2,633 research outputs found
Transcription through chromatin - link to diseases and therapeutics
The expression of chromosomal genes is regulated by posttranslational modification of both histone and nonhistone chromatin proteins and ATP-dependent remodeling of chromatin. Dysfunction of the modification and remodeling machineries can lead to several diseases, which include cancer, cardiac hypertrophy, and asthma. Many genetic diseases can also lead to malfunction of the machinery. The enzymes responsible for chromatin organization are the new targets for therapeutics. Inhibitors and activators of histone acetyltransferases and inhibitors of histone deacetylases may serve as new generation drugs
Quantifying signals with power-law correlations: A comparative study of detrended fluctuation analysis and detrended moving average techniques
Detrended fluctuation analysis (DFA) and detrended moving average (DMA) are
two scaling analysis methods designed to quantify correlations in noisy
non-stationary signals. We systematically study the performance of different
variants of the DMA method when applied to artificially generated long-range
power-law correlated signals with an {\it a-priori} known scaling exponent
and compare them with the DFA method. We find that the scaling
results obtained from different variants of the DMA method strongly depend on
the type of the moving average filter. Further, we investigate the optimal
scaling regime where the DFA and DMA methods accurately quantify the scaling
exponent , and how this regime depends on the correlations in the
signal. Finally, we develop a three-dimensional representation to determine how
the stability of the scaling curves obtained from the DFA and DMA methods
depends on the scale of analysis, the order of detrending, and the order of the
moving average we use, as well as on the type of correlations in the signal.Comment: 15 pages, 16 figure
Three flavors of extremal Betti tables
We discuss extremal Betti tables of resolutions in three different contexts.
We begin over the graded polynomial ring, where extremal Betti tables
correspond to pure resolutions. We then contrast this behavior with that of
extremal Betti tables over regular local rings and over a bigraded ring.Comment: 20 page
Robot-assisted Optical Ultrasound Scanning
Optical ultrasound, where ultrasound is both generated and received using light, can be integrated in very small diameter instruments making it ideally suited to minimally invasive interventions. One-dimensional information can be obtained using a single pair of optical fibres comprising of a source and detector but this can be difficult to interpret clinically. In this paper, we present a robotic-assisted scanning solution where a concentric tube robot manipulates an optical ultrasound probe along a consistent trajectory. A torque coil is utilised as a buffer between the curved nitinol tube and the probe to prevent torsion on the probe and maintain the axial orientation of the probe while the tube is rotating. The design and control of the scanning mechanism are presented along with the integration of the mechanism with a fibre-based imaging probe. Trajectory repeatability is assessed using electromagnetic tracking and a technique to calibrate the transformation between imaging and robot coordinates using a known model is presented. Finally, we show example images of 3D printed phantoms generated by collecting multiple OpUS A-scans within the same 3D scene to illustrate how robot-assisted scanning can expand the field of view
Chaotic to ordered state transition of cathode-sheath instabilities in DC glow discharge plasmas
Transition from chaotic to ordered state has been observed during the initial
stage of a discharge in a cylindrical dc glow discharge plasma. Initially it
shows a chaotic behavior but increasing the discharge voltage changes the
characteristics of the discharge glow and shows a period substraction of order
7 period 5 period 3 period 1 period i.e. the system goes to
single mode through odd cycle subtraction. On further increasing the discharge
voltage, the system goes through period doubling, like 1 period 2 period
4 period. On further increasing the voltage, the system goes to stable
state without having any oscillations.Comment: chathode-sheath, instabilities, chaos, period-subtraction,
bifurcation, dc-discharg
Three years of follow-up bone marrow-augmented organ transplant recipients: The impact on donor-specific immune modulation
Older adults place lower value on choice relative to young adults
Choice is highly valued in modern society, from the supermarket to the hospital; however, it remains unknown
whether older and younger adults place the same value on increased choice. The current investigation tested
whether 53 older ( M age = 75.44 years) versus 53 younger adults ( M age = 19.58 years) placed lower value on increased
choice by examining the monetary amounts they were willing to pay for increased prescription drug coverage
options — important given the recently implemented Medicare prescription drug program. Results indicate
that older adults placed lower value on increasing choice sets relative to younger adults, who placed progressively
higher value on increasingly larger choice sets. These results are discussed regarding their implications for theory
and policy
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