bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear acoustics in cicada mating calls enhance sound propagation
Authors: Hughes Derke R. , Nuttall Albert H. , Katz Richard A. , Carter G. Clifford
Published: February 2009

An analysis of cicada mating calls, measured in field experiments, indicates that the very high levels of acoustic energy radiated by this relatively small insect are mainly attributed to the nonlinear characteristics of the signal. The cicada emits one of the loudest sounds in all of the insect population with a sound production system occupying a physical space typically less than 3cc. The sounds made by tymbals are amplified by the hollow abdomen, functioning as a tuned resonator, but models of the signal based solely on linear techniques do not fully account for a sound radiation capability that is so disproportionate to the insect’s size. The nonlinear behavior of the cicada signal is demonstrated by combining the mutual information and surrogate data techniques; the results obtained indicate decorrelation when the phase-randomized and non-phase-randomized data separate. The Volterra expansion technique is used to fit the nonlinearity in the insect’s call. The second-order Volterra estimate provides further evidence that the cicada mating calls are dominated by nonlinear characteristics and also suggests that the medium contributes to the cicada’s efficient sound propagation. Application of the same principles has the potential to improve radiated sound levels for sonar applications.
Beamwidth measurement of individual lithotripter shock waves
Authors: Kreider Wayne , Bailey Michael R. , Ketterling Jeffrey A.
Published: February 2009

New lithotripters with narrower foci and higher peak pressures than the original Dornier HM3 electrohydraulic lithotripter have proven to be less effective and less safe. Hence, accurate measurements of the focal characteristics of lithotripter shock waves are important. The current technique for measuring beamwidth requires a collection of single-point measurements over multiple shock waves, thereby introducing error as a result of any shock-to-shock variability. This work reports on the construction of a hydrophone array sensor and on array measurements of individual lithotripter shock waves. Beamwidths for an electrohydraulic lithotripter with a broad-focus HM3-style reflector and a narrow-focus modified reflector were measured using both new and worn electrodes as well as two different electrical charging potentials. The array measured the waveform, beamwidth, and focal location of individual shock waves. The HM3-style reflector produced repeatable focal waveforms and beam profiles at an 18kV charging potential with new and worn electrodes. Corresponding measurements suggest a narrower beamwidth than reported previously from averaged point measurements acquired under the same conditions. In addition, a lack of consistency in the measured beam profiles at 23kV underscores the value of measuring individual shock waves.
Semantic evaluations of noise with tonal components in Japan, France, and Germany: A cross-cultural comparison
Authors: Hansen Hans , Weber Reinhard
Published: February 2009

An evaluation of tonal components in noise using a semantic differential approach yields several perceptual and connotative factors. This study investigates the effect of culture on these factors with the aid of equivalent listening tests carried out in Japan (n=20), France (n=23), and Germany (n=20). The data’s equivalence level is determined by a bias analysis. This analysis gives insight in the cross-cultural validity of the scales used for sound character determination. Three factors were extracted by factor analysis in all cultural subsamples: pleasant, metallic, and power. By employing appropriate target rotations of the factor spaces, the rotated factors were compared and they yield high similarities between the different cultural subsamples. To check cross-cultural differences in means, an item bias analysis was conducted. The a priori assumption of unbiased scales is rejected; the differences obtained are partially linked to bias effects. Acoustical sound descriptors were additionally tested for the semantic dimensions. The high agreement in judgments between the different cultural subsamples contrast the moderate success of the signal parameters to describe the dimensions.
Variability in ambient noise levels and call parameters of North Atlantic right whales in three habitat areas
Authors: Parks Susan E. , Urazghildiiev Ildar , Clark Christopher W.
Published: February 2009

The North Atlantic right whale inhabits the coastal waters off the east coasts of the United States and Canada, areas characterized by high levels of shipping and fishing activities. Acoustic communication plays an important role in the social behavior of these whales and increases in low-frequency noise may be leading to changes in their calling behavior. This study characterizes the ambient noise levels, including both natural and anthropogenic sources, and right whale upcall parameters in three right whale habitat areas. Continuous recordings were made seasonally using autonomous bottom-mounted recorders in the Bay of Fundy, Canada (2004, 2005), Cape Cod Bay, (2005, 2006), and off the coast of Georgia (2004–2005, 2006–2007). Consistent interannual trends in noise parameters were found for each habitat area, with both the band level and spectrum level measurements higher in the Bay of Fundy than in the other areas. Measured call parameters varied between habitats and between years within the same habitat area, indicating that habitat area and noise levels alone are not sufficient to predict variability in call parameters. These results suggest that right whales may be responding to the peak frequency of noise, rather than the absolute noise level in their environment.
Underwater detection of tonal signals between 0.125 and 100kHz by harbor seals (Phoca vitulina)
Authors: Kastelein Ronald A. , Wensveen Paul J. , Hoek Lean , Verboom Willem C. , Terhune John M.
Published: February 2009

