Effect of incorporated or mulched compost on leaf nutrient concentrations and performance of Vitis vinifera cv. Merlot

Compost can reduce evaporation and increase nutrient uptake by plants, but it is not clear if it can increase soil water holding capacity or stimulate leaf gas exchange, water use efficiency and yield of vines. To study these effects, compost from garden and food waste was incorporated or mulched in a vineyard at a rate of 100 m3 ha-1, three months before the measurements. The vineyard received irrigation during spring and summer. Soil water content was monitored regularly with a capacitance probe. Photosynthesis, transpiration, stem water potential and leaf area index were measured several times during the vegetation period. At harvest, yield, berry weight and quality as well as chlorophyll, N, P and K concentrations in leaves were determined. Only mulched compost increased soil water content at 10 cm depth, but the water content in the deeper layers was not affected by compost addition. Compost also did not affect transpiration rate and stomatal conductance during the vegetation period, but mulched compost increased the photosynthesis per plant at flowering, pea size and maturity periods. Compost amendment, particularly mulching, increased yield, specific berry weight, and leaf N and P concentrations, and reduced the number of chlorotic leaves at harvest. Berry quality was not affected by compost amendment. It can be concluded that mulched compost has a positive effect on grapevine yield and can be an alternative fertiliser source for vines with no adverse effect on berry quality.T.-T. Nguyen, S. Fuentes, P. Marschne

Vegetable production, consumption and its contribution to diets along the urban – rural continuum in Northern Ghana

Malnutrition continues to be a problem, with sub-Saharan Africa affected the worst. Women and children are at the pinnacle of this problem. The perpetual scourge of malnutrition in urban and periurban settings, coupled with levels of vegetable consumption below the recommended amounts, are a major problem in most African countries including West African cities. A household survey was conducted between November and December 2013 (dry season) in and around Tamale, Ghana as part of an urban food system analysis, to understand vegetable production and consumption and its contribution to household diets and income along the urban – rural continuum. Data collection was guided by a transect approach. A total of 240 households participated in the survey, with 62% males and 38% females. Additionally, 186 women of reproductive age (15 – 49 years) staying in the sampled households contributed to the computing of household dietary diversity through Women’s Dietary Diversity Scores (WDDS). Most vegetables produced were for subsistence use, considering that most households sold less than 50% of the crops and consumed the rest. Vegetable production varied significantly along the urban - rural continuum, with more households in rural areas producing all the requirements of their vegetables compared to urban and periurban areas. Nevertheless, the households in the rural areas (16%) had the lowest dietary diversity (≤ 3 WDDS) compared to urban areas (13%) and periurban areas (5%). The study showed low consumption of vegetables (especially the dark green vegetables) mostly in the rural area and limited diversity of vegetables, especially vitamin A rich vegetables and tubers, with only three vegetables (carrots, red pepper and sweet potato) consumed. There was evidence of more inclination toward staple crops compared to vegetables along the urban – rural continuum for both production and consumption, clearly shown in crops grown and food groups mostly consumed (cereals and tubers rather than dark green vegetables). There was overall low consumption of dark green leafy vegetables, such as amaranth, with only 26% reported to have consumed them during the reported period compared to food groups like cereals (98%). This study confirms the dual purpose of vegetables in complementing dishes (balanced diets) with much needed micronutrients and helping households along the urban – rural continuum to generate income.Keywords: Vegetables, dietary diversity, food groups, urban – rural continuum, Northern Ghan

Altered function of ventral striatum during reward-based decision making in old age

Normal aging is associated with a decline in different cognitive domains and local structural atrophy as well as decreases in dopamine concentration and receptor density. To date, it is largely unknown how these reductions in dopaminergic neurotransmission affect human brain regions responsible for reward-based decision making in older adults. Using a learning criterion in a probabilistic object reversal task, we found a learning stage by age interaction in the dorsolateral prefrontal cortex (dlPFC) during decision making. While young adults recruited the dlPFC in an early stage of learning reward associations, older adults recruited the dlPFC when reward associations had already been learned. Furthermore, we found a reduced change in ventral striatal BOLD signal in older as compared to younger adults in response to high probability rewards. Our data are in line with behavioral evidence that older adults show altered stimulus–reward learning and support the view of an altered fronto-striatal interaction during reward-based decision making in old age, which contributes to prolonged learning of reward associations

Basic material and technology investigations for material bonded hybrids by continuous hybrid profile fabrication

The development of multi-material hybrids by injection molding has been studied very intensively at the IPF in the past. For that, a material bonding between the different substrates was achieved by using a newly developed two-step curing powder coating material as latent reactive adhesive. The aim of the project “Hybrid Pultrusion” was to perform a novel approach for the fabrication of material bonded metal-plastic joints (profiles) in a modified pultrusion process. Therefore, powder pre-coated steel coil is combined with a glass-fiber reinforced epoxy resin matrix. For initial basic studies, the impregnated fiber material has been applied on the pre-coated steel sheets using the Resin Transfer Molding process (RTM-process). It was proved via lap shear tests, that this procedure resulted in very high adhesive strengths up to 35 MPa resulting from the formation of a covalent matrix-steel bonding as well. In addition, the failure mechanism was subsequently studied. Furthermore, by adapting the successful material combination to the pultrusion process it was demonstrated that material bonded hybrids can be achieved even under these continuous processing conditions

Iso-osmotic regulation of nitrate accumulation in lettuce (Lactuca sativa L.)

