Hybrid threshold optimization between global image and local regions in image segmentation for melasma severity assessment

Melasma image segmentation plays a fundamental role for computerized melasma severity assessment. A method of hybrid threshold optimization between a given image and its local regions is proposed and used for melasma image segmentation. An analytic optimal hybrid threshold solution is obtained by minimizing the deviation between the given image and its segmented outcome. This optimal hybrid threshold comprises both local and global information around image pixels and is used to develop an optimal hybrid thresholding segmentation method. The developed method is firstly evaluated based on synthetic images and subsequently used for melasma segmentation and severity assessment. Statistical evaluations of experimental results based on real-world melasma images show that the proposed method outperforms other state-of-the-art thresholding segmentation methods for melasma severity assessment.     

Street racing video games and risk-taking driving: An Internet survey of automobile enthusiasts

Purpose

The purpose of this study was to examine the relationships among risky driving attitudes, self-perceptions as a risky driver, playing of “drive’em up” (which rewarded players for frequent traffic and other violations) and “circuit” racing video games as well as self-reported risky driving through a web-based survey of car and racing club members in relation to a socio-cognitive model of the effects of racing video game playing.

Method

An Internet questionnaire was developed and included: (1) self-perceptions as a risky driver scales (Driver Thrill Seeking and Competitive Attitude Toward Driving); (2) attitudes regarding street racing; (3) street racing video game playing, and (4) self-reported risky driving (Risk-Taking Driving Scale). A sequential logistic regression was performed entering age and driving exposure as control variables in the first block, self-perceptions as a risky driver in the second block, attitudes in the third block and playing “drive’em up” and “circuit” racing games in the last block to examine their effects on self-reported risk-taking driving.

Results

A total of 503 survey respondents were included in the analyses and only 20% reported any risk-taking driving. Higher score on the Competitive Attitude Toward Driving Scale, more positive attitudes toward street racing, and more frequent reported playing of “drive’em up” video games were associated with higher odds on the self-reported Risk-Taking Driving Scale. However, the Driver Thrill Seeking Scale and “circuit” video game playing failed to predict self-reported risk-taking driving.

Conclusions

Self-perceptions as a risky driver, positive attitudes toward risky driving and “drive’em up” street-racing games, but not “circuit” racing games, are associated with increased risk-taking driving. These findings are congruent with experimental studies in which games that reward driving violations increased risk taking, suggesting that risk taking may be a function of type of street racing game played by affecting self-perceptions as a risky driver.     

The effects of health status, distress, alcohol and medicinal drug use on subsequent motor vehicle injuries

Objective

The purpose of this study was to examine the effects of health factors and substance use on subsequent motor vehicle collision (MVC) injuries of three different age groups, using the longitudinal dataset from the Canadian National Population Health Survey (NPHS) for the years 1994–2002.

Methods

Path analysis technique was used to determine the relations between MVC injury and four risk factors: binge drinking; health status; distress; and medication use. The three demographic variables, age at ‘baseline’, sex, and immigration status were added into the model as control variables. Three age groups were examined: young = 12–29.9; middle-aged = 30–59.9 and old = 60–85 years of age. The total sample size was 16,093.

Results

A lower percentage of males, older persons, immigrants, and non-binge drinkers reported a subsequent MVC injury, as did respondents reporting better health and lower distress scores. Medication use was associated with higher subsequent MVC injuries. Path analysis found that among younger individuals, the variable binge drinking, was the only significant risk factor associated with subsequent injuries. In contrast, among middle-aged individuals, the variable medication use, was the only statistically significant risk factor for subsequent injuries. No variables were significant risk factors of injuries for older individuals.

Conclusions

Various demographic and risk factors were found to influence injuries among a nationally representative sample of Canadians. Reported binge drinking among young individuals and medication use among middle-aged individuals were found to be risk factors for subsequent MVC injury. These findings support the need for continued focus on alcohol, drugs and traffic safety.     

Winged bean lipoxygenase—Part 1: Isolation and purification

Lipoxygenase was isolated and purified from dried winged bean seeds by ammonium sulphate fractionation, gel filtration, DEAE-Sephadex ion exchange chromatography and hydroxyapatite chromatography. Two major isoenzymes, FI and FII, were separated by ion exchange chromatography and were further purified by elution through a hydroxyapatite column. These resulted in a 105- and 171-fold purification and 7% and 9% recovery for FI and FII, respectively. FI and FII had similar Rf values of 0.25 on polyacrylamide gel electrophoresis. A minor band of Rf 0.01 was detected in ammonium sulphate fractions but was not further enriched and purified in succeeding steps.     

Cognitive stimulation in brainstorming.

Research on group brainstorming has demonstrated that it is less effective for generating large numbers of ideas than individual brainstorming, yet various scholars have presumed that group idea sharing should enhance cognitive stimulation and idea production. Three experiments examined the potential of cognitive stimulation in brainstorming. Experiments 1 and 2 used a paradigm in which individuals were exposed to ideas on audiotape as they were brainstorming, and Experiment 3 used the electronic brainstorming paradigm. Evidence was obtained for enhanced idea generation both during and after idea exposure. The attentional set of the participant and the content of the exposure manipulation (number of ideas, presence of irrelevant information) influenced this effect. These results are consistent with a cognitive perspective on group brainstorming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Trance-susceptibility, induction-susceptibility, and acquiescence as factors in hypnotic performance.

Scores from 103 Ss on a 60-item inventory of attitudes and experiences outside of hypnosis, called the Hypnotic Characteristics Inventory along with sum-true scores on an abbreviated form of the MMPI, and interviewer predictions, were entered into a correlational matrix together with later-obtained hypnotic susceptibility scores derived from Stanford Hypnotic Suggestibility Scale Forms A and C. The matrix was factor-analyzed and rotated to a hypothetical structure. Hypnotic susceptibility was characterized by 2 oblique factors, 1 termed trance-susceptibility, the other induction-susceptibility. Questionnaire measures, which were found compounded with an acquiescence tendency, were correlated with trance-susceptibility but not induction-susceptibility, indicating a limitation in hypnotic prediction from questionnaires. (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)