The practical salinity scale of 1978 and its antecedents     

E. L. Lewis 《Marine Geodesy》2013,36(4):350-357

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Modification of the polyethylene glycol 6000 precipitation method for recovering human and indicator viruses from oysters and mussels     

Gillian D. Lewis  Angela Hough  David H. Green  John E. Hay  Lynnette R. Ferguson 《新西兰海洋与淡水研究杂志》2013,47(4):443-447

Human viruses are a common contaminant of shellfish affected by human sewage wastes. They are difficult to detect as they are not easily separated from shellfish tissue. This paper describes a modification of the polyethylene glycol (PEG) precipitation technique for recovery of enteroviruses and F‐specific bacteriophages from the Pacific oyster (Crassostrea gigas) and the green‐lipped mussel (Perna canaliculus). Modifications adopted were the use of only the digestive gland tissue for virus extraction, resuspension of the primary PEG pellet in 4 volumes of eluent, and the introduction of a secondary PEG precipitation to reconcentrate the virus containing extract. The recovery rate of the virus extraction process was not affected by introduction of the secondary concentration step (overall recovery remained at 60–70% of the virus input). The advantages of reduction of tissue residue in the extract, smaller final volume, and the ability to process 2–3 times the number of individual shellfish for the same effort, improve the practicality of the method.  相似文献   

Freshwater Harpacticoid copepods of New Zealand     

Maureen H. Lewis 《新西兰海洋与淡水研究杂志》2013,47(3):277-297

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Enteroviruses in mussels and marine sediments and depuration of naturally accumulated viruses by green lipped mussels (Perna canaliculus)     

Gillian Lewis  Margaret W. Loutit  Frank J. Austin 《新西兰海洋与淡水研究杂志》2013,47(3):431-437

Surveys were carried out over 16 months to assess the distribution of enteroviruses of human origin in sediments and mussels near two sewage outfalls on the North Taranaki Coast, New Zealand. Enteroviruses were present in high numbers in both sediments and shellfish near the New Plymouth sewage outfall with maximum virus levels of 32 000 pfu 100 g^‐1 of wet mussel tissue and 59 pfu 100 g^‐1 of wet sediment material. Viruses were recovered occasionally from sediments and mussels near the Waitara Borough outfall. Coxsackievirus B4 was the predominant virus type isolated but CB5 and Poliovirus types 1, 2, and 3 were also recovered. Attempts to depurate virus‐contaminated New Plymouth mussels, by keeping them in water for 8 days with daily water replacement, did not achieve a significant reduction in virus numbers.  相似文献   

New Zealand xenophyophores: Upper bathyal distribution,photographs of growth position,and a new species     

O. S. Tendal  K. B. Lewis 《新西兰海洋与淡水研究杂志》2013,47(2):197-203

Xenophyophores are a group of giant, but extremely fragile, rhizopod protozoans generally found at lower bathyal or abyssal depths. Recent dredge samples and photographs suggest that there is a largely endemic fauna of xenophyophores with anastomosing branches living at upper bathyal depths around New Zealand. Their distribution may be related to the layer of Antarctic Intermediate water that bathes the upper slope of the New Zealand Plateau.

Photographs of the seafloor at depths of 800–1300 m on the Lord Howe Rise show hemispherical masses, 5 cm across, of which the majority appear to be Syringammina tasmanensis Lewis, 1966 and at least one specimen may be Reticulammina lamellata Tendal, 1972. The photographs indicate that these species live on the seabed, not beneath it, that they are probably filter feeders and that they can reach a density of about one specimen per square metre.

