Impact of dietary changes on hepatic homocysteine metabolism in young broilers

Information regarding the impact of sulfur amino acids (SAA) on hepatic homocysteine (Hcy) flux through the various metabolic pathways competing for Hcy in young broilers is lacking. An experiment was conducted to evaluate the impact of varying levels of dietary methionine (Met), choline, and betaine on hepatic Hcy flux in young broiler chickens. A standard starter basal diet was fed to chicks until 8 d of age; 12 experimental diets were given from 8-22 d. The experimental basal diet contained deficient levels of Met and cysteine (Cys); supplemental Met (0, 0.08, 0.16, and 0.24%) was added to the basal diet in combination with isomethyl levels of choline (0 or 0.25%) or betaine (0 or 0.28%). The 12 dietary treatments were replicated with three pens containing five chicks each (15 birds per treatment). Weight gain and feed efficiency increased (P \u3c 0.05) with Met addition and were maximized with the addition of 0.16% digestible Met. No significant interactions (P \u3e 0.05) with choline or betaine addition were noted for weight gain, feed intake, or feed efficiency, but numerical improvements for these variables were observed with the addition of choline and betaine to the Met-deficient basal diet. Analysis of liver tissue indicated that folate-dependent remethylation of Hcy predominated over betaine-dependent remethylation. Further, folate-dependent remethylation of Hcy appeared to be impacted by dietary choline and betaine levels, whereas betaine-dependent remethylation appeared to be more impacted by dietary SAA levels

Object Imaging Accomplished with an Integrated Circuit Robotic Tactile Sensor Incorporating a Piezoelectric Polyvinylidene Fluoride Thin Film

The purpose of this research effort was to investigate the performance of a piezoelectric tactile sensor design and appropriately refine it. The sensor was fabricated from an 8 x 8 electrode array MOS integrated circuit. Each taxel in the array was 400 microns x 400 microns. A 6 mm x 6 mm piece of piezoelectric polyvinylidene fluoride was adhered to the electrode array using a urethane dielectric adhesive to form the active sensing area of the sensor. An amplifier was investigated to enhance the range of the tactile sensor\u27s output signal. The amplifier is a high input\u27 impedance differential amplifier with a linear range from 1 to 17 V. The unique feature of the differential amplifier was that it used a power supply of only 12 V. The spatial resolution of the sensor is 0.7 mm. The lower force limit of the sensor is 1 g while the upper limit, limited by a previous amplifier design with a range from 2.5 to 7 V, is 130 g. The dynamic range of the sensor is 130:1. The sensor\u27s force sensitivity is 7.35 g. The pyroelectric bandwidth of the sensor is 0.083 Hz, and the temperature sensitivity of the sensor is 0.39 degrees Celsius

Realization of a superconducting atom chip

We have trapped rubidium atoms in the magnetic field produced by a superconducting atom chip operated at liquid Helium temperatures. Up to $8.2\cdot 10^5$ atoms are held in a Ioffe-Pritchard trap at a distance of 440 $\mu$m from the chip surface, with a temperature of 40 $\mu$K. The trap lifetime reaches 115 s at low atomic densities. These results open the way to the exploration of atom--surface interactions and coherent atomic transport in a superconducting environment, whose properties are radically different from normal metals at room temperature.Comment: Submitted to Phys. Rev. Let

High-resolution spatial mapping of a superconducting NbN wire using single-electron detection

Superconducting NbN wires have recently received attention as detectors for visible and infrared photons. We present experiments in which we use a NbN wire for high-efficiency (40 %) detection of single electrons with keV energy. We use the beam of a scanning electron microscope as a focussed, stable, and calibrated electron source. Scanning the beam over the surface of the wire provides a map of the detection efficiency. This map shows features as small as 150 nm, revealing wire inhomogeneities. The intrinsic resolution of this mapping method, superior to optical methods, provides the basis of a characterization tool relevant for photon detectors.Comment: 2009 IEEE Toronto International Conference, Science and Technology for Humanity (TIC-STH