42 research outputs found

    Observational evidence of temperature trends at two levels in the surface layer

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    Citation: Lin, X., Pielke, R. A., Mahmood, R., Fiebrich, C. A., & Aiken, R. (2016). Observational evidence of temperature trends at two levels in the surface layer. Atmospheric Chemistry and Physics, 16(2), 827-841. doi:10.5194/acp-16-827-2016Long-term surface air temperatures at 1.5m screen level over land are used in calculating a global average surface temperature trend. This global trend is used by the IPCC and others to monitor, assess, and describe global warming or warming hiatus. Current knowledge of near-surface temperature trends with respect to height, however, is limited and inadequately understood because surface temperature observations at different heights in the surface layer of the world are rare especially from a high-quality and long-term climate monitoring network. Here we use high-quality two-height Oklahoma Mesonet observations, synchronized in time, fixed in height, and situated in relatively flat terrain, to assess temperature trends and differentiating temperature trends with respect to heights (i.e., near-surface lapse rate trend) over the period 1997 to 2013. We show that the near-surface lapse rate has significantly decreased with a trend of -0.18 +/- 0.03 degrees C (10 m)(-1) per decade indicating that the 9m height temperatures increased faster than temperatures at the 1.5m screen level and/or conditions at the 1.5m height cooled faster than at the 9m height. However, neither of the two individual height temperature trends by themselves were statistically significant. The magnitude of lapse rate trend is greatest under lighter winds at night. Nighttime lapse rate trends were significantly more negative than daytime lapse rate trends and the average lapse rate trend was three times more negative under calm conditions than under windy conditions. Our results provide the first observational evidence of near-surface temperature changes with respect to height that could enhance the assessment of climate model predictions

    Total 18F-dopa PET tumour uptake reflects metabolic endocrine tumour activity in patients with a carcinoid tumour

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    Positron emission tomography (PET) using 6-[(18)F]fluoro-L-dihydroxyphenylalanine ((18)F-dopa) has an excellent sensitivity to detect carcinoid tumour lesions. (18)F-dopa tumour uptake and the levels of biochemical tumour markers are mediated by tumour endocrine metabolic activity. We evaluated whether total (18)F-dopa tumour uptake on PET, defined as whole-body metabolic tumour burden (WBMTB), reflects tumour load per patient, as measured with tumour markers. Seventy-seven consecutive carcinoid patients who underwent an (18)F-dopa PET scan in two previously published studies were analysed. For all tumour lesions mean standardised uptake values (SUVs) at 40% of the maximal SUV and tumour volume on (18)F-dopa PET were determined and multiplied to calculate a metabolic burden per lesion. WBMTB was the sum of the metabolic burden of all individual lesions per patient. The 24-h urinary serotonin, urine and plasma 5-hydroxindoleacetic acid (5-HIAA), catecholamines (nor)epinephrine, dopamine and their metabolites, measured in urine and plasma, and serum chromogranin A served as tumour markers. All but 1 were evaluable for WBMTB; 74 patients had metastatic disease. (18)F-dopa PET detected 979 lesions. SUV(max) on (18)F-dopa PET varied up to 29-fold between individual lesions within the same patients. WBMTB correlated with urinary serotonin (r = 0.51) and urinary and plasma 5-HIAA (r = 0.78 and 0.66). WBMTB also correlated with urinary norepinephrine, epinephrine, dopamine and plasma dopamine, but not with serum chromogranin A. Tumour load per patient measured with (18)F-dopa PET correlates with tumour markers of the serotonin and catecholamine pathway in urine and plasma in carcinoid patients, reflecting metabolic tumour activity

    The role of heterodimerization between VEGFR-1 and VEGFR-2 in the regulation of endothelial cell homeostasis

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    VEGF-A activity is tightly regulated by ligand and receptor availability. Here we investigate the physiological function of heterodimers between VEGF receptor-1 (VEGFR-1; Flt-1) and VEGFR-2 (KDR; Flk-1) (VEGFR(1-2)) in endothelial cells with a synthetic ligand that binds specifically to VEGFR(1-2). The dimeric ligand comprises one VEGFR-2-specific monomer (VEGF-E) and a VEGFR-1-specific monomer (PlGF-1). Here we show that VEGFR(1-2) activation mediates VEGFR phosphorylation, endothelial cell migration, sustained in vitro tube formation and vasorelaxation via the nitric oxide pathway. VEGFR(1-2) activation does not mediate proliferation or elicit endothelial tissue factor production, confirming that these functions are controlled by VEGFR-2 homodimers. We further demonstrate that activation of VEGFR(1-2) inhibits VEGF-A-induced prostacyclin release, phosphorylation of ERK1/2 MAP kinase and mobilization of intracellular calcium from primary endothelial cells. These findings indicate that VEGFR-1 subunits modulate VEGF activity predominantly by forming heterodimer receptors with VEGFR-2 subunits and such heterodimers regulate endothelial cell homeostasis

