Using Optically Stimulated Luminescence to Unravel Sedimentary Processes of the Usumacinta and Grijalva Rivers (SE Mexico)

This report provides an optically stimulated luminescence (OSL) chronology for sediment collected through terrace deposits of the Usumacinta and Grijalva rivers in SE Mexico. The Grijalva and Usumacinta rivers are susceptible to flooding during the hurricane season (between May and November), affecting the population of the state of Tabasco, and leaving many households at a flood risk. The present study was initiated to obtain an understanding of the sediment processes, rates and frequency of flood events in the past. The report summaries the initial luminescence profiling, using a SUERC PPSL system, and laboratory analysis, used to characterise the stratigraphy and interpret sedimentary processes in each profile, together with the quantitative quartz SAR dating used to define chronologies in each. Initial luminescence profiling revealed that the stratigraphy in each was complex, reflecting multiple cycles of deposition, with maxima, followed by a tail to lower intensities, possibly indicating deposition during extreme flood events, followed by a period in which the sediment was mixed and the luminescence signals reset. The laboratory profiling reproduced the apparent maxima/trends in the field profiling dataset. In the Grijalva section, the profiling samples encompass the full range of variations in the IRSL net signal intensities, re-affirming the complex stratigraphy. In the Usumacinta section, the profiling samples were positioned on the trend of a normal age-depth progression, which may indicate that the horizons sampled are well suited for quartz SAR dating. Given the nature of the sediment sampled, it is unsurprising that the equivalent dose distributions obtained for each of the dating samples showed considerable scatter, leading to some ambiguity in estimating a stored dose for age calculations. In each, a number of aliquots returned high equivalent dose values, implying residual luminescence signals (leading to higher apparent ages), and others, low values, implying re-setting of the luminescence signals in the modern environment. It is well recognised that fluvial sediment of this sort can enclose mixed-age populations. It has been argued elsewhere (Fuchs and Lang, 2001; Lepper et al., 2000; Olley et al., 1998; Olley et al., 1999) that the lowest population of dose(s) may best represent the burial dose of the youngest depositional component, and that an arbitrary value of say the lowest 5% be used in age calculations. However, if this method was instigated for the Mexican samples, it would include the low equivalent dose values thought to reflect contamination from the surface, by bioturbation or some other weathering process, leading to artificially young ages. Therefore, each sample was evaluated on an individual basis, where low equivalent doses were considered to represent contamination and rejected, along with high equivalent dose outliers and any aliquots which failed SAR acceptance criteria. The weighted mean and weighted standard deviation of the reduced set were used in age calculations. The dating results reported here provide a first chronology to interpret the changing fluvial dynamics of the Usumacinta and Grijalva rivers, and a means to quantify flood events through the historical period. The chronology established for the Grijalva section spans from the 6th century AD to the 12th century AD; and the chronology for the Usumacinta section from the 17th century AD to the 19th century AD

Susceptibility to disease (tropical theileriosis) is associated with differential expression of host genes that possess motifs recognised by a pathogen DNA binding protein

BACKGROUND: Knowledge of factors that influence the outcome of infection are crucial for determining the risk of severe disease and requires the characterisation of pathogen-host interactions that have evolved to confer variable susceptibility to infection. Cattle infected by Theileria annulata show a wide range in disease severity. Native (Bos indicus) Sahiwal cattle are tolerant to infection, whereas exotic (Bos taurus) Holstein cattle are susceptible to acute disease. METHODOLOGY/PRINCIPAL FINDINGS: We used RNA-seq to assess whether Theileria infected cell lines from Sahiwal cattle display a different transcriptome profile compared to Holstein and screened for altered expression of parasite factors that could generate differences in host cell gene expression. Significant differences (<0.1 FDR) in the expression level of a large number (2211) of bovine genes were identified, with enrichment of genes associated with Type I IFN, cholesterol biosynthesis, oncogenesis and parasite infection. A screen for parasite factors found limited evidence for differential expression. However, the number and location of DNA motifs bound by the TashAT2 factor (TA20095) were found to differ between the genomes of B. indicus vs. B. taurus, and divergent motif patterns were identified in infection-associated genes differentially expressed between Sahiwal and Holstein infected cells. CONCLUSIONS/SIGNIFICANCE: We conclude that divergent pathogen-host molecular interactions that influence chromatin architecture of the infected cell are a major determinant in the generation of gene expression differences linked to disease susceptibility

Goldilocks or Plain Jane? The PGE metallogeny of the Bushveld LIP as recorded by the Rooiberg lavas

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record

Artists on the edge of the world : an integrated approach to the study of Magdalenian engraved stone plaquettes from Jersey (Channel Islands)

