cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: From phosphate wealth to the health crisis
Creators: name: Yussupova, Elvira
Year: 2024

description: In dieser Arbeit wird der Wandel Naurus vom Wohlstand der Phosphat-Ära zu der kritischen Lage untersucht, in der sich Nauru heute befindet. Nauru ist ein Mikrokosmos des globalen Phänomens des Rückgangs der öffentlichen Gesundheit und der Umweltzerstörung, das die sozioökonomischen Ungleichheiten widerspiegelt und unweigerlich verstärkt. Das Hauptziel dieser Studie ist es, die Geschichte dieses Wandels nachzuzeichnen und die Gründe für die Verschlechterung der öffentlichen Gesundheit auf Nauru zu finden, indem die Verknüpfung von Gesundheit, Wohlstand und Umwelt untersucht wird. Zu diesem Zweck wurde eine Kombination aus Primär- und Sekundärquellen verwendet. Die Studie kommt zu der Schlussfolgerung, dass die Republik Nauru derzeit mit den Folgen des Phosphatabbaus zu kämpfen hat, der die Böden der Insel ruiniert und die Fähigkeit der Menschen auf Nauru, ihre eigenen Nahrungsmittel anzubauen, beeinträchtigt hat. Dies wiederum verschärfte die wirtschaftliche und gesundheitliche Krise.
description: This thesis examines the transformation of Nauru from the prosperity of the phosphate era to the critical state in which Nauru finds itself today. Nauru is a microcosm of the global phenomenon of the declining public health and environmental degradation, that reflects and inevitably reinforces socio-economic disparities. The main aim of this study is to trace the history of this change and find reasons behind the degradation of the public health on Nauru by examining the nexus of health, wealth and environment. In order to do that, a combination of primary and secondary sources was used. The study concludes that the Republic of Nauru is currently struggles with the ramifications of the phosphate mining industry, which ruined the soil of the island and impaired the ability of the Nauruans to grow their own food. That in turn intensified the economic and public health crises.
Development and Utility of a Spectral-based Approach to Peripheral Nerve Myelin Analysis
Creators: name: Grochmal, Joey
Publisher: name: Graduate Studies
Year: 2015
Subjects: subject: Neuroscience
subject: Myelin
subject: Peripheral Nervous System
subject: Spectroscopy
subject: Stem Cells

description: The overall aim of this thesis is to fill a specific methodological gap for the study of neurobiology. Our goal is to develop and apply a spectroscopic technique that can be used to study the living myelin of the peripheral nervous system. Just as modern scientists can appreciate the composition of a distant galaxy by the emission properties of the light that we receive from it, we likewise aim to glean information about living myelin biochemistry using quantifiable light principles. We suggest that the photophysical properties of myelin-incorporated solvatochromic dyes can be exploited to probe the biochemical composition of living myelin. To this end we analyze several potential dye candidates for maximum efficacy and consistency (Chapter 3). After demonstrating the superiority of Nile Red in these regards, we use this dye to probe the biochemical environment of early remyelination, both in-vitro and in-vivo, using high-resolution spectral confocal microscopy (Chapter 6). This combined work required the adaptation of a focal demyelination injury model to be amenable to cell graft therapy (Chapter 4), and also the development of a novel method of intravital imaging of the peripheral nervous system (Chapter 5). Our results demonstrate a consistent bi-phasic evolution of myelin spectra during early regeneration, both in-vitro and in-vivo. In total, this thesis presents a novel technique for probing the chemistry of PNS myelin with light, and is applicable to scenarios unworkable by existing methods of lipid chemical analysis, namely in the study of living nervous system.
Combinatorial sputter synthesis of single-phase La(XYZ)O$_{3\pmσ}$ perovskite thin film libraries: a new platform for materials discovery
Creators: name: Piotrowiak, Tobias H.
name: Zehl, Rico
name: Suhr, Ellen
name: Kohnen, Benedikt
name: Banko, Lars
name: Ludwig, Alfred
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Compositionally complex perovskites provide the opportunity to develop stable and active catalysts for electrochemical applications. The challenge lies in the identification of single-phase perovskites with optimized composition for high electrical conductivity. Leveraging a recently discovered effect of self-organized thin film growth during reactive sputtering, La-Co-Mn-O and La-Co-Mn-Fe-O perovskite (ABO3) thin film materials libraries are synthesized. These show phase-pure La-perovskites over a wide range of chemical composition variation for the B-site elements for deposition temperatures equal to or higher than 300$^\circ$C. It is demonstrated that this approach enables the discovery and tailoring of chemical compositions for desired optical bandgap and electrical conductivity, and thereby opens the path for the targeted development of e.g. new high-performance electrocatalysts.
Disinfection and Self-Sensitized Degradation of Natural Organic Matter (NOM) by TiO2 Photocatalysis with Visible light
Creators: name: Chamoli, Upasana
Publisher: name: Graduate Studies
Year: 2013
Subjects: subject: Analytical
subject: Inorganic
subject: Disinfection by-products
subject: Natural organic Matter
subject: Trihalomethane

