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Data anonymization stored in relational databases
No full textZaštita osobnih podataka postala je ključna u današnjem digitalnom društvu, osobito u kontekstu relacijskih baza podataka koje svakodnevno obrađuju velike količine osjetljivih informacija. Anonimizacija podataka omogućuje zaštitu privatnosti korisnika smanjujući rizik od reidentifikacije, što omogućava sigurno pohranjivanje, obradu i razmjenu podataka, te pomaže u ispunjavanju pravnih zahtjeva poput Opće uredbe o zaštiti podataka.
U prvom poglavlju rada definirani su ključni pojmovi poput pseudoanonimizacije i anonimizacije, te razlika između njih, uz objašnjenje kako svaka od tih tehnika doprinosi zaštiti privatnosti.
Drugo poglavlje fokusira se na najčešće korištene tehnike anonimizacije u praksi, poput supstitucije, miješanja podataka, dodavanja šuma, poništavanja, maskiranja simbolom, kriptografskih tehnika i generalizacije.
U trećem poglavlju analizirani su postojeći alati za anonimizaciju podataka, kao što su ARX, -ARGUS, SDCMicro i Amnesia, koji omogućuju različite pristupe i razine zaštite privatnosti.
Posljednje, četvrto poglavlje detaljno opisuje praktični dio diplomskog rada, u kojem je razvijena aplikacija za anonimizaciju podataka pohranjenjih u relacijskim bazama podataka pod nazivom AnonyDB. U ovom poglavlju detaljno je opisan cijeli proces razvoja aplikacije, uključujući odabir tehnologija, implementaciju ključnih funkcionalnosti i demonstraciju rezultata anonimizacije na demonstracijskoj bazi podataka. Aplikacija omogućava korisnicima da primjenjuju različite tehnike zaštite privatnosti, kao što su hashiranje, supresija i dodavanje šuma.The protection of personal data has become crucial in today's digital society, especially in the context of relational databases that process large amounts of sensitive information on a daily basis. Data anonymization ensures the protection of users' privacy by reducing the risk of re-identification, enabling the secure storage, processing, and exchange of data, while also helping to comply with legal requirements such as the General Data Protection Regulation.
The first chapter of this paper defines key terms such as pseudonymization and anonymization, and the differences between them, explaining how each technique contributes to privacy protection.
The second chapter focuses on the most commonly used anonymization techniques in practice, such as substitution, data mixing, noise addition, suppression, symbol masking, cryptographic techniques, and data generalization.
The third chapter analyzes existing data anonymization tools, such as ARX, -ARGUS, SDCMicro, and Amnesia, which offer various approaches and levels of privacy protection.
Finally, the fourth chapter provides a detailed description of the practical part of this thesis, in which an application for anonymizing data stored in relational databases, called AnonyDB, was developed. This chapter describes the entire development process of the application, including the selection of technologies, the implementation of key functionalities, and the demonstration of anonymization results on a sample database. The application allows users to apply various privacy protection techniques, such as hashing, suppression, and noise addition
Proteomic analysis of the role of isoleucine mistranslation in the adaptation of Escherichia coli to oxidative stress
No full textTočan prijenos genetičke informacije važan je za normalan rad bioloških sustava. Aminoacil- tRNA-sintetaze ključni su enzimi u prevođenju genetskog koda jer spajaju molekule tRNA s pripadnim aminokiselinama. Iako se ugradnja pogrešnih aminokiselina u proteine veže uz negativne posljedice, stanice od ovog procesa mogu imati pozitivne učinke, poput otpornosti na stresne uvjete. Soj bakterije Escherichia coli koji eksprimira izolecil-tRNA-sintetazu s nefunkcionalnom domenom za popravak pogreške uzgajan je u mistranslatirajućim uvjetima, te je uočena prilagodba stanica na oksidacijski stres. Radi identifikacije procesa koji omogućuju ovu prilagodbu, izvršena je proteomska analiza. U stacionarnoj fazi utvrđeno je da mistranslacija na izoleucinskim položajima uzrokuje povećanu ekspresiju šaperona, proteaza te proteina koji sudjeluju u unosu peptida. Također, dolazi do smanjene ekspresije proteina koji sudjeluju u biosintezi enterobaktina, siderofora koji omogućuje transport željeza. Uočeno je i da dolazi do promjene u ekspresiji proteina koji sudjeluju u metabolizmu nekih aminokiselina. Dodatno, primijećena je pojačana ekspresija proteina RecA i smanjena ekspesija represora LexA, što upućuje da se aktivira SOS odgovor. Daljnja istraživanja pokazat će koji od ovih procesa su ključni za prilagodbu na oksidacijski stres uslijed mistranslacije.Maintaining the accurate flow of genetic information is crucial for the normal function of all biological systems. Aminoacyl-tRNA synthetases are key enzymes in translating the genetic code, as they attach tRNA molecules to their cognate amino acids. Although incorporation of incorrect amino acids into proteins is generally associated with negative consequences, cells can sometimes benefit from this process, such as adaptation to stress. A strain of Escherichia coli expressing an isoleucyl-tRNA synthetase with a nonfunctional editing domain was cultivated under various mistranslating conditions and adaptation to oxidative stress was observed. To identify biological processes responsible for this adaptation, a proteomic analysis was performed. Analysis of proteome in stationary phase revealed that mistranslation at isoleucine positions leads to increased expression of chaperones, proteases and proteins involved in peptide uptake processes. Additionally, a decrease in the expression proteins involved in biosynthesis of enterobactin, siderophore involved in iron transport. Changes in the expression of proteins that are involved in the metabolism of amino acids were found. Also, the upregulation of RecA and downregulation of LexA expression suggests activation of SOS response. Further research will point out which of these processes are key to adaptation to oxidative stress due to mistranslation
Bora wind turbulence above complex coastal terrain
No full textTema ovog rada su mikro- i submezoskalna svojstva bure u zavjetrini sjevernog dijela Dinarida. Rad je podijeljen u tri cjeline, pri čemu se dvije cjeline odnose na turbulenciju bure u prizemnom sloju atmosfere, specifično, njene statističke značajke i numeričku simulaciju. Treća se cjelina odnosi na horizontalne rotacijske značajke pulsacija bure – njihov opis i numeričko modeliranje.
