cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Galaxy bulges and their massive black holes: a review
Creators: name: Graham, Alister W.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: History and Philosophy of Physics (physics.hist-ph)
subject: FOS: Physical sciences

description: With references to both key and oft-forgotten pioneering works, this article starts by presenting a review into how we came to believe in the existence of massive black holes at the centres of galaxies. It then presents the historical development of the near-linear (black hole)-(host spheroid) mass relation, before explaining why this has recently been dramatically revised. Past disagreement over the slope of the (black hole)-(velocity dispersion) relation is also explained, and the discovery of sub-structure within the (black hole)-(velocity dispersion) diagram is discussed. As the search for the fundamental connection between massive black holes and their host galaxies continues, the competing array of additional black hole mass scaling relations for samples of predominantly inactive galaxies are presented.
description: Invited (15 Feb. 2014) review article (submitted 16 Nov. 2014). 590 references, 9 figures, 25 pages in emulateApJ format. To appear in "Galactic Bulges", E. Laurikainen, R.F. Peletier, and D.A. Gadotti (eds.), Springer Publishing
Incorporating Nonlinear Relationships in Microarray Missing Value Imputation
Creators: name: The University of North Carolina at Chapel Hill University Libraries
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: Microarray gene expression data often contain missing values. Accurate estimation of the missing values is important for down-stream data analyses that require complete data. Nonlinear relationships between gene expression levels have not been well-utilized in missing value imputation. We propose an imputation scheme based on nonlinear dependencies between genes. By simulations based on real microarray data, we show that incorporating non-linear relationships could improve the accuracy of missing value imputation, both in terms of normalized root mean squared error and in terms of the preservation of the list of significant genes in statistical testing. In addition, we studied the impact of artificial dependencies introduced by data normalization on the simulation results. Our results suggest that methods relying on global correlation structures may yield overly optimistic simulation results when the data has been subjected to row (gene) – wise mean removal.
Imaging and Elastometry of Blood Clots Using Magnetomotive Optical Coherence Tomography and Labeled Platelets
Creators: name: Oldenburg, Amy L.
name: Wolberg, Alisa S.
name: Fischer, Thomas H.
name: Wu, Gongting
name: Spivak, Dmitry
name: Tsui, Frank
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2012

description: Improved methods for imaging and assessment of vascular defects are needed for directing treatment of cardiovascular pathologies. In this paper, we employ magnetomotive optical coherence tomography (MMOCT) as a platform both to detect and to measure the elasticity of blood clots. Detection is enabled through the use of rehydrated, lyophilized platelets loaded with superparamagnetic iron oxides (SPIO-RL platelets) that are functional infusion agents that adhere to sites of vascular endothelial damage. Evidence suggests that the sensitivity for detection is improved over threefold by magnetic interactions between SPIOs inside RL platelets. Using the same MMOCT system, we show how elastometry of simulated clots, using resonant acoustic spectroscopy, is correlated with the fibrin content of the clot. Both methods are based upon magnetic actuation and phase-sensitive optical monitoring of nanoscale displacements using MMOCT, underscoring its utility as a broad-based platform to detect and measure the molecular structure and composition of blood clots.
Robot-Assisted Needle Steering
Creators: name: Kallem, Vinutha
name: Goldberg, Ken
name: Cowan, Noah
name: Majewicz, Ann
name: Alterovitz, Ron
name: Reed, Kyle
name: Okamura, Allison
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: Needle insertion is a critical aspect of many medical treatments, diagnostic methods, and scientific studies, and is considered to be one of the simplest and most minimally invasive medical procedures. Robot-assisted needle steering has the potential to improve the effectiveness of existing medical procedures and enable new ones by allowing increased accuracy through more dexterous control of the needle tip path and acquisition of targets not accessible by straight-line trajectories. In this article, we describe a robot-assisted needle steering system that uses three integrated controllers: a motion planner concerned with guiding the needle around obstacles to a target in a desired plane, a planar controller that maintains the needle in the desired plane, and a torsion compensator that controls the needle tip orientation about the axis of the needle shaft. Experimental results from steering an asymmetric-tip needle in artificial tissue demonstrate the effectiveness of the system and its sensitivity to various environmental and control parameters. In addition, we show an example of needle steering in ex vivo biological tissue to accomplish a clinically relevant task, and highlight challenges of practical needle steering implementation.
Circularization of Tidally Disrupted Stars around Spinning Supermassive Black Holes
Creators: name: Hayasaki, Kimitake
name: Stone, Nicholas C.
name: Loeb, Abraham
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We study the circularization of tidally disrupted stars on bound orbits around spinning supermassive black holes by performing three-dimensional smoothed particle hydrodynamic simulations with Post-Newtonian corrections. Our simulations reveal that debris circularization depends sensitively on the efficiency of radiative cooling. There are two stages in debris circularization if radiative cooling is inefficient: first, the stellar debris streams self-intersect due to relativistic apsidal precession; shocks at the intersection points thermalize orbital energy and the debris forms a geometrically thick, ring-like structure around the black hole. The ring rapidly spreads via viscous diffusion, leading to the formation of a geometrically thick accretion disk. In contrast, if radiative cooling is efficient, the stellar debris circularizes due to self-intersection shocks and forms a geometrically thin ring-like structure. In this case, the dissipated energy can be emitted during debris circularization as a precursor to the subsequent tidal disruption flare. The possible radiated energy is up to ~2*10^{52} erg for a 1 Msun star orbiting a 10^6 Msun black hole. We also find that a retrograde (prograde) black hole spin causes the shock-induced circularization timescale to be shorter (longer) than that of a non-spinning black hole in both cooling cases. The circularization timescale is remarkably long in the radiatively efficient cooling case, and is also sensitive to black hole spin. Specifically, Lense-Thirring torques cause dynamically important nodal precession, which significantly delays debris circularization. On the other hand, nodal precession is too slow to produce observable signatures in the radiatively inefficient case. We also discuss the relationship between our simulations and the parabolic TDEs that are characteristic of most stellar tidal disruptions.
description: 23 pages, 18 figures, 1 appendix, accepted for publication in MNRAS (with significant improvement)
Empathy and Confrontation : Lessons for Innovators
Creators: name: Eapen, T.
Publisher: name: Zenodo
Year: 2022
Subjects: Innovation
Peter Drucker
Empathy
Confrontation

