Physiological indices of workload in a simulated flight task

The sensitivity of physiological measures to evaluate workload was investigated in a simulated flight task. Heart rate, blood pressure (from beat to beat), respiration and eye blinks were recorded in 14 subjects while they performed a complex task in a flight simulator. Workload was manipulated by introducing an additional task and by varying the task difficulty of segments of the flight scenarios. Heart rate and blood pressure were both affected by the different levels of task difficulty. Heart-rate variability was found to be confounded by respiration. Slow respiratory activity contributed considerably to heart rate variability, especially after periods of high workload (for example, after landing). The gain between blood-pressure and heart-rate variability (modulus) was sensitive to mental effort and was not influences by respiration. Eye blinks, in particular the duration, were specifically affected by the visual demands of the task and not by the workload in general. When subjects had to process visual information, the number and duration of blinks decreased.     

Electrophysiological, behavioral, and subjective indexes of workload when performing multiple tasks: manipulations of task difficulty and training

This study examined whether alpha event-related desynchronization (ERD) and theta event-related synchronization (ERS) could successfully measure changes in cognitive workload and training while an operator was engaged in a continuous, interactive, control task(s). Alpha 1 (8-10 Hz) ERD, alpha 2 (10-12 Hz) ERD, and theta (3-7 Hz) ERS were determined for a communications event that occurred during multiple task workload conditions or as a single task. Other measures (alpha and theta EEG power, heart rate, respiration, eye blinks, behavioral performance, and subjective workload ratings) were also evaluated. Results showed that alpha 2 EEG, heart rate, behavioral, and subjective measures were sensitive to changes in workload in the multiple tasks. In addition, eye blink rate and behavioral measures were sensitive to training. Alpha ERD and theta ERS were not sensitive to workload and training in our interactive, multiple task environment. However, they were effective indexes of cognitive/behavioral demands within an interactive single task.     

Attentional bias is associated with incentive-related physiological and subjective measures.

Drug cue reactivity is theoretically and clinically important. The modified Stroop task has been widely used to assess attention capture by drug cues (attentional bias). Attentional bias to drug cues is assumed to reflect the incentive value of those cues, but this has not been directly tested. The authors examined whether the smoking Stroop effect was associated with facial electromyography (EMG) assessed in real time. Heart-rate (HR) and skin conductance (SC) responses were also assessed. Smokers (n = 79) attended up to four experimental sessions. Presession Abstinence state and within-session Smoking were manipulated across sessions. Over all assessments, participants exhibited a robust smoking Stroop effect. Using Generalized Estimating Equations (GEE) analyses, the smoking Stroop effect was positively associated with zygomaticus major activity but not with corrugator supercilii activity, HR, or SC. The smoking Stroop effect was also positively associated with self-reported positive outcome expectancies from smoking and with craving. In sum, attentional bias was more strongly associated with appetitive responses (zygomaticus major activity, positive outcome expectancies) than with withdrawal responses (e.g., corrugator supercilii activity) or measures of physiological arousal (e.g., HR, SC). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physiological and subjective effects of Zen meditation and demand characteristics.

Undergraduates studied a Zen meditation exercise under 3 demand conditions: deactivation (modeling and suggesting relaxation outcome), neutral (no specific outcome), and activation (arousal outcome). Results show that Zen meditation produces small physiological changes in naive, unpracticed Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Objective compared with subjective measures of the same behavior in groups.

"Discussion behavior was measured objectively by a social analog computer, while subjective assessments were made by observers and participants aided by a check list… . There tended to be agreement between the two different methods of measurement… . Observers and participants had difficulty in inferring private events that took place during the discussion. The difficulty of rating private events suggests that observers' ratings are most appropriate for overt events. Yet the successful study of covert events require reliance on objective measurement." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physiological measures and the detection of deception.

Evaluates laboratory research on physiological measures for detecting deception. The general problems encountered in making inferences about truth and deception from physiological recordings are described, and various methods for designing tests of deception are explained and evaluated in light of these problems. It is concluded that a number of cardiovascular, electrodermal, and respiratory measures have been shown to be effective in discriminating between truth and deception. Other promising measures are identified, along with suggestions for conducting laboratory research that will be maximally generalizable to field applications of detection of deception. (66 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An evaluation of subjective and objective measures of fatigue in patients with brain injury and healthy controls