U prvoj cjelini proučavam razlike u statističkim značajkama turbulencije bure u prizemnom sloju atmosfere, i to na dvjema bliskim postajama, Senju i Vratniku (jedna u podnožju, a druga na grebenu planine), za skup podataka u trajanju od približno 6 mjeseci. Slična analiza značajki turbulencije bure do sada nije provedena za ovako dug vremenski period. Analiza potvrđuje neka saznanja prijašnjih radova temeljenih na usporedbi ove dvije postaje za jedan izdvojen događaj bure, npr. da je kinetička energija turbulencije (TKE) u Senju dvostruko veća u odnosu na Vratnik. Raspodjela viskozne disipacije TKE () na dvjema postajama približno je jednaka, što je u suprotnosti s prethodnim zaključcima utemeljenim na jednom događaju bure. Dvije vremenske skale koriste se za odvajanje turbulencije od mezoskale – konstantna (15 min) i varijabilna; potonja je korištena s ciljem odvajanja submezoskalnih gibanja od lokalne turbulencije. Zaključci su u pravilu nepromijenjeni s obzirom na odabir vremenske skale. Podaci na postajama uspoređeni su s obzirom na teoriju sličnosti neutralnog prizemnog sloja (NPS). Odstupanja od NPS-a na Vratniku su manja od onih u Senju, što znači da je ravnoteža TKE na Vratniku bliža NPS-u (tj. smično-disipacijskoj ravnoteži). Određena odstupanja karakteristična su za utjecaj sloja hrapavosti (SH), s obzirom da je visina mjernih uređaja na objema postajama usporediva s visinom elemenata hrapavosti u njihovoj blizini. Ovo je posebice zamjetno u pomacima spektralnih maksimuma prema nižim frekvencijama. Utjecaj SH također pomaže objasniti neočekivanu jednakost na dvjema postajama. Naime, jedna od značajki SH nelokalni su ponori TKE koji smanjuju , a koja uobičajeno samostalno uravnotežuje izvore TKE. Utjecaj SH je prisutan i kod ovisnosti statističkih momenata o azimutu prizemnog vjetra, što se može objasniti anizitropijom površinske hrapavosti. Izračunate su integralne duljinske skale turbulencije i intenzitet turbulencije. Postignute vrijednosti intenziteta u skladu su s preporučenim vrijednostima, ali odstupaju od vrijednosti izmjerenih na srednjem Jadranu.
Druga cjelina usredotočena je na izračun mikroskalnih svojstava bure (preciznije, TKE) numeričkim modelom. Za validaciju simulacije korišten je skup podataka prikupljen u zaleđu grada Rijeke na 100-m tornju s anemometrima na 5 visina. Ovo predstavlja dosad najviša neprekidna toranjska mjerenja brzine vjetra i turbulencije bure u prizemnom sloju atmosfere. Osim 10-min usrednjenih vrijednosti horizontalne brzine i smjera vjetra, anemometri su mjerili i standardne devijacije, što omogućava procjenu TKE i usporedbu sa simulacijom. Ovo je značajno jer je usporedba dosad provedenih simulacija, izuzev avionskih ili indirektnih mjerenja, u pravilu provedena s mjerenjima na relativno niskoj razini iznad tla. Simulacija koraka mreže 0,3 km je provedena za slučaj ekstremno dugotrajnog niza jakih do orkanskih bura iz siječnja i veljače 2012. godine, a kojeg su mjerni uređaji na tornju zabilježili u cijelosti. Točnost simulacije usrednjene vrijednosti brzine i TKE je u rasponu od razumne do izvrsne, ovisno o brzini vjetra i dubini bure. Periodi s izvrsnim podudaranjem su zabilježeni pri brzini vjetra većoj od 20 m s-1 i tijekom plitke bure, dok je podudaranje tijekom duboke bure te pri početku i kraju događaja lošije. Podudaranje je usporedivo sa simulacijama bure na južnom Jadranu, također relativno kratkog koraka mreže, dok odstupanja zabilježena kod većeg koraka mreže naglašavaju važnost reprezentacije reljefa u brdovitom terenu.
