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A method of predicting the spatial distribution of 137Cs deposition in fallout in the Arctic from atmospheric nuclear weapons testing, developed during the Arctic Monitoring and Assessment Programme (AMAP), is described. The method uses a relationship between deposition and precipitation at Tromso (Norway) calculated for each year since 1955, which is spread over the Arctic using a global precipitation data set within a geographical information system. The advantagesof this approach include the ability to cover the whole Arctic area and to predict 137Cs deposition, either integrated or decay corrected (cumulative), for any 0.5 x 0.5 deg. unit for any year. For land north of 60 deg.N, the areas with the lowest estimated ground137Cs deposition from nuclear weapons testing are the Russian far north east. north Greenland and northern Canada. The highestestimated ground deposition occurred in the coastal areas of Alaska,the southern tip of Greenland, western Canada, Iceland and the western coast of Norway. Predicted differences in the spatial distributionof global fallout are generally consistent with the trends observed by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and with reported measurements in the region above60 deg.N. A comparison of the predicted cumulative 137Cs deposition with measured values gave a significant correlation (p < 0.001). However, the current predicted deposition would probably underestimate global fallout deposition in areas receiving little precipitation and areas close to the test site. (c) 1999 Elsevier Science Ltd. [ABSTRACT FROM AUTHOR]

The objective of this study was to make a robust 137Cs inventory calculation for Reservoir 11 in the Mayak Production Associations industrial cascade of reservoirs. High resolution satellite photographs provided information about the original Techa River and floodplain environment before, during and also after Reservoir 11 was constructed. The images provided important clues about the old Techa River system and also showed the extent of the contaminated area. Sediment cores were sampled along a transect in Reservoir 11, and perpendicular to the Techa River in 1996. 137Cs contamination densities were in the range 344–4030 kBq m−2 and appear to exhibit a strong dependence on relative position along the transect, with more central positions exhibiting the highest actual levels. The contamination densities derived from the seven cores were combined with (published) data from four core samples collected in a 1994 field campaign. Sample data and images were integrated in a geographical information system (GIS). The GIS aided in the definition of distinctive floodplain classes, the so-called sediment ‘facies’, area calculations and in the positioning of 1994 and 1996 sample profiles in the reservoir. The resulting inventory estimate for Reservoir 11, is a factor 4–10 lower than earlier calculations. Analysis of the uncertainty in the calculations has been carried out and provides support for the integrity of the new method. [Copyright &y& Elsevier]

This paper provides a brief introduction to the Arctic atmospheric radioactivity monitoring network. A decade of monitoring results have shown the 137 Cs background levels in Arctic air range from 0.05 to 1.50 μBq/m 3 . The monitoring stations have sufficient sensitivity to detect 137 Cs brought to the atmosphere due to resuspension in local soil and reemissions from biomass burning in a daily temporal resolution. These observations can be used as tracers for atmospheric processes. The 133 Xe measurements obtained at Yellowknife, Resolute and Spitsbergen could support other research into how air pollution problems arise across intercontinental distances. It will help develop and improve models capable of predicting the long-distance transport and deposition of trace gases in the Arctic. Rainwater monitoring data collected in Finnish Lapland since the 1960's indicate that 3 H radioactivity concentrations reached natural background levels in early 2000s, typically around 1-2 Bq/L monthly, with an annual seasonal variation cycle consistent with the observed of other cosmogenic radionuclides., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: This paper is based on work conducted as part of AMAP’s radioactivity assessment work. The information in this paper is part of the scientific basis for the 2023 AMAP Radioactivity Assessment, (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The radionuclide (99)Tc had been discharged from the nuclear reprocessing facility in Sellafield (UK) into the Irish Sea in increased amounts in the 1990s. We compare the simulated dispersion of (99)Tc in surface water as calculated by a hydrodynamic model and an assessment box model with field-observations from 1996 to 1999 to study concentrations, pathways and travel times. The model results are consistent with the observations and show the typical pathway of dissolved radionuclides from the Irish Sea via the North Sea along the Norwegian Coast. Subsequently the contaminated water separates into three branches of which the two Arctic branches bear the potential for future monitoring of the signal in the next decades. The results of the hydrodynamic model indicate a large variability of surface concentrations in the West Spitsbergen Current which has implications for future monitoring strategies. According to the observed and simulated distributions we suggest an improved box model structure to better capture the pattern for concentrations at the surface.

