cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Managing Costs in Small Drinking Water Systems: Cost Recovery, Affordability and Revenue Shortfalls in the Alberta Context
Creators: name: Janzen, Aaron
Publisher: name: Graduate Studies
Year: 2017
Subjects: subject: Economics
subject: Engineering
subject: Engineering--Civil
subject: Engineering--Environmental
subject: small drinking water treatment systems
subject: economies of scale
subject: cost recovery
subject: grant funding
subject: affordability
subject: subsidization
subject: financial capability
subject: revenue shortfalls

description: This thesis investigates the cost of providing drinking water to municipalities with populations less than 1 000 in Alberta, Canada. Unit costs were found to vary considerably with the volume of treated water and the type of source water. Of the 25 communities investigated, only one community recovered the full cost of treating drinking water, two communities recovered their portion of the capital costs as well as the marginal costs, while seven communities recovered the marginal cost of treating drinking water. In each scenario, the remaining communities recovered less than the cost. Revenue and cost of drinking water treatment were evaluated in order to project the population below which revenue shortfalls can be expected. Recently published cost equations predict that revenue shortfalls will occur at considerably higher populations than predicted by the StatsCan-CRP equations. Alternative solutions are provided for decision makers to consider when planning water treatment plants for communities with small populations.
The Effect of Genetic Variation on Mouse Bone Strength
Creators: name: Britz, Hayley M.
Publisher: name: Graduate Studies
Year: 2016
Subjects: subject: Anatomy
subject: Genetics
subject: FOS: Biological sciences

description: Osteoporosis is a heritable bone disease which is characterized by decreased bone mass and a deterioration in bone microarchitecture. This leads to a decrease in bone strength and therefore the risk of fracturing is greater in people who have been diagnosed as being osteoporotic. The mechanism by which osteoporosis is inherited is still unknown, as are the underlying microarchitectural causes of changes in bone strength. Without knowing more about these two mechanisms we cannot begin to develop more effective treatment plans or even a cure for this disease. The aim of this dissertation was to determine whether bone strength can be influenced by vascular canal microarchitecture and whether bone strength is a heritable trait, which is determined by specific quantitative trait loci. Using the CC founder strains and their F1 crosses in a diallel analysis we found that non-additive variance accounted for the same amount or more of the heritability than additive variance. Using the same CC mice we also found that BMD, canal connectivity, canal diameter, canal orientation, cortical area, cortical thickness, and percent porosity were all heritable determinants of bone strength. The bone strength measures used in this thesis were found to be highly correlated (0.702) and there was no statistical difference between methods (p=1.000). Employing the DO population we found a significant QTL for Imax on Chromosome 1 that is 1.43 cM wide and contained 19 candidate genes, of which Cacna1e looks the most promising. The QTL analysis for MaxF and BMD also found suggestive and near suggestive QTLs on Chromosome 1, which would indicate that Chromosome 1 is important in the genetic determination of bone strength.
BL Lac Objects: Laboratories to study the environment and properties of emitting particles in relativistic jets
Creators: name: Mankuzhiyil, Nijil
name: Ansoldi, Stefano
name: Persic, Massimo
name: Tavecchio, Fabrizio
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We report the variation of the spectral energy distribution (SED) of blazars as a function of source activity, based on available, simultaneous multi-wavelength (MWL) observations of BL Lac objects. We use a fully automatized \c{hi}2 minimization procedure, instead of the commonly used eye-ball fit, to model the data sets with a one-zone Synchrotron-Self-Compton (SSC) model. The obtained SSC parameters are then analyzed as a function of source luminosity, and the correlation between parameters is shown. Possibilities of improving the present observational and modeling status of BL Lac objects are also discussed.
description: 4 pages, 4 figures; International Cosmic Ray Symposium, Beijing, 2011
Dafne Calvo, Germán Llorca-Abad, Lorena Cano-Orón i Daniel H. Cabrera, (coords.). Academia (des)acelerada. Encierros, entusiasmos y epidemias
Creators: name: García-Ull, Francisco José
Publisher: name: Quaderns del CAC
Year: 2023

description: Quaderns del CAC, Núm. 49 (2023): Universitat i pensament crític: formar en comunicació
Optimum angle for side injection of electrons into linear plasma wakefields
Creators: name: Lotov, Konstantin V.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: A unified model of electron penetration into linear plasma wakefields is formulated and studied. The optimum angle for side injection of electrons is found. At smaller angles, all electrons are reflected radially. At larger angles, electrons enter the wakefield with superfluous transverse momentum that is unfavorable for trapping. Separation of incident electrons into penetrated and reflected fractions occur in the outer region of the wakefield at some "reflection" radius that depends on the electron energy.
