Comment on "1/f noise in the Bak-Sneppen model"

Contrary to the recently published results by Daerden and Vanderzande [Phys. Rev. E 53, 4723 (1996)], we show that the time correlation function in the random-neighbor version of the Bak-Sneppen model can be well approximated by an exponential giving rise to a 1/f2 power spectrum.Comment: 2 pages, 2 figure

Cycling injuries and alcohol

Background: Most of the cycling accidents that occur in Finland do not end up in the official traffic accident statistics. Thus, there is minimal information on these accidents and their consequences, particularly in cases in which alcohol was involved. The focus of the present study is on cycling accidents and injuries involving alcohol in particular. Methods: Data on patients visiting the emergency department at North Kymi Hospital because of a cycling accident was prospectively collected for two years, from June 1, 2004 to May 31, 2006. Blood alcohol concentration (BAC) was measured on admission with a breath analyser. The severity of the cycling injuries was classified according to the Abbreviated Injury Scale (AIS). Results: A total of 217 cycling accidents occurred. One third of the injured cyclists were involved with alcohol at the time of visiting the hospital. Of these, 85% were males. A blood alcohol concentration of Conclusions: Cyclists involved with alcohol were, in most cases, heavily intoxicated and were not wearing a bicycle helmet. Head injuries were more common among these cyclists than among sober cyclists. As cycling continues to increase, it is important to monitor cycling accidents, improve the accident statistics and heighten awareness of the risks of head injuries when cycling under the influence of alcohol. (c) 2018 Elsevier Ltd. All rights reserved.Peer reviewe

A 10-Year Retrospective Study of 490 Hip Fracture Patients: Reoperations, Direct Medical Costs, and Survival

Background and Aims: Reoperations after operative treatment of hip fracture patients may be associated with higher costs and inferior survival. We examined the acute hospital costs, long-term reoperation rates, and survival of patients with a new hip fracture. Materials and Methods: A total of 490 consecutive new hip fracture patients treated at a single center between 31 December 2004 and 6 December 2006 were analyzed retrospectively. Fractures were classified according to Garden and AO. All medical records were checked manually. The costs of reoperations were calculated using the diagnosis-related groups (DRG)-based prices. Survival analysis was performed using the life-table method. The follow-up time was 10 years. Results: In all, 70/490 patients (14.3%) needed reoperations. Of all reoperations, 34.2% were performed during the first month and 72.9% within 1 year after the primary operation. The hemiarthroplasty dislocation rate was 8.5%, and mechanical failures of osteosynthesis occurred in 6.2%. Alcohol abuse was associated with a heightened risk of reoperation. The mean direct costs of primary fracture care were lower than the mean costs of reoperations (euro7500 vs euro9800). The mortality rate at 10 years was 79.8% among non-reoperated patients and 62.9% among reoperated patients. Conclusions: According to our hypothesis, the cost per patient of reoperation in acute care was 31% higher than the corresponding cost of a primary operation. Reoperations increased the overall immediate costs of index fractures by nearly 20%. One-third of all reoperations were performed during the first month and almost 75% within 1 year after the primary operation.Peer reviewe

Time--delay autosynchronization of the spatio-temporal dynamics in resonant tunneling diodes

The double barrier resonant tunneling diode exhibits complex spatio-temporal patterns including low-dimensional chaos when operated in an active external circuit. We demonstrate how autosynchronization by time--delayed feedback control can be used to select and stabilize specific current density patterns in a noninvasive way. We compare the efficiency of different control schemes involving feedback in either local spatial or global degrees of freedom. The numerically obtained Floquet exponents are explained by analytical results from linear stability analysis.Comment: 10 pages, 16 figure

An Evaluation Model For Web-based 3D Mass Customization Toolkit Design

The development of geometric modelling technologies and web technologies provides the ability to present a virtual 3D product in a mass customization (MC) toolkit. Compared with 2D graphic toolkits, 3D toolkit design requires better consideration of individual customer needs, consumer and toolkit interaction, and also a means of integrating with the underlying technical infrastructure. However, there is currently no widely accepted model or criteria to regulate and evaluate 3D MC toolkit design. Given these considerations, in this paper we provide an evaluation model for web-based 3D toolkits and a heuristic evaluation of two representative commercial web-based 3D toolkits. The evaluation results indicate the usefulness and effectiveness of the model as a scale for evaluating 3D toolkits. It also reveals that despite a fair amount of effort that has been devoted to theoretical research, current 3D toolkits are still at an early development stage. We therefore conclude this paper by identifying and encouraging further topics and questions as directions for future research

From Producer Innovation to User and Open Collaborative Innovation

In this paper we assess the economic viability of innovation by producers relative to two increasingly important alternative models: innovations by single user individuals or firms, and open collaborative innovation. We analyze the design costs and architectures and communication costs associated with each model. We conclude that both innovation by individual users and open collaborative innovation increasingly compete with and may displace producer innovation in many parts of the economy. We explain why this represents a paradigm shift with respect to innovation research, policymaking, and practice. We discuss important implications and offer suggestions for further research

North-east sector of the Greenland Ice Sheet to undergo the greatest inland expansion of supraglacial lakes during the 21st century

The formation and rapid drainage of supraglacial lakes (SGL) influences the mass balance and dynamics of the Greenland Ice Sheet (GrIS). Although SGLs are expected to spread inland during the 21st century due to atmospheric warming, less is known about their future spatial distribution and volume. We use GrIS surface elevation model and regional climate model outputs to show that at the end of the 21st century (2070-2099) approximately 9.8 ± 3.9 km3 (+113% compared to 1980-2009) and 12.6 ± 5 km3 (+174%) of meltwater could be stored in SGLs under moderate (RCP 4.5) and high (RCP 8.5) climate change scenarios respectively. The largest increase is expected in the north-eastern sector of the GrIS (191% in RCP 4.5 and 320% in RCP 8.5), whereas in west Greenland, where the most SGLs are currently observed, the future increase will be relatively moderate (55% in RCP 4.5 and 68% in RCP 8.5)

Entrepreneurial-intention constraint model: A comparative analysis among post-graduate management students in India, Singapore and Malaysia

YesAlthough literature on entrepreneurship has increasingly focused on intention-based models, not much emphasis has been laid on understanding the combined effect of contextual and situational factors along with support of university environment on the formation of entrepreneurial intention among students. In an effort to make up for this shortfall, by taking Theory of Planned Behavior as basic framework, the present study seeks to understand the influence of three of the most important factors, viz. (a) endogenous barriers, (b) exogenous environment, and (c) university environment and support on the entrepreneurial intention among management students. The study sample consisted of 1,097 students, wherein 526 students were from India, 252 from Singapore, and 319 were from Malaysia. The results indicates that along with positive attitude and perceived behavioral control that directly influences entrepreneurial intention, university environment and support and exogenous environment also have an indirect but significant impact on shaping of entrepreneurial intention among students. With this, it was found that exogenous environment was found to have a negative relationship with both attitude towards behavior and perceived behavioral control for all three countries.The full-text of this article will be released for public view at the end of the publisher embargo on 2 Jun 2018