30 research outputs found

    The Infrared Imaging Spectrograph (IRIS) for TMT: Instrument Overview

    Full text link
    We present an overview of the design of IRIS, an infrared (0.84 - 2.4 micron) integral field spectrograph and imaging camera for the Thirty Meter Telescope (TMT). With extremely low wavefront error (<30 nm) and on-board wavefront sensors, IRIS will take advantage of the high angular resolution of the narrow field infrared adaptive optics system (NFIRAOS) to dissect the sky at the diffraction limit of the 30-meter aperture. With a primary spectral resolution of 4000 and spatial sampling starting at 4 milliarcseconds, the instrument will create an unparalleled ability to explore high redshift galaxies, the Galactic center, star forming regions and virtually any astrophysical object. This paper summarizes the entire design and basic capabilities. Among the design innovations is the combination of lenslet and slicer integral field units, new 4Kx4k detectors, extremely precise atmospheric dispersion correction, infrared wavefront sensors, and a very large vacuum cryogenic system.Comment: Proceedings of the SPIE, 9147-76 (2014

    MCAO for Gemini South

    Get PDF
    The multi-conjugate adaptive optics (MCAO) system design for the Gemini-South 8-meter telescope will provide near-diffraction-limited, highly uniform atmospheric turbulence compensation at near-infrared wavelengths over a 2 arc minute diameter field-of-view. The design includes three deformable mirrors optically conjugate to ranges of 0, 4.5, and 9.0 kilometers with 349, 468, and 208 actuators, five 10-Watt-class sodium laser guide stars (LGSs) projected from a laser launch telescope located behind the Gemini secondary mirror, five Shack-Hartmann LGS wavefront sensors of order 16 by 16, and three tip/tilt natural guide star (NGS) wavefront sensors to measure tip/tilt and tilt anisoplanatism wavefront errors. The WFS sampling rate is 800 Hz. This paper provides a brief overview of sample science applications and performance estimates for the Gemini South MCAO system, together with a summary of the performance requirements and/or design status of the principal subsystems. These include the adaptive optics module (AOM), the laser system (LS), the beam transfer optics (BTO) and laser launch telescope (LLT), the real time control (RTC) system, and the aircraft safety system (SALSA)

    Muscle-Strengthening Exercise Among 397,423 U.S. Adults: Prevalence, Correlates, and Associations With Health Conditions

    No full text
    INTRODUCTION: Although muscle-strengthening exercise has multiple independent health benefits, little is known about muscle-strengthening exercise participation and associations with adverse health conditions among U.S. adults. METHODS: In 2017, data were analyzed from the U.S. 2015 Behavioral Risk Factor Surveillance System. During telephone surveys, respondents reported how many times during the past week they engaged in muscle-strengthening exercise. Weighted weekly muscle-strengthening exercise frequencies were calculated for the total sample and across sociodemographic and lifestyle characteristics. A multivariable logistic regression assessed the odds of having self-reported adverse health conditions (e.g., diabetes, coronary heart disease) according to weekly muscle-strengthening exercise frequency. RESULTS: Data were available on 397,423 adults (aged 18-80 years). Overall, 30.2% (95% CI=29.9, 30.5) met the muscle-strengthening exercise recommendations (two or more times/week) and 57.8% (95% CI=57.5, 58.2) reported no muscle-strengthening exercise. Older age, insufficient aerobic activity, lower income, lower education, poorer self-rated health, being female, and being overweight/obese were significantly associated with lower odds of meeting the muscle-strengthening exercise recommendations independently of other characteristics. After adjusting for confounders (e.g., age, sex, income, smoking, aerobic activity), when compared with those who did none, muscle-strengthening exercise was associated with lower odds for several adverse health conditions, including prevalent diabetes, cancer (non-skin), poor self-rated health, and obesity. CONCLUSIONS: Three in five U.S. adults do not engage in any muscle-strengthening exercise, despite an association for muscle-strengthening exercise with better health conditions. Future muscle-strengthening exercise promotion strategies should target older adults, females, those with low education/income, and those with a poor health status

    Muscle-strengthening exercise among 397,423 U.S. adults: prevalence, correlates, and associations with health conditions

    No full text
    INTRODUCTION: Although muscle-strengthening exercise has multiple independent health benefits, little is known about muscle-strengthening exercise participation and associations with adverse health conditions among U.S. adults. METHODS: In 2017, data were analyzed from the U.S. 2015 Behavioral Risk Factor Surveillance System. During telephone surveys, respondents reported how many times during the past week they engaged in muscle-strengthening exercise. Weighted weekly muscle-strengthening exercise frequencies were calculated for the total sample and across sociodemographic and lifestyle characteristics. A multivariable logistic regression assessed the odds of having self-reported adverse health conditions (e.g., diabetes, coronary heart disease) according to weekly muscle-strengthening exercise frequency. RESULTS: Data were available on 397,423 adults (aged 18-80 years). Overall, 30.2% (95% CI=29.9, 30.5) met the muscle-strengthening exercise recommendations (two or more times/week) and 57.8% (95% CI=57.5, 58.2) reported no muscle-strengthening exercise. Older age, insufficient aerobic activity, lower income, lower education, poorer self-rated health, being female, and being overweight/obese were significantly associated with lower odds of meeting the muscle-strengthening exercise recommendations independently of other characteristics. After adjusting for confounders (e.g., age, sex, income, smoking, aerobic activity), when compared with those who did none, muscle-strengthening exercise was associated with lower odds for several adverse health conditions, including prevalent diabetes, cancer (non-skin), poor self-rated health, and obesity. CONCLUSIONS: Three in five U.S. adults do not engage in any muscle-strengthening exercise, despite an association for muscle-strengthening exercise with better health conditions. Future muscle-strengthening exercise promotion strategies should target older adults, females, those with low education/income, and those with a poor health status

