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Distribution of the Dinaric cave tube worm (Marifugia cavatica) and growth monitoring of the selected population
No full textDinarsko krško podzemlje prepoznato je kao vruća točka bioraznolikosti podzemne faune. Dinarski špiljski cjevaš (Marifugia cavatica) jedini je poznati podzemni predstavnik porodice cjevaša (Serpulidae, Polycahaeta) do sada zabilježen u svijetu, a nastanjuje podzemne vode dinaridskog krša. Vrsta je prema Crvenoj knjizi špiljske faune Hrvatske kategorizirana kao nedovoljno poznata svojta (DD; engl. Data Deficient). Status vrste ukazuje na potrebu za daljnjim istraživanjem, stoga su ciljevi ovog rada usmjereni na pružanje doprinosa o razumijevanju i proširivanju znanja o dinarskom špiljskom cjevašu i njegovoj rasprostranjenosti. Provedena analiza fizikalno-kemijskih parametra vode na odabranim lokalitetima ukazuje na staništa bez prisutnosti onečišćenja. Usporedbom višegodišnjih fotografija jedinki populacije dinarskog špiljskog cjevaša s istovjetnih ploha iz Jame nasuprot Torka dao se uvid u godišnji prirast cjevaša. Korištena metodologija usporedbe prirasta ima potencijal primjene za dugoročno praćenje stanja (monitoring) dinarskog špiljskog cjevaša. Dodatno, u radu je prikazan popis rasprostranjenosti vrste na području Dinarida. Vrsta je zabilježena na 159 lokaliteta. U njih 68 potvrđeno je da se radi o živoj populaciji, u 4 lokaliteta zabilježene su fosilne cjevčice, u 16 fragmenti cjevčica, dok je za 71 lokalitet potrebno utvrditi radi li se o živim ili uginulim jedinkama.The Dinaric karst underground is recognized as a biodiversity hot spot of subterranean fauna. Dinaric cave tube worm (Marifugia cavatica) is the only known subterranean representative of the serpulid family (Serpulidae, Polycahaeta) worldwide. It inhabits the underground waters of the Dinaric region. According to the Red Book of Cave Fauna of Croatia, the species is categorized as Data Deficient. The status of the species indicates the need for further research. Therefore, the goals of this work aim to contribute to the understanding of the M. cavatica and its distribution. The analysis of the physico-chemical parameters of the water at the selected localities indicates favourable habitats without the presence of pollution. An examination of multi-year photographs of individuals within the population of Dinaric cave tube worms taken from identical locations in Jama nasuprot Torka provided valuable insights into the growth patterns of M. cavatica per year. This methodology has the potential for long-term monitoring of the state of M. cavatica. Additionally, this research compiles a distribution list, documenting the species in 159 localities. Of these, 68 confirmed living populations, 4 show fossil tubes, 16 tube fragments, and 71 localities require further investigation to determine whether the individuals are living or dead
Expression profiles of rac1A, rac1B and rac1C genes in single and double rac1 mutants in Dictyostelium discoideum cells
No full textProteini Rac1A, Rac1B i Rac1C iz amebe Dictyostelium discoideum pripadaju porodici GTPaza Rho i reguliraju aktinski citoskelet. Zbog velike homologije među njima i nepostojanja značajnih promjena u fenotipu jednostrukih mutanata, u literaturi se uvriježilo mišljenje da ovi proteini imaju preklapajuće funkcije. Međutim, karakterizacija mutanata pojedinačno deficijentnih za gene rac1 konstruiranih u Laboratoriju za staničnu dinamiku Instituta Ruđer Bošković u Zagrebu pokazala je da stanice rac1A- imaju defekte tijekom vegetativnog rasta. Nadalje, u odsutnosti proteina Rac1A opaženo je veliko statistički značajno povećanje ekspresije gena rac1B i rac1C. Kako bih ispitala dolazi li do povećanja ekspresije preostalog gena rac1 u dvostrukim mutantima deficijentnima za gen rac1A, u stanicama rac1A- uklonila sam gene rac1B i rac1C. Uklanjanje gena potvrdila sam metodom PCR i Southernovom metodom otiska. Potom sam metodom qPCR analizirala ekspresiju sva tri gena rac1 u stanicama divljeg tipa i mutanata. U stanicama rac1A-/rac1B- i rac1A-/rac1C- ekspresija preostalog gena rac1 ostala je značajno viša u odnosu na stanice divljeg tipa. Također opazila sam