cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Pathway Specificity of Behavioral Timescale Synaptic Plasticity (BTSP) in the Prefrontal Cortex (PFC)
Creators: name: Alsayadi, Somayah
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2024
Subjects: Neuroscience
Synaptic Plasticity
Behavioral timescale synaptic plasticity
Prefrontal Cortex
Optogenetics

description: Modern theories of synaptic plasticity, central to understanding learning and memory, suggest that synapses undergo activity-dependent changes in strength. However, traditional models like spike-timing-dependent plasticity (STDP), with their reliance on nearly coincident and repetitive neural activity, fall short of capturing the extended temporal dynamics integral to behavioral learning. This discrepancy presents a notable challenge in synaptic plasticity research, often referred to as the "temporal credit assignment problem", which requires linking actions to outcomes that are temporally separated. Behavioral timescale synaptic plasticity (BTSP) was first discovered in the hippocampus and more recently in the prefrontal cortex of mice. Utilizing a combination of optogenetics and whole-cell electrophysiology experiments we sought to determine BTSP across pathway-specific inputs to layer 5 pyramidal neurons from key brain regions including the ventral hippocampus, basolateral amygdala, mediodorsal thalamus, and contralateral PFC. Our results reveal that BTSP can be selectively induced in the ventral hippocampus-PFC and mediodorsal thalamus-PFC pathways. Additionally, adjustments to ex vivo experimental conditions to mirror physiological calcium levels reveal the need for a Hebbian eligibility trace in order to induce plasticity. These findings pave the way for future research that bridges cellular mechanisms with behavioral outcomes, offering potential pathways for therapeutic interventions in conditions like Alzheimer's disease, where such synaptic mechanisms are disrupted.
Certain Resolvable Directed Cycle Decompositions of Directed Graphs
Creators: name: Lacaze-Masmonteil, Alice
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2024
Subjects: Directed graphs
Cycle decomposition
Resolvable
Oberwolfach
Graph products

description: In this thesis, we address two problems in cycle decompositions. In the first problem, we resolve the last outstanding case of the directed Oberwolfach problem with tables of uniform length. More specifically, we address the case with two tables of equal odd length. To do so, we construct a resolvable decomposition of the complete symmetric directed graph into two directed cycles of the same odd length. This affirms a conjecture of Burgess and Šajna (2014). In the second problem addressed in this thesis, we partially solve a conjecture on directed cycle decompositions of products of directed graphs. This conjecture stipulates that, given two directed graphs G and H that both admit a decomposition into directed hamiltonian cycles, the wreath (lexicographic) product of G with H can also be decomposed into directed hamiltonian cycles. This conjecture has been shown to be true when |V (G)| is odd and |V (H)|> 2 by Ng (1998). In this thesis, we assume that |V (G)| is even and show that this conjecture is true if |V (H)| is odd and |V (H)|> 3, or |V (H)| is even, |V (H)|> 2, and G is not a directed cycle. In addition, we show that, if G is a directed cycle, where |V (G)|> 2, and H is either a directed m-cycle with m ⩾ 4 even or H is the complete symmetric directed graph on m vertices such that m ⩾ 3, then the aforementioned conjecture is also true. Lastly, we show that this conjecture is false when G is a directed cycle of even length and H is a directed cycle of length 2 or 3.
Evaluating the burden of pruritus due to atopic dermatitis in Japan by patient-reported outcomes
Creators: name: Murota, Hiroyuki
name: Koike, Yuta
name: Ishii, Kanako
name: Calimlim, Brian M.
name: Ludwikowska, Maja
name: Toumi, Mondher
name: Kawaguchi, Isao
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: Developmental Biology
subject: Science Policy

description: Although pruritus is a hallmark feature of atopic dermatitis, no study has investigated the associated impact of pruritus, due to atopic dermatitis in Japan. The study aimed to evaluate the real-life burden of atopic dermatitis by pruritus severity in adult Japanese patients. The primary objective was to assess the correlation between pruritus severity and work productivity and activity impairment. A secondary objective was to characterize the impact of pruritus on quality of life and to evaluate the burden of symptoms severity and frequency. A cross-sectional internet-based survey was conducted. Eligible patients were currently employed and working adults with atopic dermatitis for at least 6 months. Stratification on pruritus severity assessed by the Worst Pruritus Numerical Rating Scale at the screening was performed to ensure that different severity groups are represented. Correlations were assessed using Spearman’s rank-order correlation coefficient. Multivariate regression analyses were performed to assess the impact of pruritus severity on work productivity and quality of life. The study analyzed 370 patients. Pruritus severity significantly correlated with work impairment (Rho = 0.622, P value (H0: Rho > 0.5) All data were self-reported by patients via an online survey, which is associated with the risk of misclassification for diagnosis, recall bias, and limited participation of patients. The study provides evidence that pruritus is associated with the overall disease burden and impacts many important life aspects of patients with atopic dermatitis in Japan.
Lingual Abscess Case Report 14.12.23.docx
Creators: name: Shehadeh, Rabie
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 320217
subject: Otorhinolaryngology

