Disasters Implied by Equity Index Options BACKUS, DAVID; CHERNOV, MIKHAIL; MARTIN, IAN
The Journal of finance (New York),
December 2011, Letnik:
66, Številka:
6
Journal Article
Recenzirano
Odprti dostop
We use equity index options to quantify the distribution of consumption growth disasters. The challenge lies in connecting the risk-neutral distribution of equity returns implied by options to the ...true distribution of consumption growth. First, we compare pricing kernels constructed from macro-finance and option-pricing models. Second, we compare option prices derived from a macro-finance model to those we observe. Third, we compare the distribution of consumption growth derived from option prices using a macro-finance model to estimates based on macroeconomic data. All three perspectives suggest that options imply smaller probabilities of extreme outcomes than have been estimated from macroeconomic data.
•Early tumor-related hemorrhage is very rare, but potentially life-threatening complication of radiosurgery for brain metastases.•Overall, among evaluated series the median rates of this complication ...were 0.8% per patient (range, 0.4 – 1.9%) and 0.3% per tumor (range, 0.05 – 0.8%).•Out of 11 case reports providing detailed outcome, only 3 patients demonstrated good-to-moderate recovery.•Before radiosurgery, patient and his or her relatives should be informed about risk of early tumor-related hemorrhage and its possible consequences.
Early (within 72 h) tumor-related hemorrhage (TRH) after stereotactic radiosurgery (SRS) of brain metastases (BM) has been reported only occasionally. Systematic review of such cases was done.
Literature search was performed through PubMed according to PRISMA guidelines using combination of the following medical subject headings: “hemorrhage,” “stereotactic radiosurgery,” and “brain metastasis.”
In total, 7 case reports and 8 clinical series, which noted early TRH after SRS of BM were identified. Scarce and inconsistent data precluded their precise synthesis and statistical analysis. BM of renal cell carcinoma comprised around one-third of reported cases. In 4 patients with multiple BM, TRH after SRS was noted simultaneously in several irradiated tumors. Considering 17 reported cases overall, in 3 patients TRH occurred during SRS session itself, in 4 within several minutes upon completion of treatment, in 7 within several hours thereafter, and in 3 on the third posttreatment day. Out of 11 reported cases providing detailed outcome, 6 patients died shortly after the ictus, 2 others were severely disabled at discharge, and 3 demonstrated good-to-moderate recovery. Overall, among evaluated series the median rates of early TRH after SRS for BM were 0.8% per patient (range, 0.4 – 1.9%) and 0.3% per tumor (range, 0.05 – 0.8%).
Early TRH is very rare, but potentially life-threatening complication of SRS for BM; thus, its risk (while extremely low) and possible consequences should be discussed at the time of obtaining informed consent.
This paper examines model specification issues and estimates diffusive and jump risk premia using S&P futures option prices from 1987 to 2003. We first develop a time series test to detect the ...presence of jumps in volatility, and find strong evidence in support of their presence. Next, using the cross section of option prices, we find strong evidence for jumps in prices and modest evidence for jumps in volatility based on model fit. The evidence points toward economically and statistically significant jump risk premia, which are important for understanding option returns.
Effective treatment of some types of cancer can be achieved by modulating cell lineage-specific rather than tumor-specific targets. We conducted a systematic search for novel agents selectively toxic ...to cells of hematopoietic origin. Chemical library screenings followed by hit-to-lead optimization identified OT-82, a small molecule with strong efficacy against hematopoietic malignancies including acute myeloblastic and lymphoblastic adult and pediatric leukemias, erythroleukemia, multiple myeloma, and Burkitt's lymphoma in vitro and in mouse xenograft models. OT-82 was also more toxic towards patients-derived leukemic cells versus healthy bone marrow-derived hematopoietic precursors. OT-82 was shown to induce cell death by inhibiting nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the salvage pathway of NAD synthesis. In mice, optimization of OT-82 dosing and dietary niacin further expanded the compound's therapeutic index. In toxicological studies conducted in mice and nonhuman primates, OT-82 showed no cardiac, neurological or retinal toxicities observed with other NAMPT inhibitors and had no effect on mouse aging or longevity. Hematopoietic and lymphoid organs were identified as the primary targets for dose limiting toxicity of OT-82 in both species. These results reveal strong dependence of neoplastic cells of hematopoietic origin on NAMPT and introduce OT-82 as a promising candidate for the treatment of hematological malignancies.