promjene fenotipa specifične za stanice rac1A-/rac1B-. Ovi rezultati pokazuju da povećana ekspresija gena rac1B i/ili rac1C ne može u potpunosti nadomijestiti funkciju proteina Rac1A, što ukazuje na to da proteini Rac1, osim preklapajućih, imaju i specifične uloge u stanici.The D. discoideum proteins Rac1A, Rac1B and Rac1C are GTPases of the Rho family that are involved in the regulation of the actin cytoskeleton. Due to the high homology between them, it is assumed that they have overlapping functions. Furthermore, cells lacking the single Rac1 protein showed no significant phenotypic changes. However, analyzes of rac1A-, rac1B- and rac1C- mutants produced in the Laboratory of cell dynamics (RBI Zagreb) revealed that rac1A- cells are defective during vegetative growth. Moreover, rac1B and rac1C expression was significantly increased in the absence of Rac1A. To analyze the expression profile of double mutants lacking Rac1A, I generated rac1A-/rac1B- and rac1A-/rac1C- cells. After confirming the deletion of rac1B and rac1C genes in rac1A- cells by PCR and Southern blot, I analyzed the expression of the three rac1 genes by qPCR. Relative quantification of expression showed that in both rac1A-/rac1B- and rac1A-/rac1C- double mutants, the expression of the third rac1 gene remains strikingly elevated. In addition, preliminary observations indicate phenotypic changes specific to the rac1A-/rac1B- genotype. Therefore, overexpression of rac1B and/or rac1C cannot fully rescue the phenotype of mutants lacking Rac1A and Rac1 GTPases not only have overlapping functions but also perform specific roles in the cell
Synthesis of ferrocene and cellobiose conjugates
No full textU sklopu ovog diplomskog rada priređeni su konjugati ferocena i celobioze, čija je svrha proučavanje potencijalnog prijenosa kiralnosti sa šećernog dijela molekule na ferocensku jezgru putem supramolekulskih interakcija. Inspiracija za sintezu navedenih spojeva proizašla je iz klase ferocenskih peptida koji posjeduju svojstvo helikalne kiralnosti, koje potječe iz stabilizacije konformera putem intramolekuslkih vodikovih veza. Ferocenski peptidi našli su primjenu u dizajnu stereoselektivnih katalizatora i supramolekulskih sustava, ali do sada nisu istraženi njihovi analozi koji sadrže saharidne jedinice umjesto aminokiselinskih. Sinteza je započeta od celobioza-oktaacetata kojem je dodana alkilna poveznica metodom izravne glikozilacije uz brometanol. Bromid je zatim supstituiran azidom koji je reduciran do amino skupine. U standardnim uvjetima priprave amidne veze, amino skupina kondenzirana je s karboksilnom skupinom ferocenske(bis)karboksilne kiseline, dajući zaštićene konačne spojeve kao produkte, kojima su u posljednjem sintetskom koraku uklonjene acetatne zaštitne skupine. Konačni produkti i međuprodukti sinteze okarakterizirani su spektroskopskim tehnikama (NMR, IR).As part of this thesis, conjugates of ferrocene and cellobiose were prepared, aimed at studying the potential transfer of chirality from the sugar part of the molecule to the ferrocene core through supramolecular interactions. The inspiration for the synthesis of these compounds came from the class of ferrocene peptides, which possess the property of helical chirality, originating from the stabilization of conformers through intramolecular hydrogen bonds. Ferrocene peptides have found applications in the design of stereoselective catalysts and supramolecular systems, but their analogs containing saccharide units instead of amino acids have not yet been explored. The synthesis began with cellobiose octaacetate to which an alkyl linker was added by the method of direct glycosylation with bromoethanol. The bromide was then substituted with azide, which was reduced to an amino group. Under standard conditions for the preparation of amide bonds, the amino group was condensed with the carboxyl group of ferrocene(bis)carboxylic acid, yielding protected final compounds as products, from which acetate protective groups were removed in the final synthetic step. The final products and intermediates of the synthesis were characterized by spectroscopic techniques (NMR, IR)
TRIASSIC MARINE REPTILE FROM THE KRAŠIĆ AREA (ŽUMBERAK MT.)
