cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The subalgebra of graded central polynomials of an associative algebra
Creators: name: Deryabina, Galina
name: Krasilnikov, Alexei
Publisher: name: arXiv
Year: 2014
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 16R10, 16R40

description: Let $F$ be a field and let $F \langle X \rangle$ be the free unital associative $F$-algebra on the free generating set $X = \{ x_1, x_2, \dots \}$. A subalgebra (a vector subspace) $V$ in $F \langle X \rangle$ is called a $T$-subalgebra (a $T$-subspace) if $ϕ(V) \subseteq V$ for all endomorphisms $ϕ$ of $F \langle X \rangle$. For an algebra $G$, its central polynomials form a $T$-subalgebra $C(G)$ in $F \langle X \rangle$. Over a field of characteristic $p > 2$ there are algebras $G$ whose algebras of all central polynomials $C (G)$ are not finitely generated as $T$-subspaces in $F \langle X \rangle$. However, no example of an algebra $G$ such that $C(G)$ is not finitely generated as a $T$-subalgebra is known yet. In the present paper we construct the first example of a $2$-graded unital associative algebra $B$ over a field of characteristic $p>2$ whose algebra $C_2 (B)$ of all $2$-graded central polynomials is not finitely generated as a $T_2$-subalgebra in the free $2$-graded unital associative $F$-algebra $F \langle Y,Z \rangle$. Here $Y = \{ y_1, y_2, \dots \}$ and $Z = \{ z_1, z_2, \dots \}$ are sets of even and odd free generators of $F \langle Y,Z \rangle$, respectively. We hope that our example will help to construct an algebra $G$ whose algebra $C(G)$ of (ordinary) central polynomials is not finitely generated as a $T$-subalgebra in $F \langle X \rangle$.
description: 8 pages
Perturbation bounds and degree of imprecision for uniquely convergent imprecise Markov chains
Creators: name: Škulj, Damjan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60J10

description: The effect of perturbations of parameters for uniquely convergent imprecise Markov chains is studied. We provide the maximal distance between the distributions of original and perturbed chain and maximal degree of imprecision, given the imprecision of the initial distribution. The bounds on the errors and degrees of imprecision are found for the distributions at finite time steps, and for the stationary distributions as well.
description: 20 pages, 2 figures
Characterization of HPV and host genome interactions in primary head and neck cancers
Creators: name: Song, X.
name: Mahadeshwar, H.
name: Haddad, R. I.
name: Xu, A. W.
name: Ren, X.
name: Wilkerson, M. D.
name: Jung, J.
name: Gehlenborg, N.
name: Ivanova, E. V.
name: Pantazi, A.
name: Hayes, D. N.
name: Meyerson, M.
name: Zhang, J.
name: Issaeva, N.
name: El-Naggar, A. K.
name: Hadjipanayis, A. G.
name: Tang, J.
name: Parfenov, M.
name: Park, P. J.
name: Pedamallu, C. S.
name: Bristow, C. A.
name: Danilova, L.
name: Protopopov, A.
name: Seth, S.
name: Wheeler, D. A.
name: Yarbrough, W. G.
name: Ojesina, A. I.
name: Santoso, N.
name: Freeman, S. S.
name: Lee, S.
name: Yang, L.
name: Grandis, J. R.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: A significant proportion of head and neck cancer is driven by human papillomavirus (HPV) infection, and the expression of viral oncogenes is involved in the development of these tumors. However, the role of HPV integration in primary tumors beyond increasing the expression of viral oncoproteins is not understood. Here, we describe how HPV integration impacts the host genome by amplification of oncogenes and disruption of tumor suppressors as well as driving inter- and intrachromosomal rearrangements. Tumors that do and do not have HPV integrants display distinct gene expression profiles and DNA methylation patterns, which further support the view that the mechanisms by which tumors with integrated and nonintegrated HPV arise are distinct.
Asteroseismic grid-modelling of the binary system KIC 9163796
Creators: name: Grossmann, Desmond
name: Beck, Paul G.
name: Mathur, Savita
name: Johnston, Cole
name: Zinn, Joel
name: Cassisi, Santi
name: Godoy-Rivera, Diego
name: García, Rafael A.
name: Liagre, Bastien
name: Allende, Carlos
Publisher: name: Zenodo
Year: 2024

description: The age of a star cannot be measured but only inferred from observational quantities related to age. For stars in the red-giant phase, classical methods such as isochrone fitting can deliver ages with statistical uncertainties between 30% and 50%. Asteroseismic modelling is known to provide the most precise ages for red giants to date. Furthermore, modelling the observables provided by double-lined spectroscopic (SB2) binaries enables us to test the input physics and break parameter degeneracies. Combining asteroseismic constraints with those from dynamics offers a unique opportunity to improve the stellar parameters as well as the age of the system. In this talk, we present the results of the in-depth modelling analysis of KIC 9163796, an oscillating subgiant and red-giant SB2 binary system with almost identical masses, but with its components at significantly different positions in the HR diagram. Using a multi-dimensional grid computed with the stellar evolution code MESA, we modelled both binary components with different sets of observables. By exploiting the constraints from binarity, we test for the effect of the mixing-length parameter, initial helium, and the inclusion of the global seismic parameters on the joint stellar evolution. This yields an age estimation for the binary system of ~2 Gyr. We show that by combining asteroseismic and binarity constraints, the age uncertainty obtained from stellar modelling can be significantly decreased.
