38 resultados para 30-289
Resumo:
This paper tests a simple market fraction asset pricing model with heterogeneous
agents. By selecting a set of structural parameters of the model through a systematic procedure, we show that the autocorrelations (of returns, absolute returns and squared returns) of the market fraction model share the same pattern as those of the DAX 30. By conducting econometric analysis via Monte Carlo simulations, we characterize these power-law behaviours and find that estimates of the power-law decay indices, the (FI)GARCH parameters, and the tail index of the selected market fraction model closely match those of the DAX 30. The results strongly support the explanatory power of the heterogeneous agent models.
Resumo:
The Faroe-Shetland channel is situated in the main path of the inflow of warm North Atlantic surface water to the Nordic seas and further provides an escape route for the cold Norwegian Sea Deep Water. AMS 14C dates of planktonic foraminifera covering Marine Isotope Stage 3 from two cores in the Faroe-Shetland channel will be used to trace past variability of the Atlantic Meridional Overturning Circulation (AMOC). The reservoir age R shows considerable variability ranging between 50 to 2750 14C years. In particular high R values are observed during Heinrich event 4 (H4) with values around 1550 14C years and during the Laschamp magnetic excursion with R values as high as 2700 14C years. The period between Greenland interstadial 8 (GI8) and GI5 show highly variable R values with interstadial R values around 500 – 650 14C years, i.e. slightly higher than ‘normal’, whereas stadials show either significantly higher or lower R values. From GI5 towards the Last Glacial Maximum R values are generally around 1000 14C years or higher. Using magnetic susceptibility, IRD and δ13C and δ18O values measured on the planktic foraminifera species Neogloboquadrina pachyderma, we compare the observed R variability with reconstructed changes in the Atlantic Meridional Overturning Circulation (AMOC). Furthermore a climate model of intermediate complexity (GENIE) including 14C is used as conceptual tool for identifying oceanographic configuration explaining the observed R variability.
Resumo:
We present optical photometry and spectra of the superluminous Type II/IIn supernova (SN) CSS121015:004244+132827 (z = 0.2868) spanning epochs from -30 d (rest frame) to more than 200 d after maximum. CSS121015 is one of the more luminous SNe ever found and one of the best observed. The photometric evolution is characterized by a relatively fast rise to maximum (~40 d in the SN rest frame), and by a linear post-maximum decline. The light curve shows no sign of a break to an exponential tail. A broad Hα is first detected at ~+40 d (rest frame). Narrow, barely resolved Balmer and [O iii] 5007 Å lines, with decreasing strength, are visible along the entire spectral evolution. The spectra are very similar to other superluminous supernovae (SLSNe) with hydrogen in their spectrum, and also to SN 2005gj, sometimes considered Type Ia interacting with H-rich circumstellar medium. The spectra are also similar to a subsample of H-deficient SLSNe. We propose that the properties of CSS121015 are consistent with the interaction of the ejecta with a massive, extended, opaque shell, lost by the progenitor decades before the final explosion, although a magnetar-powered model cannot be excluded. Based on the similarity of CSS121015 with other SLSNe (with and without H), we suggest that the shocked-shell scenario should be seriously considered as a plausible model for both types of SLSN. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.
Resumo:
Background: Outwith clinical trials, patient outcomes specifically related to SACT (systemic anti-cancer therapy) are not well reported despite a significant proportion of patients receiving active treatment at the end of life. The NCEPOD reviewing deaths within 30 days of SACT found SACT caused or hastened death in 27% of cases.
Method: Across the Northern Ireland cancer network, 95 patients who died within 30 days of SACT for solid tumours were discussed at the Morbidity and Mortality monthly meeting during 2013. Using a structured template, each case was independently reviewed, with particular focus on whether SACT caused or hastened death.
Results: Lung, GI and breast cancers were the most common sites. Performance status was recorded in 92% at time of final SACT cycle (ECOG PS 0-2 89%).
In 57% the cause of death was progressive disease. Other causes included thromboembolism (13%) and infection (5% neutropenic sepsis, 6% non-neutropenic sepsis). In 26% with death from progressive disease, the patient was first cycle of first line treatment for metastatic disease. In the majority discussion regarding treatment aims and risks was documented. Only one patient was receiving SACT with curative intent, who died from appropriately managed neutropenic sepsis.
A definitive decision regarding SACT's role in death was made in 60%: in 49% SACT was deemed non-contributory and in 11% SACT was deemed the cause of death. In 40% SACT did not play a major role, but a definitive negative association could not be made.
Conclusion: Development of a robust review process of 30-day mortality after SACT established a benchmark for SACT delivery for future comparisons and identified areas for SACT service organisation improvement. Moreover it encourages individual practice reflection and highlights the importance of balancing patients' needs and concerns with realistic outcomes and risks, particularly in heavily pre-treated patients or those of poor performance status.
Resumo:
This is a note on the Northern Ireland High Court decision of 30 June 2015 that the Northern Ireland Executive had acted unlawfully in failing to fulfil its statutory duty to adopt a strategy setting out proposals for tackling poverty, social exclusion and patterns of deprivation based on objective need.
Resumo:
1. We analysed 41 years of data (1968–2008) from Blelham Tarn, U.K., to determine the consequences of eutrophication and climate warming on hypolimnetic dissolved oxygen (DO).
2. The establishment of thermal stratification was strongly related to the onset of DO depletion in the lower hypolimnion. As a result of a progressively earlier onset of stratification and later overturn, the duration of stratification increased by 38 ± 8 days over the 41 years.
3. The observed rate of volumetric hypolimnetic oxygen depletion (VHODobs) ranged from 0.131 to 0.252 g O2 m−3 per day and decreased significantly over the study period, despite the increase in the mean chlorophyll a (Chl a) concentration in the growing season. The vertical transport of DO represented from 0 to 30% of VHODobs, while adjustments for interannual differences in hypolimnetic temperature were less important, ranging from −11 to 9% of VHODobs.
4. The mean wind speed during May made the strongest significant contribution to the variation in VHODobs. VHODobs adjusted for the vertical transport of DO and hypolimnetic temperature differences, VHODadj, was significantly related to the upper mixed layer Chl a concentration during spring.
5. Hypolimnetic anoxia (HA) ranged from 27 to 168 days per year and increased significantly over time, which undoubtedly had negative ecological consequences for the lake.
6. In similar small temperate lakes, the negative effects of eutrophication on hypolimnetic DO are likely to be exacerbated by changes in lake thermal structure brought about by a warming climate, which may undermine management efforts to alleviate the effects of anthropogenic eutrophication.
Resumo:
By testing a simple asset pricing model of heterogeneous agents to characterize the power-law behavior of the DAX 30 from 1975 to 2007, we provide supporting evidence on empirical findings that investors and fund managers use combinations of fixed and switching strategies based on fundamental and technical analysis when making investment decisions. By conducting econometric analysis via Monte Carlo simulations, we show that the autocorrelation patterns, the estimates of the power-law decay indices, (FI)GARCH parameters, and tail index of the model match closely the corresponding estimates for the DAX 30. A mechanism analysis based on the calibrated model provides further insights into the explanatory power of heterogeneous agent models.