cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Investigation of the behavioral processes and neurobiological substrates involved in the motivation for voluntary wheel running in the rat
Creators: name: Basso, Julia Colette
Publisher: name: No Publisher Supplied
Year: 2013

description: Rats engage with voluntary running wheels spontaneously and come to run tremendous, stable distances over the first 3 weeks of wheel exposure, with males and females showing significant differences in this behavior. Though voluntary running has been utilized extensively to study its effects on the body and brain, less has been done to examine the behavior itself, and specifically lacking are studies that focus on the motivation for the behavior and any gender differences within. Here, I investigate, in a comprehensive, quantitatively comparable manner, details of voluntary wheel running and variables that affect it in both male and female Sprague Dawley rats. Using both unconditioned and conditioned techniques, I explore my primary hypothesis that voluntary wheel running is a motivated behavior with positive incentive salience, with a focus on the motivation for this behavior during both the acquisition and habitual phases of running. I then utilize these behavioral techniques to explore the involvement of discrete brain regions in the motivation for voluntary wheel running. Results from this work support the hypothesis that voluntary wheel running is a motivated behavior with positive incentive salience. The data reveal that females acquire the behavior more quickly and during habitual phases of running, run significantly farther distances at faster rates. Additionally, I show using high-performance liquid chromatography that participating in voluntary wheel running throughout life alters neurotransmitter content in brain areas including the caudate putamen, ventral tegmental area, medial prefrontal cortex (mPFC) and medial preoptic area, and that engaging in this motivated behavior throughout life alters both the neurochemical and behavioral responsiveness to an acute dose of cocaine. Though males and females show an equally robust conditioned place preference for the total experience of running during the acquisition phase, the reinstatement of running after a period of forced wheel abstinence is greater for females than males, with males showing a stronger preference for the aftereffects of wheel running. Finally, I reveal for the first time that the prelimbic mPFC and nucleus accumbens core may be necessary for the motivation for voluntary wheel running.
Hydrocarbon Contamination in Angstrom-scale Channels
Creators: name: Sajja, Ravalika
name: You, Yi
name: Qi, Rongrong
name: Solleti, Goutham
name: Bhardwaj, Ankit
name: Rakowski, Alexander
name: Haigh, Sarah
name: Keerthi, Ashok
name: Radha, Boya
Publisher: name: arXiv
Year: 2021
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Nonspecific molecular adsorption like airborne contamination occurs on most surfaces including those of 2D materials and alters their properties. While the surface contamination is studied using a plethora of techniques, the effect of contamination on a confined system such as nanochannels, nanopores leading to their clogging is still lacking. We report a systematic investigation of hydrocarbon adsorption in the angstrom slit channels of varied heights. Hexane is chosen to mimic the hydrocarbon contamination and the clogging of the angstrom-channels is evaluated via a Helium gas flow measurement. The level of the hexane adsorption, in other words, the degree of clogging depends on the size difference between the channels and hexane. A dynamic transition of the clogging and revival process is shown in sub-2 nm thin channels. Long-term storage and stability of our angstrom-channels is demonstrated here up to three years, alleviating the contamination and unclogging the channels using thermal treatment. This study highlights the importance of the nanochannels stability and demonstrates self-cleansing nature of sub-2 nm thin channels enabling a robust platform for molecular transport and separation studies. We provide a method to assess the cleanliness of the nanoporous membranes, which is vital for the practical applications of nanofluidics in various fields such as molecular sensing, separation and power generation.
Shining Light on the Microscopic Resonant Mechanism Responsible for Cavity-Mediated Chemical Reactivity
Creators: name: Schäfer, Christian
name: Flick, Johannes
name: Ronca, Enrico
name: Narang, Prineha
name: Rubio, Angel
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Strong light-matter interaction in cavity environments is emerging as a promising approach to control chemical reactions in a non-intrusive and efficient manner. The underlying mechanism that distinguishes between steering, accelerating, or decelerating a chemical reaction has, however, remained unclear, hampering progress in this frontier area of research. We leverage quantum-electrodynamical density-functional theory to unveil the microscopic mechanism behind the experimentally observed reduced reaction rate under cavity induced resonant vibrational strong light-matter coupling. We observe multiple resonances and obtain the thus far theoretically elusive but experimentally critical resonant feature for a single strongly-coupled molecule undergoing the reaction. While we do not explicitly account for collective coupling or intermolecular interactions, the qualitative agreement with experimental measurements suggests that our conclusions can be largely abstracted towards the experimental realization. Specifically, we find that the cavity mode acts as mediator between different vibrational modes. In effect, vibrational energy localized in single bonds that are critical for the reaction is redistributed differently which ultimately inhibits the reaction.
description: Improved discussion around figure 3 and minor changes for clarity
Tyrosine hydroxylase-expressing interneurons in intact and dopamine-depleted striatum
Creators: name: Ünal, Bengi
Publisher: name: No Publisher Supplied
Year: 2012

