954 research outputs found
Effect of C60 fullerene on recovery of muscle soleus in rats after atrophy induced by achillotenotomy
Biomechanical and biochemical changes in the muscle soleus of rats during imitation of hind limbs unuse were studied in the model of the Achilles tendon rupture (Achillotenotomy). Oral administration of water-soluble C 60 fullerene at a dose of 1 mg/kg was used as a therapeutic agent throughout the experiment. Changes in the force of contraction and the integrated power of the muscle, the time to reach the maximum force response, the mechanics of fatigue processes development, in particular, the transition from dentate to smooth tetanus, as well as the levels of pro- and antioxidant balance in the blood of rats on days 15, 30 and 45 after injury were described. The obtained results indicate a promising prospect for C 60 fullerene use as a powerful antioxidant for reducing and correcting pathological conditions of the muscular system arising from skeletal muscle atrophy
A compact statistical model of the song syntax in Bengalese finch
Songs of many songbird species consist of variable sequences of a finite
number of syllables. A common approach for characterizing the syntax of these
complex syllable sequences is to use transition probabilities between the
syllables. This is equivalent to the Markov model, in which each syllable is
associated with one state, and the transition probabilities between the states
do not depend on the state transition history. Here we analyze the song syntax
in a Bengalese finch. We show that the Markov model fails to capture the
statistical properties of the syllable sequences. Instead, a state transition
model that accurately describes the statistics of the syllable sequences
includes adaptation of the self-transition probabilities when states are
repeatedly revisited, and allows associations of more than one state to the
same syllable. Such a model does not increase the model complexity
significantly. Mathematically, the model is a partially observable Markov model
with adaptation (POMMA). The success of the POMMA supports the branching chain
network hypothesis of how syntax is controlled within the premotor song nucleus
HVC, and suggests that adaptation and many-to-one mapping from neural
substrates to syllables are important features of the neural control of complex
song syntax
The MutSβ complex is a modulator of p53-driven tumorigenesis through its functions in both DNA double-strand break repair and mismatch repair
Loss of the DNA mismatch repair (MMR) protein MSH3 leads to the development of a variety of tumors in mice without significantly affecting survival rates, suggesting a modulating role for the MutSβ (MSH2-MSH3) complex in late-onset tumorigenesis. To better study the role of MSH3 in tumor progression, we crossed Msh3(-/-) mice onto a tumor predisposing p53-deficient background. Survival of Msh3/p53 mice was not reduced compared with p53 single mutant mice; however, the tumor spectrum changed significantly from lymphoma to sarcoma, indicating MSH3 as a potent modulator of p53-driven tumorigenesis. Interestingly, Msh3(-/-) mouse embryonic fibroblasts displayed increased chromatid breaks and persistence of γH2AX foci following ionizing radiation, indicating a defect in DNA double-strand break repair (DSBR). Msh3/p53 tumors showed increased loss of heterozygosity, elevated genome-wide copy-number variation and a moderate microsatellite instability phenotype compared with Msh2/p53 tumors, revealing that MSH2-MSH3 suppresses tumorigenesis by maintaining chromosomal stability. Our results show that the MSH2-MSH3 complex is important for the suppression of late-onset tumors due to its roles in DNA DSBR as well as in DNA MMR. Further, they demonstrate that MSH2-MSH3 suppresses chromosomal instability and modulates the tumor spectrum in p53-deficient tumorigenesis and possibly has a role in other chromosomally unstable tumors as well
Ground state properties and bubble structure of superheavy nuclei
We calculate the ground state properties of recently synthesized superheavy
nuclei starting from =105-120. The nonrelativistic and relativistic mean
field formalisms is used to evaluate the binding energy, charge radius,
quadrupole deformation parameter and the density distribution of nucleons. We
analyzed the stability of the nuclei based on the binding energy and neutron to
proton ratio. We also studied the bubble structure of the nucleus which reveals
about the special features of the superheavy nucleus
Influence of C(60) fullerene on the ischemia-reperfusion injury in the skeletal muscle of rat limb: mechanokinetic and biochemical analysis
