Differential stress distribution in a polarisation-holding fibre coupler

Differential stress distribution in a fused cross-sectional area of a polarisation-holding fibre coupler has been measured by using a Senarmont compensator. The stress profile is found to be effective for holding linear polarisations through the coupling region, i.e. the maximum stress difference is induced in the core region for the fibre coupler.     

Expression of cyclin-dependent kinase 5 and associated cyclins in Leydig and Sertoli cells of the testis

Sixty patients with a sudden onset of motor disability were assessed for illness behavior and depression. In 30 of the patients, etiology was attributed to a definite structural lesion. The remaining 30 patients were diagnosed as having conversion disorder. The Illness Behaviour Questionnaire (IBQ) and the Hamilton Rating Depression Scale (HRDS) were used as instruments for assessment. The mean HRDS score was significantly higher in the conversion group, indicating a higher degree of affective disease in these patients. According to the results of the IBQ, the patients with conversion disorder showed a higher degree of irritability, disease conviction, and phobic preoccupation, and also, to a greater extent, rejected psychological explanations for their symptoms. Denial was high in both patient groups, coexisting with affective symptoms in the conversion patients but not in the neurological patients. Although valuable information could be extracted from the IBQ, it was not found to be a reliable instrument for distinguishing between psychogenic and organic causes of motor disability.     

Copper Homeostasis as a Therapeutic Target in Amyotrophic Lateral Sclerosis with SOD1 Mutations

Amyotrophic lateral sclerosis (ALS) is a lethal neurodegenerative disease affecting both upper and lower motor neurons, and currently, there is no cure or effective treatment. Mutations in a gene encoding a ubiquitous antioxidant enzyme, Cu,Zn-superoxide dismutase (SOD1), have been first identified as a cause of familial forms of ALS. It is widely accepted that mutant SOD1 proteins cause the disease through a gain in toxicity but not through a loss of its physiological function. SOD1 is a major copper-binding protein and regulates copper homeostasis in the cell; therefore, a toxicity of mutant SOD1 could arise from the disruption of copper homeostasis. In this review, we will briefly review recent studies implying roles of copper homeostasis in the pathogenesis of SOD1-ALS and highlight the therapeutic interventions focusing on pharmacological as well as genetic regulations of copper homeostasis to modify the pathological process in SOD1-ALS.     

Identification of auxotrophic mutants of the yeast Kluyveromyces marxianus by non‐homologous end joining‐mediated integrative transformation with genes from Saccharomyces cerevisiae

The isolation and application of auxotrophic mutants for gene manipulations, such as genetic transformation, mating selection and tetrad analysis, form the basis of yeast genetics. For the development of these genetic methods in the thermotolerant fermentative yeast Kluyveromyces marxianus, we isolated a series of auxotrophic mutants with defects in amino acid or nucleic acid metabolism. To identify the mutated genes, linear DNA fragments of nutrient biosynthetic pathway genes were amplified from Saccharomyces cerevisiae chromosomal DNA and used to directly transform the K. marxianus auxotrophic mutants by random integration into chromosomes through non‐homologous end joining (NHEJ). The appearance of transformant colonies indicated that the specific S. cerevisiae gene complemented the K. marxianus mutant. Using this interspecific complementation approach with linear PCR‐amplified DNA, we identified auxotrophic mutations of ADE2, ADE5,7, ADE6, HIS2, HIS3, HIS4, HIS5, HIS6, HIS7, LYS1, LYS2, LYS4, LYS9, LEU1, LEU2, MET2, MET6, MET17, TRP3, TRP4 and TRP5 without the labour‐intensive requirement of plasmid construction. Mating, sporulation and tetrad analysis techniques for K. marxianus were also established. With the identified auxotrophic mutant strains and S. cerevisiae genes as selective markers, NHEJ‐mediated integrative transformation with PCR‐amplified DNA is an attractive system for facilitating genetic analyses in the yeast K. marxianus. Copyright © 2013 John Wiley & Sons, Ltd.     

Preparation of Sn‐Doped Zinc Phosphate Amorphous Thin Film and its Emission Properties

Using liquid‐phase synthesis, SnO – ZnO – P₂O₅ amorphous coating films exhibiting broad emission of Sn²⁺ center were prepared. It is found that the P – O – Zn bonds of the film were generated during the heat‐treatment. The emission property due to Sn²⁺ depended on the heat‐treatment temperature, which correlated with the residual chloride ion content. Although the peak position of the photoluminescence (PL) excitation band was almost constant, that of PL red‐shifted with increasing amount of SnO, which was quite different from the result observed for SnO – ZnO – P₂O₅ bulk glass containing Sn²⁺ center.     

