Evaluation of health risks from a buried mass of diesel fuel before and after bioremediation

Plans are being formulated for in situ bioremediation of a subsurface plume of diesel fuel No. 2 that resulted from an accidental fuel release. Raoult's law and the aqueous solubilities of the toxic components were used to estimate organic contaminant concentrations in leachate from the untreated fuel mass. Carcinogenic risks and noncarcinogenic hazard indices were calculated for undiluted leachate. An 80% decrease in hydrocarbon mass and increases in the average molecular weights of the component fractions were assumed to result from the treatment. Sample calculations are provided to show how to evaluate results of analyses for petroleum hydrocarbons after bioremediation.     

杭州西湖水质预测方法和结果分析

本文利用二维对流扩散模型对西湖水质总磷浓度进行预测,给出方程的理论基础,编制FORTRAN77程序,在386微机上实现预测,并对预测结果作了较为详细的分析．本模型对水质环境防治决策具有实际意义．     

INTRACELLULAR LOCALIZATION OF THE TASTE/ODOR METABOLITE 2-METHYLISOBORNEOL IN OSCILLATORIA LIMOSA (CYANOPHYTA)1

The monoterpene derivative, 2-methylisoborneol (MIB), is produced by many blue-green algae and often is responsible for the “musty” taste/odor in aquaculturally raised finfish and potable water supplies. Although previous researchers have suggested that taste/odor metabolites are partitioned among cell constituents and that coregulation with pigment biosynthesis occurs, no structural evidence for these hypotheses exists. MIB was localized in cells of Oscillatoria limosa (Roth) Agardh at the ultrastructural level using standard gold-labeled antibody techniques. There was no apparent relationship between age of the cells and MIB synthesis; cells that were and were not undergoing active division had similar amounts of MIB label. There was no consistent partitioning of MIB label within cells. However, occasionally, specific label was observed along photosynthetic lamellae, suggesting a potential linkage of MIB synthesis and/or binding to the pigment systems.     

青皮核桃采后病害生防菌贝莱斯芽胞杆菌XRD006全基因组分析及防治效果研究

【目的】探究生防菌贝莱斯芽胞杆菌(Bacillus velezensis) XRD006对青皮核桃采后病害的生防能力及其贮藏保鲜效果,解析菌株的基因特性和次级代谢产物,了解菌株的抑菌机制。【方法】通过抑菌试验确定XRD006对青皮核桃采后病原菌的抑制能力。利用活体抑菌及贮藏试验探究生防菌对青皮核桃采后病原菌的抑制能力及对青皮核桃贮藏品质的影响。以全基因组测序了解菌株XRD006的基因组特征及潜在抑菌相关基因;利用antiSMASH软件预测XRD006的次级代谢产物;结合比较基因组学分析XRD006和贝莱斯芽胞杆菌标准株FZB42、SQR9之间的共线性关系和次级代谢产物基因簇差异。利用高效液相色谱(high performance liquid chromatography,HPLC)和质谱鉴定XRD006次级代谢产物并通过牛津杯法测定其抑菌能力。【结果】抑菌试验表明菌株XRD006对青皮核桃采后病原菌隐秘刺盘孢(Colletotrichum aenigma)、暹罗炭疽菌(Colletotrichum siamense)、葡萄座腔菌(Botryosphaeria dothidea)和藤仓...     

Prediction of near-term climate change impacts on UK wheat quality and the potential for adaptation through plant breeding

Wheat is a major crop worldwide, mainly cultivated for human consumption and animal feed. Grain quality is paramount in determining its value and downstream use. While we know that climate change threatens global crop yields, a better understanding of impacts on wheat end-use quality is also critical. Combining quantitative genetics with climate model outputs, we investigated UK-wide trends in genotypic adaptation for wheat quality traits. In our approach, we augmented genomic prediction models with environmental characterisation of field trials to predict trait values and climate effects in historical field trial data between 2001 and 2020. Addition of environmental covariates, such as temperature and rainfall, successfully enabled prediction of genotype by environment interactions (G × E), and increased prediction accuracy of most traits for new genotypes in new year cross validation. We then extended predictions from these models to much larger numbers of simulated environments using climate scenarios projected under Representative Concentration Pathways 8.5 for 2050–2069. We found geographically varying climate change impacts on wheat quality due to contrasting associations between specific weather covariables and quality traits across the UK. Notably, negative impacts on quality traits were predicted in the East of the UK due to increased summer temperatures while the climate in the North and South-west may become more favourable with increased summer temperatures. Furthermore, by projecting 167,040 simulated future genotype–environment combinations, we found only limited potential for breeding to exploit predictable G × E to mitigate year-to-year environmental variability for most traits except Hagberg falling number. This suggests low adaptability of current UK wheat germplasm across future UK climates. More generally, approaches demonstrated here will be critical to enable adaptation of global crops to near-term climate change.     

Carryover effects from environmental change in early life: An overlooked driver of the amphibian extinction crisis?

