Solid chemosorbent for sampling sub-ppm levels of acrolein and glutaraldehyde in air

A personal air sampling method using Amberlite XAD-2 coated with 2,4-dinitrophenylhydrazine has been developed for acrolein and glutaral dehyde. Acrolein in the 0.01 to 1.2 mg/m³ range or glutaraldehyde in the 0.03 to 3.5 mg/m³ range is easily analysed in a 5 1 air sample. Recoveries are high (80–100%), and samples stable at least for two weeks if stored in the dark until analysed.     

Synthesis of halogenated diphenyl ethers and dibenzofurans - A discussion of specific isomers available

Synthetic routes for the preparation of halogenated diphenyl ethers and dibenzofurans are reviewed, and isomers reported in the literature are listed. In addition, the routes preferred for the synthesis of specific chlorinated isomers - especially from the point of view of an unambiguous structural assignment - are discussed in detail. The route recommended for chlorinated diphenyl ethers is the coupling of biaryliodonium salts with phenols, and for chlorinated dibenzofurans the palladium acetate-promoted cyclization of diphenyl ethers. Chlorinated isomers of diphenyl ethers and dibenzofurans which are available via these routes are listed. Furthermore, the synthesis of a new octachlorodiphenyliodonium salt and its coupling with three different chlorophenols are described, and the cyclization of an octachlorodiphenyl ether to octachlorodibenzofuran is shown.     

Sampling of epichlorohydrin and ethylene chlorohydrin in workroom air using Amberlite XAD-7 resin

Activated charcoal, Amberlite XAD-2 and Amberlite XAD-7 were evaluated for the adsorption of epichlorohydrin and ethylene chlorohydrin from air followed by desorption with solvent. Ethylene chlorohydrin was found to be unstable on activated charcoal in the presence of carbon disulfide. Recoveries from XAD-2 were low, and XAD-7 was found to be the best adsorbent for the sampling of these compounds from air.     

Inspiring England's urban fringes: multi-functionality and planning

The urban fringe has been described as 'planning's last frontier'; a zone of transition and interface between town and country where a broad variety of land uses and activities come together, and where development pressure is often intense.

In this paper, we argue that the urban fringe possesses special characteristics, making it more than simply a transitional landscape. These characteristics centre on patterns of land use, biodiversity and leisure/development opportunity which are unique to the urban edge and to land extending away from built-up areas. The uniqueness, diversity and particular dynamics of the urban fringe demands a special brand of planning and management response. Therefore we suggest that the principle of 'multi-functionality' provides a framework for action, showing how diversity can be managed and supported. Through brief case studies, we demonstrate how functional interactions at the urban fringe might be promoted in the future.     

Health Impact of Injuries: A Population-Based Epidemiological Investigation in a Local Community of Bangladesh

Due to the lack of valid injury data, the objective of this study was to assess the injury morbidity and mortality in a local community of Bangladesh. A population-based survey of 3,258 households was conducted in 1996. The information was collected by trained field-level health workers using three pretested structured forms. The estimated crude morbidity from injuries was 311 per 1,000 population per year, and injury accounted for 13% of all morbidity. The children and old-age groups experienced higher injury rates than others, and male children aged 5–15 years had the highest incidence rates (546/1,000 person-years). Falls and cutting injuries tended to be the most frequently (62.4%) observed types of injuries in this survey. The home (42%) and workplace (42%) were where most of the injuries occurred, and the majority (70.7%) of the injuries were minor. Of all deaths, mortality from injuries was 2.9%, and drowning (27.8%) and homicide (16.7%) were found as common forms of injury-causing deaths. This study invites more detailed investigation on injury morbidity and mortality.     

Sexual selection and cues for female choice in leks of Jackson's widowbird Euplectes jacksoni

Summary Sexual selection through female mate choice was investigated in the lekking Jackson's widowbird by applying multivariate selection analysis to observational data from four leks. Males perform a stereotyped jump display on small display courts (dance rings) constructed by the males in open grassland. Females visit the lek solely for mating and nest on their own, away from the lek area. Few cases of interference during courtship and absence of position effects on mating success indicated that female choice within the leks was not pre-empted by male-male competition. In a set of 11 male traits with mating success as the dependent fitness measure, significant selection differentials (covariances) were found for the length of the conspicuous tail and the rate of the jump display, suggesting sexual selection of these traits. They also showed the largest selection gradients (partial effects) and thereby seem to be the cues on which females base their choice. The success of males in obtaining copulations appears to depend on two components: display rate and lek attendance affect the number of female visits, whereas tail length seems to primarily influence the chance of copulating with a visiting female. Tail length was positively related to a measure of body condition, which is of interest with regard to the suggestions that sexual ornaments may serve as indicators of male viability.     