description: This essay draws from art and science to demonstrate that innovators have to use the conflicting principles of empathy and confrontation to arrive at valuable ideas.
description: Winner of the the 2013 Peter Drucker Essay Contest held in Vienna, Austria. This file was uploaded by the author of the essay.
Asymptotically Optimal Motion Planning for Learned Tasks Using Time-Dependent Cost Maps
Creators: name: Ye, Gu
name: Alterovitz, Ron
name: Bowen, Chris
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2015

description: In unstructured environments in people’s homes and workspaces, robots executing a task may need to avoid obstacles while satisfying task motion constraints, e.g., keeping a plate of food level to avoid spills or properly orienting a finger to push a button. We introduce a sampling-based method for computing motion plans that are collision-free and minimize a cost metric that encodes task motion constraints. Our time-dependent cost metric, learned from a set of demonstrations, encodes features of a task’s motion that are consistent across the demonstrations and, hence, are likely required to successfully execute the task. Our sampling-based motion planner uses the learned cost metric to compute plans that simultaneously avoid obstacles and satisfy task constraints. The motion planner is asymptotically optimal and minimizes the Mahalanobis distance between the planned trajectory and the distribution of demonstrations in a feature space parameterized by the locations of task-relevant objects. The motion planner also leverages the distribution of the demonstrations to significantly reduce plan computation time. We demonstrate the method’s effectiveness and speed using a small humanoid robot performing tasks requiring both obstacle avoidance and satisfaction of learned task constraints.
Epicardial Conductors Can Lower the Defibrillation Threshold in Rabbit Hearts
Creators: name: Sims, J.A.
name: Knisley, S.B.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: During a defibrillation shock, epicardial conductors can introduce anti-stimulatory effects due to lowering of the voltage gradient in myocardial tissue under the conductor and stimulatory effects due to membrane polarization near edges. We hypothesized that increasing the area of conductors increases the defibrillation threshold (DFT), while increasing the amount of stimulatory edge of conductors decreases the DFT. To test this, we measured the DFT in excised rabbit hearts with and without sets of rectangular conductors having 250 or 500 mm2 area and 100, 200 or 400 mm length of edges perpendicular to the line intersecting the shock electrodes. Unlike previous reports in which conductors increased or did not change DFT, present results indicate a conductor geometry having area of 250 mm2 and edge of 200 mm decreases the DFT. This result is consistent with the hypothesis that stimulatory effects of the edge of a conductor can enhance defibrillation shock efficacy.
A new near octagon and the Suzuki tower
Creators: name: Bishnoi, Anurag
name: De Bruyn, Bart
Publisher: name: arXiv
Year: 2015
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05E18, 05E30, 51E12, 51E25

description: We construct and study a new near octagon of order $(2,10)$ which has its full automorphism group isomorphic to the group $\mathrm{G}_2(4){:}2$ and which contains $416$ copies of the Hall-Janko near octagon as full subgeometries. Using this near octagon and its substructures we give geometric constructions of the $\mathrm{G}_2(4)$-graph and the Suzuki graph, both of which are strongly regular graphs contained in the Suzuki tower. As a subgeometry of this octagon we have discovered another new near octagon, whose order is $(2,4)$.
description: 24 pages, revised version with added remarks and references
Stimulatory Current at the Edge of an Inactive Conductor in an Electric Field: Role of Nonlinear Interfacial Current–Voltage Relationship
Creators: name: Pollard, A.E.
name: Sims, J.A.
name: Knisley, S.B.
name: White, P.S.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2010

