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- Hammer, Edith, et al.
(författare)
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Biochar increases arbuscular mycorrhizal plant growth enhancement and ameliorates salinity stress
- 2015
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Ingår i: Applied Soil Ecology. - : Elsevier BV. - 0929-1393. ; 96, s. 114-121
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Tidskriftsartikel (refereegranskat)abstract
- We examined combined effects of biochar, arbuscular mycorrhizal (AM) fungi and salinity on plant growth and physiology to test whether and how biochar influences AM fungi mediated growth and nutrition enhancements, and whether and how biochar provides amelioration in salt stressed soils. We carried out a full three-factorial greenhouse experiment with Lactuca sativa; and a second study with a wider range of biochar and salt additions to examine physicochemical effects on soil parameters. Biochar together with AM fungal inoculation resulted in an additional plant yield increase compared to each alone under non-saline conditions. In parallel with increased plant growth, we found increased uptake of P and Mn with AM fungi and biochar addition, but to a lesser extent than biochar-induced growth promotion. Both factors, but especially biochar alleviated salinity-caused growth depressions, and improved Na/K ratio in salinity stressed plants. Reduced Na uptake of plants and reduced conductivity in biochar-ameliorated soils suggest that a likely mechanism involves ion adsorption to biochar surfaces. Our results suggest that plants depend on symbiotic microorganisms to fully exploit biochar benefits in soils, suggesting avenues for joint management in agriculture. Biochar may be advantageous in saline soils, but long-term studies are required before recommendations should be given. (C) 2015 Elsevier B.V. All rights reserved.
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| 2. |
- Pollnau, Markus, et al.
(författare)
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DNA separation and fluorescent detection in an optofluidic chip with sub-base-pair resolution
- 2015
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Ingår i: Microfluidics, BioMEMS, and Medical Microsystems XIII. - : SPIE - International Society for Optical Engineering. - 9781628414103
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Konferensbidrag (refereegranskat)abstract
- DNA sequencing in a lab-on-a-chip aims at providing cheap, high-speed analysis of low reagent volumes to, e.g., identify genomic deletions or insertions associated with genetic illnesses. Detecting single base-pair insertions/deletions from DNA fragments in the diagnostically relevant range of 150-1000 base-pairs requires a sizing accuracy of S < 10(-3). Here we demonstrate S = 4x10(-4). A microfluidic chip was post-processed by femtosecond-laser writing of an optical waveguide. 12 blue-labeled and 23 red-labeled DNA fragments were separated in size by capillary electrophoresis, each set excited by either of two lasers power-modulated at different frequencies, their fluorescence detected by a photomultiplier, and blue/red signals distinguished by Fourier analysis. Different calibration strategies were tested: a) use either set of DNA molecules as reference to calibrate the set-up and identify the base-pair sizes of the other set in the same flow experiment, thereby eliminating variations in temperature, wall-coating and sieving-gel conditions, and actuation voltages; b) use the same molecular set as reference and sample with the same fluorescence label, flown in consecutive experiments; c) perform cross-experiments based on different molecular sets with different labels, flown in consecutive experiments. From the results we conclude: Applying quadratic instead of linear fit functions improves the calibration accuracy. Blue-labeled molecules are separated with higher accuracy. The influence of dye label is higher than fluctuations between two experiments. Choosing a single, suitable dye label combined with reference calibration and sample investigation in consecutive experiments results in S = 4x10(-4), enabling detection of single base-pair insertion/deletion in a lab-on-a-chip.
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