夏季珠江口叶绿素a和营养盐分布特征及其与环境因子的关系

本研究基于2019年夏季珠江口附近海域的现场调查数据,分析了珠江口叶绿素a（chlorophyll a,Chl a）和营养盐的分布特征,并结合环境因子进行了探讨。结果表明:夏季珠江口海域表层Chl a和溶解氧（dissolved oxygen,DO）浓度分别为4.192～88.209 μg/L和4.610～10.586 mg/L;溶解无机氮（dissolved inorganic nitrogen,DIN）、活性磷酸盐（PO₄-P）和活性硅酸盐（SiO₃-Si）浓度分别为0.168～1.247 mg/L、0.011～0.044 mg/L和0.694～6.916 mg/L。夏季珠江口浮游植物生长旺盛,依据美国河口营养状况评价（NEEA-ASSETS）标准,44.4%的站位处于高度富营养化（20 μg/L60 μg/L）。珠江径流量是夏季珠江口浮游植物空间分布的主要驱动因素,珠江口口门内浮游植物生长受光限制和径流稀释影响并未出现高值,珠江口口门外浮游植物旺发消耗了大量磷酸盐,磷成为浮游植物生长的限制因子。Chl a与盐度、PO₄-P呈显著负相关性,与DIN、DIN/P呈显著正相关性,表明河口冲淡水对浮游植物生长影响显著。     

天津地区冬季总悬浮颗粒物中PAHs污染特征

采集并分析了天津不同区县13个样点冬季总悬浮颗粒物(TSP)中16种优控多环芳烃(PAHs)含量.结果表明不同样品间PAHs含量差异明显,东部开发区和中北部区县含量明显高于其它地区,大港油田的颗粒物中PAHs含量很低,市区、南部区县和北部山区居中.根据毒性等效因子计算了等效浓度,不同样品PAHs总等效浓度差异不大,占总浓度50%的高环PAHs毒性贡献达90%.     

Agricultural production and bird conservation in complex landscapes of the dry Chaco

The South American dry Chaco is a mosaic of woody vegetation and grasslands with high deforestation rates in recent decades. Considering forests and grasslands as the main natural habitats, we assessed the trade-offs between bird populations and agricultural production to compare the potential consequences of different land use strategies (‘sharing’, ‘sparing’, and intermediate) for populations of bird species sensitive to agriculture, while attaining a regional production target. We evaluated how populations responded to scenarios with different proportions of forest and grasslands, considering three reference states (100% forest, 80:20% and 50:50% forest and grasslands, respectively); and scenarios capable of meeting three after-farming scenarios, with land destined to reach a regional production target with three variations of forest:grasslands within spared land. We fitted curves to relate bird abundance to agricultural yield along a gradient of meat production intensity; and we classified bird species as ‘losers’ (if their populations were lower than the baseline population in the reference state, at any level of production) and ‘winners’ (if their current populations were higher than the baseline population). At the ‘current’ (c. 2010) level of regional agricultural production, we found a similar number of loser species maximized by land-sparing and land-sharing strategies; while intermediate strategies were the least favourable to balance production and bird populations. Under the most probable scenarios of increases in regional meat production, most loser bird species populations were maximized by a land-sparing strategy, suggesting that if meat production targets are going to increase in the region, this can be more efficiently achieved by combining well-protected forests and grasslands, and high-yielding mechanized agriculture (e.g. soybean). Our results highlight the importance of assessing all the important natural habitats (e.g. forests and grasslands) of a region to explore conservation strategies at a regional scale.     

