5,479 research outputs found

    Mary and Salvation in the Twentieth Century: A Reaction

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    RESILIENCE AT THE TIP OF THE SPEAR: IDENTIFYING THE MINDFULNESS PRESCRIPTION FOR SPECIAL OPERATIONS FORCES

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    After 20 years of combat, continuous deployments have left special operations forces (SOF) searching for ways to improve their holistic health. One evidence-based avenue is mindfulness meditation, shown to decrease stress and improve performance. This research examined how mindfulness techniques affect SOF's ability to downregulate stress from routine, stress-inducing duties. Researchers conducted a randomized controlled trial to test the efficacy of informal mindfulness practice in reducing stress in SOF operators. Researchers assigned participants to 1 of 2 conditions: (a) an Oura ring-based mindfulness meditation five times a week for six weeks and (b) a no-treatment control group that also wore Oura rings but did not conduct mindfulness meditations. At the beginning and end of the study, researchers measured stress utilizing a stress event that induced physiological and cognitive stress. Measurements of stress included blood pressure, subjective surveys, and heart rate variability. The experimental group displayed a 28-second decrease in time taken to return to baseline blood pressure levels than the control group's 15-second decrease. Additionally, subjective surveys suggested Oura rings to increase overall health. Data supports the efficacy of informal mindfulness as a practical, portable, and low-cost manner for SOF to improve holistic health across the force; however, research must continue to narrow the prescription.Major, United States ArmyMajor, United States ArmyApproved for public release. Distribution is unlimited

    Surface control system for the 15 meter hoop-column antenna

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    The 15-meter hoop-column antenna fabricated by the Harris Corporation under contract to the NASA Langley Research Center is described. The antenna is a deployable and restowable structure consisting of a central telescoping column, a 15-meter-diameter folding hoop, and a mesh reflector surface. The hoop is supported and positioned by 48 quartz cords attached to the column above the hoop, and by 24 graphite cords from the base of the antenna column. The RF reflective surface is a gold plated molybdenum wire mesh supported on a graphite cord truss structure which is attached between the hoop and the column. The surface contour is controlled by 96 graphite cords from the antenna base to the rear of the truss assembly. The antenna is actually a quadaperture reflector with each quadrant of the surface mesh shaped to produce an offset parabolic reflector. Results of near-field and structural tests are given. Controls structures and electromagnetics interaction, surface control system requirements, mesh control adjustment, surface control system actuator assembly, surface control system electronics, the system interface unit, and control stations are discussed

    In situ anticaries efficacy of dentifrices with different formulations – A pooled analysis of results from three randomized clinical trials

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    Objectives Data generated from three similar in situ caries crossover studies presented the opportunity to conduct a pooled analysis to investigate how dentifrice formulations with different fluoride salts and combinations at concentrations of 1400–1450 ppm F, different abrasive systems and in some cases, carbomer (Carb), affect enamel caries lesion remineralization and fluoridation. Methods Subjects continuously wore modified partial dentures holding two gauze-covered partially-demineralized human enamel specimens for 14 days and brushed 2×/day with their assigned dentifrice: Study 1: sodium fluoride (NaF)/Carb/silica, NaF/silica, NaF + monofluorophosphate (MFP)/chalk; Study 2: NaF/Carb/silica, NaF + MFP/dical, amine fluoride (AmF)/silica; Study 3: NaF/Carb/silica, NaF + stannous fluoride (SnF2)/silica/hexametaphosphate (HMP). All studies included Placebo (0 ppm F) and/or dose-response controls (675 ppm F as NaF [675F-NaF]) ±Carb. Specimens were evaluated for percentage surface microhardness recovery (SMHR) and enamel fluoride uptake (EFU). Results All 1400–1450 ppm F dentifrices except NaF + SnF2/silica/HMP provided significantly greater lesion remineralization than Placebo (p < 0.0001): differences in SMHR ranged from 17.46% (NaF + MFP/dical) to 26.66% (AmF/silica). For EFU (back-transformed log EFU), all 1400–1450 ppm F dentifrices gave significant fluoride uptake compared to Placebo (p < 0.0001): increases in EFU ranged from 4.95 μg F/cm2 (NaF + SnF2/silica/HMP) to 16.32 μg F/cm2 (NaF/carb/silica). Dentifrices containing NaF or AmF as sole fluoride source provided the greatest remineralization and fluoridation; Carb addition did not alter fluoride efficacy; some excipients appeared to interfere with the cariostatic action of fluoride. Treatments were generally well-tolerated with ≤4 treatment-related adverse events per study. Conclusion Commercially available fluoride dentifrices varied greatly in their ability to remineralize and fluoridate early caries lesions. Clinical significance Fluoride dentifrices are the most impactful anticaries modality worldwide. While clinical caries trials have not consistently shown the superiority of one formulation over another, these findings using a sensitive in situ caries model indicated that dentifrices containing NaF or AmF as the sole fluoride source provided the greatest remineralization and fluoridation benefits

