Sourcing limestone masonry for restoration of historic buildings: a spectroscopic study

This study presents a combined Fourier transform (FT) mid-infrared, laser Raman and Commission internationale d’éclairage (CIE) L*a*b*system analysis of quarry-derived impure limestone and fallen masonry from a medieval listed building situated in the south east of England, to ascertain how spectroscopic information can be collectively employed to identify the most exacting possible replacement stone source.Data shows that subtle differences in [Al] and [Fe3+] octahedral and tetrahedral site occupancy in glauconite group clays registered in the mid-infrared [3530 cm−1/3620 cm−1] absorption ratio exerts some influence on L*Cab*hab*values. Increases in L*and Cabare associated with decreasing clay content. Theoverall weakness of correlations between infrared and visible range spectral attributes indicates multiple contributing sources to overall color. Evidence indicates that the degree of laser Raman induced background noise is related to the overall calcite content and that activators of fluorescence at 785 nmexcitation wave length may also contribute to rock color. The results are utilized to define closest matching quarry samples to the fallen masonry

Chronological variations in handaxes: patterns detected from fluvial archives in north-west Europe

The use of handaxe morphology as a cultural and temporal marker within the Quaternary Lower–Middle Palaeolithic record has had a very chequered history, and abuses in the past have led recent generations of archaeologist to reject it out of hand. In Britain, however, advances in dating Pleistocene sediments, setting their ages within a framework of ∼11 glacial–interglacial cycles over the past 1 Ma, has revealed several patterns in technology and morphology that must be related to changing practices and cultural preferences over time. These are not predictable, nor are they linear, but nevertheless they may aid understanding of the movements of different peoples in and out of Britain over the past 500 000 years. It is also clear that such patterns are to be expected over a much wider region of the nearby continent, although they might not be identical, or even similar, to those established for southern Britain. This paper extends from explanation of the British patterns to an exploration of the extent to which something comparable can be recognized in neighbouring areas of continental Europe: a baseline for a planned collaborative survey of data from the Acheulean of north-west European river systems

Investigating the Mechanisms Underlying the Heterogeneous VSMC Contribution to Vascular Disease

In healthy blood vessels, vascular smooth muscle cells (VSMCs) exist in a contractile, quiescent state but upon vascular insult can switch phenotype to activate proliferation, migration and remodelling of the extracellular matrix. Phenotypically switched VSMCs contribute most cells within neointimal lesions, characteristic of atherosclerosis and in-stent restenosis, diseases that underlie heart attack and stroke. Using multicolour “Confetti” VSMC-specific lineage tracing in animal models of vascular disease, our lab and others have shown that the extensive VSMC contribution to these lesions results from the clonal expansion of few cells. To understand how oligoclonal VSMC lesion contribution arises and to identify the signals activating VSMC proliferation in vivo, I used quantified VSMC clonal development over time in two models of vascular disease. Following acute vascular injury, the number and sizes of patches of clonally expanded VSMCs steadily increased before reaching a plateau, suggesting rare activation of VSMC proliferation in few cells, rather than clonal competition following widespread VSMC activation. Interestingly, only a subset of medial patches gave rise to neointimal patches, suggesting that VSMC lesion invasion represents a second selective event underlying mature lesion oligoclonality. Infrequent activation of VSMC proliferation in atherosclerosis was evidenced by the absence of plaques with high numbers of colours at any stage of plaque development. Tamoxifen-inducible, VSMC-specific deletion of contractile master regulator Myocd in adult mice had modest phenotypic effects on baseline VSMC contractile marker expression, and on injury-induced VSMC transcriptional response and clonality. In both vascular disease models, VSMC activation was greatly enriched in vascular regions displaying elastic lamina alterations, medial acellularity and immune cell recruitment, implicating these as potential proliferation-inducing cues. However, not all VSMCs in these regions formed patches, suggesting that VSMCs must be primed to respond proliferatively. Consistent with the hypothesis that VSMCs marked by stem cell antigen-1 (SCA1) may represent such a primed population, profiling of chromatin accessibility in SCA1+ VSMCs revealed substantial opening of chromatin at genes showing increased expression in injury-activated compared to healthy VSMCs. Manipulation of RUNX1 and CEBP, transcription factors whose motifs were enriched at activation-specific open chromatin regions, could allow for control of VSMC priming and proliferation.British Heart Foundatio

Mechanisms of vascular smooth muscle cell investment and phenotypic diversification in vascular diseases.

In contrast with the heart, the adult mammalian vasculature retains significant remodelling capacity, dysregulation of which is implicated in disease development. In particular, vascular smooth muscle cells (VSMCs) play major roles in the pathological vascular remodelling characteristic of atherosclerosis, restenosis, aneurysm and pulmonary arterial hypertension. Clonal lineage tracing revealed that the VSMC-contribution to disease results from the hyperproliferation of few pre-existing medial cells and suggested that VSMC-derived cells from the same clone can adopt diverse phenotypes. Studies harnessing the powerful combination of lineage tracing and single-cell transcriptomics have delineated the substantial diversity of VSMC-derived cells in vascular lesions, which are proposed to have both beneficial and detrimental effects on disease severity. Computational analyses further suggest that the pathway from contractile VSMCs in healthy arteries to phenotypically distinct lesional cells consists of multiple, potentially regulatable, steps. A better understanding of how individual steps are controlled could reveal effective therapeutic strategies to minimise VSMC functions that drive pathology whilst maintaining or enhancing their beneficial roles. Here we review current knowledge of VSMC plasticity and highlight important questions that should be addressed to understand how specific stages of VSMC investment and phenotypic diversification are controlled. Implications for developing therapeutic strategies in pathological vascular remodelling are discussed and we explore how cutting-edge approaches could be used to elucidate the molecular mechanisms underlying VSMC regulation

DInSAR estimation of land motion using intermittent coherence with application to the South Derbyshire and Leicestershire coalfields

Differential interferometric synthetic aperture radar (DInSAR) is a recognized remote-sensing method for measuring the land motion occurring between two satellite radar acquisitions. Advanced DInSAR techniques such as persistent scatterers and small baseline methods are excellent over urban and rocky environments but generally poor over more rural and natural terrain where the signal can be intermittently good and bad. Here, we describe the Intermittent Small Baseline Subset (ISBAS) method, which appears to improve results over natural, woodland and agricultural terrain. This technique uses a multi-looked, low-resolution approach, which is particularly suitable for deriving the linear components of subsidence for large-scale deformations. Application of the ISBAS method over a coal mining area in the UK indicates that it is able to significantly improve upon a standard small baseline approach