New results on rewrite-based satisfiability procedures

Program analysis and verification require decision procedures to reason on theories of data structures. Many problems can be reduced to the satisfiability of sets of ground literals in theory T. If a sound and complete inference system for first-order logic is guaranteed to terminate on T-satisfiability problems, any theorem-proving strategy with that system and a fair search plan is a T-satisfiability procedure. We prove termination of a rewrite-based first-order engine on the theories of records, integer offsets, integer offsets modulo and lists. We give a modularity theorem stating sufficient conditions for termination on a combinations of theories, given termination on each. The above theories, as well as others, satisfy these conditions. We introduce several sets of benchmarks on these theories and their combinations, including both parametric synthetic benchmarks to test scalability, and real-world problems to test performances on huge sets of literals. We compare the rewrite-based theorem prover E with the validity checkers CVC and CVC Lite. Contrary to the folklore that a general-purpose prover cannot compete with reasoners with built-in theories, the experiments are overall favorable to the theorem prover, showing that not only the rewriting approach is elegant and conceptually simple, but has important practical implications.Comment: To appear in the ACM Transactions on Computational Logic, 49 page

Comparative chondrogenesis of human cells in a 3D integrated experimental/computational mechanobiology model

We present an integrated experimental–computational mechanobiology model of chondrogenesis. The response of human articular chondrocytes to culture medium perfusion, versus perfusion associated with cyclic pressurisation, versus non-perfused culture, was compared in a pellet culture model, and multiphysic computation was used to quantify oxygen transport and flow dynamics in the various culture conditions. At 2 weeks of culture, the measured cell metabolic activity and the matrix content in collagen type II and aggrecan were greatest in the perfused+ pressurised pellets. The main effects of perfusion alone, relative to static controls, were to suppress collagen type I and GAG contents, which were greatest in the non-perfused pellets. All pellets showed a peripheral layer of proliferating cells, which was thickest in the perfused pellets, and most pellets showed internal gradients in cell density and matrix composition. In perfused pellets, the computed lowest oxygen concentration was 0.075mM (7.5% tension), the maximal oxygen flux was 477.5 nmol/m2/s and the maximal fluid shear stress, acting on the pellet surface, was 1.8mPa (0.018 dyn/cm2). In the non-perfused pellets, the lowest oxygen concentration was 0.003mM (0.3% tension) and the maximal oxygen flux was 102.4nmol/m2/s.Alocal correlationwas observed, between the gradients in pellet properties obtained from histology, and the oxygen fields calculated with multiphysic simulation. Our results showup-regulation of hyalinematrix protein production by human chondrocytes in response to perfusion associated with cyclic pressurisation. These results could be favourably exploited in tissue engineering applications

Antenatal automatic diagnosis of cleft lip via unsupervised clustering method relying on 3D facial soft tissue landmarks

Objectives Ultrasound (US) is the first-choice device to detect different types of facial dysmorphisms. Anyway, at present no standard protocol has been defined for automatic nor semi-automatic diagnosis. Even though the practitioner's contribution is core, steps towards automatism are to be undertaken. We propose a methodology for diagnosing cleft lip on 3D US scans. Methods A bounded Depth Minimum Steiner Trees (D-MST) clustering algorithm is proposed for discriminating groups of 3D US faces relying on the presence/absence of a cleft lip. The analysis of 3D facial surfaces via Differential Geometry is adopted to extract landmarks. Thus, the extracted geometrical information is elaborated to feed the unsupervised clustering algorithm and produce the classification. The clustering returns the probability of being affected by the pathology, allowing physicians to focus their attention on risky individuals for further analysis. Results The feasibility is tested upon the available 3D US scans data and then deeply investigated for a large dataset of adult individuals. 3D facial Bosphorus database is chosen for the testing, which seven cleft lip-affected individuals are added to, by artificially creating the defect. The algorithm correctly separates left and right-sided cleft lips, while healthy individuals create a unique cluster; thus, the method shows accurate diagnosis results. Conclusions Even if further testing is to be performed on tailored datasets made exclusively of fetal images, this techniques gives hefty hints for a future tailored algorithm. This method also fosters the investigation of the scientific formalisation of the "normotype", which is the representative face of a class of individuals, collecting all the principal anthropometric facial measurements, in order to recognise a normal or syndromic fetus