    Bioinspired engineering of exploration systems for NASA and DoD

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    A new approach called bioinspired engineering of exploration systems (BEES) and its value for solving pressing NASA and DoD needs are described. Insects (for example honeybees and dragonflies) cope remarkably well with their world, despite possessing a brain containing less than 0.01% as many neurons as the human brain. Although most insects have immobile eyes with fixed focus optics and lack stereo vision, they use a number of ingenious, computationally simple strategies for perceiving their world in three dimensions and navigating successfully within it. We are distilling selected insect-inspired strategies to obtain novel solutions for navigation, hazard avoidance, altitude hold, stable flight, terrain following, and gentle deployment of payload. Such functionality provides potential solutions for future autonomous robotic space and planetary explorers. A BEES approach to developing lightweight low-power autonomous flight systems should be useful for flight control of such biomorphic flyers for both NASA and DoD needs. Recent biological studies of mammalian retinas confirm that representations of multiple features of the visual world are systematically parsed and processed in parallel. Features are mapped to a stack of cellular strata within the retina. Each of these representations can be efficiently modeled in semiconductor cellular nonlinear network (CNN) chips. We describe recent breakthroughs in exploring the feasibility of the unique blending of insect strategies of navigation with mammalian visual search, pattern recognition, and image understanding into hybrid biomorphic flyers for future planetary and terrestrial applications. We describe a few future mission scenarios for Mars exploration, uniquely enabled by these newly developed biomorphic flyers

    Natural product libraries: Assembly, maintenance, and screening

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    This review discusses successful strategies and potential pitfalls to assembling a natural product-based library suitable for high-throughput screening. Specific extraction methods for plants, microorganisms, and marine invertebrates are detailed, along with methods for generating a fractionated sub-library. The best methods to store, maintain and prepare the library for screening are addressed, as well as recommendations on how to develop a robust high-throughput assay. Finally, the logistics of moving from an assay hit to pure bioactive compound are discussed

    Enamel demineralization and remineralization under plaque fluid-like conditions – a QLF study

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    The present study investigated de- and remineralization in enamel lesions under plaque fluid (PF)-like conditions using quantitative light-induced fluorescence (QLF). Preformed lesions were exposed to partially saturated lactic acid solutions, varying in pH and fluoride concentration ([F]) based on a 5 × 3 factorial study design (0/0.1/0.5/1.5/4 ppm F; pH 4.9/5.2/5.5). Average fluorescence loss (ΔF) was monitored for 11 days. Subsequently, lesions were demineralized in a partially saturated acetic acid solution for two 24-hour periods. Data were analyzed using repeated measures analysis of covariance. Lesions exposed to PF at 4 ppm F and pH 5.5 showed not only the most remineralization (ΔΔF = 28.2 ± 14.0%) for all groups after 11 days, but also the most demineralization (ΔΔF = –19.3 ± 13.5%) after subsequent acetic acid exposure. Increased [F] resulted in more remineralization, regardless of pH. Higher pH values resulted in more remineralization. No remineralization was observed in lesions exposed to F-free solutions, regardless of pH. Remineralization was noticeable under the following conditions: pH 4.9 – [F] = 4 ppm, pH 5.2 – [F] ≧ 1.5 ppm, and pH 5.5 – [F] ≧ 0.5 ppm. Overall, [F] had a stronger effect on remineralization than pH. Subsequent demineralization showed that little protection was offered by PF-like solutions, and further demineralization compared with baseline was observed on lesions not remineralized initially. [F] had a stronger effect on net mineral change than pH. The present study has shown that QLF is a valuable tool in studying lesion de- and remineralization under PF-like conditions, where [F] was shown to be more important than pH

    The necessary shift from diagnostic to prognostic research

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    Background: Do doctors really need to establish an etiological diagnosis each time a patient presents? Or might it often be more effective to treat simply on the basis of symptoms and signs alone, relying on research and on our experience of outcomes for patients who presented in similar ways in the past? Discussion: At a time of increase health care costs especially in pharmaceuticals and expensive diagnostic tests, this article uses examples from recent research to address this question. Our examples come from general practice, because that is where doctors frequently see patients presenting with a yet undifferentiated disease which is consequently difficult to diagnose. The examples include respiratory tract infections, low back pain and shoulder pain. Finally we discuss the 'something is wrong' feeling. Summary: We conclude that, in addition to diagnostic research, a renewed focus on prognostic research is needed. </p
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