Discovery of Two High-Magnetic-Field Radio Pulsars

We report the discovery of two young isolated radio pulsars with very high inferred magnetic fields. PSR J1119-6127 has period P = 0.407 s, and the largest period derivative known among radio pulsars, Pdot = 4.0e-12. Under standard assumptions these parameters imply a characteristic spin-down age of only tau = 1.6 kyr and a surface dipole magnetic field strength of B = 4.1e13 G. We have measured a stationary period-second-derivative for this pulsar, resulting in a braking index of n = 2.91+-0.05. We have also observed a glitch in the rotation of the pulsar, with fractional period change Delta_P/P = -4.4e-9. Archival radio imaging data suggest the presence of a previously uncataloged supernova remnant centered on the pulsar. The second pulsar, PSR J1814-1744, has P = 3.975 s and Pdot = 7.4e-13. These parameters imply tau = 85 kyr, and B = 5.5e13 G, the largest of any known radio pulsar. Both PSR J1119-6127 and PSR J1814-1744 show apparently normal radio emission in a regime of magnetic field strength where some models predict that no emission should occur. Also, PSR J1814-1744 has spin parameters similar to the anomalous X-ray pulsar (AXP) 1E 2259+586, but shows no discernible X-ray emission. If AXPs are isolated, high magnetic field neutron stars (``magnetars''), these results suggest that their unusual attributes are unlikely to be merely a consequence of their very high inferred magnetic fields.Comment: 7 pages, 3 embedded EPS figures, to be published in Ap

XMM-Newton observation of SNR J0533-7202 in the Large Magellanic Cloud

Aims. We present an X-ray study of the supernova remnant SNR J0533-7202 in the Large Magellanic Cloud (LMC) and determine its physical characteristics based on its X-ray emission. Methods. We observed SNR J0533-7202 with XMM-Newton (flare-filtered exposure times of 18 ks EPIC-pn and 31 ks EPIC-MOS1/MOS2). We produced X-ray images of the SNR, performed an X-ray spectral analysis, and compared the results to multi-wavelength studies. Results. The distribution of X-ray emission is highly non-uniform, with the south-west region brighter than the north-east. The X-ray emission is correlated with the radio emission from the remnant. We determine that this morphology is likely due to the SNR expanding into a non-uniform ambient medium and not an absorption effect. We estimate the size to be 53.9 (\pm 3.4) x 43.6 (\pm 3.4) pc, with the major axis rotated ~64 degrees east of north. We find no spectral signatures of ejecta and infer that the X-ray plasma is dominated by swept-up interstellar medium. Using the spectral fit results and the Sedov self-similar solution, we estimate an age of ~17-27 kyr, with an initial explosion energy of (0.09-0.83) x 10^51 erg. We detected an X-ray source located near the centre of the remnant, namely XMMU J053348.2-720233. The source type could not be conclusively determined due to the lack of a multi-wavelength counterpart and low X-ray counts. We find that it is likely either a background active galactic nucleus or a low-mass X-ray binary in the LMC. Conclusions. We detected bright thermal X-ray emission from SNR J0533-7202 and determined that the remnant is in the Sedov phase of its evolution. The lack of ejecta emission prohibits us from typing the remnant with the X-ray data. Therefore, the likely Type Ia classification based on the local stellar population and star formation history reported in the literature cannot be improved upon.Comment: 7 pages, 4 figures, accepted for publication in Astronomy and Astrophysic

Online occupational education in community colleges: Prevalence and contextual factors

This study examined the current state of online occupational programs in community colleges and explored issues related to institutional, economic, and social indicators that influence (a) the offering of online programs and (b) the programmatic connection to workforce development needs. This project is the first national study that categorizes and inventories specific types of online occupational programs in community colleges. The study included a national random sample of 321 institutions in the United States. Data were collected through institutional websites, statewide websites, follow-up emails, and phone inquiries to institutions. The following sections summarize key findings.https://scholarlycommons.pacific.edu/ed-facbooks/1056/thumbnail.jp

