Junior Must Pay: Pricing the Implicit Put in Privatizing Social Security

Proposals that portion of the Social Security Trust Fund assets be invested in equities entail the possibility that a severe decline in equity prices renders the Fund assets insufficient to provide the currently mandated level of benefits. In this event, existing taxpayers may be compelled to act as insurers of last resort. The cost to taxpayers of such an implicit commitment equals the value of a put option with payoff equal to the benefit's shortfall. We calibrate an OLG model that generates realistic equity premia and value the put. With 20 percent of the Fund assets invested in equities, the highest level currently under serious discussion, we value a put that guarantees the currently mandated level of benefits at one percent of GDP, or a temporary increase in Social Security taxation of at most 25 percent. We value a put that guarantees 90 percent of benefits at merely .03 percent of GDP. In contrast to earlier literature, our results account for the significant changes in the distribution of security returns resulting from Trust Fund purchases. We also explore the inter-generational welfare implications of the guarantee.

Junior is Rich: Bequests as Consumption

We explore the consequences for asset pricing of admitting a bequest motive into an otherwise standard overlapping generations model where agents trade equity and perpetual debt securities. Prices of securities are seen to be approximately 50% higher in an economy with bequests as compared to an otherwise identical one where bequests are absent. Robust estimates of the equity premium are obtained in several cases where the desire to leave bequests is modest relative to the desire for old age consumption.

Evanescent character of the repulsive thermal Casimir force

The physical origin of the negative thermal correction to the Casimir force between metals is clarified. For this purpose the asymptotic behavior of the thermal Casimir force is analyzed at large and small distances in the real frequency representation. Contributions from propagating and evanescent waves are considered separately. At large distances they cancel each other in substantial degree so that only the attractive Lifshitz limit survives. At smaller separations the repulsive evanescent contribution of s-polarization dominates in the case of two metals or a metal and a high-permittivity dielectric. Common origin and order of magnitude of the repulsion in these two cases demonstrate naturalness of the controversial large thermal correction between metals.Comment: to be published in Phys. Rev.

A study of the application of singular perturbation theory

A hierarchical real time algorithm for optimal three dimensional control of aircraft is described. Systematic methods are developed for real time computation of nonlinear feedback controls by means of singular perturbation theory. The results are applied to a six state, three control variable, point mass model of an F-4 aircraft. Nonlinear feedback laws are presented for computing the optimal control of throttle, bank angle, and angle of attack. Real Time capability is assessed on a TI 9900 microcomputer. The breakdown of the singular perturbation approximation near the terminal point is examined Continuation methods are examined to obtain exact optimal trajectories starting from the singular perturbation solutions

Novel High-Molecular Weight Fucosylated Milk Oligosaccharides Identified in Dairy Streams

peer-reviewedOligosaccharides are the third largest component in human milk. This abundance is remarkable because oligosaccharides are not digestible by the newborn, and yet they have been conserved and amplified during evolution. In addition to encouraging the growth of a protective microbiota dominated by bifidobacteria, oligosaccharides have anti-infective activity, preventing pathogens from binding to intestinal cells. Although it would be advantageous adding these valuable molecules to infant milk formula, the technologies to reproduce the variety and complexity of human milk oligosaccharides by enzymatic/organic synthesis are not yet mature. Consequently, there is an enormous interest in alternative sources of these valuable oligosaccharides. Recent research has demonstrated that bovine milk and whey permeate also contain oligosaccharides. Thus, a thorough characterization of oligosaccharides in bovine dairy streams is an important step towards fully assessing their specific functionalities. In this study, bovine milk oligosaccharides (BMOs) were concentrated by membrane filtration from a readily available dairy stream called “mother liquor”, and analyzed by high accuracy MALDI FT-ICR mass spectrometry. The combination of HPLC and accurate mass spectrometry allowed the identification of ideal processing conditions leading to the production of Kg amount of BMO enriched powders. Among the BMOs identified, 18 have high-molecular weight and corresponded in size to the most abundant oligosaccharides present in human milk. Notably 6 oligosaccharides contained fucose, a sugar monomer that is highly abundant in human milk, but is rarely observed in bovine milk. This work shows that dairy streams represent a potential source of complex milk oligosaccharides for commercial development of unique dairy ingredients in functional foods that reproduce the benefits of human milk.This project was supported by the University of California Discovery Program (05GEB01NHB), the National Institute of Environmental Health Sciences (P42ES004699), the National Institutes of Health award R01AT00707, the California Dairy Research Foundation (08 GEB-04 NH) and the CHARGE study (P01 ES11269). The authors acknowledge financial support from the Irish Department of Agriculture, Fisheries and Food through the Food Institutional Research Measure (FIRM–05/R&D/TD/368)

