Metallothionein-like proteins in the livers of squaloid and carcharhinid sharks

Liver extracts from three species of shark (Etmopterus spinax, Galeorhinus galeus, Scymnorhinus licha), were analysed using Differential Pulse Polarography. All three extracts gave significant polarographic responses, indicating the presence of cysteine containing proteins. On the basis of previous work, these proteins were considered to be metallothionein-like in nature. These results mark the first data on MT in natural populations of sharks and in mid- to deep-water species.     

Mid-ocean ridge popping rocks: implications for degassing at ridge crests

The vesicle size distribution (VSD) and rare gas abundances in popping rocks from 14°N on the Mid-Atlantic Ridge provide constraints on the behavior of volatiles during ridge crest volcanism. These popping rocks, which contain 16–18 volume percent vesicles, are rare mid-ocean ridge basalt (MORB) magmas which appear to have retained much of their volatile inventory. The logarithm of vesicle population density displays the same linear correlation with decreasing size in two of the samples studied. This implies that continuous and simultaneous nucleation and bubble growth have occurred during magma ascent, with no significant perturbations due to accumulation, coalescence or loss of bubbles. In contrast, most MORB magmas display low vesicularities and we suggest that they have suffered some degree of pre-eruptive vesicle loss. We tentatively propose that large vesicles are produced by coalescence when MORB melt is at rest in chambers and conduits, and may be lost during early gas-rich episodes. Most MORB would represent residual liquids which erupt after vesicle loss has occurred, whereas popping rocks would represent a rare case where physical sorting of vesicles from melt did not occur, because storage in a magma chamber did not occur.The rare gas concentrations in the studied popping rocks are the highest yet measured in glassy ridge basalts ([He] > 50 μccSTP/g). The rare gas abundance pattern of these popping rocks probably resembles the pattern for non-vesiculated MORB magma and potentially reflects that of the depleted mantle source. This pattern is similar to the “mean MORB” pattern (computed from MORB glasses with⁴⁰Ar/³⁶Ar > 10,000) although a higher enrichment in He (and possibly Ne) compared to the heavier rare gases is observed in MORB. The overall similarity in abundance patterns for MORB and popping rocks indicates that vesiculation and vesicle loss do not fractionate the ArKrXe relative abundances from those in non-vesiculated magma, and that the modern flux ratios of these gases at ridges are similar to their elemental ratios in the depleted mantle. The degassing flux of He at ridge crests estimated from the MORB He deficit relative to popping rocks is comparable to the flux derived from the³He budget for the abyssal ocean. This suggests that degassing at ridges may be strongly influenced by the dynamics and style of submarine volcanism.     

Chemistry and mineralogy of podiform chromitite deposits,southern NSW,Australia: a guide to their origin and evolution

Summary Many small podiform chromitite deposits occur within two alpine-type serpentinite belts (of uncertain age) in southern NSW. Most of these deposits are enclosed in massive serpentinised chromite-rich dunite which cross-cuts primary layering within the main harzburgite body. In the western belt, the chromitites are all Cr-rich, whereas in the eastern belt there is a spectrum from Cr-rich to highly Al-rich chromitites, all of which have a fairly Complex geographic distribution. All of the chromitites are ophiolitic in character and the chemistry of both the chromitites and discrete chromite grains is reasonably Constant within a deposit, but varies widely between deposits. The REE concentrations are very low and lack any systematic geographic distribution. Most of the hromitites have an opholitic PGE signature, although some exceptions do occur and this is ascribed to localised remobilisation during serpentinisation. PIXE proton probe results show that the chromite grains are enriched, relative to the. serpentine fracture-fill, in Mn, Ni, Zn and Ga and depleted in As and Cu. Inclusions Completely enclosed within the chromite grains include Al-rich chromite, PGE-bearing nickel sulphides, palladian gold, forsteritic olivine, pargasitic amphiboles and a member of the gedrite/anthophyllite group. PGE-bearing fracture-fill phases include millerite, heazlewoodite, polydymite, chalcopyrite, trevorite, native gold, ruthenium, palladium and Ni₃Pt(?). Other fracture-fill phases include awaruite, magnetite, pentlandite, lizardite 6T, chrysotile 2M, antigorite, talc, clinochlore IIb, uvarovite garnet, diopside and ferritchromit. The chromitites were derived from a different magma than the peridotite and the present distribution of low Al, intermediate Al and high Al Chromitites reflects the spatial distribution of a progressively fractionating parental magma rather than different magmatic sources. Both the trace element and REE Chemistries of the chromitites yield little insight into the genesis of the chromitite pods and their distribution Could reflect either an inhomogeneous distribution in the parental magma or localised remobilisation during serpentinisation. During serpentinisation, PGE within the chromities and hostrock dunites and harzburgites were released, and precipitated within the crack seal breccia environment of the chromitites. Provided that the inclusions enclosed within the chromite grains formed in the presence of the same fluid as the chromite, this magmatic chromite and olivine forming liquid must have had a minor concentrated volatile-rich component. Subsequent serpentinisation of the chromitites was responsbile for the localised remobilisation of metals, PGE, S and the REE.

