99 research outputs found

    DRIVERS OF DEMOGRAPHIC AND SOCIOECONOMIC SHIFTS AT THE BRIDGE RIVER SITE (EeRl4), BRITISH COLUMBIA

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    ABSTRACT Nowell, Sarah, M.A. Spring 2017 Anthropology Drivers of Demographic and Socioeconomic Shifts Regarding the Bridge River II – Bridge River III Transition at the Bridge River Village (EeRl4), British Columbia Chairperson: Dr. Anna Marie Prentiss The Bridge River site is located near the confluence of the Bridge and Fraser Rivers in the Mid-Fraser canyon near Lillooet, British Columbia. This region has long been popular for archaeologists seeking to understand the emergence of wealth-based inequality in complex hunter-gatherers. Housepit 54 is one of over 80 pithouses or s7ístken that was continuously occupied throughout most of the village history. It contains 17 intact anthropogenic or manmade floors, allowing archaeologists to address many types of cultural variation over time at the household level. This thesis seeks to understand the underlying processes that drive socioeconomic and demographic growth as evidenced by variation in lithic technology as well as feature contents and distribution as they relate to the structural expansion that occurred between two occupational floors. It draws heavily on ethnographic record, ethnoarchaeology, household archaeology, and past studies of complex hunter-gatherers to determine whether this expansion might have resulted from a demographic spike that necessitated the structural addition, or whether members of the household held feasting events or other social activities designed to increase household status and attract new members. While access to prestige and non-local lithic materials does not change in a way that indicates an increase in production related to feasting and social events, analysis of feature types and locations in either occupational floor does show that the changes that occur in storage strategy as well as hearth density and placement indicate that there was a shift to a more centralized or communal household organization. This thesis finds that the feasting hypothesis is the most likely scenario and discusses ways in which to expand this line of inquiry in future studies

    Models of hyperelliptic curves over p-adic fields

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    Let C : y² = f(x) be a hyperelliptic curve, with tame potentially semistable reduction, over a local field with algebraically closed residue field. The p-adic distances between the roots of f(x) can be described by a purely combinatorial object known as a cluster picture. We show that the cluster picture of C, along with the leading coefficient of f, completely determines the dual graph of the special fibre of the minimal strict normal crossings (SNC) model of C. In particular, we give an explicit description of the special fibre in terms of this data. Further to this, we define open quotient BY trees, showing there is a one-to-one correspondence between these and cluster pictures of hyperelliptic curves with tame reduction. Using these trees we introduce a way of classifying reduction types of hyperelliptic curves. As a demonstration of our results we give a complete classification in genus 2 using cluster pictures and open quotient BY trees

    A user's guide to the local arithmetic of hyperelliptic curves

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    A new approach has been recently developed to study the arithmetic of hyperelliptic curves y2=f(x)y^2=f(x) over local fields of odd residue characteristic via combinatorial data associated to the roots of ff. Since its introduction, numerous papers have used this machinery of "cluster pictures" to compute a plethora of arithmetic invariants associated to these curves. The purpose of this user's guide is to summarise and centralise all of these results in a self-contained fashion, complemented by an abundance of examples.Comment: Minor changes. To appear in the Bulletin of the London Mathematical Societ

    Assembly of high nuclearity clusters from a family of tripodal tris-carboxylate ligands

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    A family of four tris-carboxylic acid ligands 1,3,5-tris(4′-carboxybiphenyl-2-yl)benzene (H3L1), 1,3,5-tris-2-carboxyphenylbenzene (H3L2), 1,3,5-tris(4″-carboxy-para-terphenyl-2-yl)benzene (H3L3) and 1,3,5-tris(3′-carboxybiphenyl-2-yl)benzene (H3L4) have been synthesised and reacted with first row transition metal cations to give nine complexes which have been structurally characterised by X-ray crystallography. The ligands share a common design motif having three arms connected to a benzene core via three ortho-disubstituted phenyl linkers. The ligands vary in length and direction of the carboxylic acid functionalised arms and are all able to adopt tripodal conformations in which the three arms are directed facially. The structures of [Zn8(μ4-O)(L1)4(HCO2)2(H2O)0.33(DMF)2] (1a-Zn), [Co14(L2)6((μ3-OH)8(HCO2)2(DMF)4(H2O)6] (2-Co), [Ni14(L2)6(μ3-OH)8(HCO2)2(DMF)4(H2O)6] (2-Ni), [Zn8(μ4-O)(L3)4(DMF)(H2O)4(NO3)2] (3-Zn), [Ni5(μ-OH)4(L2)2(H2O)6(DMF)4] (5-Ni), [Co8(μ4-O)4(L4)4(DMF)3(H2O)] (6-Co) and Fe3(μ3-O)(L4)2(H2O)(DMF)2)] (7-Fe) contain polynuclear clusters surrounded by ligands (L1–4)3− in tripodal conformations. The structure of [Zn2(HL1)2(DMF)4] (1b-Zn) shows it to be a binuclear complex in which the two ligands (HL2)2− are partially deprotonated whilst {[Zn3(L2)2(DMF)(H2O)(C5H5N)]·6(DMF)}n (4-Zn) is a 2D coordination network containing {Zn2(RCO2)4(solv)2} paddlewheel units. The conformations of the ligand arms in the complexes have been analysed, confirming that the shared ortho-disubstituted phenyl ring motif is a powerful and versatile tool for designing ligands able to form high-nuclearity coordination clusters when reacted with transition metal cations

