Desorption of Water Soluble Phosphorus from Soil

A consecutive extraction method was developed which allows to determine the total amount of water soluble phosphorus in soil. For that, soil was shaken with deionized water, which was removed and replaced after one hour; this procedure was repeated ten times. The concentrations measured at each extraction step allow to quantify desorption of total water soluble phosphorus. Seven soils of the Ultuna long term soil organic matter experiment, Sweden, were used to test the method. Two additional soils from a horse paddock were used for method development. Soils treated with farmyard manure and sewage sludge showed the highest release of total water soluble phosphorus, whereas calcium nitrate and ammonium sulfate showed the lowest. Fallow, green manure and peat treatments showed intermediate release. The amount of total water soluble phosphorus was controlled by pH, total P and P-AL. The increase in potentially releasable water soluble P is about 20 per cent of total P but 55 per cent of P-AL in average among all soils tested. Data were compared with an earlier phosphorus fractionation of four of the soils used showing that all resin P and part of sodium bicarbonate P was released by consecutive extraction with water. The relative decline in consecutive P release was inversely related to the P quantity/intensity ratio. The estimation of total water soluble phosphorus obtained by the method showed that the actual availability of P in soil to plants seems not to be limited by chemical binding and release of P to the soil solution, but by the ability of plants to obtain P from the soil solution

In vitro selection using a dual RNA library that allows primerless selection

High affinity target-binding aptamers are identified from random oligonucleotide libraries by an in vitro selection process called Systematic Evolution of Ligands by EXponential enrichment (SELEX). Since the SELEX process includes a PCR amplification step the randomized region of the oligonucleotide libraries need to be flanked by two fixed primer binding sequences. These primer binding sites are often difficult to truncate because they may be necessary to maintain the structure of the aptamer or may even be part of the target binding motif. We designed a novel type of RNA library that carries fixed sequences which constrain the oligonucleotides into a partly double-stranded structure, thereby minimizing the risk that the primer binding sequences become part of the target-binding motif. Moreover, the specific design of the library including the use of tandem RNA Polymerase promoters allows the selection of oligonucleotides without any primer binding sequences. The library was used to select aptamers to the mirror-image peptide of ghrelin. Ghrelin is a potent stimulator of growth-hormone release and food intake. After selection, the identified aptamer sequences were directly synthesized in their mirror-image configuration. The final 44 nt-Spiegelmer, named NOX-B11-3, blocks ghrelin action in a cell culture assay displaying an IC(50) of 4.5 nM at 37°C

Nitrogen Budgets and Soil Nitrogen Stocks of Organic and Conventional Cropping Systems: Trade-Off between Efficiency and Sustainability of Nitrogen Use

Organic and conventional cropping systems differ in the nature and amounts of nitrogen (N) inputs, which may affect efficiency and sustainability of N use. In the DOK (bio-Dynamic, bio-Organic, Konventionell) field experiment, organic and conventional cropping systems have been compared since 1978 at two fertilization levels. Nitrogen inputs via manure and/or mineral fertilizers, and N exports from plots with harvested products have throughout been recorded. For all treatments, N outputs with harvests have exceeded the inputs with fertilizers. Over the past years, symbiotic N2 fixation by soybean and clover grown in the trial has additionally been assessed, indicating average annual inputs of about 100 kg ha-1 yr-1 of N fixed from the atmosphere. Soil surface budgets opposing N inputs via fertilization, symbiotic fixation, seeds and deposition to N outputs via harvested products have been computed at the plot level for the duration from 1985 to 2012. The resulting balances range from negative values of about -20 kg N ha-1 yr-1 (where outputs exceed the sum of said N inputs) to surpluses of about +50 kg N ha-1 yr-1. The budget based N use efficiency (NUE; N output via harvested products divided by sum of N inputs) in the case of negative balances suggests irrationally high NUE (>100%), while positive balances are related to lower NUE for treatments with inputs exceeding outputs. Negative balances, however, indicate soil N mining, while surpluses point to a risk of N losses, and/or N accumulation in the soil. Estimation of soil N stock changes based on yearly total N concentration measurements in the topsoil layer is currently ongoing. Preliminary results suggest that soil N stocks in the topsoil decreased under all treatments more than expected from the N balance, and that positive N balances are needed to maintain topsoil N stocks. An increase in soil N concentration was observed in none of the treatments. In conclusion, the results indicate an efficiency-sustainability trade-off. Treatments with a higher NUE lose more soil stock N than those with a lower NUE. Treatments with lower NUE indicate higher N losses from the studied crop-topsoil system. Sustainable soil N management in addition to organic fertilizer inputs might at this site require reduced soil tillage. The significance of N contained in deeper soil layers, and deep rooting crops in recovering leached N should as well be investigated

Soil phosphorus (P) budgets, P availability and P use efficiencies in conventional and organic cropping systems of the DOK trial

Cropping systems rely on the provision of adequate amounts of phosphorus (P) to enable stable crop yields. A balanced application of P is necessary to avoid reduced crop yields (in case of too low application rates), but also to avoid P losses to other ecosystems (in case of too high application rates). While in conventional cropping systems the use of synthetic P fertilizers is common practice, organic cropping systems mostly rely on organic P inputs such as farmyard manure or compost. We aimed to answer if different cropping systems attain balanced P application rates in the long run, and how plant P availability is affected by different cropping systems and forms of fertilizers applied

