22 research outputs found
Greatly enhanced acoustic noise and the onset of stimulated Brillouin scattering
Experiments using near-infrared to ultraviolet lasers offer the potential to study the acoustic noise in plasmas. As the onset of stimulated Brillouin scattering (SBS) has come to be closely examined, the evidence indicates that the acoustic noise may often or always be far above thermal levels. Evidence regarding the noise is reported here, from two recent experiments which confirmed the theoretically anticipated onset behavior for SBS. In one case, the noise appears to be greatly enhanced above thermal levels. In the other case, the data place an upper limit on the noise level. There is physical grounds to believe that enhanced acoustic noise may be ubiquitous in plasmas, even in the absence of plasma instabilities which drive turbulence. © 1997 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70848/2/PHPAEN-4-5-1825-1.pd
Supernova hydrodynamics experiments on the Nova laser
In studying complex astrophysical phenomena such as supernovae, one does not have the luxury of setting up clean, well-controlled experiments in the universe to test the physics of current models and theories. Consequently, creating a surrogate environment to serve as an experimental astrophysics testbed would be highly beneficial. The existence of highly sophisticated, modern research lasers, developed largely as a result of the world-wide effort in inertial confinement fusion, opens a new potential for creating just such an experimental testbed utilizing well-controlled, well-diagnosed laser-produced plasmas. Two areas of physics critical to an understanding of supernovae are discussed that are amenable to supporting research on large lasers: (1) compressible nonlinear hydrodynamic mixing and (2) radiative shock hydrodynamics. © 1997 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69962/2/PHPAEN-4-5-1994-1.pd
Laser experiments to simulate supernova remnants
An experiment using a large laser facility to simulate young supernova remnants (SNRs) is discussed. By analogy to the SNR, the laboratory system includes dense matter that explodes, expansion and cooling to produce energetic, flowing plasma, and the production of shock waves in lower-density surrounding matter. The scaling to SNRs in general and to SN1987A in particular is reviewed. The methods and results of x-ray radiography, by which the system in diagnosed, are discussed. The data show that the hohlraum used to provide the energy for explosion does so in two ways—first, through its radiation pulse, and second, through an additional impulse that is attributed to stagnation pressure. Attempts to model these dynamics are discussed. © 2000 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69889/2/PHPAEN-7-5-2142-1.pd
Supernova hydrodynamics experiments on Nova
We are developing experiments using the Nova laser to investigate (1) compressible nonlinear hydrodynamic mixing relevant to the first few hours of the supernova (SN) explosion and (2) ejecta-ambient plasma interactions relevant to the early SN remnant phase. The experiments and astrophysical implications are discussed. We discuss additional experiments possible with ultra-high-intensity lasers. © 1998 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87451/2/551_1.pd
Governing England through the Manor Courts, c.1550-1850
Using records from 113 manors in Yorkshire and elsewhere, this article surveys the changing role of manor courts in English local government over three centuries. These institutions allowed juries of established tenants to deal cheaply and easily with a variety of chronic concerns, including crime, migration, retailing, common lands, and infrastructure. Their focus varied significantly according to region, topography, settlement size, and time period, but active courts existed in most parts of the country throughout the seventeenth and eighteenth centuries. Ultimately, they had many valuable functions which historians have barely begun to explore. This article thus offers the most systematic analysis to date of the role of these institutions in making and enforcing by-laws in this period, showing that many of the courts evolved to suit the changing priorities of local tenants rather than falling rapidly into ruin as has sometimes been assumed
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Improved Spatial Filter for high power Lasers
A new pinhole architecture incorporates features intended to reduce the rate of plasma generation in a spatial filter for high-energy laser pulse beams. An elongated pinhole aperture is provided in an apertured body for rejecting off-axis rays of the laser pulse beam. The internal surface of the elongated aperture has a diameter which progressively tapers from a larger entrance cross-sectional area at an inlet to a smaller output cross-sectional area at an outlet. The tapered internal surface causes off-axis rays to be refracted in a low density plasma layer that forms on the internal surface or specularly reflected at grazing incidence from the internal surface. Off-axis rays of the high-energy pulse beam are rejected by this design. The external surface of the apertured body adjacent to the larger entrance cross-sectional area at the inlet to the elongated aperture is angled obliquely with respect to the to direction of the path of the high-energy laser pulse beam to backscatter off-axis rays away from the high-energy pulse beam. The aperture is formed as a truncated cone or alternatively with a tapered square cross-section. The internal surface of the aperture is coated with an ablative material, preferably high-density material which can be deposited with an exploding wire
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Symptom burden profiles in men with advanced prostate cancer undergoing androgen deprivation therapy
To identify symptom burden profiles among men with advanced prostate cancer undergoing androgen-deprivation therapy and examine their association with baseline sociodemographic and medical characteristics and psychosocial outcomes over time. Latent profile analysis was employed to identify distinct groups based on the Expanded Prostate Index Composite and the McGill Pain Questionnaire at baseline. Psychosocial outcomes were assessed at baseline, 6- and 12-month follow-ups. Three profiles emerged: “high symptom burden,” “high sexual bother,” and “low symptom burden.” Men with “high symptom burden” were younger and exhibited higher baseline levels of depression, stress, cancer-specific distress, and anxiety than men in the other two groups. However, men with “high symptom burden” also demonstrated improvement in these psychosocial outcomes over time. Men with advanced prostate cancer who experience multiple co-occurring symptoms demonstrate worse psychosocial adjustment. Patients with substantial symptom burden, and specifically young men, may benefit from prompt referral to supportive care services.Division of Cancer Prevention, National Cancer Institute12 month embargo; published: 02 February 2022This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
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Integrating PROMIS® computerized adaptive tests into a web-based intervention for prostate cancer
This study outlined the implementation and feasibility of delivering PROMIS® computer adaptive tests (CATs) using a web-based method to evaluate the impact of a technological adaptation of Cognitive-Behavioral Stress Management (CBSM) on the psychosocial functioning of men with advanced prostate cancer (APC) undergoing hormone therapy.
