cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Combining statistics and scattering calculations for improved predictions of molecular collision observables
Creators: name: Cui, Jie
Publisher: name: University of British Columbia
Year: 2015

description: This thesis describes four types of cold molecular collision systems with increasing complexity: from simple atom-diatomic molecule to complicated polyatomic molecule-polyatomic molecule. The early thesis work is concerned with three open questions pertaining to collision dynamics of cold molecules. We demonstrate the possibility of controlling collisional decoherence of ultracold molecules by tuning an external magnetic field. We then provide insight into the feasibility of evaporative cooling of molecules, and for the first time incorporate the uncertainty analysis of the potential energy surface (PES) into scattering calculations. In addition, we use classical trajectory methods to study the effects of the interaction strength and the geometry of rigid polyatomic molecules on the formation of long-lived collision complexes at low collision energies. The second half of the thesis work is focused on combining statistical methodology and scattering calculations to address two major problems in molecular dynamics calculations: increasing computational complexity and uncertainties due to inaccuracies of PES. Using a small number of scattering calculations, we show that we can build a Gaussian Process (GP) model to statistically approximate collision outcomes for complex molecules, and then perform the uncertainty analysis and the sensitivity analysis. We also demonstrate that trained by a combination of classical and quantum calculations, a GP model can provide an accurate description of the quantum scattering cross sections, even near scattering resonances.
title: Critical Making, Critical Design
Creators: name: Fan, Lai-Tze
Publisher: name: Electronic Book Review
Year: 2021

description: The journals electronic book review (digital literary studies, est. 1995) and The Digital Review (born-digital arts and writing, est. 2020) are proud to announce their first collaboration: a special double issue on “Critical Making, Critical Design” that pairs digital works of making or design with critical and scholarly mediation.
The symbiotic system AG Draconis. Soft X-ray bremsstrahlung from the nebulae
Creators: name: Contini, Marcella
name: Angeloni, Rodolfo
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The modeling of UV and optical spectra emitted from the symbiotic system AG Draconis, adopting collision of the winds, predicts soft X-ray bremsstrahlung from nebulae downstream of the reverse shock with velocities > 150 km/s and intensities comparable to those of the white dwarf black body flux. At outbursts, the envelop of debris, which corresponds to the nebula downstream of the high velocity shocks (700-1000 km/s) accompanying the blast wave, absorbs the black body soft X-ray flux from the white dwarf, explains the broad component of the H and He lines, and leads to low optical-UV-X-ray continuum fluxes. The high optical-UV flux observed at the outbursts is explained by bremsstrahlung downstream of the reverse shock between the stars. The depletion of C, N, O, and Mg relative to H indicates that they are trapped into dust grains and/or into diatomic molecules, suggesting that the collision of the wind from the white dwarf with the dusty shells, ejected from the red giant with about 1 year periodicity, leads to the U-band fluctuations during the major bursts.
description: 12 pages, 5 figures, 2 tables. New Astronomy, in press
The "Good Dyad" : examining the impact of personality and behavior on dyadic accuracy in first impressions
Creators: name: Rogers, Katherine Helen
Publisher: name: University of British Columbia
Year: 2015

description: Much research on the accuracy of interpersonal perception has focused on either the good judge– the individual who accurately perceives others’ personality (e.g., Letzring, 2008), or the good target– the individual whose personality is accurately perceived by others (e.g., Human & Biesanz, 2013). Despite there being reliable variance attributable to the dyad (Biesanz, 2010) previous work has largely overlooked the importance of the dyad and little is known as to why some dyads result in more accurate and more positive impressions than do others. To more fully understand the process of impression formation, it is imperative to investigate the characteristics of the good dyad. As such, this dissertation examines the mechanisms associated with changes in dyadic accuracy in first impressions of personality. In order to understand the behaviors and characteristics associated with dyadic accuracy, 77 participants were videotaped engaging in a total of 437 unstructured 3-minute interactions with another previously unacquainted participant. Raters then coded participants’ behavior and personality, as well as general aspects of the interaction. This dissertation investigates dyadic characteristics and processes associated with dyadic accuracy, how behavior changes across interactions, and the role of changes in behavior in understanding dyadic accuracy. Using the social accuracy model (SAM; Biesanz, 2010), the good dyad is considered in terms of two components of accuracy: distinctive accuracy, understanding an individual’s own unique patterning of traits, and normative accuracy, viewing an individually positively and as similar to the average person. For distinctive accuracy, stable characteristics of the individuals in the dyad impacted the degree to which targets were viewed in line with their own unique traits. Further, between-person differences in behavior generally moderated the impact of within-person changes in behavior on distinctive accuracy. For normative accuracy, the quality of the interaction, interpersonal attraction, and engagement impacted the positivity impressions. Additionally, changes in behavior mediated the impact of changes in dyadic characteristics (e.g., engagement) on normative accuracy. In sum, examining dyadic characteristics and processes, as well as behavior allows greater insight into the process of impression formation by looking beyond stable individual differences and considering variability across dyadic interactions.
