A dynamical model of a GRID market

We discuss potential market mechanisms for the GRID. A complete dynamical model of a GRID market is defined with three types of agents. Providers, middlemen and users exchange universal GRID computing units (GCUs) at varying prices. Providers and middlemen have strategies aimed at maximizing profit while users are 'satisficing' agents, and only change their behavior if the service they receive is sufficiently poor or overpriced. Preliminary results from a multi-agent numerical simulation of the market model shows that the distribution of price changes has a power law tail.Comment: 4 pages, 3 figure

Implementation of Pediatric Emergency Care Applied Research Network (PECARN) guidelines for traumatic brain injury in a rural tertiary care center

Objectives: To evaluate changes in imaging practices for pediatric head trauma following publication of the Pediatric Emergency Care Applied Research Network (PECARN) guidelines, explore areas for quality improvement regarding neuroradiology referrals. We also sought to determine the prevalence of incidental findings discovered on CTs attained for minor head trauma and ascertain disposition in these cases. Methods: This retrospective study was conducted at a rural academic center and included 156 children who received CTs for head trauma between 2005 and 2015. Subjects were divided into two groups: pre-PECARN publication and post-PECARN publication. Electronic medical records were reviewed to determine whether or not head CTs were obtained according to PECARN guidelines. The proportion of scanned cases and incidental findings in each group were then compared. Results: Significantly more subjects met PECARN criteria for head CT during the pre-PECARN period (67.1% vs 50.6%, p=0.04). Among those who met PECARN criteria, severe mechanism of injury was the most common criterion met in both groups (43.8% pre-PECARN and 26.5% post-PECARN). Nine (5.7%) subjects had incidental findings (similar for both study periods), of which three prompted additional diagnostic testing or invasive intervention. Among those who did not meet PECARN criteria, the most common mechanism of injury was fall (\u3c 3 feet). Conclusions: Implementation of PECARN guidelines at our center remained limited in the five years after publication of this practice guide. Clinically insignificant incidental findings were often detected and may heighten patient anxiety

Meeting India’s future water needs: policy options

River basinsWater shortageWater transferGroundwater irrigationWater productivity

Compressible laminar streaks with wall suction

Peer reviewedPublisher PD

A compact to revitalise large-scale irrigation systems using a leadership-partnership-ownership ‘theory of change’

In countries with transitional economies such as those found in South Asia, large-scale irrigation systems (LSIS) with a history of public ownership account for about 115 million ha (Mha) or approximately 45% of their total area under irrigation. In terms of the global area of irrigation (320 Mha) for all countries, LSIS are estimated at 130 Mha or 40% of irrigated land. These systems can potentially deliver significant local, regional and global benefits in terms of food, water and energy security, employment, economic growth and ecosystem services. For example, primary crop production is conservatively valued at about US$355 billion. However, efforts to enhance these benefits and reform the sector have been costly and outcomes have been underwhelming and short-lived. We propose the application of a 'theory of change' (ToC) as a foundation for promoting transformational change in large-scale irrigation centred upon a 'global irrigation compact' that promotes new forms of leadership, partnership and ownership (LPO). The compact argues that LSIS can change by switching away from the current channelling of aid finances controlled by government irrigation agencies. Instead it is for irrigators, closely partnered by private, public and NGO advisory and regulatory services, to develop strong leadership models and to find new compensatory partnerships with cities and other river basin neighbours. The paper summarises key assumptions for change in the LSIS sector including the need to initially test this change via a handful of volunteer systems. Our other key purpose is to demonstrate a ToC template by which large-scale irrigation policy can be better elaborated and discussed