We developed a system to monitor periodic luciferase activity from cell cycle-regulated promoters in synchronous cells. Reporters were driven by a minimal human E2F1 promoter with peak expression in ...G1/S or a basal promoter with six Forkhead DNA-binding sites with peak expression at G2/M. After cell cycle synchronization, luciferase activity was measured in live cells at 10-min intervals across three to four synchronous cell cycles, allowing unprecedented resolution of cell cycle-regulated gene expression. We used this assay to screen Forkhead transcription factors for control of periodic gene expression. We confirmed a role for FOXM1 and identified two novel cell cycle regulators, FOXJ3 and FOXK1. Knockdown of FOXJ3 and FOXK1 eliminated cell cycle-dependent oscillations and resulted in decreased cell proliferation rates. Analysis of genes regulated by FOXJ3 and FOXK1 showed that FOXJ3 may regulate a network of zinc finger proteins and that FOXK1 binds to the promoter and regulates DHFR, TYMS, GSDMD, and the E2F binding partner TFDP1. Chromatin immunoprecipitation followed by high-throughput sequencing analysis identified 4329 genomic loci bound by FOXK1, 83% of which contained a FOXK1-binding motif. We verified that a subset of these loci are activated by wild-type FOXK1 but not by a FOXK1 (H355A) DNA-binding mutant.
We present high spatial and spectral resolution observations of 16 Galactic compact and ultracompact H ii regions in the Ne ii 12.8 mum fine-structure line. The small thermal width of the neon line ...and the high dynamic range of the maps provide an unprecedented view of the kinematics of compact and ultracompact H ii regions. These observations solidify an emerging picture of the structure of ultracompact H ii regions suggested in our earlier studies of G29.96-0.02 and Mon R2 IRS 1; systematic surface flows, rather than turbulence or bulk expansion, dominate the gas motions in the H ii regions. The observations show that almost all of the sources have significant (5-20 km s super(-1)) velocity gradients and that most of the sources are limb-brightened. In many cases, the velocity pattern implies tangential flow along a dense shell of ionized gas. None of the observed sources clearly fits into the categories of filled expanding spheres, expanding shells, filled blister flows, or cometary H ii regions formed by rapidly moving stars. Instead, the kinematics and morphologies of most of the sources lead to a picture of H ii regions confined to the edges of cavities created by stellar wind ram pressure and flowing along the cavity surfaces. In sources where the radio continuum and Ne ii morphologies agree, the majority of the ionic emission is blueshifted relative to nearby molecular gas. This is consistent with sources lying on the near side of their natal clouds being less affected by extinction and with gas motions being predominantly outward, as is expected for pressure-driven flows.
A pilot program was initiated to identify genes from the American oyster, Crassostrea virginica, that are potentially involved in the stress response for use as bioindicators of exposure to ...environmental pollutants and to toxic and infectious agents. A PCR-based method was used to construct cDNA libraries from pooled embryos and the hemocytes of a single individual. A total of 998 randomly selected clones (expressed sequence tags, ESTs) were sequenced. Approximately 40% of the ESTs are novel sequences. Several potential biomarkers identified include an antimicrobial peptide, recognition molecules (lectin receptors), proteinases and proteinase inhibitors, and a novel metallothionein. Diversity analysis shows that 363 and 286 unique genes were identified from the hemocyte and embryo libraries, respectively, indicating that full-scale EST collection is a valuable approach for the discovery of new genes of potential significance in the molluscan stress response.
