Cut and paste invariants of manifolds via algebraic K-theory

Recent work of Jonathan Campbell and Inna Zakharevich has focused on building machinery for studying scissors congruence problems via algebraic $K$-theory, and applying these tools to studying the Grothendieck ring of varieties. In this paper we give a new application of their framework: we construct a $K$-space that recovers the classical $\mathrm{SK}$ ("schneiden und kleben," German for "cut and paste") groups for manifolds on $\pi_0$, and we construct a derived version of the Euler characteristic

Overview of Plasma Lens Experiments and Recent Results at SPARC_LAB

Beam injection and extraction from a plasma module is still one of the crucial aspects to solve in order to produce high quality electron beams with a plasma accelerator. Proper matching conditions require to focus the incoming high brightness beam down to few microns size and to capture a high divergent beam at the exit without loss of beam quality. Plasma-based lenses have proven to provide focusing gradients of the order of kT/m with radially symmetric focusing thus promising compact and affordable alternative to permanent magnets in the design of transport lines. In this paper an overview of recent experiments and future perspectives of plasma lenses is reported

NF-κB Hyper-Activation by HTLV-1 Tax Induces Cellular Senescence, but Can Be Alleviated by the Viral Anti-Sense Protein HBZ

Activation of I-κB kinases (IKKs) and NF-κB by the human T lymphotropic virus type 1 (HTLV-1) trans-activator/oncoprotein, Tax, is thought to promote cell proliferation and transformation. Paradoxically, expression of Tax in most cells leads to drastic up-regulation of cyclin-dependent kinase inhibitors, p21CIP1/WAF1 and p27KIP1, which cause p53-/pRb-independent cellular senescence. Here we demonstrate that p21CIP1/WAF1-/p27KIP1-mediated senescence constitutes a checkpoint against IKK/NF-κB hyper-activation. Senescence induced by Tax in HeLa cells is attenuated by mutations in Tax that reduce IKK/NF-κB activation and prevented by blocking NF-κB using a degradation-resistant mutant of I-κBα despite constitutive IKK activation. Small hairpin RNA-mediated knockdown indicates that RelA induces this senescence program by acting upstream of the anaphase promoting complex and RelB to stabilize p27KIP1 protein and p21CIP1/WAF1 mRNA respectively. Finally, we show that down-regulation of NF-κB by the HTLV-1 anti-sense protein, HBZ, delay or prevent the onset of Tax-induced senescence. We propose that the balance between Tax and HBZ expression determines the outcome of HTLV-1 infection. Robust HTLV-1 replication and elevated Tax expression drive IKK/NF-κB hyper-activation and trigger senescence. HBZ, however, modulates Tax-mediated viral replication and NF-κB activation, thus allowing HTLV-1-infected cells to proliferate, persist, and evolve. Finally, inactivation of the senescence checkpoint can facilitate persistent NF-κB activation and leukemogenesis

Distinct functions of HTLV-1 Tax1 from HTLV-2 Tax2 contribute key roles to viral pathogenesis

While the human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent of adult T-cell leukemia/lymphoma (ATL), to date, its close relative HTLV-2 is not associated with ATL or other types of malignancies. Accumulating evidence shows that HTLV-1 Tax1 and HTLV-2 Tax2 have many shared activities, but the two proteins have a limited number of significantly distinct activities, and these distinctions appear to play key roles in HTLV-1 specific pathogenesis. In this review, we summarize the functions of Tax1 associated with cell survival, cell proliferation, persistent infection as well as pathogenesis. We emphasize special attention to distinctions between Tax1 and Tax2

Institute of Archaeology & Horn Archaeological Museum Newsletter Volume 17.4

Horn Fund Awarded, David Merling Younker Elected ASOR Trustee, Philip R. Drey Donations, Philip R. Drey Lectures, Philip R. Drey Inscription Found at Ekron, Editors Visitors, Philip R. Drey New Secretary, Philip R. Drey APOT Available, Editors Herr and Clark Update, Larry G. Herr Al-Maktába: The Bookstore Random Surveyhttps://digitalcommons.andrews.edu/iaham-news/1128/thumbnail.jp

