Automated and Participative Decision Support in Computer-aided Credibility Assessment

History has shown that inaccurate assessments of credibility can result in tremendous costs to businesses and society. This study uses Signal Detection Theory (SDT) to improve the accuracy of credibility assessments through combining automated and participatory decision support. Participatory decision support is also proposed to encourage acceptance of the decision aid’s recommendation. A new hybrid decision aid is designed to perform automated linguistic analysis and elicit and analyze perceptual cues (i.e., indirect cues) from an observer. The results suggest that decision aids that collect both linguistic and indirect cues perform better than decision aids that collect only one type of cue. Users of systems that collect linguistic cues experience improved credibility assessment accuracy; yet, users of systems that collect both types of cues or only indirect cues do not experience higher accuracy. However, collecting indirect cues increases the user’s acceptance of decision-aid recommendations

The structure and evolution of chaos in dynamical systems

An in depth study of temporal chaotic systems, both discrete and continuous, is presented. The techniques for the characterization of chaotic attractors are: Lyapunov stability, dimension spectra and unstable periodic orbits. Comparison of numerical and analytical methods clarify some of the limitations of these techniques. A two dimensional hyperbolic baker map with a complete set of unstable orbits is examined. The evolution of structure and changes in the f(a) spectrum for this map are related to changes in an underlining Cantor set. Numerical calculation of unstable periodic orbits for a related baker map with an incomplete set of unstable orbits allow the investigation of the properties of a pruned Cantor set. The effects of the pruning on the associated f(a) spectrum are investigated. It is also shown that the unstable manifold of a hyperbolic toral map does not wind densely around the torus, but consists of an infinite number of line segments. This facilitates the efficient computation of the dimension spectrum through a rotation of this manifold. A new structure not previously observed m discrete systems is characterized. Intermittency theory previously applied to dissipative systems is applied to a variety of two dimensional non-dissipative systems. A new type of intermittency is found from a detailed comparison between existing theory and numerical experiments. The important and unresolved problem of the correspondence between continuous and discrete systems is investigated using analytical and numerical techniques. Properties of the chaotic attractors of infinite dimensional delayed differential equations are examined as a function of the time delay and nonlinearity parameters

Increases in ROPS Pricing from 2006-2012 and the Impact on ROPS Demand

In 2006, a social marketing campaign was developed to increase the installation of rollover protective structures (ROPS) on unprotected New York tractors. Using data gathered from the program\u27s hotline, the impact of price increases on farmers\u27 interest in ROPS is examined. Pricing data were obtained for all rigid ROPS kits commercially available in the U.S. since 2006. These data were stratified into two groups of ROPS suppliers: (1) tractor manufacturers that sell ROPS for their own tractors, referred to in this study as original equipment manufacturers (OEMs), and (2) aftermarket (AM) ROPS suppliers. The trend in price increases was contrasted with the change in the consumer price index (CPI), the probability of retrofitting within quintiles of cost was estimated, and the increase in ROPS prices over time was plotted The average price increase for a ROPS kit (excluding shipping and installation) over the six years of the study was 23.3% for OEM versus 60.5% for AM (p \u3c 0.0001). Out-of-pocket expenses held steady for OEM versus a six-year increase of $203 for AM (p = 0.098). The probability of a farmer retrofitting dropped monotonically from 66.9% in the lowest ROPS cost quintile to 23% in the highest. If these trends continue, the proportion of inquiries resulting in a ROPS retrofit will fall below 20% by 2020 for AM ROPS. Based on other trends identified in the literature, it is reasonable to assume that decreases in ROPS installation are likely to affect the tractor owners who are most likely to need these safety devices

Wavelength Scaling and Square/Stripe and Grain Mobility Transitions in Vertically Oscillated Granular Layers

Laboratory experiments are conducted to examine granular wave patterns near onset as a function of the container oscillation frequency f and amplitude A, layer depth H, and grain diameter D. The primary transition from a flat grain layer to standing waves occurs when the layer remains dilated after making contact with the container. With a flat layer and increasing dimensionless peak container acceleration G = 4 pi^2 f^2 A/g (g is the acceleration due to gravity), the wave transition occurs for G=2.6, but with decreasing G the waves persist to G=2.2. For 2.2<G<3.8, patterns are squares for f<f_ss and stripes for f>f_ss; H determines the square/stripe transition frequency f_ss=0.33(g/H)^0.5. The dispersion relations for layers with varying H collapse onto the curve L/H=1.0+1.1[f(H/g)^0.5]^(-1.32 +/- 0.03) (L is the wavelength) when the peak container velocity v exceeds a critical value v_gm of approximately 3 (Dg)^0.5. Local collision pressure measurements suggest that v_gm is associated with a transition in the horizontal grain mobility: for v>v_gm, there is a hydrodynamic-like horizontal sloshing motion, while for v<v_gm, the grains are essentially immobile and the stripe pattern apparently arises from a bending of the granular layer. For f at v_gm less than f_ss and v<v_gm, patterns are tenuous and disordered.Comment: 21 pages, 15 figures, submitted to Physica

