Hydrogen-donating mechanism of rosmariquinone, an antioxidant found in rosemary

Rosmariquinone (RQ), an ortho-quinone diterpenoid found in rosemary, was shown to act as a hydrogen-donating antioxidant. The proposed mechanism is based on the isolation of the catechol intermediate arucadiol (AD) in methyl oleate test systems. AD was also observed in a bulk soybean oil oxidation experiment, which supports the observation that RQ is converted to AD during oxidation of the oil. Because AD was found in both light-induced oxidation and autoxidation test systems, the antioxidant mechanism proceeds in a similar manner. The antioxidant activities of RQ and AD were not significantly different in the autoxidation experiments, while AD was a significantly better (P<0.05) antioxidant than RQ in the light-induced oxidation.     

Perceived racism and cardiovascular reactivity and recovery to personally relevant stress.

This study evaluated cardiovascular responses (CVR) to an active speech task with blatantly discriminatory (BRC) versus neutral (NRC) stimuli and an anger recall task in a sample of Black men (N = 73; age 18 to 47). Diastolic blood pressure scores were higher for NRC versus BRC stimuli during anger recall (p = .05). Moreover, persons in the NRC group who perceived high levels of racism (vs. no racism or BRC group) during active speech showed larger increases in blood pressure across postspeech rest, anger recall, and subsequent rest (p = .03). The notable elevation in CVR in response to an ambiguous event extends current models of racism suggesting that subtle racism is a psychosocial stressor that erodes health through chronically elevated CVR. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A normal form approach to approximate input-output linearizationfor maximum phase nonlinear SISO systems

A control synthesis scheme is presented for nonlinear single-input-single-output systems which have completely unstable (antistable) zero dynamics. The approach is similar in spirit to linear approaches for nonminimum phase systems and involves the derivation of an input-output linearizing controller for a suitably-defined nonlinear minimum phase approximation to the original system. The linearizing controller achieves an approximately linear input-output response and internal stability     

Cortical Responses in Rats Predict Perceptual Sensitivities to Complex Sounds.

The common assumption that perceptual sensitivities are related to neural representations of sensory stimuli has seldom been directly demonstrated. The authors analyzed the similarity of spike trains evoked by complex sounds in the rat auditory cortex and related cortical responses to performance in an auditory task. Rats initially learned to identify 2 highly different periodic, frequency-modulated sounds and then were tested with increasingly similar sounds. Rats correctly classified most novel sounds; their accuracy was negatively correlated with acoustic similarity. Rats discriminated novel sounds with slower modulation more accurately than sounds with faster modulation. This asymmetry was consistent with similarities in cortical representations of the sounds, demonstrating that perceptual sensitivities to complex sounds can be predicted from the cortical responses they evoke. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of pulling rope wear and coefficient of friction forpipe-type cables

The coefficient of friction between the pulling rope and cable pipe for a high-pressure fluid-filled cable was determined in order to characterize the effects of pulling tension and sidewall pressure on this parameter. Pipe wear was also measured. The study found that variations in pulling tension were more strongly affected by pulling rope wear than pipe wear. The coefficient of friction of the pulling rope varied from 0.27 to 0.75. Pipe wear of 1.52 mm (60 mils) was measured during 430 m (1425 ft.) of pulls at 1414 kgf/m (950 lbs./ft.) sidewall pressure and 1.02 mm (40 mils) of wear was measured during 290 m (950 ft.) of pulls at 610 kgf/m (410 lbs./ft.) sidewall pressure     

Dynamic behaviour of anchors in cracked and uncracked concrete: a progress report

In early 1993, the US Nuclear Regulatory Commission began a research program at The University of Texas at Austin, dealing with the dynamic behavior of anchors in cracked and uncracked concrete. In this paper, the progress of that research program is reviewed. The test program is summarized, and work performed to date is reviewed, with emphasis on the dynamic and static behavior of single tensile anchors in uncracked concrete. General conclusions from that work are discussed, and future plans are presented.     

Modality effects in false recall and false recognition.

R. E. Smith and R. R. Hunt (1998) reported a dramatic reduction in false remembering in a list-learning paradigm by switching from auditory to visual presentation at study. The current authors replicated these modality effects in college students, using written recall and visual recognition tests but obtained smaller effects than those in Smith and Hunt's study. In contrast, no modality effect occurred on auditory recognition tests. Manipulating study and test modality within-subjects (Experiment 2) and between-subjects (Experiment 3) yielded similar results. It was also found that subjectss frequently judged critical nonstudied words as having been presented in the modality of their corresponding study lists. The authors concluded that subjects could retrieve distinctive information about a study list's presentation modality to reduce false remembering but only did so under certain conditions. The modality effect on false remembering is a function of both encoding and retrieval factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mind your own business! Longitudinal relations between perceived privacy invasion and adolescent-parent conflict.

Privacy coordination between adolescents and their parents is difficult, as adolescents’ changing roles require adjustments to expectations about family boundaries. Adolescents’ perceptions of privacy invasion likely provoke conflicts with parents, but higher levels of conflict may also foster invasion perceptions. This longitudinal study assessed relations between privacy invasion and conflict frequency among adolescents, mothers, and fathers (N = 309). Bidirectional relations were present; all reports showed that invasion provoked conflict in later adolescence, but the timing and direction of conflict-to-invasion relations differed between respondents and measurement waves. The findings suggest a functional role for conflict in adolescent-parent privacy negotiations, in that it both draws attention to discrepant expectations and provides youths with a means of directly managing perceived boundary violations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of linear programming in model predictive control

The linear programming formulations of model predictive control are known to exhibit degenerate solution behavior. In this work, a multi-parametric linear programming technique is utilized to analyze the control laws that are generated from various linear programming based MPC routines. These various routines explore a number of factors, including objective function selection and constraint handling on the control laws generated from LP based MPC. A single input single output system is used to demonstrate that the use of input velocity penalties, input blocking, and ∞-norm objective functions can limit or eliminate this undesirable behavior. Finally, a paper machine cross directional control problem is used to demonstrate the control laws generated from LP based MPC for a multivariable example.     

Processing Similarity Does Not Improve Metamemory: Evidence Against Transfer-Appropriate Monitoring.

The transfer-appropriate monitoring (TAM) hypothesis of metamemory predicts that judgment of learning (JOL) accuracy should improve when conditions during JOLs closely match conditions of the memory test. The authors devised 5 types of delayed JOLs for paired associates and varied them along with the type of memory test (cued recall or recognition). If the TAM hypothesis is correct, JOL and test type should interact to influence metamemory. Contrary to TAM, metamemory accuracy did not improve when JOL and test conditions matched but instead tended to vary according to whether the answer was apparent at time of JOL. Memory test scores and JOL magnitude were both greater when the correct target was evident during JOLs. Overall, the results are largely consistent with a monitoring retrieval view of delayed JOLs and do not support TAM as a viable account of JOL accuracy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)