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Chemismus und Mineralogie von podiformen Chromitlagerstätten, Süd-NSW, Australien: Ein Schlüssel zu ihrer Entstehung und Entwicklung

Zusammenfassung Zahlreiche kleinere podiforme Chromitlagerstätten treten in zwei alpinotypen Serpinitingürteln unsicherer Altersstellung im südlichen NSW auf. Die meisten dieser Lagerstätten sind an serpentinisierte chromitreiche Dunite, die den primären Lagenbau der Harzburgitkörper durchsetzen, gebunden. Im westlichen Gürtel sind die Chromite Cr-reich, im östlichen reicht das Spektrum von Cr- bis Al-reichen Chromititen mit komplexer geographischer Verbreitung. Alle Chromitite zeigen ophiolitischen Charakter und die Zusammensetzung der Chromitite aber auch einzelner Chromitkörner ist relativ konstant innerhalb einer Lagerstätte. Sie variiert allerdings von Lagerstätte zu Lagerstätte. Die SEE Gehalte sind sehr niedrig. Eine systematische geographische Verteilung ist nicht erkennbar. Die meisten Chromitite zeigen ophiolitische PGE Verteilungsmuster, obwohl es auch Ausnahmen, die lokaler Remobilisation im Zuge der Serpentinisierung zugeschrieben werden müssen, beobachtbar sind. Ergebnisse von PIXE Protonensondenanalysen zeigen, daß die Chromitkörner im Vegleich zu den Serpentinitrißfüllungen an Mn, Ni, Zn und Ga angereichert und an As und Cu angereichert sind. Al-reiche Chromite, PGE-führende Nickelsulfide, Gold mit Palladium, Forsterit und pargasitische Amphibole, sowie Gedrit/Antophyllit sind als Einschlüsse in Chromit nachgewiesen. In PGE-führenden Rissen kommen Millerit, Heazlewoodit, Polydymit, Kupferkies, Trevorit, gedigenes Gold, Ruthenium, Palladium und Ni₃Pt(?) vor. Andere Phasen in diesen Rißfüllungen sind Awaruit, Magnetit, Pentlandit, Lizardit 6T, Chrysotil 2M, Antigorit, Talk, Klinochlor IIb, Uvarovit, Diopsid und Ferritchromit.Die Chromitite sind von einem anderen Magma als die Peridotite abzuleiten und die nunmehrige Verteilung von Al-armen bis Al-reichen Chromititen spiegelt die räumliche Verteilung eines fraktionierenden Ausgangsmagmas eher wider als unterschiedliche Magmenquellen. Spuren- und REE-Geochemie erlauben kaum Einblicke in die Genese der Chromititkörper. Ihre unregelmäßige Verteilung könnte entweder auf Inhomogenitäten des Ausgangsmagmas oder auf lokale Remobilisation im Zuge der Serpentinisierung zurückzuführen sein. Während der Serpentinisierung wurden PGEs in den Chromititen und dunitischen und harzburgitischen Nebengesteinen freigesetzt und in den ehromititischen crack-seal Brekzien wiederausgefällt. Unter der Annahme, daß sich die Einschlüsse in den Chromitkörnen in Gegenwart desselben Fluids wie die Chromite selbst gebildet haben, müssen die magmatischen Chromit- und olivinführenden Schmelzen mit einer volatilreichen Komponente koexistiert haben. Nachträgliche Serpentinisierung der Chromitite war für die lokale Remobilisation der Metalle, der PGEs, S und der REE verantwortlich.

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With 4 Figures     

Shaping the nation state: ethnicity,class and the new population policy in Singapore

"This paper explores the relationships between ethnicity, class and the New Population Policy (NPP) in Singapore in the context of its nation state project.... The paper uses data from a sample of the Singaporean population to investigate the impact of the NPP on both ethnic and income (class) groups in order to assess the importance of the ethnic dimension in this aspect of Singapore's development strategy. It concludes that, although differences in fertility behaviour may be rooted in ethnic identity, the control that the government wishes to exert over that behaviour as part of its nation-building project has largely been effected through class interests, and may be better interpreted as part of a broader strategy of human resource management which is attracting the attention of other Asian newly industrialising countries."     

