A Novel Approach to Multimedia Ontology Engineering for Automated Reasoning over Audiovisual LOD Datasets

Multimedia reasoning, which is suitable for, among others, multimedia content analysis and high-level video scene interpretation, relies on the formal and comprehensive conceptualization of the represented knowledge domain. However, most multimedia ontologies are not exhaustive in terms of role definitions, and do not incorporate complex role inclusions and role interdependencies. In fact, most multimedia ontologies do not have a role box at all, and implement only a basic subset of the available logical constructors. Consequently, their application in multimedia reasoning is limited. To address the above issues, VidOnt, the very first multimedia ontology with SROIQ(D) expressivity and a DL-safe ruleset has been introduced for next-generation multimedia reasoning. In contrast to the common practice, the formal grounding has been set in one of the most expressive description logics, and the ontology validated with industry-leading reasoners, namely HermiT and FaCT++. This paper also presents best practices for developing multimedia ontologies, based on my ontology engineering approach

A disk of dust and molecular gas around a high-mass protostar

The processes leading to the birth of low-mass stars such as our Sun have been well studied, but the formation of high-mass (> 8 x Sun's mass) stars has heretofore remained poorly understood. Recent observational studies suggest that high-mass stars may form in essentially the same way as low-mass stars, namely via an accretion process, instead of via merging of several low-mass (< 8 Msun) stars. However, there is as yet no conclusive evidence. Here, we report the discovery of a flattened disk-like structure observed at submillimeter wavelengths, centered on a massive 15 Msun protostar in the Cepheus-A region. The disk, with a radius of about 330 astronomical units (AU) and a mass of 1 to 8 Msun, is detected in dust continuum as well as in molecular line emission. Its perpendicular orientation to, and spatial coincidence with the central embedded powerful bipolar radio jet, provides the best evidence yet that massive stars form via disk accretion in direct analogy to the formation of low-mass stars

Effects of pulsed electric field on the viscoelastic properties of potato tissue

We have investigated whether transient permeabilization caused by the application of pulsed electric field would give rise to transient changes in the potato tissue viscoelastic properties. Potato tissue was subjected to nominal field strengths (E) ranging from 30 to 500 V/cm, with a single rectangular pulse of 10−5, 10−4, or 10−3 s. The changes on the viscoelastic properties of potato tissue during pulsed electric fields (PEF) were monitored through small amplitude oscillatory dynamic rheological measurements. The elastic (G′) and viscous moduli (G″) were measured every 30 s after the delivery of the pulse and the loss tangent change (tan-δ) was calculated. The results were correlated with measurements of changes on electrical resistance during the delivery of the pulse. Results show a drastic increase of tan-δ in the first 30 s after the application of the pulse, followed by a decrease 1 min after pulsation. This response is strongly influenced by pulsing conditions and is independent of the total permeabilization achieved by the pulse. Our results, supported by similar measurements on osmotically dehydrated control samples, clearly show that PEF causes a rapid change of the viscoelastic properties of the tissue that could be attributed to a partial loss in turgor pressure. This would be an expected consequence of electroporation. The recovery of tan-δ to values similar to those before pulsation strongly suggests recovery of cell membrane properties and turgor, pointing at reversible permeabilization of the cells. A slight increase of stiffness traduced by a negative change of tan-δ after application of certain PEF conditions may also give an indication of events occurring on cell wall structure due to stress responses. This study set the basis for further investigations on the complex cell stress physiology involving both cell membrane functional properties and cell wall structure that would influence tissue physical properties upon PEF application.Fundação para a Ciência e a Tecnologia (FCT

The Latin American Consortium of Studies in Obesity (LASO)

Current, high-quality data are needed to evaluate the health impact of the epidemic of obesity in Latin America. The Latin American Consortium of Studies of Obesity (LASO) has been established, with the objectives of (i) Accurately estimating the prevalence of obesity and its distribution by sociodemographic characteristics; (ii) Identifying ethnic, socioeconomic and behavioural determinants of obesity; (iii) Estimating the association between various anthropometric indicators or obesity and major cardiovascular risk factors and (iv) Quantifying the validity of standard definitions of the various indexes of obesity in Latin American population. To achieve these objectives, LASO makes use of individual data from existing studies. To date, the LASO consortium includes data from 11 studies from eight countries (Argentina, Chile, Colombia, Costa Rica, Dominican Republic, Peru, Puerto Rico and Venezuela), including a total of 32 462 subjects. This article describes the overall organization of LASO, the individual studies involved and the overall strategy for data analysis. LASO will foster the development of collaborative obesity research among Latin American investigators. More important, results from LASO will be instrumental to inform health policies aiming to curtail the epidemic of obesity in the region

Sensitive CO and 13CO survey of water fountain stars Detections towards IRAS 18460-0151 and IRAS 18596+0315