description: Cardiac electric field stimulation is critical for the mechanism of defibrillation. The presence of certain inactive epicardial conductors in the field during defibrillation can decrease the defibrillation threshold. We hypothesized this decrease is due to stimulatory effects of current across the interface between the inactive conductor and the heart during field stimulation. To examine this current and its possible stimulatory effects, we imaged transmittance of indium-tin-oxide (ITO) conductors, tested for indium with x-ray diffraction, created a computer model containing realistic ITO interfacial properties, and optically mapped excitation of rabbit heart during electric field stimulation in the presence of an ITO conductor. Reduction of ITO to indium decreased transmittance at the edge facing the anodal shock electrode when trans-interfacial voltage exceeded standard reduction potential. The interfacial current-voltage relationship was nonlinear, producing larger conductances at higher currents. This nonlinearity concentrated the interfacial current near edges in images and in a computer model. The edge current was stimulatory, producing early postshock excitation of rabbit ventricles. Thus, darkening of ITO indicates interfacial current by indium reduction. Interfacial nonlinearity concentrates current near the edge where it can excite the heart. Stimulatory current at edges may account for the reported decrease in defibrillation threshold by inactive conductors.
It's Alive! Consumer Evaluation of New Product and Brand Vitality
Creators: name: Eapen, T.
Publisher: name: Zenodo
Year: 2022
Subjects: vitality
schema-incongruity
new products
branding
brand vitality

description: Many new products incorporate functions that resemble those of living organisms. In doing so, such products appear to be alive. We term this property as product vitality. Products that incorporate vital elements are frequently highly novel and hence appear incongruous to their product category schema. Previous studies that build on George Mandler’s influential framework show that consumers evaluate highly incongruous schema unfavorably. However, Mandler’s model suggests that highly incongruous may be evaluated positively if an alternate schema is available that enables accommodative processing. We present evidence that in the case of products that possess high levels of both vitality and incongruity, consumer evaluation can be favorable. This effect, which we term as the vital-incongruity effect is enhanced when the branding is also vital in nature.  This study contributes to the understanding of how consumers evaluate novel new products.
Negative Refraction Induced by Möbius Topology
Creators: name: Fang, Y. N.
name: Shen, Yao
name: Ai, Qing
name: Sun, C. P.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We theoretically show the negative refraction existing in Möbius molecules. The negative refractive index is induced by the non-trivial topology of the molecules. With the Möbius boundary condition, the effective electromagnetic fields felt by the electron in a Möbius ring is spatially inhomogeneous. In this regard, the $D_{N}$ symmetry is broken in Möbius molecules and thus the magnetic response is induced through the effective magnetic field. Our findings open up a new architecture for negative refractive index materials based on the non-trivial topology of Möbius molecules.
description: 14 pages, 5 figures
Automated Segmentation of Intraretinal Cystoid Fluid in Optical Coherence Tomography
Creators: name: Oldenburg, A. L.
name: Wilkins, G. R.
name: Houghton, O. M.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2012

