204 research outputs found
Charnel practices in medieval England: new perspectives
Studies of English medieval funerary practice have paid limited attention to the curation of human remains in charnel houses. Yet analysis of architectural, archaeological and documentary evidence, including antiquarian accounts, suggests that charnelling was more widespread in medieval England than has hitherto been appreciated, with many charnel houses dismantled at the sixteenth-century Reformation. The survival of a charnel house and its human remains at Rothwell, Northamptonshire permits a unique opportunity to analyse charnel practice at a medieval parish church. Employing architectural, geophysical and osteological analysis, we present a new contextualisation of medieval charnelling. We argue that the charnel house at Rothwell, a subterranean room constructed during the thirteenth century, may have been a particularly sophisticated example of an experiment born out of beliefs surrounding Purgatory. Our approach enables re-evaluation of the surviving evidence for charnel practice in England and enhances wider narratives of medieval charnelling across Europe
Macromolecular composition of phloem exudate from white lupin (Lupinus albus L.)
<p>Abstract</p> <p>Background</p> <p>Members of the legume genus <it>Lupinus </it>exude phloem 'spontaneously' from incisions made to the vasculature. This feature was exploited to document macromolecules present in exudate of white lupin (<it>Lupinus albus </it>[L.] <it>cv </it>Kiev mutant), in particular to identify proteins and RNA molecules, including microRNA (miRNA).</p> <p>Results</p> <p>Proteomic analysis tentatively identified 86 proteins from 130 spots collected from 2D gels analysed by partial amino acid sequence determination using MS/MS. Analysis of a cDNA library constructed from exudate identified 609 unique transcripts. Both proteins and transcripts were classified into functional groups. The largest group of proteins comprised those involved in metabolism (24%), followed by protein modification/turnover (9%), redox regulation (8%), cell structural components (6%), stress and defence response (6%) with fewer in other groups. More prominent proteins were cyclophilin, ubiquitin, a glycine-rich RNA-binding protein, a group of proteins that comprise a glutathione/ascorbate-based mechanism to scavenge oxygen radicals, enzymes of glycolysis and other metabolism including methionine and ethylene synthesis. Potential signalling macromolecules such as transcripts encoding proteins mediating calcium level and the Flowering locus T (FT) protein were also identified. From around 330 small RNA clones (18-25 nt) 12 were identified as probable miRNAs by homology with those from other species. miRNA composition of exudate varied with site of collection (e.g. upward versus downward translocation streams) and nutrition (e.g. phosphorus level).</p> <p>Conclusions</p> <p>This is the first inventory of macromolecule composition of phloem exudate from a species in the Fabaceae, providing a basis to identify systemic signalling macromolecules with potential roles in regulating development, growth and stress response of legumes.</p
The dietary impact of the Norman Conquest: A multiproxy archaeological investigation of Oxford, UK
Archaeology has yet to capitalise on the opportunities offered by bioarchaeological approaches to examine the impact of the 11th-century AD Norman Conquest of England. This study utilises an integrated multiproxy analytical approach to identify and explain changes and continuities in diet and foodways between the 10th and 13th centuries in the city of Oxford, UK. The integration of organic residue analysis of ceramics, carbon (δ13C) and nitrogen (δ15N) isotope analysis of human and animal bones, incremental analysis of δ13C and δ15N from human tooth dentine and palaeopathological analysis of human skeletal remains has revealed a broad pattern of increasing intensification and marketisation across various areas of economic practice, with a much lesser and more short-term impact of the Conquest on everyday lifestyles than is suggested by documentary sources. Nonetheless, isotope data indicate short-term periods of instability, particularly food insecurity, did impact individuals. Evidence of preferences for certain foodstuffs and cooking techniques documented among the elite classes were also observed among lower-status townspeople, suggesting that Anglo-Norman fashions could be adopted across the social spectrum. This study demonstrates the potential for future archaeological research to generate more nuanced understanding of the cultural impact of the Norman Conquest of England, while showcasing a method which can be used to elucidate the undocumented, everyday implications of other large-scale political events on non-elites
Identification and characterisation of seed storage protein transcripts from Lupinus angustifolius
