Does nitrate fertilization induce nox emission from scots pine (p. sylvestris) shoots?

Peer reviewe

Convergence of Quantum Annealing with Real-Time Schrodinger Dynamics

Convergence conditions for quantum annealing are derived for optimization problems represented by the Ising model of a general form. Quantum fluctuations are introduced as a transverse field and/or transverse ferromagnetic interactions, and the time evolution follows the real-time Schrodinger equation. It is shown that the system stays arbitrarily close to the instantaneous ground state, finally reaching the target optimal state, if the strength of quantum fluctuations decreases sufficiently slowly, in particular inversely proportionally to the power of time in the asymptotic region. This is the same condition as the other implementations of quantum annealing, quantum Monte Carlo and Green's function Monte Carlo simulations, in spite of the essential difference in the type of dynamics. The method of analysis is an application of the adiabatic theorem in conjunction with an estimate of a lower bound of the energy gap based on the recently proposed idea of Somma et. al. for the analysis of classical simulated annealing using a classical-quantum correspondence.Comment: 6 pages, minor correction

Convergence theorems for quantum annealing

We prove several theorems to give sufficient conditions for convergence of quantum annealing, which is a protocol to solve generic optimization problems by quantum dynamics. In particular the property of strong ergodicity is proved for the path-integral Monte Carlo implementation of quantum annealing for the transverse Ising model under a power decay of the transverse field. This result is to be compared with the much slower inverse-log decay of temperature in the conventional simulated annealing. Similar results are proved for the Green's function Monte Carlo approach. Optimization problems in continuous space of particle configurations are also discussed.Comment: 19 page

The Hydrophobicity of Lignocellulosic Fiber Network Can Be Enhanced with Suberin Fatty Acids

Suberin fatty acids were extracted from outer bark of Silver birch (Betula pendula Roth.) using an isopropanolic sodium hydroxide solution. Laboratory sheets composed of lignocellulosic fiber networks were prepared from unbleached and unrefined softwood kraft pulp and further impregnated with suberin fatty acid monomers and cured with maleic anhydride in ethanol solution. The treatment resulted in hydrophobic surfaces, in which the contact angles remained over 120 degrees during the entire measurement. The fiber network also retained its water vapor permeability and enhanced fiber–fiber bonding resulted in improved tensile strength of the sheets. Scanning electron microscopy (SEM) images revealed that the curing agent, together with suberin fatty acids, was evenly distributed on the fiber surfaces and smoothing occurred over the wrinkled microfibrillar structure. High concentrations of the curing agent resulted in globular structures containing betulinol derivates as revealed with time-of-flight secondary ion mass spectrometry (ToF-SIMS). Also, the larger amount of suberin fatty acid monomers slightly impaired the optical properties of sheets

The Hydrophobicity of Lignocellulosic Fiber Network Can Be Enhanced with Suberin Fatty Acids

Suberin fatty acids were extracted from outer bark of Silver birch (Betula pendula Roth.) using an isopropanolic sodium hydroxide solution. Laboratory sheets composed of lignocellulosic fiber networks were prepared from unbleached and unrefined softwood kraft pulp and further impregnated with suberin fatty acid monomers and cured with maleic anhydride in ethanol solution. The treatment resulted in hydrophobic surfaces, in which the contact angles remained over 120 degrees during the entire measurement. The fiber network also retained its water vapor permeability and enhanced fiber–fiber bonding resulted in improved tensile strength of the sheets. Scanning electron microscopy (SEM) images revealed that the curing agent, together with suberin fatty acids, was evenly distributed on the fiber surfaces and smoothing occurred over the wrinkled microfibrillar structure. High concentrations of the curing agent resulted in globular structures containing betulinol derivates as revealed with time-of-flight secondary ion mass spectrometry (ToF-SIMS). Also, the larger amount of suberin fatty acid monomers slightly impaired the optical properties of sheets

Ultraviolet absorbance of Sphagnum magellanicum, S. fallax and S. fuscum extracts with seasonal and species-specific variation

Bryophytes, including Sphagnum, are common species in alpine and boreal regions especially on mires, where full sunlight exposes the plants to the damaging effects of UV radiation. Sphagnum species containing UV-protecting compounds might offer a biomass source for nature-based sunscreens to replace the synthetic ones. In this study, potential compounds and those linked in cell wall structures were obtained by using methanol and alkali extractions and the UV absorption of these extracts from three common Sphagnum moss species Sphagnum magellanicum, Sphagnum fuscum and Sphagnum fallax collected in spring and autumn from western Finland are described. Absorption spectrum screening (200–900 nm) and luminescent biosensor (Escherichia coli DPD2794) methodology were used to examine and compare the protection against UV radiation. Additionally, the antioxidant potential was evaluated using hydrogen peroxide scavenging (SCAV), oxygen radical absorbance capacity (ORAC) and ferric reducing absorbance capacity (FRAP). Total phenolic content was also determined using the Folin-Ciocalteu method. The results showed that methanol extractable compounds gave higher UV absorption with the used methods. Sphagnum fallax appeared to give the highest absorption in UV-B and UV-A wavelengths. In all assays except the SCAV test, the methanol extracts of Sphagnum samples collected in autumn indicated the highest antioxidant capacity and polyphenol content. Sphagnum fuscum implied the highest antioxidant capacity and phenolic content. There was low antioxidant and UV absorption provided by the alkali extracts of these three species

Metabolic Profiling of Water-Soluble Compounds from the Extracts of Dark Septate Endophytic Fungi (DSE) Isolated from Scots Pine (Pinus sylvestris L.) Seedlings Using UPLC-Orbitrap-MS

