Background and methods: Psychiatric research can occasionally present particular ethical dilemmas, but it is not clear what kind of problems local research ethics committees actually experience in this field. We aimed to assess the type of problems that committees encounter with psychiatric research, using a postal survey of 211 LRECs.Results: One hundred and seven of those written to replied within the time limit. Twenty eight experienced few problems with psychiatric applications. Twenty six emphasised the value of a psychiatric expert on (...) the committee. The most common issues raised were informed consent and confidentiality . The use of placebos , the validity of psychiatric questionnaires and overuse of psychiatric “jargon” in psychiatric applications also raised concern.Conclusions: Our results suggest that LRECs have specific concerns regarding methodology, consent, and confidentiality in psychiatric research, and that they find psychiatric input invaluable. (shrink)

Many medical ethicists accept the thesis that there is no moral difference between withholding and withdrawing life-sustaining therapy. In this paper, we offer an interesting counterexample which shows that this thesis is not always true. Withholding is distinguished from withdrawing by the simple fact that therapy must have already been initiated in order to speak coherently about withdrawal. Provided that there is a genuine need and that therapy is biomedically effective, the historical fact that therapy has been initiated entails a (...) claim to continue therapy that cannot be attributed to patients who have not yet received therapy. This intrinsic difference between withholding and withdrawing therapy is of moral importance. In many instances, patients will waive this claim. But when one considers withdrawing therapy from one patient to help another in a setting of scarce resources, this intrinsic moral difference comes into sharp focus. In an era of shrinking medical resources, this difference cannot be ignored. (shrink)

In 1885, during initial discussions of J. C. Maxwell's celebrated thermodynamic demon, Whiting (1) observed that the demon-like velocity selection of molecules can occur in a gravitationally bound gas. Recently, a gravitational Maxwell demon has been proposed which makes use of this observation [D. P. Sheehan, J. Glick, and J. D. Means, Found. Phys. 30, 1227 (2000)]. Here we report on numerical simulations that detail its microscopic phase space structure. Results verify the previously hypothesized mechanism of its paradoxical behavior. This (...) system appears to be the only example of a fully classical mechanical Maxwell demon that has not been resolved in favor of the second law of thermodynamics. (shrink)

A laboratory-testable, solid-state Maxwell demon is proposed that utilizes the electric field energy of an open-gap p-n junction. Numerical results from a commercial semiconductor device simulator (Silvaco International–Atlas) verify primary results from a 1-D analytic model. Present day fabrication techniques appear adequate for laboratory tests of principle.

In 2000, a simple, foundational thermodynamic paradox was proposed: a sealed blackbody cavity contains a diatomic gas and a radiometer whose apposing vane surfaces dissociate and recombine the gas to different degrees (A $_{2} \rightleftharpoons $ 2A). As a result of differing desorption rates for A and A $_{2}$ , there arise between the vane faces permanent pressure and temperature differences, either of which can be harnessed to perform work, in apparent conflict with the second law of thermodynamics. Here we (...) report on the first experimental realization of this paradox, involving the dissociation of low-pressure hydrogen gas on high-temperature refractory metals (tungsten and rhenium) under blackbody cavity conditions. The results, corroborated by other laboratory studies and supported by theory, confirm the paradoxical temperature difference and point to physics beyond the traditional understanding of the second law. (shrink)

The purpose of this study was to identify and describe published research articles that were named in official findings of scientific misconduct and to investigate compliance with the administrative actions contained in these reports for corrections and retractions, as represented in PubMed. Between 1993 and 2001, 102 articles were named in either the NIH Guide for Grants and Contracts ( Findings of Scientific Misconduct ) or the U.S. Office of Research Integrity annual reports as needing retraction or correction. In 2002, (...) 98 of the 102 articles were indexed in PubMed. Eighty-five of these 98 articles had indexed corrections: 47 were retracted; 26 had an erratum; 12 had a correction described in the comment field. Thirteen had no correction, but 10 were linked to the NIH Guide Findings of Scientific Misconduct , leaving only 3 articles with no indication of any sort of problem. As of May 2005, there were 5,393 citations to the 102 articles, with a median of 26 citations per article (range 0–592). Researchers should be alert to Comments linked to the NIH Guide as these are open access, and the Findings of Scientific Misconduct’ reports are often more informative than the statements about the retraction or correction found in the journals. (shrink)

