19 research outputs found
Status and Prospects of Top-Quark Physics
The top quark is the heaviest elementary particle observed to date. Its large
mass of about 173 GeV/c^2 makes the top quark act differently than other
elementary fermions, as it decays before it hadronises, passing its spin
information on to its decay products. In addition, the top quark plays an
important role in higher-order loop corrections to standard model processes,
which makes the top quark mass a crucial parameter for precision tests of the
electroweak theory. The top quark is also a powerful probe for new phenomena
beyond the standard model. During the time of discovery at the Tevatron in 1995
only a few properties of the top quark could be measured. In recent years,
since the start of Tevatron Run II, the field of top-quark physics has changed
and entered a precision era. This report summarises the latest measurements and
studies of top-quark properties and gives prospects for future measurements at
the Large Hadron Collider (LHC).Comment: 76 pages, 35 figures, submitted to Progress in Particle and Nuclear
Physic
The phase diagram of Yang-Mills theory with a compact extra dimension
We present a non-perturbative study of the phase diagram of SU(2) Yang-Mills
theory in a five-dimensional spacetime with a compact extra dimension. The
non-renormalizable theory is regularized on an anisotropic lattice and
investigated through numerical simulations in a regime characterized by a
hierarchy between the scale of low-energy physics, the inverse compactification
radius, and the cutoff scale. We map out the structure of the phase diagram and
the pattern of lines corresponding to fixed values of the ratio between the
mass of the fifth component of the gauge field and the non-perturbative mass
gap of the four-dimensional modes. We discuss different limits of the model,
and comment on the implications of our findings.Comment: 17 pages, 9 figure
QCD and strongly coupled gauge theories : challenges and perspectives
We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe
Identification of myopia-associated WNT7B polymorphisms provides insights into the mechanism underlying the development of myopia
10.1038/ncomms7689Nature Communications
Expansion of retinal stem cells and their progeny using cell microcarriers in a bioreactor
This is the final version of the following article: Baakdhah, T, van der Kooy, D. Expansion of retinal stem cells and their progeny using cell microcarriers in a bioreactor. Biotechnol Progress. 2019; 35:e2800., which has been published at https://doi.org/10.1002/btpr.2800. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Blindness as a consequence of degenerative eye diseases (e.g., age-related macular degeneration and retinitis pigmentosa) is a major health problem and numbers are expected to increase by up to 50% by 2020. Unfortunately, adult mouse and human retinal stem cells (RSCs), unlike fish and amphibians, are quiescent in vivo and do not regenerate following disease or injury. To replace lost cells, we used microcarriers (MCs) in a suspension stirring bioreactor to help achieve numbers suitable for differentiation and transplantation. We achieved a significant 10-fold enrichment of RSC yield compared to conventional static culture techniques using a combination of FACTIII MCs and relative hypoxia (5%) inside the bioreactor. We found that hypoxia (5% O2 ) was associated with better RSC expansion across all platforms; and this can be attributed to hypoxia-induced increases in survival and/or symmetric division of stem cells. In the future, we will target the differentiation of RSCs and their progeny toward rod and cone photoreceptor phenotypes using FACTIII MCs inside bioreactors to expand their populations in order to produce the large numbers of cells needed for transplantation.Canadian Institutes of Health Research, Grant/ Award Number: FDN-148407; Krembil Foundation, Grant/Award Number: 41000502