207 research outputs found
ECONOMIC AND ENVIRONMENTAL IMPACTS OF NUTRIENT LOSS REDUCTIONS ON DAIRY AND DAIRY/POULTRY FARMS
Livestock Production/Industries,
KINEMATIC DIFFERENCES BETWEEN UPKICK AND DOWNKICK IN UNDULATORY UNDERWATER SWIMMING
Undulatory underwater swimming (UUS) is performed for up to 15 m of each lap in a swimming race, and is important for overall performance. This undulatory motion has two phases- the upkick (knee flexion and hip extension) and the downkick (the converse). This study assessed kinematic differences between the two phases, and determined whether these differences were related to performance in an elite sample. Each of the ten participants performed three 20 m UUS trials, and seven landmarks were manually digitised from the single camera view perpendicular to swimming direction. Differences between phases were found for vertical toe velocity, body wave velocity, hip and knee angular velocities and phase duration (p < 0.05), with differences in mean hip angular velocity and phase duration (p < 0.05) being strongly related to UUS performance
Automated body volume acquisitions from 3D structured-light scanning
Whole-body volumes and segmental volumes are highly related to the health and medical condition of individuals. However, the traditional manual post-processing of raw 3D scanned data is time-consuming and needs technical expertise. The purpose of this study was to develop bespoke software for obtaining whole-body volumes and segmental volumes from raw 3D scanned data automatically and to establish its accuracy and reliability. The bespoke software applied Stitched Puppet model fitting techniques to deform template models to fit the 3D raw scanned data to identify the segmental endpoints and determine their locations. Finally, the bespoke software used the location information of segmental endpoints to set segmental boundaries on the reconstructed meshes and to calculate body volume. The whole-body volumes and segmental volumes (head & neck, torso, arms, and legs) of 29 participants processed by the traditional manual operation were regarded as the references and compared to the measurements obtained with the bespoke software using the intra-method and inter-method relative technical errors of measurement. The results showed that the errors in whole-body volumes and most segmental volumes acquired from the bespoke software were less than 5%. Overall, the bespoke software developed in this study can complete the post-processing tasks without any technical expertise, and the obtained whole-body volumes and segmental volumes can achieve good accuracy for some applications in health and medicine
Comparison of automated post-processing techniques for measurement of body surface area from 3D photonic scans
Body surface area (BSA) measurement is important in engineering and medicine fields to determine parameters for various applications. Three-dimensional scanning techniques may be used to acquire the BSA directly. Nevertheless, the raw data obtained from 3D scanning usually requires some manual post-processing which is time-consuming and requires technical expertise. Automated post-processing of 3D scans enables expedient BSA calculation with minimal technical expertise. The purpose of this research was to compare the accuracy and reliability of three different automated post-processing techniques including Stitched Puppet (SP), Poisson surface reconstruction (PSR), and screened Poisson surface reconstruction (SPSR) using manual post-processing as the criterion. Twenty-nine participants were scanned twice, and raw data were processed with the manual operation and automated techniques to acquire BSAs separately. The reliability of BSAs acquired from these approaches was represented by the relative technical error of measurements (TEM). Pearson’s regressions were applied to correct BSAs acquired from the automated techniques. The limits of agreement (LOA) were used to quantify the accuracy of BSAs acquired from the automated techniques and corrected by regression models. The reliability (relative TEM) of BSAs obtained from PSR, SPSR and SP were 0.32%, 0.30%, 0.82% respectively. After removing bias with the regression models, the LOA for PSR, SPSR and SP were (-0.0134 m2, 0.0135 m2), ±0.0131 m2, ±0.0573 m2 respectively. It is concluded that PSR and SPSR are good alternative approaches to manual post-processing for applications that need reliable and accurate measurements of BSAs with large populations
Archaeological Survey of Lackland Air Force Base, Bexar County, Texas
The Center for Archaeological Research of The University of Texas at San Antonio conducted a pedestrian cultural resources survey on 3,860 acres of land at Lackland Air Force Base and Medina Base Annex in Bexar County, Texas. Base boundaries contain parts of three tributaries of the Medina River: Leon Creek, Medio Creek, and the upper reaches of Long Hollow. Limited surveys and shovel testing began in the spring of 1994 in areas slated for development. These were followed by a 100-percent-pedestrian survey with limited shovel testing of the remaining undisturbed and undeveloped areas during the fall of 1994 and spring of 1995. Selective paleontological and geomorphological evaluations also were made.
