Kurtosis and compressibility near the chiral phase transition

The properties of net quark number fluctuations in the vicinity of the QCD chiral phase transition are discussed in terms of an effective chiral model in the mean-field approximation. We focus on the ratio of the fourth- to second- order cumulants (kurtosis) and the compressibility of the system and discuss their dependence on the pion mass. It is shown that near the chiral phase transition, both observables are sensitive to the value of $m_\pi$. For physical $m_\pi$, the kurtosis exhibits a peak whereas the inverse compressibility shows a dip at the pseudocritical temperature. These structures disappear for large $m_\pi$. Our results, obtained in an effective model with two flavors, are qualitatively consistent with recent results of 2+1 flavor lattice gauge theory. We also discuss the high- and low-temperature properties of these observables and the role of the coupling of the quark degrees of freedom to the Polyakov loop

Parametar oksidativnog stresa i enzimi antioksidativne zaštite kod gojaznih osoba u Srbiji

Rad je koncipiran, dizajniran i urađen u Laborastoriji za radiobiologiju i molekularnu genetiku Instituta za nuklearne nauke “Vinča” – Institutom od nacionalnog značaja – Univerziteta u Beogradu u saradnji sa Medicinskim fakultetom Univerziteta u Novom Sadu i Univerzitetskim Kliničkim CentromVojvodine. Uvod i cilj. Reaktivne vrste kiseonika (ROS) imaju mogućnost da reaguju sa biomolekulima ćelija i telesnih tečnosti i da ih menjaju. Oksidativni stres (OxS) nastaje u ćelijskim sistemima u uslovima narušene ravnoteže između stepena produkcije i otklanjanja visokoreaktivnih molekula, odnosno, kada produkcija ROS prevazilazi antioksidativne kapacitete datih sistema. Jedan od parametara OxS je 4-hidroksi 2-nonelan (4-HNE), čija koncentracija predstavlja stepen lipidne peroksidacije. Antioksidativni zaštitni sistem (AOS) nastao je tokom procesa evolucije u aerobnim uslovima kao odgovor na toksično delovanje kiseonika. Postoji više nivoa AOS, kao što su enzimski antioksidanti i neenzimski antioksidanti. Među najznačajnijim komponentama enzimskog AOS su superoksid dismutaza (SOD), katalaza (CAT), glutation peroksidaza (GPx) glutation reduktaza (GR). Cilj rada je bio utvrđivanje promena koncentracije parametra OxS i aktivnosti enzima AOS kod gojaznih ispitanika u odnosu na normalno uhranjene ispitanike. Metode. U studiju je bilo uključeno 67 osoba oba pola, od čega 36 normalno uhranjenih osoba (kontrole) i 31 gojazna osoba. Ukupni antioksidativni status (TAS) test je meren primenom Randox TAS kita sa Troloksom kao ekvivalentnim standardom na novoj generaciji Daytona (RX) automatskom hemijskom analizatoru prema uputstvu Randox Co. Za određivanje aktivnosti SOD, GPx i GR u serumu ispitanika korišćene su kolorimetrijske metode i komercijalno dostupni Randox kitovi (Randox Labs, Crumlin, UK). Za određivanje aktivnosti CAT i za određivanje koncentracije 4-HNE u serumu ispitanika korišćeni su komercijalno dostupni OxiSelect kitovi (Cell Biolabs, Inc., San Diego, USA). Rezultati. Dobijeni rezultati pokazuju da je koncentracija 4-HNE kod gojaznih osoba bila statistički značajno viša za 36% (p<0,001) u odnosu na nivo 4-HNE merenog kod kontrola. Nivo TAS kod gojaznih ispitanika bio je statistički značajno smanjen (p<0,001) u poređenju sa vrednostima za TAS kod kontrolnih ispitanika. Procenat smanjenja aktivnosti enzima AOS kod gojaznih osoba bio je 35% za SOD (p<0,001), 21% za GR (p<0,001) i 29% za GPx (p<0,001). Nije uočena statistički značajna promena za aktivnost CAT između dve ispitivane grupe. Zaključak. Dobijeni rezultati jasno pokazuju da stanje gojaznosti dovodi do smanjenja aktivnosti AOS, kao i povećanja koncentracije markera lipidne peroksidacije. Takođe, dobijeni rezultati sugerišu da bi određivanje enzima AOS i markera lipidne peroksidacije mogli biti jedni od biomarkera predikcije nastanka gojaznosti.KES2022 : 8. Kongres endokrinologa Srbije sa međunarodnim učešćem, Nov 30 - Dec 3, 2022, Beogra

A self-organized model for cell-differentiation based on variations of molecular decay rates

