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We propose and experimentally demonstrate a near-optimal discrimination scheme for the quadrature phase shift keying (QPSK) protocol. We show in theory that the performance of our hybrid scheme is superior to the standard scheme-heterodyne detection-for all signal amplitudes and underpin the predictions with our experimental results. Furthermore, our scheme provides hitherto the best performance in the domain of highly attenuated signals. The discrimination is composed of a quadrature measurement, a conditional displacement and a threshold detector. [ABSTRACT FROM AUTHOR]

We investigate the practical scheme of engineering a qubit of two optical continuous-variable states, based on squeezed vacuum and coherently displaced photon subtraction. A fully multimode model is developed to describe a continuous wave (cw) setting of the experiment, which has been successfully implemented to generate highly pure non-classical states. The model agrees well with the experimental results and the numerical results show that the intrinsic imperfection due to the cw nature of the source is relatively small. Our photon subtraction technique could also be useful for preparing optical Schrodinger's cat-like states in arbitrary superposition, which is a basic qubit resource for linear optics coherent state quantum computing. [ABSTRACT FROM AUTHOR]

Optical pulse-position modulation (PPM) is one of the primary modulation formats being investigated for use in deep-space communications, as well as terrestrial fiber optical communications. We consider the problem of demodulating M-ary optical PPM waveforms, and propose a structured receiver whose mean probability of symbol error is smaller than all known receivers, and approaches the Helstrom (quantum) limit of the minimum probability of error (MPE) of discriminating between the coherent-state PPM signals. The receiver uses photodetection coupled with optimized phase-coherent optical feedback control through the PPM pulse slots and a phase-sensitive parametric amplifier. We present a general framework of optical receivers known as the 'conditional pulse nulling receiver', and present new results on ultimate limits and achievable regions of the trade-off space between the spectral versus photon efficiency of PPM, for the single-spatial-mode far-field pure-loss optical communication channel. [ABSTRACT FROM AUTHOR]

Chronic moderate exercise has been reported to reduce pro-inflammatory cytokines. To analyze the molecular mechanisms by which training exerts these effects, the epigenetic influences of age and exercise on the ASC gene, which is responsible for IL-lß and IL-18 secretion, were investigated by ASC gene methylation. Further, the relationship between carcinogenesis and exercise, and methylation of the p15 tumor suppressive gene was also analyzed. High-intensity interval walking exercise, consisting of 3 min low-intensity walking at 40% of peak aerobic capacity followed by a 3 min high-intensity walking period above 70% of peak aerobic capacity, was continued for 6 months. Peripheral blood DNA extracts from young control (n = 34), older control (n=153), and older exercise (n = 230) groups were then analyzed by pyrosequencing for DNA methylation. Methylation of ASC decreased significantly with age (young control vs. older control, p<0.01 ), which is indicative of an age-dependent increase in ASC expression. Compared to the older control group, the degree of ASC methylation was higher in the older exercise group (older control vs. older exercise: p<0.01), and presumably lower ASC expression. Neither exercise nor age affected the methylation of the p15. In summary, chronic moderate exercise appears to attenuate the age-dependent decrease in ASC methylation, implying suppression of excess pro-inflammatory cytokines through reduction of ASC expression. [ABSTRACT FROM AUTHOR]

The possibility of implementing a given photonic projective measurement with linear optics and photon detectors is discussed. This problem can be viewed as a single-shot discrimination of orthogonal pure quantum states. It is particularly shown that any two orthogonal states can be perfectly discriminated using only linear optics, photon counting, coherent ancillary states, and feedforward. This means that one can construct any binary projective measurement with these means, but without any nonclassical ancillary state. The statement holds in the asymptotic limit of a large number of these physical resources. To extend this result, we also address the problem of discriminating a simple set of three orthogonal states. [ABSTRACT FROM AUTHOR]

We investigate a systematic method of implementation of given measurements with linear optics and continuous measurement. We revisit the so-called Dolinar receiver, which is a quasi-physical model attaining the minimum error discrimination of binary coherent states, and show that it can be derived without heuristic assumptions. Our approach also can be applied to various kinds of measurements. © 2005 Pleiades Publishing, Inc. [ABSTRACT FROM AUTHOR]

A quantum channel consisting of continuous variable quantum teleportation based on the standard protocol is investigated. It is shown that a quantum channel for continuous variable teleportation by an aribitrary entangled state is equivalent to a generalized thermalizing channel. We also study the transmission of nonclassical states by a teleportation channel with a two-mode squeezed-vacuum state in a noisy environment. The transmisson performance is evaluated by using the Glauber-Sudarshan P function and the nonclassical depth. Finally, we compare the results obtained to those of a noisy direct transmission channel. It is shown that the teleportation channel performs better than the direct transmission channel in a certain region. [ABSTRACT FROM AUTHOR]