description: 7 pages, 4 figures
A General Relativistic Model for Magnetic Monopole-Infused Compact Objects
Creators: name: Pazameta, Zoran
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Emergent concepts from astroparticle physics are incorporated into a classical solution of the Einstein-Maxwell equations for a binary magnetohydrodynamic fluid, in order to describe the final equilibrium state of compact objects infused with magnetic monopoles produced by proton-proton collisions within the intense dipolar magnetic fields generated by these objects during their collapse. It is found that the effective mass of such an object's acquired monopolar magnetic field is three times greater than the mass of its native fluid and monopoles combined, necessitating that the interior matter undergo a transition to a state of negative pressure in order to attain equilibrium. Assuming full symmetry between the electric and magnetic Maxwell equations yields expressions for the monopole charge density and magnetic field by direct analogy with their electrostatic equivalents; inserting these into the Einstein equations then leads to an interior metric which is well-behaved from the origin to the surface, where it matches smoothly to an exterior magnetic Reissner-Nordström metric free of any coordinate pathologies. The source fields comprising the model are all described by simple, well-behaved polynomial functions of the radial coordinate, and are combined with straightforward regularity conditions to yield expressions delimiting several fundamental physical parameters pertaining to this hypothetical astrophysical object.
description: Accepted for publication in "Astrophysics and Space Science."
Optimal estimates of the diffusion coefficient of a single Brownian trajectory
Creators: name: Boyer, Denis
name: Dean, David S.
name: Mejía-Monasterio, Carlos
name: Oshanin, Gleb
Publisher: name: arXiv
Year: 2012
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Subcellular Processes (q-bio.SC)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: Modern developments in microscopy and image processing are revolutionizing areas of physics, chemistry and biology as nanoscale objects can be tracked with unprecedented accuracy. The goal of single particle tracking is to determine the interaction between the particle and its environment. The price paid for having a direct visualization of a single particle is a consequent lack of statistics. Here we address the optimal way of extracting diffusion constants from single trajectories for pure Brownian motion. It is shown that the maximum likelihood estimator is much more efficient than the commonly used least squares estimate. Furthermore we investigate the effect of disorder on the distribution of estimated diffusion constants and show that it increases the probability of observing estimates much smaller than the true (average) value.
description: 8 pages, 5 figures
title: Radiocarbon dating marine shell: challenges and opportunities in Canadian coastal archaeology
Creators: name: Dusseault, Marisa
Publisher: name: Memorial University of Newfoundland
Year: 2023

description: Marine mollusk shells are the most abundant materials found at coastal archaeology sites. They are often found in large accumulations called middens which are formed as a result of shellfish processing activities and may be features of dwelling sites. Despite the abundance of marine mollusk shells at coastal sites, terrestrial samples are often favoured for radiocarbon analysis because they are free from local marine reservoir effects. In this thesis, I investigate intra-shell radiocarbon variability in three mollusk species from coastal sites across Canada: Saxidomus gigantea from British Columbia, Mya arenaria from Nova Scotia, and Crassostrea virginica from Prince Edward Island. Each of these species has different growth strategies that must be considered to understand time-averaging effects in the radiocarbon measurements. Short-lived C. virginica samples from Prince Edward Island had the best agreement between intra-shell radiocarbon measurements. Additional radiocarbon measurements on twelve M. arenaria shells from Port Joli Harbour, Nova Scotia show good agreement with the previously published terrestrial dates and paired marine-terrestrial samples are used to calculate the first archaeological ΔR values for the region. Building confidence in marine shell radiocarbon will greatly widen the number of samples that archaeologists can study from coastal midden sites, especially ones that may be rapidly eroding and lack terrestrial samples.
Additional file 7 of Preservation of satellite cell number and regenerative potential with age reveals locomotory muscle bias
Creators: name: Arpke, Robert W.
name: Shams, Ahmed S.
name: Collins, Brittany C.
name: Larson, Alexie A.
name: Lu, Nguyen
name: Lowe, Dawn A.
name: Kyba, Michael
Publisher: name: figshare
Year: 2021
Subjects: subject: Medicine
subject: Cell Biology
subject: Genetics
subject: FOS: Biological sciences
subject: Neuroscience
subject: Physiology
subject: Biotechnology
subject: Evolutionary Biology
subject: Developmental Biology
subject: Cancer
subject: Inorganic Chemistry
subject: FOS: Chemical sciences
subject: Hematology
subject: 60506 Virology
subject: Computational Biology

description: Additional file 7. No difference observed after transplant of satellite cells isolated from the diaphragm of four month- or two-year-old Pax7-ZsGreen mice. (a) Number of ZsGreen+ cells quantified by FACS six weeks after transplant of 900 ZsGreen+ cells from the diaphragm (n=5). (b) Number of Dystrophin+ fibers six weeks after transplant of 900 ZsGreen+ from the diaphragm (n=5). (c) Number of ZsGreen+ cells quantified by FACS fifteen weeks after transplant of 900 ZsGreen+ cells from the diaphragm (n=5). (d) Number of Dystrophin+ fibers fifteen weeks after transplant of 900 ZsGreen+ cells from the diaphragm (n=5). Data shown are mean ± SE. Statistical comparisons were performed using two-tailed t tests.
