1,552 research outputs found
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Bars, Nightclubs, and Cancer Prevention: New Approaches to Reduce Young Adult Cigarette Smoking.
IntroductionTobacco contributes to multiple cancers, and it is largely preventable. As overall smoking prevalence in California declines, smoking has become concentrated among high-risk groups. Targeting social/cultural groups (i.e., "peer crowds") that share common values, aspirations, and activities in social venues like bars and nightclubs may reach high-risk young adult smokers. Lack of population data on young adult peer crowds limits the ability to assess the potential reach of such interventions.MethodsThis multimodal population-based household survey included young adults residing in San Francisco and Alameda counties. Data were collected in 2014 and analyzed in 2016. Multivariable logistic regressions assessed smoking by sociodemographic factors, attitudes, self-rated health, peer crowd affiliation, and bar/nightclub attendance.ResultsSmoking prevalence was 15.1% overall; 35.3% of respondents sometimes or frequently attended bars. In controlled analyses, bar attendance (AOR=2.13, 95% CI=1.00, 4.53) and binge drinking (AOR=3.17, 95% CI=1.59, 6.32) were associated with greater odds of smoking, as was affiliation with "Hip Hop" (AOR=4.32, 95% CI=1.48, 12.67) and "Country" (AOR=3.13, 95% CI=1.21, 8.09) peer crowds. Multivariable models controlling for demographics estimated a high probability of smoking among bar patrons affiliating with Hip Hop (47%) and Country (52%) peer crowds.ConclusionsBar attendance and affiliation with certain peer crowds confers significantly higher smoking risk. Interventions targeting Hip Hop and Country peer crowds could efficiently reach smokers, and peer crowd-tailored interventions have been associated with decreased smoking and binge drinking. Targeted interventions in bars and nightclubs may be an efficient way to address these cancer risks
Segmentation of RT3D Ultrasound with Implicit Deformable Models Without Gradients
This paper presents the implementation and validation of a new 3D deformable model method, based on the Mumford-Shah functional for segmentation of three-dimensional real-time ultrasound. An experiment on 10 patients with primary hypertension was carried out to compare three segmentation methods for quantification of right and left ventricular ejection fraction: (1) manual tracing by an expert cardiologist, (2) 2D parametric deformable model, and (3) 3D implicit deformable model implemented with a level set framework. Deformable model segmentations were performed on denoised data using a (3D+Time) brushlet expansion. The clinical study showed superior performance of the deformable model in assessing ejection fraction when compared to MRI measures. It also showed that the three-dimensional deformable model improved EF measures, which is explained by a more accurate segmentation of small and convoluted ventricular shapes when integrating the third spatial dimension
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LV Volume Quantification via Spatiotemporal Analysis of Real-Time 3-D Echocardiography
This paper presents a method of four-dimensional (4-D) (3-D+Time) space-frequency analysis for directional denoising and enhancement of real-time three-dimensional (RT3D) ultrasound and quantitative measures in diagnostic cardiac ultrasound. Expansion of echocardiographic volumes is performed with complex exponential wavelet-like basis functions called brushlets. These functions offer good localization in time and frequency and decompose a signal into distinct patterns of oriented harmonics, which are invariant to intensity and contrast range. Deformable-model segmentation is carried out on denoised data after thresholding of transform coefficients. This process attenuates speckle noise while preserving cardiac structure location. The superiority of 4-D over 3-D analysis for decorrelating additive white noise and multiplicative speckle noise on a 4-D phantom volume expanding in time is demonstrated. Quantitative validation, computed for contours and volumes, is performed on in vitro balloon phantoms. Clinical applications of this spatiotemporal analysis tool are reported for six patient cases providing measures of left ventricular volumes and ejection fraction
Psychometric properties of standardized balance confidence, fear of falling, and falls-efficacy measures in people with lower limb amputations
Background:
In Canada, \u3e50% of community-dwelling lower limb amputees (LLA) fall at least once each year, a rate that is almost twice that of community-dwelling older adults. While the physical consequences of falls may be readily apparent, psychological sequelae that follow may be just as, if not more, detrimental than an actual fall itself. Current measures of balance confidence show no change in LLA following discharge from rehabilitation. The limited detectable change may be due to content validity challenges of the measures as they were not developed for the unique challenges faced by LLA.
