Distribution of DDT residues in fish from the Songkhla Lake, Thailand

Since the early 1950s DDT has been extensively used in Thailand as a malaria repellent and as an agricultural pesticide, but was finally banned in 1994. In this study concentrations of p,p'-DDT, p,p'-DDE, and p,p'-DDD in 113 fish of four species (Scatophagus argus, Protosus canius, Channa striata and Zonichthys nigrofasciata) are reported from the large, brackish Songkhla Lake and the Gulf of Thailand. The mean sigma DDT concentrations at different locations in the analysed fish species ranged from 33 to 170 ng/g lipid wt. (0.086-7.7 ng/g fresh wt.). This is well below the recommended maximum residue levels in aquatic animals used for human consumption (5000 ng/g fresh wt.) in Thailand. The comparatively low residue levels could be due to the high temperature and solar radiation in the region, which may result in a high volatilising and degradation rate of DDT. Also, the high productivity of the lake could result in a dilution effect, when DDT is distributed in a large amount of organic matter, followed by a high biological degradation of the substance.     

Soil carbon sequestration in degraded semiarid agro-ecosystems--perils and potentials

The Kyoto Protocol opens new possibilities for using the biosphere as a carbon sink. Using agro-ecosystems as carbon sinks may be the most appropriate practice from both environmental and socioeconomic points of view. Degraded agro-ecosystems in Africa might benefit significantly from the improved land management that would be part of a carbon sequestration program. There are vast areas of these agro-ecosystems in Africa and their rehabilitation is an urgent matter. We agree with UNEP that there are potentially important synergies to be made between the Convention on Climate Change, the UN Convention to Combat Desertification and the UN Convention on Biodiversity. In this paper, we have investigated the potential for increasing soil carbon content in semiarid agro-ecosystems in the Sudan and found that increasing fallow periods will result in increased soil carbon content and converting marginal agricultural areas to rangeland will restore the carbon levels to 80% of the natural savannah carbon levels in 100 years. The economic gain from a future carbon sequestration program has the potential of a significant contribution to the household economy in these agro-ecosystems.     

Conflict resolution by participatory management: remote sensing and GIS as tools for communicating land-use needs for reindeer herding in northern Sweden

When seeking to resolve complex land-management issues, geographical assessment of resources that are in short supply or in dispute can aid the communication of knowledge and the understanding among and between different stakeholders. In this paper, we illustrate how remote sensing and GIS can be used to gather and compile information regarding land-use activities and patterns among reindeer herders and other land users (forestry, mining, tourism, etc) in northern Sweden. The project represents a novel user-oriented effort largely based on the work carried out by the principal end user, i.e. the reindeer herders themselves. The basis for development of land-use plans for reindeer husbandry, was the following: to collect and digitally systemize traditional ecological and landscape knowledge of reindeer habitat use; to integrate this information with results from field inventories and satellite-based vegetation classifications; to map activities of other land users. The resulting land-use plans provide information that can facilitate consultation between the reindeer herders and other stakeholders and can facilitate operational work in reindeer management. This project can serve as a model for participatory involvement and planning, bringing indigenous knowledge and advanced remote-sensing techniques together in an interactive process.     

瑞典驼鹿(Alces alces)萎缩综合症:背景及当前的假说

20世纪80年代,在瑞典人们经常发现驼鹿死亡或身体状况差的情况.递交给瑞典国立兽医研究所(SVA)进行尸体常规检查的驼鹿数目增加了10倍之多.艾尔夫斯堡(Alvsborg)的狩猎者们对此尤为关注.随后,人们对驼鹿这一复杂的萎缩综合症进行了相关描述并从1991年开始收集有关患病驼鹿的报道.迄今为止,仍未找到该综合症确定的潜在病因,但人们提出了一些可能的假说以解释此综合症.这些假说基本上可以分为两类:食物相关假说和宿主-寄生虫相关假说.食物相关假说认为萎缩综合症有如下根本原因:酸化/撒石灰、采食动物密度/食物产量或污染.上述假说很少经严格实验检验,多半实验仅为一些观察结果支持,之所以这些假说与人们的预计相吻合,是因为这些假说是事后试图解释这些观察到的现象而提出的.     

