1491. Palaeoecological significance of the trace fossil Circulichnis Vyalov, 1971 from the Carboniferous of the Donets Basin, UkraineVitaly Dernov, 2024, izvirni znanstveni članek Povzetek: The ichnogenus Circulichnis Vyalov is a horizontal a ring- or ellipse-shaped burrow and/or locomotion trace of an unknown producer, most likely an annelid or a “worm”, preserved on the bedding plane. This ichnogenus is known over a wide age interval (Ediacaran–Oligocene). Circulichnis demonstrates a wide ecological range and has been found in continental (Mermia ichnofacies), shelf, and relatively deep-water (turbidites) deposits. It is commonly interpreted as a sediment feeding trace, but the peculiarities of its formation remain somewhat mysterious, as it is unclear how the tracemaker reached the sediment surface, as lateral branches of the ring-shaped traces are extremely rare and have only been observed by a few researchers. A rather large specimen of Circulichnis montanus Vyalov, 1971 with a preserved lateral branch was found in the Mospyne Formation (upper Bashkirian, Lower Pennsylvanian) of the Donets Basin. This discovery confirmed the assumption made by Alfred Uchman and Bruno Ratazzi regarding the peculiarities of formation of Circulichnis. According to these authors, a single ring-shaped Circulichnis indicates an attempt to forage at a specific level in the sediment, while the lateral branches of Circulichnis are part of a vertical shaft leading to another level within the sediment. The study of Circulichnis montanus from the Donets Basin has confirmed that at least variant C of the Circulichnis formation scheme proposed by Uchman and Ratazzi is correct, i.e. the lateral branch is a horizontal or subhorizontal part of a generally vertical shaft. However, it is important to note that the correctness of variants A and B of the Uchman and Ratazzi scheme cannot be excluded. To answer this question unequivocally, new finds of well-preserved Circulichnis are necessary.
Ključne besede: trace fossils, Circulichnis, Pennsylvanian, Ukraine
Objavljeno v DiRROS: 09.07.2024; Ogledov: 254; Prenosov: 150
 Celotno besedilo (5,35 MB) |
1492. Signs of crustal extension in Lower Jurassic carbonates from central SloveniaLuka Gale, Boštjan Rožič, 2024, izvirni znanstveni članek Povzetek: The Lower Jurassic Podbukovje Formation represents a succession of shallow marine carbonate rocks deposited on the former Southern Tethyan Megaplatform and one of its successors, the Adriatic Carbonate Platform. Several outcrops of the Podbukovje Formation from central Slovenia (southern margin of the Ljubljana Moor) are presented, bearing possible evidence of Early Jurassic extensional tectonics. Peritidal facies of the lowermost, Hettangian – Sinemurian, part of the Podbukovje Formation locally interfingers with bodies of matrix supported pervasively dolomitized polymictic breccia, several metres to tens of metres thick and is locally cut by neptunian dykes some few decimetres to metres wide. The same or slightly younger part of the formation locally contains grabens/half-grabens metres to tens of metres deep and filled with poorly sorted pervasively dolomitized matrix supported polymictic breccia. Small miliolid foraminifera are present within the clasts and in the matrix. Finally, partly dolomitized blocky breccia tens of metres thick locally overlies the Pliensbachian – lowermost Toarcian limestone with lithiotid bivalves. Besides completely and partly dolomitized clasts, the breccia contains a variety of limestone clasts and preserves common radial ooids and some bioclasts within the partially dolomitized matrix.
