39 research outputs found

    Methods for the sampling and analysis of marine aerosols: results from the 2008 GEOTRACES aerosol intercalibration experiment

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    Atmospheric deposition of trace elements and isotopes (TEI) is an important source of trace metals to the open ocean, impacting TEI budgets and distributions, stimulating oceanic primary productivity, and influencing biological community structure and function. Thus, accurate sampling of aerosol TEIs is a vital component of ongoing GEOTRACES cruises, and standardized aerosol TEI sampling and analysis procedures allow the comparison of data from different sites and investigators. Here, we report the results of an aerosol analysis intercalibration study by seventeen laboratories for select GEOTRACES-relevant aerosol species (Al, Fe, Ti, V, Zn, Pb, Hg, NO3-, and SO42-) for samples collected in September 2008. The collection equipment and filter substrates are appropriate for the GEOTRACES program, as evidenced by low blanks and detection limits relative to analyte concentrations. Analysis of bulk aerosol sample replicates were in better agreement when the processing protocol was constrained (+/- 9% RSD or better on replicate analyses by a single lab, n = 7) than when it was not (generally 20% RSD or worse among laboratories using different methodologies), suggesting that the observed variability was mainly due to methodological differences rather than sample heterogeneity. Much greater variability was observed for fractional solubility of aerosol trace elements and major anions, due to differing extraction methods. Accuracy is difficult to establish without an SRM representative of aerosols, and we are developing an SRM for this purpose. Based on these findings, we provide recommendations for the GEOTRACES program to and macro-nutrients to the open ocean (Okin et al. 2011) and is a key component of the international GEOTRACES program (GEOTRACES Planning Group 2006). A priority of the GEOTRACES program is to quantify both major and trace elements (e. g., Al, Fe, Ti, V, Zn, Pb, and Hg) and species such as nitrate and sulfate in marine aerosols. Therefore, marine aerosol samples collected during GEOTRACES cruises must follow sampling protocols that permit the collection and analysis of as many elements and compounds as possible, while meeting the constraints associated with basin-wide oceanographic cruises (e. g., space limitations, high-frequency sampling, etc.)

    Transcript profiling of candidate genes in testis of pigs exhibiting large differences in androstenone levels

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    <p>Abstract</p> <p>Background</p> <p>Boar taint is an unpleasant odor and flavor of the meat and occurs in a high proportion of uncastrated male pigs. Androstenone, a steroid produced in testis and acting as a sex pheromone regulating reproductive function in female pigs, is one of the main compounds responsible for boar taint. The primary goal of the present investigation was to determine the differential gene expression of selected candidate genes related to levels of androstenone in pigs.</p> <p>Results</p> <p>Altogether 2560 boars from the Norwegian Landrace and Duroc populations were included in this study. Testicle samples from the 192 boars with most extreme high or low levels of androstenone in fat were used for RNA extraction, and 15 candidate genes were selected and analyzed by real-competitive PCR analysis. The genes Cytochrome P450 c17 (<it>CYP17A1</it>), Steroidogenic acute regulatory protein (<it>STAR</it>), Aldo-keto reductase family 1 member C4 (<it>AKR1C4</it>), Short-chain dehydrogenase/reductase family member 4 (<it>DHRS4</it>), Ferritin light polypeptide (<it>FTL</it>), Sulfotransferase family 2A, dehydroepiandrosterone-preferring member 1 (<it>SULT2A1</it>), Cytochrome P450 subfamily XIA polypeptide 1 (<it>CYP11A1</it>), Cytochrome b5 (<it>CYB5A</it>), and 17-beta-Hydroxysteroid dehydrogenase IV (<it>HSD17B4</it>) were all found to be significantly (P < 0.05) up-regulated in high androstenone boars in both Duroc and Landrace. Furthermore, Cytochrome P450 c19A2 (<it>CYP19A2</it>) was down-regulated and progesterone receptor membrane component 1 (<it>PGRMC1</it>) was up-regulated in high-androstenone Duroc boars only, while <it>CYP21 </it>was significantly down-regulated (2.5) in high-androstenone Landrace only. The genes Nuclear Receptor co-activator 4 (<it>NCOA4</it>), Sphingomyrlin phosphodiesterase 1 (<it>SMPD1</it>) and 3β-hydroxysteroid dehydrogenase (<it>HSD3B</it>) were not significantly differentially expressed in any breeds. Additionally, association studies were performed for the genes with one or more detected SNPs. Association between SNP and androstenone level was observed in <it>CYB5A </it>only, suggesting cis-regulation of the differential transcription in this gene.</p> <p>Conclusion</p> <p>A large pig material of highly extreme androstenone levels is investigated. The current study contributes to the knowledge about which genes that is differentially expressed regard to the levels of androstenone in pigs. Results in this paper suggest that several genes are important in the regulation of androstenone level in boars and warrant further evaluation of the above mentioned candidate genes, including analyses in different breeds, identification of causal mutations and possible gene interactions.</p

    A toothed turtle from the Late Jurassic of China and the global biogeographic history of turtles