Imprint of the merger and ring-down on the gravitational wave background from black hole binaries coalescence
Creators: name: Marassi, S.
name: Schneider, R.
name: Corvino, G.
name: Ferrari, V.
name: Zwart, S. Portegies
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We compute the gravitational wave background (GWB) generated by a cosmological population of (BH-BH) binaries using hybrid waveforms recently produced by numerical simulations of (BH-BH) coalescence, which include the inspiral, merger and ring-down contributions. A large sample of binary systems is simulated using the population synthesis code SeBa, and we extract fundamental statistical information on (BH-BH) physical parameters (primary and secondary BH masses, orbital separations and eccentricities, formation and merger timescales). We then derive the binary birth and merger rates using the theoretical cosmic star formation history obtained from a numerical study which reproduces the available observational data at redshifts $z < 8$. We evaluate the contributions of the inspiral, merger and ring-down signals to the GWB, and discuss how these depend on the parameters which critically affect the number of coalescing (BH-BH) systems. We find that Advanced LIGO/Virgo have a chance to detect the GWB signal from the inspiral phase with a $(S/N)=10$ only for the most optimistic model, which predicts the highest local merger rate of 0.85 Mpc$^{-3}$ Myr$^{-1}$. Third generation detectors, such as ET, could reveal the GWB from the inspiral phase predicted by any of the considered models. In addition, ET could sample the merger phase of the evolution at least for models which predict local merger rates between $[0.053 - 0.85]$ Mpc$^{-3}$ Myr$^{-1}$, which are more than a factor 2 lower the the upper limit inferred from the analysis of the LIGO S5 run\cite{Abadieetal2011}.
description: 14 pages, 10 figures, accepted for publication by Phys. Rev. D. revised version of arXiv:1104.2044
Effect of Dipolar Interaction in Molecular Crystals
Creators: name: Hoang, Danh-Tai
name: Diep, H. T.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We investigate in this paper the ground state and the nature of the transition from an orientational ordered phase at low temperature to the disordered state at high temperature in a molecular crystal. Our model is a Potts model which takes into account the exchange interaction $J$ between nearest-neighbor molecules and a dipolar interaction between molecular axes in three dimensions. The dipolar interaction is characterized by two parameters: its amplitude $D$ and the cutoff distance $r_c$. If the molecular axis at a lattice site has three orientations, say the $x$, $y$ or $z$ axes, then when D=0, the system is equivalent to the 3-state Potts model: the transition to the disordered phase is known to be of first order. When $D\neq 0$, the ground-state configuration is shown to be composed of two independent interpenetrating layered subsystems which form a sandwich whose periodicity depends on $D$ and $r_c$. We show by extensive Monte Carlo simulation with a histogram method that the phase transition remains of first order at relatively large values of $r_c$.
description: 6 pages, 7 figures
The interaction of metrical structure, tone, and phonation types in Quiaviní Zapotec
Creators: name: Chávez Peón, Mario E.
Publisher: name: University of British Columbia
Year: 2010

description: This thesis investigates the interaction between different prosodic patterns in Quiaviní Zapotec (Otomanguean), and accounts for them both at the phonetic and the phonological level. In it, I examine an array of complex patterns along multiple dimensions, including metrical structure, tone, and phonation types; as well as how these patterns interact with the fortis/lenis distinction, and syllable structure. Within the framework of Optimality Theory, my analysis sheds light on the phonetics-phonology interface and emphasizes the need for a theory with moraic structure. This dissertation presents the first thorough phonetic documentation of the prosody of Quiaviní Zapotec. It makes a significant empirical contribution by providing descriptive generalizations of vowel and consonant length, a reanalysis of tone as contrastive in Quiaviní Zapotec, and a new approach to the study of the four-way phonation contrast in this language — modal /a/, breathy /a̤/, creaky /a̰/ and interrupted /aʔ/ vowels — (cf. Munro & Lopez, 1999). In addition, this research makes significant contributions to phonological theory, with regards to both segmental and prosodic phenomena. Within an emergent feature approach, I revisit the fortis/lenis distinction, which crosscuts the obstruent-sonorant contrast in Quiaviní Zapotec. I analyze it as a composite of language-specific phonological and phonetic properties, encoded with the feature [+/-fortis]. Adding to the typology of syllable weight, fortis consonants are analyzed as moraic in coda position, but among them, only fortis sonorants may bear tone alongside vowels (i.e. *[-SON][TONE] ‘No tones on obstruents’). Furthermore, I show specific timing patterns for the phonetic implementation of tonal and laryngeal features. Quiaviní Zapotec exhibits compatibility of contrasts; compromise of phonological features (e.g. tonal contrasts are cued during modal phonation, followed by breathiness or laryngealization); or complete incompatibility, which translates into phonemic gaps. This distribution is formalized in terms of markedness interaction and grounded constraints (e.g. ‘If [+spread glottis], then Low tone’, accounting for the absence of high tone with breathy vowels). Overall, the thesis analyzes the minimal prosodic word in Quiaviní Zapotec (a bimoraic foot) as the domain where the full array of tonal and phonation type contrasts takes place, and illustrates particular mechanisms by which phonetic factors shape phonology.