description: Tyrosine hydroxylase-expressing (TH+) interneurons of the striatum stand in a critical point for our understanding of the interaction between striatal dopamine and striatal interneurons. Recent investigations from our laboratory have established that TH+ neurons comprise an electrophysiologically distinct group striatal GABAergic interneurons by using transgenic mice expressing enhanced green fluorescent protein under the control TH promoter (TH-eGFP). In order to understand the significance of striatal TH+ neurons in the normal and dopamine-depleted striatum, determining anatomical distribution of TH+ neurons with regard to their electrophysiological diversity and striatal anatomical heterogeneity was imperative. In the first part of my thesis, I investigated striatal localization of TH-eGFP neurons with respect to anatomical organization of the striatum. In the second set of experiments, I investigated the changes in anatomical distribution, morphology, and electrophysiology of TH-eGFP neurons following striatal dopamine-depletion. Data presented here indicates that the electrophysiological subtypes of TH-eGFP interneurons are equally prevalent throughout striatum. However, when patch/striosome-matrix organization is taken into account, a different pattern emerges in the dorso-ventral axis of the striatum: a significantly higher proportion of striatal TH-eGFP interneurons were located in MOR-enriched domains of the ventral striatum. Finally, TH-eGFP interneurons in both compartments extended their neurites into the neighboring compartment. In the second set of experiments, I investigated the effect of striatal dopamine loss achieved by unilateral intranigral 6-OHDA infusion on TH-eGFP interneuron anatomy and physiology. The data presented here show that dopamine loss has a temporally and regionally different effect on the number of striatal TH-eGFP interneurons. Several electrophysiological parameters of TH-eGFP interneurons show profound changes in dopamine-depleted striatum, such as reduction in plateau potentials and increase in spontaneous synaptic inputs, which were accompanied by a significant increase in spine density on these neurons. Taken together, the findings in this thesis establish that TH-eGFP neurons are a distinct group of striatal interneurons that show differential anatomical patterning throughout the dorsal-ventral axis of the striatum and respond to striatal dopamine-loss in a qualitatively and quantitatively different manner than striatal projection neurons.
Non-perturbative determination of collisional broadening and medium induced radiation in QCD plasmas
Creators: name: Moore, Guy D.
name: Schlichting, Soeren
name: Schlusser, Niels
name: Soudi, Ismail
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We supply recently obtained results from lattice EQCD with the correct UV limit to construct the collisional broadening kernel $C(b_\perp)$ in a QCD plasma. We discuss the limiting behavior of $C(b_\perp)$ at small and large impact parameters $b_\perp$, and illustrate how the results can be used to compute medium-induced radiation rates.
description: 25 pages, 4 figures
PIP-II Injector Test's Low Energy Beam Transport: Commissioning and Selected Measurements
Creators: name: Shemyakin, A.
name: Alvarez, M.
name: Andrews, R.
name: Carneiro, J. -P.
name: Chen, A.
name: D'Arcy, R.
name: Hanna, B.
name: Prost, L.
name: Scarpine, V.
name: Wiesner, C.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: FOS: Physical sciences

