15,173 research outputs found
An Age Constraint for the Very Low-Mass Stellar/Brown Dwarf Binary 2MASS J03202839-0446358AB
2MASS J03202839-0446358AB is a recently identified, late-type M dwarf/T dwarf
spectroscopic binary system for which both the radial velocity orbit for the
primary and spectral types for both components have been determined. By
combining these measurements with predictions from four different sets of
evolutionary models, we determine a minimum age of 2.0+/-0.3 Gyr for this
system, corresponding to minimum primary and secondary masses of 0.080 Msun and
0.053 Msun, respectively. We find broad agreement in the inferred age and mass
constraints between the evolutionary models, including those that incorporate
atmospheric condensate grain opacity; however, we are not able to independently
assess their accuracy. The inferred minimum age agrees with the kinematics and
absence of magnetic activity in this system, but not the rapid rotation of its
primary, further evidence of a breakdown in angular momentum evolution trends
amongst the lowest luminosity stars. Assuming a maximum age of 10 Gyr, we
constrain the orbital inclination of this system to i >~ 53 degrees. More
precise constraints on the orbital inclination and/or component masses of 2MASS
J0320-0446AB, through either measurement of the secondary radial velocity orbit
(optimally in the 1.2-1.3 micron band) or detection of an eclipse (only 0.3%
probability based on geometric constraints), would yield a bounded age estimate
for this system, and the opportunity to use it as an empirical test for brown
dwarf evolutionary models at late ages.Comment: 8 pages, 2 figures, accepted for publication to Astonomical Journa
Post-traumatic growth in adult survivors of brain injury: a qualitative study of participants completing a pilot trial of brief positive psychotherapy
Purpose: Post-traumatic growth (PTG) can occur following acquired brain injury (ABI). It has been proposed that people experiencing psychological distress following ABI may benefit from a positive psychotherapy intervention (PPT) aimed at increasing well-being; PPT may also influence PTG. We aimed to investigate PTG experiences in participants of a positive psychotherapy pilot trial.
Methods: ABI survivors who had received PPT or treatment as usual (TAU) were interviewed individually after the end of the trial. Thematic analysis was conducted, to code transcripts for known themes from PTG literature as well as newly emerging themes.
Results: Four participants (age = 46–62; n = 3 male; months since injury = 11–20) from the PPT group and three (age = 58–74; n = 2 male; months since injury = 9–22) from the TAU group were interviewed. Six themes were shared across both groups: personal strength, appreciation of life, relating to others, optimism/positive attitude, feeling fortunate compared to others, and positive emotional/behavioral changes. Two themes were expressed by PPT participants only: lifestyle improvements and new possibilities. One TAU participant reported spiritual change.
Conclusions: A greater understanding of the development of PTG following ABI may help rehabilitation clinicians to promote better adjustment by focusing on clients’ potential for positive change and enhancing their capacity for growth
The mechanical properties of inconel 718 sheet alloy at 800 deg, 1000 deg, and 1200 deg f
Mechanical properties of Inconel sheet superalloy at very high temperatures for supersonic transpor
Towards validation of a new computerised test of goal neglect: preliminary evidence from clinical and neuroimaging pilot studies
Objective:
Goal neglect is a significant problem following brain injury, and is a target for rehabilitation. It is not yet known how neural activation might change to reflect rehabilitation gains. We developed a computerised multiple elements test (CMET), suitable for use in neuroimaging paradigms.
Design:
Pilot correlational study and event-related fMRI study.
Methods:
In Study 1, 18 adults with acquired brain injury were assessed using the CMET, other tests of goal neglect (Hotel Test; Modified Six Elements Test) and tests of reasoning. In Study 2, 12 healthy adults underwent fMRI, during which the CMET was administered under two conditions: self-generated switching and experimenter-prompted switching.
Results:
Among the clinical sample, CMET performance was positively correlated with both the Hotel Test (r = 0.675, p = 0.003) and the Modified Six Elements Test (r = 0.568, p = 0.014), but not with other clinical or demographic measures. In the healthy sample, fMRI demonstrated significant activation in rostro-lateral prefrontal cortex in the self-generated condition compared with the prompted condition (peak 40, 44, 4; ZE = 4.25, p(FWEcorr) = 0.026).
Conclusions:
These pilot studies provide preliminary evidence towards the validation of the CMET as a measure of goal neglect. Future studies will aim to further establish its psychometric properties, and determine optimum pre- and post-rehabilitation fMRI paradigms
Demonstration of a multi-technique approach to assess glacial microbial populations in the field
The ability to perform microbial detection and characterization in-field at extreme environments, rather than on returned samples, has the potential to improve the efficiency, relevance and quantity of data from field campaigns. To date, few examples of this approach have been reported. Therefore, we demonstrate that the approach is feasible in subglacial environments by deploying four techniques for microbial detection: real-time polymerase chain reaction; microscopic fluorescence cell counts, adenosine triphosphate bioluminescence assay and recombinant Factor C assay (to detect lipopolysaccharide). Each technique was applied to 12 subglacial ice samples, 12 meltwater samples and two snow samples from Engabreen, Northern Norway. Using this multi-technique approach, the detected biomarker levels were as expected, being highest in debris-rich subglacial ice, moderate in glacial meltwater and low in clean ice (debris-poor) and snow. Principal component analysis was applied to the resulting dataset and could be performed in-field to rapidly aid the allocation of resources for further sample analysis. We anticipate that in-field data collection will allow for multiple rounds of sampling, analysis, interpretation and refinement within a single field campaign, resulting in the collection of larger and more appropriate datasets, ultimately with more efficient science return
A Complete Achilles Tendon Rupture-- An Anatomical Review and Case Study of the Treatment, Surgery, and Rehabilitation of One Complete Rupture
The purpose of this thesis was to study the anatomi cal structure, mechanical function, and mechanism of injury of the Achilles tendon. The surgical procedure, description and results of the rehabilitation program, developed by this researcher specifically for this injury were presented.
A case study of one twenty-three-year-old male subject was the basis of this study. A day-by-day follow-up of the subject\u27s rehabilitation program from surgery to dismissal from rehabilitation were presented.
The results of this rehabilitation program were favorable. This subject was able to return to daily activities much sooner than expected and was able to participate in a competitive activity only six months after surgery.
The program cannot be generalized as useful to the population. It was designed for a particular subject who was able to spend two hours a day in therapy. The rehabilitation program can be used as a guideline for future programs for complete Achilles tendon ruptures
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