Multiagent Systems Engineering: A Methodology for Analysis and Design of Multiagent Systems

This thesis defines a methodology for the creation of multiagent systems, the Multiagent Systems Engineering (MaSE) methodology. The methodology is a key issue in the development of any complex system and there is currently no standard or widely used methodology in the realm of multiagent systems. MaSE covers the entire software lifecycle, starting from an initial prose specification, and creating a set of formal design documents in a graphical style based on a formal syntax. The final product of MaSE is a diagram describing the deployment of a system of intelligent agents that communicate through structured conversations. MaSE was created with the mention of being supported by an automated design tool. The tool built to support MaSE, agent Tool, is a multiagent system development tool for designing and synthesizing complex multiagent systems

Attitudes of medical students to medical leadership and management: a systematic review to inform curriculum development.

BACKGROUND: There is a growing acknowledgement that doctors need to develop leadership and management competences to become more actively involved in the planning, delivery and transformation of patient services. We undertook a systematic review of what is known concerning the knowledge, skills and attitudes of medical students regarding leadership and management. Here we report the results pertaining to the attitudes of students to provide evidence to inform curriculum development in this developing field of medical education. METHODS: We searched major electronic databases and citation indexes within the disciplines of medicine, education, social science and management. We undertook hand searching of major journals, and reference and citation tracking. We accessed websites of UK medical institutions and contacted individuals working within the field. RESULTS: 26 studies were included. Most were conducted in the USA, using mainly quantitative methods. We used inductive analysis of the topics addressed by each study to identity five main content areas: Quality Improvement; Managed Care, Use of Resources and Costs; General Leadership and Management; Role of the Doctor, and Patient Safety. Students have positive attitudes to clinical practice guidelines, quality improvement techniques and multidisciplinary teamwork, but mixed attitudes to managed care, cost containment and medical error. Education interventions had variable effects on students' attitudes. Medical students perceive a need for leadership and management education but identified lack of curriculum time and disinterest in some activities as potential barriers to implementation. CONCLUSIONS: The findings from our review may reflect the relatively little emphasis given to leadership and management in medical curricula. However, students recognise a need to develop leadership and management competences. Although further work needs to be undertaken, using rigorous methods, to identify the most effective and cost-effective curriculum innovations, this review offers the only currently available summary of work examining the attitudes of students to this important area of development for future doctors.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Pharmacological postconditioning against myocardial infarction with a slow-releasing hydrogen sulfide donor, GYY4137

Exogenous hydrogen sulfide (H2S) protects against myocardial ischemia/reperfusion injury but the mechanism of action is unclear. The present study investigated the effect of GYY4137, a slow-releasing H2S donor, on myocardial infarction given specifically at reperfusion and the signalling pathway involved. Thiobutabarbital-anesthetised rats were subjected to 30min of left coronary artery occlusion and 2h reperfusion. Infarct size was assessed by tetrazolium staining. In the first study, animals randomly received either no treatment or GYY4137 (26.6, 133 or 266μmolkg-1) by intravenous injection 10min before reperfusion. In a second series, involvement of PI3K and NO signalling were interrogated by concomitant administration of LY294002 or L-NAME respectively and the effects on the phosphorylation of Akt, eNOS, GSK-3β and ERK1/2 during early reperfusion were assessed by immunoblotting. GYY4137 266μmolkg-1 significantly limited infarct size by 47% compared to control hearts (P<0.01). In GYY4137-treated hearts, phosphorylation of Akt, eNOS and GSK-3β was increased 2.8, 2.2 and 2.2 fold respectively at early reperfusion. Co-administration of L-NAME and GYY4137 attenuated the cardioprotection afforded by GYY4137, associated with attenuated phosphorylation of eNOS. LY294002 totally abrogated the infarct-limiting effect of GYY4137 and inhibited Akt, eNOS and GSK-3β phosphorylation. These data are the first to demonstrate that GYY4137 protects the heart against lethal reperfusion injury through activation of PI3K/Akt signalling, with partial dependency on NO signalling and inhibition of GSK-3β during early reperfusion. H2S-based therapeutic approaches may have value as adjuncts to reperfusion in the treatment of acute myocardial infarction

Evolution of brown dwarf disks: A Spitzer survey in Upper Scorpius

We have carried out a Spitzer survey for brown dwarf (BD) disks in the ~5 Myr old Upper Scorpius (UpSco) star forming region, using IRS spectroscopy from 8 to 12\mu m and MIPS photometry at 24\mu m. Our sample consists of 35 confirmed very low mass members of UpSco. Thirteen objects in this sample show clear excess flux at 24\mu m, explained by dust emission from a circum-sub-stellar disk. Objects without excess emission either have no disks at all or disks with inner opacity holes of at least ~5 AU radii. Our disk frequency of 37\pm 9% is higher than what has been derived previously for K0-M5 stars in the same region (on a 1.8 sigma confidence level), suggesting a mass-dependent disk lifetime in UpSco. The clear distinction between objects with and without disks as well as the lack of transition objects shows that disk dissipation inside 5 AU occurs rapidly, probably on timescales of <~10^5 years. For the objects with disks, most SEDs are uniformly flat with flux levels of a few mJy, well modeled as emission from dusty disks affected by dust settling to the midplane, which also provides indirect evidence for grain growth. The silicate feature around 10\mu m is either absent or weak in our SEDs, arguing for a lack of hot, small dust grains. Compared with younger objects in Taurus, BD disks in UpSco show less flaring. Taken together, these results clearly demonstrate that we see disks in an advanced evolutionary state: Dust settling and grain growth are ubiquituous in circum-sub-stellar disks at ages of 5 Myr, arguing for planet forming processes in BD disks. For almost all our targets, results from high-resolution spectroscopy and high-spatial resolution imaging have been published before, thus providing a large sample of BDs for which information about disks, accretion, and binarity is available. (abridged)Comment: 39 pages, 7 figures, accepted for publication in Ap