description: The PIP2IT test accelerator is under construction at Fermilab. Its ion source and Low Energy Beam Transport (LEBT) in its initial (straight) configuration have been commissioned to full specification parameters. This paper introduces the LEBT design and summarizes the outcome of the commissioning activities.
description: 11 p
Does the repulsive interatomic potential determine fragility in metallic liquids?
Creators: name: Pueblo, Christopher E.
name: Sun, Minhua
name: Kelton, Kenneth F.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The dynamical behavior of liquids is frequently characterized by the fragility, which can be defined from the temperature dependence of the shear viscosity, η. For a strong liquid, the activation energy for η changes little with cooling towards the glass transition temperature, Tg. The change is much greater in fragile liquids, with the activation energy becoming very large near Tg. While fragility is widely recognized as an important concept, for example believed to play an important role in glass formation, the microscopic origin of fragility is poorly understood. Here, we present new experimental evidence showing that fragility reflects the strength of the repulsive part of the interatomic potential, which can be determined from the steepness of the pair distribution function near the hard-sphere cutoff. Based on an analysis of scattering data from ten different metallic alloy liquids, we show that stronger liquids have steeper repulsive potentials.
New results unearthed from urtexts of quantum state diffusion
Creators: name: Diósi, Lajos
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Thirty years ago, the present author discussed pure state unraveling (stochastic quantum trajectories) of Markovian open system dynamics. The fact that he considered all positive dynamics, not restricted for the Lindblad-Gorini-Kossakowski-Sudarshan complete-positive subclass, has remained unnoticed so far. Here we point out the importance of the transition rate operator and the merit of invariant (representation-independent) approach, with reference to invariant condition of positive dynamics and extension of quantum state diffusion beyond complete-positive dynamics. A new result, description of all diffusive unravelings of positive dynamics directly follows.
description: 3pp
Multicomponent exciton gas in cuprous oxide: cooling behaviour and the role of Auger decay
Creators: name: Semkat, Dirk
name: Sobkowiak, Siegfried
name: Schöne, Florian
name: Stolz, Heinrich
name: Koch, Thomas
name: Fehske, Holger
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: In this paper we present a hydrodynamic model to describe the dynamics of para- and orthoexcitons in cuprous oxide at ultralow temperatures inside a stress induced potential trap. We take into account the finite lifetime of the excitons, the excitation process and exciton-phonon as well as exciton-exciton interaction. Furthermore, we model the two-body loss mechanism assuming an Auger-like effect and compare it to an alternative explanation which relies on the formation of biexcitons. We discuss in detail the influence on the numerical results and compare the predictions to experimental data.
description: 10 pages, 8 figures, submitted to J. Phys. B
Maximizing Survey Volume for Large-Area Multi-Epoch Surveys with Voronoi Tessellation
Creators: name: Lam, Marco C.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The survey volume of a proper motion-limited sample is typically much smaller than a magnitude-limited sample. This is because of the noisy astrometric measurements from detectors that are not dedicated for astrometric missions. In order to apply an empirical completeness correction, existing works limit the survey depth to the shallower parts of the sky that hamper the maximum potential of a survey. The number of epoch of measurement is a discrete quantity that cannot be interpolated across the projected plane of observation, so that the survey properties change in discrete steps across the sky. This work proposes a method to dissect the survey into small parts with Voronoi tessellation using candidate objects as generating points, such that each part defines a `mini-survey' that has its own properties. Coupling with a maximum volume density estimator, the new method is demonstrated to be unbiased and recovered {\sim}20% more objects than the existing method in a mock catalogue of a white dwarf-only solar neighbourhood with Pan--STARRS 1-like characteristics. Towards the end of this work, we demonstrate one way to increase the tessellation resolution with artificial generating points, which would be useful for analysis of rare objects with small number counts.
description: 10 pages, 2 tables, 8 figures, accepted by MNRAS on 10 April 2017
Fusion in the periodic Temperley-Lieb algebra and connectivity operators of loop models
Creators: name: Ikhlef, Yacine
name: Morin-Duchesne, Alexi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mathematical Physics (math-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In two-dimensional loop models, the scaling properties of critical random curves are encoded in the correlators of connectivity operators. In the dense O($n$) loop model, any such operator is naturally associated to a standard module of the periodic Temperley-Lieb algebra. We introduce a new family of representations of this algebra, with connectivity states that have two marked points, and argue that they define the fusion of two standard modules. We obtain their decomposition on the standard modules for generic values of the parameters, which in turn yields the structure of the operator product expansion of connectivity operators.
description: v2: 46 pages (including appendices)
On momentum operators given by Killing vectors whose integral curves are geodesics
Creators: name: Schürmann, Thomas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We consider momentum operators on intrinsically curved manifolds. Given that the momentum operators are Killing vector fields whose integral curves are geodesics, it is shown that the corresponding manifold is either flat, or otherwise of compact type with positive constant sectional curvature and dimension equal to 1, 3 or 7. Explicit representations of momentum operators and the associated Casimir element will be discussed for the 3-sphere $S^3$. It will be verified that the structure constants of the underlying Lie algebra are proportional to $2\hbar/R$, where $R$ is the curvature radius of $S^3$. This results in a countable energy and momentum spectrum of freely moving particles in $S^3$. It is shown that the maximum resolution of the possible momenta is given by the de-Broglie wave length $λ_R=πR$, which is identical to the diameter of the manifold. The corresponding covariant position operators are defined in terms of geodesic normal coordinates and the associated commutator relations of position and momentum are established.
description: 8 pages
Molecular Dynamics Simulations Correlating Mechanical Property Changes of Alumina with Atomic Voids under Triaxial Tension Loading
Creators: Chang, Junhao
Chen, Zengtao
Hogan, James D.
Publisher: name: University of Alberta Library
Year: 2023

