8,598 research outputs found
Children’s early helping in action: Piagetian developmental theory and early prosocial behavior
After a brief overview of recent research on early helping, outlining some central problems and issues, this paper examines children’s early helping through the lens of Piagetian moral and developmental theory, drawing on Piaget’s ‘Moral Judgment of the Child’ (1932/1997), ‘Play, Dreams, and Imitation in Childhood’ (1945/1951), and the ‘Grasp of Consciousness’ (1974). Piaget refers to a level of moral development in action that precedes heteronomous and autonomous moral reasoning. This action level allows children to begin to interact with people and objects. In his later work, Piaget explores the gradual construction of understanding from this activity level. Taken together, these elements of Piagetian theory provide a promising conceptual framework for understanding the development of early helping
The Trapped Polarized Fermi Gas at Unitarity
We consider population-imbalanced two-component Fermi gases under external
harmonic confinement interacting through short-range two-body potentials with
diverging s-wave scattering length. Using the fixed-node diffusion Monte Carlo
method, the energies of the "normal state" are determined as functions of the
population-imbalance and the number of particles. The energies of the trapped
system follow, to a good approximation, a universal curve even for fairly small
systems. A simple parameterization of the universal curve is presented and
related to the equation of state of the bulk system.Comment: 4 pages, 2 tables, 2 figure
Electrical characterization of a Mapham inverter using pulse testing techniques
Electric power requirements for aerospace missions have reached megawatt power levels. Within the next few decades, it is anticipated that a manned lunar base, interplanetary travel, and surface exploration of the Martian surface will become reality. Several research and development projects aimed at demonstrating megawatt power level converters for space applications are currently underway at the NASA Lewis Research Center. Innovative testing techniques will be required to evaluate the components and converters, when developed, at their rated power in the absence of costly power sources, loads, and cooling systems. Facilities capable of testing these components and systems at full power are available, but their use may be cost prohibitive. The use of a multiple pulse testing technique is proposed to determine the electrical characteristics of large megawatt level power systems. Characterization of a Mapham inverter is made using the proposed technique and conclusions are drawn concerning its suitability as an experimental tool to evaluate megawatt level power systems
The few-body problem in terms of correlated gaussians
In their textbook, Suzuki and Varga [Y. Suzuki and K. Varga, {\em Stochastic
Variational Approach to Quantum-Mechanical Few-Body Problems} (Springer,
Berlin, 1998)] present the stochastic variational method in a very exhaustive
way. In this framework, the so-called correlated gaussian bases are often
employed. General formulae for the matrix elements of various operators can be
found in the textbook. However the Fourier transform of correlated gaussians
and their application to the management of a relativistic kinetic energy
operator are missing and cannot be found in the literature. In this paper we
present these interesting formulae. We give also a derivation for new
formulations concerning central potentials; the corresponding formulae are more
efficient numerically than those presented in the textbook.Comment: 10 page
Leech Parasitism of the Gulf Coast Box Turtle, Terrapene carolina major (Testudines:Emydidae) in Mississippi, USA
Ten leeches were collected from a Gulf Coast box turtle, Terrapene carolina major, found crossing a road in Gulfport, Harrison County, Mississippi, USA. Eight of the leeches were identified as Placobdella multilineata and 2 were identified as Helobdella europaea. This represents the second vouchered report of leeches from a box turtle. Helobdella europaea is reported for the first time associated with a turtle and for the second time from the New World
An investigation of the performance portability of OpenCL
This paper reports on the development of an MPI/OpenCL implementation of LU, an application-level benchmark from the NAS Parallel Benchmark Suite. An account of the design decisions addressed during the development of this code is presented, demonstrating the importance of memory arrangement and work-item/work-group distribution strategies when applications are deployed on different device types. The resulting platform-agnostic, single source application is benchmarked on a number of different architectures, and is shown to be 1.3–1.5× slower than native FORTRAN 77 or CUDA implementations on a single node and 1.3–3.1× slower on multiple nodes. We also explore the potential performance gains of OpenCL’s device fissioning capability, demonstrating up to a 3× speed-up over our original OpenCL implementation
Effects of a torsion field on Big Bang nucleosynthesis
In this paper it is investigated whether torsion, which arises naturally in
most theories of quantum gravity, has observable implications for the Big Bang
nucleosynthesis. Torsion can lead to spin flips amongst neutrinos thus turning
them into sterile neutrinos. In the early Universe they can alter the helium
abundance which is tightly constrained by observations. Here I calculate to
what extent torsion of the string theory type leads to a disagreement with the
Big Bang nucleosynthesis predictions.Comment: accepted by General Relativity and Gravitatio
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