An Original Halo-Alkaline Protease from <Emphasis Type="Italic">Bacillus halodurans</Emphasis> Strain US193: Biochemical Characterization and Potential Use as Bio-Additive in Detergents

Over a hundred of halophilic/halotolerant microorganisms were screened for alkaline protease production. The bacterium showing the highest enzyme production was characterized and identified as Bacillus halodurans US193 on the basis of 16S rRNA gene analysis. It was alkalophilic, thermophilic and halotolerant since it grew optimally at pH 9.7 and 50?°C with tolerance of up to 125 g NaCl l^?1. The alkaline protease was purified 4.9 times with about 40186.1 U/mg as specific activity. It exhibited optimal activity at pH 10, 70?°C and 0.25 M NaCl with perfect stability at wide ranges of pH (6–12), temperatures (30–60?°C) and NaCl concentrations (0–2 M). The serine alkaline protease maintained high stability in the presence of Cu²⁺, Mg²⁺, Ba²⁺ and Ca²⁺ ions, various organic solvents [50% (v/v)] and ionic and non ionic detergent additives. In addition, it was more compatible with various commercialized detergents than other reported detergent proteases, and was very efficient in blood stain removal. These findings let B. halodurans US193 alkaline protease be an ideal candidate for many industrial processes at harsh conditions, especially as a bio-additive in detergent industry.     

Household costs and benefits of biodiversity conservation: case study of Sichuan giant panda reserves in China

Households in communities in and around nature reserves are important stakeholders in biodiversity conservation; they are the focus of the conflict between ecological protection and community development. This study surveyed 927 households in 16 giant panda reserves in Sichuan Province, China, to calculate the costs and benefits to households of biodiversity conservation, and the differences for those inside and outside reserves. A multilevel regression model was used to measure the factors influencing the costs and benefits. There are three main findings. First, the direct economic cost for average biodiversity conservation for households inside reserves (1166.83 yuan/year) is significantly higher at the 1% level than for those outside (578.27 yuan/year), while the direct economic benefit for average biodiversity conservation to households living inside reserves (3881.94 yuan/year) is not statistically different than those outside (3653.47 yuan/year). Second, the influence of biodiversity conservation on households is significantly different depending on whether they live inside or outside the reserve, regarding employment opportunities, ties with the outside world, infrastructure, and the community environment. There is also a significant difference between those inside and those outside in perceptions with regard to restrictions in the collection of wild plants and destruction of traditional culture by biodiversity conservation. Third, the factors that affect the costs for and benefits to households of biodiversity conservation include, at the household level, the head of household’s education level, village cadres, number of migrant workers, distance from the town market, reserve-based employment, development projects, and ecotourism management participation, and, at the reserve level, establishment time, level of reserve, protective effect, and location.     

Numerical Simulation of Gas Injection in Vertical Water Saturated Porous Media

We present numerical simulations of drainage induced by air injection in a vertical water-saturated Hele-Shaw cell filled with glass microbeads. We use the macroscale Subsurface Transport Over Multiple Phases (STOMP) simulator developed by the Pacific Northwest National Laboratory’s Hydrology Group. To trigger fingering, we use random permeability fields consistent to capillary entry pressure fields. We compare the numerical results to our own experimental results shown in a previous study. We analyze the effects of the microheterogeneity degree as well as the macroscopic parameters on the gas saturation results. The main objective of the work is to investigate how microscopic effects could be accounted for by macroscopic variables during drainage.     

Causal interactions between environmental degradation,renewable energy,nuclear energy and real GDP: a dynamic panel data approach

Renewable energy as well as nuclear energy are low carbon power that presents the life cycle emissions of greenhouse gases than fossil fuel energy. However, analyzing the relationship between the consumption of renewable energy, consumption of nuclear energy, CO₂ emissions and economic growth is crucial for the economic and energy policy decision; we address this question for developed countries. This paper deals with the relationships between nuclear energy, environmental degradation, real GDP and renewable energy. We apply a panel data model for a global panel consisting of nine developed countries during the period 1990–2013. The group studied consists of Canada, France, Japan, Netherlands, Spain, Sweden, Switzerland, UK and the USA. The empirical findings suggest that: (1) a causal link between emissions and real income, (2) a unidirectional causality running from renewable energy to nuclear energy, (3) a unidirectional causal relationship running from capital to environmental degradation, (4) a unidirectional causal relationship running from income to nuclear energy consumption, since the growth hypothesis is valid, (5) a unidirectional causality running from capital to income, (6) no an outstanding role of renewable energy use in the contribution of CO₂ emissions.     