The underwater hearing sensitivities of two 1-year-old female harbor seals were quantified in a pool built for acoustic research, using a behavioral psychoacoustic technique. The animals were trained to respond when they detected an acoustic signal and not to respond when they did not (go/no-go response). Pure tones (0.125–0.25kHz) and narrowband frequency modulated (tonal) signals (center frequencies 0.5–100kHz) of 900ms duration were tested. Thresholds at each frequency were measured using the up-down staircase method and defined as the stimulus level resulting in a 50% detection rate. The audiograms of the two seals did not differ statistically: both plots showed the typical mammalian U-shape, but with a wide and flat bottom. Maximum sensitivity (54dB re 1μPa, rms) occurred at 1kHz. The frequency range of best hearing (within 10dB of maximum sensitivity) was from 0.5to40kHz (613 octaves). Higher hearing thresholds (indicating poorer sensitivity) were observed below 1 and above 40kHz. Thresholds below 4kHz were lower than those previously described for harbor seals, which demonstrates the importance of using quiet facilities, built specifically for acoustic research, for hearing studies in marine mammals. The results suggest that under unmasked conditions many anthropogenic noise sources and sounds from conspecifics are audible to harbor seals at greater ranges than formerly believed.
Optimal design of minimum mean-square error noise reduction algorithms using the simulated annealing technique
Authors: Bai Mingsian R. , Hsieh Ping-Ju , Hur Kur-Nan
Published: February 2009

The performance of the minimum mean-square error noise reduction (MMSE-NR) algorithm in conjunction with time-recursive averaging (TRA) for noise estimation is found to be very sensitive to the choice of two recursion parameters. To address this problem in a more systematic manner, this paper proposes an optimization method to efficiently search the optimal parameters of the MMSE-TRA-NR algorithms. The objective function is based on a regression model, whereas the optimization process is carried out with the simulated annealing algorithm that is well suited for problems with many local optima. Another NR algorithm proposed in the paper employs linear prediction coding as a preprocessor for extracting the correlated portion of human speech. Objective and subjective tests were undertaken to compare the optimized MMSE-TRA-NR algorithm with several conventional NR algorithms. The results of subjective tests were processed by using analysis of variance to justify the statistic significance. A post hoc test, Tukey’s Honestly Significant Difference, was conducted to further assess the pairwise difference between the NR algorithms.
Detecting incipient inner-ear damage from impulse noise with otoacoustic emissions
Authors: Marshall Lynne , Lapsley Miller Judi A. , Heller Laurie M. , Wolgemuth Keith S. , Hughes Linda M. , Smith Shelley D. , Kopke Richard D.
Published: February 2009

Audiometric thresholds and otoacoustic emissions (OAEs) were measured in 285 U.S. Marine Corps recruits before and three weeks after exposure to impulse-noise sources from weapons’ fire and simulated artillery, and in 32 non-noise-exposed controls. At pre-test, audiometric thresholds for all ears were ≤25dB HL from 0.5to3kHz and ≤30dB HL at 4kHz. Ears with low-level or absent OAEs at pre-test were more likely to be classified with significant threshold shifts (STSs) at post-test. A subgroup of 60 noise-exposed volunteers with complete data sets for both ears showed significant decreases in OAE amplitude but no change in audiometric thresholds. STSs and significant emission shifts (SESs) between 2 and 4kHz in individual ears were identified using criteria based on the standard error of measurement from the control group. There was essentially no association between the occurrence of STS and SES. There were more SESs than STSs, and the group of SES ears had more STS ears than the group of no-SES ears. The increased sensitivity of OAEs in comparison to audiometric thresholds was shown in all analyses, and low-level OAEs indicate an increased risk of future hearing loss by as much as ninefold.
A functional-magnetic-resonance-imaging investigation of cortical activation from moving vibrotactile stimuli on the fingertip
Authors: Summers Ian R. , Francis Susan T. , Bowtell Richard W. , McGlone Francis P. , Clemence Matthew
Published: February 2009

Using a 100-element tactile stimulator on the fingertip during functional-magnetic-resonance imaging, brain areas were identified that were selectively activated by a moving vibrotactile stimulus (the sensation of a moving line being dragged over the fingertip). Activation patterns elicited by tactile motion, contrasted to an equivalent stationary stimulus, were compared in six human subjects with those generated by a moving visual stimulus, contrasted to an equivalent stationary stimulus. Results provide further evidence for a neuroanatomical convergence of tactile-motion processing and visual-motion processing in humans. The sites of this convergence are found to lie in the middle temporal complex (hMT+∕V5), an area with known specialization for visual-motion processing, and in the intraparietal area of the posterior parietal cortex. In an advance on previous studies, the present study includes separate delineation of activations for moving tactile stimuli and activations for moving visual stimuli. Results suggest that the two sets of activations are not entirely collocated. Compared to the visual-motion activations, the tactile-motion activations are found to lie nearer the midline of the brain and further superior.
Binaural sluggishness precludes temporal pitch processing based on envelope cues in conditions of binaural unmasking
Authors: Krumbholz Katrin , Magezi David A. , Moore Rosanna C. , Patterson Roy D.
Published: February 2009