    Sublithospheric diamond ages and the supercontinent cycle.

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    Subduction related to the ancient supercontinent cycle is poorly constrained by mantle samples. Sublithospheric diamond crystallization records the release of melts from subducting oceanic lithosphere at 300-700 km depths1,2 and is especially suited to tracking the timing and effects of deep mantle processes on supercontinents. Here we show that four isotope systems (Rb-Sr, Sm-Nd, U-Pb and Re-Os) applied to Fe-sulfide and CaSiO3 inclusions within 13 sublithospheric diamonds from Juína (Brazil) and Kankan (Guinea) give broadly overlapping crystallization ages from around 450 to 650 million years ago. The intracratonic location of the diamond deposits on Gondwana and the ages, initial isotopic ratios, and trace element content of the inclusions indicate formation from a peri-Gondwanan subduction system. Preservation of these Neoproterozoic-Palaeozoic sublithospheric diamonds beneath Gondwana until its Cretaceous breakup, coupled with majorite geobarometry3,4, suggests that they accreted to and were retained in the lithospheric keel for more than 300 Myr during supercontinent migration. We propose that this process of lithosphere growth-with diamonds attached to the supercontinent keel by the diapiric uprise of depleted buoyant material and pieces of slab crust-could have enhanced supercontinent stability

    Notch Signaling Activates Yorkie Non-Cell Autonomously in Drosophila

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    In Drosophila imaginal epithelia, cells mutant for the endocytic neoplastic tumor suppressor gene vps25 stimulate nearby untransformed cells to express Drosophila Inhibitor-of-Apoptosis-Protein-1 (DIAP-1), conferring resistance to apoptosis non-cell autonomously. Here, we show that the non-cell autonomous induction of DIAP-1 is mediated by Yorkie, the conserved downstream effector of Hippo signaling. The non-cell autonomous induction of Yorkie is due to Notch signaling from vps25 mutant cells. Moreover, activated Notch in normal cells is sufficient to induce non-cell autonomous Yorkie activity in wing imaginal discs. Our data identify a novel mechanism by which Notch promotes cell survival non-cell autonomously and by which neoplastic tumor cells generate a supportive microenvironment for tumor growth

    A Novel murine model identifies cooperating mutations and therapeutic targets critical for chronic myeloid leukemia progression

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    The introduction of highly selective ABL-tyrosine kinase inhibitors (TKIs) has revolutionized therapy for chronic myeloid leukemia (CML). However, TKIs are only efficacious in the chronic phase of the disease and effective therapies for TKI-refractory CML, or after progression to blast crisis (BC), are lacking. Whereas the chronic phase of CML is dependent on BCR-ABL, additional mutations are required for progression to BC. However, the identity of these mutations and the pathways they affect are poorly understood, hampering our ability to identify therapeutic targets and improve outcomes. Here, we describe a novel mouse model that allows identification of mechanisms of BC progression in an unbiased and tractable manner, using transposon-based insertional mutagenesis on the background of chronic phase CML. Our BC model is the first to faithfully recapitulate the phenotype, cellular and molecular biology of human CML progression. We report a heterogeneous and unique pattern of insertions identifying known and novel candidate genes and demonstrate that these pathways drive disease progression and provide potential targets for novel therapeutic strategies. Our model greatly informs the biology of CML progression and provides a potent resource for the development of candidate therapies to improve the dismal outcomes in this highly aggressive disease.Work in the Huntly laboratory is funded by CRUK, The European Research Council (ERC), Leukaemia Lymphoma Research, the Kay Kendall Leukaemia Fund, Wellcome Trust, the Medical Research Council (UK), the Leukemia Lymphoma Society America and the Cambridge NIHR Biomedical Research centre. David Adams is funded by Cancer Research UK and Wellcome Trust. Steffen Koschmieder has received funding from Deutsche José Carreras Leukämie-Stiftung (DJCLS; grant 10/23).This is the final published version. It first appeared at http://dx.doi.org/10.1084/jem.2014166
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