description: Cystoid macular edema (CME) is observed in a variety of ocular disorders and is strongly associated with vision loss. Optical coherence tomography (OCT) provides excellent visualization of cystoid fluid, and can assist clinicians in monitoring the progression of CME. Quantitative tools for assessing CME may lead to better metrics for choosing treatment protocols. To address this need, this paper presents a fully automated retinal cyst segmentation technique for OCT image stacks acquired from a commercial scanner. The proposed method includes a computationally fast bilateral filter for speckle denoising while maintaining CME boundaries. The proposed technique was evaluated in images from 16 patients with vitreoretinal disease and three controls. The average sensitivity and specificity for the classification of cystoid regions in CME patients were found to be 91% and 96%, respectively, and the retinal volume occupied by cystoid fluid obtained by the algorithm was found to be accurate within a mean and median volume fraction of 1.9% and 0.8%, respectively.
Noncovalent Interactions by QMC: Speedup by One-Particle Basis-Set Size Reduction
Creators: name: Dubecký, Matúš
Publisher: name: arXiv
Year: 2015
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: While it is empirically accepted that the fixed-node diffusion Monte-Carlo (FN-DMC) depends only weakly on the size of the one-particle basis sets used to expand its guiding functions, limits of this observation are not settled yet. Our recent work indicates that under the FN error cancellation conditions, augmented triple zeta basis sets are sufficient to achieve a benchmark level of 0.1 kcal/mol in a number of small noncovalent complexes. Here we report on a possibility of truncation of the one-particle basis sets used in FN-DMC guiding functions that has no visible effect on the accuracy of the production FN-DMC energy differences. The proposed scheme leads to no significant increase in the local energy variance, indicating that the total CPU cost of large-scale benchmark noncovalent interaction energy FN-DMC calculations may be reduced.
description: ACS book chapter, accepted
Integration of Network Topological and Connectivity Properties for Neuroimaging Classification
Creators: name: The University of North Carolina at Chapel Hill University Libraries
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: Rapid advances in neuroimaging techniques have provided an efficient and noninvasive way for exploring the structural and functional connectivity of the human brain. Quantitative measurement of abnormality of brain connectivity in patients with neurodegenerative diseases, such as mild cognitive impairment (MCI) and Alzheimer’s disease (AD), have also been widely reported, especially at a group level. Recently, machine learning techniques have been applied to the study of AD and MCI, i.e., to identify the individuals with AD/MCI from the healthy controls (HCs). However, most existing methods focus on using only a single property of a connectivity network, although multiple network properties, such as local connectivity and global topological properties, can potentially be used. In this paper, by employing multikernel based approach, we propose a novel connectivity based framework to integrate multiple properties of connectivity network for improving the classification performance. Specifically, two different types of kernels (i.e., vector-based kernel and graph kernel) are used to quantify two different yet complementary properties of the network, i.e., local connectivity and global topological properties. Then, multikernel learning (MKL) technique is adopted to fuse these heterogeneous kernels for neuroimaging classification. We test the performance of our proposed method on two different data sets. First, we test it on the functional connectivity networks of 12 MCI and 25 HC subjects. The results show that our method achieves significant performance improvement over those using only one type of network property. Specifically, our method achieves a classification accuracy of 91.9%, which is 10.8% better than those by single network-property-based methods. Then, we test our method for gender classification on a large set of functional connectivity networks with 133 infants scanned at birth, 1 year, and 2 years, also demonstrating very promising results.
MOESM11 of Towards the restoration of the Mesoamerican Biological Corridor for large mammals in Panama: comparing multi-species occupancy to movement models
Creators: name: Meyer, Ninon
name: Moreno, Ricardo
name: Reyna-Hurtado, Rafael
name: Signer, Johannes
name: Balkenhol, Niko
Publisher: name: figshare
Year: 2020
Subjects: subject: Ecology
subject: FOS: Biological sciences
subject: 69999 Biological Sciences not elsewhere classified
subject: 80699 Information Systems not elsewhere classified
subject: FOS: Computer and information sciences

description: Additional file 11. Results - Maps with multi-species connectivity scenarios.
Scalable Dissipative Preparation of Many-Body Entanglement
Creators: name: Reiter, Florentin
name: Reeb, David
name: Sørensen, Anders S.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a technique for the dissipative preparation of highly entangled multiparticle states of atoms coupled to common oscillator modes. By combining local spontaneous emission with coherent couplings we engineer many-body dissipation that drives the system from an arbitrary initial state into a Greenberger-Horne-Zeilinger state. We demonstrate that using our technique, highly entangled steady states can be prepared efficiently in a time that scales polynomially with the system size. Our protocol assumes generic couplings and will thus enable the dissipative production of multiparticle entanglement in a wide range of physical systems. As an example, we demonstrate the feasibility of our scheme in state-of-the-art trapped-ion systems.
description: 5 + 27 pages, 3 + 1 figures. Close to published version. The scheme for W state preparation from version 1 was removed during the peer-review process and will be published elsewhere
Domain Transfer Learning for MCI Conversion Prediction
Creators: name: Shen, Dinggang
name: Liu, Mingxia
name: Munsell, Brent C.
name: Cheng, Bo
name: Zhang, Daoqiang
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2015

description: Machine learning methods have been increasingly used to predict the conversion of mild cognitive impairment (MCI) to Alzheimer's disease (AD), by classifying MCI converters (MCI-C) from MCI non-converters (MCI-NC). However, most of existing methods construct classifiers using only data from one particular target domain (e.g., MCI), and ignore data in the other related domains (e.g., AD and normal control (NC)) that could provide valuable information to promote the performance of MCI conversion prediction. To this end, we develop a novel domain transfer learning method for MCI conversion prediction, which can use data from both the target domain (i.e., MCI) and the auxiliary domains (i.e., AD and NC). Specifically, the proposed method consists of three key components: 1) a domain transfer feature selection (DTFS) component that selects the most informative feature-subset from both target domain and auxiliary domains with different imaging modalities, 2) a domain transfer sample selection (DTSS) component that selects the most informative sample-subset from the same target and auxiliary domains with different data modalities, and 3) a domain transfer support vector machine (DTSVM) classification component that fuses the selected features and samples to separate MCI-C and MCI-NC patients. We evaluate our method on 202 subjects from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) with MRI, FDG-PET and CSF data. The experimental results show that the proposed method can classify MCI-C patients from MCI-NC patients with an accuracy of 79.4%, with the aid of additional domain knowledge learned from AD and NC.
A General Fast Registration Framework by Learning Deformation–Appearance Correlation
Creators: name: The University of North Carolina at Chapel Hill University Libraries
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2012

