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The breeding areas of the Critically Endangered Slender-billed Curlew Numenius tenuirostris are all but unknown, with the only well-substantiated breeding records being from the Omsk province, western Siberia. The identification of any remaining breeding population is of the highest priority for the conservation of any remnant population. If it is extinct, the reliable identification of former breeding sites may help determine the causes of the species’ decline, in order to learn wider conservation lessons. We used stable isotope values in feather samples from juvenile Slender-billed Curlews to identify potential breeding areas. Modelled precipitation δ2H data were compared to feather samples of surrogate species from within the potential breeding range, to produce a calibration equation. Application of this calibration to samples from 35 Slender-billed Curlew museum skins suggested they could have originated from the steppes of northern Kazakhstan and part of southern Russia between 48°N and 56°N. The core of this area was around 50°N, some way to the south of the confirmed nesting sites in the forest steppes. Surveys for the species might be better targeted at the Kazakh steppes, rather than around the historically recognised nest sites of southern Russia which might have been atypical for the species. We consider whether agricultural expansion in this area may have contributed to declines of the Slender-billed Curlew population.
Several temporal and event classifications are used for the Quaternary glacial and interglacial record in the Great Lakes region of North America. Although based on contrasting principles, the classifications, as practiced, are similar to one another in most respects and they differ little from the classification proposed by Chamberlin a century ago. All are based on stratigraphic units having time-transgressive boundaries; thus the associated time spans and events are diachronous. Where application of geochronologic classification based on isochronous boundaries is not practical or useful, we advocate the use of diachronic principles to establish local and regional temporal and event classifications. Diachronic and event classifications based on such principles are proposed herein for the Great Lakes region. Well-established names, including Wisconsin, Sangamon, and Illinois, are used at the episode (or glaciation/interglaciation) rank without significant redefinition. The Hudson Episode (Interglaciation) is introduced for postglacial time, the current interglacial interval. The Wisconsin Episode is divided into the Ontario, Elgin, and Michigan Subepisodes in the eastern and northern parts of the Great Lakes region and into the Athens and Michigan Subepisodes in the southern and western parts of the Great Lakes region.
An (r,r+1)-factor of a graph G is a spanning subgraph H such that dH(v)∈{r,r+1} for all vertices v∈𝒱(G). If G is expressed as the union of edge-disjoint (r,r+1)-factors, then this expression is an (r,r+1)-factorization of G. Let μ(r) be the smallest integer with the property that if G is a regular loopless multigraph of degree d with d≥μ(r), then G has an (r,r+1)-factorization. It is shown that if r is even. The proof employs a novel list-coloring approach. Together with known results, this shows that μ(r)=r2+1 if r is odd and if r is even.
Defining the causal relationship between a microbe and encephalitis is complex. Over 100 different infectious agents may cause encephalitis, often as one of the rarer manifestations of infection. The gold-standard techniques to detect causative infectious agents in encephalitis in life depend on the study of brain biopsy material; however, in most cases this is not possible. We present the UK perspective on aetiological case definitions for acute encephalitis and extend them to include immune-mediated causes. Expert opinion was primarily used and was supplemented by literature-based methods. Wide usage of these definitions will facilitate comparison between studies and result in a better understanding of the causes of this devastating condition. They provide a framework for regular review and updating as the knowledge base increases both clinically and through improvements in diagnostic methods. The importance of new and emerging pathogens as causes of encephalitis can be assessed against the principles laid out here.
Increasingly serious shortages of water make it imperative to improve the efficiency of irrigation in agriculture, horticulture and in the maintenance of urban landscapes. The main aim of the current review is to identify ways of meeting this objective. After reviewing current irrigation practices, discussion is centred on the sensitivity of crops to water deficit, the finding that growth of many crops is unaffected by considerable lowering of soil water content and, on this basis, the creation of improved means of irrigation scheduling. Subsequently, attention is focused on irrigation problems associated with spatial variability in soil water and the often slow infiltration of water into soil, especially the subsoil. As monitoring of soil water is important for estimating irrigation requirements, the attributes of the two main types of soil water sensors and their most appropriate uses are described. Attention is also drawn to the contribution of wireless technology to the transmission of sensor outputs. Rapid progress is being made in transmitting sensor data, obtained from different depths down the soil profile across irrigated areas, to a PC that processes the data and on this basis automatically commands irrigation equipment to deliver amounts of water, according to need, across the field. To help interpret sensor outputs, and for many other reasons, principles of water processes in the soil–plant system are incorporated into simulation models that are calibrated and tested in field experiments. Finally, it is emphasized that the relative importance of the factors discussed in this review to any particular situation varies enormously.
