941 research outputs found
A study of the leisure time activities of twenty children of multiple sclerosis patients
Thesis (M.S.)--Boston Universit
Reviews
The 1991 J.R.R Tolkien Calendar. Illus. by John Howe. Reviewed by Paula DiSante.
The Land of Narnia. Brian Sibley, Illus. by Pauline Baynes. Reviewed by Nancy-Lou Patterson.
The Tale of the Rings of Power. Thomas Peterson. Reviewed by David Bratman.
The Cosmic Trilogy. C.S. Lewis. Reviewed by Nancy-Lou Patterson.
The Passionate Intellect: Dorothy L. Sayers\u27 Encounter with Dante. Barbara Reynolds. Reviewed by James E. Pearson Jr.
Taste Manipulation and Swallowing Mechanics in Trauma-Related Sensory-Based Dysphagia
Purpose: This study explored the effects of highconcentration taste manipulation trials on swallow function in persons with sensory-based dysphagia.
Method: Dysphagia researchers partnered with clinical providers to prospectively identify traumatically injured U.S. military service members (N = 18) with sensorybased dysphagia as evidenced by delayed initiation and/or decreased awareness of residue/penetration/ aspiration. Under videofluoroscopy, participants swallowed trials of 3 custom-mixed taste stimuli: unflavored (40% weight/volume [wt/vol] barium sulfate in distilled water), sour (2.7%wt/vol citric acid in 40% wt/vol barium suspension), and sweet–sour (1.11% wt/vol citric acid plus 8% wt/vol sucrose in 40% wt/vol barium suspension). Trials were analyzed and compared via clinical rating tools (the Modified Barium Swallow Impairment Profile [Martin-Harris et al., 2008] and the Penetration-Aspiration Scale [Rosenbek, Robbins, Roecker, Coyle, & Wood, 1996]). Additionally, a computational analysis of swallowing mechanics (CASM) was applied to a subset of 9 swallows representing all 3 tastants from 3 participants.
Results: Friedman’s tests for the 3 stimuli revealed significantly (p \u3c .05) improved functional ratings for Penetration-Aspiration Scale and pharyngoesophageal opening. CASM indicated differences in pharyngeal swallowing mechanics across all tastant comparisons (p ≤ .0001). Eigenvectors revealed increased tongue base retraction, hyoid elevation, and pharyngeal shortening for sweet–sour and, to a lesser extent, sour than for unflavored boluses.
Conclusion: Advantageous changes in certain parameters of oropharyngeal swallowing physiology were noted with high-intensity tastants per both clinical ratings and subsequent CASM, suggesting potential therapeutic application for taste manipulation
Population-Level Compensation Impedes Biological Control of an Invasive Forb and Indirect Release of a Native Grass
The intentional introduction of specialist insect herbivores for biological control of exotic weeds provides ideal but understudied systems for evaluating important ecological concepts related to top-down control, plant compensatory responses, indirect effects, and the influence of environmental context on these processes. Centaurea stoebe (spotted knapweed) is a notorious rangeland weed that exhibited regional declines in the early 2000s, attributed to drought by some and to successful biocontrol by others. We initiated an experiment to quantify the effects of the biocontrol agent, Cyphocleonus achates, on Ce. stoebe and its interaction with a dominant native grass competitor, Pseudoroegneria spicata, under contrasting precipitation conditions. Plots containing monocultures of each plant species or equal mixtures of the two received factorial combinations of Cy. achates herbivory (exclusion or addition) and precipitation (May–June drought or “normal,” defined by the 50-year average) for three years. Cy. achates herbivory reduced survival of adult Ce. stoebe plants by 9% overall, but this effect was stronger under normal precipitation compared to drought conditions, and stronger in mixed-species plots compared to monocultures. Herbivory had no effect on Ce. stoebe per capita seed production or on recruitment of seedlings or juveniles. In normal-precipitation plots of mixed composition, greater adult mortality due to Cy. achates herbivory resulted in increased recruitment of new adult Ce. stoebe. Due to this compensatory response to adult mortality, final Ce. stoebe densities did not differ between herbivory treatments regardless of context. Experimental drought reduced adult Ce. stoebe survival in mixed-species plots but did not impede recruitment of new adults or reduce final Ce. stoebe densities, perhaps due to the limited duration of the treatment. Ce. stoebe strongly depressed P. spicata reproduction and recruitment, but these impacts were not substantively alleviated by herbivory on Ce. stoebe. Population-level compensation by dominant plants may be an important factor inhibiting top-down effects in herbivore-driven and predator-driven cascades
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Entrainment of Dungeness Crab in the Desdemona Shoals Reach of the Lower Columbia River Navigation Channel