Ecological carryover effects, or delayed effects of the environment on an organism's phenotype, are central predictors of individual fitness and a key issue in conservation biology. Climate change imposes increasingly variable environmental conditions that may be challenging to early life-history stages in animals with complex life histories, leading to detrimental physiological and fitness effects in later life. Yet, the latent nature of carryover effects, combined with the long temporal scales over which they can manifest, means that this phenomenon remains understudied and is often overlooked in short-term studies limited to single life-history stages. Herein, we review evidence for the physiological carryover effects induced by elevated ultraviolet radiation (UVR; 280–400 nm) as a potential contributor to recent amphibian population declines. UVR exposure causes a suite of molecular, cellular and physiological consequences known to underpin carryover effects in other taxa, but there is a lack of research linking embryonic and larval UVR exposures to fitness consequences post-metamorphosis in amphibians. We propose that the key impacts of UVR on disease-related amphibian declines are facilitated through carryover effects that bridge embryonic and larval UVR exposure with potential increased disease susceptibility post-metamorphosis. We conclude by identifying a practical direction for the study of ecological carryover effects in amphibians that could guide future ecological research in the broader field of conservation physiology. Only by addressing carryover effects can many of the mechanistic links between environmental change and population declines be elucidated.     

Cover crops do not increase soil organic carbon stocks as much as has been claimed: What is the way forward?

When compared to virgin land (forest and grassland), croplands store significantly lower amounts of organic carbon (OC), mainly as a result of soil tillage, and decreased plant inputs to the soil over the whole year. Doubts have been expressed over how much reduced and zero tillage agriculture can increase OC in soils when the whole soil profile is considered. Consequently, cover-crops that are grown in-between crops instead of leaving soils bare appear as the “last man standing” in our quest to enhance cropland OC stocks. Despite the claim by numerous meta-analyses of a mean carbon sequestration rate by cover crops to be as high as 0.32 ± 0.08 ton C ha⁻¹ year⁻¹, the present analysis showed that all of the 37 existing field studies worldwide only sampled to a depth of 30 cm or less and did not compare treatments on the basis of equivalent soil mass. Thirteen studies presented information on OC content only and not on OC stocks, had inappropriate controls (n = 14), had durations of 3 years or lower (n = 5), considered only one to two data points per treatment (n = 4), or used cover crops as cash crops (i.e., grown longer that in-between two crops) instead of catch crops (n = 2), which in all cases constitutes shortcomings. Of the remaining six trials, four showed non-significant trends, one study displayed a negative impact of cover crops, and one study displayed a positive impact, resulting in a mean OC storage of 0.03 ton ha⁻¹ year⁻¹. Models and policies should urgently adapt to such new figure. Finally, more is to be done not only to improve the design of cover-crop studies for reaching sound conclusions but also to understand the underlying reasons of the low efficiency of cover crops for improved carbon sequestration into soils, with possible strategies being suggested.     

Nitrogen addition promotes terrestrial plants to allocate more biomass to aboveground organs: A global meta-analysis

A significant increase in reactive nitrogen (N) added to terrestrial ecosystems through agricultural fertilization or atmospheric deposition is considered to be one of the most widespread drivers of global change. Modifying biomass allocation is one primary strategy for maximizing plant growth rate, survival, and adaptability to various biotic and abiotic stresses. However, there is much uncertainty as to whether and how plant biomass allocation strategies change in response to increased N inputs in terrestrial ecosystems. Here, we synthesized 3516 paired observations of plant biomass and their components related to N additions across terrestrial ecosystems worldwide. Our meta-analysis reveals that N addition (ranging from 1.08 to 113.81 g m⁻² year⁻¹) increased terrestrial plant biomass by 55.6% on average. N addition has increased plant stem mass fraction, shoot mass fraction, and leaf mass fraction by 13.8%, 12.9%, and 13.4%, respectively, but with an associated decrease in plant reproductive mass (including flower and fruit biomass) fraction by 3.4%. We further documented a reduction in plant root-shoot ratio and root mass fraction by 27% (21.8%–32.1%) and 14.7% (11.6%–17.8%), respectively, in response to N addition. Meta-regression results showed that N addition effects on plant biomass were positively correlated with mean annual temperature, soil available phosphorus, soil total potassium, specific leaf area, and leaf area per plant. Nevertheless, they were negatively correlated with soil total N, leaf carbon/N ratio, leaf carbon and N content per leaf area, as well as the amount and duration of N addition. In summary, our meta-analysis suggests that N addition may alter terrestrial plant biomass allocation strategies, leading to more biomass being allocated to aboveground organs than belowground organs and growth versus reproductive trade-offs. At the global scale, leaf functional traits may dictate how plant species change their biomass allocation pattern in response to N addition.     

中国优质水果资源的分布与适宜生态环境

根据农业部在80年代两次组织评选出的全国189个优质水果产地的生态环境资料,用微型电子计算机系统建立数据库,统计分析柑桔、苹果和梨优质产品的构成比例、产区分布地域及其适宜的环境指标和主栽品种的生态适应性,为果树良种区域化栽培与选育提供依据。