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The Effects of Sleep Restriction and Time of Day on Food-Specific Impulsivity, Approach-Avoidance Bias and Delay Discounting
Full text linkBackground:
Insufficient sleep and circadian timing are both linked with obesity, primarily via unhealthy food choice, yet the cognitive mechanisms underpinning such relationships remain unclear. Methods:
Across two studies, we implemented an ecologically valid within-subjects at-home protocol. Study 1 (n = 118) involved a within-subjects examination of how sleep restriction (SR) versus well-rested (WR) sleep levels affect choices in a food-based approach-avoidance task (AAT) and go–no/go (GNG) task, a food liking task, a food-choice task, a psychomotor vigilance task (PVT), and a monetary choice task. Study 2 (n = 119) involved examining choices in the same set of tasks administered once in the afternoon (4pm) and once during the night (4am), which leveraged circadian influences on sleepiness and cognitive function. Results:
During the night, participants indicated steeper discounting rates relative to the afternoon. Furthermore, such rates predicted higher liking of high-calorie food choices regardless of time of day and when sleep restricted. Approach bias for low-calorie food interacted with the night condition in predicting both low- and high-calorie food choices. Conclusion:
Both delay discounting and approach bias may be important cognitive mechanisms predicting food liking and choice under sleep restricted and altered circadian timing conditions. Further research should replicate such results using real rewards
The Eugenic Sterilization of Puerto Rican Women: A Case of US Interests and Religious/Spiritual Freedom
Full text linkBetween the 1930s and 1970s, approximately one-third of Puerto Rican women of childbearing age (20–49) were sterilized— the highest rate in the world during that time. Driven by U.S. political and economic interests, and underpinned by eugenic ideology, Governor Blanton Winship and President Franklin D. Roosevelt championed sterilization as a solution to the island’s perceived overpopulation and its associated problems: unemployment, disease, and poverty. While Puerto Rican women were exploited as instruments of U.S. policy, sterilization paradoxically became widely accepted as a form of birth control on the island. This thesis critically examines the power dynamics and collective responses that framed the sterilization of Puerto Rican women as a successful U.S. policy initiative.
Employing an interdisciplinary framework—drawing from social sciences, theology, and literature—the study offers a multifaceted examination of the political agendas, lived experiences, and resistance strategies of Puerto Rican women affected by sterilization. It begins by exploring Puerto Rico’s political relationship with the U.S., using primary historical documents to reveal the mechanisms behind the sterilization campaign. The study then integrates Latin American feminist theology to illuminate the spiritual and religious dimensions of Puerto Rican women’s resistance—an essential yet often overlooked aspect in existing theoretical models, such as Teresa Delgado’s A Puerto Rican Decolonial Theology. Personal testimonies from Iris López’s Matters of Choice: Puerto Rican Women’s Struggle for Reproductive Freedom further highlight the limitations of conventional frameworks in capturing the full complexity of Puerto Rican women’s agency and resilience.
This thesis contends that spirituality is a crucial lens for understanding how Puerto Rican women resisted reproductive oppression—an experience that resonates across Latin America and is echoed in contemporary Latina literature. The final chapter explores Isabel Allende’s The House of the Spirits, illustrating how political history, spirituality, and religion are inextricably woven into the Latina lived experience. By employing an interdisciplinary approach, this study centers Puerto Rican women, shedding light on their systemic marginalization, constrained democratic citizenship, and resilience that has sustained their resistance over time
The Impact of Historical Memory: Polish-Russian Relations since 1991
Full text linkThe history of global foreign relations is marked by both strengthening alliances and deteriorating ties. From a historical perspective a perfect example of this dynamic is seen in the complex and ever-evolving relationship of Poland and Russia. That is why this research thesis will be focused on the history of Polish and Russians relations in connection to the Polish response to Putin’s war in Ukraine. This research project’s look into this history will serve to answer the central question of “How has the shared history of Polish and Russian relations uniquely shaped the Pole’s response to Putin’s invasion of Ukraine?” This relationship is important to answering this question because of how much history and historical events influence the collective identity of Poland. By looking at the two countries\u27 shared history since the early 1900s, this thesis will specifically focus on how Poland has used history to stand for a specific image of Russia since the fall of the Soviet Union in 1991. This will be shown through analysis of the historical depiction of Russia in past and present contexts from the Polish perspective. With sources ranging from news articles and historical works that directly analyze key events in Poland’s history where Russia is involved as explanations for the state of Polish Russian relations. The result of this research is to find that Poland’s use of historical memory as a political tool highlights histories impact on contemporary foreign relations
Revealed and Hidden Social Preferences
Full text linkThis study investigates individuals’ social preferences by examining the impact of group identity on economic decision-making through Dictator Game and Lying Dictator Game experiments conducted in different cultural contexts. The research compares students from Chapman University (USA) and Wuhan University (China), with each participant informed of their counterpart’s university affiliation. This design allows for the comparison of behaviors exhibited in in-group versus out-group settings. The results show that in the Dictator Game, allocation behavior remained consistent regardless of group identity. However, in the Lying Dictator Game, Wuhan participants displayed different levels of honesty depending on their counterpart’s university affiliation. A mixture model analysis further revealed that Wuhan participants had a higher probability of lying compared to their Chapman counterparts. These findings suggest that cultural norms and group identity play a significant role in shaping social preferences such as honesty and generosity
Modifying Tryptophan and Indole-Derived Compounds Using Engineered Indole Prenyltransferase Enzymes
No full textIndole Prenyltransferase (IPT) enzymes are present in many microorganisms. They catalyze the transfer of prenyl moieties from natural pyrophosphate donors to tryptophan and other indole-derived small molecules. Prenylation alters the structure of small molecules, enhances their hydrophobicity, and subsequently alters their interaction with cell membranes and receptors. Prenylation of small molecules has been reported to increase cytotoxicity and antimicrobial properties. This suggests that generating enzymes that lead to diprenylation can lead to further improvement in compound properties. PriB is a C-6 IPT that uses dimethylallyl pyrophosphate as a native donor to prenylate tryptophan. PriB has shown broad substrate flexibility, allowing it to modify nonnative donor and acceptor substrates. Structural analysis of PriB active site suggested three key residues that play an important role in the enzyme biocatalytic activity. Thus, site-directed mutagenesis of these three residues was performed in order to expand the active site to facilitate diprenylation, and the encoded enzymes were purified and screened. Our in vitro enzymatic reactions, coupled with HPLC-MS, kinetic data, in addition to 1- and 2D nuclear magnetic resonance spectroscopy, show that the three mutants are capable of catalyzing diprenylation reactions. This work highlights the crucial role of enzyme engineering in biocatalysis, demonstrating its ability to expand enzyme activity across diverse applications
2025 Phi Beta Kappa Induction Ceremony Program
Full text linkThe 2025 Induction Ceremony for the Psi of Chapter California was held on May 13, 2025 at the Hilbert Museum of California Art at Chapman University. In this ceremony, 35 outstanding students and one honorary member were inducted into Phi Beta Kappa.
Please click here to view photos from the ceremony.https://digitalcommons.chapman.edu/pbk_induction_programs/1005/thumbnail.jp