cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A Bayesian Model for Cross-Study Differential Gene Expression
Creators: name: Nobel, Andrew B.
name: Scharpf, Robert B.
name: Tjelmeland, Håkon
name: Parmigiani, Giovanni
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: In this paper we define a hierarchical Bayesian model for microarray expression data collected from several studies and use it to identify genes that show differential expression between two conditions. Key features include shrinkage across both genes and studies, and flexible modeling that allows for interactions between platforms and the estimated effect, as well as concordant and discordant differential expression across studies. We evaluated the performance of our model in a comprehensive fashion, using both artificial data, and a “split-study” validation approach that provides an agnostic assessment of the model's behavior not only under the null hypothesis, but also under a realistic alternative. The simulation results from the artificial data demonstrate the advantages of the Bayesian model. The 1 – AUC values for the Bayesian model are roughly half of the corresponding values for a direct combination of t- and SAM-statistics. Furthermore, the simulations provide guidelines for when the Bayesian model is most likely to be useful. Most noticeably, in small studies the Bayesian model generally outperforms other methods when evaluated by AUC, FDR, and MDR across a range of simulation parameters, and this difference diminishes for larger sample sizes in the individual studies. The split-study validation illustrates appropriate shrinkage of the Bayesian model in the absence of platform-, sample-, and annotation-differences that otherwise complicate experimental data analyses. Finally, we fit our model to four breast cancer studies employing different technologies (cDNA and Affymetrix) to estimate differential expression in estrogen receptor positive tumors versus negative ones. Software and data for reproducing our analysis are publicly available.
title: Accessory muscles of the posteromedial ankle: A descriptive study
Creators: name: Akkaya, Zehra
Publisher: name: European Society of Muscoskeletal Radiology
Year: 2018
Subjects: subject: Musculoskeletal joint
subject: Musculoskeletal soft tissue
subject: MR
subject: Diagnostic procedure
subject: Epidemiology

description: Purpose Methods and Materials Results Conclusion References Personal Information
description: Purpose: The accessory muscles of the posterior cruris, namely flexor digitorum accessorius longus (FDAL), peroneocalcaneus internus (PCI), tibiocalcaneus internus (TCI) and accessory soleus (AS) have been implicated in some clinically important and...
Three-Dimensional MHD Simulation of Caltech Plasma Jet Experiment: First Results
Creators: name: Zhai, Xiang
name: Li, Hui
name: Bellan, Paul M.
name: Li, Shengtai
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Magnetic fields are believed to play an essential role in astrophysical jets with observations suggesting the presence of helical magnetic fields. Here, we present three-dimensional (3D) ideal MHD simulationsof the Caltech plasma jet experiment using a magnetic tower scenario as the baseline model. Magnetic fields consist of an initially localized dipole-like poloidal component and a toroidal component that is continuously being injected into the domain. This flux injection mimics the poloidal currents driven by the anode-cathode voltage drop in the experiment. The injected toroidal field stretches the poloidal fields to large distances, while forming a collimated jet along with several other key features. Detailed comparisons between 3D MHD simulations and experimental measurements provide a comprehensive description of the interplay among magnetic force, pressure and flow effects. In particular, we delineate both the jet structure and the transition process that converts the injected magnetic energy to other forms. With suitably chosen parameters that are derived from experiments, the jet in the simulation agrees quantitatively with the experimental jet in terms of magnetic/kinetic/inertial energy, total poloidal current, voltage, jet radius, and jet propagation velocity. Specifically, the jet velocity in the simulation is proportional to the poloidal current divided by the square root of the jet density, in agreement with both the experiment and analytical theory. This work provides a new and quantitative method for relating experiments, numerical simulations and astrophysical observation, and demonstrates the possibility of using terrestrial laboratory experiments to study astrophysical jets.
description: accepted by ApJ 37 pages, 15 figures, 2 tables
An optimisation approach for analysing nonlinear stability with transition to turbulence in fluids as an exemplar
Creators: name: Kerswell, R. R.
name: Pringle, C. C. T.
name: Willis, A. P.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: This article introduces, and reviews recent work using, a simple optimisation technique for analysing the nonlinear stability of a state in a dynamical system. The technique can be used to identify the most efficient way to disturb a system such that it transits from one stable state to another. The key idea is introduced within the framework of a finite-dimensional set of ordinary differential equations (ODEs) and then illustrated for a very simple system of 2 ODEs which possesses bistability. Then the transition to turbulence problem in fluid mechanics is used to show how the technique can be formulated for a spatially-extended system described by a partial differential equation (the well-known Navier-Stokes equation). Within that context, the optimisation technique bridges the gap between (linear) optimal perturbation theory and the (nonlinear) dynamical systems approach to fluid flows. The fact that the technique has now been recently shown to work in this very high dimensional setting augurs well for its utility in other physical systems.
