Learning a menu selection tree: training methods compared

. Menu selection systems sometimes present learning problems for novice users. This comparison of four training methods for novice users found that the global tree diagram of the menu system was superior to command sequence and frame presentation methods, and somewhat better than trial and error. Methods were evaluated on the basis of (1) number of target nodes found, (2) mean number of selections to a target node, (3) recall of the menu structure, and (4) subjective rating of ease of learning.     

Multicommodity Network Problems: Applications and Computations

It is well documented that pure network problems can be solved from 10 to 100 times faster using specialized primal simplex software as compared to general linear programming systems. For multi-commodity network flow problems, the computational savings are a function of the number of tight-side constraints. In this study, we present three real-world multicommodity models and data concerning the number of tight-side constraints. We also present the results of a computational study on a set of 25 randomly generated test problems which have a wide range of number of tight-side constraints. We conclude that a specialized multicommodity network code is three times as fast as a general code, while a specialized network with general side constraints code has twice the speed of a general LP code.     

Optimisation of extra virgin olive oil quality

This study investigated the correlation between total polyphenol content and the stability (ie induction time by Rancimat) of oil samples according to different regions, cultivars, extraction technologies and ripening times of raw material. Results indicate a correlation of oil stability with total polyphenols, (r=0·88), a chemical variable easy to determine. We have set up an oil quality index as a measure of desirability including legal parameters, especially the Council Olive Oil International score (COI Score), stability (phenol content) and process yield into account. The study of the effects of olive ripening and storage prior to processing and olive paste mixing times and temperatures on the quality index using an experimental factorial design (2⁴) were investigated. The process variables selected in the experimental factorial design were studied and the main effects on desirability were identified. Based on this information, the extraction process was optimised for quality index in relation to fruit ripening and olive paste mixing time using a response contour to identify optimal experimental conditions. This innovative procedure shows that process conditions can be optimised as a function of D_tot, evaluated according to scientific determinations. © 1998 SCI.     

An air-cooled proton exchange membrane fuel cell with combined oxidant and coolant flow

Combining the oxidant and coolant flow in an air-cooled proton exchange membrane fuel cell can significantly simplify the fuel cell design. In this paper, an air-cooled PEM fuel cell stack with an open cathode flow field, which supplied the oxidant and removed the heat produced in the fuel cell, was fabricated and tested. The influence of different operating parameters on cell voltage performance and the overall cell ohmic resistance, such as cell temperature and airflow rate, was investigated. The cell temperature and the temperature difference between the cell and the hydrogen humidifier were shown to serve important roles in reducing the fuel cell ohmic resistance. The test results also showed a noteworthy temperature gradient between each cell of a 5-cell stack. A hydrophilic treatment of the cathode flow field channels was demonstrated to be an effective way to mitigate water management issues caused at elevated operating temperatures.     

Geographical analysis of the academic brain drain in Italy

To study the behavior of Italian researchers living in Italy with a view to creating appropriate policies to tackle the brain drain and discourage academics from weight in driving emigrating, we constructed a survey based on a sample of 4,700 Italian researchers (assistant professors) in several universities in Italy. The outlook is far from rosy: Italian researchers are generally dissatisfied with the economic and social situation of the country. Strong family ties represent the element keeping them at home in Italy. In this regard, no particular differences were noted between the North and South of the country. In analyzing the Italian academic system we identified factors that have greater weight in driving Italian intellectual talent to emigrate: the country??s higher education system leaves all dissatisfied. Furthermore, we discovered other factors that, albeit weak, keep Italian researchers in Italy. However, one wonders how much longer family and national ties will be able to keep Italian skilled agents in Italy, and whether such dissatisfaction may jeopardize the country??s future economic development.     

The Dual Role of Smad7 in the Control of Cancer Growth and Metastasis

Smad7 was initially identified as an inhibitor of Transforming growth factor (TGF)-β due mainly to its ability to bind TGF-β receptor type I and prevent TGF-β-associated Smad signaling. More recently, it has been demonstrated that Smad7 can interact with other intracellular proteins and regulate also TGF-β-independent signaling pathways thus making a valid contribution to the neoplastic processes in various organs. In particular, data emerging from experimental studies indicate that Smad7 may differently modulate the course of various tumors depending on the context analyzed. These observations, together with the demonstration that Smad7 expression is deregulated in many cancers, suggest that therapeutic interventions around Smad7 can help interfere with the development/progression of human cancers. In this article we review and discuss the available data supporting the role of Smad7 in the modulation of cancer growth and progression.