The paleoclimatic record from a 345 m long ice core from the Hans Tausen Iskappe

The 345 m long ice core retrieved from the Hans Tausen Ice Cap in 1995 (82,5°N, 38°W) in Western Peary Land was sampled in situ for later paleoclimatic δ18Omeasurements in Copenhagen. The upper 125 m covers a little more than 1000 years and indicates strong persistent warming from the late 1920-ties, a maximum warming in the early 1960-ties and a variable climate with no particular trend since the 1960-ties. The δ record over the past 100 years shows similarities with the temperature records from the Greenland west coast stations, Iceland, and the Faroe Islands. The 20th century is the warmest in the entire record, while the periode 1700-1900 A.D. is the coldest during the past 2000 years. A maximum of warm climate seems to be reached around 900-1100 A.D. which then declines to the colder conditions around 1700 A.D. The climatic interpretation of the deepest 105 m of the δ record is more complicated due to the non-steady state of the ice cap: The implication for the paleoclimatic interpretation will be discussed. No glacial ice is present in the bottom ice

Shells and humans: molluscs and other coastal resources from the earliest human occupations at the Mesolithic shell midden of El Mazo (Asturias, Northern Spain)

Human populations exploited coastal areas with intensity during the Mesolithic in Atlantic Europe, resulting in the accumulation of large shell middens. Northern Spain is one of the most prolific regions, and especially the so-called Asturian area. Large accumulations of shellfish led some scholars to propose the existence of intensification in the exploitation of coastal resources in the region during the Mesolithic. In this paper, shell remains (molluscs, crustaceans and echinoderms) from stratigraphic units 114 and 115 (dated to the early Mesolithic c. 9 kys cal BP) at El Mazo cave (Asturias, northern Spain) were studied in order to establish resource exploitation patterns and environmental conditions. Species representation showed that limpets, top shells and sea urchins were preferentially exploited. One-millimetre mesh screens were crucial in establishing an accurate minimum number of individuals for sea urchins and to determine their importance in exploitation patterns. Environmental conditions deduced from shell assemblages indicated that temperate conditions prevailed at the time of the occupation and the morphology of the coastline was similar to today (rocky exposed shores). Information recovered relating to species representation, collection areas and shell biometry reflected some evidence of intensification (reduced shell size, collection in lower areas of exposed shores, no size selection in some units and species) in the exploitation of coastal resources through time. However, the results suggested the existence of changes in collection strategies and resource management, and periods of intense shell collection may have alternated with times of shell stock recovery throughout the Mesolithic.This research was performed as part of the project “The human response to the global climatic change in a littoral zone: the case of the transition to the Holocene in the Cantabrian coast (10,000–5000 cal BC) (HAR2010-22115-C02-01)” funded by the Spanish Ministry of Economy and Competitiveness. AGE was funded by the University of Cantabria through a predoctoral grant and IGZ was funded by the Spanish Ministry of Economy and Competitiveness through a Juan de la Cierva grant. We also would like to thank the University of Cantabria and the IIIPC for providing support, David Cuenca-Solana, Alejandro García Moreno and Lucia Agudo Pérez for their help. We also thank Jennifer Jones for correcting the English. Comments from two anonymous reviewers helped to improve the paper

The co-presence of deletion 7q, 20q and inversion 16 in therapy-related acute myeloid leukemia developed secondary to treatment of breast cancer with cyclophosphamide, doxorubicin, and radiotherapy: a case report

Introduction. Therapy-related acute myeloid leukemia occurs as a complication of treatment with chemotherapy, radiotherapy, immunosuppressive agents or exposure to environmental carcinogens. Case presentation. We report a case of therapy-related acute myeloid leukemia in a 37-year-old Turkish woman in complete remission from breast cancer. Our patient presented to our facility with fatigue, fever, sore throat, peripheral lymphadenopathy, and moderate hepatosplenomegaly. On peripheral blood and bone marrow aspirate smears, monoblasts were present. Immunophenotypic analysis of the bone marrow showed expression of CD11b, CD13, CD14, CD15, CD33, CD34, CD45 and human leukocyte antigen-DR, findings compatible with the diagnosis of acute monoblastic leukemia (French-American-British classification M5a). Therapy-related acute myeloid leukemia developed three years after adjuvant chemotherapy consisting of an alkylating agent, cyclophosphamide and DNA topoisomerase II inhibitor, doxorubicin and adjuvant radiotherapy. Cytogenetic analysis revealed a 46, XX, deletion 7 (q22q34), deletion 20 (q11.2q13.1) karyotype in five out of 20 metaphases and inversion 16 was detected by fluorescence in situ hybridization. There was no response to chemotherapy (cytarabine and idarubicin, FLAG-IDA protocol, azacitidine) and our patient died in the 11th month after diagnosis. Conclusions: The median survival in therapy-related acute myeloid leukemia is shorter compared to de novo acute myeloid leukemia. Also, the response to therapy is poor. In therapy-related acute myeloid leukemia, complex karyotypes have been associated with abnormalities of chromosome 5, rather than 7. To the best of our knowledge, this is the first case of therapy-related acute myeloid leukemia showing the co-presence of deletion 7q, 20q and the inversion 16 signal. © 2012 Yonal et al; licensee BioMed Central Ltd

Hole liquids and gaskets for the ISTUK deep ice core drill

Deep boreholes in polar ice sheets have to be filled with a liquid in order to prevent hole closure due to the overburden pressure of the ice. In Greenland, at ice temperatures of -32℃, the limit for open hole drilling is 400m. In Antarctica, a depth of 900m has been obtained in an open hole. All drilling to deeper depths needs to be performed in a liquid. The borehole liquid should have a density close to that of ice, be non-toxic, available in quantities at reasonable cost, compatible with the materials in the drill, non-aggressive to ice, and have a low viscosity to allow rapid drill movement in the borehole. In practice, no liquid has been available that can fulfill all the requirements. In the past, ethanol/water mixture, DFA/Glycol, DFA/TCE, JET-A1/PCE, DFA/F113,nbutyl acetate, and D60/F113 have been used. All liquids have their own advantages and disadvantages, and the use of all have involved severe compromises. In this paper, these ideal specifications are compared to those of the actually used hole liquids

Resurvey of Bore Hole at Dye 3, South Greenland

AbstractThe 2037 m deep bore hole at Dye 3 in south Greenland was surveyed in 1981, 1983, 1985, and 1986. The directional surveys show the ice flow is planar with a surface velocity of 12.2m/year at an azimuth of 060°, which agrees with surface velocity measured by navigation satellites. Measurements of hole diameter and inclination are highly correlated with dust content in the ice. The temperature measurements show strong convection in the hole fluid with a cell height of about 20 m and an amplitude of 0.1 K. The calculated mean in-situ ice density is 921.3 ± 1.5kg/m3. Due to ice deformation, the lowest 4 m of the hole were not accessible in 1985 and the lowest 180 m were not accessible in 1986.</jats:p