No full textNa ljeto 2021. godine, u mjestu Vlašić Brdo na Žumberačkoj gori, nedaleko od Krašića, otkriven je sekundarni blok vapnenca s očuvanim kostima trijaskog morskog gmaza. Preparacija kostiju omogućila je detaljan opis i taksonomsku odredbu ostataka. Riječ je o djelomično artikuliranom dijelu posteriornog trupnog i/ili najviše anteriornog repnog dijela kralježnice, rebara i gastralija, te neodredivoj kosti uda ili zdjelice ihtiosaura iz porodice Cymbospondylidae. Bogata konodontna fauna izolirana iz vapnenca ukazuje da je uzorak srednje trijaske starosti, iz prijelaznog intervala anizika u ladinik, usporedivog s rasponom između gornje Reitzii i Curionii amonitne zone. Uz konodonte, mehaničkom je i kemijskom preparacijom samog uzorka, kemijskom ekstrakcijom mikrofosila te analizom mikropreparata utvrđena bogata fosilna zajednica koja uključuje ostatke foraminifera, radiolarija, mogućih srodnika dinoflagelata, spužva i/ili mahovnjaka, ostrakoda, brahiopoda, juvenilnih puževa, školjkaša, glavonožaca, bodljikaša te riba koštunjača i hrskavičnjača. Na temelju fosilnih ostataka rekonstruirana je hipotetska hranidbena mreža ove tafocenoze. Vapnenački mikrofacijes može se opisati kao kristalo-bioklastični pekston koji pokazuje tipične značajke dubljevodnih facijesa očekivanih u tektonski stvorenom intra-platformskom bazenu, ali i naznake veoma značajanog siliciklastičnog i/ili vulkanoklastičnog donosa.In the summer of 2021, a block of limestone preserving bones of a Triassic marine reptile was discovered at the Vlašić Brdo locality on the Žumberak Mt., not far from Krašić. Preparation of the bones allowed a detailed description and taxonomic determination of the remains. It consists of a partially articulated portion of the anterior trunk and/or posterior-most tail region of the spine, ribs and gastralia, and an unidentifiable limb or pelvic bone of an ichthyosaur from the family Cymbospondylidae. A rich conodont fauna extracted from the limestone indicates that the sample is of the Middle Triassic age, specifically from the Anisian – Ladinian boundary interval, which can be correlated with a span between Reitzii and Curionii ammonoid zones. In addition to conodonts, mechanical and chemical preparation, chemical extraction, and analysis of thin sections revealed a rich fossil community which includes remains of foraminifera, radiolarians, possible relatives of dinoflagellates, sponges and/or bryozoans, ostracods, brachiopods, juvenile snails, bivalves, cephalopods, echinoderms, and bony and cartilaginous fishes. On the basis of all these fossil remains, a hypothetical food web of this taphocenosis was reconstructed. Microfacies of the limestone can be described as a crystalo-bioclastic packstone which shows the characteristics typical of deeper-water facies expected in a tectonically induced intra-platform basin, but also exhibits evidence of very significant siliciclastic and/or volcanoclastic influx
IMMUNOGLOBULIN G GLYCOSYLATION IN DOWN SYNDROME
No full textGlikozilacija je jedna od najčešćih ko- i posttranslacijskih modifikacija proteina. Glikani vezani na imunoglobulin G (IgG) utječu na njegovu strukturu i funkciju i mijenjaju se s dobi te u brojnim fiziološkim i patološkim stanjima organizma. Znakovi preuranjenog starenja, kao i brojne druge bolesti, česti su kod Downova sindroma (DS). Tekućinskom kromatografijom ultravisoke učinkovitosti analizirana je glikozilacija IgG-a u tri populacije osoba s DS-om za koje su postojali klinički podaci o najčešćim komorbiditetima i uspoređena s onom njihovih zdravih vršnjaka. Proučen je utjecaj produkata gena kromosoma 21 B3GALT5, RUNX1 i DYRK1A na glikozilaciju IgG-a u DS-u digestijom glikana IgG-a egzoglikozidazama te kemijskom inhibicijom produkata gena u limfoblastoidnim staničnim linijama. Pokazano je kako glikozilacija IgG-a osoba s DS-om neovisno o učestalim komorbiditetima odgovara kronološki starijim zdravim osobama. U korištenim eksperimentalnim sustavima RUNX1 ima izravan utjecaj na glikozilaciju IgG-a u DS-u, dok B3GALT5 i DYRK1A