cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Hydrodynamical adaptive mesh refinement simulations of turbulent flows - II. Cosmological simulations of galaxy clusters
Creators: name: Iapichino, L.
name: Niemeyer, J. C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The development of turbulent gas flows in the intra-cluster medium and in the core of a galaxy cluster is studied by means of adaptive mesh refinement (AMR) cosmological simulations. A series of six runs was performed, employing identical simulation parameters but different criteria for triggering the mesh refinement. In particular, two different AMR strategies were followed, based on the regional variability of control variables of the flow and on the overdensity of subclumps, respectively. We show that both approaches, albeit with different results, are useful to get an improved resolution of the turbulent flow in the ICM. The vorticity is used as a diagnostic for turbulence, showing that the turbulent flow is not highly volume-filling but has a large area-covering factor, in agreement with previous theoretical expectations. The measured turbulent velocity in the cluster core is larger than 200 km/s, and the level of turbulent pressure contribution to the cluster hydrostatic equilibrium is increased by using the improved AMR criteria.
description: 13 pages, 14 figures, accepted for publication in MNRAS. Section 4.3.1 (convergence tests of the AMR criteria) and further minor changes added during the reviewing stage. Errors have been corrected in Table 3, but the conclusions are not affected
Quantum state rotation: Circularly transferring quantum states of multiple users
Creators: name: Lee, Yonghae
name: Yamasaki, Hayata
name: Lee, Soojoon
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum state exchange is a quantum communication task for two users in which the users faithfully exchange their respective parts of an initial state under the asymptotic scenario. In this work, we generalize the quantum state exchange task to a quantum communication task for $M$ users in which the users circularly transfer their respective parts of an initial state. We assume that every pair of users may share entanglement resources, and they use local operations and classical communication in order to perform the task. We call this generalized task the (asymptotic) quantum state rotation. First of all, we formally define the quantum state rotation task and its optimal entanglement cost, which means the least amount of total entanglement required to carry out the task. We then present lower and upper bounds on the optimal entanglement cost, and provide conditions for zero optimal entanglement cost. Based on these results, we find out a difference between the quantum state rotation task for three or more users and the quantum state exchange task.
description: 26 pages, 10 figures
World Virtual Indigenous Circle on Open Science and the Decolonization of Knowledge: Webinar Report
Creators: name: Lorna Wanósts'a7 Williams,
Publisher: name: Zenodo
Year: 2021
Subjects: Indigenous Knowledge, Culture, tradition, spirituality, relationships

description: The World Virtual Indigenous Circle on Open Science and the Decolonization of Knowledge took place November 12, 2020. It was organized by the UNESCO Chair in Community-Based Research and Social Responsibility in Higher Education and co-hosted by the Canadian Commission for UNESCO and the World Indigenous Nations Higher Education Consortium. Its format was designed by Lorna Wanósts’a7 Williams. The Circle featured nearly 20 Indigenous speakers and attracted some 300 registrants from around the world. Its purpose was to inform UNESCO’s forthcoming recommendation on open science and, in turn, to ensure Indigenous Knowledge is incorporated respectfully and with integrity to help reshape how institutions recognize and use it. Ultimately, the aim was to take the next of many steps toward ensuring that Indigenous Knowledge is better recognized worldwide so it can guide individuals and institutions in education, in research and in protecting the Earth.
The use of dipyrromethene and polydipyrromethene ligands in supramolecular chemistry
Creators: name: Zhang, Yongjun
Publisher: name: University of British Columbia
Year: 2009

