123 research outputs found
PRICING SOYBEANS ON THE BASIS OF OIL AND PROTEIN CONTENT
Crop Production/Industries, Demand and Price Analysis,
Beyond Bonferroni revisited: concerns over inflated false positive research findings in the fields of conservation genetics, biology, and medicine
In 2006, Narum published a paper in Conservation Genetics emphasizing that Bonferroni correction for multiple testing can
be highly conservative with poor statistical power (high Type II error). He pointed out that other approaches for multiple
testing correction can control the false discovery rate (FDR) with a better balance of Type I and Type II errors and suggested
that the approach of Benjamini and Yekutieli (BY) 2001 provides the most biologically relevant correction for evaluating
the signifcance of population diferentiation in conservation genetics. However, there are crucial diferences between the
original Benjamini and Yekutieli procedure and that described by Narum. After carefully reviewing both papers, we found
an error due to the incorrect implementation of the BY procedure in Narum (Conserv Genet 7:783–787, 2006) such that
the approach does not adequately control FDR. Since the incorrect BY approach has been increasingly used, not only in
conservation genetics, but also in medicine and biology, it is important that the error is made known to the scientifc community. In addition, we provide an overview of FDR approaches for multiple testing correction and encourage authors frst
and foremost to provide efect sizes for their results; and second, to be transparent in their descriptions of multiple testing
correction. Finally, the impact of this error on conservation genetics and other felds will be study-dependent, as it is related
to the number of true to false positives for each study
Supplementing feedlot steers and heifers with Zilmax increases proportions of strip loin, chuck clod, and top sirloin steaks exceeding Warner-Bratzler shear force thresholds, whereas aging moderates this effect
Ractopamine hydrochloride (Elanco, Greenfield, IN) and Zilmax (zilpaterol hydrochloride; Intervet/Schering-Plough, Millsboro, DE) are β-adrenergic agonists approved in the United States and several other countries to increase growth rate, improve efficiency of feed utilization, and increase carcass meat yield. Zilmax has been shown to improve feed efficiency by 26% and increase hot carcass weight, longissimus muscle area, and meat yield. However, a few studies have shown that Zilmax significantly increased Warner-Bratzler shear force values (decreased tenderness). The objectives of our research were to determine the effects of supplementing feedlot diets of steers and heifers with Zilmax for 0, 20, 30, or 40 days before harvest and the subsequent effects of 7, 14, and 21 days of aging on tenderness of steer and heifer Longissimus lumborum (from strip loins) and heifer Triceps brachii (from chuck clods) and Gluteus medius (from top sirloin butts) muscles
Immersed boundary-finite element model of fluid-structure interaction in the aortic root
It has long been recognized that aortic root elasticity helps to ensure
efficient aortic valve closure, but our understanding of the functional
importance of the elasticity and geometry of the aortic root continues to
evolve as increasingly detailed in vivo imaging data become available. Herein,
we describe fluid-structure interaction models of the aortic root, including
the aortic valve leaflets, the sinuses of Valsalva, the aortic annulus, and the
sinotubular junction, that employ a version of Peskin's immersed boundary (IB)
method with a finite element (FE) description of the structural elasticity. We
develop both an idealized model of the root with three-fold symmetry of the
aortic sinuses and valve leaflets, and a more realistic model that accounts for
the differences in the sizes of the left, right, and noncoronary sinuses and
corresponding valve cusps. As in earlier work, we use fiber-based models of the
valve leaflets, but this study extends earlier IB models of the aortic root by
employing incompressible hyperelastic models of the mechanics of the sinuses
and ascending aorta using a constitutive law fit to experimental data from
human aortic root tissue. In vivo pressure loading is accounted for by a
backwards displacement method that determines the unloaded configurations of
the root models. Our models yield realistic cardiac output at physiological
pressures, with low transvalvular pressure differences during forward flow,
minimal regurgitation during valve closure, and realistic pressure loads when
the valve is closed during diastole. Further, results from high-resolution
computations demonstrate that IB models of the aortic valve are able to produce
essentially grid-converged dynamics at practical grid spacings for the
high-Reynolds number flows of the aortic root
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Similarities and differences in the historical records of lava dome-building volcanoes: implications for understanding magmatic processes and eruption forecasting
A key question for volcanic hazard assessment is the extent to which information can be exchanged between volcanoes. This question is particularly pertinent to hazard forecasting for dome-building volcanoes, where effusive activity may persist for years to decades, and may be punctuated by periods of repose, and sudden explosive activity. Here we review historical eruptive activity of fifteen lava dome-building volcanoes over the past two centuries, with the goal of creating a hierarchy of exchangeable (i.e., similar) behaviours. Eruptive behaviour is classified using empirical observations that include patterns of SO2 flux, eruption style, and magma composition. We identify two eruptive regimes: (i) an episodic regime where eruptions are much shorter than intervening periods of repose, and degassing is temporally correlated with lava effusion; and (ii) a persistent regime where eruptions are comparable in length to periods of repose and gas emissions do not correlate with eruption rates. A corollary to these two eruptive regimes is that there are also two different types of repose: (i) inter-eruptive repose separates episodic eruptions, and is characterised by negligible gas emissions and (ii) intra-eruptive repose is observed in persistently active volcanoes, and is characterised by continuous gas emissions. We suggest that these different patterns of can be used to infer vertical connectivity within mush-dominated magmatic systems. We also note that our recognition of two different types of repose raises questions about traditional definitions of historical volcanism as a point process. This is important, because the ontology of eruptive activity (that is, the definition of volcanic activity in time) influences both analysis of volcanic data and, by extension, interpretations of magmatic processes. Our analysis suggests that one identifying exchangeable traits or behaviours provides a starting point for developing robust ontologies of volcanic activity. Moreover, by linking eruptive regimes to conceptual models of magmatic processes, we illustrate a path towards developing a conceptual framework not only for comparing data between different volcanoes but also for improving forecasts of eruptive activity
Novel genetic loci associated with hippocampal volume
The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness
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