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TAPHONOMIC AND PALAEOECOLOGICAL ALALYSIS OF THE LARG AVIFAUNAL REMAINS FROM THE ŠANDALJA II AND VLAKNO CAVES
No full textŠpilje Šandalja II u Istri i Vlakno na Dugom otoku važna su paleontološka nalazišta na kojima su pronađeni mnogobrojni fosilni, ali i arheološki ostaci iz gornjeg pleistocena i holocena. Rad je temeljen na anatomsko-taksonomskoj i tafonomskoj analizi uzoraka skeletnih ostataka velikih ptica prikupljenih za vrijeme iskopavanja samih lokaliteta. Na temelju rezultata dobivenih analizom ptičjih kostiju, utvrđeni su načini akumulacije u špiljama te paleoekološka i paleoklimatska situacija na prostoru Velike Jadranske ravnice u razdoblju gornjeg pleistocena (MIS2). U okolici špilje Vlakno u tom su razdoblju zastupljena dominantno vodena staništa, zatim otvorena staništa, stjenovita, mješovita te šumskih stepa. Dominantni čimbenici akumulacije u obje špilje su ljudi.Caves Šandalja II in Istria and Vlakno on Dugi Otok are important paleontological sites where numerous fossil and archaeological remains from the Upper Pleistocene and Holocene have been found. The study is based on anatomical-taxonomic and taphonomic analysis of samples of skeletal remains of large birds collected during excavations at the sites. Based on the results obtained from the analysis of bird bones, the modes of accumulation in the caves and the paleoecological and paleoclimatic conditions in the area of the Great Adriatic Plain during the Upper Pleistocene (MIS2) period have been determined. In the vicinity of Vlakno Cave during that period, predominantly aquatic habitats, followed by open habitats, rocky areas, mixed habitats, and forested steppes were represented. The dominant factors of accumulation in both caves are humans
Mineralogical and geochemical properties of bauxite from the open-pit mine Karamarkuša near Obrovac
No full textLežište boksita Karamarkuša nalazi se u okolici Obrovca, Hrvatska. Boksiti leže na krednim vapnencima i prekriveni su sedimentima paleogenske starosti. Prikupljeni uzorci analizirani su prolaznom i reflektirajućom svjetlosnom mikroskopijom, rendgenskom difrakcijom na prahu (XRPD), pretražnom elektronskom mikroskopijom s energijskom disperzivnim spektroskopom (SEM-EDS), infracrvenom spektroskopijom s Fourierovom transformacijom (FT-IR) te BCR sekvencijskom kemijskom analizom kako bi se utvrdile mineraloške i geokemijske karakteristike ležišta. Svi uzorci sadrže böhmit, gibbsit, goethit, hematit i anatas uz varijabilne količine kaolinita. Ovakav mineralni sastav ukazuje na umjereno oksidativne uvjete taloženja. Prosječna koncentracija elemenata rijetkih zemalja (REE) iznosi 524 ppm, s lokalnim obogaćenjima većim od 1000 ppm. Koncentracija REE raste s povećanjem dubine mineralnog ležišta. Sekvencijskom kemijskom analizom utvrđeno je da je približno 60 % REE vezano uz rezistentne minerale, uključujući cirkon, čija je prisutnost potvrđena FT-IR spektroskopijom. Geokemijska analiza pokazala je blagu negativnu europijevu anomaliju. Također, utvrđeno je da se cerij adsorbira u većoj mjeri od ostalih elemenata rijetkih zemalja na okside i hidrokside željeza, što može utjecati na njegovu mobilnost i raspodjelu u ležištu. Cerijeva anomalija i omjer La/Y upućuju na izmjene između kiselih i bazičnih uvjeta taloženja.The Karamarkuša bauxite deposit is located in the vicinity of Obrovac, Croatia. The bauxites lie on Cretaceous limestones and are covered by Paleogen sediments. Collected samples were analyzed using transmitted and reflected light microscopy, X-ray powder diffraction (XRPD), Scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FT-IR), and BCR sequential chemical analysis to determine the mineralogical and geochemical characteristics of the deposit. All samples contain böehmite, gibbsite, goethite, hematite, and anatase with variable amounts of kaolinite. This mineral composition indicates moderately oxidative depositional conditions. The average concentration of rare earth