Prediction of Transarterial Chemoembolization (TACE) - Outcome by pre- and postinterventional 13C-Methacetin breath test

BACKGROUND: Liver function is one of the most important parameters for the outcome of transarterial chemoembolization (TACE). The Liver Maximum Capacity (LiMAx) -Test is a bedside test that provides a real-time option for liver function testing. The objective of this pilot study is to investigate the suitability of the LiMAX test for estimating the TACE outcome. OBJECTIVE AND METHODS: 20 patients with intermediate-stage hepatocellular carcinoma (HCC) received a LiMAx test 24 h pre and post TACE. In addition, laboratory values were collected to determine liver function and model for endstage liver disease (MELD) scores. The success of TACE was assessed 6 weeks post intervention by morphological imaging tests using modified response evaluation criteria in solid tumors (mRECIST). RESULTS: Patients with an objective response (OR = CR + PR) according to mRECIST post TACE have significantly higher values in the pre-interventional LiMAx test than patients with a non-OR (PD or SD) post TACE (rb(14) = 0.62, p = 0.01). Higher pre-interventional LiMAx values therefore indicate OR. Patients with a disease control (DC = CR + PR + SD) according to mRECIST post TACE have significantly higher values in the pre-interventional LiMAx test than patients with a non-DC (PD) post TACE (rb(14) = 0.65, p = 0.01). Higher pre-interventional LiMAx values therefore indicate DC. The bi-serial correlations of LiMAx values pre and post TACE with the outcome OR or DC are descriptively stronger than those of MELD with OR or DC. This suggests that the LiMAx test correlates better with the treatment response than the MELD score. CONCLUSIONS: For the first time, we were able to show in our study that patients who are scheduled for TACE could benefit from a LiMAx test to be able to estimate the benefit of TACE. The higher the pre-interventional LiMAx values, the higher the benefit of TACE. On the other hand, laboratory parameters summarized in the form of the MELD score, had significantly less descriptive correlation with the TACE outcome.

Identifying Actionable Serial Correlations in Financial Markets

Financial markets are complex systems where information processing occurs at multiple levels. One signature of this information processing is the existence of recurrent sequences. In this paper, we developed a procedure for finding these sequences and a process of statistical significance testing to identify the most meaningful ones. To do so, we downloaded daily closing prices of the Dow Jones Industrial Average component stocks, as well as various assets like stock market indices, United States government bonds, precious metals, commodities, oil and gas, and foreign exchange. We mapped each financial instrument to a letter and their upward movements to words, before testing the frequencies of these words against a null model obtained by reshuffling the empirical time series. We then identify market leaders and followers from the statistically significant words in different cross sections of financial instruments, and interpret actionable trends that can be traded upon.

Robust and distributed neural representation of action values

Studies in rats, monkeys, and humans have found action-value signals in multiple regions of the brain. These findings suggest that action-value signals encoded in these brain structures bias choices toward higher expected rewards. However, previous estimates of action-value signals might have been inflated by serial correlations in neural activity and also by activity related to other decision variables. Here, we applied several statistical tests based on permutation and surrogate data to analyze neural activity recorded from the striatum, frontal cortex, and hippocampus. The results show that previously identified action-value signals in these brain areas cannot be entirely accounted for by concurrent serial correlations in neural activity and action value. We also found that neural activity related to action value is intermixed with signals related to other decision variables. Our findings provide strong evidence for broadly distributed neural signals related to action value throughout the brain.

The OHIP-EDENT B&H Questionnaire: Translation and Psychometric Properties in Treatment of Acrylic Complete Denture Wearers

