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Wild habitats adjoining farmland are potentially valuable sources of natural enemies, but also of pests. Here we tested the utility of birds as ‘sampling devices’, to identify the diversity of prey available to predators and particularly to screen for pests and natural enemies using natural ecosystems as refugia. Here we used PCR to amplify prey DNA from three sympatric songbirds foraging on small invertebrates in Phragmites reedbed ecosystems, namely the Reed Warbler (Acrocephalus scirpaceus), Sedge Warbler (Acrocephalus schoenobaenus) and Cetti's Warbler (Cettia cetti). A recently described general invertebrate primer pair was used for the first time to analyse diets. Amplicons were cloned and sequenced, then identified by reference to the Barcoding of Life Database and to our own sequences obtained from fresh invertebrates. Forty-five distinct prey DNA sequences were obtained from 11 faecal samples, of which 39 could be identified to species or genus. Targeting three warbler species ensured that species-specific differences in prey choice broadened the range of prey taken. Amongst the prey found in reedbeds were major pests (including the tomato moth Lacanobia oleracea) as well as many potentially valuable natural enemies including aphidophagous hoverflies and braconid wasps. Given the mobility of birds, this approach provides a practical way of sampling a whole habitat at once, providing growers with information on possible invasion by locally resident pests and the colonization potential of natural enemies from local natural habitats.
The potential of nanocrystalline diamond films (NDFs) for biological applications has been addressed by a variety of recent researchers. In the present work, we consider the topographical evolution of NDFs fabricated by microwave plasma assisted chemical-vapor-deposition (MPCVD) and its influence on osteoblast (bone forming cells) functions. One group of NDFs formed in this study were grown with 0.67% methane, 5%∼20% hydrogen and argon. The other group of NDFs composed of nano diamond and amorphous carbon was created with indirect exposure to plasma with 0.67% methane, 20% hydrogen and argon. Scanning electron microscope (SEM) images revealed that the nano diamond grains in the first group of NDFs evolved from round shapes into faceted and successively cubic shapes as hydrogen increased, whereas the second group of NDFs consisted of nano platelet grains. Atomic force microscopy (AFM) analysis confirmed this evolution as well as the variation of surface roughness. Cell results demonstrated that osteoblast adhesion and proliferation on NDFs varied dramatically depending on the different topographical features of the films. Specifically, results showed that NDFs with grain size less than 100 nm could be coated on the stem of a hip implant to promote cell adhesion. In contrast, NDFs with grain size greater than 200 nm or NDF with nano platelet grains may be optimal for the inside of acetabular articulation where cell adhesion is not preferred but wear-resistance is important. Further observation by contact angle measurement suggested that the differences in cellular adhesion and proliferation were related to the wettability associated to the topographical features of NDFs surfaces.
Spring wheats, Triticum aestivum L., previously identified as being lightly infested by eggs or larvae of wheat midge, Sitodiplosis mosellana (Géhin), were tested to determine if reduced infestation was the result of oviposition deterrence. Oviposition deterrence was measured as the number of eggs deposited on a wheat line relative to that on a check. Egg densities on some of these lines were 10% or less compared with the susceptible commercial cultivar 'Roblin' in choice tests and 20% or less in no-choice tests in the laboratory. These lines also deterred oviposition in the field, reducing egg densities by at least 50% in single-row and multi-row field plots. Other experimental lines showed levels of oviposition deterrence intermediate between the most deterrent lines and 'Roblin'. One of 12 commercial cultivars tested, 'AC Superb', also had low egg densities in the laboratory and in single-row field tests, but this possible oviposition deterrence was not consistently present in large plots or commercial fields. The most deterrent experimental lines showed a level of oviposition deterrence that would be agriculturally useful and desirable in combination with a previously described antibiotic resistance.
The dissolution behavior of the ceramic waste form (CWF) is being investigated to support its qualification for disposal in the proposed repository at Yucca Mountain. The CWF consists of sodalite and glass phases and has been consolidated either by hot isostatic pressuring (HIP) or by pressureless consolidation (PC). In this paper we compare the dissolution behavior of the two materials using in MCC-1 type tests at 90°C in a simulated silicate groundwater. The test solutions were periodically exchanged limit feedback effects. The solid surface area to volume ratio was 10 m-1. Five types of samples were tested: (1) HIP CWF, (2) binder glass vitrified by HIP, (3) PC CWF, (4) binder glass vitrified by PC, and HIP sodalite. Boron releases were used to monitor glass dissolution; these were similar in tests with HIP CWF, HIP glass, and PC CWF, but about 3X higher in tests with PC glass. At the end of the tests, the surfaces of the reacted materials were examined with scanning electron microscopy for signs of preferential dissolution. Differences in the dissolution behaviors of the materials are described and the implications of the test results regarding the performance of the CWF in the disposal system are discussed.
