Characterizing the Inhibition of Katanin Using Tubulin Carboxy-Terminal Tail Constructs

Understanding how the cellular cytoskeleton is maintained and regulated is important to elucidate the functions of many structures such as the mitotic spindle, cilia and flagella. Katanin p60, microtubule-severing enzymes from the ATPase associated with cellular activities (AAA+) family, has previously been shown in our lab to be inhibited by free tubulin as well as α- and β-tubulin carboxy-terminal tail (CTT) constructs. Here we investigate the inhibition ability of several different tubulin CTT sequences. We quantify the effect of the addition of these constructs on the severing and binding activity of katanin. We find that some constructs inhibit katanin better than others and two constructs that appear to enhance katanin activity. Our findings add nuance to our previous findings that consensus α-tubulin tails are less inhibitory of katanin than consensus β-tubulin [3]. Surprisingly, we find that a polyglutamate sequence activates katanin while it has previously been shown to inhibit spastin, a different microtubule-severing enzyme associated with the neuromuscular disease Hereditary Spastic Paraplegia [23]. These results highlight that different CTT sequences can control the activity of severing enzymes and ultimately affect the cytoskeletal network organization in a cell type and location-dependent manner

Black-Male Imagos and Counternarrative Resistance: An Africana Existentialist Framework for Black-Male Analysis

James Baldwin describes the Black male in the White gaze as a “fixed star,” meaning that there is only one way that Black males can be, and that way is deviant. However, we often do not examine what happens in Black-male psychology because of the social ascription of criminality, via tropes like the “Myth of the Black-Male Rapist” and “thug.” In this project, I investigate what this does to Black-male freedom and self-recognition. I make the argument that narratives influence one’s concept of self and that the political negotiation one must do in return impedes their freedom. To help solve this problem, I argue for a resistance methodology based on historical transparency and storytelling. I argue that instead of strictly doing moments of resistance in identity politics of exceptionalism, like wearing suits or code-switching to protect oneself, we should illuminate the colonial history in African-American male experiences that created these tropes and this social landscape that Black males must navigate. In doing so, the ascriptions are unveiled as lies, both conscious and subconscious, and Black males can engage in a resistance that refuses to perform against White expectations. This methodology seeks to put the agency back in Black males’ hands and assert that Black males were never normatively criminal

From Student to Teacher: Renegotiating Professional Identities

This case-study examines how first-year educators renegotiated their teacher identities as they transitioned from pre-service teachers (PSTs) to professionals. Both participants graduated from the same Teacher Education Program (TEP) and conducted their student internship in the same school as their first year of teaching. The results of this study have unique implications on first-year teachers working in the location of their student internships, as they reported isolation, internalized infantilization, and inconsistent identities. The author argues for TEPs to intentionally prepare PSTs for navigating this transition, and challenge preconceived notions of the benefits of student teaching and working in the same K-12 institution

Studies of nucleon-gold collisions at 200 GeV per nucleon pair using tagged d+Au interactions

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2006.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 201-212).The spectra of charged hadrons produced near mid-rapidity in d+Au, p+Au and n+Au collisions at - = 200 GeV are presented as a function of transverse momentum and centrality. These measurements were performed using the PHOBOS detector at the Relativistic Heavy Ion Collider (RHIC). Nucleon-nucleus interactions were extracted from the d+Au data by identifying the deuteron spectators. The deuteron spectators were measured using two calorimeters; one that detected forward-going single neutrons and a newly installed calorimeter that detected forward-going single protons. The large suppression of high-pr hadron production in central Au+Au interactions relative to a naive superposition of p+p collisions has been interpreted as evidence of partonic energy loss in a dense medium. This interpretation is founded upon the absence of such suppression in the yield of d+Au collisions. The validity of using d+Au interactions in place of a nucleon-nucleus reference is tested. It is shown that hadron production in d+Au agrees with a simple binary collision scaling of hadron production in p+Au. An ideal reference for Au+Au collisions is constructed using a weighted combination of p+Au and n+Au yields and is found to be similar to the d+Au reference.(cont.) Further, hadron production in p+Au interactions is compared to that of n+Au interactions. The single charge difference between a p+Au and a n+Au collision allows for a unique study of the ability of the interaction to transport the proton from the initial deuteron to mid-rapidity. However, no asymmetry between the positively and negatively charged hadron spectra of p+Au and n+Au interactions is observed at (qr) = 0.8. Collision centrality was determined using several different observables, including those based on the multiplicity in different regions of pseudorapidity and those based on the amount of nuclear spectator material. It is shown that measurements made on small collision systems in the mid-rapidity region are biased by centrality variables based on the mid-rapidity multiplicity. Despite this bias, a smooth evolution with centrality is observed in the Cronin enhancement of hadrons produced in d+Au collisions. It is shown that this smooth progression is independent of the choice of centrality variable when centrality is parametrized by the multiplicity measured near mid-rapidity.by Corey Reed.Ph.D

Direct oral anticoagulants or warfarin for A fib?