elements (REE) is 524 ppm, with local enrichments exceeding 1000 ppm. REE concentration increases with depth in the mineral deposit. Sequential chemical analysis determined that approximately 60% of REE are bound to resistant minerals, including zircon, whose presence was confirmed by FT-IR spectroscopy. Geochemical analysis revealed a slight negative europium anomaly. Additionally, it was found that cerium adsorbs to iron oxides and hydroxides more than other rare earth elements, which may influence its mobility and distribution in the deposit. The cerium anomaly and the La/Y ratio indicate variations between acidic and basic depositional conditions
Investigation of the properties and factors affecting concentrations and size distribution of ultrafine aerosol particles during winter in the city of Zagreb
No full textUltrafine lebdeće čestice promjera manjeg od 100 nm (PM0,1) nastaju direktnom emisijom iz prirodnih/antropogenih izvora i/ili sekundarnim procesima iz plinova u atmosferi. Prvo ispitivanje ultrafinih lebdećih čestica u Zagrebu provedeno je u stvarnom vremenu primjenom skenirajućeg sustava za određivanje veličine čestica u razdoblju od 5. siječnja do 15. veljače 2024. Etalometar je omogućio mjerenja crnog ugljika u česticama (indikator izgaranja biomase i fosilnih goriva) u stvarnom vremenu dok su kaskadnim uzorkovačem sakupljene veličinske frakcije lebdećih čestica (od 10 nm do 32 μm) kojima je gravimetrijskom metodom određena masa te koncentracije organskog ugljika primjenom visokotemperaturne katalitičke oksidacije. Dobiveni podaci uspoređeni su s meteorološkim podacima te koncentracijama PM10, PM2,5, NO2, SO2 i O3. Statističkom obradom podataka omogućen je uvid u promjenjivost koncentracija ultrafinih čestica, uključujući njihove nukleacijske (PM0,02) i Aitkenove (PM0,02-0,1) frakcije te razlučivanje dominantnih utjecaja na njihovo stvaranje i starenje u gradu Zagrebu.Ultrafine aerosol particles (diameter < 100 nm, PM0,1) are emitted directly from natural/anthropogenic sources and/or formed by secondary processes from gasses in the atmosphere. The first real time investigation of ultrafine particles in Zagreb was conducted using a Scanning Mobility Particle Sizer (SMPS) system from January 5 to February 15, 2024. Real time black carbon (indicator of biomass burning and fossil fuel combustion) was measured using an aethalometer, while aerosol size fractions (10 nm to 32 μm) collected using a cascade impactor were analysed by gravimetric methods to determine the mass and by high-temperature catalytic oxidation to determine the concentration of organic carbon. The data obtained were correlated with meteorological data and concentrations of PM10, PM2.5, NO2, SO2, and O3. Statistical analysis provided insights into the variability of ultrafine particle concentrations, including their nucleation (PM0.02) and Aitken (PM0.02-0.1) fractions, and enabled identification of dominant factors influencing their formation and aging in Zagreb
Synthesis of fulleretic composite materials by liquid-directed mechanochemical templation
No full textPredmet istraživanja je usmjeravajući učinak tekućine i fulerena u kontroliranoj mehanokemijskoj sintezi polimorfnih i kompozitnih faza cinkova imidazolata. Osim dosad poznatih faza cinkova imidazolata čije su strukture „preguste“ za apsorpciju fulerena, pripravljene su tri nove topologije kompozita cinkova imidazolata s fulerenom: C 70 @CHA- ZnIm 2 i C 60 @CHA-ZnIm 2 , C60 @X-ZnIm 2 i C 60 @T-ZnIm 2 . X i T faze su zasad nove i nepoznate topologije. Dobiveni spojevi su izučavani difrakcijom rentgenskih zraka na praškastim uzorcima, termogravimetrijom, infracrvenom spektroskopijom i elektronskom spinskom rezonancijom. Dok se CHA-ZnIm 2 i X-ZnIm 2 faza mogu pripraviti samo uz prisustvo fulerena, T-ZnIm 2 faza se može pripraviti i bez fulerena, ali manje količine enkapsuliranog fulerena dodatno stabiliziraju ovu nestabilnu fazu. Količina apsorbiranog fulerena ovisi o vrsti i količini dodanog fulerena (C 60 ili C70 ) i o tipu faze kompozita.The subject of research is the directing effect of liquid and fullerene in the controlled mechanochemical synthesis of polymorphic and composite phases of zinc imidazolate. In addition to the previously known zinc imidazolate phases whose structures are “too dense” for fullerene absorption, the inclusion of fullerene in the structure stabilized three new topologies of zinc imidazolate composites: C70 @CHA-ZnIm 2 and C 60 @CHA-ZnIm 2 , C 60 @X-ZnIm 2 and C 60 @T-ZnIm 2 . X and T phases have a new unreported topology. The obtained compounds were studied by X-ray diffraction on powder samples, thermogravimetry, infrared spectroscopy and electronic paramagnetic resonance. While the CHA-ZnIm 2 and X-ZnIm 2 phases can only be prepared with the addition of fullerene, T-ZnIm 2 phase can be prepared without the presence of fullerenes, but small amounts of encapsulated fullerene additionally stabilize the otherwise unstable phase. The amount of fullerene absorbed depends on the type of fullerene (C 60 or C 70 ), the amount of added fullerene and the type of composite phase
A contribution on the knowledge of the horticultural flora of Croatia
No full textUresna flora Hrvatske se razlikuje na kopnenom i obalnom dijelu zbog utjecaja reljefa, klime, dostupnosti biljnog materijala i kreativnosti stanovništva. Analizirano je osam ranijih florističkih istraţivanja s područja kontinentalne (Donja Stubica, Karlovac, Posavski Bregi, Virovitica) i obalne (Dubrovnik, Opatija, Susak, Veli Lošinj) Hrvatske. Dokumentirano je 457 svojti iz 106 porodica kontinentalne, te 473 svojte iz 123 porodice obalne Hrvatske. Najzastupljenije porodice kontinentalnog dijela su Asteraceae, Ranunculaceae, Rosaceae i Pinaceae, a obalnog dijela su Rosaceae, Asteraceae, Lamiaceae i Fabaceae. U kontinentalnom području najzastupljenije su euroazijske i hortikulturne svojte, dok u obalnom području dominiraju svojte azijskog, zatim euroazijsko-sjevernoafričkog (tj. sredozemnog) podrijetla. Najzastupljeniji ţivotni oblik je zeljasta trajnica, ali se u velikom broju pojavljuju i listopadni/zimzeleni grm te listopadno/zimzeleno drvo. S obzirom na status u Hrvatskoj prevladavaju alohtone svojte u kulturi i autohtone svojte, ali zabiljeţeno je i deset invazivnih svojti na obalnom te sedam na kontinentalnom području Hrvatske.The horticultural flora of Croatia differs on the mainland and the coastal part due to the influence of relief, climate, availability of plant material and the creativity of the population. Eight earlier floristic surveys from continental (Donja Stubica, Karlovac, Posavski Bregi, Virovitica) and coastal (Dubrovnik, Opatija, Susak, Veli Lošinj) areas of Croatia were analyzed. 457 taxa from 106 families of continental Croatia and 473 taxa from 123 families of coastal Croatia were documented. The most represented families of the continental part are Asteraceae, Ranunculaceae, Rosaceae and Pinaceae, and of the coastal part are Rosaceae, Asteraceae, Lamiaceae and Fabaceae. In the continental area, Euro-Asian and horticultural taxa are most represented, while in the coastal area taxa of Asian, then Euro-Asian-North African (ie Mediterranean) origin dominate. The most common life form is a herbaceous perennial, but there are also deciduous/evergreen shrubs and deciduous/evergreen trees in large numbers. Regarding the status in Croatia, allochthonous taxa in culture and autochthonous taxa predominate, but ten invasive taxa were also recorded on the coastal and seven on the continental area of Croatia
Effect of microplastics treated with heavy metals on physiological and biochemical stress parameters in duckweed (Lemna minor)
