ALBERT

Notes: During recent international debates concerning the potential resumptionof commercial whaling, whale meat has frequently been promoted as a goodfood. Recent research into the diet of Faroe Islanders and Inuit Indianshas revealed that consumption of marine mammal tissues can cause them toexceed recommended intake levels for various pollutants. Whalesthroughout the world have been found to accumulate high concentrationsof lipophilic compounds and, while the precise health risks associatedare unclear, the findings for the Faroe Islanders and Inuits may provenot to be unique, particularly if commercial whaling is resumed. Reviewsavailable data on contaminant values and related effects.

Notes: [Auszug] During the Last Glacial Maximum, ice sheets covered large areas in northern latitudes and global temperatures were significantly lower than today. But few direct estimates exist of the volume of the ice sheets, or the timing and rates of change during their advance and retreat. Here we analyse ...

Notes: Numerical modelling of postglacial rebound predics a spatially variable pattern of sea-level change. Yet, many previous models predicting Late Pleistocene sea-level change either neglect the load of water added to the oceans, or assume a spatially uniform time-dependent load over the whole ocean. This is a poor approximation of the load near the former ice sheet, since sea-level change varies geographically. In addition, the coastline goemetry changes through time.A spectral technique has been used to solve the sea-level equation on an earth model with axisymmetric distribution of ice and oceans and also for a realistic ice-ocean configuration. The axisymmetric model is useful for demonstrating the fundamental physics involved in sea-level changes caused by changes in surface loads. In particular, it can be seen that the elastic and gravitational response to the load is spread over a great distance, whereas the viscous response is more localized. A realistic ice-ocean configuration has been used to demonstrate that, neglect of the melt-water load underestimates the amount of uplift in Fennoscandia and other regions where rebound occurs in the ocean [as previously noted by Wu & Peltier (1983) in Hudson Bay], and that movement of the coastlines and spatially varying water loads must both be included in calculations for the North Sea and other near field regions with shallow seas. Sea-level calculations including these effects and careful analysis of the sea-level and ice-melting record are required to determine modifications to the viscosity profile and ice model inferred by previous inaccurate models of the ocean load in the near field.

Notes: Observations of sea-level change since the time of the last glacial maximum provide important constraints on the response of the Earth to changes in surface loading on time-scales of 103−104 years. This response is conveniently described by an effective elastic lithospheric thickness and effective viscosities for one or more mantle layers. Considerable trade-off between the parameters describing these layers can occur, and different combinations can give rise to comparable predictions of sea-level change. In particular, the trade-off between lithospheric thickness and upper-mantle viscosity can be important, and for any reasonable value for the lithospheric thickness a corresponding mantle viscosity structure can be found that gives a plausible comparison of sea-level predictions with observations. In particular, thin-lithosphere models will lead to low estimates for the upper-mantle viscosity, while thick-lithosphere models lead to high viscosity values. However, either solution may represent only a local minimum in the model parameter space, and may not correspond to the optimum solution. It becomes important, therefore, that in the inversion of observational data, a comprehensive search is conducted throughout the entire model-parameter space, to ensure that the solution identified does indeed correspond to the optimum solution. the sea-level data for the British Isles lend themselves well to such an inversion because of the relatively high quality of the data, the good geographic distribution of the data relative to the former ice sheet, and reasonable observational constraints on the dimensions of the former ice sheet and on its retreat. Furthermore, because of the contribution to the sea-level signal from the distant ice sheets, as well as from the melt-water load, the observational data base for the region also has some resolving power for the viscosity of the deeper mantle. the parameter space explored is defined by up to five mantle layers, the lithosphere of effective elastic thickness D1, and a series of upper-mantle layers, i=2-4, extending down to depths of 200, 400 and 670 km, respectively, each of viscosity i and a lower-mantle layer of viscosity lm extending down to the core-mantle boundary. the range of parameters explored is 30, D1 120 km, 3 × 1019i (i=2, 3, 4) 5 × 10 21 Pa s, 1021lm 1023 Pa s with 234lm. Simple models comprising three layers with D1∼70km, D2∼670 km, 2∼(4-5)1020 Pa s, and 3 〉 1022 Pa s describe the sea-level response to the glacial unloading well. Earth models with low-viscosity channels immediately beneath the lithosphere are not required, but if a thin lithosphere (〉50 km) is imposed in the inversion then the solution for the mantle viscosity leads to a low-viscosity (〉1020 Pa s) channel. Such a model does not, however, represent the overall least variance solution that would be obtained if D1 were also introduced as an unknown. Likewise, if a thick lithosphere (〉120 km) is imposed, then the solution points to a considerably higher value for the upper-mantle viscosity (∼ 1021 Pa s). But this also represents only a local minimum solution. the observational data do point to some stratification in the viscosity of the upper mantle, and the optimum solution is for a five-layer model with the following effective parameters: 〈displayedItem type="mathematics" xml:id="mu1" numbered="no"〉〈mediaResource alt="image" href="urn:x-wiley:0956540X:GJI340:GJI_340_mu1"/〉

Notes: Observations of Late Pleistocene and Holocene sea-level change relative to the crust exhibit very considerable variations across NW Europe in consequence of the response of the Earth's crust to the deglaciation of Fennoscandia and of the water added to the oceans from the melting of all Late Pleistocene ice sheets. Inversion of sea-level observations from a site near the centre of the Fennoscandian ice sheet and from three sites located beyond the margin of the ice sheet at the time of maximum glaciation yield a range of plausible models for the Earth's response and for the ice models. Further constraints on this range of models is placed by a comparison of observed sea-levels with predicted values at other sites near the former ice sheet margins. The resulting mantle parameters are: upper mantle viscosity (3–5) x 1020 Pa s; lower mantle viscosity (2–7) x 1021 Pa s; lithospheric thickness 100–150 km. These values represent effective parameters that describe the response of the Earth to surface loading of short to intermediate wavelengths on a time-scale of 104 yr. The lower mantle viscosity is poorly constrained but the marked increase from upper to lower mantle is a characteristic of all plausible solutions. The inversion places a constraint on the total volume of ice in the Fennoscandian ice sheet such that the equivalent sea-level rise from this contribution is about 13–14 m. A less well-determined constraint of about 10 m equivalent sea-level rise is suggested for the Barents–Kara ice sheet. The inversion also indicates that a small amount of melt-water, from ice sheets far away from Europe, continued to be added into the oceans during Late Holocene time so as to raise the equivalent sea-level by about 3 m during the past 6000 yr, consistent with similar inversions of data from sites in the Australian and Pacific regions.

Notes: Summary Cyh3 and cyh4, multiple drug resistant strains of Schizosaccharomyces pombe, show a much reduced uptake of trichodermin, chloramphenicol, cycloheximide, L-lysine, glycine, L-threonine, L-glutamine, L-arginine and L-glutamic acid when compared to wild type. The plasma membrane and mitochondrial ATPase activities of these mutants are also greatly reduced. Since the uptake of such compounds is likely to be driven by a proton electrochemical gradient set up by the membrane ATPase it is suggested that the primary effect of these mutations is at the level of the membrane ATPase. Another drug resistant strain, cyh1, which is resistant only to high levels of cycloheximide, shows increased uptake of trichodermin, L-lysine, glycine, L-threonine, L-glutamine when compared to wild type. The plasma membrane and mitochondrial ATPases of cyh1 are considerably greater than those of wild type. It has been shown previously that cyh1 possesses an altered 60S ribosonal subunit protein when compared to wild type and this makes it resistant to cycloheximide. There is no obvious explanation as to how this change could lead to the alterations in drug and amino acid uptake and in ATPase activities observed.