Symmetry and Lie-Frobenius reduction of differential equations
Creators: name: Gaeta, Giuseppe
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mathematical Physics (math-ph)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: Twisted symmetries, widely studied in the last decade, proved to be as effective as standard ones in the analysis and reduction of nonlinear equations. We explain this effectiveness in terms of a Lie-Frobenius reduction; this requires to focus not just on the prolonged (symmetry) vector fields but on the distributions spanned by these and on systems of vector fields in involution in Frobenius sense, not necessarily spanning a Lie algebra.
description: 27 pages; to appear in J. Phys. A
An optimal method for scheduling observations of large sky error regions for finding optical counterparts to transients
Creators: name: Rana, Javed
name: Singhal, Akshat
name: Gadre, Bhooshan
name: Bhalerao, Varun
name: Bose, Sukanta
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The discovery and subsequent study of optical counterparts to transient sources is crucial for their complete astrophysical understanding. Various gamma ray burst (GRB) detectors, and more notably the ground--based gravitational wave detectors, typically have large uncertainties in the sky positions of detected sources. Searching these large sky regions spanning hundreds of square degrees is a formidable challenge for most ground--based optical telescopes, which can usually image less than tens of square degrees of the sky in a single night. We present algorithms for optimal scheduling of such follow--up observations in order to maximize the probability of imaging the optical counterpart, based on the all--sky probability distribution of the source position. We incorporate realistic observing constraints like the diurnal cycle, telescope pointing limitations, available observing time, and the rising/setting of the target at the observatory location. We use simulations to demonstrate that our proposed algorithms outperform the default greedy observing schedule used by many observatories. Our algorithms are applicable for follow--up of other transient sources with large positional uncertainties, like Fermi--detected GRBs, and can easily be adapted for scheduling radio or space--based X--ray followup.
description: Submitted to ApJ. 18 pages, 15 figures
Childhood bullying involvement predicts low-grade systemic inflammation into adulthood
Creators: name: Worthman, C.
name: Lereya, S. T.
name: Shanahan, L.
name: Copeland, W. E.
name: Wolke, D.
name: Costello, E. J.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: Bullying is a common childhood experience that affects children at all income levels and racial/ethnic groups. Being a bully victim has long-term adverse consequences on physical and mental health and financial functioning, but bullies themselves display few ill effects. Here, we show that victims suffer from greater increases in low-grade systemic inflammation from childhood to young adulthood than are seen in others. In contrast, bullies showed lower increases in inflammation into adulthood compared with those uninvolved in bullying. Elevated systemic low-grade inflammation is a mechanism by which this common childhood social adversity may get under the skin to affect adult health functioning, even many years later.
Errors bounds for finite approximations of coherent lower previsions on finite probability spaces
Creators: name: Škulj, Damjan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 90C90

description: Coherent lower previsions are general probabilistic models allowing incompletely specified probability distributions. However, for complete description of a coherent lower prevision -- even on finite underlying sample spaces -- an infinite number of assessments is needed in general. Therefore, they are often only described approximately by some less general models, such as coherent lower probabilities or in terms of some other finite set of constraints. The magnitude of error induced by the approximations has often been neglected in the literature, despite the fact that it can be significant, with substantial impact on consequent decisions. An apparent reason is that no widely used general method for estimating the error seems to be available at the moment. This paper provides a practically applicable method that allows calculating an upper bound for the maximal error induced by approximating a coherent lower probability with its values on a finite set of gambles. An algorithm is also provided with an estimation of its computational complexity.
description: 23 pages, 5 figures, 1 table, 2 algorithms
Cryo-EM structure of the small subunit of the mammalian mitochondrial ribosome
Creators: name: Booth, T. M.
name: Spremulli, L. L.
name: Sanbonmatsu, K. Y.
name: Agrawal, R. K.
name: Sharma, M. R.
name: Tung, C.-S.
name: Kaushal, P. S.
name: Haque, E. M.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: The mitochondrial ribosome (mitoribosome) is a macromolecular complex that plays a central role in mitochondrial protein synthesis. Its small subunit is involved directly in the recruitment and decoding of mitochondrial mRNAs. Defects in mitochondrial translation, including mutations in components of the mitoribosome, are known to cause numerous human genetic diseases. Thus, knowledge of the molecular architecture of the mitoribosome is essential for a better understanding of those diseases and of the process of translation. To our knowledge, this article describes the first detailed cryo-EM structure of the small subunit of the mammalian mitoribosome. The study provides important clues about the evolution of this macromolecular complex and reveals unique structural features that could be important in the translation of the unusual mitochondrial mRNAs.