Dissipation-driven superconductor-insulator transition in linear arrays of Josephson junctions capacitively coupled to metallic films
Creators: name: Lobos, Alejandro M.
name: Giamarchi, Thierry
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We study the low-temperature properties of linear Josephson-junction arrays capacitively coupled to a proximate two-dimensional diffusive metal. Using bosonization techniques, we derive an effective model for the array and obtain its critical properties and phases at T = 0 using a renormalization group analysis and a variational approach. While static screening effects given by the presence of the metal can be absorbed in a renormalization of the parameters of the array, backscattering originated in the dynamically screened Coulomb interaction produces a non-trivial stabilization of the insulating groundstate and can drive a superconductor-insulator transition. We study the consequences for the transport properties in the low-temperature regime. In particular, we calculate the resisitivity as a function of the temperature and the parameters of the array, and obtain clear signatures of a superconductor-insulator transition that could be observed in experiments.
description: 10 pages, 5 figures, submitted to Physical Review B
Health-related information practices and the experiences of young parents
Creators: name: Greyson, Devon
Publisher: name: University of British Columbia
Year: 2017

description: Background: Young parents are targeted by a variety of health information interventions, aiming to educate and monitor them in order to improve population health. However, we know little about the ways young parents use health information or experience health information interventions in their everyday lives. Objectives: The objectives of the dissertation are to use a series of article-style chapters to: (1) describe the health-related information practices of young parents (Chapter 3); (2) explore how knowledge and expertise are discursively constructed within young parents’ health information worlds (Chapter 4); and (3) examine the functioning and values of population health information interventions in the lives of young parents (Chapter 5). Methods: The analyses presented in this dissertation are based on data collected via ethnographic observation at two Young Parent Programs and individual interviews with 37 young mothers and 2 young fathers ages 15-24 in Greater Vancouver, British Columbia. Data was analyzed in accordance with constructivist grounded theory and situational analysis. Results: Young parents in Greater Vancouver were often sophisticated health information seekers. Information assessment was a major task, for which young parents employed various methods of triangulation. These practices took place in social worlds that discursively constructed the “teen mom” as paradoxically knowledgeable (in matters of sexuality and technology) and ignorant (in matters of parenting and health. Population health information interventions (communication and surveillance) were prominent in these social worlds, and carried ethical implications for social justice. Young parent acceptance varied depending on the positionality of those implementing interventions, as well as their intrusiveness and level of stigmatization of young parents. Conclusion: By investigating, documenting, and theorizing the ways young parents interact with health information in the contexts of their everyday lives, this study generated theory that can help inform information interventions aimed at supporting this public health priority population. Programs and materials for young parents should take into account the heterogeneity of their childcare experience and parenting knowledge, as well as cultural norms. Future research should further explore the intersection between individual information practices and health information interventions, and test the emergent theoretical propositions related to population health information interventions.
Migration of pairs of giant planets in low-viscosity discs
Creators: name: Griveaud, P.
name: Crida, A.
name: Lega, E.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: When considering the migration of Jupiter and Saturn, a classical result is to find the planets migrating outwards and locked in the 3:2 mean motion resonance (MMR). These results were obtained in the framework of viscously accreting discs, in which the observed stellar accretion rates constrained the viscosity values. However, it has recently been shown observationally and theoretically that discs are probably less viscous than previously thought. Therefore, in this paper, we explore the dynamics of pairs of giant planets in low-viscosity discs. We performed two-dimensional hydrodynamical simulations using the grid-based code FARGOCA. In contrast to classical viscous discs, we find that the outer planet never crosses the 2:1 resonance and the pair does not migrate outwards. After a wide parameter exploration, including the mass of the outer planet, we find that the planets are primarily locked in the 2:1 MMR and in some cases in the 5:2 MMR. We explain semi-analytically why it is not possible for the outer planet to cross the 2:1 MMR in a low-viscosity disc. We find that pairs of giant planets migrate inwards in low-viscosity discs. Although, in some cases, having a pair of giant planets can slow down the migration speed with respect to a single planet. Such pairs of slowly migrating planets may be located, at the end of the disc phase, in the population of exoplanets of 'warm Jupiters'. However, the planets never migrate outwards. These results could have strong implications on the Solar System's formation scenarios if the Sun's protoplanetary disc had a low viscosity.
