672 research outputs found
Electronic filters, repeated signal charge conversion apparatus, hearing aids and methods
An electronic filter for filtering an electrical signal. Signal processing circuitry therein includes a logarithmic filter having a series of filter stages with inputs and outputs in cascade and respective circuits associated with the filter stages for storing electrical representations of filter parameters. The filter stages include circuits for respectively adding the electrical representations of the filter parameters to the electrical signal to be filtered thereby producing a set of filter sum signals. At least one of the filter stages includes circuitry for producing a filter signal in substantially logarithmic form at its output by combining a filter sum signal for that filter stage with a signal from an output of another filter stage. The signal processing circuitry produces an intermediate output signal, and a multiplexer connected to the signal processing circuit multiplexes the intermediate output signal with the electrical signal to be filtered so that the logarithmic filter operates as both a logarithmic prefilter and a logarithmic postfilter. Other electronic filters, signal conversion apparatus, electroacoustic systems, hearing aids and methods are also disclosed
Electronic filters, signal conversion apparatus, hearing aids and methods
An electronic filter for filtering an electrical signal. Signal processing circuitry therein includes a logarithmic filter having a series of filter stages with inputs and outputs in cascade and respective circuits as GOVERNMENT SUPPORT This invention was made with U.S. Government support under Veterans Administration Contract VA KV 674P857 and National Aeronautics and Space Administration (NASA) Research Grant No. NAG10-0040. The U.S. Government has certain rights in this invention
Evaluation of Dried Distillers Grains with Solubles as a Feedstuff for Heifers in the Last Trimester fo Gestation
Ninety-six crossbred heifers were used in an experiment to evaluate the effect of dried distillers grains plus solubles (DDGS), fed in the last trimester of gestation, on heifer performance and reproduction. Animals were blocked by previous heifer development strategy (Antelope Research Station range developed = ANT 1; Antelope Research Station dry lot developed = ANT 2; Cottonwood research station = CTW), stratified by expected calving date, body weight and body condition score, and randomly allotted to one of twelve pens. Each pen was randomly assigned to one of two treatments (6 pens/treatment; 4 pens per block). Treatments were 1) dried distillers grains and grass hay (DDGS) or 2) soybean hulls and grass hay (SBH). Treatments were applied during the last-trimester of gestation. Diets were developed utilizing the 1996 NRC computer model and designed to meet nutrient requirements at 240 days of gestation under thermo-neutral conditions. Treatment diets offered similar amounts of NEm each day based on assumptions of the energy content of SBH and DDGS (assumed SBH = 80% TDN and DDGS = 88% TDN). Heifers fed the DDGS had a greater (P\u3c0.01) increase in body weight and a heavier (P=0.03) final weight compared to the heifers fed SBH. Body condition score was not affected by diet. Calf birth weights were similar for both the DDGS and SBH treatments with a mean birth weight of 87.0 lbs ± 5.3lb and 85.0 lbs ± 3.4lbs respectively. Treatment had no effect on calving ease or calf vigor scores. These results suggest that in limit fed situations DDGS and SBH can both be supplemented at 40 percent of the diet with no negative affects on cow performance, calf birth weight, or calving difficulty
Evaluation of Reproduction and Blood Metabolites in Beef Heifers Fed Dried Distillers Grains Plus Solubles and Soybean Hulls During Late Gestation
Dried distillers grains plus solubles (DDGS) contain a significant amount of both undegradable intake protein and fat, which have both been shown to increase reproductive performance when supplemented to heifers during gestation. The mechanisms leading to enhanced reproduction when fat or UIP are supplemented have not been fully defined. The objective of this experiment was to evaluate DDGS or soybean hulls (SBH) fed during the last trimester of gestation on circulating concentrations of growth hormone (GH) and insulin-like growth factor-I (IGF-I) and reproductive efficiency. Ninety-five crossbred heifers were grouped by expected calving date, BW, BCS, and randomly assigned to DDGS or SBH (n = 6 pens per treatment). Diets were formulated to be isoenergetic and meet the nutrient requirements at d 240 of gestation. Diets were limit fed during the last trimester of gestation until parturition. Blood samples were collected prior to calving and once per week for 4 weeks following calving . Treatment had no effect on circulating concentrations of GH or IGF-I. Time influenced both GH and IGF-I. Circulating concentrations of GH were elevated at calving and decreased by 4 d after calving. Circulating concentrations of IGF-I rose for the first 2 d following calving and then decreased through d 6. At the start of the breeding season there was no difference between DDGS and SBH in the percent of heifers that had initiated estrous cycles (74% and 70%, respectively). There was a tendency for more DDGS treated heifers to become pregnant during a 64 d natural service breeding season compared to SBH treated heifers (92% vs 80%, respectively). There was no difference in the distribution of pregnancies throughout the breeding season between treatments. In summary, DDGS and SBH fed during the last trimester of pregnancy to heifers resulted in similar patterns of circulating concentrations of GH and IGF, but DDGS treated heifers tended to have improved pregnancy rates during a defined breeding season
