886 resultados para Earth’s early history
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Cover title: Early history of Dewsbury.
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The genesis and the early history of the Woods Hole Laboratory (WHL), to a lesser extent the Marine Biological Laboratory (MBL), and to some degree the Woods Hole Oceanographic Institution (WHOI), were elegantly covered by Paul S. Galtsoff (1962) in his BCF Circular "The Story of the Bureau of Commercial Fisheries Biological Laboratory, Woods Hole, Massachusetts." It covers the period from the beginning in 1871 to 1958. Galtsoffs more than 35-year career in the fishery service was spent almost entirely in Woods Hole. I will only briefly touch on that portion of the Laboratory's history covered by Galtsoff. Woods Hole, as a center of marine science, was conceived and implemented largely by one man, Spencer Fullerton Baird, at that time Assistant Secretary of the Smithsonian and who was also instrumental in the establishment of the National Museum and Permanent Secretary of the newly established American Association for the Advancement of Science. He was appointed by President Ulysses S. Grant in 1871 as the first U.S. Commissioner of Fisheries. Fisheries research began here as early as 1871, but a permanent station did not exist until 1885.
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Advances in genome technology have facilitated a new understanding of the historical and genetic processes crucial to rapid phenotypic evolution under domestication(1,2). To understand the process of dog diversification better, we conducted an extensive genome-wide survey of more than 48,000 single nucleotide polymorphisms in dogs and their wild progenitor, the grey wolf. Here we show that dog breeds share a higher proportion of multi-locus haplotypes unique to grey wolves from the Middle East, indicating that they are a dominant source of genetic diversity for dogs rather than wolves from east Asia, as suggested by mitochondrial DNA sequence data(3). Furthermore, we find a surprising correspondence between genetic and phenotypic/functional breed groupings but there are exceptions that suggest phenotypic diversification depended in part on the repeated crossing of individuals with novel phenotypes. Our results show that Middle Eastern wolves were a critical source of genome diversity, although interbreeding with local wolf populations clearly occurred elsewhere in the early history of specific lineages. More recently, the evolution of modern dog breeds seems to have been an iterative process that drew on a limited genetic toolkit to create remarkable phenotypic diversity.
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Rising sea level is perhaps the most severe consequence of climate warming, as much of the world’s population and infrastructure is located near current sea level (Lemke et al. 2007). A major rise of a metre or more would cause serious problems. Such possibilities have been suggested by Hansen and Sato (2011) who pointed out that sea level was several metres higher than now during the Holsteinian and Eemian interglacials (about 250,000 and 120,000 years ago, respectively), even though the global temperature was then only slightly higher than it is nowadays. It is consequently of the utmost importance to determine whether such a sea level rise could occur and, if so, how fast it might happen. Sea level undergoes considerable changes due to natural processes such as the wind, ocean currents and tidal motions. On longer time scales, the sea level is influenced by steric effects (sea water expansion caused by temperature and salinity changes of the ocean) and by eustatic effects caused by changes in ocean mass. Changes in the Earth’s cryosphere, such as the retreat or expansion of glaciers and land ice areas, have been the dominant cause of sea level change during the Earth’s recent history. During the glacial cycles of the last million years, the sea level varied by a large amount, of the order of 100 m. If the Earth’s cryosphere were to disappear completely, the sea level would rise by some 65 m. The scientific papers in the present volume address the different aspects of the Earth’s cryosphere and how the different changes in the cryosphere affect sea level change. It represents the outcome of the first workshop held within the new ISSI Earth Science Programme. The workshop took place from 22 to 26 March, 2010, in Bern, Switzerland, with the objective of providing an in-depth insight into the future of mountain glaciers and the large land ice areas of Antarctica and Greenland, which are exposed to natural and anthropogenic climate influences, and their effects on sea level change. The participants of the workshop are experts in different fields including meteorology, climatology, oceanography, glaciology and geodesy; they use advanced space-based observational studies and state-of-the-art numerical modelling.
