Representing and reasoning about preferences in requirements engineering

The priorities that stakeholders associate with requirements may vary from stakeholder to stakeholder and from one situation to the next. Differing priorities, in turn, imply different design decisions for the system to be. While elicitation of requirement priorities is a well-studied activity, modeling and reasoning with prioritization has not enjoyed equal attention. In this paper, we address this problem by extending a state-of-the-art goal modeling notation to support the representation of preference (??nice-to-have??) requirements. In our extension, preference goals are distinguished from mandatory ones. Then, quantitative prioritizations of the former are constructed and used as criteria for evaluating alternative ways to achieve the latter. To generate solutions, an existing preference-based planner is utilized to efficiently search for alternatives that best satisfy a given set of mandatory and preferred requirements. With such a planning tool, analysts can acquire a better understanding of the impact of high-level stakeholder preferences on low-level design decisions.     

Default consequence relations from topology and measure theory

Annals of Mathematics and Artificial Intelligence - A default consequence relation is a well-behaved collection of conditional assertions (defaults). A default conditional $alpha mathrel...     

Antioxidant Properties of Carotenoids In Vitro and In Vivo

Carotenoids are a class of natural pigments familiar to all through the orange-red to yellow colors of many fruits, vegetables, and flowers, as well as for the provitamin A activity that some of them possess. A body of scientific evidence suggests that carotenoids may scavenge and deactivate free radicals, acting thereby as antioxidants both in food systems (in vitro) and in the human organism (in vivo). Overall, epidemiological evidence links higher carotenoid intakes and tissue concentrations with reduced cancer and cardiovascular disease risk. However, research has also shown that the antioxidant activity of carotenoids may shift to a prooxidant character depending mainly on the biological environment in which they act. A summary of the antioxidant potential of natural carotenoids both in oil model systems and in vivo is presented in this article.     

Investigation of an autonomous hybrid solar thermal ORC–PV RO desalination system. The Chalki island case

The use of efficient, innovative and cost effective renewable energy systems in order to produce potable water seems to be a very promising research objective for scientists, engineers and economists, since the choice of the appropriate technologies is combined with the fact that these systems should be economically feasible. This paper presents a general concept of designing a desalination system which uses a solar collectors’ field to drive a reverse osmosis process through an Organic Rankine Cycle. The auxiliary equipment power demand (i.e. cooling pump, collectors’ circulator and working fluid pump) is satisfied by a hybrid system based on a PV generator. An inverter is used to convert the DC to AC current while a battery array is also integrated into the system as energy storage. In order to make a complete study of the system, the pumping loads through the sea and to the area’s municipal water network have been taken into consideration.The objective of the current work is to study an autonomous desalination system that can be applied to several Greek islands where two problems are to be solved at the same time: the lack of potable water and the absence of electrical grid.The investigation of the financial conditions for the realization of a feasible project of an integrated hybrid desalination system (including Solar Thermal and PV technology) is finally presented.     

A monolithic silicon optoelectronic transducer as a real-time affinity biosensor

An optical real-time affinity biosensor, which is based on a monolithic silicon optoelectronic transducer and a microfluidic module, is described. The transducer monolithically integrates silicon avalanche diodes as light sources, silicon nitride optical fibers, and p/n junction detectors and efficiently intercouples these elements through a self-alignment technique. The transducer surface is hydrophilized by oxygen plasma treatment, silanized with (3-aminopropyl)triethoxysilane and bioactivated through adsorption of the biomolecular probes. The use of a microfluidic module allows real-time monitoring of the binding reaction of the gold nanoparticle-labeled analytes with the immobilized probes. Their binding within the evanescent field at the surface of the optical fiber causes attenuated total reflection of the waveguided modes and reduction of the detector photocurrent. The biotin-streptavidin model assay was used for the evaluation of the analytical potentials of the device developed. Detection limits of 3.8 and 13 pM in terms of gold nanoparticle-labeled streptavidin were achieved for continuous- and stopped-flow assay modes, respectively. The detection sensitivity was improved by silver plating of the immobilized gold nanoparticles, and a detection limit of 20 fM was obtained after 20-min of silver plating. In addition, two different analytes, streptavidin and anti-mouse IgG, were simultaneously assayed on the same chip demonstrating the multianalyte potential of the sensor developed.     

Promising Biomarkers in Head and Neck Cancer: The Most Clinically Important miRNAs

Head and neck cancers (HNCs) comprise a heterogeneous group of tumors that extend from the oral cavity to the upper gastrointestinal tract. The principal etiologic factors for oral tumors include tobacco smoking and alcohol consumption, while human papillomavirus (HPV) infections have been accused of a high incidence of pharyngeal tumors. Accordingly, HPV detection has been extensively used to categorize carcinomas of the head and neck. The diverse nature of HNC highlights the necessity for novel, sensitive, and precise biomarkers for the prompt diagnosis of the disease, its successful monitoring, and the timely prognosis of patient clinical outcomes. In this context, the identification of certain microRNAs (miRNAs) and/or the detection of alterations in their expression patterns, in a variety of somatic fluids and tissues, could serve as valuable biomarkers for precision oncology. In the present review, we summarize some of the most frequently studied miRNAs (including miR-21, -375, -99, -34a, -200, -31, -125a/b, -196a/b, -9, -181a, -155, -146a, -23a, -16, -29, and let-7), their role as biomarkers, and their implication in HNC pathogenesis. Moreover, we designate the potential of given miRNAs and miRNA signatures as novel diagnostic and prognostic tools for successful patient stratification. Finally, we discuss the currently ongoing clinical trials that aim to identify the diagnostic, prognostic, or therapeutic utility of miRNAs in HNC.     

Back-analysis of Shimizu Tunnel No. 3 by distinct element modeling

The paper presents a numerical back-analysis of the response of Shimizu Tunnel No. 3 during construction. The 1.1 km long Shimizu Tunnel No. 3, which was completed in Japan in 1998, is a research tunnel along the proposed Tomei II highway. It was excavated in a region consisting mainly of soft to hard sedimentary rocks, such as locally weathered sandstone, underlain by interbedded sandstone and mudstone, using a sequential tunneling technique known in Japan as the “TBM pilot and enlargement method” along with NATM techniques. The tunnel response was analyzed using “ground characteristic curves” and the “convergence-confinement method” which were adapted to the distinct element method (DEM) and the computer code UDEC. Parametric analyses were performed to study the behavior of the wide tunnel geometry under various conditions. The results of the simulations using UDEC and the convergence-confinement method yielded results which are comparable to the monitored data on tunnel deformation and tunnel support loads.     

High-performance emulation of hierarchical structures on hypercube supercomputers

The problem or emulating multilevel structures on hypercube supercomputers is studied in the paper. The frequently used pyramid belongs to the class of multilevel structures. Several algorithms have been published in the literature for the emulation of pyramids by hypercubes. The paper extends the most important of these algorithms to make them applicable for multilevel structures. Results for the Connection Machine system CM-2 with 16,384 processors are presented and comparative analysis of the new algorithms is carried out. It is shown that very often higher performance can be obtained for multilevel structures other than the pyramid.