Digital repository of Slovenian research organisations

Search the repository
A+ | A- | Help | SLO | ENG

Query: search in
search in
search in
search in

Options:
  Reset


Query: "author" (Pi��kur Mitja) .

61 - 70 / 286
First pagePrevious page3456789101112Next pageLast page
61.
62.
63.
Oljka, sušne razmere, tla in deficitno namakanje
Maja Podgornik, Jakob Fantinič, Milena Bučar-Miklavčič, Vasilij Valenčič, Bojan Butinar, Dominik Vodnik, Helena Gramc, Damijana Kastelec, Mitja Ferlan, Marina Pintar, 2022, scientific monograph

Abstract: Monografija obsega pregled znanja na področju prilagoditve oljk na sušne razmere ter pregled tehnologij namakanja oljk. Res je, da je oljka manj zahtevna vrsta, saj lahko uspeva v izjemno skeletnih tleh in je zelo dobro prilagojena na pomanjkanje vode v njih, a kljub fiziološkim prilagoditvam, lahko sušne razmere negativno vplivajo na rast, razvoj in pridelek oljk. Sušni stres lahko pri oljkah blažimo z deficitnim namakanjem. Deficitni način namakanja je oblika nadgradnje namakanja, saj z nadzorovanim primanjkljajem vode zagotovimo kakovost pridelka, obstoj rastline ter hkrati zmanjšamo porabo vode in energije. Deficitni način namakanja, temelji na načelu, da obrok vode dodamo takrat, ko ga rastlina najbolj gospodarno uporabi. Pri tem je ključnega pomena poznavanje rastlinske vrste, njenih anatomskih in morfoloških značilnosti, fizioloških prilagoditev na sušo, biokemijski odziv na stresne dejavnike in s tem vpliv na kakovost plodov in olja. Poleg tega je potrebno tudi poznavanje dejavnikov, ki vplivajo na pridelovalne sposobnosti oljk, kot so lastnosti tal s svojimi vodno zadrževalnimi sposobnostmi ter dostopna voda v tleh. Ob skrbnem upoštevanju potreb rastline in okoljskih razmer z ustreznim delovanjem namakalnega sistema lahko dosežemo usklajeno razmerje med kakovostjo in količino pridelka o hkratnem varovanju potencialov naravnih virov.
Published in DiRROS: 14.06.2022; Views: 654; Downloads: 444
.pdf Full text (8,87 MB)
This document has many files! More...

64.
Artificial neural networks as an alternative method to nonlinear mixed-effects models for tree height predictions
Mitja Skudnik, Jernej Jevšenak, 2022, original scientific article

Abstract: Tree heights are one of the most important aspects of forest mensuration, but data are often unavailable due to costly and time-consuming field measurements. Therefore, various types of models have been developed for the imputation of tree heights for unmeasured trees, with mixed-effects models being one of the most commonly applied approaches. The disadvantage here is the need of sufficient sample size per tree species for each plot, which is often not met, especially in mixed forests. To avoid this limitation, we used principal component analysis (PCA) for the grouping of similar plots based on the most relevant site descriptors. Next, we compared mixed-effects models with height-diameter models based on artificial neural networks (ANN). In terms of root mean square error (RMSE), mixed-effects models provided the most accurate tree height predictions at the plot level, especially for tree species with a smaller number of tree height measurements. When plots were grouped using the PCA and the number of observations per category increased, ANN predictions improved and became more accurate than those provided by mixed-effects models. The performance of ANN also increased when the competition index was included as an additional explanatory variable. Our results show that in the pursuit of the most accurate modelling approach for tree height predictions, ANN should be seriously considered, especially when the number of tree measurements and their distribution is sufficient.
Keywords: height-diameter models, national forest inventory, permanent sample plot, mixed forests, model comparison, principal component analysis
Published in DiRROS: 08.06.2022; Views: 495; Downloads: 206
URL Link to file

