Experimental investigation of pulsed entangled photons and photonic quantum channels

The development of key devices and systems in quantum information technology, such as entangled particle sources, quantum gates and quantum cryptographic systems, requires a reliable and well-established method for characterizing how well the devices or systems work. We report our recent work on experimental characterization of pulsed entangled photonic states and photonic quantum channels, using the methods of state and process tomography. By using state tomography, we could reliably evaluate the states generated from a two-photon source under development and develop a highly entangled pulsed photon source. We are also devoted to characterization of single-qubit and two-qubit photonic quantum channels. Characterization of typical single-qubit decoherence channels has been demonstrated using process tomography. Characterization of two-qubit channels, such as classically correlated channels and quantum mechanically correlated channels is under investigation. These characterization techniques for quantum states and quantum processes will be useful for developing photonic quantum devices and for improving their performances.Comment: 12 pages, 8 figures, in Quantum Optics in Computing and Communications, Songhao Liu, Guangcan Guo, Hoi-Kwong Lo, Nobuyuki Imoto, Eds., Proceedings of SPIE Vol. 4917, pp.13-24 (2002

Macular Retinal Ganglion Cell Complex Thickness and Its Relationship to the Optic Nerve Head Topography in Glaucomatous Eyes with Hemifield Defects

Purpose. To evaluate the relationship between the macular ganglion cell complex (mGCC) thickness, which is the sum of the retinal nerve fiber, ganglion cell, and inner plexiform layers, measured with a spectral-domain optical coherence tomograph and the optic nerve head topography measured with a confocal scanning laser ophthalmoscope in glaucomatous eyes with visual field defects localized predominantly to either hemifield. Materials and Methods. The correlation between the mGCC thickness in hemispheres corresponding to hemifields with and without defects (damaged and intact hemispheres, respectively) and the optic nerve head topography corresponding to the respective hemispheres was evaluated in 18 glaucomatous eyes. Results. The mGCC thickness was significantly correlated with the rim volume, mean retinal nerve fiber layer thickness, and cross-sectional area of the retinal nerve fiber layer in both the intact and the damaged hemispheres (P < .05). Discussion. For detecting very early glaucomatous damage of the optic nerve, changes in the thicknesses of the inner retina in the macular area and peripapillary RNFL as well as rim volume changes in the optic nerve head are target parameters that should be carefully monitored

A GO intervention program for enhancing elementary school children's cognitive functions and control abilities of emotion and behavior: study protocol for a randomized controlled trial

BACKGROUND: Executive function is critical for children's healthy development. We propose an intervention program to enhance children's executive function using the game, GO. Many neuroimaging studies have revealed that playing GO is related to executive function. In addition, previous studies also revealed that executive function can be enhanced by training. We will perform a randomized controlled trial to investigate the effectiveness of a GO intervention group and a control group without intervention. METHODS/DESIGN: 35 elementary school children aged 8 to 10 were recruited from Edogawa elementary school in Tokyo, Japan. They will be randomized into two groups; either the 5-week GO intervention group or no-intervention control group. We will ask the participants of the intervention group to join the GO course which will be held once every week for five weeks (total: six times). In the GO course, the children will be taught GO by the GO masters of the Nihon Ki-in and enjoy it for an hour. Besides the course, the participants will perform GO problems about twenty minutes a day, three times a week during the intervention period. We will use the Stroop task, the digit span, the Raven's colored progressive matrices, the Span-board task, and the Behavioral inhibition/behavioral activation scale for the outcome measures. Outcomes will be measured at a baseline (Assessment 1) and 5 weeks after the intervention program started (Assessment 2). The intervention group will be compared with the control group using one-way analyses of covariance with the difference between Assessment 1 and Assessment 2 measures as dependent variables and pretest scores as covariates. DISCUSSION: To our knowledge, this study will be the first RCT to investigate the efficacy of a GO intervention program for elementary school children. If this intervention is effective, we will be able to take the next steps in making an educational program to enhance children's executive function and other cognitive abilities using GO. In addition, we further will investigate the transfer effects of the GO intervention program through executive function. We also will investigate neuroplasticity with the GO intervention using neuroimaging. TRIAL REGISTRATION: UMIN Clinical Trials Registry UMIN00000632

Hypothesis testing for an entangled state produced by spontaneous parametric down conversion

Generation and characterization of entanglement are crucial tasks in quantum information processing. A hypothesis testing scheme for entanglement has been formulated. Three designs were proposed to test the entangled photon states created by the spontaneous parametric down conversion. The time allocations between the measurement vectors were designed to consider the anisotropic deviation of the generated photon states from the maximally entangled states. The designs were evaluated in terms of the p-value based on the observed data. It has been experimentally demonstrated that the optimal time allocation between the coincidence and anti-coincidence measurement vectors improves the entanglement test. A further improvement is also experimentally demonstrated by optimizing the time allocation between the anti-coincidence vectors. Analysis on the data obtained in the experiment verified the advantage of the entanglement test designed by the optimal time allocation.Comment: 7 figures, 9 pages. This paper is revised for increasing the readership for experimentalists. Hence, the mathematical part is moved to a new manuscript quant-ph/060802

