Uptake and depuration of I by the macroalgae Catenella nipae - Potential use as an environmental monitor for radiopharmaceutical waste

A study was initiated to establish the suitability of the macroalgae, Catenella nipae as an environmental surveillance monitor for radiopharmaceutical waste discharges to aquatic environments. A series of experiments were conducted to establish the radioactive iodine (¹³¹I) concentration factor, and uptake and depuration characteristics of C. nipae. The steady state concentration factor was estimated to be 630 ± 80 mL g⁻¹, with an uptake half-time of 160 ± 20 min. Elimination of ¹³¹I was found to follow a two phase model, the first having a rapid elimination rate with a half-time of <1 min, followed by the second phase with a half-time of 3.2 days. Application of the Michaelis-Menton model allowed calculation of an estimate for activity concentration of ¹³¹I in environmental waters from C. nipae sampling devices in the Brisbane River estuary, Australia. The results suggest that C. nipae may be used as an environmental radioactive waste sentinel.     

Large and growing environmental reservoirs of Deca-BDE present an emerging health risk for fish and marine mammals

Polybrominated diphenyl ethers (PBDEs) have been the subject of intense scientific and regulatory scrutiny during recent years. Of the three commercial forms (Penta, Octa and Deca) of PBDEs that have been widely used as flame retardants in textiles, furniture upholstery, plastics, and electronics, only Deca-BDE remains on the general market in North America, while a recent ruling of the European Court spells an impending end to its use in Europe. We review here highlights of aquatic research documenting the rapid emergence of PBDEs as a high priority environmental concern in Canada. PBDEs are being introduced in large quantities to the aquatic environment through sewage discharge and atmospheric deposition. In certain environmental compartments, the single congener BDE-209, the main ingredient in the Deca-BDE formulation, has surpassed the legacy PCBs and DDT as the top contaminant by concentration. Limited biomagnification of BDE-209 in aquatic food webs reflects its high log K_ow and preferential partitioning into the particle phase. As a result, large environmental reservoirs of BDE-209 are being created in sediments, and these may present a long-term threat to biota: BDE-209 breaks down into more persistent, more bioaccumulative, more toxic, and more mobile PBDE congeners in the environment.     

Using 'the body' as an 'instrument of research': kimch'i and pavlova

Often researchers position themselves in relation to race, age and gender, but the body is less often discussed as an actual 'instrument of research'. We aim to extend thinking on this point by reflecting on a project we conducted on migrant women and food in New Zealand. We present a vignette as an example of how we used our bodies as 'instruments of research' at a 'shared lunch' attended by new migrants from a range of different countries. At the lunch some combined on their plates spicy dishes such as kimch'i (fermented vegetables) and sweet dishes such as pavlova (a meringue dessert). For others this combination prompted feelings of disgust. We conclude that the body is a primary tool through which all interactions and emotions filter in accessing research subjects and their geographies.     

ASIANS,PACIFIC ISLANDERS,AND ETHNOBURBS IN AUCKLAND,NEW ZEALAND

ABSTRACT. Recent work on Asian ethnic minority immigrants to cities in the Anglophone Pacific Rim argues that their settlement patterns do not conform to those of earlier migrant streams. Instead of concentrating in high‐density, low‐quality, inner‐city housing, these new residents are moving directly to suburban areas where they form much less intensive concentrations—ethnoburbs—than has been typical of other culturally distinct migrant groups. We evaluate this thesis for Asian migrants in the Auckland metropolitan area, whose numbers more than quadrupled between 1991 and 2006. Their residential pattern is compared with that of Pacific Islanders also resident there, providing supporting evidence for the ethnoburb hypothesis.     

Genetic diversity and metal tolerance of two marine species: a comparison between populations from contaminated and reference sites

Long-term contamination of the marine environment surrounding a lead smelter offered a unique opportunity to examine how pollutants might have acted to alter genetic characteristics of populations of organisms in the receiving system. This study used random amplified polymorphic DNA analysis to compare the genetic diversity of populations of the prawn, Leander intermedius, and the isopod, Platynympha longicaudata from the smelter discharge site with reference populations. The genetic diversity of the prawn population from the smelter discharge site (Port Pirie) was lower than that found in one reference population, and not significantly different from the other two reference populations. Genetic diversity of the Port Pirie population of isopods was found to be significantly lower than that of all reference populations. Prawns and isopods were also exposed to metal mixtures in the laboratory in a similar ratio to that found in seston near the smelter effluent discharge site. Both pre-exposed and reference populations of prawns tolerated elevated levels of metals and exhibited no significant difference in response. This contrasted with the isopods, with the pre-exposed isopod population showing greater tolerance to elevated metal levels compared with the reference population. These results highlight the need to include a number of reference populations for comparative purposes in genetic diversity studies, and the need to assess the influence of pollution on the genetic diversity of more than one species if genetic diversity analyses are to be used to gauge remediation success.     