description: 14 pages, 14 figures. Accepted to A&A
What to learn next: recommending commands in a feature-rich environment
Creators: name: Zolaktaf, Sedigheh
Publisher: name: University of British Columbia
Year: 2016

description: Despite an abundance of commands to make tasks easier to perform, the users of feature-rich applications, such as development environments and AutoCAD applications, use only a fraction of the commands available due to a lack of awareness of the existence of many commands. Earlier work has shown that command recommendation can improve the usage of a range of commands available within such applications. In this thesis, we address the command recommendation problem, in which, given the command usage history of a set of users, the objective is to predict a command that is likely useful for the user to learn. We investigate two approaches to address the problem. The first approach is built upon the hypothesis that users of feature-rich applications who have similar features tend to use the same commands, and also, a specific user tends to use commands with similar features. Building on this hypothesis, we describe a supervised learning framework that exploits features from a user-command network to predict new links among users and commands. The second approach is built upon three hypotheses. First, we hypothesize that in feature-rich applications there exists co-occurrence patterns between commands. Second, we hypothesize that users of feature-rich applications have prevalent discovery patterns. Finally, we hypothesize that users need different recommendations based on the time elapsed between their last activity and the time of recommendation. To generate recommendations, we obtain co-occurrence and discovery patterns from the command usage history of a large set of users of the same feature-rich application. Subsequently, for each user, we produce recommendations based on the user's command usage history, co-occurrence and discovery patterns, and time elapsed since the last command usage. We refer to the algorithm we developed according to this approach as CoDis. Empirical experiments on data submitted by users of an integrated development environment (Eclipse) demonstrate that CoDis achieves significant performance improvements over link prediction, standard algorithms used for command recommendation, and matrix factorization techniques that are known to perform well in other domains. Compared to ADAGRAD, the best performing baseline, it achieves an improvement of 10.22% in recall, for a top-N recommendation task (N=20).
Lopsided Satellite Distributions around Isolated Host Galaxies in a LCDM Universe
Creators: name: Samuels, Adam
name: Brainerd, Tereasa G.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: A recent observational study found that the projected spatial distributions of the satellites of bright, isolated host galaxies tend to be lopsided with respect to the locations of the hosts. Here, we examine the spatial distributions of the satellites of a large number of bright, isolated host galaxies that were obtained from mock redshift surveys of a LCDM simulation. Host galaxies and their satellites were identified using selection criteria that are identical to those used in the observational study, allowing a direct comparison of the results for the simulated and observed systems. To characterize the spatial distribution of the satellites, we adopt two statistics: [1] the pairwise clustering of the satellites and [2] the Mean Resultant Length. In agreement with the observational study, we find a strong tendency for satellites in the simulation to be located on the same side of their host, and the signal is most pronounced for the satellites of blue hosts. These lopsided satellite distributions are not solely attributable to incompleteness of the observed satellite catalog or the presence of objects that have been falsely identified as satellites. In addition, satellites that joined their hosts' halos in the distant past (> 8 Gyr) show a pronounced lopsidedness in their spatial distributions and, therefore, the lopsidedness is not solely attributable to late-time accretion of satellites.
Confirmation of Color Dependent Centroid Shift Measured After 1.8 years with HST
Creators: name: Bhattacharya, Aparna
name: Bennett, David
name: Beaulieu, Jean Philippe
name: Bond, Ian
name: Koshimoto, Naoki
name: Lu, Jessica
name: Blackman, Joshua
name: Ranc, Clement
name: Vandorou, Aikaterini
name: Terry, Sean
name: Marquette, Jean
name: Cole, Andrew
name: Fukui, Akihiko
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We measured precise masses of the host and planet in OGLE-2003-BLG-235 system, when the lens and source were resolving, with 2018 Keck high resolution images. This measurement is in agreement with the observation taken in 2005 with the Hubble Space Telescope (HST). In 2005 data, the lens and sources were not resolved and the measurement was made using color-dependent centroid shift only. Nancy Grace Roman Space Telescope will measure masses using data typically taken within 3-4 years of the peak of the event which is much shorter baseline compared to most of the mass measurements to date. Hence, color dependent centroid shift will be one of the primary method of mass measurements for Roman. Yet, mass measurements of only two events (OGLE-2003-BLG-235 and OGLE-2005-BLG-071) are done using the color dependent centroid shift method so far. The accuracy of the measurements using this method are neither completely known nor well studied. The agreement of Keck and HST results, shown in this paper, is very important since this agreement confirms the accuracy of the mass measurements determined at a small lens-source separation using the color dependent centroid shift method. This also shows that with >100 high resolution images, Roman telescope will be able to use color dependent centroid shift at 3-4 years time baseline and produce mass measurements. We find that OGLE-2003-BLG-235 is a planetary system consists of a 2.34 +- 0.43M_Jup planet orbiting a 0.56 +- 0.06M_Sun K-dwarf host star at a distance of 5.26 +- 0.71 kpc from the Sun.
