@inproceedings{10748, abstract = {The study of fluxoid states and fluxoid dynamics in mesoscopic iron-based superconducting rings is valuable for characterizing the basic properties of the superconductor, and may also provide important insight into the superconducting paring symmetry. We report the fabrications of micron-sized rings and disks from thin films of Fe(Se, Te) grown by molecular beam epitaxy. In order to study fluxoid states in rings we developed a custom-tailored version of magnetic force microscopy (MFM). This technique has a number of qualitative advantages for working with mesoscopic superconducting samples in comparison to the conventional MFM and other imaging techniques. We observed metastable fluxoid states in rings of different sizes. Thermally activated fluxoid dynamics of these states was studied and modeled. In addition, we found different regimes of interaction between Fe(Se, Te) ring and MFM tip which are explained. Possibilities of the existence of exotic vortex states and proposals for experiments to test the symmetry of the superconducting order parameter in iron based superconductors are analyzed.}, author = {Polshyn, Hryhoriy and Zhang, Can and Naibert, Tyler and Eckstein, James and Budakian, Raffi}, booktitle = {APS March Meeting 2015}, issn = {0003-0503}, location = {San Antonio, TX, United States}, number = {1}, publisher = {American Physical Society}, title = {{Study of Fe (Se, Te) micron-sized rings by magnetic force microscopy}}, volume = {60}, year = {2015}, } @article{10794, abstract = {Mathematical models are of fundamental importance in the understanding of complex population dynamics. For instance, they can be used to predict the population evolution starting from different initial conditions or to test how a system responds to external perturbations. For this analysis to be meaningful in real applications, however, it is of paramount importance to choose an appropriate model structure and to infer the model parameters from measured data. While many parameter inference methods are available for models based on deterministic ordinary differential equations, the same does not hold for more detailed individual-based models. Here we consider, in particular, stochastic models in which the time evolution of the species abundances is described by a continuous-time Markov chain. These models are governed by a master equation that is typically difficult to solve. Consequently, traditional inference methods that rely on iterative evaluation of parameter likelihoods are computationally intractable. The aim of this paper is to present recent advances in parameter inference for continuous-time Markov chain models, based on a moment closure approximation of the parameter likelihood, and to investigate how these results can help in understanding, and ultimately controlling, complex systems in ecology. Specifically, we illustrate through an agricultural pest case study how parameters of a stochastic individual-based model can be identified from measured data and how the resulting model can be used to solve an optimal control problem in a stochastic setting. In particular, we show how the matter of determining the optimal combination of two different pest control methods can be formulated as a chance constrained optimization problem where the control action is modeled as a state reset, leading to a hybrid system formulation.}, author = {Parise, Francesca and Lygeros, John and Ruess, Jakob}, issn = {2296-665X}, journal = {Frontiers in Environmental Science}, keywords = {General Environmental Science}, publisher = {Frontiers}, title = {{Bayesian inference for stochastic individual-based models of ecological systems: a pest control simulation study}}, doi = {10.3389/fenvs.2015.00042}, volume = {3}, year = {2015}, } @inproceedings{10796, abstract = {We consider concurrent mean-payoff games, a very well-studied class of two-player (player 1 vs player 2) zero-sum games on finite-state graphs where every transition is assigned a reward between 0 and 1, and the payoff function is the long-run average of the rewards. The value is the maximal expected payoff that player 1 can guarantee against all strategies of player 2. We consider the computation of the set of states with value 1 under finite-memory strategies for player 1, and our main results for the problem are as follows: (1) we present a polynomial-time algorithm; (2) we show that whenever there is a finite-memory strategy, there is a stationary strategy that does not need memory at all; and (3) we present an optimal bound (which is double exponential) on the patience of stationary strategies (where patience of a distribution is the inverse of the smallest positive probability and represents a complexity measure of a stationary strategy).