Variations in the levels of 3-methyl-l-histidine of the myosins within the bovine carcass

The 3-methyl-l-histidine levels were determined in the whole muscles from cheek, flank, round, neck and loin regions of the bovine carcass and in the corresponding myosins prepared from them. Titres were similar between the muscles in the latter three locations, but very low in cheek muscle. This finding was reflected by a very low titre for the myosin prepared from this source.     

我国创业投资机构发展现状及其存在的问题

根据对全国36家创业投资机构和53家创业企业的调查及对多家创投机构的现场访谈，分析了我国创业投资机构的发展现状，指出存在的人才匮乏、激励和约束不力、难选合格的创业企业、获得信息不真实、风险防范意识差和多家同时投资多个行业这6个问题。     

Cardiovascular and eye activity measures as indices for momentary changes in mental effort during simulated flight

This study examines effects of momentary changes in mental effort on cardiovascular and eye activity measures. A total of 19 male pilots performed an instrument flight task. Task load was manipulated by having the pilots perform flight manoeuvres of varying complexity. Multilevel analyses demonstrated clear effects of momentary changes in mental effort on both the cardiovascular and the eye activity measures. An increase in task load resulted in an increase of heart rate and a decrease in heart rate variability, mean dwell time and fixation duration. Heart rate differentiated between resting period and task execution. Heart rate variability from short data segments provided more insight in intermediate levels of mental effort. The eye activity measures were sensitive to intermediate levels of mental effort as well. Attitude changes resulted in an increase of mean dwell time and mean fixation duration. Task analysis is required to use eye measures as valid indices of mental effort. Having indications of the effects of changing mental demands during daily work of operators is of great importance nowadays. This paper presents an approach to estimate such effects on the basis of heart rate and eye activity measures. In particular, the use of averaged short-term heart rate variability measures is a relatively new aspect.     

QRS complexes detection for ECG signal: the Difference Operation Method

This paper proposes a simple and reliable method termed the Difference Operation Method (DOM) to detect the QRS complex of an electrocardiogram (ECG) signal. The proposed DOM includes two stages. The first stage is to find the point R by applying the difference equation operation to an ECG signal. The second stage looks for the points Q and S based on the point R to find the QRS complex. From the QRS complex, the T wave and P wave can be obtained by the existing methods. Some records (QRS complex and T and P waves) of ECG signals in MIT-BIH arrhythmia database is tested to show the DOM has a much more precise detection rate and faster speed than other methods.     

A validation of a posture matching approach for the determination of 3D cumulative back loads

The purpose of this project was to investigate the amount of error in calculating cumulative lumbar spine kinetics using a posture matching approach (3DMatch) compared to a 3D coordinate electromagnetic tracking approach (FASTRAK). Six subjects were required to perform five repeats each of two symmetrical and two asymmetrical lifts while being simultaneously recorded from 4 camera views at viewing angles of 0 degrees , 45 degrees , 60 degrees and 90 degrees to the sagittal plane while wearing eight FASTRAK sensors to define an 8 segment rigid link model (RLM) of the head, arms, and trunk. Four hundred and eighty lifts (6 subjects x20 lifts x4 camera views) were analyzed using the 3DMatch posture-matching program to calculate the following cumulative loads at the L4/L5 joint: compression, anterior shear, posterior shear, reaction shear and extension moment. The errors in cumulative load calculation were determined as the difference between the values calculated for the same lifts using a 3D RLM that used electromagnetic motion tracking sensors (FASTRAK) positioned at the segment center of masses as model inputs. No significant difference (p<0.05) in the relative error for any of the cumulative loading variables between the four camera views and the 3D RLM approach was found. Furthermore the relative errors for cumulative compression, joint anterior shear, reaction anterior shear and extension moment were all below 12%. These results suggest that posture matching by trained users can provide reasonable 3D data to calculate cumulative low back loads with a biomechanical model.     

Development of a stable source of atomic oxygen with a pulsed high-voltage discharge and its application to crossed-beam reactions

To investigate the reactions of oxygen atoms with ethene and silane in a crossed-beam condition, we developed a stable, highly intense, and short-pulsed source of atomic oxygen with a transient high-voltage discharge. Mixtures of O(2) and He served as discharge media. Utilizing a crossed molecular-beam apparatus and direct vacuum-ultraviolet ionization, we measured the temporal profiles of oxygen atoms and the time-of-flight spectra of reaction products. With O(2) 3% seeded in He as a discharge medium, oxygen atoms might have a full width as small as 13.5 micros at half maximum at a location 193 mm downstream from the discharge region. Most population of oxygen atoms is in the ground state (3)P but some in the first excited state (1)D, depending on the concentration of precursor O(2). This discharge device analogously generates carbon, nitrogen, and fluorine atoms from precursors CO, N(2), and F(2), respectively.     

Examining cognitive interference and adaptive safety behaviours in tactical vehicle control

Concurrent mental workload degrades some aspects of driving performance, but drivers might be able to modify their behaviour adaptively to accommodate cognitive impairments. For example, they might maintain longer vehicle headway in dual-task conditions to compensate for slowed response times. Studies documenting such adaptive behaviours typically use steady-state driving scenarios such as car following. Yet, driving often involves tactical control situations in which drivers need to monitor multiple aspects of their traffic environment and to accommodate changing goals. In two simulator experiments, this study examined the impact of mental workload on safety margins (distances) that drivers keep when engaged in a tactical control task: passing other vehicles. Although drivers did increase their headway adaptively when engaged in steady-state car following (experiment 2), they did not adapt their behaviour to accommodate cognitive load when performing tactical control manoeuvres. Implications of this difference between steady-state and tactical control driving contexts, both for driving research and for driving safety, are discussed.     

T-S region-based fuzzy control with multiple performance constraints

Takagi-Sugeno fuzzy control problems with minimizing H2/Hinfinity norm are investigated in this paper. A redesigned T-S fuzzy model and controller are called a T-S Region-based Fuzzy Model (TSRFM) and a T-S Region-based Fuzzy Controller (TSRFC), respectively, which are derived from the fuzzy region concept and the robust control technique. The fuzzy region concept is used to divide the general plant rules into several fuzzy regions and the robust control technique is used to stabilize all plant rules of each fuzzy region. In this case, the stability conditions with H2/Hinfinity performance are derived from Lyapunov criterion, which are expressed in terms of LMIs. For the fuzzy model involving large plant rules, the proposed idea greatly reduces the total number of LMIs and controller rules so that TSRFC is easy to implement with simple hardware. Although the controller rules are reduced, TSRFC is able to provide performance as good as former designs.