Observations of Arp 220 using Herschel-SPIRE: An Unprecedented View of the Molecular Gas in an Extreme Star Formation Environment
We present Herschel SPIRE-FTS observations of Arp~220, a nearby ULIRG. The
FTS continuously covers 190 -- 670 microns, providing a good measurement of the
continuum and detection of several molecular and atomic species. We detect
luminous CO (J = 4-3 to 13-12) and water ladders with comparable total
luminosity; very high-J HCN absorption; OH+, H2O+, and HF in absorption; and CI
and NII. Modeling of the continuum yields warm dust, with T = 66 K, and an
unusually large optical depth of ~5 at 100 microns. Non-LTE modeling of the CO
shows two temperature components: cold molecular gas at T ~ 50 K and warm
molecular gas at T ~1350 K. The mass of the warm gas is 10% of the cold gas,
but dominates the luminosity of the CO ladder. The temperature of the warm gas
is in excellent agreement with H2 rotational lines. At 1350 K, H2 dominates the
cooling (~20 L_sun/M_sun) in the ISM compared to CO (~0.4 L_sun/M_sun). We
found that only a non-ionizing source such as the mechanical energy from
supernovae and stellar winds can excite the warm gas and satisfy the energy
budget of ~20 L_sun/M_sun. We detect a massive molecular outflow in Arp 220
from the analysis of strong P-Cygni line profiles observed in OH+, H2O+, and
H2O. The outflow has a mass > 10^{7} M_sun and is bound to the nuclei with
velocity < 250 km/s. The large column densities observed for these molecular
ions strongly favor the existence of an X-ray luminous AGN (10^{44} ergs/s) in
Arp 220.Comment: Accepted in ApJ on September 1, 201
Vibrational renormalisation of the electronic band gap in hexagonal and cubic ice.
Electron-phonon coupling in hexagonal and cubic water ice is studied using first-principles quantum mechanical methods. We consider 29 distinct hexagonal and cubic ice proton-orderings with up to 192 molecules in the simulation cell to account for proton-disorder. We find quantum zero-point vibrational corrections to the minimum electronic band gaps ranging from -1.5 to -1.7 eV, which leads to improved agreement between calculated and experimental band gaps. Anharmonic nuclear vibrations play a negligible role in determining the gaps. Deuterated ice has a smaller band-gap correction at zero-temperature of -1.2 to -1.4 eV. Vibrations reduce the differences between the electronic band gaps of different proton-orderings from around 0.17 eV to less than 0.05 eV, so that the electronic band gaps of hexagonal and cubic ice are almost independent of the proton-ordering when quantum nuclear vibrations are taken into account. The comparatively small reduction in the band gap over the temperature range 0 - 240 K of around 0.1 eV does not depend on the proton ordering, or whether the ice is protiated or deuterated, or hexagonal, or cubic. We explain this in terms of the atomistic origin of the strong electron-phonon coupling in ice
The high resolution array (HiRA) for rare isotope beam experiments
Abstract The High Resolution Array (HiRA) is a large solid-angle array of silicon strip-detectors that has been developed for use in a variety of nuclear structure, nuclear astrophysics and nuclear reaction experiments with short lived beta-unstable beams. It consists of 20 identical telescopes each composed of a thin ( 65 μ m ) single-sided silicon strip-detector, a thick (1.5 mm) double-sided silicon strip-detector, and four CsI(Tl) crystals read out by photodiodes. The array can be easily configured to meet the detection requirements of specific experiments. To process the signals from the 1920 strips in the array, an Application Specific Integrated Circuit (ASIC) was developed. The design and performance characteristics of HiRA are described
A Screen against Leishmania Intracellular Amastigotes: Comparison to a Promastigote Screen and Identification of a Host Cell-Specific Hit
The ability to screen compounds in a high-throughput manner is essential in the process of small molecule drug discovery. Critical to the success of screening strategies is the proper design of the assay, often implying a compromise between ease/speed and a biologically relevant setting. Leishmaniasis is a major neglected disease with limited therapeutic options. In order to streamline efforts for the design of productive drug screens against Leishmania, we compared the efficiency of two screening methods, one targeting the free living and easily cultured promastigote (insect–infective) stage, the other targeting the clinically relevant but more difficult to culture intra-macrophage amastigote (mammal-infective) stage. Screening of a 909-member library of bioactive compounds against Leishmania donovani revealed 59 hits in the promastigote primary screen and 27 in the intracellular amastigote screen, with 26 hits shared by both screens. This suggested that screening against the promastigote stage, although more suitable for automation, fails to identify all active compounds and leads to numerous false positive hits. Of particular interest was the identification of one compound specific to the infective amastigote stage of the parasite. This compound affects intracellular but not axenic parasites, suggesting a host cell-dependent mechanism of action, opening new avenues for anti-leishmanial chemotherapy
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