description: The case report discusses a young adult male presenting with a severe anterolateral lingual abscess, characterized by a painful, swollen tongue and difficulty breathing. Despite maintaining normal oxygen levels, urgent intervention was needed to prevent airway obstruction. The patient had no history of oral infections or relevant medical conditions. The diagnosis involved detailed clinical assessment, imaging with contrast-enhanced CT and ultrasonography, and collaboration with a maxillofacial surgeon. Treatment included surgical incision, drainage, and a course of antibiotics, leading to significant improvement and successful resolution. The case underscores the importance of prompt diagnosis, precise diagnostic techniques, and a multidisciplinary approach for optimal patient outcomes.
การประเมินลักษณะทนแล้งใน chromosome substitution lines (CSSL) ของข้าวขาวดอกมะลิ 105 ในระยะออกดอก (The Evaluation of Some Drought Stress Tolerance Phenotypes in Chromosome Substitution
Lines (CSSL) of KhaoDok Mali 105 Rice (Oryza sativa  L.
Creators: name: วราลักษณ์ เกษตรานันท์
Publisher: name: Genetics Society of Thailand
Year: 2013
Subjects: rice, drought, leaf water potential, cell membrane stability, stay green phenotype

description: S1 (Special Issue 1), S.1, Thai Journal of Genetics
Transcorrelated coupled cluster methods
Creators: name: Schraivogel, Thomas
name: Cohen, Aron J.
name: Alavi, Ali
name: Kats, Daniel
Publisher: name: arXiv
Year: 2021
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Transcorrelated coupled cluster and distinguishable cluster methods are presented. The Hamiltonian is similarity transformed with a Jastrow factor in the first quantisation, which results in up to three-body integrals. The coupled cluster with singles and doubles equations on this transformed Hamiltonian are formulated and implemented. It is demonstrated that the resulting methods have a superior basis set convergence and accuracy to the corresponding conventional and explicitly correlated methods. Additionally, approximations for three-body integrals are suggested and tested.
การโคลนและศึกษาคุณสมบัติของยีน OSB2 ซึ่งควบคุมการสังเคราะห์แอนโทไซยานินในข้าว (Cloning and Characterization of OSB2 Gene Controlling Anthocyanin Biosynthesis in Rice)
Creators: name: พูนศรี อินต๊ะ
Publisher: name: Genetics Society of Thailand
Year: 2013
Subjects: OSB2 gene, rice, anthocyanin

description: S1 (Special Issue 1), S.1, Thai Journal of Genetics
Strong Convergence towards homogeneous cooling states for dissipative Maxwell models
Creators: name: Carlen, Eric A.
name: Carrillo, Jose A.
name: Carvalho, Maria C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 82C40, 35B40

description: We show the propagation of regularity, uniformly in time, for the scaled solutions of the inelastic Maxwell model for small inelasticity. This result together with the weak convergence towards the homogenous cooling state present in the literature implies the strong convergence in Sobolev norms and in the $L^1$ norm towards it depending on the regularity of the initial data. The strategy of the proof is based on a precise control of the growth of the Fisher information for the inelastic Boltzmann equation. Moreover, as an application we obtain a bound in the $L^1$ distance between the homogeneous cooling state and the corresponding Maxwellian distribution vanishing as the inelasticity goes to zero.
description: 2 figures
A Conversation with Peter Huber
Creators: name: Buja, Andreas
name: Künsch, Hans R.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Peter J. Huber was born on March 25, 1934, in Wohlen, a small town in the Swiss countryside. He obtained a diploma in mathematics in 1958 and a Ph.D. in mathematics in 1961, both from ETH Zurich. His thesis was in pure mathematics, but he then decided to go into statistics. He spent 1961--1963 as a postdoc at the statistics department in Berkeley where he wrote his first and most famous paper on robust statistics, ``Robust Estimation of a Location Parameter.'' After a position as a visiting professor at Cornell University, he became a full professor at ETH Zurich. He worked at ETH until 1978, interspersed by visiting positions at Cornell, Yale, Princeton and Harvard. After leaving ETH, he held professor positions at Harvard University 1978--1988, at MIT 1988--1992, and finally at the University of Bayreuth from 1992 until his retirement in 1999. He now lives in Klosters, a village in the Grisons in the Swiss Alps. Peter Huber has published four books and over 70 papers on statistics and data analysis. In addition, he has written more than a dozen papers and two books on Babylonian mathematics, astronomy and history. In 1972, he delivered the Wald lectures. He is a fellow of the IMS, of the American Association for the Advancement of Science, and of the American Academy of Arts and Sciences. In 1988 he received a Humboldt Award and in 1994 an honorary doctorate from the University of Neuchâtel. In addition to his fundamental results in robust statistics, Peter Huber made important contributions to computational statistics, strategies in data analysis, and applications of statistics in fields such as crystallography, EEGs, and human growth curves.
description: Published in at http://dx.doi.org/10.1214/07-STS251 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Double quantum dot as detector of spin bias
Creators: name: Sun, Qing-feng
name: Xing, Yanxia
name: Shen, Shun-Qing
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: It was proposed that a double quantum dot can be used to be a detector of spin bias. Electron transport through a double quantum dot is investigated theoretically when a pure spin bias is applied on two conducting leads contacted to the quantum dot. It is found that the spin polarization in the left and right dots may be induced spontaneously while the intra-dot levels are located within the spin bias window and breaks the left-right symmetry of the two quantum dots. As a result, a large current emerges. For an open external circuit an charge bias instead of a charge current will be induced in equilibrium, which is believed to be measurable according to the current nanotechnology. This method may provide a practical and whole electrical approach to detect the spin bias (or the spin current) by measuring the charge bias or current in a double quantum dot.
description: 13 pages, 5 figures
Vortex: Extending the RISC-V ISA for GPGPU and 3D-GraphicsResearch
Creators: name: Tine, Blaise
name: Elsabbagh, Fares
name: Yalamarthy, Krishna
name: Kim, Hyesoon
Publisher: name: arXiv
Year: 2021
Subjects: subject: Hardware Architecture (cs.AR)
subject: FOS: Computer and information sciences

