Observations of Jupiter at 26.3 MHz using a large array     

Michael D. Desch  Thomas D. Carr  Jorge Levy 《Icarus》1975,25(1):12-17

A 640 element phase-steerable dipole array has been used to make highly sensitive observations of the planet Jupiter during the 1973 apparition. The satellite Io is found to have very little influence at the low flux levels, whereas the definition of sources A and B appears to be relatively flux independent. A two-dimensional analysis of the data in the Jupiter-Io plane has revealed considerable source B activity at low intensities which is not influenced by Io.  相似文献   

Time scales of magma storage and differentiation of voluminous high-silica rhyolites at Yellowstone caldera, Wyoming   总被引：5，自引：4，他引：5  

Jorge A. Vazquez  Mary R. Reid 《Contributions to Mineralogy and Petrology》2002,144(3):274-285

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Flowpath Delineation and Ground Water Age, Allequash Basin, Wisconsin   总被引：4，自引：0，他引：4  

Christine D. Pint  Randall J. Hunt  Mary P. Anderson 《Ground water》2003,41(7):895-902

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The respiratory environment of the Namib Desert Golden Mole     

Roger S. Seymour  Mary K. Seely 《Journal of Arid Environments》1996,32(4):453-461

We measured the partial pressure of oxygen (PO₂) in the interstitial gas surrounding the sand-swimming Namib moleEremitalpa granti namibensis. At a sand temperature of 26 °C, which produced a nearly maximal rate of oxygen consumption, thePO₂near the noses of the animals averaged only 0·9 kPa (6·7 Torr) below the level in the free atmosphere. High oxygen availability was a result of the notably low metabolic rate in the 20 g mammals and the dry, porous and metabolically inactive nature of dune sand. A mathematical model indicated that normal mammals weighing 200 g or more could comfortably exist completely encased in dune sand. We concluded that the moles' small size and low metabolic rate are not adaptations to hypoxia or hypercapnia underground but are probably related to low food availability and the energetic cost of foraging in their desert environment.  相似文献   

Data buoy measurements of phytoplankton dynamics in southampton water, UK, a temperate latitude estuary with high nutrient inputs     

Paul N. Wright  David J. Hydes  Mary Lou Lauria  Jonathan Sharples  Duncan A. Purdie 《Ocean Dynamics》1997,49(2-3):203-211

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To Be or Not to Be…     

Mary P. Anderson 《Ground water》2004,42(1):1-1

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Advection Within Shallow Pore Waters of a Coastal Lagoon, Florida   总被引：2，自引：0，他引：2  

Jaye E. Cable  Jonathan B. Martin  Peter W. Swarzenski  Mary K. Lindenberg  Joel Steward 《Ground water》2004,42(7):1011-1020

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Viruses as potential regulators of regional brown tide blooms caused by the alga,Aureococcus anophagefferens     

Mary Downes Gastrich  Justine A. Leigh-Bell  Christopher J. Gobler  O. Roger Anderson  Steven W. Wilhelm  Martha Bryan 《Estuaries and Coasts》2004,27(1):112-119

Blooms of the brown tide organismAureccoccus anophagefferens have recurred in the coastal bays in New Jersey since 1995 and in the coastal bays of Long Island since 1985. Intracellular viral-like particles (VLPs) were documented during 1999–2000 brown tide blooms in Little Egg Harbor, New Jersey, but it was not determined whether cells were infected during the termination of the bloom. The objective of this study was to determine if VLPs infected and lysed natural populations ofA. anophagefferens in coastal bays of New Jersey and New York in 2002 with the same frequency as in 1999–2000 and especially at the termination of the bloom. Our results confirmed that the highest percentage (37.5%) of VLP-infected cells occurred at the termination of the brown tide bloom in New Jersey in 2002. Intracellular VLPs were present throughout the bloom event. The percentage of visibly infected cells was higher at the beginning of the bloom than during the peak of the bloom. The intracellular VLPs in natural populations ofA. anophagefferens were consistent in size and shape (approximately 140 nm in diameter) and comparable to those in previous studies. Concentrated viral isolates, prepared from waters during brown tide blooms in New York and New Jersey in 2002, infected healthy laboratoryA. anophagefferens cultures in vitro. The viral isolates associated with the highest laboratory viral activity (lysis positive) were concentrated from water samples having the highest viral and bacteria concentrations. The intracellular viruses in these virally infected laboratory cultures ofA. anophagefferens were similar in size and shape to those found in natural populations. The successful isolation of a virus specific toA. anophagefferens from a brown tide bloom in the field, the similarity of ultrastructure of VLPs infecting both natural populations and laboratory infected cultures, and the pattern of VLP infection during bloom activity in combination with the observed high percentage of VLP-infected cells during bloom termination, supports, the hypothesis that viruses may be a major source of mortality for brown tide blooms in regional coastal bays of New Jersey and New York.  相似文献   

A Comparison of Public Lands and Farmlands for Grassland Bird Conservation     

Mary Ann Cunningham 《The Professional geographer》2005,57(1):51-65

Midwestern states have invested extensively in grasslands for wildlife conservation, yet these public lands make up a minority of grassland habitat. How effective are public grasslands, relative to private lands, for conserving native songbird populations? I compare private and public lands in southern Minnesota using bird survey data from Conservation Reserve Program (CRP) fields and public lands and assessing fragmentation in a GIS. Bird abundance and diversity were greater on CRP lands. Vegetation composition, field isolation, and field size appear to explain differences in bird counts. Land cover data show that grassland habitat on public lands is scarce and widely scattered. The CRP provides more, and here better, habitat for grassland birds. Funding partly explains this disparity. Trends in farm set‐aside program rules and distribution, which can be vary greatly over time, will strongly influence the success or failure of biodiversity conservation in this region.  相似文献   

Repositioning ourselves     

Robin Kearns  Scott Nichol  Mary Flaws Editors 《New Zealand geographer》2005,61(1):1-2

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