Discovery of a pair density wave state in a monolayer high-Tc iron-based superconductor
Creators: name: Liu, Yanzhao
name: Wei, Tianheng
name: He, Guanyang
name: Zhang, Yi
name: Wang, Ziqiang
name: Wang, Jian
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The pair density wave (PDW) is an extraordinary superconducting state where Cooper pairs carry nonzero momentum. It can emerge when the full condensation of zero momentum Cooper pairs is frustrated. Evidence for the existence of intrinsic PDW order in high-temperature (high-Tc) cuprate superconductors and kagome superconductors has emerged recently. However, the PDW order in iron-based high-Tc superconductors has not been observed experimentally. Here, using scanning tunneling microscopy/spectroscopy, we report the discovery of the PDW state in monolayer iron-based high-Tc Fe(Te,Se) films grown on SrTiO3(001) substrates. The PDW state with a period of λ~3.6a_Fe (a_Fe is the distance between neighboring Fe atoms) is observed at the domain walls by the spatial electronic modulations of the local density of states, superconducting gap, and the π-phase shift boundaries of the PDW around the dislocations of the intertwined charge density wave order. The discovery of the PDW state in the monolayer Fe(Te,Se) film provides a low-dimensional platform to study the interplay between the correlated electronic states and unconventional Cooper pairing in high-Tc superconductors.
Developmental Strengths, School Bonding, and Academic Achievement in First Nation's Youth
Creators: name: Winterflood, Harriet
Publisher: name: Graduate Studies
Year: 2016
Subjects: Educational Psychology

description: The present study explored the developmental strengths that youth from Tsuut’ina Middle and Senior High school possess. It explored what developmental assets - internal and external – are self-reported by a sample of Tsuut’ina First Nation youth, as well as the degree to which students are connected to their school (i.e., school bonding). Correlational analyses were conducted to determine whether school bonding and developmental assets were related to one’s academic achievement. Results revealed that both internal and external assets were deemed to be within the ‘fair’ range. Middle school students reported greater levels of total assets compared to senior high school students. Further, Tsuut’ina First Nation youth reported moderate level of school bonding, reporting strong attachment, and moderate belief in school rules and commitment. There were few significant associations found between developmental assets and academic achievement, or school bonding and academic achievement. Interpretations and implications of these results are provided.
Refugees, Environmental Resource Use and Local Integration in Ghana
Creators: name: Agblorti, Samuel Kofi Miledzi
Publisher: name: Arts
Year: 2016
Subjects: subject: Geography
subject: Refugees
subject: Political Ecology
subject: Environmental resources
subject: Local integration
subject: Gender and Development
subject: Social Exchange Theory

description: The world has seen a dramatic upsurge in the number of displaced persons since World War II. As the international community and host governments struggle to cope with the ever increasing number of new refugee inflows, a more staggering number of refugees live in protracted situations in refugee camps located in insecure environments and under precarious socio-economic conditions in the global South. While this situation is perpetrated by the unending conflicts in most origin countries of refugees and the limitations of resettling refugees in third country destinations, stakeholders have consistently advocated for a regional approach, which favours the integration of refugees in host countries. Although this approach potentially offers refugees the opportunity to formalise their stay in host countries and therefore engage in productive activities to improve their living conditions, conflicts over access and use of environmental resources between refugees and host community members pose significant threat to the success of local integration. Drawing on Political Ecology, Social Exchange Theory and Irritation Index as analytical tools, this research employed mixed methods to investigate the implications of environmental resource use conflicts between refugees and their hosts for local integration of refugees in Ghana. The findings show that contrary to the popular claim that refugees are often not interested in local integration as a durable solution, a significant proportion of the refugees considered local integration as a viable solution once it comes with an acceptable package. Disagreements over environmental resource use accounted for more than half of all conflicts between 2003 and 2013, yet both hosts and refugees considered local integration as a feasible option. Nevertheless, host government’s unilateral decisions regarding how land was acquired for camp construction posed significant threat to local integration. While the willingness of both refugees and hosts to accept local integration serves as a boost, stakeholders need to do more in terms of resources in order to push ahead the agenda of locally integrating refugees in protracted situations.
Real-time Quality Feedback System for Screening Colonoscopy
Creators: name: Angulo Rodriguez, Leticia Magdalena
Publisher: name: Graduate Studies
Year: 2013
Subjects: subject: Biomedical
subject: Colonoscopy
subject: Real-time
subject: Quality
subject: Assessment

description: Colonoscopy is the gold standard method for the diagnosis of colorectal cancer and the identification of precancerous polyps. Unfortunately, there is not yet a metric (formally recommended by consensus guidelines) for the quantification of colonoscopy quality. Though, there are established quality indicators such as the bowel preparation and the withdrawal time; fast withdrawal time is highly correlated with adenoma detection rate. Current metric tools for these parameters are not objective. This limitation leads to the formalization of the present study, which focuses on the development of a real-time, novel colonoscopy evaluation system and the assessment of its clinical efficacy. The proposed tool consists of an embedded system that can automatically measure: a) the quantity of stool and waste matter existing within the patient during a colonoscopy procedure; b) withdrawal velocity; c) image clarity; and d) determination of colonoscope direction and traveling distance. The proposed method can be used to create practice standards for colonoscopy training, or as part of medical skill evaluation.
