Uniqueness of Current Cosmic Acceleration

One of the strongest arguments against the cosmological constant as an explanation of the current epoch of accelerated cosmic expansion is the existence of an earlier, dynamical acceleration, i.e. inflation. We examine the likelihood that acceleration is an occasional phenomenon, putting stringent limits on the length of any accelerating epoch between recombination and the recent acceleration; such an epoch must last less than 0.05 e-fold (at z>2) or the matter power spectrum is modified by more than 20%.Comment: 6 pages, 5 figures; v2 corrected typo in Eq.

Strong Gravitational Lensing and Dark Energy Complementarity

In the search for the nature of dark energy most cosmological probes measure simple functions of the expansion rate. While powerful, these all involve roughly the same dependence on the dark energy equation of state parameters, with anticorrelation between its present value w_0 and time variation w_a. Quantities that have instead positive correlation and so a sensitivity direction largely orthogonal to, e.g., distance probes offer the hope of achieving tight constraints through complementarity. Such quantities are found in strong gravitational lensing observations of image separations and time delays. While degeneracy between cosmological parameters prevents full complementarity, strong lensing measurements to 1% accuracy can improve equation of state characterization by 15-50%. Next generation surveys should provide data on roughly 10^5 lens systems, though systematic errors will remain challenging.Comment: 7 pages, 5 figure

Parametric resonance for antineutrino conversions using LSND best-fit results with a 3+1 flavor scheme

An analytical solution to a parametric resonance effect for antineutrinos in a 3+1 flavor (active+sterile) scheme using multiple non-adiabatic density shifts is presented. We derive the conditions for a full flavor conversion for antineutrino oscillations $\bar{\nu}_\alpha \to \bar{\nu}_s$ $(\alpha=e,\mu,\tau)$ under the assumption that LSND best-fits for the mixing parameters are valid in a short-baseline accelerator experiment. We show that the parametric resonance effect can be exploited to increase the effective antineutrino oscillation length by a factor of 10-40, thus sustaining a high oscillation probability for a much longer period of time than in the vacuum scenario. We propose a realistic experimental setup that could probe for this effect which leaves a signature in terms of a specific oscillation probability profile. Moreover, since the parametric resonance effect is valid in any 2 or 1+1 flavor approximation, our results could be suggestive for future short-baseline accelerator neutrino detection experiments.Comment: 6 pages, 4 figure

A Retrospective Study Describing Documentation of Advance Care Planning in a Long Term Care Setting

Problem: Increased life expectancy and aging baby boomers will increase the population of those 65 years of age and older to nearly 20% of the United States population by 2030. It is estimated that 40-70% of this population will need long term care during their lifetime, and by 2020, 40% of patients in long term care will die there. As patients age, advance care planning (ACP) and advance directives (AD) should be completed to make their wishes known to healthcare providers and family. Despite legal requirements for completion at entry to healthcare settings, less than 95% of hospitalized patients and 50% of long term care patients have an AD or ACP. Significance: Advance care planning increases patients’ quality of life, may decrease stress and ease decision making at end of life for patients and families. There is little research on the completion levels of ACP in long term care. Purpose: The primary purpose of this retrospective study is to describe the level of ACP documentation in a long term care setting. A secondary purpose is to describe potential relationships between demographic, past medical history (PMH) and ACP variables Design: Retrospective descriptive chart review Results: More than 76% of patients at the facility were over the age of 65. Less than 43% of patients had an AD listed in their chart, and less than 31% of patients had an AD completed prior to admission at the long term care facility. At admission to the facility, only 7 of 29 (12.7%) patients that came from the hospital had an AD or ACP documented. Seven patients at the facility were listed as Hospice patients, and only three of seven (42.8%) had ACP documented. Only 33% of patients had an ACP meeting at the facility listed in their chart. Of ACP meetings that occurred, there was a high level of patient and family involvement in end of life decision making. A correlation was found between Alzheimer’s disease and ACP completion, as well as Medicaid insurance and ACP completion