cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Expectations and Risk Premia at 8:30 a.m.: Deciphering the Responses of Bond Yields to Macroeconomic Announcements
Creators: name: Hördahl, Peter
name: Remolona, Eli M.
name: Valente, Giorgio
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Medicine
subject: Genetics
subject: FOS: Biological sciences
subject: Neuroscience
subject: Pharmacology
subject: 69999 Biological Sciences not elsewhere classified
subject: 80699 Information Systems not elsewhere classified
subject: FOS: Computer and information sciences
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics
subject: 111714 Mental Health
subject: FOS: Health sciences
subject: Plant Biology

description: What explains the sharp movements of the yield curve upon the release of major U.S. macroeconomic announcements? To answer this question, we estimate an arbitrage-free dynamic term structure model with macroeconomic fundamentals as risk factors. We assume that the yield curve reacts to announcements primarily because of the information they contain about the fundamentals of output, inflation, and the Fed’s inflation target. We model the updating process by linking the factor shocks to announcement surprises. Fitting this process to data on yield curve movements in 20-min event windows, we find that most major announcements, especially those about the labor market, are informative largely about the output gap rather than about inflation. The resulting changes in short-rate expectations account for the bulk of observed yield movements. But adjustments in risk premia are also sizable. In partly offsetting the effects of short-rate expectations, these adjustments help to account for the well-known hump-shaped pattern of yield reactions across maturities.
Multiple Absorption-Line Spectroscopy of the Intergalactic Medium. I. Model
Creators: name: Yao, Yangsen
name: Shull, J. Michael
name: Danforth, Charles W.
name: Keeney, Brian A.
name: Stocke, John T.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present a physically-based absorption-line model for the spectroscopic study of the intergalactic medium (IGM). This model adopts results from Cloudy simulations and theoretical calculations by Gnat and Sternberg (2007) to examine the resulting observational signatures of the absorbing gas with the following ionization scenarios: collisional ionization equilibrium (CIE), photoionization equilibrium, hybrid (photo- plus collisional ionization), and non-equilibrium cooling. As a demonstration, we apply this model to new observations made with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope of the IGM absorbers at z~0.1877 along the 1ES 1553+113 sight line. We identify Ly alpha, C III, O VI, and N V absorption lines with two distinct velocity components (blue at z_b=0.18757; red at z_r=0.18772) separated by Delta(cz)/(1+z)~38 km/s. Joint analyses of these lines indicate that none of the examined ionization scenarios can be applied with confidence to the blue velocity component, although photoionization seems to play a dominant role. For the red component, CIE can be ruled out, but pure photoionization and hybrid scenarios (with T<1.3E5 K) are more acceptable. The constrained ranges of hydrogen density and metallicity of the absorbing gas are n_H=(1.9-2.3)E-5 cm^-3 and Z=(0.43-0.67)Z_solar. These constraints indicate OVI and HI ionization fractions, f_OVI=0.10-0.15 and f_HI=(3.2-5.1)E-5, with total hydrogen column density N_H=(0.7-1.2)E18 cm^-2. This demonstration shows that joint analysis of multiple absorption lines can constrain the ionization state of an absorber, and results used to estimate the baryonic matter contained in the absorber.
description: Accepted for publication in the ApJ, 6 pages, 4 figs, 2 tables
Applying integrated knowledge translation to address mental health among young immigrant and refugee men in Canada
Creators: name: Hilario, Carla T.
Publisher: name: University of British Columbia
Year: 2018

description: Background: The mental health of young immigrant and refugee men has drawn much recent attention worldwide. Increased awareness regarding depression and suicide among men has intersected with pressing dialogues around how to best address the health needs of immigrant and refugee populations. Despite this attention, integrated knowledge translation (iKT) research in the field of mental health has yet to engage this group and virtually no studies have focused on their mental health experiences. The purpose of this research was to examine mental health and distress from the perspectives of immigrant and refugee young men living in Greater Vancouver, British Columbia, Canada. Methods: An iKT approach was applied to integrate the perspectives of (1) research collaborators, who were six immigrant and refugee young men, and (2) an advisory group, comprised of service providers and program leaders into the study design and mobilization of the study findings. Narrative analysis methods, informed by the analytical lenses of social context and critical masculinities, were used to collect and examine the data from individual and group interviews with thirty-three immigrant and refugee young men (ages 15-22 years). Participatory video methods were used to facilitate the co-creation of a film with the collaborators based on qualitative data from the research interviews. A reflexive analysis was used to examine ethnographic field notes documenting the iKT design and the participatory video methods. Findings: The results reveal that (1) the participants’ distress-related experiences were shaped in part by masculine discourses; (2) experiences of second-class citizenship, in the context of their everyday life, influenced how young men perceived their mental health; and (3) iKT and participatory video methods can lead to new insights about power and representation. Conclusions: This dissertation contributes to the literature on immigrant and refugee youth mental health and young men’s experiences of distress. It provides insights to guide future iKT and participatory video research. The findings can inform equity-oriented practice, policy, and future research to support the mental health of immigrant and refugee young men in Canada.
Large Bayesian VARs: A Flexible Kronecker Error Covariance Structure
Creators: name: Chan, Joshua C. C.
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: Ecology
subject: 80699 Information Systems not elsewhere classified
subject: FOS: Computer and information sciences
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics
subject: 110309 Infectious Diseases
subject: FOS: Health sciences

