1,881 research outputs found
Unexpected monophyletic origin of Ephoron shigae unisexual reproduction strains and their rapid expansion across Japan
The burrowing polymitarcyid mayfly Ephoron shigae is distributed across Japan, Korea, northeast China and far east Russia. Some populations are bisexual, and others are unisexual, i.e. geographically parthenogenetic throughout Japan. In general, parthenogenetic organisms are often found in harsh environments, such as at high latitudes and altitudes, in xeric as opposed to mesic conditions, in isolated habitats such as islands and island-like areas, and at the peripheral regions of the taxon's range. In E. shigae, however, the distributions of bisexual and unisexual populations overlap broadly in their respective geographical ranges. In the analysis of mitochondrial 16S rRNA and COI, we revealed that unisexual populations were of monophyletic origin and recently differentiated somewhere in western Japan. In the nuclear DNA EFI-alpha analysis, parthenogenetic strains had two genotypes, i.e. the heterozygous genotype of E1/E3 and the homozygous genotype of E1/E1 or E3/E3, while specimens of bisexual lineage had 20 genotypes. These results are consistent with an automixis mode of reproduction for the parthenogenetic strains, and also support the monophyletic origin of the parthenogenetic strains. Furthermore, there would be no gene flow between the specimens of the bisexual lineage and those of the parthenogenetic strain.ArticleROYAL SOCIETY OPEN SCIENCE. 2(6):150072 (2015)journal articl
Magnetic field-induced one-magnon Raman scattering in the magnon Bose-Einstein condensation phase of TlCuCl
We report the observation of the -symmetric one-magnon Raman peak
in the magnon Bose-Einstein condensation phase of TlCuCl. Its Raman shift
traces the one-magnon energy at the magnetic point, and its intensity
is proportional to the squared transverse magnetization. The appearance of the
one-magnon Raman scattering originates from the exchange magnon Raman process
and reflects the change of the magnetic-state symmetry. Using the bond-operator
representation, we theoretically clarify the Raman selection rules, being
consistent with the experimental results.Comment: 6 pages, 4 figure
Longitudinal magnetic excitation in KCuCl3 studied by Raman scattering under hydrostatic pressures
We measure Raman scattering in an interacting spin-dimer system KCuCl3 under
hydrostatic pressures up to 5 GPa mediated by He gas. In the pressure-induced
quantum phase, we observe a one-magnon Raman peak, which originates from the
longitudinal magnetic excitationand is observable through the second-order
exchange interaction Raman process. We report the pressure dependence of the
frequency, halfwidth and Raman intensity of this mode.Comment: 4 pages, 3 figures, inpress in JPCS as a proceeding of LT2
Generic phase diagram of active polar films
We study theoretically the phase diagram of compressible active polar gels
such as the actin network of eukaryotic cells. Using generalized hydrodynamics
equations, we perform a linear stability analysis of the uniform states in the
case of an infinite bidimensional active gel to obtain the dynamic phase
diagram of active polar films. We predict in particular modulated flowing
phases, and a macroscopic phase separation at high activity. This qualitatively
accounts for experimental observations of various active systems, such as
acto-myosin gels, microtubules and kinesins in vitro solutions, or swimming
bacterial colonies.Comment: 4 pages, 1 figur
Therapeutic Efficacy of Adoptive Cell Transfer on Survival of Patients with Glioblastoma Multiforme: Case Reports
Glioblastoma multiforme (GBM), which occurs mostly in individuals over the age of 40, accounts for 12–15% of all primary brain tumors. Patients with GBM have a poor prognosis, even after aggressive upfront therapies. The present study documents that in 5 of these patients, the use of a novel immunotherapeutic approach combined with standard initial therapies resulted in a prolonged survival of over 3 years, which is significantly longer than the expected survival time with conventional therapies. During the course of intravenous cell-transfer immunotherapy, axial magnetic resonance images of the tumor region were monitored for over 5 years. The discontinuation of adoptive transfer regimens resulted in the rapid deterioration of patients with development of Gd-enhancing regions, indicating the initiation of tumor recurrence. Among patients with recurrence, the reinstatement of adoptive cell regimens with more frequent cell-transfers resulted in an apparent re-regression of tumors. Significantly longer survival times were seen in patients receiving transferred autologous lymphoid cells which were expanded in vitro, and which had a considerable proportion of γδT cells. We conclude that immunotherapy, combined with standard treatment, plays a significant role in the management of GBM patients and provides patients with a better prognosis
Coherent oscillations of electrons in tunnel-coupled wells under ultrafast intersubband excitation
Ultrafast intersubband excitation of electrons in tunnell-coupled wells is
studied depending on the structure parameters, the duration of the infrared
pump and the detuning frequency. The temporal dependencies of the photoinduced
concentration and dipole moment are obtained for two cases of transitions: from
the single ground state to the tunnel-coupled excited states and from the
tunnel-coupled states to the single excited state. The peculiarities of
dephasing and population relaxation processes are also taken into account. The
nonlinear regime of the response is also considered when the splitting energy
between the tunnel-coupled levels is renormalized by the photoexcited electron
concentration. The dependencies of the period and the amplitude of oscillations
on the excitation pulse are presented with a description of the nonlinear
oscillations damping.Comment: 8 pages, 12 figure
Confirmation of a one-dimensional spin-1/2 Heisenberg system with ferromagnetic first-nearest-neighbor and antiferromagnetic second-nearest-neighbor interactions in RbCuMoO
We have investigated magnetic properties of RbCuMoO
powder. Temperature dependence of magnetic susceptibility and magnetic-field
dependence of magnetization have shown that this cuprate is a model compound of
a one-dimensional spin-1/2 Heisenberg system with ferromagnetic
first-nearest-neighbor (1NN) and antiferromagnetic second-nearest-neighbor
(2NN) competing interactions (competing system). Values of the 1NN and 2NN
interactions are estimated as K and K (). This value of suggests that the ground state is a
spin-singlet incommensurate state. In spite of relatively large and
, no magnetic phase transition appears down to 2 K, while an
antiferromagnetic transition occurs in other model compounds of the competing
system with ferromagnetic 1NN interaction. For that reason,
RbCuMoO is an ideal model compound to study properties of
the incommensurate ground state that are unconfirmed experimentally.Comment: 6 pages, 4 figure
Decaying shock studies of phase transitions in MgOSiO2 systems: implications for the Super-Earths interiors
We report an experimental study of the phase diagrams of periclase (MgO),
enstatite (MgSiO3) and forsterite (Mg2SiO4) at high pressures. We investigated
with laser driven decaying shocks the pressure/temperature curves of MgO,
MgSiO3 and Mg2SiO4 between 0.2-1.2 TPa, 0.12-0.5 TPa and 0.2-0.85 TPa
respectively. A melting signature has been observed in MgO at 0.47 TPa and 9860
K, while no phase changes were observed neither in MgSiO3 nor in Mg2SiO4. An
increasing of reflectivity of MgO, MgSiO3 and Mg2SiO4 liquids have been
detected at 0.55 TPa -12 760 K, 0.15 TPa - 7540 K, 0.2 TPa - 5800 K,
respectively. In contrast to SiO2, melting and metallization of these compounds
do not coincide implying the presence of poor electrically conducting liquids
close to the melting lines. This has important implications for the generation
of dynamos in Super-earths mantles
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