A Perspective on Hadron Physics

The phenomena of confinement and dynamical chiral symmetry breaking are basic to understanding hadron observables. They can be explored using Dyson-Schwinger equations. The existence of a systematic, nonperturbative and symmetry preserving truncation of these equations enables the proof of exact results in QCD, and their illustration using simple but accurate models. We provide a sketch of the material qualitative and quantitative success that has been achieved in the study of pseudoscalar and vector mesons. Efforts are now turning to the study of baryons, which we exemplify via a calculation of nucleon weak and pionic form factors.Comment: 16 pages, 5 figures. Contribution to the proceedings of the "Xth Mexican Workshop on Particles and Fields," Morelia, Mexico, 6-12 Nov. 200

Genome Analysis: Birds of a Feather

This Birds-of-a-Feather session presents the national infrastructure serving genome science, including NCGAS, iPlant, XSEDE, and networks, detailing goals, resources, and projects.This research is supported by NSF Award 1062432 – ABI Development: National Center for Genome Analysis Support (NCGAS).  This research was also supported by a generous grant from the Lilly Endowment, Inc. to the Indiana University Pervasive Technology Institute

Towards Designing Profitable Courses: Predicting Student Purchasing Behaviour in MOOCs

Since their ‘official’ emergence in 2012 (Gardner and Brooks 2018), massive open online courses (MOOCs) have been growing rapidly. They offer low-cost education for both students and content providers; however, currently there is a very low level of course purchasing (less than 1% of the total number of enrolled students on a given online course opt to purchase its certificate). The most recent literature on MOOCs focuses on identifying factors that contribute to student success, completion level and engagement. One of the MOOC platforms’ ultimate targets is to become self-sustaining, enabling partners to create revenues and offset operating costs. Nevertheless, analysing learners’ purchasing behaviour on MOOCs remains limited. Thus, this study aims to predict students purchasing behaviour and therefore a MOOCs revenue, based on the rich array of activity clickstream and demographic data from learners. Specifically, we compare how several machine learning algorithms, namely RandomForest, GradientBoosting, AdaBoost and XGBoost can predict course purchasability using a large-scale data collection of 23 runs spread over 5 courses delivered by The University of Warwick between 2013 and 2017 via FutureLearn. We further identify the common representative predictive attributes that influence a learner’s certificate purchasing decisions. Our proposed model achieved promising accuracies, between 0.82 and 0.91, using only the time spent on each step. We further reached higher accuracy of 0.83 to 0.95, adding learner demographics (e.g. gender, age group, level of education, and country) which showed a considerable impact on the model’s performance. The outcomes of this study are expected to help design future courses and predict the profitability of future runs; it may also help determine what personalisation features could be provided to increase MOOC revenue

Dynamical chiral symmetry breaking and a critical mass

On a bounded, measurable domain of non-negative current-quark mass, realistic models of QCD's gap equation can simultaneously admit two inequivalent dynamical chiral symmetry breaking (DCSB) solutions and a solution that is unambiguously connected with the realisation of chiral symmetry in the Wigner mode. The Wigner solution and one of the DCSB solutions are destabilised by a current-quark mass and both disappear when that mass exceeds a critical value. This critical value also bounds the domain on which the surviving DCSB solution possesses a chiral expansion. This value can therefore be viewed as an upper bound on the domain within which a perturbative expansion in the current-quark mass around the chiral limit is uniformly valid for physical quantities. For a pseudoscalar meson constituted of equal mass current-quarks, it corresponds to a mass m_{0^-}~0.45GeV. In our discussion we employ properties of the two DCSB solutions of the gap equation that enable a valid definition of in the presence of a nonzero current-mass. The behaviour of this condensate indicates that the essentially dynamical component of chiral symmetry breaking decreases with increasing current-quark mass.Comment: 9 pages, 7 figures. Minor wording change

Consistent Paternity Skew through Ontogeny in Peron's Tree Frog (Litoria peronii)

