11. Quality-assurance of heat-flow data: the new structure and evaluation scheme of the IHFC Global Heat Flow DatabaseSven Fuchs, Ben Norden, Florian Neumann, Norbert Kaul, Akiko Tanaka, Ilmo T. Kukkonen, Christophe Pascal, Rodolfo Christiansen, Gianluca Gola, Dušan Rajver, 2023, izvirni znanstveni članek Povzetek: Since 1963, the International Heat Flow Commission has been fostering the compilation of the Global Heat Flow Database to provide reliable heat-flow data. Over time, techniques and methodologies evolved, calling for a reorganization of the database structure and for a reassessment of stored heat-flow data. Here, we provide the results of a collaborative, community-driven approach to set-up a new, quality-approved global heat-flow database. We present background information on how heat-flow is determined and how this important thermal parameter could be systematically evaluated. The latter requires appropriate documentation of metadata to allow the application of a consistent evaluation scheme. The knowledge of basic data (name and coordinates of the site, depth range of temperature measurements, etc.), details on temperature and thermal-conductivity data and possible perturbing effects need to be given. The proposed heat-flow quality evaluation scheme can discriminate between different quality aspects affecting heat flow: numerical uncertainties, methodological uncertainties, and environmental effects. The resulting quality codes allow the evaluation of every stored heat-flow data entry. If mandatory basic data are missing, the entry is marked accordingly. In cases where more than one heat-flow determination is presented for one specific site, and all of them are considered for the site, the poorest evaluation score is inherited to the site level. The required data and the proposed scheme are presented in this paper. Due to the requirements of the newly developed evaluation scheme, the database structure as presented in 2021 has been updated and is available in the appendix of this paper. The new quality scheme will allow a comprehensible evaluation of the stored heat-flow data for the first time.
Ključne besede: heat-flow density, quality scheme, thermal geophysics, global heat flow database (GHFD), thermal parameter, data information system, International Heat Flow Commission (IHFC)
Objavljeno v DiRROS: 09.08.2023; Ogledov: 504; Prenosov: 189
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12. Inter-person differences in isometric coactivations of triceps surae and tibialis anterior decrease in young, but not in older adults after 14 days of bed restMatjaž Divjak, Gašper Sedej, Nina Murks, Mitja Gerževič, Uroš Marušič, Rado Pišot, Boštjan Šimunič, Aleš Holobar, 2022, izvirni znanstveni članek Povzetek: We examined activation patterns of the gastrocnemius medialis (GM), gastrocnemius lateralis (GL), soleus (SO), and tibialis anterior (TA) muscles in eight older (58.4 ± 3.3 years) and seven young (23.1 ± 2.9 years) participants, before and after 14 days of horizontal bed rest. Visual feedback on the exerted muscle torque was provided to the participants. The discharge patterns of individual motor units (MUs) were studied in three repetitions of isometric plantar flexion at 30 and 60% of Maximum Voluntary Contraction (MVC), before, and 1 day after the 14-day bed rest, respectively. In the GL and GM muscles, the older participants demonstrated higher MU discharge rates than the young, regardless of the contraction level, both before and after the bed rest. In the TA and SO muscles, the differences between the older and young participants were less consistent. Detailed analysis revealed person-specific changes in the MU discharge rates after the bed rest. To quantify the coactivation patterns we calculated the correlation coefficients between the cumulative spike trains of identified MUs from each muscle, and measured the root mean square difference of the correlation coefficients between the trials of the same session (intra-session variability) and between different sessions (inter-session variability) in each participant (intra-person comparison) and across participants (inter-person comparison). In the intra-person comparison, the inter-session variability was higher than the intra-session variability, either before or after the bed rest. At 60% MVC torque, the young demonstrated higher inter-person variability of coactivation than the older participants, but this variability decreased significantly after the bed rest. In older participants, inter-person variability was consistently lower at 60% than at 30% MVC torque. In young participants, inter-person variability became lower at 60% than at 30% MVC torque only after the bed rest. Precaution is required when analyzing the MU discharge and coactivation patterns, as individual persons demonstrate individual adaptations to aging or bed rest.
