936 research outputs found

    The Effects of a High-Carbohydrate Versus a High-Fat Shake on Biomarkers of Metabolism and Glycemic Control When Used to Interrupt a 38-Hour Fast: A Randomized Crossover Study

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    As the link between metabolic health and chronic diseases have come into focus, it has highlighted the need to establish methods for improving metabolic flexibility. The ability to efficiently switch metabolic fuels from glucose to fatty acid-derived ketones is an indication of good metabolic health. Regular fasting allows the body to make the metabolic switch to ketones more often, which is commonly identified through the measurement of the ketone beta-hydroxybutyrate (BHB). Measuring both BHB and glucose levels can provide information about the body’s response to various foods, fasting regimens, or other metabolic stressors, and give valuable insights to measuring a metabolic switch. PURPOSE: The primary aim of this study was to determine the impact of various fast-interrupting shakes on markers of glycemic control including glucose, β-hydroxybutyrate (BHB), insulin, glucagon, GLP-1, and GIP. METHODS: Twenty-seven adults (12 female, 15 male) completed all three conditions of this study. One condition consisted of a 38-hour water-only fast, and the other two conditions were similar but the fasts were interrupted at 24 hours by either a high carbohydrate/low fat (HC/LF) or a low carbohydrate/high fat (LC/HF) shake. RESULTS: The water only fast resulted in 135.3% more BHB compared to the HC/LF condition (t = 7.77, p\u3c 0.0001) and 69.6% more compared to the LC/HF condition (t = 5.12, p \u3c 0.0001). Conversely, the LC/HF condition exhibited a 38.8% higher BHB level than the HC/LF condition (t = 2.70, p = 0.0086). Additionally, the area under the curve (AUC) for glucose was 14.2% higher in the HC/LF condition than in the water condition (t = 6.23, p \u3c 0.0001) and 6.9% higher compared to the LC/HF condition (t = 3.14, p =0.0024), with the LC/HF condition yielding 7.8% more glucose than the water condition (t = 3.21, p = 0.0020). At the 25-hour mark, insulin was significantly elevated in the HC/LF condition compared to the LC/HF condition (F = 3.84, p = 0.0002) and compared to the water condition (F = 7.00, p \u3c 0.0001). Furthermore, insulin was increased in the LC/HF condition compared to the water condition at 25 hours (F = 3.19, p = 0.0016). CONCLUSION: While a LC/HF shake does not mimic a fast completely, it does preserve some of the metabolic changes including elevated BHB and glucagon, and decreased glucose and insulin compared to a HC/LF shake

    The Effects of Initiating a 24-hour Fast with a Low Versus a High Carbohydrate Shake on pancreatic hormones in the Elderly: A Randomized Crossover Study

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    Begin PURPOSE: The aim of this study is to understand how the macronutrient composition of the fast-initiating meal influences glucose regulating hormones during, and 24-hours after a 24-hour fast in older, sedentary, and abdominally obese adults. Understanding these outcomes will inform fasting protocols such as time restricted eating and alternate day fasting, which offer potential long-term health benefits. METHODS: We had 16 participants (7 male, 9 female). Each participant completed two 24-hour fasts (water only). In random order, one fast began with a high carb/low fat (HC/LF) shake and the other with a low carbohydrate/high fat shake (LC/HF) (equal calorie, volume and fiber). Venous blood draws were taken at hours 0, 1, 24, and 48. Participants fasted for 24 hours under free living conditions. RESULTS: There was a significant condition by time interaction for insulin (F = 4.08, P \u3c 0.01), amylin (F = 3.34, P = 0.02) and glucagon (F = 7.93, P \u3c 0.01). One hour after the consumption of the pre-fast shakes the LC/HF shake resulted in lower insulin (P = 0.02), amylin (P = 0.01) and higher glucagon (P = 0.05) compared to the HC/LF shake. However, there was no difference between conditions for insulin, glucagon or amylin at 0, 24 or 48 hours. CONCLUSION: Starting a fast with a LC/HF meal reduces the insulin response and increases glucagon which is beneficial for the switching of metabolic fuels from glucose to fat oxidation. However, this difference between conditions in hormone concentrations was not sustained over the course of the fast, as values for both glucagon, amylin and insulin were similar between conditions by 24 hours

    Dietary predictors of visceral adiposity in overweight young adults

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    The purpose of the present study was to determine the dietary predictors of visceral adipose tissue (VAT) area in overweight young adults. A total of 109 young adults (fifty males and fifty-nine females) ate ad libitum in a university cafeteria for 14 d. All food and beverages consumed in the cafeteria were measured using observer-recorded weighed plate waste. Food consumption outside the cafeteria (i.e. snacks) was assessed by multiple-pass 24 h recall procedures. VAT was determined using computed tomography. Stepwise regression demonstrated that the best predictor of visceral adiposity in women was total dietary fat (P# 0–05). In men, the model for predicting visceral adiposity included Ca and total dietary fat. We concluded that total dietary fat is the best predictor of VAT area in both men and women. While this relationship was independent in women, in men there was a synergistic relationship between dietary fat consumption and Ca consumption in predicting VAT