Modulation of Pro-inflammatory Cytokines Expression of the Biofield Energy (The Trivedi Effect®) Based Herbomineral Formulation in Mouse Splenocytes
Creators: name: Yamin, Yusif Sarkis
Publisher: name: SMN - The ScienceMedia Network
Year: 2019
Subjects: Natural Sciences

description: With the increasing popularity of herbomineral preparations in healthcare, a new proprietary herbomineral formulation was formulated with ashwagandha root extract and three minerals viz. zinc, magnesium, and selenium. The aim of the study was to evaluate the immunomodulatory potential of Biofield Energy Healing (The Trivedi Effect®) on the herbomineral formulation using murine splenocyte cells. The test formulation was divided into two parts. One was the control without the Biofield Energy Treatment. The other part was labelled the Biofield Energy Treated sample, which received the Biofield Energy Healing Treatment remotely by twenty renowned Biofield Energy Healers. Through MTT assay, all the test formulation concentrations from 0.00001053 to 10.53 µg/mL were found to be safe with cell viability ranging from 102.61% to 194.57% using splenocyte cells. The Biofield Treated test formulation showed a significant (p≤0.01) inhibition of TNF-α expression by 15.87%, 20.64%, 18.65%, and 20.34% at 0.00001053, 0.0001053, 0.01053, and 0.1053, µg/mL, respectively as compared to the vehicle control (VC) group. The level of TNF-α was reduced by 8.73%, 19.54%, and 14.19% at 0.001053, 0.01053, and 0.1053 µg/mL, respectively in the Biofield Treated test formulation compared to the untreated test formulation. The expression of IL-1β reduced by 22.08%, 23.69%, 23.00%, 16.33%, 25.76%, 16.10%, and 23.69% at 0.00001053, 0.0001053, 0.001053, 0.01053, 0.1053, 1.053 and 10.53 µg/mL, respectively compared to the VC. Additionally, the expression of MIP-1α significantly (p≤0.001) reduced by 13.35%, 22.96%, 25.11%, 22.71%, and 21.83% at 0.00001053, 0.0001053, 0.01053, 1.053, and 10.53 µg/mL, respectively in the Biofield Treated test formulation compared to the VC. The Biofield Treated test formulation significantly down-regulated the MIP-1α expression by 10.75%, 9.53%, 9.57%, and 10.87% at 0.00001053, 0.01053, 0.1053 and 1.053 µg/mL, respectively compared to the untreated test formulation. The results showed the IFN-γ expression was also significantly (p≤0.001) reduced by 39.16%, 40.34%, 27.57%, 26.06%, 42.53%, and 48.91% at 0.0001053, 0.001053, 0.01053, 0.1053, 1.053, and 10.53 µg/mL, respectively in the Biofield Treated test formulation compared to the VC. The Biofield Treated test formulation showed better suppression of IFN-γ expression by 15.46%, 13.78%, 17.14%, and 13.11% at concentrations 0.001053, 0.01053, 0.1053, and 10.53 µg/mL, respectively compared to the untreated test formulation. Overall, the results demonstrated that The Trivedi Effect®- Biofield Energy Healing (TEBEH) has the capacity to potentiate the immunomodulatory and anti-inflammatory activity of the test formulation. Biofield Energy may also be useful in organ transplants, anti-aging, and stress management by improving overall health and quality of life.
Fermi edge singularity in neutral electron-hole system
Creators: name: Choksy, D. J.
name: Szwed, E. A.
name: Butov, L. V.
name: Baldwin, K. W.
name: Pfeiffer, L. N.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: In neutral dense electron-hole (e-h) systems at low temperatures, theory predicts Cooper-pair-like excitons at the Fermi energy and a BCS-like exciton condensation. Optical excitation allows creating e-h systems with the densities controlled by the excitation power. However, the intense optical excitations required to achieve high densities cause substantial heating of the e-h system that prevents the realization of dense and cold e-h systems in conventional semiconductors. In this work, we study e-h systems created by optical excitation in separated electron and hole layers. The layer separation increases the e-h recombination time and, in turn, the density for a given optical excitation by orders of magnitude and, as a result, enables the realization of the dense and cold e-h system. We found a strong enhancement of photoluminescence intensity at the Fermi energy of the neutral dense ultracold e-h system that evidences the emergence of excitonic Fermi edge singularity due to the Cooper-pair-like excitons at the Fermi energy.
