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.

The ‘flickering switch’ of late Pleistocene climate change

Abstract: POLAR ice contains a unique record of past climate variations; previous Greenland ice cores have documented relatively warm ‘interstadial’ periods during the last glaciation and short (centuryscale) returns to colder conditions during the glacial to interglacial warming (see, for example, ref. 1). These climate features have also been observed to varying degrees in ocean sediment cores2–4 and terrestrial pollen and insect records5–7. Here we report electrical conductivity measurements from a new Greenland ice core, which confirm these previous observations, and also reveal a hitherto unrecognized mode of rapid climate variation. Fluctuations in ice conductivity on the scales of <5–20 years reflect rapid oscillations in the dust content of the atmosphere. This ‘flickering’ between two preferred states would seem to require extremely rapid reorganizations in atmospheric circulation.

The large-scale freshwater cycle of the Arctic

Abstract: This paper synthesizes our understanding of the Arctic's large-scale freshwater cycle. It combines terrestrial and oceanic observations with insights gained from the ERA-40 reanalysis and land surface and ice-ocean models. Annual mean freshwater input to the Arctic Ocean is dominated by river discharge (38%), inflow through Bering Strait (30%), and net precipitation (24%). Total freshwater export from the Arctic Ocean to the North Atlantic is dominated by transports through the Canadian Arctic Archipelago (35%) and via Fram Strait as liquid (26%) and sea ice (25%). All terms are computed relative to a reference salinity of 34.8. Compared to earlier estimates, our budget features larger import of freshwater through Bering Strait and larger liquid phase export through Fram Strait. While there is no reason to expect a steady state, error analysis indicates that the difference between annual mean oceanic inflows and outflows (∼8% of the total inflow) is indistinguishable from zero. Freshwater in the Arctic Ocean has a mean residence time of about a decade. This is understood in that annual freshwater input, while large (∼8500 km3), is an order of magnitude smaller than oceanic freshwater storage of ∼84,000 km3. Freshwater in the atmosphere, as water vapor, has a residence time of about a week. Seasonality in Arctic Ocean freshwater storage is nevertheless highly uncertain, reflecting both sparse hydrographic data and insufficient information on sea ice volume. Uncertainties mask seasonal storage changes forced by freshwater fluxes. Of flux terms with sufficient data for analysis, Fram Strait ice outflow shows the largest interannual variability.

Replications in Psychology Research: How Often Do They Really Occur?

Abstract: Recent controversies in psychology have spurred conversations about the nature and quality of psychological research. One topic receiving substantial attention is the role of replication in psychological science. Using the complete publication history of the 100 psychology journals with the highest 5-year impact factors, the current article provides an overview of replications in psychological research since 1900. This investigation revealed that roughly 1.6% of all psychology publications used the term replication in text. A more thorough analysis of 500 randomly selected articles revealed that only 68% of articles using the term replication were actual replications, resulting in an overall replication rate of 1.07%. Contrary to previous findings in other fields, this study found that the majority of replications in psychology journals reported similar findings to their original studies (i.e., they were successful replications). However, replications were significantly less likely to be successful when there was no overlap in authorship between the original and replicating articles. Moreover, despite numerous systemic biases, the rate at which replications are being published has increased in recent decades.

Oxidative stress causes coral bleaching during exposure to elevated temperatures

Abstract: Elevated temperatures and solar ultraviolet (UV) radiation have been implicated as recent causes for the loss of symbiotic algae (i.e., bleaching) in corals and other invertebrates with photoautotrophic symbionts. One hypothesized mechanism of coral bleaching involves the production of reduced oxygen intermediates, or toxic oxygen, in the dinoflagellate symbionts and host tissues that subsequently causes cellular damage and expulsion of symbionts. Measurements of photosynthesis in the Caribbean coral Agaricia tenuifolia, taken during temperature-induced stress and exposure to full solar radiation, showed a decrease in photosynthetic performance followed by bleaching. Exposure of corals to exogenous antioxidants that scavenge reactive oxygen species during temperature-induced stress improves maximum photosynthetic capacity to rates indistinguishable from corals measured at the ambient temperature of their site of collection. Additionally, these antioxidants prevent the coral from “ bleaching ” and affect the mechanism of symbiont loss from the coral host. These observations confirm a role for oxidative stress, whether caused by elevated temperatures or exposure to UV radiation, in the bleaching phenomenon.