Detection of brown adipose tissue and thermogenic activity in mice by hyperpolarized xenon MRI
Creators: name: Burant, Alex
name: Floyd, Carlos S.
name: White, Christian
name: Zhang, Le
name: He, Ting
name: Branca, Rosa Tamara
name: Freeman, Matthew
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: In recent years, there has been a growing interest in brown adipose tissue (BAT), a tissue specialized in nonshivering thermogenesis and considered to be the next therapeutic target against obesity and diabetes. However, the detection of this very sparse tissue still represents a major challenge. To our knowledge, we report the first in vivo detection of BAT and thermogenic activity by hyperpolarized xenon gas MRI. We show that during thermogenic activity a more than 15-fold enhancement in xenon uptake by BAT enables us to clearly differentiate this tissue from the surrounding tissue and to thereby overcome the major limitations of conventional imaging methods. We also use lipid-dissolved hyperpolarized xenon chemical shift to demonstrate direct in vivo MR thermometry of BAT.
Collisions of three-dimensional bipolar optical solitons in an array of carbon nanotubes
Creators: name: Zhukov, Alexander V.
name: Bouffanais, Roland
name: Malomed, Boris A.
name: Leblond, Hervé
name: Mihalache, Dumitru
name: Fedorov, Eduard G.
name: Rosanov, Nikolay N.
name: Belonenko, Mikhail B.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We study interactions of extremely short three-dimensional bipolar electromagnetic pulses propagating towards each other in an array of semiconductor carbon nanotubes, along any direction perpendicular to their axes. The analysis provides a full account of the effects of the nonuniformity of the pulses' fields along the axes. The evolution of the electromagnetic field and charge density in the sample is derived from the Maxwell's equations and the continuity equation, respectively. In particular, we focus on indirect interaction of the pulses via the action of their fields on the electronic subsystem of the nanotube array. Changes in the shape of pulses in the course of their propagation and interaction are analyzed by calculating and visualizing the distribution of the electric field in the system. The numerical analysis reveals a possibility of stable post-collision propagation of pulses over distances much greater than their sizes.
Detection of genomic variations and DNA polymorphisms and impact on analysis of meiotic recombination and genetic mapping
Creators: name: Chen, Yamao
name: Qi, Ji
name: Copenhaver, Gregory P.
name: Ma, Hong
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: Genetic analyses require allelic markers, which are often DNA polymorphisms and can be analyzed by using short reads from high-throughput sequencing. Therefore, accuracy in genetic studies depends on correct identification of DNA polymorphic markers, but genomic structural variants increase the complexity of allelic detection and must be carefully accounted for to avoid errors. Here, we examine potential mistakes in single-nucleotide polymorphism calling caused by structural variants and their impact on detecting meiotic recombination events. Our results demonstrate that it is crucial to examine structural variants in genetic analysis with DNA marker detection by using short reads, with implications for a wide range of genetic analyses.
INDIGENOUS PRACTICES MILITATING AGAINST BIODIVERSITY CONSERVATION IN CROSS RIVER STATE, NIGERIA.
Creators: name: Ulayi, Agnes
name: Omang, Theresa
name: Ojong, Aganyi
name: Onnoghen, Usang  Nkanu
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 410401
subject: Conservation and biodiversity

description: The main purpose of the study was to describe the influence of indigenous practices militating against biodiversity conservation as a veritable tool for sustainable development in Cross River State, Nigeria. “Three purpose of the study and three null hypothesis were used in the study''. Literature was reviewed based on the variable under study. Survey research design was adopted for the study. The population of the study was 360 farmers who dwells within the state rainforest and a sample of 184 respondents was used for the study using 51% of the total population. An instrument named ''Indigenous Practices Militating against Biodiversity Conservation Questionnaire was used for data collection. The reliability of the instrument was determined using Cronbach Alpha reliability method at .05 level of significance. Data collected were analyzed using Simple linear regression test statistics. The findings from the results revealed that indigenous practices have a significant influence with biodiversity conservation in Cross River State, Nigeria. It is therefore recommended that environmental educators should be employed at the grass root level to conduct advocacy programmes for sustainable development practices for equitable environmental sustainability, and the need for indigenous knowledge should be emphasized while making environmental policies.