Copper effects on reproductive stages of Baltic Sea Fucus vesiculosus

Copper is an active ingredient in many antifouling products, and pleasure boats are estimated to be the major single source of copper pollution in Swedish coastal waters. For this reason, the effects of copper were studied on egg volume, fertilization, germination and development of apical hairs of Baltic Sea Fucus vesiculosus L. Germination was the most sensitive stage and was studied at different concentrations of copper, different salinities and different ages of zygotes. Low concentrations of copper, 2.5 g Cu l^-1, added to natural brackish water before fertilization, adversely affected germination at the ambient, suboptimal salinity of 6, suggesting that as little as a doubling of the copper levels in the studied area will severely affect the germination frequency of F. vesiculosus. The addition of 20 g Cu l^-1 caused about 70 to 80% decline in germination at 6S but also at 20S which is higher than optimum. At a salinity close to optimum (14S) no negative effect was noticed on germination when 20 g Cu l^-1 was added. The results suggest that the degree of salinity stress acting upon the zygotes is a more important factor for the response to copper than the influence of salinity on metal availability. When 2.5 to 60 g Cu l^-1 was added to the medium 24 h after fertilization, the zygotes were more resistant, resembling the response of adult marine fucoid tissue.     

瑞典大湖中大型植物的发展及其生境特性

在20世纪70年代,对瑞典的维纳恩湖、韦特恩湖、哈马伦和梅拉伦等四大湖泊进行了红外摄影航空测量.沿这些湖泊的小坡度梯度区域,挺水植物群落漫延数百米宽,而在较深坡度区只有几米宽.因为梅拉伦湖分成几部分,因此拥有很长的岸线,促进了水陆交界区域植被的生长.由于存在很多的掩蔽条件,睡莲以及其它浮叶的和自由漂浮的植物十分丰富.露出水面的和浸在水下的大型植物在寡营养的韦特恩湖最北端茁壮生长.在维纳恩湖无掩蔽的湖滩占多数,掩蔽的湾和半岛生长着过盛的芦苇.在哈马伦湖浅水区,单一的芦苇丛Phragmutesaustralis占主导地位.在20世纪90年代再次对梅拉伦湖和维纳恩湖所进行的调查表明,其变化可能与地下水层的波动有关.自第一次调查以来一直是比较稳定的.芦苇和睡莲在各湖泊的掩蔽区蔓延,而在深水边界区的芦苇的生长在减少.     

Relationship between photosynthesis and non-photochemical quenching of chlorophyll fluorescence in two red algae with different carotenoid compositions

Algae are continuously exposed to short-term fluctuations in irradiance. We investigate how two red algae species regulate photosynthetic efficiency to cope with such changes and identify some strategies that differ from higher plants. Two red algae, Gracilaria domingensis and Kappaphycus alvarezii, with antheraxanthin and lutein as major xanthophylls, respectively, reacted to the onset of low light (below E _k) with a substantial decrease of NPQ. This is different from higher plants, but similar to previous observations in, e.g. cyanobacteria where it indicates an increase in the effective absorbance cross-section of Photosystem II (PSII) by state transition. Kinetic studies in continuous light revealed a high susceptibility of PSII to light stress ((1-q _P)/NPQ) in K. alvarezii immediately after the sudden onset of high light, followed by a decrease. This was caused by a slower onset of NPQ in K. alvarezii, followed by acclimation. In G. domingensis, susceptibility of PSII to light stress was stable with time, but absolute values of (1-q _P)/NPQ were higher than in K. alvarezii. These observations suggest that K. alvarezii may be better adapted to high light levels, but is less well prepared for large sudden changes in irradiation. In K. alvarezii, photosynthesis continued to increase with increasing irradiation when NPQ was saturated. As (1-q _P) and NPQ were still balanced in this situation, most likely, processes other than photosynthetic oxygen release are responsible for the increasing net O₂ production observed.