Selecting a Leader in a Network of Finite State Machines

This paper studies a variant of the leader election problem under the stone age model (Emek and Wattenhofer, PODC 2013) that considers a network of n randomized finite automata with very weak communication capabilities (a multi-frequency asynchronous generalization of the beeping model\u27s communication scheme). Since solving the classic leader election problem is impossible even in more powerful models, we consider a relaxed variant, referred to as k-leader selection, in which a leader should be selected out of at most k initial candidates. Our main contribution is an algorithm that solves k-leader selection for bounded k in the aforementioned stone age model. On (general topology) graphs of diameter D, this algorithm runs in O~(D) time and succeeds with high probability. The assumption that k is bounded turns out to be unavoidable: we prove that if k = omega (1), then no algorithm in this model can solve k-leader selection with a (positive) constant probability

Genetic diversity of Bm86 sequences in Rhipicephalus (Boophilus) microplus ticks from Mexico: analysis of haplotype distribution patterns

Artículo científico derivado de Tesis doctoral de Saúl Gabriel Martínez ArzateBackground: Ticks are a problem for cattle production mainly in tropical and subtropical regions, because they generate great economic losses. Acaricides and vaccines have been used to try to keep tick populations under control. This has been proven difficult given the resistance to acaricides and vaccines observed in ticks. Resistance to protein rBm86-based vaccines has been associated with the genetic diversity of Bm86 among the ectoparasite’s populations. So far, neither genetic diversity, nor spatial distribution of circulating Bm86 haplotypes, have been studied within the Mexican territory. Here, we explored the genetic diversity of 125 Bm86 cDNA gene sequences from R. microplus from 10 endemic areas of Mexico by analyzing haplotype distribution patterns to help in understanding the population genetic structure of Mexican ticks. Results: Our results showed an average nucleotide identity among the Mexican isolates of 98.3%, ranging from 91.1 to 100%. Divergence between the Mexican and Yeerongpilly (the Bm86 reference vaccine antigen) sequences ranged from 3.1 to 7.4%. Based on the geographic distribution of Bm86 haplotypes in Mexico, our results suggest gene flow occurrence within different regions of the Mexican territory, and even the USA. Conclusions: The polymorphism of Bm86 found in the populations included in this study, could account for the poor efficacy of the current Bm86 antigen based commercial vaccine in many regions of Mexico. Our data may contribute towards designing new, highly-specific, Bm86 antigen vaccine candidates against R. microplus circulating in Mexico.SIEAE UAEM FES

An Almost Singularly Optimal Asynchronous Distributed MST Algorithm

A singularly (near) optimal distributed algorithm is one that is (near) optimal in \emph{two} criteria, namely, its time and message complexities. For \emph{synchronous} CONGEST networks, such algorithms are known for fundamental distributed computing problems such as leader election [Kutten et al., JACM 2015] and Minimum Spanning Tree (MST) construction [Pandurangan et al., STOC 2017, Elkin, PODC 2017]. However, it is open whether a singularly (near) optimal bound can be obtained for the MST construction problem in general \emph{asynchronous} CONGEST networks. We present a randomized distributed MST algorithm that, with high probability, computes an MST in \emph{asynchronous} CONGEST networks and takes $\tilde{O}(D^{1+\epsilon} + \sqrt{n})$ time and $\tilde{O}(m)$ messages, where $n$ is the number of nodes, $m$ the number of edges, $D$ is the diameter of the network, and $\epsilon >0$ is an arbitrarily small constant (both time and message bounds hold with high probability). Our algorithm is message optimal (up to a polylog$(n)$ factor) and almost time optimal (except for a $D^{\epsilon}$ factor). Our result answers an open question raised in Mashregi and King [DISC 2019] by giving the first known asynchronous MST algorithm that has sublinear time (for all $D = O(n^{1-\epsilon})$) and uses $\tilde{O}(m)$ messages. Using a result of Mashregi and King [DISC 2019], this also yields the first asynchronous MST algorithm that is sublinear in both time and messages in the $KT_1$ CONGEST model. A key tool in our algorithm is the construction of a low diameter rooted spanning tree in asynchronous CONGEST that has depth $\tilde{O}(D^{1+\epsilon})$ (for an arbitrarily small constant $\epsilon > 0$) in $\tilde{O}(D^{1+\epsilon})$ time and $\tilde{O}(m)$ messages. To the best of our knowledge, this is the first such construction that is almost singularly optimal in the asynchronous setting.Comment: 27 pages, accepted to DISC 202

