Is visible infarction on computed tomography associated with an adverse prognosis in acute ischemic stroke?

BACKGROUND AND PURPOSE: It is unclear whether visible infarction on a CT scan at any time after the stroke is an adverse prognostic factor once other factors such as stroke severity are taken into consideration. We examined whether visible infarction was associated with a poor outcome after stroke using univariate and multivariate analyses, including easily identifiable clinical baseline variables, and adjusting for time from stroke onset to CT. METHODS: All inpatients and outpatients with an acute ischemic stroke attending our hospital stroke service were examined by a stroke physician and entered into a register prospectively. The CT scan was coded prospectively for the site and size of any relevant recent visible infarct. The patients were followed up at 6 months to ascertain their functional status with the use of the modified Rankin Scale. Analyses of the effect of visible infarction on the outcomes "dead or dependent" or "dead" at 6 months were performed with adjustment for time from stroke to CT, clinical stroke type (lacunar, hemispheric, or posterior circulation), and in a multiple logistic regression model to adjust for confounding baseline variables such as stroke severity. RESULTS: In 993 patients in the stroke registry, visible infarction increased the risk of being dead or dependent at 6 months (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.9 to 3.3) or dead (OR, 4.5; 95% CI, 2.7 to 7.5), both on its own and after adjustment for time from stroke to CT, stroke symptoms, and other important clinical prognostic variables (OR for death or dependence in the predictive model, 1.5; 95% CI, 1.0 to 2.0; OR for death, 2.4; 95% CI, 1.4 to 4.1). CONCLUSIONS: Visible infarction on CT is an adverse prognostic indicator (albeit of borderline significance) even after adjustment for stroke severity and time lapse between the stroke and the CT scan.     

The visual fields of American horseshoe crabs: two different eye shapes in Limulus polyphemus

The optical alignment of individual cuticular cones in the dioptric array of the lateral eye of Limulus polyphemus was determined with a precision two-circle goniometer constructed and mounted to the stage of a compound microscope and using a new formaldehyde-induced fluorescence procedure. All measurements were made from the corneal surface of the excised eye mounted in seawater through an air/water interface perpendicular to the optic axis of the microscope. Our results revealed two variants of visual field and eye curvature which can actually be discriminated in casual examination of adult animals. We call animals possessing these two variants "morlocks" and "eloi." Adult male and female morlocks about 25 cm across the carapace have eyes which are relatively elongated, often darker in pigmentation, smaller, and relatively flatter in curvature. Morlocks have a monocular field of view of about 3.13 steradians or 50% of a hemisphere. The coverage averages 115 deg along the vertical axis and 168 deg along the horizontal axis of the eye, with maximum resolution in the anteroventral quadrant. Adult male and female eloi of comparable size have eyes which are relatively more round, often lighter in pigmentation, larger with more ommatidia, and relatively more bulged. Eloi have a monocular field of view of approximately 3.83 steradians or 61% of a hemisphere that covers 145 deg vertically and 185 deg horizontally. Eloi have more uniform resolution than morlocks with best resolution in the posteroventral quadrant. All horseshoe crabs examined, whether morlocks or eloi, have an identical orientation of the margin of the eye relative to the animals' coordinates.     

VisCoMET: Visually Analyzing Team Collaboration in Medical Emergency Trainings

Handling emergencies requires efficient and effective collaboration of medical professionals. To analyze their performance, in an application study, we have developed VisCoMET, a visual analytics approach displaying interactions of healthcare personnel in a triage training of a mass casualty incident. The application scenario stems from social interaction research, where the collaboration of teams is studied from different perspectives. We integrate recorded annotations from multiple sources, such as recorded videos of the sessions, transcribed communication, and eye-tracking information. For each session, an information-rich timeline visualizes events across these different channels, specifically highlighting interactions between the team members. We provide algorithmic support to identify frequent event patterns and to search for user-defined event sequences. Comparing different teams, an overview visualization aggregates each training session in a visual glyph as a node, connected to similar sessions through edges. An application example shows the usage of the approach in the comparative analysis of triage training sessions, where multiple teams encountered the same scene, and highlights discovered insights. The approach was evaluated through feedback from visualization and social interaction experts. The results show that the approach supports reflecting on teams' performance by exploratory analysis of collaboration behavior while particularly enabling the comparison of triage training sessions.     

Workspace zone differentiation and visualization for virtual humans

Human performance measures such as discomfort and joint displacement play an important role in product design. The virtual human Santos, a new generation of virtual humans developed at the University of Iowa, goes directly to the computer-aided design model to evaluate a design, saving time and money. This paper presents an optimization-based workspace zone differentiation and visualization. Around the workspace of virtual humans, a volume is discretized to small zones and the posture prediction on each central point of the zone will determine whether the points are outside the workspace as well as the values of different objective functions. Visualization of zone differentiation is accomplished by showing different colours based on values of human performance measures on points that are located inside the workspace. The proposed method can subsequently help ergonomic design. For example, in a vehicle's interior, the controls should not only lie inside the workspace, but also in the zone that encloses the most comfortable points. Using the palette of colours inside the workspace as a visual guide, a designer can obtain a reading of the discomfort level of product users.     

