1,373 research outputs found
Satellite geological and geophysical remote sensing of Iceland: Preliminary results from analysis of MSS imagery
A binational, multidisciplinary research effort in Iceland is directed at an analysis of MSS imagery from ERTS-1 to study a variety of geologic, hydrologic, oceanographic, and agricultural phenomena. A preliminary evaluation of available MSS imagery of Iceland has yielded several significant results - some of which may have direct importance to the Icelandic economy. Initial findings can be summarized as follows: (1) recent lava flows can be delineated from older flows at Askja and Hekla; (2) MSS imagery from ERTS-1 and VHRR visible and infrared imagery from NOAA-2 recorded the vocanic eruption on Heimaey, Vestmann Islands; (3) coastline changes, particularly changes in the position of bars and beaches along the south coast are mappable; and (4) areas covered with new and residual snow can be mapped, and the appearance of newly fallen snow on ERTS-1, MSS band 7 appears dark where it is melting. ERTS-1 imagery provides a means of updating various types of maps of Iceland and will permit the compilation of special maps specifically aimed at those dynamic environmental phenomena which impact on the Icelandic economy
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
Bragg spectroscopic interferometer and quantum measurement-induced correlations in atomic Bose-Einstein condensates
We theoretically analyze the Bragg spectroscopic interferometer of two
spatially separated atomic Bose-Einstein condensates that was experimentally
realized by Saba et al. [Science 2005 v307 p1945] by continuously monitoring
the relative phase evolution. Even though the atoms in the light-stimulated
Bragg scattering interact with intense coherent laser beams, we show that the
phase is created by quantum measurement-induced back-action on the homodyne
photo-current of the lasers, opening possibilities for quantum-enhanced
interferometric schemes. We identify two regimes of phase evolution: a running
phase regime which was observed in the experiment of Saba et al., that is
sensitive to an energy offset and suitable for an interferometer, and a trapped
phase regime, that can be insensitive to applied forces and detrimental to
interferometric applications.Comment: 14 pages, 3 figure
Mapping the potential use of endectocide-treated cattle to reduce malaria transmission
Treating cattle with endectocide is a longstanding
veterinary practice to reduce the load of endo and
ectoparasites, but has the potential to be added to the malaria
control and elimination toolbox, as it also kills malaria
mosquitoes feeding on the animals. Here we used openly available
data to map the areas of the African continent where high
malaria prevalence in 2-10 year old children coincides with a
high density of cattle and high density of the partly zoophilic
malaria vector Anopheles arabiensis. That is, mapping the areas
where treating cattle with endectocide would potentially have
the greatest impact on reducing malaria transmission. In regions
of Africa that are not dominated by rainforest nor desert, the
map shows a scatter of areas in several countries where this
intervention shows potential, including central and eastern
sub-Saharan Africa. The savanna region underneath the Sahel in
West Africa appears as the climatic block that would benefit to
the largest extent from this intervention, encompassing several
countries. West Africa currently presents the highest under-10
malaria prevalence and elimination within the next twenty years
cannot be contemplated there with currently available
interventions alone, making the use of endectocide treated
cattle as a complementary intervention highly appealing
The Most Commonly Occurring Papillary Thyroid Cancer in the United States Is Now a Microcarcinoma in a Patient Older than 45 Years
Background: The incidence of papillary thyroid cancer (PTC) is growing at a faster rate than any other malignancy. However, it is unknown what effect age is having on the changing PTC incidence rates. With the goal of understanding the role of age in thyroid cancer incidence, this study analyzes the changing demographics of patients with PTC over the past three decades. Methods: This was a retrospective evaluation of the incidence rates of PTC from 1973 to 2006 reported by the National Cancer Institute's Surveillance, Epidemiology, and End Results database. Results: From 1973-2006 the age group most commonly found to have PTC has shifted from patients in their 30s to patients in the 40-50-year-old age group. In 1973 60% of PTC cases were found in patients younger than 45, and the majority of cases continued to occur in younger patients until 1999. After 1999 PTC became more common in patients older than 45 years, and in 2006, 61% of PTC cases were in patients older than 45 years. From 1988 to 2003 there has been an increasing incidence of all sizes of PTC in all age groups with the largest increase in tumors <1-cm in patients older than 45. Forty-three percent of tumors in patients older than 45 are now <1-cm, whereas only 34% are <1-cm in patients younger than 45. Of the nearly 20,000 thyroid cancer cases in 2003, 24% were microcarcinomas in patients over the age of 45. Conclusions: The incidence of PTC is increasing disproportionally in patients older than 45 years. The number of PTC tumors smaller than 1-cm is increasing in all age groups, and now the most commonly found PTC tumor in the United States is a microcarcinoma in a patient older than 45 years. These changing patterns relating age and incidence have important prognostic and treatment implications for patients with PTC.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90466/1/thy-2E2010-2E0137.pd
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