Bioactive peptides of different sources and biological functionalities, like endothelins, sarafotoxins, bee and scorpion venom toxins, contain a consensus cystine framework, Cys-(X)1-Cys/Cys-(X)3-Cys, which has been found to induce and stabilize a homologous folding motif named the cystine-stabilized alpha-helix (CSH). This is composed of an alpha-helical segment spanning the Cys-(X)3-Cys sequence portion that is crosslinked by two disulfide bridges to the sequence portion Cys-(X)1-Cys, itself folded in an extended beta-strand type structure. Search for sequence homologies of peptides and proteins in the SWISS-PROT and PDB data banks provided additional multiple examples of this type of cystine framework in serine proteinase inhibitors, in insect and plant defense proteins, as well as in members of the growth factor family with the cystine-knot. A comparative analysis of the known 3D-structures of these peptides and proteins confirmed that the presence of this peculiar cystine framework leads in all cases to a high degree of local structural homology that consists of the CSH motif, except for the cystine-knot, of the superfamily of the growth factors. In this case the cyclic structure formed by the parallel cysteine connectivities of Cys-(X)1-Cys/Cys-(X)3-Cys framework is penetrated by a third disulfide bond with formation of a concatenated knot, and the two disulfide-bridged peptide chains Cys-(X)1-Cys and Cys-(X)3-Cys are located in beta-strands. Conversely, peptides and proteins containing Cys-(X)m-Cys/Cys-(X)n-Cys cystine frameworks that differ from m/n = 1/3 were found to fold only sporadically into local alpha-helical structures.     

Relationships between subjective ratings and objective measures of performance in speechreading sentences

Ninety-six participants with normal hearing and 63 with severe-to-profound hearing impairment viewed 100 CID Sentences (Davis & Silverman, 1970) and 100 B-E Sentences (Bernstein & Eberhardt, 1986b). Objective measures included words correct, phonemes correct, and visual-phonetic distance between the stimulus and response. Subjective ratings were made on a 7-point confidence scale. Magnitude of validity coefficients ranged from .34 to .76 across materials, measures, and groups. Participants with hearing impairment had higher levels of objective performance, higher subjective ratings, and higher validity coefficients, although there were large individual differences. Regression analyses revealed that subjective ratings are predictable from stimulus length, response length, and objective performance. The ability of speechreaders to make valid performance evaluations was interpreted in terms of contemporary word recognition models.     

Objective sleep measures and subjective sleep satisfaction: How do older adults with insomnia define a good night's sleep?

The relationship between objective sleep measures and subjective sleep satisfaction was explored in a sample of 47 older adults (59 years and older; 35 women, 12 men) with primary insomnia. Participants submitted to all-night sleep evaluations (polysomnography) for 2 nights. After each night, participants provided subjective sleep-satisfaction ratings. Depth of sleep (decreased Stage 1 sleep and increased Stages 3 and 4 sleep) and sleep latency were the best predictors of subjective sleep satisfaction. For other sleep variables such as sleep efficiency and wake time after sleep onset, no value predicted satisfaction on a particular night. However, for these sleep variables, relative improvement from Night 1 to Night 2 predicted greater subjective satisfaction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physiological and subjective responses to thermal transients of exercising subjects dressed in cold-protective clothing

Intercellular adhesion molecules play an important role in the generation of T lymphocyte-mediated immune responses. Here, we describe a novel accessory molecule, DNAX accessory molecule-1 (DNAM-1), that is constitutively expressed on the majority of peripheral blood T lymphocytes. DNAM-1 is a 65 kDa transmembrane glycoprotein consisting of 318 aa including two immunoglobulin-like domains. Anti-DNAM-1 monoclonal antibody (MAb) inhibits T and NK cell-mediated cytotoxicity against a variety of tumor cell targets and blocks cytokine production by alloantigen-specific T cells. In addition, DNAM-1 is a tyrosine-phosphorylated signal-transducing molecule that participates in primary adhesion during cytotoxic T lymphocyte (CTL)-mediated cytotoxicity.     

Physiological responses of deer mice (Peromyscus maniculatus) to infection with Capillaria hepatica (Nematoda)

The plant hormone ethylene is generated from a unique precursor, 1-aminocyclopropane-1-carboxylate (ACC). In previous studies, ACC deaminase, which degrades ACC to alpha-ketobutyrate and ammonia, was found in four strains of Pseudomonas, characterized, and sequenced. To verify the wider distribution of ACC deaminase in microorganisms, we purified and sequenced ACC deaminase from the yeast Hansenula saturnus. The purified enzyme was active toward ACC, D-serine and dl-coronamic acid, indicating the same stereospecificity as the Pseudomonas enzyme, but unlike the bacterial enzyme it was not active toward beta-chloro-D-alanine and O-acetyl-D-serine. Analyses of peptides from proteolytic digests of the purified and modified ACC deaminase covered more than 90% of its amino acid sequence and showed a blocked N-terminal residue as N-acetylserine. A cDNA encoding the ACC deaminase was isolated from H. saturnus cells incubated in alpha-aminoisobutyrate medium, and sequenced. The yeast enzyme has 441 amino acid residues, of which 60 to 63% are identical to those of reported Pseudomonas enzymes. The open reading frame encoding ACC deaminase was subcloned into pET-11d and expressed in Escherichia coli BL21 (DE3) as an active enzyme.     

