Soil structure formation through the action of plants

During soil formation, the interaction of different biota (plants, soil fauna, microbes) with weathered mineral material shape unique structures depending on the parental material and the site specific climatic conditions. We here explore soil structure formation on a chronosequence in Rheinisch lignite mining area. In this area loess material from a depth of 4-10 m is used for reclamation in a standardized procedure since 24 years. Thus, it is an ideal site for studying soil structure formation as a function of time. Changes in soil pore system are characterised by parameters such as tortuosity, connectivity and pore size distribution. To derive these, undisturbed soil columns with a diameter of 10 cm were taken from two different depths (0-20 cm and 40-60 cm) with sites ranging in age from 0 to 24 years. X-ray CT is used for scanning the original columns as well as undisturbed subsamples of 3 and 1 cm diameter. This hierarchical sampling scheme was developed to overcome the trade-off between sample size and resolution – starting with an effective resolution of 57 µm for 10 cm cores via 19 µm for 3 cm columns to 6 µm for the smallest samples size of 1 cm. Subsamples therefore reveal information on micropores and small roots. The importance of roots for soil structure / pore system development in not only investigated in the CT images but also by destructive analyses and determination of root length with WinRHIZO The dataset is complemented by HYPROP measurements of water retention curves and unsaturated hydraulic conductivities; both functions of the pore system. In cooperation with project partners, VisNIR images from different slices of the soil columns will be taken to combine information about the local distribution of chemical features (iron oxides and organic compounds) with structural information of pores and roots. The current study is part of the DFG-Project Soil Structure (AOBJ: 628683)

Role of soil spatial organization for replant disease

Apple replant disease (ARD) is a complex phenomenon that affects young trees in replanted orchard sites causing necrotic lesions on roots, stunted tree growth and reduced yields (1). One assumption to explain this phenomenon is that through soil cultivation spatial organization/differentiation created by previous crops is lost and hence new roots cannot grow in favorable sites or avoid unfavorable sites. Unfavorable conditions could be high toxin concentrations, signaling substances or high number and abundance of pathogens. The aim of our work is to detect the spatial distribution of possible ARD causing factors, both in the bulk soil and in the rhizosphere. Therefore 4 different treatments consisting of acryl glass cylinders filled with undisturbed ARD soil (intact field structure), homogenous ARD soil, sterilized homogenous ARD soil and virgin homogenous soil without expression of ARD (control) are established. The ARD and control soil were taken from Ellerhoop in southern Schleswig-Holstein. On each cylinder an apple seedling (M 26) is planted and grown for 4 weeks in a climate chamber. In situ measurements of roots and shoots were conducted during the experiment, i.e. determination of leaf area and SPAD value (amount of chlorophyll in leaves), extraction of soil solution. Furthermore apple root growth is observed in situ by X- ray computed tomography. After CT scanning, the observed root growth can be analysed in relation to soil structure and conclusions can be drawn on ARD causing factors and their spatial distribution in the soil. In addition, roots and shoots were sampled destructively after termination of the experiment. Destructive sampling enables the determination of leaf areas and root length and root diameters classes with WinRHIZO. Further chemical analysis of bulk and rhizosphere soil, nutrient analysis of shoots and determination of pH, conductivity and chemical compounds of soil solution will be conducted. The experimental approach and first results on root and shoot growth in the different treatments will be presented

Soil texture is a stronger driver of the maize rhizosphere microbiome and extracellular enzyme activities than soil depth or the presence of root hairs

