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Trypanosome mRNAs share a common 5' spliced leader sequence.
A 5'-terminal leader sequence of 35 nucleotides was found to be present on multiple trypanosome RNAs. Based on its representation in cDNA libraries, we estimate that many, if not all, trypanosome mRNAs contain this leader. This same leader was originally identified on mRNAs encoding the molecules responsible for antigenic variation, variant surface glycoproteins. Studies of selected cDNAs containing this leader sequence revealed that leader-containing transcripts can be stage-specific, stage-regulated, or constitutive. They can be abundant or rare, and transcribed from single or multigene families. No linkage between the genomic leader sequences and the structural gene exons was observed. Possible mechanisms by which the leader sequences are added to trypanosome mRNAs are discussed
Comment on Bramwell et al, "Universal Fluctuations in Correlated Systems"
This is a comment on "Universal Fluctuations in Correlated Systems", by
Bramwell et al, Phys. Rev. Lett., 84, 3744 (2000.Comment: To appear in Phys. Rev. Let
What can we infer about the underlying physics from burst distributions observed in an RMHD simulation ?
We determine that the sizes of bursts in mean-square current density in a
reduced magnetohydrodynamic (RMHD)simulation follow power-law probability
density function (PDF). The PDFs for burst durations and waiting time between
bursts are clearly not exponential and could also be power-law. This suffices
to distinguish their behaviour from the original Bak et al. sandpile model
which had exponential waiting time PDFs. However, it is not sufficient to
distinguish between turbulence, some other SOC-like models, and other red noise
sources.Comment: In press, Planetary and Space Science. Proceedings of a session at
European Geophysical Society General Assembly, Nice, 200
Optimal Moments for the Analysis of Peculiar Velocity Surveys
We present a new method for the analysis of peculiar velocity surveys which
removes contributions to velocities from small scale, nonlinear velocity modes
while retaining information about large scale motions. Our method utilizes
Karhunen--Lo\`eve methods of data compression to construct a set of moments out
of the velocities which are minimally sensitive to small scale power. The set
of moments are then used in a likelihood analysis. We develop criteria for the
selection of moments, as well as a statistic to quantify the overall
sensitivity of a set of moments to small scale power. Although we discuss our
method in the context of peculiar velocity surveys, it may also prove useful in
other situations where data filtering is required.Comment: 25 Pages, 3 figures. Submitted to Ap
Power law burst and inter-burst interval distributions in the solar wind: turbulence or dissipative SOC ?
We calculate for the first time the probability density functions (PDFs) P of
burst energy e, duration T and inter-burst interval tau for a known turbulent
system in nature. Bursts in the earth-sun component of the Poynting flux at 1
AU in the solar wind were measured using the MFI and SWE experiments on the
NASA WIND spacecraft. We find P(e) and P(T) to be power laws, consistent with
self-organised criticality (SOC). We find also a power law form for P(tau) that
distinguishes this turbulent cascade from the exponential P(tau) of ideal SOC,
but not from some other SOC-like sandpile models. We discuss the implications
for the relation between SOC and turbulence.Comment: 3 pages, 1 figure. Submitted to PRL on 25th February 2000. Revised
version re-submitted on 9th May 2000. Second revised version submitted Phys.
Rev. E on 26th June, 200
The Cannibal Cop: Why the Federal Courts Should Allow for a Free-Speech Defense in Conspiracy Cases
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Technology and the history-social science framework
California state history/social studies framework -- Image acquisition and digitization -- Interdisciplinary approach
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