100039 research outputs found
Sort by
A Model of Changeover Behavior in Concurrent Schedules of Reinforcement
Get PDFAnimals in the wild have access to a variety of food sources, and they must allocate their time between them in an efficient manner. This requires deciding when to depart from the source currently being exploited to travel to a different one. A general model of this decision process can be derived from three assumptions well supported by the learning literature. The first one is the so-called matching law, which says that the proportion of time allocated to any one behavior equals the proportion of total value obtained from that option. The second one is that the dwell times (i.e., the length of time spent at a food source before departing) follow an exponential distribution; that is, the probability of departing at any moment remains constant across time. The last assumption is that the sum of the leaving rates (i.e., the number of departures from a food source per unit of time) depends only on the total food rate produced by all the available sources. This thesis provides an overview of a first version of this model and its assessment using two large datasets from published experiments. It also describes an experiment with rats that was designed to refine the model based on the limitations noted during the assessment. Rats were placed in operant chambers where they could press two levers to produce food at rates chosen in a pseudorandom fashion at the beginning of each daily session. The results were consistent with the assumptions of the model, and suggested ways in which its equations could be improved. The updated version of the model accurately described the data while also suggesting ways to incorporate other factors known to affect how animals make decisions. Ways in which the model could be applied to other situations, both at the basic and applied level, are discussed
The Utah Statesman, March 24, 2025
Get PDFWeekly student newspaper of Utah State University in Logan.https://digitalcommons.usu.edu/newspapers/2895/thumbnail.jp
The Utah Statesman, April 14, 2025
Get PDFWeekly student newspaper of Utah State University in Logan.https://digitalcommons.usu.edu/newspapers/2898/thumbnail.jp
A Review of Plant–Microbe Interactions in the Rhizosphere and the Role of Root Exudates in Microbiome Engineering
Get PDFMicrobial interactions within the rhizosphere are fundamental to plant health, influencing nutrient availability, stress tolerance, and pathogen resistance. Beneficial microbes, such as plant growth-promoting microbes (PGPMs), including bacteria and mycorrhizal fungi, enhance plant resilience through mechanisms like nutrient solubilization, phytohormone production, and pathogen suppression via antimicrobial compounds and siderophores. Root exudates, composed of sugars, organic acids, and secondary metabolites, act as chemoattractants that shape the rhizosphere microbiome by recruiting beneficial microbes. Microbial metabolites can, in turn, modulate plant physiology and exudate profiles, thereby reinforcing mutualistic interactions. Stress conditions alter exudate composition, enabling plants to attract specific microbes that aid in stress mitigation. Given the growing interest in microbiome-based agricultural solutions, this review aims to synthesize recent literature on plant–microbe interactions, with a focus on bidirectional signaling between plants and microbes. A structured literature search was conducted using databases such as PubMed, Scopus, and ScienceDirect to identify key studies on root exudation, microbial functions, and synthetic microbial communities (SynComs). We highlight major findings on how engineered microbiomes can enhance plant growth, resilience, and productivity, particularly under stress conditions. This review also explores how advances in SynCom design can promote sustainable agriculture by reducing reliance on chemical inputs
Nature\u27s Medicine? The Associations of Organized Youth Sport, Unstructured Physical Activity, And Land-Use Recreation with Children\u27s Mental Health, Emotional Control, And Social Well-Being
Get PDFPhysical activity is well-established as beneficial for children’s physical and mental health, yet limited research has explored how different activity types impact psychosocial outcomes. This is a cross-sectional study that examined associations between youth participation in organized sport, unstructured physical activity, and land-use recreation and their psychosocial health. Survey data were collected from 3246 caregivers of children in the Intermountain West region of the United States. Respondents reported on children’s physical activity engagement and psychosocial outcomes, including mental health, emotional control, and social well-being. All three activity types were significantly associated with improved psychosocial health (p \u3c 0.001). Compared to organized sport, unstructured physical activity and land-use recreation were associated with significantly higher levels of mental health and emotional control (padj \u3c 0.001), although with a small effect size (η2 \u3c 0.006). No significant differences were observed in social well-being across activity types (p = 0.2928). When controlling for gender and community type, distinct psychosocial benefits emerged between activity types. These findings suggest that, while all forms of physical activity support psychosocial development, unstructured and naturebased activities may offer particular advantages. Findings highlight the importance of promoting diverse forms of physical activity and considering individual and contextual factors in maximizing their psychosocial benefits
Taking Kinship into the Classroom by Indigenous Knowing: We Are ALL Related Somehow
Get PDFThis article explores the integration of Indigenous knowledge into the classroom. It has been claimed that studies which do not promote revitalization of Indigenous communities should not be conducted. However, this article\u27s intent is to support Indigenous communities and our way of knowing. The purpose of this paper is to stimulate thinking within Indigenous educational communities about the possibilities of incorporating kinship within students’ and teachers’ interactions for successful educational purposes. An alternative approach to how teachers and students interact in the classroom. This topic will also demonstrate the importance of Indigenous epistemologies with a theory that permits Indigenous scholars to justify their epistemological and ontological concerns. Though, to speak broadly about scholarly practice regarding kinship from an Indigenous perspective is to speak about it differently from non-Indigenous academics who speak from a single worldview of kinship. Therefore, blood relationship is not the primary focus, but the acknowledgement of the connection to others. The validation for Indigenous Knowledge for future Indigenous scholars to reclaim our cultural identities is important as well. It is important to acknowledge the Indigenous perspectives of kinship and its practice because different viewpoints allow different knowledge or new knowledge
The Soldier Saint: Latter-Day Saint Veterans of the Vietnam War
Get PDFThis digital exhibit and accompanying paper explore the experiences and contributions of Latter-day Saint veterans during the Vietnam War, focusing on their role within both military and religious contexts. Despite representing only a small percentage of the American military forces in Vietnam, Latter-day Saints influenced the war\u27s cultural and spiritual landscape. Through personal narratives, interviews, and historical analysis, the study sheds light on how these veterans navigated the complexities of their faith amidst the challenges of combat.
