177,732 research outputs found
Exploring adaptations to the modified shuttle walking test
No full textABSTRACT
Objective: The 10 m modified shuttle walking test
(MSWT) is recommended to determine the functional
capacity in older individuals and for patients entering
cardiac rehabilitation. Participants are required to
negotiate around cones set 1 m from the end markers.
However, consistent comments indicate that for some
individuals manoeuvring around the cones can be
quite difficult. Therefore, the objective of this study
was to explore differences within and between noncardiac
and postmyocardial infarction (MI) males
during MSWT with and without the cones.
Design: Comparative study.
Participants: 20 post-MI (64.8±6.6, range
51–74 years) and 20 non-cardiac male controls
(64.1±5.7, range 52–74 years) participated.
Methods: Participants performed MSWT with and
without cones. Throughout, the participants expired
air, and the heart rate (bpm) (HR) and ratings of
perceived exertion (RPE) were measured. Participant
protocol preference was recorded verbatim.
Results: One-way analysis of variance found no
significant difference in VO2 peak (cones 20.4±5.1 vs nocones
21.9±4.8 ml/kg/min, p=0.197) or distance ambulated
(cones 631.8±132.9 m vs no-cones 662.4±164.1 m,
p=0.371) between protocols or groups. Analysis comparing
lines of regression showed a significant trajectory difference
in VO2 (ml/kg/min) (p<0.01) between protocols with higher
HR (p<0.01) and respiratory exchange ratio (RER, p<0.001)
values during cones. RPEs were higher for post-MIs versus
controls during both protocols (p<0.05). Post-MIs taking
?-blockers produce significantly lower HR values. The ?2
analysis found no significant difference in protocol
preference (no-cones: all n=25, 63%; post-MIs n=13, 65%;
and controls n=12, 60%).
Conclusions: Post-MIs found both protocols
subjectively harder than controls with no significant
difference in the VO2 peak. However, both groups worked
at a lesser percentage of their anaerobic threshold during
no-cones protocol as indicated by lower RER values.
Importantly, for the post-MIs, this would reduce their risk
of functional impairment. Therefore, though more
research is required, indicators at present are more
favourable for the use of the no-cones with post-MIs
The effect of high carbohydrate meals with different glycemic indices on recovery of performance during prolonged intermittent high intensity shuttle running
No full textThis study examined the effect of high carbohydrate meals with different glycemic indices (GI) on recovery of performance during prolonged intermittent high-intensity shuttle running. Seven male semi-professional soccer players (age 23 ± 2 y, body mass [BM] 73.7 ± 9.0 kg and maximal oxygen uptake 58 ± 1.0 mL · kg-1 · min-1) participated in two trials in a randomized cross-over design. On day 1, the subjects performed 90 min of an intermittent high-intensity shuttle running protocol [Loughborough Intermittent Shuttle Test (LIST)]. They then consumed a mixed high carbohydrate recovery diet (8 g/kg BM) consisting of either high (HGI) (GI: 70) or low (LGI) (GI: 35) GI foods. Twenty-two hours later (day 2) the subjects completed 75 min of the LIST (part A) followed by alternate sprinting and jogging to fatigue (part B). No differences were found between trials in time to fatigue (HGI 25.3 ± 4.0 min vs. LGI 22.9 ± 5.6 min, P = 0.649). Similarly, no differences were found between trials for sprint performance and distance covered during part B of the LIST. In conclusion, the GI of the diet during the 22 h recovery did not affect sprint and endurance performance the following day
Shuttle-C: A Shuttle Derived Launch Vehicle
No full textThe Shuttle-C will usher in a new era of transportation capability for the United States. It will provide a nearterm, unmanned heavy lift launch capability based upon existing, in-place technology. Shuttle-C (for cargo) uses the main engines, solid rocket boosters, external tanks, and launch facilities of the present space shuttle. The shuttle orbiter is replaced by an unmanned cargo carrier. Shuttle-C is designed to place payloads weighing 100,000 to 150,000 pounds into low earth orbit, compared to the space shuttle\u27s design capacity of 65,000 pounds. It is intended for launch and assembly of large space structures such as the Space Station, and for launching large planetary payloads requiring heavy upper stages, as well as a test bed for advanced technology developments
Shuttle HAT for mild alkene transfer hydrofunctionalization
No full textHydrogen atom transfer (HAT) from a metal-hydride is a reliable and powerful method for functionalizing unsaturated C–C bonds in organic synthesis. Cobalt hydrides (Co–H) have garnered significant attention in this field, where the weak Co–H bonds are most commonly generated in a catalytic fashion through a mixture of stoichiometric amounts of peroxide oxidant and silane reductant. Here we show that the reverse process of HAT to an alkene, i.e. hydrogen atom abstraction of a C–H adjacent to a radical, can be leveraged to generate catalytically active Co–H species in a new application of shuttle catalysis coined shuttle HAT. This method obviates the need for stoichiometric reductant/oxidant mixtures thereby greatly simplifying the generation of Co–H under exceedingly mild reaction conditions. This approach opens the door for the introduction of functional handles (e.g., iodides) that were previously inaccessible through other catalytic approaches, and paves the way for new reagent design which incorporates this shuttle HAT platform. To demonstrate the generality of this shuttle HAT platform, five different reaction manifolds are shown, including the late-stage C(sp3) iodination of structurally diverse FDA approved drugs
Enhancing the efficacy of the 20 m multistage shuttle run test
