Degradation characteristics and metabolic pathway of 4-nitrophenol by a halotolerant bacterium Arthrobacter sp. CN2

Arthrobacter sp. strain CN2, capable of degrading 4-nitrophenol, was isolated from activated sludge. Degradation of 4-nitrophenol was optimized at pH 7.7, 30?°C, and 0.53% of glucose. Salt tolerance of 4-nitrophenol degradation was as high as 6% (w/v). Several biodegradation intermediates were identified and quantified by high-performance liquid chromatography and mass spectrometry. 4-Nitrocatechol is involved in the degradation of 4-nitrophenol by CN2. Scale-up of 4-nitrophenol degradation was conducted in a bioreactor with different salinity. When the salinity was below 7%, the degradation rate of 4-nitrophenol was above 90% (100 mg L^?1, 3 L).     

纳米硫化镉对A549细胞的损伤研究

研究纳米硫化镉(Nano-Cd S)材料对肺癌细胞系A549的毒性及氧化损伤作用。培养A549细胞,经传代后接种于6孔板中,每孔2 m L完全培养基,接种次日进行染毒。用直径20~30 nm、长度80~100 nm的Nano-Cd S进行染毒,染毒浓度分别为0、5、10、20、40和80 mg·L~(-1)。染毒24 h后用MTT检测细胞存活率,以存活率在80%左右的浓度为后续实验染毒浓度。应用流式细胞技术,用荧光探针法检测A549细胞的活性氧(reactive oxygen species,ROS)含量,PI-Annexin-V法检测细胞凋亡情况;用试剂盒检测细胞中超氧化物岐化酶(superoxide dismutase,SOD)和过氧化氢酶(catalase,CAT)活性以及丙二醛(malondialdehyde,MDA)含量,判断细胞氧化损伤情况。不同浓度Nano-Cd S处理细胞24 h之后,细胞存活率随剂量的增加而下降,浓度为10、20、40和80μg·L~(-1)时,存活率分别为(88.71%±0.80%)、(81.93%±3.06%)、(75.23%±1.13%)和(70.66%±5.63%),且各组间差异均具有统计学意义(P0.05)。以浓度为10和20 mg·L~(-1)的Nano-Cd S染毒24 h后,胞内ROS含量和细胞凋亡率随染毒剂量的增加而增加(P0.05);浓度为10 mg·L~(-1)时,细胞凋亡率为(6.26%±0.44%)。与对照相比,各染毒组SOD和CAT活性和MDA含量升高,20 mg·L~(-1)染毒组SOD和CAT活性和MDA含量高于10 mg·L~(-1)染毒组(P0.05)。研究表明,纳米硫化镉能引起A549细胞的氧化损伤和细胞凋亡,具有明显的细胞毒性。     

基于自适应遗传小波神经网络的水质评价建模

水环境污染过程的非确定性和非线性,使得传统的水质评价方法存在局限性。为了提高水质评价的准确性,提出了一种基于改进小波神经网络(wavelet neural network,WNN)的水质评价模型。采用自适应遗传算法(adaptive genetic algorithm,AGA)对小波神经网络的初始权值进行优化,再通过小波神经网络算法对网络进行训练,最后对训练好的网络展开测试。仿真结果表明,自适应遗传算法和小波神经网络的结合提高了网络的训练效率,该方法可以用于水质评价建模,并且评价结果具有较高的精度和准确性。     

区域水资源可持续利用评价指标体系构建

基于区域水资源可持续利用评价指标体系（Indicators System for Sustainability AssessmentofWater Resources Use, ISSAWRU）构建的一般方法与步骤,论文围绕初始、优化和评价检验三个过程构建ISSAWRU;针对ISSAWRU构建中的指标信息重复和干扰问题,提出相关分析与粗糙集Horafa 属性约简算法相结合的方法实现指标体系的优化,并采用灰色系统理论与粗糙集耦合的评价方法对优化结果进行评价检验。以福建省为例,9 个设区市为研究单元,依据可持续发展理论,从水资源条件、开发利用状况、生态环境和社会经济四个方面,构建由30 项指标组成的初始ISSAWRU,通过筛选得到由12 项指标构成的优化ISSAWRU,进而对这两套指标体系进行评价。结果分析表明：相关分析与粗糙集Horafa 属性约简算法相结合的指标信息优化方案是可靠的;筛除重复和干扰指标信息,简化了繁杂的指标体系,降低了后续评价的计算复杂度,并且信息筛选后的优化ISSAWRU比初始ISSAWRU评价结果更合理。     