The functionalization of nanoporous ceramics for applications in healthcare and defence necessitates the study of the effects of geometric structures on their fundamental mechanical properties. However, there is a lack of research on their stiffness and fracture strength along diverse directions under multi-axial loading conditions, particularly with the existence of typical voids in the models. In this study, accurate atomic models and corresponding properties were meticulously selected and validated for further investigation. Comparisons were made between typical material geometric and elastic properties with measured results to ensure the reliability of the selected models. The mechanical behavior of nanoporous alumina under multiaxial stretching was explored through molecular dynamics simulations. The results indicated that the stiffness of nanoporous alumina ceramics under uniaxial tension was greater, while the fracture strength was lower compared to that under multiaxial loading. The fracture of nanoporous ceramics under multi-axial stretching, was mainly dominated by void and crack extension, atomic bond fracture, and cracking with different orientations. Furthermore, the effects of increasing strain rates on the void volume fraction were found to be similar across different initial radii. It was also found that the increasing tension loading rates had greater effects on decreasing the fracture strain. These findings provide additional insight into the fracture mechanisms of nanoporous ceramics under complex loading states, which can also contribute to the development of higher-scale models in the future.
Effect of Pre-Training Scale on Intra- and Inter-Domain Full and Few-Shot Transfer Learning for Natural and Medical X-Ray Chest Images
Creators: name: Cherti, Mehdi
name: Jitsev, Jenia
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Increasing model, data and compute budget scale in the pre-training has been shown to strongly improve model generalization and transfer learning in vast line of work done in language modeling and natural image recognition. However, most studies on the positive effect of larger scale were done in scope of in-domain setting, with source and target data being in close proximity. To study effect of larger scale for both in-domain and out-of-domain setting when performing full and few-shot transfer, we combine here for the first time large, openly available medical X-Ray chest imaging datasets to reach a scale for medical imaging domain comparable to ImageNet-1k, routinely used for pre-training in natural image domain. We then conduct supervised pre-training, while varying network size and source data scale and domain, being either large natural (ImageNet-1k/21k) or large medical chest X-Ray datasets, and transfer pre-trained models to different natural or medical targets. We observe strong improvement due to larger pre-training scale for intra-domain natural-natural and medical-medical transfer. For inter-domain natural-medical transfer, we find improvements due to larger pre-training scale on larger X-Ray targets in full shot regime, while for smaller targets and for few-shot regime the improvement is not visible. Remarkably, large networks pre-trained on very large natural ImageNet-21k are as good or better than networks pre-trained on largest available medical X-Ray data when performing transfer to large X-Ray targets. We conclude that substantially increasing model and generic, medical domain-agnostic natural image source data scale in the pre-training can enable high quality out-of-domain transfer to medical domain specific targets, removing dependency on large medical domain-specific source data often not available in the practice.
description: Short version published in MedNeurIPS 2021. Long version published in IJCNN 2022. Code: https://github.com/SLAMPAI/large-scale-pretraining-transfer
Far-Ultraviolet Observation of the Globular Cluster NGC 6397
Creators: name: Dieball, Andrea
name: Rasekh, Armin
name: Knigge, Christian
name: Shara, Michael
name: Zurek, David
Publisher: name: arXiv
Year: 2017
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present an observational far-UV (FUV) and near-UV (NUV) study of the core region of the globular cluster NGC 6397. The observations were obtained with the Space Telescope Imaging Spectrograph (STIS, FUV), and the Wide Field Camera 3 (WFC3, NUV) on board the Hubble Space Telescope. Here, we focus on the UV bright stellar populations such as blue stragglers (BSs), white dwarfs (WDs) and cataclysmic variables (CVs). We present the first FUV-NUV color-magnitude diagram (CMD) for this cluster. To support our classification of the stellar populations, we compare our FUV-NUV CMD with optical data from the ACS Survey of Galactic Globular Clusters. The FUV-NUV CMD indicates 16 sources located in the WD area, and ten BSs within the 25"x 25" of the STIS FUV data. Eighteen Chandra X-ray sources are located within the FUV field of view. Thirteen of those have a NUV counterpart, of which nine sources also have a FUV counterpart. Out of those, five sources are previously suggested CVs, and indeed all five are located in the WD/CV region in our FUV-NUV CMD. Another CV only has a FUV but no NUV counterpart. We also detect a NUV (but no FUV) counterpart to the MSP located in the core of this cluster. The NUV lightcurves of the CVs and MSP show flickering behaviour typical of CVs. We found that the BSs and CVs are the most centrally concentrated population. This might be an effect of mass segregation or indicate the preferred birth place of BSs and CVs via dynamical interactions in the dense core region of GCs. HB stars are the least centrally concentrated population and absent in the innermost area of the core.
description: 13 pages, MNRAS accepted
On Asymptotic Regimes of Orthogonal Polynomials with Complex Varying Quartic Exponential Weight
Creators: name: Bertola, Marco
name: Tovbis, Alexander
Publisher: name: arXiv
Year: 2016
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Mathematical Physics (math-ph)
subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We study the asymptotics of recurrence coefficients for monic orthogonal polynomials $π_n(z)$ with the quartic exponential weight $\exp[-N(\frac 12 z^2+\frac 14 tz^4)]$, where $t\in {\mathbb C}$ and $N\in{\mathbb N}$, $N\to\infty$. Our goal is to describe these asymptotic behaviors globally for $t\in {\mathbb C}$ in different regions. We also describe the "breaking" curves separating these regions, and discuss their special (critical) points. All these pieces of information combined provide the global asymptotic "phase portrait" of the recurrence coefficients of $π_n(z)$, which was studied numerically in [Constr. Approx. 41 (2015), 529-587, arXiv:1108.0321]. The main goal of the present paper is to provide a rigorous framework for the global asymptotic portrait through the nonlinear steepest descent analysis (with the $g$-function mechanism) of the corresponding Riemann-Hilbert problem (RHP) and the continuation in the parameter space principle. The latter allows to extend the nonlinear steepest descent analysis from some parts of the complex $t$-plane to all noncritical values of $t$. We also provide explicit solutions for recurrence coefficients in terms of the Riemann theta functions. The leading order behaviour of the recurrence coefficients in the full scaling neighbourhoods the critical points (double and triple scaling limits) was obtained in [Constr. Approx. 41 (2015), 529-587, arXiv:1108.0321] and [Asymptotics of complex orthogonal polynomials on the cross with varying quartic weight: critical point behaviour and the second Painlevé transcendents, in preparation].
Cholinergic-GABAergic circuits in the neostriatum
Creators: name: English, Daniel F.
Publisher: name: No Publisher Supplied
Year: 2012