Study of galaxies in the Lynx-Cancer void. II. The element abundances
Creators: name: Pustilnik, S. A.
name: Tepliakova, A. L.
name: Kniazev, A. Y.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: In the framework of the study of the evolutionary status of galaxies in the nearby Lynx-Cancer void, we present the results of the SAO RAS 6-m telescope spectroscopy for 20 objects in this region. The principal faint line [OIII]4363A, used to determine the electron temperature and oxygen abundance (O/H) by the classical method, is clearly detected in only about 2/3 of the studied objects. For the remaining galaxies this line is either faint or undetected. To obtain the oxygen abundances in these galaxies we as well apply the semi-empirical method by Izotov and Thuan, and/or the empirical methods of Pilyugin et al., which are only employing the intensities of sufficiently strong lines. We also present our O/H measurements for 22 Lynx-Cancer void galaxies, for which the suitable Sloan Digital Sky Survey (SDSS) spectra are available. In total, we present the combined O/H data for 48 Lynx-Cancer void galaxies, including the data adopted from the literature and our own earlier results. We make a comparison of their locations on the (O/H)-M_B diagram with those of the dwarf galaxies of the Local Volume in the regions with denser environment. We infer that the majority of galaxies from this void on the average reveal an about 30% lower metallicity. In addition, a substantial fraction (not less than 10%) of the void dwarf galaxies have a much larger O/H deficiency (up to a factor of 5). Most of them belong to the tiny group of objects with the gas metallicity Z < Zo/20 or 12+log(O/H)
description: 26 pages, 8 figures, 25 tables
NMPC in Active Subspaces: Dimensionality Reduction with Recursive Feasibility Guarantees
Creators: name: Pan, Guanru
name: Faulwasser, Timm
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optimization and Control (math.OC)
subject: Systems and Control (eess.SY)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Dimensionality reduction of decision variables is a practical and classic method to reduce the computational burden in linear and Nonlinear Model Predictive Control (NMPC). Available results range from early move-blocking ideas to singular-value decomposition. For schemes more complex than move-blocking it is seemingly not straightforward to guarantee recursive feasibility of the receding-horizon optimization. Decomposing the space of decision variables related to the inputs into active and inactive complements, this paper proposes a general framework for effective feasibility-preserving dimensionality reduction in NMPC. We show how -- independently of the actual choice of the subspaces -- recursive feasibility can be established. Moreover, we propose the use of global sensitivity analysis to construct the active subspace in data-driven fashion based on user-defined criteria. Numerical examples illustrate the efficacy of the proposed scheme. Specifically, for a chemical reactor we obtain a significant reduction by factor $20-40$ at a closed-loop performance decay of less than $0.05\%$.
description: 10 pages
Coherent tunneling via adiabatic passage in a three-well Bose-Hubbard system
Creators: name: Bradly, C. J.
name: Rab, M.
name: Greentree, A. D.
name: Martin, A. M.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We apply the Bose-Hubbard Hamiltonian to a three-well system and show analytically that coherent transport via adiabatic passage (CTAP) of $N$ non-interacting particles across the chain is possible. We investigate the effect of detuning the middle well to recover CTAP when on-site interparticle interactions would otherwise disrupt the transport. The case of small interactions is restated using first-order perturbation theory to develop criteria for adibaticity that define the regime where CTAP is possible. Within this regime we investigate restricting the Hilbert space to the minimum necessary basis needed to demonstrate CTAP, which dramatically increases the number of particles that can be efficiently considered. Finally, we compare the results of the Bose-Hubbard model to a mean-field three-mode Gross-Pitaevskii analysis for the equivalent system.
description: 10 pages including 8 figures
Query-based Hard-Image Retrieval for Object Detection at Test Time
Creators: name: Ayers, Edward
name: Sadeghi, Jonathan
name: Redford, John
name: Mueller, Romain
name: Dokania, Puneet K.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: There is a longstanding interest in capturing the error behaviour of object detectors by finding images where their performance is likely to be unsatisfactory. In real-world applications such as autonomous driving, it is also crucial to characterise potential failures beyond simple requirements of detection performance. For example, a missed detection of a pedestrian close to an ego vehicle will generally require closer inspection than a missed detection of a car in the distance. The problem of predicting such potential failures at test time has largely been overlooked in the literature and conventional approaches based on detection uncertainty fall short in that they are agnostic to such fine-grained characterisation of errors. In this work, we propose to reformulate the problem of finding "hard" images as a query-based hard image retrieval task, where queries are specific definitions of "hardness", and offer a simple and intuitive method that can solve this task for a large family of queries. Our method is entirely post-hoc, does not require ground-truth annotations, is independent of the choice of a detector, and relies on an efficient Monte Carlo estimation that uses a simple stochastic model in place of the ground-truth. We show experimentally that it can be applied successfully to a wide variety of queries for which it can reliably identify hard images for a given detector without any labelled data. We provide results on ranking and classification tasks using the widely used RetinaNet, Faster-RCNN, Mask-RCNN, and Cascade Mask-RCNN object detectors. The code for this project is available at https://github.com/fiveai/hardest.
