61 research outputs found

    Soil moisture under no-tillage and tillage systems in maize long-term experiment

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    The aim of the study was to evaluate the impact of conventional till (CT) and no-till (NT) cultivation systems in long term experiment with maize on soil water dynamics using continuous soil moisture (SM) measurements in the 2014, 2015, 2016 vegetation seasons. The ability of HERMES model to simulate SM was also evaluated in Polish conditions. The long term experiment with maize is located in the Grabów Experimental Farm of Institute of Soil Science and Plant Cultivation – State Research Institute in Masovian Voivodeship – Central Poland (51˚21´18´´N, 21˚40´09´´E). The HERMES model was calibrated by modification of temperature sums in crop parameters file and capacity parameters (field capacity and wilting point) of the experimental site. The results show that NT system has a positive impact on soil water content. However, this improvement is dependent on a year, phenological phase and soil layer. The results showed also that calibrated (until now) model HERMES is able to simulate SM in a wet year. For simulation of SM in a dry year there is still need for future improvement of calibration parameters

    Computation and programmability at the nano-bio interface

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    PhD ThesisThe manipulation of physical reality on the molecular level and construction of devices operating on the nanoscale has been the focal point of nanotechnology. In particular, nanotechnology based on DNA and RNA has a potential to nd applications in the eld of Synthetic Biology thanks to the inherent compatibility of nucleic acids with biological systems. Sca olded DNA origami, proposed by P. Rothemund, is one of the leading and most successful methods in which nanostructures are realised through rational programming of short 'staple' oligomers which fold a long single-stranded DNA called the 'sca old' strand into a variety of desired shapes. DNA origami already has many applications; including intelligent drug delivery, miniaturisation of logic circuits and computation in vivo. However, one of the factors that are limiting the complexity, applicability and scalability of this approach is the source of the sca old which commonly originates from viruses or phages. Furthermore, developing a robust and orthogonal interface between DNA nanotechnology and biological parts remains a signi cant challenge. The rst part of this thesis tackles these issues by challenging the fundamental as- sumption in the eld, namely that a viral sequence is to be used as the DNA origami sca old. A method is introduced for de novo generation of long synthetic sequences based on De Bruijn sequence, which has been previously proposed in combinatorics. The thesis presents a collection of algorithms which allow the construction of custom- made sequences that are uniquely addressable and biologically orthogonal (i.e. they do not code for any known biological function). Synthetic sca olds generated by these algorithms are computationally analysed and compared with their natural counter- parts with respect to: repetition in sequence, secondary structure and thermodynamic addressability. This also aids the design of wet lab experiments pursuing justi cation and veri cation of this novel approach by empirical evidence. The second part of this thesis discusses the possibility of applying evolutionary op- timisation to synthetic DNA sequences under constraints dictated by the biological interface. A multi-strand system is introduced based on an alternative approach to DNA self-assembly, which relies on strand-displacement cascades, for molecular data storage. The thesis demonstrates how a genetic algorithm can be used to generate viable solutions to this sequence optimisation problem which favours the target self- assembly con guration. Additionally, the kinetics of strand-displacement reactions are analysed with existing coarse-grained DNA models (oxDNA). This thesis is motivated by the application of scienti c computing to problems which lie on the boundary of Computer Science and the elds of DNA Nanotechnology, DNA Computing and Synthetic Biology, and thus I endeavour to the best of my ability to establish this work within the context of these disciplines

    Review of Soil Moisture and Plant Water Stress Models Based on Satellite Thermal Imagery

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    The paper analyzes the advantages and disadvantages of the most commonly used groups of models of soil moisture and plant water stress based on satellite thermal imagery. We present a simple proof of linking NDTI and CWSI indicators with plants water stress and quantitative justification for the shape of the points cloud on the chart Ts-NDVI

    On the nature of spin- and orbital-resolved Cu+NOCu^{+}-NO charge transfer in the gas phase and at Cu(I) sites in zeolites