description: The basal ganglia are a system of subcortical nuclei whose functions include regulating the motivation for voluntary actions. One key aspect of this function is to assist in action selection, often referred to popularly as decision making, by keeping track of past results and utilizing this information to produce ideal decisions and by signaling the motivational significance of environmental events. Two types of basal ganglia neurons have been most extensively studied in terms of their role in these functions: the dopaminergic neurons of the substantia nigra pars compacta and the tonically active cholinergic interneurons of the neostriatum. Both have stereotypic responses to motivationally salient stimuli, and it is assumed that this information is used in choosing the most beneficial response. The focus of my thesis work was to investigate how the responses of neostriatal cholinergic interneurons to motivationally salient stimuli (commonly termed the pause response) are translated into downstream effects in projection neurons. My underlying hypothesis was that if these signals are to participate in the translation of a temporally brief and important environmental event into changes in behavior, that there must be a fast and temporally precise effect on the projection neuron output to other brain structures. Although striatal projection neurons express receptors for acetylcholine, they are of the slow acting muscarinic type, not the fast acting nicotinic type. Therefore, fast cholinergic regulation of projection neurons is assumed to be mediated by changes in synaptic input. We utilized technologies including optogenetics, transgenic mice and molecular biology to experimentally recapitulate the pause response of cholinergic interneurons in acute murine brain slice preparations, which preserve much of the intrinsic neostriatal circuitry, as well in behaving mice. We were then able to simultaneously record neostriatal neurons using in vitro whole-cell intracellular and in vivo extracellular electrophysiological recordings. These experiments revealed a novel neostriatal cholinergic-GABAergic circuit involving a recently described GABAergic interneuron similar to cortical neurogliaform GABAergic interneurons, which translate the pause response of cholinergic interneurons into fast and powerful inhibition of projection neurons. In addition to uncovering an unknown and unpredicted mechanism of action of acetylcholine in the neostriatum, these results demonstrate the power of combining traditional electrophysiological recording methods with current optogenetic, transgenic
Towards Social Role-Based Interruptibility Management
Creators: name: Anderson, Christoph
name: Heinisch, Judith Simone
name: Deldari, Shohreh
name: Salim, Flora D.
name: Ohly, Sandra
name: David, Klaus
name: Pejovic, Veljko
Publisher: name: arXiv
Year: 2021
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: Pervasive and ubiquitous computing facilitates immediate access to information in the sense of always-on. Information such as news, messages, or reminders can significantly enhance our daily routines but are rendered useless or disturbing when not being aligned with our intrinsic interruptibility preferences. Attention management systems use machine learning to identify short-term opportune moments, so that information delivery leads to fewer interruptions. Humans' intrinsic interruptibility preferences - established for and across social roles and life domains - would complement short-term attention and interruption management approaches. In this article, we present our comprehensive results towards social role-based attention and interruptibility management. Our approach combines on-device sensing and machine learning with theories from social science to form a personalized two-stage classification model. Finally, we discuss the challenges of the current and future AI-driven attention management systems concerning privacy, ethical issues, and future directions.
description: 10 pages, 6 figures, submitted on December 2022, to appear in IEEE Pervasive Computing, Special Issue - Human-Centered AI
Even denominator fractional quantum Hall state in bilayer graphene
Creators: name: Li, J. I. A.
name: Tan, C.
name: Chen, S.
name: Zeng, Y.
name: Taniguchi, T.
name: Watanabe, K.
name: Hone, J.
name: Dean, C. R.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The multi-component nature of bilayer graphene (BLG), together with the ability to controllably tune between the various ground state orders, makes it a rich system in which to explore interaction driven phenomena. In the fractional quantum Hall effect (FQHE) regime, the unique Landau level spectrum of BLG is anticipated to support a non-Abelian even-denominator state that is tunable by both electric and magnetic fields. However, observation of this state, which is anticipated to be stronger than in conventional systems, has been conspicuously difficult. Here we report transport measurements of a robust even denominator FQHE in high-mobility, dual gated BLG devices. We confirm that the stability of the energy gap can be sensitively tuned and map the phase diagram. Our results establish BLG as a dynamic new platform to study topological ground states with possible non-Abelian excitations.
description: 6 pages, 4 figures. v2, a typo has been corrected
Elliptic cohomology is unique up to homotopy
Creators: name: Davies, Jack Morgan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 55N34, 55N22, 55P43