<p>Abstract</p> <p>Background</p> <p>In legumes, seed storage proteins are important for the developing seedling and are an important source of protein for humans and animals. <it>Lupinus angustifolius </it>(L.), also known as narrow-leaf lupin (NLL) is a grain legume crop that is gaining recognition as a potential human health food as the grain is high in protein and dietary fibre, gluten-free and low in fat and starch.</p> <p>Results</p> <p>Genes encoding the seed storage proteins of NLL were characterised by sequencing cDNA clones derived from developing seeds. Four families of seed storage proteins were identified and comprised three unique α, seven β, two γ and four δ conglutins. This study added eleven new expressed storage protein genes for the species. A comparison of the deduced amino acid sequences of NLL conglutins with those available for the storage proteins of <it>Lupinus albus </it>(L.), <it>Pisum sativum </it>(L.), <it>Medicago truncatula </it>(L.), <it>Arachis hypogaea </it>(L.) and <it>Glycine max </it>(L.) permitted the analysis of a phylogenetic relationships between proteins and demonstrated, in general, that the strongest conservation occurred within species. In the case of 7S globulin (β conglutins) and 2S sulphur-rich albumin (δ conglutins), the analysis suggests that gene duplication occurred after legume speciation. This contrasted with 11S globulin (α conglutin) and basic 7S (γ conglutin) sequences where some of these sequences appear to have diverged prior to speciation. The most abundant NLL conglutin family was β (56%), followed by α (24%), δ (15%) and γ (6%) and the transcript levels of these genes increased 10<sup>3 </sup>to 10<sup>6 </sup>fold during seed development. We used the 16 NLL conglutin sequences identified here to determine that for individuals specifically allergic to lupin, all seven members of the β conglutin family were potential allergens.</p> <p>Conclusion</p> <p>This study has characterised 16 seed storage protein genes in NLL including 11 newly-identified members. It has helped lay the foundation for efforts to use molecular breeding approaches to improve lupins, for example by reducing allergens or increasing the expression of specific seed storage protein(s) with desirable nutritional properties.</p
Theory of x-ray absorption by laser-aligned symmetric-top molecules
We devise a theory of x-ray absorption by symmetric-top molecules which are
aligned by an intense optical laser. Initially, the density matrix of the
system is composed of the electronic ground state of the molecules and a
thermal ensemble of rigid-rotor eigenstates. We formulate equations of motion
of the two-color (laser plus x rays) rotational-electronic problem. The
interaction with the laser is assumed to be nonresonant; it is described by an
electric dipole polarizability tensor. X-ray absorption is approximated as a
one-photon process. It is shown that the equations can be separated such that
the interaction with the laser can be treated independently of the x rays. The
laser-only density matrix is propagated numerically. After each time step, the
x-ray absorption is calculated. We apply our theory to study adiabatic
alignment of bromine molecules (Br2). The required dynamic polarizabilities are
determined using the ab initio linear response methods coupled-cluster singles
(CCS), second-order approximate coupled-cluster singles and doubles (CC2), and
coupled-cluster singles and doubles (CCSD). For the description of x-ray
absorption on the sigma_g 1s --> sigma_u 4p resonance, a parameter-free
two-level model is used for the electronic structure of the molecules. Our
theory opens up novel perspectives for the quantum control of x-ray radiation.Comment: 14 pages, 4 figures, 1 table, RevTeX4, revise
Chiral discrimination in optical trapping and manipulation
When circularly polarized light interacts with chiral molecules or nanoscale particles powerful symmetry principles determine the possibility of achieving chiral discrimination, and the detailed form of electrodynamic mechanisms dictate the types of interaction that can be involved. The optical trapping of molecules and nanoscale particles can be described in terms of a forward-Rayleigh scattering mechanism, with trapping forces being dependent on the positioning within the commonly non-uniform intensity beam profile. In such a scheme, nanoparticles are commonly attracted to local potential energy minima, ordinarily towards the centre of the beam. For achiral particles the pertinent material response property usually entails an electronic polarizability involving transition electric dipole moments. However, in the case of chiral molecules, additional effects arise through the engagement of magnetic counterpart transition dipoles. It emerges that, when circularly polarized light is used for the trapping, a discriminatory response can be identified between left- and right-handed polarizations. Developing a quantum framework to accurately describe this phenomenon, with a tensor formulation to correctly represent the relevant molecular properties, the theory leads to exact analytical expressions for the associated energy landscape contributions. Specific results are identified for liquids and solutions, both for isotropic media and also where partial alignment arises due to a static electric field. The paper concludes with a pragmatic analysis of the scope for achieving enantiomer separation by such methods
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