Circumstellar disks and planets. Science cases for next-generation optical/infrared long-baseline interferometers

We present a review of the interplay between the evolution of circumstellar disks and the formation of planets, both from the perspective of theoretical models and dedicated observations. Based on this, we identify and discuss fundamental questions concerning the formation and evolution of circumstellar disks and planets which can be addressed in the near future with optical and infrared long-baseline interferometers. Furthermore, the importance of complementary observations with long-baseline (sub)millimeter interferometers and high-sensitivity infrared observatories is outlined.Comment: 83 pages; Accepted for publication in "Astronomy and Astrophysics Review"; The final publication is available at http://www.springerlink.co

Integrating organizational, social, and individual perspectives in Web 2.0-based workplace e-learning

From the issue entitled 'Special Issue: Emerging Social and Legal Aspect'E-learning is emerging as a popular approach of education in the workplace by virtue of its flexibility to access, just-in-time delivery, and cost-effectiveness. To improve social interaction and knowledge sharing in e-learning, Web 2.0 is increasingly utilized and integrated with e-learning applications. However, existing social learning systems fail to align learning with organizational goals and individual needs in a systemic way. The dominance of technology-oriented approaches makes elearning applications less goal-effective and poor in quality and design. To solve the problem, we address the requirement of integrating organizational, social, and individual perspectives in the development of Web 2.0 elearning systems. To fulfill the requirement, a key performance indicator (KPI)-oriented approach is presented in this study. By integrating a KPI model with Web 2.0 technologies, our approach is able to: 1) set up organizational goals and link the goals with expertise required for individuals; 2) build a knowledge network by linking learning resources to a set of competences to be developed and a group of people who learn and contribute to the knowledge network through knowledge creation, sharing, and peer evaluation; and 3) improve social networking and knowledge sharing by identifying each individual's work context, expertise, learning need, performance, and contribution. The mechanism of the approach is explored and elaborated with conceptual frameworks and implementation technologies. A prototype system for Web 2.0 e-learning has been developed to demonstrate the effectiveness of the approach. © Springer Science + Business Media, LLC 2009.postprin

Local convergence of a relaxed two-step Newton like method with applications

We present a local convergence analysis for a relaxed two-step Newton-like method. We use this method to approximate a solution of a nonlinear equation in a Banach space setting. Hypotheses on the first Fr,chet derivative and on the center divided-difference of order one are used. In earlier studies such as Amat et al. (Numer Linear Algebra Appl 17:639-653, 2010, Appl Math Lett 25(12):2209-2217, 2012, Appl Math Comput 219(24):11341-11347, 2013, Appl Math Comput 219(15):7954-7963, 2013, Reducing Chaos and bifurcations in Newton-type methods. Abstract and applied analysis. Hindawi Publishing Corporation, Cairo, 2013) these methods are analyzed under hypotheses up to the second Fr,chet derivative and divided differences of order one. Numerical examples are also provided in this work

Collagen I and III and metalloproteinase gene and protein expression in prostate cancer in relation to Gleason score

PURPOSE: To evaluate if the expression of metalloproteinase, collagen I and III are related to Gleason score, preoperative PSA and pathological stage in prostate cancer. MATERIALS AND METHODS: Our study group included radical prostatectomy specimens of 33 patients with prostatic adenocarcinoma who underwent surgery from 2001 to 2009. Patients were divided into 3 groups: Gleason score=6 (13 patients), Gleason score=7 (10 patients), Gleason score>8 (10 patients). The control group included prostates of patients submitted to cystoprostatectomy and benign prostatic tissues adjacent to the cancer area. Specific areas of tissues were selected under microscope and further processed for collagen I and III analysis by real time PCR. In addition, 10 deparaffined sections of each group were used to evaluate collagen I, III and metalloproteinase immune expression. The results were correlated with Gleason score, preoperative PSA and pathological stage. RESULTS: We found significant difference in both collagen I and III gene expression between benign and tumoral areas in the prostate samples from Gleason score=6 (collagen I=0.4±0.2 vs 5±2.4, p<0.05; collagen III=0.2±0.06 vs 0.7±0.1, p<0.05) and Gleason score>8 (collagen I=8±3.4 vs 1.4±0.8, p<0.07; collagen III=1.8±0.5 vs 0.6±0.1, p<0.05). There was no correlation of collagen expression with Gleason score, preoperative PSA or pathological stage. There was a positive correlation between metalloproteinase expression and Gleason score (r²=0.47). CONCLUSIONS: The positive correlation between metalloproteinase expression and Gleason score suggests that metalloproteinase could be a promising factor to improve Gleason score evaluation. Its expression and regulation do not seem to be related with collagen degradation