U trećoj cjelini proučavam rotacijske značajke pulsacija bure u horizontalnoj ravnini – njihovu strukturu, orijentaciju i smjer rotacije – koristeći rotacijsku spektralnu analizu. Metoda je primijenjena na događaje bure iz istog skupa podataka u Senju kao u prvoj cjelini. Struktura pulsacija je kvazilinearna, tj. česti zraka osciliraju duž izduženih elipsa, a os oscilacije nije jednaka smjeru prizemnog vjetra, već je bliža smjeru vektora smicanja. Doprinos predstavlja rotacija pulsacija u horizontalnoj ravnini, a koja je gotovo isključivo pozitivna, tj. u smjeru suprotnom od kazaljke na satu. Ove značajke ukazuju da su na promatranom skupu događaja bure najvjerojatniji uzroci nastanka pulsacija Kelvin-Helmholtzova nestabilnost ili horizontalno propagirajući zavjetrinski valovi, iako ne nude objašnjenje prevladavajućeg smjera rotacije. Numerička simulacija ljetnog događaja bure je provedena s ciljem proučavanja ovog zapažanja. Simulacija je uspješna s obzirom na period, prevladavajući smjer rotacije i kut između smjera prizemnog vjetra i osi oscilacije pulsacija. Amplituda pulsacija osjetljiva je na vertikalni i horizontalni korak mreže, ali rotacijske značajke nisu. Uzrok pulsacija u simulaciji je Kelvin-Helmholtzova nestabilnost. Ohrabren podudaranjem simulacije i mjerenja, proučio sam prostornu raspodjelu rotacijskih značajki u Velebitskom kanalu. Pozitivna rotacijska komponenta nadjačava negativnu na gotovo čitavom području kanala, iako je njihova relativna jakost vremenski promjenjiva. Iznad Senja i u blizini planinskih vrhova, prevladavajući smjer rotacije pulsacija koreliran je s poljem vremenski usrednjene vertikalne komponente vrtložnosti, a iznad otvorenog mora sa smicanjem smjera vjetra na vrhu niske mlazne struje. Predlažem da je rotacija na frekvenciji pulsacija uzrokovana naginjanjem vrtložnih linija lateralne komponente vrtložnosti unutar ili ispod vrhova Kelvin-Helmholtzovih valova. U prisustvu smicanja smjera vjetra, naginjanje može imati prevladavajući smjer. Budući rad trebao bi se usredotočiti na analizu polja vertikalne komponente vrtložnosti u simulacijama sa stvarnim i idealiziranim reljefom.EXTENDED ABSTRACT
1 Introduction
Bora is a strong, gusty wind that occurs along the eastern coast of the Adriatic. It belongs to the category of downslope windstorms (e.g., Ólafsson and Ágústsson 2007), and it develops due to synoptic disturbances which pull or push air over the Dinarides. Interest in the study of bora is driven mainly by its gustiness (over 60 m s-1; e.g., Grisogono and Belušić 2009) and spatial heterogeneity, which causes a myriad of problems in tourism, architecture and traffic (e.g., Keresturi 2014).
Bora research started at the end of the 19th century (Mohorovičić 1889). It initially focused on the spatial and temporal variability of the mean wind speed and duration (e.g., Poje 1992). The analysis of synoptic charts and radiosoundings yielded two classifications of bora events, one with respect to the synoptic disturbance causing the cross-mountain flow, and the second with respect to the flow depth. As a result, bora event can be cyclonic, anticyclonic or frontal (e.g., Yoshino 1976; Jurčec 1988; Heimann 2001), and shallow or deep. Several subjective and objective weather-type classifications have been developed as a prognostic aid (e.g., Poje 1965; Vozila et al. 2021), newest of which claim that the winter cyclonic bora events (associated with the highest wind speed) will become less frequent in the future warming scenarios (Vozila et al. 2021). When it comes to the understanding of the physical causes of severe bora, the most important development occured as a result of ALPEX (Kuettner and O’Neill 1981) and MAP (Bougeault et al. 2001) projects. Works by Smith (1987) and Klemp and Durran (1987) did away with the notion of bora as a katabatic wind, showing instead that the flow speedup can be caused by two mechanisms, hydraulic transition from sub- to supercritical flow (can be described by two-layer shallow water models), and nonlinear amplification and breaking of mountain waves (the stratified fluid case). Both mechanisms can be present at the same time, and their relative importance depends on the stratification profile, presence and height of the critical level (level where the cross-mountain flow component is zero) and other effects (e.g., Smith and Skyllingstad 2011). In both cases, the resulting lee flow structure is similar – a strong low-level jet (LLJ) develops, topped by a layer of low wind speed and near neutral static stability (the stagnation zone).
The breaking mountain wave and the LLJ present a „stage“ of sorts for this thesis. It is split into three chapters; two deal with the turbulence developed at the lower boundary of the LLJ, and the third aims to describe the horizontal rotational characteristics of bora pulsations (submesocale motion originating from the wave breaking region or the boundary between the LLJ and the stagnation zone; Figure 3) using point measurements and a numerical model simulation. The next three subsections summarize the relevant literature and motivation for each chapter, while the fourth presents the goals and structure of the rest of the text.
1.1 Bora turbulence measurements
As a result of strong shear at the LLJ top and bottom, strong turbulence is developed in the lee of the mountain. Turbulence strength in the lower layer is characterized by a handful of statistical properties like the turbulence kinetic energy (TKE), its dissipation rate () and turbulent fluxes of heat, momentum, moisture, etc. Specialized fields like wind engineering use different but related statistical properties like the turbulence intensity, gust speed and integral turbulence length scales. How these properties relate to each other and vary with height is published in engineering compendia as benchmarks in calculating wind loads on structures.