description: The main objective of this work was to study the use of dipynomethene and polydipyrromethene ligands in supramolecular chemistry. Numerous poly-dipyrromethene metal complexes were synthesized via selfassembly and characterized by mass and NMR spectrometry and X-ray crystallography. Some of their structures were simulated using Hyperchem release 5.01 MM+ force field. Methylene and directly linked bis(dipyrromethene) coordinated to metal ions to form complexes 60a, 60b and 59 which are dimer ((ligands^Mo). X-ray structures of these complexes showed them to have helical geometry. Ethylene-linked bis(dipyrromethene) once coordinated to metal ion, gave a mixture of monomer ((ligand)M) 61a and dimmer 61b ((ligand)2M2). Molecular modeling showed that simulated complex 61a possess a helical double-stranded geometry and 61b a distorted tetrahedral geometry. The methylene-linked tris(dipyrromethene) zinc complex 87 was also synthesized and shown to contain helical double-stranded structure by X-ray crystallography. Dipyrromethenes which contain a raeso-phenyl group and are free at α and β positions coordinated to trivalent metal ions forming octahedral complexes 131-135. The oxidation reaction of porphyrins with oxaziridines was studied and this leads to a new synthetic method towards the synthesis of chlorins which are potential photosensitizers in photodynamic therapy. Chlorins 179 and 180 were synthesized and characterized. The longest wavelength absorptions of these chlorins have an approximate 20 nm bathochromic shift and a significant increase in intensity as compared with octaethyl porphyrin. Their structures were determined by ¹H and ¹³C NMR spectrometry. A mechanistic proposal for this reaction will be presented.
Statistical mechanics of lossy compression using multilayer perceptrons
Creators: name: Mimura, Kazushi
name: Okada, Masato
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Statistical mechanics is applied to lossy compression using multilayer perceptrons for unbiased Boolean messages. We utilize a tree-like committee machine (committee tree) and tree-like parity machine (parity tree) whose transfer functions are monotonic. For compression using committee tree, a lower bound of achievable distortion becomes small as the number of hidden units K increases. However, it cannot reach the Shannon bound even where K -> infty. For a compression using a parity tree with K >= 2 hidden units, the rate distortion function, which is known as the theoretical limit for compression, is derived where the code length becomes infinity.
description: 12 pages, 5 figures
Vanishing thermal equilibration for hole-conjugate fractional quantum Hall states in graphene
Creators: name: Srivastav, Saurabh Kumar
name: Kumar, Ravi
name: Spånslätt, Christian
name: Watanabe, K.
name: Taniguchi, T.
name: Mirlin, Alexander D.
name: Gefen, Yuval
name: Das, Anindya
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Transport through edge-channels is responsible for conduction in quantum Hall (QH) phases. Topology dictates quantization of both charge and thermal transport coefficients. These turn out to approach robust quantized values when incoherent equilibration processes become dominant. Here, we report on measurements of both electrical and thermal conductances of integer and fractional quantum Hall (FQH) phases, realized in hBN encapsulated graphite gated bilayer graphene devices. Remarkably, for the complex edge at filling factors $ν=5/3$ and $ν=8/3$, which correspond to the paradigmatic hole-conjugate FQH phase $ν=2/3$ of the partially filled Landau level, we find vanishing thermal equilibration. This is striking, given that, at the same time, our results for the electrical conductance indicate efficient charge equilibration. These results are in accord with our theoretical analysis, pointing to a divergent thermal equilibration length in the limit of strong electrostatic interaction. Our results elucidate the subtle nature of the crossover from mesoscopic to robust topology-dominated transport in electronic two-dimensional topological phases.
description: 47 pages including Supplementary information. There are 3 main figure and 4 extended figures
A Proof of the Security of Quantum Key Distribution
Creators: name: Biham, Eli
name: Boyer, Michel
name: Boykin, P. Oscar
name: Mor, Tal
name: Roychowdhury, Vwani
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: Cryptography and Security (cs.CR)
subject: Information Theory (cs.IT)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We prove the security of theoretical quantum key distribution against the most general attacks which can be performed on the channel, by an eavesdropper who has unlimited computation abilities, and the full power allowed by the rules of classical and quantum physics. A key created that way can then be used to transmit secure messages such that their security is also unaffected in the future.
description: 64 pages; Accepted for publication in J. of Cryptology; replaces quant-ph/9912053; short version appeared in STOC'2000 pages 715-724
The Environmental Impacts of Electricity Restructuring: Looking Back and Looking Forward
Creators: name: Palmer, Karen L.
name: Burtraw, Dallas
name: Palmer, Karen L.
name: Burtraw, Dallas
Publisher: name: Unknown
Year: 2005
Subjects: subject: Resource /Energy Economics and Policy
subject: electricity
subject: electric utilities
subject: regulation
subject: competition
subject: environment
subject: air pollution
subject: natural gas
subject: coal
subject: nuclear
subject: renewables
subject: customer choice

description: In the mid-1990s, when the Federal Energy Regulatory Commission was preparing to release Order 888 requiring open access to the transmission grid, the commission, environmental groups, and the Environmental Protection Agency, among others, raised the question of how open access and greater competition in wholesale electricity markets might affect the environment. If open access worked as expected, underutilized older coal-fired generators in the Midwest and elsewhere might find new markets for their power, leading to associated increases in air pollution emissions. Restructuring also might lead to retirements of inefficient nuclear facilities, whose generation would be replaced by fossil generation, further increasing emissions. On the other hand, some suggested that in the long run, the anticipated increase in investment in new gas-fired generators might accelerate a switch from coal to gas that would decrease emissions. Lastly, if restructuring produced the desired result of lower electricity prices, many observers suggested that an increase in electricity demand would lead to more generation and higher emissions. The counterargument was that restructuring would lead to product differentiation and customer choice, including the opportunity for customers to willingly select "green electricity." In this paper we review the prospective literature on the possible or anticipated effects of restructuring on the environment and the evidence from changes in the intervening years to utilization of coal facilities, performance of existing nuclear plants, investment in natural gas generation, and electricity prices. We assess how actual experience compares with prior expectations. We discuss other changes in upstream fuel markets, energy policy, and environmental regulations and the role that each of these factors plays in the efforts to evaluate the environmental effects of restructuring. Today the movement toward restructuring has stalled, leaving the country divided into competitive and regulated regions. We discuss the implications of this division for the future of environmental policy and the complicated relationships between policy agendas concerning mitigation of climate change and further restructuring of the electricity industry.
CPT groups for spinor field in de Sitter space
Creators: name: Varlamov, V. V.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 15A66; 15A90; 20545