description: submitted copy (33 pages, 9 figures)- accepted copy on first author's website
Long-time dynamics of the Cahn--Hilliard equation with kinetic rate dependent dynamic boundary conditions
Creators: name: Garcke, Harald
name: Knopf, Patrik
name: Yayla, Sema
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 35B40, 35B41, 35K35, 35K61, 35Q92, 37L30

description: We consider a Cahn--Hilliard model with kinetic rate dependent dynamic boundary conditions that was introduced by Knopf, Lam, Liu and Metzger (ESAIM Math. Model. Numer. Anal., 2021) and will thus be called the KLLM model. In the aforementioned paper, it was shown that solutions of the KLLM model converge to solutions of the GMS model proposed by Goldstein, Miranville and Schimperna (Physica D, 2011) as the kinetic rate tends to infinity. We first collect the weak well-posedness results for both models and we establish some further essential properties of the weak solutions. Afterwards, we investigate the long-time behavior of the KLLM model. We first prove the existence of a global attractor as well as convergence to a single stationary point. Then, we show that the global attractor of the GMS model is stable with respect to perturbations of the kinetic rate. Eventually, we construct exponential attractors for both models, and we show that the exponential attractor associated with the GMS model is robust against kinetic rate perturbations.
description: This version contains some minor modifications compared to the journal version
Intrinsic Regression Models for Positive-Definite Matrices With Applications to Diffusion Tensor Imaging
Creators: name: Zhu, Hongtu
name: Ibrahim, Joseph G.
name: Chen, Yasheng
name: Hall, Colin
name: Lin, Weili
name: Li, Yimei
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: The aim of this paper is to develop an intrinsic regression model for the analysis of positive-definite matrices as responses in a Riemannian manifold and their association with a set of covariates, such as age and gender, in a Euclidean space. The primary motivation and application of the proposed methodology is in medical imaging. Because the set of positive-definite matrices do not form a vector space, directly applying classical multivariate regression may be inadequate in establishing the relationship between positive-definite matrices and covariates of interest, such as age and gender, in real applications. Our intrinsic regression model, which is a semiparametric model, uses a link function to map from the Euclidean space of covariates to the Riemannian manifold of positive-definite matrices. We develop an estimation procedure to calculate parameter estimates and establish their limiting distributions. We develop score statistics to test linear hypotheses on unknown parameters and develop a test procedure based on a resampling method to simultaneously assess the statistical significance of linear hypotheses across a large region of interest. Simulation studies are used to demonstrate the methodology and examine the finite sample performance of the test procedure for controlling the family-wise error rate. We apply our methods to the detection of statistical significance of diagnostic effects on the integrity of white matter in a diffusion tensor study of human immunodeficiency virus. Supplemental materials for this article are available online.
title: The faces of Paget's disease
Creators: name: TELLERIA BAJO, AINHOA
Publisher: name: European Society of Muscoskeletal Radiology
Year: 2018
Subjects: subject: Education
subject: PACS
subject: Musculoskeletal bone
subject: Metabolic disorders

description: Learning objectives Background Imaging findings OR Procedure Details Conclusion References Personal Information
description: Learning objectives: To update knowledge about Paget disease. To review radiological features in Paget's. To show a range of representative cases evaluated with different imaging techniques and collected in our hospital in recent...
BUDHIES IV: Deep 21-cm neutral Hydrogen, optical and UV imaging data of Abell 963 and Abell 2192 at z $\simeq$ 0.2
Creators: name: Gogate, Avanti
name: Verheijen, Marc
name: Deshev, Boris
name: Montero-Castaño, Maria
name: van Gorkom, Jacqueline
name: van der Hulst, Thijs
name: Jaffé, Yara
name: Poggianti, Bianca
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In this paper, we present data from the Blind Ultra-Deep HI Environmental Survey (BUDHIES), which is a blind 21-cm HI spectral line imaging survey undertaken with the Westerbork Synthesis Radio Telescope (WSRT). Two volumes were surveyed, each with a single pointing and covering a redshift range of 0.164 < z < 0.224. Within these two volumes, this survey targeted the clusters Abell 963 and Abell 2192, which are dynamically different and offer unique environments to study the process of galaxy evolution within clusters. With an integration time of 117x12h on Abell 963 and 72x12h on Abell 2192, a total of 166 galaxies were detected and imaged in HI. While the clusters themselves occupy only 4 per cent of the 73,400 Mpc$^3$ surveyed by BUDHIES, most of the volume consists of large-scale structures in which the clusters are embedded, including foreground and background overdensities and voids. We present the data processing and source detection techniques and counterpart identification based on a wide-field optical imaging survey using the Isaac Newton Telescope (INT) and deep ultra-violet GALEX imaging. Finally, we present HI and optical catalogues of the detected sources as well as atlases of their global HI properties, which include integrated column density maps, position-velocity diagrams, global HI profiles, and optical and UV images of the HI sources.