description: We introduce a class of large Bayesian vector autoregressions (BVARs) that allows for non-Gaussian, heteroscedastic, and serially dependent innovations. To make estimation computationally tractable, we exploit a certain Kronecker structure of the likelihood implied by this class of models. We propose a unified approach for estimating these models using Markov chain Monte Carlo (MCMC) methods. In an application that involves 20 macroeconomic variables, we find that these BVARs with more flexible covariance structures outperform the standard variant with independent, homoscedastic Gaussian innovations in both in-sample model-fit and out-of-sample forecast performance.
How citation boosts promote scientific paradigm shifts and Nobel Prizes
Creators: name: Mazloumian, Amin
name: Eom, Young-Ho
name: Helbing, Dirk
name: Lozano, Sergi
name: Fortunato, Santo
Publisher: name: arXiv
Year: 2011
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Digital Libraries (cs.DL)
subject: Social and Information Networks (cs.SI)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Nobel Prizes are commonly seen to be among the most prestigious achievements of our times. Based on mining several million citations, we quantitatively analyze the processes driving paradigm shifts in science. We find that groundbreaking discoveries of Nobel Prize Laureates and other famous scientists are not only acknowledged by many citations of their landmark papers. Surprisingly, they also boost the citation rates of their previous publications. Given that innovations must outcompete the rich-gets-richer effect for scientific citations, it turns out that they can make their way only through citation cascades. A quantitative analysis reveals how and why they happen. Science appears to behave like a self-organized critical system, in which citation cascades of all sizes occur, from continuous scientific progress all the way up to scientific revolutions, which change the way we see our world. Measuring the "boosting effect" of landmark papers, our analysis reveals how new ideas and new players can make their way and finally triumph in a world dominated by established paradigms. The underlying "boost factor" is also useful to discover scientific breakthroughs and talents much earlier than through classical citation analysis, which by now has become a widespread method to measure scientific excellence, influencing scientific careers and the distribution of research funds. Our findings reveal patterns of collective social behavior, which are also interesting from an attention economics perspective. Understanding the origin of scientific authority may therefore ultimately help to explain, how social influence comes about and why the value of goods depends so strongly on the attention they attract.
description: 6 pages, 6 figures
Electronic Supplementary Material 1 from Elevated compositional change in plant assemblages linked to invasion
Creators: name: Kortz, Alessandra R.
name: Moyes, Faye
name: Pivello, Vânia R.
name: Pyšek, Petr
name: Dornelas, Maria
name: Visconti, Piero
name: Magurran, Anne E.
Publisher: name: The Royal Society
Year: 2023
Subjects: subject: Ecology
subject: FOS: Biological sciences

