2,656 research outputs found

    Approaches for Carbon Budget Analyses of the Siberian Forests

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    This report carried out by Timo Karjalainen and Jari Liski is a contribution to the analyses of carbon balances of the Siberian forests. The report contains two inter-linked sections. The aim of the first section was to develop a method to assess carbon budget for tree biomass at ecoregional level in Siberia. Tree biomass carbon budgets contain estimates on the initial amounts of carbon in the whole tree biomass, as well as its dynamics. The calculation method developed based on the structure of the Russian forest database at IIASA and available models describing tree growth and biomass allocation in Siberia. Calculated litter production is used as input for separate calculations on the soil organic matter carbon budget (Liski, 1997). Stand level analyses showed that the developed method describes vegetation carbon budget in a plausible manner. The stand level analyses are the platform for regional assessments. There are, however, several matters that should be taken into account in the regional assessments. These relate to stand structure, description of stand replacing disturbances, and availability of data. In the second section, different models describing the dynamics of organic C in forest soils were developed and then compared. The model judged to describe the dynamics of soil C in the most realistic way contains five compartments for different litter and three for soil organic matter (the so called soil C model). Temperature was considered the most important climatic factor that regulates the decomposition in boreal forests. The effective temperature sum with a +5 degree C threshold was chosen to describe the temperature impact on the decomposition. The application of the developed models was tested on the issues of impacts of species, harvesting intervals and harvesting residues left on the site. For a full-scale application of the developed soil carbon models for Siberia and Russia, the special features of permafrost soils and peatlands need to be added to the models

    The SU(N) Wilson Loop Average in 2 Dimensions

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    We solve explicitly a closed, linear loop equation for the SU(2) Wilson loop average on a two-dimensional plane and generalize the solution to the case of the SU(N) Wilson loop average with an arbitrary closed contour. Furthermore, the flat space solution is generalized to any two-dimensional manifold for the SU(2) Wilson loop average and to any two-dimensional manifold of genus 0 for the SU(N) Wilson loop average.Comment: 20p. LaTex, typos and some factors of N correcte

    Optimisation of wood logistics

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    KIC 10449976: discovery of an extreme-helium subdwarf in the Kepler field

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    Optical spectroscopy of the blue star KIC 10449976 shows that it is an extremely helium-rich subdwarf with effective temperature T=40000+/-300 K and surface gravity log g=5.3+/-0.1. Radial-velocity measurements over a five-day timescale show an upper variability limit of ~50+/-20 km/s. Kepler photometry of KIC 10449976 in both long and short cadence modes shows evidence for a periodic modulation on a timescale of ~3.9 days. We have examined the possibility that this modulation is not astrophysical but conclude it is most likely real. We discuss whether the modulation could be caused by a low-mass companion, by stellar pulsations, or by spots. The identification of any one of these as cause has important consequences for understanding the origin of helium-rich subdwarfs.Comment: Accepted by MNRA

    Insulin autoantibodies as determined by competitive radiobinding assay are positively correlated with impaired beta-cell function — The Ulm-Frankfurt population study

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    Out of a random population of 4208 non-diabetic pupils without a family history of Type I diabetes 44 (1.05%) individuals had islet cell antibody (ICA) levels greater or equal to 5 Juvenile Diabetes Foundation (JDF) units. 39 of these ICA-positives could be repeatedly tested for circulating insulin autoantibodies (CIAA) using a competitive radiobinding assay. The results were compared with the insulin responses in the intravenous glucose tolerance tests (IVGTT) and with HLA types. Six pupils were positive for CIAA. All of them had complement-fixing ICA, and 5 of them were HLA-DR4 positive. Three of the 6 showed a first-phase insulin response below the first percentile of normal controls. Our data indicate that in population-based studies CIAA can be considered as a high risk marker for impaired beta-cell function in non-diabetic ICA-positive individuals

    Identification of the VAl-ON defect complex in AlN single crystals

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    In this Rapid Communication, we report positron annihilation results on in-grown and proton irradiation-induced vacancies and their decoration in aluminium nitride (AlN) single crystals. By combining positron lifetime and coincidence Doppler measurements with ab initio calculations, we identify in-grown VAl−ON complexes in the concentration range 10 exp 18 cm exp −3 as the dominant form of VAl in the AlN single crystals, while isolated VAl were introduced by irradiation. Further, we identify the UV absorption feature at around 360 nm that involves VAl.Peer reviewe