description: The reaction of natural organic matter (NOM) with chlorine results in formation of disinfection by products (DBPs), known carcinogens. Fulvic acid (FA), a key component of NOM is likely a precursor to DBPs. Photocatalytic advanced oxidation using TiO2 is efficient under UV irradiation and known to degrade humics with reduction of DBPs. However, TiO2 may be dye “sensitized” for visible light, where the dye excited state transfers an electron to TiO2 conduction band. NOM adsorbs on the surface of TiO2 and sensitizes (“self-sensitization”). NOM undergoes an initial oxidative step upon visible light absorption and transfers an electron to the TiO2 conduction band. Oxygen captures the electron, forming superoxide which can aid in degradation of NOM. Model studies with Suwannee river fulvic acid are reported and then extended to “real water samples” from Southern Alberta. The humic model shows different degradation behavior from ‘real’ samples. In addition to reduction of NOM by “self-sensitization”, the active species also achieve reduction of Total coliform and Escherichia coli. The objective of this research is to treat NOM and simultaneously enhance disinfection.
Improved lower bounds for the 2-page crossing numbers of K_{m,n} and K_n via semidefinite programming
Creators: name: de Klerk, Etienne
name: Pasechnik, Dmitrii V.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Combinatorics (math.CO)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 05C35, 90C22

description: It has been long conjectured that the crossing numbers of the complete bipartite graph K_{m,n} and of the complete graph K_n equal Z(m,n) (the value conjectured by Zarankiewicz, who came up with a drawing reaching this value) and Z(n) :=Z(n,n-2)/4, respectively. In a 2-page drawing of a graph, the vertices are drawn on a straight line (the spine), and each edge is contained in one of the half-planes of the spine. The 2-page crossing number v_2(G) of a graph G is the minimum number of crossings in a 2-page drawing of G. Somewhat surprisingly, there are 2-page drawings of K_{m,n} (respectively, K_n) with exactly Z(m, n) (respectively, Z(n)) crossings, thus yielding the conjectures (I) v_2(Km,n) =Z(m,n), and (II) v_2(Kn) = Z(n). It is known that (I) holds for min{m, n} <=6, and that (II) holds for n<=14. In this paper we prove that (I) holds asymptotically (that is, lim_n v_2 (K_{m,n})/Z (m, n) = 1) for m=7 and 8. We also prove (II) for 15<=n<=18 and n=20,24, and establish the asymptotic estimate lim_n v_2(K_n)/Z(n) >= 0.9253. The previous best-known lower bound involved the constant 0.8594.
description: 20 pages (ignore pages 21 and 22 produced by the arxive.org script, with copies of pictures inserted elsewhere in the text)
Constraining ultralight dark matter using the Fermi-LAT pulsar timing array
Creators: name: Xia, Zi-Qing
name: Tang, Tian-Peng
name: Huang, Xiaoyuan
name: Yuan, Qiang
name: Fan, Yi-Zhong
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Ultralight dark matter (ULDM) is proposed as a theoretical candidate of dark matter particles with masses of approximately $10^{-22}$ eV. The interactions between ULDM particles and standard model particles would cause variations in pulse arrival times of millisecond pulsars, which means that the pulsar timing array (PTA) can be used to indirectly detect ULDM. In this letter, we use the gamma-ray PTA composed of 29 millisecond pulsars observed by the Fermi Large Area Telescope (Fermi-LAT) to test four ULDM effects, including gravitational effects for generalized ULDM with different Spin-0/1, the fifth-force coupling effect of dark photon, and the modified gravitational effect of the Spin-2 ULDM. The gamma-ray pulsar timing is not affected by the ionized interstellar medium and suffers relatively simple noises, unlike that of the radio band. Our work is the first time that the gamma-ray PTA has been used to search for the ULDM. No significant signals of ULDM are found based on the Fermi-LAT PTA for all four kinds of ULDM models. Constraints on ULDM parameters are set with the 95% confidence level, which provides a complementary check of the nondetection of ULDM for radio PTAs and direct detection experiments.
description: 11 pages, 4 figures, 2 tables; publish as a Letter in Phys. Rev. D
Failure Probability Estimation and Detection of Failure Surfaces via Adaptive Sequential Decomposition of the Design Domain
Creators: name: Gerasimov, Aleksei
name: Vořechovský, Miroslav
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Probability (math.PR)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: J.2
subject: 60-08

