Influence of ACTN3 R577X polymorphism on ventilatory thresholds related to endurance performance     

Leonardo A. Pasqua  Salomão Bueno  Guilherme G. Artioli  Antônio H. Lancha JR.  Monique Matsuda  Mônica V. Marquezini 《Journal of sports sciences》2016,34(2):163-170

The purpose of this study was to verify the association between ACTN3 polymorphism and physiological parameters related to endurance performance. A total of 150 healthy male volunteers performed a maximal incremental running test to determine the speeds corresponding to ventilatory threshold (VT) and respiratory compensation point (RCP). Participants were genotyped and divided into terciles based on the analysed variables. Genotype frequencies were compared through χ² test between lower and higher terciles, with the lowest or highest values of each analysed variable. ACTN3 XX genotype was over-represented in higher tercile for VT and RCP. Odds ratio also showed significantly higher chances of XX individuals to be in higher tercile compared to RR (7.3) and RR + RX (3.5) for VT and compared to RR genotype (8.1) and RR + RX (3.4) for RCP. Thus, XX individuals could attain the VT and RCP at higher speeds, suggesting that they are able to sustain higher running speeds in lower exercise intensity domains. It could result in higher lipid acids oxidation, saving muscle glycogen and delaying the fatigue during prolonged exercises, which could be the advantage mechanism of this genotype to endurance performance.  相似文献   

The Accuracy of Dixon’s Formula for Obtaining Critical F-Values     

James R. Morrow JR.  Kenneth D. Hopkins 《Journal of Experimental Education》2013,81(2):113-115

The F-distribution approximation suggested by Dixon was investigated at various combinations of alpha and degrees of freedom. Tabled values were compared with values computed utilizing the suggested formula. The results indicate that while the formula is not useful in all cases, the adequacy of the approximation generally increases as alpha, v₁, and v₂ increase. It is suggested that the approximation may be utilized when certain restrictions regarding alpha, v1, and v2 are met.  相似文献   

Phonological Spelling and Reading Deficits in Children With Spelling Disabilities     

Angela Friend  Richard K. Olson 《Scientific Studies of Reading》2013,17(1):90-105

Spelling errors in the Wide Range Achievement Test were analyzed for 77 pairs of children, each of which included one older child with spelling disability (SD) and one spelling-level-matched younger child with normal spelling ability from the Colorado Learning Disabilities Research Center database. Spelling error analysis consisted of a percent graphotactic-accuracy (GA) score based on syllable position and existence in English, and a phonological accuracy score (PA). The SD group scored significantly worse in the PA measure and nonsignificantly better than controls on the GA measure. The Group × Measure interaction was significant. Spelling matched pairs had very similar scores for word recognition and orthographic coding, but the SD group exhibited significant deficits in reading measures of phonological decoding and in language measures of phonological awareness.  相似文献   

The use of reading tests in primary schools: a progress report     

Peter Friend 《Literacy》1981,15(2):15-20

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Problems of Construct Validation and the GNC Scale     

GEORGE L. NEWSOME  JR.  D. B. GOWIN 《Educational theory》1968,18(4):338-353

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Fabrication of microfluidic devices using polydimethylsiloxane   总被引：1，自引：0，他引：1  

James Friend  Leslie Yeo 《Biomicrofluidics》2010,4(2)

Polydimethylsiloxane (PDMS) is nearly ubiquitous in microfluidic devices, being easy to work with, economical, and transparent. A detailed protocol is provided here for using PDMS in the fabrication of microfluidic devices to aid those interested in using the material in their work, with information on the many potential ways the material may be used for novel devices.  相似文献   

Effect of surface acoustic waves on the viability, proliferation and differentiation of primary osteoblast-like cells     

Haiyan Li  James Friend  Leslie Yeo  Ayan Dasvarma    Kathy Traianedes 《Biomicrofluidics》2009,3(3)

Surface acoustic waves (SAWs) have been used as a rapid and efficient technique for driving microparticles into a three-dimensional scaffold matrix, raising the possibility that SAW may be effective in seeding live cells into scaffolds, that is, if the cells were able to survive the infusion process. Primary osteoblast-like cells were used to specifically address this issue: To investigate the effects of SAW on the cells’ viability, proliferation, and differentiation. Fluorescence-labeled osteoblast-like cells were seeded into polycaprolactone scaffolds using the SAW method with a static method as a control. The cell distribution in the scaffold was assessed through image analysis. The cells were far more uniformly driven into the scaffold with the SAW method compared to the control, and the seeding process with SAW was also significantly faster: Cells were delivered into the scaffold in seconds compared to the hour-long process of static seeding. Over 80% of the osteoblast-like cells were found to be viable after being treated with SAW at 20 MHz for 10–30 s with an applied power of 380 mW over a wide range of cell suspension volumes (10–100 μℓ) and cell densities (1000–8000 cells∕μℓ). After determining the optimal cell seeding parameters, we further found that the treated cells offered the same functionality as untreated cells. Taken together, these results show that the SAW method has significant potential as a practical scaffold cell seeding method for tissue and orthopedic engineering.  相似文献   

Adults' attribution of responsibility for success and failure of children from different social backgrounds     

Ronald M. Friend  Lorraine E. Wood 《Psychology in the schools》1973,10(3):339-344

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Focused ion beam milling of microchannels in lithium niobate     

Sridhar M  Maurya DK  Friend JR  Yeo LY 《Biomicrofluidics》2012,6(1):12819-1281911

We present experimental and simulation results for focused ion beam (FIB) milling of microchannels in lithium niobate in this paper. We investigate two different cuts of lithium niobate, Y- and Z-cuts, and observe that the experimental material removal rate in the FIB for both Y-cut and Z-cut samples was 0.3 μm³/nC, roughly two times greater than the material removal rate previously reported in the literature but in good agreement with the value we obtain from stopping and range of ions in matter (SRIM) simulations. Further, we investigate the FIB milling rate and resultant cross-sectional profile of microchannels at various ion beam currents and find that the milling rate decreases as a function of ion dose and correspondingly, the cross-sectional profiles change from rectangular to V-shaped. This indicates that material redeposition plays an important role at high ion dose or equivalently, high aspect ratio. We find that the experimental material removal rate decreases as a function of aspect ratio of the milled structures, in good agreement with our simulation results at low aspect ratio and in good agreement with the material removal rates previously reported in the literature at high aspect ratios. Our results show that it is indeed easier than previously assumed to fabricate nanochannels with low aspect ratio directly on lithium niobate using the FIB milling technique.  相似文献   

Librarianship and Information Science in The Sahel 1966–1999: An Annotated Bibliography     

STERLING COLEMAN  JR. 《International Information and Library Review》2001,33(4):275

This work is an annotated bibliography that consists of articles, books, conference papers, dissertations, reports, etc., published in various library and information science forums on the subject of librarianship in the Sahel.The Encyclopaedia Britannica Online defines the term Sahel as an English translation of the Arab termSahil which refers to the semi-arid region of western and north-central Africa extending from Senegal to The Sudan. The Sahel for the purposes of this work consists of the region of West Africa and the nations of Gambia, Ivory Coast, Mali, Mauritania, Niger, Senegal, and Sierra Leone. Nigerian library literature will be given a full and separate treatment in two subsequent articles.While this work is by no means an exhaustive analysis of the entire Sahelian library, literature, it does strive to be comprehensive in terms of its country-by-country breakdown of librarianship within the region. In providing a citation for a non-English language work, the English equivalent of the title of that work will be given next to the non-English title.  相似文献