nemaju.Glycosylation is one of the most common co- and posttranslational modifications. Glycans attached to immunoglobulin G (IgG) affect its function and change with age and in numerous physiological and pathological conditions. Signs of premature aging, along with many other diseases, are common in Down syndrome (DS). IgG glycosylation of three DS populations that had clinical data on the most common comorbidities was analyzed by ultra-high performance liquid chromatography and compared to their healthy peers. The impact of chromosome 21 gene products B3GALT5, DYRK1A and RUNX1 on IgG glycosylation was studied using enzymatic digestions of IgG glycans and IgG-producing lymphoblastoid cell lines obtained from individuals with and without DS. IgG glycosylation was revealed to be significantly shifted in the direction of aging in DS, showing a ubiquitous trend independent of comorbidities, and an insight into the effect of gene products B3GALT5, DYRK1A and RUNX1 on IgG glycosylation was provided
Effect of cannabidiol on viability of SH-SY5Y cells in the presence of toxic concentrations of copper ions
No full textOksidacijski stres uzrokovan poremećenom regulacijom homeostaze bakra jedan je od važnih čimbenika u patofiziologiji neurodegenerativnih bolesti. Razvoj potencijalnih terapija često uključuje spojeve koji pokazuju antioksidacijska svojstva. Kanabinoidi su skupina lipidnih spojeva s pokazanim antioksidacijskim, protuupalnim i neuroprotektivnim djelovanjem posredstvom endokanabinoidnog sustava. U ovom istraživanju ispitan je učinak kanabidiola na preživljenje stanica SH-SY5Y u fiziološkim uvjetima te u uvjetima oksidacijskog stresa izazvanog visokim koncentracijama bakra. Kanabidiol je, suprotno očekivanjima, djelovao neurotoksično te smanjio preživljenje stanica. Iako nije utjecao na proizvodnju reaktivnih kisikovih vrsta, smanjio je omjer reduciranog i oksidiranog glutationa (GSH/GSSG) kao i aktivnost antioksidacijskog enzima superoksid dismutaze. Također, tretman kanabidiolom je povećao aktivnost izvršnih kaspaza 3 i 7 te kondenzaciju kromatina, kao i otpuštanje laktat dehidrogenaze u stanični medij, što upućuje na staničnu smrt procesima apoptoze i nekroze. Primjena selektivnih inhibitora signalnih puteva povezanih s aktivacijom receptora CB1, kao ni dodatak liganada receptora CB1 nije modificirala učinak kanabidiola na preživljenje stanica, upućujući na to da kanabidiol ne ostvaruje svoje učinke vezivanjem na kanabinoidne receptore.Oxidative stress caused by disturbed regulation of copper homeostasis is one of the important factors in the pathophysiology of neurodegenerative diseases. The development of potential therapies often involves compounds with antioxidant properties. Cannabinoids are lipid compounds with antioxidant, anti-inflammatory and neuroprotective effects achieved through the endocannabinoid system. In this study, the effect of cannabidiol on the survival of SH-SY5Y cells was examined in physiological conditions and in oxidative stress conditions induced by high concentrations of copper. Contrary to expectations, cannabidiol demonstrated neurotoxic effects and reduced cell survival. Although it did not affect the production of reactive oxygen species, it reduced the ratio of reduced and oxidized glutathione (GSH/GSSG), as well as the activity of the antioxidant enzyme superoxide dismutase. Treatment with cannabidiol also increased the activity of executive caspases 3/7 and chromatin condensation, as well as the release of lactate dehydrogenase into the culture medium, which indicates cell death by apoptosis and necrosis. The use of selective inhibitors of signaling pathways associated with CB1 receptor activation, as well as the addition of CB1 receptor ligands did not modify cell survival, suggesting that cannabidiol does not exert its effects via cannabinoid receptors
Vascular flora of Kraljevec Forest Park (Zagreb)
