4,148 research outputs found

    Lightweight LCP Construction for Very Large Collections of Strings

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    The longest common prefix array is a very advantageous data structure that, combined with the suffix array and the Burrows-Wheeler transform, allows to efficiently compute some combinatorial properties of a string useful in several applications, especially in biological contexts. Nowadays, the input data for many problems are big collections of strings, for instance the data coming from "next-generation" DNA sequencing (NGS) technologies. In this paper we present the first lightweight algorithm (called extLCP) for the simultaneous computation of the longest common prefix array and the Burrows-Wheeler transform of a very large collection of strings having any length. The computation is realized by performing disk data accesses only via sequential scans, and the total disk space usage never needs more than twice the output size, excluding the disk space required for the input. Moreover, extLCP allows to compute also the suffix array of the strings of the collection, without any other further data structure is needed. Finally, we test our algorithm on real data and compare our results with another tool capable to work in external memory on large collections of strings.Comment: This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ The final version of this manuscript is in press in Journal of Discrete Algorithm

    The Effect of Background Music on Ad Processing: A Contingency Explanation

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    Music is an increasingly prominent and expensive feature of broadcast ads, yet its effects on message reception are controversial. The authors propose and test a contingency that may help resolve this controversy. Experimental results suggest that message reception is influenced by the interplay of two musical properties: attention-gaining value and music-message congruency. Increasing audience attention to music enhances message reception when the music evokes message-congruent (versus incongruent) thoughts

    The Effects of Background Music in Advertising: A Reassessment

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    Gorn's (1982) pioneering article on the effects of background music in advertising has spurred a significant controversy and inspired vigorous interest in the topic. Following the recommendation of Allen and Madden (1985), we conducted three experiments that attempted to replicate Gorn's results. Contrary to Gorn's findings, there was no evidence that product preferences can be conditioned through a single exposure to appealing or unappealing music

    Functional evolution of the feeding system in rodents

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    The masticatory musculature of rodents has evolved to enable both gnawing at the incisors and chewing at the molars. In particular, the masseter muscle is highly specialised, having extended anteriorly to originate from the rostrum. All living rodents have achieved this masseteric expansion in one of three ways, known as the sciuromorph, hystricomorph and myomorph conditions. Here, we used finite element analysis (FEA) to investigate the biomechanical implications of these three morphologies, in a squirrel, guinea pig and rat. In particular, we wished to determine whether each of the three morphologies is better adapted for either gnawing or chewing. Results show that squirrels are more efficient at muscle-bite force transmission during incisor gnawing than guinea pigs, and that guinea pigs are more efficient at molar chewing than squirrels. This matches the known diet of nuts and seeds that squirrels gnaw, and of grasses that guinea pigs grind down with their molars. Surprisingly, results also indicate that rats are more efficient as well as more versatile feeders than both the squirrel and guinea pig. There seems to be no compromise in biting efficiency to accommodate the wider range of foodstuffs and the more general feeding behaviour adopted by rats. Our results show that the morphology of the skull and masticatory muscles have allowed squirrels to specialise as gnawers and guinea pigs as chewers, but that rats are high-performance generalists, which helps explain their overwhelming success as a group
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