Simultaneous adoption of integrated soil fertility management technologies in the Chinyanja Triangle,Southern Africa

Empirical scientific evidence indicates that there is still room for increasing food production by improving land productivity. This study aimed at identifying the key determinants that govern farmers’ decisions to adopt multiple components of integrated soil fertility management (ISFM) in a maize mixed cropping system of the Chinyanja Triangle, Southern Africa. Revealed preferences of ISFM components were collected from 320 randomly selected households and multivariate probit (MVP) model was used to analyse the simultaneous effects on adoption based on biophysical plot and household‐level socioeconomic attributes. The results show that farmers’ choices of a set of ISFM components are determined by a mix of factors that address the trade‐offs and synergies among them. Non‐farm income, moderate land quality perception, and education influence simultaneous technology adoption, while gender and crop loss increase the likelihood of farmers’ decisions to adopt independent options. Having other sources of income supports co‐adoption of inorganic fertilizer, residue incorporation, and crop rotation. Input/output market access, access to information, financial sources, and climate variability also play pivotal role in technology adoption. These results indicate that resource availability, learning costs, finances, and risk aversion need to be considered when designing and promoting ISFM technologies as a package.     

New epizooic symbioses between sponges of the genera Plakortis and Xestospongia in cryptic habitats of the Caribbean

Three new cases of sponge symbiosis between species of Plakortis and Xestospongia were found in reef caves and mesophotic reef habitats of the Caribbean. Plakortis sp. 1 from the Bahamas associates exclusively with Xestospongia deweerdtae which was originally described living freely on the deep fore-reef and caves of Jamaica. In addition, we found Plakortis sp. 2 from Puerto Rico which associates with both X. deweerdtae and a different Xestospongia sp. Sponge specimens were identified using cytochrome oxidase subunit 1, 28S rRNA and 18S rRNA gene sequence fragments, spicule analysis, and histological sections with SEM. Unlike previous sponge pairs, Xestospongia spp. not only grew as a thin veneer of tissue over the Plakortis host sponge but through the mesohyl, forming inner channels (0.1–1 cm) that may provide a benefit by facilitating more efficient water transport through the dense Plakortis tissue. Symbioses with both Plakortis spp. were documented from an early recruit stage through adulthood. Spicule measurements conducted on symbiotic versus free-living X. deweerdtae revealed significantly smaller spicule sizes for symbiotic individuals, suggesting a cost in terms of silicon availability, or a benefit in terms of a lower investment in skeleton synthesis for support. This study reveals new specialized symbiotic associations between distantly related sponge genera that likely represent an alternative strategy of adaptation for life in reef caves and mesophotic reefs.     

奶牛粪便翻堆式与槽式堆肥过程气体排放规律及养分损失原位监测

为探究奶牛粪便翻堆式与槽式堆肥过程中温室气体和氨气(NH₃)排放规律及养分损失情况,采用原位监测的方法,通过静态采气箱和气体在线监测设备,分别对奶牛粪便翻堆式和槽式堆体开展为期36 d的气体监测。结果表明,翻堆式堆肥过程中甲烷(CH₄)、氧化亚氮(N2_O)和NH₃排放主要集中于翻堆阶段;槽式堆肥过程中CH₄和NH₃排放主要集中于堆肥前期,N2_O排放则主要集中于堆肥中后期。堆体管理措施及物料特性显著影响堆肥气体的排放。翻堆式堆肥过程中翻堆对气体排放的影响大于堆肥理化因子如温度、含水率以及pH值;而槽式堆肥过程中,降低堆体的平均温度可同时减缓堆肥过程中CH₄、二氧化碳(CO₂)和NH₃的释放。从养分损失来看,翻堆式和槽式堆肥过程中碳素总损失量分别占堆肥物料初始总碳含量(TC)的27.16%和21.53%,其中约80%以上的碳素损失来自CO₂-C。而堆肥过程中氮素总损失量分别占堆肥物料初始总氮含量(TN)的18.67%和13.44%,其中约80%以上的氮素损失来源于NH₃N。该研究表明,在保证堆体物料腐熟的前提下,降低翻堆频率可显著减缓翻堆式堆肥过程中温室气体和NH₃的排放;降低槽式堆肥堆体的温度可显著减少堆肥过程中CH₄、CO₂和NH₃的排放。该研究结果对于减少堆肥过程气态污染物排放和养分损失,提高堆肥效率具有重要的指导意义。     

Microbial responses to combined oxidation and catalysis treatment of 1,4-dioxane and co-contaminants in groundwater and soil

Post-treatment impacts of a novel combined hydrogen peroxide (H₂O₂) oxidation and WO_x/ZrO₂ catalysis used for the removal of 1,4-dioxane and chlorinated volatile organic compound (CVOC) contaminants were investigated in soil and groundwater microbial community. This treatment train removed ~90% 1,4-dioxane regardless of initial concentrations of 1,4-dioxane and CVOCs. The Illumina Miseq platform and bioinformatics were used to study the changes to microbial community structure. This approach determined that dynamic shifts of microbiomes were associated with conditions specific to treatments as well as 1,4-dioxane and CVOCs mixtures. The biodiversity was observed to decrease only after oxidation under conditions that included high levels of 1,4-dioxane and CVOCs, but increased when 1,4-dioxane was present without CVOCs. WO_x/ZrO₂ catalysis reduced biodiversity across all conditions. Taxonomic classification demonstrated oxidative tolerance for members of the genera Massilia and Rhodococcus, while catalyst tolerance was observed for members of the genera Sphingomonas and Devosia. Linear discriminant analysis effect size was a useful statistical tool to highlight representative microbes, while the multidimensional analysis elucidated the separation of microbiomes under the low 1,4-dioxane-only condition from all other conditions containing CVOCs, as well as the differences of microbial population among original, post-oxidation, and post-catalysis states. The results of this study enhance our understanding of microbial community responses to a promising chemical treatment train, and the metagenomic analysis will help practitioners predict the microbial community status during the post-treatment period, which may have consequences for long-term management strategies that include additional biodegradation treatment or natural attenuation.

