Oregon State University

About: Oregon State University is a education organization based out in Corvallis, Oregon, United States. It is known for research contribution in the topics: Population & Gene. The organization has 28192 authors who have published 64044 publications receiving 2634108 citations. The organization is also known as: Oregon Agricultural College & OSU.

Estimating Nonlinear Selection Gradients Using Quadratic Regression Coefficients: Double Or Nothing?

Abstract: The use of regression analysis has been instrumental in allowing evolutionary biologists to estimate the strength and mode of natural selection. Although directional and correlational selection gradients are equal to their corresponding regression coefficients, quadratic regression coefficients must be doubled to estimate stabilizing/disruptive selection gradients. Based on a sample of 33 papers published in Evolution between 2002 and 2007, at least 78% of papers have not doubled quadratic regression coefficients, leading to an appreciable underestimate of the strength of stabilizing and disruptive selection. Proper treatment of quadratic regression coefficients is necessary for estimation of fitness surfaces and contour plots, canonical analysis of the γ matrix, and modeling the evolution of populations on an adaptive landscape.

Bacterivory and herbivory: Key roles of phagotrophic protists in pelagic food webs.

Abstract: Research on “microbial loop” organisms, heterotrophic bacteria and phagotrophic protists, has been stimulated in large measure by Pomeroy's seminal paper published in BioScience in 1974. We now know that a significant fate of bacterioplankton production is grazing by 20-µm ciliates and heterotrophic dinoflagellates in the microzooplankton. Protists can grow as fast as, or faster than their phytoplankton prey. Phototrophic cells grazed by protists range from bacterial-sized prochlorophytes to large diatom chains (which are preyed upon by extracellularly-feeding dinoflagellates). Recent estimates of microzooplankton herbivory in various parts of the sea suggest that protists routinely consume from 25 to 100% of daily phytoplankton production, even in diatom-dominated upwelling blooms. Phagotrophic protists should be viewed as a dominant biotic control of both bacteria and of phytoplankton in the sea.

Evidence for General and Domain‐Specific Elements of Teacher–Child Interactions: Associations With Preschool Children's Development

Abstract: This study evaluates a model for considering domain-general and domain-specific associations between teacher-child interactions and children's development, using a bifactor analytic strategy. Among a sample of 325 early childhood classrooms there was evidence for both general elements of teacher-child interaction (responsive teaching) and domain-specific elements related to positive management and routines and cognitive facilitation. Among a diverse population of 4-year-old children (n = 1,407) responsive teaching was modestly associated with development across social and cognitive domains, whereas positive management and routines was modestly associated with increases in inhibitory control and cognitive facilitation was associated with gains in early language and literacy skills. The conceptual and methodological contributions and challenges of this approach are discussed.

Self‐regulation in early childhood: Improving conceptual clarity and developing ecologically valid measures.

Abstract: — Children’s ability to direct their attention and behavior to learning tasks provides a foundation for healthy social and academic development in early schooling. Although an explosion of research on this topic has occurred in recent years, the field has been hindered by a lack of conceptual clarity, as well as debate over underlying components and their significance in predicting school success. In addition, few measures tap these skills as children move into formal schooling. This article describes the aspects of self-regulation that are most important for early school success. It then discusses methodological challenges in reliably and validly assessing these skills in young children and describes recent advances in direct measures of self-regulation that are reliable and ecologically valid and that predict children’s school success. It concludes by summarizing critical issues in the study of self-regulation in school contexts and discussing next steps.

Lead and Helium Isotope Evidence from Oceanic Basalts for a Common Deep Source of Mantle Plumes

Abstract: Linear arrays in lead isotope space for mid-ocean ridge basalts (MORBs) converge on a single end-member component that has intermediate lead, strontium, and neodymium isotope ratios compared with the total database for oceanic island basalts (OIBs) and MORBs. The MORB data are consistent with the presence of a common mantle source region for OIBs that is sampled by mantle plumes. 3He/4He ratios for MORBs show both positive and negative correlation with the 206Pb/204Pb ratios, depending on the MORB suite. These data suggest that the common mantle source is located in the transition zone region. This region contains recycled, oceanic crustal protoliths that incorporated some continental lead before their subduction during the past 300 to 2000 million years.