description: Homotopy theory folklore tells us that the sheaf defining the cohomology theory Tmf of topological modular forms is unique up to homotopy. Here we provide a proof of this fact, although we claim no originality for the statement. This retroactively reconciles all previous constructions of Tmf.
description: 18 pages, comments are very welcome
Associative properties of the perirhinal network
Creators: name: Unal, Gunes
Publisher: name: No Publisher Supplied
Year: 2012

description: The perirhinal cortex (PRC), comprised of Brodmann areas 35 and 36, is a rostrocaudally-oriented strip of cortex in the medial temporal lobe, whose lesion produces memory impairments. Previous in vivo recording studies have revealed that a reduction in the responsiveness of perirhinal neurons to familiar stimuli underlies object recognition memory; whereas the opposite behavior, an increase in responsiveness, is required for associative memory formation between two paired stimuli. Both phenomena rely on long-term plasticity in the PRC. However, it is currently unclear how, as a result of experience, the same network could support these two seemingly opposite forms of long-term plasticity. PRC receives topographically organized projections from many high-order neocortical areas, mostly from the adjacent temporal neocortex; and it possesses an intrinsic network that distributes these neocortical inputs throughout its rostrocaudal axis. Previous studies suggest that neocortical inputs strongly recruit perirhinal inhibitory interneurons located at the same transverse level. In contrast, distant neocortical inputs only lead to excitation because longitudinal perirhinal connections engage few inhibitory interneurons. Given these facts, it is possible that the PRC acts as a Hebbian network to associate coincident but spatially distributed inputs. Consequently, the main objective of this thesis is to shed light on the mechanisms allowing neocortical inputs to undergo long-term depression (LTD) or potentiation (LTP), depending on to what extent they recruit the intrinsic perirhinal connections. Thus, using electrophysiological and imaging techniques in the whole guinea pig brain in vitro, I show that theta-frequency stimulation (TFS) at a single neocortical site leads to an input-specific group I mGluR-dependent LTD at all perirhinal levels, whereas paired TFS of two distant neocortical sites recruits the intrinsic circuit of the PRC and results in a NMDAR-dependent LTP to the paired inputs. Consistent with these results, utilizing anterograde tracing in rats and electron microscopic observations, this thesis shows that there are more inhibitory synapses formed by direct neocortical inputs to PRC and short-range perirhinal connections compared to long-range neocortical and perirhinal axons coursing in the PRC. Together, these findings suggest a mechanism whereby PRC associates temporally relevant but spatially distributed neocortical inputs.
Image Analysis Using a Dual-Tree $M$-Band Wavelet Transform
Creators: name: Chaux, Caroline
name: Duval, Laurent
name: Pesquet, Jean-Christophe
Publisher: name: arXiv
Year: 2017
Subjects: subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Functional Analysis (math.FA)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: We propose a 2D generalization to the $M$-band case of the dual-tree decomposition structure (initially proposed by N. Kingsbury and further investigated by I. Selesnick) based on a Hilbert pair of wavelets. We particularly address (\textit{i}) the construction of the dual basis and (\textit{ii}) the resulting directional analysis. We also revisit the necessary pre-processing stage in the $M$-band case. While several reconstructions are possible because of the redundancy of the representation, we propose a new optimal signal reconstruction technique, which minimizes potential estimation errors. The effectiveness of the proposed $M$-band decomposition is demonstrated via denoising comparisons on several image types (natural, texture, seismics), with various $M$-band wavelets and thresholding strategies. Significant improvements in terms of both overall noise reduction and direction preservation are observed.
Micromechanical damage analysis of Al-Al2O3 composites via cold-spray additive manufacturing
Creators: Sayahlatifi, Saman
Zaiemyekeh, Zahra
Shao, Chenwei
McDonald, André
Hogan, James D.
Publisher: name: University of Alberta Library
Year: 2023

