Development of the vestibular system

This review mainly focuses on the development of the vestibular system in humans and other mammals, but reference is made to anurans and other species where applicable. In the first section, the steps involved in the development of undifferentiated cells into mature vestibular receptors are analysed. Available data indicate that in humans, maturation of the vestibular receptor and its afferent innervations involves a similar sequence of events as in other mammalian species. In the second section, morphological and physiological aspects of the maturation of the central vestibular system are presented. Undifferentiated neuron precursors have been identified in specific segregrated domains of the hindbrain neural tube, and these can develop into secondary vestibular neurons with unique properties. Several neuronal populations in the vestibulospinal and vestibulo-ocular pathways have been found to correlate with rhombomeric domains at early embryonic stages. In rodents, the vestibular system continues to develop postnatally in terms of morphology and function until it achieves its final form. The postnatal changes in the properties of vestibular nuclear neurons are chronologically matched with structural changes and serve to prime the development of vestibular-induced reflexes. Copyright © 2002 S. Karger AG, Basel.published_or_final_versio

An evaluation of logistics policy enablers between Taiwan and the UK

Purpose: This paper aims to empirically identify crucial international logistics policy enablers and to examine their impacts on logistics performance using survey data collected from 169 responding firms in Taiwan and 109 responding firms in the UK including logistics companies, freight forwarders, shipping companies, agencies and airline companies. Design/methodology/approach: A multiple regression analysis is used as a method to empirically validate the research model. Findings: Results indicate the five most important logistics policy enablers according to Taiwanese logistics firms are information technology system, inland transport linkage, simplifying the customs clearance procedures, ports and maritime transport and having a policy to ensure efficient service operation and multiplicity of services. In contrast, for the UK logistics firms, the five most important logistics policy enablers are telecommunications, information technology system, avoidance of unnecessary regulation, inland transport linkage and ports and maritime transport. Results also indicate that logistics policy dimensions in terms of regulation, integration, infrastructure and logistics education have a positive influence on firms’ logistics service quality and efficiency. Originality/value: Theoretical and policy implications from the research findings on logistics policy between these two countries are discussed in this paper

Effects of annealing temperature on sensing properties of Pt/HfO2/SiC Schottky-diode hydrogen sensor

Hafnium oxide (HfO 2) is successfully used as gate insulator for fabricating Metal-Insulator-SiC (MISiC) Schottky-diode hydrogen sensor. Sensors undergone N 2 annealing at different temperatures are fabricated for investigation. The hydrogen-sensing properties of these samples are compared with each other by taking the measurements at high temperature under various hydrogen concentrations using a computer-controlled measurement system. Experimental results show that sensitivity increases with the annealing temperature. Higher annealing temperature can enhance the densification of the HfO 2 film; improve the oxide stoichiometry; and facilitate the growth of a SiO 2 interfacial layer to give better interface quality, thus causing a remarkable reduction of the current of the sensor under air ambient. The effects of hydrogen adsorption on the barrier height and hydrogen-reaction kinetics are also investigated. © 2008 IEEE.published_or_final_versio

Enhanced sensing performance of MISiC schottky-diode hydrogen sensor by using HfON as gate insulator

MISiC Schottky-diode hydrogen sensor with HfON gate insulator fabricated by NO nitridation is investigated. The hydrogen-sensing characteristics of this novel sensor are studied by doing steady-state and transient measurements at different temperatures and hydrogen concentrations using a computer-controlled measurement system. Experimental results show that this novel sensor can rapidly respond to hydrogen variation and can give a significant response even at a low H 2 concentration of 48-ppm, e.g., a sensitivity of 81% is achieved at 450°C and 2.5 V, which is two times higher than its HfO 2 counterpart. The enhanced sensitivity of the device should be attributed to a remarkable reduction of the current of the sensor before hydrogen exposure by the NO nitridation because the NO nitridation can passivate the O vacancies in the insulator and facilitate the formation of a SiO 2 interlayer to suppress the leakage current associated with high-k materials. © 2006 IEEE.published_or_final_versio

Improved Sensing Characteristics of a Novel Pt/HfTiO2/SiC Schottky-Diode Hydrogen Sensor

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Atorvastatin correlates with decreased risk of esophageal cancer: A population-based casecontrol study from Taiwan

