Sedentary work and the risks of colon and rectal cancer by anatomical sub-site in the Canadian census health and environment cohort (CanCHEC)

BackgroundSedentary behaviour is a potential risk factor for colorectal cancer. We examined the association between sedentary work, based on body position, and colorectal cancer risk in Canadians.MethodsA working body position category (a. sitting; b. standing and walking; c. sitting, standing, and walking; d. other) was assigned to occupations reported by 1991 Canadian Census respondents based on national occupational counselling guidelines. Adjusted hazard ratios (HRs) and 95% confidence intervals (CI) were estimated for cancers of the colon (overall, proximal, and distal) and rectum in men and women newly diagnosed from 1992 to 2010.ResultsCompared to “sitting” jobs, men in occupations with “other” (non-sitting, −standing, or −walking) body positions had a weakly significant reduced colon cancer risk (HR = 0.93, 95% CI: 0.89, 0.98) primarily attributed to protection at the distal site (HR = 0.90, 95% CI: 0.84, 0.97). Men in “standing and walking” and “sitting, standing, and walking” jobs did not have significantly reduced colon cancer risks. No effects were observed for rectal cancer in men or colon and rectal cancer in women.ConclusionThe two significant findings of this analysis should be followed-up in further investigations with additional information on potential confounders. Null findings for rectal cancer were consistent with other studies.     

Individual Differences in the Diurnal Cortisol Response to Stress

The objectives of this study were to explore individual differences associated with diverse reactions in cortisol secretion under different stress levels. This study was part of a larger project concerning working hours and health. Thirty-four white-collar workers participated under two different conditions; one work week with a high stress level (H) and one with a lower stress level (L) as measured through self-rated stress during workdays. Based on the morning cortisol concentration during a workday subjects were divided into two groups. One group consisted of subjects whose morning level of cortisol increased in response to the high-stress week, compared to their morning levels in the low-stress condition (Group 1). The other group consisted of subjects whose morning cortisol response was the opposite, with a lower level under the high stress condition (Group 2). Subjects wore actiwatches, completed a sleep diary, and rated their sleepiness and stress for one work week in each condition, i.e., high and low stress. Saliva samples for measures of cortisol were collected on a Wednesday. Group 2 reported higher workload, fatigue, and exhaustion during both weeks. Since there were no differences in perceived stress, neither within nor between groups, the data indicate that there are other factors influencing morning cortisol. The results suggest that one component modulating the cortisol response might be the level of exhaustion, probably related to work overload. Higher levels of stress in exhausted individuals might suppress morning cortisol levels.     

Life stresses of slavery

Skeletal evidence exists for life stresses of 120 Black individuals from 25 sites in Maryland, Virginia, and the Carolinas. Periods for statistical comparison are eighteenth century, 1690-1770; Catoctin Furnace, Maryland industrial slaves, 1790-ca.1820; 1800-ca.1860, nineteenth century; and a twentieth-century Black sample compiled from forensic (accidental deaths) cases. From these archaeological sources, skeletal age at death shifts from 36 years, female, and 30 years, male in eighteenth century (N = 29) to 34.8, female, and 36.3, male in nineteenth century (N = 56). Catoctin Furnace slaves' longevity may reflect special conditions for skilled males (34.6 years, female; 41.2 years, male (N = 16). Nutritional stresses are indicated by dental lesions, hypoplasias, stature, and skull base height and pelvic brim index. Occupational stress occurs in some adolescents and in many adults as exaggerated development of lifting muscles (deltoid and pectoral crests) and early vertebral and shoulder breakdown. Lead content of bone may reflect site of occupation. The most common pathology is anemia or sicklemia; parietal depressions and ulna fractures ("parry") indicate violence-related trauma.     

Life stresses of the free black community as represented by the First African Baptist Church, Philadelphia, 1823-1841

The congregation of the Reverend Henry Simmons (First African Baptist Church at 8th & Vine, Philadelphia) from 1823 to 1841 used a cemetery rediscovered through subway expansion which was carefully excavated by M. Parrington and S. Pinter in 1983-1984; currently 75 adults were available for study. As an overall health indicator, longevity at 38.9 years (N = 39) female and 44.8 (N = 36) male indicates more stress on females. Probable causes of stress are inadequate nutrition for the performance of arduous labor, pregnancy, and childrearing, unsanitary living conditions, limited exposure to sun, and extensive exposure to infectious diseases. Nutritional indicators of stature, dental lesions, skull base height, and pelvic brim index scarcely advance over 1790-1820 Catoctin Furnace, Maryland, slaves' indicators. Disease evidence includes limb-distorting rickets in one child who died at age 8, anemia, and arthritis; but the incidence of arthritis was less than at Catoctin. Genetic traits are chiefly African. Family links show in details: os acromiale in about 30%. This plus less violence (fewer fractures) suggests community strength developing.     

Train drivers' sleep quality and quantity during extended relay operations

Relay operations are an important mode of freight transportation within Australia. Relay work requires multiple crews to drive the train continuously from one specified destination to another and return. Importantly, the nature of relay work requires train drivers to sleep on-board during designated resting shifts. The main aim of the present study was to investigate the quality and quantity of sleep obtained in on-board rest facilities (relay vans) during extended (four-day) relay operations. Drivers (n=9) working the Port Augusta to Darwin relay operation volunteered to participate. The first leg of the trip typically took 40 h followed by an overnight stay in Darwin (between 8-12 h) prior to return. Two crews, each consisting of two drivers, changed every 8 h, giving the crew an 8 h rest in the relay van prior to each 8 h working shift. Using polysomnography, home sleep data were collected prior to and following each trip using a standard five-channel EEG montage. All sleep periods during the relay trip (including Darwin) were also recorded. Additionally, subjective sleep quality ratings were recorded following each sleep period. Analyses revealed that the quantity of sleep obtained in the relay vans (3.3 h) was significantly reduced compared to home (6.8 h). In general, the total sleep time was increased at night and reduced during the day. In terms of quality, sleep onset latency, sleep efficiency, and amount of slow wave and rapid eye movement sleep did not differ significantly between home and the relay vans. The results of the study highlight sleep quantity as the main concern during extended relay operations. Future research should focus on investigating the subjective and objective impact of this sleep reduction on waking functions.     

