Vine Copula Specifications for Stationary Multivariate Markov Chains

Vine copulae provide a graphical framework in which multiple bivariate copulae may be combined in a consistent fashion to yield a more complex multivariate copula. In this article, we discuss the use of vine copulae to build flexible semiparametric models for stationary multivariate higher‐order Markov chains. We propose a new vine structure, the M‐vine, that is particularly well suited to this purpose. Stationarity may be imposed by requiring the equality of certain copulae in the M‐vine, while the Markov property may be imposed by requiring certain copulae to be independence copulae.     

The Choice of the Desired Impulse Response in Combined Linear-Viterbi Algorithm Equalizers

Equalizer structures using the Viterbi Algorithm achieve at least order of magnitude performance improvement over linear equalizers on some intersymbol interference channels. Using a linear equalizer to shape the original channel impulse response to some shorter desired impulse response (DIR) is a technique which reduces the complexity of the Viterbi Algorithm equalizer. This paper looks at three techniques for choosing a DIR. These are choosing the DIR by truncation, minimum mean square error and matching the power spectrum to that of the original channel. Using effective signal to noise ratio as the figure of merit for comparison, results are given for one particular channel.     

Resistant starch type 4‐enriched diet lowered blood cholesterols and improved body composition in a double blind controlled cross‐over intervention

A metabolic health crisis is evident as cardiovascular diseases (CVD) remain the leading cause of mortality in the United States. Effects of resistant starch type 4 (RS4), a prebiotic fiber, in comprehensive management of metabolic syndrome (MetS) remain unknown. This study examined the effects of a blinded exchange of RS4‐enriched flour (30% v/v) with regular/control flour (CF) diet on multiple MetS comorbidities. In a double blind (participants–investigators), placebo‐controlled, cluster cross‐over intervention (n = 86, age≥18, 2–12 week interventions, 2‐week washout) in the United States, individuals were classified as having MetS (With‐MetS) or not (No‐MetS) following International Diabetes Federation (IDF)‐criteria. RS4 consumption compared with CF resulted in 7.2% (p = 0.002) lower mean total cholesterol, 5.5% (p = 0.04) lower non‐HDL, and a 12.8% (p < 0.001) lower HDL cholesterol in the With‐MetS group. No‐MetS individuals had a 2.6% (p = 0.02) smaller waist circumference and 1.5% (p = 0.03) lower percent body fat following RS4 intervention compared to CF. A small but significant 1% increase in fat‐free mass was observed in all participants combined (p = 0.02). No significant effect of RS4 was observed for glycemic variables and blood pressures. RS4 consumption improved dyslipidemia and body composition. Incorporation of RS4 in routine diets could offer an effective strategy for public cardio‐metabolic health promotion.     

Nutritional studies of partially hydrogenated rapeseed oil

In three experiments rats were fed a purified basal diet with 20% by weight of partially hydrogenated rapeseed oil. One sample promoted, greater weight gains that the unhydrogenated oil. Another sample, containing a higher concentration of octadecadienoic acids other than 9,12-linoleic acid, produced the same response as the unhydrogenated material. With other samples of hydrogenated rapeseed oil, possessing less linoleic acid but other octadecadienoic acids, significantly lower weight gains were obtained. The alterations in the C₁₈ fatty acids resulting from hydrogenation of rapeseed oil appeared to be responsible for differing responses in weight gain.     

Randomized phase II study of two schedules of topotecan in previously treated patients with ovarian cancer: a National Cancer Institute of Canada Clinical Trials Group study

PURPOSE: As topotecan is S-phase-specific, its efficacy is likely schedule-dependent. Therefore, a randomized study using a "pick the winner" design was undertaken to compare two schedules in patients with recurrent ovarian cancer. PATIENTS AND METHODS: Patients with recurrent epithelial ovarian cancer previously treated with no more than two separate regimens of chemotherapy, one of which had to be platinum-containing, were randomized to either topotecan 1.5 mg/m2 intravenously (i.v.) over 30 minutes daily for 5 days repeated every 21 days (arm A, the standard arm), or topotecan 1.75 mg/m2 as a 24-hour infusion once a week for 4 weeks repeated every 6 weeks (arm B, the experimental arm). RESULTS: Sixty-six patients were eligible and 63 were assessable for response. The response rate in arm A was 22.6% (95% confidence interval [CI], 9.6% to 41.2%), which was significantly superior to that in arm B, 3.1% (95% CI, 0.1% to 16%) (P = .026). The regimens were not equitoxic, with 94% of patients on arm A experiencing grade 3 or 4 granulocytopenia as opposed to 52% on arm B. CONCLUSION: The weekly 24 hour infusion of topotecan at 1.75 mg/m2 was ineffective in relapsed ovarian cancer. The daily-times-five schedule remains the schedule of choice. As the regimens were not equitoxic, one cannot differentiate between an ineffective schedule and an ineffective dose as the reason for the differing response rates. However, the degree of myelotoxicity that already occurs will preclude any substantially higher dosing with the weekly regimen.     

The ability of color defectives to judge signal lights at sea.

Measures were made of the ability of color-defective men to judge correctly the colors of navigation lights (red, green, or white) presented to them at night under realistic sea conditions. Eighty-one color-defective men were employed; they were categorized as to type and degree of defect using a battery of five color-vision tests. While the average performance of the color-defective men was considerably poorer than that of 24 color normals, there were large individual differences within each category of defect. Attempts to account for these differences in performance by variations in acuity, intelligence, and motivation failed. The extent to which the data can be accounted for by modern color-vision theory is discussed.     

An insect vision-based motion detection chip

The architectural and circuit design aspects of a mixed analog/digital very large scale integration (VLSI) motion detection chip based on models of the insect visual system are described. The chip comprises two one-dimensional 64-cell arrays as well as front-end analog circuitry for early visual processing and digital control circuits. Each analog processing cell comprises a photodetector, circuits for spatial averaging and multiplicative noise cancellation, differentiation, and thresholding. The operation and configuration of the analog cells is controlled by digital circuits, thus implementing a reconfigurable architecture which facilitates the evaluation of several newly designed analog circuits. The chip has been designed and fabricated in a 1.2-μm CMOS process and occupies an area of 2×2 mm²     

Judgments of relative motion in tactical displays.

Two experiments examined the speed with which the direction of relative motion could be inferred from static tactical displays. In Exp I, 12 25–40 yr old experienced right-handed male naval officers responded more rapidly to displays depicting target motion to the right than to the left, but 12 inexperienced officers did not. For both groups, 1 of the 3 tactical geometries yielded significantly longer response times than the others (a "tactic" effect). In Exp II, the influence of decision strategy on the tactic effect was evaluated in 18 22–52 yr old naive Ss. Control of strategy through instruction and order of problem presentation did not reduce the tactic effect but did interact with the directional bias related to target motion. The tactic effect is discussed in terms of directional incongruity among displayed and inferred stimulus elements. Implications for training are discussed. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)