265 research outputs found

    Seismic data reveal eastern Black Sea Basin structure

    Get PDF
    Rifted continental margins are formed by progressive extension of the lithosphere. The development of these margins plays an integral role in the plate tectonic cycle, and an understanding of the extensional process underpins much hydrocarbon exploration. A key issue is whether the lithosphere extends uniformly, or whether extension varies\ud with depth. Crustal extension may be determined using seismic techniques. Lithospheric extension may be inferred from the waterloaded subsidence history, determined from\ud the pattern of sedimentation during and after rifting. Unfortunately, however, many rifted margins are sediment-starved, so the subsidence history is poorly known.\ud To test whether extension varies between the crust and the mantle, a major seismic experiment was conducted in February–March 2005 in the eastern Black Sea Basin (Figure 1), a deep basin where the subsidence history is recorded\ud by a thick, post-rift sedimentary sequence. The seismic data from the experiment indicate the presence of a thick, low-velocity zone, possibly representing overpressured sediments. They also indicate that the basement and\ud Moho in the center of the basin are both several kilometers shallower than previously inferred. These initial observations may have considerable impact on thermal models of the petroleum system in the basin. Understanding\ud the thermal history of potential source rocks is key to reducing hydrocarbon exploration risk. The experiment, which involved collaboration between university groups in the United Kingdom, Ireland, and Turkey, and BP and\ud Turkish Petroleum (TPAO), formed part of a larger project that also is using deep seismic reflection and other geophysical data held by the industry partners to determine the subsidence history and hence the strain evolution of\ud the basin

    Hematopoetic stem cell transplantation for solid tumors in Europe

    Get PDF
    Background: Hematopoetic stem cell transplants (HSCT) are discussed as treatment options for patients with solid tumors. Transplant numbers have changed substantially over the last decade, few controlled studies are available and different opinions prevail. Objective information on current practice is needed. Patients and methods: Data from 27 902 HSCT for solid tumors (2% allogeneic, 98% autologous), collected by the European Group for Blood and Marrow Transplantation (EBMT) activity survey from 1991 to 2002 were used to assess trends, transplant rates and coefficient of variation of transplant rates in Europe. Results: Transplant numbers increased from 536 in 1991 to 4154 in 1997 and decreased to 1913 in 2002. Indications were neuroblastoma (2504 HSCT; 9%), glioma (662 HSCT; 2%), soft tissue sarcoma (1253 HSCT; 4%), germ cell cancer (3291 HSCT; 12%), breast cancer (13 524 HSCT; 48%), Ewing's sarcoma (1896 HSCT; 7%), lung cancer (387 HSCT; 1%), ovarian cancer (845 HSCT; 3%) and other solid tumors (3540 HSCT; 14%). Allogeneic cells were used in <20 cases up to 1997; since then allogeneic HSCT increased to 159 in 2002, mainly for renal cell carcinoma. Low coefficients of variation in transplant rates (<60%) are observed for Ewing's sarcoma (<56.5%), suggesting consensus for this indication. Conclusions: These data give an overview on current practice of HSCT for solid tumors in Europe. They provide objective information for health-care providers and patient counsellin

    A note on uncertainty due to infectious diseases and output growth of the United States : a mixed-frequency forecasting experiment

    Get PDF
    Utilizing a mixed data sampling (MIDAS) approach, we show that a daily newspaper-based index of uncertainty associated with infectious diseases can be used to predict, both in- and out-of-samples, low-frequency movements of output growth for the United States (US). The predictability of monthly industrial production growth and quarterly real Gross Domestic Product (GDP) growth during the current period of heightened economic uncertainty due to the COVID-19 pandemic is likely to be of tremendous value to policymakers.http://www.worldscientific.com/worldscinet/afehj2023Economic

    Oil price uncertainty shocks and global equity markets : evidence from a GVAR model