We give some sufficient conditions for an (S, U)-outline T-factorization of Kn to be an (S, U)-amalgamated T-factorization of Kn. We then apply these to give various necessary and sufficient conditions for edge coloured graphs G to have recoverable embeddings in T-factorized Kn's.
Those $(2m-1)$-edge-colourings of a spanning subgraph of $K_{2m}$, consisting of $K_{r}$ and independent edges, that can be embedded in a $(2m-1)$-edge-colouring of $K_{2m}$ are characterised.
AuTiAlTi, AuPdAlTi and AuAlTi ohmic contacts to AlGaN/GaN layers rapid thermal annealed at temperatures up to 950°C have been characterised using conventional and chemical transmission electron microscopy techniques. The relationship between the as-deposited metallic structure, annealing temperature, post-anneal interfacial microstructure and contact resistance is examined.
The presence of a TiN interfacial layer is found to correlate with the onset of ohmic behaviour. Ti and Pd barrier layers are found to be ineffective at stopping the diffusion of Au to the interface. Au is implicated in the development of the inclusions, which are associated with threading dislocations. Once activated, the presence of the inclusions has little influence on the ohmic behaviour of the sample.
The well-known Oberwolfach problem is to show that it is possible to 2-factorize Kn (n odd) or Kn less a 1-factor (n even) into predetermined 2-factors, all isomorphic to each other; a few exceptional cases where it is not possible are known. A completely new technique is introduced that enables it to be shown that there is a solution when each 2-factor consists of k r-cycles and one (n−kr)-cycle for all n [ges ] 6kr−1. Solutions are also given (with three exceptions) for all possible values of n when there is one r-cycle, 3 [les ] r [les ] 9, and one (n−r)-cycle, or when there are two r-cycles, 3 [les ] r [les ] 4, and one (n−2r)-cycle.
Mitochondrial DNA (mtDNA) defects are responsible for symptom complexes that are characteristically heterogeneous but are typically represented by muscle weakness and neurological deficits. One common feature of mitochondrial disease is deafness. This report details the assessment and outcome of a patient with a previously undescribed mtDNA rearrangement who underwent cochlear implantation. The patient shows a marked improvement in sentence recognition tests and recognition of environmental sounds. Patients with profound sensorineural hearing loss due to mtDNA defects should be considered as candidates for cochlear implantation when they no longer benefit from conventional hearing aids.
The core of a graph G is the subgraph GΔ induced by the vertices of maximum degree. We define the deleted core D(G) of G. We extend an earlier sufficient condition due to Hoffman [7] for a graph H to be the core of a Class 2 graph, and thereby provide a stronger sufficient condition. The new sufficient condition is in terms of D(H). We show that in some circumstances our condition is necessary; but it is not necessary in general.
Advanced materials are being designed and tested for high-stress, high-cycle ball bearing applications. Important information about the tribological performance of these materials is gained through rolling contact fatigue (RCF) measurements. No such data have been reported to date for hybrid bearings consisting of titanium carbide (TiC)-coated REX20 steel balls and REX20 steel raceways. Chemical vapor deposition (CVD) was used for depositing the TiC coating. In this paper, we present the first report of the effects of RCF tests on this particular combination of hybrid bearings. Post-test characterizations of these bearings are discussed. Our investigations include plan-view and cross-sectional scanning electron microscopy, chemical compositional analyses, X-ray diffraction, and nano-indentation measurements. Results of these investigations provide a detailed understanding of the TiC coating on REX20 steel balls following extended rolling contact.
Abstract. We introduce the concept of a weighted quasigroup. We show that, corresponding to any weighted quasigroup, there is a quasigroup from which it can be obtained in a certain natural way, which we term amalgamation. Not all commutative weighted quasigroups can be obtained from commutative quasigroups by amalgamation; however, given a commutative weighted quasigroup whose weights are all even, we give a necessary and sufficient condition for the existence of a commutative quasigroup from which it can be obtained by amalgamation. We also discuss conjugates of weighted quasigroups.
