1,090 research outputs found

    Notch/Delta signaling constrains reengineering of pro-T cells by PU.1

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    PU.1 is essential for early stages of mouse T cell development but antagonizes it if expressed constitutively. Two separable mechanisms are involved: attenuation and diversion. Dysregulated PU.1 expression inhibits pro-T cell survival, proliferation, and passage through Ī²-selection by blocking essential T cell transcription factors, signaling molecules, and Rag gene expression, which expression of a rearranged T cell antigen receptor transgene cannot rescue. However, Bcl2 transgenic cells are protected from this attenuation and may even undergo Ī²-selection, as shown by PU.1 transduction of defined subsets of Bcl2 transgenic fetal thymocytes with differentiation in OP9-DL1 and OP9 control cultures. The outcome of PU.1 expression in these cells depends on Notch/Delta signaling. PU.1 can efficiently divert thymocytes toward a myeloid-like state with multigene regulatory changes, but Notch/Delta signaling vetoes diversion. Gene expression analysis distinguishes sets of critical T lineage regulatory genes with different combinatorial responses to PU.1 and Notch/Delta signals, suggesting particular importance for inhibition of E proteins, Myb, and/or Gfi1 (growth factor independence 1) in diversion. However, Notch signaling only protects against diversion of cells that have undergone T lineage specification after Thy-1 and CD25 up-regulation. The results imply that in T cell precursors, Notch/Delta signaling normally acts to modulate and channel PU.1 transcriptional activities during the stages from T lineage specification until commitment

    World of Viruses: the Frozen Horror

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    https://digitalcommons.unmc.edu/coph_books/1000/thumbnail.jp

    The Grizzly, September 28, 1993

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    The Quilt\u27s Arrival: To Remember ā€¢ Dawleys Appointed Biology Co-Chairs ā€¢ Russian President Yeltsin Dissolves Parliament ā€¢ Model UN Seeks New Delegation ā€¢ Billy Joel Rocks Philly ā€¢ Javapalooza ā€¢ Big Al Day Exposed ā€¢ Fitness Forum ā€¢ Freshman Primer ā€¢ Letter: Faculty Members Point Out Error ā€¢ Tutorial Program Strengthens Ursinus ā€¢ Ursinus Perceived as Anti-Gay ā€¢ UC Training Staff Saves the Day ā€¢ Bear Pack Way Ahead Again ā€¢ Football Holds Off Western Maryland ā€¢ Scooter\u27s Dayhttps://digitalcommons.ursinus.edu/grizzlynews/1319/thumbnail.jp

    The Grizzly, October 5, 1993

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    Girls\u27 Pledging Returns Full-Force! ā€¢ India Shattered by Earthquakes ā€¢ Acting PA Governor Will Hold TV Town Meeting at Ursinus ā€¢ Freshman to Compete in Karate\u27s World Cup ā€¢ Henry Moore Exhibit Opens Today ā€¢ Charles Fambrough Quintet to Play Ursinus ā€¢ Editorial: Pledging; Wellness Center ā€¢ Intramurals Begin: Sign Up! ā€¢ Bears Crush Garnet Into Pebbleshttps://digitalcommons.ursinus.edu/grizzlynews/1320/thumbnail.jp

    The Grizzly, October 26, 1993

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    Colvin, Reynolds to Serve on Captains\u27 Council ā€¢ Verdict Returned in Reginald Denny Trial ā€¢ Ursinus Loses Friend and Supporter ā€¢ Student Apathy Strikes Again ā€¢ Ursinus Students to Perform in State Choral Festival ā€¢ Gaijin-Eyes Exhibit to Open ā€¢ Literary Society ā€¢ Self-Realization in the Big Apple: Wiggly Blocks and The Piano ā€¢ Bears Win Homecoming ā€¢ Phillies Lose World Serieshttps://digitalcommons.ursinus.edu/grizzlynews/1322/thumbnail.jp

    Developmental and Molecular Characterization of Emerging Ī²- and Ī³Ī“-Selected Pre-T Cells in the Adult Mouse Thymus

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    The first checkpoint in T cell development, Ī² selection, has remained incompletely characterized for lack of specific surface markers. We show that CD27 is upregulated in DN3 thymocytes initiating Ī² selection, concomitant with intracellular TCR-Ī² expression. Clonal analysis determined that CD27^(high) DN3 cells generate CD4^+CD8^+ progeny with more than 90% efficiency, faster and more efficiently than the CD27^(low) majority. CD27 upregulation also occurs in Ī³Ī“-selected DN3 thymocytes in TCR-Ī²āˆ’/āˆ’ mice and in IL2-GFP transgenic reporter mice where GFP marks the earliest emerging TCR-Ī³Ī“ cells from DN3 thymocytes. With CD27 to distinguish pre- and postselection DN3 cells, a detailed gene expression analysis defined regulatory changes associated with checkpoint arrest, with Ī² selection, and with Ī³Ī“ selection. Ī³Ī“ selection induces higher CD5, Egr, and Runx3 expression as compared to Ī² selection, but it triggers less proliferation. Our results also reveal differences in Notch/Delta dependence at the earliest stages of divergence between developing Ī±Ī² and Ī³Ī“ T-lineage cells

    Evidence-Based Background Material Underlying Guidance for Federal Agencies in Implementing Strategic Sustainability Performance Plans - Implementing Sustainability: The Institutional-Behavioral Dimension

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    This document is part of a larger, programmatic effort to assist federal agencies in taking action and changing their institutions to achieve and maintain federal sustainability goals, while meeting their mission goals. FEMP is developing guidance for federal agency efforts to enable institutional behavior change for sustainability, and for making sustainability ā€œbusiness as usual.ā€ The driving requirement for this change is Executive Order (EO) 13514, Federal Leadership in Environmental, Energy, and Economic Performance. FEMP emphasizes strategies for increasing energy efficiency and renewable energy utilization as critical components of attaining sustainability, and promotes additional non-energy action pathways contained in EO 13514. This report contributes to the larger goal by laying out the conceptual and evidentiary underpinnings of guidance to federal agencies. Conceptual frameworks focus and organize the development of guidance. We outline a series of progressively refined conceptual frameworks, including a multi-layer approach, key steps in sustainability implementation, a process view of specific approaches to institutional change, the agency Strategic Sustainability Performance Plans (SSPPs), and concepts related to context-specific rules, roles and tools for sustainability. Additionally, we tap pertinent bodies of literature in drawing eight evidence-based principles for behavior change. These principles are important foundations upon which to build in selecting strategies to effect change in organizations. Taken together, this report presents a suite of components that inform the training materials, presentations, web site, and other products that provide guidance to federal agencies
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