1. Celostni model vpliva cikličnega gvanozin monofosfata na molekularne mehanizme znotrajcelične kalcijeve signalizacije v gladkih mišičnih celicah arterij : magistrsko deloKatarina Meštrović, 2025, magistrsko delo Opis: V magistrski nalogi preučujemo molekularne mehanizme vpliva cikličnega gvanozin monofosfata (cGMP) na kalcijevo (Ca2+) signalizacijo v gladkih mišičnih celicah (GMC) arterij ter posledično na njihovo kontrakcijo oziroma relaksacijo. Obstoječi fizikalno-matematični model, ki vsebuje šest mehanizmov, preko katerih cGMP posredno ali neposredno vpliva na signal Ca2+, nadgradimo z dvema dodatnima mehanizmoma delovanja cGMP. To sta vpliv cGMP na od Ca2+ odvisne klorove (Cl-) kanale (ClCa), ki se nahajajo v celični membrani, in na črpalke za Ca2+ v membrani sarkoplazemskega retikuluma (SERCA). Študij vpliva cGMP na ClCa je zanimiv predvsem zaradi razlik med tipi teh kanalov v pljučni in mezenterični arteriji. Mezenterična arterija vsebuje dva tipa ClCa kanalov: od cGMP neodvisne ClCa in od cGMP odvisne ClCa (ClCacGMP), medtem ko pljučna arterija vsebuje zgolj od cGMP neodvisen tip teh kanalov (ClCa). S fizikalno-matematičnim modelom za oba tipa arterij simuliramo učinek cGMP na signal Ca2+ v GMC, ki se lahko izraža v obliki oscilacij ali stacionarnega stanja ter določimo povprečno koncentracijo Ca2+ v citoplazmi, ki odraža stopnjo kontrakcije. Poleg tega preučujemo tudi vpliv cGMP na SERCA. Rezultati simulacij kažejo, da visoka koncentracija cGMP v modelu, ki vključuje ClCacGMP, privede do povišane povprečne znotrajcelične koncentracije Ca2+. To se zgodi pri koncentracijah nad 10 µM. Nasprotno pa v modelu brez kanalov ClCacGMP višanje koncentracije cGMP zniža povprečno znotrajcelično koncentracijo Ca2+, kar je skladno s pričakovanji glede relaksacijskega učinka pri visokih koncentracijah cGMP. Iz simulacij je tudi razvidno, da je kanal ClCacGMP zaradi svoje večje občutljivosti na Ca2+ pri visokih koncentracijah cGMP odgovoren za povečan vstop Ca2+ v celico, kar povzroči višjo koncentracijo citosolnega Ca2+ v mezenterični arterij.
Ključne besede: gladka mišična celica, ciklični gvanozin monofosfat, od kalcija odvisni klorovi kanali, pljučna arterija, mezenterična arterija, kalcijeva signalizacija, fizikalno-matematični model
Objavljeno v DKUM: 08.05.2025; Ogledov: 0; Prenosov: 4
 Celotno besedilo (2,50 MB) |
2. Collective dynamics of swarmalators with higher-order interactionsMd Sayeed Anwar, Gourab Kumar Sar, Matjaž Perc, Dibakar Ghosh, 2024, izvirni znanstveni članek Opis: Higher-order interactions shape collective dynamics, but how they affect transitions between different states in swarmalator systems is yet to be determined. To that effect, we here study an analytically tractable swarmalator model that incorporates both pairwise and higher-order interactions, resulting in four distinct collective states: async, phase wave, mixed, and sync states. We show that even a minute fraction of higher-order interactions induces abrupt transitions from the async state to the phase wave and the sync state. We also show that higher-order interactions facilitate an abrupt transition from the phase wave to the sync state bypassing the intermediate mixed state. Moreover, elevated levels of higher-order interactions can sustain the presence of phase wave and sync state, even when pairwise interactions lean towards repulsion. The insights gained from these findings unveil self-organizing processes that hold the potential to explain sudden transitions between various collective states in numerous real-world systems.