    Initial Investigation of Reaction Control System Design on Spacecraft Handling Qualities for Earth Orbit Docking

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    A program of research, development, test, and evaluation is planned for the development of Spacecraft Handling Qualities guidelines. In this first experiment, the effects of Reaction Control System design characteristics and rotational control laws were evaluated during simulated proximity operations and docking. Also, the influence of piloting demands resulting from varying closure rates was assessed. The pilot-in-the-loop simulation results showed that significantly different spacecraft handling qualities result from the design of the Reaction Control System. In particular, cross-coupling between translational and rotational motions significantly affected handling qualities as reflected by Cooper-Harper pilot ratings and pilot workload, as reflected by Task-Load Index ratings. This influence is masked but only slightly by the rotational control system mode. While rotational control augmentation using Rate Command Attitude Hold can reduce the workload (principally, physical workload) created by cross-coupling, the handling qualities are not significantly improved. The attitude and rate deadbands of the RCAH introduced significant mental workload and control compensation to evaluate when deadband firings would occur, assess their impact on docking performance, and apply control inputs to mitigate that impact

    The Roles of Extrinsic and Intrinsic Factors in the Freshwater Life-History Dynamics of a Migratory Salmonid

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    Key life-cycle transitions, such as metamorphosis or migration, can be altered by a variety of external factors, such as climate variation, strong species interactions, and management intervention, or modulated by density dependence. Given that these life-history transitions can influence population dynamics, understanding the simultaneous effects of intrinsic and extrinsic controls on life-history expression is particularly relevant for species of management or conservation importance. Here, we examined how life histories of steelhead (Oncorhynchus mykiss) are affected by weather, pink salmon abundance (Oncorhynchus gorbuscha), experimental nutrient addition, and density-dependent processes. We tested for impacts on the size of steelhead smolts (juveniles migrating to the sea), as well as their age and abundance across four decades in the Keogh River, British Columbia, Canada. Larger steelhead smolts were associated with warmer years and artificial nutrient addition. In addition, higher pink salmon abundance and artificial nutrient addition correlated with juvenile steelhead migrating at younger ages. While density dependence appeared to be the primary factor regulating the abundance of steelhead smolts, nutrient addition and temperature were positively and negatively associated with smolt production, respectively, prior to 1991, and pink salmon spawning abundance was positively associated with smolt production after 1990. Thus, this study provides evidence that the temporal dynamics of one species of salmon is linked to the juvenile life history of co-occurring steelhead. A complex interplay of species interactions, nutrient subsidies, density dependence, and climatic variation can control the life-history expression of species with complex life cycles

    A Lean, Fast Mars Round-trip Mission Architecture: Using Current Technologies for a Human Mission in the 2030s

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    We present a lean fast-transfer architecture concept for a first human mission to Mars that utilizes current technologies and two pivotal parameters: an end-to-end Mars mission duration of approximately one year, and a deep space habitat of approximately 50 metric tons. These parameters were formulated by a 2012 deep space habitat study conducted at the NASA Johnson Space Center (JSC) that focused on a subset of recognized high- engineering-risk factors that may otherwise limit space travel to destinations such as Mars or near-Earth asteroid (NEA)s. With these constraints, we model and promote Mars mission opportunities in the 2030s enabled by a combination of on-orbit staging, mission element pre-positioning, and unique round-trip trajectories identified by state-of-the-art astrodynamics algorithms

    The Effect of CardioWaves Interval Training on Resting Blood Pressure, Resting Heart Rate, and Mind-Body Wellness

