13,151 research outputs found

    Scientific Bounty Among Meteorites Recovered from the Dominion Range, Transantarctic Mountains

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    The US Antarctic Meteorite Pro-gram has visited the Dominion Range in the Transantarctic Mountains during several different sea-sons, including 1985, 2003, 2008, 2010, 2014 and 2018. Total recovered meteorites from this region is close to 3000. The 1985 (11 samples), 2003 (141 samples), 2008 (521 samples), 2010 (901 samples), 2014 (562 samples) seasons have been fully classified, and 2018 (865 samples) are in the process of being classified and characterized. Given that close to 2200 samples have been classified so far, with more expected in 2020, now is a good time to summarize the state of the collection. Here we describe the significant samples documented from this area, as well as a large meteorite shower that dominates the statistics of the region

    A simple method for detection of mitochondrial DNA polymorphisms

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    Polymorphisms were identified in mtDNA of Heterobasidion annosum by digesting total genomic DNA with HaeIII, CfoI, or MspI, which recognize the restriction sites GGCC, GCGC, and CCGG, respectively. Most DNA was digested to fragments of less than 2 kb, while AT-rich fragments of 1.7 to 17 kb stood out as bands of uniform intensity after ethidium bromide staining. These fragments hybridized to mtDNA probes and were inherited in a uniparental fashion

    Fault-tolerant quantum computation with high threshold in two dimensions

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    We present a scheme of fault-tolerant quantum computation for a local architecture in two spatial dimensions. The error threshold is 0.75% for each source in an error model with preparation, gate, storage and measurement errors.Comment: 4 pages, 4 figures; v2: A single 2D layer of qubits (simple square lattice) with nearest-neighbor translation-invariant Ising interaction suffices. Slightly improved threshol

    Delays in Leniency Application: Is There Really a Race to the Enforcer's Door?

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    This paper studies cartels’ strategic behavior in delaying leniency applications, a take-up decision that has been ignored in the previous literature. Using European Commission decisions issued over a 16-year span, we show, contrary to common beliefs and the existing literature, that conspirators often apply for leniency long after a cartel collapses. We estimate hazard and probit models to study the determinants of leniency-application delays. Statistical tests find that delays are symmetrically affected by antitrust policies and macroeconomic fluctuations. Our results shed light on the design of enforcement programs against cartels and other forms of conspiracy

    Total Molecular Gas Masses of Planck - Herschel Selected Strongly Lensed Hyper Luminous Infrared Galaxies

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    We report the detection of CO(1 - 0) line emission from seven Planck and Herschel selected hyper luminous (LIR(8-1000um) > 10^13Lsun) infrared galaxies with the Green Bank Telescope (GBT). CO(1 - 0) measurements are a vital tool to trace the bulk molecular gas mass across all redshifts. Our results place tight constraints on the total gas content of these most apparently luminous high-z star-forming galaxies (apparent IR luminosities of LIR > 10^(13-14) Lsun), while we confirm their predetermined redshifts measured using the Large Millimeter Telescope, LMT (zCO = 1.33 - 3.26). The CO(1 - 0) lines show similar profiles as compared to Jup = 2 -4 transitions previously observed with the LMT. We report enhanced infrared to CO line luminosity ratios of = 110 (pm 22) Lsun(K km s^-1 pc^-2)^-1 compared to normal star-forming galaxies, yet similar to those of well-studied IR-luminous galaxies at high-z. We find average brightness temperature ratios of = 0.93 (2 sources), = 0.34 (5 sources), and = 0.18 (1 source). The r31 and r41 values are roughly half the average values for SMGs. We estimate the total gas mass content as uMH2 = (0.9 - 27.2) x 10^11(alphaCO/0.8)Msun, where u is the magnification factor and alphaCO is the CO line luminosity to molecular hydrogen gas mass conversion factor. The rapid gas depletion times are, on average, tau = 80 Myr, which reveal vigorous starburst activity, and contrast the Gyr depletion timescales observed in local, normal star-forming galaxies.Comment: published in MNRAS, 9pages, 5fig

    Electromagnetic multipole theory for optical nanomaterials

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    Optical properties of natural or designed materials are determined by the electromagnetic multipole moments that light can excite in the constituent particles. In this work we present an approach to calculate the multipole excitations in arbitrary arrays of nanoscatterers in a dielectric host medium. We introduce a simple and illustrative multipole decomposition of the electric currents excited in the scatterers and link this decomposition to the classical multipole expansion of the scattered field. In particular, we find that completely different multipoles can produce identical scattered fields. The presented multipole theory can be used as a basis for the design and characterization of optical nanomaterials

