Structural equivalences are essential, pictorial conventions are not: Evidence from haptic drawing development in children born completely blind.

Arnheim hypothesized that as children develop they invent increasingly more structural equivalents. Thus, in their drawings children should increase the number and complexity of both representational concepts (e.g., object edges) and associated object shape features (e.g., line junctions). The authors tested whether a framework derived from this hypothesis could describe the progression of raised-line (haptic) drawings made during nine months by three children born totally blind. With no drawing tuition, these children made drawings of objects such as cars, human figures, trees, and flowers. Later drawings had more features than earlier ones and could be mapped onto more complex, predicted representational concepts, supporting Arnheim's conjecture. Because this applied even if children did not have visible models, the increase in features occurred not because children learned to copy ornate pictures (or increasingly more conventions) but because they developed increasingly complex concepts to describe the many features of objects. Our findings and reframing of structural equivalences suggest a view of children's drawing as expression of "everyday aesthetics" through the development of personal creativity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hermes: a simple and efficient algorithm for building the AOC-poset of a binary relation

Given a relation ?? ? ?? × ?? on a set ?? of objects and a set ?? of attributes, the AOC-poset (Attribute/Object Concept poset), is the partial order defined on the “introducers” of objects and attributes in the corresponding concept lattice. In this paper, we present Hermes, a simple and efficient algorithm for building an AOC-poset which runs in O(m i n{n m, n ^α }), where n is the number of objects plus the number of attributes, m is the size of the relation, and n ^α is the time required to perform matrix multiplication (currently α = 2.376). Finally, we compare the runtime of Hermes with the runtime of other algorithms computing the AOC-poset: Ares, Ceres and Pluton. We characterize the cases where each algorithm is the more relevant.     

Characterizing functional dependencies in formal concept analysis with pattern structures

Computing functional dependencies from a relation is an important database topic, with many applications in database management, reverse engineering and query optimization. Whereas it has been deeply investigated in those fields, strong links exist with the mathematical framework of Formal Concept Analysis. Considering the discovery of functional dependencies, it is indeed known that a relation can be expressed as the binary relation of a formal context, whose implications are equivalent to those dependencies. However, this leads to a new data representation that is quadratic in the number of objects w.r.t. the original data. Here, we present an alternative avoiding such a data representation and show how to characterize functional dependencies using the formalism of pattern structures, an extension of classical FCA to handle complex data. We also show how another class of dependencies can be characterized with that framework, namely, degenerated multivalued dependencies. Finally, we discuss and compare the performances of our new approach in a series of experiments on classical benchmark datasets.     

Mint: MDL-based approach for Mining INTeresting Numerical Pattern Sets

Data Mining and Knowledge Discovery - Pattern mining is well established in data mining research, especially for mining binary datasets. Surprisingly, there is much less work about numerical...     

METTL3 Inhibitors for Epitranscriptomic Modulation of Cellular Processes

The methylase METTL3 is the writer enzyme of the N⁶-methyladenosine (m⁶A) modification of RNA. Using a structure-based drug discovery approach, we identified a METTL3 inhibitor with potency in a biochemical assay of 280 nM, while its enantiomer is 100 times less active. We observed a dose-dependent reduction in the m⁶A methylation level of mRNA in several cell lines treated with the inhibitor already after 16 h of treatment, which lasted for at least 6 days. Importantly, the prolonged incubation (up to 6 days) with the METTL3 inhibitor did not alter levels of other RNA modifications (i. e., m¹A, m⁶A_m, m⁷G), suggesting selectivity of the developed compound towards other RNA methyltransferases.     

Evaluation of the repair on multiple leaf stone masonry by acoustic emission

Aim of this research was to evaluate the possible application of the AE technique to study the response of multiple leaf masonry repaired with different techniques. The results of shear tests carried out on three specimens repaired after failure are presented on an explorative basis; on two of them the acoustic emission (AE) technique was also used. Through a number of sensors and by triangulation, this technique makes it possible to identify the location of the damage, unknown initially, and subsequently to assess the stability of its evolution. Using the AE technique the area of the material where the cracks propagated during shear tests was identified. These analyses made it possible to evaluate the effectiveness of repair interventions through parameters other than stress and strain, and contributed to the identification of the most suitable methodology for their optimisation.     

Iterative flattening search for resource constrained scheduling

Iterative flattening search (ifs) is a meta-heuristic strategy for solving multi-capacity scheduling problems. Given an initial solution, ifs iteratively applies: (1) a relaxation-step, in which a subset of scheduling decisions are randomly retracted from the current solution; and (2) a flattening-step, in which a new solution is incrementally recomputed from this partial schedule. Whenever a better solution is found, it is retained, and, upon termination, the best solution found during the search is returned. Prior research has shown ifs to be an effective and scalable heuristic procedure for minimizing schedule makespan in multi-capacity resource settings. In this paper we experimentally investigate the impact on ifs performance of algorithmic variants of the flattening step. The variants considered are distinguished by different computational requirements and correspondingly vary in the type and depth of search performed. The analysis is centered around the idea that given a time bound to the overall optimization procedure, the ifs optimization process is driven by two different and contrasting mechanisms: the random sampling performed by iteratively applying the “relaxation/flattening” cycle and the search conducted within the constituent flattening procedure. On one hand, one might expect that efficiency of the flattening process is key: the faster the flattening procedure, the greater the number of iterations (and number of sampled solutions) for a given time bound; and hence the greater the probability of finding better quality solutions. On the other hand, the use of more accurate (and more costly) flattening procedures can increase the probability of obtaining better quality solutions even if their greater computational cost reduces the number of ifs iterations. Comparative results on well-studied benchmark problems are presented that clarify this tradeoff with respect to previously proposed flattening strategies, identify qualitative guidelines for the design of effective ifs procedures, and suggest some new directions for future work in this area.