Ključne besede: collective dynamics, nonlinear oscillator, higher-order interactions, complex network, statistical physics
Objavljeno v DKUM: 07.05.2025; Ogledov: 0; Prenosov: 0
Celotno besedilo (2,75 MB)
Gradivo ima več datotek! Več... |
3. Izbira habitata evropskega bobra Castor fiber (Rodentia: Castoridae) na Goričkem (severovzhodna Slovenija)Laura Kološa, Franc Janžekovič, Tina Klenovšek, 2024, izvirni znanstveni članek Opis: Evropski bober je v Sloveniji in večjem delu Evrope v začetku 20. stoletja veljal za izumrlo vrsto. Ob koncu 20. stoletja se je po številnih reintrodukcijah in uveljavitvi ohranitvenih ukrepov ponovno razširil. V Sloveniji se je vnovič naselil leta 1998, na Goričkem leta 2016. V zimi 2021/22 smo na Goričkem popisali šest vodnih teles, na katerih je bilo med letoma 2016 in 2020 potrjeno pojavljanje te vrste. Namen popisa je bil ugotoviti značilnosti bobrovega habitata na Goričkem glede na ključne okoljske dejavnike, ki mu omogočajo preživetje. Zaradi zgodnje faze naselitve smo domnevali, da je bober za svoj teritorij izbral optimalne habitate. Na izbranih odsekih vodnih teles smo popisali 82 ploskev. Aktivnost bobra je bila potrjena na 71 % ploskev s stoječo in 26 % ploskev s tekočo vodo. Najpogostejši tip kopenskega habitata so bile njive. Gozd je pokrival le 18 % ploskev. Bober je bil najpogosteje zabeležen prav na ploskvah z gozdom (73 %). Brežine vodnih teles so bile v glavnem zelo strme (> 60°). Sledovi bobra so bili najpogosteje najdeni na brežinah z višino do vključno 1 m, naklonom 30°–60° in povprečno 500 m oddaljenostjo od naselij. Vodotoki, ki jih je na Goričkem naselil bober, so razmeroma ozki in plitki, a jih bober kljub temu naseljuje. Najpomembnejši okoljski dejavnik za bobre je razpoložljivost ustrezne lesne vegetacije, s katero se hrani predvsem jeseni in pozimi. Poznavanje značilnosti in izbire habitata je pomembno za varstveno upravljanje in monitoring bobra na Goričkem in v Sloveniji.
Ključne besede: Castor fiber, evropski bober, ekološke spremenljivke
Objavljeno v DKUM: 06.05.2025; Ogledov: 0; Prenosov: 1
Celotno besedilo (4,64 MB)
Gradivo ima več datotek! Več... |
4. Discrete memristive Hindmarsh-Rose neural model with fractional-order differencesFatemeh Parastesh, Karthikeyan Rajagopal, Sajad Jafari, Matjaž Perc, 2025, izvirni znanstveni članek Opis: Discrete systems can offer advantages over continuous ones in certain contexts, particularly in terms of simplicity and reduced computational costs, though this may vary depending on the specific application and requirements. Recently, there has been growing interest in using fractional differences to enhance discrete models' flexibility and incorporate memory effects. This paper examines the dynamics of the discrete memristive Hindmarsh-Rose model by integrating fractional-order differences. Our results highlight the complex dynamics of the fractional-order model, revealing that chaotic firing depends on both the fractional-order and magnetic strength. Notably, certain magnetic strengths induce a transition from periodic firing in the integer-order model to chaotic behavior in the fractional-order model. Additionally, we explore the dynamics of two coupled discrete systems, finding that electrical coupling leads to the synchronization of chaotic dynamics, while chemical coupling ultimately results in a quiescent state.
Ključne besede: memristive Hindmarsh-Rose model, discrete systems, fractional-order differences
Objavljeno v DKUM: 06.05.2025; Ogledov: 0; Prenosov: 0
Celotno besedilo (7,00 MB)
Gradivo ima več datotek! Več... |
5. Structural roles and gender disparities in corruption networksArthur A. B. Pessa, Alvaro F. Martins, Mônica V. Prates, Sebastián Gonçalves, Cristina Masoller, Matjaž Perc, Haroldo V. Ribeiro, 2025, izvirni znanstveni članek Opis: Criminal activities are predominantly due to males, with females exhibiting a significantly lower involvement, especially in serious offenses. This pattern extends to organized crime, where females are often perceived as less tolerant to illegal practices. However, the roles of males and females within corruption networks are less understood. Here, we analyze data from political scandals in Brazil and Spain to shed light on gender differences in corruption networks. Our findings reveal that females constitute 10% and 20% of all agents in the Brazilian and Spanish corruption networks, respectively, with these proportions remaining stable over time and across different scandal sizes. Despite this disparity in representation, centrality measures are comparable between genders, except among highly central individuals, for which males are further overrepresented. Additionally, gender has no significant impact on network resilience, whether through random dismantling or targeted attacks on the largest component. Males are more likely to be involved in multiple scandals than females, and scandals predominantly involving females are rare, though these differences are explained by a null network model in which gender is randomly assigned while maintaining gender proportions. Our results further reveal that the underrepresentation of females partially explains gender homophily in network associations, although in the Spanish network, male-to-male connections exceed expectations derived from a null model.