Binaural sluggishness refers to the binaural system’s inability to follow fast changes in the interaural configuration of the incoming sound stream. Several studies have measured binaural sluggishness by measuring signal detection in conditions of binaural unmasking when the interaural configuration of the masker is changed over time. However, it has been shown that, in conditions of binaural unmasking, binaural sluggishness also affects the perception of temporal changes in the properties of the signal (i.e., its frequency or level) and not just in the interaural configuration of the masker. By measuring the temporal modulation transfer function for sinusoidally modulated noise presented in conditions of binaural unmasking, the first experiment of the current study showed that, due to binaural sluggishness, the internal representation of binaurally unmasked sounds conveys little or no information about envelope fluctuations with rates within the pitch range (i.e., above 30Hz). The second experiment measured the masked detection threshold for musical interval recognition in binaurally unmasked harmonic tones and showed that, in conditions of binaural unmasking, pitch wanes when the harmonics become unresolved by the cochlear filters. These results suggest that binaural sluggishness precludes temporal pitch processing based on envelope cues in binaurally unmasked sounds.
Unsupervised joint prosody labeling and modeling for Mandarin speech
Authors: Chiang Chen-Yu , Chen Sin-Horng , Yu Hsiu-Min , Wang Yih-Ru
Published: February 2009

An unsupervised joint prosody labeling and modeling method for Mandarin speech is proposed, a new scheme intended to construct statistical prosodic models and to label prosodic tags consistently for Mandarin speech. Two types of prosodic tags are determined by four prosodic models designed to illustrate the hierarchy of Mandarin prosody: the break of a syllable juncture to demarcate prosodic constituents and the prosodic state to represent any prosodic domain’s pitch-level variation resulting from its upper-layered prosodic constituents’ influences. The performance of the proposed method was evaluated using an unlabeled read-speech corpus articulated by an experienced female announcer. Experimental results showed that the estimated parameters of the four prosodic models were able to explore and describe the structures and patterns of Mandarin prosody. Besides, certain corresponding relationships between the break indices labeled and the associated words were found, and manifested the connections between prosodic and linguistic parameters, a finding further verifying the capability of the method presented. Finally, a quantitative comparison in labeling results between the proposed method and human labelers indicated that the former was more consistent and discriminative than the latter in prosodic feature distributions, a merit of the method developed here on the applications of prosody modeling.
Coupled vibration analysis of the thin-walled cylindrical piezoelectric ceramic transducers
Authors: Aronov Boris
Published: February 2009

Analysis of electromechanical transducers employing axially symmetric vibrations of piezoelectric ceramic thin-walled tubes of arbitrary aspect ratio is presented based on application of the energy method [B. S. Aronov, J. Acoust. Soc. Am. 117, 210–220 (2005)]. The suggestion made by Giebe and Blechshmidt [Ann. Physik, Ser. 5 18, 417–485 (1933)] regarding representation of a tube vibration as a coupled vibration of two partial systems is used to choose the assumed modes of the piezoceramic tube vibration, and the energy of the flexural deformations accompanying the extensional vibration of a tube is also taken into consideration. The Lagrange type equations describing the transducer vibrations are derived, and the equivalent electromechanical circuit is introduced that conveniently represents the solution. The resonance frequencies, effective coupling coefficients, and velocity distributions for differently poled piezoceramic tubes as functions of their height-to-diameter aspect ratio are calculated. The validity of the equivalent circuit is extended to the case that a piezoceramic tube is mechanically and acoustically loaded on the ends and acoustically loaded on its outer surface. The results of calculations are in good agreement with the results of experimental investigations.
Estimation of the center frequency of the highest modulation filter
Authors: Moore Brian C. J. , Füllgrabe Christian , Sek Aleksander
Published: February 2009

For high-frequency sinusoidal carriers, the threshold for detecting sinusoidal amplitude modulation increases when the signal modulation frequency increases above about 120Hz. Using the concept of a modulation filter bank, this effect might be explained by (1) a decreasing sensitivity or greater internal noise for modulation filters with center frequencies above 120Hz; and (2) a limited span of center frequencies of the modulation filters, the top filter being tuned to about 120Hz. The second possibility was tested by measuring modulation masking in forward masking using an 8kHz sinusoidal carrier. The signal modulation frequency was 80, 120, or 180Hz and the masker modulation frequencies covered a range above and below each signal frequency. Four highly trained listeners were tested. For the 80-Hz signal, the signal threshold was usually maximal when the masker frequency equaled the signal frequency. For the 180-Hz signal, the signal threshold was maximal when the masker frequency was below the signal frequency. For the 120-Hz signal, two listeners showed the former pattern, and two showed the latter pattern. The results support the idea that the highest modulation filter has a center frequency in the range 100–120Hz.
Ossicular resonance modes of the human middle ear for bone and air conduction
Authors: Homma Kenji , Du Yu , Shimizu Yoshitaka , Puria Sunil
Published: February 2009

The mean resonance frequency of the human middle ear under air conduction (AC) excitation is known to be around 0.8–1.2kHz. However, studies suggest that the mean resonance frequency under bone conduction (BC) excitation is at a higher frequency around 1.5–2kHz. To identify the cause for this difference, middle-ear responses to both AC and BC excitations were measured at the umbo and lateral process of the malleus using five human cadaver temporal bones. The resonance modes identified from these measurements, along with finite element analysis results, indicate the presence of two ossicular modes below 2kHz. The dominant mode under AC excitation is the first mode, which typically occurs around 1.2kHz and is characterized by a “hinging” ossicular motion, whereas the dominant mode under BC excitation is the second mode, which typically occurs around 1.7kHz and is characterized by a “pivoting” ossicular motion. The results indicate that this second mode is responsible for the translational component in the malleus handle motion. The finding is also consistent with the hypothesis that a middle-ear structural resonance is responsible for the prominent peak seen at 1.5–2kHz in BC limit data.
Lanczos iterated time-reversal
Authors: Oberai Assad A. , Feijóo Gonzalo R. , Barbone Paul E.
Published: February 2009

