Tuning the average path length of complex networks and its influence to the emergent dynamics of the majority-rule model

We show how appropriate rewiring with the aid of Metropolis Monte Carlo computational experiments can be exploited to create network topologies possessing prescribed values of the average path length (APL) while keeping the same connectivity degree and clustering coefficient distributions. Using the proposed rewiring rules we illustrate how the emergent dynamics of the celebrated majority-rule model are shaped by the distinct impact of the APL attesting the need for developing efficient algorithms for tuning such network characteristics.Comment: 10 figure

Introduction of hybrid minimally invasive esophagectomy and comparison of perioperative outcomes following open versus hybrid esophagectomy; a propensity-matched retrospective study.

INTRODUCTION: Esophagectomy is associated with increased rate of postoperative complications, making it one of the procedures with the highest impact on patients’ quality of life. Hybrid Ivor Lewis esophagectomy with laparoscopy and thoracotomy has been developed with the aim to reduce postoperative morbidity without to compromise oncological outcomes. We conducted this survey under the hypothesis that the hybrid approach results in reduced postoperative complications with equivalent oncological outcomes in two similarly matched groups of patients. METHODS: Propensity score matching was used to remove bias attributed to observational studies. After generating propensity scores using the variables age, body mass index, pulmonary comorbidities, cardiac comorbidities, histologic type, and neoadjuvant treatment, 17 patients in the hybrid group were matched with 17 patients in the open group. Surgical outcomes, oncological outcomes, and postoperative complications according to the guidelines of the Esophageal Complications Consensus Group were compared between the two groups. RESULTS: Open and hybrid procedures showed similar surgical and oncological outcomes. Although the hybrid group spent more time in the intensive care unit, the length of hospital stay was comparable between the groups. The rate of postoperative complications was similar between the two approaches. DISCUSSION: Our hypothesis that laparoscopy could reduce postoperative complications was not confirmed. Hybrid Ivor Lewis esophagectomy is a safe procedure, resulting in radical oncological resection and similar morbidity with open esophagectomy. Surgeons who are proficient in open approach and laparoscopic anti-reflux and gastric surgery can safely adopt the hybrid approach without significant learning curve associated morbidity

Recombinant human growth hormone in the treatment of Turner syndrome

Turner syndrome (TS) is a common chromosomal disorder in women that is associated with the absence of one of the X chromosomes. Severe short stature and a lack of pubertal development characterize TS girls, causing psychosocial problems and reduced bone mass. The growth impairment in TS seems to be due to multiple factors including an abnormal growth hormone (GH) – insulin-like growth factor (IGF) – IGF binding protein axis and haploinsufficiency of the short stature homeobox-containing gene. Growth hormone and sex steroid replacement therapy has enhanced growth, pubertal development, bone mass, and the quality of life of TS girls. Recombinant human GH (hGH) has improved the height potential of TS girls with varied results though, depending upon the dose of hGH and the age of induction of puberty. The best final adult height and peak bone mass achievement results seem to be achieved when hGH therapy is started early and puberty is induced at the normal age of puberty in a regimen mimicking physiologic puberty. The initiation of estradiol therapy at an age-appropriate time may also help the TS patients avoid osteoporosis during adulthood. Recombinant hGH therapy in TS seems to be safe. Studies so far show no adverse effects on cardiac function, glucose metabolism or any association with neoplasms but research is still in progress to provide conclusive data on long-term safety

Testing money supply endogeneity : the case of Greece (1975-1998)

The main purpose of this paper is to trace whether, for a prolonged period of time (1975-1998), money supply in Greece was endogenously or exogenously determined. In the theoretical part, we briefly report the Orthodox vis-a-vis the post Keynesian views on the issue. From the statistical evidence we conclude that : a) the deregulation process of the late 80’s did not produce any structural break in the Greek monetary aggregates and b) under specific assumptions, money in Greece can be considered as endogenously determined. This implies that in the Greek monetary system the central bank behaves as a lender of last resort.peer-reviewe

Synthesis and Characterization of Greener Ceramic Materials with Lower Thermal Conductivity Using Olive Mill Solid Byproduct

In the current research, the valorization of olive mill solid waste as beneficial admixture into clay bodies for developing greener ceramic materials with lower thermal conductivity, thus with increased thermal insulation capacity towards energy savings, is investigated. Various clay/waste mixtures were prepared. The raw material mixtures were characterized and subjected to thermal gravimetric analysis, in order to optimize the mineral composition and maintain calcium and magnesium oxides content to a minimum. Test specimens were formed employing extrusion and then sintering procedure at different peak temperatures. Apparent density, water absorption capability, mechanical strength, porosity and thermal conductivity were determined on sintered specimens and examined in relation to the waste percentage and sintering temperature. The experimental results showed that ceramic production from clay/olive-mill solid waste mixtures is feasible. In fact, the mechanical properties are not significantly impacted with the incorporation of the waste in the ceramic body. However, the thermal conductivity decreases significantly, which can be of particular interest for thermal insulating materials development. Furthermore, the shape of the produced ceramics does not appear to change with the sintering temperature increase

Coarse-Grained Analysis of Microscopic Neuronal Simulators on Networks: Bifurcation and Rare-events computations

We show how the Equation-Free approach for mutliscale computations can be exploited to extract, in a computational strict and systematic way the emergent dynamical attributes, from detailed large-scale microscopic stochastic models, of neurons that interact on complex networks. In particular we show how the Equation-Free approach can be exploited to perform system-level tasks such as bifurcation, stability analysis and estimation of mean appearance times of rare events, bypassing the need for obtaining analytical approximations, providing an "on-demand" model reduction. Using the detailed simulator as a black-box timestepper, we compute the coarse-grained equilibrium bifurcation diagrams, examine the stability of the solution branches and perform a rare-events analysis with respect to certain characteristics of the underlying network topology such as the connectivity degre

The impact of imperfect weather forecasts on wind power forecasting performance: Evidence from two wind farms in Greece

Weather variables are an important driver of power generation from renewable energy sources. However, accurately predicting such variables is a challenging task, which has a significant impact on the accuracy of the power generation forecasts. In this study, we explore the impact of imperfect weather forecasts on two classes of forecasting methods (statistical and machine learning) for the case of wind power generation. We perform a stress test analysis to measure the robustness of different methods on the imperfect weather input, focusing on both the point forecasts and the 95% prediction intervals. The results indicate that different methods should be considered according to the uncertainty characterizing the weather forecasts