4,140 research outputs found

    Development of Athletes Conceptions of Sport Officials Authority

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    This study examined baseball players\u27 conceptions of umpires\u27 authority. Eighty male players, ages 6-22 years, completed an abbreviated Inventory of Piaget\u27s Developmental Tasks (Furth, 1970), which was used to measure cognitive development. They then heard recorded scenarios describing conflicts with an umpire and a parent. Players indicated if they would argue with the authorities, why they obey the authorities (obedience), and why the authorities get to make decisions (legitimacy). Obedience and legitimacy responses were categorized into Damon\u27s (1977) three levels. Measures of arguing, obedience, and legitimacy were analyzed for four age levels and three levels of cognitive development. Older and more cognitively developed players were more likely to argue with authorities. Conceptions of obedience and legitimacy were positively associated with age, though they were not related to scores of cognitive development. The positive relationship between age and authority conceptions and the absence of a relationship between cognitive development and authority conceptions are both consistent with Damon\u27s position

    51 Eri and GJ 3305: A 10-15 Myr old binary star system at 30 parsecs

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    Following the suggestion of Zuckerman et al. (2001, ApJ, 562, L87), we consider the evidence that 51 Eri (spectral type F0) and GJ 3305 (M0), historically classified as unrelated main sequence stars in the solar neighborhood, are instead a wide physical binary system and members of the young beta Pic moving group (BPMG). The BPMG is the nearest (d < 50 pc) of several groups of young stars with ages around 10 Myr that are kinematically convergent with the Oph-Sco-Cen Association (OSCA), the nearest OB star association. Combining SAAO optical photometry, Hobby-Eberly Telescope high-resolution spectroscopy, Chandra X-ray data, and UCAC2 catalog kinematics, we confirm with high confidence that the system is indeed extremely young. GJ 3305 itself exhibits very strong magnetic activity but has rapidly depleted most of its lithium. The 51 Eri/GJ 3305 system is the westernmost known member of the OSCA, lying 110 pc from the main subgroups. The system is similar to the BPMG wide binary HD 172555/CD -64d1208 and the HD 104237 quintet, suggesting that dynamically fragile multiple systems can survive the turbulent environments of their natal giant molecular cloud complexes, while still being imparted high dispersion velocities. Nearby young systems such as these are excellent targets for evolved circumstellar disk and planetary studies, having stellar ages comparable to that of the late phases of planet formation.Comment: 27 pages, 7 figures. Accepted for publication in the Astronomical Journal. For a version with high resolution figures, see http://www.astro.psu.edu/users/edf/51Eri.pd

    Orbifold projection in supersymmetric QCD at N_f\leq N_c

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    Supersymmetric orbifold projection of N=1 SQCD with relatively small number of flavors (not larger than the number of colors) is considered. The purpose is to check whether orbifolding commutes with the infrared limit. On the one hand, one considers the orbifold projection of SQCD and obtains the low-energy description of the resulting theory. On the other hand, one starts with the low-energy effective theory of the original SQCD, and only then perfoms orbifolding. It is shown that at finite N_c the two low-energy theories obtained in these ways are different. However, in the case of stabilized run-away vacuum these two theories are shown to coincide in the large N_c limit. In the case of quantum modified moduli space, topological solitons carrying baryonic charges are present in the orbifolded low-energy theory. These solitons may restore the correspondence between the two theories provided that the soliton mass tends to zero in the large N_c limit.Comment: 10 pages; misprint corrected, reference adde

    Floods of June 2012 in Northeastern Minnesota

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    U.S. Geological Survey Scientific Investigations Report 2012–5283. Reston, VA: U.S. Geological Survey.This report is a summary description of the 2012 flooding in the Fond du Lac region of Lake Superior from a meteorological and hydrologic perspective. The report notes that the extent and depth of flooding in communities can be used for flood recovery efforts. Key points are reproduced below. Abstract: “During June 19–20, 2012, heavy rainfall, as much as 10 inches locally reported, caused severe flooding across northeastern Minnesota. The floods were exacerbated by wet antecedent conditions from a relatively rainy spring, with May 2012 as one of the wettest Mays on record in Duluth. The June 19–20, 2012, rainfall event set new records in Duluth, including greatest 2-day precipitation with 7.25 inches of rain. The heavy rains fell on three major watersheds: the Mississippi Headwaters; the St. Croix, which drains to the Mississippi River; and Western Lake Superior, which includes the St. Louis River and other tributaries to Lake Superior. Widespread flash and river flooding that resulted from the heavy rainfall caused evacuations of residents, and damages to residences, businesses, and infrastructure. In all, nine counties in northeastern Minnesota were declared Federal disaster areas as a result of the flooding. Peak-of-record streamflows were recorded at 13 U.S. Geological Survey stream gages as a result of the heavy rainfall. Flood-peak gage heights, peak streamflows, and annual exceedance probabilities were tabulated for 35 U.S. Geological Survey stream gages. Flood-peak streamflows in June 2012 had annual exceedance probabilities estimated to be less than 0.002 (0.2 percent; recurrence interval greater than 500 years) for five stream gages, and between 0.002 and 0.01 (1 percent; recurrence interval greater than 100 years) for four stream gages. High-water marks were identified and tabulated for the most severely affected communities of Barnum (Moose Horn River), Carlton (Otter Creek), Duluth Heights neighborhood of Duluth (Miller Creek), Fond du Lac neighborhood of Duluth (St. Louis River), Moose Lake (Moose Horn River and Moosehead Lake), and Thomson (Thomson Reservoir outflow near the St. Louis River). Flood-peak inundation maps and water-surface profiles were produced for these six severely affected communities. The inundation maps were constructed in a geographic information system by combining high-water-mark data with high-resolution digital elevation model data. The flood maps and profiles show the extent and depth of flooding through the communities and can be used for flood response and recovery efforts by local, county, State, and Federal agencies.

