Nitrogen balances in farmers fields under alternative uses of a cover crop legume: a case study from Nicaragua

Canavalia brasiliensis (canavalia), a drought tolerant legume, was introduced into the smallholder traditional crop-livestock production system of the Nicaraguan hillsides as green manure to improve soil fertility or as forage during the dry season for improving milk production. Since nitrogen (N) is considered the most limiting nutrient for agricultural production in the target area, the objective of this study was to quantify the soil surface N budgets at plot level in farmers fields over two cropping years for the traditional maize/bean rotation and the alternative maize/canavalia rotation. Mineral fertilizer N, seed N and symbiotically fixed N were summed up as N input to the system. Symbiotic N₂ fixation was assessed using the ¹⁵N natural abundance method. Nitrogen output was quantified as N export via harvested products. Canavalia derived in average 69% of its N from the atmosphere. The amount of N fixed per hectare varied highly according to the biomass production, which ranged from 0 to 5,700 kg ha^?1. When used as green manure, canavalia increased the N balance of the maize/canavalia rotation but had no effect on the N uptake of the following maize crop. When used as forage, it bears the risk of a soil N depletion up to 41 kg N ha^?1 unless N would be recycled to the plot by animal manure. Without N mineral fertilizer application, the N budget remains negative even if canavalia was used as green manure. Therefore, the replenishment of soil N stocks by using canavalia may need a few years, during which the application of mineral N fertilizer needs to be maintained to sustain agricultural production.     

Functionalized gold nanoparticles: a detailed in vivo multimodal microscopic brain distribution study

In the present study, the in vivo distribution of polyelectrolyte multilayer coated gold nanoparticles is shown, starting from the living animal down to cellular level. The coating was designed with functional moieties to serve as a potential nano drug for prion disease. With near infrared time-domain imaging we followed the biodistribution in mice up to 7 days after intravenous injection of the nanoparticles. The peak concentration in the head of mice was detected between 19 and 24 h. The precise particle distribution in the brain was studied ex vivo by X-ray microtomography, confocal laser and fluorescence microscopy. We found that the particles mainly accumulate in the hippocampus, thalamus, hypothalamus, and the cerebral cortex.     

Feeding the city: food consumption and flow of nitrogen, Paris, 1801-1914

The flows of foodstuffs (and the nitrogen they contain) through the city of Paris in the 19th and early 20th century were evaluated. Between 1801 and 1914, the fivefold increase in the population of Paris, as well as the threefold increase in the number of horses used in urban transport, gave rise to increased needs for food and feed. The corresponding inputs of nitrogen increased from 6000 tN/year in 1817 to 25,000 tN/year from the rural hinterland to the city. The corresponding per capita inflows were relatively stable throughout the period and may be divided into four more or less equal parts (flour, meat, other human foodstuffs, forage), each representing about 6 gN per inhabitant per day. In total, the demand for foodstuffs was of the order of 24 gN per inhabitant per day, one quarter of which was for transport. The fate of this dietary nitrogen after consumption changed a lot with the techniques used for exploiting urban excreta of all kinds, particularly of nitrogen, which was in great demand until the development of synthetic fertilizers. Dietary nitrogen flow diagrams are established for the years 1817, 1869 and 1913, and reveal an increasing improvement of the agricultural reuse (from 20 to 40% of the inflowing N).     

The Application of Mealworm (Tenebrio molitor) Oil in Cosmetic Formulations

The depletion of natural resources, the increasing use of valuable land surface for human activities, and the generation of waste are detrimental to the planet. Sustainable alternatives to guarantee a sufficient supply of food, feed, and biomaterials are needed. Insects may hold an interesting position in a circular economy to tackle contemporary societal challenges. Using insects for food, feed, biomaterial production, and to valorize side-streams, have gained increased interest. Mealworms are amenable to large-scale farming. Herein, the potential of mealworm oil for implementation in a cosmetic hand cream is evaluated. It is shown that mealworms are rich in oil (≈30% of the dry weight), and the oil can be extracted using hexane or ethyl acetate as a solvent. The euthanization step of mealworms has profound effect on the free fatty acid content. The fatty acid profile indicates a large proportion of unsaturated fatty acids, which is promising for use in cosmetic applications. In a proof of concept, the mealworm oil is implemented in a hand cream and compared to hand cream containing macadamia nut oil. No differences in odor and aspect/stability are observed, but mealworm creams are slightly less white color. Mealworm oil is suitable for cosmetics applications. Practical applications: Several insect species can be sustainably reared on low-value organic side-streams, requiring only small amounts of land-surface, less water, and producing less greenhouse gases. In addition, they have short life cycles and can be reared continuously and locally. This implies that insects are an interesting source of biological materials including proteins and oils. Insect oils, including oil of mealworms, have interesting fatty acid profiles that make them amenable to replace oils of vegetable origin for applications within cosmetics. The results indicate that mealworm oil can be a novel, sustainable ingredient for use in the cosmetics industry.     

