Lyndon Array Construction during Burrows-Wheeler Inversion

In this paper we present an algorithm to compute the Lyndon array of a string $T$ of length $n$ as a byproduct of the inversion of the Burrows-Wheeler transform of $T$. Our algorithm runs in linear time using only a stack in addition to the data structures used for Burrows-Wheeler inversion. We compare our algorithm with two other linear-time algorithms for Lyndon array construction and show that computing the Burrows-Wheeler transform and then constructing the Lyndon array is competitive compared to the known approaches. We also propose a new balanced parenthesis representation for the Lyndon array that uses $2n+o(n)$ bits of space and supports constant time access. This representation can be built in linear time using $O(n)$ words of space, or in $O(n\log n/\log\log n)$ time using asymptotically the same space as $T$

On Smiles, Winks, and Handshakes as Coordination Devices

In an experimental study we examine a variant of the 'minimum effort game', a coordination game with Pareto ranked equilibria, and risk considerations pointing to the least efficient equilibrium.We focus on the question whether simple cues such as smiles, winks and handshakes could be recognized and employed by the players as a tell-tale sign of each other's trustworthiness, thus enabling them to coordinate on the more risky but more rewarding Pareto efficient equilibrium.Our experimental results show that such cues may indeed play a role as coordination devices as their information value is significant and substantial

Community Plan William Dunbar and William Saville Houses. South Kilburn Estate

The aim of this document is to provide a community vision that informs South Kilburn SPD 2017. The document provides a proposal for refurbishment of the existing 147 homes, infill densification with 47 additional homes, which makes a total of 194 homes, nine new community with 366 m2 of floor space, 6 new retail units with 250 m2 of floor space, and a total of 24 car park spaces for residents. As this document explains, the proposed scheme follows the general principles of the 2016 Masterplan Review and the South Kilburn SPD 2017, as well as many of the specific proposals for the WDWS site (except demolishing the buildings and continuing Denmark Road). Since it follows many of the principles of Brent Council’s Masterplan, it can be considered as a community vision that can inform the regeneration of the WDWS site. This document is an independent study carried out by UCL researchers. WDWS Tenants and Residents Association can, if they consider it appropriate, present it to Brent Council to show a community vision for the regeneration of the WDWS site

Predicting the deleterious effects of mutation load in fragmented populations.

Human-induced habitat fragmentation constitutes a major threat to biodiversity. Both genetic and demographic factors combine to drive small and isolated populations into extinction vortices. Nevertheless, the deleterious effects of inbreeding and drift load may depend on population structure, migration patterns, and mating systems and are difficult to predict in the absence of crossing experiments. We performed stochastic individual-based simulations aimed at predicting the effects of deleterious mutations on population fitness (offspring viability and median time to extinction) under a variety of settings (landscape configurations, migration models, and mating systems) on the basis of easy-to-collect demographic and genetic information. Pooling all simulations, a large part (70%) of variance in offspring viability was explained by a combination of genetic structure (F(ST)) and within-deme heterozygosity (H(S)). A similar part of variance in median time to extinction was explained by a combination of local population size (N) and heterozygosity (H(S)). In both cases the predictive power increased above 80% when information on mating systems was available. These results provide robust predictive models to evaluate the viability prospects of fragmented populations

An investigation of perceptions of football players and officials on the provision of employee assistance programs by football clubs in South Africa.

The aim of this study was to investigate the perceptions of football players and officials on the provision of employee assistance programs by football clubs in South Africa. The study used interviews to collect data from ten football players playing for different football clubs in the Premier Soccer League (PSL) of South Africa, two officials from the PSL and two officials from South African Football Players Union. The results of this study indicate that football players believe that employee assistance programs need to be made available by football clubs. Although football officials consider the provision of employee assistance programs to be significant, they shifted the responsibility for its provision to football clubs. The results led to the conclusion that South African clubs must provide EAPs to improve the morale and performance of players. Direction for future research could focus on investigating the provision of EAPs by football clubs in Africa and in Europe to compare the differences between clubs that offer EAPs and clubs that do not

External memory BWT and LCP computation for sequence collections with applications

We propose an external memory algorithm for the computation of the BWT and LCP array for a collection of sequences. Our algorithm takes the amount of available memory as an input parameter, and tries to make the best use of it by splitting the input collection into subcollections sufficiently small that it can compute their BWT in RAM using an optimal linear time algorithm. Next, it merges the partial BWTs in external memory and in the process it also computes the LCP values. We show that our algorithm performs O(n maxlcp) sequential I/Os, where n is the total length of the collection and maxlcp is the maximum LCP value. The experimental results show that our algorithm outperforms the current best algorithm for collections of sequences with different lengths and when the average LCP of the collection is relatively small compared to the length of the sequences. In the second part of the paper, we show that our algorithm can be modified to output two additional arrays that, combined with the BWT and LCP arrays, provide simple, scan based, external memory algorithms for three well known problems in bioinformatics: the computation of the all pairs suffix-prefix overlaps, the computation of maximal repeats, and the construction of succinct de Bruijn graphs