Vittrup Man–The life-history of a genetic foreigner in Neolithic Denmark

The lethally maltreated body of Vittrup Man was deposited in a Danish bog, probably as part of a ritualised sacrifice. It happened between c. 3300 and 3100 cal years BC, i.e., during the period of the local farming-based Funnel Beaker Culture. In terms of skull morphological features, he differs from the majority of the contemporaneous farmers found in Denmark, and associates with hunter-gatherers, who inhabited Scandinavia during the previous millennia. His skeletal remains were selected for transdisciplinary analysis to reveal his life-history in terms of a population historical perspective. We report the combined results of an integrated set of genetic, isotopic, physical anthropological and archaeological analytical approaches. Strontium signature suggests a foreign birthplace that could be in Norway or Sweden. In addition, enamel oxygen isotope values indicate that as a child he lived in a colder climate, i.e., to the north of the regions inhabited by farmers. Genomic data in fact demonstrates that he is closely related to Mesolithic humans known from Norway and Sweden. Moreover, dietary stable isotope analyses on enamel and bone collagen demonstrate a fisher-hunter way of life in his childhood and a diet typical of farmers later on. Such a variable life-history is also reflected by proteomic analysis of hardened organic deposits on his teeth, indicating the consumption of forager food (seal, whale and marine fish) as well as farmer food (sheep/goat). From a dietary isotopic transect of one of his teeth it is shown that his transfer between societies of foragers and farmers took place near to the end of his teenage years

Tailoring ZnO nanostructures by spray pyrolysis and thermal annealing

We report a novel synthesis of ZnO nanorods with hexagonal pyramid-like heads by a simple and low cost technique of spray pyrolysis with the help of zinc acetate and tin (IV) chloride pentahydrate precursors. In the present study, the growth of ZnO nanorods is optimized by varying a number of sprays and annealing temperatures in the synthesis process. FESEM analysis reveals that ZnO nanorods are observed when the number of sprays exceeds 150 and film-like structure is observed below 150 sprays. Nanorods are formed when the molar ratio of zinc acetate to tin (IV) chloride pentahydrate in the solution mixture is 3:1. The optimum annealed temperature for the growth of nanorods is determined to be 350 degrees C. The length and diameter of the vertically aligned nanorods are in the range of 1-3 mu m and 80 nm, respectively. XRD diffraction patterns and HRTEM analysis confirm that the ZnO nanorods are single crystals with a preferred growth direction of 0 0 0 1. The effect of various growth parameters including molar ratio of zinc acetate to tin (IV) chloride pentahydrate in the mixture, number of sprays and annealing temperatures on the growth of ZnO nanorods are systematically studied. A plausible growth mechanism for hexagonal pyramidal heads of ZnO nanorods is discussed. These ZnO nanorods with hexagonal pyramid tips have potential application in photovoltaic devices. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved

Catalyst free single-step fabrication of SnO2/ZnO core–shell nanostructures

Facile catalyst-free synthesis of SnO2/ZnO core–shell nanowires and hierarchical nanostructures grown via a one-step carbon assisted thermal evaporation method under ambient pressure is reported. A white wool-like mass forms at the side and on top of a quartz boat during the process that was analyzed by field emission scanning electron microscopy (FESEM). X-ray diffraction patterns exhibit that the as-synthesized SnO2/ZnO nanostructures consist of single phase of ZnO and SnO2. Transmission electron microscopy (TEM) suggests that the wool-like mass contains core–shell type SnO2/ZnO nanowires as well as hierarchical nanostructures. In the core–shell nanowires, SnO2 forms the core, while ZnO is the shell. In the hierarchical nanostructures, hexagonal shaped ZnO branches grow on the ZnO shell layer at long growth duration. Both types of nanostructures formed in the quartz boat are suggested to grow by the vapor–solid (VS) mechanism. Structural characteristics of the nanostructures are discussed. These nanostructures may have potential applications in chemical gas sensors and photovoltaic devices

Gas sensing properties of zinc stannate (Zn2SnO4) nanowires prepared by carbon, assisted thermal evaporation process

