A5061917731- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Particle physics theoretical and experimental studies
- Atomic and Subatomic Physics Research
- Radio Astronomy Observations and Technology
- Gamma-ray bursts and supernovae
- Particle Detector Development and Performance
- Cosmology and Gravitation Theories
- Forest ecology and management
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- Particle accelerators and beam dynamics
- Bacterial Genetics and Biotechnology
- Plant Pathogens and Fungal Diseases
- Forest Insect Ecology and Management
- Forest Management and Policy
- Geochemistry and Geologic Mapping
- Scientific Research and Discoveries
- Computational Physics and Python Applications
- Solar and Space Plasma Dynamics
- Nuclear reactor physics and engineering
- Bacteriophages and microbial interactions
- Telomeres, Telomerase, and Senescence
- Race, Genetics, and Society
Red Deer College
2023
Curtin University
2014-2022
Bridgewater State University
2009-2017
Ghent University
2009-2014
Ghent University Hospital
2010-2013
University of Maryland, College Park
2011
University of Sheffield
2002-2009
Imperial College London
2009
Rutherford Appleton Laboratory
2009
University of Oxford
2009
We have constructed a series of plasmid vectors (pBAD vectors) containing the PBAD promoter araBAD (arabinose) operon and gene encoding positive negative regulator this promoter, araC. Using phoA fusions to monitor expression in these vectors, we show that ratio induction/repression can be 1,200-fold, compared with 50-fold for PTAC-based vectors. modulated over wide range inducer concentrations reduced extremely low levels by presence glucose, which represses expression. Also, kinetics...
We report on results of an all-sky search for high-energy neutrino events interacting within the IceCube detector conducted between May 2010 and 2012. The follows up previous detection two PeV events, with improved sensitivity extended energy coverage down to about 30 TeV. Twenty-six additional were observed, substantially more than expected from atmospheric backgrounds. Combined, both searches reject a purely origin 28 at 4σ level. These which include highest neutrinos ever have flavors,...
We report on the observation of two neutrino-induced events which have an estimated deposited energy in IceCube detector 1.04±0.16 and 1.14±0.17 PeV, respectively, highest neutrino energies observed so far. These are consistent with fully contained particle showers induced by neutral-current ν(e,μ,τ) (ν(e,μ,τ)) or charged-current ν(e) (ν(e)) interactions within detector. The were discovered a search for ultrahigh neutrinos using data corresponding to 615.9 days effective live time. expected...
A cdc13 temperature-sensitive mutant of Saccharomyces cerevisiae arrests in the G2 phase cell cycle at restrictive temperature as a result DNA damage that activates RAD9 checkpoint. The lesions present after failure Cdc13p function appear to be located almost exclusively telomere-proximal regions, on basis profile induced mitotic recombination. rad9 cells dividing contain single-stranded corresponding telomeric and sequences eventually lose telomere-associated sequences. These results...
We have performed a search for muon neutrinos from dark matter annihilation in the center of Sun with 79-string configuration IceCube neutrino telescope. For first time, DeepCore sub-array is included analysis, lowering energy threshold and extending to austral summer. The 317 days data collected between June 2010 May 2011 are consistent expected background atmospheric muons neutrinos. Upper limits therefore set on rate, conversions spin-dependent spin-independent WIMP-proton cross-sections...
We have used data from a TeV $\ensuremath{\gamma}$-ray flare associated with the active galaxy Markarian 421 to place bounds on possible energy dependence of speed light in context an effective quantum gravitational scale. Recent theoretical work suggests that such scale could be less than Planck mass and perhaps as low ${10}^{16}$ GeV. The limits derived here indicate this excess $6\ifmmode\times\else\texttimes\fi{}{10}^{16}$ GeV for at least one approach gravity D-brane string theory. To...
A measurement of the atmospheric muon neutrino energy spectrum from 100 GeV to 400 TeV was performed using a data sample about 18 000 up-going events in IceCube. Boosted decision trees were used for event selection reject misreconstructed muons and obtain events. Background contamination final is less than 1%. This first neutrinos up TeV, fundamental understanding impact this background on astrophysical observations with The measured consistent predictions...
