System design and user evaluation of Co-Star: An immersive stereoscopic system for cable harness design

The system design and results of a user evaluation of Co-Star an immersive design system for cable harness design is described. The system used a stereoscopic head mounted graphical display, user motion tracking and hand-gesture controlled interface to enable cable harnesses to be designed using direct 3D user interaction with a product model. In order to determine how such a system interface would be used by a designer and to obtain user feedback on its main features a practical user evaluation was undertaken involving ten participants each completing three cable harness design tasks with the system. All user interactions with the system were recorded in a time stamped log file during each of the tasks, which were also followed by questionnaire (5 point scale) and interview sessions with each participant. The recorded interaction data for the third task was analysed using functional decomposition techniques and used to construct a single activity profile for the task based on the mean results obtained from the participant group. The goal was to identify in general terms the relative distribution of user activity between specific purposes during practical system operation, and it was found that in this task Navigation accounted for 41%, Design 27%, System Operation 23% and looking at Task Instructions 9% of all user activity. The scored questionnaire data collected immediately after the completion of each task was used to rank the major features of the system according to user opinion. This was further enhanced by also collecting real interview comments from the user group about these same features. The combination of both quantitative performance analysis and subjective user opinion data obtained during a practical design exercise has enabled an in depth evaluation of the system, leading to a much greater understanding of many of the key user and interface requirements that should be considered during the development of immersive interfaces and systems for practical engineering applications.     

Interindividual differences in the levels of the glutamate transporters GLAST and GLT, but no clear correlation with Alzheimer's disease

Alzheimer's disease is a common progressive neurodegenerative disease of unknown etiology. Several different pathological processes have been identified in the brains of Alzheimer patients. To determine if reduced glutamate uptake is a contributing factor, we have measured the levels of the glutamate transporter proteins GLAST (EAAT1) and GLT (EAAT2) in human autopsy samples. The postmortem proteolysis of these proteins turned out to be fairly rapid. Brains from 10 Alzheimer and 10 control patients were therefore obtained with a relatively short postmortem delay (5 hr on average). GLT (N-terminal and central parts), GLAST (C-terminal), glial fibrillary acidic protein (GFAP) and inositol (1,4,5)-triphosphate (IP3)-receptor immunoreactivities were determined in the cingulate and inferior temporal gyri by immunoblotting. The Na+-dependent "binding" of D-[3H]aspartate and the glutamate uptake after solubilization and reconstitution in liposomes were determined for comparison. An individual variation in GLAST and GLT levels was found, but no significant correlation with Alzheimer's disease, except for a 14% lower ratio of N-terminal to central GLT immunoreactivity (P < 0.04). The levels of GLAST and GLT showed negative correlation in agreement with the idea that these proteins are differentially regulated. In conclusion, Alzheimer's disease brains can have both normal and reduced levels of GLAST and GLT.     

Land Conflicts in Informal Settlements: Wallacedene in Cape Town,South Africa

Given the history of South Africa, which has resulted in a significantly skewed pattern of access to scarce resources in favor of a wealthy racial minority, the issue of access to land and shelter is a central and emotive one. It is also a potential arena of conflict and social and political divisions. It is therefore important to understand, monitor, and resolve these conflicts. This paper is the first in a series of case studies, drawn from within greater Cape Town, which examine conflicts over land and housing and how these conflicts are being managed. This case is that of Wallacedene, a primarily informal settlement in the north of the city, which has been the subject of an informal settlement upgrading process. Different forms of conflict occur over the life cycle of an informal settlement. Community-based institutions form an essential component of conflict management strategies. However, there have to be checks and balances on how these institutions operate. Moreover, accurate, local level records of transactions in land rights, which are often informal transactions, are an essential part of land and housing delivery.     

Long-term follow-up after temporal lobe resection for lesions associated with chronic seizures

A follow-up study was conducted on 60 patients who had standard en bloc anterior temporal lobe resection, including mesiotemporal structures, as treatment for temporal lobe lesions associated with chronic, medically intractable seizures. Lesions were identified as glial tumors, hamartomas, or vascular malformations. Long-term outcome was assessed in terms of seizure frequency and certain psychosocial sequelae. Seizure onset occurred at an average age of 15 years (median = 13.5 years), and patients experienced seizures for an average of 13 years prior to surgery. The mean time of follow-up was 8.4 years postsurgery (median = 6 years). The Kaplan-Meier curve at median follow-up showed a seizure-free rate of 80%. Late seizure recurrence was documented for three patients; two had been seizure-free for 10 years and one for 15 years after surgery, before re-onset of seizures in the absence of tumor recurrence. A prolonged history of seizures prior to surgery was associated with a poorer seizure outcome (p = 0.06), suggesting that secondary epileptogenesis at sites distant to the lesion may develop with years of uncontrolled seizures. There was a low tumor recurrence rate of 3.3% (two cases). The psychosocial outcome was generally good, with 67% working or engaged in educational studies, and improvement noted in 59% of cases for one or more of the psychosocial factors investigated. This study confirms that anterior temporal lobe resection for temporal lesions associated with chronic seizures is a successful treatment with a high seizure-free rate following surgery and good psychosocial outcome.     

