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.

A ubiquitous thermoacidophilic archaeon from deep-sea hydrothermal vents

Abstract: In spite of the extreme environmental conditions, deep-sea hydrothermal vents are home to a multitude of microbial species. But one ingredient was missing: terrestrial hot acid springs are inhabited by acidophiles, but although theory predicts the presence of acidic microhabitats in sulphide deposits at deep-seavents, until now all microbes isolated from these deposits have been neutrophiles, or at best acid tolerant. Now, at last, an extreme thermoacidophilic microbe has been isolated from a hydrothermal vent. It's not a bacterium, but a member of the Archaea DHVE2 (deep-sea hydrothermal vent Euryarchaeota 2) lineage. It grows at pHs between 3.3 and 5.8 and at temperatures of 55–75°C. It constitutes up to 15% of the archaeal population so may be the main player in the iron and sulphurcycles in these environments. Isolation and cultivation of an extreme thermoacidophilic archaeon from hydrothermal vents suggests that this organism may be important in the iron and sulphur cycles in these environments. Deep-sea hydrothermal vents are important in global biogeochemical cycles, providing biological oases at the sea floor that are supported by the thermal and chemical flux from the Earth's interior. As hot, acidic and reduced hydrothermal fluids mix with cold, alkaline and oxygenated sea water, minerals precipitate to form porous sulphide–sulphate deposits. These structures provide microhabitats for a diversity of prokaryotes that exploit the geochemical and physical gradients in this dynamic ecosystem1. It has been proposed that fluid pH in the actively venting sulphide structures is generally low (pH < 4.5)2, yet no extreme thermoacidophile has been isolated from vent deposits. Culture-independent surveys based on ribosomal RNA genes from deep-sea hydrothermal deposits have identified a widespread euryarchaeotal lineage, DHVE2 (deep-sea hydrothermal vent euryarchaeotic 2)3,4,5,6. Despite the ubiquity and apparent deep-sea endemism of DHVE2, cultivation of this group has been unsuccessful and thus its metabolism remains a mystery. Here we report the isolation and cultivation of a member of the DHVE2 group, which is an obligate thermoacidophilic sulphur- or iron-reducing heterotroph capable of growing from pH 3.3 to 5.8 and between 55 and 75 °C. In addition, we demonstrate that this isolate constitutes up to 15% of the archaeal population, providing evidence that thermoacidophiles may be key players in the sulphur and iron cycling at deep-sea vents.

Acoustic alarms reduce porpoise mortality

Abstract: The most serious danger to dolphins and porpoises around the world is the threat from various forms of gill-net fishing. One potential way to reduce the number of deaths of marine mammals is the use of active acoustic alarms to warn animals about the presence of nets1. Until now, acoustic alarms have not been tested in field experiments with sufficient statistical power2. Here we describe a field experiment showing that acoustic alarms are effective at reducing the number of deaths of harbour porpoises (Phocoena phocoena) in sink gill-nets.

Spatial correlation of solar-wind turbulence from two-point measurements

Abstract: Interplanetary turbulence, the best studied case of low frequency plasma turbulence, is the only directly quantified instance of astrophysical turbulence. Here, magnetic field correlation analysis, using for the first time only proper two-point, single time measurements, provides a key step in unraveling the space-time structure of interplanetary turbulence. Simultaneous magnetic field data from the Wind, ACE, and Cluster spacecraft are analyzed to determine the correlation (outer) scale, and the Taylor microscale near Earth's orbit.