Purpose: Physicians are often reluctant to discuss “Do Not Resuscitate” orders with patients. Although perceived self-efficacy is a known prerequisite for behavioural change, little is understood about the confidence of physicians regarding DNR discussions.Subjects and methods: A survey of 217 internal medicine attendings and 132 housestaff at two teaching hospitals about their attitudes and confidence regarding DNR discussions.Results: Participants were significantly less confident about their ability to discuss DNR orders than to discuss consent for medical procedures , and this was (...) true for both attendings and housestaff . In a multivariate logistic model of confidence regarding DNR discussions, women were less confident than men ; house officers were less confident than attendings , those who were less confident of their ability to discuss medical procedures were less confident discussing DNR , and those who found talking to patients about DNR orders very difficult reported less confidence than those who did not .Conclusion: We conclude that physicians’ confidence regarding DNR discussions is low compared with their confidence regarding other medical discussions and that confidence varies by sex and perceived difficulty of the task. Efforts to improve DNR discussions should explore the need to tailor educational interventions to fit these characteristics. (shrink)

In 1885, during initial discussions of J. C. Maxwell's celebrated thermodynamic demon, Whiting(1) observed that the demon-like velocity selection of molecules can occur in a gravitationally bound gas. Recently, a gravitational Maxwell demon has been proposed which makes use of this observation [D. P. Sheehan, J. Glick, and J. D. Means, Found. Phys. 30, 1227 (2000)]. Here we report on numerical simulations that detail its microscopic phase space structure. Results verify the previously hypothesized mechanism of its paradoxical behavior. This system (...) appears to be the only example of a fully classical mechanical Maxwell demon that has not been resolved in favor of the second law of thermodynamics. (shrink)

A new member of a growing class of unresolved second law paradoxes is examined.(1–7) In a sealed blackbody cavity, a spherical gravitator is suspended in a low density gas. Infalling gas suprathermally strikes the gravitator which is spherically asymmetric between its hemispheres with respect to surface trapping probability for the gas. In principle, this system can be made to perform steady-state work solely at the expense of heat from the heat bath, this in apparent violation of the second law of (...) thermodynamics. Detailed three-dimensional test particle simulations of this system support this prediction. Standard resolutions to the paradox are discussed and found to be untenable. Experiments corroborating a central physical process of the paradox are discussed briefly. The paradox is discussed in the context of the Maxwell demon. (shrink)

This study examined health professionals’ (HPs) experience, beliefs and attitudes towards brain death (BD) and two types of donation after circulatory death (DCD)—controlled and uncontrolled DCD. Five hundred and eighty-seven HPs likely to be involved in the process of organ procurement were interviewed in 14 hospitals with transplant programs in France, Spain and the US. Three potential donation scenarios—BD, uncontrolled DCD and controlled DCD—were presented to study subjects during individual face-to-face interviews. Our study has two main findings: (1) In the (...) context of organ procurement, HPs believe that BD is a more reliable standard for determining death than circulatory death, and (2) While the vast majority of HPs consider it morally acceptable to retrieve organs from brain-dead donors, retrieving organs from DCD patients is much more controversial. We offer the following possible explanations. DCD introduces new conditions that deviate from standard medical practice, allow procurement of organs when donors’ loss of circulatory function could be reversed, and raises questions about “death” as a unified concept. Our results suggest that, for many HPs, these concerns seem related in part to the fact that a rigorous brain examination is neither clinically performed nor legally required in DCD. Their discomfort could also come from a belief that irreversible loss of circulatory function has not been adequately demonstrated. If DCD protocols are to achieve their full potential for increasing organ supply, the sources of HPs’ discomfort must be further identified and addressed. (shrink)