Myotis chiloensis
Creators: name: Carrion-Bonilla, Carlos Alberto
name: Cook, Joseph Anthony
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Chiroptera
Vespertilionidae
Myotis
Myotis chiloensis

description: Myotis chiloensis.
 ARGENTINA (n = 1): 19 km N Villa La Angostura along Hwy 234 (SNOMNH 23496).
description: Published as part of Carrion-Bonilla, Carlos Alberto & Cook, Joseph Anthony, 2020, A new bat species of the genus Myotis with comments on the phylogenetic placement of M. keaysi and M. pilosatibialis, pp. 508-532 in Therya 11 (3) on page 524, DOI: 10.12933/therya-20-999, http://zenodo.org/record/10260821
Experimental investigations of synchrotron radiation at the onset of the quantum regime
Creators: name: Andersen, Kristoffer K.
name: Esberg, J.
name: Knudsen, H.
name: Thomsen, H. D.
name: Uggerhøj, U. I.
name: Sona, P.
name: Mangiarotti, A.
name: Ketel, T. J.
name: Dizdar, A.
name: Ballestrero, S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The classical description of synchrotron radiation fails at large Lorentz factors, $γ$, for relativistic electrons crossing strong transverse magnetic fields $B$. In the rest frame of the electron this field is comparable to the so-called critical field $B_0 = 4.414\cdot10^9$ T. For $χ= γB/B_0 \simeq 1$ quantum corrections are essential for the description of synchrotron radiation to conserve energy. With electrons of energies 10-150 GeV penetrating a germanium single crystal along the $<110>$ axis, we have experimentally investigated the transition from the regime where classical synchrotron radiation is an adequate description, to the regime where the emission drastically changes character; not only in magnitude, but also in spectral shape. The spectrum can only be described by quantum synchrotron radiation formulas. Apart from being a test of strong-field quantum electrodynamics, the experimental results are also relevant for the design of future linear colliders where beamstrahlung - a closely related process - may limit the achievable luminosity.
description: 11 pages, 18 figures, submitted to PRD
Magnetic properties of spin diluted iron pnictides from muSR and NMR in LaFe1-xRuxAsO
Creators: name: Bonfà, Pietro
name: Carretta, Pietro
name: Sanna, Samuele
name: Lamura, Gianrico
name: Prando, Giacomo
name: Martinelli, Alberto
name: Palenzona, Andrea
name: Tropeano, Matteo
name: Putti, Marina
name: De Renzi, Roberto
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The effect of isoelectronic substitutions on the microscopic properties of LaFe1-xRuxAsO, for 0< x< 0.8, has been investigated by means of muSR and 139La NMR. It was found that Ru substitution causes a progressive reduction of the Nèel temperature (T_N) and of the magnetic order parameter without leading to the onset of superconductivity. The temperature dependence of 139La nuclear spin-lattice relaxation rate 1/T_1 can be suitably described within a two-band model. One band giving rise to the spin density wave ground-state, while the other one is characterized by weakly correlated electrons. Fe for Ru substitution yields to a progressive decrease of the density of states at the Fermi level close to the one derived from band structure calculations. The reduction of T_N with doping follows the predictions of the J_1-J_2 model on a square lattice, which appears to be an effective framework to describe the magnetic properties of the spin density wave ground-state.
description: 6 pages, 8 figures
Weak-Coupling Theory of Pair Density-Wave Instabilities in Transition Metal Dichalcogenides
Creators: name: Shaffer, Daniel
name: Burnell, F. J.
name: Fernandes, Rafael M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The possibility of realizing pair density wave (PDW) phases, in which Cooper pairs have a finite momentum, presents an interesting challenge that has been studied in a wide variety of systems. In conventional superconductors, this is only possible when external fields lift the spin degeneracy of the Fermi surface, leading to pair formation at an incommensurate momentum. Here, we study a second possibility, potentially relevant to transition metal dichalcogenides, in which the Fermi surface consists of a pair of pockets centered at the $\pm K$ points of the Brillouin zone as well as a central pocket at the $Γ$ point. In the limit where these three pockets are identical, the pairing susceptibility has a logarithmic divergence at the non-zero wave-vectors $\pm \mathbf{K}$, allowing for a weak-coupling analysis of the PDW instability. We find that repulsive electronic interactions combine to yield effective attractive interactions in the singlet and triplet PDW channels, as long as the $Γ$ pocket is present. Because these PDW channels decouple from the uniform superconducting channel, they can become the leading unconventional pairing instability of the system. Upon solving the linearized gap equations, we find that the PDW instability is robust against small trigonal warping of the $\pm K$ pockets and small detuning between the $Γ$ and $\pm K$ pockets, which affect the PDW transition in a similar way as the Zeeman magnetic field affects the uniform superconducting transition. We also derive the Ginzburg-Landau free energy for the PDW gaps with momenta $\pm \mathbf{K}$, analyzing the conditions for and consequences of the emergence of FF-type and LO-type PDW ground states. Our classification of the induced orders in each ground state reveals unusual phases, including an odd-frequency charge-$2e$ superconductor in the LO-type PDW.
