Influence of Caloric Expenditure on Postprandial Triglyceride and Glucose Responses Following a High-Carbohydrate Meal

Purpose: To examine the effects of aerobic exercise expending 350 and 700 kcal of energy on postprandial triglyceride (Tg) and glucose responses following a high carbohydrate (CHO) meal. Methods: Non-active individuals (n=9 women/4 men; age=22.8±3.7 yrs; Ht=169±10.4 cm; Wt=75.7± 22.4 kg; BMI=26.1±5.8 kg/m2; VO2 max=34.1±6.9 ml/kg/min) completed three trials in a random order: 1) control trial, 2) single exercise session expending 350 kcal (EX350), and 3) single exercise session expending 700 kcal (EX700). Exercise consisted of treadmill walking at 60% VO2 max until 350 and 700 kcal of energy had been expended. The control session consisted of seated rest. The morning after each experimental session, a fasting (12hr) blood sample was collected followed by consumption of a high-CHO liquid meal (2.44 g/kg of fat free mass (CHO), 0.33 g/kg FFM fat, and 0.56 g/kg FFM protein. Blood was collected again at 1, 2, 3, 4, 5, and 6 hrs post-meal and analyzed for (Tg) and glucose concentrations. The areas under the curve (AUC) were calculated for both (Tg) and glucose concentrations. A repeated measures ANOVA was used to determine statistical significance (p\u3c0.05). Results: Baseline glucose concentrations were not different between trials (p=0.71). Postprandial AUC for glucose concentrations were not different between trials (p=0.38). Baseline Tg concentrations were not altered with exercise (p=.94) of 350 kcal (102.7±77.1 mg/dl) or 700 kcal (112.2±80.6 mg/dl) when compared with rest (115.3±113.9 mg/dl). Postprandial Tg concentrations following rest (937.3± 928.4 mg/dl) were not altered (p=0.37) following exercise of 350 kcal (807.1±605.1 mg/dl) or 700 kcal (867.3±672.6). Conclusion: The glucose and Tg responses following a high-CHO meal were unaffected by a prior exercise session. These results are in contrast to previous investigations that have used high-fat test meals demonstrating that a single bout of exercise reduces the postprandial Tg response. Substantial inter-subject variability was seen in the postprandial Tg responses following exercise ranging from reductions of 27.4% to increments of 17.4%. This study was supported by Texas Woman’s University’s Research Enhancement Program

Simultaneous Measurements of Atmospheric HONO and NO2 via Absorption Spectroscopy using Tunable Mid-Infrared Continuous-wave Quantum Cascade Lasers

Nitrous acid (HONO) is important as a significant source of hydroxyl radical (OH) in the troposphere and as a potent indoor air pollutant. It is thought to be generated in both environments via heterogeneous reactions involving nitrogen dioxide $(NO_2)$. In order to enable fast-response HONO detection suitable for eddy-covariance flux measurements and to provide a direct method that avoids interferences associated with derivatization, we have developed a 2-channel tunable infrared laser differential absorption spectrometer (TILDAS) capable of simultaneous high-frequency measurements of HONO and NO2. Beams from two mid-infrared continuous-wave mode quantum cascade lasers (cw-QCLs) traverse separate 210 m paths through a multi-pass astigmatic sampling cell at reduced pressure for the direct detection of HONO $(1660 cm^{−1})$ and $(NO_2)$ $(1604 cm^{−1})$. The resulting one-second detection limits (S/N=3) are 300 and 30 ppt (pmol/mol) for HONO and $(NO_2)$, respectively. Our HONO quantification is based on revised line-strengths and peak positions for cis-HONO in the 6-micron spectral region that were derived from laboratory measurements. An essential component of ambient HONO measurements is the inlet system and we demonstrate that heated surfaces and reduced pressure minimize sampling artifacts.Earth and Planetary SciencesEngineering and Applied Science

Spatial-spectral flexible optical networking:enabling switching solutions for a simplified and efficient SDM network platform

The traffic carried by core optical networks grows at a steady but remarkable pace of 30-40% year-over-year. Optical transmissions and networking advancements continue to satisfy the traffic requirements by delivering the content over the network infrastructure in a cost and energy efficient manner. Such core optical networks serve the information traffic demands in a dynamic way, in response to requirements for shifting of traffics demands, both temporally (day/night) and spatially (business district/residential). However as we are approaching fundamental spectral efficiency limits of singlemode fibers, the scientific community is pursuing recently the development of an innovative, all-optical network architecture introducing the spatial degree of freedom when designing/operating future transport networks. Spacedivision- multiplexing through the use of bundled single mode fibers, and/or multi-core fibers and/or few-mode fibers can offer up to 100-fold capacity increase in future optical networks. The EU INSPACE project is working on the development of a complete spatial-spectral flexible optical networking solution, offering the network ultra-high capacity, flexibility and energy efficiency required to meet the challenges of delivering exponentially growing traffic demands in the internet over the next twenty years. In this paper we will present the motivation and main research activities of the INSPACE consortium towards the realization of the overall project solution