Calderón-Zygmund operators in the Bessel setting
Creators: name: Betancor, Jorge J.
name: Castro, Alejandro J.
name: Nowak, Adam
Publisher: name: arXiv
Year: 2010
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 42C05 (Primary) 42C20 (Secondary)

description: We study several fundamental operators in harmonic analysis related to Bessel operators, including maximal operators related to heat and Poisson semigroups, Littlewood-Paley-Stein square functions, multipliers of Laplace transform type and Riesz transforms. We show that these are (vector-valued) Calderón-Zygmund operators in the sense of the associated space of homogeneous type, and hence their mapping properties follow from the general theory.
description: 21 pages
The Next Generation Virgo cluster Survey. V. modelling the dynamics of M87 with the Made-to-Measure method
Creators: name: Zhu, Ling
name: Long, R. J.
name: Mao, Shude
name: Peng, Eric W.
name: Liu, Chengze
name: Caldwell, Nelson
name: Li, Biao
name: Blakeslee, John P.
name: Cote, Patrick
name: Cuillandre, Jean-Charles
name: Durrell, Patrick
name: Emsellem, Eric
name: Ferrarese, Laura
name: Gwyn, Stephen
name: Jordan, Andres
name: Lancon, Ariane
name: Mei, Simona
name: Munoz, Roberto
name: Puzia, Thomas
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We study the dynamics of the giant elliptical galaxy M87 from the central to the outermost regions with the made-to-measure (M2M) method. We use a new catalogue of 922 globular cluster line-of- sight velocities extending to a projected radius of 180 kpc (equivalent to 25 M87 effective radii), and SAURON integral field unit data within the central 2.4 kpc. 263 globular clusters, mainly located beyond 40 kpc, are newly observed by the Next Generation Virgo Survey (NGVS). For the M2M modelling, the gravitational potential is taken as a combination of a luminous matter potential with a constant stellar mass-to-light ratio and a dark matter potential modelled as a logarithmic potential. Our best dynamical model returns a stellar mass-to-light ratio in the I band of M/LI = 6.0(+ -0.3) M_sun/L_sun with a dark matter potential scale velocity of 591(+ -50) km/s and scale radius of 42(+ -10) kpc. We determine the total mass of M87 within 180 kpc to be (1.5 + - 0.2) 10^13 M_sun. The mass within 40 kpc is smaller than previous estimates determined using globular cluster kinematics that did not extend beyond 45 kpc. With our new globular cluster velocities at much larger radii, we see that globular clusters around 40 kpc show an anomalously large velocity dispersion which affected previous results. The mass we derived is in good agreement with that inferred from ROSAT X-ray observation out to 180 kpc. Within 30 kpc our mass is also consistent with that inferred from Chandra and XMM-Newton X-ray observations, while within 120 kpc it is about 20% smaller. The model velocity dispersion anisotropy beta parameter for the globular clusters in M87 is small, varying from -0.2 at the centre to 0.2 at 40 kpc, and gradually decreasing to zero at 120 kpc.
description: 20 pages, 16 figures, Accepted by ApJ
Random Effects Models in a Meta-Analysis of the Accuracy of Two Diagnostic Tests Without a Gold Standard
Creators: name: Louis, Thomas A.
name: Chen, Sining
name: Chu, Haitao
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: In studies of the accuracy of diagnostic tests, it is common that both the diagnostic test itself and the reference test are imperfect. This is the case for the microsatellite instability test, which is routinely used as a prescreening procedure to identify individuals with Lynch syndrome, the most common hereditary colorectal cancer syndrome. The microsatellite instability test is known to have imperfect sensitivity and specificity. Meanwhile, the reference test, mutation analysis, is also imperfect. We evaluate this test via a random effects meta-analysis of 17 studies. Study-specific random effects account for between-study heterogeneity in mutation prevalence, test sensitivities and specificities under a nonlinear mixed effects model and a Bayesian hierarchical model. Using model selection techniques, we explore a range of random effects models to identify a best-fitting model. We also evaluate sensitivity to the conditional independence assumption between the microsatellite instability test and the mutation analysis by allowing for correlation between them. Finally, we use simulations to illustrate the importance of including appropriate random effects and the impact of overfitting, underfitting, and misfitting on model performance. Our approach can be used to estimate the accuracy of two imperfect diagnostic tests from a meta-analysis of multiple studies or a multicenter study when the prevalence of disease, test sensitivities and/or specificities may be heterogeneous among studies or centers.
title: The role of CT in the Neer classification system for proximal humerus fractures – A pictorial review
Creators: name: Lameiras, Raquel
Publisher: name: European Society of Muscoskeletal Radiology
Year: 2018
Subjects: subject: Musculoskeletal system
subject: Trauma
subject: Anatomy
subject: CT
subject: Diagnostic procedure
subject: Trauma

description: Learning objectives Background Imaging findings OR Procedure Details Conclusion References Personal Information
description: Learning objectives: To review the anatomy of the proximal humerus. To review the role of CT in the Neer classification for proximal humerus...