Zn2SnO4 nanowires are successfully synthesized by a carbon assisted thermal evaporation process with the help of a gold catalyst under ambient pressure. The as-synthesized nanowires are characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) equipped with an energy dispersive X-ray spectroscopy (EDS). The XRD patterns and elemental mapping via TEM-EDS clearly indicate that the nanowires are Zn2SnO4 with face centered spinel structure. HRTEM image confirms that Zn2SnO4 nanowires are single crystalline with an interplanar spacing of 0.26 nm, which is ascribed to the d-spacing of (3 1 1) planes of Zn2SnO4. The optimum processing condition and a possible formation mechanism of these Zn2SnO4 nanowires are discussed. Additionally, sensor performance of Zn2SnO4 nanowires based sensor is studied for various test gases such as ethanol, methane and hydrogen. The results reveal that Zn2SnO4 nanowires exhibit excellent sensitivity and selectivity toward ethanol with quick response and recovery times. The response of the Zn2SnO4 nanowires based sensors to 50 ppm ethanol at an optimum operating temperature of 500 degrees C is about 21.6 with response and recovery times of about 116 s and 182 s, respectively. (C) 2014 Elsevier B.V. All rights reserved

Enhanced Ethanol Gas Sensing Properties of SnO2-Core/ZnO-Shell Nanostructures

An inexpensive single-step carbon-assisted thermal evaporation method for the growth of SnO2-core/ZnO-shell nanostructures is described, and the ethanol sensing properties are presented. The structure and phases of the grown nanostructures are investigated by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques. XRD analysis indicates that the core-shell nanostructures have good crystallinity. At a lower growth duration of 15 min, only SnO2 nanowires with a rectangular cross-section are observed, while the ZnO shell is observed when the growth time is increased to 30 min. Core-shell hierarchical nanostructures are present for a growth time exceeding 60 min. The growth mechanism for SnO2-core/ZnO-shell nanowires and hierarchical nanostructures are also discussed. The sensitivity of the synthesized SnO2-core/ZnO-shell nanostructures towards ethanol sensing is investigated. Results show that the SnO2-core/ZnO-shell nanostructures deposited at 90 min exhibit enhanced sensitivity to ethanol. The sensitivity of SnO2-core/ZnO-shell nanostructures towards 20 ppm ethanol gas at 400 °C is about ~5-times that of SnO2 nanowires. This improvement in ethanol gas response is attributed to high active sensing sites and the synergistic effect of the encapsulation of SnO2 by ZnO nanostructures

Vittrup Man–The life-history of a genetic foreigner in Neolithic Denmark

Acknowledgements: We acknowledge a conservation specialist from Finland (NLES, previous employee of Bevaringscenter Nordjylland) for calling attention to the archaic appearance of the Vittrup skull; Paula Reimer (14CHRONO, Queen’s University Belfast), for providing methodological clarifications on AMS dates and isotopic measurements; Paul Fullagar (University of North Carolina-Chapel Hill) and David Dettman (University of Arizona, Tucson) for effective handling of our enamel Sr and δ13C & δ18O samples, respectively, during a complicated period of pandemic close downs; Poul Otto Nielsen (Danish National Museum) for access to archives and for assistance in having artefact photos produced for the paper. Moreover, we express our sincere thanks to Niels Lynnerup (Copenhagen University), Poul Otto Nielsen (Danish National Museum) and Kurt Gron (Durham University) for useful comments on earlier versions of the manuscript.Funder: Riksbankens Jubileumsfond; funder-id: http://dx.doi.org/10.13039/501100004472; Grant(s): M16-0455:1Funder: FP7 People: Marie-Curie Actions; funder-id: http://dx.doi.org/10.13039/100011264; Grant(s): 300554The lethally maltreated body of Vittrup Man was deposited in a Danish bog, probably as part of a ritualised sacrifice. It happened between c. 3300 and 3100 cal years BC, i.e., during the period of the local farming-based Funnel Beaker Culture. In terms of skull morphological features, he differs from the majority of the contemporaneous farmers found in Denmark, and associates with hunter-gatherers, who inhabited Scandinavia during the previous millennia. His skeletal remains were selected for transdisciplinary analysis to reveal his life-history in terms of a population historical perspective. We report the combined results of an integrated set of genetic, isotopic, physical anthropological and archaeological analytical approaches. Strontium signature suggests a foreign birthplace that could be in Norway or Sweden. In addition, enamel oxygen isotope values indicate that as a child he lived in a colder climate, i.e., to the north of the regions inhabited by farmers. Genomic data in fact demonstrates that he is closely related to Mesolithic humans known from Norway and Sweden. Moreover, dietary stable isotope analyses on enamel and bone collagen demonstrate a fisher-hunter way of life in his childhood and a diet typical of farmers later on. Such a variable life-history is also reflected by proteomic analysis of hardened organic deposits on his teeth, indicating the consumption of forager food (seal, whale and marine fish) as well as farmer food (sheep/goat). From a dietary isotopic transect of one of his teeth it is shown that his transfer between societies of foragers and farmers took place near to the end of his teenage years.</jats:p