渤海海域夏季大型底栖动物群落特征

根据2017年渤海海域47个站位大型底栖动物的调查资料,对该海域大型底栖动物进行了群落特征分析。调查共采集到大型底栖动物107种,研究海域大型底栖动物的平均密度为82 个/m²。优势种类分别为彩虹明樱蛤、不倒翁虫、长叶索沙蚕。聚类结果显示,渤海海域大致可按地理位置分为4个群落。与历史数据的对比显示,传统的较大个体的底栖种类,如棘皮动物、双壳类,已经被更小个体的多毛类、软体动物所取代,底栖动物的种类结构表现出了小型化的特征,这与近年来渤海海域底栖动物研究结果一致。研究表明,近年来受人类活动影响,渤海海域大型底栖动物群落结构已经发生了变化。     

一株呕吐毒素高效降解菌的筛选鉴定和降解特性表征

脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)是一种广泛存在于自然界中的生物毒素污染物. 本文利用富集培养的方法和微生物纯化分离技术,通过添加辅助因子吡咯喹啉醌(pyrroloquinoline quinone disodium salt,PQQ),从黄粉虫(Tenebrio molitor)幼虫的排泄物中分离得到1株可高效降解DON的菌株. 该菌在30 ℃,pH 7.0的条件下,72 h内对浓度为50 μg·mL⁻¹的DON降解率高达100%,降解产物为3-keto-DON. 通过形态学鉴定和基于16S rDNA序列构建的系统发育树分析,该菌的分类地位归属为德沃斯氏菌属(Devosia sp.). 对该菌在不同温度、pH、PQQ浓度和不同脱毒方式下进行降解性质表征,发现该菌静息细胞在好氧或者静置, 30 ℃、pH 7.0—9.0、PQQ浓度为0.01—10 μmol·L⁻¹的条件下具有良好的DON降解能力. 为了确定该菌降解的活性物质,取未处理、加热处理和SDS处理的菌悬液和菌体细胞裂解上清液分别对DON进行降解,结果显示该菌利用自身产生的酶对DON进行降解.     

Implementing pro-poor policies in a decentralized context: the case of the Rural Water Supply and Sanitation Program in Tanzania

This paper examines the challenge of achieving a balance between the implementation of centrally designed pro-poor policies and the decentralization of responsibilities to local governments in many African countries. It analyzes the implementation of the Rural Water Supply and Sanitation Program in Tanzania. Key mechanisms for planning and allocating resources are analyzed at ministry, district, and village levels. Results show that a mixture of policy incoherencies, technical shortcomings and political influence determine that only a small proportion of funds reaches the underserved areas. We argue that a greater connection between the bottom-up and top-down planning mechanisms, and a sharp increase of downwards accountability are needed before decentralized decision-making result in better resources allocation. Meanwhile a bigger intervention from central government is needed.     

Cadmium and chromium removal kinetics from solution by two aquatic macrophytes

The aim of this work was to determine chromium and cadmium bioaccumulation processes of two free-floating macrophytes commonly used in wetlands for water treatment: Salvinia herzogii and Pistia stratiotes. Metal removal from the solution involves two stages: a fast one and a slow one. The fast stage of the Cd uptake is significantly different for each species, while it is not significantly different in Cr uptake. The most important processes of Cd uptake are biological ones in S. herzogii and adsorption, chelation and ionic exchange are in P. stratiotes. The main processes of Cr uptake in both macrophytes are adsorption, chelation and ion exchange. The slow stage is different for each species and metal. Cr precipitation induced by roots occurs in P. stratiotes. Cr uptake through leaves is probably the main cause of the increase of Cr in the aerial parts of S. herzogii.     

