3,932 research outputs found
Liver-dependent protection during pneumonia and sepsis
Pneumonia and sepsis are distinct but linked public health concerns. Each condition is the leading cause of the other; however, the responses controlling the susceptibility between the two disease processes remain speculative. The acute phase response (APR) is an important component of the host immune response during pneumonia and sepsis, and primarily driven by the activation of hepatocyte transcription factors NF-κB RelA and STAT3.
While the NF-κB pathway is essential for inflammation and hepatocyte function, its inactivation has been associated with hepatotoxicity. Liver injury is an independent risk factor for sepsis morbidity and mortality, suggesting that pathways promoting liver homeostasis may limit the systemic consequences of pneumonia. To identify conditions in which NF-κB RelA is required for liver resilience, we challenged mice lacking hepatocyte RelA (hepRelAΔ/Δ) and wildtype (WT) controls with E. coli, K. pneumoniae, S. pneumoniae, LPS, or αGalCer to induce pneumonia, sepsis, and/or NKT cell activation. Severe hepatotoxicity was observed in hepRelAΔ/Δ mice in all conditions examined in association with apoptosis, which could be prevented by neutralization of TNFα. Lastly, these changes were associated with remodeling of the hepatic transcriptome, likely reflecting both the cause and consequence of hepatoxicity.
We have previously shown that activation of STAT3 in hepatocytes limits pneumonia susceptibility during endotoxemia, but the mechanisms whereby this liver APR provides protection are unknown. Iron sequestration is a defense mechanism against bacterial infections, which require iron for growth. Based on previous observations that alveolar lining fluid is favorable for bacteria in the absence of liver STAT3, we investigated whether liver APR limits pneumonia susceptibility during sepsis by withholding iron to prevent bacterial outgrowth. WT mice or mice lacking hepatocyte STAT3 (hepSTAT3Δ/Δ) mice were challenged with endotoxemia followed by E. coli pneumonia, or cecal ligation and puncture (CLP). Induction of mRNA encoding several essential iron-regulating factors was ablated in hepSTAT3Δ/Δ mice after endotoxemia and pneumonia, and post CLP. Additionally, liver STAT3 activation significantly remodeled the pulmonary transcriptome during endotoxemia, which potentially represents other protective mechanisms.
Taken together, these results suggest that hepatic APR is an important immunological interface modulating pneumonia and sepsis interaction and susceptibility
Musical Portraiture In Acht Korte Karakterschetsen Voor Piano Vierhandig By Hans Osieck
Hans Osieck (1910-2000) was a Dutch composer, pianist, and teacher. His musical portraits, Acht Korte Karakterschetsen voor piano vierhandig (Eight Short Character Sketches for Four Hands), are a valuable addition to the piano duo repertoires for intermediate and advanced students. In Eight Sketches, Osieck musically portrays eight of his students using simple compositional techniques, much like the brushstrokes and color palette of an artistic portrait. As a result of their programmatic nature and relatable subjects, Osieck’s Eight Sketches can be particularly useful for students developing their imaginations and learning to perform expressively. As a piano duo, Eight Sketches also serves to improve the performers’ ensemble skills. Unfortunately, many performers are unfamiliar with these charming works, because Osieck and his music are not well-known.
The primary aim of this document is to introduce performers, listeners, and teachers to Osieck’s Eight Short Character Sketches and explore the compositional tools Osieck uses to “paint” each of his musical portraits. To provide context, I begin with a brief biography of the composer, including the compositional techniques that permeate his oeuvre. These compositional elements include repeated rhythmic patterns, syncopation, chromatic melodies, various ornamentations, jazz-like chord progressions, and dance elements such as waltz and boogie-woogie.
