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Accurate estimation of Jujube leaf chlorophyll content using optimized spectral indices and machine learning methods integrating geospatial information
Get PDFLeaf chlorophyll content (LCC) is vital for photosynthesis and ecosystem functioning; it influences carbon, water, and energy exchanges while serving as an indicator of photosynthetic activity and nitrogen levels in precision agriculture. Hyperspectral data enable precise LCC monitoring by extracting spectral indices through optimal band combination (OBC) and predicting LCC with machine learning. However, OBC faces dimensionality issues, and machine learning models often overlook geographical influences, potentially reducing prediction accuracy. This study hypothesizes that developing spectral indices from important wavelengths and integrating geospatial data into machine learning models can address these issues and increase prediction accuracy. To test this hypothesis, a framework was developed that first uses elastic net (EN) and the successive projection algorithm (SPA) for wavelength selection, followed by spectral index creation with OBC and ranking with random forest (RF). Support vector regression (SVR), random forest regression (RFR), and geographically weighted least squares support vector regression (GWLS-SVR) were then used to assess the prediction accuracy. Finally, the optimal variables and regression model were identified. The results revealed that the EN- and SPA-based indices had stronger correlations and importance than defined indices. The double-difference index (DDn) and the anti-reflectance index (ARI) are the most robust three-dimensional and two-dimensional spectral indices, respectively. GWLS-SVR requires fewer indices (1–4) to achieve optimal results, with EN-DDn (2R519-R775-R936)-GWLS-SVR performing best (R2 = 0.95, RMSE = 0.61, PBIAS = -0.02). This research presents a robust framework with strong adaptability for estimating LCC in a specific study area and region, demonstrating substantial potential for the precise estimation of agroforestry vegetation parameters
Family-Based Support as a Social Determinant of Health-Protective Factor for Children with Autism Spectrum Disorder
Get PDFParents of children with autism spectrum disorder (ASD) demonstrate resilience and resourcefulness in managing the demands of caregiving. This study highlights the critical role of family based support as a social determinant of health-protective factor (SDHPF) that enhances the well-being of parents, helping to mitigate depressive symptoms. Using a secondary dataset of 199 parents/ caregivers of children with ASD, this study examines how family based support, child symptom severity, and financial resources (income) influence parental mental health. The findings show that strong family support is positively associated with lower levels of depression, underscoring the strength of social networks in enhancing mental health. Results suggest that fostering family-based support systems can be a powerful tool in promoting resilience and reducing depression in parents of children with ASD. The study’s implications for professional development and training, clinical practice, and policy development focus on leveraging these strengths to further support the mental health of caregivers
The Lived Personal History of Queer Teachers Engaged in Queer Pedagogy
Get PDFThis study examines a group of five queer teachers of varied ages and genders who discussed their lived experiences navigating the heteronormativity of public school structures in conjunction with their work using queer pedagogy to support students. It answers the research question: How does the lived personal history of queer educators influence how, when, and in what ways they take up queer pedagogy? Employing a life history interview methodology, along with queer theory as a theoretical framework, this study explores intersections of the participants’ life history and their engagement in queer pedagogy to examine why and how they are driven towards LGBTQ+ inclusive practices, and what keeps them dedicated in spite of the ever-present obstacles. The study’s purpose is to contribute to the greater body of research about the lived experiences of queer teachers and to provide models for future educators looking to take up this work. The research offers insight into critical incidents in the pre-service lives of the teachers as well as their in-service history up to and including their present work. Findings revealed queer teachers navigating challenges ranging from microaggressions to significant oppression and injustice. It also found that the participants’ personal history served as an intrinsic motivator for them to support queering their schools, and they positioned themselves as queer change agents seeking professional learning and support for themselves and others in their school communities
