464 research outputs found
True Colors
Assess your strengths while gaining an appreciation for others around you. A true colors assessment will help you develop leadership and effective team-building skills among your coworkers
Reconstruction and actual trends of landslide activities in Bruust–Haltiwald, Horw, canton of Lucerne, Switzerland
A spatiotemporal reconstruction of slope movements on the
edge of Lake Lucerne near the municipality of Horw, canton of Lucerne, is
presented. The reconstruction was realized by analyzing growth reactions of
beech (Fagus sylvatica L.) and fir (Abies alba Mill.) trees growing on this slope. Before
dendrochronological sampling, a detailed geomorphological mapping of the
landslide was conducted with the aim to determine the spatial extent of the
sliding area. For tree-ring analyses, 124 increment cores from 62 trees were
analyzed following standard techniques of dendrogeomorphology. In addition,
long micro-sections were prepared from the entire cores to extend the common
eccentricity analyses by microscopic determination of the onset of reaction
wood in fir and beech. Results clearly show that the area is moving at
least since 1948. A significant concentration of events was observed between
the years 1990 and 2000 as well as after 2006. The definition of a threshold
to define events using an eccentricity index alone is problematic and needs
to be adapted to specific site conditions. For this reason, we recommend always combining the application of an eccentricity index with a detailed
visual (anatomical) inspection to check for the occurrence of reaction wood.</p
Brain-derived neurotrophic factor stimulates energy metabolism in developing cortical neurons.
Brain-derived neurotrophic factor (BDNF) promotes the biochemical and morphological differentiation of selective populations of neurons during development. In this study we examined the energy requirements associated with the effects of BDNF on neuronal differentiation. Because glucose is the preferred energy substrate in the brain, the effect of BDNF on glucose utilization was investigated in developing cortical neurons via biochemical and imaging studies. Results revealed that BDNF increases glucose utilization and the expression of the neuronal glucose transporter GLUT3. Stimulation of glucose utilization by BDNF was shown to result from the activation of Na+/K+-ATPase via an increase in Na+ influx that is mediated, at least in part, by the stimulation of Na+-dependent amino acid transport. The increased Na+-dependent amino acid uptake by BDNF is followed by an enhancement of overall protein synthesis associated with the differentiation of cortical neurons. Together, these data demonstrate the ability of BDNF to stimulate glucose utilization in response to an enhanced energy demand resulting from increases in amino acid uptake and protein synthesis associated with the promotion of neuronal differentiation by BDNF
Boundary Limitation of Wavenumbers in Taylor-Vortex Flow
We report experimental results for a boundary-mediated wavenumber-adjustment
mechanism and for a boundary-limited wavenumber-band of Taylor-vortex flow
(TVF). The system consists of fluid contained between two concentric cylinders
with the inner one rotating at an angular frequency . As observed
previously, the Eckhaus instability (a bulk instability) is observed and limits
the stable wavenumber band when the system is terminated axially by two rigid,
non-rotating plates. The band width is then of order at small
() and agrees well with
calculations based on the equations of motion over a wide -range.
When the cylinder axis is vertical and the upper liquid surface is free (i.e.
an air-liquid interface), vortices can be generated or expelled at the free
surface because there the phase of the structure is only weakly pinned. The
band of wavenumbers over which Taylor-vortex flow exists is then more narrow
than the stable band limited by the Eckhaus instability. At small
the boundary-mediated band-width is linear in . These results are
qualitatively consistent with theoretical predictions, but to our knowledge a
quantitative calculation for TVF with a free surface does not exist.Comment: 8 pages incl. 9 eps figures bitmap version of Fig
Full QCD light hadron spectrum from the CP-PACS
We report on an on-going two-flavor full QCD study on CP-PACS using an
RG-improved gauge action and a tadpole-improved SW quark action. Runs are made
for three lattice spacings , 1.3, and 2.5 GeV on
, , and lattices. Four sea quark
masses having --0.6 are simulated, for each
of which hadron masses are evaluated for valence quark masses corresponding to
--0.5. Results for hadron and light quark
masses are presented and compared with those obtained in quenched QCD.Comment: LATTICE98(spectrum), 3 pages, 3 figure
The static quark potential in full QCD
We report results on the static quark potential in two-flavor full QCD. The
calculation is performed for three values of lattice spacing and 2.5 GeV on and
lattices respectively, at sea quark masses corresponding to . An RG-improved gauge action and a tadpole-improved SW clover
quark action are employed. We discuss scaling of and
effects of dynamical quarks on the potential.Comment: LATTICE98(spectrum), 3 pages, 4 figure
Quenched divergences in the deconfined phase of SU(2) gauge theory
The spectrum of the overlap Dirac operator in the deconfined phase of
quenched gauge theory is known to have three parts: exact zeros arising from
topology, small nonzero eigenvalues that result in a non-zero chiral
condensate, and the dense bulk of the spectrum, which is separated from the
small eigenvalues by a gap. In this paper, we focus on the small nonzero
eigenvalues in an SU(2) gauge field background at and . This
low-lying spectrum is computed on four different spatial lattices (,
, , and ). As the volume increases, the small eigenvalues
become increasingly concentrated near zero in such a way as to strongly suggest
that the infinite volume condensate diverges.Comment: 12 pages, 3 figures, version to appear in Physical Review
Heavy-light spectrum and decay constant from NRQCD with two flavors of dynamical quarks
We report on a study of B mesons on N_f = 2 full QCD configurations using an
RG-improved gauge action, NRQCD heavy quark action and tadpole-improved clover
light quark action. Results on the heavy-light spectrum and the decay constants
from 16^3x32 lattices at a^{-1} ~ 1.5 GeV are presented, and compared with
quenched results obtained with the same action combination at matching lattice
spacings.Comment: 3 pages, LaTeX, 2 PS figures, talk presented at LATTICE`99 (heavy
quarks
Eigenvalues of the hermitian Wilson-Dirac operator and chiral properties of the domain-wall fermion
Chiral properties of QCD formulated with the domain-wall fermion (DWQCD) are
studied using the anomalous quark mass m_{5q} and the spectrum of the
4-dimensional Wilson-Dirac operator. Numerical simulations are made with the
standard plaquette gauge action and a renormalization-group improved gauge
action. Results are reported on the density of zero eigenvalue obtained with
the accumulation method, and a comparison is made with the results for m_{5q}.Comment: Lattice 2000(Chiral Fermions), 4 pages, 6 eps figures,
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