description: We propose an algorithm for an optimal adaptive selection of points from the design domain of input random variables that are needed for an accurate estimation of failure probability and the determination of the boundary between safe and failure domains. The method is particularly useful when each evaluation of the performance function g(x) is very expensive and the function can be characterized as either highly nonlinear, noisy, or even discrete-state (e.g., binary). In such cases, only a limited number of calls is feasible, and gradients of g(x) cannot be used. The input design domain is progressively segmented by expanding and adaptively refining mesh-like lock-free geometrical structure. The proposed triangulation-based approach effectively combines the features of simulation and approximation methods. The algorithm performs two independent tasks: (i) the estimation of probabilities through an ingenious combination of deterministic cubature rules and the application of the divergence theorem and (ii) the sequential extension of the experimental design with new points. The sequential selection of points from the design domain for future evaluation of g(x) is carried out through a new learning function, which maximizes instantaneous information gain in terms of the probability classification that corresponds to the local region. The extension may be halted at any time, e.g., when sufficiently accurate estimations are obtained. Due to the use of the exact geometric representation in the input domain, the algorithm is most effective for problems of a low dimension, not exceeding eight. The method can handle random vectors with correlated non-Gaussian marginals. The estimation accuracy can be improved by employing a smooth surrogate model. Finally, we define new factors of global sensitivity to failure based on the entire failure surface weighted by the density of the input random vector.
description: 42 pages, 24 figures
Measuring the NuMI Beam Flux for MINERvA
Creators: name: Jerkins, Melissa T.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: MINERvA is employing multiple tools to understand its neutrino beam flux. We utilize external hadron production data, but we also depend heavily on in situ techniques in which we reduce our hadron production uncertainties by tuning our Monte Carlo to both MINERvA detector data and muon monitor data.
description: NuInt 2011 conference proceeding, 6 pages, 4 figures
Gauge and time-reparametrization invariant spin-half fields
Creators: name: Valenzuela, Mauricio
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present a fermion model characterized by an anticommuting-parameter shift symmetry. The Hamiltonian formulation exhibits a combination of first-class and second-class constraints. We derive the well-known Dirac equation by fixing the gauge in a covariant manner, enabling the fields to propagate accordingly. Notably, the model inherently possesses invariance under reparametrizations of time. Consequently, the Hamiltonian vanishes, setting it apart from the conventional framework of Dirac's theory. Furthermore, we establish a correspondence between these particles and the zero-modes of the massless Rarita-Schwinger system, bringing forth the intriguing implication that they may describe a supergravity ground state.
description: Final version
Finitistic Dimension Conjecture and Conditions on Ideals
Creators: name: Wei, Jiaqun
Publisher: name: arXiv
Year: 2011
Subjects: subject: Rings and Algebras (math.RA)
subject: K-Theory and Homology (math.KT)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 16E05, 16E10, 16G20

description: The notion of Igusa-Todorov classes is introduced in connection with the finitistic dimension conjecture. As application we consider conditions on special ideals which imply the Igusa-Todorov and other finiteness conditions on modules proving the finitistic dimension conjecture and related conjectures in those cases.
Astrophysical cloaking of a naked singularity
Creators: name: Vieira, Ronaldo S. S.
name: Kluźniak, Włodek
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: A massive naked singularity would be cloaked by accreted matter, and thus may appear to a distant observer as an opaque \mbox{(quasi-)}spherical surface of a fluid, not unlike that of a star or planet. We present here analytical solutions for levitating atmospheres around a wide class of spherically symmetric naked singularities. Such an atmosphere can be constructed in every spacetime which possesses a zero-gravity radius and which is a solution of a (modified-)gravity theory possessing the usual conservation laws for matter. Its density peaks at the zero-gravity radius and the atmospheric fluid is supported against infall onto the singularity by gravity alone. In an astrophysical context, an opaque atmosphere would be formed in a very short time by accretion of ambient matter onto the singularity -- in a millisecond for an X-ray binary, in a thousand seconds for a singularity traversing interstellar space, and a thousand years for a singularity that is the central engine of an AGN.
description: 9 pages, 4 figures. Accepted in MNRAS
An Investigation of Sleep and Physical Activity in Young Adults with Autism Spectrum Disorder and the Effects of a Physical Activity Intervention
Creators: name: Benson, Sarah
Publisher: name: Graduate Studies
Year: 2017
Subjects: subject: Physiology
subject: FOS: Biological sciences
subject: Rehabilitation and Therapy
subject: Psychology--Developmental
subject: Psychology--Experimental
subject: Autism Spectrum Disorder
subject: Sleep
subject: Physical Activity
subject: Sleepiness
subject: Actigraphy