The first high-frequency measurements of bora-related turbulence were undertaken within ALPEX and MAP projects (aircraft-mounted instruments sampled alongshore and cross-shore profiles of TKE; Smith 1987; Večenaj 2012). First mast-mounted instrument was installed in 2001 at the town of Senj (cup anemometer; 1 Hz sampling rate); Belušić et al. (2006) used these measurements to distinguish local turbulence and low-frequency pulsations. From 2004 to 2006, a pair of 3D anemometers (4 Hz sampling rate) was mounted at Senj and at the Vratnik pass (~10 km to the east of Senj). Using this data, Belušić and Klaić (2006) show that TKE at Senj can reach values as high as 40 m2 s-2. Večenaj (2012) compared a single bora event that occured simultaneously at the two stations, and concluded that both TKE and are twice as large at Senj; therefore, turbulence strength grew along the downslope (Senj is located at the foothill, and Vratnik at the mountain ridge). The importance of turbulence averaging interval selection was emphasized; overly large averaging interval can include motions such as pulsations into turbulence, inflating TKE and related statistics by as much as ~30%. Belušić et al. (2013) also used this dataset to identify simultaneous flow regimes between the two stations via clustering.
Sustained interest in bora turbulence lead to further experiments. Within the frame of the WINDEX project (Horvath et al. 2010a, b), a tower with ultrasonic anemometers at several heights was installed in the hinterland of the city of Split. This dataset was used to point out the error in applying established engineering codes (mostly developed from data measured over flat, homogeneous terrain) to areas under the influence of bora (Lepri et al. 2015; 2017), to test the applicability of the Monin-Obukhov (MOST) similarity theory (Babić 2013; Babić et al. 2016b; Lisac 2014), to evaluate higher statistical moments (Večenaj et al. 2021) and the TKE balance, etc. Further instruments were installed at the Maslenica bridge (Večenaj et al. 2015), and used to show that the distributions of the turbulence statistical properties do not depend on the bora synoptic type (Šoljan et al. 2018) and to study jugo wind turbulence (Zajec 2022). The most recent measurement campaign – project SESAR – focused on the effect of the bora turbulence on the air traffic at the Dubrovnik airport (e.g., Jurković et al. 2018).
Within the context of the bora turbulence properties, these studies fall into one of the two categories. In the first, a large dataset at a particular station is analyzed (e.g., Lepri et al. 2017; Lepri 2023). In the second, two measurement locations are compared for a single simultaneous bora event (Večenaj 2012). A long-term comparison of bora turbulence statistics for two or more stations was not undertaken thus far. This represents the main motivation for this chapter. Best candidates for this comparison are the stations in Senj and at the Vratnik pass; the first is located at the foothill of the coastal mountain range, and the second one is located atop the ridgeline, ~10 km to the east of Senj. Both stations have recorded a large amount of simultaneous bora events spanning the 9-month interval from September 2004 to June 2005.
1.2 Numerical modeling of bora turbulence
Measurement campaigns outlined in the previous section were followed by numerical experiments with steadily decreasing numerical grid spacing. Along-coast jet and wake distribution was successfully reproduced even with ~3 km grid spacing (Enger and Grisogono 1998; Grubišić 2004; Belušić and Klaić 2006). Decreasing the spacing to ~1 km enabled study of submesoscale structures such as pulsations, rotors and lee waves (Belušić et al. 2007; Stiperski et al. 2012; Horvath et al. 2013). This decrease was especially important for the reproduction of near-ground wind in the immediate lee of coastal mountains. A good recent example is the well-reproduced wind speed at the Dubrovnik airport (ZLD) in Večenaj et al. (2019); they used a 0.5 km grid spacing and achieved substantial improvements with respect to coarse 8- and 4 km simulations (Simić 2019). A good example of errors caused by coarse grid spacing in the study of downslope windstorms is provided in e.g., Águstsson and Ólafsson (2014).
Micrometeorological measurements described in the previous section also sparked interest in studying the ability of numerical models and planetary boundary layer (PBL) schemes to reproduce bora turbulence statistics. Here as well, the errors tend to decrease with grid spacing, although it depends on the vicinity of complex terrain. Offshore, even coarse grid spacing may yield good agreement with the measurements of TKE and its dissipation rate (Večenaj et al. 2012). This is not true in the immediate lee of the mountains, e.g., Belušić and Klaić (2006) and Simić (2019) compared surface TKE measurements at, respectively, Senj and Vratnik and at the ZLD (~10 m instrument mounting height) with simulations with 3 and 4 km grid spacing. TKE is in both cases underestimated by a factor of 3–4. Večenaj et al. (2019) simulated a bora event at the ZLD, but they instead used a 0.5 km grid spacing and obtained very good agreement with the TKE measurements. Even finer simulations (in the so-called large-eddy mode) were used to study TKE balance in the hinterland of Split (Horvath et al. 2013); the model output was verified using measurements at 10 m, 22 m and 40 m above the ground.
