Newcastle upon Tyne, the Eye of the North

Newcastle upon Tyne is one of England’s great cities. Many think of it mainly as a product of the Industrial Revolution when abundant resources of coal, iron ore and water came together to create a Victorian industrial powerhouse. In fact, Newcastle’s long and proud history began in Roman times when Hadrian’s Wall marked the northernmost point of the Roman Empire.Newcastle became a thriving medieval port, with trading connections around the North Sea, the Atlantic, the Baltic countries and the Mediterranean. By the mid-17th century, Newcastle was not only a major European port, but was also becoming the pre-eminent exporter of coal fuelling the incipient industrial revolution. This volume brings together the archaeological evidence for occupation in the historic core of Newcastle between the prehistoric period and 1650. It places the evidence in the context of the evolving historical communities who made and occupied the site, and in the wider context of medieval and early modern European urban life.The volume synthesizes archaeological and historical evidence, highlighting material only known through excavation – like the early medieval use of the decaying Roman fort for a cemetery and probable church – as well as throwing new light on documented activities – like the way in which the waterfront was physically extended and consolidated to support trade from the 12th century onwards. Taking its name from a castle of national significance, planted after the Norman Conquest as a bulwark against Northern rebels and Scottish aggression, Newcastle was established as the king’s ‘Eye of the North’

Newcastle upon Tyne, the Eye of the North

Newcastle upon Tyne is one of England’s great cities. Many think of it mainly as a product of the Industrial Revolution when abundant resources of coal, iron ore and water came together to create a Victorian industrial powerhouse. In fact, Newcastle’s long and proud history began in Roman times when Hadrian’s Wall marked the northernmost point of the Roman Empire.Newcastle became a thriving medieval port, with trading connections around the North Sea, the Atlantic, the Baltic countries and the Mediterranean. By the mid-17th century, Newcastle was not only a major European port, but was also becoming the pre-eminent exporter of coal fuelling the incipient industrial revolution. This volume brings together the archaeological evidence for occupation in the historic core of Newcastle between the prehistoric period and 1650. It places the evidence in the context of the evolving historical communities who made and occupied the site, and in the wider context of medieval and early modern European urban life.The volume synthesizes archaeological and historical evidence, highlighting material only known through excavation – like the early medieval use of the decaying Roman fort for a cemetery and probable church – as well as throwing new light on documented activities – like the way in which the waterfront was physically extended and consolidated to support trade from the 12th century onwards. Taking its name from a castle of national significance, planted after the Norman Conquest as a bulwark against Northern rebels and Scottish aggression, Newcastle was established as the king’s ‘Eye of the North’

The pairing state in KFe2As2 studied by measurements of the magnetic vortex lattice

Understanding the mechanism and symmetry of electron pairing in iron-based superconductors represents an important challenge in condensed matter physics [1-3]. The observation of magnetic flux lines - "vortices" - in a superconductor can contribute to this issue, because the spatial variation of magnetic field reflects the pairing. Unlike many other iron pnictides, our KFe2As2 crystals have very weak vortex pinning, allowing small-angle-neutron-scattering (SANS) observations of the intrinsic vortex lattice (VL). We observe nearly isotropic hexagonal packing of vortices, without VL-symmetry transitions up to high fields along the fourfold c-axis of the crystals, indicating rather small anisotropy of the superconducting properties around this axis. This rules out gap nodes parallel to the c-axis, and thus d-wave and also anisotropic s-wave pairing [2, 3]. The strong temperature-dependence of the intensity down to T<<Tc indicates either widely different full gaps on different Fermi surface sheets, or nodal lines perpendicular to the axis.Comment: 13 pages, 3 figure

Domain State Diagnosis in Rock Magnetism: Evaluation of Potential Alternatives to the Day Diagram

The Day diagram is used extensively in rock magnetism for domain state diagnosis. It has been shown recently to be fundamentally ambiguous for ten sets of reasons. This ambiguity highlights the urgency for adopting suitable alternative approaches to identify the domain state of magnetic mineral components in rock magnetic studies. We evaluate ten potential alternative approaches here and conclude that four have value for identifying data trends, but, like the Day diagram, they are affected by use of bulk parameters that compromise domain state diagnosis in complex samples. Three approaches based on remanence curve and hysteresis loop unmixing, when “supervised” by independent data to avoid non-uniqueness of solutions provide valuable component-specific information that can be linked by inference to domain state. Three further approaches based on first-order reversal curve (FORC) diagrams provide direct domain state diagnosis with varying effectiveness. Environmentally important high coercivity hematite and goethite are represented with variable effectiveness in the evaluated candidate approaches. These minerals occur predominantly in non-interacting single domain particle assemblages in paleomagnetic contexts, so domain state diagnosis is more critical for ferrimagnetic minerals. Treating the high-coercivity component separately following normal rock magnetic procedures allows focus on the more vexing problem of diagnosing domain state in ferrimagnetic mineral assemblages. We suggest a move away from non-diagnostic methods based on bulk parameters and adoption of approaches that provide unambiguous component-specific domain state identification, among which various FORC-based approaches provide diagnostic information.European Research Council (ERC) Australian Research Council (ARC

Positive Energy Unitary Irreducible Representations of the Superalgebras osp(1|2n,R)

