Analogical transfer of verification proofs for state-based specifications

The amount of user interaction is the prime cause of costs in interactive program verification. This paper describes an internal analogy technique that reuses subproofs in the verification of state-based specifications. It identifies common patterns of subproofs and their justifications in order reuse these subproofs; thus significant savings on the number of user interactions in a verification proof are achievable

Island Planning and Refinement

Planning for realistic problems in a static and deterministic environment with complete information faces exponential search spaces and, more often than not, should produce plans comprehensible for the user. This article introduces new planning strategies inspired by proof planning examples in order to tackle the search-space-problem and the structured-plan-problem. Island planning and refinement as well as subproblem refinement are integrated into a general planning framework and some exemplary control knowledge suitable for proof planning is given

LeActiveMath

LeActiveMath (Language-Enhanced, User-Adaptive, Interactive eLearning for Mathematics) is an interdisciplinary European effort that develops an internationalized Web-based intelligent e-Learning system for mathematics that can be used in high school and university as well as for self study. The many technological innovations serve a moderate constructivist and competency-based pedagogical approach. LeActiveMath integrates a number of services and tools and advances the state-of-the-art in semantic search and other usages of semantic representations, presentation of maths on the Web, course generation, coherence of material, exercise selection, modeling of motivation, modeling of competencies, annotation and structure of exercises, feedback and tutorial dialogues in exercises, First evaluations are completed and large ones ahead

Course generation as a hierarchical task network planning problem

This thesis presents course generation based on Hierarchical Task Network planning (HTN planning). This course generation framework enables the formalization and application of complex and realistic pedagogical knowledge. Compared to previous course generation, this approach generates structured courses that are adapted to a variety of different learning goals and to the learners\u27; competencies. The thesis describes basic techniques for course generation, which are used to formalize seven different types of courses (for instance introducing the learner to previously unknown concepts and supporting him during rehearsal) and several elementary learning goals (e. g., selecting an appropriate example or exercise). The course generator developed in this thesis is service-oriented thus allowing the integration of learning supporting services into the generated course in a generic and pedagogically sensible way. Furthermore, learning environments can access the functionality of the course generator using a Web-service interface. Repositories are treated as services that can register at the course generator and make their content available for course generation. The registration is based on an ontology of instructional objects. Its classes allow categorizing learning objects according to their pedagogical purpose in a more precise way than existing metadata specifications; hence it can be used for intelligent pedagogical functionalities other than course generation. Course generation based on HTN planning is implemented in Paigos and was evaluated by technical, formative and summative evaluations. The technical evaluation primarily investigated the performance to Paigos; the formative and summative evaluations targeted the users\u27; acceptance of Paigos and of the generated courses.Diese Arbeit stellt Kursgenerierung vor, die auf Hierarchical Task Network Planung (HTN Planung) basiert. Der gewählte Rahmen erlaubt die Formalisierung von komplexem und realistischem pädagogischem Wissen und ermöglicht im Vergleich zu bisherigen Techniken die Generierung von strukturierten Kursen, die an eine Vielzahl von Lernzielen angepasst sind. Aufbauend auf allgemeinen Techniken zur Kursgenerierung wird das pädagogische Wissen für sieben verschiedene Kurstypen und für eine Reihe von elementaren Lernzielen formalisiert. Die in dieser Arbeit vorgestellte Kursgenerierung ist service-orientiert. Dadurch steht ein generischer Rahmen zu Verfügung, in dem externe Lernsysteme in die generierten Kurse eingebunden werden und dem Lernenden zur Verfügung gestellt werden können, wenn es pädagogisch sinnvoll ist. Weiterhin können andere Lernsysteme über eine Web-Service Schnittstelle auf die Funktionalitäten des Kursgenerators zugreifen: Datenbanken werden als Services betrachtet, die an dem Kursgenerator registriert werden können, und auf die während der Kurserstellung zugegriffen wird. Die Registrierung verwendet eine Ontologie, die verschiedene instruktionale Typen von Lernobjekten repräsentiert und es erlaubt, Lernobjekte nach ihrem pädagogischen Verwendungszweck zu klassifizieren. Sie geht dabei über existierende Metadatenspezifikationen hinaus und ermöglicht pädagogische komplexe Funktionalitäten, so wie beispielsweise Kursgenerierung und weitere. Die vorgestellte Kursgenerierung ist implementiert in Paigos und wurde durch technische, formative und summative Evaluationen untersucht. Die technische Evaluation analysierte in erster Linie die Performanz von Paigos; die formative und summative Evaluationen widmeten sich der Frage der Akzeptanz und Verständlichkeit der von Paigos erzeugten Kurse aus Benutzersicht