Aims Different drivers are known to shape rhizosphere microbiome assembly. How soil texture (Texture) and presence or lack of root hairs (Root Hair) of plants affect the rhizosphere microbiome assembly and soil potential extracellular enzyme activities (EEA) at defined rooting depth (Depth) is still a knowledge gap. We investigated effects of these drivers on microbial assembly in rhizosphere and on potential EEA in root-affected soil of maize. Methods Samples were taken from three depths of root hair defective mutant rth3 and wild-type WT maize planted on loam and sand in soil columns after 22 days. Rhizosphere bacterial, archaeal, fungal and cercozoan communities were analysed by sequencing of 16S rRNA gene, ITS and 18S rRNA gene fragments. Soil potential EEA of ss-glucosidase, acid phosphatase and chitinase were estimated using fluorogenic substrates. Results The bacterial, archaeal and cercozoan alpha- and beta-diversities were significantly and strongly altered by Texture, followed by Depth and Root Hair. Texture and Depth had a small impact on fungal assembly, and only fungal beta-diversity was significantly affected. Significant impacts by Depth and Root Hair on beta-diversity and relative abundances at taxonomic levels of bacteria, archaea, fungi and cercozoa were dependent on Texture. Likewise, the patterns of potential EEA followed the trends of microbial communities, and the potential EEA correlated with the relative abundances of several taxa. Conclusions Texture was the strongest driver of rhizosphere microbiome and of soil potential EEA, followed by Depth and Root Hair, similarly to findings in maize root architecture and plant gene expression studies

Percent error of ultrasound examination to estimate fetal weight at term in different categories of birth weight with focus on maternal diabetes and obesity

Background: Sonography based estimate of fetal weight is a considerable issue for delivery planning. The study evaluated the influence of diabetes, obesity, excess weight gain, fetal and neonatal anthropometrics on accuracy of estimated fetal weight with respect to the extent of the percent error of estimated fetal weight to birth weight for different categories. Methods: Multicenter retrospective analysis from 11,049 term deliveries and fetal ultrasound biometry performed within 14 days to delivery. Estimated fetal weight was calculated by Hadlock IV. Percent error from birth weight was determined for categories in 250 g increments between 2500 g and 4500 g. Estimated fetal weight accuracy was categorized as accurate +/- 10% - +/- 20% and > 20%. Results: Diabetes was diagnosed in 12.5%, obesity in 12.6% and weight gain exceeding IOM recommendation in 49.1% of the women. The percentage of accurate estimated fetal weight was not significantly different in the presence of maternal diabetes (70.0% vs. 71.8%, p = 0.17), obesity (69.6% vs. 71.9%, p = 0.08) or excess weight gain (71.2% vs. 72%, p = 0.352) but of preexisting diabetes (61.1% vs. 71.7%; p = 0.007) that was associated with the highest macrosomia rate (26.9%). Mean percent error of estimated fetal weight from birth weight was 2.39% +/- 9.13%. The extent of percent error varied with birth weight with the lowest numbers for 3000 g-3249 g and increasing with the extent of birth weight variation: 5% +/- 11% overestimation in the lowest and 12% +/- 8% underestimation in the highest ranges. Conclusion: Diabetes, obesity and excess weight gain are not necessarily confounders of estimated fetal weight accuracy. Percent error of estimated fetal weight is closely related to birth weight with clinically relevant over- and underestimation at both extremes. This work provides detailed data regarding the extent of percent error for different birth weight categories and may therefore improve delivery planning

Lithium-ion battery fast charging: A review

In the recent years, lithium-ion batteries have become the battery technology of choice for portable devices, electric vehicles and grid storage. While increasing numbers of car manufacturers are introducing electrified models into their offering, range anxiety and the length of time required to recharge the batteries are still a common concern. The high currents needed to accelerate the charging process have been known to reduce energy efficiency and cause accelerated capacity and power fade. Fast charging is a multiscale problem, therefore insights from atomic to system level are required to understand and improve fast charging performance. The present paper reviews the literature on the physical phenomena that limit battery charging speeds, the degradation mechanisms that commonly result from charging at high currents, and the approaches that have been proposed to address these issues. Special attention is paid to low temperature charging. Alternative fast charging protocols are presented and critically assessed. Safety implications are explored, including the potential influence of fast charging on thermal runaway characteristics. Finally, knowledge gaps are identified and recommendations are made for the direction of future research. The need to develop reliable in operando methods to detect lithium plating and mechanical degradation is highlighted. Robust model-based charging optimisation strategies are identified as key to enabling fast charging in all conditions. Thermal management strategies to both cool batteries during charging and preheat them in cold weather are acknowledged as critical, with a particular focus on techniques capable of achieving high speeds and good temperature homogeneities

