543 research outputs found
Early Cardiogenesis in the Newt Embryo
The migration of cardiogenic cells and the formation of a tubular heart in newt embryos were examined mainly by scanning electron microscopy (SEM). Cardiogenic cells are known to localize at the border region of lateral mesoderm migrating in the space between the ectoderm and the endoderm. They initially (before stage 20 or mid-neurula) appeared to attach to the basal surface of the ectoderm, whereas later (after stage 22 or late neurula) they changed their scaffold to the endoderm. On the scaffold cell surface, very fine fibrils of extracellular matrix (ECM) were found. These fibrils were proved to be composed partly of fibronectin by the immunofluorescence method as well as by immunoSEM using latex bead-labeled antibody, suggesting their seemingly important role in migration of cardiogenic cells. At stage 26 or the early tail bud stage, when the tips of bilateral cardiogenic areas begin to fuse under the foregut, several free vasoformative cells are seen there and the mesodermal sheet itself splits into two layers to produce a coelomic cavity. The splanchnic wall of the coelomic or pericardial cavity was recognized to form a trough consisting of cobblestone-like myocardial cells not yet covered with the epicardium
Tuning the electrocaloric enhancement near the morphotropic phase boundary in lead-free ceramics
This project was funded by EPSRC (EP/G060940/1 and EP/P505674/1) and the Grant Agency of the Slovak
Academy of Sciences (2/0057/14)
Constructing a Large Variety of Dirac-Cone Materials in the BiSb Thin Film System
We theoretically predict that a large variety of Dirac-cone materials can be
constructed in BiSb thin films, and we here show how to
construct single-, bi- and tri- Dirac-cone materials with various amounts of
wave vector anisotropy. These different types of Dirac cones can be of special
interest to electronic devices design, quantum electrodynamics and other
fields
Colletotrichum higginsianum extracellular LysM proteins play dual roles in appressorial function and suppression of chitin-triggered plant immunity
<p>The genome of the hemibiotrophic anthracnose fungus, Colletotrichum higginsianum, encodes a large repertoire of candidate-secreted effectors containing LysM domains, but the role of such proteins in the pathogenicity of any Colletotrichum species is unknown. Here, we characterized the function of two effectors, ChELP1 and ChELP2, which are transcriptionally activated during the initial intracellular biotrophic phase of infection. Using immunocytochemistry, we found that ChELP2 is concentrated on the surface of bulbous biotrophic hyphae at the interface with living host cells but is absent from filamentous necrotrophic hyphae. We show that recombinant ChELP1 and ChELP2 bind chitin and chitin oligomers in vitro with high affinity and specificity and that both proteins suppress the chitin-triggered activation of two immune-related plant mitogen-activated protein kinases in the host Arabidopsis. Using RNAi-mediated gene silencing, we found that ChELP1 and ChELP2 are essential for fungal virulence and appressorium-mediated penetration of both Arabidopsis epidermal cells and cellophane membranes in vitro. The findings suggest a dual role for these LysM proteins as effectors for suppressing chitin-triggered immunity and as proteins required for appressorium function.</p
Search for the pentaquark via the reaction at 1.92 GeV/
The pentaquark baryon was searched for via the
reaction in a missing-mass resolution of 1.4 MeV/(FWHM) at J-PARC.
meson beams were incident on the liquid hydrogen target with the beam momentum
of 1.92 GeV/. No peak structure corresponding to the mass was
observed. The upper limit of the production cross section averaged over the
scattering angle of 2 to 15 in the laboratory frame was
obtained to be 0.26 b/sr in the mass region of 1.511.55 GeV/.The
upper limit of the decay width using the effective Lagrangian
approach was obtained to be 0.72 MeV/ and 3.1 MeV/ for
and , respectively.Comment: 5 pages, 3 figures, 1 tabl
Prediction of Anisotropic Single-Dirac-Cones in BiSb Thin Films
The electronic band structures of BiSb thin films can be
varied as a function of temperature, pressure, stoichiometry, film thickness
and growth orientation. We here show how different anisotropic
single-Dirac-cones can be constructed in a BiSb thin film for
different applications or research purposes. For predicting anisotropic
single-Dirac-cones, we have developed an iterative-two-dimensional-two-band
model to get a consistent inverse-effective-mass-tensor and band-gap, which can
be used in a general two-dimensional system that has a non-parabolic dispersion
relation as in a BiSb thin film system
The neurotropic black yeast Exophiala dermatitidis has a possible origin in the tropical rain forest
The black yeast Exophiala dermatitidis is known as a rare
etiologic agent of neurotropic infections in humans, occurring particularly in
East and Southeast Asia. In search of its natural habitat, a large sampling
was undertaken in temperate as well as in tropical climates. Sampling sites
were selected on the basis of the origins of previously isolated strains, and
on the basis of physiological properties of the species, which also determined
a selective isolation protocol. The species was absent from outdoor
environments in the temperate climate, but present at low abundance in
comparable habitats in the tropics. Positive outdoor sites particularly
included faeces of frugivorous birds and bats, in urban as well as in natural
areas. Tropical fruits were found E. dermatitidis positive at low
incidence. Of the human-made environments sampled, railway ties contaminated
by human faeces and oily debris in the tropics were massively positive, while
the known abundance of the fungus in steam baths was confirmed. On the basis
of the species' oligotrophy, thermotolerance, acidotolerance, moderate
osmotolerance, melanization and capsular yeast cells a natural life cycle in
association with frugivorous animals in foci in the tropical rain forest,
involving passage of living cells through the intestinal tract was
hypothesized. The human-dominated environment may have become contaminated by
ingestion of wild berries carrying fungal propagule
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