Concerns about possible health hazards arising from human consumption of lettuce and other edible vegetable crops with high concentrations of nitrate have generated demands for a greater understanding of processes involved in its uptake and accumulation in order to devise more sustainable strategies for its control. This paper evaluates a proposed iso-osmotic mechanism for the regulation of nitrate accumulation in lettuce (Lactuca sativa L.) heads. This mechanism assumes that changes in the concentrations of nitrate and all other endogenous osmotica (including anions, cations and neutral solutes) are continually adjusted in tandem to minimise differences in osmotic potential of the shoot sap during growth, with these changes occurring independently of any variations in external water potential. The hypothesis was tested using data from six new experiments, each with a single unique treatment comprising a separate combination of light intensity, N source (nitrate with or without ammonium) and nitrate concentration carried out hydroponically in a glasshouse using a butterhead lettuce variety. Repeat measurements of plant weights and estimates of all of the main soluble constituents (nitrate, potassium, calcium, magnesium, organic anions, chloride, phosphate, sulphate and soluble carbohydrates) in the shoot sap were made at intervals from about 2 weeks after transplanting until commercial maturity, and the data used to calculate changes in average osmotic potential in the shoot. Results showed that nitrate concentrations in the sap increased when average light levels were reduced by between 30 and 49 % and (to a lesser extent) when nitrate was supplied at a supra-optimal concentration, and declined with partial replacement of nitrate by ammonium in the external nutrient supply. The associated changes in the proportions of other endogenous osmotica, in combination with the adjustment of shoot water content, maintained the total solute concentrations in shoot sap approximately constant and minimised differences in osmotic potential between treatments at each sampling date. There was, however, a gradual increase in osmotic potential (ie a decline in total solute concentration) over time largely caused by increases in shoot water content associated with the physiological and morphological development of the plants. Regression analysis using normalised data (to correct for these time trends) showed that the results were consistent with a 1:1 exchange between the concentrations of nitrate and the sum of all other endogenous osmotica throughout growth, providing evidence that an iso-osmotic mechanism (incorporating both concentration and volume regulation) was involved in controlling nitrate concentrations in the shoot

Enzyme in Bewegung ? - Verlagerung von extrazellulären Enzymen mit dem Sickerwasser

Extrazelluläre Enzyme tragen wesentlich zum Umsatz organischen Materials im Boden bei. Durch die Bestimmung Ihrer Aktivität können Aussagen zum Nährstoffstatus und Umsatzbedingungen im Boden getroffen werden. Die meisten Studien, die sich bisher mit Aktivitäten von extrazellulären Enzymen beschäftigt haben, legten ihren Fokus auf die Rolle und Funktion der Enzyme im Nährstoffumsatz, wohingegen nur wenige Studien Verlagerungen von Enzymen, zum Beispiel mit dem Sickerwasserstrom untersuchten. Durch eine mögliche Verlagerung können extrazelluläre Enzyme in tiefere Horizonte des Bodens eingetragen werden und hier zum Abbau der nur in geringen Mengen vorhandenen organischen Substanz beitragen. Um diesen möglichen Eintrag abschätzen zu können, werden im Rahmen der SUBSOM-Forschergruppe Sickerwasserproben aus drei unterschiedlichen Tiefen (10, 50, 150cm) einer Braunerde unter Buchenwald (40km nordwestlich von Hannover, Niedersachsen) entnommen. Die Sickerwasserproben wurden mit Hilfe von Saugplatten aus drei am Standort eingebauten Lysimetern (Durchmesser: 1,5m; Tiefe: 2,00m) gewonnen und anschließend im Hinblick auf die Aktivität unterschiedlicher extrazellulärer Enzyme aus dem C-, N-, und P-Kreislauf im Labor analysiert. Vorläufige Ergebnisse zeigen, dass die Gesamtaktivität der extrazellulären Enzyme im Sickerwasser in allen Tiefen mit 0,59-371 pmol ml h-1 im Vergleich zum Boden sehr gering ist. Die Aktivitäten von β-Xylosidase und Leucine-Aminopeptidase konnten in allen Tiefen nachgewiesen werden, während Phosphatase nur in Tiefe 10 und 50cm aktiv war. Im oberen Unterboden (10cm) konnten keine Aktivitäten von Sulfatase, α-Glucosidase, β-Cellobiosidase, Arginin-Aminopeptidase and Tyrosin-Aminopeptidase gemessen werden, obwohl sie in der Tiefe 50 und 150cm wieder auftraten. Generell zeigte sich, dass extrazelluläre Enzyme im Sickerwasser aktiv sind und somit in tiefere Bodenhorizonte verlagert werden können und dort zum Nährstoffumsatz beitragen könnten

Sketch-based modeling with a differentiable renderer

© 2020 The Authors. Computer Animation and Virtual Worlds published by John Wiley & Sons, Ltd. Sketch-based modeling aims to recover three-dimensional (3D) shape from two-dimensional line drawings. However, due to the sparsity and ambiguity of the sketch, it is extremely challenging for computers to interpret line drawings of physical objects. Most conventional systems are restricted to specific scenarios such as recovering for specific shapes, which are not conducive to generalize. Recent progress of deep learning methods have sparked new ideas for solving computer vision and pattern recognition issues. In this work, we present an end-to-end learning framework to predict 3D shape from line drawings. Our approach is based on a two-steps strategy, it converts the sketch image to its normal image, then recover the 3D shape subsequently. A differentiable renderer is proposed and incorporated into this framework, it allows the integration of the rendering pipeline with neural networks. Experimental results show our method outperforms the state-of-art, which demonstrates that our framework is able to cope with the challenges in single sketch-based 3D shape modeling