description: Submitted to AJ, under review. arXiv admin note: substantial text overlap with arXiv:2009.02329
Distances to 10 nearby galaxies observed with the Hubble space telescope
Creators: name: Karachentsev, I. D.
name: Tikhonov, N. A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Images of 10 galaxies in F814W and F606W filters obtained on the Hubble Space Telescope (HST) are used to construct color-magnitude diagrams for the star population of these galaxies. The distances to the galaxies are estimated from the luminosity of the tip of the red giant branch. The galaxies examined here have radial velocities from 250 to 760 km/s relative to the centroid of the Local Group and distances ranging from 3.7 to 13.0 Mpc. Several other observed galaxies with low radial velocities are noted at distances beyond the limit of 13 Mpc.
description: 7 pages, 1 table, 4 figures, published in Astrofizica
Nonlinear dynamics and rheology of active fluids: simulations in two dimensions
Creators: name: Fielding, S. M.
name: Marenduzzo, D.
name: Cates, M. E.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We report simulations of a continuum model for (apolar, flow aligning) active fluids in two dimensions. Both free and anchored boundary conditions are considered, at parallel confining walls that are either static or moving at fixed relative velocity. We focus on extensile materials and find that steady shear bands, previously shown to arise ubiquitously in 1D for the active nematic phase at small (or indeed zero) shear rate, are generally replaced in 2D by more complex flow patterns that can be stationary, oscillatory, or apparently chaotic. The consequences of these flow patterns for time-averaged steady-state rheology are examined.
description: 16 pages, 15 eps figures, submitted to Phys. Rev. E
Capillary filling of polymer chains in nanopores
Creators: name: Zhang, Jianwei
name: Lei, Jinyu
name: Tian, Wenzhang
name: Zhang, Guangzhao
name: Floudas, George
name: Zhou, Jiajia
Publisher: name: arXiv
Year: 2023
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We performed molecular dynamics simulations with a coarse-grained model to investigate the capillary filling dynamics of polymer chains in nanopores. Short chains fill slower than predicted by the Lucas-Washburn equation but long chains fill faster. The analysis shows that the combination of the confinement effect on the free energy of chains and the reduction of the effective radius due to the "dead zone" slow down the imbibition. Reduction of the entanglements is the main factor behind the reversing dynamics because of the lower effective viscosity, which leads to a faster filling. This effect is enhanced in the smaller capillary and more profound for longer chains. The observed increase in the mean square radius of gyration during capillary filling provides a clear evidence of chain orientation, which leads to the decrease in the number of entanglements. For the scaling relation between the effective viscosity and the degree of polymerization, we find the exponent will increase in the larger nanopore.
description: 32 pages, 12 figures, SI included
CHANGES IN CLINICAL CHARACTERISTICS AND BIOCHEMICAL INDICES OF FUR ANIMALS AND POULTRY BLOOD UNDER EIMERIA INVASION
Creators: name: Dovhiy Y.Y.
name: Kot T.F.
name: O.V., Rudik
name: Dovhiy M. Y.
name: Rudik, V.V.
Publisher: name: Colloquium-journal
Year: 2020
Subjects: rabbits
nutrias
chickens
quails
invasion
agent
eimerias
metabolites
blood.

description: The research has revealed the invasion agents like: Eimeria perforans, E. magna, E. stiedae in rabbits and nutrias, in a small amount– E. coecicola, E. pisiformis and E. intestinalis in rabbits, Е. maxima, E. tenella, E. necatrix and E. acervulina in chickens and quails. Rapidly infected fur animals (280 rabbits and 180 nutrias), 3468 chickens and 1800 quails were examined while conducting a research. Under the localization of a path-alogic process, the disease appeared in poultry in a mixed pattern; in rabbits and nutrias in an intestinal pat-tern (11.9 % and 11 %), in a hepatic pattern (8.1 % and 11 %) and mostly in a mixed pattern (80 % and 78 % respectively). The research showed that sick rabbits and nutrias were weak, mucous membranes of eyes and nose were pale (50.5 and 49 %), yellowish (38 and 42 %). Occasional watery feces (80 and 91 %), flatus were observed, the abdomen was increased and infirm (87.1 and 85 %). Under complications the rabbits had intermittent fever (5%), acute bouts of cramps (7.14 %). Death was observed in rabbits under a severe disease in two weeks time (10%) and in nutrias in 3-5 weeks (7%). Digestive unsets were a characteristic feature under an asymptomatic disease course. From among the blood biochemical indices of nutrias and rabbits, a decrease in the count of hemoglobu-line, in the amount of albumen, crude protein as compared to a control group was registered. A depressed state, thirst, (27th day), 1-2 ºС temperature rise, drowsiness, awkward gait (35th day), watery feces, feces with blood admixtures were registered in chickens, and the quails manifested unwillingness to eat, gathered in warm places, they also had white-and-green watery feces, labored respiration and accelerated cardiac rate. Some decrease in the amount of red blood cells, pseudoeosinophils as well as some increase in the amount of white blood cells and eosonophils were registered in the blood of sick chickens and quails. Some decrease in the count of hemoglobulin, in the amount of creatinine and urine was registered in blood serum of the infected chickens and quails. Thus, some changes in blood indices of chickens and quails which suffered from protozoal invasion testi-fied to a toxic and trophic effects of eimerias and their metabolites on the organisms.
