Ontology-based feature modeling: an empirical study in changing scenarios

A software product line (SPL) is a set of software systems that have a particular set of common features\ud and that satisfy the needs of a particular market segment or mission. Feature modeling is one of the key\ud activities involved in the design of SPLs. The feature diagram produced in this activity captures the commonalities\ud and variabilities of SPLs. In some complex domains (e.g., ubiquitous computing, autonomic\ud systems and context-aware computing), it is difficult to foresee all functionalities and variabilities a\ud specific SPL may require. Thus, Dynamic Software Product Lines (DSPLs) bind variation points at runtime\ud to adapt to fluctuations in user needs as well as to adapt to changes in the environment. In this context,\ud relying on formal representations of feature models is important to allow them to be automatically analyzed\ud during system execution. Among the mechanisms used for representing and analyzing feature\ud models, description logic (DL) based approaches demand to be better investigated in DSPLs since it provides\ud capabilities, such as automated inconsistency detection, reasoning efficiency, scalability and\ud expressivity. Ontology is the most common way to represent feature models knowledge based on DL reasoners.\ud Previous works conceived ontologies for feature modeling either based on OWL classes and properties\ud or based on OWL individuals. However, considering change or evolution scenarios of feature\ud models, we need to compare whether a class-based or an individual-based feature modeling style is\ud recommended to describe feature models to support SPLs, and especially its capabilities to deal with\ud changes in feature models, as required by DSPLs. In this paper, we conduct a controlled experiment to\ud empirically compare two approaches based on each one of these modeling styles in several changing scenarios\ud (e.g., add/remove mandatory feature, add/remove optional feature and so on). We measure time to\ud perform changes, structural impact of changes (flexibility) and correctness for performing changes in our\ud experiment. Our results indicate that using OWL individuals requires less time to change and is more\ud flexible than using OWL classes and properties. These results provide insightful assumptions towards\ud the definition of an approach relying on reasoning capabilities of ontologies that can effectively support\ud products reconfiguration in the context of DSPL.CNPqCAPE

A Platform for Processing Expression of Short Time Series (PESTS)

<p>Abstract</p> <p>Background</p> <p>Time course microarray profiles examine the expression of genes over a time domain. They are necessary in order to determine the complete set of genes that are dynamically expressed under given conditions, and to determine the interaction between these genes. Because of cost and resource issues, most time series datasets contain less than 9 points and there are few tools available geared towards the analysis of this type of data.</p> <p>Results</p> <p>To this end, we introduce a platform for Processing Expression of Short Time Series (PESTS). It was designed with a focus on usability and interpretability of analyses for the researcher. As such, it implements several standard techniques for comparability as well as visualization functions. However, it is designed specifically for the unique methods we have developed for significance analysis, multiple test correction and clustering of short time series data. The central tenet of these methods is the use of biologically relevant features for analysis. Features summarize short gene expression profiles, inherently incorporate dependence across time, and allow for both full description of the examined curve and missing data points.</p> <p>Conclusions</p> <p>PESTS is fully generalizable to other types of time series analyses. PESTS implements novel methods as well as several standard techniques for comparability and visualization functions. These features and functionality make PESTS a valuable resource for a researcher's toolkit. PESTS is available to download for free to academic and non-profit users at <url>http://www.mailman.columbia.edu/academic-departments/biostatistics/research-service/software-development</url>.</p

DODAB and DODAC bilayer-like aggregates in the micromolar surfactant concentration domain

