119 research outputs found

    Early and Middle Holocene Hunter-Gatherer Occupations in Western Amazonia: The Hidden Shell Middens

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    We report on previously unknown early archaeological sites in the Bolivian lowlands, demonstrating for the first time early and middle Holocene human presence in western Amazonia. Multidisciplinary research in forest islands situated in seasonally-inundated savannahs has revealed stratified shell middens produced by human foragers as early as 10,000 years ago, making them the oldest archaeological sites in the region. The absence of stone resources and partial burial by recent alluvial sediments has meant that these kinds of deposits have, until now, remained unidentified. We conducted core sampling, archaeological excavations and an interdisciplinary study of the stratigraphy and recovered materials from three shell midden mounds. Based on multiple lines of evidence, including radiocarbon dating, sedimentary proxies (elements, steroids and black carbon), micromorphology and faunal analysis, we demonstrate the anthropogenic origin and antiquity of these sites. In a tropical and geomorphologically active landscape often considered challenging both for early human occupation and for the preservation of hunter-gatherer sites, the newly discovered shell middens provide evidence for early to middle Holocene occupation and illustrate the potential for identifying and interpreting early open-air archaeological sites in western Amazonia. The existence of early hunter-gatherer sites in the Bolivian lowlands sheds new light on the region's past and offers a new context within which the late Holocene "Earthmovers" of the Llanos de Moxos could have emerged. © 2013 Lombardo et al

    Gendering the careers of young professionals: some early findings from a longitudinal study. in Organizing/theorizing: developments in organization theory and practice

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    Wonders whether companies actually have employees best interests at heart across physical, mental and spiritual spheres. Posits that most organizations ignore their workforce – not even, in many cases, describing workers as assets! Describes many studies to back up this claim in theis work based on the 2002 Employment Research Unit Annual Conference, in Cardiff, Wales

    Unemployment as a liminoid phenomenon:Identity trajectories in times of crisis

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    This article explores the formation of work identities in times of financial crisis and extreme austerity. In particular, we build upon prior studies of liminality, a state of in-betweenness and ambiguity, and explore how individuals, whose employment opportunities and career paths have been disrupted, construct their work/professional identities. The study draws on 39 semi-structured interviews conducted in Greece, where high levels of unemployment and economic stagnation prevail. Persistent crisis and austerity have prompted extended periods of instability and unpredictability during which the unemployed narratively (re)construct their past, present and future work selves. We propose that frequent job changes and persistent lack of work are not linear experiences but instead, require multiple and at times, ambiguous, fluid and incomplete identifications. These identifications include attempts to re-affirm prior stable professional identities, to institute new, yet still unidentified, careers or to enact what we term ‘liminoid identity positions’. When in liminoid positions, instead of pursuing intangible work futures, the unemployed create anti-structural spaces in which they collectively practice alternative forms of work and organization. Concluding, the article provides grounds for the study of individuals’ capacity to challenge the neoliberal restructuring of work and the possibilities for transformation in periods of unemployment and crisis.© 2017, published by SAGE. The attached document is an author produced version of a paper, uploaded in accordance with the publisher’s self- archiving policy. The final published version (version of record) is available online at the link below. Some minor differences between this version and the final published version may remain. We suggest you refer to the final published version should you wish to cite from it

    Thermal degradation of rye and maize straw: Lipid pattern changes as a function of temperature

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    Future climatic conditions may coincide with an increased potential for wildfires in grassland and forest ecosystems, whereby charred biomass would be incorporated into soils. Molecular changes in biomass upon charring have been frequently analysed with a focus on black carbon. Aliphatic and aromatic hydrocarbons, known to be liberated during incomplete combustion of biomass have been preferentially analysed in soot particles, whereas determinations of these compounds in charred biomass residues are scarce. We discuss the influence of increasing charring temperature on the aliphatic and aromatic hydrocarbon composition of crop grass combustion residues. Straw from rye, representing C3 grasses and maize, representing C4 grasses, was charred in the presence of limited oxygen at 300, 400 and 500 °C. Typical n-alkane distribution patterns with a strong predominance of long chain odd-numbered n-alkanes maximising at C31 were observed in raw straw. Upon combustion at 300 °C aliphatic hydrocarbons in char were dominated by sterenes, whereas at 400 °C sterenes disappeared and medium chain length n-alkanes, maximising around n-C20, with a balanced odd/even distribution were present. At a charring temperature of 500 °C n-alkane chain length shifted to short chain homologues, maximising at C18 with a pronounced predominance of even homologues. Even numbered, short chain n-alkanes in soils may thus serve as a marker for residues of charred biomass. Aromatic hydrocarbons indicate an onset of aromatization of biomass already at 300 °C, followed by severe aromatization upon incomplete combustion at 400–500 °C. The diagnostic composition of aliphatic and aromatic hydrocarbons from charred biomass affords potential for identifying residues from burned vegetation in recent and fossil soils and sediments

    Carbon accrual in the Atacama Desert

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    The Atacama Desert is the oldest and driest desert on Earth, nevertheless traces of life have been observed in several places, accumulating residues of organic matter (OM) in the desert soil. We evaluated to which degree the distribution of soil organic carbon (SOC) stocks depends on aridity. We questioned that these OM traces of life preferentially accumulate in topsoil and investigated whether there was also an enrichment of OM in deeper subsoil. We sampled four west-east directed transects with increasing distance to the coast, spanning the Atacama Desert from north to south, plus a hyperarid site at Yungay in the centre of the desert. With a nested sampling design we addressed topsoil heterogeneity at each sampling site (n ≤ 18). For 12 of these sites soil profiles were dug to 0.6–2.0 m depth. The SOC concentrations were determined for each sample by temperature-dependent differentiation of total carbon

    Chemical interactions between Bi2Sr3CaO7(Bi-2310) and Bi2Sr2Ca0.8Dy0.2Cu2O8 (Bi-2212(Dy))

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    The chemical interactions between Bi2Sr3CaO7 (Bi-2310) and Bi2Sr2Ca0.8Dy0.2Cu2O8 (Bi-2212(Dy)) at 965 degrees C were investigated by means of: (i) an interdiffusion couple and (ii) layers deposited by dip coating on oxidized nickel Substrates. The samples were characterized by optical and electron microscopies, energy-dispersive x-ray (EDX) analysis and x-ray diffraction. It turns out that at the peritectic temperature Of Bi-2212(Dy), the Bi-2310 phase reacts with the liquid phase resulting from the peritectic decomposition of the Bi-2212(Dy) phase. Dissolution of Bi-2310 leads to an enrichment in Sr and an impoverishment in Cu of the liquid phase, resulting in a shift of the composition of the insoluble phase towards the Ca-rich end of the (Ca, Sr)O Solid Solution
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