Paradigms representing the relationship between the inner of a brain and the outer world

Neuroscience was initially based on simple computer models, and the resulting assumption of blocks of information and step‐by‐step information processing disregards the dynamic features of living neuronal networks. Building semiartificial intelligence in a culture dish using a simple living neuronal network makes comparison with an engineering model easier than when analyzing a complicated brain network. We hypothesize that the status of the neuronal network changes autonomously according to both its own internal state and input from the outer world. Our investigation of such network suggests that an electrical stimulus can make the living neuronal network shift to a particular state, and the response pattern to each input is loosely coupled rather than strictly linked. The critical point we propose regarding brain‐like information processing is that the internal state of the autonomous neuronal network is modified by input from the outer world. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Stress resistance of biofilm and planktonic Lactobacillus plantarum subsp. plantarum JCM 1149

The purpose of this study was to investigate the change in resistance of biofilm and planktonic food spoilage lactic acid bacteria (LAB) to environmental stresses, which strongly inhibit bacterial growth and are important in food preservation or in disinfection. The stress responses of biofilm and planktonic cells of Lactobacillus plantarum subsp. plantarum JCM 1149, which was used as a model spoilage bacterium, in various organic acids (namely, acetic acid, citric acid, lactic acid, and malic acid), ethanol, and sodium hypochlorite, were investigated using survival tests. The bacterial cells in biofilms showed greater resistance to all treatments than the planktonic bacterial cells in either the stationary or logarithmic phase. The planktonic bacterial cells showed reduced resistance to acetic acid after the cell suspension was diluted; however, intriguingly, the bacterial cells in biofilms maintained their resistance to acetic acid even after they were suspended or the cell suspension was diluted. These findings suggested the risk for food spoilage due to LAB derived from biofilms and suspended or diluted in foods, and demonstrated the importance of controlling biofilms of LAB in the food industry.     

Fatigue damage monitoring of round shape specimen by acoustic microscopy

Acoustic microscope can detect microstructural features with high resolving power compared to other lower frequency acoustic techniques. Many non-destructive evaluations using acoustic microscope, several of them used in industrial fields, were investigated. However, acoustic measurement of curved surface structure was restricted to basic studies as conventional acoustic microscope system was designed for flat specimen. We have developed a modified acoustic microscope for curved surface specimen testing and have measured acoustic image of round bar specimen. In this study, using this system, velocities of round bar specimen during fatigue test are monitored using the V(z) curve method. Measurement errors depending on curved surface measurement were investigated and it was found that the acoustic velocity tends to increase as fatigue damage increases.     

MRI-Compatible Pneumatic Robot for Transperineal Prostate Needle Placement

Magnetic resonance imaging (MRI) can provide high-quality 3-D visualization of prostate and surrounding tissue, thus granting potential to be a superior medical imaging modality for guiding and monitoring prostatic interventions. However, the benefits cannot be readily harnessed for interventional procedures due to difficulties that surround the use of high-field (1.5T or greater) MRI. The inability to use conventional mechatronics and the confined physical space makes it extremely challenging to access the patient. We have designed a robotic assistant system that overcomes these difficulties and promises safe and reliable intraprostatic needle placement inside closed high-field MRI scanners. MRI compatibility of the robot has been evaluated under 3T MRI using standard prostate imaging sequences and average SNR loss is limited to 5%. Needle alignment accuracy of the robot under servo pneumatic control is better than 0.94 mm rms per axis. The complete system workflow has been evaluated in phantom studies with accurate visualization and targeting of five out of five 1 cm targets. The paper explains the robot mechanism and controller design, the system integration, and presents results of preliminary evaluation of the system.     

Lateral n?p?n avalanche photodiode with an AlInAs multiplication layer

A quasi-planar AllnAs avalanche photodiode (APD) with a lateral n-p-n structure for optical fibre communications is reported. Although both the anode and the cathode contact the n-type regions, it is demonstrated that the n-p-n APD has the same performance as a normal p-n APD. The n-p-n structure enables the p-type conversion process of thermal Zn diffusion to be omitted, and AlInAs with a large gain bandwidth product and low noise to be utilised for a multiplication region. The n-p-n AlInAs APDs can provide better receiver sensitivity at 10 Gbit/s than commercially available InP APDs.