description: In this paper, we propose a general framework for performance improvement of the current state-of-the-art registration algorithms in terms of both accuracy and computation time. The key concept involves rapid prediction of a deformation field for registration initialization, which is achieved by a statistical correlation model learned between image appearances and deformation fields. This allows us to immediately bring a template image as close as possible to a subject image that we need to register. The task of the registration algorithm is hence reduced to estimating small deformation between the subject image and the initially warped template image, i.e., the intermediate template (IT). Specifically, to obtain a good subject-specific initial deformation, support vector regression is utilized to determine the correlation between image appearances and their respective deformation fields. When registering a new subject onto the template, an initial deformation field is first predicted based on the subject’s image appearance for generating an IT. With the IT, only the residual deformation needs to be estimated, presenting much less challenge to the existing registration algorithms. Our learning-based framework affords two important advantages: 1) by requiring only the estimation of the residual deformation between the IT and the subject image, the computation time can be greatly reduced; 2) by leveraging good deformation initialization, local minima giving suboptimal solution could be avoided. Our framework has been extensively evaluated using medical images from different sources, and the results indicate that, on top of accuracy improvement, significant registration speedup can be achieved, as compared with the case where no prediction of initial deformation is performed.
Single-word Geomnemonic Addressing with Generative Imagery
Creators: name: Eapen, T.
Publisher: name: Zenodo
Year: 2022
Subjects: Geomnemonic

description: In this paper, we present a geomnemonic addressing scheme (Eapen et al. 2022) where a single word, either in the form compound word such as “ax-diamond” or a portmanteau word “axmond” is used to represent to uniquely identify geolocation within a larger locale such as a city.
Sensorless Motion Planning for Medical Needle Insertion in Deformable Tissues
Creators: name: Alterovitz, R.
name: Goldberg, K.Y.
name: Hsu, I.-C.
name: Pouliot, J.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: Minimally invasive medical procedures such as biopsies, anesthesia drug injections, and brachytherapy cancer treatments require inserting a needle to a specific target inside soft tissues. This is difficult because needle insertion displaces and deforms the surrounding soft tissues causing the target to move during the procedure. To facilitate physician training and preoperative planning for these procedures, we develop a needle insertion motion planning system based on an interactive simulation of needle insertion in deformable tissues and numerical optimization to reduce placement error. We describe a 2-D physically based, dynamic simulation of needle insertion that uses a finite-element model of deformable soft tissues and models needle cutting and frictional forces along the needle shaft. The simulation offers guarantees on simulation stability for mesh modications and achieves interactive, real-time performance on a standard PC. Using texture mapping, the simulation provides visualization comparable to ultrasound images that the physician would see during the procedure. We use the simulation as a component of a sensorless planning algorithm that uses numerical optimization to compute needle insertion offsets that compensate for tissue deformations. We apply the method to radioactive seed implantation during permanent seed prostate brachytherapy to minimize seed placement error.
Application of reconstruction-based scatter compensation to thallium-201 SPECT: implementations for reduced reconstructed image noise
Creators: name: Tsui, B.M.W.
name: Kadrmas, D.J.
name: Frey, E.C.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1998

description: Scatter compensation in Tl-201 single photon emission computed tomography (SPECT) presents an interesting challenge because of the multiple emission energies and relatively large proportion of scattered photons. In this paper, we present a simulation study investigating reconstructed image noise levels arising from various implementations of iterative reconstruction-based scatter compensation (RBSC) in Tl-201 SPECT. A two-stage analysis was used to study single and multiple energy window implementations of reconstruction-based scatter compensation, and RBSC was compared to the upper limits on performance for other approaches to handling scatter. In the first stage, singular value decomposition of the system transfer matrix was used to analyze noise levels in a manner independent of the choice of reconstruction algorithm, providing results valid across a wide range of regularizations. In the second stage, the data were reconstructed using maximum-likelihood expectation-maximization, and the noise properties of the resultant images were analyzed. The best RBSC performance was obtained using multiple energy windows, one for each emission photopeak, and RBSC outperformed the upper limit on subtraction-based compensation methods. Implementing RBSC with the correct choice of energy window acquisition scheme is a promising method for performing scatter compensation for Tl-201 SPECT.
A characterization of $1$-rectifiable doubling measures with connected supports
Creators: name: Azzam, Jonas
name: Mourgoglou, Mihalis
Publisher: name: arXiv
Year: 2015
Subjects: subject: Metric Geometry (math.MG)
subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 28A75, 28A78