A slow process in confined polymer melts: layer exchange dynamics at a polymer solid interface
Creators: name: Yelash, L.
name: Virnau, P.
name: Binder, K.
name: Paul, W.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Employing Molecular Dynamics simulations of a chemically realistic model of 1,4-polybutadiene between graphite walls we show that the mass exchange between layers close to the walls is a slow process already in the melt state. For the glass transition of confined polymers this process competes with the slowing down due to packing effects and intramolecular rotation barriers.
Reducing post-silicon coverage monitoring overhead with emulation and statistical analysis
Creators: name: Ochoa Gallardo, Ricardo
Publisher: name: University of British Columbia
Year: 2015

description: With increasing design complexity, post-silicon validation has become a critical problem. In pre-silicon validation, coverage is the primary metric of validation effectiveness, but in post-silicon, the lack of observability makes coverage measurement problematic. On-chip coverage monitors are a possible solution, where a coverage monitor is a hardware circuit that sets to one when the coverage event of interest occurs. However, prior research has shown that the overhead is prohibitive for anything beyond a small number of coverage monitors. In this thesis, I explore techniques that reduce the number of instrumented coverage monitors, while still being able to imply full coverage with high probability. These techniques use a deterministic forward feature selection algorithm with the objective functions based on statistical information. For gathering the required statistical information, the method relies on emulation, where all coverage monitors of interest are instrumented on a version of the design. On this emulator, such as an FPGA, I stress the design with randomly generated tests to collect the data from the instrumented coverage monitors. I propose three objective functions for the feature selection algorithm: the first estimates the probability of a coverage monitor being set during a test; the next objective function builds a Bayesian Network (BN), then takes advantage of the relationship information between nodes (coverage monitors), which the network provides; the last objective function directly estimates the conditional probability of coverage from the gathered data. I demonstrate these techniques on a non-trivial system-on-chip, by measuring the code coverage achieved after executing randomly generated test programs. Depending on the objective function, results show a 67.7% to 95.5% reduction in the number of required coverage monitors. In the ASIC implementation, this would translate into an impact of 0.33-1.96% in silicon area overhead and 0.40-2.70% in static power overhead. These results show my technique works, by proving it is possible to track a smaller number of coverage events that statistically represent the whole set.
Identification of arabic word from bilingual text using character features
Creators: name: Haboubi, Sofiene
name: Maddouri, Samia
name: Amiri, Hamid
Publisher: name: arXiv
Year: 2011
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: The identification of the language of the script is an important stage in the process of recognition of the writing. There are several works in this research area, which treat various languages. Most of the used methods are global or statistical. In this present paper, we study the possibility of using the features of scripts to identify the language. The identification of the language of the script by characteristics returns the identification in the case of multilingual documents less difficult. We present by this work, a study on the possibility of using the structural features to identify the Arabic language from an Arabic / Latin text.
description: FAHR 2010 - the 1st International Workshop on Frontiers in Arabic Handwriting Recognition
High-resolution He I 10830 Å narrowband imaging for precursors of chromospheric jets and their quasi-periodic properties
Creators: name: Wang, Ya
name: Zhang, Qingmin
name: Hong, Zhenxiang
name: Shen, Jinhua
name: Ji, Haisheng
name: Cao, Wenda
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Solar jets are well-collimated plasma ejections in the solar atmosphere. They are prevalent in active regions, the quiet Sun, and even coronal holes. They display a range of temperatures, yet the nature of the cool components has not been fully investigated. In this paper, we show the existence of the precursors and quasi-periodic properties for two chromospheric jets, mainly utilizing the He i 10830 Å narrowband filtergrams taken by the Goode Solar Telescope (GST). The extreme ultraviolet (EUV) counterparts present during the eruption correspond to a blowout jet (jet 1) and a standard jet (jet 2), as observed by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory (SDO). The high-resolution He i 10830 Å observation captures a long-lasting precursor for jet 1, signified by a series of cool ejections. They are recurrent jet-like features with a quasi-period of about five minutes. On the other hand, the cool components of jet 2, recurrently accompanied by EUV emissions, present a quasi-periodic behavior with a period of about five minutes. Both the EUV brightening and He i 10830 Å absorption show that there was a precursor for jet 2 that occurred about five minutes before its onset. We propose that the precursor of jet 1 may be the consequence of chromospheric shock waves, since the five-minute oscillation from the photosphere can leak into the chromosphere and develop into shocks. Then, we find that the quasi-periodic behavior of the cool components of jet 2 may be related to magnetic reconnections modulated by the oscillation in the photosphere.
