Could light harvesting complexes exhibit non-classical effects at room temperature?

Mounting experimental and theoretical evidence suggests that coherent quantum effects play a role in the efficient transfer of an excitation from a chlorosome antenna to a reaction center in the Fenna-Matthews-Olson protein complex. However, it is conceivable that a satisfying alternate interpretation of the results is possible in terms of a classical theory. To address this possibility, we consider a class of classical theories satisfying the minimal postulates of macrorealism and frame Leggett-Garg-type tests that could rule them out. Our numerical simulations indicate that even in the presence of decoherence, several tests could exhibit the required violations of the Leggett-Garg inequality. Remarkably, some violations persist even at room temperature for our decoherence model.Comment: 10 pages, 4 figures, 2 tables, submitted to the Proceedings of the Royal Society

Muscle Mass Loss in Active Adults

PROBLEM: It is generally concluded that muscle mass declines with increasing age. Most of the research in this area is focused on the general population which is largely sedentary. The purpose of this study was to examine the muscle mass of highly active adults using several independent methods. METHODS: 167 women aged 50.91 +/- 14.03 yrs and 219 men aged 52.08 +/- 13.45 yrs underwent body composition analysis via 8-lead bioelectric impedance analysis, anthropometric measurements to assess limb circumference, and 24 hour creatinine clearance. Comparative data for the general population (GP) was obtained from the Baltimore Longitudinal Study of Aging, National Health and Nutrition Examination Survey III and The American College of Sports Medicine and Center for Disease Control recommended physical activity guidelines. Highly active subjects were all masters swimmers and a priori categorized as highly active (USMS). To verify this, the USMS were found to participate in 447 min/wk of moderate to vigorous physical activity which was much greater than 150 min/wk reported for the GP. ANALYSIS: Muscle mass was the primary the dependent variable. Single sample t-tests were used to examine muscle mass differences between groups separated by age and sex. Linear regression analysis was used to describe the trend of muscle mass versus age. RESULTS: USMS women had more muscle mass than GP in the 30-39, 40-49, 50-59, 60-69, & 70-79 age groups. Y-intercepts were significantly (p < .05) different for both sexes between the highly active and general population. No significant differences were found for between men v USMS and GP in 30-39, 40-49, 50-59, & 80 + age groups. Linear regression analysis of the USMS men and women yielded losses of approximately 0.3 lbs per year. DISCUSSION: Highly active subjects participated in significantly greater amounts of dedicated physical activity per week when compared to values available for the general population (NHANES III). Comparisons of the muscle mass slopes yielded no differences between the GP and the USMS. Muscle mass loss occurs at similar rates in both populations. Importantly, and specifically, in the USMS women, muscle mass is greater any given age. However, this was not true for the USMS men. Intensive activity may combat many problems associated with losses in muscle mass, especially those within older women. Why this is not evident in the men requires additional research.Submitted to the Faculty of the University Graduate School in partial fulfillment of the requirements for the degree Master of Science in the Department of Kinesiology of the School of Health, Physical Education, and Recreation Indiana University December 200

The clustering properties of radio-selected AGN and star-forming galaxies up to redshifts z~3

We present the clustering properties of a complete sample of 968 radio sources detected at 1.4 GHz by the VLA-COSMOS survey with radio fluxes brighter than 0.15 mJy. 92% have redshift determinations from the Laigle et al. (2016) catalogue. Based on their radio-luminosity, these objects have been divided into two populations of 644 AGN and 247 star-forming galaxies. By fixing the slope of the auto-correlation function to gamma=2, we find r_0=11.7^{+1.0}_{-1.1} Mpc for the clustering length of the whole sample, while r_0=11.2^{+2.5}_{-3.3} Mpc and r_0=7.8^{+1.6}_{-2.1} Mpc (r_0=6.8^{+1.4}_{-1.8} Mpc if we restrict our analysis to z<0.9) are respectively obtained for AGN and star-forming galaxies. These values correspond to minimum masses for dark matter haloes of M_min=10^[13.6^{+0.3}_{-0.6}] M_sun for radio-selected AGN and M_min=10^[13.1^{+0.4}_{-1.6}] M_sun for radio-emitting star-forming galaxies (M_min=10^[12.7^{+0.7}_{-2.2}] M_sun for z<0.9). Comparisons with previous works imply an independence of the clustering properties of the AGN population with respect to both radio luminosity and redshift. We also investigate the relationship between dark and luminous matter in both populations. We obtain /M_halo/M_halo<~10^{-2.4} in the case of star-forming galaxies. Furthermore, if we restrict to z<~0.9 star-forming galaxies, we derive /M_halo<~10^{-2.1}, result which clearly indicates the cosmic process of stellar build-up as one moves towards the more local universe. Comparisons between the observed space density of radio-selected AGN and that of dark matter haloes shows that about one in two haloes is associated with a black hole in its radio-active phase. This suggests that the radio-active phase is a recurrent phenomenon.Comment: 11 pages, 7 figures, minor changes to match published version on MNRA

An Invisible Quantum Tripwire

We present here a quantum tripwire, which is a quantum optical interrogation technique capable of detecting an intrusion with very low probability of the tripwire being revealed to the intruder. Our scheme combines interaction-free measurement with the quantum Zeno effect in order to interrogate the presence of the intruder without interaction. The tripwire exploits a curious nonlinear behaviour of the quantum Zeno effect we discovered, which occurs in a lossy system. We also employ a statistical hypothesis testing protocol, allowing us to calculate a confidence level of interaction-free measurement after a given number of trials. As a result, our quantum intruder alert system is robust against photon loss and dephasing under realistic atmospheric conditions and its design minimizes the probabilities of false positives and false negatives as well as the probability of becoming visible to the intruder.Comment: Improved based on reviewers comments; 5 figure