Global Governance Behind Closed Doors : The IMF Boardroom, the Enhanced Structural Adjustment Facility, and the Intersection of Material Power and Norm Change in Global Politics

Up on the 12th floor of its 19th Street Headquarters, the IMF Board sits in active session for an average of 7 hours per week. Although key matters of policy are decided on in the venue, the rules governing Boardroom interactions remain opaque, resting on an uneasy combination of consensual decision-making and weighted voting. Through a detailed analysis of IMF Board discussions surrounding the Enhanced Structural Adjustment Facility (ESAF), this article sheds light on the mechanics of power in this often overlooked venue of global economic governance. By exploring the key issues of default liability and loan conditionality, I demonstrate that whilst the Boardroom is a more active site of contestation than has hitherto been recognized, material power is a prime determinant of both Executive Directors’ preferences and outcomes reached from discussions. And as the decisions reached form the backbone of the ‘instruction sheet’ used by Fund staff to guide their everyday operational decisions, these outcomes—and the processes through which they were reached—were factors of primary importance in stabilizing the operational norms at the heart of a controversial phase in the contemporary history of IMF concessional lending

Arsenite efflux is not enhanced in the arsenate-tolerant phenotype of Holcus lanatus

P>Arsenate tolerance in Holcus lanatus is achieved mainly through suppressed arsenate uptake. We recently showed that plant roots can rapidly efflux arsenite to the external medium. Here, we tested whether arsenite efflux is a component of the adaptive arsenate tolerance in H. lanatus. Tolerant and nontolerant phenotypes were exposed to different arsenate concentrations with or without phosphate for 24 h, and arsenic (As) speciation was determined in nutrient solutions, roots and xylem sap. At the same arsenate exposure concentration, the nontolerant phenotype took up more arsenate and effluxed more arsenite than the tolerant phenotype. However, arsenite efflux was proportional to arsenate uptake and was not enhanced in the tolerant phenotype. Within 2-24 h, most (80-100%) of the arsenate taken up was effluxed to the medium as arsenite. About 86-95% of the As in the roots and majority of the As in xylem sap (c. 66%) was present as arsenite, and there were no significant differences between phenotypes. Arsenite efflux is not adaptively enhanced in the tolerant phenotype H. lanatus, but it could be a basal tolerance mechanism to greatly decrease cellular As burden in both phenotypes. Tolerant and nontolerant phenotypes had a similar capacity to reduce arsenate in roots. New Phytologist (2009) 183: 340-348doi: 10.1111/j.1469-8137.2009.02841.x

Awareness and perception of multidrug-resistant organisms and antimicrobial therapy among internists vs. surgeons of different specialties: Results from the German MR2 Survey

Background: Recently, antibiotic resistance rates have risen substantially and care for patients infected with multidrug-resistant organisms (MDRO) has become a common problem in most in – and outpatient settings. The objectives of the study were to compare the awareness, perception, and knowledge of MDRO and rational antibiotic use between physicians from different medical specialties in German hospitals. Methods: A 35-item questionnaire was sent to specialists in internal medicine (internists), gynecologists, urologists, and general surgeons (non-internists) in 18 German hospitals. Likert-scales were used to evaluate awareness and perception of personal performance regarding care for patients infected with MDRO and rational use of antibiotics. Additionally, two items assessing specific knowledge in antibiotic therapy were included. The impact of medical specialty on four predetermined endpoints was assessed by multivariate logistic regression. Results: 43.0 (456/1061) of recipients responded. Both internists and non-internists had low rates of training in antibiotic stewardship. 50.8 of internists and 58.6 of non-internists had attended special training in rational antibiotic use or care for patients infected with MDRO in the 12 months prior to the study. Internists deemed themselves more confidently to choose the indications for screening patients for colonization with methicillin-resistant Staphylococcus aureus (P=0.004) and to initiate adequate infection control measures (P=0.002) than other specialties. However, there was no significant difference between internists and other specialists regarding the two items assessing specific knowledge in antibiotic therapy and infection control. Conclusion: Among the study participants, a considerable need for advanced training in the study subjects was seen, regardless of the medical specialty