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In this Comment, I show that the free energy expression for a glass proposed by La Nave [Phys. Rev. E 68, 032103 (2003)] cannot be correct since it violates the second law of thermodynamics.
In the paper we comment on [Rudiger and Shalybkov (RS), Phys. Rev. E 69, 016303 (2004)], the instability of the Taylor-Couette flow interacting with a homogeneous background field subject to the Hall effect is studied. We correct a falsely generalizing interpretation of results presented there which could be taken to disprove the existence of the Hall-drift-induced magnetic instability described in Rheinhardt and Geppert, Phys. Rev. Lett. 88, 101103 (2002). It is shown that, in contrast to what is suggested by RS, no additional shear flow is necessary to enable such an instability with a nonpotential magnetic background field, whereas for a curl-free one it is. In the latter case, the instabilities found in RS in situations where neither a hydrodynamic nor a magnetorotational instability exists are demonstrated to be most likely magnetic instead of magnetohydrodynamic. Further, some minor inaccuracies are clarified.
Very recently Willis [Phys. Rev. E 69, 056612 (2004)] have used a collective variable theory to explain the appearance of a nonzero energy current in an ac-driven, damped sine-Gordon equation. In this Comment, we prove rigorously that the time-averaged energy current in an ac-driven nonlinear Klein-Gordon system is strictly zero.
Fujima [T. Fujima, H. Frusawa, and K. Ito, Phys. Rev. E 66, 031503 (2002)] report on broadband dielectric relaxation measurements on two glass-formers. They find that the relaxation times of the beta relaxation follow different temperature dependences above and below the glass-transition temperature, Tg; i.e., there appears to be a crossover at Tg where the activation energy of the beta relaxation change. In this Comment we show that the observed behavior can be explained by analyzing the merging of the alpha and beta relaxations using an approach proposed by Williams. This analysis clearly shows that the low temperature (below Tg) behaviors of the alpha and beta relaxations can be used to describe also the high-temperature behavior (above Tg). The apparent change in activation energy is thus not to be identified with a change in relaxation mechanism.
In Electrical Impedance Imaging (EII), the spatial distribution of electrical resistivity of a volume conductor is reconstructed from measurements of potential which result from an externally applied electric field. The ability of such a system to distinguish a target inhomogeneity and the discussion of several measures of distinguishability has been a subject of a recent study. In this communication a few comments are added to those of. The medical device safety regulations limit the maximum total input current which can be applied to the human thorax. Based on the currently existing safety regulations, if the input current to the thorax is limited and constant, patterns applied between opposite electrodes result in higher distinguishability of a centered target than the cosine current patterns as suggested by.
This letter comments on a recent study of the drift rate of 115 cesium standards. The conclusion here is that no aging effect is visible in the results of the study.
The following comments are given on the guidelines suggested by Türker (1988) for studies on oral reflexes using the surface EMG of the masseter muscles in man, including the silent period. (i) Attention should not be confined to electrical stimulation since mechanoreceptors in the periodontium, especially in the periodontal ligament, can only be activated by mechanical stimulation of a tooth. Furthermore, different modes of stimulation and stimulation sites do not yield equivalent reflex complexes. Weak and transient mechanical stimulation of a tooth while clenching at a low level of 5 or 10% MVC is a selective model (89%) to study the influence of periodontal receptors. (ii) Statistical criteria should be applied on rectified and averaged EMG records to prevent any subjective bias in the measurements of reflex variables. Whether a period of increased EMG activity is due to clustering of action potentials of motor units firing of which was delayed by a preceding inhibition, or to a real excitatory influence, can be assessed by applying statistical criteria on averaged and subsequently rectified records. (iii) The clenching level should be less than 25% of MVC to avoid muscle fatigue, and to elicit pronounced reflexes with a weak and therefore more selective stimulus. (iv) The stimulus intensity should be much less than six times the threshold if selectivity for mechanoreceptors is desired. Furthermore, periods of increased activity in surface EMG resulting from a weak stimulus are probably due to real excitatory influences and not to clustering of motor unit action potentials after an inhibition. (v) Jaw separation and the use of a force transducer are not always advantageous. If mechanical stimulation is applied to a tooth, clenching in full habitual occlusion causes a complete suppression of the influence of muscle spindles. A shift in activity between the various elevator muscles, and hence a change in activity of the muscle studied, may occur during an experimental session if biting force is used as a feedback. Such a shift is not relevant if feedback is carried out on rectified and low-pass filtered (1.6 Hz) EMG of the muscle studied.
This comment is submitted with the intent of stimulating some exchange between researchers. Although I chose the Woodward et al. study as a vehicle for my statement, I might easily have chosen examples outside the family therapy area.
Epileptic lesions often affect two of the most important functions in human behavior, memory and emotion. While cognitive functions, e.g, speech and memory, are normally carefully studied, emotional and psychosocial aspects of behavior are often overlooked in the pre- and postoperative evaluation of epilepsy patients. In my comment, I will address the need for methodological and theoretical refinement, especially regarding measurements of emotional and psychosocial aspects. In evaluating memory functions, a functionalistic approach is suggested; that is, in contrast to the entity view, studies should focus on the interaction between task demands and the available cognitive capabilities of the rememberer. We should develop a broad set of tests and demonstrate dissociations between different tasks that tap different capabilities and different memory systems: we should look for patterns of results rather than single scores.
