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91.
The authors examined the ability of younger and older adults to detect changes in dynamic displays. Older and younger adults viewed displays containing numerous moving objects and were asked to respond when a new object was added to the display. Accuracy, response times, and eye movements were recorded. For both younger and older participants, the number of eye movements accounted for a large proportion of variance in transient detection performance. Participants who actively searched for the change performed significantly worse than did participants who employed a passive or covert scan strategy, indicating that passive scanning may be a beneficial strategy in certain dynamic environments. The cost of an active scan strategy was especially high for older participants in terms of both accuracy and response times. However, older adults who employed a passive or covert scan strategy showed greater improvement, relative to older active searchers, than did younger adults. These results highlight the importance of individual differences in scanning strategy in real-world dynamic, cluttered environments. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
92.
Stephen Balakirsky Zeid Kootbally Thomas Kramer Anthony Pietromartire Craig Schlenoff Satyandra Gupta 《Robotics and Autonomous Systems》2013,61(11):1205-1214
This article presents a newly developed knowledge methodology/model that was designed to support the IEEE Robotics and Automation Society’s Ontologies for Robotics and Automation Working Group. This methodology/model allows for the creation of systems that demonstrate flexibility, agility, and the ability to be rapidly re-tasked. The methodology/model will be illustrated through a case study in the area of robotic kit building. Through this case study, the knowledge model will be presented, and automatic tools for optimizing the knowledge representation for planning systems and execution systems will be discussed. 相似文献
93.
94.
John K. G. Kramer Frank D. Sauer Edward R. Farnworth Dan Stevenson Gail A. Rock 《Lipids》1998,33(1):1-10
Canola oil is not presently permitted in infant formulations in the United States because of lack of information concenring
the effects of feeding canola oil to the newborn. We have previously reported a transient decrease in platelet counts and
an increase in platelet size in newborn piglets fed canola oil for 4 wk, and have confirmed this in the present study. In
canola oil-fed piglets, changes in platelet size and number were overcome by adding either long-chain saturated fatty acids
from cocoa butter (16:0 and 18:0), or shorter-chain saturates from coconut oil (12:0 and 14:0). Feeding a high erucic acid
rapeseed (HEAR) oil, with 20% 22:1n−9, led to an even greater platelet reduction and increased platelet size throughout the
4-wk trial. Bleeding times were longer in piglets fed canola oil or HEAR oil compared to sow-reared and soybean oil-fed piglets.
There were no other diet-related changes. Diet-induced platelet changes were not related to platelet lipid class composition,
but there were fatty acid changes. The incorporation of 22:1n−9 into platelet phospholipids of piglets fed canola oil was
low (0.2–1.2%), and even for the HEAR oil group ranged from only 0.2% in phosphatidylinositol to 2.4% in phosphatidylserine.
A much greater change was observed in the concentration of 24:1n−9 and in the 24:1n−9/24:0 ratio in platelet sphingomyelin
(SM). The 24:1n−9 increased to 49% in the HEAR oil group compared to about 12% in animals fed the control diets (sow-reared
piglets and soybean oil-fed group), while the 24:1n−9/24:0 ratio increased from about 1 to 12. Even feeding canola oil, prepared
to contain 2% 22:1n−9, led to a marked increase in 24:1n−9 to 29% and had a 24:1n−9/24:0 ratio of 5. The canola oil/cocoa
butter group, which also contained 2% 22:1n−9, showed a lower level of 24:1n−9 (20%) and the 24:1n−9/24:0 ratio (3) compared
to the canola oil group. The results suggest that the diet-related platelet changes in newborn piglets may be related to an
increase in 24:1n−9 in platelet SM, resulting from chain elongation of 22:1n−9. The inclusion of canola oil as the sole source
of fat in the milk-replacer diets of newborn piglets resulted in significant platelet and lipid changes. 相似文献
95.
A method is described for visualizing the three-dimensional structure of horseradish peroxidase-labelled neurons in the central nervous system of Xenopus laevis tadpoles. The reconstruction is simple, and performed on a commercially available image processing system. Minimal operational skill is required for using this method. Also, various improvements were made where user's simplicity (user-friendliness), speed and required computer memory are concerned. In addition, the excellent properties of the IBAS II system, such as image filtering and image editing functions are fully available, offering a fast, clean and complete final image reconstruction. 相似文献
96.
ISO Recommended Reference Radiations for the Calibration and Proficiency Testing of Dosemeters and Dose Rate Meters used in Radiation Protection 总被引:1,自引:0,他引:1
97.
98.
In this paper a muIt,ivariat.e EWMA chart for time series is introduced. In principle, it is a generalization of the control scheme of Lowry et al. (I992) for multivarite indendent observations. The autocovariances of the EWMA recursion are derived for stationary multivariate time series. IYsing tllese reslllts a co11t.rol chart hased or1 t11 illt.ivariate EWMA recursion is proposed. For a multivariate autoregressive process of order 1, a sufficient. condition is given such that the in-control average run length (ARL) is invariant, withrespect to the covariance of the White Noise process. This scheme is compared with the MEWMA control chart of Lowry et al. (1992) applied to the residuals. By an extensive Monte carlo study the ARL of both charts are determined for several multivariate autoregressive processses. 相似文献
99.
Silver-ion high-performance liquid chromatographic separation and identification of conjugated linoleic acid isomers 总被引:38,自引:21,他引:17
Najibullah Sehat Martin P. Yurawecz John A. G. Roach Magdi M. Mossoba John K. G. Kramer Youh Ku 《Lipids》1998,33(2):217-221
This is the first report of the application of silverion impregnated high-performance liquid chromatography (Ag+-HPLC) to the separation of complex mixtures of conjugated linolenic acid (CLA) isomers present in commercial CLA sources
and foods and in biological specimens. This method showed a clear separation of CLA isomers into three groups related to their
trans,trans, cis,trans or trans,cis, and cis,cis configuration of the conjugated double-bound system. In addition, this method separated within each geometrical isomeric
group. Following Ag+-HPLC isolation, gas chromatography (GC)-electron impact mass spectrometry, and GC-direct deposition-Fourier transformed infrared
spectroscopy were used to confirm the identity of two major positional isomers in the cis/trans region, i.e., Δ8,10- and Δ11,13-octadecadienoic acid, which had not been chromatographically resolved previously, Furthermore,
the potential of this method was demonstrated by showing different Ag+-HPLC profiles exhibiting patterns of isomeric distributions for biological specimens from animals fed a diet containing a
commerical CLA preparation, as well as for a commerical cheese product. 相似文献
100.
Real time small-angle X-ray scattering (SAXS) from polystyrene (PS) crazed in cyclic three-point bending is investigated using intense X-ray radiation from the Cornell High Energy Synchrotron Source, CHESS. The SAXS patterns are recorded using a two-dimensional image intensifier/TV camera/video tape recorder system, operating at 30 frames/sec. At the maximum of the load cycle the SAXS pattern has a well defined streak normal to the craze fibrils. During the unloading portion of the cycle, however, the streak decreases in intensity and is spread into a diffuse fan. The loss of intensity is due to the decrease in volume of craze matter in the beam as the craze closes while the spreading of the diffraction pattern is due to the disorientation of the craze fibrils as they buckle in response to compression by the surrounding polymer matrix. Whilst reloading of the sample causes a relatively narrow SAXS streak to reappear, at the maximum load irreversible changes occur in the pattern from one cycle to the next. These changes are due to both an increase in craze fibril volume in the beam (craze growth) and to fibril breakdown and permanent disorientation. 相似文献