Regression Models for Identifying Noise Sources in Magnetic Resonance Images
Creators: name: Gao, Wei
name: Ibrahim, Joseph G.
name: Lin, Weili
name: Zhu, Hongtu
name: Chen, Yashen
name: Shi, Xiaoyan
name: Peterson, Bradley S.
name: An, Hongyu
name: Rowe, Daniel B.
name: Li, Yimei
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: Stochastic noise, susceptibility artifacts, magnetic field and radiofrequency inhomogeneities, and other noise components in magnetic resonance images (MRIs) can introduce serious bias into any measurements made with those images. We formally introduce three regression models including a Rician regression model and two associated normal models to characterize stochastic noise in various magnetic resonance imaging modalities, including diffusion-weighted imaging (DWI) and functional MRI (fMRI). Estimation algorithms are introduced to maximize the likelihood function of the three regression models. We also develop a diagnostic procedure for systematically exploring MR images to identify noise components other than simple stochastic noise, and to detect discrepancies between the fitted regression models and MRI data. The diagnostic procedure includes goodness-of-fit statistics, measures of influence, and tools for graphical display. The goodness-of-fit statistics can assess the key assumptions of the three regression models, whereas measures of influence can isolate outliers caused by certain noise components, including motion artifacts. The tools for graphical display permit graphical visualization of the values for the goodness-of-fit statistic and influence measures. Finally, we conduct simulation studies to evaluate performance of these methods, and we analyze a real dataset to illustrate how our diagnostic procedure localizes subtle image artifacts by detecting intravoxel variability that is not captured by the regression models.
Robust Model-Free Multiclass Probability Estimation
Creators: name: Zhang, Hao Helen
name: Liu, Yufeng
name: Wu, Yichao
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2010

description: Classical statistical approaches for multiclass probability estimation are typically based on regression techniques such as multiple logistic regression, or density estimation approaches such as linear discriminant analysis (LDA) and quadratic discriminant analysis (QDA). These methods often make certain assumptions on the form of probability functions or on the underlying distributions of subclasses. In this article, we develop a model-free procedure to estimate multiclass probabilities based on large-margin classifiers. In particular, the new estimation scheme is employed by solving a series of weighted large-margin classifiers and then systematically extracting the probability information from these multiple classification rules. A main advantage of the proposed probability estimation technique is that it does not impose any strong parametric assumption on the underlying distribution and can be applied for a wide range of large-margin classification methods. A general computational algorithm is developed for class probability estimation. Furthermore, we establish asymptotic consistency of the probability estimates. Both simulated and real data examples are presented to illustrate competitive performance of the new approach and compare it with several other existing methods.
Complex networks of interacting stochastic tipping elements: cooperativity of phase separation in the large-system limit
Creators: name: Kohler, Jan
name: Wunderling, Nico
name: Donges, Jonathan F.
name: Vollmer, Jürgen
Publisher: name: arXiv
Year: 2021
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Chaotic Dynamics (nlin.CD)
subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: Tipping elements in the Earth System receive increased scientific attention over the recent years due to their nonlinear behavior and the risks of abrupt state changes. While being stable over a large range of parameters, a tipping element undergoes a drastic shift in its state upon an additional small parameter change when close to its tipping point. Recently, the focus of research broadened towards emergent behavior in networks of tipping elements, like global tipping cascades triggered by local perturbations. Here, we analyze the response to the perturbation of a single node in a system that initially resides in an unstable equilibrium. The evolution is described in terms of coupled nonlinear equations for the cumulants of the distribution of the elements. We show that drift terms acting on individual elements and offsets in the coupling strength are sub-dominant in the limit of large networks, and we derive an analytical prediction for the evolution of the expectation (i.e., the first cumulant). It behaves like a single aggregated tipping element characterized by a dimensionless parameter that accounts for the network size, its overall connectivity, and the average coupling strength. The resulting predictions are in excellent agreement with numerical data for Erdös-Rényi, Barabási-Albert and Watts-Strogatz networks of different size and with different coupling parameters.
Weighted Distance Weighted Discrimination and Its Asymptotic Properties
Creators: name: Liu, Yufeng
name: Zhang, Hao Helen
name: Todd, Michael J.
name: Qiao, Xingye
name: Marron, J. S.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2010

description: While Distance Weighted Discrimination (DWD) is an appealing approach to classification in high dimensions, it was designed for balanced datasets. In the case of unequal costs, biased sampling, or unbalanced data, there are major improvements available, using appropriately weighted versions of DWD (wDWD). A major contribution of this paper is the development of optimal weighting schemes for various nonstandard classification problems. In addition, we discuss several alternative criteria and propose an adaptive weighting scheme (awDWD) and demonstrate its advantages over nonadaptive weighting schemes under some situations. The second major contribution is a theoretical study of weighted DWD. Both high-dimensional low sample-size asymptotics and Fisher consistency of DWD are studied. The performance of weighted DWD is evaluated using simulated examples and two real data examples. The theoretical results are also confirmed by simulations.