description: The importance of open-source hardware and software has been increasing. However, despite GPUs being one of the more popular accelerators across various applications, there is very little open-source GPU infrastructure in the public domain. We argue that one of the reasons for the lack of open-source infrastructure for GPUs is rooted in the complexity of their ISA and software stacks.In this work, we first propose an ISA extension to RISC-V that supports GPGPUs and graphics. The main goal of the ISA extension proposal is to minimize the ISA changes so that the corresponding changes to the open-source ecosystem are also minimal, which makes for a sustainable development ecosystem. To demonstrate the feasibility of the minimally extended RISC-V ISA, we implemented the complete software and hardware stacks of Vortex on FPGA. Vortex is a PCIe-based soft GPU that supports OpenCL and OpenGL.Vortex can be used in a variety of applications, including machine learning, graph analytics, and graphics rendering. Vortex can scale up to 32 cores on an Altera Stratix 10 FPGA, delivering a peak performance of 25.6 GFlops at 200 Mhz.
Ascending-descending and direct-inverse cascades of Reynolds stresses in turbulent Couette flow
Creators: name: Chiarini, Alessandro
name: Mauriello, Mariadebora
name: Gatti, Davide
name: Quadrio, Maurizio
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The interaction between small- and large-scale structures, and the coexisting bottom-up and top-down processes are studied in a turbulent plane Couette flow, where space-filling longitudinal rolls appear at relatively low values of the Reynolds number $Re$. A DNS database at $Re_τ=101$ is built to replicate the highest $Re$ considered in a recent experimental work by Kawata and Alfredsson (Phys. Rev. Lett., vol.120, 2018, 244501). Our study is based on the exact budget equations for the second-order structure function tensor $\langle δu_i δu_j \rangle$, i.e. the Anisotropic Generalized Kolmogorov Equations (AGKE). The AGKE study production, redistribution, transport and dissipation of every Reynolds stress tensor component, considering simultaneously the physical space and the space of scales, and properly define the concept of scale in the inhomogeneous wall-normal direction. We show how the large-scale energy-containing motions are involved in the production and redistribution of the turbulent fluctuations. Both bottom-up and top-down interactions occur, and the same is true for direct and inverse cascading. The wall-parallel components $\langle δu δu \rangle$ and $\langle δw δw \rangle$ show that the both small and large near-wall scales feed the large scales away from the wall. The wall-normal component $\langle δv δv \rangle$ is different, and shows a dominant top-down dynamics, being produced via pressure-strain redistribution away from the wall and transferred towards near-wall larger scales via an inverse cascade. The off-diagonal component shows a top-down interaction, with both direct and inverse cascade, albeit the latter takes place within a limited range of scales.
Two elementary proofs of the Wigner theorem on symmetry in quantum mechanics
Creators: name: Simon, R.
name: Mukunda, N.
name: Chaturvedi, S.
name: Srinivasan, V.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In quantum theory, symmetry has to be defined necessarily in terms of the family of unit rays, the state space. The theorem of Wigner asserts that a symmetry so defined at the level of rays can always be lifted into a linear unitary or an antilinear antiunitary operator acting on the underlying Hilbert space. We present a proof of this theorem which is both elementary and economical. Central to our proof is the recognition that a given Wigner symmetry can, by post-multiplication by a unitary symmetry, be taken into either the identity or complex conjugation. Our analysis involves a judicious interplay between the effect a given Wigner symmetry has on certain two-dimensional subspaces and the effect it has on the entire Hilbert space.
description: A second proof of Wigner's theorem added and, consequently, the title slightly changed. 8 pages, Latex, no figures
Beam coupling in holograms stored in LiNbO₃
Creators: name: Woods, Randall J.
Publisher: name: University of British Columbia
Year: 2010

