Editorial: Effect of root anatomy and apoplastic barrier development on cadmium uptake in rice

<正>Cadmium (Cd) is a toxic metal with high mobility from soil and known translocation into plants (Song et al., 2015).Because the main source of human exposure to Cd is from food consumption, there has been increased research examining Cd uptake in agricultural plants (Li et al., 2014; Rizwan et al., 2016; Song et al., 2015). Rice (Oryza sativa L.) has been identified as a major crop that contains relatively high     

Value of information analysis: the state of application

The value of information (VoI) is a decision analytic method for quantifying the potential benefit of additional information in the face of uncertainty. This paper reviews the prevalence of VoI applications reported in the peer-reviewed literature from the years 1990–2011. We categorize papers’ applications across the types of uncertainties considered, modeling choices, and contexts of social importance (such as health care and environmental science). We obtain and analyze statistics on the range of applications and identify trends and patterns in them, and conclude with an interpretation of what these mean for researchers and practitioners as they pursue new efforts. Key results include a substantial increase over the last 20 years in published papers utilizing VoI, particularly in the medical field. Nineteen trends in VoI applications from the period of 1990–2000 to 2001–2011 were found to be at least weakly significant. Beyond simple trends, some characteristics of VoI usage depend on the area of application, and in some cases, certain sets of characteristics tend to be found together.     

SiO_2-NH_2/Fe_3O_4的制备及制药废水的深度处理

以溶剂热法制备Fe_3O_4磁性粒子,通过改良的St?ber法在其上包覆Si O_2,并用3-氨丙基三乙氧基硅烷对表面进行氨基修饰,制得Si O_2-NH_2/Fe_3O_4磁性复合材料,并将其用于制药废水二级出水的吸附处理(吸附剂投加量1 g/L、吸附时间120 min)。表征结果显示:Si O_2-NH_2/Fe_3O_4为粒径(510.0±3.6)nm的球形粒子。实验结果表明:在废水p H为5时,Si O_2-NH_2/Fe_3O_4对TOC、蛋白质、腐殖酸的吸附效果最佳,三者的去除率分别达44.14%,35.58%,33.07%,与Fe_3O_4相比分别提高了25.27,21.76,21.05百分点;废水p H为6时,Si O_2-NH_2/Fe_3O_4对多糖和色度的去除效果最佳,二者的去除率分别达26.03%和62.94%,与Fe_3O_4的最高去除率(p H=5时)相比分别提高了17.84百分点和22.45百分点;Si O_2-NH_2/Fe_3O_4重复使用4次,TOC和色度去除率均达初次使用时的87%以上。     

Studies on design of heterogeneous catalysts for biodiesel production

The production of biodiesel is gaining momentum with the ever increasing demand of the fuel. Presently, limited literature is available with respect to well designed solid heterogeneous catalyst for biodiesel production considering all the characteristics, process and operation parameters. Hence, a study was conducted to design effective heterogeneous catalyst for biodiesel production. Further, the significant impact of different catalysts, different feed stock, various reaction conditions such as temperature, methanol oil molar ratio, catalyst concentrations and stability/inactivation of the catalysts, are detailed out for transesterification process of biodiesel production. Based on the studies it can be concluded that well designed heterogeneous catalyst can yield high throughput of biodiesel.     

Enzymatic conversion of newspaper and office paper to fermentable sugars

Two types of waste paper materials, newspaper and office paper, were evaluated for their potential to be used as renewable feedstock for the production of fermentable sugars via the enzymatic hydrolysis of their cellulose fractions. The effects of four factors (hydrolysis time, enzyme loading, surfactant addition and phosphoric acid pretreatment) on the extent of sugar yield were assessed and quantified by using a methodical approach based on response surface methodology. The statistical experimental design used in this study requires fewer experimental runs compared to some commonly used experimental designs. In the newspaper hydrolysis case, response surface plots revealed that the degree of sugar release increased with an increase in hydrolysis time but it was hardly affected by the enzyme loading and acid pretreatment factors. The surfactant addition factor exhibited a positive effect when the enzyme loading level was relatively low. With office paper as the substrate, three of the four factors (hydrolysis time, enzyme loading and acid pretreatment) exhibited positive effects on the extent of sugar release. At local optimum conditions, the maximum sugar yield from office paper was found to be 0.82 g of reducing sugars per gram of paper, which was about 4.8 times higher than the maximum sugar release from the newspaper substrate.     