description: Garnett, Killip, and Schul have exhibited a doubling measure $μ$ with support equal to $\mathbb{R}^{d}$ which is $1$-rectifiable, meaning there are countably many curves $Γ_{i}$ of finite length for which $μ(\mathbb{R}^{d}\backslash \bigcup Γ_{i})=0$. In this note, we characterize when a doubling measure $μ$ with support equal to a connected metric space $X$ has a $1$-rectifiable subset of positive measure and show this set coincides up to a set of $μ$-measure zero with the set of $x\in X$ for which $\liminf_{r\rightarrow 0} μ(B_{X}(x,r))/r>0$.
description: Made suggested referee changes. Published in Anal. PDE 9 (2016), no. 1, 99--109
Entanglement of Spatial Regions vs. Entanglement of Particles
Creators: name: Mondal, Swapnamay
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Consider an arbitrary local quantum field theory with a gap or an arbitrary gapless free theory. We consider states in such a theory, that describe two entangled particles localized in disjoint regions of space. We show that in such a state, to leading order, Rényi entropies of spatial regions, containing only one of the particles are same as their quantum mechanical counterparts, after subtraction of vacuum contribution. Subleading corrections depend on overlap of wave functions. These results suggest that Von Neumann entropy of a spatial region, after subtraction of vacuum contribution, can serve as a measure of entanglement of indistinguishable particles in pure states.
description: 14 pages, v5: JHEP published version
Measuring tortuosity of the intracerebral vasculature from MRA images
Creators: name: Aylward, S.R.
name: Bullitt, E.
name: Gerig, G.
name: Pizer, S.M.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2003

description: The clinical recognition of abnormal vascular tortuosity, or excessive bending, twisting, and winding, is important to the diagnosis of many diseases. Automated detection and quantitation of abnormal vascular tortuosity from three-dimensional (3D) medical image data would therefore be of value. However, previous research has centered primarily upon 2D analysis of the special subset of vessels whose paths are normally close to straight.
Climate service as a decision-support tool for winter tourism industry - User-friendly climate information for securing snow
Creators: name: Mettiäinen, Ilona
name: Coath, Martin
name: Contreras, Roxana
name: Toivonen, Jusu
name: Moore, John C.
name: Koivurova, Timo
Publisher: name: Zenodo
Year: 2020
Subjects: climate service
winter tourism
climate adaptation
ski resorts

description: Presentation to the PROSNOW (EU Horizon 2020) project on 20.3.2020 in a clustering and collaboration meeting between the Blue-Action: Arctic Impact on Weather and Climate (EU Horizon 2020) WP5 CS1 and PROSNOW.
A Statistical Analysis of Brain Morphology Using Wild Bootstrapping
Creators: name: Rowe, D.B.
name: Bansal, R.
name: Peterson, B.S.
name: Ibrahim, J.G.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2007

description: Methods for the analysis of brain morphology, including voxel-based morphology and surface-based morphometries, have been used to detect associations between brain structure and covariates of interest, such as diagnosis, severity of disease, age, IQ, and genotype. The statistical analysis of morphometric measures usually involves two statistical procedures: 1) invoking a statistical model at each voxel (or point) on the surface of the brain or brain subregion, followed by mapping test statistics (e.g., t test) or their associated p values at each of those voxels; 2) correction for the multiple statistical tests conducted across all voxels on the surface of the brain region under investigation. We propose the use of new statistical methods for each of these procedures. We first use a heteroscedastic linear model to test the associations between the morphological measures at each voxel on the surface of the specified subregion (e.g., cortical or subcortical surfaces) and the covariates of interest. Moreover, we develop a robust test procedure that is based on a resampling method, called wild bootstrapping. This procedure assesses the statistical significance of the associations between a measure of given brain structure and the covariates of interest. The value of this robust test procedure lies in its computationally simplicity and in its applicability to a wide range of imaging data, including data from both anatomical and functional magnetic resonance imaging (fMRI). Simulation studies demonstrate that this robust test procedure can accurately control the family-wise error rate. We demonstrate the application of this robust test procedure to the detection of statistically significant differences in the morphology of the hippocampus over time across gender groups in a large sample of healthy subjects.
A quick proof of nonvanishing for asymptotic syzygies
Creators: name: Ein, Lawrence
name: Erman, Daniel
name: Lazarsfeld, Robert
Publisher: name: arXiv
Year: 2015
Subjects: subject: Algebraic Geometry (math.AG)
subject: Commutative Algebra (math.AC)
subject: FOS: Mathematics
subject: 14J40, 13D02

