456 research outputs found

    Three-body non-additive forces between spin-polarized alkali atoms

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    Three-body non-additive forces in systems of three spin-polarized alkali atoms (Li, Na, K, Rb and Cs) are investigated using high-level ab initio calculations. The non-additive forces are found to be large, especially near the equilateral equilibrium geometries. For Li, they increase the three-atom potential well depth by a factor of 4 and reduce the equilibrium interatomic distance by 0.9 A. The non-additive forces originate principally from chemical bonding arising from sp mixing effects.Comment: 4 pages, 3 figures (in 5 files

    Failing boys and moral panics: perspectives on the underachievement debate

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    The paper re-examines the underachievement debate from the perspective of the ‘discourse of derision’ that surrounds much writing in this area. It considers the contradictions and inconsistencies which underpin much of the discourse – from a reinterpretation of examination scores, to the conflation of the concepts of ‘under’ and ‘low’ achievement and finally to the lack of consensus on a means of defining and measuring the term underachievement. In doing so, this paper suggests a more innovative approach for understanding, re-evaluating and perhaps rejecting the notion of underachievement

    Low intensity pulsed ultrasound (LIPUS) for bone healing: A clinical practice guideline

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    Does low intensity pulsed ultrasound (LIPUS) accelerate recovery in adults and children who have experienced bone fractures or osteotomy (cutting of a bone)? An expert panel rapidly produced these recommendations based on a linked systematic review triggered by a large multi-centre randomised trial in adults with tibial fracture

    Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

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    We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

    Prospective organisation of neonatal arm movements : a motor foundation of embodied agency, disrupted in premature birth

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    Prospective motor control moves the body into the future, from where one is to where one wants to be. It is a hallmark of intentionality. But its origins in development is uncertain. In this study, we tested whether or not the arm movements of newborn infants were prospectively controlled. We measured the spatiotemporal organisation of 480 neonatal arm movements and 384 arm movements of infants prematurely born at-risk for neurodevelopmental disorder. We found 75% of healthy term-birth neonatal movements and 68% of prematurely-born infant movements conformed to the tauG-coupling model of prospective sensorimotor control. Prospective coupling values were significantly reduced in the latter (p = .010, r = .087). In both cases prospectively controlled movements were tightly organised by fixed-duration units with a base duration of 218 ms and additional temporal units of 145 ms. Yet distances remained constant. Thus, we demonstrate for the first time a precise prospective spatiotemporal organisation of neonatal arm movements and demonstrate at-risk infants exhibit reduced sensorimotor control. Prospective motor control is a hallmark of primary sensorimotor intentionality and gives a strong embodied foundation to conscious motor agency

    Why is management research irrelevant?

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    At least since 1980, there has been a practically continuous, but somewhat fragmented discussion on the relevance of management research. This discussion has addressed practically all fields of management; here, besides general management, operations management, project management and construction management are examined in more detail. Although many different proposals have been made to rectify the situation, no definitive resolution has been found. In this paper, it is argued that prior analyses have not reached the root causes of the irrelevance problem. By an analysis of the recent history of management research, the following novel findings are reached. First, the root cause of the irrelevance is argued to lie in the 1959 reports on American business education, written by Pierson and Gordon & Howell. Second, while the proposed direction in the 1959 reports was deficient in several ways, the rejection of production as an integral part of organizations and management has been perhaps the most damaging feature of those reports. Third, current research on management suffers from a variety of immediate causes for irrelevance, insufficiently recognized by the scholarly community. It is suggested that reaching the root causes for irrelevance will facilitate finding suitable cures
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