Development of passive sampling devices for bioavailable contaminants of current and emerging concern: Waitemata Harbour case study

Bioavailable contaminant concentrations are an important component in assessing environmental effects as they directly affect ecosystem health. Shellfish contaminant monitoring programmes have traditionally filled this requirement but are being phased out in some jurisdictions. Passive sampling devices (PSDs) have the potential to replace shellfish monitoring; however, there are still knowledge gaps to address before this can occur. This study assessed the suitability of three different PSDs in providing the required information to replace shellfish monitoring. PSDs were deployed at three historic mussel monitoring sites with different levels of urban influence in the Waitemata Harbour, Auckland, New Zealand. Contaminants of interest were urban heavy metals, plus current and emerging organic contaminants. PSDs provided extremely low detection limits and, for some contaminants, very strong correlations to shellfish. PSDs can currently complement shellfish in monitoring, but it is premature to make conclusions as to the suitability of PSDs in replacing shellfish monitoring until more information is available.     

Species‐specific photosynthetic responses of symbiotic zoanthids to thermal stress and ocean acidification

Increasing sea‐surface temperatures and ocean acidification (OA) are impacting physiologic processes in a variety of marine organisms. Many sea anemones, corals and jellies in the phylum Cnidaria form endosymbiotic relationships with Symbiodinium spp. (phylum Dinoflagellata) supply the hosts with fixed carbon from photosynthesis. Much work has focused on the generally negative effects of rising temperature and OA on calcification in Symbiodinium‐coral symbioses, but has not directly measured symbiont photosynthesis in hospite or fixed carbon translocation from symbiont to host. Symbiodinium species or types vary in their environmental tolerance and photosynthetic capacity; therefore, primary production in symbiotic associations can vary with symbiont type. However, symbiont type has not been identified in a large portion of Symbiodinium?cnidarian studies. Future climate conditions and OA may favor non‐calcifying, soft‐bodied cnidarians, including zoanthids. Here we show that two zoanthid species, Palythoa sp. and Zoanthus sp., harboring different symbiont types (C1 and A4), had very different responses to increased temperature and increased partial pressure of CO₂ (pCO₂), or dissolved CO₂, and low pH. Thermal stress did not affect carbon fixation or fixed carbon translocation in the Zoanthus sp./A4 association, and high pCO₂/low pH increased carbon fixation. In contrast, both thermal stress and high pCO₂/low pH greatly inhibited carbon fixation in the Palythoa sp./C1 association. However, the combined treatment of high temperature and high pCO₂ increased carbon fixation relative to the treatment of high temperature alone. Our observations support the growing body of evidence that demonstrates that the response of symbiotic cnidarians to thermal stress and OA must be considered on a host‐specific and symbiont‐specific basis. In addition, we show that the effects of increased temperature and pCO₂ on photosynthesis may change when these two stressors are combined. Understanding how carbon fixation and translocation varies among different host?symbiont combinations is critical to predicting which Symbiodinium associations may persist in warm, acidified oceans.     

Modeling Nonprofit Resilience in Long-Term Recovery in Christchurch,New Zealand

Following the 2010–2011 earthquakes in Christchurch, New Zealand, many nonprofit organizations changed or expanded services to address emergent or compounded risks. This research is based on interviews with thirty local community nonprofit managers and discussions with five staff focus groups conducted in 2014. Preexisting nonprofits with flexible organizational structures and emergent nonprofits succeeded in providing services during the emergency response and early recovery phases; nonprofits contracted with the government were better suited for long-term recovery. Shared resources among nonprofit agency connections contributed to successful transitions from response to recovery. Similar organizational resilience factors might occur in other major cities following disasters.     

Absolute measurements and computed values for Martian irradiance between 10.5 and 12.5 μm

The combination of seasonal and orbital changes in Martian insolation result in complex latitude dependent surface temperature variations that effect the total radiance of the planet as seen from the earth. These surface temperature variations have been calculated, based upon a computer simulation of the thermal environment of the planet. The temperature variations are then integrated to yield the total radiance of the planet as seen from the earth as a function of time. The absolute radiance of Mars was measured on April 4, 1971, with a balloon-borne radiometer system operating in the wavelength range between 10.5 and 12.5 μm. The average brightness temperature of the Mars disk determined from these measurements was 254°K with a 1 σ error of 4°K.