    Barium Concentration in Rock Varnish: Implications for Calibrated Rock Varnish Dating Curves

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    Cation-ratio dating of rock varnish is a recently developed technique for obtaining surface exposure ages of a wide variety of geomorphic surfaces. As originally proposed, the technique utilizes a ratio among minor cations [(K+Ca)/Ti] in rock varnish. Although this varnish cation ratio is related to the Ti concentration, it can also be affected by the presence of Ba that may be partially included in the analyzed concentration of Ti. Barium is a minor constituent found in virtually all rock varnishes sampled from the Lake Mead area, Las Vegas Valley, and the Crater Flat region of southern Nevada. Barium is heterogeneously distributed in rock varnish, associated predominantly with Mn and secondarily with sulfur (detrital barite). Barium concentrations are apparently greater in varnishes found on young surfaces (\u3c 100 ka) than in varnishes found on older surfaces (\u3e 500 ka), and they are apparently greater in varnishes on low elevation surfaces than in varnishes on hill-slope or ridge deposits. In energy dispersive spectroscopy (EDS), Ba Lα and LÎČ peaks overlap with Ti Kα and KÎČ peaks. Unless decomposed , the overlapping peaks may yield erroneously large values for Ti. We have compared the effect of Ba concentration on calculated varnish cation ratios using: (I) quantitative EDS with the scanning electron microscope (SEM) that decomposes Ti and Ba peaks; (2) quantitative wavelength-dispersive spectroscopy (WDS) with an electron probe microanalyzer (EPM); (3) semiquantitative EDS with the SEM that decomposes Ti and Ba peaks; and (4) semi-quantitative EDS with the SEM that does not decompose Ti and Ba lines. Results suggest small amounts of Ba relative to Ti will not significantly change the value of the calculated varnish cation ratio with or without decomposition. However, if Ba concentrations are high relative to Ti, the effect on cation ratios is pronounced, resulting in anomalously low cation ratios. As younger varnishes and varnishes on topographically lower surfaces apparently have higher Ba concentrations, the effect of Ba on cation ratios calculated for younger rock varnishes and lower surfaces will be greater

    Gambling advertising during live televised male sporting events in Ireland: a descriptive study

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    Objectives: There are no data relating to gambling advertisements shown during live sporting events in Ireland. The aim of the present study was to analyze gambling advertisements shown during live sporting events broadcast in Ireland and to assess these advertisements for responsible gambling (RG) practices. Methods: Sixty-five live televised sporting events comprising Association Football (soccer), Rugby Union, and Gaelic Athletic Association (GAA) matches broadcast in Ireland were analyzed. Pre-match (up to 30 minutes before kick-off), half-time, and post-match (up to 30 minutes after the match has ended) advertisement breaks were analyzed for gambling advertisements, including in-game fixed (static advertising) and dynamic (electronic advertisements changing at regular intervals) pitch-side advertising. Gambling advertisements were studied for evidence of RG practices. Results: A total of 3602 television advertisements, 618 dynamic advertisements, and 394 static advertisements were analyzed. Gambling advertisements were shown in 75.4% (n = 49) games and were the seventh most commonly televised advertisement shown overall. Gambling advertising was more common in football (fourth most common advertisement) compared to rugby (12th most common) and GAA (13th most common). Static and dynamic gambling advertising were common during football matches (second and first most common advertisements, respectively). The majority of advertisements contained RG messaging, an age limit, and an RG organization. No advertisements showing responsible gambling tools were observed. Conclusions: Gambling advertisements are commonly shown during live televised sporting broadcasts in Ireland, especially during live football matches and typically before the adult television watershed. Gambling legislation is required to minimize harm to vulnerable groups including children

    Temperature dependence of instantons in QCD

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    We investigate the temperature dependence of the instanton contents of gluon fields, using unquenched lattice QCD and the cooling method. The instanton size parameter deduced from the correlation function decreases from 0.44fm below the phase-transition temperature TcT_c (≈150\approx 150MeV) to 0.33fm at 1.3 TcT_c. The instanton charge distribution is Poissonian above TcT_c, but it deviates from the convoluted Poisson at low temperature. The topological susceptibility decreases rapidly below TcT_c, showing the apparent restoration of the U(1)AU(1)_A symmetry already at T≈TcT \approx T_c.Comment: 8 pages TEX, 3 Postscript figures available at http://www.krl.caltech.edu/preprints/MAP.htm
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