844 resultados para Dalton
Resumo:
We report the isolation and characterization of CDC45, which encodes a polypeptide of 650 amino acids that is essential for the initiation of chromosomal DNA replication in the budding yeast, Saccharomyces cerevisiae. CDC45 genetically interacts with at least two members of the MCM (minichromosome maintenance) family of replication genes, CDC46 and CDC47, which are proposed to perform a role in restricting initiation of DNA replication to once per cell cycle. Like mutants in several MCM genes, alleles of CDC45 also show a severe minichromosome maintenance defect. Together, these observations imply that Cdc45p performs a role in the control of initiation events at chromosomal replication origins. We investigated this possibility further and present evidence demonstrating that Cdc45p is assembled into complexes with one MCM family member, Cdc46p/Mcm5p. These observations point to a role for Cdc45p in controlling the early steps of chromosomal DNA replication in conjunction with MCM polypeptide complexes. Unlike the MCMs, however, the subcellular localization of Cdc45p does not vary with the cell cycle, making it likely that Cdc45p interacts with MCMs only during the nuclear phase of MCM localization in G1.
Resumo:
The CDC47 gene was isolated by complementation of a cdc47 temperature-sensitive mutant in Saccharomyces cerevisiae and was shown to encode a predicted polypeptide, Cdc47, of 845 aa. Cdc47 belongs to the Cdc46/Mcm family of proteins, previously shown to be essential for initiation of DNA replication. Using indirect immunofluorescence microscopy and subcellular fractionation techniques, we show that Cdc47 undergoes cell cycle-regulated changes in its subcellular localization. At mitosis, Cdc47 enters the nucleus, where it remains until soon after the initiation of DNA replication, when it is rapidly exported back into the cytoplasm. Cdc47 protein levels do not vary with the cell cycle, but expression of CDC47 and nascent synthesis of Cdc47 occur late in the cell cycle, coinciding with mitosis. Together, these results show that Cdc47 is not only imported into the nucleus at the end of mitosis but is also exported back into the cytoplasm at the beginning of S phase. The observation that Cdc47 is exported from the nucleus at the beginning of S phase has important implications for how initiation of DNA replication is controlled.
Resumo:
The Alaska Natural Gas Pipeline (ANGP) is proposed for construction on the North Slope in 2016. It will be aligned through Arctic caribou habitat and evidence shows that caribou are negatively affected by human development. This Capstone identifies potential adverse affects of ANGP on Arctic caribou using interviews from expert caribou biologists and the 1977 Trans-Alaska Pipeline System (TAPS) as a model. Based on a synthesis of the interviews and TAPS analysis, this capstone proposes and examines a set of seventeen conservation measures to be implemented during construction and operation of ANGP to minimize adverse impacts on caribou herds. These conservation measures can be used as a baseline for future developments on the North Slope to promote caribou herd management.
Resumo:
Chiral rhodium hybrid nanocatalysts have been prepared by covalent anchorage of pyrrolidine-based diphosphine ligands onto functionalized CNTs. This work constitutes the first attempt at covalent anchoring of homogeneous chiral catalysts on CNTs. The catalysts, prepared with two different chiral phosphines, were characterized by ICP, XPS, N2 adsorption and TEM, and have been tested in the asymmetric hydrogenation of two different substrates: methyl 2-acetamidoacrylate and α-acetamidocinnamic acid. The hybrid nanocatalysts have shown to be active and enantioselective in the hydrogenation of α-acetamidocinnamic acid. A good recyclability of the catalysts with low leaching and without loss of activity and enantioselectivity was observed.