description: Alien species are widely linked to biodiversity change, but the extent to which they are associated with the reshaping of ecological communities is not well understood. One possible mechanism is that assemblages where alien species are found exhibit elevated temporal turnover. To test this, we identified assemblages of vascular plants in the BioTIME database for those assemblages in which alien species are either present or absent and used the Jaccard measure to compute compositional dissimilarity between consecutive censuses. We found that, although alien species are typically rare in invaded assemblages, their presence is associated with an increase in the average rate of compositional change. These differences in compositional change between invaded and uninvaded assemblages are not linked to differences in species richness but rather to species replacement (turnover). Rapid compositional restructuring of assemblages is a major contributor to biodiversity change, and as such, our results suggest a role for alien species in bringing this about.
Doping and temperature dependence of Mn 3d states in A-site ordered manganites
Creators: name: García-Fernández, M.
name: Staub, U.
name: Bodenthin, Y.
name: Pomjakushin, V.
name: Mirone, A.
name: Fernández-Rodríguez, J.
name: Scagnoli, V.
name: Mulders, A. M.
name: Lawrence, S. M.
name: Pomjakushina, E.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We present a systematic study of the electronic structure in A-site ordered manganites as function of doping and temperature. The energy dependencies observed with soft x-ray resonant diffraction (SXRD) at the Mn L_{2,3} edges are compared with structural investigations using neutron powder diffraction as well as with cluster calculations. The crystal structures obtained with neutron powder diffraction reflect the various orbital and charge ordered phases and show an increase of the Mn-O-Mn bond angle as function of doping and temperature. Cluster calculations show that the observed spectral changes in SXRD as a function of doping are more pronounced than expected from an increase in bandwitdh due to the increase in Mn-O-Mn bond angle, and are best described by holes that are distributed at the neighbouring oxygen ions. These holes are not directly added to the Mn 3d shell, but centered at the Mn site. In contrast, the spectral changes in SXRD as function of temperature are best described by an increase of magnetic correlations. This demonstrates the strong correlations between orbitals and magnetic moments of the 3d states.
Evidence for a merger-revived radio phoenix in MaxBCG J217.95869+13.53470
Creators: name: Ogrean, G. A.
name: Brueggen, M.
name: van Weeren, R.
name: Simionescu, A.
name: Roettgering, H.
name: Croston, J. H.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We use XMM-Newton observations of the galaxy cluster MaxBCG J217.95869+13.53470 to analyze its physical properties and dynamical state. MaxBCG J217.95869+13.53470 is found at a redshift of 0.16, has a mass of ~1x10^14 Msun, and a luminosity of 7.9x10^43 erg/s. The temperature map shows the presence of hot regions towards the north and west of the brightest cluster galaxy (BCG). From the entropy distribution, regions of high entropy match the location of the hot regions; more high entropy regions are found to the west, and ~165 kpc to the southwest of the central AGN. A second X-ray bright galaxy is visible ~90 kpc to the northeast of the BCG, at a redshift of 0.162. This galaxy is likely to be the BCG of a smaller, infalling galaxy cluster. The mass of the smaller cluster is ~10 percent the mass of MaxBCG J217.95869+13.53470, yielding an impact parameter of ~30-100 kpc. We compare the results of our X-ray observations with GMRT observations of the radio source VLSS J1431.8+1331, located at the center of the cluster. Two sources are visible in the radio: a central elongated source that bends at its northern and southern ends, and a southwestern source that coincides with a region of high entropy. The radio sources are connected by a bridge of faint radio emission. We speculate that the southwestern radio source is a radio relic produced by compression of old radio plasma by a merger shock.
description: 9 pages, 8 figures, 1 table; accepted to MNRAS
Advection, diffusion and delivery over a network
Creators: name: Heaton, Luke L. M.
name: Lopez, Eduardo
name: Maini, Philip K.
name: Fricker, Mark D.
name: Jones, Nick S.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Tissues and Organs (q-bio.TO)
subject: Mathematical Physics (math-ph)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: Many biological, geophysical and technological systems involve the transport of resource over a network. In this paper we present an algorithm for calculating the exact concentration of resource at any point in space or time, given that the resource in the network is lost or delivered out of the network at a given rate, while being subject to advection and diffusion. We consider the implications of advection, diffusion and delivery for simple models of glucose delivery through a vascular network, and conclude that in certain circumstances, increasing the volume of blood and the number of glucose transporters can actually decrease the total rate of glucose delivery. We also consider the case of empirically determined fungal networks, and analyze the distribution of resource that emerges as such networks grow over time. Fungal growth involves the expansion of fluid filled vessels, which necessarily involves the movement of fluid. In three empirically determined fungal networks we found that the minimum currents consistent with the observed growth would effectively transport resource throughout the network over the time-scale of growth. This suggests that in foraging fungi, the active transport mechanisms observed in the growing tips may not be required for long range transport.
description: 54 pages including appendix, 10 figures
Vector potential, electromagnetic induction and "physical meaning"
Creators: name: Giuliani, Giuseppe
Publisher: name: arXiv
Year: 2010
Subjects: subject: History and Philosophy of Physics (physics.hist-ph)
subject: FOS: Physical sciences