Onset of action of eformoterol by dry powder inhaler: objective and subjective measures

Fluorescence microscopy of caudal epididymal spermatozoa stained with 3, 3' dihexyloxacarbocyanine iodide (DiOC6(3)) showed intense fluorescence along the concave surface of the apical hook of spermatozoa of Rattus species and along the upper concave margin of the sperm head in Mus musculus. In the spermatozoa of Hydromys chrysogaster, Melomys cervinipes, and Pseudomys australis, the two ventral processes also fluoresced brightly. In P. australis, fluorescence in the apical hook of sperm heads was largely localized to its upper and lower surfaces. The sperm of N. alexis did not show consistent positive fluorescence. The localization of fluorescence in these spermatozoa after staining with DiOC6(3) was mainly restricted to regions where a large accumulation of perinuclear theca material lies beneath the plasmalemma. The reason for this remains to be determined, but DiOC6(3) may be useful for quickly demonstrating areas of abundant perinuclear thecal material in sperm heads of eutherian mammals by light microscopy.     

The place of xerography combined with routine conventional mammography (author's transl)

Xeroradiography is a valuable supplement to conventional mammography, especially in cases with dense glandular structure. In our patient material this new procedure was necessary for clarification of findings on conventional mammography in 16% of cases and improved diagnostic yield. Indirect and direct signs of carcinoma were more easely recognized with xeroradiography, since more detail is visualized because of greater latitude and edge contrast enhancement. Moreover the area visualized is considerably greater. The soft tissue structures can be seen to the level of the thoracic wall. Viewing the films is less tiring than reviewing conventional mammography films. A relatively greater exposure latitude and short exposure times are further advantages of this method.     

Energy expenditure and clearing snow: a comparison of shovel and snow pusher

In order to assess the energy demands of manual clearing of snow, nine men did snow clearing work for 15 min with a shovel and a snow pusher. The depth of the snowcover was 400-600 mm representing a very heavy snowfall. Heart rate (HR), oxygen consumption (VO2), pulmonary ventilation (VE), respiratory exchange ratio (R), and rating of perceived exertion (RPE) were determined during the work tasks. HR, VE, R, and RPE were not significantly different between the shovel and snow pusher. HR averaged (+/- SD) 141 +/- 20 b min-1 with the shovel, and 142 +/- 19 beats.min-1 with the snow pusher. VO2 was 2.1 +/- 0.41.min-1 (63 +/- 12%VO2 max) in shovelling and 2.6 +/- 0.51.min-1 (75 +/- 14%VO2max) in snow pushing (p < 0.001). In conclusion manual clearing of snow in conditions representing heavy snowfalls was found to be strenuous physical work, not suitable for persons with cardiac risk factors, but which may serve as a mode of physical training in healthy adults.     

Synthetic library techniques: subjective (biased and generic) thoughts and views

Various aspects of synthetic diversity generation and screening are discussed. Controversial issues are raised and different points of view are presented. We hope the article will stimulate thinking about the utilization of library techniques and start a discussion about questions concerning their application.     

The safety of pramoxine hydrochloride when used as a topical (surface) anesthetic

The correct diagnosis of pathological lesions of endodontic origin should allow for differentiation from those arising from other sources. A case of periapical cemental dysplasia (cementoma) is presented, whereby incorrect diagnosis resulted in not only inappropriate treatment, but an endodontic mishap and the superimposition of acute apical periodontitis in a previously disease-free site. This case report highlights the need for appropriate examination, simple special tests and diagnosis prior to management of lesions of questionable aetiology.     

Classification of black-pigmented anaerobes by pyrolysis mass spectrometry (PMS) and conventional tests (CTs)

Clinical (66: dental 53; vaginal 4; wound 9) and reference (5*) strains of pigmented Gram-negative anaerobic bacilli were examined in pyrolysis mass spectrometry (PMS) and conventional tests (CTs). The strains were identified in CTs as: Prevotella intermedia (48*); Pr. melaninogenica (1); Pr. corporis (7); Porphyromonas asaccharolytica (12*); P. endodontalis (1*) and P. gingivalis (2*). Numerical classification based on CTs resolved five clusters comprising strains identified as (I) Pr. corporis, (II) Pr. melaninogenica, (III) Pr. intermedia, (IV) P. gingivalis and (V) P. asaccharolytica and P. endodontalis. Numerical classification based on PMS showed a similar division, with decreasing homogeneity in the order Pr. intermedia, Pr. corporis, P. asaccharolytica, in agreement with the ordering of homogeneity for these species in CTs. PMS clusters corresponding the Porphyromonas spp. were clearly distinct from those of Prevotella spp. PMS and CT classifications disagreed on cluster membership for only six of the strains. PMS identification from blind challenge sets agreed with conventional identification for 64 of 67 strains.