54 research outputs found
Two-hundred-year Record of Biogenic Sulfur in a South Greenland Ice Core (20D)
The concentration of methanesulfonic acid (MSA) was determined in a shallow south central Greenland ice core(20D). This study provides a high-resolution record of the DMS-derived biogenic sulfur in Greenland precipitation over the past 200 years. The mean concentration of MSA is 3.30 ppb(σ = 2.38 ppb,n = 1134). The general trend of MSA is an increase from 3.01 to 4.10 ppb between 1767 and 1900, followed by a steady decrease to 2.34 ppb at the present time. This trend is in marked contrast to that of non-sea-salt sulfate (nss SO42-), which increases dramatically after 1900 due to the input of anthropogenic sulfur. The MSA fraction ((MSA/(MSA+ nss SO42-))* 100) ranges from a mean of 15% in preindustrial ice to less than 5% in recent ice. These MSA fraction suggest that approximately 5 to 40% of the sulfur in recent Greenland ice is of biological origin. It is suggested that there is a significant low-latitude component to the biogenic sulfur in the core and that variations in the MSA fraction reflect changes in the relative strengths of low- and high-latitude inputs. The data shown o evidence for a strong dependence of dimethyl sulfide(DMS) emissions on sea surface temperature during the last century. There is also no indication that the yield of MSA from DMS oxidation has been altered by increased NOx levels over the North Atlantic during this period
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
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
Two-hundred-year record of biogenic sulfur in a south Greenland ice core (20D)
The concentration of methanesulfonic acid (MSA) was determined in a shallow south central Greenland ice core(20D). This study provides a high-resolution record of the DMS-derived biogenic sulfur in Greenland precipitation over the past 200 years. The mean concentration of MSA is 3.30 ppb(σ = 2.38 ppb,n = 1134). The general trend of MSA is an increase from 3.01 to 4.10 ppb between 1767 and 1900, followed by a steady decrease to 2.34 ppb at the present time. This trend is in marked contrast to that of non-sea-salt sulfate (nss SO42-), which increases dramatically after 1900 due to the input of anthropogenic sulfur. The MSA fraction ((MSA/(MSA+ nss SO42-))* 100) ranges from a mean of 15% in preindustrial ice to less than 5% in recent ice. These MSA fraction suggest that approximately 5 to 40% of the sulfur in recent Greenland ice is of biological origin. It is suggested that there is a significant low-latitude component to the biogenic sulfur in the core and that variations in the MSA fraction reflect changes in the relative strengths of low- and high-latitude inputs. The data shown o evidence for a strong dependence of dimethyl sulfide(DMS) emissions on sea surface temperature during the last century. There is also no indication that the yield of MSA from DMS oxidation has been altered by increased NOx levels over the North Atlantic during this period
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