Supplier credits, limited liquidity, and timely demand information

We consider supplier-credit contracting between a manufacturer and a liquidity-constrained dealer. We show that the timeliness according to which the dealer receives demand information has a significant impact on the optimal contract. If the manufacturer cannot be sure that a dealer without liquidity has demand information when the contract is written, the optimal contract assigns the same quantity to an ignorant dealer and a dealer who knows that there are unfavorable demand conditions. However, dealers with favorable demand information are screened. If the dealer??s liquidity rises, the manufacturer proposes a contract that resembles the solution of a classic adverse selection model in the spirit of Harris et?al. (Manag Sci 28:604?C620, 1982). For high liquidity, the optimal supplier-credit contract assigns the same quantity to an ignorant dealer and dealers who have favorable demand information whereas dealers with unfavorable demand information are screened.     

Circulating Tumor Cells (CTC) and Cell-Free DNA (cfDNA) Workshop 2016: Scientific Opportunities and Logistics for Cancer Clinical Trial Incorporation

Despite the identification of circulating tumor cells (CTCs) and cell-free DNA (cfDNA) as potential blood-based biomarkers capable of providing prognostic and predictive information in cancer, they have not been incorporated into routine clinical practice. This resistance is due in part to technological limitations hampering CTC and cfDNA analysis, as well as a limited understanding of precisely how to interpret emergent biomarkers across various disease stages and tumor types. In recognition of these challenges, a group of researchers and clinicians focused on blood-based biomarker development met at the Canadian Cancer Trials Group (CCTG) Spring Meeting in Toronto, Canada on 29 April 2016 for a workshop discussing novel CTC/cfDNA technologies, interpretation of data obtained from CTCs versus cfDNA, challenges regarding disease evolution and heterogeneity, and logistical considerations for incorporation of CTCs/cfDNA into clinical trials, and ultimately into routine clinical use. The objectives of this workshop included discussion of the current barriers to clinical implementation and recent progress made in the field, as well as fueling meaningful collaborations and partnerships between researchers and clinicians. We anticipate that the considerations highlighted at this workshop will lead to advances in both basic and translational research and will ultimately impact patient management strategies and patient outcomes.     

Preparation and soft lithographic printing of nano-sized ITO-dispersions for the manufacture of electrodes for TFTs

The production of printed electronics exhibits an enormous economical potential due to the possibility to manufacture innovative products at low cost. At the moment, one of the major challenges for the fabrication of printed electronics is the controllability of the material properties during processing and the miniaturization of the deposited structures. In this context, the application of soft lithographic techniques appears promising, because they allow a defined patterning of the materials in the range of few nanometers, which is far below the limits of other printing techniques like inkjet-printing or screen printing. This work proves the applicability of the soft lithographic technique micro-molding in capillaries (MIMIC) for the manufacture of conductive indium tin oxide (ITO) electrodes. For the creation of stable dispersions of ITO nano-sized particles, steric as well as electrostatic stabilization concepts are applied. The prepared dispersions are characterized with regard to the later processing via MIMIC. The geometry and the electrical properties of the soft lithographically deposited structures are determined to prove their functionality. Special attention is paid to the influence of the wetting behavior of the dispersions on the resulting geometry of the structures. Finally, the applicability of the optimized structures is demonstrated by the assembly of a thin film transistor (TFT), in which the deposited structures serve as source and drain electrodes.     

Role of transverse temperature gradients in the generation of lamellar eutectic solidification patterns

In directional solidification, a sample is pulled in an externally imposed temperature gradient. When the pulling direction and the temperature gradient are not perfectly aligned, a transverse temperature gradient is generated in the sample. We investigate the dynamics of lamellar eutectic patterns, both by experimental observations and by numerical simulations, and find that it is dramatically affected by a transverse gradient. Whereas, in its absence, the labyrinth patterns that are formed in the initial stage of solidification persist over the entire duration of the experiments, a transverse temperature gradient induces a drift of the pattern which rapidly generates a regular array of lamellae. The drift speed is found to be consistently larger than expected from the normal growth hypothesis, both in simulations and experiments.