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Abstract: V svetu invazivne tujerodne vrste rastlin (ITVR) povzročajo mnoge spremembe v okolju. Za zatiranje ITVR je znanih precej metod, primernost posamezne in posledično tudi uspešnost pa sta odvisni od vsakega primera posebej – predvsem od cilja, ki ga želimo doseči z zatiranjem. V študiji smo spremljali zatiranje navadne barvilnice v okviru nege mladja, tj. z rezjo pri tleh. Študija je potekala na objektu s površino 2,82 ha, dela so izvajali trije delavci. Cilji študije so bili ugotoviti porabo časa na površino in pridobiti manjkajoča znanja na področju izvajanja dodatnih ukrepov pri negi mladja. V povprečju so delavci za en hektar obžetve potrebovali 18,8 ure produktivnega časa. Po simulaciji študije na osemurni delavnik faktor neproduktivnega časa znaša 1,39 (σ = 0,053) in je nižji od priznanega državnega faktorja neproduktivnega časa (1,58) za sečnjo. Pri interpretaciji rezultatov je potrebna previdnost, ker so pri kratkotrajnih (manj obsežnih) študijah pogosto podcenjeni faktorji neproduktivnega časa. Teoretični izračun, ki temelji na linearni regresiji podatkov, kaže, da je za obžetev enega hektara v celoti potrebno okrog dvaindvajset ur. Kljub že tako nizkemu faktorju neproduktivnega časa je še rezerva za optimizacijo delovnega procesa, vendar so za to potrebne dolgotrajnejše in obsežnejše študije časa.
Keywords: gozdarstvo, invazivne rastline, zatiranje, nega pomladka, časovna študija, Phytolacca americana
Published in DiRROS: 24.07.2024; Views: 248; Downloads: 98
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Keywords: anatomija lesa, značilnosti lesa, drevesne vrste, oljka, (Olea europaea L.)
Published in DiRROS: 24.07.2024; Views: 283; Downloads: 110
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Abstract: Purpose Increased sedimentation due to land use intensification is increasingly affecting carbon processing in streams and rivers around the globe. This study describes the design of a laboratory-scale flow-through incubation system as a tool for the rapid estimation of sediment respiration. The measurements were compared with those obtained using an in situ closed chamber respiration method. The influence of sediment size on respiration rates was also investigated. Materials and methods Measurements were conducted on a pre-alpine gravel-bed river sediment separated into the following grain size fractions: > 60 mm (14.3%), 60–5 mm (60.2%), 5–2 mm (13.7%), 2–0.063 mm (11.1%) and <0.063 mm (0.6%). Concurrently, in situ and laboratory measurements were carried out on a naturally heterogeneous sediment. In situ respiration was determined in closed chambers as O2 consumption over time, while in the laboratory, respiration was determined using flow-through respiration chambers. Oxygen concentrations were measured using a fibre-optic oxygen meter positioned at the inflow and outflow from the chamber. Results and discussion The mean respiration rates within naturally mixed riverbed sediments were 1.27 ± 0.3 mg O2 dm−3 h−1 (n = 4) and 0.77 ± 0.1 mg O2 dm−3 h−1 (n = 3) for the flow-through chamber system and closed chamber system, respectively. Respiration rates were statistically significantly higher in the flow-through chamber system (t test, p < 0.05), indicating that closed chamber measurements underestimated the oxygen consumption within riverbed sediments. Sediment grain size was found to significantly affect respiration rates in both systems (ANOVA, p < 0.001) with the fine sediment fraction (particle size <0.063 mm) having the highest respiration rate (rflow-through = 51 ± 23 mg O2 dm−3 h−1). The smallest fractions (2–0.063 and <0.063 mm), which represent approximately 12% of total sediment volume, contributed 60% of total respiration. Conclusions The study demonstrated that flow-through respiration chambers more accurately estimate the respiration rate within riverbed sediments than in situ closed chambers, since the former experiment imitates the natural conditions where continuous interstitial flow occurs in the sediments. We also demonstrated that fine sediments (<5 mm) substantially contribute to heterotrophic respiration in the studied gravel-bed river.