description: A forgotten experiment by André Blondel (1914) proves, as held on the basis of theoretical arguments in a previous paper, that the time variation of the magnetic flux is not the cause of the induced $emf$: the physical agent is instead the vector potential through the term $-\partial\vec A/\partial t$ (when the induced circuit is at rest). The "good electromagnetic potentials" are determined by the Lorenz condition and retarded formulas. Other pairs of potentials derived through appropriate gauge functions are only mathematical devices for calculating the fields: they are not physically related to the sources. The physical meaning of a theoretical term relies, primarily, on theoretical grounds: a theoretical term has physical meaning if it cannot be withdrawn without reducing the predictive power of a theory or, in a weaker sense, if it cannot be withdrawn without reducing the descriptive proficiency of a theory.
The Skorohod oblique reflection problem in time-dependent domains
Creators: name: Nyström, Kaj
name: Önskog, Thomas
Publisher: name: arXiv
Year: 2010
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: The deterministic Skorohod problem plays an important role in the construction and analysis of diffusion processes with reflection. In the form studied here, the multidimensional Skorohod problem was introduced, in time-independent domains, by H. Tanaka [61] and further investigated by P.-L. Lions and A.-S. Sznitman [42] in their celebrated article. Subsequent results of several researchers have resulted in a large literature on the Skorohod problem in time-independent domains. In this article we conduct a thorough study of the multidimensional Skorohod problem in time-dependent domains. In particular, we prove the existence of càdlàg solutions $(x,λ)$ to the Skorohod problem, with oblique reflection, for $(D,Γ,w)$ assuming, in particular, that $D$ is a time-dependent domain (Theorem 1.2). In addition, we prove that if $w$ is continuous, then $x$ is continuous as well (Theorem 1.3). Subsequently, we use the established existence results to construct solutions to stochastic differential equations with oblique reflection (Theorem 1.9) in time-dependent domains. In the process of proving these results we establish a number of estimates for solutions to the Skorohod problem with bounded jumps and, in addition, several results concerning the convergence of sequences of solutions to Skorohod problems in the setting of time-dependent domains.
description: Published in at http://dx.doi.org/10.1214/10-AOP538 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org)
First Order Phase Transition in a Model of Quasicrystals
Creators: name: Aristoff, David
name: Radin, Charles
Publisher: name: arXiv
Year: 2011
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We introduce a family of two-dimensional lattice models of quasicrystals, using a range of square hard cores together with a soft interaction based on an aperiodic tiling set. Along a low temperature isotherm we find, by Monte Carlo simulation, a first order phase transition between disordered and quasicrystalline phases.
description: future versions available from http://www.ma.utexas.edu/users/radin/papers.html
The Finite Sample Performance of Inference Methods for Propensity Score Matching and Weighting Estimators
Creators: name: Bodory, Hugo
name: Camponovo, Lorenzo
name: Huber, Martin
name: Lechner, Michael
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Medicine
subject: Biotechnology
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics
subject: Science Policy

description: This article investigates the finite sample properties of a range of inference methods for propensity score-based matching and weighting estimators frequently applied to evaluate the average treatment effect on the treated. We analyze both asymptotic approximations and bootstrap methods for computing variances and confidence intervals in our simulation designs, which are based on German register data and U.S. survey data. We vary the design w.r.t. treatment selectivity, effect heterogeneity, share of treated, and sample size. The results suggest that in general, theoretically justified bootstrap procedures (i.e., wild bootstrapping for pair matching and standard bootstrapping for “smoother” treatment effect estimators) dominate the asymptotic approximations in terms of coverage rates for both matching and weighting estimators. Most findings are robust across simulation designs and estimators.
Radiative electron capture in the first forbidden unique decay of 81Kr
Creators: name: Mianowski, S.
name: Werner-Malento, E.
name: Korgul, A.
name: Pomorski, M.
name: Pachucki, K.
name: Pfützner, M.
name: Szweryn, B.
name: Żylicz, J.
name: Hornshøj, P.
name: Nilsson, T.
name: Rykaczewski, K.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The photon spectrum accompanying the orbital K-electron capture in the first forbidden unique decay of 81Kr was measured. The total radiation intensity for the photon energies larger than 50 keV was found to be 1.47(6) x 10^{-4} per K-capture. Both the shape of the spectrum and its intensity relative to the ordinary, non-radiative capture rate, are compared to theoretical predictions. The best agreement is found for the recently developed model which employs the length gauge for the electromagnetic field.
description: 7 pages, 6 figures
Transformation-Kernel Estimation of Copula Densities
Creators: name: Wen, Kuangyu
name: Wu, Ximing
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Space Science
subject: Neuroscience
subject: Biotechnology
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics
subject: Marine Biology
subject: Inorganic Chemistry
subject: FOS: Chemical sciences

