University of Maine

About: University of Maine is a education organization based out in Orono, Maine, United States. It is known for research contribution in the topics: Population & Ice sheet. The organization has 8637 authors who have published 16932 publications receiving 590124 citations. The organization is also known as: University of Maine at Orono.

What aspects of peer relationships are impaired in children with attention-deficit/hyperactivity disorder?

Abstract: Participants included 165 children with attention-deficit/hyperactivity disorder (ADHD; 130 boys, 35 girls) and their 1,298 same-sex classmates (1,026 boys, 272 girls) who served as raters. For each child with ADHD, a child of the same sex was randomly selected from the same classroom to serve as a comparison child, which yielded 165 dyads. Consistent with predictions, contrasted with the comparison children, those with ADHD were lower on social preference, higher on social impact, less well liked, and more often in the rejected social status category; they also had fewer dyadic friends. When liking ratings that children made versus received were examined, children with ADHD had less positive imbalance and greater negative imbalance relative to comparison children. Analyses that considered the types of peers who chose children with ADHD as friends or nonfriends demonstrated that children with ADHD were nominated as nonfriends by children of higher social preference and who were better liked by others.

Carbon-based primary productivity modeling with vertically resolved photoacclimation

Abstract: [1] Net primary production (NPP) is commonly modeled as a function of chlorophyll concentration (Chl), even though it has been long recognized that variability in intracellular chlorophyll content from light acclimation and nutrient stress confounds the relationship between Chl and phytoplankton biomass. It was suggested previously that satellite estimates of backscattering can be related to phytoplankton carbon biomass (C) under conditions of a conserved particle size distribution or a relatively stable relationship between C and total particulate organic carbon. Together, C and Chl can be used to describe physiological state (through variations in Chl:C ratios) and NPP. Here, we fully develop the carbon-based productivity model (CbPM) to include information on the subsurface light field and nitracline depths to parameterize photoacclimation and nutrient stress throughout the water column. This depth-resolved approach produces profiles of biological properties (Chl, C, NPP) that are broadly consistent with observations. The CbPM is validated using regional in situ data sets of irradiance-derived products, phytoplankton chlorophyll:carbon ratios, and measured NPP rates. CbPM-based distributions of global NPP are significantly different in both space and time from previous Chl-based estimates because of the distinction between biomass and physiological influences on global Chl fields. The new model yields annual, areally integrated water column production of ∼52 Pg C a−1 for the global oceans.

Antarctic climate change and the environment

Abstract: The Antarctic climate system varies on timescales from orbital, through millennial to sub-annual, and is closely coupled to other parts of the global climate system. We review these variations from the perspective of the geological and glaciological records and the recent historical period from which we have instrumental data (the last 50 years). We consider their consequences for the biosphere, and show how the latest numerical models project changes into the future, taking into account human actions in the form of the release of greenhouse gases and chlorofluorocarbons into the atmosphere. In doing so, we provide an essential Southern Hemisphere companion to the Arctic Climate Impact Assessment.