Proposed dredging of the Columbia River has raised concerns about related impacts on Dungeness crab in the Columbia River Estuary (CRE). This study follows two major efforts, sponsored by the Portland District of the U. S. Army Corps of Engineers (USACE) to quantify the number of crabs entrained by a hopper dredge working in the CRE. From June 2002 through September 2002, Pacific Northwest National Laboratory (PNNL) conducted direct measurements of crab entrainment in the CRE from the mouth of the Columbia River (MCR, river mile -3 to +3) upriver as far as Miller Sands (river mile 21 to 24). These studies constituted a major step in quantifying crab entrainment in the CRE, and allowed statistically bounded projections of adult equivalent loss (AEL) for Dungeness crab populations under a range of future construction dredging and maintenance dredging scenarios (Pearson et al. 2002, 2003). In 2004, PNNL performed additional measurements to improve estimates of crab entrainment at Desdemona Shoals and at Flavel Bar, a reach near Astoria that had not been adequately sampled in 2002 (Figure 1). The 2004 data were used to update the crab loss projections for channel construction to 43 ft MLLW. In addition, a correlation between bottom salinity and adult (age 2+ and 3+, >100 mm carapace width) crab entrainment was developed using 2002 data, and elaborated upon with the 2004 data. This crab salinity model was applied to forecasting seasonal (monthly) entrainment rates and AEL using seasonal variations in salinity (Pearson et al. 2005). In the previous studies, entrainment rates in Desdemona Shoals were more variable than in any of the other reaches. Pearson et al. (2005) concluded that ?the dynamics behind the variable entrainment rates at Desdemona Shoals are not fully understood,? as well as finding that juvenile crab entrainment was not significantly correlated with salinity as it was for older crab. The present study was undertaken to address the question of whether the high age 1+ entrainment rate at Desdemona Shoals in June 2002 unusual, or would it be observed again under similar conditions? PNNL and USACE personnel directly measured crab entrainment by the USACE hopper dredge Essayons working in Desdemona Shoals in June 2006. In addition to quantifying crab entrainment of all age classes, bottom salinity was directly measured in as many samples as possible, so that the relationship between crab entrainment and salinity could be further evaluated. All 2006 data were collected and analyzed in a manner consistent with the previous entrainment studies (Pearson et al. 2002, 2003, 2005)
Early Eocene Arctic volcanism from carbonate-metasomatized mantle
Melilitite, nephelinite, basanite, and alkali basalt, along with phonolite differentiates, form the Freemans Cove Complex (FCC) in the south-eastern extremity of Bathurst Island (Nunavut, Canada). New 40Ar/39Ar chronology indicates their emplacement between ~ 56 and ~ 54 million years ago within a localized extensional structure. Melilitites and nephelinites, along with phonolite differentiates, likely relate to the beginning and end phases of extension, whereas alkali basalts were emplaced during a main extensional episode at ~ 55 Ma. The melilitites, nephelinites, and alkali basalts show no strong evidence for significant assimilation of crust, in contrast to some phonolites. Partial melting occurred within both the garnet- and spinel-facies mantle and sampled sources with He, O, Nd, Hf, and Os isotope characteristics indicative of peridotite with two distinct components. The first, expressed in higher degree partial melts, represents a relatively depleted component (“A”; 3He/4He ~ 8 RA, εNdi ~ + 3 εHfi ~ + 7, γOsi ~ 0). The second was an enriched component (“B” 3He/4He + 70) sampled by the lowest degree partial melts and represents carbonate-metasomatized peridotite. Magmatism in the FCC shows that rifting extended from the Labrador Sea to Bathurst Island and reached a zenith at ~ 55 Ma, during the Eurekan orogeny. The incompatible trace-element abundances and isotopic signatures of FCC rocks indicate melt generation occurred at the base of relatively thin lithosphere at the margin of a thick craton, with no mantle plume influence. FCC melt compositions are distinct from other continental rift magmatic provinces worldwide, and their metasomatized mantle source was plausibly formed synchronously with emplacement of Cretaceous kimberlites. The FCC illustrates that the range of isotopic compositions preserved in continental rift magmas are likely to be dominated by temporal changes in the extent of partial melting, as well as by the timing and degree of metasomatism recorded in the underlying continental lithosphere
3D Dynamic Visualization of Swallowing from Multi-Slice Computed Tomography
Human swallowing and its disorders (dysphagia) are still poorly understood, and yet many speech-language pathologists (SLPs) need to be trained to recognize correct, incorrect, and potentially dangerous swallows. The anatomy of the head and neck region is notoriously complex and difficult to visualize and study. Currently, training programs that teach SLPs to recognize swallowing disorders use artistically derived animations of swallowing, rendered at fixed viewpoints, to help students visualize the anatomy of the head and neck region.
This work improves on these animations by using state-of-the-art medical images to create a dynamic, interactive, 3D simulation of human swallowing. Images of a male subject during swallow were captured in a single shot using a 320-slice CT scanner [Inamoto et al. 2011]. The images have very high spatial resolution (0:5 x 0:5 x 0:5 mm3), but low temporal resolution (10 Hz). The low temporal resolution resulted in blurring of the fluid being swallowed, making automatic segmentation and visualizations of the fluid difficult to generate
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