title: Diagnostic accuracy of magnetic resonance arthrography of the shoulder: A comparison with arthroscopy
Creators: name: Tilden, William
Publisher: name: European Society of Muscoskeletal Radiology
Year: 2018
Subjects: subject: Trauma
subject: Arthrography
subject: MR
subject: Musculoskeletal joint
subject: Musculoskeletal bone

description: Purpose Methods and Materials Results Conclusion References Personal Information
description: Purpose: Magnetic resonance arthrography (MRA) has become a key imaging tool in identifying and characterising pathology of the glenoid labrum, with intracapsular distension of the shoulder joint allowing passage of contrast into the labral...
TinyLev Acoustically Levitated Water: Direct Observation of Collective, Inter-Droplet Effects through Morphological and Thermal Analysis of Multiple Droplets
Creators: name: McElligott, Adam
name: Guerra, André
name: Wood, Michael J.
name: Rey, Alejandro D.
name: Kietzig, Anne-Marie
name: Servio, Phillip
Publisher: name: arXiv
Year: 2023
Subjects: subject: Applied Physics (physics.app-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Initially, the acoustic field forced the droplets into an oblate spheroid shape, though the counteracting force of the cooling stream caused them to circularize. Droplet geometry was thus the net result of streaming forces and surface tension at the acoustic boundary layer/air-liquid interface. Nucleation was determined to be neither homogeneous nor heterogeneous but secondary, and thus dependent on the cooling rate and not on the degree of supercooling. It was likely initiated by aerosolized ice particles from the air or from droplets that had already nucleated and broken up. The latter secondary ice production process resulted in multi-drop systems with statistically identical nucleation times. Notably, this meant that the presence of interfacial rupture at an adjacent droplet could influence the crystallization behaviour of another. After the formation of an initial ice shell around the individual droplets, dendritic protrusions grew from the droplet surface, likely seeded by the same ice particles that caused nucleation, but at a quasi-liquid layer. When freezing was complete, it was determined that the frozen core had undergone a volumetric expansion of 30.75%, compared to 9% for pure, sessile water expansion. This significantly greater expansion may have resulted from entrained air bubbles at the inner solid-liquid interface and oscillations at the moving phase boundary caused by changes in local acoustic forces. Soon after melting began, acoustic streaming, the buoyancy of the remaining ice, and convective currents caused by an inner thermal gradient and thermocapillary effects along the air-liquid interface, all contributed to the droplet spinning about the horizontal axis.
Variation operators for semigroups associated with Fourier-Bessel expansions
Creators: name: Betancor, Jorge J.
name: Castro, Alejandro J.
name: De León-Contreras, Marta
Publisher: name: arXiv
Year: 2021
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics

description: In this paper we establish $L^p$-boundedness properties for variation operators defined by semigroups associated with Fourier-Bessel expansions.
The globular cluster system of NGC1316. III. Kinematic complexity
Creators: name: Richtler, Tom
name: Hilker, Michael
name: Kumar, Brijesh
name: Bassino, Lilia P.
name: Gomez, Matias
name: Dirsch, Boris
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The merger remnant NGC 1316 (Fornax A) is one of the most important objects regarding the investigation of merger-related processes. We use kinematical data of globular clusters (GCs) and the diffuse stellar light to investigate the global structure of NGC 1316 and to constrain the dark matter content. We perform multi-object-spectroscopy with VLT/FORS2 and MXU. Out of 562 slits, we extract radial velocities for 177 GCs. Moreover, we measure radial velocities of the integrated galaxy light, using slits with a sufficiently bright "sky". To these data, we add 20 cluster velocities from Goudfrooij et al. (2001). In an appendix, we identify new morphological features of NGC 1316 and its companion galaxy NGC 1317. The GC sample based on radial velocities confirms the colour peaks already found in our photometric study. The bright clusters, which probably have their origin in a 2 Gyr-old starburst and younger star formation events, avoid the systemic velocity. A Gaussian velocity distribution is found only for clusters fainter than about m_R=22 mag. The velocity distribution of clusters shows a pronounced peak at 1600 km/s. These clusters populate a wide area in the south-western region which we suspect to be a disk population. Globular clusters or subsamples of them do not show a clear rotation signal. This is different from the galaxy light, where rotation along the major axis is discernable out to 3 arcmin radius. A simple spherical model like that suggested by dynamical analyses of planetary nebulae reproduces also the velocity dispersions of the faint GCs. The central dark matter density of the present model resembles a giant elliptical galaxy. This contradicts population properties which indicate spiral galaxies as pre-merger components. MOND would provide a solution, but the kinematical complexity of NGC 1316 does not allow a really firm conclusion. (abridged)
description: 20 pages, A&A accepted (before language editing)
A Statistical Framework for the Analysis of ChIP-Seq Data
Creators: name: Keleş, Sündüz
name: Stewart, Ron
name: Pan, Guangjin
name: Kuan, Pei Fen
name: Chung, Dongjun
name: Thomson, James A.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: Chromatin immunoprecipitation followed by sequencing (ChIP-Seq) has revolutionalized experiments for genome-wide profiling of DNA-binding proteins, histone modifications, and nucleosome occupancy. As the cost of sequencing is decreasing, many researchers are switching from microarray-based technologies (ChIP-chip) to ChIP-Seq for genome-wide study of transcriptional regulation. Despite its increasing and well-deserved popularity, there is little work that investigates and accounts for sources of biases in the ChIP-Seq technology. These biases typically arise from both the standard pre-processing protocol and the underlying DNA sequence of the generated data.