No full textMikroplastika (MP) je kompleksno onečišćivalo te je sveprisutna u morskim, slatkovodnim i kopnenim ekosustavima. Pod utjecajem abiotičkih i biotičkih čimbenika njezina se svojstva mijenjaju, a time i potencijalna toksičnost za okoliš. U ovom radu je istražen utjecaj čiste MP (smjesa polietilena, polistirena, polipropilena i gume), kao i MP tretirane smjesom teških metala (olovo, cink i bakar) na vodenu leću (Lemna minor L.) putem Lemna testa i različitih fizioloških i biokemijskih pokazatelja stresa (sadržaj fotosintetskih pigmenata, karbonila i malondialdehida, te aktivnost antioksidacijskih enzima). Rezultati su pokazali da dolazi do otpuštanja metala s površine MP u hranjivu podlogu. Utvrđeno je nakupljanje Zn i Cu u vodenoj leći izloženoj najvećoj koncentraciji MP. Sedmodnevno izlaganje vodene leće česticama čiste MP ili MP s adsorbiranim metalima nije bitno utjecalo na rast vodene leće, izuzev čiste MP u koncentraciji 100 i 1000 čestica/L. Mikroplastika je izazvala promjene u aktivnosti antioksidacijskih enzima, no nije utvrđena lipidna peroksidacija ni oksidacijsko oštećenje proteina. Zamijećena je jača adsorpcija čestica MP (uglavnom polipropilena) na listićima vodene leće. Na temelju dobivenih rezultata može se zaključiti da je vodena leća pogodna za fitoremedijaciju čestica MP.Microplastics (MP) are very complex pollutants that are ubiquitous in the marine, freshwater and terrestrial enviroments. MP is affected by various biotic and abiotic factors that can change its properties and potential toxicity for the environment. In the present study, the effect of pristine MP (mixture of polyethylene, polypropylene, polystyrene and tyre wear particles) and MP treated with heavy metals (lead, copper, zinc) on duckweed (Lemna minor L.) has been evaluated using Lemna test and various physiological and biochemical stress parameters (photosynthetic pigments, carbonyls and malondialdehide as well as activity of antioxidant enzymes). The results showed that metals leached out from MP into the Steinberg medium. Metals Zn and Cu accumulated in duckweed exposed to the highest concentration of MP. Pristine MP and MP treated with heavy metals did not significantly affect the growth rate of Lemna minor, except pristine MP at higher concentration (100 and 1000 particles / L). Microplastics caused modulation of antioxidant enzyme activities, but lipid peroxidation and oxidative damage to proteins was not observed. Furthermore, MP (polypropylene) was found to strongly adsorb on duckweed fronds. Based on the obtained results, it can be concluded that the Lemna minor is suitable for the phytoremediation of MP
Preparation of peptidomimetics with Ugi multicomponent reaction
No full textU ovom radu opisana je priprava šest peptidomimetika Ugijevom reakcijom koji do sada nisu opisani u literaturi. Za sintezu odabranih spojeva varirana je karboksilna komponenta te su korištene benzojeva kiselina, 3-brombenzojeva kiselina, 3-klorbenzojeva kiselina, 3-nitrobenzojeva kiselina, octena kiselina i 3-indoloctena kiselina. Kao ostale potrebne komponente za Ugijevu reakciju odabrani su paraformaldehid, benzilamin i 4-(2-izocijanoetil)morfolin. Istraženi su uvjeti za sintezu klasičnim postupkom, mehanokemijskom sintezom i sintezom uz mikrovalno zračenje. Reakcije su praćene tankoslojnom kromatografijom, produkt pročišćen kromatografijom na stupcu silikagela, a struktura spojeva potvrđena infracrvenom spektroskopijom, 1D i 2D spektroskopijom nuklearne magnetske rezonancije te spektrometrijom masa. Pripravljenim spojevima izmjeren je inhibitorni potencijal (korištenjem Ellmanove metode) prema enzimu butirilkolinesterazi (EC 3.1.1.8.) izoliranoj iz konjskog seruma. Dobivene su IC50 vrijednosti u rasponu od 10 do 270 μmol dm–3.This thesis describes preparation of peptidomimetics by Ugi reaction, which has not been described in the literature so far. For the synthesis of a certain α-acylamino-amide, the carboxyl component was varied: benzoic acid, 3-bromobenzoic acid, 3-chlorobenzoic acid, 3-nitrobenzoic acid, acetic acid and 3-indolacetic acid. Other used components were: paraformaldehyde, benzylamine and 4-(2-isocyanoethyl)morpholine. The best reaction conditions were determined for the classical methods of organic synthesis, mechanochemical synthesis and microwave-assisted synthesis. The reactions were monitored by thin-layer chromatography and purified by column chromatography. The structures of compounds were confirmed by infrared spectroscopy, 1D and 2D nuclear magnetic resonance spectroscopy and mass spectrometry. The inhibitory activity of all prepared compounds toward the enzyme butyrylcholinesterase (EC 3.1.1.8.) isolated from horse serum was also measured using the Ellman method. IC50 values were found to be in range from 10 to 270 μmol dm–3