One of the main issues regarding the simulation of turbulence in downslope windstorms, except the terrain representation which in principle can be solved by using more computational resources, concerns the parametrization schemes of the momentum, heat and moisture exchanges in the surface layer and the PBL. Most of these schemes were developed using data above flat and homogeneous terrain, often underestimating turbulence length scales (Grisogono and Belušić 2009; Večenaj et al. 2010; Večenaj 2015). Consequently, surface wind speed can be overestimated and position of the lee rotor can be misjudged (e.g., Muñoz-Esparza et al. 2016). These discrepancies are, in part, due to a lack of measurements, especially at heights above a few dozen meters above the ground level (a.g.l.). From the measurement campaigns outlined in the previous section, only the WINDEX campaign delivered high-frequency measurements above 20 m a.g.l., although this was partially supplemented by airplane (MAP project; Bougeault et al. 2001), sodar (Stiperski et al. 2012; Horvath et al. 2013) and lidar measurements (Jurković et al. 2018). Therefore, additional measurements of the mean wind speed and turbulence are needed, especially above ~20 m a.g.l. Using such measurements, the ability of the numerical model to reproduce vertical wind and turbulence profiles can be evaluated. In January 2012, a 100-m tower with anemometers at five heights was installed in the hinterland of the city of Rijeka. Besides the mean wind speed and direction, the instruments also recorded their standard deviations, thus enabling the estimation of the TKE and its comparison to numerical model results. In January and February of 2012, the instruments recorded a three-week series of strong to severe bora events. Presenting this dataset and comparing it to the model output presents the main motivation of this chapter.
1.3 Bora pulsations
Pulsations, i.e., quasi-periodic motions with periods of 1–20 min represent a type of secondary instability caused by the strong shear in the wave breaking region and at the LLJ-stagnation zone interface (e.g., Figure 1). They were first studied in the famous Boulder windstorm (e.g., Zipser and Bedard 1982), where structures with decoherence length of ~10 km could be observed (via lidar) moving with the mean wind (Neiman et al. 1988). In numerical experiments, three pulsation generation mechanisms were identified, Kelvin-Helmholtz instability (KHI; Scinocca and Peltier 1989; Peltier and Scinocca 1990), tilting of the base-state vorticity associated with the breaking mountain wave (Clark and Farley 1984), and the trapped, travelling lee waves (Clark and Hall 1994). A schematic view of all three mechanisms is shown in Figure 3. Pulsations exist in bora as well. First measurements and theoretical considerations originate in the late 1980s (Rakovec 1987; Petkovšek 1987). Further development occured at the start of 2000s due to the installation of a high-frequency (1 Hz) anemometer at the town of Senj. In a series of papers, Belušić et al. (2004; 2006; 2007) reveal the underlying phenomena regarding the cessation of pulsations and the appearance of a high-level jet. They simulate the pulsations using COAMPS model, identifying KHI as the generating mechanism for that particular bora event. Furthermore, Orlić et al. (2005) use 3D anemometer data (mounted at Senj in 2004) to point out the difference in pulsations and turbulence. Pulsations were studied at other locations at the Adriatic cost as well, e.g., Horvath et al. (2013) observed pulsations with periods of 3–15 min. They found that the latter are connected to the upstream variation in profiles of wind speed and static stability.
The research focus in the past was the period, wavelength and phase speed of the pulsations, as well as their numerical simulation. The aim of this chapter is to study the characteristic structure of pulsations in the horizontal plane using the rotational spectral analysis method – RSA (Gonella 1972; O’Brien and Pillsbury 1974). RSA (described in the Section 4.3.3) decomposes the 2D vector time series (at a certain frequency) into a positively and negatively rotating component, and can give insight into properties such as the preferred sense of rotation, coherence and the type of motion (rectilinear, circular or elliptical). RSA was previously used at the Adriatic coast in the study of diurnal rotation of sea breeze (Prtenjak et al. 2008) and the rotational characteristics of bora in the vertical plane (Orlić et al. 2005). Latter example is notable since RSA showed that pulsations and local turbulence exhibit different structures, and thus have different generating mechanisms. The choice of the subject and the method was motivated by observing a large set of bora events recorded by a 3D anemometer at the town of Senj. After the rotation of the data into the mean-wind system, I noticed large variability in the ratio of the pulsation energy in the along-wind and cross-wind directions, even within a single bora event. This variability implies change in either the orientation of the structure, or its type (i.e., from rectilinear to circular). Since different pulsation generation mechanisms produce different structures in the horizontal plane (Section 3.2), RSA can be used to deduce the dominant one. Finally, a numerical model (WRF-ARW) can be used to reproduce these characteristics and (if successful) study their spatial and temporal variability.
1.4 Objectives and structure
The aim of the first chapter is to compare the statistical properties of the bora turbulence at two nearby stations, one at the foot of the mountain and the other at a ridgeline, for a large number of bora events. The combination of length of the analyzed dataset and the comparison of turbulence statistical properties at two stations represents the original contribution of this chapter. After the selection of an appropriate turbulence averaging interval (constant or variable), I will calculate the TKE, , momentum flux and other relevant parameters. Because of the differences in the surface cover and instrument mounting height (Section 4.1.2), the data is compared in the context of the statically neutral surface layer similarity (Section 3.1). The deviation of the nondimensional statistical properties from theoretical values can point towards possible differences in the TKE balance between the two stations.