No full textIstraživana park šuma Kraljevec pripada gospodarski, socijalno, prirodoznanstveno, ekološki vrijednim, a floristički sporadično istraženim park šumama Zagreba. Ciljevi su rada bili determinirati i analizirati vaskularnu floru taksonomski, horološki, prema životnim oblicima, podrijetlu i kronoelementu, provesti analizu ekoloških indeksa, indeksa urbanizacije i antropogenizacije, invazivnosti, ugroženosti i zaštićenosti, usporediti floru s floristički istraženim park šumama te izraditi fotokatalog primjenjiv u nastavi. Flora je popisivana od veljače do listopada 2023. godine. Zabilježena je 261 biljna svojta svrstana u 78 porodica. Najzastupljenije su porodice: Compositae (11,88 %) Rosaceae (8,43 %) i Poaceae (6,51 %). Od životnih oblika najdominantniji su hemikriptofiti (46,33 %), slijede geofiti (19,69 %), terofiti (16,99 %) te fanerofiti (16,60 %). Većina svojti pripada euroazijskom (46,90 %) i europskom flornom elementu (17,44 %) te kultiviranim i adventivnim biljkama (12,02 %). Dominiraju autohtone svojte (76,25 %) i svojte rastuće na prirodnim staništima i staništima pod slabijim antropogenim utjecajem. Najzastupljenije su biljke polusjene, kojima odgovaraju temperature brežuljkastog pojasa te koje rastu na umjereno vlažnim tlima. Prisutno je 13 invazivnih, tri najmanje zabrinjavajuće, dvije osjetljive, jedna gotovo ugrožena, jedna nedovoljno poznata te dvije strogo zaštićene vrste. Park šuma Kraljevec bogata je biljnim vrstama, prometno dobro povezana što ju čini odličnim odredište za izvođenje terenske nastave.The investigated Kraljevec Forest Park belongs to the economically, socially, naturalistically, ecologically valuable, and floristically sporadically explored forest parks in Zagreb. The aim of this study was to determine and analyze vascular flora taxonomically, horologically, according to the life forms, origin and chronoelements, conduct an analysis of ecological indices, levels of urbanity, indicators of anthropogenisation, invasiveness, endangerment and protection, compare the flora with floristically researched forest parks and create photo catalog applicable in class. The flora was surveyed from February to October 2023, recording a total of 261 species categorized into 78 families. The most numerous families are Compositae (11.88 %), Rosaceae (8.43 %) and Poaceae (6.51 %). The most dominant life forms are hemicryptophytes (46.33 %), then geophytes (19.69 %), therophytes (16.99 %) and phanerophytes (16.60 %). Most taxa belong to the Euroasian (17.44 %) and European floral element (17.44 %) and also to cultivated and adventitious plants (12.02 %). Autochthonous species are dominant (76.25 %) also as the species that grow in natural habitats and habitats under low anthropogenic impact. The most represented plants are shade-tolerant, corresponding to temperatures typical of a colline zone and growing in moderately moist conditions. 13 invasive species were recorded, three of least concern, two vulnerable, one near threatened, one data-deficient, and two species with legal protection. Kraljevec Forest Park is rich in plant species and traffically well-connected, which makes it an excellent destination for holding a field trip
Computational analysis of the correlation between vaginal microbiota and HPV status in the general female population
No full textIako zauzima oko 9% mikrobioma žena, mikrobiom rodnice važan je za zdravlje ženskog reproduktivnog sustava. Zdrav mikrobiom rodnice karakterizira visoka zastupljenost bakterijskog roda Lactobacillus koji, osim snižavanjem pH, rodnicu često štiti proizvodnjom vodikova peroksida (H2O2). Mikrobiom se može proučavati metodama uzgoja bakterija, ali je na taj način nemoguće zabilježiti cjelokupnu mikrobnu bioraznolikost, niti je jednostavno proučavati ulogu, funkciju i interakciju mikrobioma s ogranizmom domaćinom. Umjesto toga, zahvaljujući napretku visokoprotočnog sekvenciranja, koristi se metagenomika. Njome se mikrobiom može proučavati izravno, bez uzgoja pojedinih vrsta ili sojeva, čime se, uz pripadajuću bioinformatičku analizu, mikrobiom može bolje taksonomski opisati, a omogućava se i njegovo funkcijsko opisivanje, primjerice analizom učestalosti