1,422 research outputs found
The quest for the Cabibbo Kobayashi Maskawa Matrix
A piece of the Standard Model presently undergoing intense experimental
scrutiny is the Cabibbo Kobayashi Maskawa matrix. Several different
measurements are planned to enrich the spectrum of experimental constraints and
thus provide one of the most stringent tests of Standard Model validity. The
success of this program is closely related to theoretical progress in
evaluating QCD matrix elements in a non-perturbative regime, as we need to
extract fundamental quark properties from observations on decays involving
hadrons. This interplay between experimental and theoretical progress will be
illustrated in the context of the present knowledge of the magnitudes of the
quark mixing parameters and .Comment: 10 pages, 1 figure, contributed paper to BEAUTY 200
Gene Combination Transfer to Block Autoimmune Damage in Transplanted Islets of Langerhans
Islet transplantation therapy would be applicable to a
wider range of diabetic patients if donor islet acceptance
and protection were possible without systemic immunosuppression
of the recipient. To this aim, gene transfer
to isolated donor islets ex vivo is one method that has
shown promise. This study examines the combined effect of
selected immunomodulatory and anti-inflammatory genes
known to extend the functional viability of pancreatic islet
grafts in an autoimmune system. These genes, indoleamine
2,3-dioxygenase (IDO), manganese superoxide dismutase
(MnSOD), and interleukin (IL)-1 receptor antagonist protein
(IRAP), were transferred to isolated NOD donor islets
ex vivo then transplanted to NODscid recipients and evaluated
in vivo after diabetogenic T-cell challenge. The length
of time the recipient remained euglycemic was used to measure
the ability of the transgenes to protect the graft from
autoimmune destruction. Although the results of these cotransfections
gave little evidence of a synergistic relationship,
they were useful to show that gene combinations can be used to more efficiently protect islet grafts from diabetogenic
T cells
Survival Estimates of Western Gray Whales \u3ci\u3eEschrichtius robustus\u3c/i\u3e Incorporating Individual Heterogeneity and Temporary Emigration
Gray whales Eschrichtius robustus exist as a 2 geographically and genetically distinct populations in the eastern and western North Pacific. Subjected to intensive commercial whaling during the 19th and 20th centuries, the western population presently numbers approximately 100 individuals and is regarded as one of the most endangered baleen whale populations in the world
An oligofluorene truxene based distributed feedback laser for biosensing applications
The first example of an all-organic oligofluorene truxene based distributed feedback laser for the detection of a specific protein–small molecule interaction is reported. The protein avidin was detected down to View the MathML source1μgmL−1 using our biotin-labelled biosensor platform. This interaction was both selective and reversible when biotin was replaced with desthiobiotin. Avidin detection was not perturbed by Bovine Serum Albumin up to View the MathML source50,000μgmL−1. Our biosensor offers a new detection platform that is both highly sensitive, modular and potentially re-usable
Survival Estimates of Western Gray Whales \u3ci\u3eEschrichtius robustus\u3c/i\u3e Incorporating Individual Heterogeneity and Temporary Emigration
Gray whales Eschrichtius robustus exist as a 2 geographically and genetically distinct populations in the eastern and western North Pacific. Subjected to intensive commercial whaling during the 19th and 20th centuries, the western population presently numbers approximately 100 individuals and is regarded as one of the most endangered baleen whale populations in the world
Lofar Low-Band Antenna Observations of the 3C 295 and Bootes Fields: Source Counts and Ultra-Steep Spectrum Sources
We present Low Frequency Array (LOFAR) Low Band observations of the Boötes and 3C 295 fields. Our images made at 34, 46, and 62 MHz reach noise levels of 12, 8, and 5 mJy beam-1, making them the deepest images ever obtained in this frequency range. In t
Direct CP Violation in B -> X_s gamma Decays as a Signature of New Physics
We argue that the observation of a sizable direct CP asymmetry A_{CP} in the
inclusive decays B -> X_s gamma would be a clean signal of New Physics. In the
Standard Model, A_{CP} can be calculated reliably and is found to be below 1%
in magnitude. In extensions of the Standard Model with new CP-violating
couplings, large CP asymmetries are possible without conflicting with the
experimental value of the branching ratio for the decays B -> X_s gamma. In
particular, large asymmetries arise naturally in models with enhanced
chromo-magnetic dipole operators. Some generic examples of such models are
explored and their implications for the semileptonic branching ratio and charm
yield in B decays discussed.Comment: several references added and some numerical results updated to
include QED corrections (version to appear in Physical Review D
The Generation of Successive Unmarked Mutations and Chromosomal Insertion of Heterologous Genes in Actinobacillus pleuropneumoniae Using Natural Transformation
We have developed a simple method of generating scarless, unmarked mutations in Actinobacillus pleuropneumoniae by exploiting the ability of this bacterium to undergo natural transformation, and with no need to introduce plasmids encoding recombinases or resolvases. This method involves two successive rounds of natural transformation using linear DNA: the first introduces a cassette carrying cat (which allows selection by chloramphenicol) and sacB (which allows counter-selection using sucrose) flanked by sequences to either side of the target gene; the second transformation utilises the flanking sequences ligated directly to each other in order to remove the cat-sacB cassette. In order to ensure efficient uptake of the target DNA during transformation, A. pleuropneumoniae uptake sequences are added into the constructs used in both rounds of transformation. This method can be used to generate multiple successive deletions and can also be used to introduce targeted point mutations or insertions of heterologous genes into the A. pleuropneumoniae chromosome for development of live attenuated vaccine strains. So far, we have applied this method to highly transformable isolates of serovars 8 (MIDG2331), which is the most prevalent in the UK, and 15 (HS143). By screening clinical isolates of other serovars, it should be possible to identify other amenable strains
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