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An Automated Machine Learning Approach to the Retrieval of Daily Soil Moisture in South Korea Using Satellite Images, Meteorological Data, and Digital Elevation Model
Get PDFSoil moisture is a critical parameter that significantly impacts the global energy balance, including the hydrologic cycle, land–atmosphere interactions, soil evaporation, and plant growth. Currently, soil moisture is typically measured by installing sensors in the ground or through satellite remote sensing, with data retrieval facilitated by reanalysis models such as the European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis 5 (ERA5) and the Global Land Data Assimilation System (GLDAS). However, the suitability of these methods for capturing local-scale variabilities is insufficiently validated, particularly in regions like South Korea, where land surfaces are highly complex and heterogeneous. In contrast, artificial intelligence (AI) approaches have shown promising potential for soil moisture retrieval at the local scale but have rarely demonstrated substantial products for spatially continuous grids. This paper presents the retrieval of daily soil moisture (SM) over a 500 m grid for croplands in South Korea using random forest (RF) and automated machine learning (AutoML) models, leveraging satellite images and meteorological data. In a blind test conducted for the years 2013–2019, the AutoML-based SM model demonstrated optimal performance, achieving a root mean square error of 2.713% and a correlation coefficient of 0.940. Furthermore, the performance of the AutoML model remained consistent across all the years and months, as well as under extreme weather conditions, indicating its reliability and stability. Comparing the soil moisture data derived from our AutoML model with the reanalysis data from sources such as the European Space Agency Climate Change Initiative (ESA CCI), GLDAS, the Local Data Assimilation and Prediction System (LDAPS), and ERA5 for the South Korea region reveals that our AutoML model provides a much better representation. These experiments confirm the feasibility of AutoML-based SM retrieval, particularly for local agrometeorological applications in regions with heterogeneous land surfaces like South Korea
Exploring Variations in STEM Instructors’ Approaches to Office Hours
Get PDFOffice hours are an integral component of science, technology, engineering, and math (STEM) courses at nearly all colleges and universities. Despite their ubiquity as a support mechanism, there has only been limited work examining how instructors approach office hours and what shapes these approaches. Here, we conduct a phenomenographic study to investigate how instructors of STEM courses experience office hours and how these experiences may impact their approaches to promoting and managing office hours. We identified variations in how instructors promoted office hours, the modality of office hours (i.e., when and where office hours were held), and how instructors facilitated learning during office hours. These variations spanned from student-centric (strategies instructors use with students’ interest in mind, e.g., wanting to increase student learning, accessibility, comfort, etc.) to instructor-centric (strategies the instructors use with their own self-interest in mind, e.g., saving time and/or bandwidth, personal needs, comfort, etc.). Additionally, we identify several challenges and barriers, including a lack of formal training or opportunities to discuss office hour approaches with other faculty, and conclude with general recommendations for instructors and administrators in STEM departments for engaging and supporting students during office hours
Young Children’s Mental Well-Being in Low-Income South African Settings: A Qualitative Study
Get PDFThis qualitative study aimed to capture community perspectives of the risks and protective factors for social emotional development and mental health of young children in low-income South Africa settings, and was conducted as one component of a larger study with the ultimate aim of co-designing the Mazi Umntanakho (‘know your child’) digital tool. Twenty focus group discussions (n = 154, 97% female) were held with staff of community-based organisations (CBOs) and community health worker (CHW) programmes in urban and rural sites from four geographical regions. Data were analysed thematically, and grouped according to components of nurturing care (responsive caregiving, safety and security, good health, adequate nutrition, opportunities for early learning) and risk and protective factors. Risks reported by participants far outweighed protective factors, and the most dominant theme identified was risks associated with responsive caregiving from CBO and CHW perspectives. These related to participants’ perceptions of caregivers’ attitudes, knowledge, beliefs, behaviours, and challenges not conducive to the provision of responsive caregiving. The most commonly perceived risks to safety and security were substance abuse, along with economic challenges, neglect, abuse and violence. Basic needs not being met was reported as the main risk to adequate nutrition and good health, followed by insufficient services. Limited resources and caregivers’ limited education and literacy were perceived to be risks to early learning. These findings highlight the urgent need to mitigate risks and amplify protective factors for the social emotional development and mental health of young children in South Africa. It is critical that these are considered within the contextual realities of low-income communities
The Social Contract: Duty and Discrimination in Public Service
Get PDFWhat do citizens owe the government? And conversely, what does the government owe its people, particularly those who volunteer for military or public service? The works in this portfolio attempt to answer these questions and delve into the social contract between the American government and its citizens, often through the lens of sexual orientation. Using original correspondence from the Center for War Letters at Chapman University as well as existing works concerning Don’t Ask, Don’t Tell and the Lavender Scare, the collected essays aim to tell the story of everyday Americans who answered the call to public service only to find indifferent or even hostile treatment by government they sought to serve. Through poor planning or discrimination, the U.S. government routinely violated its oath to its people at key points throughout the nation’s history, but this portfolio demonstrates how dedicated citizens strove to update and improve the social contract in order to produce the more perfect union promised in the nation’s constitution
Bibliography for Vietnamese Culture Display
Get PDFA bibliography created to accompany a display about Vietnamese culture and Tết in February 2024 at the Leatherby Libraries at Chapman University
Analysis of US Food and Drug Administration New Drug and Biologic Approvals, Regulatory Pathways, and Review Times, 1980–2022
Get PDFU.S. laws enacted since 1983 have aimed to enhance the development and marketing of new pharmaceutical products. We thoroughly characterized all new molecular entities, therapeutic biologics, and gene and cell therapies approved by the US Food and Drug Administration (FDA) during the period 1980–2022 in the context of these laws and regulations. Throughout the study period, the FDA approved 1355 new pharmaceutical products. The median FDA review time decreased from 26.6 months prior to the Prescription Drug User Fee Act (1992), which authorized the FDA to collect fees from drug companies to 9.9 months after the Food and Drug Administration Safety and Innovation Act (2012), which created new designations that eliminated the requirement for evidence of added therapeutic benefit for FDA expedited drug review. The greatest increase in approvals occurred in antineoplastic and immunomodulating drugs, biologics, and orphan drugs. More than half of new drug approvals benefited from regulatory designations and pathways that did not require addressing unmet medical needs or demonstrating therapeutic benefit over available alternatives. The legislative goal of bringing more drugs to the market faster has been achieved. Further studies are needed to determine the therapeutic value to patients of new drugs approved using expedited approval pathways
Motherhood to Motherhoods: Ideologies of the “Feminine”
No full textThe eleven essays in this special issue originated from the “Motherhood to mother-hoods: Ideologies of the ‘Feminine’” conference held at Chapman University in Orange, California, on April 28-30, 2023. Against the background of intense discussions on women’s reproductive rights in the United States (US), the conference provided a fertile ground for reexamining motherhood as a concept extending beyond essentialist and biological determinations