65.
66.
67.
Natural history of the hymenoptera venom sensitivity reactions in adults : study design
Simona Perčič, Lidija Bojanić, Mitja Košnik, Andreja Kukec, 2022, original scientific article

Abstract: Background: Allergic reactions to Hymenoptera stings can have varying levels of severity, according to the Müller grading system. Methods: By an epidemiological concept, this is a retrospective cohort study. The observed cohort was represented by patients referred to the University Clinic Golnik due to Hymenoptera allergic reaction in the period from 1997 to 2015. From the immunological database of the University Clinic Golnik, we obtained laboratory data (sIgE, skin tests and basophil activation test). The clinical characteristics of patients were obtained from BIRPIS. With the help of a questionnaire, which was sent to each patient in the period from May 2019 to April 2021, we obtained epidemiological data. For the assessment of the association between the severity of allergic reaction for the observed outcome, the severity of the first allergic reaction after Hymenoptera sting was used. Other variables were grouped according to risk factors. Discussion: We will identify the risk factors that could play an important role in a severe systemic reaction: the aetiology of the Hymenoptera sting, sex, age, history and severity of previous systemic reactions, being re-stung in an interval of two months, the frequency of re-stings, atopy, genetic predisposition, preventive medication use, other medication use, beekeeping or living next to beehives and why immunotherapy was not taken. Laboratory data will also be analysed to determine if there is any association with laboratory tests and the severity of the allergic reactions after Hymenoptera stings. Conclusions: Several new approaches are introduced in the study design. The most important is that the protocol covers epidemiological data gained from the questionnaire, as well as clinical data gained from the Immunological database and BIRPIS database. We expect to obtain significant results that will explain the risk factors for the natural history of Hymenoptera sting allergic reactions and will help allergologists, as well as general doctors, when facing those patients allergic to Hymenoptera venom without immunotherapy.
Keywords: hymenoptera venom allergy, risk factors, epidemiological association
Published in DiRROS: 06.04.2022; Views: 779; Downloads: 347
.pdf Full text (786,63 KB)

68.
Characterizing the groundwater flow regime in a landslide recharge area using stable isotopes: a case study of the Urbas landslide area in NW Slovenia
Katja Koren, Luka Serianz, Mitja Janža, 2022, original scientific article

Abstract: Slope stability strongly depends on the prevailing hydrological and hydrogeological conditions. The amount and intensity of precipitation and changing groundwater levels are important landslide triggering factors. Environmental tracers, including the chemical and stable isotope compositions of precipitation and groundwater, were used to gain insight into the groundwater dynamics of the Urbas landslide. The landslide is situated in a mountainous area with steep slopes and high precipitation amount and poses a high risk for the safety of the Koroška Bela settlement that lies downstream. The stable isotope analyses of oxygen-18 (18O) and deuterium (2H) in the precipitation and groundwater were used to estimate the groundwater mean residence time and the average altitude of the landslide recharge area. This information will help to plan and prioritize remedial landslide measures aiming to reduce the recharge of the landslide body and, thus, lower the risk of transformation of the sliding material into debris flow. The results of the chemical analysis of samples taken from springs and a piezometer show a Ca–HCO3 water type. This indicates low water–rock interaction in a landslide area composed of Upper Carboniferous and Permian clastic rocks and points to upper laying carbonate rocks and scree deposits as the main recharge area. Water samples for stable isotope analyses of δ18O and δ2H were collected from a rain gauge, springs, and a piezometer over a two-year period (2018–2020). The estimated mean recharge altitude of the groundwater at sampling points was from approximately 1700 to 1800 m a.s.l. with a mean residence time of 2–5 months.
Keywords: landslide, groundwater, stable isotopes, oxygen-18, deuterium, hydrogeology, recharge dynamic
Published in DiRROS: 16.03.2022; Views: 696; Downloads: 296
.pdf Full text (3,55 MB)

69.
70.
Search done in 0.34 sec.
Back to top