The aim of this study was to systematically review and meta-analyze the efficiency and safety of using the Robotic Stereotactic Assistance (ROSA®) device (Zimmer Biomet; Warsaw, IN, USA) for ...stereoelectroencephalography (SEEG) electrode implantation in patients with drug-resistant epilepsy. Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a literature search was carried out. Overall, 855 nonduplicate relevant articles were determined, and 15 of them were selected for analysis. The benefits of the ROSA® device use in terms of electrode placement accuracy, as well as operative time length, perioperative complications, and seizure outcomes, were evaluated. Studies that were included reported on a total of 11,257 SEEG electrode implantations. The limited number of comparative studies hindered the comprehensive evaluation of the electrode implantation accuracy. Compared with frame-based or navigation-assisted techniques, ROSA®-assisted SEEG electrode implantation provided significant benefits for reduction of both overall operative time (mean difference MD, −63.45 min; 95% confidence interval CI from −88.73 to −38.17 min; P < 0.00001) and operative time per implanted electrode (MD, −8.79 min; 95% CI from −14.37 to −3.21 min; P = 0.002). No significant differences existed in perioperative complications and seizure outcomes after the application of the ROSA® device and other techniques for electrode implantation. To conclude, the available evidence shows that the ROSA® device is an effective and safe surgical tool for trajectory-guided SEEG electrode implantation in patients with drug-resistant epilepsy, offering benefits for saving operative time and neither increasing the risk of perioperative complications nor negatively impacting seizure outcomes.
Introduction
Tumor recurrence patterns after resection of intracranial low-grade gliomas (LGG) generally remain obscured. The objective of the present retrospective study was their multifaceted ...analysis, evaluation of associated factors, and assessment of impact on prognosis.
Methods
Study group comprised 81 consecutive adult patients (46 men and 35 women; median age, 37 years) with recurrent diffuse astrocytomas (DA; 51 cases) and oligodendrogliomas (OD; 30 cases). The median length of follow-up after primary surgery was 6.7 years.
Results
Early (within 2 years after primary surgery) and non-early (> 2 years after primary surgery) recurrence was noted in 23 (28%) and 58 (72%) cases, respectively. Fast (≤ 6 months) and slow ( > 6 months) radiological progression of relapse was noted in 31 (38%) and 48 (59%) cases, respectively. Tumor recurrence was local and non-local in 71 (88%) and 10 (12%) cases, respectively. Recurrence patterns have differed in OD,
IDH1
-mutant DA, and
IDH
wild-type DA. Early onset, fast radiological progression, and non-local site of relapse had statistically significant negative impact on overall survival of patients and were often associated with malignant transformation of the tumor (38 cases). However, in subgroup with extent of resection ≥ 90% (56 cases) no differences in recurrence characteristics were found between 3 molecularly defined groups of LGG.
Conclusions
Recurrence patterns after resection of LGG show significant variability, differ in distinct molecularly defined types of tumors, and demonstrate definitive impact on prognosis. Aggressive resection at the time of primary surgery may result in more favorable characteristics of recurrence at the time of its development.
Due to various historical events, in the Russian Federation, in addition to the radioactive waste storage facilities used in world practice, there are various nuclear and radiation hazardous ...facilities that require special procedures for monitoring and decommissioning. One of these facilities is the disposal site for LRW on the territory of the JSC Siberian Chemical Plant, where specially prepared waste is injected into sand reservoirs lying at depths of 300–350 m between clayey strata. This study examines in detail the features of the lithological and mineral composition of reservoir sands and aquitards. The processes of environmental transformation in reservoir sands, which lead to changes in the composition and structure of rocks, were characterized. These processes manifest themselves in the form of the development of leaching zones and their “healing” with newly formed smectite, the destruction of terrigenous grains, including the development of cracks, and the growth of newly formed smectite in the pore space of reservoirs. The forms of occurrence and localization of authigenic smectite formed as a result of technogenic impact are described. It has been shown that, despite the obvious impact of highly reactive solutions accompanying liquid radioactive waste, the insulating properties of the geological environment are maintained and even improved to some extent.
Explicit presence of reorganization in addition to liquidation leads to conflicts of interest between borrowers and lenders. In the first-best outcome, reorganization adds value to both parties via ...higher debt capacity, lower credit spreads, and improved overall firm value. If control of the ex ante reorganization timing and the ex post decision to liquidate is given to borrowers, most of the benefits are appropriated by borrowers ex post. Lenders can restore the first-best outcome by seizing this control or by the ex post transfer of control rights. Reorganization is more likely and liquidation is less likely relative to the benchmark case with liquidation only.
PDF