description: The potential use of photorefractive crystals in optical data handling applications has received considerable attention during the past decade. The photorefractive effect in LiNbO₃:Fe involves the photoliberation and inhomo-geneous redistribution of electrons which are subsequently trapped in the new distribution. The resulting electric fields set up a similar distribution of variations in the refractive index allowing the formation of thick phase holograms. In the case of an elementary hologram (that written by a simple interference pattern between two equal intensity beams of monochromatic light), the holographic grating may be displaced from the fringe pattern that wrote it. This phase shift gives rise to a redistribution of energy between the two beams, called beam coupling. Measurements of the beam coupling can be used to obtain a value for the phase shift, and this in turn is useful in studying the electron transport mechanisms which give rise to the shift. Previous attempts to measure the beam coupling have not yielded reproducible results and have consequently not been very useful in determining the phase shift or studying it causes. The present set of experiments have shown that the phase shift is not constant in time during the writing process, and repeated measurements as the hologram was written showed that this variation is a linear function of time for any particular experiment. The causes of this variation can be attributed to the nature of the writing process, thermal expansion and mechanical creep of the optical components. Repeated experiments showed that the value of the shift extrapolated to t=0 of the writing process was a constant for the crystal used. Because the holograms were written under conditions which made the bulk photovoltaic effect the dominant process, it was possible to calculate the transport length due to this effect. The value arrived at was 13±3 nm.
Searching for Dark Matter with X-ray Observations of Local Dwarf Galaxies
Creators: name: Jeltema, Tesla E.
name: Profumo, Stefano
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A generic feature of weakly interacting massive particle (WIMP) dark matter models is the emission of photons over a broad energy band resulting from the stable yields of dark matter pair annihilation. Inverse Compton scattering off cosmic microwave background photons of energetic electrons and positrons produced in dark matter annihilation is expected to produce significant diffuse X-ray emission. Dwarf galaxies are ideal targets for this type of dark matter search technique, being nearby, dark matter dominated systems free of any astrophysical diffuse X-ray background. In this paper, we present the first systematic study of X-ray observations of local dwarf galaxies aimed at the search for WIMP dark matter. We outline the optimal energy and angular ranges for current telescopes, and analyze the systematic uncertainties connected to electron/positron diffusion. We do not observe any significant X-ray excess, and translate this null result into limits on the mass and pair annihilation cross section for particle dark matter. Our results indicate that X-ray observations of dwarf galaxies currently constrain dark matter models at the same level or even more strongly than gamma-ray observations of the same systems, although at the expenses of introducing additional assumptions and related uncertainties in the modeling of diffusion and energy loss processes. The limits we find constrain portions of the supersymmetric parameter space, particularly if the effect of dark matter substructures is included. Finally, we comment on the role of future X-ray satellites (e.g. Constellation-X, XEUS) and on their complementarity with GLAST and other gamma-ray telescopes in the quest for particle dark matter.
description: 30 pages, 5 figures; accepted for publication in ApJ
Combining Unoccupied Aerial Vehicles and Satellite Multispectral Data to Improve Mapping of Intertidal Seaweed Habitats
Creators: name: Borges, Débora
name: Gonçalves, José Alberto
name: Sousa-Pinto, Isabel
name: Giusti, Andrea
name: Valente, André
Publisher: name: Zenodo
Year: 2025
Subjects: subject: Seaweed
subject: Atlantic Living Lab

description: Seaweed assemblages are essential components of coastal ecosystems, providing numerous ecological, economic, and social benefits. Unoccupied Aerial Vehicles (UAV) with different sensors, have been increasingly applied in the recent years to locally map seaweed coverage and habitats. Satellite multispectral data, on the other hand, covers wide areas but has coarser resolutions which limits their use in the narrow and complex intertidal zones. Our methodology combines high-resolution UAV multispectral data, in situ precise georeferencing and lower-resolution Sentinel 2 imagery from Copernicus to provide improved spatial estimates of intertidal seaweed habitats over larger areas.
title: U.S. Seaports Face Elevated Risks in a Warmer World with Higher Seas
Creators: name: Goodman, Samuel
name: Carlson, Dylan
Publisher: name: United States International Trade Commission
publisherIdentifier: https://ror.org/05hsggr76
publisherIdentifierScheme: ROR
Year: 2022