Evolution of rhythmic topography of the Lopata beach (Island of Dugi otok)
No full textU ovom radu analiziran je mehanizam nastanka ritmične topografije na žalu Lopata (Dugi otok). Ritmičnu topogafiju čine mnogobrojne pravilno razmaknute grupacije sedimenta sličnih oblika. Za vrijeme terenskog rada u rujnu 2023. godine fotografiran je sediment duž žala unutar kojeg je uočen detritus vrste Posidonia oceanica. S pomoću fotografija sedimenta izračunata je veličina zrna u programu ImageJ i definirana njegova zaobljenost. Prikupljeni su podaci o brzini jugoistočnog vjetra te s pomoću njih izračunata visina i period vala u moru ograničenog privjetrišta i ograničenog trajanja puhanja vjetra. Žalo Lopata fotografirano je dronom u razdoblju od studenog 2020. do travnja 2021. godine. Fotografije su obrađene metodom digitalne fotogrametrije u programu AgiSoft Metashape te su potom od novonastalih digitalnih elevacijskih modela izrađene konturne i razlikovne karte modela u programu Surfer. Ritmična topografija na žalu Lopata postojana je na dvije razine; na nižoj razini su oblici manjih dimenzija i sitnijeg sedimenta, a na višoj razini su oblici većih dimenzija i krupnijeg sedimenta. Jugoistočan vjetar uvjetuje visinu valova koja je bitna za stvaranje oblika ritmične topografije, a mehanizam nastanka može se povezati s refrakcijom valova koji dolaze na žalo Lopata.This thesis analyses the mechanism of rhythmic topography genesis on beach Lopata (island Dugi otok). Rhythmic topography consists of many evenly distributed sediment groups of similar shapes. The sediment on the beach was photographed in September of 2023. Detritus of Posidonia oceanica was recorded among the sediment. Sediment particle roundness was evaluated and size calculated using program ImageJ. Wave height and period were calculated using the speed of southeastern wind. The beach Lopata was also photographed with a drone from November of 2020 to April of 2021. These photos were edited using digital photogrammetry program AgiSoft Metashape and Surfer. Rhythmic topography of beach Lopata is recorded in two levels; lower altitude level consists of smaller and more frequent rhythmic pattern and finer sediment; higher altitude level consists of bigger and wider rhythmic pattern and sediment particles of larger size. Rhythmic topography of beach Lopata appears due to the refraction of waves which are created by the southeastern wind during storms
The choice of tourist destination and personal experiences of women traveling alone
No full textSolo putovanja postaju sve popularniji oblik turizma te se sve više žena odlučuje se na takvu vrstu putovanja iz različitih motiva. Pregledom relevantne literature pruža se uvid u povijest solo putovanja, koncepte feminističke geografije i geografije ženskog straha, motive, ograničenja te iskustva žena koje putuju same. Cilj rada je istražiti motive, izazove i dobrobiti samostalnih ženskih putovanja kombiniranjem sekundarnih izvora podataka s primarnim podacima dobivenim anketom i intervjuima. Rezultati otkrivaju da su samostalne putnice motivirane psihološkim i praktičnim razlozima, poput bijega od rutine, stjecanja samopouzdanja, slobode i fleksibilnosti. Sklone su preferirati destinacije koje se percipiraju kao sigurne, kulturno slične i lako dostupne, dok izbjegavaju destinacije koje se percipiraju kao rizične, kulturno različite i udaljene. Također, suočavaju se s raznim izazovima i ograničenjima, poput društvenih i kulturnih očekivanja, osobnih strahova i prostornih