ABSTRACT
Despite the advanced stage of epidemic modeling, there is a major demand for methods to incorporate behavioral responses to the spread of a disease, such as social distancing and adoption of prevention methods. Mobility plays an important role on epidemic dynamics and is also affected by behavioral changes, but there are many situations in which real mobility data is incomplete or inaccessible. We present a model for epidemic spreading in temporal networks of mobile agents that incorporates local behavioral responses. Susceptible agents are allowed to move towards the opposite direction of infected agents in their neighborhood. We show that this mechanism considerably decreases the stationary prevalence when the spatial density of agents is low. However, for higher densities, the mechanism causes an abrupt phase transition, where a new bistable phase appears. We develop a semi-analytic approach for the case when the mobility is fast compared to the disease dynamics, and use it to argue that the bistability is caused by the emergence of spatial clusters of susceptible agents. Finally, we characterize the temporal networks formed in the fast mobility regime, showing how the degree distributions and other metrics are affected by the behavioral mechanism. Our work incorporates results previously known from adaptive networks into population of mobile agents, which can be further developed to be used in mobility-driven models. © 2022
ABSTRACT
Purpose: The protective role of Vitamin D as an immunomodulator has been demonstrated in different pathologies included the viral etiology. This effect has been described by different mechanisms among these acting as an immunoprotein inducer, participates in growth and cell differentiation and acts as a mediator of apoptosis. Some evidence suggests that it could influence the SARS-COV 2 infection and its prognosis. Kidney transplant (KT) patients are more susceptible to 25 (OH) VitD (Calcidiol) deficiencies. The purpose of this study is to evaluate the Vitamin D status in transplant patients who have been diagnosed with COVID-19 and its possible correlation with prognosis. Methods: It is an observational, retrospective, cross-sectional and descriptive study that includes kidney transplant patients diagnosed with COVID-19 and with serum 25 (OH) Vit D Results: 79 patients were evaluated. The mean age was 58 years, 60.8% were men. 86% were KT, 11% were simultaneous pancreas and kidney transplant (SPK). 39 (48%) presented neumonia, 22 (28%)flu-like syndrom. 14 (17%) asyntomatic and 2(2,5%) fever. From this patients 39,2% had not changes in the antiinflamatorie therapy, 20.3%, required increased dose of corticosteroids, and 30.4% required methylprednisolone bolus or initiation of anti-interleukin therapy. The mean of Vit D was 21.41+/- 11% we found that 52% has Vit D <20 ng/ dl. 25% between 20 -30 ng / dl and 21,51% > 30 ng / dl In 32 patientes who required intensification of treatment we found that 73% had Vit D levels <20 ng. 11 patients need an citical care unit, of these 62.5% had levels below <20 ng / dl. There were 12 deaths. 66% of deaths had vitamin D values <20 ng / dl. Conclusions: We were able to observe that vitamin D levels could influence in the prognosis of SARS-COV 2 infection. Vitamin D deficiency was found in a high percentage of transplant patients with COVID 19. Low levels of 25 OH Vit D were evidenced in patients who required greater intensification of antiinflamatory treatment and in deaths.