description: Background: Physical inactivity, motor coordination difficulties, and sleep problems are often present in autism spectrum disorder (ASD). Sleep problems seem to persist into young adulthood. Physical activity (PA) may positively impact both sleep and daytime behaviour. Objectives: The first part of the study investigated sleep, sleepiness, and PA in 15 young adults (age 18-35 years old) with ASD compared to typically developing controls (TDC). The second part of the study investigated the effects of a 15-week PA intervention on PA levels, gross motor proficiency, daytime functioning, and sleep in 12 of the young adults with ASD. Methods: Young adults with an autism diagnosis (inclusive of all levels of functioning) and TDC wore a wrist-worn actigraph to gather objective PA and sleep data. Questionnaires on sleep, sleepiness, and PA were completed through participant or parent-report. Further, the ASD sample completed a daytime functioning measure, gross motor proficiency, and autism symptom severity assessment. Results: The ASD group had more sleep duration but took longer to fall asleep than TDC. Objective PA levels were lower in the ASD sample, but those with more PA had increased sleepiness and earlier bedtimes and wake times. Fewer wake minutes during the sleep period in the ASD group were associated with more PA the following day. Results included an autism symptom severity by time interaction effect for objective PA, an improvement in subjective sleep quality, a reduction in behaviour problems - specifically Attention Deficit/Hyperactivity (AD/H) problems - and an improvement in physical strength. Correlations were found between objective PA and bilateral coordination, AD/H, and antisocial personality problems. Conclusion: Our findings support previous research that demonstrates differences in sleep parameters and PA between ASD and TDC. Interventions aimed at increasing PA in ASD may be beneficial for sleep and more PA the following day. These findings indicate the potential benefit of group-based PA interventions on PA level, gross motor proficiency, daytime functioning, and sleep in young adults with ASD.
Generic mobility edges in several classes of duality-breaking one-dimensional quasiperiodic potentials
Creators: name: Vu, DinhDuy
name: Sarma, Sankar Das
Publisher: name: arXiv
Year: 2023
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We obtain approximate solutions defining the mobility edge separating localized and extended states for several classes of generic one-dimensional quasiperiodic models. We validate our analytical ansatz with exact numerical calculations. Rather amazingly, we provide a single simple ansatz for the generic mobility edge, which is satisfied by quasiperiodic models involving many different types of nonsinusoidal incommensurate potentials as well as many different types of long-range hopping models. Our ansatz agrees precisely with the well-known limiting cases of the sinusoidal Aubry-André model (which has no mobility edge) and the generalized Aubry-André models (which have analytical mobility edges). Our work provides a practical tool for estimating the location of mobility edges in quasiperiodic systems.
description: 8 pages, 7 figures
The Role of ING5 in Maintaining Stemness of Brain Tumor Initiating Cells
Creators: name: Wang, Fangwu
Publisher: name: Graduate Studies
Year: 2016
Subjects: subject: Biology--Cell
subject: Biology--Molecular
subject: Biochemistry
subject: glioblastoma
subject: cancer stem cells
subject: ING
subject: stemness

description: Brain tumor initiating cells (BTICs) are believed to account for the recurrence of glioblastomas following treatment. Recent studies have shown that the stemness of BTICs and intratumoral differentiation hierarchy are determined largely on the epigenetic level. The ING family of epigenetic regulators function in diverse growth regulatory, metastasis and chemoresistance pathways, through targeting different histone acetyltransferase (HAT) and histone deacetylase (HDAC) complexes to the H3K4me3 mark to alter histone acetylation. ING5, a stoichiometric unit of three HAT complexes, has been directly implicated in the maintenance of epidermal stem cells. Here we found that ING5 was highly expressed in BTICs and rapidly downregulated upon in vitro differentiation. Ectopic expression of ING5 promoted self-renewal, prevented lineage differentiation and increased the stem cell pool in the BTIC population, accompanied by an elevated expression of stem cell core transcription factors OCT4, OLIG2 and Nestin. ING5 enhanced the activity of the PI3K/AKT and MEK/ERK pathways in the absence of growth factors to sustain self-renewal of BTICs over serial sphere passage. Transcriptome analysis indicated ING5 was an inducer of the intracellular calcium signaling and follicle stimulating hormone pathways, which were confirmed to co-operatively enhance the self-renewal of BTICs. This study identifies ING5 as a positive regulator of BTIC stem cell character, whose expression negatively correlates with patient prognosis, especially in the Proneural subtype and tumors with low SOX2 expression, therefore suggesting that altering histone acetylation status and the signaling pathways induced by ING5 may provide useful clinical targets to reduce recurrence in glioblastoma.
The Experiences of Adolescent Boys in Tobago Whose Fathers Have Migrated
Creators: name: Dillon, Mona
Publisher: name: Graduate Studies
Year: 2015
Subjects: subject: Social Work
subject: FOS: Sociology
subject: Caribbean males
subject: Father outmigration
subject: Adolescent males
subject: participatory action research
subject: Photovoice
subject: Tobago