No full textOBJECTIVE: Maximal oxygen uptake (Vo(2max)) of 44 ml kg(-1) min(-1) is an accepted criterion (Vo(2CR)) below which health and fitness for young male adults may be compromised. New algorithms validated for Vo(2CR) screening using the 20 m multistage shuttle run test (20mMST) were developed. METHODS: Vo(2max) was assessed in 110 males using a stationary gas analyser in a treadmill test (TT) and in 40 of these subjects using a portable gas analyser in the 20mMST. Vo(2max) predicted from the 20mMST in 70 subjects was used for cross validation. Two equations predicting Vo(2max) during 20mMST (EQ(MST)) and TT (EQ(TT)) were developed. RESULTS: Significant energy cost variance (EC(V)) was detected between TT and 20mMST (p0.05) between predicted and measured values. Prevalence of low fitness based on Vo(2CR) was 0.37. McNemar chi(2) indicated significant differences in sensitivity (p0.05), mean predicted Vo(2max) from EQ(LEG) was significantly higher compared to TT Vo(2max) (p<0.001). CONCLUSION: These algorithms increase the efficacy of 20mMST to accurately evaluate aspects of health and fitness
An oil flow study of the reference Shuttle-C configuration
No full textAn oil flow study of the reference Shuttle-C configuration is presented. The Shuttle-C vehicle was a proposed shuttle derived vehicle where the orbiter was to be replaced by an unmanned cargo carrier element. Oil flows are shown for the range of Mach numbers from Mach 1.10 to 3.48 at various angles-of-attack and roll angles. The major flow field phenomena over the Shuttle-C reference configuration are shown in these oil flows. Using the oil flows, a qualitative understanding of the flow around the vehicle can be determined, aiding the quantitative definition of aerodynamic data from theoretical analyses and test results. The oil flows presented in this study were obtained from configurations tested in the NASA Marshall Space Flight Center's 14-Inch Trisonic Wind Tunnel from October 1988 through February 1989
Shuttle 5 STS 51-C Launch Invite 1985
No full textA NASA Pocket Guide Invitation for the STS-51C Shuttle Launch
Measuring fitness of Kenyan children with polyparasitic infections using the 20-meter shuttle run test as a morbidity metric.
No full textBACKGROUND: To date, there has been no standardized approach to the assessment of aerobic fitness among children who harbor parasites. In quantifying the disability associated with individual or multiple chronic infections, accurate measures of physical fitness are important metrics. This is because exercise intolerance, as seen with anemia and many other chronic disorders, reflects the body's inability to maintain adequate oxygen supply (VO(2) max) to the motor tissues, which is frequently linked to reduced quality-of-life in terms of physical and job performance. The objective of our study was to examine the associations between polyparasitism, anemia, and reduced fitness in a high risk Kenyan population using novel implementation of the 20-meter shuttle run test (20mSRT), a well-standardized, low-technology physical fitness test.
METHODOLOGY/PRINCIPAL FINDINGS: Four villages in coastal Kenya were surveyed during 2009-2010. Children 5-18 years were tested for infection with Schistosoma haematobium (Sh), malaria, filaria, and geohelminth infections by standard methods. After anthropometric and hemoglobin testing, fitness was assessed with the 20 mSRT. The 20 mSRT proved easy to perform, requiring only minimal staff training. Parasitology revealed high prevalence of single and multiple parasitic infections in all villages, with Sh being the most common (25-62%). Anemia prevalence was 45-58%. Using multiply-adjusted linear modeling that accounted for household clustering, decreased aerobic capacity was significantly associated with anemia, stunting, and wasting, with some gender differences.
CONCLUSIONS/SIGNIFICANCE: The 20 mSRT, which has excellent correlation with VO(2), is a highly feasible fitness test for low-resource settings. Our results indicate impaired fitness is common in areas endemic for parasites, where, at least in part, low fitness scores are likely to result from anemia and stunting associated with chronic infection. The 20 mSRT should be used as a common metric to quantify physical fitness and compare sub-clinical disability across many different disorders and community settings
Paper Session IV-B - Shuttle-C Engineering Development and Operations
No full textThe Shuttle-C is a cargo vehicle derived from the Space Shuttle to provide the Space Transportation System (STS) with heavy-lift capability: This early system enhancement can deliver 100,000 to 150,000 pounds of payload to low earth orbit from the Kennedy Space Center (KSC) launch complex within 4 years of authority to proceed.
This paper reviews the derivation of the Shuttle-C from the STS, their commonality and similarities, and planned enhancements. A full-scale engineering development unit (EDU) for early Shuttle-C mockup and systems installation has been completed and will be converted to a functional test bed later this year. Wind tunnel tests are under way at Marshall Space Flight Center (MSFC). Other major development tests include structural static and vibration.
Shuttle-C will be integrated with Shuttle processing at KSC in the same facilities. To support the planned operational launch rate of 14 Shuttles and 3 Shuttle-C\u27s a year, additional capability will be provided as the program matures. The facility activation and initial Shuttle-C flow plans are included in the paper
Overview Of The Shuttle Imaging Radar (SIR-C)
No full textThe Shuttle Imaging Radar-C (SIR-C) Experiment is the next evolutionary step in the Spaceborne Imaging Radar Program at the Jet Propulsion Laboratory (JPL). SIR-C is currently scheduled to fly in August, 1991 and again in December, 1992. SIR-C will provide increased capability over Seasat and the two previous Shuttle Imaging Radars by acquiring digital images simultaneously at two microwave frequencies (L- and C-band) with multiple signal polarizations (HH, VV, HV, VH). SIR-C will be a dual bandwidth system so that investigators can choose a high or low resolution mode (20 and 10 MHz, respectively). In addition, a German/Italian X-band SAR with VV polarization will be flown with SIR-C, resulting in a three-frequency capability. SIR-C prototype data will be acquired using an Airborne Imaging Radar (AIR) to test several new designs that will be implemented on SIR-C, to develop the overall calibration strategy for SIR-C, and to develop data analysis tools for SIR-C data
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