Not Just a White People\u27s Book Club: The Participatory Action Research of an Educator Collaborative
Get PDFThis participatory action research (PAR) study investigated the learning and action of a racial and social justice book club composed of educators within a public school district. Over several years, the group engaged in collaborative cycles of inquiry, reflection, and systemic action to deepen understanding of racism, power, and equity in education. Framed by Bronfenbrenner’s Ecological Systems Theory, Relational-Cultural Theory, and Transformative Learning Theory, this study explored how learning in community supported both personal and collective transformation. Findings highlight that the book club functioned as a relational and intellectual space where vulnerability, critical reflection, and mutual accountability fostered growth-fostering relationships and critical consciousness. The study demonstrated how educator-led collectives rooted in PAR can serve as effective mechanisms for justice-oriented professional learning and systemic change in public education. This dissertation contributes to the literature on critical professional development, racial and social justice education, and action research. It underscores the importance of relational approaches to equity work and offers an actionable model for practitioner-driven transformation grounded in reflection, dialogue, and courageous collective action
Effects of Solvent Viscosity, Temperature, and E47D Mutation on Thermotoga maritima IGP Synthase Catalysis
No full textThermotoga maritima indole-3-glycerol phosphate synthase (T. maritima IGP synthase) is a monomeric thermostable enzyme. T. maritima IGP synthase catalyzes the fifth step in the tryptophan biosynthesis pathway, which functions in the conversion of 1-(o-carboxyphenylamino)-1-deoxyribulose-5-phosphate (CdRP) to indole-3-glycerol phosphate (IGP). This research investigates the temperature-dependent catalytic activity and substrate binding of the thermophilic enzyme T. maritima IGP synthase to understand its unique adaptations to environments such as hot springs. Enzyme kinetic assays, kinetic solvent viscosity effects (KSVE), and Arrhenius plots were used to analyze the catalytic activity and substrate binding of wildtype and E47D T. maritima IGP synthase at temperatures ranging from 25 °C to 80 °C. We propose that the kinetic parameters governing these processes have different temperature dependencies. Previous studies reported the wildtype kcat value of 0.11 s-1 and a KM value of 0.006 μM at 25 °C. Here we report that the wildtype has a kcat value of 0.15 s-1 ± 0.01 and a KM value of 0.033 ± 0.007 μM, which suggests a 6-fold decrease in substrate binding affinity. The E47D resulted in a lower kcat value of 0.018 s-1 ± 0.001 and a decreased KM value of 0.008 ± 0.003 μM at 25 °C, indicating higher substrate affinity. However, temperature effect revealed high catalytic activity at higher temperatures. These results demonstrate that the E47D mutation in the active site residues of IGP synthase drastically reduces its catalytic activity but contributes significantly to its thermostability. These findings highlight the significance of residue E47 in T. maritima IGP synthase
Magnesium, iron, and calcium isotope signatures of Chicxulub impact spherules: Isotopic fingerprint of the projectile and plume thermodynamics
Get PDFThe Cretaceous-Paleogene boundary (KPB) represents a massive extinction event in Earth\u27s history, probably triggered by the Chicxulub asteroid impact ∼66 Ma. The event dispersed vast volumes of ejecta materials including exceptionally preserved impact spherules in the Gorgonilla Island KPB section. Previous work identified three populations of spherules at Gorgonilla: 1) ballistically transported molten spherules, 2) a mixture of molten and condensed spherules dispersed by the expansion of a high-temperature, turbulent cloud (the pyrocloud ), and 3) tiny droplets condensed from the plume (the fireball layer ). We determine the Mg, Fe, and Ca isotopic compositions of pristine spherules to better understand the evaporation and condensation thermodynamics within the pyrocloud. We detect enrichment in mass bias corrected µ48Ca and µ26Mg* isotope signatures from the terrestrial value corresponding to an impactor contribution of ∼17–25%, most likely from a CM or CO chondrite-like asteroid. The mass-dependent δ25Mg and δ56Fe compositions are generally light or unfractionated, suggesting incomplete recondensation as the pyrocloud cooled and expanded. Combined δ25Mg and δ56Fe signatures reveal decoupling of these isotope systems, likely due to differing condensation rates. Thus, we calculate a higher average condensation rate of Fe than Mg, reflecting the thermodynamic decoupling and more complete recondensation signatures of Fe in the pyrocloud vapor. While we uncover information about the evaporation and condensation thermodynamics in the pyrocloud, the exact formation mechanisms of the complete suite of spherules remain complex with some spherules potentially forming from multiple mechanisms, including recondensation and splash–melting