Ena/VASP Enabled is a highly processive actin polymerase tailored to self-assemble parallel-bundled F-actin networks with Fascin
Creators: name: Bilancia, C. G.
name: Peifer, M.
name: Winkelman, J. D.
name: Kovar, D. R.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: Enabled/vasodilator-stimulated phosphoprotein (Ena/VASP) proteins are required for the formation and maintenance of filopodia, finger-like projections at the leading edge of migrating cells that are composed of parallel actin filaments bundled by Fascin. We imaged individual fluorescently labeled Drosophila Ena molecules on both single and Fascin-bundled actin filaments in vitro. Ena stimulates actin assembly by remaining continuously associated with the barbed end and increasing the elongation rate by approximately two- to threefold. Remarkably, the frequency and length of Ena’s processive runs are enhanced on filaments within a Fascin bundle, which drives a positive feedback cycle that allows the assembly of uniformly thick filopodia-like F-actin bundles composed of multiple filaments with aligned ends.
Marginal and Conditional Second Laws of Thermodynamics
Creators: name: Crooks, Gavin E.
name: Still, Susanne E.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We consider the entropy production of a strongly coupled bipartite system. The total entropy production can be partitioned into various components, which we use to define local versions of the Second Law that are valid without the usual idealization of weak coupling. The key insight is that causal intervention offers a way to identify those parts of the entropy production that result from feedback between the sub-systems. From this the central relations describing the thermodynamics of strongly coupled systems follow in a few lines.
Transiting Planets with LSST I: Potential for LSST Exoplanet Detection
Creators: name: Lund, Michael B.
name: Pepper, Joshua
name: Stassun, Keivan G.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The Large Synoptic Survey Telescope (LSST) has been designed in order to satisfy several different scientific objectives that can be addressed by a ten-year synoptic sky survey. However, LSST will also provide a large amount of data that can then be exploited for additional science beyond its primary goals. We demonstrate the potential of using LSST data to search for transiting exoplanets, and in particular to find planets orbiting host stars that are members of stellar populations that have been less thoroughly probed by current exoplanet surveys. We find that existing algorithms can detect in simulated LSST light curves the transits of Hot Jupiters around solar-type stars, Hot Neptunes around K dwarfs, and planets orbiting stars in the Large Magellanic Cloud. We also show that LSST would have the sensitivity to potentially detect Super-Earths orbiting red dwarfs, including those in habitable zone orbits, if they are present in some fields that LSST will observe. From these results, we make the case that LSST has the ability to provide a valuable contribution to exoplanet science.
description: 18 pages, 12 figures, 2 tables; accepted to Astronomical Journal
Engineered kinase activation reveals unique morphodynamic phenotypes and associated trafficking for Src family isoforms
Creators: name: Dagliyan, O.
name: Karginov, A. V.
name: Elston, T. C.
name: Chu, P.-H.
name: Tsygankov, D.
name: Gomez, S. M.
name: Hahn, K. M.
name: Berginski, M. E.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: Src family kinases (SFKs), critical in many aspects of homeostasis and disease, occur as multiple isoforms. It has been difficult to dissect the unique function of each isoform because their structures are so similar. Here we specifically activated each SFK isoform through insertion of an engineered domain. The domain caused the kinases to be catalytically inactive until they were reactivated by the small molecule rapamycin. Computational methods for quantifying dynamic changes in cell shape revealed that activation of each isoform produced dramatically different cell behaviors. Quantitative analysis showed that these behaviors correlated with specific patterns of subcellular trafficking, and depended on isoform acylation.
Growth mechanisms of perturbations in boundary layers over a compliant wall
Creators: name: Malik, M.
name: Skote, Martin
name: Bouffanais, Roland
Publisher: name: arXiv
Year: 2017
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The temporal modal and nonmodal growth of three-dimensional perturbations in the boundary-layer flow over an infinite compliant flat wall is considered. Using a wall-normal velocity/wall-normal vorticity formalism, the dynamic boundary condition at the compliant wall admits a linear dependence on the eigenvalue parameter, as compared to a quadratic one in the canonical formulation of the problem. This greatly simplifies the accurate calculation of the continuous spectrum by means of a spectral method, thereby yielding a very effective filtering of the pseudospectra as well as a clear identification of instability regions. The regime of global instability is found to be matching the regime of the favorable phase of the forcing by the flow on the compliant wall so as to enhance the amplitude of the wall. An energy-budget analysis for the least-decaying hydroelastic (static-divergence, traveling-wave-flutter and near-stationary transitional) and Tollmien--Schlichting modes in the parameter space reveals the primary routes of energy flow. Moreover, the flow exhibits a slower transient growth for the maximum growth rate of a superposition of streamwise-independent modes due to a complex dependence of the wall-boundary condition with the Reynolds number. The initial and optimal perturbations are compared with the boundary-layer flow over a solid wall; differences and similarities are discussed. Unlike the solid-wall case, viscosity plays a pivotal role in the transient growth. A slowdown of the maximum growth rate with the Reynolds number is uncovered and found to originate in the transition of the fluid-solid interaction from a two-way to a one-way coupling. Finally, a term-by-term energy budget analysis is performed to identify the key contributors to the transient growth mechanism.