description: The standard kernel estimator of copula densities suffers from boundary biases and inconsistency due to unbounded densities. Transforming the domain of estimation into an unbounded one remedies both problems, but also introduces an unbounded multiplier that may produce erratic boundary behaviors in the final density estimate. We propose an improved transformation-kernel estimator that employs a smooth tapering device to counter the undesirable influence of the multiplier. We establish the theoretical properties of the new estimator and its automatic higher-order improvement under Gaussian copulas. We present two practical methods of smoothing parameter selection. Extensive Monte Carlo simulations demonstrate the competence of the proposed estimator in terms of global and tail performance. Two real-world examples are provided. Supplementary materials for this article are available online.
The sequence of low and high mass star formation in the young stellar cluster IRAS 19343+2026
Creators: name: Ojha, D. K.
name: Kumar, M. S. N.
name: Davis, C. J.
name: Grave, J. M. C.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: BVRIJHK photometry, Spitzer-GLIMPSE photometry and HK band spectroscopy were used to study the stellar content of IRAS 19343+2026, a (proto)star/cluster candidate, located close to the Galactic plane. The data suggest that IRAS 19343+2026 is a rich cluster associated with a massive protostar of 7.6 Msol with an age of ~ 10^5 yr. Three point sources in the vicinity of the far-infrared (FIR) peak are also found to be early B type stars. The remaining (predominantly low mass) members of the cluster are best represented by a 1 - 3 Myr pre-main-sequence (PMS) population. HK band spectra of two bright and five faint point sources in the cluster confirm that the results obtained from the photometry are good representations of their young stellar object (YSO) nature. Thus, IRAS 19343+2026 is a young cluster with at least four early B-type stars classified as young (10^4 - 10^5 yr), that are surrounded by a somewhat older (1 - 3 Myr) population of low mass YSOs. Together, these results argue for a scenario in which low mass stars form prior to massive stars in a cluster forming environment. We compute the Initial Mass Function (IMF) for this cluster using the K-band luminosity function; the slope of the IMF is shallower than predicted by the Salpeter's mass function. The cluster mass, Mtot, is estimated to be in the range ~ 307 Msol (from the data completeness limit) - 585 Msol (extrapolated down to the brown dwarf limit, assuming a certain IMF).
description: 24 pages, 9 figures. Accepted for publication in the MNRAS.
Gravitationally induced inhibitions of dispersion according to the Schrödinger-Newton Equation
Creators: name: Giulini, Domenico
name: Großardt, André
Publisher: name: arXiv
Year: 2011
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences
subject: 35Q40

description: We re-consider the time dependent Schrödinger-Newton equation as a model for the self-gravitational interaction of a quantum system. We numerically locate the onset of gravitationally induced inhibitions of dispersion of Gaussian wave packets and find them to occur at mass values more than 6 orders of magnitude higher than reported by Salzman and Carlip (2006, 2008), namely at about $10^{10}\,\mathrm{u}$. This fits much better to simple analytical estimates but unfortunately also questions the experimental realisability of the proposed laboratory test of quantum gravity in the foreseeable future, not just because of large masses, but also because of the need to provide sufficiently long coherence times.
description: 19 pages, 7 figures
Volatility Martingale Difference Divergence Matrix and Its Application to Dimension Reduction for Multivariate Volatility
Creators: name: Lee, Chung Eun
name: Shao, Xiaofeng
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Cell Biology
subject: Physiology
subject: FOS: Biological sciences
subject: Evolutionary Biology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified
subject: 80699 Information Systems not elsewhere classified
subject: FOS: Computer and information sciences
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics
subject: Cancer
subject: Science Policy
subject: 110309 Infectious Diseases
subject: FOS: Health sciences

description: In this article, we propose the so-called volatility martingale difference divergence matrix (VMDDM) to quantify the conditional variance dependence of a random vector Y∈Rp given X∈Rq, building on the recent work on martigale difference divergence matrix (MDDM) that measures the conditional mean dependence. We further generalize VMDDM to the time series context and apply it to do dimension reduction for multivariate volatility, following the recent work by Hu and Tsay and Li et al. Unlike the latter two papers, our metric is easy to compute, can fully capture nonlinear serial dependence and involves less user-chosen numbers. Furthermore, we propose a variant of VMDDM and apply it to the estimation of conditional uncorrelated components model (Fan, Wang, and Yao 2008). Simulation and data illustration show that our method can perform well in comparison with the existing ones with less computational time, and can outperform others in cases of strong nonlinear dependence.
Liposomal-encapsulated enzymes can be delivered to and modify platelet function ex vivo
Creators: name: Chan, Vivienne Wai Tung
Publisher: name: University of British Columbia
Year: 2018

