332 research outputs found
Interallelic relations among endosperm variants in sorghum
The inheritance of four endosperm variants of sorghum that exhibit xenia effects was studied in the F1, F2, and backcross seed of crosses among variants and with the normal type. It was concluded that the endosperm variants vanl, sugary (su), and high lysine (h1) are controlled by three Independent single recessive alleles and that dimpled endosperm is controlled by a single recessive allele (dp) allellc to that controlling the vanl endosperm trai
The behaviour of random forest permutation-based variable importance measures under predictor correlation
<p>Abstract</p> <p>Background</p> <p>Random forests (RF) have been increasingly used in applications such as genome-wide association and microarray studies where predictor correlation is frequently observed. Recent works on permutation-based variable importance measures (VIMs) used in RF have come to apparently contradictory conclusions. We present an extended simulation study to synthesize results.</p> <p>Results</p> <p>In the case when both predictor correlation was present and predictors were associated with the outcome (H<sub>A</sub>), the unconditional RF VIM attributed a higher share of importance to correlated predictors, while under the null hypothesis that no predictors are associated with the outcome (H<sub>0</sub>) the unconditional RF VIM was unbiased. Conditional VIMs showed a decrease in VIM values for correlated predictors versus the unconditional VIMs under H<sub>A </sub>and was unbiased under H<sub>0</sub>. Scaled VIMs were clearly biased under H<sub>A </sub>and H<sub>0</sub>.</p> <p>Conclusions</p> <p>Unconditional unscaled VIMs are a computationally tractable choice for large datasets and are unbiased under the null hypothesis. Whether the observed increased VIMs for correlated predictors may be considered a "bias" - because they do not directly reflect the coefficients in the generating model - or if it is a beneficial attribute of these VIMs is dependent on the application. For example, in genetic association studies, where correlation between markers may help to localize the functionally relevant variant, the increased importance of correlated predictors may be an advantage. On the other hand, we show examples where this increased importance may result in spurious signals.</p
A genetic study of popping quality in Sorghum (Sorghum bicolor (L.) Moench)
Two crosses of sorghum, Sorghum bicolor (L.) Moench (IS 1054 Ă ICSV-1, and IS 5604 Ă IS 1054) were evaluated in parental, F1, F2, and backcross generations for the variation in their popping quality as measured by pop volume (ml). Dominance was in the direction of low pop volume. Dominance and additive gene effects, in that order, governed most of the variation, while significant dominance x dominance type of interaction effects could also be detected. There was no evidence for higher order gene interactions
Using audio stimuli in acceptability judgment experiments
In this paper, we argue that moving away from written stimuli in acceptability judgment experiments is necessary to address the systematic exclusion of particular empirical phenomena, languages/varieties, and speakers in psycholinguistics. We provide userâfriendly guidelines for conducting acceptability experiments which use audio stimuli in three platforms: Praat, Qualtrics, and PennController for Ibex. In supplementary materials, we include data and R script from a sample experiment investigating English constituent order using written and audio stimuli. This paper aims not only to increase the types of languages, speakers, and phenomena which are included in experimental syntax, but also to help researchers who are interested in conducting experiments to overcome the initial learning curve. Video Abstract link: https://www.youtube.com/watch?v=GoWYY1O9ugsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156434/2/lnc312377_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156434/1/lnc312377.pd
The Optical Design and Characterization of the Microwave Anisotropy Probe
The primary goal of the MAP satellite, now in orbit, is to make high fidelity
polarization sensitive maps of the full sky in five frequency bands between 20
and 100 GHz. From these maps we will characterize the properties of the cosmic
microwave background (CMB) anisotropy and Galactic and extragalactic emission
on angular scales ranging from the effective beam size, <0.23 degree, to the
full sky. MAP is a differential microwave radiometer. Two back-to-back shaped
offset Gregorian telescopes feed two mirror symmetric arrays of ten corrugated
feeds. We describe the prelaunch design and characterization of the optical
system, compare the optical models to the measurements, and consider multiple
possible sources of systematic error.Comment: ApJ in press; 22 pages with 11 low resolution figures; paper is
available with higher quality figures at
http://map.gsfc.nasa.gov/m_mm/tp_links.htm
The role of neuroticism in self-harm and suicidal ideation:Results from two UK population-based cohorts
Young Women With Type 1 Diabetes Have Lower Bone Mineral Density That Persists Over Time
OBJECTIVEâIndividuals with type 1 diabetes have decreased bone mineral density (BMD), yet the natural history and pathogenesis of osteopenia are unclear. We have previously shown that women with type 1 diabetes (aged 13â35 years) have lower BMD than community age-matched nondiabetic control subjects. We here report 2-year follow-up BMD data in this cohort to determine the natural history of BMD in young women with and without diabetes
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