Rsp5/Nedd4 clears cells of heat-damaged proteins

Protein quality control systems protect cells from proteotoxicity caused by the accumulation of aberrantly folded polypeptides. The Rsp5 ubiquitin ligase (mammalian homologue Nedd4) is now identified as a major constituent of a clearance pathway that degrades misfolded cytosolic proteins after exposure to heat

Large scale processing of seismic data in search of regional and global stress patterns

A composite compute program has been devised for a fast reduction of multistation seismic data in the period range 50–500 sec for mantle surface waves and 20–100 sec for body waves. The analysis aims at the reconstruction of the seismic source from the spectrum of its far radiation field and the correlation of its parameters with its depth, size and regional environment. The capability of the computational procedure has been demonstrated in two studies of WWNSS records: one includes a spectral analysis of surface waves from a shallow shock in the Kurile Islands; the other includes a spectral analysis of P waves from 9 shocks in the depth range 550–700 km at Fiji, Mariana, Java, Japan, Peru and Brazil. Other applications of the proposed data processing routine are foreseen; a tsunami warning system and focal depth determination from spectral modal ratios. It is believed that a persistent search for stress patterns, based on the processing of a sufficiently large sample of seismic events, is essential to any future program of earthquake prediction

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

Ertrag und Wurzelkolonisation mit arbuskulären Mykorrhiza- Pilzen von organisch oder mineralisch gedüngtem Weizen auf trockenem, sandigen Boden

We investigated wheat yield and arbuscular mycorrhiza (AM) fungal root colonization and spore formation in response to fertilization, either with high or low amounts of mineral fertilizer or cattle manure since 27 years. At low rates there was no difference in yield between minerally and organically fertilized plants. High rates of mineral fertilizers reduced yields. Reasons can be that either the high nitrogen availability was less effectively used for grain development of minerally fertilized plants, or the mineral fertilization rendered the plants more sensitive towards drought stress. The extent of AM fungal root colonization appeared to depend on the plant P nutritional status rather than the type of fertilizer applied. The lower fertilization showed higher rates of AM root colonization. The number of AM spores, however, was higher in organically compared with minerally fertilized soil, indicating that organic fertilization increased reproduction of these beneficial microbes under dry soil conditions

Yield and arbuscular myccorhiza fungal root colonization of organically or minerally fertilized wheat grown on a dry, sandy soil

We investigated wheat yield and arbuscular mycorrhiza (AM) fungal root colonization and spore formation in response to long-term mineral or organic soil fertilization. Plots were either fertilized with high or low amounts of mineral fertilizer or cattle manure since 27 years. At low fertilization levels there was no difference in yield between minerally and organically fertilized plants. High levels of mineral fertilizer application reduced wheat yields. Probable reasons can be that either the high nitrogen availability was less effectively used for grain development of minerally fertilized plants, or the mineral fertilization rendered the plants more sensitive towards drought stress. The extent of AM fungal root colonization appeared to depend on the plant P nutritional status rather than the type of fertilizer applied. The low fertilization treatments showed higher rates of AM root colonization. The number of AM spores, however, was higher in organically compared with minerally fertilized soil, indicating that organic fertilization increased reproduction of these beneficial microbes under dry soil conditions

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

A numerical model for meltwater channel evolution in glaciers

Meltwater channels form an integral part of the hydrological system of a glacier. Better understanding of how meltwater channels develop and evolve is required to fully comprehend supraglacial and englacial meltwater drainage. Incision of supraglacial stream channels and subsequent roof closure by ice deformation has been proposed in recent literature as a possible englacial conduit formation process. Field evidence for supraglacial stream incision has been found in Svalbard and Nepal. In Iceland, where volcanic activity provides meltwater with temperatures above 0 °C, rapid enlargement of supraglacial channels has been observed. Supraglacial channels provide meltwater through englacial passages to the subglacial hydrological systems of big ice sheets, which in turn affects ice sheet motion and their contribution to eustatic sea level change. By coupling, for the first time, a numerical ice dynamic model to a hydraulic model which includes heat transfer, we investigate the evolution of meltwater channels and their incision behaviour. We present results for different, constant meltwater fluxes, different channel slopes, different meltwater temperatures, different melt rate distributions in the channel as well as temporal variations in meltwater flux. The key parameters governing incision rate and depth are channel slope, meltwater temperature loss to the ice and meltwater flux. Channel width and geometry are controlled by melt rate distribution along the channel wall. Calculated Nusselt numbers suggest that turbulent mixing is the main heat transfer mechanism in the meltwater channels studied

Phosphorus (P) availability and P transformation rates in Amazonian Dark Earth determined by 33P isotopic dilution.

Amazonian Dark Earth (ADE) often shows increased soil fertility compared to surrounding soils, likely linked to its increased concentration of soil organic matter and macronutrients such as phosphorus (P). For P, there is little knowledge whether the higher P availability is a result of increased biological processes (such as organic P mineralization) or physico-chemical processes (such as sorption/desorption), or both

Nitrogen budgets and soil nitrogen stocks of organic and conventional cropping systems: how reconcile 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 (with level 2 being typical for the respective system and level 1 receiving half of this dose)

Der Vorteil von Stallmist gegenüber pflanzlichem organischem Dünger für den Ertrag von Rotklee und den Humusgehalt des Bodens

Die Wirkung pflanzlicher organischer Dünger (meist Leguminosenschrot) wurde bislang vorwiegend im Jahr der Anwendung, aber nicht als Langzeiteffekt auf Erträge und Bodenentwicklung untersucht. Ein direkter Vergleich mit Stallmist unter Feldbedingungen findet in der Regel nicht statt. Deshalb haben wir in einem Langzeitversuch (seit 1996) Stallmistdüngung, organische Dünger pflanzlicher Herkunft (meist Ackerbohnenschrot) und Mineraldüngung miteinander verglichen. In allen drei Schnitten brachte die Nachwirkung der pflanzlichen Dünger niedrigere Frisch- und Trockenmasse-Erträge als die N-gleichen Stallmistvarianten. Der Ertrag nach Mineraldüngung lag zwischen den beiden anderen Düngerarten, kam aber der Mistvariante meist näher als der Ackerbohnenvariante. Den insgesamt höchsten Ertrag lieferte Rotklee nach Stallmist in höherer Aufwandmenge. Die gleiche Differenzierung zeigten zuvor schon die Humusgehalte. Auch hier lag die pflanzliche organische Düngung mit 0,74 % Corg statistisch auf dem Niveau der Mineraldüngung