Topics in emerging technologies:Cost optimization methods in the design of next generation networks

A key development of telecommunication systems during the past two decades has been the evolution from the circuit-switched network toward the packet-switched network paradigm. Many operators are now migrating their PSTNs from circuit switched into multipurpose packet switched networks. This new approach is often called the next-generation network (NGN). NGN enables network operators to run all services (i.e., voice, data and video) on one network. In this article the migration of Iceland Telecom's circuit-switched PSTN toward NGN will be described. A cost model of the telecommunications system has been developed to enable cost and benefits analysis of transforming the network to NGN. Methods of optimization and their application to determine the optimal number and position of nodes in the future network will be described. The optimization produces a network structure with the lowest possible total cost of ownership, and the model can also indicate how deviations from the optimum affect cost. The feasibility of NGN can be assessed by comparing the cost of NGN migration to that of maintaining the current circuitswitched network

Satellite geological and geophysical remote sensing of Iceland: Preliminary results of geologic, hydrologic, oceanographic, and agricultural studies with ERTS-1 imagery

The author has identified the following significant results. The wide variety of geological and geophysical phenomena which can be observed in Iceland, and particularly their very direct relation to the management of the country's natural resources, has provided great impetus to the use of ERTS-1 imagery to measure and map the dynamic natural phenomena in Iceland. MSS imagery is being used to study a large variety of geological and geophysical eruptive products, geologic structure, volcanic geomorphology, hydrologic, oceanographic, and agricultural phenomena of Iceland. Some of the preliminary results from this research projects are: (1) a large number of geological and volcanic features can be studied from ERTS-1 imagery, particularly imagery acquired at low sun angle, which had not previously been recognized; (2) under optimum conditions the ERTS-1 satellite can discern geothermal areas by their snow melt pattern or warm spring discharge into frozen lakes; (3) various maps at scales of 1:1 million and 1:500,000 can be updated and made more accurate with ERTS-1 imagery; (4) the correlation of water reserves with snowcover can improve the basis for planning electrical production in the management of water resources; (5) false-color composites (MSS) permitted the mapping of four types of vegetation: forested; grasslands, reclaimed, and cultivated areas, and the seasonal change of the vegetation, all of high value to rangeland management

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博士（文学）神戸大

Metagenomic analyses of a microbial assemblage in a subglacial lake beneath the Vatnajökull ice cap, Iceland

Skaftárkatlar are two subglacial lakes located beneath the Vatnajökull ice cap in Iceland associated with geothermal and volcanic activity. Previous studies of these lakes with ribosomal gene (16S rDNA) tag sequencing revealed a limited diversity of bacteria adapted to cold, dark, and nutrient-poor waters. In this study, we present analyses of metagenomes from the lake which give new insights into its microbial ecology. Analyses of the 16S rDNA genes in the metagenomes confirmed the existence of a low-diversity core microbial assemblage in the lake and insights into the potential metabolisms of the dominant members. Seven taxonomic genera, Sulfuricurvum, Sulfurospirillum, Acetobacterium, Pelobacter/Geobacter, Saccharibacteria, Caldisericum, and an unclassified member of Prolixibacteraceae, comprised more than 98% of the rDNA reads in the library. Functional characterisation of the lake metagenomes revealed complete metabolic pathways for sulphur cycling, nitrogen metabolism, carbon fixation via the reverse Krebs cycle, and acetogenesis. These results show that chemolithoautotrophy constitutes the main metabolism in this subglacial ecosystem. This assemblage and its metabolisms are not reflected in enrichment cultures, demonstrating the importance of in situ investigations of this environment

Modeling Historic Rangeland Management and Grazing Pressures in Landscapes of Settlement

Defining historic grazing pressures and rangeland management is vital if early landscape threshold crossing and long–term trajectories of landscape change are to be properly understood. In this paper we use a new environmental simulation model, Búmodel, to assess two contrasting historical grazing landscapes in Mývatnssveit Iceland for two key periods—the colonization period (ca. Landnám, A.D. 872–1000) and the early eighteenth century A.D. Results suggest that there were spatial and temporal variations in productivity and grazing pressure within and between historic grazing areas and indicate that land degradation was not an inevitable consequence of the livestock grazing introduced with settlement. The results also demonstrate the significance of grazing and livestock management strategies in preventing overgrazing, particularly under cooler climatic conditions. The model enables detailed consideration of historic grazing management scenarios and their associated landscape pressures

POGZ Is Required for Silencing Mouse Embryonic β-like Hemoglobin and Human Fetal Hemoglobin Expression

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesFetal globin genes are transcriptionally silenced during embryogenesis through hemoglobin switching. Strategies to derepress fetal globin expression in the adult could alleviate symptoms in sickle cell disease and β-thalassemia. We identified a zinc-finger protein, pogo transposable element with zinc-finger domain (POGZ), expressed in hematopoietic progenitor cells. Targeted deletion of Pogz in adult hematopoietic cells in vivo results in persistence of embryonic β-like globin expression without affecting erythroid development. POGZ binds to the Bcl11a promoter and erythroid-specific intragenic regulatory regions. Pogz+/- mice show elevated embryonic β-like globin expression, suggesting that partial reduction of Pogz expression results in persistence of embryonic β-like globin expression. Knockdown of POGZ in primary human CD34+ progenitor cell-derived erythroblasts reduces BCL11A expression, a known repressor of embryonic β-like globin expression, and increases fetal hemoglobin expression. These findings are significant, since new therapeutic targets and strategies are needed to treat β-globin disorders.Frederick National Laboratory for Cancer Research, NIH intramural research program of the NHLBI, NIH intramural research program of the NIDDK, NIH USUH

Comparison of treatment with insulin degludec and glargine U100 in patients with type 1 diabetes prone to nocturnal severe hypoglycaemia:The HypoDeg randomized, controlled, open-label, crossover trial

AIM: To investigate whether the long‐acting insulin analogue insulin degludec compared with insulin glargine U100 reduces the risk of nocturnal symptomatic hypoglycaemia in patients with type 1 diabetes (T1D). METHODS: Adults with T1D and at least one episode of nocturnal severe hypoglycaemia during the last 2 years were included in a 2‐year prospective, randomized, open, multicentre, crossover trial. A total of 149 patients were randomized 1:1 to basal‐bolus therapy with insulin degludec and insulin aspart or insulin glargine U100 and insulin aspart. Each treatment period lasted 1 year and consisted of 3 months of run‐in or crossover followed by 9 months of maintenance. The primary endpoint was the number of blindly adjudicated nocturnal symptomatic hypoglycaemic episodes. Secondary endpoints included the occurrence of severe hypoglycaemia. We analysed all endpoints by intention‐to‐treat. RESULTS: Treatment with insulin degludec resulted in a 28% (95% CI: 9%‐43%; P = .02) relative rate reduction (RRR) of nocturnal symptomatic hypoglycaemia at level 1 (≤3.9 mmol/L), a 37% (95% CI: 16%‐53%; P = .002) RRR at level 2 (≤3.0 mmol/L), and a 35% (95% CI: 1%‐58%; P = .04) RRR in all‐day severe hypoglycaemia compared with insulin glargine U100. CONCLUSIONS: Patients with T1D prone to nocturnal severe hypoglycaemia have lower rates of nocturnal symptomatic hypoglycaemia and all‐day severe hypoglycaemia with insulin degludec compared with insulin glargine U100