description: U.S. commercial maritime ports will likely face substantial challenges associated with climate change
throughout this century. If the effects of rising sea levels and increased temperatures increasingly stall
port operations or cause infrastructure deterioration, they can pose a risk to trade flows. This Executive
Briefing on Trade examines a recent set of climate change projections, focusing on continental U.S.-
specific trends that pose the greatest risks to seaports.
Conjugate Hard X-ray Footpoints in the 2003 October 29 X10 Flare: Unshearing Motions, Correlations, and Asymmetries
Creators: name: Liu, Wei
name: Petrosian, Vahe
name: Dennis, Brian R.
name: Holman, Gordon D.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a detailed imaging and spectroscopic study of the conjugate hard X-ray (HXR) footpoints (FPs) observed with RHESSI in the 2003 October 29 X10 flare. The double FPs first move toward and then away from each other, mainly parallel and perpendicular to the magnetic neutral line, respectively. The transition of these two phases of FP unshearing motions coincides with the direction reversal of the motion of the loop-top (LT) source, and with the minima of the estimated loop length and LT height. The FPs show temporal correlations between HXR flux, spectral index, and magnetic field strength. The HXR flux exponentially correlates with the magnetic field strength, which also anti-correlates with the spectral index before the second HXR peak's maximum, suggesting that particle acceleration sensitively depends on the magnetic field strength and/or reconnection rate. Asymmetries are observed between the FPs: on average, the eastern FP is 2.2 times brighter in HXR flux and 1.8 times weaker in magnetic field strength, and moves 2.8 times faster away from the neutral line than the western FP; the estimated coronal column density to the eastern FP from the LT source is 1.7 times smaller. The two FPs have marginally different spectral indexes. The eastern-to-western FP HXR flux ratio and magnetic field strength ratio are anti-correlated only before the second HXR peak's maximum. Neither magnetic mirroring nor column density alone can explain the totality of these observations, but their combination, together with other transport effects, might provide a full explanation. We have also developed novel techniques to remove particle contamination from HXR counts and to estimate effects of pulse pileup in imaging spectroscopy, which can be applied to other RHESSI flares in similar circumstances.
description: 22 pages, 14 figures, 4 tables; ApJ 2009, in press
The biology and impact of the lodgepole terminal weevil in the Cariboo Forest Region
Creators: name: Maher, T. F.
Publisher: name: University of British Columbia
Year: 2010

