Short-Term Changes in LDL Density and Lipoprotein Particle Number in Trained Men After 3 Different Modes of Exercise

Short-Term Changes in LDL Density and Lipoprotein Particle Number in Trained Men After 3 Different Modes of Exercise Jonathan M. Oliver, Steven E. Martin, Shawn P. Glowacki, Wade Womack, John S. Green, FACSM, and Stephen F. Crouse, FACSM, Texas A&M University, TX 77843, (Sponsor: S. F. Crouse) PURPOSE: To determine the short-term changes in LDL density and lipoprotein particle number after three different modes of exercise in trained men. METHODS: Twenty seven subjects were randomly assigned to complete either (resistance [RE], endurance [EE], or combination resistance/endurance [CE]) exercise. Fasting blood samples were obtained 24 h before (baseline) and 24 h after exercise. The average group characteristics were as follows: [RE: n = 9, age = 22 + 1 yr, weight = 75.7 ± 4 kg, %fat = 14 + 1, V.O2peak = 3.43 + 0.1 L/min], [EE: n = 9, age = 23 + 1 yr, weight = 87.7 ± 4 kg, %fat = 17 + 3, V.O2peak = 4.0 + 0.10 L/min], [CE: n = 9, age = 22 + 1 yr, weight = 99.7 + 5 kg, %fat = 21 + 3, V.O2peak = 3.94 + 0.10 L/min]. RESULTS: of a 3 (GROUP) x 2 (TIME) ANOVA (repeated for TIME) for all dependent variables were as follows: No significant GROUP x TIME interactions were determined for any of the plasma volume adjusted dependent variables. A GROUP main effect was observed for LDL density. LDL density was significantly higher in both RE and EE groups compared to the CE group. A TIME main effect was observed for LDL density and the number of LDL3 and LDL4 particles. Significant increases in LDL density (1.0314 g/cm2 to 1.0316 g/cm2), and the number of LDL3 (7.8%), and LDL4 (7.1%) particles occurred 24 h after exercise compared to baseline values. CONCLUSION: These data show that regardless of exercise group, LDL density and the number of LDL3 and LDL4 particles were significantly elevated 24 h after a single exercise session in trained men

Dietary Intake in NCAA Division IA Football Players During the Off-Season

Off-season football player interaction with athletic personnel is limited and may result in the athletes’ diets not meeting current ACSM guidelines for macronutrient intake or recommendations for key micronutrients, having a negative impact on performance and health. Purpose: To examine the dietary intake of NCAA Division IA football players during the summer off-season to determine if ACSM nutrition guidelines were being met. Methods: Fifty-nine NCAA Division IA football players (20 ± 2 yrs, 186.7 ± 6.4 cm, 102.9 ± 18.5 kg) completed a 24 hour dietary recall administered by a Registered Dietitian. Recalls were obtained during the summer off-season when players were not required to participate in scheduled practice or conditioning workouts. Diets were analyzed for nutrient content using Nutribase 8.0 software. Acceptable intake of micronutrients defined as \u3e 75% Dietary Reference Intake (DRI). Results: All players met (22%) or exceeded (78%) the recommendation for % calories from fat. Carbohydrate intake was not met by 54 players (92%), while 42 (71%) met or exceeded guidelines for protein intake. Results of selected micronutrient analyses are shown in the table. Micronutrients Vitamin B1 Vitamin B2 Vitamin B3 Vitamin B5 Vitamin B6 Folate Vitamin B12 Biotin Frequency \u3e 75% DRI (n = 59) 45 57 21 31 56 21 56 8 % of n 76% 97% 36% 53% 95% 36% 95% 14% Micronutrients Vitamin C Vitamin D Vitamin E Calcium Magnesium Iron Selenium Zinc Frequency \u3e 75% DRI (n = 59) 24 15 9 48 7 58 49 45 % of n 41% 25% 15% 81% 12% 98% 83% 76% Conclusion: The majority of football players in the off season met or exceeded current protein and fat guidelines, while not consuming adequate carbohydrates. Most micronutrient intakes did not reach current recommendations suggesting players need to be further educated on the performance-related benefits of appropriately balanced diets

Designing Gram-Scale Resonators for Precision Inertial Sensors

Recent advances in glass fabrication technology have allowed for the development of high-precision inertial sensors in devices weighing in the order of grams. Gram-scale inertial sensors can be used in many applications with tight space or weight requirements. A key element of these devices' performance is the behaviour of a mechanical resonator. We present a detailed study on the design of resonators for such sensors. First, we consider how the mechanical parameters of a resonator couple with an inertial sensor's performance. Then, we look at how to geometrically design resonators to achieve specific mechanical behaviour without undergoing brittle failure. Both analytic tools and finite element analysis are used to this end. We then derive expressions that can be used to optimise the performance of an inertial sensor for a specific sensitive bandwidth. A simple geometry used throughout the field is studied as an example. However, the results are presented in a general form so they can easily be adapted to any required geometry and use case. Ultimately, the results presented here guide the design of gram-scale inertial sensors and will improve the performance of devices that follow them.Comment: Submitted to Physical Review Applie

