151 research outputs found
How Cereal Grass Shoots Perceive And Respond To Gravity
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141646/1/ajb208758.pd
Baryonic Response of Dense Holographic QCD
The response function of a homogeneous and dense hadronic system to a
time-dependent (baryon) vector potential is discussed for holographic dense QCD
(D4/D8 embedding) both in the confined and deconfined phases. Confined
holographic QCD is an uncompressible and static baryonic insulator at large N_c
and large \lambda, with a gapped vector spectrum and a massless pion.
Deconfined holographic QCD is a diffusive conductor with restored chiral
symmetry and a gapped transverse baryonic current. Similarly, dense D3/D7 is
diffusive for any non-zero temperature at large N_c and large \lambda. At zero
temperature dense D3/D7 exhibits a baryonic longitudinal visco-elastic mode
with a first sound speed \lambda/\sqrt{3} and a small width due to a shear
viscosity to baryon ratio \eta/n_B=\hbar/4. This mode is turned diffusive by
arbitrarily small temperatures, a hallmark of holography.Comment: V2: 47 pages, 7 figures, references added, typos correcte
Flavor symmetry breaking effects on SU(3) Skyrmion
We study the massive SU(3) Skyrmion model to investigate the flavor symmetry
breaking (FSB) effects on the static properties of the strange baryons in the
framework of the rigid rotator quantization scheme combined with the improved
Dirac quantization one. Both the chiral symmetry breaking pion mass and FSB
kinetic terms are shown to improve the ratio of the strange-light to
light-light interaction strengths and that of the strange-strange to
light-light.Comment: 12 pages, latex, no figure
Male predominance of pneumonia and hospitalization in pandemic influenza A (H1N1) 2009 infection
<p>Abstract</p> <p>Background</p> <p>Pandemic influenza A (H1N1) disproportionately affects different age groups. The purpose of the current study was to describe the age and gender difference of pandemic influenza A (H1N1) cases that lead to pneumonia, hospitalization or ICU admission.</p> <p>Methods</p> <p>Data were collected retrospectively between May 2009 and December 2009. All of the diagnoses of H1N1 were confirmed by real-time reverse-transcription polymerase chain reaction (RT-PCR).</p> <p>Results</p> <p>During the study period there were 3402 cases of RT-PCR positive H1N1, among which 1812 were males and 1626 were adults (> 15 years of age). 6% (206/3402) of patients required hospitalization, 3.6% (122/3402) had infiltrates on chest radiographs, and 0.70% (24/3402) were admitted to intensive care unit (ICU). The overall fatality rate was 0.1% (4/3402). The rate of hospitalization was sharply increased in patients ≥ 50 years of age especially in male. Out of 122 pneumonia patients, 68.8% (84 patients) were male. Among the patients admitted to the ICU, 70.8% (17 patients) were male. Approximately 1 of 10 H1N1-infected patients admitted to the ICU were ≥ 70 years of age.</p> <p>Conclusions</p> <p>Among the confirmed cases of H1N1, the ICU admission rate was < 1% and the case fatality rate was 0.1%. Male had a significantly higher rate of pneumonia and hospital admission. These findings should be taken into consideration when developing vaccination and treatment strategies.</p
Carisbamate Blockade of T-Type Voltage-Gated Calcium Channels
Objectives
Carisbamate (CRS) is a novel monocarbamate compound that possesses antiseizure and neuroprotective properties. However, the mechanisms underlying these actions remain unclear. Here, we tested both direct and indirect effects of CRS on several cellular systems that regulate intracellular calcium concentration [Ca2+]i.
Methods
We used a combination of cellular electrophysiologic techniques, as well as cell viability, Store Overload‐Induced Calcium Release (SOICR), and mitochondrial functional assays to determine whether CRS might affect [Ca2+]i levels through actions on the endoplasmic reticulum (ER), mitochondria, and/or T‐type voltage‐gated Ca2+ channels.
Results
In CA3 pyramidal neurons, kainic acid induced significant elevations in [Ca2+]i and long‐lasting neuronal hyperexcitability, both of which were reversed in a dose‐dependent manner by CRS. Similarly, CRS suppressed spontaneous rhythmic epileptiform activity in hippocampal slices exposed to zero‐Mg2+ or 4‐aminopyridine. Treatment with CRS also protected murine hippocampal HT‐22 cells against excitotoxic injury with glutamate, and this was accompanied by a reduction in [Ca2+]i. Neither kainic acid nor CRS alone altered the mitochondrial membrane potential (ΔΨ) in intact, acutely isolated mitochondria. In addition, CRS did not affect mitochondrial respiratory chain activity, Ca2+‐induced mitochondrial permeability transition, and Ca2+ release from the ER. However, CRS significantly decreased Ca2+ flux in human embryonic kidney tsA‐201 cells transfected with Cav3.1 (voltage‐dependent T‐type Ca2+) channels.