We also introduce the concept of a simplex zeroid, and relate this concept to that of a weighted quasigroup.
Weighted quasigroups.
Suppose that we have a finite set S with a closed binary operation. If a, b ε S, we shall denote the result of this binary operation acting on a and b by ab. If the binary operation has the two properties
(i) for each a, b ε S, the equation ax = b is uniquely solvable for x, and
(ii) for each a, b ε S the equation ya = b is uniquely solvable for y,
then S is a quasigroup. It is well-known, and easy to see, that S is a quasigroup if and only if its multiplication table is a latin square. The properties (i) and (ii) amount to the assertion that, in the multiplication table, each element of S occurs exactly once in each row and exactly once in each column.
The role of interfacial exchange coupling in the magnetic behavior of metal oxide materials has been investigated through the study of Fe3O4/NiO superlattices. We report results on a series of superlattices grown where one bilayer constituent was held to a fixed thickness while varying the other from single unit cell dimensions upward. High crystalline quality was confirmed by XRD, RHEED and neutron diffraction. Magnetization profiles show substantial deviations from bulklike iron oxide results, with an increase in domain rotation energies observed in the superlattices over that of bulk iron oxide (increasing with NiO layer thickness) indicating the strong nature of Fe3O4/NiO interfacial linkage. Neutron scattering at elevated temperatures shows that the NiO remains ordered above the 523 K bulk Néel temperature. This suggests that at least a portion of the NiO within a layer remains ordered well above the Néel temperature, with an increase in effective Néel transition temperature that approaches the Fe3O4 Curie temperature in the limit of very thin NiO layers. Although the exchange coupling dominates these effects, strain also plays an important role.
Crystal damage of GaAs(100) caused by Reactive Ion Etching (RIE) using a mixture of Cl2 and Ar gas has been assessed using Surface Roughness (Ra), Resonant Raman Spectroscopy (RRS), Schottky diodes, and Spectroscopic Ellipsometry (SE). Plasma conditions for minimum induced damage have been determined and compared to optimised RIE processes using plasma gases SiCl4, CH4-H2, CCl2F2 and Ar. The SiCl4 plasma was found to produce the least crystal damage.
The usual definition for vertex-criticality with respect to the chromatic index is that a multigraph G is vertex-critical if G is Class 2, connected, and χ'(G\υ) <χ'(G) for all υ ε V(G). We consider here an allied notion, that of vertex-criticality with respect to the chromatic class–in this case G is vertex critical if G is Class 2 and connected, but G\υ is Class 1 for all υ ε V(G). We also investigate the analogues of these two notions for edge-criticality.
1. Quadruplicate groups of rainbow trout (Sulmo gairdneri) (mean body-weight 24.9 g) were reared on six dietary treatments (practical-type diets) in a modified paired-feeding experiment for 12 weeks at 15° to determine the net energy (NE) value of starch and glucose to rainbow trout.
2. Three test diets were prepared to contain (g/kg): 0 supplemented carbohydrate (diet 1), 250 maize starch (diet 2) and 250 glucose (diet 3) and were given ad lib. to the trout with the feeding rate of the glucose- and starchfed groups being monitored after each feeding. The remaining three treatments involved controlled feeding of the trout with diet 1 at 75% of the feed intake of trout reared on diets 2 and 3, so as to provide the same levels of protein and lipids without carbohydrate, and with diet 2 at 100% of the feed intake of trout reared on diet 3.
3. The difference in the final carcass energy of the ad lib.-fed group and the respective controlled-fed group divided by the amount of dietary glucose or starch energy consumed by the trout is the NE value for that carbohydrate.
4. The determined NE value of glucose was 3.99 kJ/g and starch 2.17 kJ/g, which is 24.6 and 12.6% respectively of the gross energy values of these carbohydrates in rainbow trout.
5. The results indicate that digestible energy and calculated metabolizable energy values for carbohydrates in rainbow trout overestimate the utilizable energy content of the diet.
6. The determined NE values for glucose and starch in the present study should be used with caution since various factors (such as the feeding rate determined in the present study) may affect the utilization of dietary carbohydrates in rainbow trout.