In the millimolar concentration domain (typically 1 mM), dioctadecyldimethylammonium bromide and chloride (DODAX, X representing Br- or Cl- counterions) molecules assemble in water as large unilamellar vesicles. Differential scanning calorimetry (DSC) is a suitable technique to obtain the melting temperature (Tm) characteristic of surfactant bilayers, while fluorescence spectroscopy detects formation of surfactant aggregates, like bilayers. These two techniques were combined to investigate the assemble of DODAX molecules at micromolar concentrations, from 10 to 100 micromolar. At 1 mM surfactant, Tm ~ 45 ºC and 49 oC, respectively for DODAB and DODAC. DSC and fluorescence of Nile Red were used to show the formation of DODAX aggregates, at the surfactant concentration as low as 10 micromolar, whose Tm decreases monotonically with increasing DODAX concentration to attain the value for the ordinary vesicles. The data indicate that these aggregates are organized as bilayer-like structures.Fundação para a Ciência e a Tecnologia (FCT

Spatial and Temporal Variations in the Annual Pollen Index Recorded by Sites Belonging to the Portuguese Aerobiology Network

This study presents the findings of a 10-year survey carried out by the Portuguese Aerobiology Network (RPA) at seven pollen-monitoring stations: five mainland stations (Oporto, Coimbra, Lisbon, Évora and Portimão) and two insular stations [Funchal (Madeira archipelago) and Ponta Delgada (Azores archipelago)]. The main aim of the study was to examine spatial and temporal variations in the Annual Pollen Index (API) with particular focus on the most frequently recorded pollen types. Pollen monitoring (2003–2012) was carried out using Hirst-type volumetric spore traps, following the minimum recommendations proposed by the European Aerobiology Society Working Group on Quality Control. Daily pollen data were examined for similarities using the Kruskal–Wallis nonparametric test and multivariate regression trees. Simple linear regression analysis was used to describe trends in API. The airborne pollen spectrum at RPA stations is dominated by important allergenic pollen types such as Poaceae, Olea and Urticaceae. Statistically significant differences were witnessed in the API recorded at the seven stations. Mean API is higher in the southern mainland cities, e.g. Évora, Lisbon and Portimão, and lower in insular and littoral cities. There were also a number of significant trends in API during the 10-year study. This report identifies spatial and temporal variations in the amount of airborne pollen recorded annually in the Portuguese territory. There were also a number of significant changes in API, but no general increases in the amount of airborne pollen

Precise measurement of the W-boson mass with the CDF II detector

We have measured the W-boson mass MW using data corresponding to 2.2/fb of integrated luminosity collected in proton-antiproton collisions at 1.96 TeV with the CDF II detector at the Fermilab Tevatron collider. Samples consisting of 470126 W->enu candidates and 624708 W->munu candidates yield the measurement MW = 80387 +- 12 (stat) +- 15 (syst) = 80387 +- 19 MeV. This is the most precise measurement of the W-boson mass to date and significantly exceeds the precision of all previous measurements combined

Prognostic value of Goseki histological classification in adenocarcinoma of the cardia

Various histologic classification systems have been proposed as prognostic factors for gastric cancer. We assessed the prognostic value of Goseki classification as well as the TNM staging system, histological tumour grading, Lauren, WHO, Goseki and Siewert classifications in 100 patients with cardia carcinoma undergoing curative surgery. Two patients were lost at follow-up. The median time of follow-up in the remaining patients was 32.9 months after surgery (range: 0.1–142.1 months). No differences in survival rates were observed according to tumour grading, Lauren or WHO histologic or Siewert topographical classification. No differences were found according to Goseki classes, when considering either the mucin content of the carcinoma (types I and III vs II and IV) or the differentiation grade (types I and II vs III and IV). Multivariate analysis showed that the only lymph node positivity was a significant predictor of survival: 7.2% of patients with, but 41.5% of those without nodal involvement were alive after five years (P=0.0001). In conclusion, we found no prognostic role for Goseki or the traditional histological indexes, while the TNM staging system and particularly lymph node positivity were the main predictors of survival in patients with cardia adenocarcinoma

X-ray emission from the Sombrero galaxy: discrete sources

We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200 ks. With a detection limit of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30 kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-low indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC LF at fainter luminosities down to 1E35 erg/s. The derived index rules out a faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns