214 research outputs found

    New Producer Contract Terms and Uncertainty: Lessons From the Recent Past

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    The petroleum industry is volatile, and governments in “new producer” countries have operated at a significant information disadvantage when negotiating with international oil companies. This challenge is growing today; new producer countries face intensifying questions around whether to offer fiscal incentives to maintain investment in the face of 1) the pandemic-induced volatility in oil prices and 2) long-term questions about the future of the industry in the face of the climate crisis and the global energy transition. This confluence of short-term and long-term uncertainty is prompting a reexamination of the narrative that once took hold in many new producer countries. The traditional story was one of linear progression from being non-producers to small levels of production to ultimately having oil and gas become a major economic contributor over the long term. This notion of progression was associated with a commonly held theory: After a country’s first major discovery, the geological risk that wells will be dry was expected to decrease. Countries could therefore shift from a position of having to grant tax breaks (and other concessions) to international investors, to taking a tougher stance in laws and negotiations for new projects going forward. In this paper, co-authored with NRGI we examine whether this theory has been borne out in practice and make recommendations to support new producers in their navigation of the uncertainty associated with the energy transition

    Gender differences in health status and adverse outcomes among patients with peripheral arterial disease

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    Background Few studies have examined gender differences in health status and cardiovascular outcomes in patients with peripheral artery disease (PAD). This study assessed (1) self‐reported health status at PAD diagnosis and 12‐months later, and explored (2) whether outcomes in women with PAD differ with regard to long‐term major adverse events.Methods and Results AA total of 816 patients (285 women) with PAD were enrolled from 2 vascular clinics in the Netherlands. Baseline clinical data and subsequent adverse events were recorded and patients completed the Short Form‐12 (SF‐12, Physical Component Score [PCS] and Mental Component Score [MCS]) upon PAD diagnosis and 12‐months later. Women had similar ages and clinical characteristics, but poorer socio‐economic status and more depressive symptoms at initial diagnosis, as compared with men. Women also had poorer physical (PCS: 37±10 versus 40±10, P=0.004) and mental (MCS: 47±12 versus 49±11, P=0.005) health status at the time of presentation. At 12‐months, women still reported a poorer overall PCS score (41±12 versus 46±11, P=0.006) and MCS score (42±14 versus 49±12, P=0.002). Female gender was an independent determinant of a poorer baseline and 12‐month PCS and MCS scores. However, there were no significant differences by gender on either mortality (unadjusted hazard ratio [HR]=0.93, 95% CI 0.60;1.44, P=0.74) or major adverse events (unadjusted HR=0.90, 95% CI 0.63;1.29, P=0.57), after a median follow‐up of 3.2 years.Conclusions Women's physical and mental health status is compromised both at initial PAD diagnosis and at 12‐month follow‐up, despite experiencing a similar magnitude of change in their health scores throughout the first 12‐months after diagnosis

    Gender differences in health status and adverse outcomes among patients with peripheral arterial disease

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    Background Few studies have examined gender differences in health status and cardiovascular outcomes in patients with peripheral artery disease (PAD). This study assessed (1) self‐reported health status at PAD diagnosis and 12‐months later, and explored (2) whether outcomes in women with PAD differ with regard to long‐term major adverse events.Methods and Results AA total of 816 patients (285 women) with PAD were enrolled from 2 vascular clinics in the Netherlands. Baseline clinical data and subsequent adverse events were recorded and patients completed the Short Form‐12 (SF‐12, Physical Component Score [PCS] and Mental Component Score [MCS]) upon PAD diagnosis and 12‐months later. Women had similar ages and clinical characteristics, but poorer socio‐economic status and more depressive symptoms at initial diagnosis, as compared with men. Women also had poorer physical (PCS: 37±10 versus 40±10, P=0.004) and mental (MCS: 47±12 versus 49±11, P=0.005) health status at the time of presentation. At 12‐months, women still reported a poorer overall PCS score (41±12 versus 46±11, P=0.006) and MCS score (42±14 versus 49±12, P=0.002). Female gender was an independent determinant of a poorer baseline and 12‐month PCS and MCS scores. However, there were no significant differences by gender on either mortality (unadjusted hazard ratio [HR]=0.93, 95% CI 0.60;1.44, P=0.74) or major adverse events (unadjusted HR=0.90, 95% CI 0.63;1.29, P=0.57), after a median follow‐up of 3.2 years.Conclusions Women's physical and mental health status is compromised both at initial PAD diagnosis and at 12‐month follow‐up, despite experiencing a similar magnitude of change in their health scores throughout the first 12‐months after diagnosis

