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This paper addresses the feasibility of using innovative vacuum infused anionic polyamide-6 (PA-6) thermoplastic composites for MW-size wind turbine blades structures. To compare the performance of this fully recyclable material against commonly used less sustainable thermoset blade materials in a baseline structural MW-size blade configuration (box-spar/skins), four different blade composite material options were investigated: Glass/epoxy, carbon/epoxy, glass/PA-6, and carbon/PA-6. Blade characteristics such as weight, costs, and natural frequencies were compared for rotor blades ranging between 32.5 and 75 m in length, designed according to both stress and tip deflection criteria. Results showed that the PA-6 blades have similar weights and natural frequencies when compared to their epoxy counterpart. For glass fiber blades, a 10% reduction in material cost can be expected when using PA-6 rather than epoxy while carbon fiber blades costs were found to be similar. Considering manufacturing, processing temperatures of PA-6 are significantly higher than for epoxy systems; however, the associated cost increase is expected to be compensated for by a reduction in infusion and curing time. [DOI: 10.1115/1.2037107] Keywords: Wind turbine blade, Thermoplastic composites, Vacuum infusion

Background: Cognitive impairment is a frequent feature of COPD. However, the proportion of patients with COPD with mild cognitive impairment (MCI) is still unknown, and no screening test has been validated to date for detecting MCI in this population. The goal of this study was to determine the frequency and subtypes of MCI in patients with COPD and to assess the validity of two cognitive screening tests, the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA), in detecting MCI in patients with COPD.Methods: Forty-five patients with moderate to severe COPD and 50 healthy control subjects underwent a comprehensive neuropsychologic assessment using standard MCI criteria. Receiver operating characteristic curves were obtained to assess the validity of the MMSE and the MoCA to detect MCI in patients with COPD.Results: MCI was found in 36% of patients with COPD compared with 12% of healthy subjects. Patients with COPD with MCI had mainly the nonamnestic MCI single domain subtype with predominant attention and executive dysfunctions. The optimal MoCA screening cutoff was 26 (≤ 25 indicates impairment, with 81% sensitivity, 72% specificity, and 76% correctly diagnosed). No MMSE cutoff had acceptable validity.Conclusions: In this preliminary study, a substantial proportion of patients with COPD were found to have MCI, a known risk factor for dementia. Longitudinal follow-up on these patients is needed to determine the risk of developing more severe cognitive and functional impairments. Moreover, the MoCA is superior to the MMSE in detecting MCI in patients with COPD. [ABSTRACT FROM AUTHOR]

In this article, pulsed micro-laser line thermography (pulsed micro-LLT) was used to detect the submillimeter porosities in a 3D preformed carbon fiber reinforced polymer composite specimen. X-ray microcomputed tomography was used to verify the thermographic results. Then, finite element analysis was performed on the corresponding models on the basis of the experimental results. The same infrared image processing techniques were used for the experimental and simulation results for comparative purposes. Finally, a comparison of experimental and simulation postprocessing results was conducted. In addition, an analysis of probability of detection was performed to evaluate the detection capability of pulsed micro-LLT on submillimeter porosity.

Background/aims: Mild cognitive impairment (MCI) is frequent in Parkinson's disease (PD) and idiopathic REM sleep behavior disorder (iRBD). However, only a few studies have evaluated the validity of brief cognitive measures to detect MCI in PD or iRBD using standard diagnostic criteria for MCI. Our aim was to evaluate the validity of the Mini-Mental State Examination (MMSE) and the Mattis Dementia Rating Scale (DRS-2) to detect MCI in PD and iRBD., Methods: Forty PD patients and 34 iRBD patients were studied. Receiver operating characteristic curves were created for both tests to assess their effectiveness in identifying MCI in PD and iRBD., Results: In PD, a normality cutoff of 138 on the DRS-2 yielded the best balance between sensitivity (72%) and specificity (86%) with a correct classification of 80%. In iRBD, the optimal normality cutoff was 141 on the DRS-2, with a sensitivity of 90%, a specificity of 71% and a correct classification of 82%. No cutoff for the MMSE was found to have acceptable sensitivity or specificity., Conclusion: The DRS-2 has satisfactory validity to detect MCI in PD or iRBD. The MMSE proved to be invalid as a screening test for MCI in both populations., (Copyright © 2011 S. Karger AG, Basel.)

This study assessed the effects of an aerobic training program on reaction time tasks that manipulated preparatory intervals (PI) to produce temporal preparation effects using short (1, 3, 5 s) and long (5, 7, 9 s) PI. Older adults were assigned to either a 3-month aerobic training group or to a control group. Individuals in the training group participated in an aerobic training program of three 60-min sessions per week. The control group did not receive any training. Results indicated that 12 weeks of aerobic training induced a significant improvement in cardiorespiratory capacity (VO(2)max estimate). All participants who completed the aerobic program showed improvement after training in the choice RT task, along with enhanced preparation, such that they maintained preparation over time more efficiently after the training program. Moreover, enhanced ability to use the short PI was observed but only in lower fit individuals. Results of the present study suggest that improving aerobic fitness may enhance attentional control mechanisms in older adults.

