Pivot Selection for Median String Problem

The Median String Problem is W[1]-Hard under the Levenshtein distance, thus, approximation heuristics are used. Perturbation-based heuristics have been proved to be very competitive as regards the ratio approximation accuracy/convergence speed. However, the computational burden increase with the size of the set. In this paper, we explore the idea of reducing the size of the problem by selecting a subset of representative elements, i.e. pivots, that are used to compute the approximate median instead of the whole set. We aim to reduce the computation time through a reduction of the problem size while achieving similar approximation accuracy. We explain how we find those pivots and how to compute the median string from them. Results on commonly used test data suggest that our approach can reduce the computational requirements (measured in computed edit distances) by $8$\% with approximation accuracy as good as the state of the art heuristic. This work has been supported in part by CONICYT-PCHA/Doctorado Nacional/$2014-63140074$ through a Ph.D. Scholarship; Universidad Cat\'{o}lica de la Sant\'{i}sima Concepci\'{o}n through the research project DIN-01/2016; European Union's Horizon 2020 under the Marie Sk\l odowska-Curie grant agreement $690941$; Millennium Institute for Foundational Research on Data (IMFD); FONDECYT-CONICYT grant number $1170497$; and for O. Pedreira, Xunta de Galicia/FEDER-UE refs. CSI ED431G/01 and GRC: ED431C 2017/58

INTELLIGENT VIRTUAL ASSISTANT FOR GAMIFIED ENVIRONMENTS

As the body of Information Systems (IS) research on social media grows, it faces increasing challenges of staying relevant to real world contexts. In this research-in-progress paper, we analyze and contrast research on social media in the e-government field and in IS research, by reviewing and categorizing 63 studies published in key journal outlets, in order to identify and complement research foci and gaps. We find that in comparison with e-government social media research, IS studies tend to adopt an abstract view of the individual user, focus on a monetary view of value added by social media, and overlook the role of contextual factors. We thus propose an extended framework for mapping social media research, by including a focus on the role of context and environment, and identify a research agenda for future studies on social media-related phenomena relevant to real world contexts

Extending General Compact Querieable Representations to GIS Applications

The raster model is commonly used for the representation of images in many domains, and is especially useful in Geographic Information Systems (GIS) to store information about continuous variables of the space (elevation, temperature, etc.). Current representations of raster data are usually designed for external memory or, when stored in main memory, lack efficient query capabilities. In this paper we propose compact representations to efficiently store and query raster datasets in main memory. We present different representations for binary raster data, general raster data and time-evolving raster data. We experimentally compare our proposals with traditional storage mechanisms such as linear quadtrees or compressed GeoTIFF files. Results show that our structures are up to 10 times smaller than classical linear quadtrees, and even comparable in space to non-querieable representations of raster data, while efficiently answering a number of typical queries.Comment: This research has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Actions H2020-MSCA-RISE-2015 BIRDS GA No. 690941

Automated generation of oracled test cases with regular expressions and combinatorial techniques

One of the main challenges of software testing research is the automated addition of oracles to the generated test cases: Whereas the automated generation of operation sequences (which is one of the essential components of test cases) is in practice a solved problem, the automated addition of the oracle (another indispensable element) is still an important problem and an open research question. This article proposes an approach to get executable test suites composed by complete test cases (i.e., they include the oracle). The core of the method is based on annotated regular expressions. The test generation process, which is supported by a tool, follows three steps: (1) creation of annotated regular expressions, where each regular expression describes a set of sequences of operations to be executed against the system under test; (2) expansion of the regular expressions to get sequences of operations, which still do not have parameter values; and (3) generation of the executable test cases with oracle. In this third step, each test case is generated with the suitable oracle, depending on the conditions specified in the regular expression

The Bacillus subtilis Minimal Genome Compendium

To better understand cellular life, it is essential to decipher the contribution of individual components and their interactions. Minimal genomes are an important tool to investigate these interactions. Here, we provide a database of 105 fully annotated genomes of a series of strains with sequential deletion steps of the industrially relevant model bacterium Bacillus subtilis starting with the laboratory wild type strain B. subtilis 168 and ending with B. subtilis PG38, which lacks approximately 40% of the original genome. The annotation is supported by sequencing of key intermediate strains as well as integration of literature knowledge for the annotation of the deletion scars and their potential effects. The strain compendium presented here represents a comprehensive genome library of the entire MiniBacillus project. This resource will facilitate the more effective application of the different strains in basic science as well as in biotechnology

Altered innate immune profile in blood of systemic mastocytosis patients

[Background]: Mast cells (MC) from systemic mastocytosis (SM) patients release MC mediators that lead to an altered microenvironment with potential consequences on innate immune cells, such as monocytes and dendritic cells (DC). Here we investigated the distribution and functional behaviour of different populations of blood monocytes and DC among distinct diagnostic subtypes of SM. [Methods]: Overall, we studied 115 SM patients - 45 bone marrow mastocytosis (BMM), 61 indolent SM (ISM), 9 aggressive SM (ASM)- and 32 healthy donors (HD). Spontaneous and in vitro-stimulated cytokine production by blood monocytes, and their plasma levels, together with the distribution of different subsets of blood monocytes and DCs, were investigated. [Results]: SM patients showed increased plasma levels and spontaneous production by blood monocytes of IL1β, IL6, IL8, TNFα and IL10, associated with an exhausted ability of LPS + IFNγ-stimulated blood monocytes to produce IL1β and TGFβ. SM (particularly ISM) patients also showed decreased counts of total monocytes, at the expense of intermediate monocytes and non-classical monocytes. Interestingly, while ISM and ASM patients had decreased numbers of plasmacytoid DC and myeloid DC (and their major subsets) in blood, an expansion of AXL+ DC was specifically encountered in BMM cases. [Conclusion]: These results demonstrate an altered distribution of blood monocytes and DC subsets in SM associated with constitutive activation of functionally impaired blood monocytes and increased plasma levels of a wide variety of inflammatory cytokines, reflecting broad activation of the innate immune response in mastocytosis.This study has been funded by Instituto de Salud Carlos III (ISCIII) (grant number PI19/01166; and Centro de Investigación Biomédica en Red de Cáncer [CIBERONC] programme, grant number CB16/12/00400) and co-funded by the European Union (EU). We thank the support of the Spanish National DNA Bank Carlos III (www.bancoadn.org; biobank ID B.0000716; supported by ISCIII and co-founded by EU [grant number PT20/00085]) for providing plasma samples. APP was supported by a grant of the Government of Castilla y León (Orden EDU/556/2019), Spain; co-financed with the “European Regional Development Fund” (BDNS, Identif.:422058). We thank the support of the Spanish Association of Mastocytosis and Related Diseases