Keywords: carbon fluxes, freshwaters, geomorphology, hyporheic zone, respiration, sediments
Published in DiRROS: 24.07.2024; Views: 274; Downloads: 169
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Abstract: Background: The aim of the study was to evaluate if artificial neural networks can predict high-grade histopathology results after conisation from risk factors and their combinations in patients undergoing conisation because of pathological changes on uterine cervix. Patients and methods: We analysed 1475 patients who had conisation surgery at the University Clinic for Gynaecology and Obstetrics of University Clinical Centre Maribor from 1993-2005. The database in different datasets was arranged to deal with unbalance data and enhance classification performance. Weka open-source software was used for analysis with artificial neural networks. Last Papanicolaou smear (PAP) and risk factors for development of cervical dysplasia and carcinoma were used as input and high-grade dysplasia Yes/No as output result. 10-fold cross validation was used for defining training and holdout set for analysis. Results: Baseline classification and multiple runs of artificial neural network on various risk factors settings were performed. We achieved 84.19% correct classifications, area under the curve 0.87, kappa 0.64, F-measure 0.884 and Matthews correlation coefficient (MCC) 0.640 in model, where baseline prediction was 69.79%. Conclusions: With artificial neural networks we were able to identify more patients who developed high-grade squamous intraepithelial lesion on final histopathology result of conisation as with baseline prediction. But, characteristics of 1475 patients who had conisation in years 1993-2005 at the University Clinical Centre Maribor did not allow reliable prediction with artificial neural networks for every-day clinical practice.
Keywords: artificial neural networks, conisation, uterine cervical cancer, uterine cervical dysplasia, displazija materničnega vratu, rak materničnega vratu, konizacija, umetne nevronske mreže
Published in DiRROS: 24.07.2024; Views: 272; Downloads: 153
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Abstract: The CDK4/6 inhibitor, ribociclib in combination with endocrine therapy significantly improved progression-free survival in the first line setting in post-menopausal patients with HR+/HER2- advanced breast cancer (ABC) in a pivotal phase 3, placebo-controlled trial (MONALEESA-2) and demonstrated superior overall survival in premenopausal patients with HR+/HER2- ABC (MONALEESA-7). The multinational, phase 3b, CompLEEment-1 trial, which assessed the safety and efficacy of ribociclib plus letrozole in a broader population of patients who have not received prior endocrine therapy for advanced disease, is the largest phase 3 clinical trial to date to evaluate the safety and efficacy of a CDK4/6 inhibitor. We report a subanalysis of data from patients (N = 339) enrolled in the central and south European countries of the SERCE (Southern Europe, RUC, Central Europe) cluster of CompLEEment-1. Patients and methods: Men and women of any menopausal status with HR+/HER2- ABC received once-daily oral ribociclib 600 mg (3-weeks on/1-week-off), plus letrozole 2.5 mg continuously. Men/premenopausal women also received a GnRH-agonist. The primary outcome was the number of patients with adverse events (AEs) over a timeframe of approximately 36 months. Time-to-progression, overall response rate, and clinical benefit rate were also measured. Results: Safety results in the SERCE subgroup were consistent with those in the pivotal clinical trials of ribociclib in combination with endocrine therapy. Treatment-related AEs leading to dose adjustments/interruption occurred in 63.1% of patients but led to treatment discontinuation in only 10.6%. The most common treatment-related AEs of grade ≥ 3 were neutropenia and transaminase elevations. There were no fatal treatment-related events. Conclusions: These findings from the SERCE subgroup support the safety and manageable tolerability of ribociclib in a broad range of patients with HR+/HER2- ABC more representative of patients in real-world clinical practice.
Keywords: CDK4/6 inhibitor, HER2−, HR+, advanced breast cancer, ribociclib
Published in DiRROS: 24.07.2024; Views: 246; Downloads: 228
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