ograničenja. Rezultati sugeriraju da samostalne putnice mogu imati koristi od transformacijskih i značajnih iskustava putovanja, kao i od osobnog rasta, osnaživanja i zadovoljstva. Ističe se i važnost prilagodbe turističke djelatnosti i destinacija prema potrebama samostalnih putnica, kao i željama ne-solo putnica, s ciljem poticanja većeg broja žena da se upuste u solo putovanja.Solo travel is becoming an increasingly popular form of tourism and more and more women decide on this type of travel for various reasons. A review of the relevant literature provides a brief insight into the history of solo travel, the concepts of feminist geography and the geography of women's fear, motives, limitations and experiences of women who travel alone. The main goal of the paper is to investigate the motives, challenges and benefits of female solo by combining secondary data sources with primary data obtained through surveys and interviews. The results reveal that solo female travellers are motivated by psychological and practical reasons, such as escaping routine, gaining self-confidence, freedom and flexibility. They tend to prefer destinations that are perceived as safe, culturally similar and easily accessible, while avoiding destinations that are perceived as risky, culturally different and distant. They also face various challenges and limitations, such as social and cultural expectations, personal fears and spatial limitations. The results suggest that solo female travellers can benefit from transformative and meaningful travel experiences, as well as personal growth, empowerment and satisfaction. The importance of the convenience of the tourism industry and destinations according to the needs of independent travellers, as well as the wishes of non-solo travellers, is also emphasized, with the aim of encouraging more women to embark on solo travel
ULOGA de novo METILACIJE DNA U ODGOVORU BILJAKA NA POVIŠENU TEMPERATURU
No full textOne of the key factors affecting plant survival and agricultural yield production is temperature. In this thesis, effects of prolonged 37 °C and short-term 45 °C heat treatments were investigated in Arabidopsis thaliana, Brassica rapa ssp. pekinensis and Solanum lycopersicum. Elevated temperatures negatively affected germination, development, shoot and root growth, and flower morphology. Seedlings and inflorescences were more thermosensitive than leaves of adult plants. Global DNA methylation levels and expression of key RNA-directed DNA methylation (RdDM) genes varied in different species, tissues and under heat stress. To evaluate the role of de novo DNA methylation in heat stress, different A. thaliana lines with altered RdDM pathway were used. DNA methylation at single-base resolution in AGL14, FBW2 and RKP genes and expression of RdDM-related genes revealed differences under heat stress, indicating the importance of an intact de novo DNA methylation machinery in thermotolerance.Temperatura je jedan od ključnih čimbenika koji utječu na preživljavanje biljaka i poljoprivredne prinose. U ovom doktorskom radu istražen je utjecaj dugotrajnog izlaganja biljaka Arabidopsis thaliana, Brassica rapa ssp. pekinensis i Solanum lycopersicum temperaturi od 37 °C i kratkotrajnog izlaganja na 45 °C. Povišene su temperature negativno utjecale na klijavost, razvoj, rast izdanaka i korijena te morfologiju cvijeta. Klijanci i cvatovi bili su osjetljiviji na toplinski stres od listova odraslih biljaka. Globalne razine metilacije DNA i ekspresija ključnih gena uključenih u metilaciju DNA posredovanu malim RNA molekulama (RdDM) varirala je u različitim vrstama i tkivima te nakon izlaganja toplinskom stresu. Za procjenu uloge de novo metilacije DNA u toplinskom stresu korištene su različite linije A. thaliana u kojima je promijenjen put RdDM. Promjene u metilaciji gena AGL14, FBW2 i RKP te ekspresiji gena uključenih u RdDM uzrokovane toplinskim stresom ukazuju na važnost intaktnog de novo mehanizma metilacije DNA u toleranciji na povišenu temperaturu