Biochemical and histological alterations induced by a formulation of dicofol in the embryonic liver of Gallus domesticus

In the present investigation, hepatotoxic effect of a commercially available insecticide formulation of dicofol (Colonel–S® 18.5% emulsified concentrate) was studied in the developing chick embryo. Fertilized eggs of Gallus domesticus were immersed in three different dose concentrations, i.e. 250, 500, and 1000 mg L^?1 of Colonel–S on “0” and fourth days of incubation for 60 min at 37 °C and incubated till embryonic day 16. Severe histopathological cellular lesions, such as extensive cell degeneration and necrosis with enlarged blood sinusoids, cytoplasmic vacuolization, and leucocyte infiltrations with congestion or dilation of central vein, appeared in dose-depended manner. Dicofol treatment also caused significant decrease in the levels of total protein, glycogen, and glutathione content and an increase in alkaline phosphatase activity of embryonic liver, whereas glutamic pyruvic transaminase activity showed mixed response.     

Determination of cobalt by air-assisted liquid–liquid microextraction

Abstract

A rapid and selective technique for extraction, preconcentration and determination of trace amounts of cobalt in water and pharmaceutical samples by air-assisted liquid–liquid microextraction combined with flame atomic absorption spectrometry is proposed. 1-Nitroso-2-naphthol is used as a complexing agent and 1-octanol as an extraction solvent. Parameters relevant for analytical effectivity, i.e. pH of sample solution, concentration of complexing agent, volume of extraction solvent, and number of extraction cycles are optimized using a Box–Behnken design. At optimum conditions, a dynamic linear range of 5–600?µg L^?1 is obtained, with a limit of detection of 1.2?µg L^?1. The method is used for determination of Co(II) in environmental water and pharmaceutical samples.     

Analyses of phenolic compounds occurring in olive oil mill wastewaters by GC–MS

Phenolic compounds in olive oil mill wastewaters were analysed by HRGC–MS after extracting the acidified solution with ethyl acetate and derivatization with N,O-bis(trimethylsilyl)trifluoroacetamide. Both simple and complex phenols were detected with the latter being the most abundant. 1,2-dihydroxybenzene (catechol), p-hydroxyphenyl ethanol (tyrosol), 3,4-dihydroxyphenyl ethanol (hydroxytyrosol) and 4-hydroxy-3-methoxyphenyl ethanol (homovanillyl alcohol) predominated among the simple phenols using a gas chromatograph coupled with a mass selective detector.     

主体功能区视角下的环境污染时空格局及驱动因素——基于广东省121个县域的实证分析

基于县域污染物排放和人口社会经济数据库,运用熵权法构建水气污染综合指数测度广东省水气环境污染状况,在解析2012—2016年水气环境污染时空变化与主体功能区分异特征的基础上,采用空间计量模型考察水气环境污染的驱动因素及其在不同类型主体功能区之间的差异.研究结果表明：① 2012—2016年,广东省水气污染综合指数降幅达到46.93%,处于污染指数高值区间的县域数量大幅减少,并呈现由边缘向核心收缩的空间变化特征;② 4类主体功能区的水气环境污染均有明显改善,但相对而言,城市化地区和农产品主产区仍是广东省水气污染物排放的主要承压区;③人口规模是各类主体功能区水气环境污染的共性驱动因素,此外,城市化地区、农产品主产区和重点生态功能区还分别受到工业化水平、社会固定资产投资和财政收入分权程度的影响.建议从引导城乡居民绿色生活、持续提升清洁生产技术、增加地方财政分权激励机制中的环境效益考核入手强化区域环境污染综合治理.     

Force-Velocity Characteristics of Individual Human Skeletal Muscles: TBCIat and TBCIong. Outline of the Method

The aim of the work is to outline a procedure of finding force-velocity (F–V) characteristics (F = f(V)) of individual skeletal muscles of the human locomotor system. The presentation is based on an example concerning extensors of the elbow joint: the lateral and long heads of triceps brachii (TBCIat and TBCIong). The experimental part of the procedure involves a natural movement of using the upper extremity to push an external object of variable, adjustable load, engaging both the elbow and shoulder joint.

Five men aged 23 took part in the experiment. Their task was to push the handle of a physical pendulum whose moment of inertia could be adjusted within the range of 58 kg m²-450 kg m², so as to give it maximum angular velocity. During each trial the movement of the trunk, of the upper extremity and of the pendulum was video recorded and the force applied with the hand to the handle of the pendulum was measured.

In order to find the F–V characteristics a simulation model SHOULDER was used, which is capable of solving the synergy problem for muscles of the arm and the shoulder girdle.

It was found that despite considerable dispersion of experimental points the respective regression lines revealed a clear tendency of decreasing muscle force for increased shortening velocity of the monoarticular head (TBCIat) and of increasing muscle force for increased lengthening velocity of the biarticular head (TBCIong) of the triceps brachii muscle.     

Lead astray: scale,environmental justice and the El Paso smelter

Residents in Paso del Norte (El Paso, Texas; Sunland Park, New Mexico; and Juárez, Mexico) have been concerned about heavy metal contamination in their communities since the 1970s, when high blood lead levels were found in children living in Smeltertown – a company town for the local metals smelter. After the smelter's closure in 1999, and throughout onsite and offsite cleanup efforts, residents have continued to express concerns about these contamination issues. Using a politics of scale framework and analysing ethnographic data and government, media and scientific documents, this paper identifies a set of major disjunctures between the scales of heavy metal contamination and the scales at which that contamination is regulated. These disjunctures exacerbate regional environmental injustice by complicating public participation, neglecting vulnerability and displacing hazards to new communities. Consequently, applying a politics of scale framework to this case study highlights regulatory and policy failures to address environmental justice.     

Opportunities and challenges for development of urbanization in Western China

Urban and rural dual structure in Western China is obvious.The economic development of the central cities is relatively quick while that of the rural areas is lagging behind.The speeding up of urbanization contributes to the intensively uncoordinated development of urban and rural areas.Besides,the eco-fragile environment,shortage of available water resources,adverse geographic location,and relatively backward social economy restrict the development of urbanization in Western China.However,Western China also has the advantages of backwardness.This paper analyzes the present situation and development trend of urbanization in Western China.The results show that Western China has basically formed a development pattern with"industry promotes agriculture and urban leads to village".Therefore,combined with the present situation of Western China,this paper describes and analyzes the opportunities and challenges that may appear in the process of urbanization in Western China,puts forward the development pattern in which urban and rural areas can gain mutual support and co-development,and provides related recommendations.