7,160 research outputs found
Molecular gas and stars in the translucent cloud MBM 18 (LDN 1569)
Seven of ten candidate H-alpha emission-line stars found in an objective
grism survey of a 1 square degree region in MBM 18, were observed
spectroscopically. Four of these have weak H-alpha emission, and 6 out of 7
have spectral types M1-M4V. One star is of type F7-G1V, and has H-alpha in
absorption. The spectra of three of the M-stars may show an absorption line of
LiI, although none of these is an unambiguous detection. For the six M-stars a
good fit is obtained with pre-main-sequence isochrones indicating ages between
7.5 and 15Myr. The molecular cloud mass, derived from the integrated 12CO(1-0)
emission, is 160Mo (for a distance of 120pc), much smaller than the virial mass
(10^3Mo), and the cloud is not gravitationally bound. Nor are the individual
clumps we identified through a clump-finding routine. Considering the relative
weakness or absence of the H-alpha emission, the absence of other emission
lines, and the lack of clear LiI absorption, the targets are not T Tauri stars.
With ages between 7.5 and 15Myr they are old enough to explain the lack of
lithium in their spectra. Based on the derived distances (60-250pc), some of
the stars may lie inside the molecular cloud (120-150pc). From the fact that
the cloud as a whole, as well as the individual clumps, are not gravitationally
bound, in combination with the ages of the stars we conclude that it is not
likely that (these) stars were formed in MBM 18.Comment: Accepted for publication in Astronomy & Astrophysics (20 pages
Epigenetic engineering and the art of epigenetic manipulation
This short and focused meeting was set up to bring the audience up to date with a specific set of techniques broadly categorized as epigenetic engineering (or epigenetic editing). The speakers reminded us of very important questions that still linger, like Damocles’ sword, over the field of epigenetics: what is the real role of epigenetics during gene transcription and development? Are epigenetic modifications the cause or consequence of these processes? While the jury is still out, this meeting reminded us that the tools needed to answer these philosophical questions are finally available and improving by the hour. Moreover, there was also a general consensus that epigenetic editing might provide the next big advance in cancer treatment. Epigenetic-editing treatments might finally allow targeted modulation of gene expression and could bypass the side effects of current epigenetic drugs
A Dynamical Study of the Non-Star Forming Translucent Molecular Cloud MBM16: Evidence for Shear Driven Turbulence in the Interstellar Medium
We present the results of a velocity correlation study of the high latitude
cloud MBM16 using a fully sampled CO map, supplemented by new CO
data. We find a correlation length of 0.4 pc. This is similar in size to the
formaldehyde clumps described in our previous study. We associate this
correlated motion with coherent structures within the turbulent flow. Such
structures are generated by free shear flows. Their presence in this non-star
forming cloud indicates that kinetic energy is being supplied to the internal
turbulence by an external shear flow. Such large scale driving over long times
is a possible solution to the dissipation problem for molecular cloud
turbulence.Comment: Uses AAS aasms4.sty macros. Accepted for publication in Ap
Epigenetic engineering and the art of epigenetic manipulation
This short and focused meeting was set up to bring the audience up to date with a specific set of techniques broadly categorized as epigenetic engineering (or epigenetic editing). The speakers reminded us of very important questions that still linger, like Damocles’ sword, over the field of epigenetics: what is the real role of epigenetics during gene transcription and development? Are epigenetic modifications the cause or consequence of these processes? While the jury is still out, this meeting reminded us that the tools needed to answer these philosophical questions are finally available and improving by the hour. Moreover, there was also a general consensus that epigenetic editing might provide the next big advance in cancer treatment. Epigenetic-editing treatments might finally allow targeted modulation of gene expression and could bypass the side effects of current epigenetic drugs
Unexpected phase locking of magnetic fluctuations in the multi-k magnet USb
The spin waves in the multi-k antiferromagnet USb soften and become quasielastic well below the antiferromagnetic ordering temperature TN. This occurs without a magnetic or structural transition. It has been suggested that this change is in fact due to dephasing of the different multi-k components: a switch from 3-k to 1-k behavior. In this work, we use inelastic neutron scattering with tridirectional polarization analysis to probe the quasielastic magnetic excitations and reveal that the 3-k structure does not dephase. More surprisingly, the paramagnetic correlations also maintain the same clear phase correlations well above TN (up to at least 1.4TN)
Glutathione increase by the n-butanoyl glutathione derivative (GSH-C4) inhibits viral replication and induces a predominant Th1 immune profile in old mice infected with influenza virus
During aging, glutathione (GSH) content declines and the immune system undergoes a
deficiency in the induction of Th1 response. Reduced secretion of Th1 cytokines, which is
associated with GSH depletion, could weaken the host defenses against viral infections.
We first evaluated the concentration of GSH and cysteine in organs of old mice; then, the
effect of the administration of the N-butanoyl GSH derivative (GSH-C4) on the response of
aged mice infected with influenza A PR8/H1N1 virus was studied through the determination
of GSH concentration in organs, lung viral titer, IgA and IgG1/IgG2a production and
Th1/Th2 cytokine profile.
Old mice had lower GSH than young mice in organs. Also the gene expression of
endoplasmic reticulum (ER) stress markers involved in GSH metabolism and folding of
proteins, i.e. Nrf2 and PDI, was reduced. Following infection, GSH content remained low
and neither infection nor GSH-C4 treatment affected Nrf2 expression. In contrast, PDI
expression was upregulated during infection and appeared counterbalanced by GSH-C4.
Moreover, the treatment with GSH-C4 increased GSH content in organs, reduced viral
replication and induced a predominant Th1 response.
In conclusion, GSH-C4 treatment could be used in the elderly to contrast influenza virus
infection by inducing immune response, in particular the Th1 profile
Inhibition of E-Selectin (GMI-1271) or E-selectin together with CXCR4 (GMI-1359) re-sensitizes multiple myeloma to therapy
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