    Gender differences in health status and adverse outcomes among patients with peripheral arterial disease

    Get PDF
    Background Few studies have examined gender differences in health status and cardiovascular outcomes in patients with peripheral artery disease (PAD). This study assessed (1) self‐reported health status at PAD diagnosis and 12‐months later, and explored (2) whether outcomes in women with PAD differ with regard to long‐term major adverse events. Methods and Results A A total of 816 patients (285 women) with PAD were enrolled from 2 vascular clinics in the Netherlands. Baseline clinical data and subsequent adverse events were recorded and patients completed the Short Form‐12 (SF‐12, Physical Component Score [PCS] and Mental Component Score [MCS]) upon PAD diagnosis and 12‐months later. Women had similar ages and clinical characteristics, but poorer socio‐economic status and more depressive symptoms at initial diagnosis, as compared with men. Women also had poorer physical (PCS: 37±10 versus 40±10, P=0.004) and mental (MCS: 47±12 versus 49±11, P=0.005) health status at the time of presentation. At 12‐months, women still reported a poorer overall PCS score (41±12 versus 46±11, P=0.006) and MCS score (42±14 versus 49±12, P=0.002). Female gender was an independent determinant of a poorer baseline and 12‐month PCS and MCS scores. However, there were no significant differences by gender on either mortality (unadjusted hazard ratio [HR]=0.93, 95% CI 0.60;1.44, P=0.74) or major adverse events (unadjusted HR=0.90, 95% CI 0.63;1.29, P=0.57), after a median follow‐up of 3.2 years. Conclusions Women's physical and mental health status is compromised both at initial PAD diagnosis and at 12‐month follow‐up, despite experiencing a similar magnitude of change in their health scores throughout the first 12‐months after diagnosis

    New Producer Contract Terms and Uncertainty: Lessons From the Recent Past

    Get PDF
    The petroleum industry is volatile, and governments in “new producer” countries have operated at a significant information disadvantage when negotiating with international oil companies. This challenge is growing today; new producer countries face intensifying questions around whether to offer fiscal incentives to maintain investment in the face of 1) the pandemic-induced volatility in oil prices and 2) long-term questions about the future of the industry in the face of the climate crisis and the global energy transition. This confluence of short-term and long-term uncertainty is prompting a reexamination of the narrative that once took hold in many new producer countries. The traditional story was one of linear progression from being non-producers to small levels of production to ultimately having oil and gas become a major economic contributor over the long term. This notion of progression was associated with a commonly held theory: After a country’s first major discovery, the geological risk that wells will be dry was expected to decrease. Countries could therefore shift from a position of having to grant tax breaks (and other concessions) to international investors, to taking a tougher stance in laws and negotiations for new projects going forward. In this paper we examine whether this theory has been borne out in practice and make recommendations to support new producers in their navigation of the uncertainty associated with the energy transition

    Jack superpolynomials with negative fractional parameter: clustering properties and super-Virasoro ideals