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In Earth’s atmosphere, an ion is a cluster of molecules carrying an overall charge, known as a molecular cluster ion. Such cluster ions, with dimensions of approximately one nanometre, have usually been referred to as small ions, and their motion in air constitutes a small electric current. Large ions (or Langevin ions), by comparison, are physically larger (tens to hundreds of nm) and consequently electrically less mobile. Usage of the term “ion” to represent these molecular clusters originates from the early history of atmospheric electricity, which spans the discovery of the electron and the elucidation of the structure of matter. The distinction between large and small ions originates from distinguishing ions that could be accelerated by atmospheric electric fields (and therefore directly contribute to the conductivity of air), and those (the large ions) which were insufficiently electrically mobile to contribute to electrical conduction in air.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The Khoisan people from Southern Africa maintained ancient lifestyles as hunter-gatherers or pastoralists up to modern times, though little else is known about their early history. Here we infer early demographic histories of modern humans using whole-genome sequences of five Khoisan individuals and one Bantu speaker. Comparison with a 420 K SNP data set from worldwide individuals demonstrates that two of the Khoisan genomes from the Ju/'hoansi population contain exclusive Khoisan ancestry. Coalescent analysis shows that the Khoisan and their ancestors have been the largest populations since their split with the non-Khoisan population similar to 100-150 kyr ago. In contrast, the ancestors of the non-Khoisan groups, including Bantu-speakers and non-Africans, experienced population declines after the split and lost more than half of their genetic diversity. Paleoclimate records indicate that the precipitation in southern Africa increased similar to 80-100 kyr ago while west-central Africa became drier. We hypothesize that these climate differences might be related to the divergent-ancient histories among human populations.
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The Banks Presbyterian Church History is a history written by Mrs. Lena P. Kell entitled “The Early History of Banks Presbyterian Church” describing the history of the church from 1870s to 1947. The church is located in Waxhaw, North Carolina near Fort Mill. (Photocopies)
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The Rock Hill History is a handwritten history covering the period from the founding of the city of Rock Hill, SC in 1852 to 1890 and describes the city’s founders, merchants, industries, schools and churches, teachers, newspapers, libraries, and banking and railroad facilities.
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Discovering a History: The School of Art at the University of Denver explores the early history of art education in Denver, and the significance of visual art education at the University of Denver within that history beginning in 1865, when the first classes in art were offered, and ending in 1929 when the University acquired the Chappell School of Art—an independent art school—and appointed Vance Kirkland as director. This paper also explores competing art institutions, which at times posed great hindrances to the University. Further, it illustrates how the artists who taught at the University of Denver School of Art, such as Ida De Steiguer, Preston Powers, Emma Richardson Cherry, and Henry Read, were amongst the great contributors to Denver’s burgeoning artistic culture.
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Includes index.
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"Biographical sketches of the principal persons mentioned in this work": p. [451]-476.
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In this contribution I look at three episodes in the history of neurophysiology that bring out the complex relationship between seeing and believing. I start with Vesalius in the mid-sixteenth century who writes that he can in no way see any cavity in nerves, even in the optic nerves. He thus questions the age-old theory (dating back to the Alexandrians in the third century BC) but, because of the overarching psychophysiology of his time, does not press his case. This conflict between observation and theory persisted for a quarter of a millennium until finally resolved at the beginning of the nineteenth century by the discoveries of Galvani and Volta. The second case is provided by the early history of retinal synaptology. Schultze in 1866 had represented rod spherules and bipolar dendrites in the outer plexiform layer as being separated by a (synaptic) gap, yet in his written account, because of his theoretical commitments, held them to be continuous. Cajal later, 1892, criticized Schultze for this pusillanimity, but his own figure in La Cellule is by no means clear. It was only with the advent of the electron microscopy in the mid-twentieth century that the true complexity of the junction was revealed and it was shown that both investigators were partially right. My final example comes from the Hodgkin-Huxley biophysics of the 1950s. Their theory of the action potential depended on the existence of unseen ion pores with quite complex biophysical characteristics. These were not seen until the Nobel-Prize-winning X-ray diffraction analyses of the early twenty-first century. Seeing, even at several removes, then confirmed Hodgkin and Huxley’s belief. The relation between seeing and believing is by no means straightforward.
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This paper explores the ‘journey’ along the ‘never ending quality road’ undertaken by the Hong Kong Housing Department over the last 15 years. It briefly covers the early history of public housing in Hong Kong, the catalytic effect brought about by the discovery of the infamous 26 sub-standard blocks in the mid-80s leading to the subsequent major improvements to process control and structural quality in the period 1985-1990. It then moves onto a discussion of initiatives taken since 1991, including the formation of the List of Building Contractors and the implementation of the Performance Assessment Scoring System (PASS). The paper ends with a discussion of the current status of quality issues within the Department and touches on future initiatives being developed to further enhance the quality of public housing in Hong Kong.
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This paper introduces the creative work Distracted and discusses conceptual, aesthetic and technical aspects of the work. The work was conceived as a luminous, interactive, computational media installation informed by our interest in the Antarctica. Through the paper we focus on: how the work addresses the themes of climate change and sustainability; how we attempted to work with selected sets of scientific data to evoke the delicate yet extreme nature of the environment and the ways in which ice is a record of the earth’s geological history and recent human impacts; and how the process of making this artwork caused us to reconsider our practices and formulate strategies for redirecting our practice in a manner that addresses the challenges of sustainability.