description: We give a quick new approach to the main cases of the nonvanishing theorems of first and third authors concerning the asymptotic behavior of the syzygies of a projective variety as the positivity of the embedding line bundle grows. Specifically, we present a surprisingly elementary and concrete proof of the asymptotic nonvanishing of Veronese syzygies, and we obtain effective results for arithmetically Cohen-Macaulay varieties. The idea is that one can reduce the statements to some simple computations with monomials.
description: Typos corrected. Section numbering changed to conform to published version
MOESM1 of Towards the restoration of the Mesoamerican Biological Corridor for large mammals in Panama: comparing multi-species occupancy to movement models
Creators: name: Meyer, Ninon
name: Moreno, Ricardo
name: Reyna-Hurtado, Rafael
name: Signer, Johannes
name: Balkenhol, Niko
Publisher: name: figshare
Year: 2020
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified
subject: 80699 Information Systems not elsewhere classified
subject: FOS: Computer and information sciences
subject: Marine Biology

description: Additional file 1. Methods - Locations of camera traps used to conduct occupancy modelling across Panama.
The multi-protein targeting potential of bioactive syringin in inflammatory diseases: using molecular modelling and in-silico analysis of regulatory elements
Creators: name: Singh, Vipendra Kumar
name: Thakur, D.C.
name: Rajak, Naina
name: Mishra, Anand
name: Kumar, Ankur
name: Giri, Rajanish
name: Garg, Neha
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 310299
subject: Bioinformatics and computational biology not elsewhere classified

description: Our MD simulation analysis demonstrated the multi-protein targeting potential of bioactive glycoside syringin with inflammatory proteins.
Project Silver - Proposed Design for the Symbol for the Indian Rupee
Creators: name: Chandra Mohan, M.K.
name: Eapen, T.
name: Kiran Das, C.K.
Publisher: name: Zenodo
Year: 2009
Subjects: Rupee
Currency Symbol

description: This is a submission for the contest to select the official symbol for the Indian rupee. 

Related resources:

A contest to find a sign for Indian rupee | India News - Times of India (indiatimes.com)

Indian rupee sign - Wikipedia

Contest to finalise Rupee symbol down to final five - The Economic Times (indiatimes.com)

(24) What was your design if you have taken part in 'Rupee Symbol Design Contest' by Government of India? - Quora

Meet Udaya Kumar, the man who designed the unique rupee sign - The Hindu
MOESM2 of Towards the restoration of the Mesoamerican Biological Corridor for large mammals in Panama: comparing multi-species occupancy to movement models
Creators: name: Meyer, Ninon
name: Moreno, Ricardo
name: Reyna-Hurtado, Rafael
name: Signer, Johannes
name: Balkenhol, Niko
Publisher: name: figshare
Year: 2020
Subjects: subject: Medicine
subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Evolutionary Biology
subject: Ecology
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified

description: Additional file 2. Methods - Environmental variables and selection of characteristic scale.
MOESM3 of Towards the restoration of the Mesoamerican Biological Corridor for large mammals in Panama: comparing multi-species occupancy to movement models
Creators: name: Meyer, Ninon
name: Moreno, Ricardo
name: Reyna-Hurtado, Rafael
name: Signer, Johannes
name: Balkenhol, Niko
Publisher: name: figshare
Year: 2020
Subjects: subject: Molecular Biology
subject: Ecology
subject: FOS: Biological sciences
subject: 69999 Biological Sciences not elsewhere classified

description: Additional file 3. Methods - Transformation curves used to translate habitat suitability values into landscape resistance values.
Symplectic fillability of toric contact manifolds
Creators: name: Marinkovic, Aleksandra
Publisher: name: arXiv
Year: 2015
Subjects: subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics

description: According to Lerman, compact connected toric contact 3-manifolds with a non-free toric action whose moment cone spans an angle greater than $π$ are overtwisted, thus non-fillable. In contrast, we show that all compact connected toric contact manifolds in dimension greater than three are weakly symplectically fillable and most of them are strongly symplectically fillable. The proof is based on the Lerman's classification of toric contact manifolds and on our observation that the only contact manifolds in higher dimensions that admit free toric action are the cosphere bundle of $T^d, d\geq3$ $(T^d\times S^{d-1})$ and $T^2\times L_k,$ $k\in\mathbb{N},$ with the unique contact structure.
description: 11 pages, accepted at Period. Math. Hungar
A Note on the Validity of Statistical Bootstrapping for Estimating the Uncertainty of Tensor Parameters in Diffusion Tensor Images
Creators: name: Ibrahim, J.G.
name: Peterson, B.S.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2008

