Browsing by Author "Johnson, Sarah, committee member"
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Item Open Access A pilot study of a mindfulness-based group program in adolescents at risk for excess weight gain(Colorado State University. Libraries, 2018) Burke, Morgan, author; Shomaker, Lauren, advisor; Lucas-Thompson, Rachel, committee member; Johnson, Sarah, committee memberThere is a cross-sectional and prospective association of depressive/anxiety symptoms with excess weight in adolescents. Theoretically, intervening to decrease mental health symptoms in adolescents at-risk for excess weight gain may offer a novel approach to also decrease the risk for excess weight gain. Mindfulness-based approaches show preliminary promise in adults with obesity and in some adolescent samples; yet feasibility and acceptability in adolescents at-risk for excess weight gain has not been determined. In this study, I examined the feasibility and acceptability of a 6-week mindfulness-based group program in adolescent girls and boys at-risk for excess weight gain, and I explored the effects of participation in a mindfulness-program on perceived stress, depression, anxiety, and body mass index (BMI) indices, as compared to a 6-week health education control group program. Participants were age 12-17 years old and determined to be at-risk for excess weight gain based upon above-average BMI percentile or a strong family history of overweight. Adolescents were assessed at baseline, 6-weeks/post-treatment, and a 6-month follow-up. Fifty-four adolescents were randomized to the mindfulness group program (n=29) or the health education control group (n=25). In the mindfulness group, participants were on average 13.97 years old, 66% non-Hispanic White, and 90% had overweight or obesity (BMI >=85th percentile). In the health education control group, participants were on average 14.49 years old, 72% non-Hispanic White and 84% had overweight or obesity. Feasibility and acceptability were measured by group attendance, homework completion, and program acceptability ratings. Depression, anxiety symptoms, and perceived stress were measured by validated surveys. Adolescents' median session attendance was six out of six sessions in both the health education group and the mindfulness group. In the mindfulness group, homework completion averaged 63%. In the mindfulness group, 92% thought that the group addressed their concerns, and 100% would recommend the group to others like them. Adolescents randomized to the mindfulness group showed greater decreases in perceived stress at post-treatment than adolescents in the health education group. There were some within-condition changes in key variables, but no other significant between-condition effects at either post-treatment or 6-months follow-up were observed. In conclusion, a relatively brief mindfulness-based group program appears to be feasible and acceptable to adolescents at-risk for excess weight gain. A mindfulness-based training program may offer some acute psychological benefits, particularly in terms of perceived stress. Yet, further research is needed on mindfulness programs for adolescents at-risk for excess weight gain with longer follow-up periods, and also with adolescents with elevated depression and anxiety at baseline.Item Open Access An evaluation of yield and quality characteristics for vegetable crops grown under organic management in Fort Collins, Colorado(Colorado State University. Libraries, 2020) Mason, Tyler, author; Uchanski, Mark, advisor; Bartolo, Michael, committee member; Johnson, Sarah, committee member; Prenni, Jessica, committee memberTo view the abstract, please see the full text of the document.Item Open Access Characterization of protein-polyphenol interactions between novel plant proteins (pea and hemp) and blueberry polyphenols with respect to polyphenol binding and delivery(Colorado State University. Libraries, 2022) Chima, Bianca, author; Van Buiten, Charlene, advisor; Johnson, Sarah, committee member; Prenni, Jessica, committee memberDespite the numerous health benefits associated with polyphenols, dietary intake of this class of compounds is low in the United States due to low intake of fruits and vegetables. It has been shown that dairy foods (i.e. milk, yogurt) increase polyphenol bioavailability due to polyphenols interacting with whey protein, enhancing polyphenol stability and uptake throughout digestion. However, increasing concerns for sustainability and health have introduced a variety of novel plant-based proteins as dairy alternatives. This study aimed to investigate the abilities of edible pea and hemp protein isolates to form complexes with blueberry polyphenol extract (BPE) and characterize the physical and biological functionalities of these complexes compared to whey proteins. Protein/polyphenol solutions were analyzed using UV-Vis spectroscopy to determine if complexation occurred. Secondary structures and binding affinities were