4,140 research outputs found
Development of Athletes Conceptions of Sport Officials Authority
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
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
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
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 Po
The Yb(Si,5n) reaction at 148 MeV with thin targets was used
to populate high-angular momentum states in Po. Resulting rays
were observed with Gammasphere. A weakly-populated superdeformed band of 10
-ray transitions was found and has been assigned to Po. This is
the first observation of a SD band in the region in a nucleus
with . The of the new band is very similar to those of
the yrast SD bands in Hg and 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
We propose a new microscopic model for the 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
carbon atoms embedded in the common 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 direction, the asymmetry between the
and the directions, the infrared absorption peak
, 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
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?
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
- …