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    International Journal of Exercise Science 9(1): 89-100, 2016. An experimental study to examine the effects of CardioWaves interval training (CWIT) and continuous training (CT) on resting blood pressure, resting heart rate, and mind-body wellness. Fifty-two normotensive (blood pressure \u3c120/80 mmHg), pre-hypertensive (120–139/80–89 mmHg), and hypertensive (\u3e140/90 mmHg) participants were randomly assigned and equally divided between the CWIT and CT groups. Both groups participated in the assigned exercise protocol 30 minutes per day, four days per week for eight weeks. Resting blood pressure, resting heart rate, and mind-body wellness were measured pre- and post-intervention. A total of 47 participants (15 females and 32 males) were included in the analysis. The CWIT group had a non-significant trend of reduced systolic blood pressure (SBP) and increased diastolic blood pressure (DBP) while the CT group had a statistically significant decrease in awake SBP (p = 0.01) and total SBP (p = 0.01) and a non-significant decrease in DBP. With both groups combined, the female participants had a statistically significant decrease in awake SBP (p = 0.002), asleep SBP (p = 0.01), total SBP (p = 0.003), awake DBP (p = 0.02), and total DBP (p = 0.05). The male participants had an increase in SBP and DBP with total DBP showing a statistically significant increase (p = 0.05). Neither group had a consistent change in resting heart rate. Both groups showed improved mind-body wellness. CWIT and CT reduced resting blood pressure, with CT having a greater effect. Resting heart rate did not change in either group. Additionally, both CWIT and CT improved mind-body wellness

    Minimal resistance training improves daily energy expenditure and fat oxidation

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    This is not the published version.ABSTRACT: Long-term resistance training (RT) may result in a chronic increase in 24-hour energy expenditure (EE) and fat oxidation to a level sufficient to assist in maintaining energy balance and prevent weight gain. However, the impact of a minimal RT program on these parameters in an overweight college age population, a group at high risk for developing obesity, is unknown. PURPOSE: We aimed to evaluate the effect of 6-months of supervised minimal RT in previously sedentary, overweight (mean±SEM, BMI=27.7±0.5kg/m2) young adults (21.0±0.5yrs) on 24-hr EE, resting metabolic rate (RMR), sleep metabolic rate (SMR) and substrate oxidation using whole room indirect calorimetry 72-h after the last RT session. METHODS: Participants were randomized to RT (1 set, 3 d/wk, 3–6 repetition maximum, 9 exercises) (N=22) or control (C, N=17) groups and completed all assessments at baseline and 6 months. RESULTS: There was a significant (P<0.05) increase in 24-hr EE in the RT (527 ± 220kJ/d) and C (270 ± 168kJ/d) groups, however, the difference between groups was not significant (P=0.30). Twenty-four hour fat oxidation (g/day) was not altered after RT, however; reductions in RQ assessed during both rest (P<0.05) and sleep (P<0.05) suggested increased fat oxidation in RT compared with C during these periods. SMR (8.4±8.6%) and RMR (7.4±8.7%) increased significantly in RT (P<0.001) but not in C, resulting in significant (P<0.001) between group differences for SMR with a trend for significant (P=0.07) between group differences for RMR. CONCLUSION: A minimal RT program that required little time to complete (11 min per session) resulted in a chronic increase in energy expenditure. This adaptation in energy expenditure may have a favorable impact on energy balance and fat oxidation sufficient to assist with the prevention of obesity in sedentary, overweight young adults, a group at high risk for developing obesity

    Prospectus, June 12, 1972

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    GOVERNOR CITES PARKLAND STUDENT FOR COMMUNITY SERVICE; Harris Moeller Selected As New Dean of Students; Charles Gerron Is Student Senate President For 1972-73 School Year; Scholarships Awarded To Parkland Students; Parkland College Personnel Receive Recognition; Teacher Aides Hold Banquet; New Registration Procedures Will Begin In Fall \u2772 Quarter; Parkland Foundation Holds First Charter Meeting; Board of Trustees Have Two Very Eventful Meetings: Results of the Meeting of April 18, 1972, Results of the Meeting of May 16, 1972; Parkland Summer Session Begins June 19; New Non-Credit Courses Slated For Summer; Graebner to Speak at Parkland Commencement; Parkland Notices: Schedule changes, Vocational Information, Summer Jobs, Summer Graduate?, For Sale-Bargain!, Summer Registration, Lost; News From William J. Scott, Attorney General - State of Illinois; Parkland Student Government Passes Viet Nam Resolution; Journalism Club; A Day In The Park Has Large Turn-Out; The Editor\u27s View: Europe This Year - A-1; Student Senate Resolution; Seed For Thought; Unique Summer-Winter Program Developed In Maine; Youth Caucus \u2772 Organized In Illinois; Portfolios to Replace Grades; Coeds Bring Fraternity Ban, Other Campus News in Brief; New Academic Calendars; Entertainment & Fine Arts, Or ( We Got Culture Too! ); Movie Review: One Day In The Life Of Ivan Denisovich; Ear Wax; Orpheus Reborn: Been around the block twice..., greece looks good..., ast i..., A babe be born..., Sweet sweets..., Away To The Mountain; WLS - Wavelength; Book Review: The Assassins (Elia Kazan); Summer Session \u2772; Summer Session; Course Offerings; Angel & Clayborn in Nationals; Hart Beathttps://spark.parkland.edu/prospectus_1972/1007/thumbnail.jp
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