13 research outputs found
A Low-Complexity Detector for Memoryless Polarization-Multiplexed Fiber-Optical Channels
A low-complexity detector is introduced for polarization-multiplexed M-ary
phase shift keying modulation in a fiber-optical channel impaired by nonlinear
phase noise, generalizing a previous result by Lau and Kahn for
single-polarization signals. The proposed detector uses phase compensation
based on both received signal amplitudes in conjunction with simple
straight-line rather than four-dimensional maximum-likelihood decision
boundaries.Comment: accepted for publication in IEEE Comm. Let
Increased sinusoidal flow is not the primary stimulus to liver regeneration
Background: Hemodynamic changes in the liver remnant following partial hepatectomy (PHx) have been suggested to be a primary stimulus in triggering liver regeneration. We hypothesized that it is the increased
sinusoidal flow per se and hence the shear-stress stimulus on the endothelial surface within the liver remnant which is the main stimulus to regeneration. In order to test this hypothesis we wanted to increase the sinusoidal flow without performing a concomitant liver resection. Accordingly, we constructed an aorto-portal shunt to the
left portal vein branch creating a standardized four-fold increase in flow to segments II, III and IV. The impact of
this manipulation was studied in both an acute model (6 animals, 9 hours) using a global porcine cDNA microarray
chip and in a chronic model observing weight and histological changes (7 animals, 3 weeks).
Results: Gene expression profiling from the shunted segments does not suggest that increased sinusoidal flow per se results in activation of genes promoting mitosis. Hyperperfusion over three weeks results in the whole liver gaining a supranormal weight of 3.9% of the total body weight (versus the normal 2.5%). Contrary to our hypothesis, the weight gain was observed on the non-shunted side without an increase in sinusoidal flow.
Conclusions: An isolated increase in sinusoidal flow does not have the same genetic, microscopic or macroscopic
impact on the liver as that seen in the liver remnant after partial hepatectomy, indicating that increased sinusoidal
flow may not be a sufficient stimulus in itself for the initiation of liver regeneration
Is the high 15N natural abundance of trees in N-loaded forests caused by an internal ecosystem N isotope redistribution or a change in the ecosystem N isotope mass balance?
Serum levels of perfluorinated compounds and sperm Y:X chromosome ratio in two European populations and in Inuit from Greenland
Malleolus externus plasty for joint reconstruction in fibular aplasia: Preliminary report of a new technique
A Low-Complexity Detector for Memoryless Polarization-Multiplexed Fiber-Optical Channels
Social networks and marketing cooperation in entrepreneurial clusters: An international comparative study
Regional clusters, Social networks, Marketing cooperation, Salmon industry, Chile, Scotland,