description: The purpose of the current study is to explore the experiences of adolescent males on the Caribbean island of Tobago whose fathers have migrated, and to engage these adolescents in devising appropriate strategies to address possible problems, using participatory action research (PAR). The results of the study emphasized the gender responses in relation to the migration phenomenon on the Caribbean island of Tobago. In particular, participants’ stories described perceptions of the components of the father-son relationship and individuals’ understanding of some specific roles of a father within the family unit. Additionally, the young men pinpointed coping strategies that capitalized on resources within the individual as well as the social environment. Even more, participants used the emerging themes to identify solutions that targeted systems at the governmental, community and school levels. In the end, the young men collaborated with policymakers and the process assisted in consolidating possible short and long-term actions which could be implemented. Overall, the key findings suggest that the role of women in lives of adolescent left-behind males needs to be revisited especially in light of the family structure and relationships within Caribbean matrifocal societies where women are expected to fill gaps left by an absent father. Also, the support of the extended family, the community, and institutions is noteworthy. However such support is most effective when it includes avenues for filling the gap in the father-son relationship and recognizing the resiliency of the young men. Even more, the findings indicate that adolescent males accept substitute fathers with ambivalence and these young men of migrant fathers in Tobago are concerned about endangering the connection between father and son. Furthermore, concerning methodology, the present investigation demonstrates that engaging youth in a meaningful manner facilitates dialogue that encourages rich, in-depth description of life experiences. Also, the current study indicates that youth-friendly and male-friendly strategies such as modern technology and photography are useful for engaging youth and promoting the process of critically analyzing the impact of migration. Finally, the study supports photovoice as an effective way of creating a space for adolescent young men of migrant fathers in Tobago to discuss their issues and consider possible solutions.
Early Inductive Reasoning: Examining 11-Month-Olds' Abilities
Creators: name: Vukatana, Ena
Publisher: name: Graduate Studies
Year: 2013
Subjects: subject: Cognitive
subject: Developmental
subject: Early Inductive Reasoning
subject: Categorization

description: Induction is a fundamental aspect of human learning and reasoning, allowing individuals to generalize beyond what is known to new instances and situations. The present studies investigated inductive reasoning in 11-month-olds. In three experiments, infants were familiarized with animal-sound pairings (e.g., Animal1 [red]-Sound1). Following familiarization, infants’ acquisition of the original pairing and their ability to generalize the sound property to a new member of the familiar category (e.g., Animal2 [blue]-Sound1) were assessed. The results revealed that infants acquired the original animal-sound pairing, but did not generalize the sound property to a new member of a familiar category. Thus, infants formed one-to-one animal-sound mappings, but did not show evidence of category-based inferences.
Transverse Field Ising Ferromagnetism in Mn$_{12}$-acetate-MeOH
Creators: name: Subedi, P.
name: Kent, A. D.
name: Wen, Bo
name: Sarachik, M. P.
name: Yeshurun, Y.
name: Millis, A. J.
name: Mukherjee, S.
name: Christou, G.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report measurements of the magnetic susceptibility of single crystals of Mn$_{12}$-acetate-MeOH, a new high-symmetry variant of the original single molecule magnet Mn$_{12}$-acetate. A comparison of these data to theory and to data for the Mn$_{12}$ acetate material shows that Mn$_{12}$-acetate-MeOH is a realization of a transverse-field Ising ferromagnet in contrast to the original Mn$_{12}$ acetate material, in which solvent disorder leads to effects attributed to random field Ising ferromagnetism.
description: 6 pages, 4 figures
Stochastic phase dynamics of noise driven synchronization of uncoupled conditional coherent oscillators
Creators: name: Thompson, William F.
Publisher: name: University of British Columbia
Year: 2010

description: We consider a pair of uncoupled conditional oscillators near a subcritical Hopf bifurcation that are driven by two weak white noise sources, one intrinsic and one common. The effect of the competition between the common and intrinsic noise forcing on the synchronization behaviour of the phases of these two oscillators is studied. Using a stochastic multiple scales method, we derive the envelope equations of the oscillators and then use the theory of linearized stochastic differential equations as well as an asymptotic analysis to study the probability density of the phase difference of the oscillators. It is found that common noise increases the degree of synchrony in the pair of oscillators and that it can be characterized by the ratio of intrinsic to common noise. Furthermore, the nonlinear dynamics of the oscillators can affect the character of this synchronization in terms of the average phase difference. The results are also related to the study of spike time reliability and possible implications are brieﬂy discussed.
Runge-Gross action-integral functional re-examined
Creators: name: Schirmer, J.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: The density-based action-integral functional introduced by Runge and Gross [Phys. Rev. Lett. 52, 997(1984)] in their foundation of time-dependent density-functional theory (TDDFT) is re-examined. Based on an obvious expansion of the original definition, it becomes apparent that the action-integral functional is both trivial and non-stationary. It cannot be used to establish equations of motion for the time-evolution of quantum systems at the density-function level.
description: 5 pages
Observation of Exceptional Points in Thermal Atomic Ensembles
Creators: name: Liang, Chao
name: Tang, Yuanjiang
name: Xu, An-Ning
name: Liu, Yong-Chun
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Exceptional points (EPs) in non-Hermitian systems have recently attracted wide interests and spawned intriguing prospects for enhanced sensing. However, EPs have not yet been realized in thermal atomic ensembles, which is one of the most important platforms for quantum sensing. Here we experimentally observe EPs in multi-level thermal atomic ensembles, and realize enhanced sensing of magnetic field for one order of magnitude. We take advantage of the rich energy levels of atoms and construct effective decays for selected energy levels by employing laser coupling with the excited state, yielding unbalanced decay rates for different energy levels, which finally results in the existence of EPs. Furthermore, we propose the optical polarization rotation measurement scheme to detect the splitting of the resonance peaks, which makes use of both the absorption and dispersion properties, and shows advantage with enhanced splitting compared with the conventional transmission measurement scheme. Besides, in our system both the effective coupling strength and decay rates are flexibly adjustable, and thus the position of the EPs are tunable, which expands the measurement range. Our work not only provides a new controllable platform for studying EPs and non-Hermitian physics, but also provide new ideas for the design of EP-enhanced sensors and opens up realistic opportunities for practical applications in the high-precision sensing of magnetic field and other physical quantities.
description: 7 pages, 4 figures
Detectability of GRB optical afterglows with Gaia satellite
Creators: name: Japelj, J.
name: Gomboc, A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: With the launch of Gaia satellite, detection of many different types of transient sources will be possible, one of them being optical afterglows of gamma-ray bursts (GRBs). Using the knowledge of the satellites dynamics and properties of GRB optical afterglows we performed a simulation in order to estimate an average GRB detection rate with Gaia. Here we present the simulation results for two types of GRB optical afterglows, differing in the observer's line-of-sight compared to a GRB jet axis: regular (on-axis) and orphan afterglows. Results show that for on-axis GRBs, less than 10 detections in five years of foreseen Gaia operational time are expected. The orphan afterglows simulation results are more promising, giving a more optimistic number of several tens of detections in five years.
description: 14 pages, 10 figures, accepted to PASP
A landscape level analysis of yellow-cedar decline in coastal British Columbia
Creators: name: Wooton, Claire Evelyn
Publisher: name: University of British Columbia
Year: 2010

