Supporting Intelligence Analysts with a Trust-Based Question-Answering System

Intelligence analysts have to work in highly demanding circumstances. This causes mistakes with severe consequences, which is the reason that support systems for intelligence analysts have been developed. The support system proposed in this paper assists humans by offering support that improves their performance, without reducing them in their freedom. This is done with a trust-based question answering system (T-QAS). An important part of T-QAS are trust models which keep track of trust in each of the agents gathering information. Using these trust models, the system can support the intelligence analyst by: 1) helping to decide which agents are trusted enough to receive questions, 2) providing information about the reliability of each of the sources used, and 3) advising in making decisions based on information from possibly unreliable sources. An implementation of last two capabilities of T-QAS is evaluated in an experiment in which participants perform a decision making task with information from possibly unreliable sources. Results show that the proposed T-QAS support indeed helps participants to improve their performance. We therefore expect that future intelligence analyst support systems can benefit from the inclusion of T-QAS

Reservecapaciteit van melkleidinginstallaties

Een goed functioneren van de installatie wordt mede bepaald door een stabiel melkvacuüm

Luchtweginfecties bij paarden

Bij paarden vormen aandoeningen van de luchtwegen na kreupelheden het belangrijkste probleem op het gebied van de gezondheid

Predators marked with chemical cues from one prey have increased attack success on another prey species

1. To reduce the risk of being eaten by predators, prey alter their morphology or behaviour. This response can be tuned to the current danger if chemical or other cues associated with predators inform the prey about the risks involved. 2. It is well known that various prey species discriminate between chemical cues from predators that fed on conspecific prey and those that fed on heterospecific prey, and react stronger to the first. It is therefore expected that generalist predators are more successful in capturing a given prey species when they are contaminated with chemical cues from another prey species instead of cues from the same prey species. 3. Here, a generalist predatory mite was studied that feeds on thrips larvae as well as on whitefly eggs and crawlers. Mites were marked with cues (i.e. body fluids) of one of these two prey species and were subsequently offered thrips larva. 4. Predators marked with thrips cues killed significantly fewer thrips than predators marked with whitefly cues, even though the predator's tendency to attack was the same. In addition, more thrips larvae sought refuge in the presence of a predatory mite marked with thrips cues instead of whitefly cues. 5. This suggests that generalist predators may experience improved attack success when switching prey species.R.v.M. received a scholarship of the Technology Foundation (STW Project 7180). G.B. received a fellowship from the OECD. E.A.F. received a fellowship from Fundació Caixa Castelló-Bancaixa (E-2011-09

Estimation of the basic reproduction number for Streptococcus equi spp. equi outbreaks by meta-analysis of strangles outbreak reports

Background Streptococcus equi spp. equi (S. equi), the cause of strangles in horses, is considered a highly contagious pathogen affecting equines and the equine industry worldwide. Fundamental epidemiological characteristics of outbreaks, such as the basic reproduction number (R-0), are not well described. Objectives Estimate R-0 for S. equi in equine populations from outbreak data. Study design Systematic review and meta-analysis of published and unpublished data. Methods A literature search for outbreak reports was carried out. Depending on data available in the reports, the early epidemic growth rate or final attack rate (AR) approach was used to estimate the basic reproduction number for that outbreak. Other recorded outbreak characteristics were the type of housing (group vs. individual). An overall estimate for R-0 was computed by meta-analysis. Results Data from eight outbreaks were extracted from peer-reviewed publications. Data from two additional, non-published outbreaks was also included in the meta-analysis. A conservative estimate for R-0 was 2.2 (95% confidence interval [CI] 1.9-2.5). A less conservative estimate, including outbreaks with a 100% AR for which a lower limit R-0 was estimated, was 2.7 (95% CI 2.1-3.3). Main limitations Few papers describing longitudinal incidence data were found so most estimates were based on the outbreaks' final size. Several outbreaks had a 100% attack rate and could therefore only be included as a lower limit estimate in the meta-analysis. The reported result therefore may be an underestimation. Conclusions This estimate for R-0 for S. equi informs parameters for future mathematical modelling, quantifies desired preventive vaccine coverage and helps evaluate the effect of prevention strategies through future modelling studies