79 research outputs found
Equivariant infinite loop space theory, I. The space level story
We rework and generalize equivariant infinite loop space theory, which shows
how to construct G-spectra from G-spaces with suitable structure. There is a
naive version which gives naive G-spectra for any topological group G, but our
focus is on the construction of genuine G-spectra when G is finite.
We give new information about the Segal and operadic equivariant infinite
loop space machines, supplying many details that are missing from the
literature, and we prove by direct comparison that the two machines give
equivalent output when fed equivalent input. The proof of the corresponding
nonequivariant uniqueness theorem, due to May and Thomason, works for naive
G-spectra for general G but fails hopelessly for genuine G-spectra when G is
finite. Even in the nonequivariant case, our comparison theorem is considerably
more precise, giving a direct point-set level comparison.
We have taken the opportunity to update this general area, equivariant and
nonequivariant, giving many new proofs, filling in some gaps, and giving some
corrections to results in the literature.Comment: 94 page
Categorical Models for Equivariant Classifying Spaces
Starting categorically, we give simple and precise models for classifying spaces of equivariant principal bundles. We need these models for work in progress in equi- variant infinite loop space theory and equivariant algebraic K–theory, but the models are of independent interest in equivariant bundle theory and especially equivariant covering space theory
Institute of Archaeology & Horn Archaeological Museum Newsletter Volume 26.3
Excavations at Tall Jalul, 2005, Randall W. Younker and David Merling
Tsouparopoulou Lecture, Darrell J. Rohl
70% Off Major Archaeological Series: Offer Good Through March 31, 2006
Random Surveyhttps://digitalcommons.andrews.edu/iaham-news/1023/thumbnail.jp
Institute of Archaeology & Horn Archaeological Museum Newsletter Volume 24.3
Institute/Museum to Relocate, David Merling
Klingbeil on Surveys, Robert D. Bates
Ortiz on David, Paul J. Ray, Jr.
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Random Surveyhttps://digitalcommons.andrews.edu/iaham-news/1015/thumbnail.jp
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 -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 -space that recovers the classical ("schneiden und kleben," German for "cut and paste") groups for manifolds on , and we construct a derived version of the Euler characteristic
Institute of Archaeology & Horn Archaeological Museum Newsletter Volume 21.4
Tall Umayri 2000, Larry Herr, modified by Paul J. Ray, Jr.
Jalul 2000, Randall W. Younker and David Merling
Rendsburg at AU, Moise Isaac
Beaulieu Studies Tablets, Paul J. Ray, Jr.
Madaba Plains Project 4
Random Surveyhttps://digitalcommons.andrews.edu/iaham-news/1004/thumbnail.jp
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
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