upotrebe kodona. Pomoću dobivenih izvornih očitanja visokoprotočnog sekvenciranja metagenoma 10 uzoraka prikupljenih tijekom dobrovoljnog davanja brisa rodnice u svrhu testiranja na HPV, odredio sam taksonomski sastav mikrobioma unutar kraljevstva bakterija na svim taksonomskim razinama. Na temelju tih rezultata uzorke sam grupirao, te sam odredio gene i metaboličke puteve kojima su pojedine skupine uzoraka obogaćene. U konačnici sam ustanovio da postoje statistički značajne razlike između pojedinih skupina uzoraka u skladu s dosadašnjom literaturom, ali nisam mogao odrediti koje taksonomske skupine ili koja funkcija mikrobioma je povezana s povećanom zarazom HPV-a.Although it occupies only about 9% of female's microbiome, microbiome of the uterus is important for the health of the female reproductive system. A healthy uterine microbiome is characterised by high abundance of bacterial genus Lactobacillus. The genus is protecting uterus by lowering its pH and producing hydrogen peroxide. Microbiome can be studied by cultivation method, which is unable to cover much of a microbial diversity and it is not providing easy functional analysis. Metagenomic is an alternative method enabled by high-throughput sequencing. It can be used for a direct taxonomic characterization of a microbiome, without prior cultivation, and it facilitates functional analysis of codon bias, by applying proper bioinformatic tools. I determined taxonomic composition for kingdom of Bacteria for all taxonomic levels to group 10 samples taken from volunteers that gave the samples from uterus to test them for the presence of HPV infection. Additionally, I determined genes and metabolic pathways for which the samples were enriched. Finally, I found that certain metadata is statistically significantly different between the samples in accordiance with current literature, but I could not determine which taxonomic units or function of microbiom are in correlation with HPV infection
Analysis of the changes in the spatial structure of the City of Sisak using remote sensing methods
No full textGrad Sisak županijski je centar Sisačko-moslavačke županije, jedan od najvećih hrvatskih industrijskih gradova koji je u zadnjih nekoliko desetljeća doživio promjene u prostornoj strukturi urbanog dijela Grada te također, promjene u ruralnoj okolici koja je integrirana u administrativno područje Grada. Ovaj diplomski rad bavi se analizom prostornih promjena u gradu Sisku od 1950-ih godina do danas primjenom metoda daljinskih istraživanja. Korišteni su multispektralni satelitski snimci, povijesne karte i urbanistički planovi te avio snimke kako bi se kvantificirale promjene u korištenju zemljišta te dinamika urbanizacije. Analiza se temelji na obradi satelitskih snimaka Sentinel-2 te primjeni spektralnih indeksa (NDVI, NDBI, MBUI). Dodatno, provedena je nenadzirana klasifikacija korištenja zemljišta kako bi se identificirale glavne kategorije površina: izgrađene i neizgrađene Provedena je digitalizacija avio snimaka te su izračunati udjeli izgrađenih, neizgrađenih i industrijskih površina grada po gradskim četvrtima. Rezultati istraživanja pokazuju značajnu ekspanziju urbanog područja, smanjenje poljoprivrednih i prirodnih površina te rast industrijskih zona.The city of Sisak is the county center of Sisak-Moslavina County, one of the largest Croatian industrial cities that has experienced changes in the spatial structure of the urban part of the city in the last few decades, as well as changes in the rural surroundings that are integrated into the administrative area of the city. This thesis deals with the analysis of spatial changes in the city of Sisak from the 1950s to the present day using remote sensing methods. Multispectral satellite images, historical maps and urban plans, and aerial photographs were used to quantify changes in land use and urbanization dynamics. The analysis is based on the processing of Sentinel-2 satellite images and the application of spectral indices (NDVI, NDBI, MBUI). Additionally, an unsupervised classification of land use was performed to identify the main categories of areas: built-up, unbuilt, vegetation, and water. The aerial photographs were digitized and the shares of built-up, unbuilt, and industrial areas of the city by city districts in 1959, 1977, 2000, and 2024 were calculated. The research results show a significant expansion of the urban area, the reduction of agricultural and natural areas and the growth of industrial zones