Excavations at Les Varines were funded by Jersey Heritage through the States of Jersey Tourism Development Fund (https://www.gov.je/Leisure/Events/TourismDevelopmentFundTDF/pages/abouttdf.aspx) in 2013-15 and in 2017 (BS received the funding), by the British Museum research fund in 2016-18 (https://www.britishmuseum.org/research) (Grant nos EC164/EC208) (BS received the funding), in 2016 by British Academy (https://www.thebritishacademy.ac.uk) small grant SG152868 (CC received the funding) and Society of Antiquaries (https://www.sal.org.uk/) Research Grants R121086 in 2017 and BH181355 in 2018 (CC received the funding). Funding from the Universities of Manchester, Southampton and UCL supported student training at the excavation. Silvia Bello’s work was part of the ‘Human Behaviour in 3D’ Project funded by the Calleva Foundation. Beccy Scott’s work was also supported by the Calleva foundation (Pathways to Ancient Britain project).The Upper Palaeolithic is characterised by the appearance of iconographic expressions most often depicting animals, including anthropomorphic forms, and geometric signs. The Late Upper Palaeolithic Magdalenian saw a flourishing of such depictions, encompassing cave art, engraving of stone, bone and antler blanks and decoration of tools and weapons. Though Magdalenian settlement exists as far northwest as Britain, there is a limited range of art known from this region, possibly associated with only fleeting occupation of Britain during this period. Stone plaquettes, flat fragments of stone engraved on at least one surface, have been found in large quantities at numerous sites spanning the temporal and geographical spread of the Magdalenian, but they have been absent so far from the archaeological record of the British Isles. Between 2015 and 2018, ten fragments of stone plaquettes extensively engraved with abstract designs were uncovered at the Magdalenian site of Les Varines, Jersey, Channel Islands. In this paper, we report detailed analyses of these finds, which provide new evidence for technologies of abstract mark-making, and their significance within the lives of people on the edge of the Magdalenian world. These engraved stone fragments represent important, rare evidence of artistic expression in what is the far northern and western range of the Magdalenian and add new insight to the wider significance of dynamic practices of artistic expression during the Upper Palaeolithic.Publisher PDFPeer reviewe

A bovine lymphosarcoma cell line infected with theileria annulata exhibits an irreversible reconfiguration of host cell gene expression

Theileria annulata, an intracellular parasite of bovine lymphoid cells, induces substantial phenotypic alterations to its host cell including continuous proliferation, cytoskeletal changes and resistance to apoptosis. While parasite induced modulation of host cell signal transduction pathways and NFκB activation are established, there remains considerable speculation on the complexities of the parasite directed control mechanisms that govern these radical changes to the host cell. Our objectives in this study were to provide a comprehensive analysis of the global changes to host cell gene expression with emphasis on those that result from direct intervention by the parasite. By using comparative microarray analysis of an uninfected bovine cell line and its Theileria infected counterpart, in conjunction with use of the specific parasitacidal agent, buparvaquone, we have identified a large number of host cell gene expression changes that result from parasite infection. Our results indicate that the viable parasite can irreversibly modify the transformed phenotype of a bovine cell line. Fifty percent of genes with altered expression failed to show a reversible response to parasite death, a possible contributing factor to initiation of host cell apoptosis. The genes that did show an early predicted response to loss of parasite viability highlighted a sub-group of genes that are likely to be under direct control by parasite infection. Network and pathway analysis demonstrated that this sub-group is significantly enriched for genes involved in regulation of chromatin modification and gene expression. The results provide evidence that the Theileria parasite has the regulatory capacity to generate widespread change to host cell gene expression in a complex and largely irreversible manner

c-kitpos GATA-4 High Rat Cardiac Stem Cells Foster Adult Cardiomyocyte Survival through IGF-1 Paracrine Signalling

Resident c-kit positive (c-kitpos) cardiac stem cells (CSCs) could be considered the most appropriate cell type for myocardial regeneration therapies. However, much is still unknown regarding their biological properties and potential.We produced clones of high and low expressing GATA-4 CSCs from long-term bulk-cultured c-kitpos CSCs isolated from adult rat hearts. When c-kitpos GATA-4 high expressing clonal CSCs (cCSCs) were co-cultured with adult rat ventricular cardiomyocytes, we observed increased survival and contractility of the cardiomyocytes, compared to cardiomyocytes cultured alone, co-cultured with fibroblasts or c-kitpos GATA-4 low expressing cCSCs. When analysed by ELISA, the concentration of IGF-1 was significantly increased in the c-kitpos GATA-4 high cCSC/cardiomyocyte co-cultures and there was a significant correlation between IGF-1 concentration and cardiomyocyte survival. We showed the activation of the IGF-1 receptor and its downstream molecular targets in cardiomyocytes co-cultured with c-kitpos GATA-4 high cCSCs but not in cardiomyocytes that were cultured alone, co-cultured with fibroblasts or c-kitpos GATA-4 low cCSCs. Addition of a blocking antibody specific to the IGF-1 receptor inhibited the survival of cardiomyocytes and prevented the activation of its signalling in cardiomyocytes in the c-kitpos GATA-4 high cCSC/cardiomyocyte co-culture system. IGF-1 supplementation or IGF-1 high conditioned medium taken from the co-culture of c-kitpos GATA-4 high cCSCs plus cardiomyocytes did extend the survival and contractility of cardiomyocytes cultured alone and cardiomyocytes co-cultured with c-kitpos GATA-4 low cCSCs.c-kitpos GATA-4 high cCSCs exert a paracrine survival effect on cardiomyocytes through induction of the IGF-1R and signalling pathway