2,914 research outputs found
Rare Kaon Decays
The current status of rare kaon decay experiments is reviewed. New limits in
the search for Lepton Flavor Violation are discussed, as are new measurements
of the CKM matrix.Comment: 8 pages, 3 figures, LaTeX, presented at the 3rd International
Conference on B Phyiscs and CP Violation, Taipei December 3-7, 199
Development of a DNA-Liposome Complex for Gene Delivery Applications
The association structures formed by cationic liposomes and DNA(Deoxyribonucleic acid)-liposome have been effectively utilized as gene carriers in transfection assays. In this research study, cationic liposomes were prepared using a modified lipid film hydration method consisting of a lyophilization step for gene delivery applications. The obtained results demonstrated that the mean particle size had no significant change while the polydispersity (PDI) increased after lyophilization. The mean particle size slightly reduced after lyophilization (520 ± 12 nm to 464 ± 25 nm) while the PDI increased after lyophilization (0.094 ± 0.017 to 0.220 ± 0.004). In addition. The mean particle size of vesicles increases when DNA is incorporated to the liposomes (673 ± 27 nm). According to the Scanning Electron Microscopy(SEM) and transmission electron microscopy (TEM) images, the spherical shape of liposomes confirmed their successful preservation and reconstitution from the powder. It was found that liposomal formulation has enhanced transfection considerably compared to the naked DNA as negative control. Finally, liposomal formulation in this research had a better function than Lipofectamine® 2000 as a commercialized product because the cellular activity (cellular protein) was higher in the prepared lipoplex than Lipofectamine® 2000
Response of selected plant and insect species to simulated solid rocket exhaust mixtures and to exhaust components from solid rocket fuels
The effects of solid rocket fuel (SRF) exhaust on selected plant and and insect species in the Merritt Island, Florida area was investigated in order to determine if the exhaust clouds generated by shuttle launches would adversely affect the native, plants of the Merritt Island Wildlife Refuge, the citrus production, or the beekeeping industry of the island. Conditions were simulated in greenhouse exposure chambers and field chambers constructed to model the ideal continuous stirred tank reactor. A plant exposure system was developed for dispensing and monitoring the two major chemicals in SRF exhaust, HCl and Al203, and for dispensing and monitoring SRF exhaust (controlled fuel burns). Plants native to Merritt Island, Florida were grown and used as test species. Dose-response relationships were determined for short term exposure of selected plant species to HCl, Al203, and mixtures of the two to SRF exhaust
Analysis of factors relating to pet rabbits relinquished to two UK re-homing centres
Rabbits are a common companion animal in the UK and some reports suggest that large numbers are relinquished to re-homing centres each year. This study aimed to investigate the characteristics of rabbits relinquished to two UK re-homing centres and explore reasons given for relinquishment. The centres contributed data for all rabbits that entered their centre during 2013 (n=205). Most rabbits (59.5%) were relinquished by an owner. A similar number of males to females were relinquished and a larger number of rabbits were not neutered (72.4%) and adults (56%). Most rabbits were healthy on arrival (61.5%). The most common reasons for relinquishment were: too many rabbits / unplanned litters (30.3%) and housing problems (23.8%). Rabbit related reasons accounted for 12.2% of rabbits relinquished. Reasons for relinquishment were associated with one of the recorded rabbit characteristics. Further detailed studies are needed to explore the dynamics of pet rabbit ownership and factors that affect the breakdown of rabbit-owner relationships in the UK
Is it still worth searching for lepton flavor violation in rare kaon decays?
Prospective searches for lepton flavor violation (LFV) in rare kaon decays at
the existing and future intermediate-energy accelerators are considered. The
proposed studies are complementary to LFV searches in muon-decay experiments
and offer a unique opportunity to probe models with approximately conserved
fermion-generation quantum number with sensitivity superior to that in other
processes. Consequently, new searches for LFV in kaon decays are an important
and independent part of the general program of searches for lepton flavor
violation in the final states with charged leptons.Comment: 30 pages, 10 figures. An extended version of the talk given at the
Chicago Flavor Seminar, February 27, 2004. In the new version some misprints
were corrected and some new data for LFV-processes were added. The main
content of the paper was not changed. The paper is published in Yad. Fiz. 68,
1272 (2005
Finite-size scaling in thin Fe/Ir(100) layers
The critical temperature of thin Fe layers on Ir(100) is measured through
M\"o{\ss}bauer spectroscopy as a function of the layer thickness. From a
phenomenological finite-size scaling analysis, we find an effective shift
exponent lambda = 3.15 +/- 0.15, which is twice as large as the value expected
from the conventional finite-size scaling prediction lambda=1/nu, where nu is
the correlation length critical exponent. Taking corrections to finite-size
scaling into account, we derive the effective shift exponent
lambda=(1+2\Delta_1)/nu, where Delta_1 describes the leading corrections to
scaling. For the 3D Heisenberg universality class, this leads to lambda = 3.0
+/- 0.1, in agreement with the experimental data. Earlier data by Ambrose and
Chien on the effective shift exponent in CoO films are also explained.Comment: Latex, 4 pages, with 2 figures, to appear in Phys. Rev. Lett
Quantum Gravity and the Algebra of Tangles
In Rovelli and Smolin's loop representation of nonperturbative quantum
gravity in 4 dimensions, there is a space of solutions to the Hamiltonian
constraint having as a basis isotopy classes of links in R^3. The physically
correct inner product on this space of states is not yet known, or in other
words, the *-algebra structure of the algebra of observables has not been
determined. In order to approach this problem, we consider a larger space H of
solutions of the Hamiltonian constraint, which has as a basis isotopy classes
of tangles. A certain algebra T, the ``tangle algebra,'' acts as operators on
H. The ``empty state'', corresponding to the class of the empty tangle, is
conjectured to be a cyclic vector for T. We construct simpler representations
of T as quotients of H by the skein relations for the HOMFLY polynomial, and
calculate a *-algebra structure for T using these representations. We use this
to determine the inner product of certain states of quantum gravity associated
to the Jones polynomial (or more precisely, Kauffman bracket).Comment: 16 pages (with major corrections
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