Weber State University

We determine the composition dependence of the below-bandgap anisotropic refractive indices and dielectric functions of β-(AlxGa1−x)2O3 for x up to 25% Al. We use Mueller matrix generalized spectroscopic ellipsometry and investigate a set of high quality single crystalline bulk (x=0%,5%,10%,15%,20%,25%) and thin film (4.6%, 9.7%, 12%, 15%, 16.3%, 21%) samples grown by the Czochralski method and by plasma-assisted molecular beam epitaxy, respectively. Bulk samples with 0.2% silicon doping are cut from ingots with (100) surface and the unintentionally doped thin films samples are grown pseudomorphically on (010) β-Ga2O3. The combination of ellipsometry data from both sample sets permits to fully determine the optical properties of the transparent alloys. We employ a quasi-orthorhombic approach which ignores the very small shear components induced by the monoclinic crystal structure. We also ignore the possibly small effects due to strain within the pseudomorphically grown epitaxial samples. We report indices and dielectric functions for polarization along lattice vectors a, b, and reciprocal lattice vector c⋆. All indices reduce with increasing incorporation of aluminum while the spectral range of transparency increases due to the increase in bandgap energy with composition. We use our results to predict Bragg reflector multilayer structures on b-plane β-(Al0.20Ga0.80)2O3, for use in polarization sensitive narrow-band optical filters in the short wavelength region.

The World Health Organization recognizes that approximately half of all maternal deaths occur in the immediate postnatal period or 24h after birth. Forty-seven percent of Lao women aged 15-49 who delivered a baby in the last two years received a postnatal health check in the first two days after delivery. After leaving the presence of a provider, 98.5% of these women never received another postnatal check. The maternal mortality ratio (MMR) in Lao PDR was 126 deaths per 100,000 live births in 2020. Immediate postnatal care (PNC) is a crucial step to improving maternal mortality. The aim of this study was to identify factors associated with the lack of PNC, which is necessary for developing targeted interventions. A secondary data analysis of the Lao PDR MICS 2017 women and household data sets was completed to identify factors associated with immediate PNC. The selection of variables draws from The Behavioral Model of Health Services Use for the predisposing, enabling, and need factors. Participants included women between the ages of 15-49 who had a live birth two years before the study. The weighted sample included 4,231 participants; 2,234 (52.8%) did not receive immediate PNC, while 1,996 (47.2%) did receive immediate postnatal care. The Rao-Scott likelihood ratio chi-square identified differences in factors associated with women receiving immediate PNC. Univariate and multivariate analyses identified factors associated with immediate PNC utilization. Among the predisposing, enabling, and need factors, ethnicity, religion, literacy, region, media exposure, wealth, parity, delivery location, delivery assistant, and maternal-infant skin-to-skin were associated with PNC utilization. This study suggests that selective interventions need to be developed to improve immediate postnatal care and reduce maternal mortality and morbidity in Lao PDR, providing a foundation for targeted intervention.

Purpose Public companies with required reporting deadlines subject auditors to a compressed timeframe in which to obtain sufficient evidence to form their opinion on the financial statements. Psychology theory posits that individuals adjust their actions to avoid the penalties associated with missing deadlines. The purpose of this study is to examine the association between deadline-imposed time pressure and audit quality. Design/methodology/approach The authors measure deadline-imposed time pressure as the proximity of the auditor’s report date to the required filing deadline. The authors use different measures of audit quality – restatements and receipt of a Generally Accepted Accounting Principles or disclosure-related Securities and Exchange Commission comment letter related to a company’s Form 10-K. Findings The authors find consistent evidence of lower audit quality when the audit report date is near, at or slightly beyond the original (or extended) required filing deadline relative to companies with an audit report date preceding the required filing deadline by more than a week. In addition, although Big N auditors are able to moderate the negative effects of deadline-imposed time pressure when the audit report date is near the filing deadline (or beyond the extended deadline), these negative effects persist when completing procedures on the required filing deadline or during the extension period. Research limitations/implications The findings suggest that auditors completing procedures at or near the required filing deadline (or extended deadline) may compromise audit quality in an effort to help the client meet the reporting requirement. Originality/value The findings also highlight an opportunity for standard setters to require audit report dating information that could aid financial statement users in identifying auditors under heightened deadline-imposed time pressure.

With the advent of the Google Colab, a free, online Jupyter notebook environment, it is now possible for anyone with internet access to use Jupyter notebooks to program in Python without installing any software. In the POGIL-PCL project, Jupyter notebooks have been developed to teach basic notebook use and coding, to analyze data with linear and nonlinear optimization, and to exploit the symbolic math capabilities. A 3-session workshop for instructors to learn Jupyter and its use in teaching Physical Chemistry was developed and run during Spring 2024. In general, the workshop was well-received and sparked discussions about pedagogical uses of programming in chemistry. We will discuss best practices for notebooks in the guided inquiry environment for four main areas: reading code, data analysis and nonlinear optimization, symbolic math manipulation, and writing code.

Abstract Lithospermum (Boraginaceae) is a cosmopolitan genus of ca. 80 species native to both the Old and New Worlds. The genus has been the subject of multiple phylogenetic studies during the past 20 years, with different evolutionary relationships recovered depending on the taxon-locus combinations. Using whole plastomes and nuclear ribosomal cistrons, the phylogenetics, biogeographic patterns, and plastome selection of Lithospermum and its relatives were examined. Lithospermum is here resolved as non-monophyletic, with Ulugbekia tschimganica forming the sister group to L. hancockianum . Therefore, an expanded circumscription of Lithospermum is tentatively proposed, which aligns with other, prior studies. Based on multiple phylogenetic methods, evolutionary relationships inferred by the plastid genome are incongruent with those from the nuclear ribosomal cistron as well as prior analyses based on other nuclear DNA loci. This incongruence is likely due to incomplete lineage sorting within the nuclear genome and between nuclear and plastid markers during early diversification of the genus in the New World. Lithospermum is resolved to have originated in the Old World, with independent dispersal events to southern Africa and to North America, and a subsequent a long-distance dispersal event to the northern Andes mountain range in South America. Only six genes of the plastid genome are under positive selection, and based on prior studies, these are similar to those across Lithospermeae but differ from those among other tribes in the family.