The Hettangian-Sinemurian breccias and dykes are presumably related to the early, diffused rifting stage of the Penninic (Alpine Tethys) Ocean, whereas Toarcian breccias relate to the main, focused rifting stage. Together with evolving biota and changing paleo-oceanographic conditions, the extensional tectonics may have been an important factor behind the facies changes observed within the Podbukovje Formation
Ključne besede: carbonate platform, External Dinarides, Early Jurassic, Podbukovje Formation, neptunian dyke, breccia
Objavljeno v DiRROS: 09.07.2024; Ogledov: 266; Prenosov: 128
Celotno besedilo (10,26 MB) |
1493. Hydrogeochemical and isotopic characterisation of the Učja Aquifer, NW SloveniaPetra Žvab Rožič, 2024, izvirni znanstveni članek Povzetek: The groundwater characteristics of the Učja aquifer were investigated using geochemical and isotopic data. The water discharge and physico-chemical properties of the groundwater and the Učja River reflect the climate that is characteristic of the area. The mixed snow/rainfall regime is characteristic for the Učja Valley, with the highest discharges appearing during the spring snowmelt and autumn precipitation, and the lowest discharges in the winter and especially summer months. The temperature of the groundwater and the Učja River is lower in winter and higher in summer. The specific electrical conductivity values indicate a very permeable carbonate aquifer. Higher conductivity values were observed in spring and autumn at all sampling sites, which is related to snowy and rainy periods. The groundwater from the Učja aquifer indicates a uniform type of water (Ca-Mg-HCO3), w it h Ca2+, Mg2+ and HCO3– the most abundant ions. Differences in Ca2+ and Mg2+ concentrations and in the Mg2+/Ca2+molar ratio between sampling sites were observed. Those springs with lower Mg2+ and lower Mg2+/Ca2+ molar ratios indicate limestone recharge areas, and those springs with higher Mg2+ and molar ratios indicate interaction with the dolomite hinterland. The pH values confirm alkaline waters characteristic of carbonate aquifers. The hydrogen (δ2H) and oxygen (δ18O) isotope values suggest the main source of water is from precipitation from a complex mixing of maritime and continental air masses. An altitude isotopic effect is observed with minor δ18O and δ2H depletion at higher altitude sampling sites compared to those springs at lower altitudes. The altitude isotopic effect is most prominent in spring. The δ13CDIC values indicate the dissolution of carbonates and the degradation of organic matter.
Ključne besede: groundwater, hydrogeochemistry, isotopes, cross-border aquifer, Učja Valley
Objavljeno v DiRROS: 09.07.2024; Ogledov: 272; Prenosov: 158
Celotno besedilo (4,48 MB) |
1494. Vsebnosti potencialno strupenih elementov v sedimentih in vodah reke Meže in njenih pritokov, ki odvodnjavajo odlagališča rudarskih odpadkovMateja Gosar, Špela Bavec, Miloš Miler, Martin Gaberšek, 2024, izvirni znanstveni članek Povzetek: Predstavljeni so rezultati spremljanja vsebnosti potencialno strupenih elementov (PSE) v sedimentih (v letih 2013, 2017, 2020) in vodah (v letih 2017, 2020) reke Meže ter njenih pritokov, ki odvodnjavajo odlagališča rudarskih odpadkov. Skupno 13 vzorčnih mest je vzpostavljenih v vzorčni shemi, ki omogoča dolgoročno opazovanje vpliva odlagališč rudarskih odpadkov. V sedimentih so zaradi vplivov več kot 300-letnega delovanja rudarsko-predelovalne industrije močno povečane vsebnosti PSE, predvsem Pb, Zn, Cd, Mo in As, ki s časom precej nihajo. Razlike v vsebnostih na istih lokacijah v različnih letih so najbolj izrazite v pritokih reke Meže, ki drenirajo odlagališča rudarskih odpadkov. Na vsebnosti imajo pomemben vpliv hidrološki pogoji, saj so ob višjem vodostaju in višjem pretoku vsebnosti PSE večje. Vodna erozija odlagališč ima pomemben vpliv na dotok onesnaženega materiala v vodotoke. V nasprotju s pritoki, v zgornjem toku reke Meže nismo opazili večjega vpliva višjega vodostaja in pretoka na vsebnosti PSE v sedimentih. Dolvodno od Žerjava so nihanja vsebnosti med posameznimi leti oz. različnimi hidrološkimi pogoji tudi v Meži večja. Predstavljeni rezultati kažejo, da so v sedimentih reke Meže in njenih pritokov vsebnosti Pb, Zn, Cd, Mo in As zelo velike ter krepko presegajo zakonsko določeno kritično vrednost za tla. V površinski vodi so vsebnosti PSE lokalno povečane in se s časom bistveno ne spreminjajo. Glede na primerjavo z zakonodajnimi smernicami, so v obravnavanih vodah lokalno presežene koncentracije Pb, Cd in Zn. Ocenjujemo, da je dinamika obremenjenosti sedimentov reke Meže s PSE vzdolž krajev Črna na Koroškem, Žerjav in Mežica zelo kompleksna. Poleg odlagališč rudarskih odpadkov na vsebnosti PSE v sedimentih in vodah vplivajo tudi razpršeni viri v okolju, kot so onesnažena tla in poplavne ravnice ter njihova različna stopnja onesnaženosti, saj je okolje obremenjeno zaradi dolgoletnih rudarskih in talilniških dejavnosti. Dodaten okoljski vpliv ima morda tudi sedanja industrijska dejavnost v dolini reke Meže.