Objectives:
1) Review items from standardized scales measuring falls-related concerns with participants to determine the applicability of test items to the LLA population.
2) Solicit novel examples of relevant activities from participants to inform the development of an LLA-specific balance confidence scale.
Proposed Methods:
This cross-sectional study will include adult unilateral/bilateral LLA (n=60) recruited through the Outpatient Amputee Rehabilitation Program at Parkwood Institute. Falls-related concerns will be evaluated using seven relevant clinical measures of a concern for falling. Participants will be asked to identify inapplicable questions and to provide i) a list of activities they are physically able to do but are avoiding; and ii) a list of activities they currently do but are worried about becoming unsteady or falling when performed.
Future Directions/Implications:
The results of this project could provide important details for the creation of an amputee-specific measurement tool to better quantify psychological concerns related to falls
Lv volume quantification via spatiotemporal analysis of real-time 3-d echocardiography
Abstract—This paper presents a method of four-dimensional (4-D) (3-D + Time) space–frequency analysis for directional denoising and enhancement of real-time three-dimensional (RT3D) ultrasound and quantitative measures in diagnostic cardiac ultrasound. Expansion of echocardiographic volumes is performed with complex exponential wavelet-like basis functions called brushlets. These functions offer good localization in time and frequency and decompose a signal into distinct patterns of oriented harmonics, which are invariant to intensity and contrast range. Deformable-model segmentation is carried out on denoised data after thresholding of transform coefficients. This process attenuates speckle noise while preserving cardiac structure location. The superiority of 4-D over 3-D analysis for decorrelating additive white noise and multiplicative speckle noise on a 4-D phantom volume expanding in time is demonstrated. Quantitative validation, computed for contours and volumes, is performed on in vitro balloon phantoms. Clinical applications of this spaciotemporal analysis tool are reported for six patient cases providing measures of left ventricular volumes and ejection fraction. Index Terms—Echocardiography, LV volume, spaciotemporal analysis, speckle denoising. I
Comments on the distribution of \u3ci\u3eBotrychium lunarioides\u3c/i\u3e (Ophioglossaceae) in Texas
Botrychium lunarioides (Michx.) Sw. (Ophioglossaceae) is now known to be widespread and abundant throughout the eastern portion of Texas. In 1996, Do, et al. reported ten additional county records in the central portion of the Post Oak Savannah of Texas, thereby extending the known distribution of the species up to 273 km to the west. Additional field studies during 1996 have yielded nineteen new county records for the species in Texas. These new reports are primarily from the Post Oak Savannah, Pineywoods, and Blackland Prairies of northeast Texas and from the southern portion of the Post Oak Savannah. The most notable occurrence of the species is at Lake Bastrop State Recreation Area, Bastrop County, about 45 km ESE of Austin, which extends both the western and southern known limits of the species
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Cardiac Motion Analysis Based on Optical Flow on Real-Time Three-Dimensional Ultrasound Data
With relatively high frame rates and the ability to acquire volume data sets with a stationary transducer, 3D ultrasound systems, based on matrix phased array transducers, provide valuable three-dimensional information, from which quantitative measures of cardiac function can be extracted. Such analyses require segmentation and visual tracking of the left ventricular endocardial border. Due to the large size of the volumetric data sets, manual tracing of the endocardial border is tedious and impractical for clinical applications. Therefore the development of automatic methods for tracking three-dimensional endocardial motion is essential. In this study, we evaluate a four-dimensional optical flow motion tracking algorithm to determine its capability to follow the endocardial border in three dimensional ultrasound data through time. The four-dimensional optical flow method was implemented using three-dimensional correlation. We tested the algorithm on an experimental open-chest dog data set and a clinical data set acquired with a Philips' iE33 three-dimensional