Ključne besede: gender disparity, corruption network, political scandal, social physics, social physics
Objavljeno v DKUM: 25.04.2025; Ogledov: 0; Prenosov: 0
Celotno besedilo (3,50 MB)
Gradivo ima več datotek! Več... |
6. EEG-based finger movement classification with intrinsic time-scale decompositionMurside Degirmenci, Yilmaz Kemal Yuce, Matjaž Perc, Yalcin Isler, 2024, izvirni znanstveni članek Ključne besede: brain-computer interfaces, electroencephalogram, feature reduction, machine learning, finger movements classification, time series analysis
Objavljeno v DKUM: 16.04.2025; Ogledov: 0; Prenosov: 0
Celotno besedilo (1,44 MB)
Gradivo ima več datotek! Več... |
7. Pupal development and adult acclimation temperatures influence the cold and heat tolerance in Tenebrio molitor (Coleoptera: Tenebrionidae)Jan Podlesnik, 2025, izvirni znanstveni članek Opis: Temperature plays a crucial role in shaping the biology of insects. Developmental temperature and acclimation temperatures influence their ability to cope with extreme thermal conditions. This study investigates the effects of developmental temperatures during the pupal stage and adult acclimation temperatures on the thermal tolerance of Tenebrio molitor Linnaeus, 1758. We investigated cold tolerance based on chill-coma recovery time and heat tolerance based on heat knockdown time. Beetles were reared at five developmental temperatures (16, 21, 25, 30 and 35 °C) and later exposed to corresponding adult acclimation temperatures. From developmental temperatures of 21 and 30 °C, the group of beetles was subjected to different temperatures to induce adult acclimation at a different temperature than the developmental temperature. In cold-tolerance tests, beetles reared at lower temperatures showed better recovery from chill coma, while beetles reared at higher temperatures showed greater resistance to heat shock. Adult beetles acclimated to lower temperatures showed better cold tolerance, while those acclimated to higher temperatures performed better in the heat tolerance test. Interestingly, the developmental temperatures during the pupal stage also contributed to resistance, particularly in the heat tolerance test. However, pupal stage temperatures had no effect on cold-shock resistance, as indicated by chill-coma recovery time. The results could provide insights into the rearing of T. molitor.
Ključne besede: adult acclimation, cold tolerance, developmental acclimation, heat knockdown, heat tolerance, Tenebrio molitor, thermal tolerance, chill coma, yellow mealworm
Objavljeno v DKUM: 15.04.2025; Ogledov: 0; Prenosov: 0
Celotno besedilo (1,88 MB)
Gradivo ima več datotek! Več... |
8. |
9. Determinants of diarrhea, phenotypic and genomic characterization of Escherichia coli isolates from diarrheic and non-diarrheic patients attending public primary health facilities in Addis Ababa and Hossana, Ethiopia : dissertationWolde Deneke, 2025, doktorska disertacija Ključne besede: dissertations, Escherichia coli, antimicrobial resistance, genetic diversity, antimicrobial resistance genes, virulence-associated genes, mobile genetic elements, phylogenetic groups, whole-genome sequencing
Objavljeno v DKUM: 10.04.2025; Ogledov: 0; Prenosov: 14
Celotno besedilo (3,39 MB) |
10. Commercial SARS-CoV-2 targeted, protease inhibitor focused and protein–protein interaction inhibitor focused molecular libraries for virtual screening and drug designSebastjan Kralj, Marko Jukič, Urban Bren, 2022, pregledni znanstveni članek Opis: Since December 2019, the new SARS-CoV-2-related COVID-19 disease has caused a global
pandemic and shut down the public life worldwide. Several proteins have emerged as potential
therapeutic targets for drug development, and we sought out to review the commercially available
and marketed SARS-CoV-2-targeted libraries ready for high-throughput virtual screening (HTVS).
We evaluated the SARS-CoV-2-targeted, protease-inhibitor-focused and protein–protein-interactioninhibitor-focused libraries to gain a better understanding of how these libraries were designed. The
most common were ligand- and structure-based approaches, along with various filtering steps, using
molecular descriptors. Often, these methods were combined to obtain the final library. We recognized
the abundance of targeted libraries offered and complimented by the inclusion of analytical data;
however, serious concerns had to be raised. Namely, vendors lack the information on the library
design and the references to the primary literature. Few references to active compounds were also
provided when using the ligand-based design and usually only protein classes or a general panel
of targets were listed, along with a general reference to the methods, such as molecular docking for
the structure-based design. No receptor data, docking protocols or even references to the applied
molecular docking software (or other HTVS software), and no pharmacophore or filter design
details were given. No detailed functional group or chemical space analyses were reported, and no
specific orientation of the libraries toward the design of covalent or noncovalent inhibitors could
be observed. All libraries contained pan-assay interference compounds (PAINS), rapid elimination
of swill compounds (REOS) and aggregators, as well as focused on the drug-like model, with the
majority of compounds possessing their molecular mass around 500 g/mol. These facts do not bode
well for the use of the reviewed libraries in drug design and lend themselves to commercial drug
companies to focus on and improve.
Ključne besede: targeted libraries, focused libraries, computer-aided drug design, virtual screening, in silico drug design, high-throughput virtual screening
Objavljeno v DKUM: 09.04.2025; Ogledov: 0; Prenosov: 3
Celotno besedilo (6,53 MB)
Gradivo ima več datotek! Več... |