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    Turtles (Testudinata) are a successful lineage of vertebrates with about 350 extant species that inhabit all major oceans and landmasses with tropical to temperate climates. The rich fossil record of turtles documents the adaptation of various sub- lineages to a broad range of habitat preferences, but a synthetic biogeographic model is still lacking for the group.Results: We herein describe a new species of fossil turtle from the Late Jurassic of Xinjiang, China, Sichuanchelys palatodentata sp. nov., that is highly unusual by plesiomorphically exhibiting palatal teeth. Phylogenetic analysis places the Late Jurassic Sichuanchelys palatodentata in a clade with the Late Cretaceous Mongolochelys efremovi outside crown group Testudines thereby establishing the prolonged presence of a previously unrecognized clade of turtles in Asia, herein named Sichuanchelyidae. In contrast to previous hypotheses, M. efremovi and Kallokibotion bajazidi are not found within Meiolaniformes, a clade that is here reinterpreted as being restricted to Gondwana.Conclusions: A revision of the global distribution of fossil and recent turtle reveals that the three primary lineages of derived, aquatic turtles, including the crown, Paracryptodira, Pan-Pleurodira, and Pan- Cryptodira can be traced back to the Middle Jurassic of Euramerica, Gondwana, and Asia, respectively, which resulted from the primary break up of Pangaea at that time. The two primary lineages of Pleurodira, Pan-Pelomedusoides and Pan-Chelidae, can similarly be traced back to the Cretaceous of northern and southern Gondwana, respectively, which were separated from one another by a large desert zone during that time. The primary divergence of crown turtles was therefore driven by vicariance to the primary freshwater aquatic habitat of these lineages. The temporally persistent lineages of basal turtles, Helochelydridae, Meiolaniformes, Sichuanchelyidae, can similarly be traced back to the Late Mesozoic of Euramerica, southern Gondwana, and Asia. Given the ambiguous phylogenetic relationships of these three lineages, it is unclear if their diversification was driven by vicariance as well, or if they display a vicariance-like pattern. The clean, primary signal apparent among early turtles is secondarily obliterated throughout the Late Cretaceous to Recent by extensive dispersal of continental turtles and by multiple invasions of marine habitats

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    SERO-DIAGNOSIS OF TUBERCULOSIS WITH A60 ANTIGEN ENZYME-LINKED-IMMUNOSORBENT-ASSAY - FAILURE IN HIV-INFECTED INDIVIDUALS IN GHANA

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    In order to assess the diagnostic usefulness of the A60 (ANDA Biologicals, Strassbourg, France) sero-diagnostic enzyme-linked immunosorbent assay (ELISA) kit for tuberculosis in Africa, sera of 53 pulmonary smear-positive tuberculosis (TB) patients, 30 apparently healthy control subjects and 6 AIDS suspects were sampled in Agogo Hospital in the forest area of Ghana. These sera were analyzed for antibodies to HIV-1 and HIV-2, and IgG-antibodies to the A60 BCG-antigen, while the non-HIV individuals were tested for total IgG levels. One healthy control subject, all of 6 AIDS suspects and 7 of the TB patients has HIV infections. In the non-HIV TB group, the sensitivity-and specifity of the A60 ELISA was 78% and 86%, respectively, which was much poorer than expected from published reports about the A60 test. The A60 test failed, completely however, to discriminate between TB and non-TB in the HIV-positive group. In the non-HIV groups, total IgG levels were significantly higher in TB patients than in controls. It seems that the usefulness of the A60 ELISA test to diagnose tuberculosis is very limited in this high-incidence area, and that it seems to be of no value in patients infected with HIV.</p

    Detection of ocean white-capping by combined use of Jason radiometer and radar datasets alongside global wave model predictions

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    SEPARATE AND COMBINED EFFECTS OF CORTICOSTEROIDS AND BRONCHODILATORS ON AIR-FLOW OBSTRUCTION AND AIRWAY HYPERRESPONSIVENESS IN ASTHMA

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    We have investigated separate and interactive effects of corticosteroids and bronchodilators on airflow obstruction and airway hyperresponsiveness. Twelve allergic subjects with asthma were treated in a double-blind, crossover, randomized study with budesonide, 1.6 mg daily for 3 weeks, prednisone, 40 mg daily, for 8 days, and placebo. After each period, dose-response curves were measured on 4 study days with doubling doses of salbutamol, ipratropium, a combination of salbutamol and ipratropium, and placebo until a plateau in FEV1 was reached. A histamine challenge was then performed, and the provocation concentration causing a 20% fall in FEV1 (PC20) was calculated. The budesonide and prednisone regimens were equipotent. FEV1 was 81.2% of predicted after budesonide, 81.0% predicted after prednisone, and 67.5% predicted after placebo, bronchodilatation thus being 13.7% predicted (budesonide) and 13.5% predicted (prednisone). PC20 improved with 2.17 doubling concentrations (DCs) after budesonide, and 1.86 DCs after prednisone, compared with that of placebo. Salbutamol caused stronger bronchodilatation than ipratropium (26.2% versus 14.7% predicted) and a better protection against histamine challenge (3.95 versus 1.12 DC). The effects of corticosteroids and bronchodilators on FEV1 and PC20 were, in general, additive. This study emphasizes different modes of action on both airflow obstruction and airway hyperresponsiveness by corticosteroids and bronchodilators, and it demonstrates no enhancement of bronchodilator action by corticosteroids

    A Complete System for Operation of A Superconducting Magnet

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