Maternal immune activation impairs endocannabinoid signaling in the mesolimbic system of adolescent male offspring

Prenatal infections can increase the risk of developing psychiatric disorders such as schizophrenia in the offspring, especially when combined with other postnatal insults. Here, we tested, in a rat model of prenatal immune challenge by the viral mimic polyriboinosinic-polyribocytidilic acid, whether maternal immune activation (MIA) affects the endocannabinoid system and endocannabinoid-mediated modulation of dopamine functions. Experiments were performed during adolescence to assess i) the behavioral endophenotype (locomotor activity, plus maze, prepulse inhibition of startle reflex); ii) the locomotor activity in response to Δ9-Tetrahydrocannabinol (THC) and iii) the properties of ventral tegmental area (VTA) dopamine neurons in vivo and their response to THC; iv) endocannabinoid-mediated synaptic plasticity in VTA dopamine neurons; v) the expression of cannabinoid receptors and enzymes involved in endocannabinoid synthesis and catabolism in mesolimbic structures and vi) MIA-induced neuroinflammatory scenario evaluated by measurements of levels of cytokine and neuroinflammation markers. We revealed that MIA offspring displayed an altered locomotor activity in response to THC, a higher bursting activity of VTA dopamine neurons and a lack of response to cumulative doses of THC. Consistently, MIA adolescence offspring showed an enhanced 2-arachidonoylglycerol-mediated synaptic plasticity and decreased monoacylglycerol lipase activity in mesolimbic structures. Moreover, they displayed a higher expression of cyclooxygenase 2 (COX-2) and ionized calcium-binding adaptor molecule 1 (IBA-1), associated with latent inflammation and persistent microglia activity. In conclusion, we unveiled neurobiological mechanisms whereby inflammation caused by MIA influences the proper development of endocannabinoid signaling that negatively impacts the dopamine system, eventually leading to psychotic-like symptoms in adulthood

Towards an Intelligent Tutor for Mathematical Proofs

Computer-supported learning is an increasingly important form of study since it allows for independent learning and individualized instruction. In this paper, we discuss a novel approach to developing an intelligent tutoring system for teaching textbook-style mathematical proofs. We characterize the particularities of the domain and discuss common ITS design models. Our approach is motivated by phenomena found in a corpus of tutorial dialogs that were collected in a Wizard-of-Oz experiment. We show how an intelligent tutor for textbook-style mathematical proofs can be built on top of an adapted assertion-level proof assistant by reusing representations and proof search strategies originally developed for automated and interactive theorem proving. The resulting prototype was successfully evaluated on a corpus of tutorial dialogs and yields good results.Comment: In Proceedings THedu'11, arXiv:1202.453

Primrose syndrome: Characterization of the phenotype in 42 patients

Primrose syndrome (PS; MIM# 259050) is characterized by intellectual disability (ID), macrocephaly, unusual facial features (frontal bossing, deeply set eyes, down-slanting palpebral fissures), calcified external ears, sparse body hair and distal muscle wasting. The syndrome is caused by de novo heterozygous missense variants in ZBTB20. Most of the 29 published patients are adults as characteristics appear more recognizable with age. We present 13 hitherto unpublished individuals and summarize the clinical and molecular findings in all 42 patients. Several signs and symptoms of PS develop during childhood, but the cardinal features, such as calcification of the external ears, cystic bone lesions, muscle wasting, and contractures typically develop between 10 and 16 years of age. Biochemically, anemia and increased alpha-fetoprotein levels are often present. Two adult males with PS developed a testicular tumor. Although PS should be regarded as a progressive entity, there are no indications that cognition becomes more impaired with age. No obvious genotype-phenotype correlation is present. A subgroup of patients with ZBTB20 variants may be associated with mild, nonspecific ID. Metabolic investigations suggest a disturbed mitochondrial fatty acid oxidation. We suggest a regular surveillance in all adult males with PS until it is clear whether or not there is a truly elevated risk of testicular cancer.This article is freely available via Open Access. Click on the Publisher URL to access it via the publisher's site.published version, accepted version (12 month embargo) submitted versio

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Decomposition Techniques and their Applications in Automated Theorem Proving

This paper addresses the decomposition of proofs as a means of constructingmethods in plan-based automated theorem proving. It shows also, howdecomposition can beneficially be applied in theorem proving by analogy.Decomposition is also useful for human-style proof presentation. We proposeseveral decomposition techniques that were found to be useful in automatedtheorem proving and give examples of their application