The trucker strain monitor: an occupation-specific questionnaire measuring psychological job strain

Objectives: To develop and validate a short and user-friendly questionnaire measuring psychological job strain in truck drivers. Methods: In cooperation with an occupational physician in the Dutch road transport industry we developed items on the basis of face validity and information of existing questionnaires on the subject. These items were pilot-tested, by means of interviews, in 15 truck drivers. Study I examined the factorial structure of the initial 30-item trucker strain monitor (TSM) in a sample of 153 truck drivers. Subsequently, number of items per factor was reduced on the basis of reliability analyses (Cronbach's alpha). Study II examined construct and criterion validity of the TSM in a randomly selected group of 2,000 truck drivers, of whom 1,111 participated (adjusted response=63%). Additionally, sensitivity and specificity were assessed by examining the ability of the TSM to identify truck drivers with or without self-reported sickness absence in the past 12 months because of psychological complaints. Results: Factor analyses of the initial 30-item TSM revealed a two-factor solution. Item reduction resulted in a six-item work-related fatigue scale and four-item sleeping problems scale with high internal consistency. Results of study II confirmed the internal consistency of the TSM scales and provided support for construct and criterion validity. The composite, work-related fatigue, and sleeping problems scale had a sensitivity of 83%, 80% and 71% respectively, in identifying truck drivers with prior sickness absence because of psychological complaints. Specificity rates were 72%, 73% and 72% respectively. Conclusion: Despite methodological limitations, the results suggest that the TSM is a reliable and valid indicator of psychological job strain in truck drivers. In particular, the composite and work-related fatigue scale identified drivers with prior absenteeism because of psychological complaints, quite accurately. Future longitudinal research in specific sub-groups of truck drivers including both self-reported and objective psychological health measures should evidence whether (1) the distinction between two indicators of psychological job strain is useful, and whether (2) the TSM can be used in screening out truck drivers at risk of developing psychological health problems. Received: 20 July 2000 / Accepted: 30 March 2001     

Heat strain in cold

In spite of increased environmental cold stress, heat strain is possible also in a cold environment. The body heat balance depends on three factors: environmental thermal conditions, metabolic heat production and thermal insulation of clothing and other protective garments. As physical exercise may increase metabolic heat production from rest values by ten times or even more, the required thermal insulation of clothing may vary accordingly. However, in most outdoor work, and often in indoor cold work, too, the thermal insulation of clothing is impractical, difficult or impossible to adjust according to the changes in physical activity. This is especially true with whole body covering garments like chemical protective clothing. As a result of this imbalance, heat strain may develop. In cold all the signs of heat strain (core temperature above 38 degrees C, warm or hot thermal sensations, increased cutaneous circulation and sweating) may not be present at the same time. Heat strain in cold may be whole body heat strain or related only to torso or core temperature. Together with heat strain in torso or body core, there can be at the same time even cold strain in peripheral parts and/or superficial layers of the body. In cold environment both the preservation of insulation and facilitation of heat loss are important. Development of clothing design is still needed to allow easy adjustments of thermal insulation.     

猪种布鲁氏菌生物1型野毒株和2号菌苗的鉴别诊断

目的寻找猪种布鲁氏菌生物1型野毒株（1330S）和猪种布鲁氏菌2号菌株（S2）的鉴别诊断方法。方法采用牛、羊、绵羊、猪种型聚合酶链反应（AMOS—PCR）、脉冲场凝胶电泳（PFGE）和多位点可变数量串联重复序列（MLVA）3种方法对21株1330S菌株进行鉴别？结果AMOS—PCR和PFGE方法未能区分两类菌株;MLVA方法发现1330S和S2菌株在Bru9和Bru16两位点存在差异。结论MLVA方法可以作为两类菌株鉴别诊断的方法之一。     

志贺菌敏感株与基因转移耐多药株蛋白组学分析

目的 对志贺菌敏感株与基因转移耐多药株全菌蛋白进行蛋白质组比较,寻找细菌耐多药相关蛋白.方法 采用接合基因转移实验对临床分离鉴定志贺菌敏感株进行基因转移耐多药试验;并对志贺菌敏感株及基因转移耐多药株全菌蛋白进行双向电泳;电泳图谱采用Image Master 2D Platinum软件分析,并对差异表达蛋白进行基质辅助激光解吸飞行时间质谱(MOLDITOF-TOF)分析.结果 成功获得志贺菌基因转移耐多药株,在志贺菌敏感株与耐多药株全菌蛋白质图谱中分析别检出(946±37)和(1 013±157)个蛋白质斑点;经分析共发现43个差异表达的蛋白点,初步对其中7个差异表达蛋白进行质谱鉴定,基因转移耐多药株中发现2个新出现的耐多药相关蛋白分别为成簇插入的DNA重复序列(CRISPR)相关蛋白及Hsp60的分子伴侣蛋白(Groel-Groes-Adp7);ATP结合盒(ABC)转运蛋白、胱氨酸合成酶、预测的胞浆脂蛋白表达量上调;翻译延长因子Tu及DNA单链结合蛋白表达量下降.结论 对7个耐多药相关蛋白鉴定分析表明,供体菌中一些耐多药相关基因通过基因转移方式插入志贺菌敏感株中并大量表达,同时一些在细胞代谢中起重要作用的酶类表达量上调,ABC转运蛋白在志贺菌基因转移耐多药机制中也起重要作用.     

柯萨奇病毒A组16型

柯萨奇病毒A组16型（Coxsackievirus A Group 16 Strain,CVA16）是手足口病（Hand,Footand Mouth Disease,HFMD）的主要致病原之一,对其生物学特征、致病机理、临床表现、实验室诊断、流行病学和分子流行病学的认识,有助于提高HFMD及其它相关疾病的防治水平。研发CVA16的诊断方法和疫苗,建立健全CVA16的流行病学和实验室监测网络,可以对CVA16引起的HFMD的流行进行预测和预警,对预防CVA16引起的HFMD有重要的意义。     

Job strain and male fertility

BACKGROUND: Job strain, defined as high job demands and low job control, has not previously been explored as a possible determinant of male fertility. We collected prospective data on job strain among men, and describe the associations with semen quality and probability of conceiving a clinical pregnancy during a menstrual cycle. METHODS: Danish couples (N = 399) who were trying to become pregnant for the first time were followed for up to 6 menstrual periods. All men collected semen samples, and a blood sample was drawn from both partners. Job demand and job control were measured by a self-administered questionnaire at entry, and in each cycle the participants recorded changes in job control or job demand during the previous 30 days. RESULTS: In adjusted analyses, no associations were found between any semen characteristic or sexual hormones and any job strain variable. The odds for pregnancy were not associated with job strain. CONCLUSIONS: Psychologic job strain encountered in normal jobs in Denmark does not seem to affect male reproductive function.