    Superdeformation in 198^{198}Po

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    The 174^{174}Yb(29^{29}Si,5n) reaction at 148 MeV with thin targets was used to populate high-angular momentum states in 198^{198}Po. Resulting γ\gamma rays were observed with Gammasphere. A weakly-populated superdeformed band of 10 γ\gamma-ray transitions was found and has been assigned to 198^{198}Po. This is the first observation of a SD band in the A190A \approx 190 region in a nucleus with Z>83Z > 83. The J(2){\cal J}^{(2)} of the new band is very similar to those of the yrast SD bands in 194^{194}Hg and 196^{196}Pb. The intensity profile suggests that this band is populated through states close to where the SD band crosses the yrast line and the angular momentum at which the fission process dominates.Comment: 10 pages, revtex, 2 figs. available on request, submitted to Phys. Rev. C. (Rapid Communications

    A stacking-fault based microscopic model for platelets in diamond

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    We propose a new microscopic model for the {001}\{001\} planar defects in diamond commonly called platelets. This model is based on the formation of a metastable stacking fault, which can occur because of the ability of carbon to stabilize in different bonding configurations. In our model the core of the planar defect is basically a double layer of three-fold coordinated sp2sp^2 carbon atoms embedded in the common sp3sp^3 diamond structure. The properties of the model were determined using {\it ab initio} total energy calculations. All significant experimental signatures attributed to the platelets, namely, the lattice displacement along the [001][001] direction, the asymmetry between the [110][110] and the [11ˉ0][1\bar{1}0] directions, the infrared absorption peak BB^\prime, and broad luminescence lines that indicate the introduction of levels in the band gap, are naturally accounted for in our model. The model is also very appealing from the point of view of kinetics, since naturally occurring shearing processes will lead to the formation of the metastable fault.Comment: 5 pages, 4 figures. Submitted for publication on August 2nd, 200

    Isotopic and Compositional Variations in Single Nuclear Fuel Pellet Particles Analyzed by Nanoscale Secondary Ion Mass Spectrometry

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    Article published under an ACS AuthorChoice LicenseThe Collaborative Materials Exercise (CMX) is organized by the Nuclear Forensics International Technical Working Group, with the aim of advancing the analytical capabilities of the participating organizations and providing feedback on the best approaches to a nuclear forensic investigation. Here, model nuclear fuel materials from the 5th CMX iteration were analyzed using a NanoSIMS 50L (CAMECA) in order to examine inhomogeneities in the U-235/U-238 ratio and trace element abundance within individual, micrometer scale particles. Two fuel pellets were manufactured for the exercise and labelled CMX-5A and CMX-5B. These pellets were created using different processing techniques, but both had a target enrichment value of U-235/U-238 = 0.01. Particles from these pellets were isolated for isotopic and trace element analysis. Fifteen CMX-5A particles and 20 CMX-5B particles were analyzed, with both sample types displaying inhomogeneities in the U isotopic composition at a sub-micrometer scale within individual particles. Typical particle diameters were similar to 1.5 to 41 mu m for CMX-5A and similar to 1 to 61 mu m for CMX-5B. The CMX-5A particles were shown to be more isotopically homogeneous, with a mean U-235/U-238 atom ratio of 0.0130 +/- 0.0066. The CMX-5B particles showed a predominantly depleted mean U-235/U-238 atom ratio of 0.0063 +/- 0.0094, which is significantly different to the target enrichment value of the pellet and highlights the potential variation of U-235/U-238 in U fuel pellets at the micrometer scale. This study details the successful application of the NanoSIMS 50L in a mock nuclear forensic investigation by optimizing high-resolution imaging for uranium isotopics.Peer reviewe

    Can biological quantum networks solve NP-hard problems?

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    There is a widespread view that the human brain is so complex that it cannot be efficiently simulated by universal Turing machines. During the last decades the question has therefore been raised whether we need to consider quantum effects to explain the imagined cognitive power of a conscious mind. This paper presents a personal view of several fields of philosophy and computational neurobiology in an attempt to suggest a realistic picture of how the brain might work as a basis for perception, consciousness and cognition. The purpose is to be able to identify and evaluate instances where quantum effects might play a significant role in cognitive processes. Not surprisingly, the conclusion is that quantum-enhanced cognition and intelligence are very unlikely to be found in biological brains. Quantum effects may certainly influence the functionality of various components and signalling pathways at the molecular level in the brain network, like ion ports, synapses, sensors, and enzymes. This might evidently influence the functionality of some nodes and perhaps even the overall intelligence of the brain network, but hardly give it any dramatically enhanced functionality. So, the conclusion is that biological quantum networks can only approximately solve small instances of NP-hard problems. On the other hand, artificial intelligence and machine learning implemented in complex dynamical systems based on genuine quantum networks can certainly be expected to show enhanced performance and quantum advantage compared with classical networks. Nevertheless, even quantum networks can only be expected to efficiently solve NP-hard problems approximately. In the end it is a question of precision - Nature is approximate.Comment: 38 page
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