QUALITY QUANDARIES∗ Multiple Sources of Variation: Variance Components

A method to categorize defoliation on current year's shoots of jack pine (Pinusbanksiana Lamb.) was developed. The pattern of defoliation caused by the jack pine budworm (Choristoneurapinuspinus Free.) feeding on jack pine trees was studied in a variety of locations in Manitoba and Saskatchewan over several years. In addition to differences among locations and years, the crown level from which a sample was taken, the branch within a tree, the tree within a plot, and the plot within a study location were consistent sources of variation. In general, the upper crown was most heavily defoliated and the lower crown least so. Branches, trees, and plots are random sources of variation, and the variance components associated with each such source were analyzed to determine their contribution to the overall variance in the estimate of defoliation. The relative importance of each random source of variation varied with the percent defoliation. Variation among plots was significant at defoliation levels below 45% and peaked at 25%, indicating a patchy distribution of feeding within stands in this range of defoliation. Beyond 45% defoliation, feeding was uniformly distributed among plots within a stand. Variation in defoliation among branches and trees peaked in the 50–60% defoliation range and was negligible at the extremes. Advantage can be taken of the consistent patterns of defoliation among crown levels and knowledge of the variance components of the random sources of variation to design defoliation assessment protocols. These data were used to optimize the allocation of effort, among plots, trees, and branches, required to determine the level of defoliation in stands either with fixed level of effort or to a specified level of precision.

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Clonal selection in Cupressussempervirens: estimates of genetic parameters in juvenile growth

Canadian Journal of Forest Research ◽

10.1139/x92-011 ◽

1992 ◽

Vol 22 (1) ◽

pp. 76-81 ◽

Cited By ~ 6

Author(s):

Raffaello Giannini ◽

Sabrina Raddi

Keyword(s):

Variance Components ◽

Genetic Parameters ◽

Growth Traits ◽

Clonal Selection ◽

Central Italy ◽

Site Effect ◽

Height Growth ◽

Site Specific ◽

Sources Of Variation ◽

A Site

Fifty common cypress (Cupressussempervirens L.) clones were evaluated at two sites in central Italy over a period of 5 years (1983–1987) for height growth, degree of resistance to Seiridiumcardinale, and diameter growth (1986 and 1987 only). Phenotypic correlations between height and diameter were high, positive, and significant. No correlation was found between degree of resistance and growth traits. Analysis of variance indicated that clone, site, and site–clone interaction were the significant sources of variation for each year and trait. The trend of height variance components over years indicated that after the 1st year (planting year) site–clone interaction and experimental error remained more or less constant, while clonal effect increased and site effect decreased over years. The evaluation of the expected genetic gains from selection indicated that the costs of a site-specific breeding program, on sites similar to the two tested in this paper, were not economically justified.

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Bankruptcy as Implicit Health Insurance

The American Economic Review ◽

10.1257/aer.20131408 ◽

2015 ◽

Vol 105 (2) ◽

pp. 710-746 ◽

Cited By ~ 56

Author(s):

Neale Mahoney

Keyword(s):

At Risk ◽

Health Insurance ◽

Affordable Care Act ◽

Insurance Coverage ◽

Microsimulation Model ◽

Multiple Sources ◽

Financial Cost ◽

Coverage Decision ◽

Sources Of Variation ◽

The Affordable Care Act

This paper examines the implicit health insurance that households receive from the ability to declare bankruptcy. Exploiting multiple sources of variation in asset exemption law, I show that uninsured households with a greater financial cost of bankruptcy make higher out-of-pocket medical payments, conditional on the amount of care received. In turn, I find that households with greater wealth at risk are more likely to hold health insurance. The implicit insurance from bankruptcy distorts the insurance coverage decision. Using a microsimulation model, I calculate that the optimal Pigovian penalties are three-quarters as large as the average penalties under the Affordable Care Act. (JEL D14, H51, I13, K35)

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Contract Provisions, Default Risk, and Bond Prices

Sovereign Debt Diplomacies ◽

10.1093/oso/9780198866350.003.0014 ◽

2021 ◽

pp. 304-330

Author(s):