粮食生产系统中的镉:对敏感人群的健康威胁

本文概述了瑞典农业系统中镉的状况以及镉的人类暴露状况.农业土壤(耕层)中的镉每年增加0.03%～0.05%.饲料是当地农业系统中镉增加的重要原因.当前暴露水平下已经有一些测量表明人体肾功能受到影响.如果粮食中的水平达到欧盟允许的最大限度,那么10%～25%的瑞典人群暴露的镉水平将超过暂时可容忍的每周摄入量(PTWI,7μg Cd/kg体重).人群中的敏感者是那些低铁状况(主要是女性)和肾紊乱的个体.最近的研究表明镉对骨质疏松症有影响,但还需要进一步的研究来辨别镉是否在早期发展阶段毒害神经.必须采取坚决行动来阻止农业土壤中镉含量进一步增加.本文给出了预防及采取措施的建议.     

Evolutionary developmental biology: its concepts and history with a focus on Russian and German contributions

Evolutionary theory has been likened to a “universal acid” (Dennett 1995) that eats its way into more and more areas of science. Recently, developmental biology has been infused by evolutionary concepts and perspectives, and a new field of research—evolutionary developmental biology—has been created and is often called EvoDevo for short. However, this is not the first attempt to make a synthesis between these two areas of biology. In contrast, beginning right after the publication of Darwin’s Origin in 1859, Ernst Haeckel formulated his biogenetic law in 1872, famously stating that ontogeny recapitulates phylogeny. Haeckel was in his turn influenced by pre-Darwinian thinkers such as Karl Ernst von Baer, who had noted that earlier developmental stages show similarities not seen in the adults. In this review, written for an audience of non-specialists, we first give an overview of the history of EvoDevo, especially the tradition emanating from Haeckel and other comparative embryologists and morphologists, which has often been neglected in discussions about the history of EvoDevo and evolutionary biology. Here we emphasize contributions from Russian and German scientists to compensate for the Anglo-American bias in the literature. In Germany, the direct influence of Ernst Haeckel was felt particularly in Jena, where he spent his entire career as a professor, and we give an overview of the “Jena school” of evolutionary morphology, with protagonists such as Oscar Hertwig, Ludwig Plate, and Victor Franz, who all developed ideas that we would nowadays think of as belonging to EvoDevo. Franz ideas about “biometabolic modi” are similar to those of a Russian comparative morphologist that visited Jena repeatedly, A. N. Sewertzoff, who made important contributions to what we now call heterochrony research—heterochrony meaning changes in the relative timing of developmental events. His student I. I. Schmalhausen became an important contributor to the synthetic theory of evolution in Russia and is only partly known outside of the Russian-reading world because only one of his many books was translated into English early on. He made many important contributions to evolutionary theory and we point out the important parallels between Schmalhausen’s ideas (stabilizing selection, autonomization) and C. H. Waddington’s (canalization, genetic assimilation). This is one of the many parallels that have contributed to an increased appreciation of the internationality of progress in evolutionary thinking in the first half of the twentieth century. A direct link between German and Russian evolutionary biology is provided by N. V. Timoféeff-Ressovsky, whose work on, e.g., fly genetics in Berlin is a crucial part of the history of evo-devo. To emphasize the international nature of heterochrony research as predecessor to the modern era of EvoDevo, we include Sir G. R. de Beer’s work in the UK. This historical part is followed by a short review of the discovery and importance of homeobox genes and of some of the major concepts that form the core of modern EvoDevo, such as modularity, constraints, and evolutionary novelties. Major trends in contemporary EvoDevo are then outlined, such as increased use of genomics and molecular genetics, computational and bioinformatics approaches, ecological developmental biology (eco-devo), and phylogenetically informed comparative embryology. Based on our survey, we end the review with an outlook on future trends and important issues in EvoDevo.     

Physico-chemical characteristics of the peloid mud from Morinje Bay (eastern Adriatic coast, Croatia): suitability for use in balneotherapy

The study conducted in the Morinje Bay (Central Dalmatia, Croatia) included the investigation of the sedimentological, physico-chemical and geochemical properties of the Morinje Bay sediments in order to assess the suitability of the material for wellness-related purposes including medicinal use. The sedimentological characteristics of the Morinje mud are in accordance with the geological origin of the material; the sediment is fine grained, composed mostly of carbonates, quartz and clay minerals. The composition of the sediment determines the physico-chemical properties of the mud. The high content of carbonate minerals diminishes adsorbing the characteristics of the mud to some extent; however, they are still comparable to some commercial mud already successfully used for medicinal purposes. Geochemical analyses have shown that trace metals concentrations in the Morinje Bay samples were mostly in the range with similar material from unpolluted Adriatic environments. Only the concentrations of Cu, Pb, Zn and As were slightly higher than in the reference material, but still within acceptable limits.     