Systemic properties of living cells are the result of molecular dynamics governed by so-called genetic regulatory networks (GRN). These networks capture all possible features of cells and are responsible for the immense levels of adaptation characteristic to living systems. At any point in time only small subsets of these networks are active. Any active subset of the GRN leads to the expression of particular sets of molecules (expression modes). The subsets of active networks change over time, leading to the observed complex dynamics of expression patterns. Understanding of this dynamics becomes increasingly important in systems biology and medicine. While the importance of transcription rates and catalytic interactions has been widely recognized in modeling genetic regulatory systems, the understanding of the role of degradation of biochemical agents (mRNA, protein) in regulatory dynamics remains limited. Recent experimental data suggests that there exists a functional relation between mRNA and protein decay rates and expression modes. In this paper we propose a model for the dynamics of successions of sequences of active subnetworks of the GRN. The model is able to reproduce key characteristics of molecular dynamics, including homeostasis, multi-stability, periodic dynamics, alternating activity, differentiability, and self-organized critical dynamics. Moreover the model allows to naturally understand the mechanism behind the relation between decay rates and expression modes. The model explains recent experimental observations that decay-rates (or turnovers) vary between differentiated tissue-classes at a general systemic level and highlights the role of intracellular decay rate control mechanisms in cell differentiation.Comment: 16 pages, 5 figure

The Functional Renormalization Group and O(4) scaling

The critical behavior of the chiral quark-meson model is studied within the Functional Renormalization Group (FRG). We derive the flow equation for the scale dependent thermodynamic potential at finite temperature and density in the presence of a symmetry-breaking external field. Within this scheme, the critical scaling behavior of the order parameter, its transverse and longitudinal susceptibilities as well as the correlation lengths near the chiral phase transition are computed. We focus on the scaling properties of these observables at non-vanishing external field when approaching the critical point from the symmetric as well as from the broken phase. We confront our numerical results with the Widom-Griffiths form of the magnetic equation of state, obtained by a systematic epsilon-expansion of the scaling function. Our results for the critical exponents are consistent with those recently computed within Lattice Monte-Carlo studies of the O(4) spin system.Comment: 14 pages, 11 figure

Evaluation of the influence of terrain and traffic road conditions on the driver’s driving performances by applying machine learning

In this paper, research is done in the influence of different terrain and traffic conditions on road sections on the driver’s driving performances, i.e. on the car energy efficiency and CO2 emission. A methodology aimed at determining to which extent unfavorable traffic and/or terrain conditions on a road section contribute to the driver’s worse driving performances, and also to determine when the driver’s aggressive driving style is responsible for greater fuel consumption and greater CO2 emission is proposed. In order to apply the proposed methodology, a research study was carried out in a cargo transportation company and 12 drives who drove the same vehicle on five different road sections were selected. As many as 284014 of the instances of the data about the defined parameters of the road section and the driver’s driving style were collected, based on which and with the help of machine learning a prediction of the scores for the road section and the scores for the driver’s driving style was performed. The obtained results have shown that the proposed methodology is a useful tool for managers enabling them to simply and quickly determine potential room for increasing the energy efficiency of the vehicle fleet and decreasing CO2 emission

Risk characterization for mercury, dichlorodiphenyltrichloroethane and polychlorinated biphenyls associated with fish consumption in Serbia

The aim of this work was to assess the risk due to mercury (Hg), dichlorodiphenyltrichloroethane (DDT) and non-dioxin-like polychlorinated biphenyls (ndl PCBs) intake via fish consumption in Serbia. We have developed 24 scenarios using four concentration levels (mean, maximum, 50th and 95th percentile) of contaminants, determined in 521 samples of fish products available on Serbian market; two consumption levels (Food and Agriculture Organization/World Health Organization data and recommendation of American Heart Association); and three body weights (5th, 50th and 95th percentile). All the values concerning the intake of DDT are below the corresponding health based guidance value. Calculated weekly intake of Hg using maximal concentration, intake of 340 g/week and 5th percentile of body weight exceeded the provisional tolerable weekly intake (PTWI). When maximal and 95th percentile concentration of ndl PCBs was used, weekly intakes exceeded a "guidance value" with one exception Le., when 95th percentile of concentration along with 95th percentile of body weight were used. Concerning Hg and ndl PCBs, when extreme concentrations were used, HIs exceeded the value of 1, indicating that fish and fishery products may pose a threat to consumer's health

Some characteristics of anthropological status of women in Novi Sad – Republic of Serbia

The aim of this study was to determine the anthropological status of adult females and the prevalence of females with potential health risk using the indices of obesity. The anthropological study was conducted from 2011 to 2013 in Novi Sad, (the north of Serbia). The tested group consisted of 310 women, with mean age 41.42±6.86, involved in the project "The impact of physical activity on the risk factors in the working population." Nutritional condition was determined using the body mass index (BMI kg/m2 ), while the waist circumference and WHR were used for assessing the central obesity. According to the average BMI, the younger females are predominantly with normal weight, while higher percent of older females is characterised with pre-obesity. In total, 45.85% of females are with excessive body weight, 34.62% of them being classified as overweight and 11.23% as obese. Central obesity is more frequent in older females aged up to 40. Potential health risk increases with age, and very high health risk from abdominal and overall obesity was observed in 6.25% of younger and 13,25% of older women. The data therefore point to the necessity of continuous monitoring and a combination of existing programs with other forms of organized physical activity