Influence of the pristine C60 fullerene aqueous colloidal solution (C60FAS) on the ischemia-reperfusion injury in the skeletal muscle of rat limb was studied. Skeletal muscle damage effects were induced by 3 h lasting vascular ischemia. The impact of C60FAS was studied after its intramuscular injection immediately after 1 h of reperÂfusion at different doses, namely: 1, 2 and 3 mg/kg of body weight. Changes in the mechanokinetic parameÂters of ischemic skeletal muscle contraction at different modes of functioning and biochemical parameÂters of blood were used as markers of ischemic injury, and analyzed in detail under action of C60FAS. The obtained results indicate on great promise of use of C60FAS to reduce the consequences of ischemic muscle trauma
Leadership in strategic information (LSI) building skilled public health capacity in Ethiopia
<p>Abstract</p> <p>Background</p> <p>In many developing countries, including Ethiopia, few have the skills to use data for effective decision making in public health. To address this need, the U.S. Centers for Disease Control and Prevention (CDC), in collaboration with two local Ethiopian organizations, developed a year long Leadership in Strategic Information (LSI) course to train government employees working in HIV to use data from strategic information sources. A process evaluation of the LSI course examined the impact of the training on trainees' skills and the strengths and weaknesses of the course. The evaluation consisted of surveys and focus groups.</p> <p>Findings</p> <p>Trainees' skill sets increased in descriptive and analytic epidemiology, surveillance, and monitoring and evaluation (M and E). Data from the evaluation indicated that the course structure and the M and E module required revision in order to improve outcomes. Additionally, the first cohort had a high attrition rate. Overall, trainees and key stakeholders viewed LSI as important in building skilled capacity in public health in Ethiopia.</p> <p>Conclusion</p> <p>The evaluation provided constructive insight in modifying the course to improve retention and better address trainees' learning needs. Subsequent course attrition rates decreased as a result of changes made based on evaluation findings.</p
Determination of alpha_s using Jet Rates at LEP with the OPAL detector
Hadronic events produced in e+e- collisions by the LEP collider and recorded
by the OPAL detector were used to form distributions based on the number of
reconstructed jets. The data were collected between 1995 and 2000 and
correspond to energies of 91 GeV, 130-136 GeV and 161-209 GeV. The jet rates
were determined using four different jet-finding algorithms (Cone, JADE, Durham
and Cambridge). The differential two-jet rate and the average jet rate with the
Durham and Cambridge algorithms were used to measure alpha(s) in the LEP energy
range by fitting an expression in which order alpah_2s calculations were
matched to a NLLA prediction and fitted to the data. Combining the measurements
at different centre-of-mass energies, the value of alpha_s (Mz) was determined
to be
alpha(s)(Mz)=0.1177+-0.0006(stat.)+-0.0012$(expt.)+-0.0010(had.)+-0.0032(theo.)
\.Comment: 40 pages, 17 figures, Submitted to Euro. Phys. J.
Colour reconnection in e+e- -> W+W- at sqrt(s) = 189 - 209 GeV
The effects of the final state interaction phenomenon known as colour
reconnection are investigated at centre-of-mass energies in the range sqrt(s) ~
189-209 GeV using the OPAL detector at LEP. Colour reconnection is expected to
affect observables based on charged particles in hadronic decays of W+W-.
Measurements of inclusive charged particle multiplicities, and of their angular
distribution with respect to the four jet axes of the events, are used to test
models of colour reconnection. The data are found to exclude extreme scenarios
of the Sjostrand-Khoze Type I (SK-I) model and are compatible with other
models, both with and without colour reconnection effects. In the context of
the SK-I model, the best agreement with data is obtained for a reconnection
probability of 37%. Assuming no colour reconnection, the charged particle
multiplicity in hadronically decaying W bosons is measured to be (nqqch) =
19.38+-0.05(stat.)+-0.08 (syst.).Comment: 30 pages, 9 figures, Submitted to Euro. Phys. J.
The Solar Neutrino Puzzle: An Oscillation Solution with Maximal Neutrino Mixing
If, as suggested by the SuperKamiokande results, the mu neutrino and tau
neutrino are maximally and ``rapidly'' mixed, this alone determines the mapping
from current to mass eigenstates up to one rotation angle (theta) mixing the
electron neutrino ``more slowly'', with an equal combination of the mu neutrino
and tau neutrino. For sin 2 theta = 1, the resulting minimal number of free
parameters, yet maximal mixing, shows agreement between extant observations of
solar neutrinos and predictions by the standard solar model with minor
modifications.Comment: 10 pages, latex, revtex source, two postscript figure
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