Feasibility Study and Demonstration of an Aluminum and Ice Solid Propellant

Aluminum-water reactions have been proposed and studied for several decades for underwater propulsion systems and applications requiring hydrogen generation. Aluminum and water have also been proposed as a frozen propellant, and there have been proposals for other refrigerated propellants that could be mixed, frozen in situ, and used as solid propellants. However, little work has been done to determine the feasibility of these concepts. With the recent availability of nanoscale aluminum, a simple binary formulation with water is now feasible. Nanosized aluminum has a lower ignition temperature than micronsized aluminum particles, partly due to its high surface area, and burning times are much faster than micron aluminum. Frozen nanoscale aluminum and water mixtures are stable, as well as insensitive to electrostatic discharge, impact, and shock. Here we report a study of the feasibility of an nAl-ice propellant in small-scale rocket experiments. The focus here is not to develop an optimized propellant; however improved formulations are possible. Several static motor experiments have been conducted, including using a flight-weight casing. The flight weight casing was used in the first sounding rocket test of an aluminum-ice propellant, establishing a proof of concept for simple propellant mixtures making use of nanoscale particles

A portable neutron spectroscope (NSPECT) for detection, imaging and identification of nuclear material

We have developed, fabricated and tested a prototype imaging neutron spectrometer designed for real-time neutron source location and identification. Real-time detection and identification is important for locating materials. These materials, specifically uranium and transuranics, emit neutrons via spontaneous or induced fission. Unlike other forms of radiation (e.g. gamma rays), penetrating neutron emission is very uncommon. The instrument detects these neutrons, constructs images of the emission pattern, and reports the neutron spectrum. The device will be useful for security and proliferation deterrence, as well as for nuclear waste characterization and monitoring. The instrument is optimized for imaging and spectroscopy in the 1-20 MeV range. The detection principle is based upon multiple elastic neutron-proton scatters in organic scintillator. Two detector panel layers are utilized. By measuring the recoil proton and scattered neutron locations and energies, the direction and energy spectrum of the incident neutrons can be determined and discrete and extended sources identified. Event reconstruction yields an image of the source and its location. The hardware is low power, low mass, and rugged. Its modular design allows the user to combine multiple units for increased sensitivity. We will report the results of laboratory testing of the instrument, including exposure to a calibrated Cf-252 source. Instrument parameters include energy and angular resolution, gamma rejection, minimum source identification distances and times, and projected effective area for a fully populated instrument

Major liver resection for hepatocellular carcinoma in the morbidly obese: A proposed strategy to improve outcome

<p>Abstract</p> <p>Background</p> <p>Morbid obesity strongly predicts morbidity and mortality in surgical patients. However, obesity's impact on outcome after major liver resection is unknown.</p> <p>Case presentation</p> <p>We describe the management of a large hepatocellular carcinoma in a morbidly obese patient (body mass index >50 kg/m²). Additionally, we propose a strategy for reducing postoperative complications and improving outcome after major liver resection.</p> <p>Conclusion</p> <p>To our knowledge, this is the first report of major liver resection in a morbidly obese patient with hepatocellular carcinoma. The approach we used could make this operation nearly as safe in obese patients as it is in their normal-weight counterparts.</p

Ap39, a mitochondria-targeting hydrogen sulfide (H2 s) donor, protects against myocardial reperfusion injury independently of salvage kinase signalling

Background and Purpose H2S protects myocardium against ischaemia-reperfusion injury. This protection may involve the cytosolic reperfusion injury salvage kinase (RISK) pathway, but direct effects on mitochondrial function are possible. Here, we investigated the potential cardioprotective effect of mitochondria-specific H2S donor, AP39, at reperfusion against ischaemia/reperfusion injury. Experimental Approach Anaesthetised rats underwent myocardial (30 min ischaemia/120 min reperfusion) with randomisation to receive interventions prior to reperfusion: vehicle, AP39 (0.01, 0.1, 1 µmol kg-1), or the control compounds AP219 or ADT-OH (1 µmol kg-1). LY294002, L-NAME or ODQ were used to interrogate the involvement of RISK pathway. Myocardial samples harvested 5 minutes after reperfusion were analysed for RISK protein phosphorylation and additional experiments were conducted on isolated cardiac mitochondria to examine the direct mitochondrial effects of AP39. Key Results AP39 exerted dose-dependent infarct size limitation. Inhibition of either PI3K/Akt, eNOS or sGC did not affect the infarct limitation of AP39. Western blot analysis confirmed that AP39 did not induce phosphorylation of Akt, eNOS, GSK-3β or ERK1/2. In isolated subsarcolemmal and interfibrillar mitochondria, AP39 significantly attenuated mitochondrial ROS generation without affecting respiratory complexes I or II. Further, AP39 inhibited mitochondrial permeability transition pore (PTP) opening and co-incubation of mitochondria with AP39 and cyclosporine A induced an additive inhibition of PTP. Conclusion and Implications AP39 protects against reperfusion injury independently of the cytosolic RISK pathway. Cardioprotection could be mediated by inhibiting PTP via cyclophilin D-independent mechanism. Thus, selective delivery of H2S to mitochondria may be therapeutically applicable for harnessing the cardioprotective utility of H2S. This article is protected by copyright. All rights reserved