description: 24 pages, 11 figures
Search for a heavy composite Majorana neutrino in events with dilepton signatures from proton-proton collisions at $\sqrt{s}$ = 13 TeV
Creators: name: CMS Collaboration
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Results are presented of a search for a heavy Majorana neutrino N$_\ell$ decaying into two same-flavor leptons $\ell$ (electrons or muons) and a quark-pair jet. A model is considered in which the N$_\ell$ is an excited neutrino in a compositeness scenario. The analysis is performed using a sample of proton-proton collisions at $\sqrt{s}$ = 13 TeV recorded by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of 138 fb$^{-1}$. The data are found to be in agreement with the standard model prediction. For the process in which the N$_\ell$ is produced in association with a lepton, followed by the decay of the N$_\ell$ to a same-flavor lepton and a quark pair, an upper limit at 95% confidence level on the product of the cross section and branching fraction is obtained as a function of the N$_\ell$ mass $m_{\text{N}_\ell}$ and the compositeness scale $Λ$. For this model the data exclude the existence of N$_\text{e}$ (N$_μ$) for $m_{\text{N}_\ell}$ below 6.0 (6.1) TeV, at the limit where $m_{\text{N}_\ell}$ is equal to $Λ$. For $m_{\text{N}_\ell}$ $\approx$ 1 TeV, values of $Λ$ less than 20 (23) TeV are excluded. These results represent a considerable improvement in sensitivity, covering a larger parameter space than previous searches in pp collisions at 13 TeV.
description: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/EXO-20-011 (CMS Public Pages)
Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars. IV. Two bulge populations
Creators: name: Bensby, T.
name: Adén, D.
name: Meléndez, J.
name: Gould, A.
name: Feltzing, S.
name: Asplund, M.
name: Johnson, J. A.
name: Lucatello, S.
name: Yee, J. C.
name: Ramírez, I.
name: Cohen, J. G.
name: Thompson, I.
name: Bond, I. A.
name: Gal-Yam, A.
name: Han, C.
name: Sumi, T.
name: Suzuki, D.
name: Wada, K.
name: Miyake, N.
name: Furusawa, K.
name: Ohmori, K.
name: Saito, To.
name: Tristram, P.
name: Bennett, D.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: [ABRIDGED] Based on high-resolution (R~42000 to 48000) and high signal-to-noise (S/N~50 to 150) spectra obtained with UVES/VLT, we present detailed elemental abundances (O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Zn, Y, and Ba) and stellar ages for 26 microlensed dwarf and subgiant stars in the Galactic bulge. The analysis is based on equivalent width measurements and standard 1-D LTE MARCS model stellar atmospheres. We also present NLTE Li abundances based on line synthesis of the 7Li line at 670.8 nm. We show that the bulge metallicity distribution (MDF) is double-peaked; one peak at [Fe/H]= -0.6 and one at [Fe/H]=+0.3, and with a dearth of stars around solar metallicity. This is in contrast to the MDF derived from red giants in Baade's window, which peaks at this exact value. A simple significance test shows that it is extremely unlikely to have such a gap in the microlensed dwarf star MDF if the dwarf stars are drawn from the giant star MDF. To resolve this issue we discuss several possibilities, but we can not settle on a conclusive solution for the observed differences. We further find that the metal-poor bulge dwarf stars are predominantly old with ages greater than 10\,Gyr, while the metal-rich bulge dwarf stars show a wide range of ages. The metal-poor bulge sample is very similar to the Galactic thick disk in terms of average metallicity, elemental abundance trends, and stellar ages. Speculatively, the metal-rich bulge population might be the manifestation of the inner thin disk. If so, the two bulge populations could support the recent findings, based on kinematics, that there are no signatures of a classical bulge and that the Milky Way is a pure-disk galaxy. Also, recent claims of a flat IMF in the bulge based on the MDF of giant stars may have to be revised based on the MDF and abundance trends probed by our microlensed dwarf stars.
description: Accepted for publication in A&A, new version with with missing authors added
Data Stewardship in Electronic Medical Records and the Policy Challenges for Research Programs: A Canadian Perspective
Creators: name: Dong, Allen
Publisher: name: Graduate Studies
Year: 2013
Subjects: subject: Public Administration
subject: Policy Ethics
subject: Secondary Data Use
subject: Electronic Health Records

description: Research access to personal health information presents a challenge to policy makers and researchers alike. It is usually framed as a conflict between data access for the benefit of society and the protection of privacy. This thesis examines the policy challenge by studying the data access policies of several organizations that are affiliated with academic institutions and provide research access to personal health information. By applying a policy ethics framework that combines the Veatch matrix and the Accountability for Reasonableness conditions of Daniels and Sabin the data access policies reveal an ethically justifiable resolution of the policy challenge. A case study conducted on one of the organizations yields a policy model that interviewees report, worked well in practice in the years 1996 to 2002. The policy options that emerged from the model could be adapted for use in any jurisdiction whose legal regime is similar to that of Canada’s provinces and territories.