Orbital and In-Situ Investigation of Periodic Bedrock Ridges in Glen Torridon, Gale Crater, Mars.

Gale crater, the field site for NASA's Mars Science Laboratory Curiosity rover, contains a diverse and extensive record of aeolian deposition and erosion. This study focuses on a series of regularly spaced, curvilinear, and sometimes branching bedrock ridges that occur within the Glen Torridon region on the lower northwest flank of Aeolis Mons, the central mound within Gale crater. During Curiosity's exploration of Glen Torridon between sols ∼2300-3080, the rover drove through this field of ridges, providing the opportunity for in situ observation of these features. This study uses orbiter and rover data to characterize ridge morphology, spatial distribution, compositional and material properties, and association with other aeolian features in the area. Based on these observations, we find that the Glen Torridon ridges are consistent with an origin as wind-eroded bedrock ridges, carved during the exhumation of Mount Sharp. Erosional features like the Glen Torridon ridges observed elsewhere on Mars, termed periodic bedrock ridges (PBRs), have been interpreted to form transverse to the dominant wind direction. The size and morphology of the Glen Torridon PBRs are consistent with transverse formative winds, but the orientation of nearby aeolian bedforms and bedrock erosional features raise the possibility of PBR formation by a net northeasterly wind regime. Although several formation models for the Glen Torridon PBRs are still under consideration, and questions persist about the nature of PBR-forming paleowinds, the presence of PBRs at this site provides important constraints on the depositional and erosional history of Gale crater.

The Mars Science Laboratory (MSL) Mast cameras and Descent imager: Investigation and instrument descriptions.

The Mars Science Laboratory Mast camera and Descent Imager investigations were designed, built, and operated by Malin Space Science Systems of San Diego, CA. They share common electronics and focal plane designs but have different optics. There are two Mastcams of dissimilar focal length. The Mastcam-34 has an f/8, 34 mm focal length lens, and the M-100 an f/10, 100 mm focal length lens. The M-34 field of view is about 20° × 15° with an instantaneous field of view (IFOV) of 218 µrad; the M-100 field of view (FOV) is 6.8° × 5.1° with an IFOV of 74 µrad. The M-34 can focus from 0.5 m to infinity, and the M-100 from ~1.6 m to infinity. All three cameras can acquire color images through a Bayer color filter array, and the Mastcams can also acquire images through seven science filters. Images are ≤1600 pixels wide by 1200 pixels tall. The Mastcams, mounted on the ~2 m tall Remote Sensing Mast, have a 360° azimuth and ~180° elevation field of regard. Mars Descent Imager is fixed-mounted to the bottom left front side of the rover at ~66 cm above the surface. Its fixed focus lens is in focus from ~2 m to infinity, but out of focus at 66 cm. The f/3 lens has a FOV of ~70° by 52° across and along the direction of motion, with an IFOV of 0.76 mrad. All cameras can acquire video at 4 frames/second for full frames or 720p HD at 6 fps. Images can be processed using lossy Joint Photographic Experts Group and predictive lossless compression.

An advanced course in long term care for geriatric medicine fellows.

Long term care deserves focused attention within a geriatric medicine fellowship curriculum to ensure that graduates are prepared not only for clinical care but also for the leadership, administrative, educational, quality improvement, and health policy aspects of their future roles. This report describes the curriculum development and program evaluation of an advanced course in long term care for geriatric medicine fellows and other graduate/post-graduate health professionals at Duke University. Course evaluation had 4 goals: (1) to determine how well the learning objectives were met; (2) to evaluate individual components of the course to improve subsequent offerings; (3) to determine whether additional topics needed to be added; and (4) to evaluate the effectiveness of the discussion forum component of the course. Learner self-efficacy improved within all competency areas but especially those of practice-based learning and system-based practice. Evaluation results led to curriculum revision that has maintained course relevance and sustained it within the larger geriatrics fellowship curriculum. Components of this course can be easily adapted to other curricular settings for fellows and residents.

