Wiring Nanoscale Biosensors with Piezoelectric Nanomechanical Resonators

Nanoscale integrated circuits and sensors will require methods for unobtrusive interconnection with the macroscopic world to fully realize their potential. We report on a nanoelectromechanical system that may present a solution to the wiring problem by enabling information from multisite sensors to be multiplexed onto a single output line. The basis for this method is a mechanical Fourier transform mediated by piezoelectrically coupled nanoscale resonators. Our technique allows sensitive, linear, and real-time measurement of electrical potentials from conceivably any voltage-sensitive device. With this method, we demonstrate the direct transduction of neuronal action potentials from an extracellular microelectrode. This approach to wiring nanoscale devices could lead to minimally invasive implantable sensors with thousands of channels for in vivo neuronal recording, medical diagnostics, and electrochemical sensing

Altered perception of facially expressed tiredness in insomnia

The present study compared normal sleepers and individuals displaying insomnia symptoms in their ratings for the expression intensity of tiredness and alertness whilst observing tired and neutral faces. Fifty-six normal sleepers and 58 individuals with insomnia symptoms observed 98 facial photographs (49 neutral, 49 tired). Using a visual analogue scale, participants were required to rate the extent to which each face appeared as tired and alert. Tired faces were created by manipulating neutral photographs to include previously identified facial tiredness cues. All participants rated sleep-related faces as more tired and less alert relative to neutral photographs. A significant Group × Face × Rating interaction demonstrated that, compared with normal sleepers, the insomnia symptoms group showed lower ratings for the expression of tiredness, but not alertness, whilst observing the tired faces. The findings suggest that the presence of insomnia symptoms is associated with reduced ratings of expression intensity for sleep-related facial photographs displaying tiredness. These outcomes add to the body of literature on how facial cues of tiredness are perceived by those with insomnia symptoms. Further work is required to elucidate the mechanisms underlying the relationship between insomnia symptoms and reduced perceptions of facially expressed tiredness

Initial-Phase Spectroscopy as a Control of Entangled Systems

We introduce the concept of initial-phase spectroscopy as a control of the dynamics of entangled states encoded into a two-atom system interacting with a broadband squeezed vacuum field. We illustrate our considerations by examining the transient spectrum of the field emitted by two systems, the small sample (Dicke) and the spatially extended (non-Dicke) models. It is found that the shape of the spectral components depends crucially on the relative phase between the initial entangled state and the squeezed field. We follow the temporal evolution of the spectrum and show that depending on the relative phase a hole burning can occur in one of the two spectral lines. We compare the transient behavior of the spectrum with the time evolution of the initial entanglement and find that the hole burning can be interpreted as a manifestation of the phenomenon of entanglement sudden death. In addition, we find that in the case of the non-Dicke model, the collective damping rate may act like an artificial tweezer that rotates the phase of the squeezed field.Comment: 20 pages, 9 figure

Vacuum Polarization and Dynamical Chiral Symmetry Breaking: Phase Diagram of QED with Four-Fermion Contact Interaction

We study chiral symmetry breaking for fundamental charged fermions coupled electromagnetically to photons with the inclusion of four-fermion contact self-interaction term. We employ multiplicatively renormalizable models for the photon dressing function and the electron-photon vertex which minimally ensures mass anomalous dimension = 1. Vacuum polarization screens the interaction strength. Consequently, the pattern of dynamical mass generation for fermions is characterized by a critical number of massless fermion flavors above which chiral symmetry is restored. This effect is in diametrical opposition to the existence of criticality for the minimum interaction strength necessary to break chiral symmetry dynamically. The presence of virtual fermions dictates the nature of phase transition. Miransky scaling laws for the electromagnetic interaction strength and the four-fermion coupling, observed for quenched QED, are replaced by a mean-field power law behavior corresponding to a second order phase transition. These results are derived analytically by employing the bifurcation analysis, and are later confirmed numerically by solving the original non-linearized gap equation. A three dimensional critical surface is drawn to clearly depict the interplay of the relative strengths of interactions and number of flavors to separate the two phases. We also compute the beta-function and observe that it has ultraviolet fixed point. The power law part of the momentum dependence, describing the mass function, reproduces the quenched limit trivially. We also comment on the continuum limit and the triviality of QED.Comment: 9 pages, 10 figure