3D micro-scale finite element (FE) models were developed to analyze the stress-state-dependent initiation and growth of failure of cold-sprayed additively manufactured (CSAM) Al-Al2O3 composites. Informed by experimental particle size distributions and porosity measurements, representative volume elements (RVEs) were generated by Digimat. Stress-state-dependent constitutive models for the Al matrix and Al2O3 ceramic particles were implemented by VUMAT subroutines in ABAQUS/Explicit FE solver. For the first time in the literature on metal–ceramic composites, the microscale failure mechanisms involving matrix ductile failure, particle cracking, and matrix/particle debonding were all quantified based on the crack volume fraction, the fraction of cracked particles, and the fraction of fully debonded interfacial nodes, respectively. The FE model was quantitatively and qualitatively validated by the experimental data for Al-46 wt% Al2O3 under quasi-static uniaxial compression. The validated model was used to investigate the effect of the particle content and size on the material behavior subjected to different stress states. The results revealed that the failure mechanisms are activated in a specified order across different stress states: I. matrix/particle debonding, II. particle cracking, and III. matrix ductile failure. The material ductility observed under compression/shear vanishes under tension due to the earlier activation of debonding and the faster growth (∼ 10 times) of the particle cracking mechanism. Additionally, it was shown that the particle size minimally affects the material strength and flow stress under shear which is likely related to the low load transfer effect through the interfaces. The novelty of this work stems from the provision of a better understanding of the stress-state-dependent evolution of failure mechanisms through a systematic quantification framework whose outcomes have implications for the design of better-performing Al-Al2O3 composites via control of the evolution of failure mechanisms and developing micromechanism-based constitutive models for CSAM metal–ceramic materials.
Highdicom: A Python library for standardized encoding of image annotations and machine learning model outputs in pathology and radiology
Creators: name: Bridge, Christopher P.
name: Gorman, Chris
name: Pieper, Steven
name: Doyle, Sean W.
name: Lennerz, Jochen K.
name: Kalpathy-Cramer, Jayashree
name: Clunie, David A.
name: Fedorov, Andriy Y.
name: Herrmann, Markus D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Machine learning is revolutionizing image-based diagnostics in pathology and radiology. ML models have shown promising results in research settings, but their lack of interoperability has been a major barrier for clinical integration and evaluation. The DICOM a standard specifies Information Object Definitions and Services for the representation and communication of digital images and related information, including image-derived annotations and analysis results. However, the complexity of the standard represents an obstacle for its adoption in the ML community and creates a need for software libraries and tools that simplify working with data sets in DICOM format. Here we present the highdicom library, which provides a high-level application programming interface for the Python programming language that abstracts low-level details of the standard and enables encoding and decoding of image-derived information in DICOM format in a few lines of Python code. The highdicom library ties into the extensive Python ecosystem for image processing and machine learning. Simultaneously, by simplifying creation and parsing of DICOM-compliant files, highdicom achieves interoperability with the medical imaging systems that hold the data used to train and run ML models, and ultimately communicate and store model outputs for clinical use. We demonstrate through experiments with slide microscopy and computed tomography imaging, that, by bridging these two ecosystems, highdicom enables developers to train and evaluate state-of-the-art ML models in pathology and radiology while remaining compliant with the DICOM standard and interoperable with clinical systems at all stages. To promote standardization of ML research and streamline the ML model development and deployment process, we made the library available free and open-source.
Aperiodic Sets of Prototiles Extracted From the Penrose Rhomb Tiling
Creators: name: Winkler, Mike
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Mathematics (math.GM)
subject: FOS: Mathematics

description: We present aperiodic sets of prototiles whose shapes are based on the well-known Penrose rhomb tiling. Some decorated prototiles lead to an exact Penrose rhomb tiling without any matching rules. We also give an approximate solution to an aperiodic monotile that tessellates the plane (including five types of gaps) only in a nonperiodic way.
description: 10 pages, 16 figures, accepted by Geombinatorics Quarterly (https://geombina.uccs.edu/)
Potential health benefits of cardoon in cheese production
Creators: name: Moita, Tomás
name: Marques, Cátia
name: Belas, Adriana
name: Pedroso, Laurentina
name: Santos, Isabel
name: Lourenço, Armindo
name: Lima, Ana
Publisher: name: Revista Lusófona de Ciência e Medicina Veterinária
Year: 2024

description: Objectives: Cardoon thistle (Cynara cardunculus) is frequently used as a coagulant in Portuguese cheese production in a water-based extract called thistle-rennet, particularly in the region of Serpa in Alentejo, Serra da Estrela and Azeitão. The goal of this study was to test the potential bioactivity of cardoon and thistle-rennet, specifically against foodborne pathogens, MMP-9 (matrix metalloprotease 9) and endoprotease, which has for long been recognized as playing important roles in inflammation and cancer.


Materials and Methods: The Cardoon was collected from a cheese factory in Serpa as dry plant and flowers, and the thistle-rennet was prepared according to the manufacturer’s instructions. The thistle-rennet was used for the bioactivity tests using Escherichia coli for the antibacterial activities and a fluorometric assay and reverse and a standard gelatin zymography for the MMP-9 inhibitory effects.


