Vascular architecture:is it a helpful histopathological biomarker for hepatocellular carcinoma?

Hepatocellular carcinoma(HCC) remains one of the major public health problems throughout the world.Although originally associated with tumorigenic processes,liver angiogenesis has also been observed in the context of different liver in-flammatory,fibrotic,and ischemic conditions.Here we investigate the fractal dimension as a quantitator of non-Euclidean two-dimensional vascular geometry in a series of paired specimens of primary HCC and surrounding non-tumoral tissue,and discuss why this parameter might provide additional information regarding cancer behavior.The application of fractal geometry to the measurement of liver vascularity and the availability of a computer-aided quantitative method can eliminate errors in visual interpretation,and make it possible to obtain closer-to-reality numerals that are compulsory for any measurement process.     

Dry Skulls and Cone Beam Computed Tomography (CBCT) for Teaching Orofacial Bone Anatomy to Undergraduate Dental Students

Learning bone anatomy of the skull is a complex topic involving three-dimensional information. The impact of the use of human dry skulls and cone beam computed tomography (CBCT) imaging was investigated in the teaching of undergraduate dental students. Sixty-four first-year students in the University of Hong Kong were randomly divided into eight groups. Four teaching methods were tested: (1) CBCT followed by standard lecture, (2) CBCT followed by lecture with skulls, (3) standard lecture followed by CBCT, and (4) lecture with skulls followed by CBCT. After each, students were given a multiple-choice questionnaire to assess their objective learning outcome (20 questions) and a questionnaire for their subjective satisfaction (10 statements). Surveys were assessed with Cronbach's alpha, Kendall's tau-b, and principal components analysis. Data were analyzed with Student's t-test and a one-way ANOVA (significance α = 0.05). Standard lecture followed by CBCT showed the highest learning outcome score (81.6% ± 14.1%), but no significant difference was present among four teaching methods. Cone beam computed tomography followed by lecture with skulls scored the highest overall subjective satisfaction (4.9 ± 0.8 out of 6), but no significant difference was present among teaching methods. Nevertheless, students' perception of learning was positively influenced by the use of skulls (P = 0.018). The timing of administration of the CBCT did not affect students' subjective satisfaction or objective learning outcome. Students perceived to learn more by using skulls, but their objective learning outcomes were not significantly affected. A discrepancy seems to exist between students' perception of learning and their effective performance.     

Measuring ICT Use and Learning Outcomes: evidence from recent econometric studies

Based on PISA 2009 data, this article studies the relationship between students’ computer use and their achievement in reading, mathematics and science in 23 countries. After having categorised computer use into a set of different activities according to the skills they involve, we correlate students’ PISA test-scores with an index capturing the intensity of use for each of these activities and with the total number of activities they perform. Overall, we find that students’ PISA test scores in reading, mathematics and science increase with the intensity of computer use for Gaming activities while they decrease with the intensity of computer use for activities that are more related with school curricula (i.e. Communication and Collaboration activities; Technical Operations/Info Retrieval activities; Creation of Content and Knowledge Problem Solving activities). However, the number of activities (and hence the diversification of activities), irrespective of the intensity of computer use, is positively correlated with students’ proficiency in all three PISA domains in the vast majority of countries, indicating that computers breadth of use, as opposed to intensity of use in a given activity, has some positive effect on students’ PISA test scores.     

Open innovation and within-industry diversification in small and medium enterprises: The case of open source software firms

This paper examines the within-industry diversification of software small and medium enterprises that collaborate with the open source software community (OSS SMEs). In doing so, it offers new insights into the association between open innovation and diversification. We rely on arguments inspired by the literature and evidence collected through interviews with OSS SMEs’ top managers to investigate factors that favor or hinder within-industry diversification. First, in line with the mainstream diversification literature, we focus attention on the role of firm size. Second, in the spirit of the open innovation research, we concentrate on the mechanisms that OSS SMEs put in place to get access to the external resources of the OSS community. Econometric evidence on 100 European OSS SMEs shows that firm size is negatively associated to within-industry diversification, while OSS SMEs that have contributed to a larger number of OSS projects have a more diversified portfolio of software products. Furthermore, we provide preliminary evidence that the practice of authorizing firm programmers to contribute autonomously to OSS projects of their own choice during working hours may be positively associated to within-industry diversification only if OSS SMEs possess adequate internal technological resources.     

An exploration of the gap between highest and lowest ability readers across 20 countries

The aim of the present study, based on data from 20 countries, is to identify the pattern of variables (at country, school and student levels), which are typical of students performing below the low international benchmark compared to students performing at the advanced performance benchmark, in the Progress in International Reading Literacy Study (PIRLS) 2006. The dependent variable of the analysis is a dichotomous variable, the values of which represent the two different performance groups of students. The independent variables are two sets of Organisation for Economic Co-operation and Development educational indicators, variables from PIRLS 2006 Reading Curriculum Questionnaire data, variables and indices based on data obtained from questionnaires for teachers, schools, parents and students. The analysis is based on classification and regression trees, which is a full hierarchical non-parametric method suited to detecting and interpreting complex reciprocal influences between a large number of independent variables. The results show that pupils’ performance can be predicted by the relationships between country-level variables (the changes in teachers’ salaries at the top of the salary scale), school context variables (e.g. percentages of students from economically affluent home) and home educational resources and variables at student level (e.g. students’ reading self-concept).     

The effect of public subsidies on firms’ investment–cash flow sensitivity: Transient or persistent?

This work analyses the effect of public subsidies on firms’ investments and investment–cash flow sensitivity in a longitudinal sample of 288 Italian unlisted non-venture capital backed owner-managed new-technology-based firms (NTBFs), observed over a 15-year period from 1994 to 2008. Seventy five of these firms received one or more public subsidies in the observation period. We use an error correction model (ECM) specification and system generalised method of moment (GMM) techniques that take into account the endogeneity of public subsidies. First, we find that the investments of small NTBFs are sensitive to internal cash flows, while those of large NTBFs are not. Receipt of public subsidies by small NTBFs results in an increased investment rate and a reduced investment–cash flow sensitivity, in the immediately following year. We interpret these results as an indication of the relaxation of financial constraints. Moreover, while the increase in the investment rate does not persist in the long run, the dependence of investments on cash flow remains negligible after receipt of the first public subsidy. These results support the view that public subsidies can help small NTBFs in persistently removing the financial constraints that bind their investment activity.