The fucosylated histo-blood group antigens H type 2 (blood group O, CD173) and Lewis Y (CD174) are expressed on CD34+ hematopoietic progenitors but absent on mature lymphocytes

The expression of LeY, H2, H3, and H4 on a broad variety of human leukemia cell lines and native lymphocytes as well as on CD34 + hematopoietic progenitor cells was examined by flow cytometry and immunocytochemistry. CD34 + leukemia cell lines (KG1, KG1a, and TF1) and native CD34 + hematopoietic progenitor cells expressed H2 (CD173) and LeY (CD174). In contrast, CD34 - cell lines (HL-60, U937, JOK-1, Raji, Molt-3, Jurkat, and CEM-C7) and mature lymphocytes from peripheral blood and tonsils lacked CD173 and CD174. All cell lines and native lymphocytes as well as CD34 + precursor cells were negative for H3 and H4. Immunoprecipitation and consecutive Western blotting revealed a 170-kDa glycoprotein as the carrier molecule for the CD173 and CD174 oligosaccharide sequences on CD34 + hematopoietic precursors. The key enzyme for generating CD173 is the β-D-galactoside 2-α-L-fucosyltransferase (FUT1). As shown by RT-PCR, FUT1 was expressed in immature hematopoietic cells but absent in mature lymphocytes, which indicates that expression of CD173 within the hematopoietic system is regulated at the transcriptional level by FUT1. Due to their exclusive presence on CD34 + hematopoietic progenitor cells, CD173 and CD174 represent novel markers of early hematopoiesis. The expression of the fucosylated histo-blood group antigens CD173 and CD174 in CD34 + hematopoietic progenitor cells and down-regulation of FUT1 in mature lymphocytes may be important factors influencing the homing process of hematopoietic stem cells to the bone marrow

Cell Surface Sialylation and Ecto-sialyltransferase Activity of Human CD34 Progenitors from Peripheral Blood and Bone Marrow.

Surface expressed negatively charged sialoglycans contribute to the regulation of adhesive cellular Interactions and are thus Involved In the growth and dlfferentlaton of hematopoietic progenitor cells. In particular, the cell surface sialylatlon state may govern the liberation of CD34+ hematopoietic precursors from bone marrow stroma cells and extracellular matrbc. in order to assess the overall surface sialylatlon of live human 0034 hematopoietic precursor cells, we applied a previously described flow cytometric enzyme assay. Cells with and without slalidase pretreatmem were incubated in the presence of fluorescent CUP-siallc add and exogenous STSGall. Thus sialylatlon of surface-expressed bctosamlne residues was analysed. We demonstrated that surface lactosamlnes of CD34 precursors derived from bone marrow and peripheral blood are over 55% sialylated, predominantly in ai,B linkage. These results are In accordance with flow cytometric analysis of surface lectin staining. Sialic ackt specific lectins UAA and SNA were strongly bound whereas SBA, WA, and PNA became reactiva only after sialklase pretreatment. CD344 leukemia cell lines TF1 and KGIa also showed a high degree of surface sialylation whereas cell line KG1 expressed to the largest extent free lactosamlnes. In these cell lines, aifi and a sialylated residues were present In equal amounts, in a variation of the flow cytometric enzyme assay, live cells were incubated without exogenous STGa I to measure the activity of endogenous ecto-sialyltransferase. Ecto sialyltransferase activity was observed in all CD34+ cells which was able to resialylate major surface glycoproteins such as HLA Class I, CD45, CD43, and CD34. The ecto-sialyltransferase may serve to maintain or Increase surface sialylation rapidly without de novo synthesis.JRC.E.5-Nuclear chemistr

Institute of Archaeology & Horn Archaeological Museum Newsletter Volume 18.1

Museum Goes Electronic, David Merling Radio, Paul J. Ray, Jr. \u2796 MPP/ASOR, Douglas R. Clark Ham Lecture Series ACOR, Philip R. Drey Mattingly Lectures on the KRP, Philip R. Drey Al-Maktába: The Bookstore Random Surveyhttps://digitalcommons.andrews.edu/iaham-news/1132/thumbnail.jp