Resonances in quasiperiodic many-body localised systems
No full textSustavi koji izbjegavaju termalizaciju su fundamentalno zanimljivi jer na njih nije primjenjiva statistička fizika, a imaju i potencijalne primjene u kvantnim tehnologijama. Višečestična lokalizacija (eng. many-body localization, MBL) je mehanizam izbjegavanja termalizacije u kvantnim sustavima uzrokovan međuigrom interakcija između čestica i aperiodičnosti sustava. Nedavno je numerički primijećen spori rast entropije broja S_n u MBL režimu neuređenih sustava, što je suprotno očekivanju da se S_n saturira u lokaliziranom sustavu, te dovodi u pitanje stabilnost MBL-a u termodinamičkoj granici. Jedno moguće objašnjenje ovog rasta je postojanje rijetkih rezonancija koje lokalno omogućuju transport i u lokaliziranom režimu, bez da termaliziraju cijeli sustav. Cilj ovog rada je proučiti ponašanje S_n i utjecaj rezonancija na višečestičnu lokalizaciju u kvaziperiodičnim sustavima. Oslanjajući se na efektivni opis rezonancija dvodimenzionalnim Hamiltonijanom i determinističku strukturu kvaziperiodičnog potencijala, formuliran je model koji opisuje skaliranje broja rezonancija i saturacijskih vrijednosti S_n s jakosti i periodom potencijala, kao i ponašanje rezonancija u vremenu i vremensku ovisnost S_n. Na temelju modela je dana usporedba saturacijskih vrijednosti S_n u kvaziperiodičnim i nasumičnim sustavima, te kvalitativno predviđanje strukturiranog ponašanja S_n kvaziperiodičnih sustava na dugim vremenskim skalama. Analitički rezultati dobiveni pomoću efektivnog modela se slažu s numeričkim rezultatima, dobivenim egzaktnom dijagonalizacijom Hamiltonijana, u režimu jake lokalizacije. Također, numerički je pokazano da u kvaziperiodičnim sustavima dolazi do izraženije saturacije S_n u odnosu na nasumične sustave.Systems that avoid thermalization are of fundamental interest because statistical physics does not apply to them, and they also have potential applications in quantum technologies. Many-body localization (MBL) is a mechanism for avoiding thermalization in quantum systems due to the interplay between interactions and aperiodicity of the system. Recently, a slow growth of number entropy S_n was numerically observed in the MBL regime of disordered systems, which contradicts the expectation that S_n should saturate in a localized system, thereby questioning stability of MBL in the thermodynamic limit. One possible explanation for this growth is the presence of rare resonances that locally enable transport in localized regime, without thermalizing the entire system. The goal of this work is to study behavior of S_n and impact of resonances on many-body localization in quasiperiodic systems. Relying on the effective description of resonances with a two-dimensional Hamiltonian and deterministic structure of the quasiperiodic potential, a model was formulated that describes scaling of the number of resonances and saturation values of S_n with the strength and period of the potential, as well as the behavior of resonances in time and time dependence of S_n. Based on the model, a comparison of saturation values of S_n in quasiperiodic and random systems was presented, along with a qualitative prediction of the structured behavior of S_n on long time scales in quasiperiodic systems. Analytical results obtained from the effective model agree with the numerical results, which were obtained from exact diagonalization of the Hamiltonian, in the regime of strong localization. It was also numerically shown that in quasiperiodic systems, the saturation of S_n is more pronounced compared to random systems