University of New Hampshire

About: University of New Hampshire is a education organization based out in Durham, New Hampshire, United States. It is known for research contribution in the topics: Population & Solar wind. The organization has 9379 authors who have published 24025 publications receiving 1020112 citations. The organization is also known as: UNH.

Ectomycorrhizal fungal taxa differing in response to nitrogen deposition also differ in pure culture organic nitrogen use and natural abundance of nitrogen isotopes

Abstract: Summary • Ectomycorrhizal fungal species vary in their response to nitrogen (N) availability and ability to use organic N. We hypothesized that taxa dominant at sites with high soil inorganic N would be less likely to use organic N than taxa dominant at low soil inorganic N. We also asked whether these taxa differed in natural abundance of N isotopes. • Pure culture N use for taxa from an N deposition gradient in Alaska was examined and N isotopes of sporocarps, soils and foliage collected over this gradient were quantified. • Taxa common in low inorganic N soils grew on protein, glutamine and serine, whereas dominant taxa in high inorganic N soils grew on glutamine, but poorly on protein and serine. Sporocarp δ15N was highest in protein users, and lowest in nonprotein users. With increasing soil inorganic N, sporocarps became more isotopically enriched relative to foliage. • The importance of organic N use might decline with increasing N availability, although field tests are required. The relationship between organic N use and N isotopes also merits further study. However, sporocarp isotopic enrichment may be a useful indicator of soil N availability.

Mapping Boundaries of the Hostile Media Effect

Abstract: The hostile media perception, the tendency for partisans to judge mass media coverage as unfavorable to their own point of view, has been vividly demonstrated but not well explained. This contrast bias is intriguing because it appears to contradict a robust literature on assimilation biases—the tendency to find information more supportive, rather than more opposed, to one’s own position. We set out to explore a theoretical basis for the hostile media perception that would reconcile it with assimilation biases. To do so, we exposed partisans from opposing camps on the genetically modified foods issue to identical information presented in either a mass media or a student essay context. Consistent with the hypotheses, partisans saw the information as disagreeably biased in a news story format. In student-essay format, however, the hostile media perception disappeared, and there was some evidence of biased assimilation. In addition, content evaluations based on perceived influence on oneself vs. influence on a broader audience suggested that the hostile media perception may be explained by perceived reach of the information source. To newspaper editors it is a common, and not unwelcome, criticism. Two readers from opposing partisan groups write letters to the editor, each complaining that news coverage is biased in favor of the other side. Editors welcome such responses (and usually print them side by side) for together they suggest it is readers, not news stories, who are biased. Psychologists refer to this phenomenon— when an individual perceives information to be more disagreeable with his or her own point of view—as a contrast effect. This particular instance of the contrast effect, a familiar experience for editors and reporters, has been called the hostile media perception. The hostile media perception was first described and documented more than 15 years ago (Vallone, Ross, & Lepper, 1985). Over the next decade, two other experimental studies (Giner-Sorolla & Chaiken, 1994; Perloff, 1989) replicated the effect using the same controversial issue—conflict in the Middle East. Interest in

Genetic and ecological divergence of a monophyletic cichlid species pair under fully sympatric conditions in Lake Ejagham, Cameroon.

Abstract: Although there is mounting evidence that speciation can occur under sympatric conditions, unambiguous examples from nature are rare and it is almost always possible to propose alternative allopatric or parapatric scenarios. To identify an unequivocal case of sympatric speciation it is, therefore, necessary to analyse natural settings where recent monophyletic species flocks have evolved within a small and confined spatial range. We have studied such a case with a cichlid species flock that comprises five Tilapia forms endemic to a tiny lake (Lake Ejagham with a surface area of approximately 0.49 km 2 ) in Western Cameroon. Analysis of mitochondrial D-Loop sequences shows that the flock is very young (approximately 10 4 years) and has originated from an adjacent riverine founder population. We have focused our study on a particular pair of forms within the lake that currently appears to be in the process of speciation. This pair is characterized by an unique breeding colouration and specific morphological aspects, which can serve as synapomorphic characters to prove monophyly. It has differentiated into a large inshore and a small pelagic form, apparently as a response to differential utilization of food resources. Still, breeding and brood care occurs in overlapping areas, both in time and space. Analysis of nuclear gene flow on the basis of microsatellite polymorphisms shows a highly restricted gene flow between the forms, suggesting reproductive isolation between them. This reproductive isolation is apparently achieved by size assortative mating, although occasional mixed pairs can be observed. Our findings are congruent with recent theoretical models for sympatric speciation, which show that differential ecological adaptations in combination with assortative mating could easily lead to speciation in sympatry.