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Newcastle disease (ND) is a notifiable disease affecting chickens and other avian species caused by virulent strains of Avian paramyxovirus type 1 (APMV-1). While outbreaks of ND can have devastating consequences, avirulent strains of APMV-1 generally cause subclinical infections or mild disease. However, viruses can cause different levels of disease in different species and virulence can evolve following cross-species transmission events. This report describes the detection of three cases of avirulent APMV-1 infection in Great Britain (GB). Case 1 emerged from the ‘testing to exclude’ scheme in chickens in Shropshire while cases 2 and 3 were made directly from notifiable avian disease investigations in chicken broilers in Herefordshire and on premises in Wiltshire containing ducks and mixed species, respectively). Class II/genotype I.1.1 APMV-1 from case 1 shared 99.94% identity to the Queensland V4 strain of APMV-1. Class II/genotype II APMV-1 was detected from case 2 while the class II/genotype I.2 virus from case 3 aligned closely with strains isolated from Anseriformes. Exclusion of ND through rapid detection of avirulent APMV-1 is important where clinical signs caused by avirulent or virulent APMV-1s could be ambiguous. Understanding the diversity of APMV-1s circulating in GB is critical to understanding disease threat from these adaptable viruses.
Methylammonium-tin-iodide (MASnxI3, 0.9 ≤ x ≤ 1.4) systems were prepared by self assembly process in aqueous solutions. The “as-prepared” MASnxI3 systems exhibit a crystalline tetragonal structure (space group I4cm) with polyhedral-shaped crystallites. The as-prepared samples were annealed at T = 150 °C, t = 8 h under nitrogen and synthetic air. Under nitrogen, the CH3NH3SnxI3 systems adopted a cubic crystalline structure (space group P4mm) with crystallites of 2–4 μm length, whereas under air, the formation of noncrystalline phases was observed. The optical absorption spectra displayed absorption edges at 1107.0 nm (x = 0.9), 1098.6 nm (x = 1.0), and 1073.2 nm (x = 1.1), respectively, whereas at higher Sn-content (x ≥ 1.2), a broad tail of the absorbance profile was observed. The photoluminescence (PL) emission spectra (RT, λexc = 500 nm) showed major PL-events over 1 µm range and the appearance of additional bands at increasing the Sn-content. The fabrication of layers with a semiconducting behavior was demonstrated.
In July 2003 an ice-dammed lake was suddenly drained in an outburst flood at Qorlortorssup tasia in south Greenland, the site of a projected hydropower station. The lake developed during the first decades of the 20th century as a result of the recession of the ice cap in this area. It used to drain over a shallow rock spillway towards Sermeq kangigdleq, the adjacent outlet glacier to the north. In order to assess the hazard potential and the additional water contribution from the enlarged catchment, the glacial lake and its surroundings were investigated. Based on the analysis of available historical data, field investigations and model results, the history of lake generation and the sudden outbreak were reconstructed. With the lake formation the ice dam lost its connection to the ice cap. The flood was initiated after the ice surface became low enough for the lake water to overflow the glacier towards Qorlortorssup tasia basin, creating a gully through the glacier which drained approximately 55 × 106 m3 of water over a period of 8-10 days. Thanks to the stability of the dam and the downstream damping of the flood, there was no serious threat to a farm that is situated close to the planned power-station site. In the future, we expect much smaller floods, as a result of partial closure of the gully by ice movement or snowdrift in the winter. The new drainage pattern into Qorlortorssup tasia basin, however, will be a permanent situation. The amount of this new water contribution can only be roughly estimated since the exact size of the drainage basin is not well known.
Several hundred subglacial lakes have been identified beneath Antarctica so far. Their interaction with the overlying ice sheet and their influence on ice dynamics are still subjects of investigation. While it is known that lakes reduce the ice-sheet friction towards a free-slip basal boundary condition, little is known about how basal melting and freezing at the lake/ice interface modifies the ice dynamics, thermal regime and ice rheology. In this diagnostic study we simulate the Vostok Subglacial Lake area with a coupled full Stokes 3-D ice-flow model and a 3-D lake-circulation model. The exchange of energy (heat) and mass at the lake/ice interface increases (decreases) the temperature in the ice column above the lake by up to 10% in freezing (melting) areas, resulting in a significant modification of the highly nonlinear ice viscosity. We show that basal lubrication at the bottom of the ice sheet has a significant impact not only on the ice flow above the lake itself, but also on the vicinity and far field. While the ice flow crosses Vostok Subglacial Lake, flow divergence is observed and modelled. The heterogeneous basal-mass-balance pattern at the lake/ice interface intensifies this divergence. Instead of interactive coupling between the ice-flow model and the lake-flow model, only a single iteration is required for a realistic representation of the ice/water interaction. In addition, our study indicates that simplified parameterizations of the surface temperature boundary condition might lead to a velocity error of 20% for the area of investigation.
