Conversational discourse abilities following severe traumatic brain injury: a follow-up study

The major aim of this study was to describe the conversational abilities of a group of severely injured TBI speakers, at a minimum of 2 years post-injury. The association between conversational impairment and (a) selected measures of executive function and (b) psychosocial handicap was also examined. Twenty-four members of the group of 26 severely injured TBI speakers who had initially been assessed between 3 and 6 months post-injury were reviewed at a minimum of 2 years post-injury (mean = 2 years, 10 months). At initial assessment, TBI speakers were compared with non-TBI orthopaedic patients and with a group of university students. At follow-up, however, they were compared only with the orthopaedic patients. Conversational assessment was carried out using a modified form of Damico's Clinical Discourse Analysis. As a group, the TBI speakers' conversational abilities did not improve over time. There was, however, a subgroup (n = 8) of speakers who did improve, and these could be distinguished by greater initial severity of injury and a significantly longer period of speech-language pathology intervention than the speakers who either remained the same or worsened over time. Modest associations between conversational discourse skills and measures of executive function and a measure of psychosocial handicap were identified. These findings indicate that disruptions in conversation persist into the longer term. More assiduous efforts may need to be made to (a) identify subtle discourse changes in the early months after injury and (b) engage TBI speakers in speech-language pathology services. Such services are also required over a longer time frame, in community-based models of service provision.     

An integrated maritime surveillance system based on high-frequencysurface-wave radars. 2. Operational status and system performance

For pt.1 see ibid., vol.43, no.4, p.28-43 (2001). An integrated maritime surveillance (IMS) system, based on high-frequency surface wave radars (HFSWR), for monitoring surface and low-level air activity within the 200 nautical mile (nm) Exclusive Economic Zone (EEZ) is described in this two-part paper. The science behind the long-range performance of HFSWR was presented in Part 1(Sevgi et al. 2001). The system described was installed on Canada's east coast, where it is being used to demonstrate continuous, all-weather surveillance of the EEZ to beyond 200 nm. The system consists of two land-based HFSWRs and an operations control center (OCC). The two unmanned radars provide coverage of the Grand Banks region of Newfoundland, renowned for its offshore resources, particularly fish and oil. The system has been designed to assist authorities to more efficiently monitor such illegal activities as drug trafficking, smuggling, piracy, illicit fishing and illegal immigration. In addition, the system may be used for tracking icebergs, environmental protection, search and rescue, resource protection, sovereignty monitoring, and remote sensing of ocean surface currents and winds. Extensive performance testing of the system has been conducted using the two fully functional radars. It is shown that the HFSWR system complements existing surveillance assets to dramatically increase the effectiveness of air and surface reconnaissance missions by vectoring them directly to targets of interest     

Selective attention deficits and subjective fatigue following traumatic brain injury.

The present study aimed to investigate the relationship between subjective fatigue and selective attention deficits following traumatic brain injury (TBI). Forty-six participants with mild-severe TBI and 46 healthy controls completed fatigue scales (Visual Analogue Scale--Fatigue, Fatigue Severity Scale [FSS] and Causes of Fatigue Questionnaire [COF]), and attentional measures including subtests from the Test of Everyday Attention, and the Complex Selective Attention Task (C-SAT). TBI participants reported greater fatigue on the FSS and COF, performed more slowly on attentional measures, and made more errors on the C-SAT. After controlling for anxiety and depression, fatigue was significantly correlated with performance only on the C-SAT. Findings suggest a relationship between subjective fatigue and impairment on tasks requiring higher order attentional processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impedance of a lead acid battery negative plate

An attempt is made to interpret the impedance, measured near to E°, of various negative lead acid battery plates in H₂SO₄.     

Assessment of driving after stroke--a pluridisciplinary task

The aim of the study was to analyze the assessment procedure and identify predictors for the team decision when assessing fitness to drive a car after stroke. The material used was a retrospective data set with 200 stroke clients from Queen Elisabeth's Foundation Mobility Centre at Banstead UK. Fifty-four percent of clients were considered fit to continue driving where 9% could resume driving after car adaptation and training. Important factors for the outcome were vision (acuity and field), neuropsychological functions (divided attention), and track and/or on road test (reaction time, anticipation, speed, and positioning). Cognitive impairment was the main problem in those who failed the driving test and judged not fit for continued driving. Car adaptation, mainly comprising infrared transmitted secondary controls together with automatic transmission was recommended in 35% of the cases. CONCLUSIONS: The contribution of different specialist groups appears to be necessary for an effective evaluation, but the assessment procedure can be done more cost-effectively by dividing it into two separate parts and removing certain subtests. The in-car track test is an important part of the assessment procedure with a high face validity and could in many cases make it unnecessary to perform in-traffic tests with unsafe drivers. Car adaptation is often necessary for a client with pronounced hemi-paresis and a full road test can for those only be performed after training the use of car controls.     