Significance
Our data indicate that the neuroprotective and antiseizure activity of CRS likely results in part from decreased [Ca2+]i accumulation through blockade of T‐type Ca2+ channels
Evaluation of the Efficacy and Cross-Protectivity of Recent Human and Swine Vaccines against the Pandemic (H1N1) 2009 Virus Infection
The current pandemic (H1N1) 2009 virus remains transmissible among humans worldwide with cases of reverse zoonosis, providing opportunities to produce more pathogenic variants which could pose greater human health concerns. To investigate whether recent seasonal human or swine H1N1 vaccines could induce cross-reactive immune responses against infection with the pandemic (H1N1) 2009 virus, mice, ferrets or mini-pigs were administered with various regimens (once or twice) and antigen content (1.77, 3.5 or 7.5 µg HA) of a-Brsibane/59/07, a-CAN01/04 or RgCA/04/09xPR8 vaccine. Receipt of a-CAN01/04 (2-doses) but not a-Brisbane/59/07 induced detectable but modest (20–40 units) cross-reactive serum antibody against CA/04/09 by hemagglutinin inhibition (HI) assays in mice. Only double administration (7.5 µg HA) of both vaccine in ferrets could elicit cross-reactivity (30–60 HI titers). Similar antigen content of a-CAN01/04 in mini-pigs also caused a modest ∼30 HI titers (twice vaccinated). However, vaccine-induced antibody titers could not suppress active virus replication in the lungs (mice) or virus shedding (ferrets and pigs) of immunized hosts intranasally challenged with CA/04/09. Furthermore, neither ferrets nor swine could abrogate aerosol transmission of the virus into naïve contact animals. Altogether, these results suggest that neither recent human nor animal H1N1 vaccine could provide complete protectivity in all animal models. Thus, this study warrants the need for strain-specific vaccines that could yield the optimal protection desired for humans and/or animals
Meson Exchange Effect on Color Superconductivity
We investigate the effects of pion and gluon exchanges on the formation of
two-flavor color superconductivity at moderate density, . The
chiral quark model proposed by Manohar and Georgi containing pions as well as
gluons is employed to show that the pion exchange reduces substantially the
value of the superconducting gap gotten with the gluon exchange only. It turns
out that the pion exchanges produce a repulsion between quark-quark pair in a
spin and isospin singlet state.
We suggest that the phase consisiting of pions, gluons and quarks is one of
the candidates of in-medium QCD phase at moderate density.Comment: 8 pages, 1 figure, minor correction
Thymosin β10 Expression Driven by the Human TERT Promoter Induces Ovarian Cancer-Specific Apoptosis through ROS Production
Thymosin β10 (Tβ10) regulates actin dynamics as a cytoplasm G-actin sequestering protein. Previously, we have shown that Tβ10 diminishes tumor growth, angiogenesis, and proliferation by disrupting actin and by inhibiting Ras. However, little is known about its mechanism of action and biological function. In the present study, we establish a new gene therapy model using a genetically modified adenovirus, referred to as Ad.TERT.Tβ10, that can overexpress the Tβ10 gene in cancer cells. This was accomplished by replacing the native Tβ10 gene promoter with the human TERT promoter in Ad.TERT.Tβ10. We investigated the cancer suppression activity of Tβ10 and found that Ad.TERT.Tβ10 strikingly induced cancer-specific expression of Tβ10 as well as apoptosis in a co-culture model of human primary ovarian cancer cells and normal fibroblasts. Additionally, Ad.TERT.Tβ10 decreased mitochondrial membrane potential and increased reactive oxygen species (ROS) production. These effects were amplified by co-treatment with anticancer drugs, such as paclitaxel and cisplatin. These findings indicate that the rise in ROS production due to actin disruption by Tβ10 overexpression increases apoptosis of human ovarian cancer cells. Indeed, the cancer-specific overexpression of Tβ10 by Ad.TERT.Tβ10 could be a valuable anti-cancer therapeutic for the treatment of ovarian cancer without toxicity to normal cells
LSST Science Book, Version 2.0
A survey that can cover the sky in optical bands over wide fields to faint
magnitudes with a fast cadence will enable many of the exciting science
opportunities of the next decade. The Large Synoptic Survey Telescope (LSST)
will have an effective aperture of 6.7 meters and an imaging camera with field
of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over
20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with
fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a
total point-source depth of r~27.5. The LSST Science Book describes the basic
parameters of the LSST hardware, software, and observing plans. The book
discusses educational and outreach opportunities, then goes on to describe a
broad range of science that LSST will revolutionize: mapping the inner and
outer Solar System, stellar populations in the Milky Way and nearby galaxies,
the structure of the Milky Way disk and halo and other objects in the Local
Volume, transient and variable objects both at low and high redshift, and the
properties of normal and active galaxies at low and high redshift. It then
turns to far-field cosmological topics, exploring properties of supernovae to
z~1, strong and weak lensing, the large-scale distribution of galaxies and
baryon oscillations, and how these different probes may be combined to
constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at
http://www.lsst.org/lsst/sciboo
- …