    Evaluation of thermodynamic properties of concrete substrates and cement slurries modified with admixtures

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    The study of the creation and the stability of the interface between concrete substrates and repair systems needs the knowledge of the thermodynamic properties of materials. The measurement of the surface free energies of liquids is realised by means of Wilhelmy plate method on reference liquid and repair products. In order to determine polar and dispersive components, it is necessary to measure the contact angle of these liquids and products on reference solid surfaces and on concrete, mortars and aggregates. Centrifuged solutions of repair product systems elements were prepared in order to measure surface free energies on pure liquids without solid particles in suspension. Evolution of properties versus time were also taken into account and analysed in comparison with well-known liquids and products

    Attitudes Toward Striving for Quality and Length of Life Among Patients With Advanced Cancer and a Poor Prognosis

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    PURPOSE: When deliberating palliative cancer treatment, insight into patients' attitudes toward striving for quality of life (QL) and length of life (LL) may facilitate goal-concordant care. We investigated the (1) attitudes of patients with advanced cancer toward striving for QL and/or LL and whether these change over time, and (2) characteristics associated with these attitudes (over time). METHODS: We performed a secondary analysis of a randomized controlled trial on improving shared decision making (SDM), without differentiation between intervention arms. Patients (n = 173) with advanced cancer, a median life expectancy of < 12 months without anticancer treatment, and a median survival benefit of < 6 months from systemic therapy were included in seven Dutch hospitals. We used audio-recorded consultations and surveys at baseline (T0), shortly after the consultation (T2), at 3 and 6 months (T3 and T4). Primary outcomes were patients' attitudes toward striving for QL and LL (Quality Quantity Questionnaire; T2, T3, and T4). RESULTS: Overall, patients' attitudes toward striving for QL became less positive over 6 months (P < .01); attitudes toward striving for LL did not change on group level. Studying individual patients, 76% showed changes in their attitudes toward striving for QL and/or LL at some point during the study, which occurred in various directions. More helplessness/hopelessness (P < .001), less fighting spirit (P < .05), less state anxiety (P < .001), and more observed SDM (P < .05) related to more positive attitudes toward striving for QL. Lower education, less helplessness/hopelessness, more fighting spirit, and more state anxiety (P < .001) related to more positive attitudes toward striving for LL. CONCLUSION: Oncologists may explore patients' attitudes toward striving for QL and LL repeatedly and address patients' coping style and emotions during SDM to facilitate goal-concordant care throughout the last phase of life

    Attitudes Toward Striving for Quality and Length of Life Among Patients With Advanced Cancer and a Poor Prognosis

    No full text
    PURPOSE: When deliberating palliative cancer treatment, insight into patients' attitudes toward striving for quality of life (QL) and length of life (LL) may facilitate goal-concordant care. We investigated the (1) attitudes of patients with advanced cancer toward striving for QL and/or LL and whether these change over time, and (2) characteristics associated with these attitudes (over time). METHODS: We performed a secondary analysis of a randomized controlled trial on improving shared decision making (SDM), without differentiation between intervention arms. Patients (n = 173) with advanced cancer, a median life expectancy of < 12 months without anticancer treatment, and a median survival benefit of < 6 months from systemic therapy were included in seven Dutch hospitals. We used audio-recorded consultations and surveys at baseline (T0), shortly after the consultation (T2), at 3 and 6 months (T3 and T4). Primary outcomes were patients' attitudes toward striving for QL and LL (Quality Quantity Questionnaire; T2, T3, and T4). RESULTS: Overall, patients' attitudes toward striving for QL became less positive over 6 months (P < .01); attitudes toward striving for LL did not change on group level. Studying individual patients, 76% showed changes in their attitudes toward striving for QL and/or LL at some point during the study, which occurred in various directions. More helplessness/hopelessness (P < .001), less fighting spirit (P < .05), less state anxiety (P < .001), and more observed SDM (P < .05) related to more positive attitudes toward striving for QL. Lower education, less helplessness/hopelessness, more fighting spirit, and more state anxiety (P < .001) related to more positive attitudes toward striving for LL. CONCLUSION: Oncologists may explore patients' attitudes toward striving for QL and LL repeatedly and address patients' coping style and emotions during SDM to facilitate goal-concordant care throughout the last phase of life

    Solar Orbiter: Mission and spacecraft design

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    The main scientific goal of Solar Orbiter is to address the central question of heliophysics: ‘how does the Sun create and control the heliosphere?’ To achieve this goal, the spacecraft carries a unique combination of ten scientific instruments (six remote-sensing instruments and four in-situ instruments) towards the innermost regions of the Solar System, to as close as 0.28 AU from the Sun during segments of its orbit. The orbital inclination will be progressively increased so that the spacecraft reaches higher solar latitudes (up to 34° towards the end of the mission), making detailed studies of the polar regions of the Sun possible for the first time. This paper presents the spacecraft and its intended trip around the Sun. We also discuss the main engineering challenges that had to be addressed during the development cycle, instrument integration, and testing of the spacecraft
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