Lead concentrations in human bones from the Canadian population

Stable lead was determined in post-mortem samples of human bones from three Canadian cities. All age groups and both sexes were represented. The cities selected for investigation were Winnipeg, Montreal and Charlottetown. No significant difference was found between the locations, although levels tended to be higher for Montreal. Mean lead concentrations (micrograms Pb/g ash) were 8.98 +/- 1.17, 11.11 +/- 1.74 and 8.47 +/- 1.06 for Winnipeg, Montreal and Charlottetown, respectively. Corresponding geometric means were 6.21, 7.88 and 6.71, respectively. Individual values ranged from 0.45 to 240.07 micrograms Pb/g ash. Concentrations were highest in the greater than 20-year age group, indicating increased body burden with age. An increase in lead concentration was observed for the ages 1-11 years with a decrease for the 12-19-year age group. Differences in concentrations between the sexes were not significant. Higher than average concentrations were observed in samples obtained from Winnipeg for the period 1976-1980, particularly in the 1-4-year age group. A similar pattern was observed in the air lead concentrations, suggesting a possible correlation between the concentrations of lead in the air and in bones at Winnipeg.     

Heavy metals in human and animal bones from ancient and contemporary France

The concentrations of Cd, Pb, Zn, Ba, Mg and Ca have been determined in 180 human bones from the last five millenia, and in 22 contemporary and 20000-50000-year-old animal bones. The original concentrations of Cd and Zn in the ancient human bones were not changed by fossilization processes, whereas Pb and Mg tended to migrate out of the bones, and Ba and Ca concentrations increased with the age of the bones. The distribution of metals in the structure of both the ancient and contemporary bones is not uniform, and neglecting this may render it difficult to compare results obtained from different studies. In Europe and Peru in the late Middle Ages the concentration of Pb in human bones increased by one order of magnitude. The high level of Pb persisted in Europe for several centuries and only recently decreased by an order of magnitude. The concentration of Cd has increased in human bones in the 20th century, to about ten times above the pre-industrial level. The concentration of Pb in contemporary cow bones from France is below analytical detection limits, probably due to competition of Pb with Ca and P which are added to cow fodder as mineral additives.     

Heavy metals in human bones in different historical epochs

The concentration of the metals lead, copper, zinc, cadmium and iron was determined in bone remains belonging to 30 individuals buried in the Region of Cartagena dating from different historical periods and in eight persons who had died in recent times. The metals content with respect to lead, cadmium and copper was determined either by anodic stripping voltammetry or by atomic absorption spectroscopy on the basis of the concentrations present in the bone remains. In all cases, zinc and iron were quantified by means of atomic absorption spectroscopy. The lead concentrations found in the bone remains in our city are greater than those reported in the literature for other locations. This led to the consideration of the sources of these metals in our area, both the contribution from atmospheric aerosols as well as that from the soil in the area. Correlation analysis leads us to consider the presence of the studied metals in the analysed bone samples to be the consequence of analogous inputs, namely the inhalation of atmospheric aerosols and diverse contributions in the diet. The lowest values found in the studied bone remains correspond to the Neolithic period, with similar contents to present-day samples with respect to lead, copper, cadmium and iron. As regards the evolution over time of the concentrations of the metals under study, a clear increase in these is observed between the Neolithic period and the grouping made up of the Bronze Age, Roman domination and the Byzantine period. The trend lines used to classify the samples into 7 periods show that the maximum values of lead correspond to the Roman and Byzantine periods. For copper, this peak is found in the Byzantine Period and for iron, in the Islamic Period. Zinc shows an increasing tendency over the periods under study and cadmium is the only metal whose trend lines shows a decreasing slope.     

The significance of Cd in hair: Influence of the level of intake and the external contamination in the rat

A standardized procedure in the rat was used to study the deposition of Cd in newly grown hair and its relation to ingested Cd. The internal deposition and the absorption in the intestine were evaluated using ¹⁰⁹Cd and ^115mCd as radiotracers. Stable Cd was supplied at different levels with the drinking water and analysed in hair, and in some cases also in the liver and the kidneys, by flameless atomic absorption spectrometry. It was demonstrated by the tracer that the internal deposition is proportional to the amount ingested. The time of exposure and the body burden had no influence. The external contamination with stable Cd was very high in animals kept conventionally, but can be reduced by using metabolic cages. It was, however, not possible to appreciably isolate the “background level”, i.e. Cd was also found in hair of “unexposed” animals kept in metabolic cages. A significant increase above “background” could only be achieved at a Cd intake of > 1 mg/d. Following a prolonged period of exposure, levels of Cd newly deposited in hair were reduced to background levels, within a few days, in spite of very high Cd concentrations in the liver and kidneys of these animals. It is concluded that the internal deposition of Cd in hair is proportional to the amount absorbed, and that it is largely masked by the external contamination and the relatively high “background” level; the internal deposition only reflects intake. The body burden or the Cd accumulated in specific organs has no influence on the deposition of Cd in hair.     