    Benzothiadiazole induces the accumulation of phenolics and improves resistance to powdery mildew in strawberries

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    Benzothiadiazole (BTH) enhanced the accumulation of soluble and cell-wall-bound phenolics in strawberry leaves and also improved the resistance to powdery mildew infection under greenhouse conditions. The most pronounced change was seen in the levels of ellagitannins, which increased up to 2- to 6-fold 4 days after the BTH application, but persisted only in the inoculated plants. The induction of phenolic metabolism by BTH was also reflected in the fruits, several compounds being increased in inoculated, BTH-treated plants. Basal salicylic acid (SA) content was high in strawberry leaves, but increased in a similar fashion to other phenolics after the treatments. Several phenolic compounds were identified in strawberries for the first time. For example, ellagic acid deoxyhexose, three agrimoniin-like ellagitannins, sanguiin H-10- and lambertianin C-like ellagitannins in the leaves, ellagic acid, p-coumaric acid, gallic acid, and kaempferol hexose in the cell-wall-bound fraction of the leaves, and kaempferol malonylglucoside in the fruits. The findings show that BTH can enhance the accumulation of phenolics in strawberry plants which may then be involved in the BTH-induced resistance to powdery mildew

    Gravity-mode period spacings as seismic diagnostic for a sample of gamma Doradus stars from Kepler space photometry and high-resolution ground-based spectroscopy

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    Gamma Doradus stars (hereafter gamma Dor stars) are gravity-mode pulsators of spectral type A or F. Such modes probe the deep stellar interior, offering a detailed fingerprint of their structure. Four-year high-precision space-based Kepler photometry of gamma Dor stars has become available, allowing us to study these stars with unprecedented detail. We selected, analysed, and characterized a sample of 67 gamma Dor stars for which we have Kepler observations available. For all the targets in the sample we assembled high-resolution spectroscopy to confirm their F-type nature. We found fourteen binaries, among which four single-lined binaries, five double-lined binaries, two triple systems and three binaries with no detected radial velocity variations. We estimated the orbital parameters whenever possible. For the single stars and the single-lined binaries, fundamental parameter values were determined from spectroscopy. We searched for period spacing patterns in the photometric data and identified this diagnostic for 50 of the stars in the sample, 46 of which are single stars or single-lined binaries. We found a strong correlation between the spectroscopic vsini and the period spacing values, confirming the influence of rotation on gamma Dor-type pulsations as predicted by theory. We also found relations between the dominant g-mode frequency, the longest pulsation period detected in series of prograde modes, vsini, and log Teff.Comment: 61 pages, 61 figures, 6 tables, accepted for publication in ApJ

    The role of ICT in natural disaster management communication:a systematic literature review

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    Abstract. The number and severity of natural hazards has increased in recent decades. These natural hazards cause billions in financial damage, as well as loss of life every year. Fortunately, societies have learned to adapt to these phenomena and invested in managing and mitigating their effects. Communication plays a key role in managing these natural disasters and the effects they smite upon communities. At the same time, information and communication technologies have become ubiquitous and integral part of our lives. However, the available technologies and the ability to utilize these technologies vary. Thus, there is a need for up-to-date review of the use of these technologies. In this thesis, the role of information and communication technologies in natural disaster management communication is examined. The purpose of this thesis is to aggregate scientific knowledge on the role of information and communication technologies in natural disaster management communication. As a result, this study used systematic literature review as a research method. In addition, the aim is to identify possible best practices and discuss the findings of the systematic literature review. The results are used to inform future work on developing an opensource-based system for natural disaster management. The main contribution of this thesis is the summarization of the findings. These findings can be used as a knowledge base or to reflect upon new solutions in natural disaster management. The search strategy used in this study identified 584 studies in total from which 24 primary studies were selected. Recommended future actions involve further studying the identified best practices and their application in practice. In addition, further developing the proposed artifact is recommended
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