Clozapine-Induced Pericarditis

Objective: To report a case of a patient treated with clozapine who developed pericarditis with pericardial effusion that resolved when the drug was discontinued. Method: Case report of a 21-year-old man with psychotic disorder that had been stable on clozapine therapy for five months (after failure of atypical antipsyhotic agents) presented to the emergency department complaining of chest pain and progressive shortness of breath that had lasted for a few days. Echocardiography showed a pericardial effusion suggestive of a cardiac tamponade, and the fluid was removed by pericardiocentesis. All other possible causes of the pericardial effusion were ruled out and clozapine was suspected as the most likely explanation. Clozapine was discontinued and the patient’s symptoms improved markedly. Discussion: According to the Naranjo probability scale, clozapine is a probable cause of pericarditis. Although clozapine is a known cause of myocarditis and cardiomyopathy, there are only several reports in the literature describing clozapine-induced pericarditis and pericardial effusion. In our patient, the pericardial effusion cleared within several days following clozapine discontinuation. Conclusion: There have been only a few cases of clozapine-induced pericarditis reported in the literature, however this adverse effect of clozapine can occur, as this case report clearly  demonstrates. Cardiac adverse effects of clozapine are potentially life threatening, hence early recognition is essential to prevent serious outcomes.Key words: Clozapine; Pericarditis; Pericardial effusion; Adverse reactio

Geometrical approach to mutually unbiased bases

We propose a unifying phase-space approach to the construction of mutually unbiased bases for a two-qubit system. It is based on an explicit classification of the geometrical structures compatible with the notion of unbiasedness. These consist of bundles of discrete curves intersecting only at the origin and satisfying certain additional properties. We also consider the feasible transformations between different kinds of curves and show that they correspond to local rotations around the Bloch-sphere principal axes. We suggest how to generalize the method to systems in dimensions that are powers of a prime.Comment: 10 pages. Some typos in the journal version have been correcte

Mitigating seafloor disturbance of bottom trawl fisheries for North Sea sole Solea solea by replacing mechanical with electrical stimulation

Funding: ADR, NTH, PM, HP, JJP, TvK: European Maritime and Fisheries Fund (EMFF) through the Netherlands Ministry of Agriculture Nature and Food Quality (LNV) (Grand/Award Number: 1300021172); NO ADR, JD, ORE, NTH, AI, FO, HP, JJP, TvK: FP 7 project BENTHIS (grant no. 312088); NO.Peer reviewedPublisher PD

Violations of local realism with quNits up to N=16

Predictions for systems in entangled states cannot be described in local realistic terms. However, after admixing some noise such a description is possible. We show that for two quNits (quantum systems described by N dimensional Hilbert spaces) in a maximally entangled state the minimal admixture of noise increases monotonically with N. The results are a direct extension of those of Kaszlikowski et. al., Phys. Rev. Lett. {\bf 85}, 4418 (2000), where results for $N\leq 9$ were presented. The extension up to N=16 is possible when one defines for each N a specially chosen set of observables. We also present results concerning the critical detectors efficiency beyond which a valid test of local realism for entangled quNits is possible.Comment: 5 pages, 3 ps picture

Conceptual Inadequacy of the Shannon Information in Quantum Measurements

In a classical measurement the Shannon information is a natural measure of our ignorance about properties of a system. There, observation removes that ignorance in revealing properties of the system which can be considered to preexist prior to and independent of observation. Because of the completely different root of a quantum measurement as compared to a classical measurement conceptual difficulties arise when we try to define the information gain in a quantum measurement using the notion of Shannon information. The reason is that, in contrast to classical measurement, quantum measurement, with very few exceptions, cannot be claimed to reveal a property of the individual quantum system existing before the measurement is performed.Comment: 11 pages, 5 figures, important Ref. [6] is now cited in all appropriate place

Experimental quantum tomography of photonic qudits via mutually unbiased basis

We present the experimental quantum tomography of 7- and 8-dimensional quantum systems based on projective measurements in the mutually unbiased basis (MUB-QT). One of the advantages of MUB-QT is that it requires projections from a minimal number of bases to be performed. In our scheme, the higher dimensional quantum systems are encoded using the propagation modes of single photons, and we take advantage of the capabilities of amplitude- and phase-modulation of programmable spatial light modulators to implement the MUB-QT.Comment: Published versio

Ca2+-binding protein 2 inhibits Ca2+-channel inactivation in mouse inner hair cells

Ca2+ channels mediate excitation-secretion coupling and show little inactivation at sensory ribbon synapses, enabling reliable synaptic information transfer during sustained stimulation. Studies of Ca2+-channel complexes in HEK293 cells indicated that Ca2+-binding proteins (CaBPs) antagonize their calmodulin-dependent inactivation. Although human mutations affecting CABP2 were shown to cause hearing impairment, the role of CaBP2 in auditory function and the precise disease mechanism remained enigmatic. Here, we disrupted CaBP2 in mice and showed that CaBP2 is required for sound encoding at inner hair cell synapses, likely by suppressing Ca2+-channel inactivation. We propose that the number of activatable Ca2+ channels at the active zone is reduced when CaBP2 is lacking, as is likely the case with the newly described human CABP2 mutation

Quantum Cryptography with Coherent States

The safety of a quantum key distribution system relies on the fact that any eavesdropping attempt on the quantum channel creates errors in the transmission. For a given error rate, the amount of information that may have leaked to the eavesdropper depends on both the particular system and the eavesdropping strategy. In this work, we discuss quantum cryptographic protocols based on the transmission of weak coherent states and present a new system, based on a symbiosis of two existing ones, and for which the information available to the eavesdropper is significantly reduced. This system is therefore safer than the two previous ones. We also suggest a possible experimental implementation.Comment: 20 pp. Revtex, Figures available from the authors upon request, To be published in PRA (March 95

Accessible information and optimal strategies for real symmetrical quantum sources

We study the problem of optimizing the Shannon mutual information for sources of real quantum states i.e. sources for which there is a basis in which all the states have only real components. We consider in detail the sources ${\cal E}_M$ of $M$ equiprobable qubit states lying symmetrically around the great circle of real states on the Bloch sphere and give a variety of explicit optimal strategies. We also consider general real group-covariant sources for which the group acts irreducibly on the subset of all real states and prove the existence of a real group-covariant optimal strategy, extending a theorem of Davies (E. B. Davies, IEEE. Inf. Theory {\bf IT-24}, 596 (1978)). Finally we propose an optical scheme to implement our optimal strategies, enough simple to be realized with present technology.Comment: RevTeX, 16 pages, 4 eps figures with psfig, submitted to Phys. Rev. A, corrected output error of Fig. 1 in the previous versio

Factorizations and Physical Representations

A Hilbert space in M dimensions is shown explicitly to accommodate representations that reflect the prime numbers decomposition of M. Representations that exhibit the factorization of M into two relatively prime numbers: the kq representation (J. Zak, Phys. Today, {\bf 23} (2), 51 (1970)), and related representations termed $q_{1}q_{2}$ representations (together with their conjugates) are analysed, as well as a representation that exhibits the complete factorization of M. In this latter representation each quantum number varies in a subspace that is associated with one of the prime numbers that make up M