743 research outputs found
A Symposium on Cash Balance Pensions: Background and Introduction
Here we provide an overview to a set of papers that analyze various facets of the shift to cash balance and other hybrid pension forms that has become controversial and widely discussed phenomenon in the evolution of private, employer-sponsored pensions in the United States. These new plans take on the characteristics of defined contribution plans from the perspective of workers but continue to be funded and operated as defined benefit plans from the perspective of plan sponsors. The shift to this new style of plans began in the mid 1980s but then took off and accelerated toward the end of the 1990s. This paper describes the context in which this shift in plan types being offered by employers took place because it helps to explain various features of these plans addressed in the remaining papers and the underlying reasons that employers have adopted the new plans. The latter part of this paper provides a very brief summary of the conclusions drawn from the remaining papers in the set
The Shift to Hybrid Pensions by U.S. Employers: An Empirical Analysis of Actual Plan Conversions
For nearly two decades, employers have been restructuring traditional defined benefit pension plans to look and operate more like defined contribution plans from participants’ perspectives while retaining defined benefit funding characteristics. This shift to cash balance and pension equity plans has become controversial because some participants and outside analysts have concluded the shift to these new plan styles has been primarily motivated by the desire to cut pension costs and reduce benefits. This paper empirically documents the shift from traditional pension forms to these new hybrid forms for a sample of actual plan conversions. The analysis investigates the implications of the plan conversions on plan costs and the levels and distribution of benefits. If finds that some employers did indeed modify their plans to reduce costs but that, on average, cost savings from the shift to hybrid plans have been negligible. The paper documents that some workers will receive smaller benefits under the new plans than they would under the old but shows that most plan sponsors implemented substantial grandfathering or other transition protection to eliminate or limit the effect of the transitions on workers with substantial tenure or age at the time of conversion. The controversial “wear-away” is evaluated against provisions in the prior plans that provided subsidized benefits to early retirees and then reduced them if workers extended their career beyond early retirement eligibility. It finds that wear-away has actually been ameliorated in the shift to hybrid plans although shifted forward in the career in most cases. The paper shows that it is largely the elimination of these early retirement incentives that is at the heart of the shift to hybrid plans. This shift is resulting in new incentives to work beyond early retirement ages and is redistributing benefits more equitably across the total workforce than traditional pensions have done
Pressure Dependence of Born Effective Charges, Dielectric Constant and Lattice Dynamics in SiC
The pressure dependence of the Born effective charge, dielectric constant and
zone-center LO and TO phonons have been determined for -SiC by a linear
response method based on the linearized augmented plane wave calculations
within the local density approximation. The Born effective charges are found to
increase nearly linearly with decreasing volume down to the smallest volume
studied, , corresponding to a pressure of about 0.8 Mbar. This
seems to be in contradiction with the conclusion of the turnover behavior
recently reported by Liu and Vohra [Phys.\ Rev.\ Lett.\ {\bf 72}, 4105 (1994)]
for -SiC. Reanalyzing their procedure to extract the pressure dependence of
the Born effective charges, we suggest that the turnover behavior they obtained
is due to approximations in the assumed pressure dependence of the dielectric
constant , the use of a singular set of experimental data
for the equation of state, and the uncertainty in measured phonon frequencies,
especially at high pressure.Comment: 25 pages, revtex, 5 postscript figures appended, to be published in
Phys. Rev.
Seasonal differences of corticosterone metabolite concentrations and parasite burden in northern bald ibis (Geronticus eremita): The role of affiliative interactions
The reproductive season is energetically costly as revealed by elevated glucocorticoid concentrations, constrained immune functions and an increased risk of infections. Social allies and affiliative interactions may buffer physiological stress responses and thereby alleviate associated effects. In the present study, we investigated the seasonal differences of immune reactive corticosterone metabolite concentrations, endoparasite burden (nematode eggs and coccidian oocysts) and affiliative interactions in northern bald ibis (Geronticus eremita), a critically endangered bird. In total, 43 individually marked focal animals from a freeranging colony were investigated. The analyses included a description of initiated and received affiliative interactions, pair bond status as well as seasonal patterns of hormone and endoparasite levels. During the reproductive season, droppings contained parasite eggs more often and corticosterone metabolite levels were higher as compared to the period after reproduction. The excretion rate of endoparasite products was lower in paired individuals than in unpaired ones, but paired animals exhibited higher corticosterone metabolite concentrations than unpaired individuals. Furthermore, paired individuals initiated affiliative behaviour more frequently than unpaired ones. This suggests that the reproductive season influences the excretion patterns of endoparasite products and corticosterone metabolites and that affiliative interactions between pair partners may positively affect endoparasite burden during periods of elevated glucocorticoid levels. Being embedded in a pair bond may have a positive impact on individual immune system and parasite resistance
Influence of surface atomic structure demonstrated on oxygen incorporation mechanism at a model perovskite oxide
Perovskite oxide surfaces catalyze oxygen exchange reactions that are crucial for fuel cells, electrolyzers, and thermochemical fuel synthesis. Here, by bridging the gap between surface analysis with atomic resolution and oxygen exchange kinetics measurements, we demonstrate how the exact surface atomic structure can determine the reactivity for oxygen exchange reactions on a model perovskite oxide. Two precisely controlled surface reconstructions with (4 × 1) and (2 × 5) symmetry on 0.5 wt.% Nb-doped SrTiO3(110) were subjected to isotopically labeled oxygen exchange at 450 °C. The oxygen incorporation rate is three times higher on the (4 × 1) surface phase compared to the (2 × 5). Common models of surface reactivity based on the availability of oxygen vacancies or on the ease of electron transfer cannot account for this difference. We propose a structure-driven oxygen exchange mechanism, relying on the flexibility of the surface coordination polyhedra that transform upon dissociation of oxygen molecules.Austrian Science Fund (SFB “ Functional Oxide Surfaces and Interfaces ” - FOXSI, Project F 45)European Research Council Advanced Grant (“OxideSurfaces” (Project ERC-2011-ADG_20110209))National Science Foundation (U.S.). Division of Materials Research (CAREER Award Grant No. 1055583
Excretion patterns of coccidian oocysts and nematode eggs during the reproductive season in Northern Bald Ibis (Geronticus eremita)
Individual reproductive success largely depends on the ability to optimize behaviour, immune function and the physiological stress response. We have investigated correlations between behaviour, faecal steroid metabolites, immune parameters, parasite excretion patterns and reproductive output in a critically endangered avian species, the Northern Bald Ibis (Geronticus eremita). In particular, we related haematocrit, heterophil/lymphocyte ratio, excreted immune-reactive corticosterone metabolites and social behaviour with parasite excretion and two individual fitness parameters, namely, number of eggs laid and number of fledglings. We found that the frequency of excretion of parasites’ oocysts and eggs tended to increase with ambient temperature. Paired individuals excreted significantly more samples containing nematode eggs than unpaired ones. The excretion of nematode eggs was also significantly more frequent in females than in males. Individuals with a high proportion of droppings containing coccidian oocysts were more often preened by their partners than individuals with lower excretion rates. We observed that the more eggs an individual incubated and the fewer offspring fledged, the higher the rates of excreted samples containing coccidian oocysts. Our results confirm that social behaviour, physiology and parasite burden are linked in a complex and context-dependent manner. They also contribute background information supporting future conservation programmes dealing with this critically endangered species
Recommended from our members
Dealing with a Resource Crisis: Regulatory Regimes for Managing the World's Marine Fisheries
Recommended from our members
From Extended Jurisdiction to Privatization: International Law, Biology, and Economics in the Marine Fisheries Debates, 1937-1976
- …