    A phase i study of tomotherapy in patients with primary benign and low-grade brain tumors: Late toxicity and quality of life

    No full text
    Objectives: To evaluate longitudinal quality of life and late neurotoxicity (\u3e 12 mo) of tomotherapy in patients with primary benign and low-grade brain tumors. Methods: Between January 2006 and October 2009, 49 patients with brain tumors were treated with tomotherapy at 2 radiotherapy centers in Canada. The median age of the patients was 51.0 years (range, 21 to 74 y); there were 21 men (42.86%) and 28 women (57.14%). All 49 patients had an initial Karnofsky performance score Z70. One patient (2.04%) received 45 Gy in 25 fractions, 27 patients (55.10%) received 50.4 Gy in 28 fractions, 15 patients (30.6%) received 54 Gy in 30 fractions, and 5 patients (10.2%) received 60 Gy in 30 fractions. A total of 47 patients were analyzed for late toxicity and outcomes. Results: Changes in the Karnofsky Performance Status of the patients did not reach statistical significance (P \u3e 0.05). The majority of the quality of life parameters that reached a statistically significant level (P \u3c 0.05) of change at 2 years were changes toward improvement (drowsiness, itchy skin, emotional functioning, fatigue, nausea, and appetite). Statistically significant (P \u3c 0.05) interval deterioration in physical, role, and social functioning was observed. Actuarial overall survival at 5 years was 91.6%; disease-free survival at 5 years was 86.6%. Conclusions: IMRT helical tomotherapy is well tolerated, without statistically significant constitutional and late neurotoxicity up to the 2-year mark

    Chronic pregabalin treatment protects against spreading depolarization and alters hippocampal synaptic characteristics in a model of familial hemiplegic migraine-type 1

    No full text
    Abstract Familial hemiplegic migraine type-1 (FHM-1) is a form of migraine with aura caused by mutations in the P/Q-type (Cav2.1) voltage-gated calcium channel. Pregabalin, used clinically in the treatment of chronic pain and epilepsy, inhibits P/Q-type calcium channel activity and recent studies suggest that it may have potential for the treatment of migraine. Spreading Depolarization (SD) is a neurophysiological phenomenon that can occur during migraine with aura by propagating a wave of silenced neuronal function through cortex and sometimes subcortical brain structures. Here, utilizing an optogenetic stimulation technique optimized to allow for non-invasive initiation of cortical SD, we demonstrate that chronic pregabalin administration [12 mg/kg/day (s.c.)] in vivo increased the threshold for cortical spreading depolarization in transgenic mice harboring the clinically-relevant Cav2.1S218L mutation (S218L). In addition, chronic pregabalin treatment limited subcortical propagation of recurrent spreading depolarization events to the striatum and hippocampus in both wild-type and S218L mice. To examine contributing underlying mechanisms of action of chronic pregabalin, we performed whole-cell patch-clamp electrophysiology in CA1 neurons in ex vivo brain slices from mice treated with chronic pregabalin vs vehicle. In WT mice, chronic pregabalin produced a decrease in spontaneous excitatory postsynaptic current (sEPSC) amplitude with no effect on frequency. In contrast, in S218L mice chronic pregabalin produced an increase in sEPSC amplitude and decreased frequency. These electrophysiological findings suggest that in FHM-1 mice chronic pregabalin acts through both pre- and post-synaptic mechanisms in CA1 hippocampal neurons to elicit FHM-1 genotype-specific inhibitory action. The results highlight the potential of chronic pregabalin to limit recurrent SD to subcortical brain structures during pathophysiological events in both the genetically-normal and FHM-1 brain. The work further provides insights into FHM-1 pathophysiology and the potential for chronic pregabalin treatment to prevent SD in migraineurs

    Capacity building in physical activity and non-communicable disease prevention : a low-cost online training course can reach isolated practitioners

    No full text
    Physical inactivity is the fourth most important risk factor contributing to global noncommunicable disease (NCD) deaths, occurring in high-, middle-and low-income countries. Building capacity in NCD prevention is a daunting task, and toward this end, an introductory open online course about physical activity (PA), exercise, and NCD prevention was developed. This was led by academics from the University of Sydney and the WHO Collaborating Centre for Physical Activity, Nutrition and Obesity. The course was designed to address the needs of participants from areas where geography and economy would often prevent them from participating in NCD training programs. Around 120 participants from four continents signed up for the six-week online course, with the greatest numbers from the host country (Australia) followed by participants from Pacific Island nations and from the Middle East. The course consisted of video lectures, quizzes, and online discussions facilitated by experts. More than a third of the participants fully completed the course, which received very positive participant evaluations. This also included completion of relevant quiz questions on each section of the PA course, and averaged over 70% correct responses. This successful online course has the potential to increase knowledge and skills about PA and prevention, as part of building global capacity in NCD prevention at low cost, and importantly within easy reach of potentially isolated practitioners
    corecore