Objectives. The OHIP-EDENT (the OHIP-EDENT B&H) translated from the original English language version was assessed in complete denture wearers before and after new denture manufacture and adjustments.Materials and Methods. A total of 117 acrylic complete denture wearers participated. The convergent validity was assessed by calculating point bi-serial correlations between the OHIP-EDENT Summary scores and the quality old dentures. Responsiveness was assessed by comparison of Summary score before (old dentures) and after adjustments of new dentures. Results. Cronbach alpha coefficient was 0.80 in the patients with their old dentures and 0.76 in same patients after receiving new dentures and all adjustments provided. Convergent validity coefficients varied between 0.491 and 0.548. Responsiveness was confirmed by significantly lower scores of the OHIP-EDENT B&H after new denture delivery and adjustments, both for Summary scores (p=0.027), as well as for the domains of functional limitation (p=0.02), psychological discomfort (p=0.01), physical pain (p=0.003), and handicap (p=0.04). Conclusions. The translated version of the OHIP-EDENT B&H showed good psychometric properties. Clinical Relevance. Clinical significance of the application of the OHIP-EDENT B&H questionnaire is in the reflection of the achieved success in the therapy by acrylic complete dentures after corrections of teeth and denture surfaces at recalls.

Complexity of Forces Driving Trend of Reference Evapotranspiration and Signals of Climate Change

Understanding the trends of reference evapotranspiration (ETo) and its influential meteorological variables due to climate change is required for studying the hydrological cycle, vegetation restoration, and regional agricultural production. Although several studies have evaluated these trends, they suffer from a number of drawbacks: (1) they used data series of less than 50 years; (2) they evaluated the individual impact of a few climatic variables on ETo, and thus could not represent the interactive effects of all forces driving trends of ETo; (3) they mostly studied trends of ETo and meteorological variables in similar climate regions; (4) they often did not eliminate the impact of serial correlations on the trends of ETo and meteorological variables; and finally (5) they did not study the extremum values of meteorological variables and ETo. This study overcame the abovementioned shortcomings by (1) analyzing the 50-year (1961–2010) annual trends of ETo and 12 meteorological variables from 18 study sites in contrasting climate types in Iran, (2) removing the effect of serial correlations on the trends analysis via the trend-free pre-whitening approach, (3) determining the most important meteorological variables that control the variations of ETo, and (4) evaluating the coincidence of annual extremum values of meteorological variables and ETo. The results showed that ETo and several meteorological variables (namely wind speed, vapor pressure deficit, cloudy days, minimum relative humidity, and mean, maximum and minimum air temperature) had significant trends at the confidence level of 95% in more than 50% of the study sites. These significant trends were indicative of climate change in many regions of Iran. It was also found that the wind speed (WS) had the most significant influence on the trend of ETo in most of the study sites, especially in the years with extremum values of ETo. In 83.3% of the study sites (i.e., all arid, Mediterranean and humid regions and 66.7% of semiarid regions), both ETo and WS reached their extremum values in the same year. The significant changes in ETo due to WS and other meteorological variables have made it necessary to optimize cropping patterns in Iran.

Behaviour of Stock Returns in the KLSE: A Test of the Random Walk Hypothesis

A sample of 224 companies listed in the Kuala Lumpur Stock Exchange was taken for the period 1991-96. The serial correlations tests of varying lags and the runs tests were employed to test for the random walk theory. The bulk of the results tilts towards the rejection of non-randomness, lending weight to the argument that the stock market has no memory, and casting doubt upon the usefulness of technical analysis.

Mice tune out not in: violation of prediction drives auditory saliency

Successful navigation in complex acoustic scenes requires focusing on relevant sounds while ignoring irrelevant distractors. It has been argued that the ability to track stimulus statistics and generate predictions supports the choice of what to attend and what to ignore. However, the role of these predictions about future auditory events in drafting decisions remains elusive. While most psychophysical studies in humans indicate that expected stimuli are more easily detected, most work studying physiological auditory processing in animals highlights the detection of unexpected, surprising stimuli. Here, we tested whether in the mouse, high target probability results in enhanced detectability or whether detection is biased towards low-probability deviants using an auditory detection task. We implemented a probabilistic choice model to investigate whether a possible dependence on stimulus statistics arises from short-term serial correlations or from integration over longer periods. Our results demonstrate that target detectability in mice decreases with increasing probability, contrary to humans. We suggest that mice indeed track probability over a timescale of at least several minutes but do not use this information in the same way as humans do: instead of maximizing reward by focusing on high-probability targets, the saliency of a target is determined by surprise.