1,610 research outputs found
nNOS Increases Fiber Type-Specific Angiogenesis in Skeletal Muscle of Mice in Response to Endurance Exercise.
We studied the relationship between neuronal NO synthase (nNOS) expression and capillarity in the tibialis anterior (TA) muscle of mice subjected to treadmill training. The mRNA (+131%) and protein (+63%) levels of nNOS were higher (p †0.05) in the TA muscle of C57BL/6 mice undergoing treadmill training for 28 days than in those of littermates remaining sedentary, indicating an up-regulation of nNOS by endurance exercise. Both TA muscles of 16 C57BL/6 mice were subjected to gene electroporation with either the pIRES2-ZsGreen1 plasmid (control plasmid) or the pIRES2-ZsGreen1-nNOS gene-inserted plasmid (nNOS plasmid). Subsequently, one group of mice (n = 8) underwent treadmill training for seven days, while the second group of mice (n = 8) remained sedentary. At study end, 12-18% of TA muscle fibers expressed the fluorescent reporter gene ZsGreen1. Immunofluorescence for nNOS was 23% higher (p †0.05) in ZsGreen1-positive fibers than ZsGreen1-negative fibers from the nNOS-transfected TA muscle of mice subjected to treadmill training. Capillary contacts around myosin heavy-chain (MHC)-IIb immunoreactive fibers (14.2%; p †0.05) were only higher in ZsGreen1-positive fibers than ZsGreen1-negative fibers in the nNOS-plasmid-transfected TA muscles of trained mice. Our observations are in line with an angiogenic effect of quantitative increases in nNOS expression, specifically in type-IIb muscle fibers after treadmill training
Dust-Bounded ULIRGs? Model Predictions for Infrared Spectroscopic Surveys
The observed faintness of infrared fine-structure line emission along with
the warm far-infrared (FIR) colors of ultraluminous infrared galaxies (ULIRGs)
is a long-standing problem. In this work, we calculate the line and continuum
properties of a cloud exposed to an Active Galactic Nucleus (AGN) and starburst
spectral energy distribution (SED). We use an integrated modeling approach,
predicting the spectrum of ionized, atomic, and molecular environments in
pressure equilibrium. We find that the effects of high ratios of impinging
ionizing radiation density to particle density (i.e. high ionization
parameters, or U) can reproduce many ULIRG observational characteristics.
Physically, as U increases, the fraction of UV photons absorbed by dust
increases, corresponding to fewer photons available to photoionize and heat the
gas, producing what is known as a "dust-bounded" nebula. We show that high U
effects can explain the "[C II] deficit", the ~1 dex drop in the [C II] 158
micron /FIR ratio seen in ULIRGs when compared to starburst or normal galaxies.
Additionally, by increasing U through increasing the ionizing photon flux,
warmer dust and thus higher IRAS F(60)/F(100) ratios result. High U effects
also predict an increase in [O I]63 micron /[C II] 158 micron and a gradual
decline in [O III] 88 micron /FIR, similar to the magnitude of the trends
observed, and yield a reasonable fit to [Ne V]14 micron /FIR ratio AGN
observations.Comment: 34 pages, 13 figures, accepted for publication in the Astrophysical
Journa
Trauma and Trichotillomania: A Tenuous Relationship
Some have argued that hair pulling in trichotillomania (TTM) is triggered by traumatic events, but reliable evidence linking trauma to TTM is limited. However, research has shown that hair pulling is associated with emotion regulation, suggesting a connection between negative affect and TTM. We investigated the associations between trauma, negative affect, and hair pulling in a cross-sectional sample of treatment seeking adults with TTM (N=85). In the current study, participantsâ self-reported traumatic experiences were assessed during a structured clinical interview, and participants completed several measures of hair pulling severity, global TTM severity, depression, anxiety, experiential avoidance, and quality of life. Those who experienced trauma had more depressive symptoms, increased experiential avoidance, and greater global TTM severity. Although the presence of a trauma history was not related to the severity of hair pulling symptoms in the past week, depressive symptoms mediated the relationship between traumatic experiences and global TTM severity. These findings cast doubt on the notion that TTM is directly linked to trauma, but suggest that trauma leads to negative affect that individuals cope with through hair pulling. Implications for the conceptualization and treatment of TTM are discussed
CP Violation beyond the Standard Model
In this talk a number of broad issues are raised about the origins of CP
violation and how to test the ideas.Comment: 17 pages, LaTeX, 6 postscript figures. Uses iopart10.clo,
iopart12.clo and iopart.cls. Plenary talk given at the BSM Phenomenology
Workshop, Durham, UK, 6-11 May 2001. To appear in the proceeding
Direct Mediation and Metastable Supersymmetry Breaking for SO(10)
We examine a metastable Macroscopic SO(N) SQCD model of
Intriligator, Seiberg and Shih (ISS). We introduce various baryon and meson
deformations, including multitrace operators and explore embedding an SO(10)
parent of the standard model into two weakly gauged flavour sectors. Direct
fundamental messengers and the symmetric pseudo-modulus messenger mediate SUSY
breaking to the MSSM. Gaugino and sfermion masses are computed and compared for