Ključne besede: rudarjenje, rudarski odpadki, odlagališča odpadkov, potencialno strupeni elementi, rečni sedimenti, monitoring, onesnaženje okolja
Objavljeno v DiRROS: 09.07.2024; Ogledov: 324; Prenosov: 160
Celotno besedilo (3,23 MB) |
1495. Petrology dataset of Pliocene-Pleistocene sediments in northeastern SloveniaEva Mencin Gale, Polona Kralj, Mirka Trajanova, Luka Gale, Dragomir Skaberne, 2024, drugi znanstveni članki Povzetek: This is a dataset of petrological analysis of Pliocene-Pleistocene f luvial sediments from 14 gravely samples from the Slovenj Gradec, Nazarje, Celje and Drava-Ptuj Basin (northeastern Slovenia), collected for clast lithological analysis. The petrological analysis includes description of 155 thin sections of metamorphic, volcanic, volcaniclastic, clastic and carbonate rocks. This dataset provides grounds for determining the provenance of these gravel deposits, revealing possible resedimentation processes, and serves as a tool for drainage network interpretation in the Pliocene-Pleistocene.
Ključne besede: petrografska analiza, litološka analiza klastov, provenienca klastov, pliocensko-pleistocenski sedimenti
Objavljeno v DiRROS: 09.07.2024; Ogledov: 291; Prenosov: 132
Celotno besedilo (2,92 MB) |
1496. Exploring the safety of cannabidiol (CBD) : a comprehensive in vitro evaluation of the genotoxic and mutagenic potential of a CBD isolate and extract from Cannabis sativa LAlja Štern, Matjaž Novak, Katja Kološa, Jurij Trontelj, Sonja Žabkar, Tjaša Šentjurc, Metka Filipič, Bojana Žegura, 2024, izvirni znanstveni članek Povzetek: Cannabidiol (CBD), a naturally occurring cyclic terpenoid found in Cannabis sativa L., is renowned for its diverse
pharmacological benefits. Marketed as a remedy for various health issues, CBD products are utilized by patients
as a supplementary therapy or post-treatment failure, as well as by healthy individuals seeking promised advantages. Despite its widespread use, information regarding potential adverse effects, especially genotoxic
properties, is limited. The present study is focused on the mutagenic and genotoxic activity of a CBD isolate
(99.4 % CBD content) and CBD-rich Cannabis sativa L extract (63.6 % CBD content) in vitro. Both CBD samples
were non-mutagenic, as determined by the AMES test (OECD 471) but exhibited cytotoxicity for HepG2 cells
(~IC50 (4 h) 26 µg/ml, ~IC50 (24 h) 6–8 µg/ml, MTT assay). Noncytotoxic concentrations induced upregulation of
genes encoding metabolic enzymes involved in CBD metabolism, and CBD oxidative as well as glucuronide
metabolites were found in cell culture media, demonstrating the ability of HepG2 cells to metabolize CBD. In this
study, the CBD samples were found non-genotoxic. No DNA damage was observed with the comet assay, and no
influence on genomic instability was observed with the cytokinesis block micronucleus and the γH2AX and p-H3
assays. Furthermore, no changes in the expression of genes involved in genotoxic stress response were detected in
the toxicogenomic analysis, after 4 and 24 h of exposure. Our comprehensive study contributes valuable insights
into CBD’s safety profile, paving the way for further exploration of CBD’s therapeutic applications and potential
adverse effects.