description: Platelets are small, anucleate blood cells that are important mediators of many physiological and pathological processes. These include hemostasis, thrombosis, wound healing, inflammation, immunity, and malignancy. There are currently several uses for platelet therapy in the clinic, such as to increase platelet counts for the prevention of spontaneous bleeding, and to stop uncontrolled bleeding during trauma and surgery. Although platelet transfusions are an efficacious component in preventing and stopping bleeding in most cases, they are still insufficient to stop the most severe cases of surgical and traumatic bleeding. Traumatic bleeding is further complicated by trauma-induced coagulopathy, which often presents with platelet dysfunction and is not corrected by transfusions of normal platelets. Strategies to enhance the endogenous function of platelets to increase the efficacy of platelet transfusions has not been rigorously explored, especially during active bleeding in trauma-induced coagulopathy. When activated by specific stimuli, platelets locally secrete a variety of biologically active molecules in order to contribute to many physiological and pathophysiological processes. For example, platelets can recognize areas of vascular damage and respond by locally adhering, aggregating, and activating to initiate primary hemostasis. Platelets also release procoagulant molecules and mediate the formation of active coagulation factor complexes to ultimately form an insoluble fibrin clot and seal the wound. Taken together, developing strategies to modify the endogenous function of platelets may be a first step towards a platform system that could target many diseases. Moreover, strategies to load platelets with biomolecules could allow for the local delivery of therapeutics to disease sites using endogenous platelet machinery. This provides significant motivation to test our overarching hypothesis, that the endogenous function of platelets can be modified ex vivo through the delivery of liposome-encapsulated enzymes. The objectives of this thesis were to: i) develop a platform approach to deliver biomolecules to platelets, ii) engineer anucleate platelets to transcribe RNA, and iii) increase the coagulability of transfusable platelets. The results shown here demonstrate proof-of-concept that endogenous platelet function can be extended through the delivery of lipid-encapsulated enzymes, and provides new approaches to potentially enhancing current platelet transfusions.
MPEC 2023-X159 : 2023 XT4
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2023 XT4

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
A network model with structured nodes
Creators: name: Frisco, P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Social and Information Networks (cs.SI)
subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Physics and Society (physics.soc-ph)
subject: Molecular Networks (q-bio.MN)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: We present a network model in which words over a specific alphabet, called {\it structures}, are associated to each node and undirected edges are added depending on some distance between different structures. It is shown that this model can generate, without the use of preferential attachment or any other heuristic, networks with topological features similar to biological networks: power law degree distribution, clustering coefficient independent from the network size, etc. Specific biological networks ({\it C. Elegans} neural network and {\it E. Coli} protein-protein interaction network) are replicated using this model.
description: match MRSA gene network not present because MRSA gene network still unpublished
Gas and Dust Toward DG Tau B and VV CrA
Creators: name: Kruger, Andrew J.
name: Richter, Matthew J.
name: Carr, John S.
name: Najita, Joan R.
name: Doppmann, Greg W.
name: Seifahrt, Andreas
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present findings for DG Tau B and VV CrA, two of the objects observed in our Spitzer IRS project to search for molecular absorption in edge-on disks, along with near-IR spectroscopy of the CO fundamental transitions and mid-IR imaging. While the only gas absorption seen in the Spitzer IRS spectrum toward DG Tau B is CO$_{2}$, we use gas abundances and gas/ice ratios to argue that we are probing regions of the disk that have low organic molecule abundances. This implies the rarity of detecting molecular absorption toward even edge-on disks with Spitzer IRS is a result of high dependence on the line of sight. We also argue the disk around DG Tau B shows high amounts of grain growth and settling. For VV CrA, we use the silicate absorption feature to estimate a dust extinction, and model the disk with a spectral energy distribution fitting tool to give evidence in support of the disk geometry presented by Smith et al. (2009) where the Primary disk is the main source of extinction toward the infrared companion.
description: 29 pages, 11 figures, 9 tables. Accepted for publication in Astrophysical Journal
MPEC 2023-X160 : 2023 XU4
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2023 XU4