A more detailed examination of Eight Short Character Sketches follows, exploring the compositional devices used by Osieck, to bring the metaphorical titles of each movement to life. Each movement of Eight Short Character Sketches is only one page in length, making it quite accessible for intermediate students learning fundamental pianistic skills that contribute to a sophisticated quality of sound. Although the movements are quite short, they brilliantly depict each subject and offer student pianists an opportunity to exercise their expressive skills and develop their imaginations. As a result, Osieck’s skillful and imaginative composition techniques as well as the work’s pedagogical benefits to intermediate pianists should afford Eight Short Character Sketches and Hans Osieckk a lasting place in the piano repertory
Thermoelectric and Magnetothermoelectric Transport Measurements of Graphene
The conductance and thermoelectric power (TEP) of graphene is simultaneously
measured using microfabricated heater and thermometer electrodes. The sign of
the TEP changes across the charge neutrality point as the majority carrier
density switches from electron to hole. The gate dependent conductance and TEP
exhibit a quantitative agreement with the semiclassical Mott relation. In the
quantum Hall regime at high magnetic field, quantized thermopower and Nernst
signals are observed and are also in agreement with the generalized Mott
relation, except for strong deviations near the charge neutrality point
Correlation between superfluid density and Tc of underdoped YBa2Cu3O6+x near the superconductor-insulator transition
We report measurements of the ab-plane superfluid density Ns (magnetic
penetration depth, \lambda) of severely underdoped films of YBa2Cu3O6+x, with
Tc's from 6 to 50 K. Tc is not proportional to Ns(0); instead, we find Tc ~
Ns^{1/2.3 +/- 0.4}. At the lowest dopings, Tc is as much as 5 times larger than
the upper limit set by the KTB transition temperature of individual CuO2
bilayers.Comment: 4 pages, 2 figures, Submitted to Phys. Rev. Let
Nanoradian angular stabilization of x-ray optical components
An x-ray free electron laser oscillator (XFELO) has been recently proposed
[K. Kim, Y. Shvyd'ko, and S. Reiche, Phys. Rev. Lett. 100, 244802 (2008)].
Angular orientation and position in space of Bragg mirrors of the XFELO optical
cavity must be continuously adjusted to compensate instabilities and maximize
the output intensity. An angular stability of about 10 nrad (rms) is required
[K. Kim and Y. Shvyd'ko Phys. Rev. STAB 12, 030703 (2009)]. To approach this
goal, a feedback loop based on a null-detection principle was designed and used
for stabilization of a high energy resolution x-ray monochromator (, = 23.7 keV) and a high heat load monochromator.
Angular stability of about 13 nrad (rms) has been demonstrated for x-ray
optical elements of the monochromators.Comment: 8 figure
Why Do Women Seek Physical Beauty? : A Cross-Cultural Approach to Understand the Physical Beauty of East Asian Women
Physical beauty has been a main research agenda of the social psychology of clothing. However, the body of research that has illustrated the main reasons that women seek physical beauty has been limited. This study examined what values are sought by women through their physical beauty. The physical beauty value, a new paradigm suggested by this research, is the value acquired through the improvement of physical beauty. As the cognition of beauty is affected by sociocultural contexts (Dion et al., 1990), the physical beauty value is also formulated based on cultural characteristics. This study selected Korean, Chinese and Japanese women in their 20s and 30s, and explored their physical beauty values with a crosscultural approach. Through this perspective, this study discovered a common physical beauty value in East Asia and specific physical beauty values salient in each culture
Models for energy and charge transport and storage in biomolecules
Two models for energy and charge transport and storage in biomolecules are
considered. A model based on the discrete nonlinear Schrodinger equation with
long-range dispersive interactions (LRI's) between base pairs of DNA is offered
for the description of nonlinear dynamics of the DNA molecule. We show that
LRI's are responsible for the existence of an interval of bistability where two
stable stationary states, a narrow, pinned state and a broad, mobile state,
coexist at each value of the total energy. The possibility of controlled
switching between pinned and mobile states is demonstrated. The mechanism could
be important for controlling energy storage and transport in DNA molecules.
Another model is offered for the description of nonlinear excitations in
proteins and other anharmonic biomolecules. We show that in the highly
anharmonic systems a bound state of Davydov and Boussinesq solitons can exist.Comment: 12 pages (latex), 12 figures (ps
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