40 research outputs found
Here where it lives … bioscleave
This essay introduces the work of Arakaw and Gins to interdisciplinary specialists and scholars and practitioners who are concerned with issues of art-science convergence. The co-authors discuss several points of view to the work of these artist-turned-architects and address the difficulties and challenges that their work represents in terms of the convergence and complexity of multiple dicourse and the practical challenges to embodied experience, technlogy-based approaches ot knowledge acquisition and perceptually-based learning environments
Modeling and analysis of uncertain time-critical tasking problems
Naval Research Logistics, 53 , No. 6, (Sept. 2006), 588-599.This paper describes modeling and operational analysis of a generic asymmetric services-system situation in which (a) Red agents, potentially threatening, but in another but important interpretation, are isolated friendlies, such as downed pilots, that require assistance and "arrive" according to some partially known and potentially changing pattern in time and space: and (b) Reds have effectively limited unknown deadlines or times of availability for Blue service, i.e., detection, classification, and attack in a military setting or emergency assistance in others. We discuss various service options by Blue service agents and devise several approximations allowing one to compute efficiently those proportions of tasks of different classes that are successfully serviced, or more generally, if different rewards are associated with different classes of tasks, the percentage of the possible reward gained. We suggest heuristic policies of a Blue server to select the next task to perform and to decide how much time to allocate to that service. We discuss this for a number of specific examples
An afferent explanation for sexual dimorphism in the aortic baroreflex of rat
Sex differences in baroreflex (BRx) function are well documented. Hormones likely contribute to this dimorphism, but many functional aspects remain unresolved. Our lab has been investigating a subset of vagal sensory neurons that constitute nearly 50% of the total population of myelinated aortic baroreceptors (BR) in female rats but less than 2% in male rats. Termed “Ah,” this unique phenotype has many of the nonoverlapping electrophysiological properties and chemical sensitivities of both myelinated A-type and unmyelinated C-type BR afferents. In this study, we utilize three distinct experimental protocols to determine if Ah-type barosensory afferents underlie, at least in part, the sex-related differences in BRx function. Electron microscopy of the aortic depressor nerve (ADN) revealed that female rats have less myelin (P < 0.03) and a smaller fiber cross-sectional area (P < 0.05) per BR fiber than male rats. Electrical stimulation of the ADN evoked compound action potentials and nerve conduction profiles that were markedly different (P < 0.01, n = 7 females and n = 9 males). Selective activation of ADN myelinated fibers evoked a BRx-mediated depressor response that was 3–7 times greater in female (n = 16) than in male (n = 17) rats. Interestingly, the most striking hemodynamic difference was functionally dependent upon the rate of myelinated barosensory fiber activation. Only 5–10 Hz of stimulation evoked a rapid, 20- to 30-mmHg reduction in arterial pressure of female rats, whereas rates of 50 Hz or higher were required to elicit a comparable depressor response from male rats. Collectively, our experimental results are suggestive of an alternative myelinated baroreceptor afferent pathway in females that may account for, at least in part, the noted sex-related differences in autonomic control of cardiovascular function
A Continuum of Testing (presentation)
Prepared for the National Test & Evaluation Conference, March 200
Analysis of Star Formation in Galaxy-like Objects
Using cosmological hydrodynamical simulations, we investigate the effects of
hierarchical aggregation on the triggering of star formation in galactic-like
objects. We include a simple star formation model to transform the cold gas in
dense regions into stars. Simulations with different parameters have been
performed in order to quantify the dependence of the results on the parameters.
We then resort to stellar population synthesis models to trace the color
evolution of each object with red-shift and in relation to their merger
histories. We find that, in a hierarchical clustering scenario, the process of
assembling of the structure is one natural mechanism that may trigger star
formation.
The resulting star formation rate history for each individual galactic object
is composed of a continuous one () and a series of
star bursts.
We find that even the accretion of a small satellite can be correlated with a
stellar burst. Massive mergers are found to be more efficient at transforming
gas into starsComment: 11 postscript figures. 2000, ApJ, accepte
Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures
Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo
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Patricia Glazebrook Update
Director, Trish Glazebrook has a busy spring/summer 201
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University Scholars Day
Presentation for the 2011 University Scholars Day at the University of North Texas discussing research on the philosophical connotations of words
Recommended from our members
University Scholars Day
This paper discusses research on the philosophical connotations of words