Simultaneous registration and activation detection for fMRI

Registration using the least-squares cost function is sensitive to the intensity fluctuations caused by the blood oxygen level dependent (BOLD) signal in functional MRI (fMRI) experiments, resulting in stimulus-correlated motion errors. These errors are severe enough to cause false-positive clusters in the activation maps of datasets acquired from 3T scanners. This paper presents a new approach to resolving the coupling between registration and activation. Instead of treating the two problems as individual steps in a sequence, they are combined into a single least-squares problem and are solved simultaneously. Robustness tests on a variety of simulated three-dimensional EPI datasets show that the stimulus-correlated motion errors are removed, resulting in a substantial decrease in false-positive and false-negative activation rates. The new method is also shown to decorrelate the motion estimates from the stimulus by testing it on different in vivo fMRI datasets acquired from two different 3T scanners.     

Simplified procedure for preparation of35S-labeled brain sulfatide

A simplified procedure for the preparation of³⁵S-labeled brain cerebroside sulfates has been developed. The labeled sulfatides are synthesized in vivo after intracerebral administration of inorganic³⁵S-sulfate in developing rats. The animals are sacrificed three days later and brain homogenates extracted with chloroform-methanol. The extract is subjected to mild alkaline treatment and washed with water. The organic phase is chromatographed on triethylaminoethyl-cellulose from which sulfatides are eluted with chloroform-methanol containing potassium acetate. Radioactive fractions are pooled, concentrated, and potassium acetate removed by dialysis against water. Alternatively, salts are removed by passing radioactive fractions through Sephadex G-25. After evaporating to near dryness, the radioactive cerebroside sulfates are dissolved in a small volume of chloroform-methanol and stored at −20 C. The³⁵S-sulfatides are essentially free of lipid contaminants, and 97% of the radio-activity corresponds with sulfatides on chromatographic analysis.     

Harpin_(Ea)蛋白制剂对葡萄、杨梅产量及品质的影响

Messenger对藤捻葡萄,巨峰葡萄和丁岙杨梅的生长以及品质试验表明,能够显著地促进葡萄叶重和叶面积增加,促进春梢伸长,提高单果重和单株产量,并且使成熟期提早7-8 d;也能够促进杨梅果柄生长。能显著改善巨峰葡萄、丁岙杨梅的品质,各处理的总糖、还原糖、维生素C以及固形物等均有提高,使用浓度以30 mg/ml为最佳。     

心电图仪设计综述

介绍了心电图仪(ECG或EKG)的基本架构及心电信号的电子测量和显示的基本原理,探讨了ECG设备的模拟前端(AFE)及信号通道对心率信号实现数字化的问题,并讨论了各种ECG应用,包括自动体外除颤仪(AED)、病人监护仪和高端诊断型ECG及其所提供的多种功能。     

Room temperature and 77K dielectric properties of acetate-derived PZT,PLZT, PSZT and PBZT thin films

Abstract

Ferroelectric thin films in the PZT, PLZT, PBZT (lead barium zirconate titanate) and PSZT (lead stannate zirconate titanate) compositional systems were prepared from as-received acetate precursors. Multiple-layer thin films were fabricated via a spin coating technique and sintered at 650 – 700°C for two to three minutes per layer, yielding an overall thickness of 0.45um. The dielectric and ferroelectric hysteresis loop properties of these films were measured at room temperature and 77K. The results show that the thin films experience a substantial loss (-80% avg.) in dielectric permittivity at 77K and a significant increase in P_R, E_c and electrical breakdown strength. The phase transformation trends on cooling from room temperature to 77K were from SFE (slim-loop FE)-to-FE and AFE-to-FE. Compositions in these systems show promise for potential low temperature applications.     

利用光栅实时测量激光波长的方法

探讨了利用光栅实时测量激光波长的理论依据，并进行了误差分析；尝试并实现了利用光栅实时测量激光波长的方法，预见到光栅是实时测量宽频带、脉冲激光波长的有效元件。     

Investigation of driving performance, vection, postural sway, and simulator sickness in a fixed-based driving simulator

This paper reports the results of a pilot study conducted to determine whether there is a relationship between simulator sickness and measures of driver inputs, vection, and postural sway, in a fixed base driving simulator. Seven males and four females performed a series of alternating left and right turns (20 each), with straigth-aways inbetween. The task was designed to promote experiences of circular and linear vection, and associated sway. It was hypothesized that greater driver inputs (i.e., steering wheel and braking activity; deviation from the centerline) would correlate: with reports of vection and measures of postural sway. Ten of the eleven subjects reported moderate sickness, which precluded any statistical comparisons between “sick” and “not sick” however, there was a significant tendency for persons who reported vection to also report sickness. There were no gender differences in reported incidence of vection or sickness, however, males tended to exhibit greater lateral velocity. The next phase of investigation will necessitate reducing the strength of the stimulus (i.e., require less turns) to increase variability of sickness scores amongst subjects and permit comparisons between “sick” and “not sick.” Measurement considerations include increasing the sensitivity of vection ratings, and examination of the timecourse for the development of postural sway.     

Ethnic pride and self-control related to protective and risk factors: Test of the theoretical model for the strong African American families program.

Objective. To test a theoretical model of how ethnic pride and self-control are related to risk and protective factors. Design. A community sample of 670 African American youth (mean age = 11.2 years) were interviewed in households. Main Outcome Measures. Measures of cigarette smoking, alcohol use, and sexual behavior (lifetime to past month). Results. Structural modeling analyses indicated parenting was related to self-control and self-esteem, and racial socialization was related to ethnic pride. Self-control and self-esteem variables were related to levels of deviance-prone attitudes and to perceptions of engagers in, or abstainers from, substance use and sexual behavior. The proximal factors (behavioral willingness, resistance efficacy, and peer behavior) had substantial relations to the criterion variables. Participant gender and parental education also had several paths in the model. Results were generally similar for the 2 outcome behaviors. Conclusions. In this population, self-esteem and self-control are related to parenting approaches and have pathways to attitudes and social perceptions that are significant factors for predisposing to, or protecting against, early involvement in substance use and sexual behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)