7 research outputs found
A Functional Description of Adult Picky Eating Using Latent Profile Analysis
Abstract Objective Research has indicated that adult picky eating (PE) is associated with elevated psychosocial impairment and limited dietary variety and fruit and vegetable intake; however, research operationalizing PE behaviors is limited. Previous research identified a PE profile in children, marked by high food avoidance (satiety responsiveness, fussiness, and slow eating) and low food approach (food enjoyment and responsiveness) appetitive traits. The present study aimed to replicate a similar latent eating behavior profile in an adult sample. Methods A sample of 1339 US adults recruited through Amazon’s MTurk completed an online survey that included a modified self-report version of the Child Eating Behavior Questionnaire (CEBQ-A). Latent profile analysis was employed to identify eating profiles using the CEBQ-A subscales, ANCOVAs were employed to examine profile differences on various self-report measures, and eating profiles were compared across BMI classifications. Results Analyses converged on a four-profile solution, and a picky eater profile that closely resembled the past child profile emerged. Participants in the picky eater profile (18.1%) scored higher on measures of adult PE and social eating anxiety compared to all other profiles, scored higher on eating-related impairment and depression than moderate eating profiles, and were more likely to be of normal weight. Discussion A distinct adult PE profile was observed, indicating childhood PE and appetitive behaviors may carry over into adulthood. Research identifying meaningful groups of picky eaters will help to shed light on the conditions under which picky eating is a risk factor for significant psychosocial impairment or distress, or weight-related problems
Charge and temperature effects on biomolecule hydration: an experimental and computational investigation
The focus of this dissertation is on the role of charge and temperature on the structure of hydrated cluster ions. This is investigated using a combination of infrared photodissociation (IRPD) spectra and geometry and frequency calculations.
The particular cluster ions examined here include hydrated rubidium cluster ions and hydrated sodium- and potassium-containing tryptamine, 2-amino-1-phenylethanol and ephedrine. In every case, there are significant differences between spectra obtained at different temperatures as well as those containing different metal ions.
The argon tagging method, which was used to facilitate the temperature comparisons, had an unintended consequence: the cluster formation process trapped high-energy isomers in the experiments performed at lower temperatures. In addition, thermodynamic calculations showed the important role of entropy in determining the structures formed at warm temperatures. Both of these observations make it clear that the identification of one or two minimum-energy isomers based on zero-point energy calculations is not sufficient to mimic the isomer populations which are present during the experiments.
A summary of the methods used to explore the potential energy surfaces of the various cluster ions is also given. An in-house Monte Carlo simulation program was originally written to aid the discovery of M+(H2O)n structures and was later expanded to include additional ligands in the clusters. More recent efforts have focused on using molecular dynamics to explore the conformations of the more complex M+(Biomolecue)(H2O)n cluster ions
INFRARED SPECTRA OF K(TRYPTAMINE)(HO) AND K(TRYPTAMINE)(HO)Ar
Author Institution: Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801A balance of competing electrostatic and hydrogen bonding interactions directs the structure of hydrated gas-phase cluster ions. In K(Tryptamine) cluster ions, a favorable electrostatic interaction between the potassium cation and the tryptamine NH lone pair stabilizes the high-energy Gph(in) and Gpy(in) conformers of neutral tryptamine. Previous studies of Tryptamine(HO) clusters indicate that the hydrating water molecules stabilize the neutral minimum energy Gpy(out) tryptamine conformer. In this scheme, the first water molecule interacts directly with the NH lone pair and is located to the side of the tryptamine monomer. By incorporating a potassium cation, however, the minimum energy tryptaminewater configuration is disrupted in order to maximize the electrostatic interactions with the cation, shifting so that the tryptaminewater interaction includes a -hydrogen bond between the water and the phenyl ring of tryptamine. The infrared photodissociation spectra of K(Tryptamine)(HO) and K(Tryptamine)(HO)Ar will be presented along with parallel \textit{ab initio} and thermodynamics calculations to assist with the identification of the isomers present in each experiment
INFRARED SPECTRA OF M(2-AMINO-1-PHENYL ETHANOL)(HO)Ar (M=Na, K)
Author Institution: Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801A balance of competing electrostatic and hydrogen bonding interactions directs the structure of hydrated gas-phase cluster ions. Because of this, a biologically relevant model of cluster structures should include the effects of surrounding water molecules and metal ions such as sodium and potassium, which are found in high concentrations in the bloodstream. The molecule 2-amino-1-phenyl ethanol (APE) serves as a model for the neurotransmitters ephedrine and adrenaline. The neutral APE molecule contains an internal hydrogen bond between the amino and hydroxyl groups. In the M(APE) complex, the cation can either interrupt the internal hydrogen bond or position itself above the phenyl group, leaving the internal hydrogen bond intact. The former is preferred based on DFT calculations (B3LYP/6-31+G*) for both K and Na across the entire range from 0-400K, but infrared photodissociation (IRPD) spectra indicate a preference for the latter configuration at low temperatures. The IRPD spectra of M(HO) and M(HO)Ar (M=Na, K) will be presented along with parallel DFT and thermodynamics calculations to assist with the identification of the isomers present in each experiment
TEMPERATURE DEPENDENCE OF AND (n=3-5) CLUSTER IONS
Author Institution: Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801Competition between ionwater electrostatic interactions and waterwater hydrogen bonding allows several structural isomers of hydrated rubidium cluster ions to exist simultaneously. The cluster ion temperature plays a large role in determining which of these non-covalent interactions will dominate. Colder temperatures favor isomers with multiple hydrogen bonds while warmer temperatures favor less-structured isomers with fewer hydrogen bonds. The temperature, or internal energy, of hydrated rubidium cluster ions is controlled by varying the evaporative path available for cluster formation. If the evaporation involves loss of water molecules, the final cluster ion temperature will be in the range of . Evaporation of argon atoms generates substantially colder cluster ions with temperatures of . Infrared photodissociation spectra of are compared with \textit{(n=3-5)} spectra to illustrate entropic effects on the relative abundance of structural isomers in clusters. The identification of isomers present is aided by parallel \textit{ab initio}, RRKM-EE and thermodynamics calculations