571 research outputs found
Search for Large Rapidity Gap Events in e^+ e^- Annihilation
We investigate the cross-section for the production of a low-mass
colour-singlet cluster in annihilation with a large rapidity gap
between the colour-singlet cluster and the other jets. It is argued that such
events are the cross-channel analogue of large-rapidity-gap events in
deep-inelastic scattering, and therefore could in principle be used to
investigate the analytic continuation of the BFKL pomeron to the positive-
kinematic regime, where one would expect the trajectory to pass through
glueball states. The cross section can be calculated in perturbative QCD, so
that the infrared scale arising from non-perturbative effects, which prevents
an exponential fall-off with rapidity gap in the case of deep-inelastic
scattering, is absent in annihilation. Correspondingly, the cross
section for such events decreases rapidly with increasing rapidity gap.Comment: LATEX file - 21 pages + 15 figure
Observable Effects of Scalar Fields and Varying Constants
We show by using the method of matched asymptotic expansions that a
sufficient condition can be derived which determines when a local experiment
will detect the cosmological variation of a scalar field which is driving the
spacetime variation of a supposed constant of Nature. We extend our earlier
analyses of this problem by including the possibility that the local region is
undergoing collapse inside a virialised structure, like a galaxy or galaxy
cluster. We show by direct calculation that the sufficient condition is met to
high precision in our own local region and we can therefore legitimately use
local observations to place constraints upon the variation of "constants" of
Nature on cosmological scales.Comment: Invited Festscrift Articl
Eyewitnesses to the Suddenly Online Paradigm Shift in Education: Perspectives on the Experience, Sustaining Effective Teaching and Learning, and Forecasts for the Future
Introducing this special issue of the Journal of Literacy and Technology, the second part of the two-part special issues focusing on the COVID-19 âsuddenly onlineâ transition to remote/virtual eLearning modalities during the Spring of 2020. This article introduces the emergency voices from the field arising from the COVID-19 âsuddenly onlineâ transition to remote/virtual eLearning modalities during the Spring of 2020. This rare, and perhaps âonce in a lifetimeâ momentous COVID-19 pandemic induced a paradigmatic shift in teaching and learning modalities. The first-hand eyewitness accounts which emerged from the turbulent months of the âsuddenly onlineâ transition in education are important to capture direct reports from participant observers of the experience. That in this case, many of these participant-observers are also trained educators, academic researchers, and able to provide meta-perspectives on those experiences makes recollections, reports, and perspectives even more remarkable and essential
Providing Foundations for an Educational Revolution: Moving Towards an Integrated Perspective
The pandemic of Spring 2020 necessitated a rapid switch in teaching methods around the world. Most significantly was the revolutionary transition from face to face instruction to remote, distance, or virtual teaching/learning and the resultant online ânew normalâ that continues to ripple across the academy and society at large. This new reality has necessitated a paradigmatic shift in how scholars, teachers and administrators understand, create, employ, and assess teaching/learning. It has likewise resulted in a shift in how students, parents, families, and employers understand, value, desire, and prefer educational formats and settings. The authors point to the importance of considering aspects of theory, research, and best practices related to this transition. The article surveys resulting first response scholarship and forecast types of questions that loom large regarding the practice of online teaching in the new economic, academic, social framework
Native socio-economic development in Canada : change, promise and innovation
iii, 60 p., digital fil
Real-time PCR based on SYBR-Green I fluorescence: An alternative to the TaqMan assay for a relative quantification of gene rearrangements, gene amplifications and micro gene deletions
BACKGROUND:
Real-time PCR is increasingly being adopted for RNA quantification and genetic analysis. At present the most popular real-time PCR assay is based on the hybridisation of a dual-labelled probe to the PCR product, and the development of a signal by loss of fluorescence quenching as PCR degrades the probe. Though this so-called 'TaqMan' approach has proved easy to optimise in practice, the dual-labelled probes are relatively expensive.
RESULTS:
We have designed a new assay based on SYBR-Green I binding that is quick, reliable, easily optimised and compares well with the published assay. Here we demonstrate its general applicability by measuring copy number in three different genetic contexts; the quantification of a gene rearrangement (T-cell receptor excision circles (TREC) in peripheral blood mononuclear cells); the detection and quantification of GLI, MYC-C and MYC-N gene amplification in cell lines and cancer biopsies; and detection of deletions in the OPA1 gene in dominant optic atrophy.
CONCLUSION:
Our assay has important clinical applications, providing accurate diagnostic results in less time, from less biopsy material and at less cost than assays currently employed such as FISH or Southern blotting
The Value of the Cosmological Constant
We make the cosmological constant, {\Lambda}, into a field and restrict the
variations of the action with respect to it by causality. This creates an
additional Einstein constraint equation. It restricts the solutions of the
standard Einstein equations and is the requirement that the cosmological wave
function possess a classical limit. When applied to the Friedmann metric it
requires that the cosmological constant measured today, t_{U}, be {\Lambda} ~
t_{U}^(-2) ~ 10^(-122), as observed. This is the classical value of {\Lambda}
that dominates the wave function of the universe. Our new field equation
determines {\Lambda} in terms of other astronomically measurable quantities.
Specifically, it predicts that the spatial curvature parameter of the universe
is {\Omega}_{k0} \equiv -k/a_(0)^(2)H^2= -0.0055, which will be tested by
Planck Satellite data. Our theory also creates a new picture of self-consistent
quantum cosmological history.Comment: 6 pages. This article received Third Prize in the 2011 Gravity
Research Foundation Awards for Essays on Gravitatio
The effects of graded levels of calorie restriction : II. Impact of short term calorie and protein restriction on circulating hormone levels, glucose homeostasis and oxidative stress in male C57BL/6 mice
This work was supported by BBSRC BB009953/1 awarded to JRS and SEM. PK and CD were funded by the Erasmus exchange programme. JRS, SEM, DD, CG, LC, JJDH, YW, DELP, DL and AD are members of the BBSRC China Partnership Award, BB/J020028/1.Peer reviewedPublisher PD
Multi-Instanton Calculus and Equivariant Cohomology
We present a systematic derivation of multi-instanton amplitudes in terms of
ADHM equivariant cohomology. The results rely on a supersymmetric formulation
of the localization formula for equivariant forms. We examine the cases of N=4
and N=2 gauge theories with adjoint and fundamental matter.Comment: 29 pages, one more reference adde
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