Major element composition of the lithospheric mantle under the North Atlantic craton: Evidence from peridotite xenoliths of the Sarfartoq area,southwestern Greenland

The composition and thermal state of the lithospheric mantle under the North Atlantic craton was investigated using a suite of peridotite xenoliths from the diamond-bearing Sarfartoq kimberlite dike swarm of southwestern Greenland. Elevated olivine and whole-rock Mg# (>0.9) attest to the refractory nature of the Sarfartoq mantle showing comparable degrees of depletion to other cratonic roots. Modal analyses indicate that the Sarfartoq mantle is not typified by the orthopyroxene enrichment observed in the Kaapvaal root, but shows more affinity with the Canadian Arctic (Somerset Island), Tanzania, and East Greenland (Wiedemann Fjord) peridotites. The Sarfartoq peridotites have equilibrated at temperatures and pressures ranging from 660 to 1,280 °C and from 2.2 to 6.3 GPa, and define a relatively low mantle heat flow of 13.2±1 mW/m^2. In addition, the lithospheric mantle underneath the Sarfartoq area is compositionally layered as follows: (1) an internally stratified upper layer (70 to 180 km) consisting of coarse, un-deformed, refractory garnet-bearing and garnet-free peridotites and, (2) a lower layer (180 to 225 km) characterized by fertile, CPX-bearing, porphyroclastic garnet lherzolites. The stratification observed in the upper refractory harzburgite layer (70–180 km) is reflected by an increase in fertility (e.g., decrease in olivine abundance and forsterite content) with depth. The sharp nature of the boundary between the upper and lower layers may indicate multistage growth of the lithospheric mantle.Editorial responsibility: T.L. Grove     

Ringlets of the major planets which may consist of coagulated particles

A ringlet of Saturn, Uranus, Neptune or Jupiter may be composed of particles held in contact by their mutual gravitation, without relative motion. Lacking tensile strength, each part of the ringlet orbits as if it were a separate particle, but all parts are constrained to the same orbit by their contacts. Slight shear strength prevents flow. This configuration is stable inside Roche's limit, and outside an inner limit within which it would scatter. These limits depend on the density of the ringlet. Conversely, for an observed radius in a ring, a range of possible density is calculated. For Saturn's ring system, the density of a ringlet at the inner edge of the C ring must be at least 2.0 g cm^-3 and in the outer F ring not more than 0.73. For Uranus, the inner ring must be at least 2.3, and the outer between 1.0 and 2.3. Jupiter's ring must be in the range 1.4 to 3.9, and Neptune's, in the range 0.6 to 1.5. In extended crowded regions of a ring system, the gaps between ringlets must be at least 38% as wide as the ringlets, in the outer portions of the system, and wider than that at smaller radii. Certain observations can be explained by this model, including the sharp edges of the rings, a long life of the system, the possible existence of a partial ring, asymmetry of brightness of Saturn ring A, and forward scattering of radio waves.     

Sources of stream sulphate in headwater catchments in Otter Creek Wilderness,West Virginia,USA

Upland forested catchments in the Appalachian Plateau region receive among the greatest rates of atmospheric sulphur (S) deposition in the eastern USA, although coal mines and S‐bearing minerals in bedrock may also contribute to stream acidity in this region. Watershed mass balance and stable S isotopic values (δ³⁴S) of sulphate (SO₄^2?) were used to assess the contributions to stream SO₄^2? from atmospheric and lithogenic sources at Yellow Creek (YC), a headwater catchment on the Appalachian Plateau in West Virginia. Oxygen isotopic values (δ¹⁸O) of water were used to study catchment hydrology. Stream output of SO₄^2? was c. 60% of atmospheric S deposition during a relatively dry year, whereas atmospheric S input was nearly balanced by stream output during a year with above normal amounts of precipitation. The temporal patterns and values of δ³⁴S were similar between bulk precipitation and stream water at two upper elevation sites. At the lowest elevation site, stream δ³⁴S values were similar to bulk precipitation values during the dormant season but were slightly lower than precipitation during the low‐flow summer, probably as the result of a greater proportion of stream water being derived from deep hydrological flowpaths that have contacted S‐bearing minerals with low δ³⁴S values in coal seams. Stream δ³⁴S values at YC were significantly higher than at Coal Run, a catchment containing abandoned coal prospects and having a greater amount of S‐bearing minerals than YC. Results suggested that lithogenic S is a relatively minor source and that atmospheric deposition is the principal source of stream SO₄^2?, and thus stream acidity, at YC. Copyright © 2001 John Wiley & Sons, Ltd.     

ONE NATION OR TWO? THE CHANGING GEOGRAPHY OF UNEMPLOYMENT IN GREAT BRITAIN, 1983–1988*

Unemployment affected large numbers of people in Great Britain during the 1980s. An economic upturn since the mid-1980s has resulted in declining numbers of unemployed. Disaggregated data show that the geography of unemployment decline has not led to regional convergence in numbers out of work: unemployment has fallen most in those regions which were least affected by it.