Acupuncture fails to reduce but increases anaesthetic gas required to prevent movement in response to surgical incision.

Background: Acupuncture is used for clinical pain relief but has not been evaluated under clinical anaesthesia. This study was designed to compare movement in response to surgical incision in anaesthetized patients subjected to electro-acupuncture (EA) or sham procedures. Our hypothesis was that EA stimulation would reduce the requirements for anaesthetic gas. Methods: Forty-six healthy women, scheduled for laparoscopic sterilization at a Swedish county hospital, were randomized to have either the electro-acupuncture (n = 23) or sham (n = 23) procedure between the induction of general anaesthesia and the start of surgery. The minimal alveolar concentration (MAC) of sevoflurane required to prevent neck or major limb movements in response to surgical incision was determined in each group of patients. Results: The MAC for sevoflurane was found to be higher in the group given acupuncture than in the control group (2.1 ± 0.3% vs. 1.8 ± 0.4%; P = 0.008). Conclusion: Electro-acupuncture given during general anaesthesia with sevoflurane failed to reduce but instead increased the clinical need for anaesthetic gas, possibly by reducing the anaesthetic effect of sevoflurane and/or by facilitating nociceptive transmission and/or reflex activity

Sufficient conditions for the anti-Zeno effect

The ideal anti-Zeno effect means that a perpetual observation leads to an immediate disappearance of the unstable system. We present a straightforward way to derive sufficient conditions under which such a situation occurs expressed in terms of the decaying states and spectral properties of the Hamiltonian. They show, in particular, that the gap between Zeno and anti-Zeno effects is in fact very narrow.Comment: LatEx2e, 9 pages; a revised text, to appear in J. Phys. A: Math. Ge

Purification through Zeno-like Measurements

A series of frequent measurements on a quantum system (Zeno-like measurements) is shown to result in the ``purification'' of another quantum system in interaction with the former. Even though the measurements are performed on the former system, their effect drives the latter into a pure state, irrespectively of its initial (mixed) state, provided certain conditions are satisfied.Comment: REVTeX4, 4 pages, 1 figure; to be published in Phys. Rev. Lett. (2003

Survival law in a potential model

The radial equation of a simple potential model has long been known to yield an exponential decay law in lowest order (Breit-Wigner) approximation. We demonstrate that if the calculation is extended to fourth order the decay law exhibits the quantum Zeno effect. This model has further been studied numerically to characterize the extra exponential time parameter which compliments the lifetime. We also investigate the inverse Zeno effect.Comment: 16 pages, 2 tables, 3 figures, AMS-Te

The decay law can have an irregular character

Within a well-known decay model describing a particle confined initially within a spherical $\delta$ potential shell, we consider the situation when the undecayed state has an unusual energy distribution decaying slowly as $k\to\infty$; the simplest example corresponds to a wave function constant within the shell. We show that the non-decay probability as a function of time behaves then in a highly irregular, most likely fractal way.Comment: 4 pages, 3 eps figure

Certificates of Confidentiality: Protecting Human Subject Research Data in Law and Practice

The federal Certificate of Confidentiality plays an important role in research on sensitive topics by authorizing researchers to refuse to disclose identifiable research data in response to subpoenas in any legal setting. However, there is little known about how effective Certificates are in practice. This article draws on our legal and empirical research on this topic to fill this information gap. It includes a description of the purpose of Certificates, their legislative and regulatory history, and a summary of the few reported and unreported cases that have dealt with Certificates. In addition, we outline other statutory confidentiality protections, compare them to the Certificate\u27s protections, and analyze some of the vulnerabilities of a Certificate\u27s protections. This analysis allows us to make specific recommendations for strengthening the protections afforded to research data

Quantum Zeno effect in a probed downconversion process

The distorsion of a spontaneous downconvertion process caused by an auxiliary mode coupled to the idler wave is analyzed. In general, a strong coupling with the auxiliary mode tends to hinder the downconversion in the nonlinear medium. On the other hand, provided that the evolution is disturbed by the presence of a phase mismatch, the coupling may increase the speed of downconversion. These effects are interpreted as being manifestations of quantum Zeno or anti-Zeno effects, respectively, and they are understood by using the dressed modes picture of the device. The possibility of using the coupling as a nontrivial phase--matching technique is pointed out.Comment: 11 pages, 4 figure

Quantum Zeno subspaces

The quantum Zeno effect is recast in terms of an adiabatic theorem when the measurement is described as the dynamical coupling to another quantum system that plays the role of apparatus. A few significant examples are proposed and their practical relevance discussed. We also focus on decoherence-free subspaces.Comment: 5 pages, 1 figure, to be published in Phys. Rev. Let

Zeno dynamics yields ordinary constraints

The dynamics of a quantum system undergoing frequent measurements (quantum Zeno effect) is investigated. Using asymptotic analysis, the system is found to evolve unitarily in a proper subspace of the total Hilbert space. For spatial projections, the generator of the "Zeno dynamics" is the Hamiltonian with Dirichlet boundary conditions.Comment: 6 page

Polarizing Tweets on Climate Change

We introduce a framework to analyze the conversation between two competing groups of Twitter users, one who believe in the anthropogenic causes of climate change (Believers) and a second who are skeptical (Disbelievers). As a case study, we use Climate Change related tweets during the United Nation's (UN) Climate Change Conference - COP24 (2018), Katowice, Poland. We find that both Disbelievers and Believers talk within their group more than with the other group; this is more so the case for Disbelievers than for Believers. The Disbeliever messages focused more on attacking those personalities that believe in the anthropogenic causes of climate change. On the other hand, Believer messages focused on calls to combat climate change. We find that in both Disbelievers and Believers bot-like accounts were equally active and that unlike Believers, Disbelievers get their news from a concentrated number of news sources