A new iterative time-reversal algorithm capable of identifying and focusing on multiple scatterers in a relatively small number of iterations is developed. It is recognized that the traditional iterated time-reversal method is based on utilizing power iterations to determine the dominant eigenpairs of the time-reversal operator. The convergence properties of these iterations are known to be suboptimal. Motivated by this, a new method based on Lanczos iterations is developed. In several illustrative examples it is demonstrated that for the same number of transmitted and received signals, the Lanczos iterations based approach is substantially more accurate.
Children’s annoyance reactions to aircraft and road traffic noise
Authors: van Kempen Elise E. M. M. , van Kamp Irene , Stellato Rebecca K. , Lopez-Barrio Isabel , Haines Mary M. , Nilsson Mats E. , Clark Charlotte , Houthuijs Danny , Brunekreef Bert , Berglund Birgitta , Stansfeld Stephen A.
Published: February 2009

Since annoyance reactions of children to environmental noise have rarely been investigated, no source specific exposure-response relations are available. The aim of this paper is to investigate children’s reactions to aircraft and road traffic noise and to derive exposure-response relations. To this end, children’s annoyance reactions to aircraft and road traffic noise in both the home and the school setting were investigated using the data gathered in a cross-sectional multicenter study, carried out among 2844 children (age 9–11years) attending 89 primary schools around three European airports. An exposure-response relation was demonstrated between exposure to aircraft noise at school (LAeq,7–23h) and severe annoyance in children: after adjustment for confounders, the percentage severely annoyed children was predicted to increase from about 5.1% at 50dB to about 12.1% at 60dB. The findings were consistent across the three samples. Aircraft noise at home (LAeq,7–23h) demonstrated a similar relation with severe annoyance. Children attending schools with higher road traffic noise (LAeq,7–23h) were more annoyed. Although children were less annoyed at levels above 55dB, the shapes of the exposure-response relations found among children were comparable to those found in their parents.
Beyond “see one, do one, teach one”: toward a different training paradigm
Authors: Rodriguez-Paz J M , Kennedy M , Salas E , Wu A W , Sexton J B , Hunt E A , Pronovost P J
Published: February 2009

In the process of acquiring new skills, physicians-in-training may expose patients to harm because they lack the required experience, knowledge and technical skills. Yet, most teaching hospitals use inexperienced residents to care for high-acuity patients in complex and dynamic environments and provide limited supervision from experienced clinicians. Multiple efforts in the last few years have started to address the problem of patient safety. Examples include voluntary incident-reporting systems and team training workshops for practising clinicians. Fewer efforts have addressed the deficits in training new physicians, especially related to knowledge, skills and competence. The current apprenticeship or “see one, do one, teach one” model is insufficient because trainees learn by practising on real patients, which is particularly an issue when performing procedures. Residents have expressed that they do not feel adequately trained to perform procedures safely by themselves. In this paper, we conduct an informal review of the impact of current training methods on patient safety. In addition, we propose a new training paradigm that integrates competency-based knowledge and clinical skills, with deliberate attitudinal and behavioural changes focused on patient safety in a safe medically simulated environment. We do so with the hope of creating a better marriage between the missions of training and patient safety.
MACROSCOPIC QUANTUM ENTANGLEMENT IN LIGHT REFLECTION FROM BOSE-EINSTEIN CONDENSATES
Authors: DE MARTINI FRANCESCO , SCIARRINO FABIO , SPAGNOLO NICOLÓ , VITELLI CHIARA , CATALIOTTI FRANCESCO
Published: February 2009

The present work investigates quantum phenomena with large size systems generated in the microscopic world and then transferred in the macro one through an amplification process. Precisely, a microscopic entangled photon state is created by a nonlinear optical process, then one subsystem is injected into an optical parametric amplifier and then converted into a macro — state consisting of N ≈ 3.5 × 104 photons in a quantum superposition. By adopting a local filtering technique, we then demonstrate the entanglement of the bipartite system. The new conceptual framework paves the way toward the generation of light-matter entangled states by coupling the output radiation with a Bose-Einstein condensate. The multiphoton superposition generated by a quantum-injected optical parametric amplifier (QI-OPA) can be made to interact with a Mirror-BEC shaped as a Bragg interference structure.
THE ATTRACTOR AND THE QUANTUM STATES
Authors: ELZE HANS-THOMAS
Published: February 2009