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Glassy Dislocation Dynamics in 2-D Colloidal Dimer Crystals
Creators: name: Gerbode, Sharon J.
name: Agarwal, Umang
name: Ong, Desmond C.
name: Liddell, Chekesha M.
name: Escobedo, Fernando
name: Cohen, Itai
Publisher: name: arXiv
Year: 2010
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Although glassy relaxation is typically associated with disorder, here we report on a new type of glassy dynamics relating to dislocations within 2-D crystals of colloidal dimers. Previous studies have demonstrated that dislocation motion in dimer crystals is restricted by certain particle orientations. Here, we drag an optically trapped particle through such dimer crystals, creating dislocations. We find a two-stage relaxation response where initially dislocations glide until encountering particles that cage their motion. Subsequent relaxation occurs logarithmically slowly through a second process where dislocations hop between caged configurations. Finally, in simulations of sheared dimer crystals, the dislocation mean squared displacement displays a caging plateau typical of glassy dynamics. Together, these results reveal a novel glassy system within a colloidal crystal.
description: 4 pages + 2 page supp. mat
Strain distribution in GaN/AlN superlattices grown on AlN/sapphire templates: comparison of X-ray diffraction and photoluminescence studies
Creators: name: Wierzbicka, Aleksandra
name: Kaminska, Agata
name: Sobczak, Kamil
name: Jankowski, Dawid
name: Koronski, Kamil
name: Strak, Pawel
name: Sobanska, Marta
name: Zytkiewicz, Zbigniew R.
Publisher: name: arXiv
Year: 2025
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Series of GaN/AlN superlattices (SLs) with various periods and the same thicknesses of GaN quantum wells and AlN barriers have been investigated. X-ray diffraction, photoluminescence (PL) and transmission electron microscopy (TEM) techniques were used to study the influence of thickness of AlN and GaN sublayers on strain distribution in GaN/AlN SL structures. Detailed X-ray diffraction measurements demonstrate that the strain occurring in SLs generally decreases with an increase of well/barrier thickness. Fitting of X-ray diffraction curves allowed determining the real thicknesses of the GaN wells and AlN barriers. Since blurring of the interfaces causes deviation of calculated data from experimental results the quality of the interfaces has been evaluated as well and compared with results of TEM measurements. For the samples with thinner wells/barriers the presence of pin-holes and threading dislocations has been observed in TEM measurements. The best quality of interfaces has been found for the sample with a well/barrier thickness of 3 nm. Finally, PL spectra showed that due to Quantum-Confined Stark Effect the PL peak energies of the SLs decreased with increasing the width of the GaN quantum wells and AlN barriers. The effect is well modelled by ab initio calculations based on the density functional theory applied for tetragonally strained structures of the same geometry using a full tensorial representation of the strain in the SLs.
Higher secants of spinor varieties
Creators: name: Angelini, Elena
Publisher: name: arXiv
Year: 2010
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 15A66, 14M17, 14Q99

description: Let $S_h$ be the even pure spinors variety of a complex vector space $V$ of even dimension $2h$ endowed with a non degenerate quadratic form $Q$ and let $σ_k(S_h) $ be the $k$-secant variety of $S_h$. We decribe a probabilistic algorithm which computes the complex dimension of $σ_k(S_h) $. Then, by using an inductive argument, we get our main result: $σ_3(S_h) $ has the expected dimension except when $h\in \{7,8\} $. Also we provide theoretical arguments which prove that $S_7$ has a defective 3-secant variety and $S_8$ has defective 3-secant and 4-secant varieties.
description: 23 pages
Development of GaN-based devices for high power and high frequency electronics
Creators: name: Taube, Andrzej
Publisher: name: Zenodo
Year: 2021
Subjects: GaN
high frequency electronics
high power electronics

description: GaN-based devices, due to the excellent electrical properties of gallium nitride and related materials, such as the high value of the critical electric field, wide bandgap, and high mobility and saturation velocity of two-dimensional electron gas carriers in AlGaN/GaN quantum wells, are widely used in high-power and high-frequency electronics. In this work we present the results of development of GaN-based transistor both for high power and microwave electronics carried out at Lukasiewicz Research Network-Institute of Microelectronics and Photonics. We have developed key technological steps i.e. regrown ohmic contacts for devices on bulk semi-insulating GaN substrates, selective etching of p-GaN layers over AlGaN, deposition of proper passivation layer as well as thermally stable isolation of adjacent devices using selective Fe+ ion implantation, which were integrated in the process flow of manufacturing of high power transistors. We have shown measurements of developed microwave transistors on bulk GaN substrates as well as normally-off p-GaN gate AlGaN/GaN HEMT power transistors assembled using in-house developed process in TO-220 package. Finally, ongoing works on development of vertical GaN power transistors will be presented.
Nonlinear supratransmission in multicomponent systems
Creators: name: Anghel-Vasilescu, P.
name: Dorignac, J.
name: Geniet, F.
name: Leon, J.
name: Taki, M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: A method is proposed to solve the challenging problem of determining the supratransmission threshold (onset of instability of harmonic boundary driving inside a band gap) in multicomponent nonintegrable nonlinear systems. It is successfully applied to the degenerate three-wave resonant interaction in a birefringent quadratic medium where the process generates spatial gap solitons. No analytic expression is known for this model showing the broad applicability of the method to nonlinear systems.
description: 4 pages, 3 figures
To what extent are movement behaviours associated with emotional well-being in grades four and five children? Results from the Optimizing Movement in Children Study
Creators: name: Reimer, Renée Christine
Publisher: name: University of British Columbia
Year: 2018