Endophytes are microorganisms living inside plant hosts and are known to be beneficial for the host plant vitality. In this study, we isolated three endophytic fungus species from the roots of Scots pine seedlings growing on Finnish drained peatland setting. The isolated fungi belonged to dark septate endophytes (DSE). The metabolic profiles of the hot water extracts of the fungi were investigated using Ultrahigh Performance Liquid Chromatography with Diode Array Detection and Electron Spray Ionization source Mass Spectrometry with Orbitrap analyzer (UPLC-DAD-ESI-MS-Orbitrap). Out of 318 metabolites, we were able to identify 220, of which a majority was amino acids and peptides. Additionally, opine amino acids, amino acid quinones, Amadori compounds, cholines, nucleobases, nucleosides, nucleotides, siderophores, sugars, sugar alcohols and disaccharides were found, as well as other previously reported metabolites from plants or endophytes. Some differences of the metabolic profiles, regarding the amount and identity of the found metabolites, were observed even though the fungi were isolated from the same host. Many of the discovered metabolites have been described possessing biological activities and properties, which may make a favorable contribution to the host plant nutrient availability or abiotic and biotic stress tolerance

Impact of selenium enrichment on seed potato tubers

The aim of this study was to investigate the effect of Se enrichment on the growth of sprouts and growth vigour of seed potatoes (Solanum tuberosum L.) stored for 2 to 8 months. Our results showed that Se did not affect the duration of dormancy. At the high addition levels (0.075 and 0.9 mg kg-1 quartz sand), Se had some positive effects on the growth of sprouts. The peak sprouting capacity was reached after 8 months of storage. The highest Se enrichment of tubers had some positive effect on the free putrescine content in sprouts. However, the better growth of sprouts was not consistent with the growth vigour of the seed tubers and yield produced. Selenium had no significant effect on the malondialdehyde (MDA) or on the concentration of soluble sugars and starch. No significant effect of added Se on the early growth, stem and tuber numbers and yield parameters was observed. Irrespective of the level of Se added, the highest yield was harvested from plants produced with seed tubers stored for 6 months. Our results indicate that Se had some positive effects on the growth of sprouts, but it had no consistent effect on the growth vigour of seed tubers.;Suomessa perunaa joudutaan varastoimaan pitkaan. Varastoinninaikana siemenperunassa tapahtuu fysiologisia ja biokemiallisia muutoksia, jotka johtavat hiljalleen fysiologiseen vanhenemiseen ja sita kautta mukulan elinvoiman ja sadonmuodostuskyvyn alenemiseen. Seleeni (Se) on valttamaton alkuaine ihmisten ja elainten terveydelle. Viljelykasvien ei ole katsottu valttamatta tarvitsevan seleenia. Kuitenkin pienen seleenilisayksen on havaittu lisaavan kasvien antioksidatiivista kapasiteettia, parantavan kasvien kasvua, satoa ja laatua seka hidastavan kasvien vanhenemista. Helsingin yliopistossa Soveltavan biologian laitoksella tutkittiin voiko seleeni edistaa siemenperunan elinvoiman sailymista seka hidastaa vanhenemista varastoinnin aikana. Seleenirikastetut siemenperunat tuotettiin edellisena kasvukautena kasvihuoneessa kasveissa, jotka kasvatettiin nousevilla seleenimaarilla (0, 0.0035, 0.01, 0.075 ja 0.9 mg Se kg-1) lannoitetussa kvartsihiekassa, joilla siemenperunoiden seleenipitoisuudet olivat keskimaarin 0.01, 0.09, 0.20, 1.33 and 16 Êg Se g-1 kuivapainoa, tassa jarjestyksessa. Seleenin vaikutusta siemenperunan itujen kasvuun tutkittiin maarittamalla itujen lukumaara ja itamiskapasiteetti. Iduista maaritettiin vapaiden polyamiinien pitoisuus. Malondialdehydin (MDA) ja liukoisten sokereiden kertyminen sekä tärkkelyksen hajoaminen määritettiin siemenperunoista varastoinnin aikana. Siemenperunoiden elinvoima tutkittiin kasvihuonekokeissa määrittämällä taimettumisaika, kukinnan alkamisaika, pääversojen lukumäärä sekä kasvikohtaisesti sato, mukulalukumäärä ja mukulapaino. Tutkimuksen tulokset osoittivat, että korkeimmat seleenilisäykset (0.075 ja 0.9 mg kg-1) paransivat itämiskapasiteettia eli suurempi osa olemassa olevista iduista oli lähtenyt kasvuun. Korkeimmalla seleenirikastuksella oli positiivinen vaikutus itujen vapaan putreskiinin pitoisuuteen. Lisääntynyt itujen kasvu ei ollut yhteydessä siemenperunoiden elinvoimaan eli tuotetun sadon määrään. Seleenirikastuksella ei ollut vaikutusta perunoiden MDA:n eikä liukoisten sokereiden kertymiseen eikä tärkkelyksen hajoamiseen. Korkein sato tuotettiin kuusi kuukautta varastoidulla siemenperunalla, riippumatta seleenilisäyksestä. Kahdeksan kuukautta varastoidut siemenperunat sen sijaan tuottivat alhaisemman sadon, mikä viittaa siihen, että siemenperunan optimaalinen ikä oli jo ohitettu. Tulokset osoittavat, että seleenirikastuksella ei ollut selvää siemenperunoiden vanhenemista hidastavaa eikä niiden elinvoimaa edistävää vaikutusta