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.

Assessment of risk of insect-resistant transgenic crops to nontarget arthropods

Abstract: An international initiative is developing a scientifically rigorous approach to evaluate the potential risks to nontarget arthropods (NTAs) posed by insect-resistant, genetically modified (IRGM) crops. It adapts the tiered approach to risk assessment that is used internationally within regulatory toxicology and environmental sciences. The approach focuses on the formulation and testing of clearly stated risk hypotheses, making maximum use of available data and using formal decision guidelines to progress between testing stages (or tiers). It is intended to provide guidance to regulatory agencies that are currently developing their own NTA risk assessment guidelines for IRGM crops and to help harmonize regulatory requirements between different countries and different regions of the world.

Technology on the Move: Recent and Forthcoming Innovations for Tracking Migratory Birds

Abstract: Basic questions about the life histories of migratory birds have confounded scientists for generations, yet we are nearing an era of historic discovery as new tracking technologies make it possible to determine the timing and routes of an increasing number of bird migrations. Tracking small flying animals as they travel over continental-scale distances is a difficult logistical and engineering challenge. Although no tracking system works well with all species, improvements to traditional technologies, such as satellite tracking, along with innovations related to global positioning systems, cellular networks, solar geolocation, radar, and information technology are improving our understanding of when and where birds go during their annual cycles and informing numerous scientific disciplines, including evolutionary biology, population ecology, and global change. The recent developments described in this article will help us answer many long-standing questions about animal behavior and life histories.

The Influence of Nonlinear Mesoscale Eddies on Near-Surface Oceanic Chlorophyll

Abstract: Oceanic Rossby waves have been widely invoked as a mechanism for large-scale variability of chlorophyll (CHL) observed from satellites. High-resolution satellite altimeter measurements have recently revealed that sea-surface height (SSH) features previously interpreted as linear Rossby waves are nonlinear mesoscale coherent structures (referred to here as eddies). We analyze 10 years of measurements of these SSH fields and concurrent satellite measurements of upper-ocean CHL to show that these eddies exert a strong influence on the CHL field, thus requiring reassessment of the mechanism for the observed covariability of SSH and CHL. On time scales longer than 2 to 3 weeks, the dominant mechanism is shown to be eddy-induced horizontal advection of CHL by the rotational velocities of the eddies.

Phylogeny and classification of Pinus

Abstract: We used chloroplast DNA sequences from matK and rbcL to infer the phylogeny for 101 of the approximately 111 species of Pinus (Pinaceae). At the level of subsection and above, the cpDNA tree is congruent with phylogenies based on nuclear DNA with one notable exception: cpDNA sequences from subsect. Contortae are sister to all other North American hard pines rather than occupying a more derived position in the same clade. We used the cpDNA tree plus evidence from nuclear ribosomal DNA and morphology to propose a new classification for the genus. The molecular phylogenies are symmetrical at the deepest branches of the genus, allowing for the delineation of two subgenera, each with two sections that form sister groups. Within sections, clades were slightly asymmetric and sometimes ambiguously resolved. To accomodate ambiguity in some interrelationships, avoid the creation of new ranks, and retain traditional names, we recognised up to three monophyletic subsections per section. Subgenus Pinus (the diploxylon, or hard pines) is divided into the predominantly Eurasian and Mediterranean section Pinus, composed of subsections Pinus and Pinaster, and the strictly North American section Trifoliae, composed of subsections Australes, Ponderosae, and Contortae. Subgenus Strobus (the haploxylon, or soft pines) is divided into the strictly North American section Parrya, composed of subsections Cembroides, Nelsoniae, and Balfourianae, and the Eurasian and North American section Quinquefoliae, composed of subsections Gerardianae, Krempfianae, and Strobus. Mapping of ten morphological and distributional characters indicates that two were diagnostic for infrageneric taxa: the number of vascular bundles per leaf distinguishes subgenus Pinus from subgenus Strobus, and a terminal-positioned umbo on the ovulate cone scale is diagnostic of subsect. Strobus.