BackgroundA large number of studies in postcopulatory sexual selection use paternity success as a proxy for fertilization success. However, selective mortality during embryonic development can lead to skews in paternity in situations of polyandry and sperm competition. Thus, when assessment of paternity fails to incorporate mortality skews during early ontogeny, this may interfere with correct interpretation of results and subsequent evolutionary inference. In a previous series of in vitro sperm competition experiments with amphibians (Litoria peronii), we showed skewed paternity patterns towards males more genetically similar to the female.Methodology/Principal FindingsHere we use in vitro fertilizations and sperm competition trials to test if this pattern of paternity of fully developed tadpoles reflects patterns of paternity at fertilization and if paternity skews changes during embryonic development. We show that there is no selective mortality through ontogeny and that patterns of paternity of hatched tadpoles reflects success of competing males in sperm competition at fertilization.Conclusions/SignificanceWhile this study shows that previous inferences of fertilization success from paternity data are valid for this species, rigorous testing of these assumptions is required to ensure that differential embryonic mortality does not confound estimations of true fertilization success.<br /

National Center for Genome Analysis Program Year 2 Report – September 15, 2012 – September 14, 2013

On September 15, 2011, Indiana University (IU) received three years of support to establish the National Center for Genome Analysis Support (NCGAS). This technical report describes the activities of the second 12 months of NCGASThe facilities supported by the Research Technologies division at Indiana University are supported by a number of grants. The authors would like to acknowledge that although the National Center for Genome Analysis Support is funded by NSF 1062432, our work would not be possible without the generous support of the following awards received by our parent organization, the Pervasive Technology Institute at Indiana University. • The Indiana University Pervasive Technology Institute was supported in part by two grants from the Lilly Endowment, Inc. • NCGAS has also been supported directly by the Indiana METACyt Initiative. The Indiana METACyt Initiative of Indiana University is supported in part by the Lilly Endowment, Inc. • This material is based in part upon work supported by the National Science Foundation under Grant No. CNS-0521433. Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation (NSF)

Technical Report: TeraGrid eXtreme Digital Campus Cyberinfrastructure and Campus Bridging Requirements Elicitation Meeting

In an effort to systematically investigate requirements for TeraGrid XD, the XROADS collaboration held during 2009 a series of requirements elicitation meetings (REM) with small groups of stakeholders. This report summarizes the conduct of and results from a requirements elicitation meeting on the topics of campus bridging and campus cyberinfrastructure. The meeting’s goal was to develop a clearer and more functional definition of what the next phase of the TeraGrid should do to be a resource broadly useful to and used by university and college campuses throughout the US.This report depends very much on the prior involvement of several XROADS partners in the TeraGrid, which has been funded in part by the NSF via the following grant awards: 0504086, 0503697, and 0742145 to the University of Chicago; 0451237 and 0504075 to Indiana University; and 0122272, 0332113, 0451566, 0503944, 0910847 to the University of California San Diego

Growth Mindset: Associations with Apprehension, Self-Perceived Competence, and Beliefs about Public Speaking

The relationships among growth mindset for public speaking (i.e., the implicit theory that public speaking abilities can be developed and improved) and beliefs about the nature of public speaking, public speaking apprehension (PSA), and self-perceived public speaking competence (SPPSC) were investigated in intensive and traditional formats of a general education public speaking course. In general, growth mindset was associated with lower PSA, higher SPPSC, and more sophisticated beliefs about public speaking. Mindset remained somewhat stable, PSA significantly decreased, and SPPSC significantly increased from the beginning to the end of the course. More sophisticated beliefs about public speaking as an expressive, transformational, and audience-centric endeavor also tended to increase. However, there were several important differences between intensive and traditional formats. In particular, changes in the intensive format were more consistent across variables and had larger effect sizes

Cyberinfrastructure, Science Gateways, Campus Bridging, and Cloud Computing

Computers accelerate our ability to achieve scientific breakthroughs. As technology evolves and new research needs come to light, the role for cyberinfrastructure as “knowledge” infrastructure continues to expand. This article defines and discusses cyberinfrastructure and the related topics of science gateways and campus bridging; identifies future challenges in cyberinfrastructure; and discusses challenges and opportunities related to the evolution of cyberinfrastructure, “big data” (datacentric, data-enabled, and data-intensive research and data analytics), and cloud computing.This material is based upon work supported by the National Science Foundation under grants 0504075, 0451237, 0723054, 1062432, 0116050, 0521433, 0503697, and 1053575, and several IBM Shared University Research grants and support provided by Lilly Endowment, Inc. for the Indiana University Pervasive Technology Institute. Any opinions, findings and conclusions or recommendations expressed herein are those of the authors and do not necessarily reflect the views of the supporting agencies