description: Yellow-cedar (Chamaecyparis nootkatensis) is currently undergoing a dramatic decline in western North America, with concentrated areas of decline located in southeast Alaska and coastal British Columbia. Recent research suggests that a shift in climate is responsible for the decline and a working hypothesis concerning the role of climate and site specific factors has been proposed. The main objective of this research was to contribute to the understanding of the yellow-cedar decline phenomenon by examining the spatial pattern of the decline and assessing the relations with topographic variables in coastal British Columbia. The research questions were addressed through a combination of remote sensing and Geographic Information System (GIS) techniques. Sample points were distributed across the landscape according to a stratified sampling scheme and the presence/absence of decline at each point was determined using a forest cover dataset and aerial photograph interpretation. Spatial patterns of topographic factors (e.g. elevation, slope, aspect) were derived from a 25 m digital elevation model of the province. To assess the strength of relations between the distribution of decline and the various environmental predictors, logistic regression and decision-tree models were applied. The lasso technique was used to select a significant set of coefficients and the selection was then validated through bootstrap analysis. Model results indicated that low elevation sites close to the coast, which are more exposed and have more variation in elevation, are more likely to show evidence of decline. The logistic model fit the data well (Nagelkerke R² = 0.846, Hosmer-Le Cessie omnibus test failed to find any evidence of lack of fit) and had high predictive accuracy (AUC = 0.98). The topographic variables identified by the model influence degree of soil saturation, temperatures and snowpack presence in a forest stand, supporting the proposed associations in the current decline hypothesis. The analysis also highlighted the utility of the lasso logistic model for selecting significant variables and mapping high risk areas for decline. Knowledge of the determinants of the spatial pattern of decline will improve predictability and provide critical information for the conservation and management of yellow-cedar.
Toward a Hermeneutic of Religion in the Public Sphere: Encouraging a Robust Public Discourse
Creators: name: Napier, Jonathan
Publisher: name: Graduate Studies
Year: 2015
Subjects: subject: Education--Religious
subject: Religion--Philosophy of
subject: Canadian Studies
subject: Multiculturalism
subject: Diversity
subject: Public Policy
subject: Hermeneutics
subject: Secularism
subject: Ethics
subject: Public Sphere
subject: Charles Taylor
subject: Paul Ricoeur

