475 research outputs found
Radiative corrections to inverse muon decay for accelerator neutrinos
Inverse muon decay () is a promising tool to
constrain neutrino fluxes with energies .
Radiative corrections introduce percent-level distortions to energy spectra of
outgoing muons and depend on experimental details. In this paper, we generalize
the calculation of radiative corrections in muon decay to the scattering
processes and . We evaluate virtual and real
contributions and present the muon energy spectrum for both channels,
double-differential distributions in muon energy and muon scattering angle, in
photon energy and photon scattering angle, and photon energy spectrum for the
dominant process. We discuss how radiative
corrections modify experimentally interesting distributions.Comment: 21 pages, 8 figures, v2, structure changed, new cross sections adde
AMCIS 2010 Panel Report: External Benchmarks in Information Systems Program Assessment
Accrediting bodies and other external constituencies are placing increased emphasis on the assessment of academic degree programs for continuous improvement. Most assessment plans are focused on determining how well program outcomes or goals are being met. However, benchmarking a degree program across institutions is rarely considered. This article provides general principles for assessing information systems programs and presents quantitative and qualitative methodologies and tools for benchmarking student learning in Information Systems programs
RESULTS OF THE FIRST SIMULTANEOUS X-RAY, OPTICAL, AND RADIO CAMPAIGN ON THE BLAZAR PKS 1622-297
Coordinated X-ray, optical, and radio observations of the blazar PKS 1622-297 were obtained during a three-week campaign in 2006 using the Rossi X-Ray Timing Explorer (RXTE), the University of Michigan Radio Astronomy Observatory, and optical telescopes at Cerro Tololo Inter-American Observatory. The RXTE observations indicate that this object is a comparatively weak X-ray emitter for a Flat-Spectrum Radio Quasar. The observed broadband spectral shape indicates that X-rays were most likely produced by the Inverse Compton processes. Optical observations of this object produced unexpected results in that this object appeared redder when in a bright state and bluer when in a faint state, contrary to the observed behavior of BL Lac objects
Register shifting of an insulin peptide–MHC complex allows diabetogenic T cells to escape thymic deletion
A single amino acid shift in TCR recognition of self peptide–MHC determines whether potentially diabetogenic CD4 T cells will be purged in the thymus or have the opportunity to undergo activation in the islets of Langerhans of mice
Prion-like α-synuclein pathology in the brain of infants with Krabbe disease
Krabbe disease is an infantile neurodegenerative disorder resulting from pathogenic variants in the GALC gene that causes accumulation of the toxic sphingolipid psychosine. GALC variants are also associated with Lewy body diseases, an umbrella term for age-associated neurodegenerative diseases in which the protein α-synuclein aggregates into Lewy bodies. To explore whether α-synuclein in Krabbe disease has pathological similarities to that in Lewy body disease, we performed an observational post-mortem study of Krabbe disease brain tissue (n = 4) compared to infant controls (n = 4) and identified widespread accumulations of α-synuclein. To determine whether α-synuclein in Krabbe disease brain displayed disease-associated pathogenic properties we evaluated its seeding capacity using the real-time quaking-induced conversion assay in two cases for which frozen tissue was available and strikingly identified aggregation into fibrils similar to those observed in Lewy body disease, confirming the prion-like capacity of Krabbe disease-derived α-synuclein. These observations constitute the first report of prion-like α-synuclein in the brain tissue of infants and challenge the putative view that α-synuclein pathology is merely an age-associated phenomenon, instead suggesting it results from alterations to biological pathways, such as sphingolipid metabolism. Our findings have important implications for understanding the mechanisms underlying Lewy body formation in Lewy body disease
2-Deoxy-D-glucose couples mitochondrial DNA replication with mitochondrial fitness and promotes the selection of wild-type over mutant mitochondrial DNA
Pathological variants of human mitochondrial DNA (mtDNA) typically co-exist with wild-type molecules, but the factors driving the selection of each are not understood. Because mitochondrial fitness does not favour the propagation of functional mtDNAs in disease states, we sought to create conditions where it would be advantageous. Glucose and glutamine consumption are increased in mtDNA dysfunction, and so we targeted the use of both in cells carrying the pathogenic m.3243A>G variant with 2-Deoxy-D-glucose (2DG), or the related 5-thioglucose. Here, we show that both compounds selected wild-type over mutant mtDNA, restoring mtDNA expression and respiration. Mechanistically, 2DG selectively inhibits the replication of mutant mtDNA; and glutamine is the key target metabolite, as its withdrawal, too, suppresses mtDNA synthesis in mutant cells. Additionally, by restricting glucose utilization, 2DG supports functional mtDNAs, as glucose-fuelled respiration is critical for mtDNA replication in control cells, when glucose and glutamine are scarce. Hence, we demonstrate that mitochondrial fitness dictates metabolite preference for mtDNA replication; consequently, interventions that restrict metabolite availability can suppress pathological mtDNAs, by coupling mitochondrial fitness and replication.publishedVersio
Inducing behavioural change in society through communication and education in sustainable manufacturing
The United Nations considers the mobilization of the broad public to be the essential requirement for achieving a shift towards a more sustainable development. Science can play a vital role in Education for Sustainable Development (ESD) by contributing to ESD-related research and development on the one hand, and by becoming active awareness raisers themselves in education and multiplier networks. Specifically, the use of special Learnstruments, and investment inOpen Educationformats among other educational tools, may pave the way for accelerated apprehension and appreciation of sustainable manufacturing topics among the greater populace
A colitogenic memory CD4+ T cell population mediates gastrointestinal graft-versus-host disease
Damage to the gastrointestinal tract is a major cause of morbidity and mortality in graft-versus-host disease (GVHD) and is attributable to T cell–mediated inflammation. In this work, we identified a unique CD4+ T cell population that constitutively expresses the β2 integrin CD11c and displays a biased central memory phenotype and memory T cell transcriptional profile, innate-like properties, and increased expression of the gut-homing molecules α4β7 and CCR9. Using several complementary murine GVHD models, we determined that adoptive transfer and early accumulation of β2 integrin–expressing CD4+ T cells in the gastrointestinal tract initiated Th1-mediated proinflammatory cytokine production, augmented pathological damage in the colon, and increased mortality. The pathogenic effect of this CD4+ T cell population critically depended on coexpression of the IL-23 receptor, which was required for maximal inflammatory effects. Non–Foxp3-expressing CD4+ T cells produced IL-10, which regulated colonic inflammation and attenuated lethality in the absence of functional CD4+Foxp3+ T cells. Thus, the coordinate expression of CD11c and the IL-23 receptor defines an IL-10–regulated, colitogenic memory CD4+ T cell subset that is poised to initiate inflammation when there is loss of tolerance and breakdown of mucosal barriers
Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt{s}=1.96 TeV using Lepton + Jets Events with Secondary Vertex b-tagging
We present a measurement of the ttbar production cross section using events
with one charged lepton and jets from ppbar collisions at a center-of-mass
energy of 1.96 TeV. In these events, heavy flavor quarks from top quark decay
are identified with a secondary vertex tagging algorithm. From 162 pb-1 of data
collected by the Collider Detector at Fermilab, a total of 48 candidate events
are selected, where 13.5 +- 1.8 events are expected from background
contributions. We measure a ttbar production cross section of 5.6^{+1.2}_{-1.1}
(stat.) ^{+0.9}_{0.6} (syst.) pb.Comment: 28 pages, 20 figures. Published in Physical Review
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