description: A group structure of the discrete transformations (parity, time reversal and charge conjugation) for spinor field in de Sitter space are studied in terms of extraspecial finite groups. Two $CPT$ groups are introduced, the first group from an analysis of the de Sitter-Dirac wave equation for spinor field, and the second group from a purely algebraic approach based on the automorphism set of Clifford algebras. It is shown that both groups are isomorphic to each other.
description: 7 pages
[Kashaya field notes]
Creators: name: Munro, Pamela
name: Silva, Anita
name: Zakaria, Oliviana
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2015
Subjects: subject: kju
subject: Kashaya language

description: Photocopy of notes from the field methods course LSA 310 taught by Pam Munro at the 2009 LSA Linguistic Institute at UC Berkeley.
Climate Policy in the United States and Japan: Prospects in 2005 and Beyond, Workshop Summary
Creators: name: Pizer, William A.
name: Tamura, Kentaro
name: Pizer, William A.
name: Tamura, Kentaro
Publisher: name: Unknown
Year: 2005
Subjects: subject: Environmental Economics and Policy
subject: climate change
subject: global warming
subject: United States
subject: Japan
subject: Kyoto

description: Resources for the Future and the Institute for Global Environmental Strategies convened a one and one-half day workshop on domestic and international climate policy May 11-12, 2005, in Tokyo, Japan. The first day included 49 participants hearing presentations from 13 speakers and discussing domestic activities, economics, and politics. The second day included a smaller group of participants listening to a panel of four experts and discussing opportunities for future international climate regimes. Participants included government officials from the Japanese Ministry of the Environment; the Japanese Ministry of Economy, Trade and Industry; the U.S. Environmental Protection Agency; the U.S. Department of State; and the Massachusetts Department of Commonwealth Development; representatives from business and environmental groups; and academic experts. Over the course of both days, it was clear that great opportunities exist for regularly informing experts from both countries on recent policy developments, economic analyses, and political nuances in the other country. For example, U.S. participants had an opportunity to learn the process through which Japanese technology standards are set and implemented, the subtle evolution of mandatory policy discussions, and details of current policies on voluntary trading and an emission registry. Japanese participants benefited from a frank discussion with U.S. experts of how and why it would be difficult to link different domestic emissions trading markets, the current process to establish a regional emissions trading program, and the evolving dynamics in the U.S. Senate. Looking forward, important lessons may be taken from past negotiating experiences. A small group of national leaders, including large emitters of greenhouse gases and major economies, addressing not only climate change but also developmental issues, could be a useful vehicle for meaningful international efforts. Such a small-group process should be carried out in parallel with the multilateral United Nations Framework Convention on Climate Change process. In addition, policies in both the United States and Japan reflect a strong emphasis on technology development and commercialization; this may be an area where bilateral cooperation could be particularly beneficial.
Direct proof of unconditional asymptotic consensus in the Hegselmann-Krause model with transmission-type delay
Creators: name: Haskovec, Jan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: We present a direct proof of asymptotic consensus in the nonlinear Hegselmann-Krause model with transmission-type delay, where the communication weights depend on the particle distance in phase space. Our approach is based on an explicit estimate of the shrinkage of the group diameter on finite time intervals and avoids the usage of Lyapunov-type functionals or results from nonnegative matrix theory. It works for both the original formulation of the model with communication weights scaled by the number of agents, and the modification with weights normalized a'la Motsch-Tadmor. We pose only minimal assumptions on the model parameters. In particular, we only assume global positivity of the influence function, without imposing any conditions on its decay rate or monotonicity. Moreover, our result holds for any length of the delay.
description: 12 pages. arXiv admin note: text overlap with arXiv:2005.13589
Fission Decay Widths for Heavy-Ion Fusion-Fission Reactions
Creators: name: McCalla, S. G.
name: Lestone, J. P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Cross-section and neutron-emission data from heavy-ion fusion-fission reactions are consistent with a Kramers-modified statistical model which takes into account the collective motion of the system about the ground state; the temperature dependence of the location of fission transition points; and the orientation degree of freedom. We see no evidence to suggest that the nuclear viscosity departs from the surface-plus-window dissipation model. The strong increase in the nuclear viscosity above a temperature of ~1 MeV deduced by others is an artifact generated by an inadequate fission model.
description: 14 pg, 6 fig, submitted to Physical Review
Location Efficient Mortgages: Is the Rationale Sound?
Creators: name: Blackman, Allen
name: Krupnick, Alan J.
name: Blackman, Allen
name: Krupnick, Alan J.
Publisher: name: Unknown
Year: 1999
Subjects: subject: Land Economics/Use
subject: urban sprawl
subject: location efficiency
subject: mortgage
subject: default

