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This study proposes a nabla discrete fractional-order system of differential equations to model lung cancer and its interactions with lung epithelial cells, mutated cells, oncogenes, tumor suppressor genes, immune cells, cytokines, growth factors, angiogenic factors, and extracellular matrix. The proposed model can help predict cancer growth, metastasis, and response to treatment. Analytical results show the system is stable with a unique solution, and the model predicts that the immune system responds to cancer cells but eventually becomes overpowered. The numerical analysis employed the forward and backward Euler method and demonstrated that changes in parameter values have significant effects on the steady-state solution. The findings show that the growth of lung epithelial cells or their interaction with immune cells can cause an increase in the number of lung cancer cells. Conversely, an increase in cell death or a reduction in the interaction between lung epithelial cells and immune cells can decrease the number of lung cancer cells. The study highlights the usefulness of the nabla discrete fractional model in studying lung cancer dynamics.

Antibiotic resistance is becoming one of the threats to global health. This crisis has been attributed to the over-the-counter and overuse of antibiotics leading bacteria to gain the ability to resist and survive even in the presence of antimicrobial agents. Escherichia coli (E. coli) is one of the major gram-negative bacteria that are the representative indicators of antibiotic resistance. One of the mechanisms of gaining antibiotic resistance is the ability of E. coli to gain the production of extended-spectrum beta-lactamases (ESBL). In this study, Near East University Hospital data from 2016 to 2019 were used to study the dynamics of ESBL-producing (ESBL+{\text{ESBL}}^{+}) and non-ESBL-producing (ESBL−{\text{ESBL}}^{-}) E. coli infections by using a mathematical model. In our study, the aim was to evaluate the distribution of infections caused by resistant E. coli strains in later years and to increase the success of treatment in patients infected with E. coli by reducing the problem of antibiotic resistance. By using the mathematical model and data of the patients, basic reproduction number (R 0) values were calculated to study epidemiologic dynamics of the disease. The R0E−{R}_{0}^{{E}^{-}} and R0E+{R}_{0}^{{E}^{+}}values for ESBL−{\text{ESBL}}^{-} and ESBL+ {\text{ ESBL}}^{+}\text{ } E. coli infections were calculated, respectively. According to the model and the data used within the study, it was calculated that R0E−{R}_{0}^{{E}^{-}}to be 1,266,403 and R0E+{R}_{0}^{{E}^{+}}to be 2,096,747. Since the values for R0E−{R}_{0}^{{E}^{-}} and R0E+{R}_{0}^{{E}^{+}} were equal or greater than 1, this suggests that currently the ESBL−\hspace{.25em}{\text{ESBL}}^{-} and ESBL+ {\text{ ESBL}}^{+}\text{ } E. coli infections are in epidemic character for Cyprus. Furthermore, when simulation analyses were carried out for the model, it was predicted that in 2042 the ESBL−{\text{ESBL}}^{-} and ESBL+{\text{ ESBL}}^{+} E. coli infection trends will equalize. After 2042, the ESBL− {\text{ESBL}}^{-}\text{ } E. coli infections will indicate a descending pattern whereas ESBL+ {\text{ ESBL}}^{+}\text{ } E. coli infection will increase constantly.

Objective: The Mediterranean island of Cyprus has a high rate of human transit as a result of tourism, human trafficking, and migration, which could contribute to the rate of HIV infection. The island is divided into 2 states - the northern portion is mainly populated by Turkish-Cypriots, and the southern portion is populated by Greek-Cypriots. The aim of this study was to assess the dynamics of HIV infection in both segments of Cyprus using a mathematical model. Materials and Methods: Data of HIV-positive individuals diagnosed during the period 1997-2018 in northern Cyprus were obtained from the Turkish Republic of Northern Cyprus Ministry of Health database, yielding a total of 129 cases, and data for the southern region, the Republic of Cyprus, were retrieved from a European Centre for Disease Prevention and Control (ECDC) 2013 report and ECDC/World Health Organization 2017 data. The total number of reported HIV infections was 1057. A mathematical model was used to evaluate the current and future HIV infection rate. Results: Stability analysis of the equilibrium point - disease-free or endemic - was conducted using the Lyapunov function. The basic reproduction number, represented as R0, is a measure of the potential for disease spread and serves as a threshold for stability. The R0 value was 0.83 in northern Cyprus and 0.040 in southern Cyprus. An R0 indicated a disease-free equilibrium. Conclusion: The calculations suggest that there is no current HIV epidemic on either part of the island; however, the model predicted a significant increase in the near future. [ABSTRACT FROM AUTHOR]

Northern Cyprus has implemented relatively strictmeasures in the battle against the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The measures were introduced at the beginning of the COVID-19 pandemic, in order to prevent the spread of the disease. One of these measures was the use of two separate realtime reverse transcription polymerase chain reaction (rRT-PCR) tests for SARS-CoV-2 referred to as the double screening procedure, which was adopted following the re-opening of the sea, air and land borders for passengers after the first lockdown. The rRT-PCR double screening procedure involved reporting a negative rRT-PCR test which was carried in 72 to 120 h before departure whilst presenting no known symptoms of the COVID-19 and performing a second rRT-PCR test at the point of arrival. This study compares the results of SARS-CoV-2 rRT-PCR tests performed on incoming flight passengers from the 1st July to 9th of September 2020 to Northern Cyprus. The rRT-PCR test results collected by theNear EastUniversity (NEU)DESAMCOVID-19 laboratory were compared with the rRT-PCR test results collected by theMinistry of Health and/or private COVID-19 laboratories in Northern Cyprus. This comparative study was conducted using binomial distribution. In addition, by applying the Susceptible-Exposed-Infected-Removed (SEIR)model to Northern Cyprus, overall basic reproduction number (R0) value of the COVID-19 was analysed for the same time period to act as a threshold for this comparison. In both the statistical and SEIR mathematical model, R0 was calculated. It was assumed that, the more similar the R0 results of NEU DESAM COVID-19 laboratory and other laboratories were with the overall R0 value of Northern Cyprus, the more reliable the results would be. We calculated that the median R0 values of the NEU DESAM COVID-19 laboratory and other laboratories performing the SARS-CoV-2 rRT-PCR on air passengers during the studied period to be 0.96 and 1.29, respectively, compared to Northern Cyprus median R0 value which was 0.99. The rRT-PCR screening results from the NEU DESAM COVID-19 laboratory were closely aligned with the screening results of Northern Cyprus whereas the screening results reported by other laboratories were not in a fit with the regional pattern. This study also aimed to point out the importance of the rRT-PCR screening procedure since asymptomatic positive SARS-CoV-2 cases entery to Northern Cyprus was inhibited and this prevented the spread of the disease within the population. [ABSTRACT FROM AUTHOR]