Studies on Dibenzyl Sulphide & Dibenzyl Selenide Complexes of lridium(III)

1048-105

Correlation of endothelial cell proliferation with vascular endothelial growth factor in endometrium of women with menorrhagia

Background: Approximately 30% of women of reproductive age experience excessive blood loss during menstruation. In 50% of cases, menorrhagia has no underlying pathology. However, until recently, the only permanent cure for menorrhagia was hysterectomy. In this study we aim to determine the correlation of vascular endothelial growth factor (VEGF) expression with markers of endometrial endothelial cell proliferation like proliferating cell nuclear antigen (PCNA) and Cluster Determination (CD34).Methods: A total of 100 patients with history of menorrhagia were selected for study. Double Immunohistochemistry was performed on these endometrial biopsy sections. Proliferating endothelial cells were identified by an immunohistochemical double staining technique with PCNA and CD34. VEGF expression was also seen in endometrial biopsy.Results: In general, expression of both VEGF and PCNA was more in functional layer than basal layer in both menorrhagic patients as well as non menorrhagic patients.  When glandular cytoplasmic VEGF expression was compared with PCNA the association was statistically significant whereas completely opposite findings was seen with glandular luminal surface VEGF positivity but the association was statistically significant. In secretory phase (p-value<0.001) there was highly statistically significant association in PCNA grading with glandular luminal surface VEGF positivity whereas when we correlated PCNA with  cytoplasmic  glandular VEGF in secretory phase it was statistically significant (p-value<0.001).Conclusions: The endothelial proliferation was significantly higher in menorrhagia patients during late secretory phase of cycle than controls. We were able to demonstrate increased endothelial proliferation in patients in the premenstrual part of cycle

Impact of carbonates on the mineralisation of surface soil organic carbon in response to shift in tillage practice

The inorganic soil C pool is a major source of CO2 emission into the atmosphere along with the soil respiratory CO2 fluxes but is comparatively less studied than the organic C mineralisation processes. This study aims to understand how soil available carbonates influence the soil C dynamics under different tillage, mulching and temperature regimes. A 90-day incubation experiment was conducted by adding calcite nodules to soils (10% w/w) collected from an agricultural field maintained with or without 5 t ha−1 mulching under no-till (NT) or conventional tillage (CT) systems. Environmental Scanning Electron Microscope (ESEM) examination indicated greater morphological changes in the calcite nodules incubated with CT than NT soils. Soil samples incubated with calcite and mulching recorded 6.3% greater CO2 evolution than the un-mulched condition. Under the CT system, the overall CO2 emission rate was higher in the control treatment (43%), followed by a combined treatment of 5 t ha−1 mulch + CaCO3 (10% w/w) (29.2%), 5 t ha−1 mulch only treatment (27.9%), and 10% CaCO3 (w/w) (16.5%) treatment, with a rise in incubation temperature from 22 °C to 37 °C. Kinetic model calculations for CO2 emission indicated a greater half-life of easily mineralisable C pools in the NT system at 22 °C. Microbial biomass carbon (MBC) results further verified that the high temperature and disturbed soil conditions limit the availability of soil MBC under the CT systems, indicating a higher decomposition rate. Eventually, these results indicated that agricultural management practices, including tillage shift, explicitly influence the different functional components of soil organic matter (SOM)