    Get PDF
    This paper examines the propagation of oil price uncertainty shocks to real equity prices using a large-scale Global Vector Autoregressive (GVAR) model of 26 advanced and emerging stock markets. The GVAR framework allows us to capture the transmission of local and global shocks, while simultaneously accounting for individual-country peculiarities. Utilising a recently developed model-free, robust estimate of oil price uncertainty, we document a statistically significant and negative effect of uncertainty shocks emanating from oil prices on the large majority of global stock markets, with the adverse effect of oil price uncertainty shocks found to be stronger for emerging economies as well as net oil-exporting nations. Interestingly, however, global stock markets exhibit a great deal of heterogeneity in their recovery following oil uncertainty shocks as some experience rapid corrections in stock valuations while others suffer from extended slumps. While the results are sensitive to the oil uncertainty measure utilised, they suggest that country diversification in the face of rising oil market uncertainty can still be beneficial for global investors as global stock markets exhibit a rather heterogeneous pattern in their recovery rates against oil market shocks.DATA AVAILABILITY STATEMENT : The GVAR data used for this study can be obtained from https://sites. google.com/site/gvarmodelling/data, accessed on 17 July 2022. Data for the oil uncertainty index which is not captured in the GVAR dataset can be obtained from https://sites.google.com/site/ nguyenhoaibao/oil-market-uncertainty?authuser=0, accessed on 17 July 2022.https://www.mdpi.com/journal/jrfmEconomic

    Global financial cycle and the predictability of oil market volatility : evidence from a GARCH-MIDAS model

    Get PDF
    This study examines the predictive power of the global financial cycle (GFCy) over oil market volatility using the GARCH-MIDAS framework. The GARCH-MIDAS model provides an appropriate setting to forecast high frequency oil market volatility using global predictors that are only available at low frequency. We show that the global financial cycle carries significant predictive information over both oil market volatility proxies, both in- and out-of-sample. The predictive relationship is found to be positive, more strongly during the pre-GFC period, suggesting that rising global asset prices coupled with improved cross-border capital flows and risk appetite are associated with rising volatility in the oil market. Further economic analysis suggests that the GARCH-MIDAS-GFCy model yields economic gains compared to the conventional GARCH-MIDAS-RV specification for a typical mean-variance investor, especially in the pre-GFC period, and the stance is found to be robust to risk aversion and leverage ratio. The economic gains observed from the GARCH-MIDAS-GFCy model, particularly during the pre-GFC period when world markets experienced a steady rise in global asset prices and cross-border capital flows, underline the potential role of risk appetite (or behavioural factors) in commodity market forecasts. Overall, our results suggest that global asset market conditions can provide significant forecasting gains for energy market models, with significant implications for both investors and policymakers.https://www.elsevier.com/locate/eneecohj2022Economic

    The financial US uncertainty spillover multiplier : evidence from a GVAR model

    Get PDF
    This study examines the role of the global financial cycle (GFCy) in the propagation of uncertainty shocks from the United States to other national economies using a large-scale global vector autoregressive model of 33 countries. Although the dominant role of US uncertainty over global economic dynamics is established, the findings highlight the moderating role of the GFCy in the spillover effects of uncertainty shocks. The US uncertainty shocks, compared with own-domestic uncertainty shocks, are found to have a more prominent negative impact on output during stressed market conditions, implied by low values of the GFCy, while the impact turns largely insignificant during high GFCy states. The findings provide evidence in favour of a US uncertainty spillover multiplier, suggesting that the design of monetary policy as a response to US uncertainty needs to be contingent on the state of the integrated global financial markets, captured by the GFCy.The data that support the findings of this study are available at : http://www.econ.cam.ac.uk/peoplefiles/emeritus/mhp1/GVAR/GVAR.html for the GVAR database and http://policyuncertainty.com/wui_quarterly.html for Economic policy uncertainty.http://wileyonlinelibrary.com/journal/infihj2022Economic

    Firm-level business uncertainty and the predictability of the aggregate U.S. stock market volatility during the COVID-19 pandemic

    Get PDF
    In this paper, we analyze the predictive role of firm-level business expectations and uncertainties derived from a panel survey of U.S. 1750 business executives from 50 states for the realized variance (sum of daily squared log-returns over a month) of the S&P500 index over the monthly period of September 2016 to July 2021. Unlike standard models, our predictive framework adopts a time-varying approach due to the existence of multiple structural breaks in the relationship between volatility and the predictors in the model, which in turn leads to statistically insignificant causal effects in a constant parameter set-up. Our time-varying results suggest that the predictive power of firm-level business uncertainty is concentrated during the early part of the sample associated with the U.S.-China trade war and towards the end of our data coverage in the wake of the outbreak of the COVID-19 pandemic. Since in-sample predictability does not guarantee the same over an out-sample, we also conducted a full-fledged forecasting exercise to show that subjective expectations and uncertainties associated with sales growth rates and employment produce statistically significant predictability gains over January 2020 to July 2021, given an in-sample of September 2016 to December 2019. Our results suggest that subjective measures of business uncertainty at the firm level indeed capture predictive information regarding aggregate stock market uncertainty, which has important implications for investors and economic projections at the policy level.http://www.elsevier.com/locate/qrefhj2023Economic
    corecore