In the second chapter, I intend to verify the ability of the WRF-
Geochemical and sedimentological characteristics of the Morinje Bay (Middle Dalmatia): influences of natural and anthropogenic factors
No full textMorinjski zaljev je zatvoreni zaljev u središnjoj Dalmaciji koji je pod opterećenjem negativnih antropogenih učinaka. U sjeverozapadnom dijelu zaljeva nalazi se odlagalište medicinskog pepela, a obalom zaljeva prostire se mnoštvo građevinskog, plastičnog i drugih vrsta otpada te automobilskih guma. Cilj ovog rada jest istražiti geokemijske i sedimentološke značajke sedimenata i tala prikupljenih oko Morinjskog zaljeva temeljem granulometrijske analize, vrijednosti pH, udjela karbonatne komponente i organske tvari te raspodjelom koncentracija metala i metaloida. Temeljem rezultata istraživanja utvrđeno je da postoji zagađenje bakrom, olovom, cinkom i kositrom u neposrednoj blizini odlagališta medicinskog pepela te da se ono lateralno proširilo zaljevom u smjeru jugozapada.The Morinje Bay is an enclosed bay in central Dalmatia that is under the burden of negative anthropogenic effects. In the northwestern part of the bay there is a disposal site for medical ash, while large amounts of construction debris, plastic and other types of waste, including automobile tires, are scattered along the shoreline of the bay. The aim of this study is to investigate the geochemical and sedimentological characteristics of sediments and soils collected around Morinje Bay based on granulometric analysis, pH values, carbonate component and organic matter content as well as the distribution of metal and metalloid concentrations. Based on the research results, it has been determined that there is pollution with copper, lead, zinc and tin in the immediate vicinity of the medical ash disposal site and that it has spread laterally through the bay in a southwest direction
The role of androgens and androgen receptors in the metastatic potential of head and neck tumors
No full textMuškarci imaju dva do četiri puta veći rizik od obolijevanja od tumora glave i vrata što može biti
posljedica različitih životnih navika muškaraca i žena ili pak posljedica utjecaja njihovih
različitih hormona. Androgeni nastaju sintezom iz kolesterola te obuhvaćaju sve hormone koji
imaju maskulinizirajuće djelovanje. Androgeni svoje djelovanje ostvaruju vezivanjem na jezgrin
(AR) ili membranske receptore (CACNA1C, OXER1, SLC39A9). Hipoteza ovog istraživanja je
da bi androgeni i receptori androgena mogli imati ulogu u razvoju tumora glave i vrata te da bi se
terapija deplecije kolesterola statinima mogla koristiti u liječenju ovog tipa tumora. Metodom
kvantitativne lančane reakcije polimerazom u stvarnom vremenu odredila sam ekspresijski profil
gena za jezgrin i membranske receptore androgena u uzorcima zdravih sluznica, primarnih
tumora, metastatskih limfnih čvorova te u staničnom modelu metastatskog tumora glave i vrata
(stanična linija Detroit 562). Testovima zacjeljivanja rana i formiranja kolonija provjerila sam
migratornu sposobnost stanica nakon aktivacije receptora androgena dihidrotestosteronom i
nakon deplecije kolesterola simvastatinom. Rezultati su pokazali da bi jedino jezgrin receptor
androgena AR mogao imati ulogu u razvoju i metastaziranju tumora glave i vrata te da terapija
deplecije kolesterola predstavlja potencijal u liječenju ovog tipa tumora.Men are at twofold to fourfold higher risk for developing head and neck cancer, which may be a
result of the different lifestyle habits between men and women or a result of their different
hormones. Androgens are synthesised from cholesterol and they include all hormones that have a
masculinizing effect. Androgens exert their action by binding to nuclear (AR) or membrane
receptors (CACNA1C, OXER1, SLC39A9). The hypothesis of this research is that androgens
and androgen receptors could play a role in the development of head and neck tumors and that
cholesterol depletion therapy (caused by statins) could be used in the treatment of this type of
tumor. By using the quantitative polymerase chain reaction in real time, I determined the gene
expression profile for nuclear and membrane androgen receptors in samples of healthy mucosa,
primary tumors, metastatic lymph nodes and also in a metastatic head and neck tumor cell model
(Detroit 562 cell line). By using wound healing and colony forming assays, I investigated the
migratory ability of cells after the activation of androgen receptors with dihydrotestosterone and
after cholesterol depletion with simvastatin. The results showed that only the nuclear androgen
receptor AR could have a role in the development and metastasis of head and neck tumors and
that cholesterol depletion therapy represents a potential novel therapy for this type of tumor
EFFECTS OF MULTIPLE ENVIRONMENTAL STRESSORS ON METABOLIC RESPONSES OF FRESHWATER ORGANISMS