Independent thinking: Cross-cultural possibilities

This performative vignette represents a snapshot taken from a recent cross-disciplinary Action Research/Action Learning project at Curtin University of Technology. The cameo conveys the nature of our participation as staff, students and facilitator in addressing the development and enhancement of the FLOTE (first language other than English) students' communication skills in the context of their postgraduate studies. You will hear the multiple voices of the supervisors from Pharmacy, Social Work and Teacher Education, together with those of their respective PhD and Masters students, and that of the project facilitator. We focus upon the elusive nature of the concept of independent thinking in advanced scholarship. This has necessitated that we become mindful of the students' 'totality', power relations and interpersonal communication within the supervisory process, and the necessity for reflective practice. In representing how the different stakeholders dialogued on these complex issues, we hope to convey some of the process and outcomes attached to this Action Research Project

THE RELATIONSHIP BETWEEN MUSCULOSKELETAL STRENGTH, PHYSIOLOGICAL CHARACTERISTICS, AND KNEE KINESTHESIA FOLLOWING FATIGUING EXERCISE

Fatiguing exercise may result in impaired functional joint stability and increased risk of unintentional injury. While there are several musculoskeletal and physiological characteristics related to fatigue onset, their relationship with proprioceptive changes following fatigue has not been examined. The purpose of this study was to establish the relationship between musculoskeletal and physiological characteristics and changes in proprioception, measured by threshold to detect passive motion (TTDPM), following fatiguing exercise. Twenty, physically active females participated (age: 28.65 ± 5.6 years, height: 165.6 ± 4.3 cm, weight: 61.8 ± 8.0 kg, BMI: 22.5± 2.3 kg/m2, BF: 23.3 ± 5.4%). During Visit 1, subjects completed an exercise history and 24-hour dietary questionnaire, and body composition, TTDPM familiarization, isokinetic knee strength, and maximal oxygen uptake/lactate threshold assessments. During Visit 2, subjects completed TTDPM and isometric knee strength testing prior to and following a fatiguing exercise protocol. Wilcoxon signed rank tests determined TTDPM and isometric knee strength changes from pre- to post- fatigue. Spearman’s rho correlation coefficients determined the relationship between strength and physiological variables with pre- to post-fatigue changes in TTDPM and with pre-fatigue and post-fatigue TTDPM in extension and flexion (α=0.05). No significant differences were demonstrated from pre-fatigue to post-fatigue TTDPM despite a significant decrease in isometric knee flexion strength (P<0.01) and flexion/extension ratio (P<0.05) following fatigue. No significant correlations were observed between strength or physiological variables and changes in TTDPM from pre- to post-fatigue in extension or flexion. Flexion/extension ratio was significantly correlated with pre-fatigue TTDPM in extension (r=-0.231, P<0.05). Peak oxygen uptake was significantly correlated with pre-fatigue (r=-0.500, P<0.01) and post-fatigue (r=-0.520, P<0.05) TTDPM in extension. No significant relationships were demonstrated between musculoskeletal and physiological characteristics and changes in TTDPM following fatigue. The results suggest that highly trained individuals may have better proprioception, and that the high fitness level of subjects in this investigation may have contributed to absence of TTDPM deficits following fatigue despite reaching a high level of perceptual and physiological fatigue. Future studies should consider various subject populations, other musculoskeletal strength characteristics, and different modalities of proprioception to determine the most important contributions to proprioceptive changes following fatigue

Monte Carlo direct simulation technique user's manual

User manual for Monte Carlo direct simulation techniqu

X-ray observations of the compact central object in supernova remnant G347.3-0.5

We present Chandra, XMM-Newton and RXTE observations of 1WGA J1713.4-3949, a compact source at the center of the galactic supernova remnant (SNR) G347.3-0.5. The X-ray spectrum of the source is well-fitted by the sum of a blackbody component with a temperature of about 0.4 keV plus a power law component with photon index about 4. We found no pulsations down to 4% in the 0.01-0.16 Hz range and down to 25% in the 0.01-128 Hz range. This source resembles other compact central objects (CCOs) in SNRs, and we suggest that 1WGA J1713.4-3949 is the associated neutron star for G347.3--0.5. We also measured the properties of the adjacent radio pulsar PSR J1713-3945 with a 392 ms period and show that it is not associated with 1WGA J1713.4-3949 nor, most probably, with SNR G347.3-0.5 as well.Comment: 8 pages, 2 figures, accepted for publication in ApJ Letter