988 resultados para Old Mission Church (Mackinac Island, Mich.)
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The formation of many arctic wetlands is associated with the occurrence of polygon-patterned permafrost. Existing scenarios to describe and explain surface landforms in arctic wetlands (low-center and high-center polygons and polygon ponds) invoke competing hypotheses: a cyclic succession (the thaw-lake hypothesis) or a linear succession (terrestrialization). Both hypotheses infer the predictable development of polygon-patterned wetlands over millennia. However, very few studies have applied paleoecological techniques to reconstruct long-term succession in tundra wetlands and thereby test the validity of existing hypotheses. This paper uses the paleoecological record of diatoms to investigate long-term development of individual polygons in a High Arctic wetland. Two landform processes were examined: (1) the millennial-scale development of a polygon-pond, and (2) the transition from low-center to erosive high-center polygons. Diatom assemblages were quantified from habitats associated with contrasting landforms in the present-day landscape, and used as an analog to reconstruct past transitions between polygon types. On the basis of this evidence, the paleoecological record does not support either of the existing models describing the predictable succession of polygon landforms in an arctic wetland. Our results indicate a need for greater paleoecological understanding, in combination with in situ observations in present-day geomorphology, in order to identify patterns of polygon wetland development and elucidate the long-term drivers of these landform transitions.
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Future oceans are predicted to contain less oxygen than at present. This is because oxygen is less soluble in warmer water and predicted stratification will reduce mixing. Hypoxia in marine environments is thus likely to become more widespread in marine environments and understanding species-responses is important to predicting future impacts on biodiversity. This study used a tractable model, the Antarctic clam, Laternula elliptica, which can live for 36 years, and has a well-characterized ecology and physiology to understand responses to hypoxia and how the effect varied with age. Younger animals had a higher condition index, higher adenylate energy charge and transcriptional profiling indicated that they were physically active in their response to hypoxia, whereas older animals were more sedentary, with higher levels of oxidative damage and apoptosis in the gills. These effects could be attributed, in part, to age-related tissue scaling; older animals had proportionally less contractile muscle mass and smaller gills and foot compared with younger animals, with consequential effects on the whole-animal physiological response. The data here emphasize the importance of including age effects, as large mature individuals appear to be less able to resist hypoxic conditions and this is the size range that is the major contributor to future generations. Thus, the increased prevalence of hypoxia in future oceans may have marked effects on benthic organisms' abilities to persist and this is especially so for long-lived species when predicting responses to environmental perturbation.
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At least 50 species of birds are represented in 241 bird bones from five late Pleistocene and Holocene archaeological sites on New Ireland (Bismarck Archipelago, Papua New Guinea). The bones include only two of seabirds and none of migrant shorebirds or introduced species. Of the 50 species, at least 12 (petrel, hawk, megapode, quail, four rails, cockatoo, two owls, and crow) are not part of the current avifauna and have not been recorded previously from New Ireland. Larger samples of bones undoubtedly would indicate more extirpated species and refine the chronology of extinction. Humans have lived on New Ireland for ca. 35,000 years, whereas most of the identified bones are 15,000 to 6,000 years old. It is suspected that most or all of New Ireland’s avian extinction was anthropogenic, but this suspicion remains undetermined. Our data show that significant prehistoric losses of birds, which are well documented on Pacific islands more remote than New Ireland, occurred also on large, high, mostly forested islands close to New Guinea.
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v.36:no.8(1957)
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Correspondence concerning an illness, which Odell believed was palsy or the King's evil (scrofula), that afflicted his five-year-old daughter. Odell writes that her symptoms included loss of speech and feeling in her right side, and a throat blockage, and he requests advice from Winthrop on the course of treatment the family should pursue. Odell writes again in 1653 thanking Winthrop for the ointment and electuary he had prescribed for the child. Her symptoms had persisted, however, and he requested further advice. Odell adds several lines regarding rumors of an insurrection of a Native American tribe, inquiring if Winthrop has any information regarding "how matters stand & between the Dutch & the English."
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John Hubbard Church wrote these twelve letters to his friend and classmate William Jenks between 1795 and 1798. Church wrote the letters from Boston, Rutland, Cambridge, and Chatham in Massachusetts and from Somers, Connecticut; they were sent to Jenks in Cambridge and Boston, where for a time he worked as an usher in Mr. Vinall's school and Mr. Webb's school. Church's letters touch on various subjects, ranging from his increased interest in theology and his theological studies under Charles Backus to his seasickness during a sailing voyage to Cape Cod. Church also informs Jenks of what he is reading, including works by John Locke, P. Brydone, James Beattie, John Gillies, Plutarch, and Alexander Pope. He describes his work teaching that children of the Sears family in Chatham, Massachusetts, where he appears to have spent a significant amount of time between 1795 and 1797. Church's letters are at times very personal, and he often expresses great affection for Jenks and their friendship.
