Human acclimation and acclimatization to heat: A compendium of research, 1968-1978

Abstracts and annotations of the majority of scientific works that elucidate the mechanisms of short-term acclimation to heat in men and women are presented. The compendium includes material from 1968 through 1977. Subject and author indexes are provided and additional references of preliminary research findings or work of a peripheral nature are included in a bibliography

Imaging Earth's crustal magnetic field with satellite data: a regularized spherical triangle tessellation approach

We present a method for imaging the global crustal magnetic field at Earth's surface using a local basis representation and a minimum norm model regularization approach. The local basis consists of a spherical triangle tessellation (STT) parametrization of the radial component of the crustal field at Earth's reference spherical surface. The Green's function for Laplace's equation in spherical geometry with Neumann boundary conditions provides the necessary forward modelling scheme. We solve the inverse problem of estimating the crustal field from satellite magnetic observations by minimizing an objective function comprising a mean absolute deviation (L1-norm) measure of misfit plus a norm measuring model complexity. Both quadratic and entropy measures of field complexity are investigated. We report results from synthetic tests performed on a geophysically motivated scenario; these include a successful benchmark of the method and a comparison between quadratic and entropy regularization strategies. Applying our technique to real observations collected by the CHAMP, Ørsted and SAC-C satellites, we obtain stable images of the crustal magnetic field at Earth's surface that include sharp features with high amplitudes. We present details of two prototype crustal field models STT-CRUST-Q and STT-CRUST-E regularized using quadratic and entropy norms respectively; these provide a perspective complementary to that given by conventional spherical harmonic crustal field model

Spontaneous helping behavior of autistic and non-autistic (Pre-)adolescents: A matter of motivation?

Young autistic people have a range of social difficulties, but it is not yet clear how these difficulties can be explained. In addition, emerging research is suggesting that autistic girls may differ from boys in terms of their social behaviors, but yet unknown is if they differ in terms of their pro‐social behavior, such as helping. The present study investigated spontaneous helping behavior using an in vivo paradigm and related this to participants' levels of social motivation (based on parent reports). Participants were 233 autistic and non‐autistic (pre‐)adolescents (M = 12.46 years, SD = 15.54 months). Our results demonstrated that autistic girls and boys have lower levels of social motivation compared to their non‐autistic peers, but social motivation was unrelated to helping behavior in both groups. Furthermore, when the experimenter needed help, the autistic boys and girls looked and smiled to the same extent as their peers of the same gender, but they actually helped significantly less than their non‐autistic peers. However, most autistic youngsters did help, highlighting the great individual differences in autistic individuals. We discuss the possibility that lower levels of helping behavior are due to difficulty initiating action in a social context, rather than lower social motivation

Light emission patterns from stadium-shaped semiconductor microcavity lasers

We study light emission patterns from stadium-shaped semiconductor (GaAs) microcavity lasers theoretically and experimentally. Performing systematic wave calculations for passive cavity modes, we demonstrate that the averaging by low-loss modes, such as those realized in multi-mode lasing, generates an emission pattern in good agreement with the ray model's prediction. In addition, we show that the dependence of experimental far-field emission patterns on the aspect ratio of the stadium cavity is well reproduced by the ray model.Comment: 5 pages, 4 figure

Ergodicity of the Δ3\Delta_3 statistic and purity of neutron resonance data

The $\Delta_3(L)$ statistic characterizes the fluctuations of the number of levels as a function of the length of the spectral interval. It is studied as a possible tool to indicate the regular or chaotic nature of underlying dynamics, detect missing levels and the mixing of sequences of levels of different symmetry, particularly in neutron resonance data. The relation between the ensemble average and the average over different fragments of a given realization of spectra is considered. A useful expression for the variance of $\Delta_3(L)$ which accounts for finite sample size is discussed. An analysis of neutron resonance data presents the results consistent with a maximum likelihood method applied to the level spacing distribution.Comment: 24 pages, 19 figures, 1 tabl

Emotion regulation and internalizing symptoms in children with Autism Spectrum Disorders

The aim of this study was to examine the unique contribution of two aspects of emotion regulation (awareness and coping) to the development of internalizing problems in 11-year-old high-functioning children with an autism spectrum disorder (HFASD) and a control group, and the moderating effect of group membership on this. The results revealed overlap between the two groups, but also significant differences, suggesting a more fragmented emotion regulation pattern in children with HFASD, especially related to worry and rumination. Moreover, in children with HFASD, symptoms of depression were unrelated to positive mental coping strategies and the conviction that the emotion experience helps in dealing with the problem, suggesting that a positive approach to the problem and its subsequent emotion experience are less effective in the HFASD group

Quantum chaos in nanoelectromechanical systems

We present a theoretical study of the electron-phonon coupling in suspended nanoelectromechanical systems (NEMS) and investigate the resulting quantum chaotic behavior. The phonons are associated with the vibrational modes of a suspended rectangular dielectric plate, with free or clamped boundary conditions, whereas the electrons are confined to a large quantum dot (QD) on the plate's surface. The deformation potential and piezoelectric interactions are considered. By performing standard energy-level statistics we demonstrate that the spectral fluctuations exhibit the same distributions as those of the Gaussian Orthogonal Ensemble (GOE) or the Gaussian Unitary Ensemble (GUE), therefore evidencing the emergence of quantum chaos. That is verified for a large range of material and geometry parameters. In particular, the GUE statistics occurs only in the case of a circular QD. It represents an anomalous phenomenon, previously reported for just a small number of systems, since the problem is time-reversal invariant. The obtained results are explained through a detailed analysis of the Hamiltonian matrix structure.Comment: 14 pages, two column

Casimir force between integrable and chaotic pistons

We have computed numerically the Casimir force between two identical pistons inside a very long cylinder, considering different shapes for the pistons. The pistons can be considered as quantum billiards, whose spectrum determines the vacuum force. The smooth part of the spectrum fixes the force at short distances, and depends only on geometric quantities like the area or perimeter of the piston. However, correcting terms to the force, coming from the oscillating part of the spectrum which is related to the classical dynamics of the billiard, are qualitatively different for classically integrable or chaotic systems. We have performed a detailed numerical analysis of the corresponding Casimir force for pistons with regular and chaotic classical dynamics. For a family of stadium billiards, we have found that the correcting part of the Casimir force presents a sudden change in the transition from regular to chaotic geometries.Comment: 13 pages, 10 figure

Chaotic scattering of atoms at a standing laser wave

Atoms, propagating across a detuned standing laser wave, can be scattered in a chaotic way even in the absence of spontaneous emission and any modulation of the laser field. Spontaneous emission masks the effect in some degree, but the Monte Carlo simulation shows that it can be observed in real experiments by the absorption imaging method or depositing atoms on a substrate. The effect of chaotic scattering is explained by a specific behavior of the dipole moments of atoms crossing the field nodes and is shown to depend strongly on the value of the atom-laser detuning.Comment: arXiv admin note: substantial text overlap with arXiv:1201.032