title: Interventional radiology of the spine: Everything you need to know
Creators: name: Karimaghaei, Raham
Publisher: name: European Society of Muscoskeletal Radiology
Year: 2018
Subjects: subject: Neoplasia
subject: Equipment
subject: Drainage
subject: Biopsy
subject: Ultrasound
subject: Fluoroscopy
subject: CT
subject: Musculoskeletal spine
subject: Interventional non-vascular
subject: Bones

description: Learning objectives Background Imaging findings OR Procedure Details Conclusion References Personal Information
description: Learning objectives: Learning objectives: To understand approaches to non vascular spinal intervention using different imaging modalities. To provide an introduction to vertebral, paraspinal and disc biopsy/drainage...
Correcting for Population Stratification in Genomewide Association Studies
Creators: name: Zeng, D.
name: Lin, D. Y.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: Genomewide association studies have become the primary tool for discovering the genetic basis of complex human diseases. Such studies are susceptible to the confounding effects of population stratification, in that the combination of allele-frequency heterogeneity with disease-risk heterogeneity among different ancestral subpopulations can induce spurious associations between genetic variants and disease. This article provides a statistically rigorous and computationally feasible solution to this challenging problem of unmeasured confounders. We show that the odds ratio of disease with a genetic variant is identifiable if and only if the genotype is independent of the unknown population substructure conditional on a set of observed ancestry-informative markers in the disease-free population. Under this condition, the odds ratio of interest can be estimated by fitting a semiparametric logistic regression model with an arbitrary function of a propensity score relating the genotype probability to ancestry-informative markers. Approximating the unknown function of the propensity score by B-splines, we derive a consistent and asymptotically normal estimator for the odds ratio of interest with a consistent variance estimator. Simulation studies demonstrate that the proposed inference procedures perform well in realistic settings. An application to the well-known Wellcome Trust Case-Control Study is presented. Supplemental materials are available online.
Vector-meson production and vector meson dominance
Creators: name: Xu, Yin-Zhen
name: Chen, Si-Yang
name: Yao, Zhao-Qian
name: Binosi, Daniele
name: Cui, Zhu-Fang
name: Roberts, Craig D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Lattice (hep-lat)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We consider the fidelity of the vector meson dominance (VMD) assumption as an instrument for relating the electromagnetic vector-meson production reaction $e + p \to e^\prime + V + p$ to the purely hadronic process $V + p \to V+p$. Analyses of the photon vacuum polarisation and the photon-quark vertex reveal that such a VMD Ansatz might be reasonable for light vector-mesons. However, when the vector-mesons are described by momentum-dependent bound-state amplitudes, VMD fails for heavy vector-mesons: it cannot be used reliably to estimate either a photon-to-vector-meson transition strength or the momentum dependence of those integrands that would arise in calculations of the different reaction amplitudes. Consequently, for processes involving heavy mesons, the veracity of both cross-section estimates and conclusions based on the VMD assumption should be reviewed, e.g., those relating to hidden-charm pentaquark production and the origin of the proton mass.
description: 12 pages, 2 figures, 2 tables
title: Stratigraphic Evidence for Indigenous Use of Fire as a Dryland Agricultural Landscape Management Tool on the Northern Colorado Plateau
Creators: name: Walzer, Mariah
Publisher: name: Utah State University
Year: 2024

description: While documented in ethnography and traditional ecological knowledge, Indigenous burning practices are rarely recognized in the archaeological record of the Great Basin and Colorado Plateau. I analyzed charcoal from an arroyo wall to understand the relationship between Indigenous farmers and fire at the Cub Creek archaeological site (AD 300-1300) in Dinosaur National Monument. The size, shape, and amount of charcoal in each sediment layer indicates the fuel types (woody or grassy) and relative size and/or intensity of fires. I compared my data to a precipitation reconstruction for the area to evaluate the influence of climate on fire activity. The results indicated that fires were rare and small for over 1,000 years, despite the occurrence of drought conditions, while Indigenous peoples lived on and managed the land. Fire activity did increase around the introduction of maize agriculture about AD 300. After Indigenous people left the Cub Creek area around AD 1300, large fires returned to the landscape, particularly during periods of drought. This study demonstrates that fire histories can be constructed in settings without good fire scar datasets and within complex stratigraphic settings such as ancient arroyos. It also contributes to the archaeological evidence for Indigenous fire management practices in the American Southwest, which can help us understand how to live with fire in the face of an increasingly extreme climate
title: MR Imaging of Soft Tissue Impingement Syndromes About the Hip and Knee: Pictorial Review
Creators: name: ULUSOY, LEVENT
Publisher: name: European Society of Muscoskeletal Radiology
Year: 2018
Subjects: subject: Image verification
subject: Education and training
subject: Screening
subject: Diagnostic procedure
subject: MR
subject: Musculoskeletal soft tissue
subject: Anatomy

description: Learning objectives Background Imaging findings OR Procedure Details Conclusion References Personal Information
description: Learning objectives: The aim of this educational exhibit is to provide an overview and present imaging characteristics of soft tissue impingement syndromes in and around the hip and knee. Also to present the anatomy of the musculoskeletal structures involved by...