Determining the role of scavenger receptor class B type I as a source of cholesterol for de novo androgen synthesis in castration-resistant prostate cancer
Creators: name: Midha, Ankur
Publisher: name: University of British Columbia
Year: 2015

description: Existing therapies for castration-resistant prostate cancer (CRPC) extend life and provide clinical benefit; however, patients develop therapeutic resistance. Persistent androgen signaling in CRPC is maintained in part by intratumoral steroidogenesis from the precursor cholesterol. The high density lipoprotein-cholesterol (HDL) receptor, scavenger receptor class B type I (SR-BI), is upregulated in CRPC models in vitro and in vivo. This thesis tests the hypothesis that depriving CRPC cells of HDL as a cholesterol source by silencing SR-BI will diminish de novo steroidogenesis and resultant androgen receptor-mediated signaling necessary for CRPC viability. The effects of SR-BI silencing were studied using CRPC C4-2 cells transfected with either Stealth RNAi duplexes targeting SR-BI (SRBI-KD) or Lo GC Negative Control (NC) duplexes. Cells cultured in androgen-depleted conditions for varying times post-transfection were assessed for SR-BI expression, prostate specific antigen (PSA) expression by chemiluminescence, cholesterol levels by fluorometry, and steroid levels by liquid-chromatography-mass spectrometry. HDL-uptake was measured by flow cytometry of the fluorescent cholesterol mimetic 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI-HDL). Cell cycle state was assessed by flow cytometry of propidium iodide DNA staining, while cell cycle markers were assessed by immunoblotting. Adaptive stress responses were assessed by immunoblotting for autophagy markers, as well by flow cytometry for senescence associated beta-galactosidase (SA-β-gal) using a fluorogenic substrate, 5-dodecanoylaminofluorescein di-β-D-galactopyranoside. SRBI-KD treatment reduced SR-BI levels by ~57% by 2 days and ~86% by 4 days post-transfection. This correlated with reduced DiI-HDL-uptake by 22%, reduced cellular testosterone levels two-fold, and reduced PSA secretion by 39% compared to NC cells. These changes were accompanied by reduced proliferation, G₁S cell cycle arrest, and a small, but measurable increase in cell death at 4 to 6 days post-transfection. Cell stress was evidenced by enhanced autophagy activity and induced stress marker expression while senescence was evidenced by increased SA-β-gal activity. These studies indicate that SR-BI silencing reduced DiI-HDL uptake which reduced cellular androgen content and androgen signaling, resulting in induction of an adaptive stress response characterized by cell cycle arrest, autophagy, senescence, and eventually death of these CRPC cells. The data presented herein provide support for SR-BI as a cholesterol source for androgen synthesis in CRPC cells.
A second superconducting energy gap of Nb_3Sn observed by breakjunction point-contact spectroscopy
Creators: name: Marz, M.
name: Goldacker, W.
name: Lortz, R.
name: Goll, G.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We report on investigations of the superconducting energy gap of the A15 superconductor Nb_3Sn by point-contact spectroscopy of breakjunctions. The voltage-dependent differential conductance dI/dV reveals features of a second energy gap besides the energy gap known from previous tunnel measurements with maxima at Δ_1=3.92 +/- 0.16 meV and Δ_2=0.85 +/- 0.17 meV as derived from a histogram summarizing the data of more than 60 contacts. These findings are the first spectroscopic evidence that Nb_3Sn belongs to the class of two-band superconductors and they are in line with low-temperature specific-heat measurements on Nb_3Sn.