Ključne besede: cannabidiol, CBD, metabolism, cytotoxicity, genotoxicity, mutagenicity
Objavljeno v DiRROS: 09.07.2024; Ogledov: 274; Prenosov: 218
Celotno besedilo (4,31 MB)
Gradivo ima več datotek! Več... |
1497. A new perspective on the molecular dating of the stone crayfsh with an extended phylogeographic information on the speciesDavid Stanković, Katarina Zorić, Simona Đuretanović, Gorana Stamenković, Marija Ilić, Vanja Marković, Saša Marić, 2024, izvirni znanstveni članek Povzetek: Reconstructing the origin and historical
biogeography of the Austropotamobius torrentium is
hampered by insufcient phylogeographic coverage
of the Balkans and deep contradictions in previous
molecular dating. The present work extends the phylogeographic coverage to Serbia, a country crucial for
understanding the species southward dispersal. Our
analysis revealed that the Southern Balkans lineage
occurs in most of the country, the Central and southeastern Europe lineage is restricted to the southwest
and northeast of the country, while a single population in the north of the country harbors the Lika and
Dalmatia lineage, which was previously thought to be
restricted to the northern-central Dinarides. Dataset
expansion led to revised phylogenetic relationships,
which indicated that the Apuseni lineage is not nested
within Northern-central Dinarides lineages but arose
after the most basal split within Austropotamobius
torrentium. This ‘Apuseni frst’ phylogeny provides
a new perspective for molecular dating, according to
which the split between Austropotamobius pallipes
and A. torrentium took place in the Late Oligocene,
while the formation of the phyletic lineages and the
dispersal from the Dinarides to Serbia occurred in
the late Miocene and is probably associated with the
complex and protracted process of disintegration of
the Neogene freshwater lakes in southeastern Europe.
Ključne besede: Austropotamobius torrentium, Austropotamobius bihariensis, divergence time estimation conficts, historical biogeography, neogene lakes, Serbia
Objavljeno v DiRROS: 09.07.2024; Ogledov: 322; Prenosov: 227
Celotno besedilo (3,73 MB)
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1498. Five-year monitoring of the ecological status of the Cymodocea nodosa meadow near the Port of KoperMartina Orlando-Bonaca, Diego Bonaca, Romina Bonaca, Erik Lipej, Domen Trkov, 2024, izvirni znanstveni članek Povzetek: Seagrass meadows are among the most productive ecosystems in marine environments worldwide and are
often considered to symbolise near-pristine conditions on sedimentary bottoms, but their condition is associated to various types of anthropogenic stressors. In the Mediterranean Sea, Cymodocea nodosa is considered
an effective indicator of environmental change, due to its universal distribution, its sensitivity to various natural
and anthropogenic pressures, and the measurability of the species’ responses to these impacts. The aim of this
study is to present the improvement of the ecological status of the C. nodosa meadow near the port of Koper
over a period of five years and to compare these results with the reference site in the northern Adriatic Sea.
Ključne besede: Cymodocea nodosa, MediSkew index, Port of Koper, status assessment, northern Adriatic Sea
Objavljeno v DiRROS: 09.07.2024; Ogledov: 372; Prenosov: 258
Celotno besedilo (1,49 MB)
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1499. Singular $p$-biharmonic problem with the Hardy potentialAmor Drissi, Abdeljabbar Ghanmi, Dušan Repovš, 2024, izvirni znanstveni članek Povzetek: The aim of this paper is to study existence results for a singular problem involving the $p$-biharmonic operator and the Hardy potential. More precisely, by combining monotonicity arguments with the variational method, the existence of solutions is established. By using the Nehari manifold method, the multiplicity of solutions is proved. An example is also given to illustrate the importance of these results.
Ključne besede: p-biharmonic equation, variational methods, existence of solutions, Hardy potential, Nehari manifold, fibering map
Objavljeno v DiRROS: 08.07.2024; Ogledov: 375; Prenosov: 148
Celotno besedilo (436,45 KB)
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