5,168 research outputs found
Rational points on X_0^+ (p^r)
We show how the recent isogeny bounds due to \'E. Gaudron and G. R\'emond
allow to obtain the triviality of X_0^+ (p^r)(Q), for r>1 and p a prime
exceeding 2.10^{11}. This includes the case of the curves X_split (p). We then
prove, with the help of computer calculations, that the same holds true for p
in the range 10 < p < 10^{14}, p\neq 13. The combination of those results
completes the qualitative study of such sets of rational points undertook in
previous papers, with the exception of p=13.Comment: 16 pages, no figur
AN INVESTIGATION OF CONCENTRATED AND DISTRIBUTED STRAIN INDUCING CONSTRAINTS FOR TRAINING SHAPE MEMORY ALLOYS
This research explores concentrated and distributed strain inducing constraints for Two Way Shape Memory (TWSM) training of cantilevered NiTiNOL shape memory alloy strips via the constrained thermal cycling of deformed Martensite training method. The goal is to evaluate the performance of a tip-moment trained sample actuator, which is characterized by constant strain along the sample length, and compare it with the performance of tip-force trained sample actuators, which have root concentrated strain. The shape and net tip displacement of trained specimens is expected to vary with training constraint type and training load magnitude, rendering it uncertain which sample will have greater work potential. A training structure and systems for introducing thermal and mechanical loads were developed to provide the explored training constraints and induce TWSM. The work performance was evaluated by measuring vertical displacement of tip weights. The experimental results indicate that samples subject to strain distributing constraints during training have higher work potential than samples subject to concentrated strain inducing constraints
Network structure determines patterns of network reorganization during adult neurogenesis
New cells are generated throughout life and integrate into the hippocampus
via the process of adult neurogenesis. Epileptogenic brain injury induces many
structural changes in the hippocampus, including the death of interneurons and
altered connectivity patterns. The pathological neurogenic niche is associated
with aberrant neurogenesis, though the role of the network-level changes in
development of epilepsy is not well understood. In this paper, we use
computational simulations to investigate the effect of network environment on
structural and functional outcomes of neurogenesis. We find that small-world
networks with external stimulus are able to be augmented by activity-seeking
neurons in a manner that enhances activity at the stimulated sites without
altering the network as a whole. However, when inhibition is decreased or
connectivity patterns are changed, new cells are both less responsive to
stimulus and the new cells are more likely to drive the network into bursting
dynamics. Our results suggest that network-level changes caused by
epileptogenic injury can create an environment where neurogenic reorganization
can induce or intensify epileptic dynamics and abnormal integration of new
cells.Comment: 28 pages, 10 figure
Concise Review: Exciting Cells: Modeling Genetic Epilepsies with PatientâDerived Induced Pluripotent Stem Cells
Human induced pluripotent stem cell (iPSC) models of epilepsy are becoming a revolutionary platform for mechanistic studies and drug discovery. The skyrocketing pace of epilepsy gene discovery is vastly outstripping the development of in vivo animal models. Currently, antiepileptic drug prescribing to patients with specific genetic epilepsies is based on smallâscale clinical trials and empiricism; however, rapid production of patientâderived iPSC models will allow for precision therapy. We review iPSCâbased studies that have already afforded novel discoveries in diseases with epileptic phenotypes, as well as challenges to using iPSCâbased neurological disease models. We also discuss iPSCâderived cardiomyocyte studies of arrhythmiaâinducing ion channelopathies that exemplify novel drug discovery and use of multielectrode array technology that can be translated to epilepsy research. Beyond initial studies of Rett, Timothy, PhelanâMcDermid, and Dravet syndromes, the stage is set for groundbreaking iPSCâbased mechanistic and therapeutic discoveries in genetic epilepsies with the potential to impact patient treatment and quality of life. Stem Cells 2016;34:27â33Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134416/1/stem2203_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134416/2/stem2203.pd
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