description: The potential mechanisms driving the optimal, healthy physical and psychological development of children have been studied extensively (Janssen et al., 2010; Milteer, Ginsburg, & Mulligan, 2012; Parfitt & Eston, 2005). Specific movement behaviours, including physical activity, sedentary time, and sleep have been studied independently to examine their influence on health outcomes. Emotional well-being, which encompasses a variety of psychological concepts including optimism, general self-concept, satisfaction with life, and sadness, is considered an important element in the healthy development of children (Guerra & Bradshaw, 2008). This study examined the extent to which four objectively-measured movement behaviours – light physical activity (LPA), moderate to vigorous physical activity (MVPA), sedentary time, and sleep – are associated with emotional well-being in a sample of grades four and five children (N = 21). This study had three objectives: 1) to examine independent associations between the four separate movement behaviours and emotional well-being, 2) to examine the relationship between one movement behaviour and emotional well-being relative to time spent in other movement behaviours using compositional analysis, and 3) to examine whether time spent in sedentary screen activities versus non-screen sedentary activities moderated the relationship between objectively-measured sedentary time and emotional well-being. For objective 1, among the independent Spearman correlations, only MVPA was significantly and positively correlated with emotional well-being (ρ = 0.77, p < 0.001). Using compositional analysis for objective 2, no significant relationships were found between any one of the four movement behaviours and emotional well-being relative to time spent in other movement behaviours. Finally, for objective 3, no significant moderating effects were found for time spent in sedentary screen time versus non-screen sedentary time on the relationship between objectively-measured sedentary time and emotional well-being. This study concluded that objectively-measured MVPA was significantly and positively associated with emotional well-being in the sample; however, future studies with a larger sample size are recommended, as these findings were limited by a small sample size.
Drying and deposition of poly(ethylene oxide) droplets determined by Péclet number
Creators: name: Baldwin, Kyle Anthony
name: Granjard, Manon
name: Willmer, David
name: Sefiane, Khellil
name: Fairhurst, David John
Publisher: name: arXiv
Year: 2011
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We report results of a detailed experimental investigation into the drying of sessile droplets of aqueous poly(ethylene oxide) (PEO) polymer solutions under various experimental conditions. Samples are prepared with a range of initial concentrations c_0 and are filtered to remove traces of undissolved PEO clusters. In typical experiments, droplets with initial volumes between 5\muL and 50\muL are left to evaporate while temperature and relative humidity are monitored. Droplets either form a disk-like solid "puddle" or a tall conical "pillar". The droplet mass is monitored using a microbalance and the droplet profile is recorded regularly using a digital camera. Subsequent processing of the data allows values of droplet volume V, surface area A, base radius R, contact angle θ and height h to be determined throughout drying. From this data we identify four stages during pillar formation: pinned drying; pseudo-dewetting; bootstrap building; solid contraction and propose physical models to explain key aspects of each stage and to predict the transition from each stage to the next. The experimental parameters of relative humidity, temperature, pressure, droplet volume and initial contact angle are all systematically varied and observed to influence the drying process and consequently whether the droplet forms a pillar or a puddle. We combine these parameters into a dimensionless Péclet number Pe, which compares the relative effects of evaporation and diffusion, and show that the drying behaviour is only dependent on c_0 and Pe.
description: 21 pages, 10 figures
Astrometric search for a planet around VB 10
Creators: name: Lazorenko, P. F.
name: Sahlmann, J.
name: Segransan, D.
name: Figueira, P.
name: Lovis, C.
name: Martin, E.
name: Mayor, M.
name: Pepe, F.
name: Queloz, D.
name: Rodler, F.
name: Santos, N.
name: Udry, S.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We observed VB 10 in August and September 2009 using the FORS2 camera of the VLT with the aim of measuring its astrometric motion and of probing the presence of the announced planet VB 10b. We used the published STEPS astrometric positions of VB 10 over a time-span of 9 years, which allowed us to compare the expected motion of VB 10 due to parallax and proper motion with the observed motion and to compute precise deviations. The achieved single-epoch precisions of our observations are about 0.1 mas and the data showed no significant residual trend, while the presence of the planet should have induced an apparent proper motion larger than 10 mas/yr. Subtraction of the predicted orbital motion from the observed data produces a large trend in position residuals of VB 10. We estimated the probability that this trend is caused by random noise. Taking all the uncertainties into account and using Monte-Carlo resampling of the data, we are able to reject the existence of VB 10b with the announced mass of 6.4 M_J with the false alarm probability of only 0.0005. A 3.2 M_J planet is also rejected with a false alarm probability of 0.023.
description: 6 pages, 6 figures, 2 tables, accepted for publication in A&A
Charge fluctuations for particles on a surface exposed to plasma
Creators: name: Sheridan, T. E.
name: Hayes, A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: We develop a stochastic model for the charge fluctuations on a microscopic dust particle resting on a surface exposed to plasma. We find in steady state that the fluctuations are normally distributed with a standard deviation that is proportional to $CT_{e})^{1/2}$, where $C$ is the particle-surface capacitance and $T_{e}$ is the plasma electron temperature. The time for an initially uncharged ensemble of particles to reach the steady state distribution is directly proportional to $CT_{e}$.
description: 9 pages, 3 figures