Time efficient k-shot broadcasting in known topology radio networks

The paper considers broadcasting protocols in radio networks with known topology that are efficient in both time and energy. The radio network is modelled as an undirected graph G = (V, E) where |V| = n. It is assumed that during execution of the communication task every node in V is allowed to transmit at most once. Under this assumption it is shown that any radio broadcast protocol requires transmission rounds, where D is the diameter of G. This lower bound is complemented with an efficient construction of a deterministic protocol that accomplishes broadcasting in rounds. Moreover, if we allow each node to transmit at most k times, the lower bound on the number of transmission rounds holds. We also provide a randomised protocol that accomplishes broadcasting in rounds. The paper concludes with a number of open problems in the area. The research of L. Gąsieniec, D.R. Kowalski and C. Su supported in part by the Royal Society grant Algorithmic and Combinatorial Aspects of Radio Communication, IJP - 2006/R2. The research of E. Kantor and D. Peleg supported in part by grants from the Minerva Foundation and the Israel Ministry of Science.     

Cities under fire: Crisis communication on home front versus frontline cities' Facebook pages during operation ‘guardian of the walls’

Social media has been widely adopted by local governments during emergencies and crises and its role as a communication platform has been discussed in various studies on natural hazards, pandemics and terror attacks. However, research in the field has not addressed how municipalities use social media to communicate valuable information during armed conflicts and military operations. The current study examined the ways five major cities in Israel used their Facebook pages to connect to their residents during operation ‘Guardian of the Walls' in 2021. We examined the social media usage and the strategies of these cities during the 12 days of the operation. The findings revealed significant differences between cities that are considered as home front versus frontline regions regarding content type and information dissemination strategies. Additionally, differences regarding content types in terms of sentiment and overall rates of engagement were also identified. These findings highlight the need to further investigate local municipalities' usage of social media during armed conflicts concerning the civil population.     

Molecular distillation of copaiba oleoresin—A clean process for diterpenes enrichment

Copaiba oleoresin has sesquiterpenes and diterpenes with significant medicinal properties, including being antimicrobial, antiparasitic, and wound healing, among others. Thus, the objective of this work was to study the diterpene enrichment of the copaiba oleoresin from Copaifera officinalis via molecular distillation. Evaporator temperature (EVT) and feed flow rate (Q) were evaluated using an experimental design (2² with central point) considering the ratio of distillate and residue streams (DTR) as the response to optimize the residue recovery. EVT and Q were the main effects for diterpenes recovery, with the best experimental condition at 100°C (EVT) and 15 ml/min (Q) under 0.001 mbar, of which the residue stream had a diterpenes content of 99.25%. With the molecular distillation process, it was possible to add value to the copaiba streams, separating and purifying diterpenes with applicability in the biomedical and pharmaceutical industries since no solvent is used in this process (clean).