An analysis of the determinants of youth's weekend physical activity participation
Creators: name: Copperman, Rachel Batya Anna, 1982-
Publisher: name: The University of Texas at Austin
Year: 2005
Subjects: Youth time-use patterns
Youth’s physical activity
2000 San Francisco Bay Area travel survey

description: This thesis examines the out-of-home, weekend, time-use patterns of children and adolescents aged 5 through 17 years, with a specific emphasis on their physical activity participation. The impact of several types of factors, including individual and household demographics, neighborhood demographics, built environment characteristics, and activity day variables, on physical activity participation is analyzed using a joint nested multiple discrete-continuous extreme value-binary choice model. The sample for analysis is drawn from the 2000 San Francisco Bay Area Travel Survey. The model developed in the paper can be used to assess the impacts of changing demographics and built environment characteristics on youth’s physical activity levels
Gravity and axions from a random UV QFT
Creators: name: Kiritsis, Elias
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: It is postulated that the UV QFT is enormous and random. The coupling of the Standard Model to such QFT is analyzed. It is argued that massless 4d gravity and axions are general avatars of the postulate. The equivalence principle emerges naturally as well as a concrete set of sources for its breaking. The axion scale is related to the 4d Planck scale as $f=M_P/N$, where $N$ is the "number of colors" of the (almost) hidden UV CFT.
description: Latex, 39 pages
Enhancement of thermoelectric properties by Se substitution in layered bismuth-chalcogenide LaOBiS2-xSex
Creators: name: Mizuguchi, Yoshikazu
name: Omachi, Atsushi
name: Goto, Yosuke
name: Kamihara, Yoichi
name: Matoba, Masanori
name: Hiroi, Takafumi
name: Kajitani, Joe
name: Miura, Osuke
Publisher: name: arXiv
Year: 2014
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We have investigated the thermoelectric properties of the novel layered bismuth chalcogenides LaOBiS2-xSex. The partial substitution of S by Se produced the enhancement of electrical conductivity (metallic characteristics) in LaOBiS2-xSex. The power factor largely increased with increasing Se concentration. The highest power factor was 4.5 uW/cmK2 at around 470 deg. C for LaOBiS1.2Se0.8. The obtained dimensionless figure-of-merit (ZT) was 0.17 at around 470 deg. C in LaOBiS1.2Se0.8.
description: 13 pages, 3 figs
Hard or Soft Classification? Large-Margin Unified Machines
Creators: name: Wu, Yichao
name: Liu, Yufeng
name: Zhang, Hao Helen
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: Margin-based classifiers have been popular in both machine learning and statistics for classification problems. Among numerous classifiers, some are hard classifiers while some are soft ones. Soft classifiers explicitly estimate the class conditional probabilities and then perform classification based on estimated probabilities. In contrast, hard classifiers directly target on the classification decision boundary without producing the probability estimation. These two types of classifiers are based on different philosophies and each has its own merits. In this paper, we propose a novel family of large-margin classifiers, namely large-margin unified machines (LUMs), which covers a broad range of margin-based classifiers including both hard and soft ones. By offering a natural bridge from soft to hard classification, the LUM provides a unified algorithm to fit various classifiers and hence a convenient platform to compare hard and soft classification. Both theoretical consistency and numerical performance of LUMs are explored. Our numerical study sheds some light on the choice between hard and soft classifiers in various classification problems.
