4,883 research outputs found
Digital multiplexed mRNA analysis of functionally important genes in single human oocytes and correlation of changes in transcript levels with oocyte protein expression
Objective
To investigate functionally important transcripts in single human oocytes with the use of NanoString technology and determine whether observed differences are biologically meaningful.
Design
Analysis of human oocytes with the use of NanoString and immunoblotting.
Setting
University-affiliated reproductive medicine unit.
Patients
Women undergoing in vitro fertilization.
Intervention
Human oocytes were analyzed with the use of NanoString or immunoblotting.
Main Outcome Measures
The abundance of transcripts for ten functionally important genes—AURKA, AURKC, BUB1, BUB1B (encoding BubR1), CDK1, CHEK1, FYN, MOS, MAP2K1, and WEE2—and six functionally dispensable genes were analyzed with the use of NanoString. BubR1 protein levels in oocytes from younger and older women were compared with the use of immunoblotting.
Result(s)
All ten functional genes but none of the six dispensable genes were detectable with the use of NanoString in single oocytes. There was 3- to 5-fold variation in BUB1, BUB1B, and CDK1 transcript abundance among individual oocytes from a single patient. Transcripts for these three genes—all players within the spindle assembly checkpoint surveillance mechanism for preventing aneuploidy—were reduced in the same oocyte from an older patient. Mean BUB1B transcripts were reduced by 1.5-fold with aging and associated with marked reductions in BubR1 protein levels.
Conclusion(s)
The abundance of functionally important transcripts exhibit marked oocyte-to-oocyte heterogeneity to a degree that is sufficient to affect protein expression. Observed variations in transcript abundance are therefore likely to be biologically meaningful, especially if multiple genes within the same pathway are simultaneously affected
On the Complexity of Quantum ACC
For any , let \MOD_q be a quantum gate that determines if the number
of 1's in the input is divisible by . We show that for any ,
\MOD_q is equivalent to \MOD_t (up to constant depth). Based on the case
, Moore \cite{moore99} has shown that quantum analogs of AC,
ACC, and ACC, denoted QAC, QACC, QACC respectively,
define the same class of operators, leaving as an open question. Our
result resolves this question, proving that QAC QACC
QACC for all . We also develop techniques for proving upper bounds for QACC
in terms of related language classes. We define classes of languages EQACC,
NQACC and BQACC_{\rats}. We define a notion -planar QACC operators and
show the appropriately restricted versions of EQACC and NQACC are contained in
P/poly. We also define a notion of -gate restricted QACC operators and
show the appropriately restricted versions of EQACC and NQACC are contained in
TC. To do this last proof, we show that TC can perform iterated
addition and multiplication in certain field extensions. We also introduce the
notion of a polynomial-size tensor graph and show that families of such graphs
can encode the amplitudes resulting from apply an arbitrary QACC operator to an
initial state.Comment: 22 pages, 4 figures This version will appear in the July 2000
Computational Complexity conference. Section 4 has been significantly revised
and many typos correcte
The resilience of the refugee: how Kindertransport memoirs complicate understandings of “resilience”
MECHANICAL DAMPING SYSTEM FOR STRUCTURES
A mechanical damping system for a structure is provided. The mechanical damping system comprises a tubular impact frame secured to the structure. A support frame is secured to the structure with the support frame spaced from the impact frame. An elongated member is provided having a first end and a second end. The first end is secured within the support frame and the second end is free from connection and extends into the impact frame. At least one impact mass is secured to the second end of the elongated member, the impact mass movable within and contactable with the impact frame
Relation of the Accountancy Instructor to the Development of Professional Standards in the Practice of Accountancy
Teachers' experiences of their third year in post : technical report on Phase V of the Becoming a Teacher survey
Stability Analysis of Negative Resistance-Based Source Combining Power Amplifiers
An investigation into the stability of negative resistance-based source combining power amplifiers is conducted in this thesis. Two different negative resistance-based source combining topologies, a series and parallel version, are considered. Stability is analyzed using a simple and intuitive broadband approach that leverages linear circuit stability criterion and two different linearization methods: linearization around the operating point and in the frequency domain. Using this strategy, it is shown that conditions for self-sustained oscillation exist for both topologies. For the series combining topology, self-sustained oscillation is prevented by means of injection locking
Recent Langley helicopter acoustics contributions
The helicopter acoustics program at NASA Langley has included technology for elements of noise control ranging from sources of noise to receivers of noise. The scope of Langley contributions for about the last decade is discussed. Specifically, the resolution of two certification noise quantification issues by subjective acoustics research, the development status of the helicopter system noise prediction program ROTONET are reviewed and the highlights from research on blade rotational, broadband, and blade vortex interaction noise sources are presented. Finally, research contributions on helicopter cabin (or interior) noise control are presented. A bibliography of publications from the Langley helicopter acoustics program for the past 10 years is included
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