Functional trait space and the latitudinal diversity gradient
Creators: name: McGill, B. J.
name: Blonder, B.
name: Wiser, S. K.
name: Schildhauer, M.
name: Regetz, J.
name: Spencer, N.
name: Piel, W. H.
name:  imova, I.
name: Donoghue, J. C.
name: Violle, C.
name: Svenning, J.-C.
name: Peet, R. K.
name: Enquist, B. J.
name: Buzzard, V.
name: Dolins, S.
name: Boyle, B.
name: Marcuse-Kubitza, A.
name: Sandel, B.
name: Morueta-Holme, N.
name: Lamanna, C.
name: Jorgensen, P. M.
name: Thiers, B.
name: Kraft, N. J. B.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: We present a conceptual framework for testing theories for the latitudinal gradient of species richness in terms of variation in functional diversity at the alpha, beta, and gamma scales. We compared ecological community theory with large-scale observational data of tree species richness and functional diversity. We found that the patterns of functional trait diversity are not consistent with any one theory of species diversity. These conflicting results indicate that none of the broad classes of biodiversity theory considered here is alone able to explain the latitudinal gradient of species diversity in terms of functional trait space.
Cold and warm atomic gas around the Perseus molecular cloud I: Basic Properties
Creators: name: Stanimirovic, Snezana
name: Murray, Claire E.
name: Lee, Min-Young
name: Heiles, Carl
name: Miller, Jesse
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: (Abridged) Using the Arecibo Observatory we have obtained neutral hydrogen (HI) absorption and emission spectral pairs in the direction of 26 background radio continuum sources in the vicinity of the Perseus molecular cloud. Strong absorption lines were detected in all cases allowing us to estimate spin temperature (T_s) and optical depth for 107 individual Gaussian components along these lines of sight. Basic properties of individual HI clouds (spin temperature, optical depth, and the column density of the cold and warm neutral medium, CNM and WNM) in and around Perseus are very similar to those found for random interstellar lines of sight sampled by the Millennium HI survey. This suggests that the neutral gas found in and around molecular clouds is not atypical. However, lines of sight in the vicinity of Perseus have on average a higher total HI column density and the CNM fraction, suggesting an enhanced amount of cold HI relative to an average interstellar field. Our estimated optical depth and spin temperature are in stark contrast with the recent attempt at using Planck data to estimate properties of the optically thick HI. Only ~15% of lines of sight in our study have a column density weighted average spin temperature lower than 50 K, in comparison with >85% of Planck's sky coverage. The observed CNM fraction is inversely proportional to the optical-depth weighted average spin temperature, in excellent agreement with the recent numerical simulations by Kim et al. While the CNM fraction is on average higher around Perseus relative to a random interstellar field, it is generally low, 10-50%. This suggests that extended WNM envelopes around molecular clouds, and/or significant mixing of CNM and WNM throughout molecular clouds, are present and should be considered in the models of molecule and star formation.
description: 23 pages; accepted for publication in ApJ
Genetic variation associated with euphorigenic effects of d-amphetamine is associated with diminished risk for schizophrenia and attention deficit hyperactivity disorder
Creators: name: Hultman, C. M.
name: Crosbie, J.
name: Kahler, A. K.
name: Palmer, A. A.
name: Buitelaar, J. K.
name: Hart, A. B.
name: McGough, J. J.
name: Sullivan, P. F.
name: Engelhardt, B. E.
name: Faraone, S. V.
name: Kuntsi, J.
name: Sklar, P.
name: Cormand, B.
name: Neale, B. M.
name: Elia, J.
name: Casas, M.
name: Banaschewski, T.
name: Neale, B.
name: de Wit, H.
name: Cox, N. J.
name: Kent, L.
name: Bayes, M.
name: Faraone, S. V.
name: Doyle, A. E.
name: Loo, S. K.
name: Franke, B.
name: Asherson, P.
name: Medland, S. E.
name: Lesch, K.-P.
name: Gamazon, E. R.
name: Biederman, J.
name: Anney, R.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: We show that the genetic susceptibility to the euphoric effects of d-amphetamine also influences the genetic predisposition to schizophrenia and attention deficit hyperactivity disorder (ADHD). These results reinforce the idea that dopamine plays a role in schizophrenia and ADHD; this so-called dopamine hypothesis has been debated for several decades. Specifically, we found that the alleles associated with increased euphoric response to d-amphetamine were associated with decreased risk for schizophrenia and ADHD. These results illustrate how an acute challenge with a pharmacological agent can reveal a genetic predisposition that will manifest itself as psychiatric illness over the lifetime of an individual. Finally, our study offers a relatively novel paradigm for the analysis of endophenotypes for which large sample sizes are not typically available.
