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12. Climatic regulation of leaf and cambial phenology in Quercus pubescens : their interlinkage and impact on xylem and phloem conduitsJožica Gričar, Jernej Jevšenak, Polona Hafner, Peter Prislan, Mitja Ferlan, Martina Lavrič, Dominik Vodnik, Klemen Eler, 2022, izvirni znanstveni članek Povzetek: Increased frequency and severity of stressful events affects the growth patterns and functioning of trees which adjust their phenology to given conditions. Here, we analysed environmental effects (temperature, precipitation, VPD and SWC) on the timing of leaf phenology, seasonal stem radial growth patterns, and xylem and phloem anatomy of Quercus pubescens in the sub-Mediterranean in the period 2014%2019, when various adverse weather events occurred, i.e. spring drought in 2015, summer fire in 2016 and summer drought in 2017. Results showed that the timings of leaf and cambium phenology do not occur simultaneously in Q. pubescens, reflecting different environmental and internal constraints. Although year-to-year variability in the timings of leaf and cambial phenology exists, their chronological sequence is fairly fixed. Different effects of weather conditions on different stages of leaf development in spring were observed. Common climatic drivers (i.e., negative effect of hot and dry summers and a positive effect of increasing moisture availability in winter and summer) were found to affect the widths of xylem and phloem increments with more pronounced effect on late formed parts. A legacy effect of the timing of leaf and cambial phenology of the previous growing season on the timing of phenology of the following spring was confirmed. Rarely available phloem data permitted a comprehensive insight into the interlinkage of the timing of cambium and leaf phenology and adjustment strategies of vascular tissues in Mediterranean pubescent oak to various environmental constraints, including frequent extreme events (drought, fire). Our results suggest that predicted changes in autumn/winter and spring climatic conditions for this area could affect the timings of leaf and stem cambial phenology of Q. pubescens in the coming years, which would affect stem xylem and phloem structure and hydraulic properties, and ultimately its performance.
Ključne besede: pubescent oak, leaf development, radial growth, initial earlywood vessel, sieve tube, anatomy, cambial cell production, extreme weather events
Objavljeno v DiRROS: 06.09.2021; Ogledov: 1024; Prenosov: 332
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13. Documenting metrological traceability as intended by ISO 15189:2012 : a consensus statement about the practice of the implementation and auditing of this norm elementMarc H. M. Thelen, Florent Vanstapel, Pika Meško-Brguljan, Bernard Gouget, Guilaine Boursier, Edward Barrett, Christos Kroupis, Maria Lohmander, Luděk Šprongl, Tatjana Vodnik, 2019, izvirni znanstveni članek Povzetek: ISO15189:2012 requires medical laboratories to document metrological traceability of their results. While the ISO17511:2003 standard on metrological traceability in laboratory medicine requires the use of the highest available level in the traceability chain, it recognizes that for many measurands there is no reference above the manufacturer's selected measurement procedure and the manufacturer's working calibrator. Some immunoassays, although they intend to measure the same quantity and may even refer to the same reference material, unfortunately produce different results because of differences in analytical selectivity as manufacturers select different epitopes and antibodies for the same analyte. In other cases, the cause is the use of reference materials, which are not commutable. The uncertainty associated with the result is another important aspect in metrological traceability implementation. As the measurement uncertainty on the clinical samples is influenced by the uncertainty of all steps higher in the traceability chain, laboratories should be provided with adequate and appropriate information on the uncertainty of the value assignment to the commercial calibrators that they use. Although the between-lot variation in value assignment will manifest itself as part of the long-term imprecision as estimated by the end-user, information on worst-case to be expected lot-lot variation has to be communicated to the end-user by the IVD provider. When laboratories use ancillary equipment that potentially could have a critical contribution to the reported results, such equipment needs verification of its proper calibration and criticality to the result uncertainty could be assessed by an approach based on risk analysis, which is a key element of ISO15189:2012 anyway. This paper discusses how the requirement for metrological traceability as stated in ISO15189 should be met by the medical laboratory and how this should be assessed by accreditation bodies.
