Innovation, specialization and growth in a model of structural change

The aim of this paper is to investigate the nexus between demand patterns and innovation as it stems from research efforts and the extent of specialization. In the proposed model an innovation race conducted by entrants investing in research and development against established incumbents raises productivity at the industry level and leads to a shift in the aggregate demand pattern and consequently to a redistribution of the profit fund among industries and a restructuring of the production process in each industry. The paper argues that the degree of development as reflected in a demand share distribution is characterized by a corresponding distribution of specialized sectors that becomes more even across industries as the development process proceeds and investigates the consequences in terms of economic growth.

Clinical significance of epithelial-to-mesenchymal transition in laryngeal carcinoma: Its role in the different subsites

Background: During epithelial-to-mesenchymal transition, cancer cells lose adhesion capacity gaining migratory properties. The role of the process on prognosis has been evaluated in 50 cases of laryngeal carcinoma. Methods: E-cadherin, N-cadherin, β-catenin, α-catenin, γ-catenin, caveolin-1, and vimentin immunohistochemical expression were evaluated using a double score based on staining intensity and cellular localization. Results: Cytoplasmic E-cadherin and α/γ catenin staining were associated with a decrease in survival, cytoplasmic β-catenin was associated with advanced stage, and N-cadherin and vimentin expression were associated with poor differentiation and tumor relapse. On the basis of cancer cells, epithelial or mesenchymal morphological and immunophenotypic similarity we identified 4 main subgroups correlated with a transition to a more undifferentiated phenotype, which have a different pattern of relapse and survival. Conclusion: The negative prognostic role of epithelial-to-mesenchymal transition has been confirmed and a predictive role in glottic tumors has been suggested, leading us to propose epithelial-to-mesenchymal transition as an additional adverse feature in laryngeal carcinoma

On a microcanonical relation between continuous and discrete spin models

A relation between a class of stationary points of the energy landscape of continuous spin models on a lattice and the configurations of a Ising model defined on the same lattice suggests an approximate expression for the microcanonical density of states. Based on this approximation we conjecture that if a O(n) model with ferromagnetic interactions on a lattice has a phase transition, its critical energy density is equal to that of the n = 1 case, i.e., a system of Ising spins with the same interactions. The conjecture holds true in the case of long-range interactions. For nearest-neighbor interactions, numerical results are consistent with the conjecture for n=2 and n=3 in three dimensions. For n=2 in two dimensions (XY model) the conjecture yields a prediction for the critical energy of the Berezinskij-Kosterlitz-Thouless transition, which would be equal to that of the two-dimensional Ising model. We discuss available numerical data in this respect.Comment: 5 pages, no figure

Influence of intra-articular injections of sodium hyaluronate on clinical features and synovial fluid nitric oxide levels of temporomandibular osteoarthritis

Objective: This study was designed to assess the effect of intra-articular injection of sodium hyaluronate (SH) on clinical findings of temporomandibular osteoarthritis (OA) and on synovial fluid (SF) levels of nitric oxide (NO). Methods: Twenty seven patients (7 men, 20 women, mean (SD) age 53.9 (11.8) years) with OA of the temporomandibular joint were randomly allocated to receive an injection of either SH (2ml, Hyalgan®, Fidia SpA, Abano T., P.M. 500-700.000, 20mg/2ml; once a week for 5 weeks) or a Ringer's lactate solution (once a week for 3 weeks). Clinical evaluation was done before each procedure, and at 1 week, 1, 3 and 6 months post-injection. Intensity of temporomandibular joint pain, jaw function, maximal mouth opening and lateral jaw movements were recorded at each visit. NO was measured on SF collected by rinsing the joint with saline 1 ml before the treatment. Results: Injection of SH caused significant improvement in the main clinical symptoms until the last follow-up which was carried out 6 months after last injection. Among patients who received SH injection, those who reached a good outcome showed the lowest basal levels of NO. Conclusions: The results of this study showed that intra-articular injections of SH lead to a lasting improvement in the clinical symptoms of temporomandibular OA. Furthermore, our findings suggest that low NO levels in SF are related to a better outcome of temporomandibular OA among patients treated with SH intra-articular injection