Evaluating robustness of subnetworks for the split-star network
No full textThe robustness of subnetworks for the interconnection network of a computer system is an important consideration for the system performance. It can be measured by the extent to which subnetworks can stay fault-free when faults are present in the system. In this paper, we evaluate the subnetwork robustness for the n-dimensional split-star network Sn2. Let Sn-m2, 1 ≤ m ≤ n-3 , be a subnetwork of Sn2, and let p be the node reliability, the probability that a single node remains fault-free. We determine two values that reflect how robust Sn-m2 subnetworks are, from two perspectives. We first establish the upper/lower bounds for Fm (Sn2), the minimum number of faulty nodes to make all Sn-m2 subnetworks faulty. Then, we determine the subnetwork reliability, denoted by Rm (Sn2, p), which is the probability that at least one fault-free Sn-m2 subnetwork exists in Sn2, given the node reliability p. The upper/lower bounds and an approximation expression for Rm (Sn2, p) are obtained. We also propose a simulation method to estimate Rm (Sn2, p). The experimental results show that a) when p is relatively low, Rm (Sn2, p) can be approximated by the mean value of its upper and lower bounds, or the estimation value by the approximation expression; b) when p is high, Rm (Sn2, p) can be more accurately estimated by our simulation method
Reciprocal Learning in the Mentor-Novice Teacher Relationship in Middle School
Get PDFThis dissertation examined the mentor-novice teacher relationship in the post-2020 middle school setting in New Jersey to better understand the reciprocal learning that occurs between the mentor and novice teacher. The study addressed the relationship with a focus on learning for both the mentor and the novice teacher through the lens of mentoring. This study employed a qualitative research methodology of intrinsic single-case study and narrative inquiry. The data sources included individual and pair interviews and recorded conversations between the pair as well as instructional and curricular resources as artifacts generated by the pair. To answer the research questions, the data were analyzed using open coding and constant comparative method. The findings uncovered the role of the individual participants in the mentoring and induction experience. Both teachers recognized the challenges faced resulting from the COVID-19 pandemic. The two teachers faced these challenges using their shared experiences and approaches, those around the mentoring relationship to support the induction process, the alignment of their schedules, the way they used their time together, the curricular work they produced together, and how they each approached their work and the relationship. The findings inform possible implications for middle school mentor novice pairs, which include: the physical closeness in the building of the pair’s working relationship, the organization of the spaces used by the teachers, teaching the same grade level and subject, having the same free periods in the schedule, and the reciprocal learning through the co-construction of work
\u3cem\u3eGrasshoppers, Ants, and Philosophical Fables\u3c/em\u3e
Get PDFAesop contrasted the ant’s virtues of industry, forward planning, and group loyalty with the idleness of a cicada interested only in merry-making and music-making. That contrast is challenged in many picture book versions of his fable. What does it mean to work? What is the value of making music and art? Can finding delight in an occupation be as important as denying gratification? When is it right to refuse help to someone who asks for it? This review compares six picture books—Ant and Grasshopper by Luli Gray (2011), The Ant and the Grasshopper by Amy Lowry Poole (2000), The Ants and the Grasshopper by Rebecca Emberley (2012), The Grasshopper & the Ants by Jerry Pinkney (2015), The Grasshopper\u27s Song: An Aesop’s Fable Revisited by Nikki Giovanni (2008), and Who’s Got Game? The Ant or the Grasshopper? by Toni & Slade Morrison (2003)—that, together, turn Aesop’s fable into a philosophical quest.https://digitalcommons.montclair.edu/iapc_thinkingstories_picturebooks/1014/thumbnail.jp