Ključne besede: high density electromyography, muscle disuse, motor units, discharge rate, aging
Objavljeno v DiRROS: 05.09.2022; Ogledov: 875; Prenosov: 468
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14. Relationships between wood-anatomical features and resistance drilling density in Norway spruce and European beechDomen Arnič, Luka Krajnc, Jožica Gričar, Peter Prislan, 2022, izvirni znanstveni članek Povzetek: Environmental conditions affect tree-ring width (TRW), wood structure, and, consequently, wood density, which is one of the main wood quality indicators. Although studies on inter- and intra-annual variability in tree-ring features or density exist, studies demonstrating a clear link between wood structure on a cellular level and its effect on wood density on a macroscopic level are rare. Norway spruce with its simple coniferous structure and European beech, a diffuse-porous angiosperm species were selected to analyze these relationships. Increment cores were collected from both species at four sites in Slovenia. In total, 24 European beech and 17 Norway spruce trees were sampled. In addition, resistance drilling measurements were performed just a few centimeters above the increment core sampling. TRW and quantitative wood anatomy measurements were performed on the collected cores. Resistance drilling density values, tree-ring (TRW, earlywood width–EWW, transition-TWW, and latewood width–LWW) and wood-anatomical features (vessel/tracheid area and diameter, cell density, relative conductive area, and cell wall thickness) were then averaged for the first 7 cm of measurements. We observed significant relationships between tree-ring and wood-anatomical features in both spruce and beech. In spruce, the highest correlation values were found between TRW and LWW. In beech, the highest correlations were observed between TRW and cell density. There were no significant relationships between wood-anatomical features and resistance drilling density in beech. However, in spruce, a significant negative correlation was found between resistance drilling density and tangential tracheid diameter, and a positive correlation between resistance drilling density and both TWW + LWW and LWW. Our findings suggest that resistance drilling measurements can be used to evaluate differences in density within and between species, but they should be improved in resolution to be able to detect changes in wood anatomy.
Ključne besede: wood structure, Fagus sylvatica, Picea abies, quantitative wood anatomy, xylem anatomy, wood density, increment borer
Objavljeno v DiRROS: 08.04.2022; Ogledov: 805; Prenosov: 557
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15. A review of methane activation reactions by halogenation : catalysis, mechanism, kinetics, modeling, and reactorsDavid Bajec, Matic Grom, Damjan Lašič Jurković, Andrii Kostyniuk, Matej Huš, Miha Grilc, Blaž Likozar, Andrej Pohar, 2020, pregledni znanstveni članek Ključne besede: methane, halogenation, catalysis, density functional theory, kinetics, mechanism
Objavljeno v DiRROS: 16.04.2020; Ogledov: 2340; Prenosov: 1472
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16. Green water reconstructed for Rižana watershed, SW SloveniaSimon Poljanšek, Urša Vilhar, Tom Levanič, izvirni znanstveni članek Povzetek: In this case study, set in south-west Slovenia, the feasibility of reconstructing green water (the combined amount of evaporated and transpired water in trees and available in the soil) was investigated. In a simplifed scheme, the amounts of green water were calculated as the diference between precipitation and discharge of the Rižana river. Based on the methods of dendroclimatology, the climate signal was tested on black pine (Pinus nigra Arnold) trees growing in the south-western part of the Rižana watershed near the Slovenian sea coast. Results showed that the measured tree-ring parameters of tree-ring width and density are strongly dependent on the amount of green water. The strongest correlation was between available green water in the period May-August and tree-ring width (r=0.61) and latewood width (r=%0.64) (both n=46, p<0.001). The climate signal is signifcant and stable through time, which enabled the reconstruction of green water data into the period before instrumentally measured data. Green water data from the May-August period were extended from 1966 back to 1937 using tree-ring width, and back to 1940 using latewood width. With additional coring of older trees and the extension of existing chronologies, even longer reconstructions could be developed.
Ključne besede: tree-ring width, tree-ring density, dendrochronology, dendroclimatology, reconstruction
Objavljeno v DiRROS: 18.04.2018; Ogledov: 2971; Prenosov: 1774
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17. The effects of habitat structure on red deer (Cervus elaphus) body massKlemen Jerina, 2007, izvirni znanstveni članek Povzetek: In most mammalian species, body mass is one of the key factors affecting an individual's fitness. It is therefore important to know the causes of its variability. The present paper analyses the influences of habitat structure and other environmental factors on body mass in red deer. The research is based on data sets concerning 3,920 culled red deer from the entire Slovenia, which are geo-referenced within a kilometer spatial accuracy, and on 28 spatially explicit raster layers of population density, habitat structure variables (e.g. topography, land use, forest structure, roads) and other environmental variables (e.g. air temperature, precipitation, supplementary feeding). After controlling for sex and age of the individual and its date of culling, body weight significantly differs between population areas, most likely as a result of genotype differences and genotype impact on the phenotype, and is also negatively dependent upon population density and the percentage of conifers and positively dependent upon annual mean air temperature and forest/meadow edge density. The stated environmental factors probably influence the achieved energy balance and, therefore, the body mass of red deer by conditioning the quantity and quality of food and energy expenditure of deer.
Ključne besede: red deer, body weight, habitat, evironmental factors, population density, forest edge, conifer, temperature, Slovenia
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4735; Prenosov: 2072
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