Swarm-Enabling Technology for Multi-Robot Systems
Creators: name: Chamanbaz, Mohammadreza
name: Mateo, David
name: Zoss, Brandon M.
name: Tokić, Grgur
name: Wilhelm, Erik
name: Bouffanais, Roland
name: Yue, and Dick K. P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Swarm robotics has experienced a rapid expansion in recent years, primarily fueled by specialized multi-robot systems developed to achieve dedicated collective actions. These specialized platforms are in general designed with swarming considerations at the front and center. Key hardware and software elements required for swarming are often deeply embedded and integrated with the particular system. However, given the noticeable increase in the number of low-cost mobile robots readily available, practitioners and hobbyists may start considering to assemble full-fledged swarms by minimally retrofitting such mobile platforms with a swarm-enabling technology. Here, we report one possible embodiment of such a technology designed to enable the assembly and the study of swarming in a range of general-purpose robotic systems. This is achieved by combining a modular and transferable software toolbox with a hardware suite composed of a collection of low-cost and off-the-shelf components. The developed technology can be ported to a relatively vast range of robotic platforms with minimal changes and high levels of scalability. This swarm-enabling technology has successfully been implemented on two distinct distributed multi-robot systems, a swarm of mobile marine buoys and a team of commercial terrestrial robots. We have tested the effectiveness of both of these distributed robotic systems in performing collective exploration and search scenarios, as well as other classical cooperative behaviors. Experimental results on different swarm behaviors are reported for the two platforms in uncontrolled environments and without any supporting infrastructure. The design of the associated software library allows for a seamless switch to other cooperative behaviors, and also offers the possibility to simulate newly designed collective behaviors prior to their implementation onto the platforms.
Wikipedia and Open Access
Creators: name: Colavizza, Giovanni
Publisher: name: Zenodo
Year: 2023

description: Wikipedia is a well-known platform for disseminating knowledge, and scientific sources, such as journal articles, play a critical role in supporting its mission. The open access movement aims to make scientific knowledge openly available, and we might intuitively expect open access to help further Wikipedia's mission. However, the extent of this relationship remains largely unknown. To fill this gap, we analyzed a large dataset of citations from Wikipedia and modelled the role of open access in Wikipedia's citation patterns. We find that open-access articles are extensively and increasingly more cited in Wikipedia. What is more, they show a 15% higher likelihood of being cited in Wikipedia when compared to closed-access articles, after controlling for confounding factors. We name this the "open-access citation effect", which is particularly strong for articles with low citation counts, including recently published ones. Our results confirm how open access plays a key role in the dissemination of scientific knowledge, including by providing Wikipedia editors timely access to novel results.
Guanylate binding proteins promote caspase-11-dependent pyroptosis in response to cytoplasmic LPS
Creators: name: Ernst, R. K.
name: Yamamoto, M.
name: Hagar, J. A.
name: Miao, E. A.
name: Pfeffer, K.
name: Mason, A. K.
name: Degrandi, D.
name: Haldar, A. K.
name: Pilla, D. M.
name: Coers, J.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: A major component of the cell envelope of Gram-negative bacteria is LPS, also known as endotoxin. LPS produced during bacterial infections triggers inflammation, which can lead to septic shock and death. Our immune system can recognize LPS both outside and inside of cells. The recognition of extracellular and vacuolar LPS by LPS binding proteins is well described, but little is known about the recognition of cytoplasmic LPS. Here, we show that cytoplasmic LPS derived from the intracellular bacterial pathogen Legionella activated a proinflammatory immune response. We further identified host guanylate binding proteins as critical mediators of immunity triggered by cytoplasmic LPS. These findings are likely to advance our understanding of how cells can sense intracellular LPS.
IL-6/STAT3 promotes regeneration of airway ciliated cells from basal stem cells
Creators: name: Tadokoro, T.
name: Wang, Y.
name: Bai, Y.
name: Barak, L. S.
name: Randell, S. H.
name: Hogan, B. L. M.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: The airways of the lungs are lined by ciliated and secretory epithelial cells important for mucociliary clearance. When these cells are damaged or lost, they are replaced by the differentiation of basal stem cells. Little is known about how this repair is orchestrated by signaling pathways in the epithelium and underlying stroma. We present evidence using cultured airway cells and genetic manipulation of a mouse model of airway repair that the cytokine IL-6 promotes the differentiation of ciliated vs. secretory cells. This process involves direct Stat3 regulation of genes controlling both cell fate (Notch1) and the differentiation of multiciliated cells (Multicilin and forkhead box protein J1). Moreover, the major producer of IL-6 appears to be mesenchymal cells in the stroma rather than immune cells.