description: Traditional religious communities view multiculturalism and other forms of liberal secularism as committed to relegating religious aspects of life to the irrelevant margins of civil society by excluding them from public discourse. Faced with such institutional and structural derision, what kinds of counter-strategies can religious communities develop to carve out a space for their continued existence and growth? By translating religious worldviews into secular terms, religious adherents are able to actively engage in public discourse and enter into the fray of the public sphere. However, engaging in public discourse in this way raises questions regarding religious identity and a tradition's integrity. My project will analyse the phenomenon of translation which can be utilised by religious communities to develop a hermeneutic to guide their engagement in political dialogue. As the role of religion continues to be debated in Canada, studying religious activity in the public sphere will continue to increase in importance. I suggest that the dynamics of translation provides a key to understanding such religious strategies and their effects on their constituents as well as on the broader society. Translation is a useful frame for studying this issue as it lends itself to relevant areas of inquiry. How meaning is derived, maintained, and communicated in different contexts can be analysed through hermeneutics. For my research, I will consider the hermeneutics of religion and translation by incorporating current work in the theory of dialogue and the public sphere. In this thesis I aim to produce a novel analysis on the religious tensions within the multicultural and secular Canadian society; clarify the tension underlying the deployment of translation as counterstrategies by religious adherents against secularism; demonstrate in what ways the redescription and reinterpretation necessitated by these translations indicate how we might move forward to a more pluralist society where religious, and other identities, are not forcibly submerged into a model of multiculturalism. The ultimate objective of my research will be to show how the resources of religious traditions may be better able to contribute positively to the Canadian multicultural experiment.
On the Manipulability of Voting Systems: Application to Multi-Carrier Networks
Creators: name: Durand, François
name: Mathieu, Fabien
name: Noirie, Ludovic
Publisher: name: arXiv
Year: 2012
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Today, Internet involves many actors who are making revenues on it (operators, companies, service providers,...). It is therefore important to be able to make fair decisions in this large-scale and highly competitive economical ecosystem. One of the main issues is to prevent actors from manipulating the natural outcome of the decision process. For that purpose, game theory is a natural framework. In that context, voting systems represent an interesting alternative that, to our knowledge, has not yet been considered. They allow competing entities to decide among different options. Strong theoretical results showed that all voting systems are susceptible to be manipulated by one single voter, except for some "degenerated" and non-acceptable cases. However, very little is known about how much a voting system is manipulable in practical scenarios. In this paper, we investigate empirically the use of voting systems for choosing end-to-end paths in multi-carrier networks, analyzing their manipulability and their economical efficiency. We show that one particular system, called \Single Transferable Vote (STV), is largely more resistant to manipulability than the natural system which tries to get the economical optimum. Moreover, STV manages to select paths close to the economical optimum, whether the participants try to cheat or not.
Gauge/frame invariant variables for the numerical relativity study of cosmological spacetimes
Creators: name: Ijjas, Anna
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: To numerically evolve the full Einstein equations (or modifications thereof), simulations of cosmological spacetimes must rely on a particular formulation of the field equations combined with a specific gauge/frame choice. Yet truly physical results cannot depend on the given formulation or gauge/frame choice. In this paper, we present a resolution of the gauge problem and, as an example, numerically implement it to evaluate our previous work on contracting spacetimes.
description: 22 pages, 8 figures; v2: typos corrected
Federico da Sestri Levante dinamico notaio per magistrati e per un popolo rurale (1223-1225)
Creators: name: Polonio, Valeria
Publisher: name: Zenodo
Year: 2018
Subjects: Federico's Achievements
Precocity
Rural World
Collaboration with Magistrates
Important Career

description: Only one fragment of cartulary (consisting of 59 folios spanning the years 1223-1225, for a total of 331 acts) regarding Federico of Sestri Levante exists. Despite this, the notary can claim a number of achievements:

– He operates outside the city walls, specifically in the eastern Riviera, mainly between Sestri and Moneglia (including their hinterland);

– His activity is progressive and long-lasting – a rural notary remains a unique figure until the middle of the XIII Century;

– Furthermore, his main engagement with private clients is flanked by his collaboration with the magistrate who oversees the above territories.