description: Location efficient mortgages (LEM) programs are an increasingly popular approach to combating urban sprawl. LEMs allow families who want to live in densely-populated, transit-rich communities to obtain larger mortgages with smaller downpayments than traditional underwriting guidelines allow. LEMs are premised on the proposition that homeowners in such "location efficient" areas can safely be allowed to breach underwriting guidelines designed to prevent mortgage default because they have lower than average automobile-related transportation expenses and more income available for mortgage payments. This paper employs records of over 8,000 FHA-insured mortgages matched with data on various measures of location efficiency to test this proposition. Our results suggest that it does not hold and that LEMs-like other low-downpayment mortgage programs-will raise mortgage default rates. This cost must be weighed against any potential anti-sprawl benefits LEMs may have.
Dromaeosaurus albertensis Matthew and Brown 1922
Creators: name: Sahni, Ashok
Publisher: name: Zenodo
Year: 1972
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Reptilia
Dinosauria
Dromaeosauridae
Dromaeosaurus
Dromaeosaurus albertensis

description: Dromaeosaurus albertensis Matthew and Brown, 1922
Figure 9I
Dromaeosaurus albertensis MATTHEW AND BROWN, 1922, p. 383.
Laelaps explanatus COPE, 1876a, p. 249.
Laelapsfalculus Cope, 1876a, p. 249.
Laelaps laevifrons COPE, 1876b, p. 344.
Dromaeosaurus albertensis is a small carnivorous dinosaur described from the "Belly River Formation" of Alberta by Matthew and Brown (1922, p. 383). These authors stated that the length of the skull is one-third to one-fourth the linear size of that of Deinodon, and differs from it by "reduced number of teeth, the large premaxillary teeth and the unsymmetric form of the maxillary teeth as well as the light skull construction, large fenestrae and numerous details that might be largely associated with its small size. "
Teeth similar to those of Dromaeosaurus have been reported and figured (Russell, 1935, fig. 9) from the Milk River Formation of Alberta. They have also been reported from the Judith River Formation (Matthew and Brown, 1922, p. 378). AMNH 8516 is referable to the genus (fig. 9I). The teeth are usually smaller versions of those of Deinodon, with relatively strongly convex anterior borders. Serrations on the posterior edge of most teeth are coarser than those on the anterior, and in some specimens the anterior crest may be completely unserrated.
description: Published as part of Sahni, Ashok, 1972, The vertebrate Fauna of the Judith River formation, Montana, pp. 319-416 in Bulletin of the American Museum of Natural History 147 (6) on page 359, DOI: 10.5281/zenodo.3382461
Star-formation in NGC 4038/4039 from broad- and narrow band photometry: Cluster Destruction?
Creators: name: Mengel, Sabine
name: Lehnert, Matthew D.
name: Thatte, Niranjan
name: Genzel, Reinhard
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Accurately determining the star formation history in NGC 4038/4039 -- ``The Antennae'' is hampered by extinction. We therefore used near infrared images obtained with ISAAC at the VLT and with SOFI at the NTT to determine the recent star formation history in this merger. In combination with archival HST data, we determined ages, extinction and other parameters for single star clusters, and properties of the cluster population as a whole. About 70% of the K_s-band detected star clusters with masses >= 10^5 M_sun are younger than 10 Myrs (approximately an e-folding time for cluster ages), which we interpret as evidence for rapid dissolution but not free expansion. The total mass of K-band selected clusters is about 5-10x10^8 M_sun and represents about 3-6% of the total molecular gas. This takes into account only the detected clusters and in view of the rapid dissolution means that this is only a lower limit to the total mass of stars produced in clusters during the burst. Studies of cluster formation in other galaxies recently suggested short cluster dissolution timescales, too, which means that star formation rates may have been severely underestimated in the past. Extinction is strongly variable and very high in some regions, but around A_V=1.3 mag on average. Even though most clusters are detected at least in I-band, only the information about individual cluster ages and extinction allows to avoid uncertainties of orders of magnitude in star formation rate estimates determined from optical fluxes. From the distribution of individual cluster extinction vs. age, which is significantly higher for clusters below 8-9 Myr than for older clusters, we infer that this is the time by which a typical cluster blows free of its native dust cocoon.
description: 21 pages, 25 figures, accepted by A&A. PS-file with higher resolution figures can be downloaded from http://www.eso.org/~smengel/Antennae_imaging.ps
Calibration of the Rossi X-ray Timing Explorer Proportional Counter Array
Creators: name: Jahoda, K.
name: Markwardt, C. B.
name: Radeva, Y.
name: Rots, A.
name: Stark, M. J.
name: Swank, J. H.
name: Strohmayer, T. E.
name: Zhang, W.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the calibration and background model for the Proportional Counter Array (PCA) aboard the Rossi X-ray Timing Explorer (RXTE). The energy calibration is systematics limited below 10 keV with deviations from a power-law fit to the Crab nebula plus pulsar less than 1%. Unmodelled variations in the instrument background amount to less than 2% of the observed background below 10 keV and less than 1% between 10 and 20 keV. Individual photon arrival times are accurate to 4.4 micro-seconds at all times during the mission and to 2.5 micro-seconds after 29 April 1997. The peak pointing direction of the five collimators is known to a precision of a few arc-seconds
description: 77 pages, 34 figures. accepted by Ap J Supplement for April 2006 issue. This paper and additional calibration information are available from http://universe.gsfc.nasa.gov/xrays/programs/rxte/pca/ pcapage.html. Revised version contains minor changes to match accepted version
Proper motion measurements as indicators of binarity in open clusters
Creators: name: Bica, E.
name: Bonatto, C.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We analyze 9 open clusters with ages in the range 70 Myr to 3.2 Gyr using UCAC2 proper motion data and 2MASS photometry. For each cluster we consider the projected velocity distributions in the core and off-core regions separately. In the projected velocity distribution of all sample clusters we find a well-defined low-velocity peak, as well as an excess in the number of stars at larger velocities. The low-velocity peak is accounted for by the random motion of the single stars, while the high-velocity excess can be attributed to the large velocity changes produced by a significant fraction of unresolved binaries in a cluster. We derive kinematic parameters of the single-star distribution, in particular the projected velocity dispersion. The relatively large velocity dispersions derived in this work may reflect the non-virialized state of the clusters. Based on the relative number of high-velocity (binary) and single stars, we inferred for the sample clusters unresolved binary fractions in the range $15%-54%$, for both core and off-core regions. The present results suggest that care must be taken when applying proper-motion filters to sort out members, especially binaries in a star cluster. This paper shows that proper motions turn out to be a useful tool for identifying high-velocity stars as unresolved binary cluster members, and as a consequence, map and quantify the binary component in colour-magnitude diagrams.
description: 9 pages and 9 figures. Astronomy and Astrophysics, accepted (25/10/2004)
How Well Can Markets for Development Rights Work? Evaluating a Farmland Preservation Program
Creators: name: McConnell, Virginia D.
name: Kopits, Elizabeth
name: Walls, Margaret
name: McConnell, Virginia D.
name: Kopits, Elizabeth
name: Walls, Margaret
Publisher: name: Unknown
Year: 2003
Subjects: subject: Land Economics/Use
subject: land use
subject: farmland preservation
subject: development rights