Resumo:
This layer is a georeferenced raster image of the historic paper map entitled: New Hampshire by recent survey : made under the supreme authority and published according to law by Philip Carrigain ; J.J. Barralet, del. ; W. Harrison, sct., Philada. It was published by Philip Carrigain in 1816. Scale [ca. 1:200,000]. This layer is image 6 of 6 total images, representing the northwest portion of the six sheet source map. The image inside the map neatline is georeferenced to the surface of the earth and fit to the New Hampshire State Plane coordinate system (NAD 1983 in Feet) (Fipszone 2800). 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, drainage, public buildings, schools, churches, industry locations (e.g. mills, factories, mines, etc.), selected private buildings with names of property owners, town boundaries, land grants, and more. Relief shown pictorially and by hachures. Includes area notes, text, and table of population. Also includes illustrations: View of the Great Boars Head and Hampton Beach -- The Cap of the White Mountains -- View of the White Mountains from Shelburne; inset maps: States of the Union east of the Hudson with the adjacent British colonies. Scale [ca. 1:1,920,000] -- The middle, southern and western sections of the United States with the territories. Scale [ca. 1:4,900,000]. Includes: ms. additions with updated county boundary & township names.This layer is part of a selection of digitally scanned and georeferenced historic maps of New England from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates, scales, and map purposes.
Resumo:
This layer is a georeferenced raster image of the historic paper map entitled: Railway and highway map of the famous Berkshire Hills region, showing also villages and points of interest, by Walter Watson, C.E. for the Berkshire Life Insurance Co. of Pittsfield, Mass., 1883. Scale [1:134,376]. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). 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, or other information associated with the principal map. This map shows features such as main roads, railroads and railroad stations, drainage, mountains, schools, churches, cemeteries, town boundaries and more. Relief is shown by hachures and spot heights. Includes text and illustrations. This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.
Resumo:
This layer is a georeferenced raster image of the historic paper map entitled: Railway and highway map of the famous Berkshire Hills region : showing also villages and points of interest, by Walter Watson, C.E. for the Berkshire Life Insurance Co. of Pittsfield, Mass., 1883, corrected to 1896. Scale [1:134,376]. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). 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, or other information associated with the principal map. This map shows features such as main roads, railroads and railroad stations, drainage, mountains, schools, churches, cemeteries, town boundaries and more. Relief is shown by hachures and spot heights. Includes text and illustrations. This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.
Resumo:
This layer is a georeferenced raster image of the historic paper map entitled: Map of the county of Berkshire, Massachusetts, the details from actual surveys under the direction of Henry F. Walling, supt. of the state map. It was published by Smith, Gallup & Co. in 1858. Scale 1:50,688. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). 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, or other information associated with the principal map. This map shows features such as roads, railroads, drainage, public buildings, schools, churches, cemeteries, industry locations (e.g. mills, factories, mines, etc.), private buildings with names of property owners, town and county boundaries and more. Relief is shown by hachures. It includes many cadastral insets of individual county towns and villages, and an inset geological map of county. Includes also illustrations, business directories, and tables of statistics and distances. This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.
Resumo:
This layer is a digital raster graphic of the historic 15-minute USGS topographic quadrangle map of Becket, Massachusetts. The survey (ground condition) date is 1886. A digital raster graphic (DRG) is a scanned image of a U.S. Geological Survey (USGS) standard series topographic map, including all map collar information. The image inside the map neatline is geo-referenced to the surface of the earth and fit to the Universal Transverse Mercator projection. The horizontal positional accuracy and datum of the DRG matches the accuracy and datum of the source map. The names of quadrangles which border this one appear on the map collar in their respective positions (N,S,E,W) in relation to this map.
Resumo:
This layer is a digital raster graphic of the historic 15-minute USGS topographic map of the Greylock, Massachusetts quadrangle. The survey date (ground condition) of the original paper map is 1885, the edition date is November, 1898 and it was reprinted in July, 1901. A digital raster graphic (DRG) is a scanned image of a U.S. Geological Survey (USGS) standard series topographic map, including all map collar information. The image inside the map neatline is geo-referenced to the surface of the earth and fit to the Universal Transverse Mercator projection. The horizontal positional accuracy and datum of the DRG matches the accuracy and datum of the source map. The names of quadrangles which border this one appear on the map collar in their respective positions (N,S,E,W) in relation to this map.