The dissipative dynamics anticipated in the proof of 't Hooft's existence theorem — "For any quantum system there exists at least one deterministic model that reproduces all its dynamics after prequantization" — is constructed here explicitly. We propose a generalization of Liouville's classical phase space equation, incorporating dissipation and diffusion, and demonstrate that it describes the emergence of quantum states and their dynamics in the Schrödinger picture. Asymptotically, there is a stable ground state and two decoupled sets of degrees of freedom, which transform into each other under the energy-parity symmetry of Kaplan and Sundrum. They recover the familiar Hilbert space and its dual. Expectations of observables are shown to agree with the Born rule, which is not imposed a priori. This attractor mechanism is applicable in the presence of interactions, to few-body or field theories in particular.
NON-GAUSSIANITY AND PURITY IN FINITE DIMENSION
Authors: GENONI MARCO G. , PARIS MATTEO G. A.
Published: February 2009

We address truncated states of continuous variable systems and analyze their statistical properties numerically by generating random states in finite-dimensional Hilbert spaces. In particular, we focus to the distribution of purity and non-Gaussianity for dimension up to d = 21. We found that both quantities are distributed around typical values with variances that decrease for increasing dimension. Approximate formulas for typical purity and non-Gaussianity as a function of the dimension are derived.
EPR "PARADOX", PROJECTION POSTULATE, TIME SYNCHRONIZATION "NONLOCALITY"
Authors: KHRENNIKOV ANDREI
Published: February 2009

We show that the projection postulate plays a crucial role in the discussion on the so called "quantum nonlocality," in particular in the EPR-argument. We stress that the original von Neumann projection postulate was crucially modified by extending it to observables with degenerate spectra (the Lüders postulate) and we show that this modification is highly questionable from a physical point of view, and it is the real source of "quantum nonlocality." The use of the original von Neumann postulate eliminates this problem: instead of "action at the distance"-nonlocality, we obtain a classical measurement nonlocality. The latter is related to the synchronization of two measurements (on the two parts of a composite system). It seems that EPR did mistake in their 1935-paper: if one uses correctly von Neumann projection postulate, no "elements of reality" can be assigned to entangled systems. Our analysis of the EPR and projection postulate makes clearer Bohr's considerations in his reply to Einstein.
BIPHOTON WAVE PACKETS GENERATED IN APERIODICALLY POLED CRYSTALS
Authors: KITAEVA G. KH. , KOVALEV S. P. , KUZNETSOV K. A.
Published: February 2009

The influence of disordering of quasi-phase-matched structures on the properties of biphoton fields generated by spontaneous parametric down-conversion in periodically poled crystals is studied in the general form, taking into consideration arbitrary one-dimensional spatial distribution of the crystal second-order susceptibility. It is shown that the spectral amplitudes of the biphoton wave function become complex and gain frequency- and angle-dependent phase shifts in the structures with unequal lengths of domains. Effects of the spectrum broadening and the phase shifting are expressed in terms of the crystal non-linear transfer function. Spectrum of the first-order correlation function is found to be strictly dependent on the transfer function module, but insensitive to the phase shifts. Availability of the phase shifts makes the second-order temporal correlation function of the broadened as-generated biphoton field to be almost the same as in case of a single-domain crystal. At the same time, possibility of strong temporal biphoton compression appears further if an additional phase-compensating element is placed after the aperiodically poled crystal.
ZENO HEATING AND ANTI-ZENO COOLING BY FREQUENT QUANTUM MEASUREMENTS
Authors: GORDON GOREN , EREZ NOAM , KURIZKI GERSHON
Published: February 2009

We study disturbances of thermal equilibrium between two-level systems (TLS) and a bath by frequent and brief quantum measurements of the TLS energy-states. If the measurements induce either the Zeno or the anti-Zeno regime, namely, the slowdown or speedup of the TLS relaxation, then the resulting entropy and temperature of both the system and the bath are found to be completely determined by the measurement rate, and unrelated to what is expected by standard thermodynamical rules that hold for markovian baths. These anomalies allow for very fast control heating, cooling and state-purification (entropy reduction) of quantum systems much sooner than their thermal equilibration time.
BERRY PHASE IN MAGNETOELECTRIC MATERIALS
Authors: KWEK L. C. , KWAN M. K.
Published: February 2009

Weak magnetism of antiferromagnetic crystals, such as MnCO3 , CoCO3 , and spin arrangement in antiferromagnets of low symmetry can be studied using the Dzyaloshinskii-Moriya (DM) interaction. Such interactions may also be present sometimes in some spin-chain systems like magnetoelectric multiferroics. These materials could in principle be prime candidates for solid state NMR quantum computing based on manipulation of geometric phases. However, recent preliminary studies appear to show that a small presence of DM interaction could dampen magnitudes of the geometric phases.
A CASE OF ENTANGLEMENT GENERATION BETWEEN CAUSALLY DISCONNECTED ATOMS
Authors: LEÓN JUAN , SABÍN CARLOS
Published: February 2009

We analyze the entanglement generated in a finite time between a pair of space-like separated atoms, one of which emits a photon. As we show to order e2, the origin of entanglement can be traced back to the uncertainty about which one of the atoms emitted the photon. We check this by comparing the time behaviors of the emission processes allowed by energy conservation versus those forbidden by the same reason. No physical signal propagates between the atoms in the processes considered, however an effective light cone separating non-entangled from entangled regions in space-time emerges from our calculations.
TESTS OF QUANTUM MECHANICS AGAINST A SIMPLE FAMILY OF LOCAL HIDDEN-VARIABLES MODELS VIA POLARIZATION CORRELATION EXPERIMENTS
Authors: SANTOS EMILIO
Published: February 2009

