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 magnetic reconnection X-line extending more than 390 Earth radii in the solar wind

Abstract: Magnetic reconnection in a current sheet converts magnetic energy into particle energy, a process that is important in many laboratory, space and astrophysical contexts. It is not known at present whether reconnection is fundamentally a process that can occur over an extended region in space or whether it is patchy and unpredictable in nature. Frequent reports of small-scale flux ropes and flow channels associated with reconnection in the Earth's magnetosphere raise the possibility that reconnection is intrinsically patchy, with each reconnection X-line (the line along which oppositely directed magnetic field lines reconnect) extending at most a few Earth radii (R(E)), even though the associated current sheets span many tens or hundreds of R(E). Here we report three-spacecraft observations of accelerated flow associated with reconnection in a current sheet embedded in the solar wind flow, where the reconnection X-line extended at least 390R(E) (or 2.5 x 10(6) km). Observations of this and 27 similar events imply that reconnection is fundamentally a large-scale process. Patchy reconnection observed in the Earth's magnetosphere is therefore likely to be a geophysical effect associated with fluctuating boundary conditions, rather than a fundamental property of reconnection. Our observations also reveal, surprisingly, that reconnection can operate in a quasi-steady-state manner even when undriven by the external flow.

Morphology and Lexical Semantics

Abstract: Morphology and Lexical Semantics explores the meanings of morphemes and how they combine to form the meanings of complex words, including derived words (writer, unionise), compounds (dog bed, truck driver) and words formed by conversion. Rochelle Lieber discusses the lexical semantics of word formation in a systematic way, allowing the reader to explore the nature of affixal polysemy, the reasons why there are multiple affixes with the same function and the issues of mismatch between form and meaning in word formation. Using a series of case studies from English, this book develops and justifies the theoretical apparatus necessary for raising and answering many questions about the semantics of word formation. Distinguishing between a lexical semantic skeleton that is featural and hierarchically organised and a lexical semantic body that is holistic, it shows how the semantics of word formation has a paradigmatic character.

The atmosphere during the younger dryas.

Abstract: One of the most dramatic climate change events observed in marine and ice core records is the Younger Dryas, a return to near-glacial conditions that punctuated the last deglaciation. High-resolution, continuous glaciochemical records, newly retrieved from central Greenland, record the chemical composition of the arctic atmosphere at this time. This record shows that both the onset and the termination of the Younger Dryas occurred within 10 to 20 years and that massive, frequent, and short-term (decadal or less) changes in atmospheric composition occurred throughout this event. Changes in atmospheric composition are attributable to changes in the size of the polar atmospheric cell and resultant changes in source regions and to the growth and decay of continental biogenic source regions.

Yeast Sugar Transporters

Abstract: Transport of sugars is a fundamental property of all eukaryotic cells. Of particular importance is the uptake of glucose, a preferred carbon and energy source. The rate of glucose utilization in yeast is often dictated by the activity and concentration of glucose transporters in the plasma membrane. Given the importance of transport as a site of control of glycolytic flux, the regulation of glucose transporters is necessarily complex. The molecular analysis of these transporters in Saccharomyces has revealed the existence of a multigene family of sugar carriers. Recent data have raised the question of the actual role of all of these proteins in sugar catabolism, as some appear to be lowly expressed, and point mutations of these genes may confer pleiotropic phenotypes, inconsistent with a simple role as catabolic transporters. The transporters themselves appear to be intimately involved in the process of sensing glucose, a model for which there is growing support.