We give the classification of the positive energy (lowest weight) unitary irreducible representations of the superalgebras osp(1|2n,R).Comment: 20 pages, LATEX2e (revtex4,amsmath,amssymb), Plenary talk by VKD at X International Conference on Symmetry Methods in Physics, Yerevan, 13-21.8.2003; added acknowledgements; corrected misprint

AdS/SCFT in Superspace

A discussion of the AdS/CFT correspondence in IIB is given in a superspace context. The main emphasis is on the properties of SCFT correlators on the boundary which are studied using harmonic superspace techniques. These techniques provide the easiest way of implementing the superconformal Ward identities. The Ward identities, together with analyticity, can be used to give a compelling argument in support of the non-renormalisation theorems for two- and three-point functions, and to establish the triviality of extremal and next-to-extremal correlation functions. The OPE in is also briefly discussed.Comment: 10 pages; talk given by PSH at 2nd Gursey Memorial Conference, June 200

Surprisingly Simple Spectra

The large N limit of the anomalous dimensions of operators in ${\cal N}=4$ super Yang-Mills theory described by restricted Schur polynomials, are studied. We focus on operators labeled by Young diagrams that have two columns (both long) so that the classical dimension of these operators is O(N). At large N these two column operators mix with each other but are decoupled from operators with $n\ne 2$ columns. The planar approximation does not capture the large N dynamics. For operators built with 2, 3 or 4 impurities the dilatation operator is explicitly evaluated. In all three cases, in a certain limit, the dilatation operator is a lattice version of a second derivative, with the lattice emerging from the Young diagram itself. The one loop dilatation operator is diagonalized numerically. All eigenvalues are an integer multiple of $8g_{YM}^2$ and there are interesting degeneracies in the spectrum. The spectrum we obtain for the one loop anomalous dimension operator is reproduced by a collection of harmonic oscillators. This equivalence to harmonic oscillators generalizes giant graviton results known for the BPS sector and further implies that the Hamiltonian defined by the one loop large $N$ dilatation operator is integrable. This is an example of an integrable dilatation operator, obtained by summing both planar and non-planar diagrams.Comment: 34 page

An automatic model selection‐based machine learning framework to estimate FORC distributions

First‐order reversal curve (FORC) distributions are a powerful diagnostic tool for characterizing and quantifying magnetization processes in fine magnetic particle systems. Estimation of FORC distributions requires the computation of the second‐order mixed derivative of noisy magnetic hysteresis data. This operation amplifies measurement noise, and for weakly magnetic systems, it can compromise estimation of a FORC distribution. Previous processing schemes, which are based typically on local polynomial regression, have been developed to smooth FORC data to suppress detrimental noise. Importantly, the smoothed FORC distribution needs to be consistent with the measurement data from which it was estimated. This can be a challenging task even for expert users, who must adjust subjectively parameters that define the form and extent of smoothing until a “satisfactory” FORC distribution is obtained. For nonexpert users, estimation of FORC distributions using inappropriate smoothing parameters can produce distorted results corrupted by processing artifacts, which can lead to spurious inferences concerning the magnetic system under investigation. We have developed a statistical machine learning framework based on a probabilistic model comparison to guide the estimation of FORC distributions. An intuitive approach is presented that reveals regions of a FORC distribution that may have been smoothed inappropriately. An associated metric can also be used to compare data preparation and local regression schemes to assess their suitability for processing a given FORC data set. Ultimately, our approach selects FORC smoothing parameters in a probabilistic fashion, which automates the derivative estimation process regardless of user expertise

A strategy for the characterization of minute chromosome rearrangements using multiple color fluorescence in situ hybridization with chromosome-specific DNA libraries and YAC clones

The identification of marker chromosomes in clinical and tumor cytogenetics by chromosome banding analysis can create problems. In this study, we present a strategy to define minute chromosomal rearrangements by multicolor fluorescence in situ hybridization (FISH) with whole chromosome painting probes derived from chromosome-specific DNA libraries and Alu-polymerase chain reaction (PCR) products of various region-specific yeast artificial chromosome (YAC) clones. To demonstrate the usefulness of this strategy for the characterization of chromosome rearrangements unidentifiable by banding techniques, an 8p+ marker chromosome with two extra bands present in the karyotype of a child with multiple anomalies, malformations, and severe mental retardation was investigated. A series of seven-color FISH experiments with sets of fluorochrome-labeled DNA library probes from flow-sorted chromosomes demonstrated that the additional segment on 8p+ was derived from chromosome 6. For a more detailed characterization of the marker chromosome, three-color FISH experiments with library probes specific to chromosomes 6 and 8 were performed in combination with newly established telomeric and subtelomeric YAC clones from 6q25, 6p23, and 8p23. These experiments demonstrated a trisomy 6pter6p22 and a monosomy 8pter8p23 in the patient. The present limitations for a broad application of this strategy and its possible improvements are discusse

Matching three-point functions of BMN operators at weak and strong coupling

The agreement between string theory and field theory is demonstrated in the leading order by providing the first calculation of the correlator of three two-impurity BMN states with all non-zero momenta. The calculation is performed in two completely independent ways: in field theory by using the large-$N$ perturbative expansion, up to the terms subleading in finite-size, and in string theory by using the Dobashi-Yoneya 3-string vertex in the leading order of the Penrose expansion. The two results come out to be completely identical.Comment: 14 pages, 1 figur