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This layer is a georeferenced raster image of the historic paper map entitled: Map of the city of Providence, Rhode Island, from surveys under the direction of H.F. Walling ; engraved, printed, compiled & mounted at H.F. Walling's Map Establishment, no. 90 Fulton St., New York. It was published by F.A. Baker in 1857. Scale [1:4,200]. Covers a portion of East Providence, Rhode Island.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Rhode Island NAD 1983 coordinate system (in Feet) (Fipszone 3800) coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, railroads, railroad stations, drainage, public buildings, schools, churches, cemeteries, industry locations (e.g. mills, factories, etc.), docks and wharves, private buildings with selected names of property owners, town district boundaries, and more. Relief shown by hachures. Includes also illustrations of buildings in upper and lower margins: New Custom House, Post Office and U.S. court rooms -- Brown University -- Providence Institution for Savings -- Butler Hospital for the Insane -- First Baptist Meeting House -- Grace Church -- General railroad passenger station -- Central Congregational Church -- Providence Athenaeum -- Central Baptist Church.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.
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Terrestrial permafrost archives along the Yukon Coastal Plain (northwest Canada) have recorded landscape development and environmental change since the Late Wisconsinan at the interface of unglaciated Beringia (i.e. Komakuk Beach) and the northwestern limit of the Laurentide Ice Sheet (i.e. Herschel Island). The objective of this paper is to compare the late glacial and Holocene landscape development on both sides of the former ice margin based on permafrost sequences and ground ice. Analyses at these sites involved a multi-proxy approach including: sedimentology, cryostratigraphy, palaeoecology of ostracods, stable water isotopes in ground ice, hydrochemistry, and AMS radiocarbon and infrared stimulated luminescence (IRSL) dating. AMS and IRSL age determinations yielded full glacial ages at Komakuk Beach that is the northeastern limit of ice-free Beringia. Herschel Island to the east marks the Late Wisconsinan limit of the northwest Laurentide Ice Sheet and is composed of ice-thrust sediments containing plant detritus as young as 16.2 cal ka BP that might provide a maximum age on ice arrival. Late Wisconsinan ice wedges with sediment-rich fillings on Herschel Island are depleted in heavy oxygen isotopes (mean d18O of -29.1 per mil); this, together with low d-excess values, indicates colder-than-modern winter temperatures and probably reduced snow depths. Grain-size distribution and fossil ostracod assemblages indicate that deglaciation of the Herschel Island ice-thrust moraine was accompanied by alluvial, proluvial, and eolian sedimentation on the adjacent unglaciated Yukon Coastal Plain until ~11 cal ka BP during a period of low glacio-eustatic sea level. The late glacial-Holocene transition was marked by higher-than-modern summer temperatures leading to permafrost degradation that began no later than 11.2 cal ka BP and caused a regional thaw unconformity. Cryostructures and ice wedges were truncated while organic matter was incorporated and soluble ions were leached in the thaw zone. Thermokarst activity led to the formation of ice-wedge casts and deposition of thermokarst lake sediments. These were subsequently covered by rapidly accumulating peat during the early Holocene Thermal Maximum. A rising permafrost table, reduced peat accumulation, and extensive ice-wedge growth resulted from climate cooling starting in the middle Holocene until the late 20th century. The reconstruction of palaeolandscape dynamics on the Yukon Coastal Plain and the eastern Beringian edge contributes to unraveling the linkages between ice sheet, ocean, and permafrost that have existed since the Late Wisconsinan.
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The stratigraphic position of the glacially transported 'Scholle' (large-size erratic block) at Schobüll near Husum (Schleswig-Holstein) is now considered to be Devonian rather than 'Rotliegendes'. The 'Scholle', consisting of red clay and dolomite, is overlain by red-colored till without any flint but with up to 90% carbonate clasts (containing 15% dolomite), which indicates an eastern Baltic origin. The relationship of the 'Scholle' with the glacial till also points to an eastern Baltic origin for it, with up to 1 000 km transport distance.
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Lyndon Township, Mich. residences. Inset: The Old Home. Publication information: Chicago, Ill. : Everts & Stewart, 1874.