A Technique for Narrowband Time Series Photometry: the X-ray Star V2116 Oph

We have used innovative features of the Taurus Tunable Filter instrument on the 3.9-m Anglo-Australian Telescope to obtain nearly-continuous, high-throughput, linear photometry of V2116 Oph in a 7 Angstrom bandpass at the center of the O I 8446 emission line. This instrumental technique shows promise for applications requiring precise, rapid, narrowband photometry of faint objects. The spectrum of V2116 Oph, the counterpart of GX 1+4 (=X1728-247), is exotic, even among the unusual spectra of other optical counterparts of compact Galactic X-ray sources. The second strongest emission line is an unusual one, namely extremely prominent O I 8446, which is likely to result from pumping by an intense Ly beta radiation field. As the X-radiation from GX 1+4 is steadily pulsed, with typical pulsed fractions of 0.4, the O I 8446 emission in V2116 Oph may also be strongly modulated with the current 127 s period of the X-ray source. If so, this may well allow us to obtain high signal-to-noise radial velocity measurements and thus to determine the system parameters. However, no such pulsations are detected, and we set an upper limit of ~1% (full-amplitude) on periodic 8446 oscillations at the X-ray frequency. This value is comparable to the amplitude of continuum oscillations observed on some nights by other workers. Thus we rule out an enhancement of the pulsation amplitude in O I emission, at least at the time of our observations.Comment: 9 pages including 4 figures and no tables. Accepted for publication in PASP; to appear in Volume 110, August 199

Discovery of a 500 pc shell in the nucleus of Centaurus A

Spitzer Space Telescope mid-infrared images of the radio galaxy Centaurus A reveal a shell-like, bipolar, structure 500 pc to the north and south of the nucleus. This shell is seen in 5.8, 8.0 and 24 micron broad-band images. Such a remarkable shell has not been previously detected in a radio galaxy and is the first extragalactic nuclear shell detected at mid-infrared wavelengths. We estimate that the shell is a few million years old and has a mass of order million solar masses. A conservative estimate for the mechanical energy in the wind driven bubble is 10^53 erg. The shell could have created by a small few thousand solar mass nuclear burst of star formation. Alternatively, the bolometric luminosity of the active nucleus is sufficiently large that it could power the shell. Constraints on the shell's velocity are lacking. However, if the shell is moving at 1000 km/s then the required mechanical energy would be 100 times larger.Comment: submitted to ApJ Letter

A Qualitative Study of Stressors, Stress Symptoms, and Coping Mechanisms Among College Students Using Nominal Group Process

Background: Stress is part of the college experience; however, how students deal with stress can greatly impact their behaviors and health status. Purpose: The purpose of this study was to qualitatively assess sources of stress, types of stressors, and coping mechanisms employed among undergraduate students. Methods: Nominal group process was utilized to obtain information related to study variables and help prioritize the accounts provided by study participants (n = 173). Results: Participants gave insight into the unique stress faced by this generation (grades, GPA, multitasking, parental expectations), stress symptoms (more psychological in nature), and coping strategies (prayer, talking to mom, surfing the net, and social networking). The top stressors included: schoolwork, money, time management, parents, and friends. Moodiness/irritability, anxiety, and sleep problems were the highest-ranked symptoms of stress cited by study participants. The three most-reported coping mechanisms were: working out, prayer, and talking to mom. Conclusions: Although the themes of stressors, symptoms, and coping mechanisms for college students might not have changed through the years, the sources that underlie these themes have changed as compared to past generations

Spin rotons and supersolids in binary antidipolar condensates

We present a theoretical study of a mixture of antidipolar and nondipolar Bose-Einstein condensates confined to an infinite tube. We predict the presence of a spin roton and its associated instability, which triggers a continuous unmodulated--to--supersolid phase transition. We characterize the phase diagram of the binary system, ranging from the quasi-1D to the radial Thomas-Fermi (elongated 3D) regimes. We also present the dynamic formation of supersolids following a quench from the uniform miscible phase, which maintains phase coherence across the system.Comment: 13 pages main text, 5 figures, submission to SciPost Physics Cor

A Search for the Optical Counterpart of the Luminous X-ray Source in NGC 6652

We examine images of the field of X1832-330, the luminous (Lx ~ 10^36 erg/s) X-ray burst source near the center of the globular cluster NGC 6652, in order to identify the optical counterpart for further study. U and B ground-based images allow us to set a limit M_B > 3.5 for the counterpart at the time of those observations, provided that the color is (U-B)_0 ~ -1, similar to the sources known in other clusters. Archival Hubble Space Telescope observations survey most but not all of the 1 sigma X-ray error circle, and allow us to set limits M_B > 5.9 and M_B > 5.2 in the WF/PC and WFPC2 regions, respectively. In the WF/PC images we do weakly detect a faint object with UV-excess, but it is located 11.7'' from the ROSAT X-ray position. This considerable (2.3 sigma) discrepancy in position suggests that this candidate be treated with caution, but it remains the only reasonable one advanced thus far. We measure for this star m_439 = 20.2 +- 0.2, (m_336 - m_439) = -0.5 +- 0.2, and estimate M_B = 5.5, (U-B)_0 = -0.9, similar to other known optical counterparts. If this candidate is not the identification, our limits imply that the true counterpart, not yet identified, is probably the optically-faintest cluster source yet known, or alternatively that it did not show significant UV excess at the time of these observations. Finally, we assess the outlook for the identification of the remaining luminous globular cluster X-ray sources.Comment: 15 pages including 5 figures and no tables. Accepted for publication in The Astronomical Journal; to appear in Volume 116, September 1998. A preprint with full resolution figures may be downloaded from http://www.astro.washington.edu/deutsch/pubs