Trends in space occupation by the encrusting sponge Crambe crambe: variation in shape as a function of size and environment

The relationship between sponge size, habitat and shape was studied in the encrusting sponge Crambe crambe (Schmidt, 1862), which is distributed widely throughout the shallow Mediterranean littoral. Examination of sponge patches in shaded and well-illuminated habitats showed that the degree of peripheral irregularity of the edges of a patch is directly related to patch size. This relationship is valid only for sponges of >100 mm² in area. Photophilic and sciaphilous sponges display different growth forms. The pattern of growth is interpreted in terms of competition for space. The directional growth of sciaphilous sponges may be due to the presence of dominant neighbours that are good space competitors, and the irregular growth of photophilic sponges to the absence of such neighbours.     

Medium scale spatial structures of Polycyclic Aromatic Hydrocarbons in the topsoil of Tianjin area

The spatial distribution patterns of Polycyclic Aromatic Hydrocarbons (PAHs) in soil are important to regional environmental assessment. In this paper, the spatial structural features of sixteen prior PAH compounds in the topsoil of Tianjin area, as well as soil properties, were studied. Results shown that medium scale spatial autocorrelations were well revealed. Spherical models with sills could be used to fit all experimental variograms. The spatial structures of PAHs contents demonstrated significant anisotropy. Air precipitation caused by the combustion of coal was the key factor in the formation of the spatial structural patterns of PAHs in the topsoil of Tianjin area.     

Sediment accumulation rate and radiological characterisation of the sediment of Palmones River estuary (southern of Spain)

Chemical analyses and radioecological methods were combined in order to estimate the sediment accumulation rate in the upper 20 cm depth of the Palmones River estuary. Organic matter, total carbon, C:N and (137)Cs vertical profiles showed changes at 13 cm depth. These changes could be associated with the decrease in river input since 1987 when a dam situated in the upper part of the estuary started to store water. Using 1987 as reference to date the sediment, accumulation rate was 1.2 cm yr(-1). As alternative method, two layer model of (210)Pb(xs) vertical distribution showed a sedimentation rate of 0.7 cm yr(-1) with a surface mixing layer of 7 cm thickness. The high ammonium, potassium and sodium content in pore water and the strong correlation between (137)Cs activities and organic matter in dry sediment suggests that (137)Cs (the only anthropogenic product detected) is mainly accumulated in the estuary associated with the particulate organic material from the catchment area.     

Seasonal variation and background levels of heavy metals in two green seaweeds

Seasonal variation in the contents of different metals (Al, Cr, Cu, Fe, Mn, Ni and Zn) in two genera of macroalgae, Ulva and Enteromorpha was studied at 22 sites on the northwest coast of Spain. The seasonal variation in the different metals followed a similar pattern in both seaweeds and appeared to be caused by dilution during the period of maximum growth and concentration during periods of slow growth. Fluvial inputs of Al, Fe and Mn in autumn and winter appeared to accentuate the latter effect: the concentrations of these three metals in both macroalgae and of Cr in Enteromorpha were highest at those sites most influenced by inputs from rivers. The background levels of Cr, Cu, Ni and Zn in the algae in summer and winter were established.     

Determination of 2-butoxyethanol emissions from selected consumer products and its application in assessment of inhalation exposure associated with cleaning tasks

Consumer products are important sources of human exposure to certain chemicals. Recent regulatory requirements for assessing human exposure to three glycol ethers, namely 2-methoxyethanol (ME), 2-ethoxyethanol (EE) and 2-butoxyethanol (BE), have prompted the investigation of these chemicals in consumer products and their emission characteristics. Thirteen products were selected for investigation based on their potential of containing the chemicals. Headspace results indicated that ME and EE were not present in any of the 13 selected products, while BE was detected in the headspace samples of seven products, of which five were household cleaning agents. Other related compounds such as 2-hexyloxyethanol (HE) and 2-(2-butoxyethoxy)ethanol (BEE) were also detected in the headspace samples of some products. BE emissions from five cleaning related products were measured using a field and laboratory emission cell (FLEC) with its subunit to provide emission data for inhalation exposure assessment purposes. These products had initial emission factors ranging from 145 to 938 mg m(-2) h(-1) under the experimental conditions. It was found that the emission factor of BE was inversely proportional to the dilution factor of the products. A good relationship was established between the emission factor of BE and its concentrations in water-based products. Based on product use scenarios developed by US EPA and an assumed "standard room," average daily inhalation exposure levels of a resident as a result of performing cleaning tasks were estimated to be 0.075 and 0.186 mg (kg b.w.)(-1) day(-1) for two all-purpose spray cleaners, and 0.004 and 0.006 mg (kg b.w.)(-1) day(-1) for two-spray glass cleaners, respectively.