Copper sulphate use in South African traditional medicine

Copper (Cu) is an essential element to humans; however, exposure to elevated concentrations through occupational hazard and/or environmental means may be detrimental. This paper provides results of a cross-sectional study aimed to determine the prevalence of copper sulphate (CuSO₄) use in South African traditional medicine by traditional health practitioners (THPs) and details the use thereof. A total of 201 THPs were enrolled from two main municipal areas of KwaZulu-Natal (South Africa). Information on demographic characteristics of THPs, reasons for using or not using CuSO₄ as well as administration methods and age groups of recipients were collected. Of the 201 THPs interviewed, 145 (72 %) use CuSO₄ for healing purposes. The use of CuSO₄ was strongly associated with gender (p = 0.009) where the proportion of CuSO₄ users was higher for female than male THPs. CuSO₄ was reportedly administered to individuals of all ages, including infants and children. The main routes of administration were enema (n = 110; 76 %), oral (n = 40; 28 %) and use in bath (n = 40; 28 %). The reasons cited for use are diverse and included skin rashes (n = 43; 30 %), aches, pains and swelling (n = 38; 28 %) as well as sexually transmitted diseases (n = 28; 19 %). This study identified a high prevalence of THPs using CuSO₄ for healing purposes. These findings support the need to regulate South African traditional medicine to safeguard the user.     

Identification of volatiles from Pinus silvestris attractive for Monochamus galloprovincialis using a SPME-GC/MS platform

Introduction

A myriad of volatile organic compounds (VOCs) released by terrestrial vegetation plays an important role in environmental sciences. A thorough chemical identification of these species at the molecular level is essential in various fields, ranging from atmospheric chemistry to ecology of forest ecosystems. In particular, the recognition of VOCs profiles in a context of plant?Cinsect communication is a key issue for the development of forest protection tools.

Purpose

This work was aimed at the development of a simple, robust and reliable method for the identification of volatiles emitted from plant materials, which can attract or deter pest insects. Specifically, volatiles emitted from the bark of Pinus sylvestris were studied, which might attract the black pine sawyer beetle Monochamus galloprovincialis??a serious pest of the tree and a vector of a parasitic nematode Bursaphelenchus xylophius.

Method

The volatiles from bark samples were collected using a solid-phase micro-extraction technique, and subsequently analysed by gas-chromatography/mass-spectrometry (GC/MS). The characterisation of the volatile fraction was based on the comparison with data in mass spectral libraries, and in most cases, with the available authentic standards. The identified compounds were screened against the available entomological data to select insect attractors.

Results

The identified components included terpenes (??-pinene, ?-3-carene, and para-cymenene), oxygenated terpenes (??-terpineol and verbenone), sesquiterpenes (??-longipinene, longifolene, E-??-farnesene, ??-cadinene and pentadecane), and diterpenes (manoyl oxide and (+)-pimaral). Of these, longifolene and (+)-pimaral are of particular interest as plausible attractors for the M. galloprovincialis beetle that might find application in the construction of insect bait traps.     

Driver hand-held cellular phone use: a four-year analysis

INTRODUCTION: The use of hand-held cellular (mobile) phones while driving has stirred more debate, passion, and research than perhaps any other traffic safety issue in the past several years. There is ample research showing that the use of either hand-held or hands-free cellular phones can lead to unsafe driving patterns. Whether or not these performance deficits increase the risk of crash is difficult to establish, but recent studies are beginning to suggest that cellular phone use elevates crash risk. METHODS: The purpose of this study was to assess changes in the rate of hand-held cellular phone use by motor-vehicle drivers on a statewide level in Michigan. This study presents the results of 13 statewide surveys of cellular phone use over a 4-year period. Hand-held cellular phone use data were collected through direct observation while vehicles were stopped at intersections and freeway exit ramps. Data were weighted to be representative of all drivers traveling during daylight hours in Michigan. RESULTS: The study found that driver hand-held cellular phone use has more than doubled between 2001 and 2005, from 2.7% to 5.8%. This change represents an average increase of 0.78 percentage points per year. The 5.8% use rate observed in 2005 means that at any given daylight hour, around 36,550 drivers were conversing on cellular phones while driving on Michigan roadways. The trend line fitted to these data predicts that by the year 2010, driver hand-held cellular phone use will be around 8.6%, or 55,000 drivers at any given daylight hour. CONCLUSIONS: These results make it clear that cellular phone use while driving will continue to be an important traffic safety issue, and highlight the importance of continued attempts to generate new ways of alleviating this potential hazard.