So-called annual banding has been identified in a number of speleothems in which the number of bands approximates the time interval between successive U-series dates. The apparent annual resolution of speleothem records, however, remains largely untested. Here we statistically compare variations in band thickness from a late Holocene stalagmite in Carlsbad Cavern, Southern New Mexico, USA, with three independent tree-ring chronologies form the same region. We found no correspondence. Although there may be various explanations for the discordance, this limited exercise suggests that banded stalagmites should be held to the same rigorous standards in chronology building and climatic inference as annually resolved tree rings, corals, and ice cores.
Cow-calf operations dominate cattle production in the Southeast. The 1978 January 1 U.S. cattle inventory report shows that breeding cows make up 45 percent of the total inventory in Region 41 compared with 33.3 percent nationally [3]. Further, in 1977 cow slaughter accounted for 64.8 percent of federally inspected cattle slaughter in Region 4 compared with 23.6 percent nationally [8].
The triennium 1536–38 marks the crisis of Henry VIII's reign. The palace coup that toppled Anne Boleyn in May and June 1536 and apparently left Thomas Cromwell more firmly in control instead ushered in a series of further threats to both Cromwell and Henry. The upheaval of the Pilgrimage of Grace convulsed the north in late 1536 and early 1537 and looked for a time as if it would shake Henry's throne. The Pilgrims' calls for the upstart Cromwell's removal forced the chief minister to withdraw behind the scenes for a time, always a tricky maneuver. The battle of wits and wills between the king and his cousin and sometime protégé Reginald Pole runs as counterpoint throughout these dislocations. Pole's intemperate attack on Henry's divorce from Catherine of Aragon, De unitate, arrived at the extremely sensitive moment of June 1536 and announced the beginning of an eighteen-month struggle that finally led to an irreparable breach between Henry and Pole. De unitate has often been taken to signal Pole's crossing of the Rubicon. It should certainly have discomfited Pole's potential allies just as many of his partisans thought they had jockeyed themselves into power by engineering Anne's downfall. In fact, the work had a minimal effect, mainly because the committee entrusted with reading it was heavily stacked with Pole's friends. Henry probably never saw De unitate. Despite its violent language, neither Pole nor his supporters were then quite ready to give up on Henry. Early the next year the situation changed. Paul III created the new cardinal Pole a legate and dispatched him to Flanders, traditional locus of plots against England.
The distribution of alloying elements in the constituent phases of a C-containing γ-TiAl based alloy has been characterized locally by atom probe tomography. The major elements of the alloy under consideration – Ti, Al, Nb, and Mo – are distributed uniformly within each of the constituent phases. Furthermore, Mo is preferentially dissolved in the βo-phase, whereas Nb content is similar in all phases. The selected C concentration of the alloy is below the overall solubility limit as no precipitates have been observed. Therefore, C is enriched in the α2-phase, whereas the βo-phase is depleted of C. In addition, βo/γ-interfaces have been prepared by site specific sample preparation and characterized by atom probe tomography. Segregation of Mo and C into the interfaces and their close vicinity was observed.
An antenna concept for direction of arrival estimation in azimuth and elevation is proposed for 77 GHz automotive radar sensors. This concept uses the amplitude information of the radar signal for the azimuth angle and the phase information for the elevation angle. The antenna consists of a combination of a series-fed-array structure with a cylindrical dielectric lens. This concept is implemented into a radar sensor based on SiGe MMICs for validation. A two- and a four-beam configuration are presented and discussed with respect to angular accuracy and ambiguities.