煤壁突出孔洞的形成机理研究

依据关于突出机理的“球壳失稳”假说对突出孔洞及压出孔洞的形成过程进行了研究。通过突出模拟试验证实压出实际上是一种弱突出现象,论证了突出孔洞的形状与煤体的初始释放与其膨胀能大小有关,并对突出孔洞及压出孔洞的形成机理进行了解释。     

Lead in human bones. Investigations on an occupationally non-exposed population in southern Bavaria (F.R.G.). I. Adults

The concentration of lead in three different bones (pelvic bone, cortical part of the mid-femur, petrous portion of the temporal bone) of 240 occupationally non-exposed adults who died between October 1983 and February 1985 was determined by electrothermal atomic absorption spectrometry. As far as sex, age and domicile (urban and rural) are concerned, a balanced distribution was achieved (for each age decade 10 urban females, 10 rural females, 10 urban males and 10 rural males). The predominantly cortical femur (geom. mean, 3.86 mg Pb/kg bone wet wt.) and temporal bones (5.59) showed higher Pb concentrations than the trabecular pelvic bone (1.65) (in each case n = 240). For each of the three types of bone, the mean lead content of the males (n = 120) was significantly higher than those of the females (n = 120): e.g. for pelvic bone by 38.3%, mid-femur by 51.3% and temporal bone by 24.8%. No statistically significant difference was obtained when comparing residents of Munich (population greater than 1 X 10(6] (n = 120) with people in the remaining parts of Southern Bavaria (n = 120). The Pb content of the temporal bone increased steadily with age. In contrast, in the mid-femur and the pelvic bone the Pb content reaches a plateau in middle age with a decrease at higher ages; this decline is more distinct for females. The mean lead body burden was calculated to be 41.4 +/- 24.2 mg for all males (n = 120) and 24.1 +/- 12.5 mg for all females (n = 120). We conclude that the lead burden, at least in the area investigated, has been reduced in the last decade, probably because of a reduction in the lead content of petrol.     

Lead concentration profiles in lead-210 dated Lake Ontario sediment cores

Lead concentrations were measured in sediment cores from four sites distributed among the three major sedimentary basins — Niagara, Mississauga and Rochester — of Lake Ontario for which sedimentation rates had been previously determined by ²¹⁰Pb dating.Around 90% of the total lead present in fine-grained surface sediments was removed by CH₃CO₂H/NH₂OH · HCl leaching, concentrations ranging from 137 μg/g in surface sections to a constant background of 12–13 μg/g at unpolluted depths. Lead-210 dating indicated that increases in lead concentrations commenced ca. 1850–1875 with 5, 10, 35 and 50% of the total “excess” lead inventory in the sediment column being assigned to the pre-1900 period and successive 25-year intervals during the 20th Century, respectively. Anthropogenic inputs of lead from such sources as the combustion of leaded gasoline and coal are responsible for these increases.About 10 μg/g lead remained in the sediment residue after leaching. The total natural lead flux to the sediments ranged from 0.4–1.3 μg/cm²/yr while “excess” lead of anthropogenic origin varied from 1.2–6.7 μg/cm²/yr and totalled 0.5–1.5 g/m² at the four sites.Various potential modes of introduction of anthropogenic lead and of ²¹⁰Pb to the lake are considered in conjunction with the ratio of Pb/²¹⁰Pb fluxes to the sediment.     