Rapid changes in growth,condition, size and age of small pelagic fish in the Mediterranean

Since 2007, the ecosystem of the Gulf of Lions has shifted to a different regime, characterised by a low anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) biomass and a remarkably high sprat (Sprattus sprattus) biomass. Surprisingly, the abundance and recruitment of anchovy and sardine remained high. To understand which processes (bottom-up or top-down control, etc.) could have caused this shift, we studied the changes in body condition, growth and size and age of anchovy, sardine and sprat over 1984–1985 and 1992–2012, using data from scientific surveys. The annual age structure of anchovy and sardine was estimated using Bayesian mixture models based on size frequency data with priors on the age–length relationship derived from independent otolith readings. The results indicated periods during which anchovy and sardine were in an average (1992–2004), good (2005–2007) or poor (2008–2012) overall state of condition. For sardine, the shift towards smaller fish observed during these past 4 years was explained by a combination of slower growth and the disappearance of older individuals (ages 2+). Despite the increase in biomass of sprat since 2008, indications were found that sprat was also smaller than in the past. As growth and condition decreased and overexploitation has not been documented or suspected for those three species in this area, we propose that the current decline in sardine and anchovy biomass could be due to qualitative and/or quantitative modifications in the planktonic production (i.e. a bottom-up control) or mass mortalities of adults due to an epidemic disease.     

Relative contribution of dietary carotenoids and vitamin E to visual and chemical sexual signals of male Iberian green lizards: an experimental test

Carotenoid-based sexual ornaments are widespread, but the role of carotenoids as honest signalers in the trade-off between coloration and antioxidant protection remains controversial. It has been suggested that the function of carotenoids might not be an antioxidant per se, but that colorful carotenoids may indirectly reflect the levels of nonpigmentary antioxidants, such as melatonin or vitamin E. We experimentally fed male Iberian green lizards (Lacerta schreiberi) additional carotenoids or vitamin E alone, or a combination of carotenoids and vitamin E dissolved in soybean oil, whereas a control group only received soybean oil. We examined the effects of the dietary supplementations on characteristics of lizard sexual coloration and of the chemical profile of femoral gland secretions. Results indicated that both carotenoids and vitamin E in the diet increased the expression of some visual signals (head and chest, but not dorsum) in comparison to controls. However, different traits were differentially affected, and in many cases, the addition of vitamin E, alone or in combination with carotenoids, had a greater effect on the expression of coloration than the addition of carotenoids alone, even for carotenoid-dependent ornaments. Our results support the idea that other nonpigmentary antioxidants, such as vitamin E, are needed in addition to carotenoids to increase the expression of coloration of L. schreiberi lizards. Therefore, coloration may only indirectly reflect the levels of nonpigmentary antioxidants. In contrast, an increase in dietary nonpigmentary antioxidant vitamin E was directly reflected in the chemical signals. Because of an observed concordance between visual and chemical signals, we suggest that both may be used in different contexts albeit conveying similar messages in different sensory channels.     

Determination of polychlorinated biphenyl and polycyclic aromatic hydrocarbon marine regional Sediment Quality Guidelines within the European Water Framework Directive

Marine regional Sediment Quality Guidelines (SQG) for polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH) from the Basque coast (SE Bay of Biscay) were determined, on the basis of sediment chemistry, toxicity and benthic community disturbance from analysis of 756 estuarine and coastal samples. The SQG were calculated using a percentile approach (based upon effect and non-effect data), using non-normalised and normalised concentration, by total organic carbon. However, normalisation by total organic carbon did not result in any improvement in accuracy compared with non-normalised values. Hence, this study proposes non-normalised SQG values for assessment of the chemical and physicochemical status in marine waters in the Basque Country, within the Water Framework Directive: 24.6–29 μg kg^?1 for total PCBs; 164–285 μg kg^?1 for low molecular weight PAH; 922–1537 μg kg^?1 for high molecular weight PAH; and 1607–2617 μg kg^?1 for total PAH.