After almost three decades of intensive fundamental research and development activities intermetallic titanium aluminides based on the -TiAl phase have found applications in automotive and aircraft engine industries. The advantages of this class of innovative high-temperature materials are their low density as well as their good strength and creep properties up to 750°C. A drawback, however, is their limited ductility at room temperature, which is reflected by a low plastic strain at fracture. This behavior can be attributed to a limited dislocation movement along with microstructural inhomogeneity. Advanced TiAl alloys, such as β-solidifying TNM™ alloys, are complex multi-phase materials which can be processed by ingot or powder metallurgy as well as precision casting methods. Each production process leads to specific microstructures which can be altered and optimized by thermo-mechanical processing and/or subsequent heat-treatments. The background of these heat-treatments is at least twofold, i.e. concurrent increase of ductility at room temperature and creep strength at elevated temperature. In order to achieve this goal the knowledge of the occurring solidification processes and phase transformation sequences is essential. Therefore, thermodynamic calculations were conducted to predict phase fraction diagrams of engineering TiAl alloys. After experimental verification, these phase diagrams provided the base for the development of heat treatments to adjust balanced mechanical properties. To determine the influence of deformation and kinetic aspects, sophisticated ex- and in-situ methods have been employed to investigate the evolution of the microstructure during thermo-mechanical processing and subsequent multi-step heat-treatments. For example, in-situ high-energy X-ray diffraction was conducted to study dynamic recovery and recrystallization processes during hot-deformation tests. Summarizing all results a consistent picture regarding microstructure formation and its impact on mechanical properties in TNM alloys can be given.
Over the last decades, high-throughput screening (HTS) of small molecule libraries has developed into a very powerful tool for drug discovery. Although HTS capabilities initially were developed almost exclusively in the domain of pharmaceutical and biotech commercial ventures, they have more recently become available in academia. The Molecular Library Initiative of the National Institutes of Health (NIH) is one example that HTS has established itself as a routine technology in biomedical research [1].
The popularity of HTS is due to rapid developments in four different areas:
Robotic systems. Once exotic and expensive, robotic systems and automatic liquid handling have become more affordable and easier to operate. Turnkey systems are available for the most common applications.
Chemical libraries. Chemical libraries are becoming more readily available and affordable to the scientific community in academia and industry. Even large compound libraries, such as the one developed for the above-mentioned Molecular Library Initiative, are accessible to the general scientific community.
Plate reader platforms. Reader platforms have undergone rapid development over the last two decades. As of today, high-speed microplate readers are available to very rapidly scan microplates in the 96-, 384-, and 1536-well formats or even higher densities. Automated confocal and conventional microscopes and other image-based reader platforms have evolved at an astonishing speed. Sophisticated image-based readers and corresponding image recognition and analysis software have led to the development of complex, high-content cell-based assays.
Detection technologies. A whole array of luminescence-based technologies have been developed and commercialized over the last few years. Among those are fluorescent proteins, high-yield fluorochromes, and luminescence substrates.
The development of suitable hot-forming processes, e.g. forging, is an important step towards the serial production of TiAl parts. Several microstructure parameters change during hot-forming. However, the underlying mechanisms can normally only be inferred from post process metallographic studies.
We used a deformation dilatometer modified for working in the HZG synchrotron beamlines at DESY for hot-deformation experiments. This setup enables the in situ monitoring of the interaction and evolution of microstructure parameters during processing. We observed the evolution of phase fractions, grain size and crystallographic texture during deformation while simultaneously recording the process parameters, like temperature, force and length change.
Here we present the hot compressive deformation behaviour of a Ti-43Al-4Nb-1Mo-0.1B (in at.%) alloy. Several specimens were deformed at three temperatures each with two compression rates. During the experiments the Debye-Scherrer diffraction rings were continuously recorded.
In the last decades there was a growing interest in developing new light-weight intermetallic alloys, which are able to substitute the heavy superalloys at a certain temperature range. At present a new Ti-Al-Nb-Mo family, called TNM™ alloys, is being optimized to fulfill the challenging requirements. The aim of the present work was to study the microscopic mechanisms of defect mobility at high temperature in TNM alloys in order to contribute to the understanding of their influence on the mechanical properties and hence to promote the further optimization of these alloys. Mechanical spectroscopy has been used to study the internal friction and the dynamic modulus up to 1460 K of a TNM alloy under different thermal treatments. These measurements allow to follow the microstructural evolution during in-situ thermal treatments. A relaxation process has been observed at about 1050 K and was characterized as a function of temperature and frequency in order to obtain the activation parameters of the responsible mechanism. In particular, the activation enthalpy has been determined to be H= 3 eV. The results are discussed and an atomic mechanism is proposed to explain the observed relaxation process.