794 research outputs found
ATP Hydrolysis Activity and Polymerization State of Ribulose-1,5-Bisphosphate Carboxylase Oxygenase Activase (Do the Effects of Mg2+, K+, and Activase Concentrations Indicate a Functional Similarity to Actin?)
The Genetic Basis of Tomato Aroma
Tomato (Solanum lycopersicum L.) aroma is determined by the interaction of volatile compounds (VOCs) released by the tomato fruits with receptors in the nose, leading to a sensorial impression, such as âsweetâ, âsmokyâ, or âfruityâ aroma. Of the more than 400 VOCs released by tomato fruits, 21 have been reported as main contributors to the perceived tomato aroma. These VOCs can be grouped in five clusters, according to their biosynthetic origins. In the last decades, a vast array of scientific studies has investigated the genetic component of tomato aroma in modern tomato cultivars and their relatives. In this paper we aim to collect, compare, integrate and summarize the available literature on flavour-related QTLs in tomato. Three hundred and 5ifty nine (359) QTLs associated with tomato fruit VOCs were physically mapped on the genome and investigated for the presence of potential candidate genes. This review makes it possible to (i) pinpoint potential donors described in literature for specific traits, (ii) highlight important QTL regions by combining information from different populations, and (iii) pinpoint potential candidate genes. This overview aims to be a valuable resource for researchers aiming to elucidate the genetics underlying tomato flavour and for breeders who aim to improve tomato aroma.</p
Magnetic order in double-layer manganites (La(1-z)Pr(z))1.2Sr1.8Mn2O7: intrinsic properties and role of the intergrowths
We report on an investigation of the double-layer manganite series
(La(1-z)Pr(z))1.2Sr1.8Mn2O7 (0 <= z <= 1), carried out on single crystals by
means of both macroscopic magnetometry and local probes of magnetism (muSR,
55Mn NMR). Muons and NMR demonstrate an antiferromagnetically ordered ground
state at non-ferromagnetic compositions (z >= 0.6), while more moderate Pr
substitutions (0.2 <= z <= 0.4) induce a spin reorientation transition within
the ferromagnetic phase.
A large magnetic susceptibility is detected at {Tc,TN} < T < 250K at all
compositions. From 55Mn NMR spectroscopy, such a response is unambiguously
assigned to the intergrowth of a ferromagnetic pseudocubic phase
(La(1-z)Pr(z))(1-x)Sr(x)MnO3, with an overall volume fraction estimated as
0.5-0.7% from magnetometry. Evidence is provided for the coupling of the
magnetic moments of these inclusions with the magnetic moments of the
surrounding (La(1-z)Pr(z))1.2Sr1.8Mn2O7 phase, as in the case of finely
dispersed impurities. We argue that the ubiquitous intergrowth phase may play a
role in the marked first-order character of the magnetic transition and the
metamagnetic properties above Tc reported for double-layer manganites.Comment: 11 pages, 9 figures. Submitted to Phys. Rev.
On an exact solution of the Thomas-Fermi equation for a trapped Bose-Einstein condensate with dipole-dipole interactions
We derive an exact solution to the Thomas-Fermi equation for a Bose-Einstein
condensate which has dipole-dipole interactions as well as the usual s-wave
contact interaction, in a harmonic trap. Remarkably, despite the non-local
anisotropic nature of the dipolar interaction the solution is an inverted
parabola, as in the pure s-wave case, but with a different aspect ratio.
Various properties such as electrostriction and stability are discussed.Comment: 11 pages, 5 figure
Evaluating the effectiveness of moxidectin treatment in mite-infested mice and development of an in-house PCR assay for detecting Myobia musculi DNA.
Detection and eradication of fur mite infestations in mouse colonies can present a challenge to a laboratory animal facility
Observation of Individual Josephson Vortices in YBCO Bicrystal Grain-boundary Junctions
The response of YBCO bicrystal grain-boundary junctions to small dc magnetic
fields (0 - 10 Oe) has been probed with a low-power microwave (rf) signal of
4.4 GHz in a microwave-resonator setup. Peaks in the microwave loss at certain
dc magnetic fields are observed that result from individual Josephson vortices
penetrating into the grain-boundary junctions under study. The system is
modeled as a long Josephson junction described by the sine-Gordon equation with
the appropriate boundary conditions. Excellent quantitative agreement between
the experimental data and the model has been obtained. Hysteresis effect of dc
magnetic field is also studied and the results of measurement and calculation
are compared.Comment: 11 pages, 4 figure
Non-linear microwave impedance of short and long Josephson Junctions
The non-linear dependence on applied field () or current () of the microwave (ac) impedance of both
short and long Josephson junctions is calculated under a variety of excitation
conditions. The dependence on the junction width is studied, for both field
symmetric (current anti-symmetric) and field anti-symmetric (current symmetric)
excitation configurations.The resistance shows step-like features every time a
fluxon (soliton) enters the junction, with a corresponding phase slip seen in
the reactance. For finite widths the interference of fluxons leads to some
interesting effects which are described. Many of these calculated results are
observed in microwave impedance measurements on intrinsic and fabricated
Josephson junctions in the high temperature superconductors, and new effects
are suggested. When a field () or current () is applied,
interesting phase locking effects are observed in the ac impedance
. In particular an almost periodic dependence on the dc bias is
seen similar to that observed in microwave experiments at very low dc field
bias. These results are generic to all systems with a potential
in the overdamped limit and subjected to an ac drive.Comment: 7 pages, 11 figure
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