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    Electronic factors essential for NO activation by Cu(I) sites in zeolites are investigated within spin-resolved analysis of electron transfer channels (natural orbitals for chemical valence). NOCV analysis is performed for three DFT-opti- mized models of Cu(I)–NO site in ZSM-5: [CuNO] ? , (T1)CuNO, and (M7)CuNO. NO as a non-innocent, open- shell ligand reveals significant differences between inde- pendent deformation density components for a and b spins. Four distinct components are identified: (i) unpaired electron donation from NO p k * antibonding orbital to Cu s,d ; (ii) backdonation from copper d yz to p \ * antibonding orbital; (iii) donation from occupied p k and Cu d xz to bonding region, and (iv) donation from nitrogen lone-pair to Cu s,d . Channel (i), corresponding to one-electron bond, shows-up solely for spin majority and is effective only in the interaction of NO with naked Cu ? . Channel (ii) dominates for models b and c: it strongly activates NO bond by populating antibonding p * orbital and weakens the N–O bond in contrast to channel (i), depopulating the antibonding orbital and strengthening N–O bond. This picture perfectly agrees with IR experiment: interaction with naked Cu ? imposes small blue-shift of N stretching frequency while it becomes strongly red-shifted for Cu(I) site in ZSM-5 due to enhanced backdonation

    Z badań nad rolnictwem społecznie zrównoważonym (15)

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    Seria: Program Wieloletni 2011-2014. Konkurencyjność Polskiej Gospodarki Żywnościowej w Warunkach Globalizacji i Integracji Europejskiej; nr 50Bilans węgla i emisji gazów cieplarnianych (dwutlenku węgla, metanu i podtlenku azotu) w polskim rolnictwie. Rolnictwo ekologiczne w Polsce - stan i perspektywa. Czynniki kształtujące poziom zrównoważenia gospodarstw rolnych. Uwarunkowania i czynniki rozwoju rolnictwa zrównoważonego.Kamila Sobieck

    Cereal yield gaps across Europe

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    peer-reviewedEurope accounts for around 20% of the global cereal production and is a net exporter of ca. 15% of that production. Increasing global demand for cereals justifies questions as to where and by how much Europe’s production can be increased to meet future global market demands, and how much additional nitrogen (N) crops would require. The latter is important as environmental concern and legislation are equally important as production aims in Europe. Here, we used a country-by-country, bottom-up approach to establish statistical estimates of actual grain yield, and compare these to modelled estimates of potential yields for either irrigated or rainfed conditions. In this way, we identified the yield gaps and the opportunities for increased cereal production for wheat, barley and maize, which represent 90% of the cereals grown in Europe. The combined mean annual yield gap of wheat, barley, maize was 239 Mt, or 42% of the yield potential. The national yield gaps ranged between 10 and 70%, with small gaps in many north-western European countries, and large gaps in eastern and south-western Europe. Yield gaps for rainfed and irrigated maize were consistently lower than those of wheat and barley. If the yield gaps of maize, wheat and barley would be reduced from 42% to 20% of potential yields, this would increase annual cereal production by 128 Mt (39%). Potential for higher cereal production exists predominantly in Eastern Europe, and half of Europe’s potential increase is located in Ukraine, Romania and Poland. Unlocking the identified potential for production growth requires a substantial increase of the crop N uptake of 4.8 Mt. Across Europe, the average N uptake gaps, to achieve 80% of the yield potential, were 87, 77 and 43 kg N ha−1 for wheat, barley and maize, respectively. Emphasis on increasing the N use efficiency is necessary to minimize the need for additional N inputs. Whether yield gap reduction is desirable and feasible is a matter of balancing Europe’s role in global food security, farm economic objectives and environmental targets.We received financial contributions from the strategic investment funds (IPOP) of Wageningen University & Research, Bill & Melinda Gates Foundation, MACSUR under EU FACCE-JPI which was funded through several national contributions, and TempAg (http://tempag.net/)

    ENVIRONMENTAL EFFICIENCY OF ROOT CROP CULTIVATION

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    In this study environmental efficiency of main root crop (sugar beets and potatoes) cultivation in Poland is evaluated. Survey data from 62 sugar beet and 74 potato farms in the years 2016 and 2017 were used for analysis. To assess efficiency, the slack based Data Envelopment Analysis model (SBM-DEA) was used, where greenhouse gas emissions were assumed as undesirable output. The reasons for inefficiency in cultivation were explained using the fractional regression model (FRM), with habitat and organizational conditions as independent variables. Differences in the structure of greenhouse gas emissions from the crops under study were indicated as a result of differences in technology used at each farm. The estimated average carbon footprint on the analysed farms for sugar beet cultivation was 0.057 (±0.042) kg CO2 e/kg and 0.13 (±0.17) kg CO2 e/kg for potato cultivation. The obtained results indicate that effective farms growing sugar beet emit, on average, 14.5% less greenhouse gases, achieving a slightly higher yield. In potato cultivation, this reduction is 15.3% with a 27% increase in yield. It has been shown that weather conditions and the economic size of farms can significantly affect the environmental efficiency of both analysed crops
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