Fluid intake and hydration: critical indicators of nursing home quality.

Hydration issues are important considerations for the elderly and infirm. What was previously taken for granted often becomes the focus of daily attention. Nursing homes must take a proactive stance in designing systems and training staff to deal with hydration. The minimum daily fluid requirements, and the steps necessary to investigate suspected dehydration, should be well known and understood by all members of the staff.

Physical function in sedentary and exercising older veterans as compared to national norms.

We examined the associations between sedentary older veterans, those regularly involved in an outpatient exercise program and physical function. Sedentary and currently exercising older veterans performed a 30 s chair-stand test and 6 min walk test as part of an exercise program. Test results were then compared to national norms. The exercisers' test scores were not significantly different from the national averages. However, their mean 6 min walk score approached being significantly better than the national average (p = 0.095). The sedentary group's scores were significantly lower (p < or = 0.05) than the exercisers' scores and the national averages for both tests. In this cohort, older veterans who maintain a regular program of physical activity function at a level considered average or slightly above average compared to their age-matched peers, while sedentary veterans are significantly below average. Healthcare providers need to stress the importance of regular exercise to their older veteran patients.

Medical assessment for health advocacy and practical strategies for exercise initiation.

The universal caution to consult your family doctor before beginning an exercise program creates an image of exercise as potentially harmful. Moreover, insistence on extensive screening prior to exercise is both unrealistic and often inappropriate for the older adult. Recasting the role of the physician as a physical activity advocate rather than as a gatekeeper is recommended for incorporation into guidelines for exercise screening. A geriatric assessment focusing on identification of specific parameters predictive of disablement risk can be incorporated into the exercise prescription as a guide for initiating exercise. The purpose of this article is to: (1). review the role of the primary care physician in screening and advocating exercise; (2). examine objectively the risk of exercise among older adults and place these risks in context with current screening guidelines with a particular emphasis on the exercise test; and (3). examine how key concepts derived from epidemiologic studies of disability can be distilled into practical guidelines for exercise therapy. We provide an overview of relevant literature related to screening and initiating exercise. Key challenges are highlighted and discussed. Suggestions for changes in policy are recommended. Given the apparent discordance between screening guidelines for the older adult and risk of adverse events, and between existing recommendations for physical activity and epidemiologic studies of disability, an evidence-based approach is recommended to review and revise screening and prescribing practices.

Exercise adherence and 10-year mortality in chronically ill older adults.

OBJECTIVES: To compare mortality of adherents and nonadherents of an exercise program. DESIGN: Prospective intervention study. SETTING: Supervised geriatric fitness program called Gerofit. PARTICIPANTS: One hundred thirty-five adults aged 65 and older who enrolled in Gerofit between January 1, 1990, and November 30, 1999. All participants had a baseline medical screen and exercise test. They were classified as adherent (n = 70) if they participated in Gerofit for more than 47 sessions or nonadherent (n = 65) if they did not complete 47 sessions within the first 6-month period. INTERVENTION: Program participation was voluntary and consisted of aerobic, strength, flexibility, and balance exercises. The program met three times week for 90 minutes. MEASUREMENTS: All-cause mortality. RESULTS: Twenty-six deaths occurred within the 10-year follow-up period. Using proportional hazards, time to death was not related to adherence group. However, in multivariate analyses controlling for age, sex, race, baseline risk/health status, history of heart disease, cancer, diabetes mellitus, and baseline smoking status, there was significant group-by-time interaction (P =.004), indicating a crossover in mortality risk. The initial survival benefit observed in nonadherers changed over time, resulting in a long-term protective survival effect on mortality for the adherent group (hazard rate = 0.75, 95% confidence interval = 0.61-0.91 for the interaction term). CONCLUSIONS: Older adults with chronic diseases experience a long-term beneficial mortality effect from participation in exercise programs. Physicians should strongly encourage their patients, including those with comorbidities, to maintain a regular exercise program.