Train Drivers' Sleep Quality and Quantity during Extended Relay Operations

Relay operations are an important mode of freight transportation within Australia. Relay work requires multiple crews to drive the train continuously from one specified destination to another and return. Importantly, the nature of relay work requires train drivers to sleep on‐board during designated resting shifts. The main aim of the present study was to investigate the quality and quantity of sleep obtained in on‐board rest facilities (relay vans) during extended (four‐day) relay operations. Drivers (n=9) working the Port Augusta to Darwin relay operation volunteered to participate. The first leg of the trip typically took 40 h followed by an overnight stay in Darwin (between 8–12 h) prior to return. Two crews, each consisting of two drivers, changed every 8 h, giving the crew an 8 h rest in the relay van prior to each 8 h working shift. Using polysomnography, home sleep data were collected prior to and following each trip using a standard five‐channel EEG montage. All sleep periods during the relay trip (including Darwin) were also recorded. Additionally, subjective sleep quality ratings were recorded following each sleep period. Analyses revealed that the quantity of sleep obtained in the relay vans (3.3 h) was significantly reduced compared to home (6.8 h). In general, the total sleep time was increased at night and reduced during the day. In terms of quality, sleep onset latency, sleep efficiency, and amount of slow wave and rapid eye movement sleep did not differ significantly between home and the relay vans. The results of the study highlight sleep quantity as the main concern during extended relay operations. Future research should focus on investigating the subjective and objective impact of this sleep reduction on waking functions.     

急诊手术的职业暴露及防护对策

目的:通过对医务人员在急诊手术中职业暴露的情况调查,了解急诊手术中标准预防现状,提出合理化建议和措施。方法:对2007年6月-2010年5月手术患者乙肝、丙肝、梅毒、艾滋病的阳性率进行比较,现场调查急诊手术中防护用品的使用情况。结果:手术患者乙肝、丙肝、梅毒、艾滋病的阳性率逐年上升,职业暴露的危险性越来越大;急诊手术中医务人员防护用品使用率的高低取决于血液、体液、分泌物的污染程度。结论:对医务人员要加强职业安全教育,强化标准预防,提高医务人员的整体防护水平,避免或减少职业暴露的危害,在救死扶伤的同时,保护好自身安全。     

Charles Darwin goes to school: the role of cartoons and narrative in setting science in an historical context

Science education is under revision. Recent changes in society require changes in education to respond to new demands. Scientific literacy can be considered a new goal of science education and the epistemological gap between natural sciences and literacy disciplines must be overcome. The history of science is a possible bridge to link these ‘two cultures’ and to foster an interdisciplinary approach in the classroom. This paper acknowledges Darwin's legacy and proposes the use of cartoons and narrative expositions to put this interesting chapter of science into its historical context. A five-lesson didactic sequence was developed to tell part of the story of Darwin's expedition through South America for students from 10 to 12 years of age. Beyond geological and biological perspectives, the inclusion of historical, social and geographical facts demonstrated the beauty and complexity of the findings that Darwin employed to propose the theory of evolution.     

Distribution of macroalgae and macroalgal communities in gradients of physical conditions in Potter Cove, King George Island, Antarctica

The vegetation of a small fjord and its adjacent open shore was documented by subaquatic video. The distribution of individual species of macroalgae and the composition of assemblages were compared with gradients of light availability, hydrography, slope inclination, substratum, and exposition to turbulence and ice. The sublittoral fringe is usually abraded by winterly ice floes and devoid of large, perennial algae. Below this zone, the upper sublittoral is dominated by Desmarestia menziesii on steep rock faces, where water movements become irregular, or by Ascoseira mirabilis and Palmaria decipiens on weakly inclined slopes with steady rolling water movements. In the central sublittoral above 15 m, where turbulence is still active, Desmarestia anceps is outcompeting all other species on solid substratum, However, the species is not able to persist on loose material under these conditions. Instead, Himantothallus grandifolius may occur. Deeper, where turbulence usually is negligible, Desmarestia anceps also covers loose material. The change of dominance to Himantothallus grandifolius in the deep sublittoral cannot completely be explained at present. Himantothallus grandifolius also prevails in a mixed assemblage under the influence of grounding icebergs. Most of the smaller algae are opportunists with different degrees of tolerance for turbulence, but some apparently need more stable microhabitats and thus are dependent from continuing suppression of competitive large phaeophytes.The present work is part of the Argentinian-German cooperation program RASCALS (Research on Antarctic shallow coastal and littoral systems).     

城市新规划地土壤动物群落组成和多样性: 以上海市世博会会址为例

作者采用野外调查和群落多样性指标数据统计结合的方法, 对上海市世博会会址区域内土壤动物群落组成和多样性进行了研究, 目的是了解该地区的土壤健康状况, 并为城市规划提供科学依据。采样共获得土壤动物10,765头, 隶属于23个类群。中小型土壤动物中蜱螨目是该地区的主要优势类群, 弹尾纲是次优势类群; 大型土壤动物中, 后孔寡毛目为主要优势类群, 等足目、鞘翅目和腹足纲为次优势类群。总体结果显示: 该地区土壤动物种类丰富, 其垂直分布整体遵循随土壤层的加深而递减的趋势; 但水平分布因采样点的不同存在显著性差异。