description: Transferable development rights (TDRs) can be used as a local planning tool to preserve land for particular uses. TDRs separate ownership of the right to develop land from ownership of the land itself, creating a market in which the development rights can be bought and sold. Landowners who sell TDRs permanently preserve their land in an undeveloped state; those TDRs are then used to increase the density of development elsewhere. In this paper, we evaluate a TDR program for preserving farmland in Calvert County, Maryland. We evaluate the performance of the TDR market over the 23-year life of the program by looking at the number of transactions and TDRs sold and the level and dispersion of prices over time. We also look closely at the influence of the county government as a participant in the market. We locate the properties that have been preserved in the county as well as the subdivisions that have used TDRs to increase the density of development. We find that the program is achieving Calvert's farmland preservation goals and the TDR market appears to have operated efficiently, at least since 1993 when the county increased its role in the TDR market. At that time, the county began purchasing a small number of development rights each year at a fixed and known price and also began publishing a newsletter providing information about the program. These actions stabilized prices and appear to have bolstered participants' faith in the longevity of the program. Most of the agricultural properties preserved in the program are in areas less profitable for development. The demand for TDRs to increase density is greatest in subdivisions in the northern part of the county, closer to the major urban cities, and interestingly, in relatively rural areas with low-density zoning. There appears to be little demand for TDRs and the associated higher density in town centers or areas zoned with residential zoning.
Positivity bounds on Minimal Flavor Violation
Creators: name: Bonnefoy, Quentin
name: Gendy, Emanuele
name: Grojean, Christophe
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: From general analyticity and unitarity requirements on the UV theory, positivity bounds on the Wilson coefficients of the dimension-8 operators composed of 4 fermions and two derivatives appearing in the Standard Model Effective Field Theory have been derived recently. We explore the fate of these bounds in the context of models endowed with a Minimal Flavor Violation (MFV) structure, models in which the flavor structure of higher dimensional operators is inherited from the one already contained in the Yukawa sector of the Standard Model Lagrangian. Our goal is to check whether the general positivity bounds translate onto bounds on the Yukawa coefficients and/or on elements of the CKM matrix. MFV fixes the coefficients of dimension-8 operators up to some multiplicative flavor-blind factors and we find that, in the most generic setup, the freedom left by those unspecified coefficients is enough as not to constrain the parameters of the renormalizable Yukawa sector. On the contrary, the latter shape the allowed region for the former. Requiring said overall coefficients to take natural $\mathcal{O}(1)$ values could give rise to bounds on the Yukawa couplings. Remarkably, at leading order in an expansion in powers of the Yukawa matrices, no bounds on the CKM entries can be retrieved.
description: 21 pages + appendices, 5 figures; references added, additional comments in the conclusions added
Constraints on radiatively inefficient accretion history of active galactic nuclei from hard cosmological X-ray background
Creators: name: Cao, Xinwu
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The transition of a standard thin disk to a radiatively inefficient accretion flow (RIAF) is expected to occur, when its dimensionless accretion rate is lower than the critical value. The RIAF is very hot, and it radiates mostly in the hard X-ray band (>100 keV). Assuming that the accretion disk in every bright active galactic nucleus (AGN) will finally undergo a RIAF phase while the accretion rate is lower than the critical value, we calculate the contribution of the RIAFs in AGNs to the cosmological X-ray background of 10-1000 keV. We find that the timescale of the RIAF accreting at slightly below the critical rate should be shorter than 0.01 of the bright AGN lifetime if the critical accretion rate is 0.01, i.e., the accretion rate declines from the critical value to a rate significantly lower than this critical rate within this RIAF timescale. The derived RIAF timescale is affected by the parameters adopted in the model calculations, which is also discussed in this Letter.
description: 4 pages, accepted for publication in ApJ Letters
The Brownfields Phenomenon: Much Ado about Something or the Timing of the Shrewd?
Creators: name: Wernstedt, Kris
name: Heberle, Lauren
name: Alberini, Anna
name: Meyer, Peter
name: Wernstedt, Kris
name: Heberle, Lauren
name: Alberini, Anna
name: Meyer, Peter
Publisher: name: Unknown
Year: 2004
Subjects: subject: Environmental Economics and Policy
subject: brownfields
subject: contamination
subject: economic development
subject: infill