analyzed by far-UV CD Spectroscopy and fluorimetry, respectively. In vitro digestion was performed to determine whether the protein profile changed in the presence of BPE via SDS-PAGE and determination of free amino acids using the ninhydrin method. Protein isolates from pea and hemp successfully formed complexes with BPE with binding affinities for the compound similar to whey protein. Relative helicity of the hemp protein was higher than the other protein sources and increased upon complexation with BPE. Furthermore, the SDS-PAGE profiles of all the proteins were the same whether BPE was present or not and the free amino acid content increased after digestion for the protein and protein/polyphenol solutions. Overall, complexation of BPE with plant proteins was successful. Fluorescence quenching and changes to the secondary structure of the proteins in the presence of BPE indicate that polyphenols were bound but the mechanisms and structures responsible for complexation seem to vary between proteins. More research is needed to determine the interactions that cause binding between the polyphenols and the proteins and whether the bioavailability of the compounds will increase when bound to the proteins in cell model and/or clinical study. This study provides a foundation for exploring the effects of plant-based proteins on phytochemical functionality in complex, "whole food" matrices.Item Open Access Dynamic manipulation of far-red light and temperature for the production of microgreens in controlled environments(Colorado State University. Libraries, 2024) Fulton, Oliver Wynne, author; Craver, Joshua, advisor; Bousselot, Jennifer, committee member; Johnson, Sarah, committee memberMicrogreens are becoming increasingly popular for controlled environments due to their ease of production, profitability, and high concentration of nutrients. However, to date there is little information on how light spectra and temperature interactively affect plant growth and morphology to optimize the production of horticultural crops, including microgreens. Therefore, the objective of this study was to investigate the benefit of reducing air temperature as well as supplementing with far-red (700-750 nm) photons to enhance the morphology and phytochemical concentrations of three Brassica microgreen species. Seeds of mustard (Brassica juncea 'Garnet Giant'), kohlrabi (Brassica oleracea var. gongylodes), and red cabbage (Brassica oleracea var. capitata) were sown on rockwool substrate and grown in walk-in growth chambers using ebb and flow hydroponic systems at the CSU Spur campus. Upon germination, microgreens were grown under ambient air temperature of either 18 or 21 °C and subjected to the following lighting treatments: photosynthetic photon flux density (PPFD) of 165 μmol·m−2·s−1 (PAR165); PPFD of 200 μmol·m−2·s−1 (PAR200); and PPFD of 165 μmol·m−2·s−1 + 35 μmol·m−2·s−1 of far-red light (PAR165+FR35). Expected shade avoidance responses (e.g., increased hypocotyl elongation) due to a low R:FR value occurred in all three species under PAR165+FR35, regardless of temperature. Additionally, fresh weight of red cabbage and kohlrabi was greatest under PAR165+FR35 or similar between PAR165+FR35 and PAR200, respectively, at both temperatures. While an interaction with temperature was not observed, results support the role of far-red light in the manipulation of both microgreen quality and biomass accumulation. A follow-up experiment was conducted with red cabbage microgreens grown under the previous far-red lighting treatment (PAR165+FR35) to explore the dynamic manipulation of air temperature throughout production. While production under PAR165+FR35 should result in characteristic shade avoidance responses, including a potential decrease in pigmentation, we hypothesized that a reduction in air temperature during production could serve as a secondary stressor to increase phytochemical concentrations (e.g., anthocyanins). Using the same experimental setup described for the previous experiment, red cabbage microgreens were grown at an air temperature of 21 °C for 12 days (Control) or moved 6, 8, 10, or 11 days after sowing to an air temperature of 16 °C. Shade avoidance responses (e.g., hypocotyl elongation) and both fresh and dry weight were reduced for microgreens transferred to the air temperature of 16 °C on days 6 and 10 compared to all other treatments. Interestingly, microgreens transferred to the air temperature of 16 °C resulted in greater dry weight compared to Control. While results were not significant, an anticipated trend of increased relative anthocyanin content in response to longer durations at the 16 °C air temperature was observed. Although the dynamic manipulation of both far-red light and temperature could lead to microgreens with optimal yield, morphological characteristics, and phytochemical concentrations, future research is warranted to elucidate target environmental setpoints, durations, and possible interactions.