Alaskan resources, current development. Traditional cultural values, and the role of LANDSAT data in current and future land use management planning

Past, present, and proposed applications of LANDSAT data for renewable resource assessments in Alaska are described. Specific projects briefly discussed include: a feasibility investigation applying LANDSAT data to caribou habitat mapping in northeast Alaska, analysis of a native corporate region in southwest Alaska, analysis of a game management unit in interior Alaska, and two proposed analyses in northwest Alaska. These analyses principally address range evaluations concerning caribou, moose, and Dall sheep, but results have application to other renewable resource themes. Application of resource assessment results to a statewide land use management plan is discussed

Application of ERTS imagery to the study of caribou movements and winter habitat

There are no author-identified significant results in this report

Nutrient chemistry of a large, deep lake in subarctic Alaska

Project Officer Eldor W. Schallock Assessment and Criteria Development Division Corvallis Environmental Research Laboratory Corvallis, Oregon 97330;Corvallis Environmental Research Laboratory Office of Research and Development U. S. Environmental Protection Agency Corvallis, Oregon 97330; R800276The primary objective of this project was to assess the state of the water quality of Harding Lake, and to attempt to predict the effects of future development within its watershed. Since the major effect of degradation of water quality due to human activity is the promotion of nuisance growths of plants, the major emphasis was placed on measurements of plant growth and concentrations of the major nutrients they require. Planktonic algal growth was found to be low, below 95.6 gm/m2/year, and the growth of submerged rooted plants was found to be relatively less important at approximately 1.35 gm/m2/year. Measurements of the growth of attached algae were not conducted, therefore the relative importance of their growth is currently unknown. A model for predicting the effect of future real estate development in the watershed was modified and applied to this lake. This model adequately describes current water quality conditions, and is assumed to have some predictive ability, but several cautions concerning application of this model to Harding Lake are discussed. A secondary objective was to study the thermal regime of a deep subarctic lake. Intensive water temperature measurements were made throughout one year and less intensive measurements were conducted during two additional years. The possibility that this lake may occasionally stratify thermally under the ice and not mix completely in the spring was discovered. The implications of this possibility are discussed for management of subarctic lakes. Hydrologic and energy budgets of this lake are attempted; the annual heat budget is estimated at 1.96 x 104 ± 1.7 x 103 cal/cm2. The results of a study of domestic water supply and waste disposal alternatives in the watershed, and the potential for enteric bacterial contamination of the lake water are presented. Limited work on the zooplankton, fishes, and benthic macroinvertebrates of this lake is also presented

Caribou Feeding Sites in Relation to Snow Characteristics in Northeastern Alaska

Caribou select areas of relatively shallow snow for winter feeding, and do so on at least two levels: broad area and microsite. They do not normally select sites with snow-packs having mean integrated Ram hardness values in excess at 85. However, in areas of relatively shallow hard-packed snow, which is easily fractured into slab-like pieces, they can obtain access to vegetation with less expenditure of energy than Ram hardness values alone would suggest. Alpine feeding areas in the Porcupine Lake basin of northeastern Alaska had this type of snow-pack in the winter of 1972-73. In typical taiga winter range, caribou use areas where the snow depth is less than 50 centimetres

Use of LANDSAT imagery for wildlife habitat mapping in northeast and eastcentral Alaska

There are no author-identified significant results in this report

White and Gray Matter Abnormalities After Cranial Radiation in Children and Mice

PurposePediatric patients treated with cranial radiation are at high risk of developing lasting cognitive impairments. We sought to identify anatomical changes in both gray matter (GM) and white matter (WM) in radiation-treated patients and in mice, in which the effect of radiation can be isolated from other factors, the time course of anatomical change can be established, and the effect of treatment age can be more fully characterized. Anatomical results were compared between species.Methods and MaterialsPatients were imaged with T1-weighted magnetic resonance imaging (MRI) after radiation treatment. Nineteen radiation-treated patients were divided into groups of 7 years of age and younger (7−) and 8 years and older (8+) and were compared to 41 controls. C57BL6 mice were treated with radiation (n=52) or sham treated (n=52) between postnatal days 16 and 36 and then assessed with in vivo and/or ex vivo MRI. In both cases, measurements of WM and GM volume, cortical thickness, area and volume, and hippocampal volume were compared between groups.ResultsWM volume was significantly decreased following treatment in 7− and 8+ treatment groups. GM volume was unchanged overall, but cortical thickness was slightly increased in the 7− group. Results in mice mostly mirrored these changes and provided a time course of change, showing early volume loss and normal growth. Hippocampal volume showed a decreasing trend with age in patients, an effect not observed in the mouse hippocampus but present in the olfactory bulb.ConclusionsChanges in mice treated with cranial radiation are similar to those in humans, including significant WM and GM alterations. Because mice did not receive any other treatment, the similarity across species supports the expectation that radiation is causative and suggests mice provide a representative model for studying impaired brain development after cranial radiation and testing novel treatments