each deformation type. We also explore reducing the rank of the magnetic quark
matrix of the ISS model and find an additional fundamental messenger.Comment: 43 pages, Latex. Version to appear in JHEP
The Piezoresponse in WOâ Thin Films Due to Nâ-Filled Nanovoids Enrichment by Atom Probe Tomography
Tungsten trioxide (WO3) is a versatile n-type semiconductor with outstanding chromogenic properties highly used to fabricate sensors and electrochromic devices. We present a comprehensive experimental study related to piezoresponse with piezoelectric coefficient d33 = 35 pmVâ1 on WO3 thin films ~200 nm deposited using RF-sputtering onto alumina (Al2O3) substrate with post-deposit annealing treatment of 400 °C in a 3% H2/N2-forming gas environment. X-ray diffraction (XRD) confirms a mixture of orthorhombic and tetragonal phases of WO3 with domains with different polarization orientations and hysteresis behavior as observed by piezoresponse force microscopy (PFM). Furthermore, using atom probe tomography (APT), the microstructure reveals the formation of N2-filled nanovoids that acts as strain centers producing a local deformation of the WO3 lattice into a non-centrosymmetric structure, which is related to piezoresponse observations
Radio Foregrounds for the 21cm Tomography of the Neutral Intergalactic Medium at High Redshifts
Absorption or emission against the cosmic microwave background radiation
(CMB) may be observed in the redshifted 21cm line if the spin temperature of
the neutral intergalactic medium prior to reionization differs from the CMB
temperature. This so-called 21cm tomography should reveal important information
on the physical state of the intergalactic medium at high redshifts. The
fluctuations in the redshifted 21 cm, due to gas density inhomogeneities at
early times, should be observed at meter wavelengths by the next generation
radio telescopes such as the proposed {\it Square Kilometer Array (SKA)}. Here
we show that the extra-galactic radio sources provide a serious contamination
to the brightness temperature fluctuations expected in the redshifted 21 cm
emission from the IGM at high redshifts. Unless the radio source population
cuts off at flux levels above the planned sensitivity of SKA, its clustering
noise component will dominate the angular fluctuations in the 21 cm signal. The
integrated foreground signal is smooth in frequency space and it should
nonetheless be possible to identify the sharp spectral feature arising from the
non-uniformities in the neutral hydrogen density during the epoch when the
first UV sources reionize the intergalactic medium.Comment: 5 pages emulateapj with 1 figure, accepted to Ap
How big were the first cosmological objects?
We calculate the cooling times at constant density for halos with virial
temperatures from 100 K to 10^5 K that originate from a 3-sigma fluctuation of
a CDM power spectrum in three different cosmologies. Our intention is to
determine the first objects that can cool to low temperatures, but not to
follow their dynamical evolution. We identify two generations of halos: those
with low virial temperatures, Tvir < 9000 K that remain largely neutral, and
those with larger virial temperatures that become ionized. The
lower-temperature, lower-mass halos are the first to cool to 75 percent of
their virial temperature. The precise temperature and mass of the first objects
are dependent upon the molecular hydrogen (H2) cooling function and the
cosmological model. The higher-mass halos collapse later but, in this paradigm,
cool much more efficiently once they have done so, first via electronic
transitions and then via molecular cooling: in fact, a greater residual
ionization once the halos cool below 9000 K results in an enhanced H2
production and hence a higher cooling rate at low temperatures than for the
lower-mass halos, so that within our constant-density model it is the former
that are the first to cool to really low temperatures. We discuss the possible
significance of this result in the context of CDM models in which the shallow
slope of the initial fluctuation spectrum on small scales leads to a wide range
of halo masses (of differing overdensities) collapsing over a small redshift
interval. This ``crosstalk'' is sufficiently important that both high- and
low-mass halos collapse during the lifetimes of the massive stars which may be
formed at these epochs. Further investigation is thus required to determine
which generation of halos plays the dominant role in early structure formation.Comment: 11 pages, 8 figures. Accepted for publication in MNRAS. Inclusion of
Helium in the reaction networ
Superpartner spectrum of minimal gaugino-gauge mediation
We evaluate the sparticle mass spectrum in the minimal four-dimensional
construction that interpolates between gaugino and ordinary gauge mediation at
the weak scale. We find that even in the hybrid case -- when the messenger
scale is comparable to the mass of the additional gauge particles -- both the
right-handed as well as the left-handed sleptons are lighter than the bino in
the low-scale mediation regime. This implies a chain of lepton production and,
consequently, striking signatures that may be probed at the LHC already in the
near future.Comment: 8 pages, 3 figures; V2: refs and a few comments added; V3 title
change
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