OBJECTIVES: To redefine and comment on terms on a pathological basis, in order to avoid the confusion due to the use of terms with different meanings, to standardise usage among clinicians, radiologists and pathologists, and to facilitate literature searches. METHODS: Within the Committee of Pathology of the European League against Rheumatism, a study group was set up to analyse the medical literature and common practice concerning the nomenclature of rheumatic spinal diseases. The group tried to amalgamate the main trends in the field, to reconcile etymology, historical background, morphology, and common practice. RESULTS: The group warns against use of the terms 'acquired hyperostosis syndrome', '(von) Bechterew's disease', 'Kümmel's disease', 'pseudospondylolisthesis', 'rheumatoid spondylitis', 'spondylarthropathy' in the sense of spondarthritis, and 'spondylosis'. It recommends intercorporal or interapophyseal rather than intervertebral (osteo) chondrosis, zygapophyseal diverticulum rather than cyst, disc hernia rather than prolapse, spondyloarthritis rather than spondyloarthropathy, marginal rather than anterior spondylitis, and discarthrosis. It proposes 'zygarthrosis' to designate zygapophyseal osteoarthrosis. CONCLUSIONS: Knowledge of the pathological basis of diseases and an understanding of the original definitions given by those who coined new terms make it possible to avoid most of the confusion arising from improper use of spinal terms.
The paper comments on Scott Dunbar's "An obstructed death and medical ethics," arguing contra Dunbar that we should not view truth-telling to the terminally ill as primarily governed by principles of veracity and respect for autonomy. All such rules are of limited value in medical ethics. We should instead turn to an ethics deriving from the centrality of moral relationships and virtues. A brief analysis of the connections between moral relationships and moral rules is offered. Such an ethics would lower the value that philosophical fashion places on truth-telling and autonomy and leave decisions about truth-telling and the terminally ill more dependent on the circumstances of particular cases.
In Canada, the Assisted Human Reproduction Act received royal assent on 29 March 2004. The approach proposed by the federal government responds to Canadians' strong desire for an enforceable legislative framework in the field of reproduction technologies through criminal law. As a result of the widening gap between the rapid pace of technological change and governing legislation, a distinct need was perceived to create a regulatory framework to guide decisions regarding reproductive technologies. In this article the three main topics covered in the new legislation are commented on: cloning, germline therapy, and purchase of gametes and embryos. Some important issues also covered in the new legislation, such as privacy and access to information, data protection, identity of donors, and inspection, will not be addressed.
By way of comment, I suggest: 1) That the definitions of 'competence' and 'rationality' require some modification. 2) That Professor Sherlock is right to argue that a competent but irrational decision to refuse beneficial treatment ought to be overruled; but in practice it is extremely difficult to be sufficiently sure that the decision is really irrational and the treatment really will be beneficial, except when the patient's life is in danger or he is refusing basic necessities. 3) That in practice the issue is further complicated by such questions as whether there are alternative treatments, whether persuasion is possible, what the doctor's or institution's legal obligations are, and what resources are available. 4) That the presumption should be against coercion, and the patient--however irritating this may be to some doctors--should be considered 'rational until proved irrational'.
The constitutional right to treatment has now become an accepted premise of litigation in the United States. It lacks only the imprimatur of the Supreme Court. The author presents a brief description of the history of right to treatment cases and comments on the problems and possibilities the law holds for psychiatry. He warns that psychiatric institutions must be aware of the costs and benefits of such litigation and must obtain skilled legal counsel to advise them of their rights and obligations. He calls on psychiatry as a profession to participate in right to treatment litigation and to attempt to shape legal standards so that future generations of psychiatrists can provide appropriate care to patients.
The authors asked that this paper be published as a comment on the preceding article by Dr. Winsberg and associates, who approved the suggestion.
The ventromedial temporal area has a complicated topography and neuroanatomy that has yielded secrets only grudgingly. The major features of surface topography are reviewed here as well as recent neuroanatomical findings that establish the ventromedial temporal area as both a recipient of cortical input and the origin for widespread output back to the cortex. The devastating involvement of all ventromedial temporal areas in Alzheimer's disease is highlighted, and comments are offered on the tentorium cerebelli and on mechanical injury to the area.
Following the introduction of a consistent method of adding informative comments to the laboratory report of the plasma concentrations of the anticonvulsants phenytoin, carbamazepine and phenobarbitone, there was a significant increase in the proportion of results falling within the therapeutic range to 64, 65 and 62% respectively. This increase was mainly at the expense of results which previously fell below this range.
We assess a previously described scoring system for the appropriateness of interpretative comments on clinical biochemistry reports over 21 distributed cases and over a group of 41 UK-based participants. The distributed cases covered a range of clinical scenarios and included pre- and post-analytical problems. The UK-based participants had all registered an interest in using this case participation for their continuing professional development; all had higher professional qualifications in clinical biochemistry, and the group included participants based in teaching hospitals and district general hospitals as well as those with a medical or a scientific background. Although the present scoring system favours participants who mention more than one possible outcome and who include several ideas for further investigation, its advantages seem to outweigh its disadvantages. The scored cases are currently unique, and are seen to be of major educational value not only by active participants but also by those who are using them for teaching or in discussion groups.