The Shadow of a Doubt: discovering a new work by Edith Wharton

No abstract available

Computational self-assembly

International audienceThe object of this paper is to appreciate the computational limits inherent in the combinatorics of an applied concurrent (aka agent-based) language kappa. That language is primarily meant as a visual and concise notation for biological signalling pathways. Descriptions in kappa, when enriched with suitable kinetic information, generate simulations as continuous time Markov chains. However, kappa can be studied independently of the intended application, in a purely computational fashion, and this is what we are doing here. Specifically, we define a compilation of kappa into a language where interactions can involve at most two agents at a time. That compilation is generic, the blow up in the number of rules is linear in the total rule set size, and the methodology used in deriving the compilation relies on an implicit causality analysis. The correctness proof is given in details, and correctness is spelt out in terms of the existence of a specific weak bisimulation. To compensate for the binary restriction, one allows components to create unique identifiers (aka names). An interesting by-product of the analysis is that when using acyclic rules, one sees that name creation is not needed, and can be fully reduced to binary form

The Logic of Spectacle c. 1970

This paper examines the site plan and theme exhibit of the Osaka Expo of 1970, together with a week-long protest staged in the Tower of the Sun, which was the main element of the Theme Exhibit. Attempts to communicate a critical account of contemporary society and so transform the visitor were undercut by the Expo's ability to accommodate diverse interests and investments and to account for almost anything that was exhibited or staged on site. The Expo thus suggests that we need to supplement our understanding of spectacle as communication with an analysis of spectacle as a system

An anthropological investigation of urban land development : a thesis presented in partial fulfilment of the requirements for the degree of M.A. in Social Anthropology at Massey University

The impetus for this project came from examples of neighbours' disempowerment in the land and property development process. There is a growing academic consensus that dominant approaches to land development fail to adequately address this issue. NeoMarxist approaches focus on conflict, power, and exploitation, but effectively eliminate the role of the actual developer in exercising power. Case study approaches, on the other hand, have been concerned with conflict and disempowerment, but have focused on specific instances of neighbourhood opposition and resistance. Explanation is often confined to local and national features of the social and geographical environment. These inadequacies pointed to the need to investigate the increasingly significant role that professional, entrepreneurial developers play at the nexus of the contemporary development process. An ethnographic methodology was used to provide a richer understanding of the land and property development process. The principal participants in the study are a set of 'entrepreneurial developers' operating in and around Palmerston North. Interviews, participant observation, and the examination of case studies are employed. This is complemented by an investigation of the Regulatory Procedure, including interviews with Council Officers, and examination of Council case studies. The research also uses interviews with neighbours, and a wide body of material published within the development industry. Planning for the study drew on Giddens' 'Theory of Structuration' (1979,1984) which stresses the interrelationship between the social structures of the development process, and the agency of developers. The research sought to elucidate the dominant forms of action and ideology which development agents acknowledge, and which therefore constitute the action and ideology of the development industry. The interpretation of the empirical data uses three interrelated perspectives: The first, provides a broad, industry-level, perspective on the local development industry. It asks, 'What are the major influences which shape and structure the contemporary development industry?'; The second, examines the level of action. It asks 'What are the actions of most significance to developers?', and 'What forms of conduct constitute the Institutional structures of the Regulatory Procedure?'; The third focuses on ideology. It asks, 'What are the dominant motivations which direct and influence developers' conduct?', and 'How do developers legitimate and rationalise conduct?'. An interesting aspect to the thesis is the extent to which developers share patterns of ideology, not only with each other, but also with a wider business community. Much of this characteristic ideology parallels findings in other ethnographic studies of capitalistic systems. The research highlights the fact that ethnography, and the notion of 'culture', provide an insightful and useful perspective of both the business world, and the study of development