No full textAntropogeni pritisci značajno utječu na biološku raznolikost i prirodne resurse. Istraživanje je ispitivalo pojedinačne i kombinirane učinke višestrukih stresora (onečišćujuće tvari/otpadne vode i povišena temperatura vode) na slatkovodne zajednice kroz mikrokozmos (tulari i mahovina) i mezokozmos (slatkovodni beskraljšnjaci i mahovina) eksperiment. Koristeći non-target analizu metabolita i lipida te DNA barkodiranje, proučavane su promjene u fiziološkim, metaboličkim i genetskim odgovorima ne-modelnih organizama na odabrane stresore. Odgovori su se razlikovali ovisno o promatranom svojstvu, vrsti, spolu te životnom stadiju. Molekularni indikatori (tj. metabolom, lipidom, filogenetska raznolikost) su pokazali brže odgovore na stresore nego tradicionalni pokazatelji zdravlja ekosustava (tj. tjelesna težina, preživljavanje, sastav zajednice). Metoda DNA barkodiranja otkrila je suptilne genetičke varijacije potaknute stresorima kod pojedinih vrsta. Negativni učinci povišene temperature na rast i razvoj vodenih kukaca pojačani su prisutnošću onečišćujućih tvari, što upućuje na moguće negativne posljedice za prijenos hranjivih tvari i energije iz vodenih u kopnene ekosustave.Anthropogenic impacts are leaving a mark on biodiversity and natural resources. This research investigated the single and combined effects of several stressors (emerging contaminants/wastewater and increased water temperature) on freshwater biota in a microcosm (caddisflies and moss) and a mesocosm (benthic invertebrates and moss) experiment. Using non-targeted metabolomics and lipidomics, as well as DNA barcoding, the study investigated changes in physiological, metabolic, and genetic responses of non-model freshwater organisms to selected stressors. The responses to stressors were trait-, species-, sex- and life stage-specific. Molecular indicators (i.e. metabolome, lipidome, phylogenetic diversity) responded faster to stressors then ecosystem health indicators (i.e. body mass, survival, community composition). The DNA barcoding method revealed subtle and species-dependent genetic variations triggered by stressors. Negative effects of increased temperature on development-related traits of aquatic insects appear to be intensified by the presence of contaminants in water, suggesting potential negative effects for aquatic-terrestrial subsidies
Seasonal differences in susceptibility of macroalga Cystoseira crinita to copper nanoparticle toxicity
No full textNanočestice bakra se zbog svojih jedinstvenih svojstava sve više koriste u različitim industrijskim granama što dovodi do njihovog većeg ispuštanja u morski okoliš. Dosadašnja provedena toksikološka istraživanja dokazala su toksičnost nanočestica bakra na različite morske organizme, no vrlo je malo istraživanja provedeno na morskim makroalgama. Cystoseira crinita je morska makroalga koja pruža stanište, skrovište i hranu brojim morskim organizmima. Stoga su ciljevi ovoga rada bili utvrditi razinu učinka nanočestica bakra na C. crinita te utvrditi postoji li razlika u toksičnom učinku nanočestica ovisno o specijaciji bakra tj. kada bakar ima oksidacijsko stanje 0 (CuNP), +I (Cu2ONP) i +II (CuONP), utvrditi je li morska makroalga osjetljivija na potencijalno toksične učinke nanočestica bakra tijekom aktivnog rasta (proljeće) ili u stacionarnoj fazi (niskog rasta) tijekom jeseni. Toksičnost nanočestica bakra nakon 72 sata izlaganja makroalge, istraživana je pomoću biomarkera enzimskih i neenzimskih antioksidansa te produkta peroksidacije lipida. Zabilježen je različit učinak nanočestica bakra, a ovisio je o specijaciji bakra. Najveći učinak pokazale su Cu2ONPs. Zabilježeno je da su makroalge u jesenskom razdoblju osjetljivije na tretman nanočesticama bakra u odnosu na makroalge iz proljetnog razdoblja.Due to their unique properties, copper nanoparticles are used in various industries, which leads to discharge into the marine environment. Toxicological research has proven the toxicity of copper nanoparticles on various marine organisms, but very little research has been carried out on marine macroalgae. Cystoseira crinita is a marine macroalgae that provides habitat, shelter and food for numerous marine organisms. Therefore, goals of this work were to determine the level effect of copper nanoparticles on C. crinita and to determine whether there is a difference in the toxic effect of nanoparticles depending on copper speciation, i.e. when copper has oxidation state 0 (CuNP), +I (Cu2ONP) and +II (CuONP), determine whether the marine macroalgae C. crinita is more sensitive to the potentially toxic effects of copper nanoparticles during active growth (spring) or in the stationary phase during autumn. The toxicity of copper nanoparticles after 72 hours of exposure was investigated using biomarkers of enzymatic and non-enzymatic antioxidants and lipid peroxidation products. A different effect of copper nanoparticles was recorded, and it depended on copper speciation. Cu2ONPs showed the greatest impact. It has been noted that macroalgae in autumn are more sensitive to treatment of copper nanoparticles than macroalgae in spring
Methodical approach to students with intellectual disabilities in geography teaching
No full textSvako dijete, pa tako i dijete s intelektualnim teškoćama ima zakonsko pravo obrazovanja. Ova skupina djece najčešće se javlja u osnovnim školama, no ovisno o njihovim sposobnostima, mogu doseći i srednjoškolsko obrazovanje. Stoga je potrebno prilagoditi metodički pristup tijekom njihovog obrazovanja. Cilj obrazovanja je osposobiti dijete za život, u skladu sa njegovim mogućnostima i sposobnostima. Ovaj cilj ostvaruje se i na nastavi geografije. Rad predstavlja kombinaciju proučavanja stručne literature te empirijskog rada. Na početku rada dana je definicija intelektualnih teškoća te njihova klasifikacija. Istražena je osposobljenost nastavnika geografije za rad s učenicima s intelektualnim teškoćama te sposobnosti koje učenici mogu dosegnuti. Na kraju rada predložene su metode poučavanja učenika s ovim oblikom teškoća.Every child, including a child with intellectual disabilities, has a legal right to education. This group of children most often appears in primary schools, but depending on their abilities, they may also achieve secondary education. Therefore, it is necessary to adapt the methodical approach during their education. The goal of education is to prepare the child for life, in accordance with their possibilities and abilities. This goal is also pursued in geography lessons. The paper represents a combination of examining professional literature and conducting empirical work. At the beginning of the paper, a definition of intellectual disabilities and their classification is given. The preparedness of geography teachers to work with students with intellectual disabilities was explored, as well as the abilities these students can achieve. At the end of the paper, teaching methods for students with this form of difficulty are proposed