description: The objectives of this study were to define the life history of the lodgepole terminal weevil (Pissodes terminalis Hopping) in the Cariboo Forest Region, to quantify the magnitude of damage resulting from weevil attacks, and to determine if P. terminalis activity was associated with measurable tree and stand parameters such as leader dimensions and density. Four study plots in juvenile lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) stands near Riske Creek, B. C. were selected to provide data on the biology of the lodgepole terminal weevil. In each plot, weekly collections of 10 weevil-attacked terminal shoots were made from June 3 to August 29, 1980, and monthly collections were taken during September through November. All leaders were dissected and the numbers of each P. terminalis life stage and associated predators/parasitiods were recorded. Seventy-one survey plots in lodgepole pine stands between 8 and 29 years of age throughout the Cariboo Forest Region were assessed for weevil activity. Each survey plot contained 25 trees over 2 metres in height, and each tree was measured for height, diameter at breast height, leader length, and basal leader diameter. Stand age, elevation, density, and all weevil attacks (including year of attack and type of resultant stem deformity) were also recorded. Weevil development appeared to be fairly uniform regardless of stand density and/or elevation; therefore, the data from all four biology study plots were combined to construct a life history diagram. In 46% of the survey plots one or both of the leader dimensions was significantly greater for attacked trees as compared to unattacked trees. In 28% of the plots attacked trees were either significantly taller or larger in diameter. Over 50% of the trees in stands of less than 4,000 stems per hectare had been attacked by P. terminalis at least once. Severe stem deformities such as forks and "stag-heads" comprised a larger proportion of damaged trees in the lower stand density classes. Weevil activity appeared to be higher in 1980 than in 1979. It was concluded that the lodgepole terminal weevil is currently a widely distributed and serious pest of young lodgepole pine stands in the Cariboo Forest Region. Given the present levels of weevil-caused damage as well as the possibility of future attacks, it was recommended that the activity of P. terminalis be considered when silvicultural practices such as juvenile spacing are undertaken in these stands.
Spectroscopic Confirmation of Faint Lyman Break Galaxies at Redshifts Four and Five in the Hubble Ultra Deep Field
Creators: name: Rhoads, James E.
name: Malhotra, Sangeeta
name: Pirzkal, Norbert
name: Dickinson, Mark
name: Cohen, Seth
name: Grogin, Norman
name: Hathi, Nimish
name: Xu, Chun
name: team, the PEARS
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the faintest spectroscopically confirmed sample of redshift four and five Lyman break galaxies to date. The sample is based on slitless grism spectra of the Hubble Ultra Deep Field region from the GRAPES (Grism ACS Program for Extragalactic Science) and PEARS (Probing Evolution and Reionization Spectroscopically) projects, using the G800L grism on the HST Advanced Camera for Surveys. We report here confirmations of 39 galaxies, pre-selected as candidate Lyman break galaxies using photometric selection criteria. We compare a "traditional" V-dropout selection to a more liberal one (with V-i > 0.9), and find that the traditional criteria are about 64% complete and 81% reliable. We also study the Lyman alpha emission properties of our sample. We find that Lyman alpha emission is detected in about 1/4 of the sample, and that our broad-band color selected sample includes 55% of previously published line-selected Lyman alpha sources. Finally, we examine our stacked 2D spectra. We demonstrate that strong, spatially extended (arcsecond scale) Lyman alpha emission is not a generic property of these Lyman break galaxies, but that a modest extension of the Lyman alpha photosphere (compared to the starlight) may be present in those galaxies with prominent Lyman alpha emission.
description: Submitted to The Astrophysical Journal. Reduced spectra from both GRAPES and PEARS are available from STScI, at http://www.stsci.edu/science/grapes/ and at http://archive.stsci.edu/prepds/pears/
The Early Statistical Years: 1947--1967 A Conversation with Howard Raiffa
Creators: name: Fienberg, Stephen E.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Howard Raiffa earned his bachelor's degree in mathematics, his master's degree in statistics and his Ph.D. in mathematics at the University of Michigan. Since 1957, Raiffa has been a member of the faculty at Harvard University, where he is now the Frank P. Ramsey Chair in Managerial Economics (Emeritus) in the Graduate School of Business Administration and the Kennedy School of Government. A pioneer in the creation of the field known as decision analysis, his research interests span statistical decision theory, game theory, behavioral decision theory, risk analysis and negotiation analysis. Raiffa has supervised more than 90 doctoral dissertations and written 11 books. His new book is Negotiation Analysis: The Science and Art of Collaborative Decision Making. Another book, Smart Choices, co-authored with his former doctoral students John Hammond and Ralph Keeney, was the CPR (formerly known as the Center for Public Resources) Institute for Dispute Resolution Book of the Year in 1998. Raiffa helped to create the International Institute for Applied Systems Analysis and he later became its first Director, serving in that capacity from 1972 to 1975. His many honors and awards include the Distinguished Contribution Award from the Society of Risk Analysis; the Frank P. Ramsey Medal for outstanding contributions to the field of decision analysis from the Operations Research Society of America; and the Melamed Prize from the University of Chicago Business School for The Art and Science of Negotiation. He earned a Gold Medal from the International Association for Conflict Management and a Lifetime Achievement Award from the CPR Institute for Dispute Resolution. He holds honorary doctor's degrees from Carnegie Mellon University, the University of Michigan, Northwestern University, Ben Gurion University of the Negev and Harvard University. The latter was awarded in 2002.
description: Published in at http://dx.doi.org/10.1214/088342307000000104 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org)
New Aspects of Heterotic--F Theory Duality
Creators: name: Hayashi, Hirotaka
name: Tatar, Radu
name: Toda, Yukinobu
name: Watari, Taizan
name: Yamazaki, Masahito
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In order to understand both up-type and down-type Yukawa couplings, F-theory is a better framework than the perturbative Type IIB string theory. The duality between the Heterotic and F-theory is a powerful tool in gaining more insights into F-theory description of low-energy chiral multiplets. Because chiral multiplets from bundles /\^2 V and /\^2 V^x as well as those from a bundle V are all involved in Yukawa couplings in Heterotic compactification, we need to translate descriptions of all those kinds of matter multiplets into F-theory language through the duality. We find that chiral matter multiplets in F-theory are global holomorphic sections of line bundles on what we call covering matter curves. The covering matter curves are formulated in Heterotic theory in association with normalization of spectral surface, while they are where M2-branes wrapped on a vanishing two-cycle propagate in F-theory. Chirality formulae are given purely in terms of (possibly primitive) four-form flux. In order to complete the translation, the dictionary of the Heterotic--F theory duality has to be refined in some aspects. A precise map of spectral surface and complex structure moduli is obtained, and with the map, we find that divisors specifying the line bundles correspond precisely to codimension-3 singularities in F-theory.
description: 100 pages; v2. corrections in section 6.2; v4. an open problem on ramification points solved, and typos corrected (not in Nucl.Phys.)
Delving Deeper into the Tumultuous Lives of Galactic Dwarfs: Modeling Star Formation Histories
Creators: name: Orban, Chris
name: Gnedin, Oleg Y.
name: Weisz, Daniel R.
name: Skillman, Evan D.
name: Dolphin, Andrew E.
name: Holtzman, John A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The paucity of observed dwarf galaxies in the Local Group relative to the abundance of predicted dark matter halos remains one of the greatest puzzles of the LCDM paradigm. Solving this puzzle now requires not only matching the numbers of objects but also understanding the details of their star formation histories. We present a summary of such histories derived from the HST data using the color-magnitude diagram fitting method. To reduce observational uncertainties, we condense the data into five cumulative parameters -- the fractions of stellar mass formed in the last 1, 2, 5, and 10 Gyr, and the mean stellar age. We interpret the new data with a phenomenological model based on the mass assembly histories of dark matter halos and the Schmidt law of star formation. The model correctly predicts the radial distribution of the dwarfs and the fractions of stars formed in the last 5 and 10 Gyr. However, in order to be consistent with the observations, the model requires a significant amount of recent star formation in the last 2 Gyr. Within the framework of our model, this prolonged star formation can be achieved by adding a stochastic variation in the density threshold of the star formation law. The model results are not sensitive to late gas accretion, the slope of the Schmidt law, or the details of cosmic reionization. A few discrepancies still remain: our model typically predicts too large stellar masses, only a modest population of ultra-faint dwarfs, and a small number of dwarfs with anomalously young stellar populations. Nevertheless, the observed star formation histories of Local Group dwarfs are generally consistent the expected star formation in cold dark matter halos.
description: 17 pages, 7 figures, 8 tables; version accepted by ApJ; includes new subsection with results from a redshift-dependent minimum density threshold for star formation
Spin Nernst effect and Nernst effect in two-dimensional electron systems
Creators: name: Cheng, Shu-guang
name: Xing, Yanxia
name: Sun, Qing-feng
name: Xie, X. C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We study the Nernst effect and the spin Nernst effect, that a longitudinal thermal gradient induces a transverse voltage and a spin current. A mesoscopic four-terminal cross-bar device having the Rashba spin-orbit interaction (SOI) under a perpendicular magnetic field is considered. For zero SOI, the Nernst coefficient peaks when the Fermi level crosses the Landau Levels. In the presence of the SOI, the Nernst peaks split, and the spin Nernst effect appears and exhibits a series of oscillatory structures. The larger SOI is or the weaker magnetic field is, the more pronounced the spin Nernst effect is. The results also show that the Nernst and spin Nernst coefficients are sensitive to the detailed characteristics of the sample and the contacts. In addition, the Nernst effect is found to survive in strong disorder than the spin Nernst effect does.
description: 5 pages, 5 figures
Chromospheric Activity, Rotation, and Rotational Braking in M and L Dwarfs
Creators: name: Reiners, Ansgar
name: Basri, Gibor
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present results from a high-resolution spectroscopic survey of 45 L dwarfs, which includes both very low-mass stars and brown dwarfs. Our spectra allow us to derive a significant number of new rotational velocities, and discover a slowly rotating (in projected velocity) L dwarf that allows more accurate measurement of spectroscopic rotations for these objects. We measure chromospheric activity (and often its variability) through the H$α$ emission line. Our primary new result is good evidence that magnetic braking dominates the angular momentum evolution of even brown dwarfs, although spindown times appear to increase as mass decreases. We confirm that activity decreases as effective temperature decreases, though a larger fraction of L dwarfs are active than has previously been reported. Essentially all active objects are also variable. We confirm the lack of a rotation-activity connection for L dwarfs. We find a minimum limit for rotational velocities that increases with later spectral types, rising from near zero in older mid-M stars to more than 20 km s$^{-1}$ for mid-L objects. There is strong evidence that all L dwarfs are rapid rotators. We derive a braking law that can depend on either temperature or mass which can explain all the rotational results and provides an age dependence for the angular momentum evolution. It is clear that angular momentum loss mechanisms in smaller and cooler objects become more inefficient starting at the fully convective boundary.
description: 19 pages, accepted for publication in ApJ
Non-Thermal Dark Matter from Cosmic Strings
Creators: name: Cui, Yanou
name: Morrissey, David E.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Cosmic strings can be created in the early universe during symmetry-breaking phase transitions, such as might arise if the gauge structure of the standard model is extended by additional U(1) factors at high energies. Cosmic strings present in the early universe form a network of long horizon-length segments, as well as a population of closed string loops. The closed loops are unstable against decay, and can be a source of non-thermal particle production. In this work we compute the density of WIMP dark matter formed by the decay of gauge theory cosmic string loops derived from a network of long strings in the scaling regime or under the influence of frictional forces. We find that for symmetry breaking scales larger than 10^10 GeV, this mechanism has the potential to account for the observed relic density of dark matter. For symmetry breaking scales lower than this, the density of dark matter created by loop decays from a scaling string network lies below the observed value. In particular, the cosmic strings originating from a U(1) gauge symmetry broken near the electroweak scale, that could lead to a massive Z' gauge boson observable at the LHC, produce a negligibly small dark matter relic density by this mechanism.
description: 22 pages, 4 figures, added discussion about boosted decay products from loop cusps
Investigation of the subsurface structure of a sunspot based on the spatial distribution of oscillation centers inferred from umbral flashes
Creators: name: Cho, Kyuhyoun
name: Chae, Jongchul
name: Madjarska, Maria S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The subsurface structure of a solar sunspot is important in the stability of the sunspots and the energy transport therein. Two subsurface structure models have been proposed, the monolithic and cluster models, but no clear observational evidence supporting a particular model has been found so far. To obtain clues about the subsurface structure of sunspots, we analyzed umbral flashes in merging sunspots registered by IRIS Mg II 2796 Angstrom slit-jaw images (SJIs). Umbral flashes are regarded as an observational manifestation of magnetohydrodynamic (MHD) shock waves originating from convection cells below the photosphere. By tracking the motion of individual umbral flashes, we determined the position of the convection cells that are the oscillation centers located below the umbra. We found that the oscillation centers are preferentially located at dark nuclei in the umbral cores rather than in bright regions such as light bridges or umbral dots. Moreover, the oscillation centers tend to deviate from the convergent interface of the merging sunspots where vigorous convection is expected to occur. We also found that the inferred depths of the convection cells have no noticeable regional dependence. These results suggest that the subsurface of the umbra is an environment where convection can occur more easily than the convergent interface, and hence support the cluster model. For more concrete results, further studies based on umbral velocity oscillations in the lower atmosphere are required.
description: 13 pages, 8 figures. Accepted for publication in A&A
Inuit Perspectives in and on "Arctic Show Trials"
Creators: name: Angnakak, Sharon
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2024
Subjects: Arctic sovereignty
Arctic Show Trials
Interpreter Bias
Christianity
Historical Reinterpretation