Short-term prediction of influent flow rate and ammonia concentration in municipal wastewater treatment plants

The prediction of the influent load is of great importance for the improvement of the control system to a large wastewater treatment plant. A systematic data analysis method is presented in this paper in order to estimate and predict the periodicity of the influent flow rate and ammonia （NH3） concentrations： 1） data filtering using wavelet decomposition and reconstruction; 2） typical cycle identification using power spectrum density analysis; 3） fitting and prediction model establishment based on an autoregressive model. To give meaningful information for feedforward control systems, predictions in different time scales are tested to compare the corresponding predicting accuracy. Considering the influence of the rainfalls, a linear fitting model is derived to estimate the relationship between flow rate trend and rain events. Measurements used to support coefficient fitting and model testing are acquired from two municipal wastewater treatment plants in China. The results show that 1） for both of the two plants, the periodicity affects the flow rate and NH3 concentrations in different cycles （especially cycles longer than 1 day）; 2） when the flow rate and NH3 concentrations present an obvious periodicity, the decreasing of prediction accuracy is not distinct with increasing of the prediction time scales; 3） the periodicity influence is larger than rainfalls; 4） the rainfalls will make the periodicity of flow rate less obvious in intensive rainy periods.     

Cytogenetic status of human lymphocytes after exposure to low concentrations of p,p'-DDT, and its metabolites (p,p'-DDE, and p,p'-DDD) in vitro

Despite that the use of DDT has been restricted for more than 40 years to malaria affected areas, low doses of this pesticide and its metabolites DDE and DDD can be found in the environment around the world. Although it has been shown that these pollutants induce cell and DNA damage, the mechanisms of their cytogenotoxic activity remains largely unknown. This study looks into their possible genotoxic effects, at doses that can be found in body fluids, on human lymphocytes using the cytokinesis-block micronucleus assay and the comet assay. After exposure for 1, 6, and 24 h compounds p,p′-DDT (0.1 μg mL⁻¹), p,p′-DDE (4.1 μg mL⁻¹), and p,p′-DDD (3.9 μg mL⁻¹) showed increase in DNA damage. The most significant results were observed at exposure period of 24 h where number of micronucleated cells increased from control 2.5 ± 0.71 to 23.5 ± 3.54, 13.5 ± 0.71, and 16.5 ± 6.36 for DDT, DDE, and DDD, respectively. Similar effect was observed using comet test where the percentage of DNA in comets tail increased from control 1.81 ± 0.16 to 17.24 ± 0.55, 11.21 ± 0.56 and 9.28 ± 0.50 for each compound, respectively. At the same time Fpg-comet assay failed to report induction of oxidative DNA damage of these pollutants. Additionally, the type of cell death was determined using diffusion assay and necrosis dominated. Our findings suggest that even at low concentrations, these pesticides could induce cytogenetic damage to human peripheral blood lymphocytes and in that manner have the impact on human health as well.     

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) in consumer products in Norway - a pilot study

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are used in numerous industrial and consumer products because of their special chemical properties, for instance the ability to repel both water and oil. A broad variety of PFAS have been introduced into the Norwegian market through industrial use (e.g. via fire fighting foams and paints) as well as in treated customer products such as textiles and coated paper. Our present knowledge of the exact chemical PFAS compositions in preparations using perfluorinated compounds is limited. This lack of knowledge means that it is difficult to provide an accurate assessment of human exposure to these compounds or to the amount of waste that may contain treated products. It is a growing concern that these potentially harmful compounds can now be found throughout the global environment.Samples of consumer products and preparations were collected in Norway, with supplemental samples from Sweden. In 27 of the 30 analyzed consumer products and preparations a number of polyfluorinated substances that were analyzed were detected but this does not exclude the occurrence of unknown PFAS. Notable was that perfluorooctanesulphonate (PFOS), which has been strictly regulated in Norway since 2007, was found in amounts close to or exceeding the EU regulatory level in 4 of the 30 analyzed products, all within the leather or carpet product groups. High amounts of fluorotelomer alcohols (FTOHs) were found in waterproofing agents, carpets and textiles, consistent with earlier findings by Fiedler et al. (2010). The presence of PFAS in a broad range of consumer products can give rise to a constant diffuse human exposure that might eventually result in harm to humans.