Mild cognitive impairment (MCI) is a frequent feature in idiopathic REM sleep behavior disorder (RBD), a sleep disturbance that can be a preclinical stage of Parkinson's disease or Lewy body dementia. We evaluated the sensitivity and specificity of two brief screening tools, the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE), in detecting MCI in idiopathic RBD. Thirty-eight idiopathic RBD patients underwent a comprehensive neuropsychological assessment, including the MoCA and the MMSE. Receiver operating characteristic curves were created for the MoCA and the MMSE to assess their ability to identify MCI in idiopathic RBD patients, with neuropsychological assessment as the gold standard. For the MoCA, a normality cutoff of 26 yielded the best balance between sensitivity (76%) and specificity (85%) with a correct classification of 79%. For the MMSE, the optimal normality cutoff was 30, with a sensitivity of 84% and a specificity of 54% and a correct classification of 74%. The MoCA is superior to the MMSE in detecting MCI in idiopathic RBD patients, showing good sensitivity and very good specificity., ((c) 2010 Movement Disorder Society.)

Early studies found that electroencephalographic (EEG) recordings during somnambulistic episodes were characterized by a combination of alpha, theta, and delta frequencies, without evidence of clear wakefulness. Three postarousal EEG patterns associated with slow-wave sleep (SWS) arousals were recently identified in adults with sleepwalking and sleep terrors. The goal of the present study was to evaluate the distribution of these postarousal EEG patterns in 10 somnambulistic patients (three males, seven females, mean age: 25.1, SD: 4.1) evaluated at baseline and following 38 h of sleep deprivation. A total of 44 behavioral arousals were recorded in the laboratory; seven episodes at baseline (five from SWS, two from stage 2 sleep) and 37 episodes during recovery sleep (30 from SWS, seven from stage 2 sleep). There was no significant difference in the distribution of postarousal EEG patterns identified during baseline and recovery sleep. One pattern, comprised of diffuse rhythmic and synchronous delta activity, was preferentially associated with relatively simple behavioral episodes but did not occur during episodes from stage 2 sleep. Overall, delta activity was detected in 48% of the behavioral episodes from SWS and in 22% of those from stage 2. There was no evidence of complete awakening during any of the episodes. The results support the view of somnambulism as a disorder of arousal and suggest that sleepwalkers' atypical arousal reactions can manifest themselves in stage 2 sleep in addition to SWS.

During wakefulness, the cerebral cortex, which is responsible for generating mental activities, is activated by brain stem ascending influences. This is evidenced by classic electrophysiological field and unitary activities, gamma range activity and cortical blood flow. However, aminergic ascending neurons exert mainly diffuse inhibitory influences. These two kinds of influences together support reflective and rational psychological activities. During slow wave sleep, both kinds of ascending influences decrease and the mental content comprises low-intensity thought-like activities, similar to the waking mode of functioning, although dreams have been described. During rapid eye movement sleep, the principal dreaming stage, the cortex is activated but significantly disinhibited since all aminergic neurons are silent except the dopaminergic ones. We hypothesize that, in addition to this unusual state, the persistent release of dopamine associated with the specific silence of noradrenergic neurons could explain the characteristics of dream mental activity which are somewhat similar to psychotic symptoms.

This study assessed a proposed sleep-preserving role for sleep spindles by evaluating variations in this activity as a function of factors, both naturally occurring and experimentally induced, known to affect and effect arousal from sleep. These factors included age, auditory stimulation, and experimentally induced arousal from sleep. Analyses were based on data from 84 males (5-49 yrs. old) from normal and clinical (hyperactive, enuretic, and chronic pain) populations who had participated in sleep auditory arousal threshold studies involving adaptation and 1-2 experimental nights. Spindles on experimental nights were visually analyzed and incidence determined for the two minutes preceding and throughout all Stage 2 arousal attempts. Prestimulation spindle occurrence in 39 preadolescent subjects with two experimental nights did not vary significantly from night-to-night, and prestimulation period comparisons between clinical groups and their respective controls were also non-significant. Anticipated relationships between spindle activity and indices of arousal-either inverse with respect to known variations in arousal threshold, i.e., decreases with age and across the night, or direct with respect to stimulus intensity particularly on trials when arousal did not occur-were not observed. Instead, all age groups showed significant decreases in spindle density as an increasing negative function of stimulus intensity. These findings suggest that to the extent to which sleep spindles can be considered to play a role in sleep preservation by inhibiting or attenuating potentially arousing stimuli, these effects appear to be restricted to endogenously generated stimuli and are passive rather than reactive in nature.