The Yucca Mountain site was designated in July 2002 as the United States' location for a geological repository for spent nuclear fuel and other high-level radioactive wastes. This site designation was a watershed event in the history of the project, enabling the U.S. Department of Energy to seek a license from the U.S. Nuclear Regulatory Commission to construct and operate a geologic repository. Summarized below are the history and technical basis for this site designation and some key anticipated future events. Many of the significant events to date have been framed by the Nuclear Waste Policy Act (and Amendments) and the requirements of the regulatory standard.
There is now considerable evidence of residual effects of both energy and protein supply during the dry period on performance in the next lactation. Changes in forage intake and eating/rumination behaviour in the dry period have been implicated in predisposition to metabolic disorders in the subsequent lactation. In particular, there is a close association between intake either side of calving (Grummer, 1995). The primary objective of this experiment was to identify the effects, and interactions, of pre-partum energy and protein supply on forage intake and particle size reduction (as an index of rumination behaviour) of cows in the dry period.
Fifty-two Holstein-Friesian cows, calving from September to November 1996, were used in a continuous design experiment The cows were dried off 8 weeks before their anticipated calving date and grazed on bare pasture for one week before training to use Calan gates (using grass silage only).
With great attention now being given to the wide band gap materials for electronic and optoelectronic device applications, there is interest in using ion implantation to introduce dopants into selected regions of devices. Work on ion implantation into SiC and the III-V nitrides is reviewed, new device concepts are given, and recent results are presented. These include SiC implantations at elevated temperatures, a GaN sample implanted with Si having an electron mobility after annealing of 106 cm2/V-s, and a novel GaN np junction diode created by implantation.
Shock-wave experiments on pure iron preheated to 1573 K were conducted in the 17–73 GPa range. The shock-wave equation of state of γ-iron at an initial temperature of 1573 K can be fit with us = 4.102 (0.015) km/s + 1.610(0.014) up with ρo = 7.413±0.012 Mg/m3 We obtain for γ-iron's bulk modulus and pressure derivative the values: 124.7±1.1 GPa and 5.44±0.06, respectively.
We present new data for sound velocities in the γ- and liquid-phases. In the γ-phase, to a first approximation, the longitudinal sound velocity is linear with respect to density: Vp = −3.13 (0.72) + 1.119(0.084) p(units for Vp and p are km/s and Mg/m3, respectively). Melting was observed in the highest pressure (about 70–73 GPa) experiments at a calculated shock temperature of 2775±160 K. This result is consistent with a previously calculated melting curve (for ε-iron) which is close to those measured by Boehler  and Saxena et al. . The liquid iron sound velocity data yields a Grüneisen parameter value of 1.63±0.28 at 9.37±0.02 Mg/m3 at 71.6 GPa. The quantity γρ is 15.2±2.6 Mg/m3, which agrees with the uncertainty bounds of Brown and McQueen  (13.3–19.6 Mg/m3). Based on upward pressure and temperature extrapolation of the melting curve of γ-iron, the estimated inner core-outer core boundary temperature is 5500±400 K, the temperature at the core-mantle boundary on the outer core side is 3930±630 K.
Radio-frequency eddy current heating of metallic samples in shock wave, ultrasonic and diamond anvil apparatus provides a methodology for obtaining hot samples or hot metallic gaskets (containing a sample) and yet not heating the entire target, ultrasonic assembly or diamond cell. Analysis of a previous design of a radio-frequency (∼0.5 MHz) coil demonstrated that the center of 13 mm diameter shock wave experiment sample discs were underheated and the experimental temperatures achieved resulted from conduction of heat from the overheated sample edges relative to the center of the sample. We show, using the Biot-Savant law, that the ratio of magnetic field in the center to that at the edge of the sample, f, can be maximized to a value of f=1.8, by decreasing the radius of the heater coil, relative to the 13 mm diameter of sample. A simple analysis provides the thermal gradient across the sample thickness. An electric skin depth for iron of ∼1 mm for the 0.45 MHz frequency of the heater power supply of our system is obtained. This leads to a maximum temperature gradient of ∼52 K over the 4 mm thickness of the shock wave sample discs.
The 4 configuration, distorted wave calculation of Bhatia & Doschek (1995) (hereafter referred to as BD95), together with the ground transition calculation of Pelan & Berrington (1995) are here used to predict the intensities of the Fe X EUV lines, which are then used to derive electron densities from several solar spectra, including the recent SERTS spectra.
The temperature dependence of the Hall voltage and resistivity of highly carbon doped GaN were measured. From the sign of the Hall voltage, the material appears to be p-type. Charge transport takes place in an impurity band and the valence band. The effective activation energy as estimated from the maximum in the temperature versus Hall voltage relation is 10–30 meV.
