Electronic structure and magnetism in two-dimensional hexagonal 5d transition metal carbides, Tan+1Cn (n=1,2,3)

Density functional calculations are used to investigate the electronic structure of two-dimensional 5d tantalum carbides with honeycomb-like lattice structures. We focus on changes in the low-energy bands near the Fermi level with dimensionality. We find that the Ta 5d states dominate, but the extended nature of the wavefunctions makes them weakly correlated. The carbide sheets are prone to long range magnetic order. We evaluate the stability of these states to enhanced electron--electron interactions through a Hubbard U correction. Lastly, we find spin orbit interactions strongly renormalize the band structure for n=2, but play a minor role in n=1 and 3.Comment: 4 pages, 4 figure

Calibration of Computational Models with Categorical Parameters and Correlated Outputs via Bayesian Smoothing Spline ANOVA

It has become commonplace to use complex computer models to predict outcomes in regions where data does not exist. Typically these models need to be calibrated and validated using some experimental data, which often consists of multiple correlated outcomes. In addition, some of the model parameters may be categorical in nature, such as a pointer variable to alternate models (or submodels) for some of the physics of the system. Here we present a general approach for calibration in such situations where an emulator of the computationally demanding models and a discrepancy term from the model to reality are represented within a Bayesian Smoothing Spline (BSS) ANOVA framework. The BSS-ANOVA framework has several advantages over the traditional Gaussian Process, including ease of handling categorical inputs and correlated outputs, and improved computational efficiency. Finally this framework is then applied to the problem that motivated its design; a calibration of a computational fluid dynamics model of a bubbling fluidized which is used as an absorber in a CO2 capture system

Otx but Not Mitf Transcription Factors Are Required for Zebrafish Retinal Pigment Epithelium Development

Otx and Mitf transcription factors have been implicated in the development of the retinal pigmented epithelium (RPE), but the relationship between these factors and their specific roles in the development of the RPE have not been fully defined. The role of the three Otx transcription factors (Otx1a, Otx1b, and Otx2) and two Mitf transcription factors (Mitfa and Mitfb) in the development of the zebrafish RPE was explored in these experiments. The loss of Otx activity through morpholino knockdown produced variable eye defects, ranging from delayed RPE pigmentation to severe coloboma, depending on the combination of Otx factors that were targeted. Expression analysis through in situ hybridization demonstrates that otxtranscription factors are necessary for the proper expression of mitfa and mitfb while Mitf transcription factors are not required for the expression of otx genes. Surprisingly, the loss of Mitf activity in mitfa, mitfb, or double mitf mutant zebrafish had no effect on RPE pigmentation or development. Moreover, histological analysis revealed that retinal lamination is unaffected inmitf mutants, as well as in otx morphants, even in regions lacking RPE. Otx and Mitf combined loss of function experiments suggest that mitfa and mitfb may still influence zebrafish RPE development. This is further supported by the ability of mitfa to induce pigmentation in the zebrafish retina when misexpressed. These findings suggest that one or more Otx targets in addition to mitfa and mitfb, possibly another mitf family member, are necessary for development of the RPE in zebrafish

Carbon-13 in groundwater from English and Norwegian crystalline rock aquifers: a tool for deducing the origin of alkalinity?

The 13C signature is evaluated for various environmental compartments (vegetation, soils, soil gas, rock and groundwater) for three crystalline rock terrains in England and Norway. The data are used to evaluate the extent to which stable carbon isotopic data can be applied to deduce whether the alkalinity in crystalline bedrock groundwaters has its origin in hydrolysis of carbonate or silicate minerals by CO2. The resolution of this issue has profound implications for the role of weathering of crystalline rocks as a global sink for CO2. In the investigated English terrain (Isles of Scilly), groundwaters are hydrochemically immature and DIC is predominantly in the form of carbonic acid with a soil gas signature. In the Norwegian terrains, the evidence is not conclusive but is consistent with a significant fraction of the groundwater DIC being derived from silicate hydrolysis by CO2. A combined consideration of pH, alkalinity and carbon isotope data, plotted alongside theoretical evolutionary pathways on bivariate diagrams, strongly suggests real evolutionary pathways are likely to be hybrid, potentially involving both open and closed CO2 conditions

Exploring Intersections of Race, Gender, Culture, and Power: Collaborative Autoethnography, Freire, and Model for Reform

In a time when the Critical Race Theory is being used as a weapon to eliminate educational learning by ratifying American history at a proliferated rate, this study illustrates the individual experiences of racial inequity across race, gender, culture, and power. This collaborative autoethnography is informed by the Critical Race Theory and Freire’s Pedagogy of the Oppressed. Crenshaw observes about criticism of CRT, “It’s not about a theory. … It’s about an effort to shut down all conversation about the sources and the reproduction of racial inequality” (2021, p. 7). Defending the application of CRT in American classrooms is beyond the scope of this study. This study illustrates that promotion of equality through having honest conversations about inequality

Higher-dimensional Algebra and Topological Quantum Field Theory

The study of topological quantum field theories increasingly relies upon concepts from higher-dimensional algebra such as n-categories and n-vector spaces. We review progress towards a definition of n-category suited for this purpose, and outline a program in which n-dimensional TQFTs are to be described as n-category representations. First we describe a "suspension" operation on n-categories, and hypothesize that the k-fold suspension of a weak n-category stabilizes for k >= n+2. We give evidence for this hypothesis and describe its relation to stable homotopy theory. We then propose a description of n-dimensional unitary extended TQFTs as weak n-functors from the "free stable weak n-category with duals on one object" to the n-category of "n-Hilbert spaces". We conclude by describing n-categorical generalizations of deformation quantization and the quantum double construction.Comment: 36 pages, LaTeX; this version includes all 36 figure

Health-related quality of life measurement in pediatric clinical practice: An appraisal and precept for future research and application

Health-related quality of life (HRQOL) measurement has emerged as an important health outcome in clinical trials, clinical practice improvement strategies, and healthcare services research and evaluation. HRQOL measures are also increasingly proposed for use in clinical practice settings to inform treatment decisions. In settings where HRQOL measures have been utilized with adults, physicians report such measures as useful, some physicians alter their treatment based on patient reports on such instruments, and patients themselves generally feel the instruments to be helpful. However, there is a dearth of studies evaluating the clinical utility of HRQOL measurement in pediatric clinical practice. This paper provides an updated review of the literature and proposes a precept governing the application of pediatric HRQOL measurement in pediatric clinical practice. Utilizing HRQOL measurement in pediatric healthcare settings can facilitate patient-physician communication, improve patient/parent satisfaction, identify hidden morbidities, and assist in clinical decision-making. Demonstrating the utility of pediatric HRQOL measurement in identifying children with the greatest needs, while simultaneously demonstrating the cost advantages of providing timely, targeted interventions to address those needs, may ultimately provide the driving force for incorporating HRQOL measurement in pediatric clinical practice

Purple Medicine

In response to a broad set of complex national security challenges of the twenty-first century, the Quadrennial Defense Review (QDR) report of Febru- ary 2006 advised that all the organizations, processes, and practices within the Department of Defense be given a high degree of agility, flexibility, responsive- ness, and ultimately effectiveness in supporting the joint war fighter and future national defense goals