Deaf, Dumb, and Chatting Robots, Enabling Distributed Computation and Fault-Tolerance Among Stigmergic Robot

We investigate ways for the exchange of information (explicit communication) among deaf and dumb mobile robots scattered in the plane. We introduce the use of movement-signals (analogously to flight signals and bees waggle) as a mean to transfer messages, enabling the use of distributed algorithms among the robots. We propose one-to-one deterministic movement protocols that implement explicit communication. We first present protocols for synchronous robots. We begin with a very simple coding protocol for two robots. Based on on this protocol, we provide one-to-one communication for any system of n \geq 2 robots equipped with observable IDs that agree on a common direction (sense of direction). We then propose two solutions enabling one-to-one communication among anonymous robots. Since the robots are devoid of observable IDs, both protocols build recognition mechanisms using the (weak) capabilities offered to the robots. The first protocol assumes that the robots agree on a common direction and a common handedness (chirality), while the second protocol assumes chirality only. Next, we show how the movements of robots can provide implicit acknowledgments in asynchronous systems. We use this result to design asynchronous one-to-one communication with two robots only. Finally, we combine this solution with the schemes developed in synchronous settings to fit the general case of asynchronous one-to-one communication among any number of robots. Our protocols enable the use of distributing algorithms based on message exchanges among swarms of Stigmergic robots. Furthermore, they provides robots equipped with means of communication to overcome faults of their communication device

IDF21-0168 pathway to clinical diabetes services in COVID-19 era : what has changed and what are the implications?

BACKGROUND: The known barriers to delivering clinical NCD services in lower-middle-income countries (LMICs) have been exacerbated with the onset of COVID-19. Health facility-instituted COVID-19 control measures could compromise the pathway for seeking care and impact chronic disease care that needs to be examined for future policy direction. AIM: This paper examines the changes COVID-19 has brought to diabetes service delivery in LMICs, using Ghana as a case study, and raises questions on the implication of such changes on the individual- and population-level diabetes treatment outcomes by exploring service provider perspectives. Ghana first recorded COVID-19 cases in March 2020, and from April, the government started implementing lockdown measures as well as closing hospitals’ outpatient services, including diabetes clinics and other NCDs services. METHOD: We conducted eighteen semi-structured personal interviews with healthcare providers in primary, secondary and tertiary facilities within the Ghana Health Service. The topic guide was developed from a literature review conducted for this study and addressed issues such as COVID-19 and service organisation, staffing, referrals, patient concerns, data management and insurance. The interviews were conducted between November 2020 and February 2021, when outpatient services, including diabetes clinics, resumed operations. The analysis was performed using inductive and deductive methods in NVivo 1.4.1. RESULTS AND DISCUSSION: The study found that suboptimal patient appointments and reminder systems result in overcrowded diabetes clinics, further increasing the risk of COVID19 epidemic in hospitals. Tackling overcrowded diabetes clinics is urgently needed with the potential for patients and providers becoming infected with COVID-19. Engineering controls, e.g. fans instead of air conditioners to improve air circulation and ventilation, can help minimize transmission in hospital buildings. COVID-19 controls, e.g., extended time intervals between reviews, fewer appointments per clinic day, and shorter consultation durations, limit opportunities for clinicians to intervene in patients’ conditions and consequently lead to poor treatment outcomes. Health systems need to investigate the cost effectiveness of such controls to support policy decisions. National health insurance and drug policies limit health facilities and diabetes patients access to medicines in the COVID-19 era. Restrictions on the procurement and sales of insured medicines to patients contributed to the shortage of diabetes medication. Granted permission to procure medicines on the open market, a limit on the profit margin to put on medicine cost can result in a loss for health facilities. Known diabetes service delivery challenges, e.g. few trained providers, high treatment cost, and drug shortage, were aggravated, particularly in ambulatory care, during the pandemic. The UK and Italy adapted Facebook chatting, video tele-consultation and government websites for delivering diabetes care during the COVID-19 pandemic. However, we are aware that resource constraints may limit the implementation of similar strategies in LMICs. Our study suggests that COVID-19 presents additional challenges and worsens existing barriers to diabetes service delivery for clinicians and people living with diabetes. These challenges could have negative implications for population-level diabetes treatment outcome, interfering with the sustainable development goals. Further research remains to assess the effect of COVID-19-related structural changes on treatment adherence and outcomes in practice

A generalization of the concept of distance based on the simplex inequality

We introduce and discuss the concept of n-distance, a generalization to n elements of the classical notion of distance obtained by replacing the triangle inequality with the so-called simplex inequality d(x1,…,xn)≤K∑i=1nd(x1,…,xn)zi,x1,…,xn,z∈X, where K=1. Here d(x1,…,xn)zi is obtained from the function d(x1,…,xn) by setting its ith variable to z. We provide several examples of n-distances, and for each of them we investigate the infimum of the set of real numbers K∈]0,1] for which the inequality above holds. We also introduce a generalization of the concept of n-distance obtained by replacing in the simplex inequality the sum function with an arbitrary symmetric function

Mobile agent rendezvous: A survey

Abstract. Recent results on the problem of mobile agent rendezvous on distributed networks are surveyed with an emphasis on outlining the various approaches taken by researchers in the theoretical computer science community.

Interdependent Utilities: How Social Ranking Affects Choice Behavior

Organization in hierarchical dominance structures is prevalent in animal societies, so a strong preference for higher positions in social ranking is likely to be an important motivation of human social and economic behavior. This preference is also likely to influence the way in which we evaluate our outcome and the outcome of others, and finally the way we choose. In our experiment participants choose among lotteries with different levels of risk, and can observe the choice that others have made. Results show that the relative weight of gains and losses is the opposite in the private and social domain. For private outcomes, experience and anticipation of losses loom larger than gains, whereas in the social domain, gains loom larger than losses, as indexed by subjective emotional evaluations and physiological responses. We propose a theoretical model (interdependent utilities), predicting the implication of this effect for choice behavior. The relatively larger weight assigned to social gains strongly affects choices, inducing complementary behavior: faced with a weaker competitor, participants adopt a more risky and dominant behavior

Accounting for Equity Considerations in Cost-Effectiveness Analysis : A Systematic Review of Rotavirus Vaccine in Low- and Middle-Income Countries

Additional file 3: Appendix C. Full data table of results