description: This dissertation explores two significant criminal court cases, commonly referred to as "Arctic show trials", which implicated Inuit in Canada in the early decades of the twentieth century. The context of world conflict at the time of the trials and the perceived threat to Canadian Arctic sovereignty reveal a complex interplay of legal, cultural, and historical narratives. The first part examines the 1917 trials of Sinnisiak and Uluksak, the first criminal court case in Canada's history that required an interpretation between Inuktut and English, and a pivotal direction in Canada's assertion of Arctic sovereignty with the establishment of Inuit as Canadians subject to British law. It highlights the embellished narratives by Roman Catholic Oblates who portrayed their missionaries, Jean-Baptiste Rouvière and Guillaume Le Roux as martyrs, emphasizing the religious and anthropological aspects that influenced the trial's perception and aftermath. The second part examines the 1941 Belcher Island murder trials, underscoring the Euro-Christian biases of the original interpreters and how those original biased interpretations skewed the current understanding of those trials. This dissertation emphasizes the necessity of viewing historical events that implicated Inuit from an Inuit perspective to correct misrepresentations and fabrications prevalent in standard historical accounts. Utilizing a strength-based theoretical framework, this study challenges the deficit discourse commonly applied to Inuit history, advocating for a narrative that recognizes the rational and lawful nature of Inuit social structures. By applying Inuit Qaujimajatuqangit and re-interpreting events with a focus on Inuktut, which emphasizes accurate and culturally sensitive interpretations, this dissertation aims to bridge historical knowledge with Inuit cultural understanding, offering a nuanced view of Inuit engagement with Canadian law in the early decades of the twentieth century.
title: Технология машиностроения. Разработка технологических процессов изготовления деталей
Creators: name: ELS IPR BOOKS
Publisher: name: Ай Пи Ар Медиа
Year: 2025