Würde: Negation und Anerkennung in einem konkreten Kontext der Befreiung
Creators: name: Dussel, Enrique
Publisher: name: Concilium
Year: 1970

description: Concilium, Bd. 39 Nr. 2 (2003): Concilium: Internationale Zeitschrift für Theologie, Band 39, Heft 2
Experience Replay Using Transition Sequences
Creators: name: Karimpanal, Thommen George
name: Bouffanais, Roland
Publisher: name: arXiv
Year: 2017
Subjects: subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Experience replay is one of the most commonly used approaches to improve the sample efficiency of reinforcement learning algorithms. In this work, we propose an approach to select and replay sequences of transitions in order to accelerate the learning of a reinforcement learning agent in an off-policy setting. In addition to selecting appropriate sequences, we also artificially construct transition sequences using information gathered from previous agent-environment interactions. These sequences, when replayed, allow value function information to trickle down to larger sections of the state/state-action space, thereby making the most of the agent's experience. We demonstrate our approach on modified versions of standard reinforcement learning tasks such as the mountain car and puddle world problems and empirically show that it enables better learning of value functions as compared to other forms of experience replay. Further, we briefly discuss some of the possible extensions to this work, as well as applications and situations where this approach could be particularly useful.
description: 23 pages, 6 figures
Three-dimensional light bullets in a Bragg medium with carbon nanotubes
Creators: name: Zhukov, Alexander V.
name: Bouffanais, Roland
name: Belonenko, Mikhail B.
name: Dvuzhilov, Ilya S.
name: Nevzorova, Yulia V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optics (physics.optics)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We present a theoretical study of the propagation of three-dimensional extremely short electromagnetic pulses (a.k.a. light bullets) through a Bragg medium containing an immersed array of carbon nanotubes. We demonstrate the possible stable propagation of such light bullets. In particular, our results suggest these light bullets can carry information about the Bragg medium itself.
description: To appear in Appl. Phys. B
Improving the lens design and performance of a contemporary electromagnetic shock wave lithotripter
Creators: name: Mitran, Sorin
name: Lipkin, Michael Eric
name: Kuntz, Nicholas John
name: Zhong, Pei
name: Neisius, Andreas
name: Madden, John Francis
name: Smith, Nathan B.
name: Fovargue, Daniel E.
name: Sankin, Georgy
name: Preminger, Glenn M.
name: Simmons, Walter Neal
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: Electromagnetic (EM) shock wave lithotripters are widely used for noninvasive treatment of kidney stone patients. Here, we report the design of a new acoustic lens to rectify three fundamental drawbacks in contemporary EM lithotripters, based on in situ pulse superposition, leading to significantly improved stone comminution both in vitro and in vivo with minimal tissue injury. The new lens design improves the pressure distribution around the lithotripter focus with better alignment of the peak pressure and cavitation activities with the kidney stones under clinically relevant treatment conditions. The general principle of the new lens design is applicable to different lenses or reflectors and with further optimizations may enhance the performance and safety of contemporary EM lithotripters.
Plane-extraction from depth-data using a Gaussian mixture regression model
Creators: name: Marriott, Richard T.
name: Paschevich, Alexander
name: Horaud, Radu
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: We propose a novel algorithm for unsupervised extraction of piecewise planar models from depth-data. Among other applications, such models are a good way of enabling autonomous agents (robots, cars, drones, etc.) to effectively perceive their surroundings and to navigate in three dimensions. We propose to do this by fitting the data with a piecewise-linear Gaussian mixture regression model whose components are skewed over planes, making them flat in appearance rather than being ellipsoidal, by embedding an outlier-trimming process that is formally incorporated into the proposed expectation-maximization algorithm, and by selectively fusing contiguous, coplanar components. Part of our motivation is an attempt to estimate more accurate plane-extraction by allowing each model component to make use of all available data through probabilistic clustering. The algorithm is thoroughly evaluated against a standard benchmark and is shown to rank among the best of the existing state-of-the-art methods.
description: 11 pages, 2 figures, 1 table
INAUGURAL ARTICLE by a Recently Elected Academy Member:Lineage-specific expansions of TET/JBP genes and a new class of DNA transposons shape fungal genomic and epigenetic landscapes
Creators: name: Zhang, Dapeng
name: Rao, Anjana
name: Pukkila, Patricia J.
name: Iyer, Lakshminarayan M.
name: de Souza, Robson F.
name: Aravind, L.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: 5-Methylcytosine in DNA of eukaryotes, such as humans, is an important epigenetic mark. The recently characterized TET/JBP enzymes generate oxidized derivatives of methylcytosine, such as hydroxy-, formyl-, and carboxymethylcytosine in mammals, which serve as further epigenetic marks or intermediates for demethylation. Unlike animals, which contain one to three TET genes, fungi, such as mushrooms and rusts, display lineage-specific expansions with numerous TET/JBP genes, which are often associated with a unique class of transposable elements. We present evidence that expansion and turnover of these elements and associated TET/JBP genes play important roles in genomic organization, epigenetics, and speciation of fungal lineages, especially basidiomycetes (mushrooms, rusts, and smuts). Domesticated versions of these transposons might also participate in genome rearrangements or repair in humans.
Are the different layers of a social network conveying the same information?