Additionally, it considers the relationship between military service and missionary efforts, highlighting how the presence of Latter-day Saint soldiers contributed to later religious outreach in Vietnam. The research underscores themes of resilience, service, and spiritual growth, offering a broader perspective on the intersection of faith and wartime experience. By recognizing their contributions, this work seeks to provide a deeper understanding of their impact within both their religious community and the larger historical context of the Vietnam War
Uptake, Distribution, and Activity of Pluronic F68 Adjuvant in Wheat and its Endophytic \u3cem\u3eBacillus\u3c/em\u3e Isolate
Get PDFSurfactants are widely utilized in agriculture as emulsifying, dispersing, anti-foaming, and wetting agents. In these adjuvant roles, the inherent biological activity of the surfactant is secondary to the active ingredients. Here, the hydrophilic non-ionic surface-active tri-block copolymer Pluronic® F68 is investigated for direct biological activity in wheat. F68 binds to and inserts into lipid membranes, which may benefit crops under abiotic stress. F68’s interactions with Triticum aestivum (var Juniper) seedlings and a seed-borne Bacillus spp. endophyte are presented. At concentrations below 10 g/L, F68-primed wheat seeds exhibited unchanged emergence. Root-applied fluorescein-F68 (fF68) was internalized in root epidermal cells and concentrated in highly mobile endosomes. The potential benefit of F68 in droughted wheat was examined and contrasted with wheat treated with the osmolyte, glycine betaine (GB). Photosystem II activity of droughted plants dropped significantly below non-droughted controls, and no clear benefit of F68 (or GB) during drought or rehydration was observed. However, F68-treated wheat exhibited increased transpiration values (for watered plants only) and enhanced shoot dry mass (for watered and droughted plants), not observed for GB-treated or untreated plants. The release of seed-borne bacterial endophytes into the spermosphere of germinating seeds was not affected by F68 (for F68-primed seeds as well as F68 applied to roots), and the planktonic growth of a purified Bacillus spp. seed endophyte was not reduced by F68 applied below the critical micelle concentration. These studies demonstrated that F68 entered wheat root cells, concentrated in endosomes involved in transport, significantly promoted shoot growth, and showed no adverse effects to plant-associated bacteria
Women’s Evolving Roles: Gender, Authority, And the History of Latter-Day Saint Patriarchy
No full textThis project aims to further understand contemporary women’s issues within the Church of Jesus Christ of Latter-day Saints by answering three questions. 1) What social and doctrinal factors have influenced the development of patriarchal structures within the LDS Church, and how have these factors evolved? 2) What are the current leadership and decision-making roles available to LDS women, and how does church membership feel about them? 3) What ideas exist for progress in gender equality and women’s leadership? This discussion provides relevant historical context, outlines current issues regarding LDS women’s authority challenges and theological interpretations, and numerous proposed solutions from historians, academics, activists, and church leaders. Since the establishment of the Church, Latter-day Saint (Mormon) women have had a longstanding relationship with the Church’s patriarchy. While polygamy was oppressive to some through limitations of free speech, it empowered others to develop a strong internal authority and even defend the practice. Over a century, the church’s views on polygamy and women’s roles in administration shifted, with polygamy’s illegalization and a stronger emphasis on traditional roles encroaching over decades. While some in the contemporary church are complacent with current gender roles, recent events have prompted others to challenge the church’s structure— suggesting that the doctrine of Heavenly Parents and the admonition to emulate Them point to a side-by-side archetypal leadership for the church. Many saints push for progress through study, protest, and dialogue to advocate for further leadership and representation of women in the church
Impacts of Reef Fish Length on Foraging Radius: Exploring Behavioral Patterns Within a Patch Reef Ecosystem
No full textReef fish exhibit various behaviors upon the Great Barrier Reef. One of these behaviors includes that of limiting their grazing distances from a patch reef refuge to a certain maximum distance in order to avoid predators. This is defined as a ‘foraging radius’ or ‘margin of safety’. This ‘foraging radius’ varies among fish due to many factors- including species, morphology, ontogenesis, habitat complexity, and importantly: speed. Quicker fish can outswim predators to safety more efficiently than slower fish, and can therefore afford to travel farther distances to forage. Speed varies among fish for a number of reasons, including fish size and shape. In this study, we looked at how fish length affects its foraging radius within a patch reef ecosystem. We found that there was a positive correlation between length and foraging radius, but that this relationship was highly variable among species. The positive relationship was the strongest within the Damselfish family (Pomacentridae), and was also strong within all site-fidelic reef fish species. Overall, a fish’s body shape and maneuverability may contribute more to their foraging radii rather than just their sizes, though many confounding variables also likely impact this relationship. Further research should focus on investigating the effects of these additional factors in order to better understand and protect coral reef ecological dynamics in the face of ongoing reef bleaching caused by a warming climate and ocean acidification