description: This paper provides an overview of the cleanup and redevelopment of contaminated properties known as "brownfields." It has three principal parts. First, we introduce the brownfields phenomenon and its drivers, drawing on the body of available empirical evidence to discuss characteristics of individual brownfield redevelopment projects. Second, we present findings from a recent study we have conducted that examines the relative attractiveness to private developers of public interventions to promote brownfields redevelopment. Third, we briefly summarize some of the problems with brownfields development and policy and propose an approach to promote wider societal benefits of brownfields development. We conclude with several broad questions about brownfields policy and practice.
EO4Agri - User Requirements and Gap Analysis in Different Sectors
Creators: name: EO4Agri Consortium
Publisher: name: Zenodo
Year: 2021
Subjects: Earth Observation
Agriculture
User Requirements
EO4Agri

description: The table includes a user requirements analysed during the EO4Agri project. The requirements are categorised as gold, silver and bronze. Requirements that are common to three or more stakeholder groups were labeled as gold requirements, overlapping requirements between two stakeholder groups were labelled as silver requirements and bronze requirements are those belonging to just one stakeholder group.
Potential for Carbon Forest Plantations in Marginal Timber Forests: The Case of Patagonia, Argentina
Creators: name: Sedjo, Roger A.
name: Sedjo, Roger A.
Publisher: name: Unknown
Year: 1999
Subjects: subject: Environmental Economics and Policy
subject: carbon sequestration
subject: forest plantations
subject: carbon offsets
subject: present value
subject: Kyoto Protocol
subject: Argentina
subject: developing countries

description: With the advent of the Kyoto Protocol and its recognition of the use of forestry activities and carbon sinks as acceptable tools for addressing the issue of the build-up of atmospheric carbon, the potential role of planted forests as a vehicle for carbon sequestration has taken on a new significance. Additionally, the emergence of tradable emission permits and now tradable carbon offsets provides a vehicle for financially capturing the benefits of carbon emission reductions and carbon offsetting activities. In a world where carbon sequestration has monetary value, investments in planted forests can be made with an eye to revenues to (at least two) joint outputs: timber and the carbon sequestration services. The first section of this paper examines the Patagonia region of Argentina, as an example of an area where carbon sequestration values combined with timber values create financial incentives for creating planted forests, which could not be justified on the bases of timber values alone. The paper uses a present value approach to evaluate the costs and benefits of plantation forestry in a "representative" site in Patagonia. A basic timber harvest scenario is developed and then a number of alternative scenarios are examined. These introduce carbon as an additional product to be produced "jointly" with timber. The scenarios include alternative rotation periods, alternative prices for carbon offsets, and a brief examination of the effect of undertaking a specific silvicultural activity. In the second section of the paper the results of this analysis are considered in the context of a discussion of the various types of institutional arrangements that might be required to provide a market for the carbon sequestration services provided by the planted forests. The paper identifies, examines and discusses a number of potential institutional arrangements that exist or are under discussion for marketing carbon sequestration services. A number of problems that may arise with offset credits and some of the innovative institutions that may be created are identified and discussed.
Saxbyoceras Kröger, 2025, gen. nov.
Creators: name: Kröger, Björn
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Cephalopoda
Uranoceratidae
Saxbyoceras