Summary Background The structural integrity of the blood vessels such as small arteries and veins is studied less frequently in malignant tumours than is angiogenesis. Objectives To clarify the characteristics of small arteries and small veins of melanoma lesions. Methods We immunohistochemically investigated various types of melanocytic tumours using antibodies specific for endothelial and vascular smooth muscle cells, and analysed the relationship between the expression of these molecules in the blood vessels and the biological characteristics of the tumours. Formalin-fixed, paraffin-embedded sections of 15 cases of benign melanocytic tumours and 64 cases of malignant melanomas were investigated. Results Significant suppression of expression of h-caldesmon (h-CD) and calponin h1 (CNh1) was observed in the blood vessels of malignant melanomas compared with both benign melanocytic tumours and normal tissues. In particular, the level of h-CD expression was inversely correlated with the frequency of metastasis and positively correlated with the survival rate in patients with malignant melanoma. Conclusions These findings suggest that alterations of the tumour vessels are an important factor for the prognosis of malignant melanoma, and that suppression of h-CD and CNh1 in the blood vessels in malignant melanoma reflects a structural fragility of the vessels, leading to their easy penetration by tumour cells. Defective expression of these molecules is likely to be an important marker for metastatic potential and for poor prognosis of melanoma. [ABSTRACT FROM AUTHOR]

To examine cardiopulmonary function during exercise in a mountainous region at moderate altitude, we measured cardiac frequency, oxygen consumption $$\left( {\dot VO_2 } \right)$$ , and percentage arterial hemoglobin oxygen saturation (%SaO) before and after a bicycle race with a starting point at 638 m and finishing point at 1980 m. The time required to ascend an elevation of 10 m was prolonged with increasing altitude, and heart rate also increased with altitude. The %SaO at the starting point and at the finishing point differed significantly ( P<0.01). Faster cyclists exhibited higher %SaO and lower $$\dot VO_2 $$ , while slower cyclists exhibited a reduction in %SaO and an increase in $$\dot VO_2 $$ immediately after the race. The %SaO recovery time was significantly correlated with the racing time ( r=0.54, P<0.001). Therefore, the faster cyclists' oxygen debt upon completion of the race may be small and recovery of cardiopulmonary function may be fast, while the slower cyclists' oxygen debt may be large and recovery of cardiopulmonary function may be slow. [ABSTRACT FROM AUTHOR]

By immersion of rabbit's earlobes into a cold liquid at −5 to −10‡C, the blood vessels begin to constrict or dilate alternately. This is reflected in the vessel temperature: temperatures were recorded and the patterns analyzed. In each unit wave, the height and the period were designated as X and Y. From a series of about 10 waves, the standard deviation SD, coefficient of variation CV and correlation coefficient R for X and/or Y were obtained. These were considered as three fundamental parameters describing the characteristics of scatter diagrams for X and Y. The successive changes of RXY for the diagrams indicated in most cases the periodic tendency. In such cases, it can be regarded as a pantograph-like change of the successive scattered diagrams. The time course of CV also showed a similar tendency but nonperiodic time courses sometimes appeared. For weaker stimuli above 0‡C, the wave patterns tended to become more irregular. [ABSTRACT FROM AUTHOR]

Summary:A 5-year-old girl with Ph-positive chronic myelogenous leukemia, who underwent umbilical cord blood transplantation, developed two episodes of electrical status epilepticus while receiving tacrolimus (FK506) then cyclosporin A (CsA), as treatment against graft-versus-host disease. MRI including diffusion weighted MR imaging of the brain revealed abnormalities in the hippocampus and posterior white matter following FK506 and CsA treatment, respectively. While posterior white matter injury has been described with both FK506 and CsA, no previous report describes hippocampal injury from either drug. The MRI changes in the hippocampus in our case suggest possible increased susceptibility to hippocampal injury with FK506.Bone Marrow Transplantation (2003) 32, 523-525. doi:10.1038/sj.bmt.1704168 [ABSTRACT FROM AUTHOR]

We numerically evaluate the deep-space communication performance in a broadband lossy channel of coherent pulse position modulation (PPM) with an on/off receiver, single-symbol square root detection, and Holevo information. We also consider quadrature amplitude modulation (QAM) signals and phase-shift keying signals with dyne-type detections. We show the quantitative gap between these detection strategies in terms of the capacity, particularly in the quantum-limited region where the quantum noise seriously limits the transmission rate. In particular, we find that for an extremely weak signal input power, use of a multilevel PPM system is a good strategy, whereas for an extremely strong signal, use of a multilevel QAM system is recommended. [ABSTRACT FROM PUBLISHER]