489 research outputs found
A Genome-Wide Analysis of FRT-Like Sequences in the Human Genome
Efficient and precise genome manipulations can be achieved by the
Flp/FRT system of site-specific DNA recombination.
Applications of this system are limited, however, to cases when target sites for
Flp recombinase, FRT sites, are pre-introduced into a genome
locale of interest. To expand use of the Flp/FRT system in
genome engineering, variants of Flp recombinase can be evolved to recognize
pre-existing genomic sequences that resemble FRT and thus can
serve as recombination sites. To understand the distribution and sequence
properties of genomic FRT-like sites, we performed a
genome-wide analysis of FRT-like sites in the human genome
using the experimentally-derived parameters. Out of 642,151 identified
FRT-like sequences, 581,157 sequences were unique and
12,452 sequences had at least one exact duplicate. Duplicated
FRT-like sequences are located mostly within LINE1, but
also within LTRs of endogenous retroviruses, Alu repeats and other repetitive
DNA sequences. The unique FRT-like sequences were classified
based on the number of matches to FRT within the first four
proximal bases pairs of the Flp binding elements of FRT and the
nature of mismatched base pairs in the same region. The data obtained will be
useful for the emerging field of genome engineering
Primary myxofibrosarcoma of the parotid: case report
<p>Abstract</p> <p>Background</p> <p>Myxofibrosarcoma is common in the extremities of elderly people and is characterized by a high frequency of local recurrence.</p> <p>Case presentation</p> <p>We report a 37 year old female who presented with a 4-month history of facial pain and a 3-month history of painful progressive swelling in the preauricular area. She underwent a total parotidectomy. The tumor was histopathologically and immunohistochemically diagnosed as a low-grade myxofibrosarcoma. The patient was free of disease 9 months after surgery with uneventful post-operative clinical course.</p> <p>Conclusions</p> <p>Parotid area swelling should always alert doctors. To our knowledge, this is the first case of parotid myxofibrosarcoma. It should be added to the differential diagnosis of diseases of the parotid. We have to recognize this disease and seek adequate treatment for it.</p
Expression in Antennae and Reproductive Organs Suggests a Dual Role of an Odorant-Binding Protein in Two Sibling Helicoverpa Species
Odorant-binding proteins (OBPs) mediate both perception and release of semiochemicals in insects. These proteins are the ideal targets for understanding the olfactory code of insects as well as for interfering with their communication system in order to control pest species. The two sibling Lepidopteran species Helicoverpa armigera and H. assulta are two major agricultural pests. As part of our aim to characterize the OBP repertoire of these two species, here we focus our attention on a member of this family, OBP10, particularly interesting for its expression pattern. The protein is specifically expressed in the antennae of both sexes, being absent from other sensory organs. However, it is highly abundant in seminal fluid, is transferred to females during mating and is eventually found on the surface of fertilised eggs. Among the several different volatile compounds present in reproductive organs, OBP10 binds 1-dodecene, a compound reported as an insect repellent. These results have been verified in both H. armigera and H. assulta with no apparent differences between the two species. The recombinant OBP10 binds, besides 1-dodecene, some linear alcohols and several aromatic compounds. The structural similarity of OBP10 with OBP1 of the mosquito Culex quinquefasciatus, a protein reported to bind an oviposition pheromone, and its affinity with 1-dodecene suggest that OBP10 could be a carrier for oviposition deterrents, favouring spreading of the eggs in these species where cannibalism is active among larvae
First Observation of and Decays
We have observed new channels for decays with an in the final
state. We study 3-prong tau decays, using the and
\eta\to 3\piz decay modes and 1-prong decays with two \piz's using the
channel. The measured branching fractions are
\B(\tau^{-}\to \pi^{-}\pi^{-}\pi^{+}\eta\nu_{\tau})
=(3.4^{+0.6}_{-0.5}\pm0.6)\times10^{-4} and \B(\tau^{-}\to
\pi^{-}2\piz\eta\nu_{\tau}
=(1.4\pm0.6\pm0.3)\times10^{-4}. We observe clear evidence for
substructure and measure \B(\tau^{-}\to
f_1\pi^{-}\nu_{\tau})=(5.8^{+1.4}_{-1.3}\pm1.8)\times10^{-4}. We have also
searched for production and obtain 90% CL upper limits
\B(\tau^{-}\to \pi^{-}\eta'\nu_\tau)<7.4\times10^{-5} and \B(\tau^{-}\to
\pi^{-}\piz\eta'\nu_\tau)<8.0\times10^{-5}.Comment: 11 page postscript file, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Search for the Decays B^0 -> D^{(*)+} D^{(*)-}
Using the CLEO-II data set we have searched for the Cabibbo-suppressed decays
B^0 -> D^{(*)+} D^{(*)-}. For the decay B^0 -> D^{*+} D^{*-}, we observe one
candidate signal event, with an expected background of 0.022 +/- 0.011 events.
This yield corresponds to a branching fraction of Br(B^0 -> D^{*+} D^{*-}) =
(5.3^{+7.1}_{-3.7}(stat) +/- 1.0(syst)) x 10^{-4} and an upper limit of Br(B^0
-> D^{*+} D^{*-}) D^{*\pm} D^\mp and
B^0 -> D^+ D^-, no significant excess of signal above the expected background
level is seen, and we calculate the 90% CL upper limits on the branching
fractions to be Br(B^0 -> D^{*\pm} D^\mp) D^+
D^-) < 1.2 x 10^{-3}.Comment: 12 page postscript file also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to Physical Review Letter
Production in Two-Photon Interactions at CLEO
Using the CLEO detector at the Cornell storage ring, CESR, we study
the two-photon production of , making the first
observation of . We present the
cross-section for as a function of
the center of mass energy and compare it to that predicted by
the quark-diquark model.Comment: 10 pages, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Observation of the Decay
Using e+e- annihilation data collected by the CLEO~II detector at CESR, we
have observed the decay Ds+ to omega pi+. This final state may be produced
through the annihilation decay of the Ds+, or through final state interactions.
We find a branching ratio of [Gamma(Ds+ to omega pi+)/Gamma(Ds+ to eta
pi+)]=0.16+-0.04+-0.03, where the first error is statistical and the second is
systematic.Comment: 9 pages, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
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