Lattice dynamics and vibrational spectra of the orthorhombic, tetragonal and cubic phases of methylammonium lead iodide

The hybrid halide perovskite CH3NH3PbI3 exhibits a complex structural behaviour, with successive transitions between orthorhombic, tetragonal and cubic polymorphs at ca. 165 K and 327 K. Herein we report first-principles lattice dynamics (phonon spectrum) for each phase of CH3NH3PbI3. The equilibrium structures compare well to solutions of temperature-dependent powder neutron diffraction. By following the normal modes we calculate infrared and Raman intensities of the vibrations, and compare them to the measurement of a single crystal where the Raman laser is controlled to avoid degradation of the sample. Despite a clear separation in energy between low frequency modes associated with the inorganic PbI3 network and high-frequency modes of the organic CH3NH3+ cation, significant coupling between them is found, which emphasises the interplay between molecular orientation and the corner-sharing octahedral networks in the structural transformations. Soft modes are found at the boundary of the Brillouin zone of the cubic phase, consistent with displacive instabilities and anharmonicity involving tilting of the PbI6 octahedra around room temperature.Comment: 9 pages, 4 figure

The effect of weak inertia in rotating high-aspect-ratio vessel bioreactors

One method to grow artificial body tissue is to place a porous scaffold seeded with cells, known as a tissue construct, into a rotating bioreactor filled with a nutrient-rich fluid. The flow within the bioreactor is affected by the movement of the construct relative to the bioreactor which, in turn, is affected by the hydrodynamical and gravitational forces the construct experiences. The construct motion is thus coupled to the flow within the bioreactor. Over the timescale of a few hours, the construct appears to move in a periodic orbit but, over tens of hours, the construct drifts from periodicity. In the biological literature, this effect is often attributed to the change in density of the construct that occurs via tissue growth. In this paper, we show that weak inertia can cause the construct to drift from its periodic orbit over the same timescale as tissue growth. We consider the coupled flow and construct motion problem within a rotating high-aspect- ratio vessel bioreactor. Using an asymptotic analysis, we investigate the case where the Reynolds number is large but the geometry of the bioreactor yields a small reduced Reynolds number, resulting in a weak inertial effect. In particular, to accurately couple the bioreactor and porous flow regions, we extend the nested boundary layer analysis of Dalwadi et al. (J. Fluid Mech. vol. 798, pp. 88–139, 2016) to include moving walls and the thin region between the porous construct and the bioreactor wall. This allows us to derive a closed system of nonlinear ordinary differential equations for the construct trajectory, from which we show that neglecting inertia results in periodic orbits; we solve the inertia-free problem analytically, calculating the periodic orbits in terms of the system parameters. Using a multiple-scale analysis, we then systematically derive a simpler system of nonlinear ordinary differential equations that describe the long-time drift of the construct due to the effect of weak inertia. We investigate the bifurcations of the construct trajectory behaviour, and the limit cycles that appear when the construct is less dense than the surrounding fluid and the rotation rate is large enough. Thus, we are able to predict when the tissue construct will drift towards a stable limit cycle within the bioreactor and when it will drift out until it hits the bioreactor edg

Fine-tuning of whispering gallery modes in on-chip silica microdisk resonators within a full spectral range

We investigate an efficient method for fine-tuning whispering gallery mode resonances in disk-type silica microresonators to reach an arbitrary frequency within the free spectral range of the system. This method is based on a post-production hydrofluoric acid etching process to precisely resize the radius of such microresonators. We show the effectiveness of this approach by tuning their resonance frequency within 10 GHz of specific hydrogen cyanide reference lines (P16, P18). This technique allows for simple and exact matching of narrow-linewidth lasers or spectroscopic lines with the high-Q resonances of on-chip silica microresonators. (C) 2013 American Institute of Physics. (http://dx.doi.org/10.1063/1.4789755

Effect of Strength on Velocity and Power During Back Squat Exercise in Resistance-Trained Men and Women

The purpose was to examine load-velocity and load-power relationships of back squat in resistance-trained men (n = 20, 21.3 ± 1.4 years, 183.0 ± 8.0 cm, 82.6 ± 8.0 kg, 11.5 ± 5.0% total body fat) and women (n = 18; 20.0 ± 1.0 years; 166.5 ± 6.9 cm; 63.9 ± 7.9 kg, 20.3 ± 5.0% body fat). Body composition testing was performed followed by determination of back squat 1 repetition maximum (1RM). After at least 72 hours of recovery, subjects returned to the laboratory and completed 2 repetitions at each of 7 separate loads (30, 40, 50, 60, 70, 80, and 90% 1RM) in a random order. During each repetition, peak and average velocity and power were quantified using a commercially available linear position transducer. Men produced higher absolute peak and average power and velocity at all loads. When power output was normalized for body mass, significant differences remained. However, when normalizing for strength, no significant differences were observed between sexes. Furthermore, when subjects were subdivided into strong and weak groups, those above the median 1RM produced higher peak power, but only at loads greater than 60% 1RM. It was concluded that differences between men and women may be a result of strength rather than biological sex. Furthermore, training for maximal strength may be an appropriate method to augment maximal power output in those athletes who exhibit low levels of strength