Inhalation of two putative Gulf War toxins by mice

We employed our inhalation methodology to examine whether biomarkers of inflammation and oxidative stress would be produced in mice following inhalation of aerosols containing carbonaceous particles or the vapor of pesticides prevalent during the first Gulf War. Exposure to two putative Gulf War Illness toxins, fine airborne particles and the pesticide malathion, increased biomarkers of inflammation and oxidative stress in Friend virus B (FVB) female mice. Mice inhaling particles 24 h before had increased lung lavage and plasma Leukotriene B4 (LTB₄) (a biomarker of inflammation) and PGF_2α (a biomarker of oxidative stress) levels, lung lavage protein and lung lavage lactic dehydrogenase (LDH) levels. These changes were a function of particle density and exposure time. Compared to particle inhalation, mice inhaling malathion 24 h before had small increase in plasma LTB₄ and PGF_2α levels but no increase in lung lavage LTB₄, lung lavage protein, lung lavage LDH, and lung lavage alveolar macrophage (AM) levels compared to unexposed control mice. AM from particle-exposed mice contained phagocytosed particles, while AM from malathion-exposed mice showed no abnormalities. Our results indicate that inhaling particles or malathion can alter inflammatory and oxidative biomarkers in mice and raise the possibility that these toxins may have altered inflammation and oxidative stress biomarkers in Gulf War-exposed individuals.     

Biosorption of alpacide blue from aqueous solution by lignocellulosic biomass: <Emphasis Type="Italic">Luffa cylindrica</Emphasis> fibers

The aim of the present work is to develop an effective and inexpensive pollutant-removal technology using lignocellulosic fibers: Luffa cylindrica, for the biosorption of an anionic dye: alpacide blue. The influence of some experimental parameters such as pH, temperature, initial concentration of the polluted solution, and mass of the sorbent L. cylindrica on the biosorption of alpacide blue by L. cylindrica fibers has been investigated. Optimal parameters for maximum quantity of biosorption dye were achieved after 2 h of treatment in a batch system using an initial dye concentration of 20 mg/L, a mass of 1 g of L. cylindrica fibers, and pH 2. In these conditions, the quantity of dye retained is 2 mg/g and the retention rate is 78 %. Finally, a mathematical modeling of kinetics and isotherms has been used for mathematical modeling; the model of pseudo-second order is more appropriate to describe this phenomenon of biosorption. Concerning biosorption isotherms, the Freundlich model is the most appropriate for a biosorption of alpacide blue dye by L. cylindrica fibers.     

Effects of sewage sludge fertilizer on heavy metal accumulation and consequent responses of sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis>)

Use of sewage sludge, a biological residue produced from sewage treatment processes in agriculture, is an alternative disposal technique of waste. To study the usefulness of sewage sludge amendment for Helianthus annuus, a pot experiment was conducted by mixing sewage sludge at 2.5, 5, and 7.5 % (w/w) amendment ratios to the agricultural soil. Soil pH decreased whereas electrical conductivity, organic matter, total N, available P, and exchangeable Na, K, and Ca increased in soil amended with sewage sludge in comparison to unamended soil. Sewage sludge amendment led to significant increase in Pb, Ni, Cu, Cr, and Zn concentrations of soil. The increased concentration of heavy metals in soil due to sewage sludge amendment led to increases in shoot and root concentrations of Cr, Cu, Ni, and Zn in plant as compared to those grown on unamended soil. Accumulation was more in roots than shoots for most of the heavy metals. Moreover, high metal removal for the harvestable parts of the crops was recorded. Sewage sludge amendment increased root and shoot length, leaves number, biomass, and antioxidant activities of sunflower. Significant increases in the activities of antioxidant enzymes and in the glutathione, proline, and soluble sugar content in response to amendment with sewage sludge may be defense mechanisms induced in response to heavy metal stress.

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Graphical abstract Origin, fate and behavior of sewage sludge fertilizer