Antisense oligodeoxynucleotides have been highly successful agents at modulating gene expression in the adult brain and widely exploited in the field of neuroendocrinology. We have also used this technique in the developing brain to explore the role of select proteins during sensitive periods of development, particularly those influenced by steroid hormones. Presented here are the technical details of using antisense oligodeoxynucleotides in the neonatal brain, as well as a review of some of our successes and failures. Our goal is to illustrate the relative ease of use of this technique in neonates and demonstrate the power such an approach offers so that other investigators will also begin to take advantage of this useful tool., (Copyright 2000 Academic Press.)

Calbindin-D28k (calbindin) is a 28 kilodalton calcium binding protein which potentially plays a role in neuroprotection. We report here the normal development and gonadal steroid modulation of a sexually dimorphic group of calbindin immunoreactive cells within the sexually dimorphic nucleus of the preoptic area (SDN) which we call the calbindin-immunoreactive SDN or CALB-SDN. Beginning on PN2, a faintly immunoreactive CALB-SDN is present, however, the volume is not sexually dimorphic. On PN4, the staining of the CALB-SDN appears more robust but the volume is still not sexually dimorphic. By PN8 and extending through PN12 and PN26, the latest age analysed, the volume of the CALB-SDN is larger in males by two- to fourfold. Cresyl violet counterstain reveals a similar developmental profile of the SDN as well as clusters of darkly staining calbindin immunonegative cells which lie around the CALB-SDN. Castration of males on PN0 decreases the volume of the CALB-SDN by PN12 and administration on the day of birth and PN1 of either testosterone propionate or oestradiol benzoate, but not dihydrotestosterone propionate to females increases the volume of the CALB-SDN by PN12. By demonstrating the sexual dimorphism and gonadal steroid modulation of the CALB-SDN, we hereby establish that calbindin is a specific marker of a subdivision of the SDN and can be used as such in future studies.

The proteins calbindin-D(28K) and calretinin buffer intracellular calcium and are speculated to be involved in the integration of neuronal signaling. Using Western blot analysis, we compared the levels of calbindin-D(28K) and calretinin in the developing male and female rat hypothalamus on postnatal days (PN) 0, PN2, PN4, PN6, PN8, and PN10. Analysis of variance (ANOVA) of mean calbindin levels indicated a significant effect of sex (p

Under the Arctic Monitoring and Assessment Programme (AMAP), studies have been undertaken to compare potential fluxes of radiocaesium via important food products. The results for three Norwegian Arctic counties are presented in this paper. The comparative importance of different foodstuffs in contributing to collective dose varies spatially due to differing rates of production and transfer. Although reindeer meat is an important contributor to the radiocaesium flux following a nuclear release, other food products such as cow milk and lamb have been identified as potentially important. Assuming an even deposition following a nuclear release the radiocaesium flux was estimated to be highest for reindeer meat in Finnmark and Troms, whereas cow milk gave the highest flux in Nordland. The total number, geographical distribution and diet composition of indigenous peoples within different Arctic regions is an important factor affecting individual and collective doses arising from a nuclear release. Finnmark has been shown to be the most vulnerable of the three counties because it has the highest flux of radiocaesium and the largest number of indigenous people. The potential contribution of foodstuffs which are known to readily accumulate radiocaesium needs further consideration, in particular, mushrooms, freshwater fish and berries.

The skeleton is a major repository for divalent cations, including toxic heavy metals such as lead. Unfortunately the effects of such agents on bone (and cartilage) have been minimally investigated in the past. With the current level of understanding of the mechanisms of bone formation and cartilage development it is now appropriate to begin to research the effects of lead on cellular processes. The following discussion describes some of the points of regulation in bone and cartilage formation where interference in metabolic processes could compromise the development of normal tissues as well as affect the homeostatic mechanisms of the skeleton.