A recent study evaluated the effectiveness of 3 direct oral anticoagulants and warfarin in patients with atrial fibrillation. So which agents came out on top? PRACTICE CHANGER: Use direct oral anticoagulants instead of warfarin in patients with atrial fibrillation because they are just as effective at preventing ischemic stroke and systemic emboli as warfarin, and because apixaban and dabigatran have lower bleeding rates. Stength of recommendation: B: Based on a single, prospective, cohort study

Does exercise relieve vasomotor menopausal symptoms?

Q: Does exercise relieve vasomotor menopausal symptoms? A: NO. Exercise doesn't decrease the frequency or severity of vasomotor menopausal symptoms (VMS) in perimenopausal and postmenopausal women (strength of recommendation: A, systematic review of randomized controlled trials [RCTs] and consistent RCT).Authors: Corey Lyon, DO; Rebecca Mullen, MD; Brandy Deffenbacher, MD; Alex Reed, PhD University of Colorado Family Medicine Residency, Denver; Joan Nashelsky, MLS Family Physicians Inquiries Network, Iowa City

Usage of Hybrid Project Management Approaches and Influences on Approach Selection

Changes in technologies and practitioner approaches to project management have led to a mix known as hybrid. This research identifies approaches practitioners currently use and determines possible influences on how a project manager selects an approach for a project. Four hundred participants completed a survey questionnaire to help identify methodologies in use. Additionally, participants reviewed a list of 39 specific project management tools and techniques to indicate their level of use for each of them. Our findings indicate that few project managers exclusively employ agile methodologies without the incorporation of predictive techniques and tools. Chi-square analysis was used to analyze industry, project manager experience level, and type of project to determine the influence on approach selection. The results showed that industry and type of project were important to selection, but a project manager\u27s level of experience was not. A qualitative analysis identified two additional important factors of company policy and team experience. Overall, the study supported that there is no best approach to managing projects, but hybrid is emerging as a predominant approach to exploit the benefits of multiple approaches. Additionally, the data implies a need for greater support, resources, or education to facilitate the successful implementation and longevity of adaptive project management approaches

Engineering, nutrient removal, and feedstock conversion evaluations of four corn stover harvest scenarios

Crop residue has been identified as a near-term source of biomass for renewable fuel, heat, power, chemicals and other bio-materials. A prototype one-pass harvest system was used to collect residue samples from a corn (Zea mays L.) field near Ames, IA. Four harvest scenarios (low cut, high-cut top, high-cut bottom, and normal cut) were evaluated and are expressed as collected stover harvest indices (CSHI). High-cut top and high-cut bottom samples were obtained from the same plot in separate operations. Chemical composition, dilute acid pretreatment response, ethanol conversion yield and efficiency, and thermochemical conversion for each scenario were determined. Mean grain yield in this study (10.1 Mg ha−1 dry weight) was representative of the average yield (10.0 Mg ha−1) for the area (Story County, IA) and year (2005). The four harvest scenarios removed 6.7, 4.9, 1.7, and 5.1 Mg ha−1 of dry matter, respectively, or 0.60 for low cut, 0.66 for normal cut, and 0.61 for the total high-cut (top+bottom) scenarios when expressed as CSHI values. The macro-nutrient replacement value for the normal harvest scenario was $57.36 ha−1 or$11.27 Mg−1. Harvesting stalk bottoms increased stover water content, risk of combine damage, estimated transportation costs, and left insufficient soil cover, while also producing a problematic feedstock. These preliminary results indicate harvesting stover (including the cobs) at a height of approximately 40 cm would be best for farmers and ethanol producers because of faster harvest speed and higher quality ethanol feedstock

Multimessenger parameter inference of gravitational-wave and electromagnetic observations of white dwarf binaries

The upcoming Laser Interferometer Space Antenna (LISA) will detect a large gravitational-wave foreground of Galactic white dwarf binaries. These sources are exceptional for their probable detection at electromagnetic wavelengths, some long before LISA flies. Studies in both gravitational and electromagnetic waves will yield strong constraints on system parameters not achievable through measurements of one messenger alone. In this work, we present a Bayesian inference pipeline and simulation suite in which we study potential constraints on binaries in a variety of configurations. We show how using LISA detections and parameter estimation can significantly improve constraints on system parameters when used as a prior for the electromagnetic analyses. We also provide rules of thumb for how current measurements will benefit from LISA measurements in the future.Comment: 8 pages, 5 figures, accepted to MNRA