Prevalence of Diabetes and Incidence of Angiopathy in Patients with Chronic Viral Liver Disease

Patients with chronic liver disease (CLD) often develops glucose intolerance. We explored the prevalence of diabetes mellitus in viral CLD, and analyzed factors profoundly affecting the diabetic angiopathies. 229 CLD patients (124 chronic hepatitis and 105 liver cirrhosis) entered the study. The diagnosis of diabetes was made with the criteria by World Health Organization. Laboratory investigation included serum asparate aminotransferase, alanine aminotransferase, albumin, fasting blood sugar, hemoglobin A1c (HbA1c), fasting immunoreactive insulin, and HOMA-R (FBS*IRI/405). The incidence of macro- and microangiopathy were also examined. Forty (17.5%) CLD patients were diagnosed diabetes, giving a significantly higher incidence than that of general cohort (5.3%) (p<0.001). Among them, 12 (30%) had the triopathy, significantly lower than that in a matched group of diabetic patients without CLD (65%) (p<0.001). Significantly increased levels of HbA1c and HOMA-R were observed in diabetic CLD with angiopathy compared with diabetic CLD without. Incidence of diabetes was increased in viral CLD patients. The rate of diabetic angiopathies in CLD, however, was relatively low, this could be explained by low coagulability in these patients. Poor control of hyperglycemia, partly due to insulin resistance, might explain the onset of angiopathy in diabetic CLD

Lack of association between estrogen receptor β dinucleotide repeat polymorphism and autoimmune thyroid diseases in Japanese patients

BACKGROUND: The autoimmune thyroid diseases (AITDs), such as Graves' disease (GD) and Hashimoto's thyroiditis (HT), appear to develop as a result of complex interactions between predisposing genes and environmental triggers. Susceptibility to AITDs is conferred by genes in the human leukocyte antigen (HLA) and genes unlinked to HLA, including the CTLA-4 gene. Recently, estrogen receptor (ER) β, located at human chromosome 14q23-24.1, was identifed. We analyzed a dinucleotide (CA)n repeat polymorphism located in the flanking region of ERβ gene in patients with AITDs and in normal subjects. High heterozygosity makes this polymorphism a useful marker in the genetic study of disorders affecting female endocrine systems. We also correlated a ERβ gene microsatellite polymorphism with bone mineral density (BMD) in the distal radius and biochemical markers of bone turnover in patients with GD in remission. RESULTS: Fourteen different alleles were found in 133 patients with GD, 114 patients with HT, and 179 controls subjects. The various alleles were designated as allele(*)1 through allele(*)14 according to the number of the repeats, from 18 to 30. There was no significant difference in the distributions of ERβ alleles between patient groups and controls. Although recent study demonstrated a significant relation between a allele(*)9 in the ERβ gene and BMD in postmenopausal Japanese women, there were no statistically significant interaction between this allele and BMD in the distal radius, nor biochemical markers in patients with GD in remission. CONCLUSIONS: The present results do not support an association between the ERβ microsatellite marker and AITD in the Japanese population. We also suggest that the ERβ microsatellite polymorphism has at most a minor pathogenic importance in predicting the risk of osteoporosis as a complication of GD

Gene Knockout and Metabolome Analysis of Carnitine/Organic Cation Transporter OCTN1

金沢大学医薬保健研究域薬学系Purpose: Solute carrier OCTN1 (SLC22A4) is an orphan transporter, the physiologically important substrate of which is still unidentified. The aim of the present study was to examine physiological roles of OCTN1. Methods: We first constructed octn1 gene knockout (octn1-/-) mice. Metabolome analysis was then performed to identify substrates in vivo. The possible association of the substrate identified with diseased conditions was further examined. Results: The metabolome analysis of blood and several organs indicated complete deficiency of a naturally occurring potent antioxidant ergothioneine in octn1-/- mice among 112 metabolites examined. Pharmacokinetic analyses after oral administration revealed the highest distribution to small intestines and extensive renal reabsorption of [3H]ergothioneine, both of which were much reduced in octn1-/- mice. The octn1-/- mice exhibited greater susceptibility to intestinal inflammation under the ischemia and reperfusion model. The blood ergothioneine concentration was also much reduced in Japanese patients with Crohn\u27s disease, compared with healthy volunteers and patients with another inflammatory bowel disease, ulcerative colitis. Conclusions: These results indicate that OCTN1 plays a pivotal role for maintenance of systemic and intestinal exposure of ergothioneine, which could be important for protective effects against intestinal tissue injuries, providing a possible diagnostic tool to distinguish the inflammatory bowel diseases. © 2010 Springer Science+Business Media, LLC