Visualising single molecules of HIV-1 and miRNA nucleic acids

BackgroundThe scarcity of certain nucleic acid species and the small size of target sequences such as miRNA, impose a significant barrier to subcellular visualization and present a major challenge to cell biologists. Here, we offer a generic and highly sensitive visualization approach (oligo fluorescent in situ hybridization, O-FISH) that can be used to detect such nucleic acids using a single-oligonucleotide probe of 19&ndash;26 nucleotides in length.ResultsWe used O-FISH to visualize miR146a in human and avian cells. Furthermore, we reveal the sensitivity of O-FISH detection by using a HIV-1 model system to show that as little as 1&ndash;2 copies of nucleic acids can be detected in a single cell. We were able to discern newly synthesized viral cDNA and, moreover, observed that certain HIV RNA sequences are only transiently available for O-FISH detection.ConclusionsTaken together, these results suggest that the O-FISH method can potentially be used for in situ probing of, as few as, 1&ndash;2 copies of nucleic acid and, additionally, to visualize small RNA such as miRNA. We further propose that the O-FISH method could be extended to understand viral function by probing newly transcribed viral intermediates; and discern the localisation of nucleic acids of interest. Additionally, interrogating the conformation and structure of a particular nucleic acid in situ might also be possible, based on the accessibility of a target sequence

Deep CCD Surface Photometry of the Edge-On Spiral NGC 4244

We have obtained deep surface photometry of the edge-on spiral galaxy NGC 4244. Our data reliably reach 27.5 R magnitude arcsec^{-2}, a significant improvement on our earlier deep CCD surface photometry of other galaxies. NGC 4244 is a nearby Scd galaxy whose total luminosity is approximately one magnitude fainter than the peak of the Sc luminosity function. We find that it has a simple structure: a single exponential disk, with a scale height h_Z = 246 +/- 2 pc, a scale length h_R = 1.84 +/- 0.02 kpc and a disk cutoff at a radius R(max) = 10.0 kpc (5.4 scale lengths). We confirm a strong cutoff in the stellar disk at R(max), which happens over only 1 kpc. We do not see any statistically significant evidence for disk flaring with radius. Unlike the more luminous Sc galaxies NGC 5907 and M 33, NGC 4244 does not show any evidence for a second component, such as a thick disk or halo, at mu(R) < 27.5 magnitude arcsec^{-2}.Comment: 36 pages, including 12 figures; accepted for publication in Sept 99 A

Prevalence of psychosis in black ethnic minorities in Britain: analysis based on three national surveys

Purpose A considerable excess of psychosis in black ethnic minorities is apparent from clinical studies, in Britain, as in other developed economies with white majority populations. This excess is not so marked in population surveys. Equitable health service provision should be informed by the best estimates of the excess. We used national survey data to establish the difference in the prevalence of psychosis between black ethnic groups and the white majority in the British general population. Methods Analysis of the combined datasets (N = 26,091) from the British national mental health surveys of 1993, 2000 and 2007. Cases of psychosis were determined either by the use of the Schedules for Clinical Assessment in Neuropsychiatry (SCAN), or from a combination of screening items. We controlled for sex, age, social class, unemployment, design features and other putative confounders, using a Disease Risk Score. Results People from black ethnic minorities had an excess prevalence rate of psychosis compared with the white majority population. The OR, weighted for study design and response rate, was 2.72 (95 % CI 1.3–5.6, p = 0.002). This was marginally increased after controlling for potential confounders (OR = 2.90, 95 % CI 1.4–6.2, p = 0.006). Conclusions The excess of psychosis in black ethnic minority groups was similar to that in two previous British community surveys, and less than that based on clinical studies. Even so it confirms a considerable need for increased mental health service resources in areas with high proportions of black ethnic minority inhabitants