Conjunctive Query Based Constraint Solving For Feature Model Configuration

Feature model configuration can be supported on the basis of various types of reasoning approaches. Examples thereof are SAT solving, constraint solving, and answer set programming (ASP). Using these approaches requires technical expertise of how to define and solve the underlying configuration problem. In this paper, we show how to apply conjunctive queries typically supported by today's relational database systems to solve constraint satisfaction problems (CSP) and -- more specifically -- feature model configuration tasks. This approach allows the application of a wide-spread database technology to solve configuration tasks and also allows for new algorithmic approaches when it comes to the identification and resolution of inconsistencies.Comment: to be presented at The 12th Conference on Information Technology and Its Application, CITA 2023, July 28-29, 2023, Da Nang, Vietnam, and to be published in the volume of the Lecture Notes in Network and Systems series (Springer

Solving Multi-Configuration Problems: A Performance Analysis with Choco Solver

In many scenarios, configurators support the configuration of a solution that satisfies the preferences of a single user. The concept of \emph{multi-configuration} is based on the idea of configuring a set of configurations. Such a functionality is relevant in scenarios such as the configuration of personalized exams, the configuration of project teams, and the configuration of different trips for individual members of a tourist group (e.g., when visiting a specific city). In this paper, we exemplify the application of multi-configuration for generating individualized exams. We also provide a constraint solver performance analysis which helps to gain some insights into corresponding performance issues.Comment: The paper was presented at ConfWS'23: 25th International Workshop on Configuration, September 6-7, 2023, M\'alaga, Spain and is published in the conference proceedings: https://ceur-ws.org/Vol-3509

An overview of video recommender systems: state-of-the-art and research issues

Video platforms have become indispensable components within a diverse range of applications, serving various purposes in entertainment, e-learning, corporate training, online documentation, and news provision. As the volume and complexity of video content continue to grow, the need for personalized access features becomes an inevitable requirement to ensure efficient content consumption. To address this need, recommender systems have emerged as helpful tools providing personalized video access. By leveraging past user-specific video consumption data and the preferences of similar users, these systems excel in recommending videos that are highly relevant to individual users. This article presents a comprehensive overview of the current state of video recommender systems (VRS), exploring the algorithms used, their applications, and related aspects. In addition to an in-depth analysis of existing approaches, this review also addresses unresolved research challenges within this domain. These unexplored areas offer exciting opportunities for advancements and innovations, aiming to enhance the accuracy and effectiveness of personalized video recommendations. Overall, this article serves as a valuable resource for researchers, practitioners, and stakeholders in the video domain. It offers insights into cutting-edge algorithms, successful applications, and areas that merit further exploration to advance the field of video recommendation

Concentrating on the Impact: Consequence-based Explanations in Recommender Systems

Recommender systems assist users in decision-making, where the presentation of recommended items and their explanations are critical factors for enhancing the overall user experience. Although various methods for generating explanations have been proposed, there is still room for improvement, particularly for users who lack expertise in a specific item domain. In this study, we introduce the novel concept of \textit{consequence-based explanations}, a type of explanation that emphasizes the individual impact of consuming a recommended item on the user, which makes the effect of following recommendations clearer. We conducted an online user study to examine our assumption about the appreciation of consequence-based explanations and their impacts on different explanation aims in recommender systems. Our findings highlight the importance of consequence-based explanations, which were well-received by users and effectively improved user satisfaction in recommender systems. These results provide valuable insights for designing engaging explanations that can enhance the overall user experience in decision-making.Comment: Preprint of the paper to be presented at IntRS'23: Joint Workshop on Interfaces and Human Decision Making for Recommender Systems, September 18, 2023, Singapore. paper will be published in the workshop proceeding

Harnessing the biodiversity value of Central and Eastern European farmland

A large proportion of European biodiversity today depends on habitat provided by low-intensity farming practices, yet this resource is declining as European agriculture intensifies. Within the European Union, particularly the central and eastern new member states have retained relatively large areas of species-rich farmland, but despite increased investment in nature conservation here in recent years, farmland biodiversity trends appear to be worsening. Although the high biodiversity value of Central and Eastern European farmland has long been reported, the amount of research in the international literature focused on farmland biodiversity in this region remains comparatively tiny, and measures within the EU Common Agricultural Policy are relatively poorly adapted to support it. In this opinion study, we argue that, 10years after the accession of the first eastern EU new member states, the continued under-representation of the low-intensity farmland in Central and Eastern Europe in the international literature and EU policy is impeding the development of sound, evidence-based conservation interventions. The biodiversity benefits for Europe of existing low-intensity farmland, particularly in the central and eastern states, should be harnessed before they are lost. Instead of waiting for species-rich farmland to further decline, targeted research and monitoring to create locally appropriate conservation strategies for these habitats is needed now.Peer reviewe

Non-Standard Errors

In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants

Hydrogen sulfide can inhibit and enhance oxygenic photosynthesis in a cyanobacterium from sulfidic springs