Persistent Müllerian Duct Syndrome in a German Shepherd Dog

In mammals, the regression of the m\ufcllerian ducts is regulated by the action of the AMH hormone which is produced by testes during embryonic development. The action of this hormone is mediated by the only known receptor AMHR2. Mutations occurring in the AHM hormone and/or in the AMHR2 receptor gene cause the lack of regression of m\ufcllerian ducts, which may therefore persist even in male embryos carrying a XY chromosomal arrangement. This is known as the persistent m\ufcllerian duct syndrome (PMDS). A female German Shepherd dog was referred to the veterinary clinic because of urinary incontinence. She also showed an anatomical structure that protruded from and enlarged the vulvar labia. From the morphological appearance, one gonad resembled an ovary and the other a testicle. The histological examination instead showed that the gonads were both testes with an underdeveloped parenchyma and without signs of spermatogenetic activity. No alterations were found with regard to the uterus which showed a correctly developed body, cervix, and horns. Genetic analysis, performed on DNA extracted from blood, showed (i) the presence of both X and Y chromosomes, (ii) the absence of chromosome XX/XY chimerism, (iii) a normal SRY gene coding sequence, (iv) a normal AMHR2 gene coding sequence, and (v) a normal AMH gene coding sequence. In this study, we report and characterize a new case of PMDS in a dog excluding that the only mutation hitherto found in the AMHR2 gene is responsible for the observed phenotype

Improving the Efficiency of Reasoning Through Structure-Based Reformulation

Abstract. We investigate the possibility of improving the efficiency of reasoning through structure-based partitioning of logical theories, combined with partitionbased logical reasoning strategies. To this end, we provide algorithms for reasoning with partitions of axioms in first-order and propositional logic. We analyze the computational benefit of our algorithms and detect those parameters of a partitioning that influence the efficiency of computation. These parameters are the number of symbols shared by a pair of partitions, the size of each partition, and the topology of the partitioning. Finally, we provide a greedy algorithm that automatically reformulates a given theory into partitions, exploiting the parameters that influence the efficiency of computation.

The emergence of 'citizenship' in popular discourse:The case of Scotland

The 2014 Scottish Referendum gauged public opinion on the possibility of Scotland leaving the United Kingdom, raising significant questions about the legitimacy of claims to citizenship in the event of independence. Through a mixed methods survey, this study explored the ways in which citizenship emerged in popular discourse in the lead up to the Scottish referendum. Findings point to an emphasis in public discourse on a commitment to and participation in society, instead of the more traditional citizenship markers of ancestry, birthplace or residency. Data indicates a view of citizenship encompassing status and practice, while identity was framed in terms of more static notions of birthplace and ancestry. The salience of social participation was noticeably greater in respondents’ assessment of others’ potential Scottish citizenship than their own. Specifically, the study highlights the salience of relational aspects of citizenship in popular discourse, with an emphasis on social citizenship in preference to legal citizenship. The study constitutes a significant contribution to ongoing discussions about ‘participatory citizenship’ in the field of Citizenship studies, by providing much needed empirical data on social conceptualizations of citizenship

Obesity-Induced Metabolic Stress Leads to Biased Effector Memory CD4+ T Cell Differentiation via PI3K p110δ-Akt-Mediated Signals.

Low-grade systemic inflammation associated to obesity leads to cardiovascular complications, caused partly by infiltration of adipose and vascular tissue by effector T cells. The signals leading to T cell differentiation and tissue infiltration during obesity are poorly understood. We tested whether saturated fatty acid-induced metabolic stress affects differentiation and trafficking patterns of CD4+ T cells. Memory CD4+ T cells primed in high-fat diet-fed donors preferentially migrated to non-lymphoid, inflammatory sites, independent of the metabolic status of the hosts. This was due to biased CD4+ T cell differentiation into CD44hi-CCR7lo-CD62Llo-CXCR3+-LFA1+ effector memory-like T cells upon priming in high-fat diet-fed animals. Similar phenotype was observed in obese subjects in a cohort of free-living people. This developmental bias was independent of any crosstalk between CD4+ T cells and dendritic cells and was mediated via direct exposure of CD4+ T cells to palmitate, leading to increased activation of a PI3K p110δ-Akt-dependent pathway upon priming

Investigating the Behavior and Personality Structure of the Aldabra Tortoise during Human Interactions and Training Events

Human–animal interaction (HAI) can be valuable for captive animals, and many zoo-housed species benefit from interactions with their keepers. There is also an increasing body of evidence that some animal species possess personalities that are temporally consistent. However, the majority of zoo research, particularly on personality and HAI, traditionally has focused on mammals, and there are comparatively fewer studies on reptiles. Research was undertaken at the Faunistic Park Le Cornelle, Italy, to investigate the effects of approach tests and food interaction events on 5 male and 5 female Aldabra tortoise (Aldrabrachelys gigantea) behavior. During human–tortoise interactions, continuous focal sampling of behavior took place. The behavioral differences between individual tortoises, interaction type (approach or training) and person involved in the interaction (keeper, vet, or observer) were analysed using general linear mixed-effects models. The personality components of the tortoises were also quantified using principal component analysis. Overall, the study revealed that individuals acted significantly differently to one another, and that while females initially appeared to display a greater number of shy behaviors, this was not consistent across the group. PCA revealed two personality dimensions in the tortoises: boldness and avoidance. Overall, the study revealed that the tortoises possessed personalities that were independent of sex or scenario. The study also revealed that many tortoises chose to interact with their keepers during training and approach tests: this suggests that human–tortoise interactions may have some enrichment value. Future research could quantify tortoise personality in other scenarios such as in social interactions with other tortoises.</jats:p