The quantum prediction for the polarization correlation of a general two-photon state (e.g. non-maximally entangled) is derived taking into account the non-ideal behavior of polarization analyzers and detectors. A simple family of local hidden-variables models is defined and the possible discrimination between that family and quantum mechanics is discussed.
DISCRETE COHERENT STATES FOR n QUBITS
Authors: MUÑOZ CARLOS , KLIMOV ANDREI B. , SÁNCHEZ-SOTO LUIS L. , BJÖRK GUNNAR
Published: February 2009

Discrete coherent states for a system of n qubits are introduced in terms of eigenstates of the finite Fourier transform. The properties of these states are pictured in phase space by resorting to the discrete Wigner function.
TOWARD REAL NOON-STATE SOURCES
Authors: D'ANGELO MILENA , GARUCCIO AUGUSTO , TAMMA VINCENZO
Published: February 2009

Path-entangled N-photon systems described by NOON states are the main ingredient of many quantum information and quantum imaging protocols. Our analysis aims to lead the way toward the implementation of both NOON-state sources and their applications. To this end, we study the functionality of "real" NOON-state sources by quantifying the effect real experimental apparatuses have on the actual generation of the desired NOON state. In particular, since the conditional generation of NOON states strongly relies on photon counters, we evaluate the dependence of both the reliability and the signal-to-noise ratio of "real" NOON-state sources on detection losses. We find a surprising result: NOON-state sources relying on nondetection are much more reliable than NOON-state sources relying on single-photon detection. Also the comparison of the resources required to implement these two protocols comes out to be in favor of NOON-state sources based on nondetection. A scheme to improve the performances of "real" NOON-state sources based on single-photon detection is also proposed and analyzed.
Study on Chronic Low-Grade Inflammation and Influential Factors of Polycystic Ovary Syndrome
Authors: Ruan Xiangyan , Dai Yujie
Published: February 2009

Objective: To determine whether or not there is an increased level of serum C-reactive protein (CRP), of peripheral white cell count and of associated factors in Chinese patients with polycystic ovary syndrome (PCOS). Subjects and Methods: Seventy-four patients with PCOS were recruited for the study. The control group consisted of 51 normal healthy women of a similar age and body mass index (BMI). The basic physical parameters, white cell count, CRP, sex hormone and fasting insulin were measured. The glycolipid metabolic index and the insulin sensitivity index were calculated. Results: The serum CRP level (2.13 vs. 0.86 mg/l, p < 0.001) and total leukocyte count (7.50 ± 1.83 vs. 6.55 ± 1.66 × 109/l, p < 0.01) were significantly higher in PCOS patients than in normal healthy women. Even PCOS patients with normal BMI had an increase in CRP and leukocyte count. The serum CRP level of PCOS patients was positively correlated with BMI (R = 0.57, p < 0.001) and triglycerides (R = 0.47, p < 0.001) and negatively correlated with the insulin sensitivity index (R = –0.60, p < 0.001). Conclusion: The data showed that chronic nonspecific inflammation exists among Chinese patients with PCOS and that this kind of inflammation was related to insulin resistance, BMI, and triglycerides.
Infliximab Reduces Myeloperoxidase Concentration in Chronic Inflammatory Joint Diseases
Authors: Feijóo Montserrat , Túnez Isaac , Tasset Inmaculada , Montilla Pedro , Pérez-Guijo Verónica , Muñoz-Gomariz Elisa , Ruiz Adela , Schiotis Ruxandra , Collantes Eduardo
Published: February 2009

The present study evaluated the effect of infliximab on the myeloperoxidase (MPO) concentration in chronic inflammatory joint disease. Eighteen patients were divided into active and inactive groups. Erythrocyte sedimentation rate, C-reactive protein, white blood cell counts, MPO concentration, and biomarkers of oxidative stress were measured before and after the infusion of infliximab. Patients with active disease showed increases in concentrations of MPO and biomarkers of oxidation, but decreases in antioxidant parameters. After infliximab treatment, both inflammatory parameters and MPO concentrations were normalized. In conclusion: (1) the MPO concentration is related to inflammatory activity and could play an important role in the maintenance and outbreak of oxidative stress present in these diseases, and (2) infliximab inhibits MPO concentration.
Higher Rate of Cord-Related Adverse Events in Neonates with Dry Umbilical Cord Care Compared to Chlorhexidine Powder
Authors: Kapellen Thomas M. , Gebauer Corinna M. , Brosteanu Oana , Labitzke Birgit , Vogtmann Christoph , Kiess Wieland
Published: February 2009