Gold‐Cobalt Nanoparticle Alloys Exhibiting Tunable Compositions,Near‐Infrared Emission,and High T2 Relaxivity

We demonstrate the synthesis of discrete, composition‐tunable gold‐cobalt nanoparticle alloys (% Co = 0–100%; diameter = 2–3 nm), in contrast with bulk behavior, which shows immiscibility of Au and Co at room temperature across all composition space. These particles are characterized by transmission electron microscopy and ¹H NMR techniques, as well as inductively coupled plasma mass spectrometry, X‐ray photoelectron spectroscopy, and photoluminescence spectroscopy. In particular, ¹H NMR methods allow the simultaneous evaluation of composition‐tunable magnetic properties as well as molecular characterization of the colloid, including ligand environment and hydrodynamic diameter. These experiments also demonstrate a route to optimize bimodal imaging modalities, where we identify Au_xCo_yNP compositions that exhibit both bright NIR emission (2884 m ^?1cm^?1) as well as some of the highest per‐particle T ₂ relaxivities (12200 mm _NP ^?1s^?1) reported to date for this particle size range.     

A laboratory for teaching computer networks

A laboratory for teaching computer networking techniques is described. Each workstation consists of a 68008 μP operating under the OS-9 operating system. The workstations are networked via an ARCNET local area network to a common file server. The workstations were initially constructed to teach microprocessors and have been designed so that external components can be interfaced to them via a proprietary bus design using prototyping boards with plug-in wires and components. The computer networking experiments use groups of four workstations connected via their serial interfaces to a simple circuit that simulates a bus. This circuit also detects a collision on the bus caused by more than one station transmitting simultaneously and signals the four workstations via their DCD lines. Two semesters of laboratory experiments have been developed. The first builds MAC layer protocols and the second builds higher layer protocols     

Inflammatory breast carcinoma: comparison of survival of those diagnosed clinically, pathologically, or with both features

Although trabeculectomy is an established surgical technique for glaucoma, in some cases it does not achieve a good filtering effect despite the use of mitomycin-C (MMC). The authors have developed a new surgical technique for uncontrollable glaucoma that uses amniotic membrane to prevent postoperative adhesion of conjunctiva and sclera. They performed trabeculectomy with a limbal-based conjunctival flap using 0.4 mg/ml of MMC for 2 minutes. Amniotic membrane was then placed under the scleral flap and sutured using 10-0 nylon. Among 14 eyes of 13 patients who underwent this procedure, intraocular pressure was controlled to less than 20 mm Hg after surgery in 13 eyes, including 3 eyes that underwent a second surgery with the same technique and 2 eyes that underwent laser trabeculoplasty. The authors' results suggest that this technique is efficacious for the reduction of intraocular pressure in high-risk glaucoma patients.     

Diagnosing old MI by searching for a linear boundary in the space of principal components.

Body surface potential mapping (BSPM) is a technique employing multiple electrodes to capture, via noninvasive means, an indication of the heart's condition. An inherent problem with this technique is the resulting high-dimensional recordings and the subsequent problems for diagnostic classifiers. A data set, recorded from a 192-lead BSPM system, containing 74 records is investigated. QRS isointegral maps, offering a summary of the information obtained during ventricular depolarization, were derived from 30 old inferior myocardial infarction and 44 normal recordings. Principal component analysis was applied to reduce the dimensionality of the recordings and a linear classifier was employed for classification. This perceptron-based classifier has been adapted so that the final weight and bias values are estimated prior to the learning process. This estimation process, referred to as the linear hyperplane approach (LHA), derives the estimated weights from a bisector hyperplane, placed orthogonal to the means of two class distributions in an n-dimensional Euclidean space. Estimating weights encourages a network to exhibit better generalization ability. Utilizing a number of different principal components as input features, the LHA achieved an average sensitivity and specificity of 79.58% and 76.45%, respectively, across all experiments. The average accuracy of 76.73% achieved with this approach was significantly better than the other benchmark classifiers evaluated against it.     

Cervical spine pseudogout with myelopathy and Charcot joints

Myelopathy due to calcium pyrophosphate dihydrate (CPPD) crystals in the cervical spine is rare. Neuropathic-like joints are also uncommon manifestations of CPPD crystal disease. We describe a 79-year-old woman with multiple neuropathic joints containing CPPD crystals. She also had a large mass containing CPPD crystals impinging on the cervical spinal cord, causing a myelopathy. She appears to be the first patient with this combination of unusual clinical features with CPPD disease.