Millimeter-wave gas spectroscopy for breath analysis of COPD patients in comparison to GC-MS

The analysis of human breath is a very active area of research, driven by the vision of a fast, easy, and non-invasive tool for medical diagnoses at the point of care. Millimeter-wave gas spectroscopy (MMWGS) is a novel, well-suited technique for this application as it provides high sensitivity, specificity and selectivity. Most of all, it offers the perspective of compact low-cost systems to be used in doctors' offices or hospitals. In this work, we demonstrate the analysis of breath samples acquired in a medical environment using MMWGS and evaluate validity, reliability, as well as limitations and perspectives of the method. To this end, we investigated 28 duplicate samples from chronic obstructive lung disease patients and compared the results to gas chromatography-mass spectrometry (GC-MS). The quantification of the data was conducted using a calibration-free fit model, which describes the data precisely and delivers absolute quantities. For ethanol, acetone, and acetonitrile, the results agree well with the GC-MS measurements and are as reliable as GC-MS. The duplicate samples deviate from the mean values by only 6% to 18%. Detection limits of MMWGS depend strongly on the molecular species. For example, acetonitrile can be traced down to 1.8 × 10−12 mol by the MMWGS system, which is comparable to the GC-MS system. We observed correlations of abundances between formaldehyde and acetaldehyde as well as between acetonitrile and acetaldehyde, which demonstrates the potential of MMWGS for breath research.Deutsche Forschungsgemeinschafthttp://dx.doi.org/10.13039/501100001659Deutsches Zentrum für Lungenforschunghttp://dx.doi.org/10.13039/501100010564Peer Reviewe

The Multifunctional Challenge Of Future Agriculture – Answers From 40 Years Dok Research

"Achieving sufficient and stable crop yields with limited cropland and without excessive use of non-renewable resources under a changing climate are the multifunctional challenges of future agriculture. We compared the performance and sustainability of organic and conventional cropping systems in the DOK long-term systems comparison after 40 years of management. For the first time we present a comprehensive evaluation of the whole DOK design including the systems with reduced stocking rates. Yield, nutrient dynamic and soil quality evaluations show clearly the trade-offs between productivity and sustainability in organic as well as in conventional systems. Low input conventional systems reveal the best input-output performance but lowered soil quality; regular organic systems were most sustainable but achieved only moderate non-legume yields.

Umweltwirkung und Produktivität von biologischen und konventionellen Systemen - Ergebnisse aus 42 Jahre DOK Versuch

Ergebnisse aus 42 Jahren Systemvergleichsversuch im DOK (Therwil,CH) zeigen das biologische im Vergleich zu konventionellen Systemen kritische Umweltbelastungen (Biodiversität, Nährstoffe, Treibhausgasemissionen) reduzieren und dabei stabilen aber um 15% verringerten Ertrag erzielen

Simulating the effect of climatic variations on the long-term performance of different agroforestry systems within field trials using virtual experiments

Agroforestry systems can reduce some of the adverse effects of climate change in agriculture by e.g. serving as a windbreak or shade provider to protect crops or grazing livestock and supporting beneficial species for pest control. The prediction of the long-term performance of different agroforestry options is however difficult to obtain through field quantify experiments due to the length of time trees grow for experiments. Numerical modelling can contribute to a better understanding of a system’s performance, since the effect of different climatic alterations can be tested using virtual experiments for different periods of time. Within the Horizon 2020 AGROMIX project, we are analysing the long-term performance of eight different agroforestry trials (Figure 1), using different modelling approaches. The trials are spread over three biogeographic regions (Mediterranean, Continental, and Atlantic) and are of varying age (4 to 33 years). In total, six silvoarable and five silvopastoral farming systems are maintained at the eight field trials. Through the use of different numerical models the effect of changes in temperature and precipitation patterns or the occurrence of extreme events such as droughts or late spring frost on the different agroforestry systems will be predicted. Additionally, experimental data on crop performance as well as animal behaviour and welfare, in particular under heat stress, are being obtained and will potentially be included in the model predictions. This poster aims to give an overview on the field trials and the numerical modelling approaches that are being applied to predict long-term system performance

DNA methylation-based classification of sinonasal tumors

The diagnosis of sinonasal tumors is challenging due to a heterogeneous spectrum of various differential diagnoses as well as poorly defined, disputed entities such as sinonasal undifferentiated carcinomas (SNUCs). In this study, we apply a machine learning algorithm based on DNA methylation patterns to classify sinonasal tumors with clinical-grade reliability. We further show that sinonasal tumors with SNUC morphology are not as undifferentiated as their current terminology suggests but rather reassigned to four distinct molecular classes defined by epigenetic, mutational and proteomic profiles. This includes two classes with neuroendocrine differentiation, characterized by IDH2 or SMARCA4/ARID1A mutations with an overall favorable clinical course, one class composed of highly aggressive SMARCB1-deficient carcinomas and another class with tumors that represent potentially previously misclassified adenoid cystic carcinomas. Our findings can aid in improving the diagnostic classification of sinonasal tumors and could help to change the current perception of SNUCs