Unionists/researchers writing a book in co-operation: Importance in training/research dynamics

This text describes two different experiences of co-operation between unionists and researchers that resulted in writing of a book. We emphasize their similarities and differences and discuss the importance of these experiences in the dynamics of research and training in Ergonomics.     

溢油胁迫下孔石莼碳氮稳定同位素的变化

为了研究溢油对海岸潮间带重要的大型绿藻孔石莼（Ulva Pertusa）的影响,本文探究了在180#燃料油的原油分散液（WAF）胁迫下,孔石莼的生长速率、叶绿素a以及碳氮稳定同位素的变化。在低WAF浓度（1.43 mg/L、2.87 mg/L和4.30 mg/L）胁迫下,对孔石莼的生长具有促进作用,生长速率均高于对照组,同时叶绿素a和碳氮稳定同位素均呈现上升的趋势;而高浓度WAF（5.72 mg/L和7.17 mg/L）会抑制藻类生长,导致生长速率低于对照组,而叶绿素a含量却高于对照组,孔石莼的δ15N和δ13C相比对照组偏负。对于孔石莼来说,C、N稳定同位素变化的趋势比叶绿素a更明显,这表明在溢油胁迫下,孔石莼的C、N稳定同位素能够更好更快速地评价溢油胁迫毒性大小,因此可以作为海洋环境监测和评价的一种新手段。     

巴西圣保罗州莫日-瓜苏河流流域中的汞:根据210Pb测年剖面估计的沿海泻湖与河流贡献之间的联系

引言 莫日-瓜苏河位于纳斯吉拉斯州,海拔高1450m.流淌470km后,该河流注入圣保罗州的帕尔杜河.其流域总面积为1400km2,其中有86%位于圣保罗州,包括一个工业化地区[1].     

黄河口及邻近海域溶解态无机磷、有机磷、总磷的分布研究

于2003年8月下旬对黄河口及邻近海域进行了十船连续同步27h采样调查,分析了调查区域的溶解态无机磷、有机磷、总磷的平面分布、断面分布、时间分布特征.结果表明,在调查区域内,溶解态无机磷浓度很低,而溶解态有机磷浓度较高(占溶解态总磷的85%以上),是溶解态总磷的主要组成部分.各形态磷的平面分布、断面分布均呈现出由河口向邻近海域降低的趋势,溶解态总磷、溶解态有机磷梯度变化较溶解态无机磷更为明显;潮汐对河口浅水区的各形态磷浓度影响较大,对邻近调查海域的影响不明显.     

二十年来渤海生态环境参数的演化和相互关系

通过系统分析近２０ａ来渤海中部海域３ａ（１９８２－１９８３，１９９２－１９９３，１９９８－１９９９年）１０航次的生态环境特征参数的变化，描述了变化趋势，初步讨论了各种特征参数之间的相互关系。研究发现，近２０ａ来，渤海中部营养盐的浓度和结构（Ｎ／Ｐ和Ｓｉ／Ｎ）均发生显著变化，表现为：硝酸盐、亚硝酸盐、总无机氮持续增加，活性磷和硅显著降低，Ｎ／Ｐ值升高，Ｓｉ／Ｎ值下降。Ｎ／Ｐ值３ａ的五月和十月平均值分     

Biomonitoring of heavy metals (Cd,Hg, and Pb) and metalloid (As) with the Portuguese common buzzard (Buteo buteo)

The accumulation of heavy metals in the environment may have a wide range of health effects on animals and humans. Thus, in this study, the concentrations of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) in the blood and tissues (liver and kidney) of Portuguese common buzzards (Buteo buteo) were determined by inductively coupled plasma-mass spectrometer (ICP-MS) in order to monitor environmental pollution to these elements. In general, Hg and As were the elements which appeared in the highest and lowest concentrations, respectively. A highest percentage of non-detected concentration was found for blood Cd (94.6 %) but, in turn, it was the only metal that was detected in all kidney samples. The kidney was the analyzed sample which showed the highest concentrations of each element evaluated. Statistically, significant differences among blood, liver, and kidney samples were observed for As and Cd (P?相似文献   

Sand as a relevant fraction in geochemical studies in intertidal environments

Soil and sediment samples from several intertidal environment exposed to different types of contamination were studied to investigate the importance of grain size in relation to the capacity of the substrates to retain trace metals. The unfractionated samples (referred to as bulk samples) were separated into the following grain/size fractions: fine–coarse sand (2?0.100 mm), very fine sand (0.100?0.050 mm), silt (0.050?0.002 mm), and clay (0.002 mm). The sample into its fractions was carried out was in a glove box under high-purity N₂ atmosphere in order to minimize any alterations to the samples. The bulk samples were characterized in terms of physicochemical properties such as pH, redox potential, and grain size. The total organic carbon (TOC), total sulfur (S), iron (Fe) pyrite, Fe, and manganese (Mn), and trace metals lead (Pb), mercury (Hg), chromium (Cr), and nickel (Ni) were analyzed in the bulk samples and in each fraction. The sand fractions were also examined by scanning electron microscopy (SEM). Comparisons of the above parameters were made between fractions and between each fraction and the corresponding bulk sample. The fine–coarse sand fraction contained high levels of the primary elements of the geochemical processes that occur in marine sedimentary environments such as TOC, total Fe, Mn, and S. The net concentrations of these four elements were higher in the fine-coarse sand fraction than in the very fine sand fraction and were similar to the net concentrations in the silt and clay fractions. Detailed SEM analysis of the sand coarse fraction revealed the presence of Fe and aluminum oxyhydroxide coatings in the oxic layers, whereas the framboidal pyrites and coatings observed in the anoxic layers were Fe sulfides. The presence of the various coatings explains why the trace metal concentrations in the sand fine–coarse fraction were similar to those in the clay fraction and higher than those in the very fine sand fraction. The present results highlight the importance of the sand fraction, which is generally disregarded in geochemical and environmental studies of sedimentary layers.     

Modeling a spatially restricted distribution in the Neotropics: How the size of calibration area affects the performance of five presence-only methods

We here examine species distribution models for a Neotropical anuran restricted to ombrophilous areas in the Brazilian Atlantic Forest hotspot. We extend the known occurrence for the treefrog Hypsiboas bischoffi (Anura: Hylidae) through GPS field surveys and use five modeling methods (BIOCLIM, DOMAIN, OM-GARP, SVM, and MAXENT) and selected bioclimatic and topographic variables to model the species distribution. Models were first trained using two calibration areas: the Brazilian Atlantic Forest (BAF) and the whole of South America (SA). All modeling methods showed good levels of predictive power and accuracy with mean AUC ranging from 0.77 (BIOCLIM/BAF) to 0.99 (MAXENT/SA). MAXENT and SVM were the most accurate presence-only methods among those tested here. All but the SVM models calibrated with SA predicted larger distribution areas when compared to models calibrated in BAF. OM-GARP dramatically overpredicted the species distribution for the model calibrated in SA, with a predicted area around 10⁶ km² larger than predicted by other SDMs. With increased calibration area (and environmental space), OM-GARP predictions followed changes in the environmental space associated with the increased calibration area, while MAXENT models were more consistent across calibration areas. MAXENT was the only method that retrieved consistent predictions across calibration areas, while allowing for some overprediction, a result that may be relevant for modeling the distribution of other spatially restricted organisms.