Single-writer k-quorum protocols achieve high availability without incurring the risk of read operations returning arbitrarily stale values: in particular, they guarantee that, even in the presence of an adversarial scheduler, any read operation will return the value written by one of the last k writes. In this paper, we expand our understanding of k-quorums in two directions: first, we present...

A quorum system is a collection of subsets of nodes, called quorums, with the property that each pair of quorums have a non-empty intersection. Quorum systems are the key mathematical abstraction for ensuring consistency in fault-tolerant and highly available distributed computing. This paper is a brief overview of the evolution of quorum systems, with emphasis on their role in two fundamental ...

Quorum sensing in the phycosphere refers to a sensor system which bacteria secrete bioactive compounds coordinate group behavior relying on cell density. It is an important way for algae and communicate with each other achieve interactions. has been determined that quorum widely presented marine phycosphere, involves variety of compounds. Focused these this review summarizes types structures co...

pectobacterium carotovorum is one of the most important bacterial pathogens of potato in the world.the expression of numerous genes including those involved in the production of virulence determinants in this bacterium are regulated by quorum sensing (qs). the signal molecules involved in qs in p. carotovorum belong to the group of n-acyl homoserine lactones (ahls). recently, several soil bacte...

Quorum sensing is a cell-density-dependent regulatory system in gram-positive bacteria and is often regulated by cyclic peptides called "quormones," which function as extracellular communication signals. With an aim to discover an antipathogenic agent targeting quorum sensing in gram-positive bacteria, we screened 153 samples of fungal butanol extracts with the guidance of the inhibition of quo...

Bacterial cell-to-cell communication (quorum sensing) refers to the regulation of bacterial gene expression in response to changes in microbial population density. Quorum sensing bacteria produce, release and respond to chemical signal molecules called autoinducers. Bacteria use two types of autoinducers, namely autoinducer-1 (AI-1) and autoinducer-2 (AI-2) where the former are N-acylhomoserine...

In the weighted voting protocol which is used to maintain the consistency of replicated data, the availability of the data to read and write operations not only depends on the availability of the nodes storing the data but also on the vote and quorum assignments used. We consider the problem of determining the vote and quorum assignments that yield the best permormance in a distributed system w...

This paper presents Timed Quorum System (TQS), a quorum system for large-scale and dynamic systems. TQS provides guarantees that two quorums, accessed at instances of time that are close together, intersect with high probability. We present an algorithm that implements TQS at its core and that provides operations that respect atomicity with high probability. This TQS implementation has quorums ...

Replicated services accessed via quorums enable each access to be performed at only a subset (quorum) of the servers, and achieve consistency across accesses by requiring any two quorums to intersect. Recently, b-masking quorum systems, whose intersections contain at least 2b + 1 servers, have been proposed to construct replicated services tolerant of b arbitrary (Byzantine) server failures. In...

Over the past decade, work on quorum systems in non-traditional scenarios has facilitated a number of advances in the field of distributed systems. This chapter surveys a selection of these results including: Byzantine quorum systems that are suitable for use when parts of the system cannot be trusted; algorithms for the deployment of quorum systems on wide area networks so as to allow for effi...