description: В учебном пособии показаны методы обработки поверхностей различных деталей в зависимости от типа машиностроительного производства и точности. Рассмотрена технологическая подготовка производства и структура технологического процесса. Описана разработка технологических процессов изготовления станин и корпусных деталей, валов, фланцев и втулок, деталей зубчатых передач. Подготовлено в соответствии с Федеральным государственным образовательным стандартом высшего образования. Учебное пособие предназначено для студентов, обучающихся по направлению подготовки «Конструкторско-технологическое обеспечение машиностроительных производств» всех форм обучения, изучающих дисциплину «Технология машиностроения».
Self-Paced Context Evaluation for Contextual Reinforcement Learning
Creators: name: Eimer, Theresa
name: Biedenkapp, André
name: Hutter, Frank
name: Lindauer, Marius
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Reinforcement learning (RL) has made a lot of advances for solving a single problem in a given environment; but learning policies that generalize to unseen variations of a problem remains challenging. To improve sample efficiency for learning on such instances of a problem domain, we present Self-Paced Context Evaluation (SPaCE). Based on self-paced learning, \spc automatically generates \task curricula online with little computational overhead. To this end, SPaCE leverages information contained in state values during training to accelerate and improve training performance as well as generalization capabilities to new instances from the same problem domain. Nevertheless, SPaCE is independent of the problem domain at hand and can be applied on top of any RL agent with state-value function approximation. We demonstrate SPaCE's ability to speed up learning of different value-based RL agents on two environments, showing better generalization capabilities and up to 10x faster learning compared to naive approaches such as round robin or SPDRL, as the closest state-of-the-art approach.
title: Технологическое оборудование. Разработка технологических процессов изготовления деталей
Creators: name: ELS IPR BOOKS
Publisher: name: Профобразование, Ай Пи Ар Медиа
Year: 2025

description: В учебном пособии рассмотрены технологическая подготовка производства и структура технологического процесса, методы обработки поверхностей различных деталей в зависимости от типа машиностроительного производства. Показаны технологические процессы изготовления станин и корпусных деталей, валов, фланцев и втулок, деталей зубчатых передач. Подготовлено в соответствии с Федеральным государственным образовательным стандартом среднего профессионального образования. Учебное пособие предназначено для студентов, обучающихся по укрупненной группе профессий и специальностей «Машиностроение», изучающих дисциплины «Разработка технологических процессов изготовления деталей машин», «Технологическое оборудование».