A global constraint for total weighted completion time for unary resources

We introduce a novel global constraint for the total weighted completion time of activities on a single unary capacity resource. For propagating the constraint, we propose an O(n ⁴) algorithm which makes use of the preemptive mean busy time relaxation of the scheduling problem. The solution to this problem is used to test if an activity can start at each start time in its domain in solutions that respect the upper bound on the cost of the schedule. Empirical results show that the proposed global constraint significantly improves the performance of constraint-based approaches to single-machine scheduling for minimizing the total weighted completion time. We then apply the constraint to the multi-machine job shop scheduling problem with total weighted completion time. Our experiments show an order of magnitude reduction in search effort over the standard weighted-sum constraint and demonstrate that the way in which the job weights are associated with activities is important for performance.     

A comparison of the structure and function of the terminal ileum in Crohn's disease using radiology, the "Dicopac" Schilling test and [14C] G.C.A. breath test

Twenty patients with Crohn's disease were studied. Thirteen had radiological evidence of involvement of the terminal ileum. None had significant bacterial overgrowth of the small bowel contents and none had had resection of the terminal ileum. In all patients a [14C] glycocholic acid ([14C] G.C.A.) breath test and a "Dicopac" Schilling test were performed to assess terminal ileal function. The data showed poor correlation between the radiological appearance of the terminal ileum and the results of the functional tests. There was also poor correlation between the results of the [14C] G.C.A. breath test and the "Dicopac" Schilling test. Without terminal ileal histology, any assessment of the extent of Crohn's disease of the terminal ileum and of its effect on terminal ileal function, must include the [14C] G.C.A. breath test as well as radiology and the "Dicopac" Schilling test. The limitations of the [14C] G.C.A. breath test as a test of terminal ileal function in Crohn's disease are discussed.     

WAIS performance in young normal, young alcoholic, and elderly normal groups: an evaluation of organicity and mental aging indices

Investigated the effects of alcoholism and advanced age on Wechsler Adult Intelligence Scale (WAIS) performance and tested the validity of indices of "organicity" and "mental aging" derived from WAIS scores. The WAIS was administered to three groups of 20 males each: young normal (mean age 31 years), young alcoholic (mean age 33 years), and elderly normal (mean age 71 years. In terms of scaled scores, the young normal group was generally superior to the other groups on Verbal and Performance subtests, and the alcoholic and elderly groups resembled each other more on the Verbal than the Performance subtests. In view of an almost 40-year difference in age between the young alcoholic and the elderly normal Ss, similarities in pattern of performance provided some evidence for the hypothesis of "premature aging" in alcholics.     

Aging and identity-in-the-world: a phenomenological analysis

This paper uses a criticism of "objectivistic" approaches to aging and identity as a vehicle for a phenomenological rethinking of those topics. This phenomenological approach to "identity-in-the-world" as it is experienced in everyday life leads necessarily to a theory of the temporal limits of that experience in the aging process; that is, a theory of identity, properly understood, is already a theory of aging. It is concluded that this approach overcomes the parallel problems of objectivism versus subjectivism and biologism versus sociologism, demanding a rethinking of conceptions of human nature that have predominated in social science.     

APPLYING MACHINE LEARNING TO LOW-KNOWLEDGE CONTROL OF OPTIMIZATION ALGORITHMS

This paper addresses the question of allocating computational resources among a set of algorithms to achieve the best performance on scheduling problems. Our primary motivation in addressing this problem is to reduce the expertise needed to apply optimization technology. Therefore, we investigate algorithm control techniques that make decisions based only on observations of the improvement in solution quality achieved by each algorithm. We call our approach "low knowledge" since it does not rely on complex prediction models, either of the problem domain or of algorithm behavior. We show that a low-knowledge approach results in a system that achieves significantly better performance than all of the pure algorithms without requiring additional human expertise. Furthermore the low-knowledge approach achieves performance equivalent to a perfect high-knowledge classification approach.     

Error-bounds for balanced model-reduction of linear time-varying systems

Error-bounds are developed for balanced truncation of linear time-varying systems, leading to an extension of the "twice the sum of the tail" formulas, well known in the time-invariant case. The approach relies on an operator-theoretic framework for analysis of linear time-varying systems. This provides a multivariable notion of frequency for such systems, which are thus characterized by rational functions of many complex variables, allowing the problem to be formulated in the linear-fractional framework. Using a time-varying version of standard necessary conditions for reduced-order modeling, based on convex operator inequalities, we show that these error-bounds for balanced truncation are related to the closest possible reduced-order modeling error in a sense which parallels the time-invariant case.