ultrasound machine. Initialized with left ventricular endocardial data points obtained from manual tracing at end-diastole, the algorithm automatically tracked these points frame by frame through the whole cardiac cycle. Finite element surfaces were fitted through the data points obtained by both optical flow tracking and manual tracing by an experienced observer for quantitative comparison of the results. Parameterization of the finite element surfaces was performed and maps displaying relative differences between the manual and semi-automatic methods were compared. The results showed good consistency with less than 10% difference between manual tracing and optical flow estimation on 73% of the entire surface. In addition, the optical flow motion tracking algorithm greatly reduced processing time (about 94% reduction compared to human involvement per cardiac cycle) for analyzing cardiac function in three-dimensional ultrasound data sets. A displacement field was computed from the optical flow output, and a framework for computation of dynamic cardiac information is introduced. The method was applied to a clinical data set from a heart transplant patient and dynamic measurements agreed with known physiology as well as experimental results
Effect of Learning to Use a Mobility Aid on Gait and Cognitive Demands in People with Mild to Moderate Alzheimer\u27s Disease: Part I - Cane
BACKGROUND: People with Alzheimer\u27s disease (AD) exhibit balance and walking impairments that increase falls risk. Prescription of a mobility aid is done to improve stability, yet also requires increased cognitive resources. Single-point canes require unique motor sequencing for safe use. The effect of learning to use a single-point cane has not been evaluated in people with AD.
OBJECTIVES: In people with AD and healthy adult controls: 1) examine changes in gait while using a cane under various walking conditions; and 2) determine the cognitive and gait costs associated with concurrent cane walking while multi-tasking.
METHODS: Seventeen participants with AD (age 82.1±5.6 years) and 25 healthy controls (age 70.8±14.1 years) walked using a single-point cane in a straight (6 meter) and a complex (Figure of 8) path under three conditions: single-task (no aid), dual-task (walking with aid), and multi-task (walking with aid while counting backwards by ones). Velocity and stride time variability were recorded with accelerometers.
RESULTS: Gait velocity significantly slowed for both groups in all conditions and stride time variability was greater in the AD group. Overall, multi-tasking produced a decrease in gait and cognitive demands for both groups, with more people with AD self-prioritizing the cognitive task over the gait task.
CONCLUSION: Learning to use a cane demands cognitive resources that lead to detrimental changes in velocity and stride time variability. This was most pronounced in people with mild to moderate AD. Future research needs to investigate the effects of mobility aid training on gait performance
Effect of Learning to Use a Mobility Aid on Gait and Cognitive Demands in People with Mild to Moderate Alzheimer\u27s Disease: Part II - 4-Wheeled Walker.
BACKGROUND: Cognitive deficits and gait problems are common and progressive in Alzheimer\u27s disease (AD). Prescription of a 4-wheeled walker is a common intervention to improve stability and independence, yet can be associated with an increased falls risk.
OBJECTIVES: 1) To examine changes in spatial-temporal gait parameters while using a 4-wheeled walker under different walking conditions, and 2) to determine the cognitive and gait task costs of walking with the aid in adults with AD and healthy older adults.
METHODS: Twenty participants with AD (age 79.1±7.1 years) and 22 controls (age 68.5±10.7 years) walked using a 4-wheeled walker in a straight (6 m) and Figure of 8 path under three task conditions: single-task (no aid), dual-task (walking with aid), and multi-task (walking with aid while counting backwards by ones).
RESULTS: Gait velocity was statistically slower in adults with AD than the controls across all conditions (all p values
CONCLUSION: Learning to use a 4-wheeled walker is cognitively demanding and any additional tasks increases the demands, further adversely affecting gait. The increased cognitive demands result in a decrease in gait velocity that is greatest in adults with AD. Future research needs to investigate the effects of mobility aid training on gait performance
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