description: Genus Saxbyoceras gen. nov.
urn:lsid:zoobank.org:act: F9537354-5080-41CB-9ADF-D443823ECEAD
Type species
Saxbyoceras kingpooli gen. et sp. nov., from Saxby shore, Kõrgessaare Formation, Vormsi Island, Estonia; Vormsi Regional Stage.
Diagnosis
Slightly endogastrically curved brevicone with smooth (or nearly so) conch surface; conch cross section circular or slightly compressed; mature body chamber slightly curved, not (or only very slightly) constricted; sutures are nearly straight and directly transverse; siphuncle eccentrically positioned toward the concave side of the conch with widely expanded segments; septal necks very short or achoanitic; endosiphuncular or cameral deposits not known.
Etymology
From Saxby, Vormsi Island, Estonia, the type locality of the type species of this genus.
Remarks
The new genus is best compared with Siljanoceras Kröger, 2013, from which it differs in having a much smaller angle of expansion (33° in Siljanoceras) and an endogastrically curved conch.
description: Published as part of Kröger, Björn, 2025, The Lyckholm acme of cephalopods - Review of the late Katian (Vormsi-Pirgu regional stages) Ordovician cephalopods of Estonia, pp. 1-169 in European Journal of Taxonomy 978 on page 57, DOI: 10.5852/ejt.2025.978.2801, http://zenodo.org/record/14988376
The Greening of Development Economics: A Survey
Creators: name: Blackman, Allen
name: Mathis, Mitchell
name: Nelson, Peter
name: Blackman, Allen
name: Mathis, Mitchell
name: Nelson, Peter
Publisher: name: Unknown
Year: 2001
Subjects: subject: International Development
subject: environment
subject: development
subject: economics
subject: literature review

description: Although ignored for decades, environmental issues now attract considerable attention in the literature on economic development. This paper describes research on environmental issues in seven topic areas that historically have been at the heart of development economics: the role of the state, economic growth, trade and industrialization, relations between rich and poor countries, structural adjustment and stabilization, population change, and the objectives and strategies of development.
No evidence of "gray" dust from composite quasar spectra
Creators: name: Willott, Chris J.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Two recent studies based on composite reddened quasar spectra have indicated the presence of `gray' dust in quasar environments. This gray dust has a relatively flat extinction law in the UV, consistent with the theoretical expectation of a lack of small dust grains close to a quasar. In contrast, individual reddened quasars in the Sloan Digital Sky Survey tend to have steep extinction laws in the UV, similar to that in the SMC. We analyze the method used in determining extinction laws from composite quasar spectra in order to resolve this discrepancy. We show that quasars reddened by SMC-type dust that are present in quasar samples have a negative correlation between E_{B-V} and redshift, due to selection effects. The fact that the highest redshift quasars (which contribute to the UV part of a composite spectrum) are less extincted leads to shallower extinction in the UV. We construct a composite quasar spectrum from a simulated sample of quasars reddened by SMC-type dust and show that the extinction curve derived from the composite does not recover the intrinsic extinction law. We conclude there is no evidence of gray dust in quasar environments.
description: 4 pages, 2 figures, ApJL, in press. Minor typos corrected, title and some text Americanized
Estimating Carbon Supply Curves for Global Forests and Other Land Uses
Creators: name: Sedjo, Roger A.
name: Sohngen, Brent
name: Mendelsohn, Robert
name: Sedjo, Roger A.
name: Sohngen, Brent
name: Mendelsohn, Robert
Publisher: name: Unknown
Year: 2001
Subjects: subject: Resource /Energy Economics and Policy
subject: carbon supply curves
subject: sequestration
subject: timber
subject: forests
subject: model
subject: global warming
subject: prices
subject: markets

