137 research outputs found
Stochastic Modeling of Early Hematopoiesis
No full textHematopoiesis is the body's way of making the cellular constituents of blood. Oxygen transport, response to infections, and control of bleeding are among the functions of different mature blood cells. These specific functions are acquired as cells mature in the bone marrow. Stem cells are the "master cells" at the top of this pedigree, having within them the capacity to reconstitute the entire system. While the latter stages of hematopoiesis are fairly well understood, the functioning of stem cells and other multi-potential cells is currently a matter of intense research. This paper presents a statistical analysis providing support for the clonal succession model of early hematopoiesis. J. L. Abkowitz and colleagues at the University of Washington have developed an experimental method for studying the kinetics of early hematopoiesis in a hybrid cat. The essence of the method is to analyze G6PD, an enzyme linked to the X-chromosome. The G6PD type of a cell forms a binary marker that is ..
Kinetics and specificity of feline leukemia virus subgroup C receptor (FLVCR) export function and its dependence on hemopexin.
No full textThe feline leukemia virus subgroup C receptor (FLVCR) is a heme export protein that is required for proerythroblast survival and facilitates macrophage heme iron recycling. However, its mechanism of heme export and substrate specificity are uncharacterized. Using [(55)Fe]heme and the fluorescent heme analog zinc mesoporphyrin, we investigated whether export by FLVCR depends on the availability and avidity of extracellular heme-binding proteins. Export was 100-fold more efficient when the medium contained hemopexin (K(d) < 1 pm) compared with albumin (K(d) = 5 nm) at the same concentration and was not detectable when the medium lacked heme-binding proteins. Besides heme, FLVCR could export other cyclic planar porphyrins, such as protoporphyrin IX and coproporphyrin. However, FLVCR has a narrow substrate range because unconjugated bilirubin, the primary breakdown product of heme, was not transported. As neither protoporphyrin IX nor coproporphyrin export improved with extracellular hemopexin (versus albumin), our observations further suggest that hemopexin, an abundant protein with a serum concentration (6.7-25 mum) equivalent to that of the iron transport protein transferrin (22-31 mum), by accepting heme from FLVCR and targeting it to the liver, might regulate macrophage heme export and heme iron recycling in vivo. Final studies show that hemopexin directly interacts with FLVCR, which also helps explain why FLVCR, in contrast to some major facilitator superfamily members, does not function as a bidirectional gradient-dependent transporter. Together, these data argue that hemopexin has a role in assuring systemic iron balance during homeostasis in addition to its established role as a scavenger during internal bleeding or hemolysis
Approaching the crisis in medical research funding: an important role for nonprofit organizations and medical societies
No full textIn the moment: Curating chamber music performance
No full textIn this thesis, Janis Cook explores ways in which the thoughtful curation of a chamber concert can enhance the reception of the musical repertoire. This avenue of research has evolved from questioning why performances of musical artworks which reflect a significant portion of Australia’s cultural inheritance attract only a niche and arguably diminishing audience.
The author establishes points of view which emphasise the deep cultural connections inherent in music, embrace the social aspect of performance, eschew the division of the expressive realm of the arts into discrete categories, and consider the role of music in the current metamodernist milieu. A scan of historical and current performance practice precedes a discussion of the power of curation as a tool of communication.
As primary research projects, three chamber-music events apply concepts from narrative theory, the philosophy of experiential time, and the general field of arts curation. Around these curated performances, para-curatorial approaches experiment with the distribution of printed programmes after the performance, and a Pay-What-You-Want business model. The methodology consists of the design and execution of the performances as curations, analysis of informal and ethics-approved feedback about the curations, and exegesis mapped by recordings of the curated performances and the overall artistic journey. Many musical examples and video links exemplify the curatorial outcomes.
A fourth and supplementary project points to the future of the performing arts in an increasingly online world. It suggests new ways of adapting the power of curation to suit digital formats, rather than mere live-streamed or pre-recorded onstage performances, by utilising the infrastructure already in place which serves the music industry at large.
Janis Cook addresses the place of chamber music in contemporary society, the role of performing artists as art performers, and the imperative for chamber players to contribute to current culture. The study reveals strong arguments for thoughtfully designing an audience’s chamber concert experience and identifies avenues for further research.Thesis (Masters)Master of Music Research (MMusRes)Queensland ConservatoriumArts, Education and LawFull Tex
Bayesian Inference By Simulation in a Stochastic Model From Hematology
No full textA particular Markov chain Monte Carlo algorithm is constructed to allow Bayesian inference in a hidden Markov model used in hematology. The algorithm has an outer Gibbsian structure, and incorporates both Metropolis and Hastings updates to move through the space of possible hidden states. While somewhat sophisticated, this algorithm still has problems getting around the infinite-dimensional space of hidden states because of strong correlations between some of the variables. A two-step variant of the Metropolis algorithm is introduced for posterior simulation. Keywords: hidden Markov model, Metropolis algorithm, Gibbs sampler, Hastings algorithm, hematopoiesis 1. A Model Suppose that each of N people in a room is holding a coin--the probability of heads for each coin is p. Independently of one another, each person flips his/her coin at random exponentially-distributed time intervals specified by a rate parameter . Over time, X, the number of facing heads, fluctuates between 0 and N . ..
Kinetics of Central Nervous System Microglial and Macrophage Engraftment: Analysis Using a Transgenic Bone Marrow Transplantation Model
No full textKinetics of Central Nervous System Microglial and Macrophage Engraftment: Analysis Using a Transgenic Bone Marrow Transplantation Model
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