An Algorithm for Distributing Coalitional Value Calculations among Cooperating Agents

The process of forming coalitions of software agents generally requires calculating a value for every possible coalition which indicates how beneficial that coalition would be if it was formed. Now, instead of having a single agent calculate all these values (as is typically the case), it is more efficient to distribute this calculation among the agents, thus using all the computational resources available to the system and avoiding the existence of a single point of failure. Given this, we present a novel algorithm for distributing this calculation among agents in cooperative environments. Specifically, by using our algorithm, each agent is assigned some part of the calculation such that the agents’ shares are exhaustive and disjoint. Moreover, the algorithm is decentralized, requires no communication between the agents, has minimal memory requirements, and can reflect variations in the computational speeds of the agents. To evaluate the effectiveness of our algorithm, we compare it with the only other algorithm available in the literature for distributing the coalitional value calculations (due to Shehory and Kraus). This shows that for the case of 25 agents, the distribution process of our algorithm took less than 0.02% of the time, the values were calculated using 0.000006% of the memory, the calculation redundancy was reduced from 383229848 to 0, and the total number of bytes sent between the agents dropped from 1146989648 to 0 (note that for larger numbers of agents, these improvements become exponentially better)

Construction of an ~700-kb transcript map around the Familial Mediterranean Fever locus on human chromosome 16p13.3

We used a combination of cDNA selection, exon amplification, and computational prediction from genomic sequence to isolate transcribed sequences from genomic DNA surrounding the familial Mediterranean fever (FMF) locus. Eighty-seven kb of genomic DNA around D16S3370, a marker showing a high degree of linkage disequilibrium with FMF, was sequenced to completion, and the sequence annotated. A transcript map reflecting the minimal number of genes encoded within the ∼700 kb of genomic DNA surrounding the FMF locus was assembled. This map consists of 27 genes with discreet messages detectable on Northerns, in addition to three olfactory-receptor genes, a cluster of 18 tRNA genes, and two putative transcriptional units that have typical intron–exon splice junctions yet do not detect messages on Northerns. Four of the transcripts are identical to genes described previously, seven have been independently identified by the French FMF Consortium, and the others are novel. Six related zinc-finger genes, a cluster of tRNAs, and three olfactory receptors account for the majority of transcribed sequences isolated from a 315-kb FMF central region (betweenD16S468/D16S3070 and cosmid 377A12). Interspersed among them are several genes that may be important in inflammation. This transcript map not only has permitted the identification of the FMF gene (MEFV), but also has provided us an opportunity to probe the structural and functional features of this region of chromosome 16.Michael Centola, Xiaoguang Chen, Raman Sood, Zuoming Deng, Ivona Aksentijevich, Trevor Blake, Darrell O. Ricke, Xiang Chen, Geryl Wood, Nurit Zaks, Neil Richards, David Krizman, Elizabeth Mansfield, Sinoula Apostolou, Jingmei Liu, Neta Shafran, Anil Vedula, Melanie Hamon, Andrea Cercek, Tanaz Kahan, Deborah Gumucio, David F. Callen, Robert I. Richards, Robert K. Moyzis, Norman A. Doggett, Francis S. Collins, P. Paul Liu, Nathan Fischel-Ghodsian and Daniel L. Kastne

Enhanced invitation methods and uptake of health checks in primary care. Rapid randomised controlled trial using electronic health records

Background: A national programme of health checks to identify risk of cardiovascular disease is being rolled out but is encountering difficulties of low uptake. Objective: To evaluate the effectiveness of an enhanced invitation method using the Question-Behaviour Effect (QBE), with or without the offer of a financial incentive to return the QBE questionnaire, at increasing the uptake of health checks. Secondary objectives were to evaluate reasons for low uptake of invitations and to compare case-mix for invited and opportunistic health checks. Trial design: Three-arm randomised trial. Participants: All participants invited for health checks from 18 general practices. Randomisation: Individual participants were randomised. Interventions: i) standard health check invitation only, ii) QBE questionnaire followed by standard invitation; iii) QBE questionnaire with offer of a financial incentive to return the questionnaire, followed by standard invitation. Outcomes: The primary outcome was completion of health check within six months of randomisation. A P value of 0.0167 was used for significance. Case-mix was evaluated for invited and opportunistic health checks. Blinding: Participants were not aware that several types of invitation were in use. The research team were blind to trial arm allocation at outcome data extraction. Results: There were 12,459 participants allocated and health check uptake was evaluated for 12,052 participants for whom outcome data were collected. Health check uptake was: standard invitation, 590 / 4,095 (14.4%); QBE questionnaire, 630 / 3,988 (15.8%); QBE questionnaire and financial incentive, 629 / 3,969 (15.9%). The increase in uptake associated with QBE questionnaire was 1.43% (95% confidence interval -0.12 to 2.97%, P=0.070) and for the QBE questionnaire and offer of financial incentive was 1.52% (-0.03 to 3.07%, P=0.054). The difference in uptake associated with the offer of an incentive to return the QBE questionnaire was -0.01% (-1.59 to 1.58%, P=0.995). During the study, 58% of health check cardiovascular risk assessments did not follow a trial invitation. People who received ‘opportunistic’ health checks had greater odds of ≥10% cardiovascular disease (CVD) risk; adjusted odds ratio 1.70, 95% confidence interval 1.45 to 1.99, P<0.001) compared with invited health checks. Conclusion: Uptake of health checks following an invitation letter is low and is not increased through an enhanced invitation method using the QBE, with or without an incentive. A high proportion of all health checks are performed opportunistically. Participants receiving opportunistic checks are at higher risk of CVD than those responding to standard invitations. Trial registration: Current Controlled Trials ISRCTN42856343