A new species, Reticulammina maini, is described from the continental slope east of Auckland. A key to the New Zealand species of xenophyophore is presented.  相似文献   

Negative diffusion in planetary rings with a nearby moon     

Mark Lewis  Glen Stewart 《Icarus》2011,213(1):201-217

This paper analyzes a process that has been observed in simulations of numerous systems where ring material is strongly perturbed by a nearby moon. If the ring particles can be imparted with a forced eccentricity on the order of 10⁻⁵ in a single pass by the moon, particle orbits are observed to move towards regions of higher density as a result of the organized collisions that occur in the dense peaks of the satellite wake. The width of the ring can decrease by as much as 90% if the forced eccentricity is greater than 3 × 10⁻⁵ and the unperturbed geometric optical depth is greater than 0.03. The fractional change in ring width is relatively insensitive to the particle size so long as the particle radius is much less than the product of the semimajor axis and the forced eccentricity. Including a power law particle size distribution with slope of −2.8 spanning a decade in particle radius reduces the fractional width change by about 10% compared to the uniform particle-size case. Adding gravitational interactions between ring particles only has a significant effect on ring confinement if the unperturbed geometric optical depth exceeds .03, but a 40% reduction in ring width is still achieved in a self-gravitating ring of geometric optical depth 0.3 if the forced eccentricity exceeds 3 × 10⁻⁵. This process does not require the material to be in resonance with the moon, nor does it have any minimum mass constraints because particle self-gravity is not required. The collisional damping of satellite wakes therefore provides a simple mechanism by which a single moon can reduce the radial extent of any ringlet that is close to it and has sufficient optical depth for collisions to be significant.  相似文献   

Response to “Comment on “Slow-mode shock candidate in the Jovian magnetosheath” by Bebesi et al.”     

Z. Bebesi  K. Szego  A. Balogh  N. Krupp  G. Erdos  A.M. Rymer  G.R. Lewis  W.S. Kurth  D.T. Young  M.K. Dougherty 《Planetary and Space Science》2011,59(5-6):445-446

Hubert and Samsonov addressed our paper published in early 2010 (Bebesi et al., 2010) about a plasma event detected in the magnetosheath of Jupiter by the plasma instruments of the Cassini spacecraft. We proposed that the characteristics of the plasma parameter variations were consistent with a slow mode shock (SMS). As our title indicated, we claimed only that the event was a possible “candidate” for an SMS according to our data, which had some restrictions as discussed in the paper. As to the origin, we proposed the following: since there was a crossing of the then highly tilted Heliospheric Current Sheet in less than two days before the event, it might have played a role in initiating the shock front.We highly appreciate the opinion of the authors, but they do not point out any hard fact that would exclude the possibility of the scenario we suggested.  相似文献   

Back analysis of landslide susceptibility zonation mapping for the 2005 Kashmir earthquake: an assessment of the reliability of susceptibility zoning maps   总被引：1，自引：0，他引：1  

Ulrich Kamp  Lewis A. Owen  Benjamin J. Growley  Ghazanfar A. Khattak 《Natural Hazards》2010,54(1):1-25

The October 2005 earthquake triggered several thousand landslides in the Lesser Himalaya of Kashmir in northern Pakistan and India. Analyses of ASTER satellite imagery from 2001 were compared with a study undertaken in 2005; the results show the extent and nature of pre- and co-/post-seismic landsliding. Within a designated study area of ~2,250 km², the number of landslides increased from 369 in 2001 to 2,252 in October 2005. Assuming a balanced baseline landsliding frequency over the 4 years, most of the new landslides were likely triggered by the 2005 earthquake and its aftershocks. These landslides mainly happened in specific geologic formations, along faults, rivers and roads, and in shrubland/grassland and agricultural land. Preliminary results from repeat photographs from 2005 and 2006 after the snowmelt season reveal that much of the ongoing landsliding occurred along rivers and roads, and the extensive earthquake-induced fissuring. Although the susceptibility zoning success rate for 2001 was low, many of the co-/post-seismic landsliding in 2005 occurred in areas that had been defined as being potentially dangerous on the 2001 map. While most of the area in 2001 was (very) highly susceptible to future landsliding, most of the area in 2005 was only moderate to low susceptible, that is, most of the landsliding in 2005 actually occurred in the potentially dangerous areas on the 2001 map. This study supports the view that although susceptibility zoning maps represent a powerful tool in natural hazard management, caution is needed when developing and using such maps.  相似文献   

As the world warmed: Human adaptations across the Pleistocene–Holocene boundary     

Lewis R. Binford 《Geoarchaeology》1999,14(4):369-371

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