Bichromatic Slowing of Metastable Helium

We examine two approaches for significantly extending the velocity range of the optical bichromatic force (BCF), to make it useful for laser deceleration of atomic and molecular beams. First, we present experimental results and calculations for BCF deceleration of metastable helium using very large BCF detunings, and discuss the limitations of this approach. We consider in detail the constraints, both inherent and practical, that set the usable upper limit of the BCF. We then show that a more promising approach is to utilize a BCF profile with a relatively small velocity range in conjunction with chirped Doppler shifts, to keep the force resonant with the atoms as they are slowed. In an initial experimental test of this chirped BCF method, helium atoms are slowed by $\sim 370$ m/s using a BCF profile with a velocity width of $\lesssim 125$ m/s. Straightforward scaling of the present results indicates that a decelerator for He* capable of loading a magneto-optical trap (MOT) can yield a brightness comparable to a much larger Zeeman slower.Comment: 11 pages, 9 figures. Published in Phys. Rev.

Milnacipran for the management of fibromyalgia syndrome

Fibromyalgia syndrome (FMS) is a widespread pain condition associated with fatigue, cognitive dysfunction, sleep disturbance, depression, anxiety, and stiffness. Milnacipran is one of three medications currently approved by the Food and Drug Administration in the United States for the management of adult FMS patients. This review is the second in a three-part series reviewing each of the approved FMS drugs and serves as a primer on the use of milnacipran in FMS treatment including information on pharmacology, pharmacokinetics, safety and tolerability. Milnacipran is a mixed serotonin and norepinephrine reuptake inhibitor thought to improve FMS symptoms by increasing neurotransmitter levels in descending central nervous system inhibitory pathways. Milnacipran has proven efficacy in managing global FMS symptoms and pain as well as improving symptoms of fatigue and cognitive dysfunction without affecting sleep. Due to its antidepressant activity, milnacipran can also be beneficial to FMS patients with coexisting depression. However, side effects can limit milnacipran tolerability in FMS patients due to its association with headache, nausea, tachycardia, hyper- and hypotension, and increased risk for bleeding and suicidality in at-risk patients. Tolerability can be maximized by starting at low dose and slowly up-titrating if needed. As with all medications used in FMS management, milnacipran works best when used as part of an individualized treatment regimen that includes resistance and aerobic exercise, patient education and behavioral therapies

Critical Thinking Activities and the Enhancement of Ethical Awareness: An application of a ‘Rhetoric of Disruption’ to the undergraduate general education classroom

This article explores how critical thinking activities and assignments can function to enhance students’ ethical awareness and sense of civic responsibility. Employing Levinas’s Othercentered theory of ethics, Burke’s notion of ‘the paradox of substance’, and Murray’s concept of ‘a rhetoric of disruption’, this article explores the nature of critical thinking activities designed to have students question their (often taken-for-granted) moral assumptions and interrogate their (often unexamined) moral identities. This article argues that such critical thinking activities can trigger a metacognitive destabilization of subjectivity, understood as a dialectical prerequisite (along with exposure to otherness) for increased ethical awareness. This theoretical model is illustrated through a discussion of three sample classroom activities designed to destabilize moral assumptions and identity, thereby clearing the way for a heightened acknowledgment of otherness. In so doing, this article provides an alternative (and dialectically inverted) strategy for addressing one of the central goals of many General Education curricula: the development of ethical awareness and civic responsibility. Rather than introducing students to alternative perspectives and divergent cultures with the expectation that heightened moral awareness will follow, this article suggests classroom activities and course assignments aimed at disrupting moral subjectivity and creating an opening in which otherness can be more fully acknowledged and the diversity of our world more fully appreciated

Photoassociative Production and Trapping of Ultracold KRb Molecules

We have produced ultracold heteronuclear KRb molecules by the process of photoassociation in a two-species magneto-optical trap. Following decay of the photoassociated KRb*, the molecules are detected using two-photon ionization and time-of-flight mass spectroscopy of KRb$^+$. A portion of the metastable triplet molecules thus formed are magnetically trapped. Photoassociative spectra down to 91 cm$^{-1}$ below the K(4$s$) + Rb (5$p_{1/2}$) asymptote have been obtained. We have made assignments to all eight of the attractive Hund's case (c) KRb* potential curves in this spectral region.Comment: 4 pages, 4 figure

Prospects for rapid deceleration of small molecules by optical bichromatic forces

We examine the prospects for utilizing the optical bichromatic force (BCF) to greatly enhance laser deceleration and cooling for near-cycling transitions in small molecules. We discuss the expected behavior of the BCF in near-cycling transitions with internal degeneracies, then consider the specific example of decelerating a beam of calcium monofluoride molecules. We have selected CaF as a prototype molecule both because it has an easily-accessible near-cycling transition, and because it is well-suited to studies of ultracold molecular physics and chemistry. We also report experimental verification of one of the key requirements, the production of large bichromatic forces in a multi-level system, by performing tests in an atomic beam of metastable helium.Comment: 11 pages, 6 figures, revised version, to be published in Physical Review

The Mass of the Black Hole in the Quasar PG 2130+099

We present the results of a recent reverberation-mapping campaign undertaken to improve measurements of the radius of the broad line region and the central black hole mass of the quasar PG 2130+099. Cross correlation of the 5100 angstrom continuum and H-beta emission-line light curves yields a time lag of 22.9 (+4.4 - 4.3) days, corresponding to a central black hole mass MBH= 3.8 (+/- 1.5) x 10^7 Msun. This value supports the notion that previous measurements yielded an incorrect lag. We re-analyzed previous datasets to investigate the possible sources of the discrepancy and conclude that previous measurement errors were apparently caused by a combination of undersampling of the light curves and long-term secular changes in the H-beta emission-line equivalent width. With our new measurements, PG 2130+099 is no longer an outlier in either the R-L or the MBH-Sigma relationships.Comment: 21 pages, 7 figures; Accepted for publication in Ap

Covariance and correlation analysis of resting state functional magnetic resonance imaging data acquired in a clinical trial of mindfulness-based stress reduction and exercise in older individuals

We describe and apply novel methodology for whole-brain analysis of resting state fMRI functional connectivity data, combining conventional multi-channel Pearson correlation with covariance analysis. Unlike correlation, covariance analysis preserves signal amplitude information, which feature of fMRI time series may carry physiological significance. Additionally, we demonstrate that dimensionality reduction of the fMRI data offers several computational advantages including projection onto a space of manageable dimension, enabling linear operations on functional connectivity measures and exclusion of variance unrelated to resting state network structure. We show that group-averaged, dimensionality reduced, covariance and correlation matrices are related, to reasonable approximation, by a single scalar factor. We apply this methodology to the analysis of a large, resting state fMRI data set acquired in a prospective, controlled study of mindfulness training and exercise in older, sedentary participants at risk for developing cognitive decline. Results show marginally significant effects of both mindfulness training and exercise in both covariance and correlation measures of functional connectivity