We apply an online optimization process based on machine learning to the production of Bose-Einstein condensates. BEC is typically created with an exponential evaporation ramp that is optimal for ergodic dynamics with two-body s-wave interactions and no other loss rates, but likely sub-optimal for real experiments. Through repeated machine-controlled scientific experimentation and observations our ’learner’ discovers an optimal evaporation ramp for BEC production. In contrast to previous work, our learner uses a Gaussian process to develop a statistical model of the (...) relationship between the parameters it controls and the quality of the BEC produced. We demonstrate that the Gaussian process machine learner is able to discover a ramp that produces high quality BECs in 10 times fewer iterations than a previously used online optimization technique. Furthermore, we show the internal model developed can be used to determine which parameters are essential in BEC creation and which are unimportant, providing insight into the optimization process of the system. (shrink)

An important contribution to the foundations of probability theory, statistics and statistical physics has been made by E. T. Jaynes. The recent publication of his collected works provides an appropriate opportunity to attempt an assessment of this contribution. * Review of E. T. JAYNES (1983): Papers on Probability, Statistics and Statistical Physics. Edited by R. D. Rosenkrantz. D. Reidel Publishing Company. US $49.50. Pp. xxiv + 434. We are grateful to Harvey Brown, Kenneth Denbigh, Udi Makov and Oliver Penrose for (...) their valuable criticisms of this paper. (shrink)

The first observations of dislocations by TEM were published in 1956. Since then the technique has been developed into an indispensable tool for the materials scientist, not only for the characterization of the extended defect structure of materials, but also for the elucidation of the mechanisms controlling their properties. To mark the 50th anniversary of the original work, this Special Issue consists of reprints of the three original papers and some 22 current state-of-the-art articles, which provide a snapshot of the (...) tremendous power and versatility of the technique at the present time. It is also hoped that this collection of papers from different areas of application and including different techniques might stimulate some cross-fertilization. In this introduction, we comment briefly on the context in which the original work was performed, trace some of the important developments that have taken place in the intervening period and identify some of the outstanding problems. (shrink)

Insect and crustacean lineages diverged over 500 Myr ago, and there are continuing uncertaintles about whether they evolved from a common arthropod ancestor or, alternatively, they evolved independently from annelid worms. Despite the diversity of their limbs and lifestyles, the nervous systems of insects and crustaeeans share many common features both in development and in function. Cellular and molecular embryology techniques reveal good evidence for homologies in the developing segmental ganglia. In the visual system, this seemingly common programme of insect (...) and crustacean CNS development culminates in common adult neural function. Comparisons of the cellular anatomy and physiology of animals as diverse as flies and crayfishes indicate that the neural circuits in the lamina of their optic lobe have been inherited largely unchanged from a common ancestor with good compound eyes. (shrink)

The European Clinical Trials Directive was issued in 2001 and aimed to simplify and harmonise the regulatory framework of clinical trials throughout Europe, thus stimulating European research. However, significant complexity and inconsistency remains due to disparate interpretation by EU member states. Critical care research has been particularly impacted due to variable and often restrictive consenting procedures for incapacitated subjects, with some countries requiring a court-appointed representative, while others recognise consent from family members and occasionally professional representatives. Furthermore, the absence of (...) a waiver of consent threatened to put an end to emergency research in Europe and was met with varied responses. Approval procedures by ethics committees are equally inconsistent, particularly those relating to provision of a single opinion for multi-centre trials. Although evidence is somewhat mixed, this complexity as well as a general increase in administrative and financial burden following the Directive has been shown to cause a reduction in clinical trial activity in Europe, particularly academic trials. We aim to clarify some of these inconsistent procedures, particularly those relating to informed consent of incapacitated subjects, as well as discussing some general weaknesses and possible improvements of the Directive ahead of its planned revision in 2011. (shrink)

In A.D. 60 Nero instituted at Rome a quinquennale certamen which he called Neronia. It was in three sections—athletics, chariot-racing, and music —after a Greek model. This model would be that of the Pythian rather than of the Olympic Games, for at the latter there was no regular musical contest; though perhaps Nero got his immediate inspiration from the Augustalia at Naples, which was an athletic and musical festival of a religious nature.