Query reformulation mining: models,patterns, and applications

Understanding query reformulation patterns is a key task towards next generation web search engines. If we can do that, then we can build systems able to understand and possibly predict user intent, providing the needed assistance at the right time, and thus helping users locate information more effectively and improving their web-search experience. As a step in this direction, we build a very accurate model for classifying user query reformulations into broad classes (generalization, specialization, error correction or parallel move), achieving 92% accuracy. We then apply the model to automatically label two very large query logs sampled from different geographic areas, and containing a total of approximately 17 million query reformulations. We study the resulting reformulation patterns, matching some results from previous studies performed on smaller manually annotated datasets, and discovering new interesting reformulation patterns, including connections between reformulation types and topical categories. We annotate two large query-flow graphs with reformulation type information, and run several graph-characterization experiments on these graphs, extracting new insights about the relationships between the different query reformulation types. Finally we study query recommendations based on short random walks on the query-flow graphs. Our experiments show that these methods can match in precision, and often improve, recommendations based on query-click graphs, without the need of users’ clicks. Our experiments also show that it is important to consider transition-type labels on edges for having recommendations of good quality.     

When Energy Conservation Seems to Fail: The Prediction of the Neutrino

A historical case study concerning the serious doubts that arose in early 1930s about the validity of the law of energy conservation in nuclear disintegrations, and the hypothesis of neutrino, will be closely analyzed with the goal of promoting understanding of the nature of science. This work is based upon primary archival and printed sources, with a particular focus on the proceedings of the first International Conference of Nuclear Physics which was held in Rome on October 1931.     

Integration in Italian schools: teachers' perceptions regarding day-to-day practice and its effectiveness

Italy is famous for having the highest percentage of students with disabilities attending ‘the school for all’ (integration). However, in recent studies, the reality of integration seems to be more complex. Integration has reached some important goals (e.g. longer school careers), but while the Italian school system envisages the full participation of all students in normal class activities, there are various problems with the way in which integration is managed day-to-day. This study has two aims: to ascertain the extent to which the Italian legislation on integration is applied in practice and to assess the effectiveness of integration in terms of reaching the learning and social development objectives for students with disabilities and the class as a whole. The article describes the data collected though an online questionnaire compiled by 3230 Italian school staff members, mostly teachers. First, it shows that the integration experience of most of the students with disabilities takes the form of partial participation in class activities. Reasons for it are hypothesised. Second, the teachers' level of satisfaction with the learning and social skills of both students with disabilities and the class is generally positive. A although by no means outstandingly so.     

Students in the Forest: The Role of Design-Build Pedagogies in Repairing Material Disconnections in Architecture Education

This article explores an intellectual disconnection in architectural education about the conception of wood as a building material. It explores initiatives to develop in future architects a deeper consciousness of the complex ecology of timber, promoting its sustainable use in the building industry. It explores six case studies drawn from architectural education to explore the ways in which the properties that make timber sustainable are explored through research and design, and how this deep understanding is transferred to students through hands-on applications.     

Entering the European Information Society: Four Rural Development Projects

This article compares four European information and communication technologies (ICT) development projects spawned by national and EU initiatives to create the “European information society.” These projects, which sought to support learning and better use of ICT, were all the result of opportunities opened up by political initiatives. The analysis indicates that the main problems that afflict these projects stem from varied expectations and interests of the major actors. These problems can be mitigated considerably if a feeling of ownership is generated among the participants. This sense of belonging, however, is difficult to foster in a “top-down” project. Hence there is a need for a better balance between the “top-down” and “bottom-up” influences in the development of such projects.     

Microfluidic-driven viral infection on cell cultures: Theoretical and experimental study

Advanced cell culture systems creating a controlled and predictable microenvironment together with computational modeling may be useful tools to optimize the efficiency of cell infections. In this paper, we will present a phenomenological study of a virus-host infection system, and the development of a multilayered microfluidic platform used to accurately tune the virus delivery from a diffusive-limited regime to a convective-dominated regime. Mathematical models predicted the convective-diffusive regimes developed within the system itself and determined the dominating mass transport phenomena. Adenoviral vectors carrying the enhanced green fluorescent protein (EGFP) transgene were used at different multiplicities of infection (MOI) to infect multiple cell types, both in standard static and in perfused conditions. Our results validate the mathematical models and demonstrate how the infection processes through perfusion via microfluidic platform led to an enhancement of adenoviral infection efficiency even at low MOIs. This was particularly evident at the longer time points, since the establishment of steady-state condition guaranteed a constant viral concentration close to cells, thus strengthening the efficiency of infection. Finally, we introduced the concept of effective MOI, a more appropriate variable for microfluidic infections that considers the number of adenoviruses in solution per cell at a certain time.     

A microfluidic platform for controlled biochemical stimulation of twin neuronal networks

Spatially and temporally resolved delivery of soluble factors is a key feature for pharmacological applications. In this framework, microfluidics coupled to multisite electrophysiology offers great advantages in neuropharmacology and toxicology. In this work, a microfluidic device for biochemical stimulation of neuronal networks was developed. A micro-chamber for cell culturing, previously developed and tested for long term neuronal growth by our group, was provided with a thin wall, which partially divided the cell culture region in two sub-compartments. The device was reversibly coupled to a flat micro electrode array and used to culture primary neurons in the same microenvironment. We demonstrated that the two fluidically connected compartments were able to originate two parallel neuronal networks with similar electrophysiological activity but functionally independent. Furthermore, the device allowed to connect the outlet port to a syringe pump and to transform the static culture chamber in a perfused one. At 14 days invitro, sub-networks were independently stimulated with a test molecule, tetrodotoxin, a neurotoxin known to block action potentials, by means of continuous delivery. Electrical activity recordings proved the ability of the device configuration to selectively stimulate each neuronal network individually. The proposed microfluidic approach represents an innovative methodology to perform biological, pharmacological, and electrophysiological experiments on neuronal networks. Indeed, it allows for controlled delivery of substances to cells, and it overcomes the limitations due to standard drug stimulation techniques. Finally, the twin network configuration reduces biological variability, which has important outcomes on pharmacological and drug screening.