Characterization of structural and mechanical properties of crystals of coordination polymers of cadmium(II) and copper(II) chloride with 3,5-dimethylpyridine by experimental and computional approach
No full textU sklopu ovog istraživanja sintetizirani su kristali jednodimenzijskih koordinacijskih polimera kadmijevih(II) i bakrovih(II) halogenida s 3,5-dimetilpiridinom (3,5-dmp): [CdCl2(3,5-dmp)2]ₙ (1), [CdBr₂(3,5-dmp)2]ₙ (2), [CuCl2(3,5-dmp)2]ₙ (3) te [CuBr2(3,5-dmp)2]ₙ (4). Iz eksperimenata savijanja kristala u tri točke utvrđeno je da kristali kadmijevih(II) polimera 1 i 2 pokazuju dvodimenzijski izotropan elastičan, dok kristali bakrovih(II) polimera 3 i 4 daju dvodimenzijski plastičan odziv. Provođenjem statičnih vlačnih eksperimenata određeni su i Youngovi moduli kristala koji su uspoređeni s računalno dobivenim vrijednostima. Primjenom računalnih periodičnih DFT metoda simulirana je anizotropna deformacija jediničnih ćelija spojeva 1−4 korištenjem PBE-D3 funkcionala. Ugađanjem dobivenih krivulja potencijalne energije na kvadratnu funkciju u skladu s Hookeovim zakonom izračunate su konstante sila za deformacije duž pojedinih kristalografskih osi. Analizom rezultata utvrđeno je da elastičan odziv proizlazi iz jačih i usmjerenijih međumolekulskih interakcija, dok slabije interakcije u kristalnoj strukturi omogućuju plastično savijanje.In this study, crystals of one-dimensional coordination polymers of cadmium(II) and copper(II) halides with 3,5-dimethylpyridine (3,5-dmp) were synthesized: [CdCl₂(3,5-dmp)₂]ₙ (1), [CdBr₂(3,5-dmp)₂]ₙ (2), [CuCl₂(3,5-dmp)₂]ₙ (3), and [CuBr₂(3,5-dmp)₂]ₙ (4). Three-point bending experiments revealed that crystals of cadmium(II) polymers 1 and 2 exhibit two-dimensional isotropic elasticity, while crystals of copper(II) polymers 3 and 4 display a two- dimensional plastic response. Through static tensile experiments, the Young’s moduli of the crystals were determined and compared with computationally obtained values. Using periodic DFT computational methods, the anisotropic deformation of the unit cells of compounds 1−4 was simulated employing the PBE-D3 functional. By fitting the resulting potential energy curves to a quadratic function in accordance with Hooke’s law, force constants for deformations along specific crystallographic axes were calculated. Analysis of the results showed that elastic response arises from stronger and more directional intermolecular interactions, whereas weaker interactions in the crystal structure allow for plastic bending
Effects of complex mixtures of plastic nanoparticles on androgen and estrogen receptors
No full textPrekomjerna upotreba plastičnih proizvoda i neprikladno gospodarenje plastičnim otpadom rezultirali su nakupljanjem mikro- i nanočestica plastike (PNP) u okolišu, čime je ugrožen i hranidbeni lanac čovjeka. Interakcija takvih čestica s ljudskim organizmom potvrđena je njihovom detekcijom u mnogim biološkim uzorcima ljudskog porijekla ali njihov učinak na zdravlje, posebice reproduktivno, nije u potpunosti razjašnjen. Zbog mogućnosti adsorpcije različitih kemikalija na površinu PNP izuzetno je važno proučavati utjecaj kompleksnih smjesa kojima je čovjek izložen. Ova doktorska disertacija je imala za cilj odrediti endokrino disruptivno djelovanje PNP ispitivanjem djelovanja pojedinih PNP i smjesa PNP na androgene i estrogene receptore te na proces steroidogeneze. Ispitivanja su provedena korištenjem 3 in vitro modela u skladu s relevantnim regulatornim smjernicama. U istraživanju je korišteno osam vrsta PNP različite veličine i polimernog sastava kako bi se ispitalo utječu li ta svojstva na njihove biološke učinke. Također, ispitan je endokrino-disruptivni učinak PNP u smjesama s oksibenzonom i metilparabenom u svrhu mogućeg otkrivanja sinergističkih i/ili antagonističkih učinaka takvih smjesa. Rezultati pokazuju da učinak PNP na receptore ovisi o vrsti polimera, a učinak je najizraženiji kod nanočestica polipropilena.Excessive use of plastic products and inappropriate management of plastic waste have resulted in the accumulation of plastic micro- and nanoparticles (PNP) in the environment, threatening also the human food chain. The interaction of such particles with the human organism has been confirmed by their detection in many human samples, but their effect on health, especially reproductive, has not been fully clarified. Due to the possibility of adsorption of various chemicals onto the surface of PNP, it is extremely important to study the impact of complex mixtures to which humans are exposed. This doctoral dissertation aimed to determine the endocrine disruptive effect of PNP by examining the interaction of individual PNPs and PNP mixtures with androgen and estrogen receptors and the process of steroidogenesis. Experiments were conducted using 3 in vitro models in accordance with relevant regulatory guidelines. The study used eight types of PNP of different sizes and polymer composition to examine whether these properties affect their biological effects. Also, the endocrine disrupting effect of PNP in mixtures with oxybenzone and methylparaben was evaluated by means of synergistic and/or antagonistic effects of such mixtures. The results show that the effect of PNP depends on the type of polymer and is most pronounced with polypropylene nanoparticles