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

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.     

Four new species of the lanternfish genus Diaphus (Myctophidae) from the Indo‐Pacific

Four new species of the genus Diaphus are described. Three of these are in the subgeneric group with a suborbital luminous organ and are members of the D. fulgens species group with a raised AOa₁ photophore. D. impostor sp. nov. from the Indo‐West Pacific is most similar to D. aliciae, differing in lower gill raker count and smaller size. D. wisneri sp. nov. from north of Hawaii and south Pacific lacks a luminous scale at the PLO and has a lower gill raker count than similar species. D. kora sp. nov. from north‐east of New Zealand has a large luminous scale at the PLO, and a longer Vn and lower gill raker counts than similar species. D. kapalae sp. nov. from the south‐western Pacific is most similar to D. splendidus and D. antonbruuni, from which it differs by the presence of an Ant, higher gill raker counts, and position of the VLO photophore.     

Lake sediment record of the geomagnetic secular variation in Britain during Holocene times

Summary. A palaeomagnetic record of the geomagnetic secular variation during the last 10000 years has been obtained from 10 cores of sediment from Loch Lomond, Scotland, Lake Windermere, North England, and Llyn Geirionydd, North Wales. A time-scale is provided by 30 radiocarbon age determinations and pollen analyses on several of the cores. The main swings and much fine detail of both declination and inclination records repeat well between cores and between lakes, and the overall record is much more detailed than previous European records.
The new record shows that neither declination nor inclination swings have been periodic over the past 10000 years, but that the main swings have become progressively shorter in duration during that time. Each swing is characterized by fine detail which enables use of the record as a secondary method of dating other European sediments.
The motion of the geomagnetic vector has been predominantly clockwise throughout the time period spanned, but confirms a period of anticlockwise motion from 1100 to 600 bp first discovered by British archaeomagnetic investigations. The record agrees with British and Czechoslovakian archaeomagnetic records, but not with Japanese archaeomagnetic or North American lake sediment records. This suggests that the secular changes are controlled by local growing and decaying, drifting sources, rather than by wobbling of the main geomagnetic dipole.     

Observations of SN1985G and SN1985H with the new faint-object spectrograph

Spectra of the supernovae SN1985G and SN1985H obtained with the Faint Object Spectrograph (FOS) on the 2.5 m Isaac Newton Telescope (INT) at the Observatorio del Roque de los Muchachos are presented in the wavelength range 4600 to 10 000 Å.     

THE SPACES OF COPING: WOMEN AND "POVERTY" IN SINGAPORE

This paper investigates the relationship between space, gender and poverty in the dynamic Pacific Asian economy of Singapore. It argues for the use of coping strategies as an analytical tool for investigating these relationships, highlighting how women construct strategies from confined spaces. Drawing on spatial stories and real life accounts, it examines the ways in which women use the labour market, the family and community services as strategies against poverty. The paper concludes that women struggle to negotiate the constraints of inadequate childcare provision and traditional attitudes, choosing instead to remain in the home or enter “liminal” spaces in the form of Family Service Centres.     

Working a fraction and making a fraction work: a rough guide for geographers in the academy

Little is known about the issues facing geographers working on fractional appointments in higher education institutions in the UK. This paper draws on a survey of UK geography departments and personal experiences to explore some of that territory for the first time. The purpose is both to set the agenda for institutional policy issues and to provide some immediate points of reflection for staff intending to take up fractional work. We consider the place of fractional working in the dominant discourses around paid work, problems of workload division and the impact on professional standing (including the RAE). We suggest that while personal 'life' reasons for fractional working are often positive, fractional workers in the academy risk professional marginalization.     

Does the polar cap disappear under an extended strong northward IMF?

The suggestion that the polar cap can completely disappear under certain northward IMF conditions is still controversial. We know that the size of the polar cap is strongly controlled by the interplanetary magnetic field (IMF). Under a southward IMF, the polar cap is usually large and filled with weak diffuse polar rain electrons. The polar cap shrinks under a northward IMF. Here we use the global auroral images and coincident particle measurements on May 15, 2005 to show that the discrete arcs (due to precipitation of both electrons and ions) expanded from the dayside oval to the nightside oval and filled the whole polar ionosphere after a long (8 h) and strong (～5–30 nT) northward IMF B_z, The observations suggested that the polar cap disappeared under a closed magnetosphere.     