Objective: Best practice for umbilical cord care (UC) still remains controversial in developed countries with aseptic perinatal care. A bicenter randomized clinical trial was performed to evaluate the efficacy of chlorhexidine (CX) powder versus dry cord care (DC) for UC. Patients and Methods: All neonates of two neonatal care units were invited to take part in the study. Participants were randomized to either DC or UC with CX powder (0.1%). Primary study outcome was the cord separation time. Secondary outcomes were omphalitis, granuloma of the umbilical ground, adverse events and parents’ treatment satisfaction. The outcome parameters were documented at a hospital-located study visit 10–14 days after birth. Results: 669 neonates were enrolled in the trial. 337 were randomized to receive CX powder for umbilical cord care, 332 to DC. Cord separation time was 7.0 ± 2.5 days in CX-treated neonates and 7.8 ± 2.9 days in DC (p < 0.001). There were 9 cases of omphalitis, 2 in the CX group, 7 in the DC group (p = 0.1). No difference in the occurrence of umbilical granuloma between the treatment regimens was detected. Neonates randomized to CX were less likely to have an adverse event (140 in 109 subjects vs. 205 in 149 subjects in the DC neonates; p = 0.001). Half of these adverse events were cord-related. Neonates randomized to DC had nearly twice as many cord-related adverse events as those with CX treatment (CX: 58 in 54 patients vs. DC: 110 in 97 patients; p < 0.001). Parents’ treatment satisfaction was significantly higher in the neonates with CX cord care. Conclusions: Cord-related adverse events in neonatal umbilical cord care remain a clinical issue. Even in an aseptic birth context in a developed country, cord care with CX powder showed a reduction of cord-related adverse events.
Necrotizing Fasciitis in a Neonate – The Role of Keratinocyte Allografts
Authors: Lee Kyu-Ha , Hahn Won-Ho , Park Sung-Shin , Cho Byoung-Soo , Kim Sung-Do
Published: February 2009

The authors report the case of a 9-day-old female infant with necrotizing fasciitis of the lower back due to methicillin-resistant Staphylococcus aureus (MRSA) to emphasize the role of keratinocyte allografts. Keratinocyte allografts were found helpful in this case to manage an extensive skin defect.
The Evolutionary Theories of Aging Revisited – A Mini-Review
Authors: Ljubuncic Predrag , Reznick Abraham Z.
Published: February 2009

This short review portrays the evolutionary theories of aging in the light of the existing discoveries from genomic and molecular genetic studies on aging and longevity. At the outset, an historical background for the development of the evolutionary theories of aging is presented through the works of August Weismann (programmed death and the germ plasm theories) including his exceptional theoretical postulation, later experimentally validated by the existence of cell division limits. Afterwards, the theory of mutation accumulation of Peter Medawar and the theory modification by Charlesworth (late-life mortality plateau) are presented as well as the antagonistic pleiotropy hypothesis of George Williams, and the disposable soma theory of Kirkwood and Holliday. These theories are discussed in the light of the different research studies, which include studies on insulin signaling and longevity, the possibility that nuclear factor kappa B may be a major mediator of aging, studies of anti-aging Sirtuins and studies on heat shock proteins and longevity and on gene sets as biomarkers of aging. Finally, the proposals for future research in biogerontology, such as studies on the control of protein synthesis, validation of biomarkers of aging, understanding the biochemistry of longevity and research in the field of gerontologic pathology are presented. Likewise, further attention is suggested regarding the work on telomere shortening, stem cells and studies on understanding the biochemical and molecular basis for longevity in centenarians.
Contribution of Vascular and Neural Segments to Baroreflex Sensitivity in Response to Postural Stress
Authors: Saeed Nazia P. , Reneman Robert S. , Hoeks Arnold P.G.
Published: February 2009

Background/Aims: The baroreflex pathway has a vascular and a neural segment, both being modulated by variations in peripheral blood pressure (BP). Besides overall baroreceptor sensitivity (BRS), defined as the spectral relationship between changes in peripheral BP and R-R interval within the frequency band of 0.05–0.15 Hz, vascular and neural segment contributions to the overall BRS can be distinguished. We test the hypothesis that changes in overall BRS following a postural maneuver mainly originate from the vascular (peripheral pressure to carotid artery diameter) rather than the neural segment (carotid artery diameter to R-R interval). Methods: Peripheral pressure (Finapress), carotid artery diameter (ultrasound in B-/M-mode) and electrocardiogram values of 20 young subjects in supine and upright-seated postures were recorded simultaneously. Transfer gains were computed for the segmental and overall responses. Results:Postural change significantly increases peripheral BP and carotid artery diameter. The vascular segment has a uniform spectral distribution. Statistical analyses revealed that postural change decreased overall (p < 0.004) and vascular (p < 0.0001) transfer gains, but did not modify neural gain. Conclusions:Unlike the neural segment, the vascular segment is frequency non-specific. The decrease in overall BRS due to a postural change is mainly explained by the reduced transfer gain of the vascular segment.
High Dose Magnesium Sulfate Exposure Induces Apoptotic Cell Death in the Developing Neonatal Mouse Brain
Authors: Dribben William H. , Creeley Catherine E. , Wang Hai Hui , Smith Derek J. , Farber Nuri B. , Olney John W.
Published: February 2009

