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21.
The (E)-ferulic acid content of the grain of nine populations of land races of maize derived from CIMMYT's collections was found to be negatively correlated to susceptibility characteristics towards the maize weevilSitophilus zeamais. Correlation coefficients for six susceptibility parameters and (E)-ferulic acid content were significant and ranged from –0.58 to –0.79. A multiple regression analysis by the SAS forward procedure using the primary seed characteristics associated with susceptibility indicated that the ferulic acid content was the only significant factor in explaining variation in at least two susceptibility parameters: the Dobie index and adult preference. In 15 CIMMYT pools, correlations between four susceptibility parameters and (E)-ferulic acid content were also significant (–0.76 to –0.81). The results suggest that phenolic acid content is a leading indicator of grain resistance or susceptibility to insects and may represent a newly identified mechanism of resistance.  相似文献   
22.
We report a study of the inhomogeneities in thin helium films due to the van der Waals potential by a resonant acoustical technique. The van der Waals constant between helium and quartz is estimated to be =65±5 K (layer)3; the model leads to a solid helium layer on the substrate of the order ofH=2.2a 0 . A comparison is made with data extracted from interferometric acoustical methods and third-sound type experiments.Associated with the Centre National de la Recherche Scientifique.  相似文献   
23.
Mobile learning is increasing in popularity, but not all university students have mobile devices to support it. Our study investigated cross-platform software that has the potential to allow education practitioners to provide mobile support to their students’ learning, while offering similar functionality to non-mobile users via more traditional computing platforms. Undergraduate students were trained in the use of multi-platform cloud-based note-taking software (Evernote), and used the software in independent study for 8 weeks. Data show adoption for a range of functions, particularly gathering and managing information, organisation and planning, and the recording of ideas. Multimedia functions were also adopted innovatively by some students. Use for reflection was rare. Non-adopters were in a minority, giving low utility appraisals and difficulty in changing habits as reasons. Subjective evaluations and recommendations showed that a majority of students felt positive about the software and found it quick and easy to use. Mobile and non-mobile users only differed on the number of locations in which they used the software, and the proportion of notes classified as ideas, both being higher in mobile users. The data provide decision support for education practitioners who wish to provide mobile learning to their students alongside traditional platforms.  相似文献   
24.
25.
Reliability centered maintenance (RCM) incorporates sound guidance for managers who wish to attain high standards of maintenance at their operating plants. Since the amount and type of maintenance which is applied depend strongly on the machine or components age (DFR, CFR or IFR), on its replacement cost as well as on the cost and safety consequences of system failure, a careful analysis of the system components based on their reliability data should be done in order to optimize the maintenance program. This paper describes the methodology which was used at an aluminum plant in order to select critical machines and to develop an optimal maintenance policy based on reliability data of each machine, safety consequences of system failure, lead time and repair time, and components criticality.  相似文献   
26.
The kinetics of fuse regrowth during temperature humidity bias (THB) stresses were modeled with a power law for relative humidity (exponent /spl sim/2.3) and a power law for bias voltage (exponent /spl sim/1.7). Using these results we determined the optimal laser cut parameters to maximize product reliability.  相似文献   
27.
In this study, the authors examined the validity of the tripartite model of anxiety and depression (L. A. Clark & D. Watson, 1991) in a community epidemiological sample of 467 urban African American youth. Participants completed the Baltimore How I Feel (N. S. Ialongo, S. G. Kellam, & J. Poduska, 1999), a measure of anxiety and depressive symptoms, in Grades 6 and 9. Confirmatory factor analyses indicated that a 3-factor model representing the tripartite model fit the data well and better than competing models. Longitudinal confirmatory factor analysis revealed configural invariance of the tripartite factor structure. However, a predicted divergence among dimensions over time was not evidenced. High correlations among the tripartite dimensions suggest that anxiety and mood symptoms may not differentiate in urban youth. Results are discussed in terms of the ethnicity and urban context of this community sample. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
28.
Miles Lambert 《Costume》2014,48(1):46-59
Specific clothing bequests form a distinct and often intimate feature in a range of English wills during the seventeenth and eighteenth centuries. Carefully and symbolically allocated to new owners, garments were thus imbued with commemoration as well as financial worth. This paper suggests that gender differentials in this practice have been exaggerated as individual men could be as committed to the process as their female counterparts. Crucially, men and women without children or partners were most disposed to draw up detailed wills reallocating a range of possessions, especially clothing. In this creation of stewardship for chosen garments, individual personality and familial situation were more decisive than any general social or economic considerations.  相似文献   
29.
An efficient disparity estimation algorithm for multi-view video sequences, recorded by a two-dimensional camera array in which the cameras are spaced equidistantly, is presented. Because of the strong geometrical relationship among views, the disparity vectors of a certain view can for most blocks be derived from the disparity vectors of other views. A frame constructed using that idea is called a D frame in this work. Three new prediction schemes which contain D frames are proposed for encoding 5 × 3 multi-view video sequences. The schemes are applied to several multi-view image sequences taken from a camera-array and they are compared in terms of quality, bit-rate and complexity. The experimental results show that the proposed prediction schemes significantly decrease the complexity of the encoder at a very low cost of quality and/or bit-rate.  相似文献   
30.
Grouped data occur frequently in practice, either because of limited resolution of instruments, or because data have been summarized in relatively wide bins. A combination of the composite link model with roughness penalties is proposed to estimate smooth densities from such data in a Bayesian framework. A simulation study is used to evaluate the performances of the strategy in the estimation of a density, of its quantiles and first moments. Two illustrations are presented: the first one involves grouped data of lead concentration in the blood and the second one the number of deaths due to tuberculosis in The Netherlands in wide age classes.  相似文献   
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