The project recorded 71 archaeological sites. Sixty-four sites had only prehistoric components, four had both historic and prehistoric components, and three had only a historic component. Additionally, three previously recorded prehistoric sites were revisited. Prehistoric site types are open campsites and/or lithic quarries. Fortunately, some of the prehistoric sites yielded diagnostic projectile points and tools. These indicate human presence in the survey area from the Early Archaic through the Late Prehistoric periods. The historic sites were classified as farmsteads dating to the late-nineteenth and early to mid-twentieth centuries.
Seventy-one of the 74 sites are deemed eligible for nomination to the National Register of Historic Places
PAWS: A performance evaluation tool for parallel computing systems
A description is given of PAWS (parallel assessment window system), a set of tools that provides an interactive user-friendly environment for analysis of existing, prototype, and conceptual machine architectures running a common application. PAWS consists of an application tool, an architectural characterization tool, a performance assessment tool, and an interactive graphical display tool. The application characterization tool provides a facility for evaluating the level and degree of an application's parallelism. The architecture characterization tool allows users to create, store, and retrieve descriptions of machines in a database. This approach permits users to evaluate conceptual machines before building any hardware. The performance assessment tool generates profile plots through the interactive graphical display tool. It shows both the ideal parallelism inherent in the machine-independent dataflow graph and
Myelinating Schwann cells ensheath multiple axons in the absence of E3 ligase component Fbxw7
In the central nervous system (CNS), oligodendrocytes myelinate multiple axons; in the peripheral nervous system (PNS), Schwann cells (SCs) myelinate a single axon. Why are the myelinating potentials of these glia so fundamentally different? Here, we find that loss of Fbxw7, an E3 ubiquitin ligase component, enhances the myelinating potential of SCs. Fbxw7 mutant SCs make thicker myelin sheaths and sometimes appear to myelinate multiple axons in a fashion reminiscent of oligodendrocytes. Several Fbxw7 mutant phenotypes are due to dysregulation of mTOR; however, the remarkable ability of mutant SCs to ensheathe multiple axons is independent of mTOR signaling. This indicates distinct roles for Fbxw7 in SC biology including modes of axon interactions previously thought to fundamentally distinguish myelinating SCs from oligodendrocytes. Our data reveal unexpected plasticity in the myelinating potential of SCs, which may have important implications for our understanding of both PNS and CNS myelination and myelin repair
The effect of pose variability and repeated reliability of segmental centres of mass acquisition when using 3D photonic scanning
Three-dimensional (3D) photonic scanning is an emerging technique to acquire accurate body segment parameter data. This study established the repeated reliability of segmental centres of mass when using 3D photonic scanning (3DPS). Seventeen male participants were scanned twice by a 3D whole-body laser scanner. The same operators conducted the reconstruction and segmentation processes to obtain segmental meshes for calculating the segmental centres of mass. The segmental centres of mass obtained from repeated 3DPS were compared by relative technical error of measurement (TEM). Hypothesis tests were conducted to determine the size of change required for each segment to be determined a true variation. The relative TEMs for all segments were less than 5%. The relative changes in centres of mass at ±1.5% for most segments can be detected (p < 0.05). The arm segments which are difficult to keep in the same scanning pose generated more error than other segments
Effect of different standing poses on whole body volume acquisition by three-dimensional photonic scanning
The present study compared whole body volumes obtained by three-dimensional (3D) photonic scanning of two different poses and discussed its effect on body composition estimation. Pose A with large angles of shoulder abduction and feet separated and Pose B with shoulders abducted slightly, the elbows extended and heels together. 16 male and 13 female participants were scanned twice in each pose using a 3D scanner. The mean of whole body volume and the mean of body composition obtained with Pose B was corrected by a regression equation and compared with the results obtained from Pose A. After correction, the whole body volumes acquired with these two poses were similar [limit of agreement = (-0.71 l,0.71 l)] but the body compositions obtained with Pose A and Pose B were different [limit of agreement = (-4.4%, 4.4%)]. The results indicated that scanning using either pose gives reliable estimations for whole body volume and body composition. The whole body volume obtained from different poses can be adjusted using the regression equation but small volumetric differences translate into much more substantial differences in body fat percentage. Hence, it is recommended to use the same scanning pose consistently when monitoring individuals longitudinally
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
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