description: This study develops cumulative carbon 'supply curves' for global forests utilizing an dynamic timber supply model for sequestration of forest carbon. Because the period of concern is the next century, and particular time points within that century, the curves are not traditional Marshallian supply curves or steady-state supply curves. Rather, the focus is on cumulative carbon cost curves (quasi-supply curves) at various points in time over the next 100 years. The research estimates a number of long-term, cumulative, carbon quasi-supply curves under different price scenarios and for different time periods. The curves trace out the relationship between an intertemporal price path for carbon, as given by carbon shadow prices, and the cumulative carbon sequestered from the initiation of the shadow prices, set at 2000, to a selected future year (2010, 2050, 2100). The timber supply model demonstrates that cumulative carbon quasi-supply curves that can be generated through forestry significantly depend on initial carbon prices and expectations regarding the time profile of future carbon prices. Furthermore, long-run quasisupply curves generated from a constant price will have somewhat different characteristics from quasisupply curves generated with an expectation of rising carbon prices through time. The 'least-cost' curves vary the time periods under consideration and the time profile of carbon prices. The quasi-supply curves suggest that a policy of gradually increasing carbon prices will generate the least costly supply curves in the shorter periods of a decade or so. Over longer periods of time, however, such as 50 or 100 years, these advantages appear to dissipate.
Testing the fireball/blastwave model by monitoring afterglows from soft gamma repeaters
Creators: name: Huang, Y. F.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The popular fireball/blastwave model of classical gamma-ray bursts is applied to soft gamma-ray bursts. It is found that X-ray afterglows from strong events may be above their quiescent levels for 40 -- 400 seconds. Optical afterglows may also be detectable. By monitoring the three repeaters, we will have an ideal way to check the fireball/blastwave model.
description: A detailed version of astro-ph/9810449, published in 1998 in "Journal of Nanjing University" already; 6 figures, 11 pages
Unraveling the orbital physics in a canonical orbital system KCuF$_3$
Creators: name: Li, Jiemin
name: Xu, Lei
name: Garcia-Fernandez, Mirian
name: Nag, Abhishek
name: Robarts, H. C.
name: Walters, A. C.
name: Liu, X.
name: Zhou, Jianshi
name: Wohlfeld, Krzysztof
name: Brink, Jeroen van den
name: Ding, Hong
name: Zhou, Ke-Jin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We explore the existence of the collective orbital excitations, orbitons, in the canonical orbital system KCuF$_3$. Using the Cu $L_3$-edge resonant inelastic X-ray scattering we show that the non-dispersive high-energy peaks result from the Cu$^{2+}$ $dd$ orbital excitations. These high-energy modes show good agreement with the {\it ab-initio} quantum chemistry calculation based on a single cluster, indicating that the $dd$ excitations are highly localized. At the same time, the low-energy excitations present clear dispersion. They match extremely well with the two-spinon continuum following the comparison with Mueller Ansatz calculations. The localized $dd$ excitations and the observation of the strongly dispersive magnetic excitations suggest that orbiton dispersion is below the resolution detection limit. Our results can reconcile with the strong {\it local} Jahn-Teller effect in KCuF$_3$, which predominantly drives orbital ordering.
description: 6 pages, 4 figures
Higgsing and Superpotential Deformations of ADE Superconformal Theories
Creators: name: Okuda, Takuya
name: Ookouchi, Yutaka
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study large classes of renormalization group flows, driven by scalar expectation values or mesonic superpotential terms, away from the conformal fixed points of the 4d supersymmetric gauge theories with $ADE$-type superpotentials. The $a$-maximization procedure allows us to compute the $R$ charges and to check the $a$-theorem conjecture. For a theory obtained by Higgsing the $D_{k+2}$ theory, we use the magnetic dual description proposed by Brodie to determine the parameter region where the resulting theory is at a non-trivial conformal fixed point.
description: 40 pages, 16 figures, v2: minor corrections, to appear in NPB
Copper(I)-mediated intramolecular conjugate additions : total synthesis of (+/-)-1-desoxyhypnophilin and (+/-)-6,7-epoxy-4(15)-hirsuten-5-ol
Creators: name: Skupinska, Krystyna A.
Publisher: name: University of British Columbia
Year: 2009

description: The use of Cu(I)-mediated intramolecular conjugate addition reactions of alkenyltrimethylstannane functions to α,β-unsaturated ketones to afford novel, functionalized tricyclic ketones 88-91, and 94 was investigated. Vinylogous esters of general structure 71 were prepared by alkylation of the vinylogous esters 76 (m=2) or 82 (m=l) with the allylic bromide 73 and Mel (for 71 where R¹=Me). Compounds 71 were readily transformed via either reduction or Grignard addition, followed by hydrolysis and dehydration of the resultant products, into enones of general structure 70. Treatment of compounds 70 with CuCN in DMSO provided tricyclic ketones 88-91 and 94. The analogous Cu(I)-mediated cyclization of aryltrimethylstannanes was also studied. Upon treatment with CuCN in DMSO, enones 112, 114, and 116 underwent cyclization to provide functionalized, tricyclic ketones 117-119, containing an aromatic ring. Further synthetic transformations involving olefinic ketones 88-91 and 54 were investigated. The oxidative cleavage of the tetrasubstituted double bond of 88-91 and 54 provided triones 142-146. Similar transformation of the olefinic ketals prepared from 88- 90 and 54 generated the ketal diones 135, 136, 137 and 141, respectively. Interestingly, treatment of the triones 142, 143 and 144 with a catalytic amount of p-toluenesulfonic acid in refluxing TFfF afforded products of the aldol condensation reaction (149, 148 and 147, respectively). Under similar reaction conditions triketone 146 generated compound 151. The Cu(I)-mediated intramolecular conjugate addition reaction of alkenyltrimethylstannane functions to enones was used in a key step of the total syntheses of the triquinane natural products, (±)-l-deoxyhypnophilin 61 and the related alcohol (±)- 62. Vinylogous ester 175 was obtained by alkylation of 82 with the allylic bromide 176. Compound 59 was prepared by treatment of the vinylogous ester 175 with methylmagnesium bromide, followed by treatment of the resultant material with ptoluenesulfonic acid. Conversion of 59 into the tricyclic ketone 60 was accomplished by treatment of the former substance with CuCN in DMSO in a sealed reaction vessel. The ketone function of 60 was reduced to the a alcohol, which was used in the hydroxydirected hydrogenation of the alkenic function to form the alcohol 196. The alcohol function of 196 was oxidized to provide ketone 174. Compound 174 was converted to the enone 197. Introduction of the a methylidene function gave the dienone 198. Monoepoxidation of the internal olefrnic function of 198 afforded the natural product (±)- 1-desoxyhypnophilin (61). Subsequent reduction of the ketone function of (±)-61 provided (±)-62.