Orbital Debris Radar Measurements from the Haystack Ultra-Wideband Satellite Imaging Radar (HUSIR): 2014-2017

For many years, the NASA Orbital Debris Program Office (ODPO) has partnered with the U.S. Department of Defense and the Massachusetts Institute of Technology Lincoln Laboratory (MIT/LL) to collect data on the orbital debris environment using the Haystack radar. These measurements are used to characterize the small debris environment in low Earth orbit (LEO), down to a noise-limited size of approximately 5 mmdepending on altitude. The Haystack radar operated by MIT Lincoln Lab underwent upgrades starting in May 2010, with operations resuming in 2014 as the Haystack Ultra-wideband Satellite Imaging Radar (HUSIR). Hence, the data collected beginning in 2014 represents the first dataset available from this upgraded sensor. HUSIR is the primary source of data used by the ODPO to statistically sample orbital debris in the 5-mm to 10-cm size regime in LEO and is a key source of data to build and validate the NASA Orbital Debris Engineering Model. In this paper, we will present recent results from measurements performed during the US Government fiscal years 2014 2017. Using the NASA Size Estimation Model, a method based on laboratory radar measurements of debris, we will compare the size distributions of selected orbital debris populations over this 4-year period and flux measurements of orbital debris greater than 1 cm

A longitudinal study of mental health in refugees from Burma: The impact of therapeutic interventions

Objective: The present study seeks to examine the impact of therapeutic interventions for people from refugee backgrounds within a naturalistic setting. Method: Sixty-two refugees from Burma were assessed soon after arriving in Australia. All participants received standard interventions provided by a resettlement organisation which included therapeutic interventions, assessment, social assistance, and referrals where appropriate. At the completion of service provision a follow-up assessment was conducted. Results: Over the course of the intervention, participants experienced a significant decrease in symptoms of post-traumatic stress disorder, anxiety, depression and somatisation. Pre-intervention symptoms predicted symptoms post-intervention for post-traumatic stress, anxiety, and somatisation. Post-migration living difficulties, the number of traumas experienced, and the number of contacts with the service agency were unrelated to all mental health outcomes. Conclusions: In the first Australian study of its kind, reductions in mental health symptoms post-intervention were significantly linked to pre-intervention symptomatology and the number of therapy sessions predicted post-intervention symptoms of post-traumatic stress. Future studies need to include larger samples and control groups to verify findings

Obscuration by Gas and Dust in Luminous Quasars

We explore the connection between absorption by neutral gas and extinction by dust in mid-infrared (IR) selected luminous quasars. We use a sample of 33 quasars at redshifts 0.7 < z < 3 in the 9 deg^2 Bo\"otes multiwavelength survey field that are selected using Spitzer Space Telescope Infrared Array Camera colors and are well-detected as luminous X-ray sources (with >150 counts) in Chandra observations. We divide the quasars into dust-obscured and unobscured samples based on their optical to mid-IR color, and measure the neutral hydrogen column density N_H through fitting of the X-ray spectra. We find that all subsets of quasars have consistent power law photon indices equal to 1.9 that are uncorrelated with N_H. We classify the quasars as gas-absorbed or gas-unabsorbed if N_H > 10^22 cm^-2 or N_H < 10^22 cm^-2, respectively. Of 24 dust-unobscured quasars in the sample, only one shows clear evidence for significant intrinsic N_H, while 22 have column densities consistent with N_H < 10^22 cm^-2. In contrast, of the nine dust-obscured quasars, six show evidence for intrinsic gas absorption, and three are consistent with N_H < 10^22 cm^-2. We conclude that dust extinction in IR-selected quasars is strongly correlated with significant gas absorption as determined through X-ray spectral fitting. These results suggest that obscuring gas and dust in quasars are generally co-spatial, and confirm the reliability of simple mid-IR and optical photometric techniques for separating quasars based on obscuration.Comment: 5 pages, 3 figure

Open Bibliography

Poster presented at the VSMF Symposium held at the Unilever Centre on 2011-01-17.More research is published currently than can be understood or followed by a researcher without the aid of a computer. We need Open shareable information on research publications, an Open Bibliography, to build the services that enable researchers to explore their field and discover the research they need. Producers of bibliographic data such as libraries, publishers, universities, scholars or social reference management communities have an important role in supporting the advance of humanity's knowledge. For society to reap the full benefits from bibliographic endeavours, it is imperative that bibliographic data be made open - that is, available for anyone to use and re-use freely for any purpose

Organizational documents : a guide for partnerships and professional corporation

https://egrove.olemiss.edu/aicpa_guides/1487/thumbnail.jp

International business; Management series

https://egrove.olemiss.edu/aicpa_guides/1827/thumbnail.jp

Managing the malpractice maze

https://egrove.olemiss.edu/aicpa_guides/1215/thumbnail.jp