Factors contributing to attentional impairments after traumatic brain injury.

The aim of the present study was to investigate the contribution of impaired information processing speed and strategic control of attention to performance on attentional tasks after traumatic brain injury (TBI). Forty moderately to severely injured rehabilitation inpatients and 40 healthy controls completed a selection of attentional tasks. Slowed processing speed in the TBI group was identified on the Symbol Digit Modalities Test (SDMT), 2&7 Selective Attention Test (2&7), Selective Attention (SAT), and Four Choice Reaction Time (4CRT) tasks. Impaired working memory was evident on the Letter Number Sequencing (LNS) task. Structural equation modeling revealed that the group difference in RT on the complex SAT was accounted for by slowed speed of processing on the simple SAT, and not working memory. TBI participants made more errors and missed responses on the complex version of the SAT, suggesting impairment in some aspects of strategic control of attention, and appeared unable to benefit from the automatic condition of the 2&7 Test. There was little evidence of deficit on the Sustained Attention to Response Task (SART). The present study provides evidence for a significant contribution of slowed processing speed to impaired performance on attentional tasks after TBI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of age on long-term cognitive function after traumatic brain injury.

Objective: To examine the association of age and time postinjury with cognitive outcome 5–22 years following traumatic brain injury (TBI), in relation to matched uninjured controls. Methods: One hundred twelve participants with mild to very severe TBI, aged 16–81 years at the time of injury, were cognitively assessed on measures of processing speed and attention, verbal and visual memory, executive function, and working memory. Results were compared with those of 112 healthy controls individually matched for current age, gender, education, and estimated IQ. Results: Older injured individuals performed worse than did younger injured individuals across all cognitive domains, after controlling for the performance of controls. In relation to matched controls, long-time survivors performed disproportionately worse than did more recently injured individuals, irrespective of age. Conclusions: After maximum spontaneous recovery from TBI, poorer cognitive functioning appears to be associated with both older age at the time of injury and increased time postinjury. These findings have implications for prognosis, early treatment recommendations, and long-term issues of differential diagnosis and management planning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An integrated maritime surveillance system based on high-frequencysurface-wave radars. 1. Theoretical background and numerical simulations

An integrated maritime surveillance (IMS) system, based on high-frequency surface-wave radars (HFSWR), is described. IMS provides low-cost, 24-hour, real-time, over-the-horizon surveillance of large ocean areas, out to the 200 nautical mile Exclusive Economic Zone (EEZ). The system can be used to coordinate search and rescue operations, and to combat smuggling, drug trafficking, illegal dumping of pollutants, and other undesirable activities. The major challenges in using HFSWR are (i) operating within the crowded HF spectrum; and (ii) maintaining effective operation in high environmental noise, ocean clutter, ionospheric clutter and other undesirable sources of interferences. The system is outlined and these problems are addressed. Numerical simulation, as well as stochastic modeling, are presented to demonstrate the physics behind the system     

Analysis of cell types and mediator production from tissues around loosening joint implants

Quantitative immunophenotypic analysis of cell types present in peri-prosthetic tissue [pseudosynovial membrane (PSM)] from aseptically loose joint implants revealed considerable heterogeneity between tissues from different individuals. The monocyte/macrophage was the commonest leucocyte type; however, its proportion varied widely. T cells normally accounted for approximately 5% of cells, but in a few cases formed > 20% of cells. In all cases, there was a high ratio of CD4 to CD8 cells. PSM leucocytes were activated in most PSMs as judged by surface expression of CD23, CD25 and CD71. Analysis of the proportions of cell types in PSM, OA synovium and RA synovium revealed similarities between the different tissue types. The levels of IL-1, IL-6 and prostaglandin E produced by the PSM were correlated, but only IL-1 and IL-6 levels correlated with markers of the monocyte/macrophage lineage. This result suggests that prostaglandin E is produced in vivo by many PSM cell types.     

Acute sciatic neuropathy complicating living donor renal transplantation

The surface structures of the eggs of house fly (M. domestica vicina) were examined by SEM. A layer of membranaous structure with small holes in clusters covering the whole egg was seen. The membranous structure is supported by large amount of tissue masses of different sizes. The submembranous tissue is dotted with numerous concave-holes. A hatching crack with a layer of very thin and vulnerable membrane runs lengthwise across the concave surface of the egg.