Background: Magnesium sulfate (MgSO4) is often used as a treatment for pre-eclampsia/eclampsia and preterm labor, resulting in the exposure of a significant number of neonates to this drug despite a lack of evidence suggesting that it is safe, or effective as a tocolytic. While there is evidence that MgSO4 may be neuroprotective in perinatal brain injury, recent reviews have suggested that the effects are dependent upon dose, and that higher doses may actually increase neonatal morbidity and mortality. There is a lack of evidence investigating the neurotoxic effects of neonatal magnesium (Mg) exposure on the developing brain, specifically in terms of neurodevelopmental apoptosis, a cell-killing phenomenon known to be potentiated by other drugs with mechanisms of action at Mg-binding sites (i.e. NMDA receptor antagonists such as MK-801, ketamine, and PCP). Objective: To investigate the effects of Mg exposure on the neonatal mouse brain at different postnatal ages to determine whether MgSO4 treatment causes significant cell death in the developing mouse brain. Methods: C57Bl/6 mice were treated with four doses of MgSO4 (250 mg/kg) on postnatal days 3 (P3), 7 (P7) or 14 (P14). Caspase-3 immunohistochemistry, cupric silver staining, and electron microscopy techniques were used to examine Mg-treated brains for neurotoxic effects. Results: Qualitative evaluation using cupric silver staining revealed widespread damage throughout the brain in P7 animals. Results of electron microscopy confirmed that the cell death process was apoptotic in nature. Quantitative evaluation of damage to the cortex, caudate-putamen, hippocampus, thalamus, and cerebellum showed that Mg treatment caused significant brain damage in animals treated on P3 and P7, but not P14. Conclusions: Administration of high doses of Mg may be detrimental to the fetal brain, particularly if exposure occurs during critical periods of neurodevelopment.
Influence of Fluoride Availability of Dentifrices on Eroded Enamel Remineralization in situ
Authors: Hara A.T. , Kelly S.A. , González-Cabezas C. , Eckert G.J. , Barlow A.P. , Mason S.C. , Zero D.T.
Published: February 2009

Remineralization of eroded enamel by dentifrices containing similar sources/concentrations of fluoride was investigated in situ. Fifty-three subjects completed a double-blind crossover study with 3 randomly assigned dentifrice treatments: placebo (0 ppm F, PD); reference (1,450 ppm NaF, RD) and test (1,450 ppm NaF + 5% KNO3, TD). Fluoride availability for each dentifrice was analyzed in vitro by standard tests (1-min fluoride release rate and enamel fluoride uptake). The subjects wore palatal appliances holding bovine enamel specimens previously eroded in vitro. Surface microhardness was determined before and after the in vitro erosive challenge, after in situ remineralization and after a second in vitro erosive challenge. ANOVA and pairwise comparisons were performed (α = 0.05). TD was superior to RD in the fluoride release tests, but similar to RD in the enamel fluoride uptake test. The mean percent surface microhardness recovery was 21.9 (standard deviation 8.0) for PD, 28.6 (8.0) for RD and 36.0 (8.0) for TD. The mean percent relative erosion resistance change was –58.8 (12.7) for PD, –31.3 (12.7) for RD and –27.3 (12.6) for TD. Both fluoride-containing dentifrices provided superior remineralization (p < 0.001) and erosion resistance (p < 0.001) compared to PD. The percent surface microhardness recovery demonstrated by the TD was significantly greater than for the RD (p < 0.001). There was no significant difference (p = 0.073) between TD and RD in relative resistance to further erosive challenge. The results suggest that fluoride availability may be different in dentifrices with similar sources/concentrations of fluoride, providing different levels of remineralization of eroded enamel.
Use of Health Services after a Myocardial Infarction
Authors: Máland John Gunnar , Havik Odd Erik
Published: February 2009

Short-term and long-term use of physician consultations and rehospitalizations were studied in 383 myocardial infarction (MI) patients in relation to demographic, medical, and psychological factors. Short-term (i.e. within 6 months post-MI) utilization of physicians was only related to patients' health locus of control. In comparison, a higher number of physician consultations 3-5 years after the MI was independently related to female sex, more non-cardiac limitations before the MI, more complications during hospitalization, less cardiac lifestyle knowledge, and higher levels of anxiety and depression short time after the MI. Every second patient was readmitted to the hospital before the 3-5 years follow-up but only 14% suffered a non-fatal reinfarction. More rehospitalizations were independently related to a higer number of previous hospitalizations for heart disease, more pre-MI cardiac limitations, less cardiac lifestyle knowledge, and higer initial level of emotional distress. Discriminant analysis identified female sex and patients' initial expectations of reduced emotional control as the best predictor variables for a rehospitalization caused by chest pain without a new infarction, whereas a reinfarction was best discriminated by the number of previous hospitalizations for heart disease. We conclude that psychological factors influence health services utilization to a comparable extent as medical factors. These findings may indicate a greater need for long-term professional support in patients with less initial cognitive and emotional control.
Preventive activities in primary health care in Stockholm county; Sweden
Authors: J. A. Haglund Bo
Published: February 2009

A survey was conducted, during November 1985, in 110 Stockholm Public Primary Health Care Centres (PHCC) to study ongoing preventive activities. In 71% of the Health Centres there was an awareness of special risk groups in the PHCC area, such as alcohol abusers, elderly people and single parents, and in 40% of more specific risk factors like unemployment and loneliness. Individualised preventive activities were provided in 25% and grouporiented activities in 50% of the health centres. There were great differences between the different regions of Stockholm County and, for example, quit-smoking groups were not distributed according to the geographical needs, i.e. to the areas with the highest prevalence of smokers. Involvement of PHC in community-based preventive activities is still rare but has started in the area of accident prevention in some PHCC. The study also underlines the need for more education as well as suport to increase the element of prevention in primary health care activities.