Quantum feedback and adaptive measurements

Summary form only given. Although real-time feedback of measured signals is an essential component of sensing and control in classical settings, models for quantum feedback that are rigorous yet useful have only become possible since the advent of measurement-based quantum trajectory theory. The quantum feedback scenario introduces new concerns of coherence and measurement backaction, but recent work has shown that these can be treated properly in a formal integration of quantum trajectory theory with standard state-space formulations of filtering and control theory. Pioneering studies by H. M. Wiseman have shown that such models can be used to design and to analyze realistic schemes for adaptive homodyne measurement and for feedback control of atomic motion. Much of the ongoing research in our group focuses on the experimental implementation of such schemes. For a broad range of quantum feedback scenarios, certain recurring technical issues arise out of the need to perform complex, high-bandwidth processing of measured signals. We are developing a "rapid-prototyping" approach to refining signal processing and feedback algorithms via quantum trajectory simulation on a PC, followed by translation of the algorithms into hardware Description language (HDL)

Saving Shortfalls and Delayed Retirement

Prior research has suggested that many older Americans have not saved enough to maintain consumption levels in old age. One way older persons might respond to inadequate savings would be to extend their worklives by delaying retirement. This paper examines evidence on this matter using the Health and Retirement Study, a nationally representative panel survey of people age 51-61 in 1992 followed for several years in a panel. We use the data to project household retirement assets and to determine how much more saving would be needed to preserve post-retirement consumption levels. Our research then examines the links between derived saving shortfall measures and delayed retirement patterns. Among nonmarried persons, there is evidence that larger shortfalls do produce delayed retirement, though the effect is not quantitatively large. For married couples, pre-retirement wealth shortfalls do not appear to be significantly associated with delayed retirement. Evidently couples have other means of handling saving shortfalls.

Properties of the ground 3^3F2_2 state and the excited 3^3P0_0 state of atomic thorium in cold collisions with 3^3He

We measure inelastic collisional cross sections for the ground $^3$F$_2$ state and the excited $^3$P$_0$ state of atomic thorium in cold collisions with $^3$He. We determine for Th ($^3$F$_2$) at 800 mK the ratio $\gamma \approx 500$ of the momentum-transfer to Zeeman relaxation cross sections for collisions with $^3$He. For Th ($^3$P$_0$), we study electronic inelastic processes and find no quenching even after $10^6$ collisions. We also determine the radiative lifetime of Th ($^3$P$_0$) to be $\tau > 130$ ms. This great stability of the metastable state opens up the possibility for further study, including trapping

Vibrational quenching of the electronic ground state in ThO in cold collisions with 3^3He

We measure the ratio $\gamma$ of the momentum-transfer to the vibrational quenching cross section for the X ($^1\Sigma^+$), $\nu=1$, $\mathrm{J=0}$ state of molecular thorium monoxide (ThO) in collisions with atomic $^3$He between 800 mK and 2.4 K. We observe indirect evidence for ThO--He van der Waals' complex formation, which has been predicted by theory. We determine the 3-body recombination rate constant $\Gamma_3$ at 2.4 K, and establish that the binding energy E$_b >$ 4 K

Modeling Lifetime Earnings Paths: Hypothetical versus Actual Workers

To assess the distributional effects of social security reform proposals, it is essential to have good information on real-world workers’ lifetime earnings trajectories. Until recently, however, policymakers have relied on hypothetical earnings profiles for policy analysis. We use actual lifetime earnings data from the Health and Retirement Study (HRS) to compare actual workers’ covered earnings profiles to these hypothetical profiles. We show that the hypothetical profiles do not track earnings patterns of current retirees; thus lifetime pay levels are much higher than for most HRS workers. Therefore, using hypothetical profiles could misrepresent benefits paid and taxes collected under such reforms.

Lifetime Earnings Variability and Retirement Wealth

This paper explores how earnings variability is related to retirement wealth. Past research has demonstrated that the average American household on the verge of retirement would need to save substantially more, in order to preserve consumption flows in old age. While several socioeconomic factors have been examined that might explain such problems, prior studies have not assessed the role of earnings variability over the lifetime as a potential explanation for poor retirement prospects. Thus two workers having identical levels of average lifetime earnings might have had very different patterns of earnings variability over their lifetimes. Such differences could translate into quite different retirement wealth outcomes. This paper evaluates the effect of earnings variability on retirement wealth using information supplied by respondents to the Health and Retirement Study (HRS). This is a rich and nationally representative dataset on Americans on the verge of retirement, with responses linked to administrative records from the Social Security Administration. Our research illuminates the key links between lifetime earnings variability and retirement wealth.

Effect of oyster mushroom (Pleurotus ostreatus) mycelia on petroleum hydrocarbon contaminated substrate

A study on the mycoremediation effect of oyster mushroom (Pleurotus ostreatus) mycelia on petroleum-hydrocarbon-contaminated substrate was carried out in the mushroom unit of the Faculty of Agriculture Demonstration Farm, located in the University of Port Harcourt, Port Harcourt, Nigeria. The study aimed at determining the degree of reduction or breakdown of chains of hydrocarbon in a petroleum-hydrocarbon-contaminated substrate over time. Mushroom substrate comprised sawdust enriched with nutrients to allow for microbial proliferation was obtained from the demonstration farm, while crude oil obtained from the Nigerian National Petroleum Company (NNPC) was used as contaminant. 230g of fully ramified mushroom substrate was weighed out in triplicates and subjected to three treatment regimes (A, B and C). Treatments A, B and C were contaminated with 20ml, 40ml and 60ml of crude oil respectively, while their corresponding controls similarly contaminated with crude oil had no mushroom mycelia and were further sterilized to eliminate any microbial life. The experiment was monitored for four weeks within which total hydrocarbon concentrations in treatments A, B and C were reduced by 90%, 87% and 85% respectively over time while no change occurred in their corresponding control groups. It is recommended that the application of mushroom mycelium is a new and effective tool in the rapid remediation of sites contaminated with petroleum hydrocarbons over a short period of time as opposed to the usual conventional, time-consuming, and inefficient methods of waste management in the environment.Keywords: Mycoremediation, Mycelia, Contaminated Soil, Oyster Mushroo

Ethical perspectives on advances in biogerontology

Worldwide populations are aging with economic development as a result of public health initiatives and advances in therapeutic discoveries. Since 1850, life expectancy has advanced by 1 year for every four. Accompanying this change is the rapid development of anti‐aging science. There are three schools of thought in the field of aging science. One perspective is the life course approach, which considers that aging is a good and natural process to be embraced as a necessary and positive aspect of life, where the aim is to improve the quality of existing lifespan and “compress” morbidity. Another view is that aging is undesirable, and that rejuvenation and indeed immortality are possible since the biological basis of aging is understood, and therefore, strategies are possible for engineering negligible senescence. Finally, a hybrid approach is that life span can be extended by anti‐aging medicines but with uncertain effects on health. While these advances offer much promise, the ethical perspectives are seldom discussed in cross‐disciplinary settings. This article discusses some of the key ethical issues arising from recent advances in biogerontology