 This is the author accepted manuscript. The final version is available from EDP Sciences via the DOI in this recordContext. Water fountain stars represent a stage between the asymptotic giant branch (AGB) and planetary nebulae phases, when the mass loss changes from spherical to bipolar. These types of evolved objects are characterized by high-velocity jets in the 22 GHz water maser emission. Aims. The objective of this work is to detect and study in detail the circumstellar gas in which the bipolar outflows are emerging. The detection and study of thermal lines may help in understanding the nature and physics of the envelopes in which the jets are developing. Methods. We surveyed the CO and 13CO line emission towards a sample of ten water fountain stars through observing the J = 1 → 0 and 2 → 1 lines of CO and 13CO, using the 30 m IRAM radio-telescope at Pico Veleta. All the water fountains visible from the observatory were surveyed. Results. Most of the line emission arises from foreground or background Galactic clouds, and we had to thoroughly analyse the spectra to unveil the velocity components related to the stars. In two sources, IRAS 18460-0151 and IRAS 18596+0315, we identified wide velocity components with a width of 35 - 40 km s-1 that are centred at the stellar velocities. These wide components can be associated with the former AGB envelope of the progenitor star. A third case, IRAS 18286-0959, is reported as tentative; in this case a pair of narrow velocity components, symmetrically located with respect to the stellar velocity, have been discovered. We also modelled the line emission using an LVG code and derived some global physical parameters, which allowed us to discuss the possible origin of this gas in relation to the known bipolar outflows. For IRAS 18460-0151 and IRAS 18596+0315, we derived molecular masses close to 0.2 M⊙, mean densities of 104 cm-3, and mass-loss rates of 10 -4 M⊙ yr-1. The kinetic temperatures are rather low, between 10 and 50 K in both cases, which suggests that the CO emission is arising from the outer and cooler regions of the envelopes. No fitting was possible for IRAS 18286-0959, because line contamination can not be discarded in this case. Conclusions. The molecular masses, mean densities, and mass-loss rates estimated for the circumstellar material associated with IRAS 18460-0151 and IRAS 18596+0315 confirm that these sources are at the end of the AGB or the beginning of the post-AGB evolutionary stages. The computed mass-loss rates are among the highest ones possible according to current evolutionary models, which leads us to propose that the progenitors of these water fountains had masses in the range from 4 to 8 M ⊙. We speculate that CO emission is detected in water fountains as a result of a CO abundance enhancement caused by current episodes of low-collimation mass-loss. © ESO, 2013.MICINNJunta de Andalucí

On Optimal Two-Impulse Earth-Moon Transfers in a Four-Body Model

In this paper two-impulse Earth-Moon transfers are treated in the restricted four-body problem with the Sun, the Earth, and the Moon as primaries. The problem is formulated with mathematical means and solved through direct transcription and multiple shooting strategy. Thousands of solutions are found, which make it possible to frame known cases as special points of a more general picture. Families of solutions are defined and characterized, and their features are discussed. The methodology described in this paper is useful to perform trade-off analyses, where many solutions have to be produced and assessed

Learning curves of basic laparoscopic psychomotor skills in SINERGIA VR simulator

Purpose: Surgical simulators are currently essential within any laparoscopic training program because they provide a low-stakes, reproducible and reliable environment to acquire basic skills. The purpose of this study is to determine the training learning curve based on different metrics corresponding to five tasks included in SINERGIA laparoscopic virtual reality simulator. Methods: Thirty medical students without surgical experience participated in the study. Five tasks of SINERGIA were included: Coordination, Navigation, Navigation and touch, Accurate grasping and Coordinated pulling. Each participant was trained in SINERGIA. This training consisted of eight sessions (R1–R8) of the five mentioned tasks and was carried out in two consecutive days with four sessions per day. A statistical analysis was made, and the results of R1, R4 and R8 were pair-wise compared with Wilcoxon signed-rank test. Significance is considered at P value <0.005. Results: In total, 84.38% of the metrics provided by SINERGIA and included in this study show significant differences when comparing R1 and R8. Metrics are mostly improved in the first session of training (75.00% when R1 and R4 are compared vs. 37.50% when R4 and R8 are compared). In tasks Coordination and Navigation and touch, all metrics are improved. On the other hand, Navigation just improves 60% of the analyzed metrics. Most learning curves show an improvement with better results in the fulfillment of the different tasks. Conclusions: Learning curves of metrics that assess the basic psychomotor laparoscopic skills acquired in SINERGIA virtual reality simulator show a faster learning rate during the first part of the training. Nevertheless, eight repetitions of the tasks are not enough to acquire all psychomotor skills that can be trained in SINERGIA. Therefore, and based on these results together with previous works, SINERGIA could be used as training tool with a properly designed training program

Systems and technologies for objective evaluation of technical skills in laparoscopic surgery

