SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
This Comment corrects some errors which appeared in the calculation of an elastic sphere eigenenergies. As a result, the symmetry of the mode having the lowest frequency is changed. Also a direction for calculating the damping of these modes for embedded elastic spheres is given.
It was recently argued [M. Nauenberg, Phys. Rev. E 67, 036114 (2003)] that the theory sometimes referred to as nonextensive statistical mechanics has no physical basis, for a considerable variety of reasons, including the impossibility of measuring the temperature out of the Boltzmann-Gibbs (BG) theory. We comment here on virtually all the physically and mathematically relevant issues, and point out what we consider to be severe inadvertences contained in that paper. In particular, we factually argue, through computer simulations, the validity of the zeroth principle of thermodynamics, and of the basic rules of thermometry for nonextensive systems. This fact further supports the possible connection with the thermodynamics of nonextensive statistical mechanics, which is already known to be consistent with the first, second, and third principles. All the foundational steps (e.g., the uniqueness of the entropy and the stationary state distribution) have already been established for nonextensive thermostatistics on similar grounds than those long known for BG statistics, the former corresponding to power laws (expected for long-range interactions when size N diverges before time t), and the latter correspond to the BG exponential law (expected for long-range interactions when N diverges after t, as well as for short-range interactions in any diverging order for N and t). We conclude that the invalidating arguments made by Nauenberg by no means apply.
We comment on the use of an inaccurate fitting formula for the energy-average electron-ion momentum transport cross section in the computation of electrical conductivity of nonideal aluminum plasma.
Recently, Garcia et al. [Phys. Rev. E 67, 046606 (2003)] studied theoretically several acoustic devices with dimensions on the order of several wavelengths. Those authors also discussed experimental results previously reported by several of us [Phys. Rev. Lett. 88, 023902 (2002)]] and concluded that it is diffraction rather than refraction that is the dominating mechanism explaining the focusing effects observed in those experiments. In this Comment we reexamined their calculations and discussed why some of their interpretations of our results are misleading.
In this Comment, I argue that the method of images used by Huang, Yu, and Gu [Phys Rev. E 65, 021401 (2002)] and Huang, Karttunen, Yu, Dong, and Gu [Phys Rev. E., 69, 051402 (2004)] to calculate electromagnetic properties of interacting spheres at finite frequencies is inapplicable and does not provide a physically meaningful approximation.
In this Comment two main issues are addressed that are pertinent to the interpretation of the transition to turbulence for shear type flows on the basis of transient chaos: the fractal character associated with this transition and the precision needed for a reliable numerical modeling. The analysis is based on a simplified model of 19 degrees of freedom for Couette flow, proposed some years ago by Eckhardt and Mersmann. We conclude that the landscape of lifetimes cannot be fractal, and that a very high numerical accuracy is needed to obtain sound results.
Recently, Wada [Phys. Rev. E 69, 031202 (2004)] presented an analysis of the long-range nature of concentration fluctuations in a binary liquid mixture subjected to a concentration gradient in a uniform shear flow as a function of the wave number k of the fluctuations. Specifically, he argued that the presence of a uniform shear causes the intensity of the concentration fluctuations to crossover from the well-known k(-4) dependence at large wave numbers to a k(-4/3) dependence for small wave numbers. The purpose of this comment is to point out that the wave-number dependence of the concentration fluctuations to be expected in realistic experimental conditions will be affected by gravity and finite-size effects.
This Comment corrects the error which appeared in the calculation of the degree distribution of random Apollonian networks [T. Zhou, G. Yan, and B. H. Wang, Phys. Rev. E. 71, 046141 (2005)]. As a result, the expression of P(k), which gives the probability that a randomly selected node has exactly k edges, has the form P(k) alpha 1/[k(k + 1)(k + 2)].
In this Comment, we show that the expression for as proposed by R. Breban, R. Vardavas, and S. Blower, Phys. Rev. E 72, 046110 (2005) is incorrect and we reveal the underlying conceptual mistake.
In this paper, errors and discrepancies in the subject paper [Cincotti et al., (2002)] are highlighted. A comment, concerning the axial resolution associated to the adopted processing procedure is also reported.
In a previous paper, direct and indirect adaptive output-feedback fuzzy decentralized controllers for a class of uncertain large-scale nonlinear systems were presented. A comment is made here to show that the proposed control schemes of the previous paper are not realizable.
This note responds to the comments published by Ni Zhao and Fu-Chun Sun in IEEE TRANSACTIONS ON SYSTEMS, MAN, AND CYBERNETICS-PART B, vol. 34, no. 6, p. 2422, Dec. 2004. Note that Theorems 3.1 and 3.2 are correct. The errors in the proofs have been fixed.
There are several important issues raised in the paper by Cattell and in the comments upon it: the empirical status of the Cattell factors; the experimental verification of factors; difficulties with confirmatory analysis and the value of P-analysis. The relevance of these points is explicated in this paper.
Krisha [J. Acoust. Soc. Am., in press (2006)] has commented that an explanation based on presynaptic calcium accumulation at the inner hair cell is an incorrect explanation for the success of a model of the auditory periphery [Meddis, R., J. Acoustic. Soc. Am. 119, 406-417 (2006)] in explaining data on first-spike auditory nerve latency. This reply accepts the criticism and accepts the strength of an alternative explanation based on expected latencies in random sequences of low-probability events. This reply also goes on briefly to explore the application of this argument to other phenomena, including the dependence of absolute auditory threshold on the duration of the stimulus. This has wide-ranging implications for the concept of "temporal integration" in psychophysics.
The Zwislocki et al. ["Earphones in Audiometry," J. Acoust. Soc. Am. 83, 1688-1689 (1988)] Letter to the Editor states that insert earphones have some unresolved technical problems, such as limited frequency response, limited dynamic range and power handling capability, intersubject variability, and hygiene safety. In evaluating circumaural earphones, Zwislocki et al. say that the lack of a standard coupler disqualifies them for audiometry. Since this letter carries the weight of a CHABA committee recommendation, these issues are commented on herein. Section I was written primarily by Mead Killion and Sec. II primarily by Edgar Villchur. For brevity throughout, the authors of the Zwislocki et al. letter will be referred to as "the authors."
The question of churches resorting to the courts to influence public policy is one that concerns the appropriate role of the courts and the appropriate conduct of religious authorities. I agree with Skene and Parker that there is no principled legal reason to exclude such interventions out of hand; but my comments are principally addressed to the political and religious reasons for being rightly concerned about such activity. These advert both to the nature of the liberal democratic compromise and to the nature and scope of religious authority (at least within Christianity).
In this comment on the contribution of A. Lesne and J.-M. Victor I provide some additional ideas on the hypothesis that higher-order chromatin structures stamp their marks on their small subunits.
The review by Arndt Benecke focuses on chromatin, a major hallmark of eukaryotic life. The dynamic of chromatin and its underlying mechanisms are discussed. In addition, theoretical properties of chromatin associated with transcriptional regulation are presented. In the present brief comment on the review by Arndt Benecke, we wish to provide additional information regarding chromatin structure and in particular on the so-called "histone code hypothesis". We will discuss about the emerging idea that chromatin structure is much more complex than previously thought. The possibility that chromatin modifications may play important roles in biology beside transcriptional regulation will also be put forward.