Results: The thistle-rennet was found to have a dose dependent effect on reducing E. coli growth as well as presented MMP-9 inhibitory activity, suggesting a strong potential antibacterial and anti-inflammatory activity.


Conclusion: Our results open promising perspectives for traditional cheese industries in Portugal and overall food safety and health. Considering cardoon is frequently used in the cheese industry and is completely GRAS (generally accepted as safe), this could be of great importance not only as an added value to the cheese industry but also as a functional food for human health purposes.


 


Keywords: Cardoon; antibacterial activity; anti-inflammatory activity; Portuguese DOP cheese; Thistle-rennet.


 


Financing: This work wassupported by a project (Cardoon) funded by FMV-Ulusófona.


 
description: Revista Lusófona de Ciência e Medicina Veterinária, v. 15 (2024): II Encontro de Investigação da FMV da Universidade Lusófona- Edição Especial
Variational Quantum Eigensolver for SU($N$) Fermions
Creators: name: Consiglio, Mirko
name: Chetcuti, Wayne J.
name: Bravo-Prieto, Carlos
name: Ramos-Calderer, Sergi
name: Minguzzi, Anna
name: Latorre, José I.
name: Amico, Luigi
name: Apollaro, Tony J. G.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Variational quantum algorithms aim at harnessing the power of noisy intermediate-scale quantum computers, by using a classical optimizer to train a parameterized quantum circuit to solve tractable quantum problems. The variational quantum eigensolver is one of the aforementioned algorithms designed to determine the ground-state of many-body Hamiltonians. Here, we apply the variational quantum eigensolver to study the ground-state properties of $N$-component fermions. With such knowledge, we study the persistent current of interacting SU($N$) fermions, which is employed to reliably map out the different quantum phases of the system. Our approach lays out the basis for a current-based quantum simulator of many-body systems that can be implemented on noisy intermediate-scale quantum computers.
description: 24 pages, 8 figures
A Small Fullerene (C24) may be the Carrier of the 11.2 micron Unidentified Infrared Band
Creators: name: Bernstein, L. S.
name: Shroll, R. M.
name: Lynch, D. K.
name: Clark, F. O.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We analyze the 11.2 μm unidentified infrared band (UIR) spectrum from NGC 7027 and identify a small fullerene (C24) as a plausible carrier. The blurring effects of lifetime and vibrational anharmonicity broadening obscure the narrower, intrinsic spectral profiles of the UIR band carriers. We use a spectral deconvolution algorithm to remove the blurring, in order to retrieve the intrinsic profile of the UIR band. The shape of the intrinsic profile, a sharp blue peak and an extended red tail, suggests that the UIR band originates from a molecular vibration-rotation band with a blue band head. The fractional area of the band-head feature indicates a spheroidal molecule, implying a non-polar molecule and precluding rotational emission. Its rotational temperature should be well approximated by that measured for non-polar molecular hydrogen, ~825 K for NGC 7027. Using this temperature, and the inferred spherical symmetry, we perform a spectral fit to the intrinsic profile that results in a rotational constant implying C24 as the carrier. We show that the spectroscopic parameters derived for NGC 7027 are consistent with the 11.2 μm UIR bands observed for other objects. We present density functional theory (DFT) calculations for the frequencies and infrared intensities of C24. The DFT results are used to predict a spectral energy distribution (SED) originating from absorption of a 5 eV photon, and characterized by an effective vibrational temperature of 930 K. The C24 SED is consistent with the entire UIR spectrum and is the dominant contributor to the 11.2 and 12.7 μm bands.
description: 20 pages, 8 figures, accepted for publication in ApJ, replaced incorrect figure 8
New Insights into the Puzzling P-Cygni Profiles of Magnetic Massive Stars
Creators: name: Erba, Christiana
name: David-Uraz, Alexandre
name: Petit, Veronique
name: Owocki, Stanley P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Magnetic massive stars comprise approximately 10% of the total OB star population. Modern spectropolarimetry shows these stars host strong, stable, large-scale, often nearly dipolar surface magnetic fields of 1 kG or more. These global magnetic fields trap and deflect outflowing stellar wind material, forming an anisotropic magnetosphere that can be probed with wind-sensitive UV resonance lines. Recent HST UV spectra of NGC 1624-2, the most magnetic O star observed to date, show atypically unsaturated P-Cygni profiles in the Civ resonant doublet, as well as a distinct variation with rotational phase. We examine the effect of non-radial, magnetically-channeled wind outflow on P-Cygni line formation, using a Sobolev Exact Integration (SEI) approach for direct comparison with HST UV spectra of NGC 1624-2. We demonstrate that the addition of a magnetic field desaturates the absorption trough of the P-Cygni profiles, but further efforts are needed to fully account for the observed line profile variation. Our study thus provides a first step toward a broader understanding of how strong magnetic fields affect mass loss diagnostics from UV lines.
description: 4 pages, 3 figures, IAUS 329 Proceedings