894 research outputs found
Determination of Technetium by Laser Induced Photoacoustic Spectroscopy Coupled with a Wave-Length Shifter Method
High-Energy Neutrino Astronomy
Kilometer-scale neutrino detectors such as IceCube are discovery instruments
covering nuclear and particle physics, cosmology and astronomy. Examples of
their multidisciplinary missions include the search for the particle nature of
dark matter and for additional small dimensions of space. In the end, their
conceptual design is very much anchored to the observational fact that Nature
accelerates protons and photons to energies in excess of and
eV, respectively. The cosmic ray connection sets the scale of cosmic
neutrino fluxes. In this context, we discuss the first results of the completed
AMANDA detector and the reach of its extension, IceCube. Similar experiments
are under construction in the Mediterranean. Neutrino astronomy is also
expanding in new directions with efforts to detect air showers, acoustic and
radio signals initiated by super-EeV neutrinos.Comment: 9 pages, Latex2e, uses ws-procs975x65standard.sty (included), 4
postscript figures. To appear in Proceedings of Thinking, Observing, and
Mining the Universe, Sorrento, Italy, September 200
Nonthermal X-radiation of SNR RX J1713.7-3946: The Relations to a Nearby Molecular Cloud
The recent X-ray and CO observations of RX J1713.7-3946 show that a
significant fraction of the nonthermal X-ray emission of this unique supernova
remnant associates, in one way or another, with a molecular cloud interacting
with the west part of the shell. This adds a new puzzle in the origin of X-ray
emission which cannot be easily explained within the standard model in
accordance of which X-rays are result of synchrotron radiation of multi-TeV
electrons accelerated by supernova shock waves. We explore an alternative
origin of the X-ray emission assuming that it is produced by secondary
electrons resulting from high energy hadronic interactions in the molecular
gas. Such a scenario could explain in a quite natural way the apparent
correlation between the X-ray and CO morphologies. However, the TeV gamma-ray
emission recently reported by H.E.S.S. significantly constrains the parameter
space of this model. Namely, this mechanism cannot reproduce the bulk of the
observed X-ray flux unless one postulates existence of a PeV cosmic-ray
component penetrating with an unusually hard spectrum into the dense cloud.Comment: 6 pages, 3 figures, to appear in Proc. of Int. Symp. on High Energy
Gamma-ray Astronomy, Heidelberg (July 2004
Computationally designed libraries of fluorescent proteins evaluated by preservation and diversity of function
To determine which of seven library design algorithms best introduces new protein function without destroying it altogether, seven combinatorial libraries of green fluorescent protein variants were designed and synthesized. Each was evaluated by distributions of emission intensity and color compiled from measurements made in vivo. Additional comparisons were made with a library constructed by error-prone PCR. Among the designed libraries, fluorescent function was preserved for the greatest fraction of samples in a library designed by using a structure-based computational method developed and described here. A trend was observed toward greater diversity of color in designed libraries that better preserved fluorescence. Contrary to trends observed among libraries constructed by error-prone PCR, preservation of function was observed to increase with a library's average mutation level among the four libraries designed with structure-based computational methods
Suzaku X-Ray Imaging and Spectroscopy of Cassiopeia A
Suzaku X-ray observations of a young supernova remnant, Cassiopeia A, were
carried out. K-shell transition lines from highly ionized ions of various
elements were detected, including Chromium (Cr-Kalpha at 5.61 keV). The X-ray
continuum spectra were modeled in the 3.4--40 keV band, summed over the entire
remnant, and were fitted with a simplest combination of the thermal
bremsstrahlung and the non-thermal cut-off power-law models. The spectral fits
with this assumption indicate that the continuum emission is likely to be
dominated by the non-thermal emission with a cut-off energy at > 1 keV. The
thermal-to-nonthermal fraction of the continuum flux in the 4-10 keV band is
best estimated as ~0.1. Non-thermal-dominated continuum images in the 4--14 keV
band were made. The peak of the non-thermal X-rays appears at the western part.
The peak position of the TeV gamma-rays measured with HEGRA and MAGIC is also
shifted at the western part with the 1-sigma confidence. Since the location of
the X-ray continuum emission was known to be presumably identified with the
reverse shock region, the possible keV-TeV correlations give a hint that the
accelerated multi-TeV hadrons in Cassiopeia A are dominated by heavy elements
in the reverse shock region.Comment: Publ. Astron. Soc. Japan 61, pp.1217-1228 (2009
The RIF1-Long splice variant promotes G1 phase 53BP1 nuclear bodies to protect against replication stress
Acknowledgements Thanks to members of the Aberdeen Chromosome Biology Group for helpful comments, and Ronan Broderick and Wojciech Niedzwiedz for advice on mitotic bridge analysis. We thank Raif Yuecel and his team at the Iain Fraser Cytometry Centre for assistance, and Kevin Mackenzie and his team at the Microscopy and Histology Core Facility. Work was supported by Cancer Research UK Studentship Award C1445/A20596 and CRUK Programme Award C1445/A19059; by JSPS KAKENHI Grants Numbers 17K15068, 18H02170 and 18H04719; by research grants from the Daiichi Sankyoâs Foundation of Life Science and the Takeda Science Foundation; and by the UK Medical Research Council (MC_UU_00007/13). Collaboration was supported by a 2017 JSPS Summer Programme Fellowship. Funding Cancer Research UK (C1445/A20596) Anne D Donaldson Cancer Research UK (C1445/A19059) Anne D Donaldson Japan Society for the Promotion of Science (17K15068) Masato T Kanemaki Japan Society for the Promotion of Science (18H02170) Masato T Kanemaki Japan Society for the Promotion of Science (18H04719) Masato T Kanemaki Medical Research Council (MC_UU_00007/13) Nick GilbertPeer reviewedPublisher PD
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