Creators: name: Manivannan, Ajaykumar
name: Yow, W. Quin
name: Bouffanais, Roland
name: Barrat, Alain
Publisher: name: arXiv
Year: 2018
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Social and Information Networks (cs.SI)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Comprehensive and quantitative investigations of social theories and phenomena increasingly benefit from the vast breadth of data describing human social relations, which is now available within the realm of computational social science. Such data are, however, typically proxies for one of the many interaction layers composing social networks, which can be defined in many ways and are typically composed of communication of various types (e.g., phone calls, face-to-face communication, etc.). As a result, many studies focus on one single layer, corresponding to the data at hand. Several studies have, however, shown that these layers are not interchangeable, despite the presence of a certain level of correlations between them. Here, we investigate whether different layers of interactions among individuals lead to similar conclusions with respect to the presence of homophily patterns in a population---homophily represents one of the widest studied phenomenon in social networks. To this aim, we consider a dataset describing interactions and links of various nature in a population of Asian students with diverse nationalities, first language and gender. We study homophily patterns, as well as their temporal evolutions in each layer of the social network. To facilitate our analysis, we put forward a general method to assess whether the homophily patterns observed in one layer inform us about patterns in another layer. For instance, our study reveals that three network layers---cell phone communications, questionnaires about friendship, and trust relations---lead to similar and consistent results despite some minor discrepancies. The homophily patterns of the co-presence network layer, however, does not yield any meaningful information about other network layers.
Surface and interface effects on a magnetic Chern insulator
Creators: name: Ozawa, Ryo
name: Udagawa, Masafumi
name: Akagi, Yutaka
name: Motome, Yukitoshi
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Effects of an open surface on a magnetic Chern insulator are investigated in comparison with those of an interface to a capping magnetic layer. In magnets, an open surface often perturbs the magnetic order by a reconstruction of the magnetic moment directions near the surface. On the other hand, in topological insulators, it leads to the formation of topologically protected surface states. These two contrasting effects may coexist in magnetic Chern insulators, which give rise to nontrivial surface reconstruction. For instance, the chiral edge current is largely enhanced by the edge reconstruction in a two-dimensional magnetic Chern insulator realized in a quarter-filled Kondo lattice model on a triangular lattice. We here show that the edge reconstruction can be described semiquantitatively by a simple junction model between the bulk topological magnetic state and a ferromagnetic capping layer. We further clarify how the chiral edge current is affected by the magnetic structure in the capping layer. Our results indicate that the topological edge state can be controlled magnetically through the junctions.
description: 6 pages, 4 figures
Integrating the invisible fabric of nature into fisheries management
Creators: name: Auster, P. J.
name: Coleman, F. C.
name: Cury, P. M.
name: Travis, J.
name: Power, M. E.
name: Wootton, J. T.
name: Orensanz, J.
name: Steneck, R. S.
name: Peterson, C. H.
name: Estes, J. A.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: Overfishing and environmental change have triggered many severe and unexpected consequences. As existing communities have collapsed, new ones have become established, fundamentally transforming ecosystems to those that are often less productive for fisheries, more prone to cycles of booms and busts, and thus less manageable. We contend that the failure of fisheries science and management to anticipate these transformations results from a lack of appreciation for the nature, strength, complexity, and outcome of species interactions. Ecologists have come to understand that networks of interacting species exhibit nonlinear dynamics and feedback loops that can produce sudden and unexpected shifts. We argue that fisheries science and management must follow this lead by developing a sharper focus on species interactions and how disrupting these interactions can push ecosystems in which fisheries are embedded past their tipping points.
Propagation of three-dimensional bipolar ultrashort electromagnetic pulses in an inhomogeneous array of carbon nanotubes
Creators: name: Fedorov, Eduard G.
name: Zhukov, Alexander V.
name: Bouffanais, Roland
name: Timashkov, Alexander P.
name: Malomed, Boris A.
name: Leblond, Hervé
name: Mihalache, Dumitru
name: Rosanov, Nikolay N.
name: Belonenko, Mikhail B.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Optics (physics.optics)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We study the propagation of three-dimensional (3D) bipolar ultrashort electromagnetic pulses in an inhomogeneous array of semiconductor carbon nanotubes. The heterogeneity is represented by a planar region with an increased concentration of conduction electrons. The evolution of the electromagnetic field and electron concentration in the sample are governed by the Maxwell's equations and continuity equation. In particular, non-uniformity of the electromagnetic field along the axis of the nanotubes is taken into account. We demonstrate that, depending on values of parameters of the electromagnetic pulse approaching the region with the higher electron concentration, the pulse is reflected from the region or passes it. Specifically, our simulations demonstrate that, after interacting with the higher-concentration area, the pulse can propagate steadily, without significant spreading. The possibility of such ultrashort electromagnetic pulses propagating in arrays of carbon nanotubes over distances significantly exceeding characteristic dimensions of the pulses makes it possible to consider them as 3D solitons.
description: Phys. Rev. A, In Press