Objectives: The aim of this study was to explore the association between the use of statins and esophageal cancer in Taiwan.Methods: We designed a casecontrol study using database from the Taiwan National Health Insurance program. In all, 549 patients (cases) aged 20 years or older diagnosed recently with esophageal cancer, from 2000 to 2009, and 2,196 subjects (controls) without esophageal cancer participated in this study. The association between esophageal cancer and the use of statins and other co-morbidities was measured.Results: After adjustment for covariates, multivariate logistic regression showed that patients with a cumulative duration of ]12 months of using atorvastatin might have a reduced risk of esophageal cancer, compared with those who did not use statins (odds ratio [OR] 0.14, 95% confidence interval [CI] 0.040.56). The other statins could not show a significant association with esophageal cancer. Age (OR 1.01, 95% CI 1.001.01), alcoholism (OR 3.83, 95% CI 3.014.89), and esophageal diseases (OR 4.60, 95% CI 3.466.12) were independent factors significantly associated with esophageal cancer.Conclusions: Use of atorvastatin ]12 months may correlate with an 86% reduction of esophageal cancer risk.Keywords: atorvastatin; esophageal cancer; stati

Atorvastatin correlates with decreased risk of esophageal cancer: A population-based casecontrol study from Taiwan

Objectives: The aim of this study was to explore the association between the use of statins and esophageal cancer in Taiwan.Methods: We designed a casecontrol study using database from the Taiwan National Health Insurance program. In all, 549 patients (cases) aged 20 years or older diagnosed recently with esophageal cancer, from 2000 to 2009, and 2,196 subjects (controls) without esophageal cancer participated in this study. The association between esophageal cancer and the use of statins and other co-morbidities was measured.Results: After adjustment for covariates, multivariate logistic regression showed that patients with a cumulative duration of ]12 months of using atorvastatin might have a reduced risk of esophageal cancer, compared with those who did not use statins (odds ratio [OR] 0.14, 95% confidence interval [CI] 0.040.56). The other statins could not show a significant association with esophageal cancer. Age (OR 1.01, 95% CI 1.001.01), alcoholism (OR 3.83, 95% CI 3.014.89), and esophageal diseases (OR 4.60, 95% CI 3.466.12) were independent factors significantly associated with esophageal cancer.Conclusions: Use of atorvastatin ]12 months may correlate with an 86% reduction of esophageal cancer risk.Keywords: atorvastatin; esophageal cancer; stati

Effects of sputtering and annealing temperatures on MOS capacitor with HfTiON gate dielectric

In this work, Al/HfTiON/n-Si capacitors with different sputtering and annealing temperatures are studied. Larger accumulation capacitance and flat-band voltage are observed for samples with higher sputtering or post-deposition annealing temperature. Gate conduction mechanisms are only affected by sputtering temperature slightly. The flat-band voltage shift and interface-state density at midgap under high-field gate injection and substrate injection are investigated, and the results imply electron detrapping in the gate dielectric. ©2009 IEEE.published_or_final_versionThe IEEE International Conference of Electron Devices and Solid-State Circuits (EDSSC 2009), Xi'an, China, 25-27 December 2009. In Proceedings of EDSSC, 2009, p. 209-21

Picosecond all-optical logic gates (XOR, OR, NOT, and AND) in a fiber optical parametric amplifier

We demonstrate all-optical XOR, OR, NOT, and AND gates in a fiber optical parametric amplifier within the same experimental setup. Error-free operation was achieved for 10Gb/s RZ signals with pulsewidth suitable for 100Gb/s operation. © 2007 Optical Society of America.published_or_final_versio

A comparison of MISiC Schottky-diode hydrogen sensors made by NO, N 2O, or NH 3 nitridations

MISiC Schottky-diode hydrogen sensors with gate insulator grown in three different nitridation gases (nitric oxide (NO), N 2O, and NH 3) are fabricated. Steady-state and transien-t-response measurements are carried out at different temperatures and hydrogen concentrations using a computer-controlled measurement system. Experimental results show that these nitrided sensors have high sensitivity and can give a rapid and stable response over a wide range of temperature. This paper also finds that N 2O provides the fastest insulator growth with good insulator quality and hence the highest sensitivity among the three nitrided samples. The N 2O- nitrided sensor can give a significant response even at a low H 2 concentration of 48-ppm H 2 in N 2, indicating a potential application for detecting hydrogen leakage at high temperature. Moreover, the three nitrided samples respond faster than the control sample. At 300°C, the response times of the N 2O, NO, and NH 3-nitrided sample to the 48-ppm H 2 in N 2 are 11, 11, and 37 s, respectively, as compared to 65 s for the control sample without the gate insulator. © 2006 IEEE.published_or_final_versio