}, author = {Chatterjee, Krishnendu and Ibsen-Jensen, Rasmus}, booktitle = {Proceedings of the Twenty-Sixth Annual ACM-SIAM Symposium on Discrete Algorithms}, isbn = {978-161197374-7}, location = {San Diego, CA, United States}, number = {1}, pages = {1018--1029}, publisher = {SIAM}, title = {{The value 1 problem under finite-memory strategies for concurrent mean-payoff games}}, doi = {10.1137/1.9781611973730.69}, volume = {2015}, year = {2015}, } @article{1106, abstract = {Circumferential skin creases Kunze type (CSC-KT) is a specific congenital entity with an unknown genetic cause. The disease phenotype comprises characteristic circumferential skin creases accompanied by intellectual disability, a cleft palate, short stature, and dysmorphic features. Here, we report that mutations in either MAPRE2 or TUBB underlie the genetic origin of this syndrome. MAPRE2 encodes a member of the microtubule end-binding family of proteins that bind to the guanosine triphosphate cap at growing microtubule plus ends, and TUBB encodes a β-tubulin isotype that is expressed abundantly in the developing brain. Functional analyses of the TUBB mutants show multiple defects in the chaperone-dependent tubulin heterodimer folding and assembly pathway that leads to a compromised yield of native heterodimers. The TUBB mutations also have an impact on microtubule dynamics. For MAPRE2, we show that the mutations result in enhanced MAPRE2 binding to microtubules, implying an increased dwell time at microtubule plus ends. Further, in vivo analysis of MAPRE2 mutations in a zebrafish model of craniofacial development shows that the variants most likely perturb the patterning of branchial arches, either through excessive activity (under a recessive paradigm) or through haploinsufficiency (dominant de novo paradigm). Taken together, our data add CSC-KT to the growing list of tubulinopathies and highlight how multiple inheritance paradigms can affect dosage-sensitive biological systems so as to result in the same clinical defect.}, author = {Isrie, Mala and Breuss, Martin and Tian, Guoling and Hansen, Andi H and Cristofoli, Francesca and Morandell, Jasmin and Kupchinsky, Zachari A and Sifrim, Alejandro and Rodriguez Rodriguez, Celia and Dapena, Elena P and Doonanco, Kurston and Leonard, Norma and Tinsa, Faten and Moortgat, Stéphanie and Ulucan, Hakan and Koparir, Erkan and Karaca, Ender and Katsanis, Nicholas and Marton, Valeria and Vermeesch, Joris R and Davis, Erica E and Cowan, Nicholas J and Keays, David and Van Esch, Hilde}, journal = {The American Journal of Human Genetics}, number = {6}, pages = {790 -- 800}, publisher = {Cell Press}, title = {{Mutations in either TUBB or MAPRE2 cause circumferential skin creases Kunze type}}, doi = {10.1016/j.ajhg.2015.10.014}, volume = {97}, year = {2015}, } @article{11079, abstract = {Aging is a major risk factor for many human diseases, and in vitro generation of human neurons is an attractive approach for modeling aging-related brain disorders. However, modeling aging in differentiated human neurons has proved challenging. We generated neurons from human donors across a broad range of ages, either by iPSC-based reprogramming and differentiation or by direct conversion into induced neurons (iNs). While iPSCs and derived neurons did not retain aging-associated gene signatures, iNs displayed age-specific transcriptional profiles and revealed age-associated decreases in the nuclear transport receptor RanBP17. We detected an age-dependent loss of nucleocytoplasmic compartmentalization (NCC) in donor fibroblasts and corresponding iNs and found that reduced RanBP17 impaired NCC in young cells, while iPSC rejuvenation restored NCC in aged cells. These results show that iNs retain important aging-related signatures, thus allowing modeling of the aging process in vitro, and they identify impaired NCC as an important factor in human aging.}, author = {Mertens, Jerome and Paquola, Apuã C.M. and Ku, Manching and Hatch, Emily and Böhnke, Lena and Ladjevardi, Shauheen and McGrath, Sean and Campbell, Benjamin and Lee, Hyungjun and Herdy, Joseph R. and Gonçalves, J. Tiago and Toda, Tomohisa and Kim, Yongsung and Winkler, Jürgen and Yao, Jun and HETZER, Martin W and Gage, Fred H.}, issn = {1934-5909}, journal = {Cell Stem Cell}, keywords = {Cell Biology, Genetics, Molecular Medicine}, number = {6}, pages = {705--718}, publisher = {Elsevier}, title = {{Directly reprogrammed human neurons retain aging-associated transcriptomic signatures and reveal age-related nucleocytoplasmic defects}}, doi = {10.1016/j.stem.2015.09.001}, volume = {17}, year = {2015}, }