Towards a unified theory of intensional logic programming

AbstractIntensional Logic Programming is a new form of logic programming based on intensional logic and possible worlds semantics. Intensional logic allows us to use logic programming to specify nonterminating computations and to capture the dynamic aspects of certain problems in a natural and problem-oriented style. The meanings of formulas of an intensional first-order language are given according to intensional interpretations and to elements of a set of possible worlds. Neighborhood semantics is employed as an abstract formulation of the denotations of intensional operators. Then we investigate general properties of intensional operators such as universality, monotonicity, finitariness and conjunctivity. These properties are used as constraints on intensional logic programming systems. The model-theoretic and fixpoint semantics of intensional logic programs are developed in terms of least (minimum) intensional Herbrand models. We show in particular that our results apply to a number of intensional logic programming languages such as Chronolog proposed by Wadge and Templog by Abadi and Manna. We consider some elementary extensions to the theory and show that intensional logic program clauses can be used to define new intensional operators. Intensional logic programs with intensional operator definitions are regarded as metatheories

Emotional Dimensions of Teaching in Elementary Education Preparation

Student teaching is a pivotal event in teacher education preparation programs, and there is a need to investigate emotions in teaching. This study examined how one elementary program navigated the emotional dimensions of teaching. Findings revealed that the emotional dimensions of student teachers were influenced by individualized factors unique to the teacher; certain emotions were perceived as more acceptable to express; and supervisors needed to support student teachers to manage and respond to the emotional dimensions of teaching. The recommendation is to go beyond the technical and academic aspects of teaching and address the emotional dimensions to best prepare the whole teacher

Emotional Dimensions of Teaching in Elementary Education Preparation

Student teaching is a pivotal event in teacher education preparation programs, and there is a need to investigate emotions in teaching. This study examined how one elementary program navigated the emotional dimensions of teaching. Findings revealed that the emotional dimensions of student teachers were influenced by individualized factors unique to the teacher; certain emotions were perceived as more acceptable to express; and supervisors needed to support student teachers to manage and respond to the emotional dimensions of teaching. The recommendation is to go beyond the technical and academic aspects of teaching and address the emotional dimensions to best prepare the whole teacher

Oncogenic R132 IDH1 Mutations Limit NADPH for De Novo Lipogenesis through (D)2-Hydroxyglutarate Production in Fibrosarcoma Sells.

Neomorphic mutations in NADP-dependent isocitrate dehydrogenases (IDH1 and IDH2) contribute to tumorigenesis in several cancers. Although significant research has focused on the hypermethylation phenotypes associated with (D)2-hydroxyglutarate (D2HG) accumulation, the metabolic consequences of these mutations may also provide therapeutic opportunities. Here we apply flux-based approaches to genetically engineered cell lines with an endogenous IDH1 mutation to examine the metabolic impacts of increased D2HG production and altered IDH flux as a function of IDH1 mutation or expression. D2HG synthesis in IDH1-mutant cells consumes NADPH at rates similar to de novo lipogenesis. IDH1-mutant cells exhibit increased dependence on exogenous lipid sources for in vitro growth, as removal of medium lipids slows growth more dramatically in IDH1-mutant cells compared with those expressing wild-type or enzymatically inactive alleles. NADPH regeneration may be limiting for lipogenesis and potentially redox homeostasis in IDH1-mutant cells, highlighting critical links between cellular biosynthesis and redox metabolism

School Leadership Support: Understanding the Experiences of Elementary-Level Teachers During a Global Health Pandemic

The purpose of this study was to better understand how the current COVID-19 global health pandemic has professionally and emotionally impacted elementary-level teachers. Teachers experienced diverse challenges during this unprecedented time with a rapid shift from in-person to online learning. Two overarching themes emerged based on participant experiences: abandoning best practices and increased stress and emotional pain. Implications for practice included the need for school leaders to evaluate the current level of support being provided to teachers and assess areas of need to support professional and emotional growth with the backdrop of the pandemic. We encourage future research with all educators to better understand how they are experiencing this health pandemic including the school leaders themselves

Hormonal Signal Amplification Mediates Environmental Conditions during Development and Controls an Irreversible Commitment to Adulthood

Many animals can choose between different developmental fates to maximize fitness. Despite the complexity of environmental cues and life history, different developmental fates are executed in a robust fashion. The nematode Caenorhabditis elegans serves as a powerful model to examine this phenomenon because it can adopt one of two developmental fates (adulthood or diapause) depending on environmental conditions. The steroid hormone dafachronic acid (DA) directs development to adulthood by regulating the transcriptional activity of the nuclear hormone receptor DAF-12. The known role of DA suggests that it may be the molecular mediator of environmental condition effects on the developmental fate decision, although the mechanism is yet unknown. We used a combination of physiological and molecular biology techniques to demonstrate that commitment to reproductive adult development occurs when DA levels, produced in the neuroendocrine XXX cells, exceed a threshold. Furthermore, imaging and cell ablation experiments demonstrate that the XXX cells act as a source of DA, which, upon commitment to adult development, is amplified and propagated in the epidermis in a DAF-12 dependent manner. This positive feedback loop increases DA levels and drives adult programs in the gonad and epidermis, thus conferring the irreversibility of the decision. We show that the positive feedback loop canalizes development by ensuring that sufficient amounts of DA are dispersed throughout the body and serves as a robust fate-locking mechanism to enforce an organism-wide binary decision, despite noisy and complex environmental cues. These mechanisms are not only relevant to C. elegans but may be extended to other hormonal-based decision-making mechanisms in insects and mammals

Imprints, Vol. 3

Imprints, Vol. 3 Laura Lundgren, Stephen F Austin State UniversitySandra L. Standley, Stephen F Austin State UniversityMelissa Miller, Stephen F Austin State UniversityCurtis Simmons, Stephen F Austin State UniversityVaughn Hamilton, Stephen F Austin State UniversitySteve Geissen, Stephen F Austin State UniversityEdward Shelton, Stephen F Austin State UniversityJames L. Choron, Stephen F Austin State UniversityAnderson Kelley, Stephen F Austin State UniversityAndrew J. Urbanus, Stephen F Austin State UniversityGordon Garrett Conner, Stephen F Austin State UniversityJames Chionsini Jr., Stephen F Austin State UniversityPaul M. Thomason, Stephen F Austin State UniversityCarol McBrayerJessica Anton, Stephen F Austin State University Download Download Full Text (5.7 MB) Description Imprints is the official publication for Sigma Tau Delta, the honorary English fraternity. The editors welcome creative works submitted by contributors and also publish winners of the annual T. E. Ferguson Writing Contest. Especially welcom are poems, fiction pieces and essays of no more than 5,000 words in length. At this time, we would like to express our gratitude to David Whitescarver, Sigma Tau Delta faculty advisor, for his unrelenting optimism and valuable help in the preparation of this journal