Stationary two-atom entanglement induced by nonclassical two-photon correlations

A system of two two-level atoms interacting with a squeezed vacuum field can exhibit stationary entanglement associated with nonclassical two-photon correlations characteristic of the squeezed vacuum field. The amount of entanglement present in the system is quantified by the well known measure of entanglement called concurrence. We find analytical formulas describing the concurrence for two identical and nonidentical atoms and show that it is possible to obtain a large degree of steady-state entanglement in the system. Necessary conditions for the entanglement are nonclassical two-photon correlations and nonzero collective decay. It is shown that nonidentical atoms are a better source of stationary entanglement than identical atoms. We discuss the optimal physical conditions for creating entanglement in the system, in particular, it is shown that there is an optimal and rather small value of the mean photon number required for creating entanglement.Comment: 17 pages, 5 figure

Double Exponential Instability of Triangular Arbitrage Systems

If financial markets displayed the informational efficiency postulated in the efficient markets hypothesis (EMH), arbitrage operations would be self-extinguishing. The present paper considers arbitrage sequences in foreign exchange (FX) markets, in which trading platforms and information are fragmented. In Kozyakin et al. (2010) and Cross et al. (2012) it was shown that sequences of triangular arbitrage operations in FX markets containing 4 currencies and trader-arbitrageurs tend to display periodicity or grow exponentially rather than being self-extinguishing. This paper extends the analysis to 5 or higher-order currency worlds. The key findings are that in a 5-currency world arbitrage sequences may also follow an exponential law as well as display periodicity, but that in higher-order currency worlds a double exponential law may additionally apply. There is an "inheritance of instability" in the higher-order currency worlds. Profitable arbitrage operations are thus endemic rather that displaying the self-extinguishing properties implied by the EMH.Comment: 22 pages, 22 bibliography references, expanded Introduction and Conclusion, added bibliohraphy reference

Pharmacovigilance in hospice/palliative care: net effect of haloperidol for nausea or vomiting

Background: Haloperidol is widely prescribed as an antiemetic in patients receiving palliative care, but there is limited evidence to support and refine its use. Objective: To explore the immediate and short-term net clinical effects of haloperidol when treating nausea and/or vomiting in palliative care patients. Design: A prospective, multicenter, consecutive case series. Setting/Subjects: Twenty-two sites, five countries: consultative, ambulatory, and inpatient services. Measurements: When haloperidol was started in routine care as an antiemetic, data were collected at three time points: baseline; 48 hours (benefits); day seven (harms). Clinical effects were assessed using the National Cancer Institute's Common Terminology Criteria for Adverse Events (NCI CTCAE). Results: Data were collected (May 2014–March 2016) from 150 patients: 61% male; 86% with cancer; mean age 72 (standard deviation 11) years and median Australian-modified Karnofsky Performance Scale 50 (range 10–90). At baseline, nausea was moderate (88; 62%) or severe (11; 8%); 145 patients reported vomiting, with a baseline NCI CTCAE vomiting score of 1.0. The median (range) dose of haloperidol was 1.5 mg/24 hours (0.5–5 mg/24 hours) given orally or parenterally. Five patients (3%) died before further data collection. At 48 hours, 114 patients (79%) had complete resolution of their nausea and vomiting, with greater benefit seen in the resolution of nausea than vomiting. At day seven, 37 (26%) patients had a total of 62 mild/moderate harms including constipation 25 (40%); dry mouth 13 (21%); and somnolence 12 (19%). Conclusions: Haloperidol as an antiemetic provided rapid net clinical benefit with low-grade, short-term harms

Learning Moore Machines from Input-Output Traces

The problem of learning automata from example traces (but no equivalence or membership queries) is fundamental in automata learning theory and practice. In this paper we study this problem for finite state machines with inputs and outputs, and in particular for Moore machines. We develop three algorithms for solving this problem: (1) the PTAP algorithm, which transforms a set of input-output traces into an incomplete Moore machine and then completes the machine with self-loops; (2) the PRPNI algorithm, which uses the well-known RPNI algorithm for automata learning to learn a product of automata encoding a Moore machine; and (3) the MooreMI algorithm, which directly learns a Moore machine using PTAP extended with state merging. We prove that MooreMI has the fundamental identification in the limit property. We also compare the algorithms experimentally in terms of the size of the learned machine and several notions of accuracy, introduced in this paper. Finally, we compare with OSTIA, an algorithm that learns a more general class of transducers, and find that OSTIA generally does not learn a Moore machine, even when fed with a characteristic sample