Alpha-Cyclodextrin-Containing Beverages for Hydration Enhancement in Humans

A substantial portion of the world’s population may be inadequately hydrated, and dehydration is associated with several disease states and acute impairments in exercise performance. As such, there is continued interest in novel strategies to promote adequate hydration. The carbohydrate alpha-cyclodextrin has recently been shown to enhance water uptake through human aquaporins expressed in a single-cell model and promote longevity in model multicellular organisms. However, there is no relevant human research examining the potential hydrating effects of alpha-cyclodextrin-containing beverages. PURPOSE: To determine if novel beverage formulations containing alpha-cyclodextrin improve a bioimpedance-based hydration marker in humans. METHODS: In a randomized, double-blind, crossover design, eight adults (5 M, 3 F; [mean ± SD] age: 24.9 ± 4.2 years; height: 169.6 ± 5.5 cm; weight: 71.2 ± 13.2 kg; body mass index: 24.6 ± 3.2 kg/m2; body fat: 17.0 ± 5.6%) completed trials including the ingestion of 1 liter of still water (control; CON), still water plus alpha-cyclodextrin (CD), or still water plus alpha- cyclodextrin and complexing agents (B-vitamins and amino acids; Complex). Before beverage ingestion, and every 15 minutes for two hours following beverage ingestion, bioimpedance spectroscopy was performed to estimate phase angle values as a noninvasive marker of cellular hydration. Phase angle was calculated as: arctan(/) × (180°/), where Xc is the reactance (indicative of the capacitive properties of the cell membrane) and R is resistance (opposition to flow of electrical current), both obtained from bioimpedance spectroscopy. Due to the pilot nature of this trial, data were analyzed using descriptive statistics only (data presented as median ± interquartile range). RESULTS: Two hours after completion of beverage ingestion, median ± interquartile range changes in phase in angle were 3.4 ± 1.7% for CON, 4.6 ± 1.2% for CD, and 5.4 ± 3.3% for Complex. Xc changes were 9.9 ± 2.9% for CON, 10.9 ± 3.0% for CD, and 11.1 ± 3.1% for Complex. R changes were 6.5 ± 1.4% for CON, 6.8 ± 1.9% for CD, and 5.6 ± 1.1% for Complex. CONCLUSION: The results of this pilot study indicate the potential for alpha-cyclodextrin- containing beverages to improve a bioimpedance-based hydration marker, phase angle, in humans, with the potential that B-vitamins and amino acids may further enhance hydration beyond alpha-cyclodextrin alone. The larger improvements in phase angle in the Complex group were due to a greater increase in bioelectrical reactance alongside a smaller increase in bioelectrical resistance. Future research with larger sample sizes should examine the potential for these beverages to improve human hydration and health

Validity of Body Volume Estimates from a Smartphone 3-Dimensional Scanning Application

Body volume (BV) indicates the total 3-dimensional (3D) space an individual occupies. BV is either used alongside body mass in density-based two-compartment models or in conjunction with other body components in multi-compartment models to estimate body composition (BC). BV estimates are typically produced by costly laboratory methods, such as hydrostatic weighing or air-displacement plethysmography (ADP). However, more accessible options are emerging. Smartphone-based 3D scanning uses the phone’s built-in camera to provide a BV estimate in a time-efficient and cost-effective manner. However, few investigations have validated this method against an accepted laboratory technique. PURPOSE: To determine the validity of BV from a 3D scanning smartphone application. METHODS: ADP and a 3D scanning smartphone application were used to estimate BV in 60 adults (28 F, 32 M; [mean ± SD] age 24.4 ± 6.5 y, body mass index 24.7 ± 4.3 kg/m2). The 3D scanning application required participants to rotate in place in front of the smartphone camera while serial images were collected, and avatars were produced from approximately 30 images using non-rigid avatar reconstruction. BV was estimated from the avatars, then corrected for estimated thoracic gas volume through published equations using basic demographic and anthropometric variables. ADP was conducted using standard practices recommended by the manufacturer. The relationship between ADP and 3D scanning BV was quantified by Deming regression, the concordance correlation coefficient (CCC), equivalence testing, and Bland-Altman analysis. RESULTS: Mean ± SD BV was 67.1 ± 10.9 L for ADP and 66.8 ± 9.9 L for 3D scanning. The Deming regression line for ADP vs. 3D scanning BV (3D=1.1×ADP - 6.5) did not significantly differ from the line of identity (i.e., y=1x + 0). The CCC between BV estimates was 0.96, and statistical equivalence was demonstrated using 2.5% equivalence regions (pCONCLUSION: The present study indicates BV estimated by a 3D scanning smartphone application may be a potential alternative to BV measured by ADP. This could increase the accessibility of BV values for BC estimation in two-compartment models and incorporation into field-based multi compartment models

Strategies and performance of the CMS silicon tracker alignment during LHC Run 2

The strategies for and the performance of the CMS silicon tracking system alignment during the 2015–2018 data-taking period of the LHC are described. The alignment procedures during and after data taking are explained. Alignment scenarios are also derived for use in the simulation of the detector response. Systematic effects, related to intrinsic symmetries of the alignment task or to external constraints, are discussed and illustrated for different scenarios