Patients were randomized to a CBSM group intervention (n = 95) or a health promotion (HP) attention-matched control condition (n = 97). Participants attended all sessions via video conference using tablets, and completed PROMIS® computer adaptive tests (CATs) assessing anxiety, depression, fatigue, pain interference, and physical function weekly during the 10-week intervention.
Assessment completion rates >50% at week 1 and week 10 demonstrated moderate feasibility of repeatedly administering PROMIS® CATs using a web-based method. Multilevel modeling demonstrated no significant group-by-time interactions from week 1 to week 10 for any of the assessed PROMIS® domains adjusting for sociodemographic and medical covariates. However, simple effects demonstrated decreases in PROMIS® anxiety scores from week 1 to 10 for both groups. Results also demonstrated significant relationships of medical variables to psychosocial functioning across time points.
Results highlight the feasibility and benefits of utilizing PROMIS® CATs to repeatedly assess psychosocial functioning using a web-based method and indicate that web-based interventions may be effective for decreasing psychosocial distress and adverse symptoms among men with APC undergoing hormone therapy. (PsycINFO Database Record (c) 2019 APA, all rights reserved)
Effects of web-based cognitive behavioral stress management and health promotion interventions on neuroendocrine and inflammatory markers in men with advanced prostate cancer: A randomized controlled trial
•Inflammatory markers decreased among men in stress management and health promotion.•Decreases in inflammatory markers were not sustained at 12 months.•More research is needed to determine whether these interventions impact biomarkers.
Cognitive behavioral stress management (CBSM) improves quality of life and mitigates stress biology in patients with early-stage cancer, including men with localized prostate cancer. However, treatments for advanced prostate cancer like androgen deprivation therapy (ADT) can lead to significant symptom burden that may be further exacerbated by stress-induced inflammation and cortisol dysregulation. The aim of this study was to examine the effects of CBSM (versus an active health promotion control) on circulating inflammatory markers and cortisol in men with advanced prostate cancer. Methods: Men with stage III or IV prostate cancer (N = 192) who had undergone ADT within the last year were randomized to CBSM or health promotion. Both interventions were 10 weeks, group-based, and delivered online. Venous blood was drawn at baseline, 6 months, and 12 months to measure circulating levels of CRP, IL-6, IL-8, IL-10, and TNF-α. Saliva samples were collected at awakening, 30 min after awakening, evening, and night for two consecutive days at baseline, 6-months, and 12-months to measure diurnal cortisol slopes. Results: Mixed modeling analyses demonstrated that changes in inflammatory markers and cortisol did not differ by intervention. Men in both CBSM and health promotion showed decreases in IL-10, IL-8, and TNF-α from baseline to 6 months (β = −3.85–−5.04, p’s = 0.004–<0.001). However, these markers generally demonstrated a rebound increase from 6 to 12 months (β = 1.91–4.06, p’s = 0.06–<0.001). Men in health promotion also demonstrated a flatter diurnal cortisol slope versus men in CBSM at 6 months (β = −2.27, p = .023), but not at 12 months. There were no intervention effects on CRP, IL-6, or overall cortisol output. Conclusions: Contrary to hypotheses, CBSM did not lead to changes in the circulating inflammatory markers and cortisol relative to health promotion. CBSM may be associated with healthy diurnal cortisol rhythm because of its focus on cognitive behavioral approaches to stress management. More research is needed to understand the impact of CBSM and health promotion on biomarkers among men with advanced prostate cancer