10,137 research outputs found
Evaluation of Insurance Products with Guarantee in Incomplete Markets
Life insurance products are usually equipped with minimum guarantee and bonus provision options. The pricing of such claims is of vital
importance for the insurance industry. Risk management, strategic asset allocation, and product design depend on the correct evaluation of the
written options. Also regulators are interested in such issues since they have to be aware of the possible scenarios that the overall industry will
face. Pricing techniques based on the Black & Scholes paradigm are often used, however, the hypotheses underneath this model are rarely met.
To overcome Black & Scholes limitations, we develop a stochastic programming model to determine the fair price of the minimum guarantee
and bonus provision options. We show that such a model covers the most relevant sources of incompleteness accounted in the financial and
insurance literature. We provide extensive empirical analyses to highlight the effect of incompleteness on the fair value of the option, and show
how the whole framework can be used as a valuable normative tool for insurance companies and regulators
Conformation of Circular DNA in 2 Dimensions
The conformation of circular DNA molecules of various lengths adsorbed in a
2D conformation on a mica surface is studied. The results confirm the
conjecture that the critical exponent is topologically invariant and
equal to the SAW value (in the present case ), and that the topology
and dimensionality of the system strongly influences the cross-over between the
rigid regime and the self-avoiding regime at a scale .
Additionally, the bond correlation function scales with the molecular length
as predicted. For molecular lengths , circular DNA behaves
like a stiff molecule with approximately elliptic shape.Comment: 4 pages, 5 figure
The N=2 Super Yang-Mills Low-Energy Effective Action at Two Loops
We have carried out a two loop computation of the low-energy effective action
for the four-dimensional N=2 supersymmetric Yang-Mills system coupled to
hypermultiplets, with the chiral superfields of the vector multiplet lying in
an abelian subalgebra. We have found a complete cancellation at the level of
the integrands of Feynman amplitudes, and therefore the two loop contribution
to the action, effective or Wilson, is identically zero.Comment: 8 pages, Latex, 2 .eps figure
Orbital-dependent electron dynamics in Fe-pnictide superconductors
We report on orbital-dependent quasiparticle dynamics in EuFeAs, a
parent compound of Fe-based superconductors and a novel way to experimentally
identify this behavior, using time- and angle-resolved photoelectron
spectroscopy across the spin density wave transition. We observe two different
relaxation time scales for photo-excited d/d and d
electrons. While d/d electrons relax faster through the
electron-electron scattering channel, showing an itinerant character, d
electrons form a quasi-equilibrium state with the lattice due to their
localized character, and the state decays slowly. Our findings suggest that
electron correlation in Fe-pnictides is an important property, which should be
taken into careful account when describing the electronic properties of both
parent and electron-doped compounds, and therefore establish a strong
connection with cuprates
Methylmercury and polycyclic aromatic hydrocarbons in mediterranean seafood: A molecular anthropological perspective
Eating seafood has numerous health benefits; however, it constitutes one of the main sources of exposure to several harmful environmental pollutants, both of anthropogenic and natural origin. Among these, methylmercury and polycyclic aromatic hydrocarbons give rise to concerns related to their possible effects on human biology. In the present review, we summarize the results of epidemiological investigations on the genetic component of individual susceptibility to methylmercury and polycyclic aromatic hydrocarbons exposure in humans, and on the effects that these two pollutants have on human epigenetic profiles (DNA methylation). Then, we provide evidence that Mediterranean coastal communities represent an informative case study to investigate the potential impact of methylmercury and polycyclic aromatic hydrocarbons on the human genome and epigenome, since they are characterized by a traditionally high local seafood consumption, and given the characteristics that render the Mediterranean Sea particularly polluted. Finally, we discuss the challenges of a molecular anthropological approach to this topic
Molecular diagnosis of carcinomas of the thyroid gland.
Our understanding of the molecular pathology of thyroid cancer has progressed significantly. It is now apparent that thyroid tumors show a very good correlation between genotype and phenotype, a correlation that is much stronger than that observed in tumors of many other organs. Activation of classic oncogenes (BRAF, RAS, RET) activate MAPK signalling. Other pathways like the PI3K/PTEN/AKT cascade are also active in many thyroid tumors. The analysis of molecular profiles is generating data that can be applied to improve patient management. The common occurrence of thyroid nodules in the general population and the widespread use of fine needle aspiration for the preoperative diagnosis of thyroid nodules creates an unprecedented opportunity to apply what we have learnt from the molecular alterations of thyroid cancer to the clinical arena
Capsule impaction presenting as acute small bowel perforation: a case series
INTRODUCTION: Perforation caused by capsule endoscopy impaction is extremely rare and, at present, only five cases of perforation from capsule endoscopy impaction are reported in the literature. CASE PRESENTATION: We report here two cases of patients with undiagnosed small bowel stenosis presenting with acute perforation after capsule endoscopy. Strictures in the small bowel were likely the inciting mechanism leading to acute small bowel obstruction and subsequent distension and perforation above the capsule in the area of maximal serosal tension. Case 1 was a 55-year-old Italian woman who underwent capsule endoscopy because of recurrent postprandial cramping pain and iron deficiency anemia, in the setting of negative imaging studies including an abdominal ultrasound, upper endoscopy, colonoscopy and small bowel follow-through radiograph. She developed a symptomatic bowel obstruction approximately 36 hours after ingestion of the capsule. Emergent surgery was performed to remove the capsule, which was impacted at a stenosis due to a previously undiagnosed ileal adenocarcinoma, leading to perforation. Case 2 was a 60-year-old Italian man with recurrent episodes of abdominal pain and diarrhea who underwent capsule endoscopy after conventional modalities, including comprehensive blood and stool studies, computed tomography, an abdominal ultrasound, upper endoscopy, colonoscopy, barium enema and small bowel follow-through, were not diagnostic. Our patient developed abdominal distension, acute periumbilical pain, fever and leukocytosis 20 hours after capsule ingestion. Emergent surgery was performed to remove the capsule, which was impacted at a previously undiagnosed ileal Crohnâs stricture, leading to perforation. CONCLUSIONS: The present report shows that, although the risk of acute complication is very low, the patient should be informed of the risks involved in capsule endoscopy, including the need for emergency surgical exploration
Coordination in closed-loop supply chain with price-dependent returns
This paper proposes two Closed-loop Supply Chain (CLSC) games in which a manufacturer sets some green activity programs efforts and a retailer sets the selling price. Both strategies influence the return rate, which is a state variable. The pricing strategy plays a key role in the identification of the best contract to achieve coordination as well as in achieving environmental objectives. The pricing strategy influences the return rate negatively, as consumers delay the return of their goods when the purchasing (and repurchasing) price is high. We then compare a wholesale price contract (WPC) and a revenue sharing contract (RSC) mechanism as both have interesting pricing policy implications. Our result shows that firms coordinate the CLSC through a (WPC) when the sharing parameter is too low while the negative effect of pricing on returns is too severe. In that case, the low sharing parameter deters the manufacturer to accept any sharing agreements. Further, firms coordinate the CLSC when the sharing parameter is medium independent of the negative impact of pricing on returns. When the sharing parameter is too high the retailer never opts for an RSC. We find that the magnitude of pricing effect on returns determines the contract to be adopted: For certain sharing parameter, firms prefer an RSC when the price effect on return is low and a WPC when this effect is high. In all other cases, firms do not have a consensus on the contract to be adopted and coordination is then not achieved
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