Evaluation of the Craniovertebral Angle in Standing versus Sitting Positions in Young Adults with and without Severe Forward Head Posture

International Journal of Exercise Science 17(1): 73-85, 2024. The purpose of this study was to examine the effects of standing versus sitting body position on the craniovertebral angle (CVA) in young adults without pathology; and to investigate whether mean differences between positional CVA measures in subjects with severe forward head posture (FHP) are distinct from age-matched controls with normal head posture. Ninety-eight young adults (68 women, 30 men) without pathology (OVERALL; n = 98) volunteered for the study; those with CVA \u3e 53° were also included in a normal posture group (NORM; n = 14); those with CVA \u3c 45° were also included in a severe FHP group (SEV; n = 15). CVA assessments were conducted in standing and sitting. Mean difference comparison of change in mean CVA between conditions revealed significantly (p \u3c 0.05) higher CVA values in standing condition (OVERALL: 50.0 ± 5.2°; NORM: 56.6 ± 2.7°; SEV: 41.2 ± 3.2°) compared to sitting condition (OVERALL: 47.8 ± 5.7°; NORM: 55.9 ± 2.8°; SEV: 39.0 ± 4.0°). Mean difference comparison of between-group change in mean CVA between conditions revealed greater CVA change (p \u3c 0.05) in the SEV group (2.2 ± 2.1°) versus the NORM group (0.8 ± 1.2°). Sitting CVA values may be lower (indicating greater FHP) than standing CVA values in young adults. Differences between standing and sitting CVA measures may be greater in young adults with severe FHP compared to peers with normal head posture. Study findings support standing as a standardized body position for CVA assessment in young adults without pathology

The Effects of Postural Education or Corrective Exercise on the Craniovertebral Angle in Young Adults with Forward Head Posture: A Randomized Controlled Trial

International Journal of Exercise Science 16(1): 954-973, 2023. The purpose of this study was to compare the effects of three different intervention strategies, postural education (PE) and two corrective exercise programs (CEPs), on the craniovertebral angle (CVA) in young adults with forward head posture (FHP). A prospective four-arm parallel randomized controlled trial with repeated measures was performed. Seventy-nine healthy young adults (55 women, 24 men; mean age: 20.08 ± 2.19 years) with FHP were randomized into four groups: PE group, self-myofascial release + stretching group (SMRS), self-myofascial release + stretching + strengthening group (SMRSS), and a control group (CG). Participant CVA (°) was assessed before and after a 4-week intervention. Seventy-two participants completed the trial. Mean difference comparisons of within-group change in mean CVA revealed an increase in the PE (MD = 3.1, p \u3c .01), SMRS (MD = 3.8, p \u3c .01), and SMRSS (MD = 4.4, p \u3c .01) groups. Mean difference comparison of between-group change in mean CVA supported greater CVA change in the SMRS and SMRSS groups compared to the CG (F(3, 68) = 5.26, p \u3c .01, ƞ2 = .188). All three interventions appear to be effective techniques for improving FHP in young adults, however CEPs may provide superior outcomes than PE alone. A 4-week CEP consisting of self-myofascial release + stretching may yield similar CVA enhancements as a CEP consisting of self-myofascial release + stretching + strengthening. Study findings can assist fitness professionals in designing evidence-based FHP intervention programs for young adults

Profile of the U 5f magnetization in U/Fe multilayers

Recent calculations, concerning the magnetism of uranium in the U/Fe multilayer system have described the spatial dependence of the 5f polarization that might be expected. We have used the x-ray resonant magnetic reflectivity technique to obtain the profile of the induced uranium magnetic moment for selected U/Fe multilayer samples. This study extends the use of x-ray magnetic scattering for induced moment systems to the 5f actinide metals. The spatial dependence of the U magnetization shows that the predominant fraction of the polarization is present at the interfacial boundaries, decaying rapidly towards the center of the uranium layer, in good agreement with predictions.Comment: 7 pages, 6 figure

Physical profile of Air Force Special Warfare trainees

International Journal of Exercise Science 16(4): 924-931, 2023. Physical fitness testing in the military is commonly used to assess whether service members are physically capable of performing the diverse physical tasks that may be required for their job. Body composition can influence an individual’s ability to physically perform. This study aimed to analyze the general physical profile of U.S. Air Force (USAF) special warfare candidates by assessing body composition results and physical assessment scores collected over the past four years. Male candidates (n = 1036) were 18.2 years to 39.5 years of age (M = 23.5, SD = 3.9) and weighed 78.8 kg (SD = 8.3) with a BMI of 25.0 (SD = 2.0) at 11.8% body fat (SD = 3.3) as measured using bioelectrical impedance. Body composition and fitness scores were similar to those noted in U.S. Navy special warfare candidates as well as individuals in other elite tactical units. These results highlight the normative body composition profile of individuals assessing for advanced military career fields