description: Diffusion tensors are estimated from magnetic resonance images (MRIs) that are diffusion-weighted, and those images inherently contain noise. Therefore, noise in the diffusion-weighted images produces uncertainty in estimation of the tensors and their derived parameters, which include eigenvalues, eigenvectors, and the trajectories of fiber pathways that are reconstructed from those eigenvalues and eigenvectors. Although repetition and wild bootstrap methods have been widely used to quantify the uncertainty of diffusion tensors and their derived parameters, we currently lack theoretical derivations that would validate the use of these two bootstrap methods for the estimation of statistical parameters of tensors in the presence of noise. The aim of this paper is to examine theoretically and numerically the repetition and wild bootstrap methods for approximating uncertainty in estimation of diffusion tensor parameters under two different schemes for acquiring diffusion weighted images. Whether these bootstrap methods can be used to quantify uncertainty in some diffusion tensor parameters, such as fractional anisotropy (FA), depends critically on the morphology of the diffusion tensor that is being estimated. The wild and repetition bootstrap methods in particular cannot quantify uncertainty in the principal direction (PD) of isotropic (or oblate) tensor. We also examine the use of bootstrap methods in estimating tensors in a voxel containing multiple tensors, demonstrating their limitations when quantifying the uncertainty of tensor parameters in those locations. Simulation studies are also used to understand more thoroughly our theoretical results. Our findings raise serious concerns about the use of bootstrap methods to quantify the uncertainty of fiber pathways when those pathways pass through voxels that contain either isotropic tensors, oblate tensors, or multiple tensors.
A Discussion on the Heisenberg Uncertainty Principle from the Perspective of Special Relativity
Creators: name: Nanni, Luca
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this note, we consider the implications of the Heisenberg uncertainty principle (HUP) when computing uncertainties that affect the main dynamical quantities, from the perspective of special relativity. Using the well-known formula for propagating statistical errors, we prove that the uncertainty relations between the moduli of conjugate observables are not relativistically invariant. The new relationships show that, in experiments involving relativistic particles, limitations of the precision of a quantity obtained by indirect calculations may affect the final result.
description: Article published on Physics Essays
Emergence of electromotive force in precession-less rigid motion of deformed domain wall
Creators: name: Farajollahpour, T.
name: Darmiani, N.
name: Phirouznia, A.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Recently it has been recognized that the electromotive force (emf) can be induced just by the spin precession where the generation of the electromotive force has been considered as a real-space topological pumping effect. It has been shown that the amount of the electromotive force is independent of the functionality of the localized moments. It was also demonstrated that the rigid domain wall (DW) motion cannot generate electromotive force in the system. Based on real-space topological pumping approach in the current study we show that the electromotive force can be induced by rigid motion of a deformed DW. We also demonstrate that the generated electromotive force strongly depends on the DW bulging. Meanwhile results show that the DW bulging leads to generation of the electromotive force both along the axis of the DW motion and normal to the direction of motion.
Restoration of DWI Data Using a Rician LMMSE Estimator
Creators: name: Kubicki, M.
name: Westin, C.-F.
name: Niethammer, M.
name: Shenton, M.E.
name: Aja-Fernandez, S.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2008

description: This paper introduces and analyzes a linear minimum mean square error (LMMSE) estimator using a Rician noise model and its recursive version (RLMMSE) for the restoration of diffusion weighted images. A method to estimate the noise level based on local estimations of mean or variance is used to automatically parametrize the estimator. The restoration performance is evaluated using quality indexes and compared to alternative estimation schemes. The overall scheme is simple, robust, fast, and improves estimations. Filtering diffusion weighted magnetic resonance imaging (DW-MRI) with the proposed methodology leads to more accurate tensor estimations. Real and synthetic datasets are analyzed.
PopTract: Population-Based Tractography
Creators: name: Gilmore, J. H.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: White matter fiber tractography plays a key role in the in vivo understanding of brain circuitry. For tract-based comparison of a population of images, a common approach is to first generate an atlas by averaging, after spatial normalization, all images in the population, and then perform tractography using the constructed atlas. The reconstructed fiber trajectories form a common geometry onto which diffusion properties of each individual subject can be projected based on the corresponding locations in the subject native space. However, in the case of high angular resolution diffusion imaging (HARDI), where modeling fiber crossings is an important goal, the above-mentioned averaging method for generating an atlas results in significant error in the estimation of local fiber orientations and causes a major loss of fiber crossings. These limitatitons have significant impact on the accuracy of the reconstructed fiber trajectories and jeopardize subsequent tract-based analysis. As a remedy, we present in this paper a more effective means of performing tractography at a population level. Our method entails determining a bipolar Watson distribution at each voxel location based on information given by all images in the population, giving us not only the local principal orientations of the fiber pathways, but also confidence levels of how reliable these orientations are across subjects. The distribution field is then fed as an input to a probabilistic tractography framework for reconstructing a set of fiber trajectories that are consistent across all images in the population. We observe that the proposed method, called PopTract, results in significantly better preservation of fiber crossings, and hence yields better trajectory reconstruction in the atlas space.