3C 220.3: a radio galaxy lensing a submillimeter galaxy
Creators: name: Haas, Martin
name: Leipski, Christian
name: Barthel, Peter
name: Wilkes, Belinda J.
name: Vegetti, Simona
name: Bussmann, R. Shane
name: Willner, S. P.
name: Westhues, Christian
name: Ashby, Matthew L. N.
name: Chini, Rolf
name: Clements, David L.
name: Fassnacht, Christopher D.
name: Horesh, Assaf
name: Klaas, Ulrich
name: Koopmans, Leon V. E.
name: Kuraszkiewicz, Joanna
name: Lagattuta, David J.
name: Meisenheimer, Klaus
name: Stern, Daniel
name: Wylezalek, Dominika
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Herschel Space Observatory photometry and extensive multiwavelength followup have revealed that the powerful radio galaxy 3C 220.3 at z=0.685 acts as a gravitational lens for a background submillimeter galaxy (SMG) at z=2.221. At an observed wavelength of 1mm, the SMG is lensed into three distinct images. In the observed near infrared, these images are connected by an arc of 1.8" radius forming an Einstein half-ring centered near the radio galaxy. In visible light, only the arc is apparent. 3C 220.3 is the only known instance of strong galaxy-scale lensing by a powerful radio galaxy not located in a galaxy cluster and therefore it offers the potential to probe the dark matter content of the radio galaxy host. Lens modeling rejects a single lens, but two lenses centered on the radio galaxy host A and a companion B, separated by 1.5", provide a fit consistent with all data and reveal faint candidates for the predicted fourth and fifth images. The model does not require an extended common dark matter halo, consistent with the absence of extended bright X-ray emission on our Chandra image. The projected dark matter fractions within the Einstein radii of A (1.02") and B (0.61") are about 0.4 +/- 0.3 and 0.55 +/- 0.3. The mass to i-band light ratios of A and B, M/L ~ 8 +/- 4 Msun/Lsun, appear comparable to those of radio-quiet lensing galaxies at the same redshift in the CASTLES, LSD, and SL2S samples. The lensed SMG is extremely bright with observed f(250um) = 440mJy owing to a magnification factor mu~10. The SMG spectrum shows luminous, narrow CIV 154.9nm emission, revealing that the SMG houses a hidden quasar in addition to a violent starburst. Multicolor image reconstruction of the SMG indicates a bipolar morphology of the emitted ultraviolet (UV) light suggestive of cones through which UV light escapes a dust-enshrouded nucleus.
description: 17 pages, 14 Figures, accepted for publication in ApJ
Resolution learning in deep convolutional networks using scale-space theory
Creators: name: Pintea, Silvia L.
name: Tomen, Nergis
name: Goes, Stanley F.
name: Loog, Marco
name: van Gemert, Jan C.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Resolution in deep convolutional neural networks (CNNs) is typically bounded by the receptive field size through filter sizes, and subsampling layers or strided convolutions on feature maps. The optimal resolution may vary significantly depending on the dataset. Modern CNNs hard-code their resolution hyper-parameters in the network architecture which makes tuning such hyper-parameters cumbersome. We propose to do away with hard-coded resolution hyper-parameters and aim to learn the appropriate resolution from data. We use scale-space theory to obtain a self-similar parametrization of filters and make use of the N-Jet: a truncated Taylor series to approximate a filter by a learned combination of Gaussian derivative filters. The parameter sigma of the Gaussian basis controls both the amount of detail the filter encodes and the spatial extent of the filter. Since sigma is a continuous parameter, we can optimize it with respect to the loss. The proposed N-Jet layer achieves comparable performance when used in state-of-the art architectures, while learning the correct resolution in each layer automatically. We evaluate our N-Jet layer on both classification and segmentation, and we show that learning sigma is especially beneficial for inputs at multiple sizes.
description: Preprint accepted by IEEE Transactions on Image Processing, 2021 (TIP). Link to final published article: https://ieeexplore.ieee.org/abstract/document/9552550
Independent Component Analysis Involving Autocorrelated Sources With an Application to Functional Magnetic Resonance Imaging
Creators: name: Lewis, Mechelle
name: Lee, Seonjoo
name: Truong, Young
name: Shen, Haipeng
name: Huang, Xuemei
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: Independent component analysis (ICA) is an effective data-driven method for blind source separation. It has been successfully applied to separate source signals of interest from their mixtures. Most existing ICA procedures are carried out by relying solely on the estimation of the marginal density functions, either parametrically or nonparametrically. In many applications, correlation structures within each source also play an important role besides the marginal distributions. One important example is functional magnetic resonance imaging (fMRI) analysis where the brain-function-related signals are temporally correlated.
Motion of a spinning particle around an improved rotating black hole
Creators: name: Ladino, Jose Miguel
name: Larrañaga, Eduard
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Using the Mathisson-Papapetrou-Dixon equations together with the Tulczyjew spin-supplementary condition, we study the circular orbits of a spinning test particle moving in the equatorial plane of a quantum improved Rotating Black Hole (RBH) spacetime. This background metric incorporates a position-dependent gravitational constant $G(r)$ and its behavior determines the quantum corrections to the properties of the Innermost Stable Circular Orbit (ISCO). The obtained results show that the radius of the event horizon as well as the radius of the ISCO for the quantum improved RBH are smaller than those of the Schwarzschild or Kerr solutions.
description: 17 pages, 8 figures