify a novel role for Mps1 subsequent to SPB duplication. We demonstrate, by using both fixed- and live-cell fluoresence techniques, that cells lacking Mps1 function show severe defects in mitotic spindle formation, sister kinetochore positioning at metaphase, and chromosome segregation during anaphase. Taken together, our experiments are consistent with an important role for Mps1 at the kinetochore in mitotic spindle assembly and function

Basal bodies bend in response to ciliary forces

Motile cilia beat with an asymmetric waveform consisting of a power stroke that generates a propulsive force and a recovery stroke that returns the cilium back to the start. Cilia are anchored to the cell cortex by basal bodies (BBs) that are directly coupled to the ciliary doublet microtubules (MTs). We find that, consistent with ciliary forces imposing on BBs, bending patterns in BB triplet MTs are responsive to ciliary beating. BB bending varies as environmental conditions change the ciliary waveform. Bending occurs where striated fibers (SFs) attach to BBs and mutants with short SFs that fail to connect to adjacent BBs exhibit abnormal BB bending, supporting a model in which SFs couple ciliary forces between BBs. Finally, loss of the BB stability protein Poc1, which helps interconnect BB triplet MTs, prevents the normal distributed BB and ciliary bending patterns. Collectively, BBs experience ciliary forces and manage mechanical coupling of these forces to their surrounding cellular architecture for normal ciliary beating

Basal body stability and ciliogenesis requires the conserved component Poc1

Centrioles are the foundation for centrosome and cilia formation. The biogenesis of centrioles is initiated by an assembly mechanism that first synthesizes the ninefold symmetrical cartwheel and subsequently leads to a stable cylindrical microtubule scaffold that is capable of withstanding microtubule-based forces generated by centrosomes and cilia. We report that the conserved WD40 repeat domain–containing cartwheel protein Poc1 is required for the structural maintenance of centrioles in Tetrahymena thermophila. Furthermore, human Poc1B is required for primary ciliogenesis, and in zebrafish, DrPoc1B knockdown causes ciliary defects and morphological phenotypes consistent with human ciliopathies. T. thermophila Poc1 exhibits a protein incorporation profile commonly associated with structural centriole components in which the majority of Poc1 is stably incorporated during new centriole assembly. A second dynamic population assembles throughout the cell cycle. Our experiments identify novel roles for Poc1 in centriole stability and ciliogenesis