We used microsensors to investigate the combinatory effect of hydrogen sulfide (H2S) and light on oxygenic photosynthesis in biofilms formed by a cyanobacterium from sulfidic springs. We found that photosynthesis was both positively and negatively affected by H2S: (i) H2S accelerated the recovery of photosynthesis after prolonged exposure to darkness and anoxia. We suggest that this is possibly due to regulatory effects of H2S on photosystem I components and/or on the Calvin cycle. (ii) H2S concentrations of up to 210μM temporarily enhanced the photosynthetic rates at low irradiance. Modelling showed that this enhancement is plausibly based on changes in the light-harvesting efficiency. (iii) Above a certain light-dependent concentration threshold H2S also acted as an inhibitor. Intriguingly, this inhibition was not instant but occurred only after a specific time interval that decreased with increasing light intensity. That photosynthesis is most sensitive to inhibition at high light intensities suggests that H2S inactivates an intermediate of the oxygen evolving complex that accumulates with increasing light intensity. We discuss the implications of these three effects of H2S in the context of cyanobacterial photosynthesis under conditions with diurnally fluctuating light and H2S concentrations, such as those occurring in microbial mats and biofilms

Hydrogen sulfide can inhibit and enhance oxygenic photosynthesis in a cyanobacterium from sulfidic springs

We used microsensors to investigate the combinatory effect of hydrogen sulfide (H2S) and light on oxygenic photosynthesis in biofilms formed by a cyanobacterium from sulfidic springs. We found that photosynthesis was both positively and negatively affected by H2S: (i) H2S accelerated the recovery of photosynthesis after prolonged exposure to darkness and anoxia. We suggest that this is possibly due to regulatory effects of H2S on photosystem I components and/or on the Calvin cycle. (ii) H2S concentrations of up to 210μM temporarily enhanced the photosynthetic rates at low irradiance. Modelling showed that this enhancement is plausibly based on changes in the light-harvesting efficiency. (iii) Above a certain light-dependent concentration threshold H2S also acted as an inhibitor. Intriguingly, this inhibition was not instant but occurred only after a specific time interval that decreased with increasing light intensity. That photosynthesis is most sensitive to inhibition at high light intensities suggests that H2S inactivates an intermediate of the oxygen evolving complex that accumulates with increasing light intensity. We discuss the implications of these three effects of H2S in the context of cyanobacterial photosynthesis under conditions with diurnally fluctuating light and H2S concentrations, such as those occurring in microbial mats and biofilms

Inflammation shapes pathogenesis of murine arrhythmogenic cardiomyopathy

Arrhythmogenic cardiomyopathy (AC) is an incurable genetic disease, whose pathogenesis is poorly understood. AC is characterized by arrhythmia, fibrosis, and cardiodilation that may lead to sudden cardiac death or heart failure. To elucidate AC pathogenesis and to design possible treatment strategies of AC, multiple murine models have been established. Among them, mice carrying desmoglein 2 mutations are particularly valuable given the identification of desmoglein 2 mutations in human AC and the detection of desmoglein 2 auto-antibodies in AC patients. Using two mouse strains producing either a mutant desmoglein 2 or lacking desmoglein 2 in cardiomyocytes, we test the hypothesis that inflammation is a major component of disease pathogenesis. We show that multifocal cardiomyocyte necrosis initiates a neutrophil-dominated inflammatory response, which also involves macrophages and T cells. Increased expression of Ccl2/Ccr2, Ccl3/Ccr5, and Cxcl5/Cxcr2 mRNA reflects the observed immune cell recruitment. During the ensuing acute disease phase, Mmp1

Early results of a real-world series with two transapical transcatheter mitral valve replacement devices

Aims!#!Transcatheter mitral valve replacement (TMVR) with dedicated devices promises to fill the treatment gap between open-heart surgery and edge-to-edge repair for patients with severe mitral regurgitation (MR). We herein present a single-centre experience of a TMVR series with two transapical devices.!##!Methods and results!#!A total of 11 patients were treated with the Tendyne™ (N = 7) or the Tiara™ TMVR systems (N = 4) from 2016 to 2020 either as compassionate-use procedures or as commercial implants. Clinical and echocardiographic data were collected at baseline, discharge and follow-up and are presented in accordance with the Mitral Valve Academic Research Consortium (MVARC) definitions. The study cohort [age 77 years (73, 84); 27.3% male] presented with primary (N = 4), secondary (N = 5) or mixed (N = 2) MR etiology. Patients were symptomatic (all NYHA III/IV) and at high surgical risk [logEuroSCORE II 8.1% (4.0, 17.4)]. Rates of impaired RV function (72.7%), severe pulmonary hypertension (27.3%), moderate or severe tricuspid regurgitation (63.6%) and prior aortic valve replacement (63.6%) were high. Severe mitral annulus calcification was present in two patients. Technical success was achieved in all patients. In 90.9% (N = 10) MR was completely eliminated (i.e. no or trace MR). Procedural and 30-day mortality were 0.0%. At follow-up NYHA class was I/II in the majority of patients. Overall mortality after 3 and 6 months was 10.0% and 22.2%.!##!Conclusions!#!TMVR was performed successfully in these selected patients with complete elimination of MR in the majority of patients. Short-term mortality was low and most patients experienced persisting functional improvement