Enabling transparent technologies for the development of highly granular flexible optical cross-connects

Flexible optical networking is identified today as the solution that offers smooth system upgradability towards Tb/s capacities and optimized use of network resources. However, in order to fully exploit the potentials of flexible spectrum allocation and networking, the development of a flexible switching node is required capable to adaptively add, drop and switch tributaries with variable bandwidth characteristics from/to ultra-high capacity wavelength channels at the lowest switching granularity. This paper presents the main concept and technology solutions envisioned by the EU funded project FOX-C, which targets the design, development and evaluation of the first functional system prototype of flexible add-drop and switching cross-connects. The key developments enable ultra-fine switching granularity at the optical subcarrier level, providing end-to-end routing of any tributary channel with flexible bandwidth down to 10Gb/s (or even lower) carried over wavelength superchannels, each with an aggregated capacity beyond 1Tb/s. © 2014 IEEE

High Intensity Interval Exercise Does Not Influence Overnight GH Secretion in Overweight Sedentary Young Women

Exercise and sleep are the two major factors that influence growth hormone (GH) secretion and it has been well established that there is a strong positive relationship between exercise intensity and GH release. This dose-dependent response may also be correlated with the lactate response to exercise, with steady-state exercise intensities above the lactate threshold eliciting a greater GH pulse. It has yet to be determined, however, if high-intensity interval exercise (HIE) can influence overnight pulsatile GH secretion, which accounts for the majority of daily GH release. PURPOSE: To determine if HIE significantly increased overnight GH secretion compared to continuous moderate-intensity exercise (MOD), or no exercise (CON) in young women. METHODS: Five young, sedentary women (mean ± SD age: 22.6 ± 1.3 y; BMI: 27.4 ± 3.1 kg/m2; body fat: 39.2 ± 1.7 %; VO2max: 29.4 ± 5.7 mL/kg/min) were studied on three different occasions during the follicular phase of their menstrual cycle (CON: no exercise; MOD: 30-min of continuous cycling at 50% of peak power determined from the VO2max test; and HIE: 4 30-s “all-out” sprints at a resistance equal to 6.5% body mass with 4.5-min recovery. Each trial was randomly assigned and separated by a minimum of one month. For each visit, participants reported to the lab at 1700h, exercised from 1730h – 1800h, and remained in the lab until 0700h the following morning. The overnight GH secretory profile of each trial was determined from 10-min sampling of venous blood from 1730h – 0600h (12.5 h) using deconvolution analysis. RESULTS: Mean power output during MOD was 80.6 ± 6.3 W (68.2 ± 9.7 %VO2max). Estimated exercising energy expenditure for MOD (145.1 ± 11.2 kcal) was significantly lower than HIE (204.5 ± 15.5 kcal, P = 0.002). Peak lactate was significantly higher during MOD (4.7 ± 0.9 mmol/L) compared to CON (0.9 ± 0.2 mmol/L, P = 0.002) and was highest during HIE (11.2 ± 2.1 mmol/L) compared to MOD (P \u3c 0.001) and CON (P \u3c 0.001). Calculated GH AUC (0 – 120 min) was significantly greater in HIE (1018.2 ± 576.1 ng· min/mL) than CON (181.7 ± 138.9 ng· min/mL, P = 0.009), but not MOD (544.7 ± 160.7 ng· min/mL). Overnight GH production rate (ng/mL/min) determined by deconvolution analysis was not significantly different between CON (1040.3 ± 242.0), MOD (1429.2 ± 206.0), and HIE (1831.2 ± 873.8, P = 0.107). Other GH secretory variables: basal GH concentration (ng/mL), number of GH peaks, GH pulse amplitude and mass, and interpulse interval were not different between the three trials. CONCLUSION: For these untrained, overweight sedentary young women, a single bout of exercise was insufficient to significantly affect overnight pulsatile GH secretion. Adiposity is a negative determinant of GH secretion, and the GH response to exercise in these women was extremely variable. Aerobic fitness, prior training, as well as several metabolic factors associated with obesity (e.g., increased insulin and circulating free fatty acids) can also influence GH secretion and should be taken into account as potential mediators of the GH response to exercise