Magnetic fluctuations and self--energy effects in two--dimensional itinerant systems with van Hove singularity of electronic spectrum
Creators: name: Igoshev, P. A.
name: Irkhin, V. Yu.
name: Katanin, A. A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We investigate a competition of tendencies towards ferromagnetic and incommensurate order in two-dimensional fermionic systems within functional renormalization group technique using temperature as a scale parameter. We assume that the Fermi surface (FS) is substantially curved, lies in the vicinity of van Hove singularity points and perform an account of the self-energy corrections. It is shown that the character of magnetic fluctuations is strongly asymmetric with respect to the Fermi level position relatively to van Hove singularity (VHS). For the Fermi level above VHS we find at low temperatures dominant incommensurate magnetic fluctuations, while below VHS level we find indications for ferromagnetic ground state. In agreement with the Mermin-Wagner theorem, at finite temperatures and in small magnetic fields we obtain rather small magnetization, which appears to be a power-law function of magnetic field. It is found that the FS curvature is slightly increased by correlation effects, and the renormalized bandwidth decreases at sufficiently low temperatures.
description: 26 pages, 14 figures, Submitted to Physical Review B
The relationship between race/ethnicity and early identification of an emotional behavioral disorder and arrest outcomes
Creators: name: House, Lexy Shyler
Publisher: name: The University of Texas at Austin
Year: 2021
Subjects: Special education
Criminal justice system
Emotional behavioral disorder
Early identification

description: Throughout the last two decades, schools have encouraged early identification of students with, or at risk for, emotional behavioral disorders (EBD; Conroy et al., 2004), with the assumption being that identification can provide this population with access to services to prevent behavioral difficulties or at least reduce their impact. Students with EBD also typically demonstrate persistent academic failure in schools leading to negative life outcomes, including involvement in the criminal justice system (U.S. Department of Education, 2014). Another important reality is that many racial and ethnic groups are disproportionately identified as having EBD (Cullinan & Kauffman, 2005). Additionally, little research has investigated whether race/ethnicity and the age of identification of an EBD is associated with involvement in the criminal justice system. Using data on students with EBD from the National Longitudinal Transition Study-2, this study used cross tabulations to examine significant differences across demographics and outcomes, and logistic regression analysis was used to understand the relationship between students’ arrest outcomes, and students’ age of identification, along with race/ethnicity of the students. Served as a guide for the development of this study, the Social-Relational Model of disability views disability as a form of social oppression (Thomas, 1999). Students with EBD often experience stigma, which can place limitations on what individuals can and cannot do, and what they can achieve. The Social-Relational Model applies to the current study because it views disability as being rooted in an unequal social relationship, resulting in disadvantage. The model restricts students from achieving certain outcomes, causing negative effects on who they become or what communities with which they are involved (e.g., the criminal justice system). Potentially, the social stigma experienced from being identified as needing special-education services may outweigh the benefits experienced by students with EBD (e.g., receiving evidence-based interventions and support). Findings demonstrated the racial/ethnic categories were not significant (Wald = .353, df = 3, p > .05) and age of youth when they started having problem/disability (Wald = .776, df = 1, p > .05) was not significant. Specifically, findings from this study indicate that race/ethnicity and the age of identification were not significantly related to arrest outcomes, suggesting that identifying students with EBD does not necessarily lead to changes that impact the likelihood of a child being arrested. Therefore, early identification does not appear to improve arrest outcomes; however, more work is needed to understand what other outcomes might be benefitted from early identification of EBD and special education supports.
Understanding the Role and Experiences of Birth Centre Aides at the Ottawa Birth and Wellness Centre: Work, Leadership, and Reproductive Justice
Creators: name: James, Yvonne
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2021
Subjects: birth centres
birth centre aides
healthcare leadership
reproductive justice

description: Free-standing birth centres (FSBCs) were formed in Ontario in 2014 and operate with the support of birth centre aides (BCAs), a novel birth worker role. As a recent introduction to the Ontario maternity care system, there have been no academic inquiries into BCAs and only a hand full of investigations on birth centres (Mattison, 2015; Mattison et al., 2020; Murray-Davis et al., 2014; Sprague et al., 2018). From a feminist perspective, an analysis of the BCA role offers a unique opportunity to conduct a feminist analysis of work in healthcare between largely women care providers (i.e., midwives and BCAs), leadership, and reproductive justice activism. My dissertation consists of three standalone papers based on empirical data gathered through in-depth semi-structured interviews and document analysis at the Ottawa Birth and Wellness Centre (OBWC). For my first paper, “Mapping the Development of Birth Centre Aides at the Ottawa Birth and Wellness Centre”, I applied a feminist sociology of professions framework (Davies, 1996; Witz, 1992) and employed an institutional ethnographic methodology (Smith, 1990) to understand how the BCA role was developed and operationalized in the OBWC. I mapped the development of the BCA role at the OBWC descriptively and visually using the documentary and interview data with key stakeholders from the OBWC (n=16), including BCAs, administrators, and midwives. In the second paper, “Feminist Leadership in Healthcare: The Case of Birth Centre Aides and the Ottawa Birth and Wellness Centre,” I integrated Tronto’s (1993) ethic of care with Dickson and Tholl’s (2014) LEADS in a Caring Environment leadership framework in an instrumental case study (Stake, 2005) to understand how BCAs lead from their position within the OBWC and how they experience feminist leadership practices in the OBWC. Finally, in my third paper, “Birth Work as Reproductive Activism: The Case of Birth Centre Aides at the Ottawa Birth and Wellness Centre,” I applied a reproductive justice theoretical framework (Ross, 2017; SisterSong, 2015) through an instrumental case study (Stake, 2005) to understand how BCAs undertake quiet reproductive activism at the OBWC. Taken together, my dissertation offers new knowledge on the role and development of BCAs in the OBWC and contributes to advancing feminist scholarship on healthcare leadership and reproductive justice activism.
