Multi-scale marine biodiversity patterns inferred efficiently from habitat image processing

Cost-effective proxies of biodiversity and species abundance, applicable across a range of spatial scales, are needed for setting conservation priorities and planning action. We outline a rapid, efficient, and low-cost measure of spectral signal from digital habitat images that, being an effective proxy for habitat complexity, correlates with species diversity and requires little image processing or interpretation. We validated this method for coral reefs of the Great Barrier Reef (GBR), Australia, across a range of spatial scales (1 m to 10 km), using digital photographs of benthic communities at the transect scale and high-resolution Landsat satellite images at the reef scale. We calculated an index of image-derived spatial heterogeneity, the mean information gain (MIG), for each scale and related it to univariate (species richness and total abundance summed across species) and multivariate (species abundance matrix) measures of fish community structure, using two techniques that account for the hierarchical structure of the data: hierarchical (mixed-effect) linear models and distance-based partial redundancy analysis. Over the length and breadth of the GBR, MIG alone explained up to 29% of deviance in fish species richness, 33% in total fish abundance, and 25% in fish community structure at multiple scales, thus demonstrating the possibility of easily and rapidly exploiting spatial information contained in digital images to complement existing methods for inferring diversity and abundance patterns among fish communities. Thus, the spectral signal of unprocessed remotely sensed images provides an efficient and low-cost way to optimize the design of surveys used in conservation planning. In data-sparse situations, this simple approach also offers a viable method for rapid assessment of potential local biodiversity, particularly where there is little local capacity in terms of skills or resources for mounting in-depth biodiversity surveys.     

Physical symptoms in young adults and their use of different computers and mobile phones

This paper presents the use of new technical equipment by young adults (30 years old or younger), and the physical symptoms they have. The paper then analyses how the symptoms are associated with the use of computers and mobile phones, taking into account the background information. The study is based on a survey of 15 000 working-age (18-65) Finns. The responses (1563) covering young adults' physical symptoms were analysed. Altogether 53.3% of all young adults had pretty often or more frequently pain, numbness or aches in the neck and 32.2% had aches in the hip and lower back. Women experienced more pain, numbness or aches in the neck (65.0%) than men (34.5%). The use of different computers at leisure quite often had an association with some symptoms in different parts of the body. In addition, exhaustion at work had associations with some physical symptoms. In the future, it is essential to note ergonomic reasons and exhaustion at work when young adults experience pain, numbness or aches.     

三峡库区城市给水厂多环芳烃分布变化评价

多环芳烃PAHs(Polycyclic Aromatic Hydrocarbons)是广泛存在的典型持久性有机污染物,了解三峡库区城市供水中PAHs的分布和变化具有重要的理论和现实意义.本文选用EPA推荐的3510c液-液萃取前处理方法和GC/MS 8270c测定方法,对三峡库区6个城市自来水厂(重庆主城3个,库区3个)原水与出厂水的多环芳烃物质的种类和含量进行了测定,并对主城某水厂两套常规处理工艺各工段PAHs的分布和水平进行了分析评价.结果表明,6个水厂的原水和出厂水中检出了萘、菲、蒽、芘、荧蒽、二氢苊共6种PAHs,其中萘、蒽、荧蒽检出率较高,枯水期含量水平在1～40 ng/L.PAHs经2种常规的水处理工艺后,浓度有所降低.但滤后水经加氯消毒等工序后,PAHs浓度有所增加.     

温度对生态浮床系统的影响

通过构建生态浮床净化临江河重污染河水,全面考察了温度对浮床系统的影响.结果表明,温度对生态浮床系统有明显的影响作用,对生态浮床系统氮、磷净化效果的影响呈抛物线型.在水温为2~29℃时,生态浮床对TN和TP的去除率随温度的增加而明显增加;当水温超过29℃时,系统对TN和TP的去除率随温度的增加呈下降趋势;且温度对TN去除效果的影响要大于对TP的影响.研究表明,浮床系统的最佳运行水温为25~29℃,此时浮床植物的平均株高为209.9cm,对氮、磷的平均累积量分别为69.84,19.73g/m2;浮床对TN和TP的去除率分别为38.7%~44.1%和38.6%~43.6%.     

Phosphate removal from wastewater by model-La（Ⅲ） zeolite adsorbents

Phosphorus is one of the primary nutrients which leads to eutrophication and accelerates aging process in enclosed water bodies. Because of the poor phosphorus selectivity of other adsorbents, the novel La(III)-modified zeolite adsorbent (LZA) was prepared by modifying 90 nm zeolite with lanthanide to selectively remove phosphate in the presence of various omnipresent anions, such as sulfates, bicarbonates, and chlorides. Through batch and fixed bed operation, the following optimum conditions were obtained: concentration of lanthanum chloride solution 0.05 mol/L; solid/liquor ratio 1/25; pH 10; calcination temperature 550℃; time 1 h. The value of the Freundlich model constants Kf and 1/n were found to be 16.76 mg/L and 0.2209, respectively. In addition, when calculated at pH 6.0, distribution coe cient KD could be as high as 36.6. Furthermore, in the alkaline pH range, solution of 0.8 mol/L NaCl was used to regenerate the saturated LZA, which could reach the high regeneration e ciency as high as 100%. Because of the good selectivity and regenerability of LZA, it might serve as a potential way for advanced phosphate removal from the sewage containing other anions.