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    The Jack polynomials P_\lambda^{(\alpha)} at \alpha=-(k+1)/(r-1) indexed by certain (k,r,N)-admissible partitions are known to span an ideal I^{(k,r)}_N of the space of symmetric functions in N variables. The ideal I^{(k,r)}_N is invariant under the action of certain differential operators which include half the Virasoro algebra. Moreover, the Jack polynomials in I^{(k,r)}_N admit clusters of size at most k: they vanish when k+1 of their variables are identified, and they do not vanish when only k of them are identified. We generalize most of these properties to superspace using orthogonal eigenfunctions of the supersymmetric extension of the trigonometric Calogero-Moser-Sutherland model known as Jack superpolynomials. In particular, we show that the Jack superpolynomials P_{\Lambda}^{(\alpha)} at \alpha=-(k+1)/(r-1) indexed by certain (k,r,N)-admissible superpartitions span an ideal {\mathcal I}^{(k,r)}_N of the space of symmetric polynomials in N commuting variables and N anticommuting variables. We prove that the ideal {\mathcal I}^{(k,r)}_N is stable with respect to the action of the negative-half of the super-Virasoro algebra. In addition, we show that the Jack superpolynomials in {\mathcal I}^{(k,r)}_N vanish when k+1 of their commuting variables are equal, and conjecture that they do not vanish when only k of them are identified. This allows us to conclude that the standard Jack polynomials with prescribed symmetry should satisfy similar clustering properties. Finally, we conjecture that the elements of {\mathcal I}^{(k,2)}_N provide a basis for the subspace of symmetric superpolynomials in N variables that vanish when k+1 commuting variables are set equal to each other.Comment: 36 pages; the main changes in v2 are : 1) in the introduction, we present exceptions to an often made statement concerning the clustering property of the ordinary Jack polynomials for (k,r,N)-admissible partitions (see Footnote 2); 2) Conjecture 14 is substantiated with the extensive computational evidence presented in the new appendix C; 3) the various tests supporting Conjecture 16 are reporte

    Measuring Black Hole Spin using X-ray Reflection Spectroscopy

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    I review the current status of X-ray reflection (a.k.a. broad iron line) based black hole spin measurements. This is a powerful technique that allows us to measure robust black hole spins across the mass range, from the stellar-mass black holes in X-ray binaries to the supermassive black holes in active galactic nuclei. After describing the basic assumptions of this approach, I lay out the detailed methodology focusing on "best practices" that have been found necessary to obtain robust results. Reflecting my own biases, this review is slanted towards a discussion of supermassive black hole (SMBH) spin in active galactic nuclei (AGN). Pulling together all of the available XMM-Newton and Suzaku results from the literature that satisfy objective quality control criteria, it is clear that a large fraction of SMBHs are rapidly-spinning, although there are tentative hints of a more slowly spinning population at high (M>5*10^7Msun) and low (M<2*10^6Msun) mass. I also engage in a brief review of the spins of stellar-mass black holes in X-ray binaries. In general, reflection-based and continuum-fitting based spin measures are in agreement, although there remain two objects (GROJ1655-40 and 4U1543-475) for which that is not true. I end this review by discussing the exciting frontier of relativistic reverberation, particularly the discovery of broad iron line reverberation in XMM-Newton data for the Seyfert galaxies NGC4151, NGC7314 and MCG-5-23-16. As well as confirming the basic paradigm of relativistic disk reflection, this detection of reverberation demonstrates that future large-area X-ray observatories such as LOFT will make tremendous progress in studies of strong gravity using relativistic reverberation in AGN.Comment: 19 pages. To appear in proceedings of the ISSI-Bern workshop on "The Physics of Accretion onto Black Holes" (8-12 Oct 2012). Revised version adds a missing source to Table 1 and Fig.6 (IRAS13224-3809) and corrects the referencing of the discovery of soft lags in 1H0707-495 (which were in fact first reported in Fabian et al. 2009

    Analysis of wavelet controller for robustness in electronic differential of electric vehicles: an investigation and numerical developments

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    In road transportation systems, differential plays an important role in preventing the vehicle from slipping on curved tracks. In practice, mechanical differentials are used, but they are bulky because of their increased weight. Moreover, they are not suitable for electric vehicles, especially those employing separate drives for both rear wheels. The electronic differential constitutes recent technological advances in electric vehicle design, enabling better stability and control of a vehicle on curved roads. This article articulates the modeling and simulation of an electronic differential employing a novel wavelet transform controller for two brushless DC motors ensuring drive in two right and left back driving wheels. Further, the proposed work uses a discrete wavelet transform controller to decompose the error between actual and command speed provided by the electronic differential based on throttle and steering angle as the input into frequency components. By scaling these frequency components by their respective gains, the obtained control signal is actually given as input to the motor. To verify the proposal, a set of designed strategies were carried out: a vehicle on a straight road, turning right and turning left. Numerical simulation test results of the controllers are presented and compared for robust performance and stability
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