989 resultados para Middle American


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Binding of different regulatory subunits and methylation of the catalytic (C) subunit carboxy-terminal leucine 309 are two important mechanisms by which protein phosphatase 2A (PP2A) can be regulated. In this study, both genetic and biochemical approaches were used to investigate regulation of regulatory subunit binding by C subunit methylation. Monoclonal antibodies selectively recognizing unmethylated C subunit were used to quantitate the methylation status of wild-type and mutant C subunits. Analysis of 13 C subunit mutants showed that both carboxy-terminal and active site residues are important for maintaining methylation in vivo. Severe impairment of methylation invariably led to a dramatic decrease in Bα subunit binding but not of striatin, SG2NA, or polyomavirus middle tumor antigen (MT) binding. In fact, most unmethylated C subunit mutants showed enhanced binding to striatin and SG2NA. Certain carboxy-terminal mutations decreased Bα subunit binding without greatly affecting methylation, indicating that Bα subunit binding is not required for a high steady-state level of C subunit methylation. Demethylation of PP2A in cell lysates with recombinant PP2A methylesterase greatly decreased the amount of C subunit that could be coimmunoprecipitated via the Bα subunit but not the amount that could be coimmunoprecipitated with Aα subunit or MT. When C subunit methylation levels were greatly reduced in vivo, Bα subunits were found complexed exclusively to methylated C subunits, whereas striatin and SG2NA in the same cells bound both methylated and unmethylated C subunits. Thus, C subunit methylation is critical for assembly of PP2A heterotrimers containing Bα subunit but not for formation of heterotrimers containing MT, striatin, or SG2NA. These findings suggest that methylation may be able to selectively regulate the association of certain regulatory subunits with the A/C heterodimer.

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Although it may sound reasonable that American education continues to be more effective at sending high school students to college, in a study conducted in 2009, The Council of the Great City Schools states that "slightly more than half of entering ninth grade students arrive performing below grade level in reading and math, while one in five entering ninth grade students is more than two years behind grade level...[and] 25% received support in the form of remedial literacy instruction or interventions" (Council of the Great City Schools, 2009). Students are distracted with technology (Lei & Zhao, 2005), family (Xu & Corno, 2003), medical illnesses (Nielson, 2009), learning disabilities and perhaps the most detrimental to academic success, the very lack of interest in school (Ruch, 1963). In a Johns Hopkins research study, Building a Graduation Nation - Colorado (Balfanz, 2008), warning signs were apparent years before the student dropped out of high school. The ninth grade was often referenced as a critical point that indicated success or failure to graduate high school. The research conducted by Johns Hopkins illustrates the problem: students who become disengaged from school have a much greater chance of dropping out of high school and not graduating. The first purpose of this study was to compare different measurement models of the Student School Engagement (SSE) using Factor Analysis to verify model fit with student engagement. The second purpose was to determine the extent to which the SSE instrument measures student school engagement by investigating convergent validity (via the SSE and Appleton, Christenson, Kim and Reschly's instrument and Fredricks, Blumenfeld, Friedel and Paris's instrument), discriminant validity (via Huebner's Student Life Satisfaction Survey) and criterion-related validity (via the sub-latent variables of Aspirations, Belonging and Productivity and student outcome measures such as achievement, attendance and discipline). Discriminant validity was established between the SSE and the Appleton, Christenson, Kim and Reschly's model and Fredricks, Blumenfeld, Friedel and Paris's (2005) Student Engagement Instruments (SEI). When confirming discriminant validity, the SSE's correlations were weak and statistically not significant, thus establishing discriminant validity with the SLSS. Criterion-related validity was established through structural equation modeling when the SSE was found to be a significant predictor of student outcome measures when both risk score and CSAP scores were used. The third purpose of this study was to assess the factorial invariance of the SSE instrument across gender to ensure the instrument is measuring the intended construct across different groups. Conclusively, configural, weak and metric invariances were established for the SSE as a non-significant change in chi-square indicating that all parameters including the error variances were invariant across groups of gender. Engagement is not a clearly defined psychological construct; it requires more research in order to fully comprehend its complexity. Hopefully, with parental and teacher involvement and a sense of community, student engagement can be nurtured to result in a meaningful attachment to school and academic success.

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This layer is a georeferenced raster image of the historic paper map entitled: Novi Belgii, quod nunc Novi Jorck vocatur, Novae q[ue] Angliae & partis Virginiae : accuratissima et novissima delineatio. It was published by J. Meurs for Arnoldus Montanus' De Nieuwe en onbekende weereld, 1671. p. 122-123. Scale [ca. 1:3,500,000]. Covers the northeast Atlantic States from Maine to Virginia, and a portion of Canada. In Latin. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Mercator (world) projection. 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 human settlements, Native American tribal lands, drainage, shoreline features, and more. Relief is shown pictorially. Includes illustrations and illustrative cartouche. 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 purposes.

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This layer is a georeferenced raster image of the historic paper map entitled: Belgii novi, angliae novae, et partis Virginiae : novissima delineatio. It was published by Ioannes Ianssonius (Jan Jansson) between 1660 and 1663. Scale [ca. 1:2,450,000]. Covers the northeast Atlantic States from Maine to Virginia, and a portion of Canada. In Latin. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Mercator (world) projection. 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 human settlements, forts, Native American tribal lands, drainage, shoreline features, and more. Relief is shown pictorially. Includes illustrations. 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 purposes.

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This layer is a georeferenced raster image of the historic paper map entitled: Novi Belgii Novaeque Angliae nec non partis Virginiae tabula : multis in locis emendata, per Nicolaum Visscher. It was published by N. Visscher ca. 1684. Scale [ca. 1:2,250,000]. Covers the northeast Atlantic States from Maine to Virginia, and a portion of Canada. In Latin and Dutch. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Mercator (world) projection. 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 human settlements, forts, Native American tribal lands, drainage, territorial boundaries, shoreline features, and more. Relief is shown pictorially. Includes decorative cartouche and inset view of Manhattan: Nieuw Amsterdam op t eylant Manhattans. 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 purposes.

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This layer is a georeferenced raster image of the historic paper map entitled: Recens edita totius Novi Belgii in America Septentrionali siti, delineatio cura et sumtibus Matthaei Seutteri (Matthaeus Seutter). It was published ca. 1730. Scale [ca. 1:2,250,000]. Covers the northeast Atlantic States from Maine to Virginia, and a portion of Canada. In Latin. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Mercator (world) projection. 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 human settlements, forts, Native American tribal lands, drainage, territory boundaries, shoreline features, and more. Relief is shown pictorially. Includes illustrations, illustrative cartouche, and inset view of Manhattan: Neu Jorck sive Neu Amsterdam. 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 purposes.

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This layer is a georeferenced raster image of the historic paper map entitled: Belgii novi, angliae novae, et partis Virginiae : novissima delineatio. It was published by Petrum Schenk and Gerardum Valk, ca. 1690. Scale [ca. 1:2,450,000]. Covers the northeast Atlantic States from Maine to Virginia, and a portion of Canada. In Latin. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Mercator (world) projection. 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 human settlements, forts, Native American tribal lands, drainage, territory boundaries, shoreline features, and more. Relief is shown pictorially. Includes illustrations and decorative cartouches. 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 purposes.

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Includes index.

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Contains bibliographical foot-notes.

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Accompanied by "Supplement, Jan. 1, 1963." (29 p.) Published: [Washington], 1963.