Theoretical electron density sensitive emission line ratios involving transitions in the 186–383 Å wavelength range are compared with observational data for a solar active region and a subflare, obtained by the Solar EUV Rocket Telescope and Spectrograph (SERTS). Electron densities derived from the majority of the ratios are consistent with one another, and are also in good agreement with the values of density estimated from diagnostic lines in other species formed at similar temperatures to Fe XII. These results provide observational support for the general accuracy of the diagnostic calculations. In addition, our analysis indicates that a line at 283.70 Å in the active region spectrum is the 3s23p32D3/2−3s3p42P1/2 transition in Fe XII, the first time (to the best of our knowledge) that this line has been identified in the solar spectrum. Several of the line ratios considered are predicted to be relatively insensitive to the adopted electron temperature and density, and the generally good agreement found between theory and observation for these provides evidence for the reliability of the SERTS instrument calibration. The application of the Fe XII diagnostics to EUVE observations of the F5 subgiant Procyon is briefly discussed.
Inaccurate prediction of silage intake is a major source of error in ration calculation. New routine methods such as electrometric titration (ET) and near infra-red reflectance spectroscopy (NIRS) have the potential to improve silage intake prediction (Offer et al., 1994). Development of new advisory models is slow because of the need to do large numbers of intake measurements. It is also essential that models are blind-tested (validated) on data not used for calibration. At SAC, sufficient animal intake data is now available for both calibration and validation although it is intended to continue to accumulate data for these purposes.
Starting with basic physical radiation principles and with Beers law formulas for the radiation characteristics of arrays of pointlike radiation sources and tubular halogen lamps are analytically derived. Different arrangements of tubular halogen lamps are considered and compared with each other. Homogeneity criteria are worked out and it is demonstrated that the minimum homogeneity distance between a plane in which all filaments are arranged parallel to each other, and an object depends only on the distance between two neighbouring filaments and thus can be given by a simple number. Interesting aspects for RTP equipment manufacturers as well as for users are demonstrated by comparing different lamp arrangements with each other: In crossed lamp fields latticelike inhomogeneity knots arise in the object plane at points where the lamp filaments of the upper and the lower lamp plane cross. If the filaments are arranged parallel to each other in two filament planes, very homogeneous results are obtained when the filaments of the two planes interlace.
Using a specific combination of energetic and chemical processes we have grown homoepitaxial diamond on and lifted it off of a type Ia natural C(100) crystal. Before growth, the C(100) crystal is exposed to a self implant of 190keV energy and dose of 1E16 cm-2. Low temperature (~600°C) homoepitaxial diamond growth conditions were used that are based on water-alcohol source chemistries. To achieve layer separation (lift-off), samples were annealed to a temperature sufficient to graphitize the buried implant-damaged region. Contactless electrochemical etching was found to remove the graphite, and a transparent synthetic (100) single crystal diamond plate of 17.5μm thickness was lifted off. This free-standing diamond single crystal plate was characterized and found to be comparable to homoepitaxial films grown on unimplanted single crystal diamond.
Inaccurate prediction of silage intake is a major source of error in ration calculation. Improvement in accuracy depends on the introduction of new routine methods to characterise better the silage fermentation. Electrometric titration has the potential to fill this role as it measures the main fermentation end-products in silage, residual sugar and gives absolute data on buffering characteristics (Offer et al., 1993).
Results are presented for years 1 and 2 of a 3 year study of the use of electrometric titration of silage juice to improve the prediction of silage true DM (TDM) intake (SDMI). Fifty seven silages have been made using a variety of grass and grass-clover mixtures and a wide range of cutting dates (between 25 May and 29 September) and ensilage methods. The following additives were used : none, formic acid (2.5 l/tonne), formic acid (>5 l/tonne), Lactobacillus inoculant, molasses (16 l/tonne), molasses + inoculant. A range of wilting times (0 to 48 hr) was used and in some cases grass was left uncovered in a heap (up to 72 hr) before ensiling.
A novel substrate preparation procedure which can be employed to remove the original surface from as-received C(001) natural diamond substrates has been developed. A description of the various substrate processing steps which includes, low-energy ion implantation of C and O, high-temperature annealing, electrochemical etching and surface plasmas treatments is presented. Also demonstrated is the growth of topographically excellent homoepitaxial films by rf-plasma-enhanced chemical vapor deposition using water/ethanol mixtures on C(001) substrates.
Experiments on microwave sintering of ceramic fibers in a single-mode cavity have revealed the presence of thermal spikes and “hot spots” which sometimes travel along the fiber and eventually disappear. They are triggered by relatively small increases in microwave power, and thus have obvious implications for the development of practical microwave-based fiber processing systems. These hot spots are conjectured to originate at slight irregularities in the tow morphology, and propagate as the result of solid phase transitions which take place at elevated temperatures and reduce the dielectric loss coefficient є”.
An elementary mathematical model of the heat transfer process was developed which reproduces the essential features of the observed phenomena, thus lending support to our conjecture. This model is based on the assumption of one-dimensional heat conduction along the axis of the fiber tow, and radiation losses at the surface.