Controlling Fractional Difference Equations Using Feedback
Creators: name: Joshi, Divya D.
name: Bhalekar, Sachin
name: Gade, Prashant M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 26A33, 39A30

description: One of the most popular methods of controlling dynamical systems is feedback. It can be used without acquiring detailed knowledge of the underlying system. In this work, we study the stability of fractional-order linear difference equations under feedback. The stability results are derived for an arbitrary feedback time $τ$. We study the cases of $τ=1$ and $τ=2$ in further detail. The extension to the stability of fixed points under feedback for nonlinear fractional order difference equations with fixed points $ x_{*}=0$ is also carried out.
description: 27 pages, 44 figures
Inductive McKay Condition in defining Characteristic
Creators: name: Späth, Britta
Publisher: name: arXiv
Year: 2010
Subjects: subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 20C15, 20C33

description: We reformulate the inductive McKay condition, from Isaacs-Malle-Navarro, and apply the new criterion to simple groups of Lie type, when the prime is the defining characteristic p. Thereby we make use of a recent result of Maslowski. This proves that these simple group satisfy the inductive McKay condition for p. In the non simply-laced types and non-classical types this reproves earlier results by Brunat and Brunat-Himstedt.
description: 12 pages
3D hydrodynamics simulations of internal gravity waves in red giant branch stars
Creators: name: Blouin, Simon
name: Mao, Huaqing
name: Herwig, Falk
name: Denissenkov, Pavel
name: Woodward, Paul R.
name: Thompson, William R.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present the first 3D hydrodynamics simulations of the excitation and propagation of internal gravity waves (IGWs) in the radiative interiors of low-mass stars on the red giant branch (RGB). We use the PPMstar explicit gas dynamics code to simulate a portion of the convective envelope and all the radiative zone down to the hydrogen-burning shell of a 1.2$M_{\odot}$ upper RGB star. We perform simulations for different grid resolutions (768$^3$, 1536$^3$ and 2880$^3$), a range of driving luminosities, and two different stratifications (corresponding to the bump luminosity and the tip of the RGB). Our RGB tip simulations can be directly performed at the nominal luminosity, circumventing the need for extrapolations to lower luminosities. A rich, continuous spectrum of IGWs is observed, with a significant amount of total power contained at high wavenumbers. By following the time evolution of a passive dye in the stable layers, we find that IGW mixing in our simulations is weaker than predicted by a simple analytical prescription based on shear mixing and not efficient enough to explain the missing RGB extra mixing. However, we may be underestimating the efficiency of IGW mixing given that our simulations include a limited portion of the convective envelope. Quadrupling its radial extent compared to our fiducial setup increases convective velocities by up to a factor 2 and IGW velocities by up to a factor 4. We also report the formation of a $\sim 0.2\,H_P$ penetration zone and evidence that IGWs are excited by plumes that overshoot into the stable layers.
description: 20 pages, 29 figures, movies at https://www.ppmstar.org, resubmitted to MNRAS
Topological Data Analysis of Ion Migration Mechanism
Creators: name: Sato, Ryuhei
name: Akagi, Kazuto
name: Takagi, Shigeyuki
name: Sau, Kartik
name: Kisu, Kazuaki
name: Li, Hao
name: Orimo, Shin-ichi
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Topological data analysis based on persistent homology has been applied to the molecular dynamics simulation for the fast ion-conducting phase ($α$-phase) of AgI, to show its effectiveness on the ion-migration mechanism analysis.Time-averaged persistence diagrams of $α$-AgI, which quantitatively records the shape and size of the ring structures in the given atomic configurations, clearly showed the emergence of the four-membered rings formed by two Ag and two I ions at high temperatures. They were identified as common structures during the Ag ion migration. The averaged potential energy change due to the deformation of four-membered ring during Ag migration agrees well with the activation energy calculated from the conductivity Arrhenius plot. The concerted motion of two Ag ions via the four-membered ring was also successfully extracted from molecular dynamics simulations by our approach, providing the new insight into the specific mechanism of the concerted motion.
description: 8 pages, 7 figures