The documents provide knowledge of a world that is rapidly evolving under the recent Genoese influence. The information covers mainly economic and social aspects, together with providing a few unexpected nuggets such as the widespread presence of notaries. It is clear that some of these aim at secure positions within the growing Genoese administration on the land. We hypothesise – with good supporting data – that Federico himself ended his long career working as a magistrates’ scriba in Bonifacio, in Corsica.
Herschel discovery of a new class of cold, faint debris discs
Creators: name: Eiroa, C.
name: Marshall, J. P.
name: Mora, A.
name: Krivov, A. V.
name: Montesinos, B.
name: Absil, O.
name: Ardila, D.
name: Arevalo, M.
name: Augereau, J. -Ch.
name: Bayo, A.
name: Danchi, W.
name: del Burgo, C.
name: Ertel, S.
name: Fridlund, M.
name: Gonzalez-Garcıa, B. M.
name: Heras, A. M.
name: Lebreton, J.
name: Liseau, R.
name: Maldonado, J.
name: Meeus, G.
name: Montes, D.
name: Pilbratt, G. L.
name: Roberge, A.
name: Sanz-Forcada, J.
name: Stapelfeldt, K.
name: Thebault, P.
name: White, G. J.
name: Wolf, S.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present Herschel PACS 100 and 160 micron observations of the solar-type stars alpha Men, HD 88230 and HD 210277, which form part of the FGK stars sample of the Herschel Open Time Key Programme (OTKP) DUNES (DUst around NEarby S tars). Our observations show small infrared excesses at 160 micron for all three stars. HD 210277 also shows a small excess at 100 micron, while the 100 micron fluxes of alpha Men and HD 88230 agree with the stellar photospheric predictions. We attribute these infrared excesses to a new class of cold, faint debris discs. alpha Men and HD 88230 are spatially resolved in the PACS 160 micron images, while HD 210277 is point-like at that wavelength. The projected linear sizes of the extended emission lie in the range from ~ 115 to ~ 250 AU. The estimated black body temperatures from the 100 and 160 micron fluxes are $\lesssim$ 22 K, while the fractional luminosity of the cold dust is Ldust/Lstar ~ 10E-6, close to the luminosity of the Solar-System's Kuiper belt. These debris discs are the coldest and faintest discs discovered so far around mature stars and cannot easily be explained by invoking "classical" debris disc models.
description: Accepted by Astronomy and Astrophysics Letters
Gate-Controlled P-I-N Junction Switching Device with Graphene Nanoribbon
Creators: name: Nakaharai, Shu
name: Iijima, Tomohiko
name: Ogawa, Shinichi
name: Miyazaki, Hisao
name: Li, Songlin
name: Tsukagoshi, Kazuhito
name: Sato, Shintaro
name: Yokoyama, Naoki
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The concept of a novel graphene P-I-N junction switching device with a nanoribbon is proposed, and its basic operation is demonstrated in an experiment. The concept aims to optimize the operation scheme for graphene transistors toward a superior on-off property. The device has two bulk graphene regions where the carrier type is electrostatically controlled by a top gate, and these two regions are separated by a nanoribbon which works as an insulator. As a result, the device forms a (P or N)-I-(P or N) junction structure. The off state is obtained by lifting the band of the bulk graphene of the source (drain) side and lowering that of the drain (source) side, so that the device forms a P-I-N (N-I-P) junction. In this configuration, the leakage current can be reduced more effectively than the conventional single gate transistors with the same band gap size due to a high barrier height and a long tunneling length in the nanoribbon. The on state is obtained by flipping the polarity of the bias of either top gate to form a P-I-P or N-I-N junction. An experiment showed that the drain current was suppressed in the cases of P-I-N and N-I-P compared to the cases of P-I-P and N-I-N, and all of the behaviors were consistent with what was expected from the device operation model.
description: 9 pages, 4 figures. To be published in Applied Physics Express
IL-12 Restores Defective NK Cell Anticryptococcal Activity in HIV-Infected Patients
Creators: name: Kyei, Stephen Kofi
Publisher: name: Graduate Studies
Year: 2015
Subjects: subject: Immunology
subject: FOS: Clinical medicine
subject: Cryptococcus
subject: HIV
subject: NK cells
subject: Interleukin

description: Cryptococcus neoformans is a pathogenic yeast that causes life-threatening pneumonia and meningitis in AIDS patients. Natural killer (NK) cells are important effector cells that directly recognize and kill C. neoformans via perforin-dependent cytotoxicity. Although it had previously been demonstrated that, NK cells from HIV-infected patients have defective anticryptococcal activity, and IL-12 restored the activity, almost nothing was known of the mechanisms causing this defect or how IL-12 restored the defect. By examining the sequential steps in NK cell killing of Cryptococcus, I determined that NK cells from HIV-infected patients had lower intracellular perforin expression, defective perforin release and defective ability to polarize perforin to the fungal synapse. Importantly, treatment of NK cells from HIV-infected patients with IL-12 reversed these defects and restored the defective anticryptococcal activity. Thus, there are multiple defects in the cytolytic machinery of NK cells from HIV-infected patients, which result in the defective anticryptococcal activity, and these defects can be reversed with IL-12.
Baryon properties from the covariant Faddeev equation
Creators: name: Sanchis-Alepuz, Helios
name: Alkofer, Reinhard
name: Williams, Richard
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: A calculation of the masses and electromagnetic properties of the Delta and Omega baryon together with their evolution with the current quark mass is presented. Hereby a generalized Bethe-Salpeter approach with the interaction truncated to a dressed one-gluon exchange is employed. The model dependence is explored by investigating two forms for the dressed gluon exchange.
description: 6 pages, 2 figures, contribution to the proceedings of the Sixth International Conference on Quarks and Nuclear Physics (QNP2012), April 16-20, 2012, Palaiseau, France
Benchmarking Actor-Critic Deep Reinforcement Learning Algorithms for Robotics Control with Action Constraints
Creators: name: Kasaura, Kazumi
name: Miura, Shuwa
name: Kozuno, Tadashi
name: Yonetani, Ryo
name: Hoshino, Kenta
name: Hosoe, Yohei
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: This study presents a benchmark for evaluating action-constrained reinforcement learning (RL) algorithms. In action-constrained RL, each action taken by the learning system must comply with certain constraints. These constraints are crucial for ensuring the feasibility and safety of actions in real-world systems. We evaluate existing algorithms and their novel variants across multiple robotics control environments, encompassing multiple action constraint types. Our evaluation provides the first in-depth perspective of the field, revealing surprising insights, including the effectiveness of a straightforward baseline approach. The benchmark problems and associated code utilized in our experiments are made available online at github.com/omron-sinicx/action-constrained-RL-benchmark for further research and development.
description: 8 pages, 7 figures, accepted to Robotics and Automation Letters