Ključne besede: laboratories, medical laboratory science, risk management, quality control, quality improvement, health care quality assurance, metrological traceability
Objavljeno v DiRROS: 22.10.2020; Ogledov: 1314; Prenosov: 291
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14. Validation and verification of examination procedures in medical laboratories : opinion of the EFLM Working Group Accreditation and ISO/CEN standards (WG-A/ISO) on dealing with ISO 15189:2012 demands for method verification and validationRoseri Roelofsen-de Beer, Jos Wielders, Guilaine Boursier, Tatjana Vodnik, Florent Vanstapel, Wim Huisman, Ines Vukasović, Michel Vaubourdolle, Çiğdem Sönmez, Solveig Linko, Pika Meško-Brguljan, 2020, izvirni znanstveni članek Povzetek: This paper reflects the opinion of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group Accreditation and ISO/CEN standards (WG-A/ISO). It aims to provide guidance for drawing up local/national documents about validation and verification of laboratory methods. We demonstrate how risk evaluation can be used to optimize laboratory policies to meet intended use requirements as well as requirements of standards. This is translated in a number of recommendations on how to introduce risk evaluation in various stages of the implementation of new methods ultimately covering the whole process cycle.
Ključne besede: opinion paper, EFLM, ISO 15189:2012, validation, verification
Objavljeno v DiRROS: 10.08.2020; Ogledov: 1466; Prenosov: 430
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15. Post-fire effects on development of leaves and secondary vascular tissues in Quercus pubescensJožica Gričar, Polona Hafner, Martina Lavrič, Mitja Ferlan, Nives Ogrinc, Bor Krajnc, Klemen Eler, Dominik Vodnik, 2020, izvirni znanstveni članek Povzetek: An increased frequency of fire events on the Slovenian Karst is in line with future climate-change scenarios for drought-prone environments worldwide. It is therefore of the utmost importance to better understand tree-fire-climate interactions for predicting the impact of changing environment on tree functioning. To this purpose, we studied the post-fire effects on leaf development, leaf carbon isotope composition (%13C), radial growth patterns and the xylem and phloem anatomy in undamaged (H-trees) and fire-damaged trees (F-trees) of Q. pubescens with good re-sprouting ability in spring 2017, the growing season after a rangeland fire in August 2016. We found that the fully developed canopy of F-trees reached only half of the LAI values measured in H-trees. Throughout the season, F-trees were characterised by higher water potential and stomatal conductivity and achieved higher photosynthetic rates compared to unburnt H-trees. The foliage of F-trees had more negative %13C values than those of H-trees. This reflects that F-trees less frequently meet stomatal limitations due to reduced transpirational area and more favourable leaf-to-root ratio. In addition, the growth of leaves in F-trees relied more on the recent photosynthates than on reserves due to the fire disturbed starch accumulation in the previous season. Cambial production stopped 3 weeks later in F-trees, resulting in 60% and 22% wider xylem and phloem increments, respectively. A novel approach by including phloem anatomy in the analyses revealed that fire caused changes in conduit dimensions in the early phloem but not in the earlywood. However, premature formation of the tyloses in the earlywood vessels of the youngest two xylem increments in F-trees implies that xylem hydraulic integrity was also affected by heat. Analyses of secondary tissues showed that although xylem and phloem tissues are interlinked changes in their transport systems due to heat damage are not necessarily coordinated.
Ključne besede: pubescent oak, cambium, radial growth, xylem, phloem, anatomy, sub-Mediterranean
Objavljeno v DiRROS: 19.03.2020; Ogledov: 2497; Prenosov: 1327
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19. Inokulacija smreke (Picea abies /L./ Karsten) z mikoriznimi glivami : vpliv na rast in razvoj v drevesnici in po presaditviDominik Vodnik, Nada Gogala, 1997, izvirni znanstveni članek Ključne besede: mikoriza, inokulacija, smreka, gliva, rast sejank, uspevanje glive, fiziologija, dejavniki okolja, onesnaženost tal, Žerjav
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4493; Prenosov: 1917
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