Anusha Chari ◽

Ryan Leary

Keyword(s):

New York ◽

Puerto Rico ◽

Credit Risk ◽

Puerto Rican ◽

Default Risk ◽

Multiple Sources ◽

Economic Stability ◽

Legal Provisions ◽

Sources Of Variation ◽

General Obligation Debt

This chapter presents a case study that investigates the pricing of key contract provisions in Puerto Rican debt. It contributes to a body of research that asks whether investors price contract provisions and, if so, whether the pricing varies with credit risk. Contract provisions across different types of Puerto Rican bonds contain multiple sources of variation. Specifically, the chapter examines investor pricing of three key legal provisions of Puerto Rican debt; general obligation debt versus the secured bonds issued by the Puerto Rico Sales Tax Financing Corporation; debt issued under New York law versus Puerto Rican law; and finally impact of the Puerto Rico Oversight, Management, and Economic Stability Act (PROMESA) which retroactively enacted collective action clauses for Puerto Rican debt. In each instance, we find evidence consistent with the hypothesis that investors value specific contract provisions and legal protections and more so when credit risk is high, and restructuring becomes likely.

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Neural structure of a sensory decoder for motor control

10.1101/2020.10.22.350371 ◽

2020 ◽

Author(s):

Seth W. Egger ◽

Stephen G. Lisberger

Keyword(s):

Motor Control ◽

Motor Behavior ◽

Control Strategies ◽

Surprising Result ◽

Neural Responses ◽

Multiple Sources ◽

Neural Structure ◽

Sources Of Variation ◽

And Control ◽

The Relationship

ABSTRACTWe seek to understand the neural mechanisms that perform sensory decoding for motor behavior, advancing the field by designing decoders based on neural circuits. A simple experiment produced a surprising result that shapes our approach. Changing the size of a target for smooth pursuit eye movements changes the relationship between the variance and mean of the evoked behavior in a way that contradicts the regime of “signal-dependent noise” and defies traditional decoding approaches. A theoretical analysis leads us to conclude that sensory decoding circuits for pursuit include multiple parallel pathways and multiple sources of variation. Behavioral and neural responses with biomimetic statistics emerge from a biologically-motivated circuit model with noise in the pathway that is dedicated to flexibly adjusting the strength of visual-motor transmission. Flexible adjustment of transmission strength applies much more broadly to issues in sensory-motor control such as Bayesian integration and control strategies to optimize motor behavior.

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ACE: a probabilistic model for characterizing gene-level essentiality in CRISPR screens

Genome Biology ◽

10.1186/s13059-021-02491-z ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Elizabeth R. Hutton ◽

Christopher R. Vakoc ◽

Adam Siepel

Keyword(s):

Cancer Research ◽

High Throughput ◽

Statistical Tests ◽

Multiple Sources ◽

Framework Analysis ◽

Modeling Framework ◽

Therapeutic Targeting ◽

Gene Level ◽

Sources Of Variation ◽

Robust Framework

AbstractHigh-throughput CRISPR-Cas9 knockout screens are widely used to evaluate gene essentiality in cancer research. Here we introduce a probabilistic modeling framework, Analysis of CRISPR-based Essentiality (ACE), that accounts for multiple sources of variation in CRISPR-Cas9 screens and enables new statistical tests for essentiality. We show using simulations that ACE is effective at predicting both absolute and differential essentiality. When applied to publicly available data, ACE identifies known and novel candidates for genotype-specific essentiality, including RNA m6-A methyltransferases that exhibit enhanced essentiality in the presence of inactivating TP53 mutations. ACE provides a robust framework for identifying genes responsive to subtype-specific therapeutic targeting.

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Multiple sources of variation.

Sampling and monitoring in crop protection: the theoretical basis for developing practical decision guides. ◽

10.1079/9780851993478.0183 ◽

2009 ◽

pp. 183-204

Author(s):

M. R. Binns ◽

J. P. Nyrop ◽

W. van der Werf

Keyword(s):

Multiple Sources ◽

Sources Of Variation

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