4,458 research outputs found
Epigenetic silencing of SOCS3 expression contributes to fibrosis in Crohnâs disease
Identified risk polymorphisms affecting the Jak-STAT3 pathway in patients with Crohnâs disease could affect TGF-β1 and collagen I expression and in the pathwayâs negative regulator, SOCS3. Genetic factors, however, account for only ~25% of disease. Epigenetic events also shape gene expression. Recent experiments showed that autocrine IL-6 production in mesenchymal cells, subepithelial myofibroblasts (SEMF) and muscle cells, of patients with fibrostenotic Crohnâs disease causes sustained Jak-STAT3 activity, excess TGF-β1 and Collagen I production and fibrosis. SOCS3 paradoxically decreased in these cells. We now identify epigenetic mechanisms that silence SOCS3 expression in SEMF of patients with fibrostenotic Crohnâs disease. In a previous experiment, using isolated SEMF of normal ileum and affected ileum from patients with each Crohnâs phenotype, inflammatory (Montreal B1), fibrostenotic (B2) and penetrating (B3), we confirmed decreased SOCS3 protein levels were unique to B2 patients. Expression of miR-19b increased in SEMF of affected ileum. SOCS3 transcriptional activity decreased after transfection of miR-19b mimic and increased when antagomiR-19b was expressed. Epigenetic silencing of SOCS3 in ileal SEMF of patients with fibrostenotic Crohnâs disease occurs by increased miR-19b mediated inhibition of SOCS3
A near infrared spectroscopic study of the interstellar gas in the starburst core of M82
Researchers used the McDonald Observatory Infrared Grating Spectrometer, to complete a program of spatially resolved spectroscopy of M82. The inner 300 pc of the starburst was observed with 4 inch (50 pc) resolution. Complete J, H and K band spectra with resolution 0.0035 micron (lambda/delta lambda=620 at K) were measured at the near-infrared nucleus of the galaxy. Measurements of selected spectral features including lines of FeII, HII and H2 were observed along the starburst ridge-line, so the relative distribution of the diagnostic features could be understood. This information was used to better define the extinction towards the starburst region, the excitation conditions in the gas, and to characterize the stellar populations there
Global Navigation Satellite System Signal Decomposition and Parameterization Algorithm
A method and apparatus is provided for intra-PIT signal decomposition of a signal received with RF front end hardware. The method begins by aligning a signal received by RF front end hardware into integer multiples of a duration of a pseudorandom noise code sequence. A search grid is computed based on an integer multiple of the aligned signal. A plurality of initial ray parameters associated with the computed search grid is coarsely estimated. Using the coarsely estimated plurality of initial ray parameters, a fine estimation of the plurality of initial ray parameters is initiated utilizing stochastic search and optimization techniques. A stopping criteria statistic is computed by comparing a peak power of the search grid with a noise power present in the search grid. Finally, in response to determining the stopping criteria statistic being less than a stopping criteria threshold, processing a next integer multiple of the aligned signal
Complete Journal Spring 1984
For historical reasons we have uploaded PDF files for volumes previously published in paper form. Attached you will find the entire volume 1, no. 1 issue from Spring 1984
Land Contract or Mortgage?
The use of land contracts in buying and selling farms is increasing in Iowa. The contract is basically different from the traditional deed and mortgage, and advantages and disadvantages should be weighed carefully
Uranium-series dating of corals from the southwest Pacific
The uranium-series technique is based on the observation
that carbonates precipitating in nature, in particular
corals and oolites, show an initial disequilibrium between
Th²³Ⱐand its parent U²³â¸.
The amount of Th²³Ⱐinitially
present in a coral is negligible in comparison to that subsequently
generated by the radioactive decay of uranium. If
the system remains closed then the ratio of Th²³Ⱐto U²³â¸
is a simple function of time. Because there is a 15 percent
excess of U²³ⴠto U²³⸠in sea water this has to be
taken into account when determining the age.
Corals from New Guinea, the Loyalty Islands, and the
east coast of Australia were provided for dating. The New
Guinea corals, from the Huon Peninsula, had been dated previously,
and so they provided a check on the reliability of
the techniques used in this study. With one exception the
ages from this study are within the error limits placed on
the original ages. The one sample that does not agree is
shown to have a high proportion-of void-filling low-Mg calcite
cement.
Corals from the Capricorn Group and Hayman Island
within the Great Barrier Reef province show relatively
young ages. One coral recovered by drilling at a depth of
17m on the Hayman Island reef indicates that the time of
recolonization of the reef towards the end of the Holocene
transgression is about 8,300 yr B.P. Coral samples below a
marked discontinuity at a depth of about 20m are extensively
recrystallized. Ages of corals from the Inner Barrier of New South
Wales show that this feature 'formed during the last inter-glacial
at about 120,000 yr B.P. The ages suggest that
there were two periods of high sea level at about this time.
Ages from reef terraces 2-6m above present sea
level from three islands of the Loyalty Archipelago show
the varying degrees of uplift of these islands. Corals
from +2m on Beautemps-Beaupre are older than 200,000 yr
B.P., while a coral at +6.5m from Ouvea gave an age of
117,000 Âą 6,000 yr B.P. Ages from the +2m terrace on
Lifou support the interpretation of a relatively high sea
level at about 180,000 yr B.P.
Ages of corals from a slightly raised fringing reef
around Mud Island, Moreton Bay indicate a sea level about
one metre higher than present during the interval 4,000 -
6,000 yrs B.P. This slightly higher sea level could have
been the result of a changing.tidal regime within the bay
A stochastic vortex structure method for interacting particles in turbulent shear flows
In a recent study, we have proposed a new synthetic turbulence method based on stochastic vortex structures (SVSs), and we have demonstrated that this method can accurately predict particle transport, collision, and agglomeration in homogeneous, isotropic turbulence in comparison to direct numerical simulation results. The current paper extends the SVS method to non-homogeneous, anisotropic turbulence. The key element of this extension is a new inversion procedure, by which the vortex initial orientation can be set so as to generate a prescribed Reynolds stress field. After validating this inversion procedure for simple problems, we apply the SVS method to the problem of interacting particle transport by a turbulent planar jet. Measures of the turbulent flow and of particle dispersion, clustering, and collision obtained by the new SVS simulations are shown to compare well with direct numerical simulation results. The influence of different numerical parameters, such as number of vortices and vortex lifetime, on the accuracy of the SVS predictions is also examined
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