The COVID-19 pandemic caused by the SARS-CoV-2 virus has inflicted significant mortality and morbidity worldwide. Continuous virus mutations have led to the emergence of new variants. The Omicron BA.1 sub-lineage prevailed as the dominant variant globally at the beginning of 2022 but was subsequently replaced by BA.2 in numerous countries. Wastewater-based epidemiology (WBE) offers an efficient tool for capturing viral shedding from infected individuals, enabling early detection of potential pandemic outbreaks without relying solely on community cooperation and clinical testing resources. This study integrated RT-qPCR assays for detecting general SARS-CoV-2 and its variants levels in wastewater into a modified triple susceptible-infected-recovered-susceptible (SIRS) model. The emergence of the Omicron-BA.1 variant was observed, replacing the presence of its predecessor, the Delta variant. Comparative analysis between the wastewater data and the modified SIRS model effectively described the BA.1 and subsequent BA.2 waves, with the decline of the Delta variant aligning with its diminished presence below the detection threshold in wastewater. This study demonstrates the potential of WBE as a valuable tool for future pandemics. Furthermore, by analyzing the sensitivity of different variants to model parameters, we are able to deduce real-life values of cross-variant immunity probabilities, emphasizing the asymmetry in their strength.

Revascularization of the myocardium under conditions of extracorporeal circulation cause clinical problems related to the effects of the intervention itself on the immune system and inflammatory response, especially systemic inflammatory response (Engl. Systemic Inflammatory Response Syndrome, SIRS). This prospective study included 100 patients who underwent single, double and triple surgical revascularization of the myocardium, at the Clinic for Cardiac Surgery of CC Niš, in the period from January 15., 2020. until January 15., 2021. 22 female persons - 22.0% and 78 male persons - 78.0%) were included. Preoperatively, as well as 8 hours after the surgical intervention, the following parameters were determined for the subjects: blood count (erythrocyte count - Rbc, hemoglobin - Hgb, hematocrit - Hct, leukocyte count - Wbc, platelet count - Plt) and CRP, soluble CD14 molecule (sCD 14) - presepsin, levels of the following cytokines: TNFα, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12 p70 and IFN γ. Patients in whom the extracorporeal circulation method was applied had, postoperatively, a higher concentration of CRP (p<0.001), as well as a concentration of presepsin (p<0.05) - a greater number of patients had a concentration of presepsin above the limit of 600 pg/ mL (p<0.01). Four patients out of 51 (7.84%) in the ECB group had elevated presepsin values over 1000 pg/ml and high risk according to clinical criteria for the development of systemic bacterial infection and sepsis. No such patients were recorded in the off pump group. Also, in the group where the extracorporeal blood flow system was applied, 17.64% of patients (9/51) met the clinical criteria for SIRS with elevated presepsin values over 600 pg/mL, while in the other group of patients, 2 out of 49 (4.08%) met the clinical criteria and laboratory criteria for SIRS. Except for TNFa, the levels of IL-1β, IL-2, IL-6 and IL-10 showed an increase after the intervention in all groups compared to the preoperative period (p<0.01). However, comparing the degree of cytokine increase in the postoperative period between the control (off pump) and the extracorporeal blood flow group did not show a statistical difference (IL-2; p=0.881, IL-1; p=0.709, IL-6; p=0.911, IL- 10, p=0.179). In the postoperative period, a higher incidence rate of SIRS was noted in patients in whom the ECB system was used, which also indicates its importance in the development of systemic inflammation and immune dysregulation.

Life evolved in an euxinic world with subsequent oxic 'invasion' leading to two parallel but interconnected biospheres, hydrogen sulphide (H₂S) and hydrogen peroxide (H₂O₂) exemplify these worlds respectively. Their concentration gradients have informational value in meromictic lakes. Similarly, it is posited, there exists a whole body chemocline in humans in which the two molecules form an inversely coupled oxic/sulphidic oscillator (OSO). The OSO is hormetic and characterised by a range of amplitudes and frequencies in health. Deviations from its baseline profile heralds the onset of SIRS before the appearance of clinical signs. Loss of oscillator status and transition to a steady state causes widespread intercellular and inter-organ communication failure presaging multi-organ dysfunction. The salient clinico-pathophysiological features of SIRS of any aetiology are emergent phenomena related to the OSO profile. Extent of recovery of organ function will mirror the recovery of the OSO profile thereby providing a tool to predict outcomes in SIRS.

Symmetry concepts in parametrized dynamical systems may reduce the number of external parameters by a suitable normalization prescription. If, under the action of a symmetry group G, parameter space A becomes a (locally) trivial principal bundle, A ~ A/G x G, then the normalized dynamics only depends on the quotient A/G. In this way, the dynamics of fractional variables in homogeneous epidemic SI(R)S models, with standard incidence, absence of R-susceptibility and compartment independent birth and death rates, turns out to be isomorphic to (a marginally extended version of) Hethcote's classic endemic model, first presented in 1973. The paper studies a 10-parameter master model with constant and I -linear vaccination rates, vertical transmission and a vaccination rate for susceptible newborns. As recently shown by the author, all demographic parameters are redundant. After adjusting time scale, the remaining 5-parameter model admits a 3-dimensional abelian scaling symmetry. By normalization we end up with Hethcote's extended 2-parameter model. Thus, in view of symmetry concepts, reproving theorems on endemic bifurcation and stability in such models becomes needless.