Phylogeography of Acesta clams from submarine seamounts and escarpments along the western margin of North America

Genetic connectivity and habitat characteristics were examined in two species of Acesta clams (Bivalvia: Limidae) from submarine seamounts and continental slopes along the western North America margin. Two species were identified from dive videos obtained with submarine remotely operated vehicles that surveyed a 2200‐km range between 27° and 46° N latitude. Acesta sphoni was only found at shallower habitats (545–860 m depth) in the southern part of this range, whereas Acesta mori was more abundant and widely distributed in deeper habitats (1029–1996 m). Both species occurred on seamounts and on the walls of submarine canyons and continental slopes. Segregation of these species by depth exposes them to correlated differences in water temperatures and dissolved oxygen concentrations. Ninety‐eight individuals sampled from seven seamounts and one escarpment locality were characterized with DNA‐barcodes based on 643 base pairs of mitochondrial cytochrome‐c ‐oxidase subunit I (COI). Further analysis of these sequences revealed no significant geographical subdivision across the sampled range. This lack of differentiation suggests ongoing genetic exchange between the seamount populations and those possibly distributed along the continental margins. Examination of regional bathymetric profiles suggested that an abundance of suitable habitat might exist along these margins.     

The temporal evolution of the large equatorial plasma depletions observed during the 29–30 October 2003 storm

This study investigates the temporal evolution of the large plasma depletions observed by ROCSAT-1 and DMSP near 295°E during the 29–30 October 2003 storm. The presence of a penetration electric field around the detection time of the large plasma depletions is supported by the observation of high upward ion drift velocity and formation of an intense equatorial ionization anomaly in the American sector. However, these ionospheric disturbances occur in broad longitude regions; a short-range polarization electric field may adequately explain the creation of the large plasma depletions. The penetration electric field may trigger the Rayleigh–Taylor instability and produce abnormally large plasma depletions during the storm. The TIMED/GUVI and CHAMP observations provide an insight for the evolution of the large depletions several hours after their formation. The large depletions appear as arch-shaped emission depletions in the TIMED/GUVI image and as symmetric depletions paired in the magnetic north and south in the CHAMP observation. These characteristics can be explained by the “plasma depletion shell” phenomenon (Kil et al., 2009) produced by the westward shear flow of the ionosphere during the storm.     

Improving exposure assessment in environmental epidemiology: Application of spatio-temporal visualization tools

A thorough assessment of human exposure to environmental agents should incorporate mobility patterns and temporal changes in human behaviors and concentrations of contaminants; yet the temporal dimension is often under-emphasized in exposure assessment endeavors, due in part to insufficient tools for visualizing and examining temporal datasets. Spatio-temporal visualization tools are valuable for integrating a temporal component, thus allowing for examination of continuous exposure histories in environmental epidemiologic investigations. An application of these tools to a bladder cancer case-control study in Michigan illustrates continuous exposure life-lines and maps that display smooth, continuous changes over time. Preliminary results suggest increased risk of bladder cancer from combined exposure to arsenic in drinking water (>25 g/day) and heavy smoking (>30 cigarettes/day) in the 1970s and 1980s, and a possible cancer cluster around automotive, paint, and organic chemical industries in the early 1970s. These tools have broad application for examining spatially- and temporally-specific relationships between exposures to environmental risk factors and disease.This study was supported by grant R01 CA96002-10, Geographic-Based Research in Cancer Control and Epidemiology, from the National Cancer Institute. Development of the STIS^TM software was funded by grants R43 ES10220 from the National Institutes of Environmental Health Sciences and R01 CA92669 from the National Cancer Institute. Access to cancer case records was provided by Michigan Cancer Surveillance Program within the Division for Vital Records and Health Statistics, Michigan Department of Community Health. The authors thank Michigan Public Health Institute for conducting the telephone interview and Stacey Fedewa and Lisa Bailey for entering written surveys into a database. The authors thank 3 anonymous reviewers for their helpful comments.