基于现行定额计价模式的“营改增”对农村土地整治项目的影响

以重庆市农村土地整治项目为研究对象,参照国家近年来“营改增”的相关政策文件,从理论测算和实际影响两个方面,分析了“营改增”对重庆市农村土地整治项目的影响,并从国家、行业、企业 3 个方面提出了相应的建议。研究表明,就理论测算而言,“营改增”后对土地整治项目税负影响较“营改增”前平均提高 1.29%,从实际调查来看,由于砂、石等材料不能开具增值税专用发票,从而“营改增”后对土地整治项目税负影响较“营改增”前平均提高 3.94%,远高于理论测算。     

IN BETWEEN SOCIAL ENGINEERING AND GENTRIFICATION: URBAN RESTRUCTURING,SOCIAL MOVEMENTS,AND THE PLACE POLITICS OF OPEN SPACE

ABSTRACT: The article examines the emergence of urban countercultures and social movements in Christiania, Copenhagen, and Haga, Gothenburg in the context of the Scandinavian welfare state, from the 1970s to the present. Specifically, it investigates the relations between urban governance, gentrification processes, and social movements in the urban restructuring of Scandinavian cities. While Christiania today remains a space for counterculture, the struggle to save Haga contributed to a gentrification of the district, as it became officially “re‐evaluated” and upgraded. The article examines the similarities and differences in the urban movement trajectories in these two cases, highlighting their “place politics of open space.”     

Lead isotopes and lead shot ingestion in the globally threatened marbled teal (Marmaronetta angustirostris) and white-headed duck (Oxyura leucocephala)

Lead isotope ratios ((206)Pb/(207)Pb and (208)Pb/(207)Pb) and concentrations in the livers and bones of marbled teal and white-headed duck found dead or moribund were determined in order to establish the main lead source in these waterfowl species. Lead concentrations in bone (dry weight) and liver (wet weight) were found to be very high in many of the white-headed ducks (bone: geometric mean=88.9 ppm, maximum=419 ppm; liver: geometric mean=16.8 ppm, maximum=57.0 ppm). Some of the marbled teal had high lead levels in the bones but liver lead levels were all low (bone: geometric mean=6.13 ppm, maximum=112 ppm; liver: geometric mean=0.581 ppm, maximum=4.77 ppm). Ingested lead shot were found in 71% of the white-headed duck and 20% of the marbled teal. The (206)Pb/(207)Pb ratio in livers and bones of white-headed ducks and marbled teals showed no significant differences compared to the ratios obtained from lead shot. The (206)Pb/(207)Pb ratio in bones of marbled teal ducklings with the highest lead concentrations tended to resemble the ratios of lead shot, which supports our hypothesis that the lead was derived from the hens. We also found that the lead ratios of lead shot and lead ratios described for soils in the area overlapped, but also that the isotopic ratio (206)Pb/(207)Pb in lead shot used in Spain has a narrow range compared with those used in North America. The principal source of lead in many of these birds was, however, most likely lead shot, as supported by the similar isotopic ratios, high lead concentrations in tissues and evidence of ingested shot.     

厚表土薄基岩煤层开采覆岩运动规律

 厚表土薄基岩煤层采用综放开采后基本顶将难于形成稳定结构,发生滑落失稳导致工作面“压架”,在对薄基岩定义的基础上,综合采用实验室试验、理论分析、数值模拟和现场实测的方法对薄基岩煤层开采上覆岩层运动规律进行了研究。研究结果表明,若其他条件不变,“砌体梁”结构的稳定主要取决于基岩厚度和上覆表土层的力学性质及厚度,具有较大承载力的厚黏土层能与薄基岩组合形成稳定的结构,降低稳定结构所需最小基岩厚度。由此建立薄基岩工作面结构力学模型,并针对司马矿具体条件分析认为当表土为松散砂土,最小基岩厚度40 m;当黏土厚度40 m,最小基岩厚度20 m;黏土厚度30 m,最小基岩厚度30 m。据此提出首采面可安全开采,在现场工业性试验中得到成功验证。     

追溯近现代城市规划的“传统”──从“社经传统”到“新城模型”

文章指出由于规划的“物质性传统”并非是近代城市规划的直接起源,在时间和意识上要略晚于“社经传统”,因而认为现代城市规划传统是“技术（工程）传统”是失之偏颇的,然而从近代规划的发展历程看,无论是郊区社区还是花园城市,近现代城市规划的思维基点是建立一个新结构,而不是在设法维护一个既有结构。“新城模型”的价值标准仍然深刻地影响着我们今天城市规划的思维方式,于是将针对规划新城的价值观、方法与经验引入既有城市的再开发规划,从而促发旧城的“新城化”现象。作者建议,今天城市规划的主要任务已经由新城建设转向既有城市的适应性维护,城市规划的价值标准也应随之作出反应。     

Lead, cadmium, iron, zinc, copper, manganese, calcium and magnesium in SPF male rats exposed to a dilution of automotive exhaust gas throughout their lives