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高残留农药福美双对斑马鱼胚胎脊索的特异性影响

福美双在我国是一种广泛使用的二硫代甲氨基甲酸盐类农药,它的高残留性已经引起世界各国的重视. 以斑马鱼胚胎作为试验动物模型,从分子水平探讨了福美双对胚胎脊索弯曲的毒性作用机制.结果表明,福美双造成斑马鱼胚胎脊索弯曲与重叠等形态学变化,脊索弯曲程度与福美双的染毒浓度呈正相关. 通过Ⅱ型胶原蛋白抗体染色表明,福美双引起软骨发育的变化与Ⅱ型胶原蛋白表达的降低密切相关. 试验进一步表明,斑马鱼胚胎适合作为农药毒性评价的模型.      

渭南市道路移动源高分辨污染物排放清单及特征研究

应用MOVES-2014a模型并对其输入参数进行了本地化修正,计算了 2018年渭南市道路移动源污染物的排放因子和排放总量.基于渭南市路网分布和GIS信息及车流分布对污染物总排放量进行了空间和时间分配,建立了 1 km×1 km和l h分辨率的排放清单.结果表明,渭南市机动车排放CO、NMVOCs、NOx、NO2、NO...     

高海拔水电水库温室气体的排放特征——以雅鲁藏布江藏木水库为例

水电水库是大气温室气体的重要来源,在一定程度上影响着区域气候变化.然而目前关于水库温室气体排放的估算仍然存在很大的不确定性,一方面原因是缺失了世界各地山区水库的数据,另一方面原因是未将受水库影响的上下游河道考虑在内.本研究重点关注雅鲁藏布江流域水电水库——藏木水库丰枯水期CO2、CH4和N2O的溶存浓度与扩散通量的时空...     

High resolution proton NMR spectroscopy of human amniotic fluid

Human amniotic fluid (HAF) is a dynamic system whose characteristics depend on continuous interchanges between fetal and maternal circulations. HAF reflects not only the environment of the fetus but may also provide information about fetal development or pathology. The concentration of HAF constituents varies with gestational age and pathological states. The number of the compounds currently implicated in fetal developmental pathology are relatively few. Currently used assay methods are not adequate to totally explain or predict the complex biochemistry of the fetus. The purpose of this work was to investigate HAF with NMR spectroscopy. In the present study HAF was obtained from 47 women undergoing routine amniocentesis. Cells were separated for karyological analysis and the supernatant was acid-extracted, lyophilized and re-suspended in D₂0 resulting in a concentration increase over native fluid. ¹H NMR spectra were obtained at 360 MHz and 60 MHz. Eighteen compounds including several amino acids, were identified using parallel reference and standard addition protocols. NMR spectroscopy detected compounds of known clinical importance including glucose, leucine, isoleucine, lactate and creatinine. In conclusion, we have demonstrated that a number of physiologically relevant compounds are readily observable in HAF using ¹H NMR spectroscopy. This technique can currently provide valuable information regarding HAF composition and has the potential of being used in vivo in the future.     

Exceptionally high levels of multiple mating in an army ant

Most species of social insects have singly mated queens, although there are notable exceptions. Competing hypotheses have been proposed to explain the evolution of high levels of multiple mating, but this issue is far from resolved. Here we use microsatellites to investigate mating frequency in the army ant Eciton burchellii and show that queens mate with an exceptionally large number of males, eclipsing all but one other social insect species for which data are available. In addition we present evidence that suggests that mating is serial, continuing throughout the lifetime of the queen. This is the first demonstration of serial mating among social hymenoptera. We propose that high paternity within colonies is most likely to have evolved to increase genetic diversity and to counter high pathogen and parasite loads.     

A science of integration: frameworks,processes, and products in a place-based,integrative study

Integrative research is increasingly a priority within the scientific community and is a central goal for the evolving field of sustainability science. While it is conceptually attractive, its successful implementation has been challenging and recent work suggests that the move towards interdisciplinarity and transdisciplinarity in sustainability science is being only partially realized. To address this from the perspective of social-ecological systems (SES) research, we examine the process of conducting a science of integration within the Southcentral Alaska Test Case (SCTC) of Alaska-EPSCoR as a test-bed for this approach. The SCTC is part of a large, 5 year, interdisciplinary study investigating changing environments and adaptations to those changes in Alaska. In this paper, we review progress toward a science of integration and present our efforts to confront the practical issues of applying proposed integration frameworks. We: (1) define our integration framework; (2) describe the collaborative processes, including the co-development of science through stakeholder engagement and partnerships; and (3) illustrate potential products of integrative, social-ecological systems research. The approaches we use can also be applied outside of this particular framework. We highlight challenges and propose improvements for integration in sustainability science by addressing the need for common frameworks and improved contextual understanding. These insights may be useful for capacity-building for interdisciplinary projects that address complex real-world social and environmental problems.