We report on the measurement of all-particle cosmic ray energy spectrum with IceTop air shower array in range from 1.58 PeV to 1.26 EeV. The is surface component IceCube Neutrino Observatory at geographical South Pole. analysis was performed using only information IceTop. data used this work were taken June 1, 2010 May 13, 2011. During that period consisted 73 stations compared 81 its final configuration. measured exhibits a clear deviation single power law above knee around 4PeV and below...
This paper describes the response of IceCube neutrino telescope located at geographic South Pole to outbursts MeV neutrinos from core collapse nearby massive stars. was completed in December 2010 forming a lattice 5160 photomultiplier tubes that monitor volume ~ 1 cubic kilometer deep Antarctic ice for particle induced photons. The designed detect with energies greater than 100 GeV. Owing subfreezing temperatures, dark noise rates are particularly low. Hence can also large numbers by...
We present the results of time-integrated searches for astrophysical neutrino sources in both northern and southern skies. Data were collected using partially completed IceCube detector 40-string configuration recorded between 2008 April 5 2009 May 20, totaling 375.5 days livetime. An unbinned maximum likelihood ratio method is used to search signals. The data sample contains 36,900 events: 14,121 from sky, mostly muons induced by atmospheric neutrinos, 22,779 high-energy muons. analysis...
We report the first observation of an anisotropy in arrival direction cosmic rays with energies multi TeV region Southern sky using data from IceCube detector. Between June 2007 and March 2008, partially-deployed detector was operated a configuration 1320 digital optical sensors distributed over 22 strings at depths between 1450 2450 meters inside Antarctic ice. is neutrino detector, but are dominated by large background ray muons. Therefore, suitable for high-statistics studies sky. The...
Keywords: neutrinos ; supernovae: general instrumentation: detectors errata addenda Reference EPFL-ARTICLE-198916doi:10.1051/0004-6361/201117810eView record in Web of Science Record created on 2014-05-19, modified 2017-05-12
Between 2009 May and 2010 May, the IceCube neutrino detector at South Pole recorded 32 billion muons generated in air showers produced by cosmic rays with a median energy of 20 TeV. With data set this size, it is possible to probe southern sky for per-mil anisotropy on all angular scales arrival direction distribution rays. Applying power spectrum analysis relative intensity map ray flux hemisphere, we show that not isotropic, but shows significant structure several scales. In addition...
We report on the observation of anisotropy in arrival direction distribution cosmic rays at PeV energies. The analysis is based data taken between 2009 and 2012 with IceTop air shower array south pole. IceTop, an integral part IceCube detector, sensitive to 100 TeV 1 EeV. With current size set, searches for 10−3 level can, first time, be extended divide set into two parts median energies 400 2 PeV, respectively. In low energy band, we observe a strong deficit angular about 30° amplitude (−...
IceCube has become the first neutrino telescope with a sensitivity below TeV flux predicted from gamma-ray bursts if are responsible for observed cosmic-ray above 10(18) eV. Two separate analyses using half-complete detector, one dedicated search neutrinos pγ interactions in prompt phase of burst fireball and other generic any emission these sources over wide range energies times, produced no evidence emission, excluding prevailing models at 90% confidence.
In this paper we report the first observation in Southern hemisphere of an energy dependence Galactic cosmic ray anisotropy up to a few hundred TeV. This measurement was performed using induced muons recorded by partially deployed IceCube observatory between May 2009 and 2010. The data include total 33$\times 10^{9}$ muon events with median angular resolution $\sim3^{\circ}$ degrees. A sky map relative intensity arrival direction over celestial is presented for energies 20 400 same...
The ftsQ gene is one of several genes thought to be specifically required for septum formation in Escherichia coli. Published work on the cell division behavior temperature-sensitive mutants suggested that FtsQ product throughout whole process formation. Here we provide additional support this hypothesis based microscopic observations defects resulting from insertional and mutations gene, constitutive overexpression its product. On basis published, predicted amino acid sequence protein our...
Self-annihilating or decaying dark matter in the Galactic halo might produce high energy neutrinos detectable with neutrino telescopes. We have conducted a search for such signal using 276 days of data from IceCube 22-string configuration detector acquired during 2007 and 2008. The effect model choice extracted limit is reduced by performing that considers outer region not Center. constrain any large scale anisotropy are able to set on self-annihilation cross section <\sigma_{A}v> \simeq...