Male pathogen free CFE albino Sprague Dawley rats were exposed 8 h per day, 5 days per week, for three years to a 1/1000 dilution of automotive exhaust gas, containing 58 ppm carbon monoxide, 0.37% carbon dioxide, 23 ppm nitrogen oxides, 2 ppm aldehydes, less than 5 mg/l hydrocarbons and 8.5 micrograms/m3 lead. Lead, cadmium, iron, zinc, calcium and magnesium were measured by atomic absorption in the femurs and tibias of the rats which died during the experiment. A comparison with two control groups revealed that the only significant difference in the elements measured in the bones was a 500% increase in lead concentration. The calculations of the correlations between the percentages of the elements in bones, the ages and the body weights of the rats, as well as cluster analysis, did not show consistent variations of the water, calcium, magnesium concentrations nor of the other studied metals related to this increase in lead concentration. Moreover, longevity was the same in the 3 groups of rats, but the body weight was statistically smaller (4%) in the group exposed to the auto exhaust dilution.     

简论张謇的区域思想

从“村落主义”梳理出张謇区域思想的基本内涵,即“自存立,自生活,自保卫”,从实业到教育到慈善,形成体系;“成聚,成邑,成都”,由点而面,渐成规模。张謇提出的“测绘-规划-建设”工作程序,堪与同时期西方学者盖迪斯(PatrickGeddes)提出的“调查-分析-规划”的规划程序相映照。张謇的区域思想是在极其复杂的社会环境下,以传统文化为根柢,借鉴西方(日本)现代化成就,通过自身艰苦实践探索,“点滴酝酿、卓绝创造与心得体会的积累”,具有独特的价值,至今仍给我们以启示。     

The conditions for successful automated collaboration in construction

A building assignment is a complex task that demands collaborative working if added value is to be achieved for users and society.The problem today is that the building object is a combination of design results, because the collaborative working is not well organized or well managed as a result of a lack of insight into relevant process variables.This study used desk research and case study research to identify variables that have an active relationship with collaborative working in design meetings.The variables that describe a design meeting were established by analyzing 37 meetings during the product and production design phases of a prototype of an industrial, flexible, and demountable building system.The result of this study is that the variables “Aim of meeting,” “Control of meeting,” “Participants,” “Tools,” and “Outcomes” are a suitable set to describe successful collaborative working in design meetings.     

城市历史性空间“再设计”途径研究—以巴黎皇家广场为例

皇家广场作为巴黎城市重要的历史性空间保存至今,经过了多次甚至不断的“再设计”改造。以景观设计学专业视角,通过观察与实地调查就皇家广场“再设计”选径进行分析研究,揭示城市历史性空间作为城市时空坐标与公共生活载体的特征。社会文化、设计学、人类需求层次、心理学、行为学等研究的“再设计”途径,主要包括把握地域文化延续城市格局、强化可迭性、引入新设计元素、营造适合当今使用的环境、设计复合型的使用活动等,它们可为我国城市历史性空间的延续高效利用提出一些参考。     

Model for the evaluation of the quality of housing 1 management

This article takes as its starting point the observation that “responsibility” is a concept widely used in housing management today and in connection with organizational change within housing management companies. Results of an anthropologically oriented organizational field study of the empirically given meaning of the “responsibility” concept are reported. The study concerns a housing company in which the concept played a central role in reorganizing local management. The managers and caretakers of the company were followed in their work and interviewed regarding a reorganization of the housing management service in which each caretaker was given “total responsibility” for an estate or housing unit composed of 65–180 flats and what this reorganization meant. The results are presented in narrative style and with illustrative case studies, the performative definition of “responsibility” here being focused upon.     

Full-Scale Prototype Structures

In an ever-changing patriarchal society, the female is faced with the decision to stay home with her family and become a “center” for the house or to go out Into the work force and pursue her Interests and a career. As she strives to balance these two roles. In her addiction to perfection, we find that the domicile, as we once knew it, is destructing … making way for a new form that must be allowed to take shape. The basic “bare bones” of the house remain; yet, in their new form, they are allowed to take on different Identities which are necessary for this “new house.” This project investigates the role of the homemaker and the home-maker: the woman and the architect, i.e., the woman architect and the house in the “middle” of it all. As the project begins to define “middle” architectonically, the patriarchal bonds to this house are broken: releasing the female.     

创造零态空间--北京中关村软件园设计理念

从人、建筑和自然的关系出发,以东方哲学为基础,总结出建筑的三态空间。其中“零态空间”是人工与自然相融合,创造建筑精神功能的重要元素,并通过中关村软件园的设计实例阐述了“零态空间”的创造。