Minimally invasive surgery is a highly demanding surgical approach regarding technical requirements for the surgeon, who must be trained in order to perform a safe surgical intervention. Traditional surgical education in minimally invasive surgery is commonly based on subjective criteria to quantify and evaluate surgical abilities, which could be potentially unsafe for the patient. Authors, surgeons and associations are increasingly demanding the development of more objective assessment tools that can accredit surgeons as technically competent. This paper describes the state of the art in objective assessment methods of surgical skills. It gives an overview on assessment systems based on structured checklists and rating scales, surgical simulators, and instrument motion analysis. As a future work, an objective and automatic assessment method of surgical skills should be standardized as a means towards proficiency-based curricula for training in laparoscopic surgery and its certification

Antibacterial activity and mode of action of selected glucosinolate hydrolysis products against bacterial pathogens

Plants contain numerous components that are important sources of new bioactive molecules with antimicrobial properties. Isothiocyanates (ITCs) are plant secondary metabolites found in cruciferous vegetables that are arising as promising antimicrobial agents in food industry. The aim of this study was to assess the antibacterial activity of two isothiocyanates (ITCs), allylisothiocyanate (AITC) and 2-phenylethylisothiocyanate (PEITC) against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes. The antibacterial mode of action was also characterized by the assessment of different physiological indices: membrane integrity, intracellular potassium release, physicochemical surface properties and surface charge. The minimum inhibitory concentration (MIC) of AITC and PEITC was 100 g/mL for all bacteria. The minimum bactericidal concentration (MBC) of the ITCs was at least 10 times higher than the MIC. Both AITC and PEITC changed the membrane properties of the bacteria decreasing their surface charge and compromising the integrity of the cytoplasmatic membrane with consequent potassium leakage and propidium iodide uptake. The surface hydrophobicity was also non-specifically altered (E. coli and L. monocytogenes become less hydrophilic; P. aeruginosa and S. aureus become more hydrophilic). This study shows that AITC and PEITC have strong antimicrobial potential against the bacteria tested, through the disruption of the bacterial cell membranes. Moreover, phytochemicals are highlighted as a valuable sustainable source of new bioactive products.This work was supported by the Operational Programme for Competitiveness Factors - COMPETE and by the Portuguese Foundation for Science and Technology through Project Phytodisinfectants - PTDC/DTP-SAP/1078/2012 (COMPETE: FCOMP-01-0124-FEDER-028765), the PhD grant awarded to Ana Abreu (SFRH/BD/84393/2012), and the post-doctoral grants awarded to Anabela Borges (SFRH/BPD/98684/2013) and Lucia C. Simoes (SFRH/BPD/81982/2011). Also, this work was undertaken as part of the European Research Project SUSCLEAN (Contract no FP7-KBBE-2011-5, project number: 287514) and the COST Action FA1202. The authors are solely responsible for this work. It does not represent the opinion of the European Community, and the Community is not responsible for any use that might be made of data appearing herein

The comparative osmoregulatory ability of two water beetle genera whose species span the fresh-hypersaline gradient in inland waters (Coleoptera: Dytiscidae, Hydrophilidae).

A better knowledge of the physiological basis of salinity tolerance is essential to understanding the ecology and evolutionary history of organisms that have colonized inland saline waters. Coleoptera are amongst the most diverse macroinvertebrates in inland waters, including saline habitats; however, the osmoregulatory strategies they employ to deal with osmotic stress remain unexplored. Survival and haemolymph osmotic concentration at different salinities were examined in adults of eight aquatic beetle species which inhabit different parts of the fresh-hypersaline gradient. Studied species belong to two unrelated genera which have invaded saline waters independently from freshwater ancestors; Nebrioporus (Dytiscidae) and Enochrus (Hydrophilidae). Their osmoregulatory strategy (osmoconformity or osmoregulation) was identified and osmotic capacity (the osmotic gradient between the animal's haemolymph and the external medium) was compared between species pairs co-habiting similar salinities in nature. We show that osmoregulatory capacity, rather than osmoconformity, has evolved independently in these different lineages. All species hyperegulated their haemolymph osmotic concentration in diluted waters; those living in fresh or low-salinity waters were unable to hyporegulate and survive in hyperosmotic media (> 340 mosmol kg(-1)). In contrast, the species which inhabit the hypo-hypersaline habitats were effective hyporegulators, maintaining their haemolymph osmolality within narrow limits (ca. 300 mosmol kg(-1)) across a wide range of external concentrations. The hypersaline species N. ceresyi and E. jesusarribasi tolerated conductivities up to 140 and 180 mS cm(-1), respectively, and maintained osmotic gradients over 3500 mosmol kg(-1), comparable to those of the most effective insect osmoregulators known to date. Syntopic species of both genera showed similar osmotic capacities and in general, osmotic responses correlated well with upper salinity levels occupied by individual species in nature. Therefore, osmoregulatory capacity may mediate habitat segregation amongst congeners across the salinity gradient