Measurements of the vertical and latitudinal variations of temperature and C2H2 and C2H6 abundances in the stratosphere of Saturn can be used as stringent constraints on seasonal climate models, ...photochemical models, and dynamics. The summertime photochemical loss timescale for C2H6 in Saturn's middle and lower stratosphere (40-10,000 years, depending on altitude and latitude) is much greater than the atmospheric transport timescale; ethane observations may therefore be used to trace stratospheric dynamics. The shorter chemical lifetime for C2H2 (1-7 years depending on altitude and latitude) makes the acetylene abundance less sensitive to transport effects and more sensitive to insolation and seasonal effects. To obtain information on the temperature and hydrocarbon abundance distributions in Saturn's stratosphere, high-resolution spectral observations were obtained on September 13-14, 2002 UT at NASA's IRTF using the mid-infrared TEXES grating spectrograph. At the time of the observations, Saturn was at a LSasymptotic to270', corresponding to Saturn's southern summer solstice. The observed spectra exhibit a strong increase in the strength of methane emission at 1230 cm-1 with increasing southern latitude. Line-by-line radiative transfer calculations indicate that a temperature increase in the stratosphere of asymptotic to10 K from the equator to the south pole between 10 and 0.01 mbar is implied. Similar observations of acetylene and ethane were also recorded. We find the 1.16 mbar mixing ratio of C2H2 at -1' and -83' planetocentric latitude to be image and image, respectively. The C2H2 mixing ratio at 0.12 mbar is found to be image at -1' planetocentric latitude and image at -83' planetocentric latitude. The 2.3 mbar mixing ratio of C2H6 inferred from the data is image and image at -1' and -83' planetocentric latitude, respectively. Further observations, creating a time baseline, will be required to completely resolve the question of how much the latitudinal variations of C2H2 and C2H6 are affected by seasonal forcing and/or stratospheric circulation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Introduction
Cerebral air embolism is a rare cause of stroke, but may occur in patients undergoing invasive cardiac and pulmonary procedures, as well as in divers suffering pulmonary barotrauma from ...rapid ascent. Cerebral air embolism during air travel, however, is particularly rare.
Case
We present a case of a previously healthy gentleman who presented with an acute stroke after a commercial flight; the stroke was initially felt to be of cardioembolic origin. A large intrapulmonary cyst was noted on his imaging studies, but thought to be an incidental finding. During a return flight, he suffered another stroke and was found to have cerebral air emboli.
Conclusion
This case suggests the importance of considering cerebral air embolism in patients with stroke associated with air travel; restricting air travel in patients with intrapulmonary cysts may be prudent.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
29.
The first detection of propane on Saturn Greathouse, Thomas K.; Lacy, John H.; Bézard, Bruno ...
Icarus (New York, N.Y. 1962),
03/2006, Volume:
181, Issue:
1
Journal Article
Peer reviewed
We report the first detection of propane, C
3H
8, in Saturn's stratosphere. Observations taken on September 8, 2002 UT at NASA's IRTF using TEXES, show multiple emission lines due to the 748 cm
−1
ν
...21
band of C
3H
8. Using a line-by-line radiative transfer code, we are able to fit the data by scaling the propane vertical mixing ratio profile from the photochemical model of Moses et al. 2000. Icarus 143, 244–298. Multiplicative factors of 0.7 and 0.65 are required to fit the −20° and −80° planetocentric latitude spectra. The resultant profiles are characterized by a 5 mbar mixing ratio of
2.7
±
0.8
×
10
−8
at −20° and
2.5
−0.8
+1.7
×
10
−8
at −80° latitude. These results suggest that the time scale for meridional circulation lies between the net photochemical lifetimes of C
2H
2 and C
3H
8,
≈
30
–
600
years.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract
Physical processes that redistribute or remove angular momentum from protoplanetary disks can drive mass accretion onto the star and affect the outcome of planet formation. Despite ...ubiquitous evidence that protoplanetary disks are engaged in accretion, the process(es) responsible remain unclear. Here we present evidence for redshifted molecular absorption in the spectrum of a Class I source that indicates rapid inflow at the disk surface. High-resolution mid-infrared spectroscopy of GV Tau N reveals a rich absorption spectrum of individual lines of C
2
H
2
, HCN, NH
3
, and H
2
O. From the properties of the molecular absorption, we can infer that it carries a significant accretion rate
∼ 10
−8
–10
−7
M
⊙
yr
−1
, comparable to the stellar accretion rates of active T Tauri stars. Thus, we may be observing disk accretion in action. The results may provide observational evidence for supersonic “surface accretion flows,” which have been found in MHD simulations of magnetized disks. The observed spectra also represent the first detection of NH
3
in the planet formation region of a protoplanetary disk. With NH
3
only comparable in abundance to HCN, it cannot be a major missing reservoir of nitrogen. If, as expected, the dominant nitrogen reservoir in inner disks is instead N
2
, its high volatility would make it difficult to incorporate into forming planets, which may help to explain the low nitrogen content of the bulk Earth.
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![[Ne II] Observations of Gas...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0067-0049/small "[Ne II] Observations of Gas Motions in Compact and Ultracompact H II Regions")
