ON NUMERICAL MODELING OF THE INVERSE EPIDEMIOLOGY PROBLEM

The article examines a mathematical compartment model of the spread of the COVID-19 coronavirus. The article consists of six paragraphs. In this study, epidemic outbreaks are studied from an interdisciplinary point of view using an extension of the susceptible-infected-recovered-deceased (SEIRD) model, which is a mathematical chamber model based on the average behavior of the studied population group. Many infectious diseases are characterized by an incubation period between exposure and the appearance of clinical symptoms. Subjects exposed to infection are much more dangerous to the public compared to subjects who have clinical symptoms. A nonlinear system of SEIRD differential equations is considered. For the numerical solution of a direct problem, the fourth-order Runge-Kutta method is considered. In modeling, the relationship is derived based on the laws of the subject area and allows you to determine the nature of changes in the framework of the work, depending on its parameters. The inverse problem is posed to determine the coefficients of this system. The inverse problem was solved by the method of a genetic algorithm. The method of the genetic algorithm is described. Numerical results are obtained and a comparative analysis with accurate data is made.

Antifungal Activity of Silver Nanoparticles with the Potential to Control Fungal Contamination in the Male Inflorescences of Palmyra Palm

Fungal contamination of the male inflorescences of palmyra palm (Borassus flabellifer Linn.) is a serious problem during their storage prior being used as the raw material for making the local One-Tambon-One-Product, a cloth holder known as “Nguang Taan Hom” made by the Phutaan Entrepreneurship, Takua Thung District PhangNga Province, Thailand. Morphological and molecular techniques were used to identify the isolated fungi from male palmyra palm inflorescences. Three major strains: Aspergillus niger, Aspergillus fumigatus and Aspergillus sclerotiorum were studied for antifungal activities and the minimum inhibitory concentration (MIC) of silver nanoparticles (AgNPs) was found to range from 13.5–27 mg mL–1. Then, the efficiency of the AgNPs and silver nanoparticles stabilizing by Polyvinylpyrrolidone (AgNPs-PVP) on the male palmyra palm inflorescences was studied by constructing a chamber model over a period for 9 weeks. The results showed that the group inoculated with Aspergillus niger, Aspergillus fumigatus and Aspergillus sclerotiorum spores developed fungal growth after 4 weeks whereas no fungal growth was observed in the group treated with AgNPs and AgNPs-PVP at 27 μg/ mL until week 7, indicating that dipping with either AgNPs or AgNPs-PVP is able to inhibit the growth of the fungi which cause damage to raw materials and also threaten human health. Therefore, it can effectively extend the storage time of male palmyra inflorescences.

Erythropoietin exposure of isolated pancreatic islets accelerates their revascularization after transplantation

Aims The exposure of isolated pancreatic islets to pro-angiogenic factors prior to their transplantation represents a promising strategy to accelerate the revascularization of the grafts. It has been shown that erythropoietin (EPO), a glycoprotein regulating erythropoiesis, also induces angiogenesis. Therefore, we hypothesized that EPO exposure of isolated islets improves their posttransplant revascularization. Methods Flow cytometric, immunohistochemical and quantitative real-time (qRT)-PCR analyses were performed to study the effect of EPO on the viability, cellular composition and gene expression of isolated islets. Moreover, islets expressing a mitochondrial or cytosolic H2O2 sensor were used to determine reactive oxygen species (ROS) levels. The dorsal skinfold chamber model in combination with intravital fluorescence microscopy was used to analyze the revascularization of transplanted islets. Results We found that the exposure of isolated islets to EPO (3 units/mL) for 24 h does not affect the viability and the production of ROS when compared to vehicle-treated and freshly isolated islets. However, the exposure of islets to EPO increased the number of CD31-positive cells and enhanced the gene expression of insulin and vascular endothelial growth factor (VEGF)-A. The revascularization of the EPO-cultivated islets was accelerated within the initial phase after transplantation when compared to both controls. Conclusion These findings indicate that the exposure of isolated islets to EPO may be a promising approach to improve clinical islet transplantation.

Use of Disinfection Chamber to Prevent Covid-19 at the Faculty of Veterinary Medicine, Universitas Airlangga

Community empowerment at the Faculty of Veterinary Medicine and Animal Education Hospital (RSHP) Universitas Airlangga aimed to prevent Covid-19 among students, picket workers, employees, veterinarians, nurses, and the client who bring animals to RSHP. The program starts from observation to implementation in May-October 2020. Implementation of community empowerment program in collaboration with the KKN program in Surabaya. This program introduced the disinfection chamber model of an automatic sprayer that is safe for health and complies with the standard operating procedure (SOP) for the use of the disinfection chamber. The existence of a disinfection chamber at the entrance to the campus and RSHP has contributed a lot to prevent the spread of Covid-19. The post-test results showed an increase in public understanding of the existence of disinfection chamber as a way to reduce the spread of Covid-19 and implement health protocols and healthy lifestyles.