First radial velocity results from the MINiature Exoplanet Radial Velocity Array (MINERVA)

The MINiature Exoplanet Radial Velocity Array (MINERVA) is a dedicated observatory of four 0.7m robotic telescopes fiber-fed to a KiwiSpec spectrograph. The MINERVA mission is to discover super-Earths in the habitable zones of nearby stars. This can be accomplished with MINERVA's unique combination of high precision and high cadence over long time periods. In this work, we detail changes to the MINERVA facility that have occurred since our previous paper. We then describe MINERVA's robotic control software, the process by which we perform 1D spectral extraction, and our forward modeling Doppler pipeline. In the process of improving our forward modeling procedure, we found that our spectrograph's intrinsic instrumental profile is stable for at least nine months. Because of that, we characterized our instrumental profile with a time-independent, cubic spline function based on the profile in the cross dispersion direction, with which we achieved a radial velocity precision similar to using a conventional "sum-of-Gaussians" instrumental profile: 1.8 m s$^{-1}$ over 1.5 months on the RV standard star HD 122064. Therefore, we conclude that the instrumental profile need not be perfectly accurate as long as it is stable. In addition, we observed 51 Peg and our results are consistent with the literature, confirming our spectrograph and Doppler pipeline are producing accurate and precise radial velocities.Comment: 22 pages, 9 figures, submitted to PASP, Peer-Reviewed and Accepte

Multireader evaluation of radiologist performance for COVID-19 detection on emergency department chest radiographs

This article is made available for unrestricted research re-use and secondary analysis in any form or be any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.BACKGROUND: Chest radiographs (CXR) are frequently used as a screening tool for patients with suspected COVID-19 infection pending reverse transcriptase polymerase chain reaction (RT-PCR) results, despite recommendations against this. We evaluated radiologist performance for COVID-19 diagnosis on CXR at the time of patient presentation in the Emergency Department (ED). MATERIALS AND METHODS: We extracted RT-PCR results, clinical history, and CXRs of all patients from a single institution between March and June 2020. 984 RT-PCR positive and 1043 RT-PCR negative radiographs were reviewed by 10 emergency radiologists from 4 academic centers. 100 cases were read by all radiologists and 1927 cases by 2 radiologists. Each radiologist chose the single best label per case: Normal, COVID-19, Other - Infectious, Other - Noninfectious, Non-diagnostic, and Endotracheal Tube. Cases labeled with endotracheal tube (246) or non-diagnostic (54) were excluded. Remaining cases were analyzed for label distribution, clinical history, and inter-reader agreement. RESULTS: 1727 radiographs (732 RT-PCR positive, 995 RT-PCR negative) were included from 1594 patients (51.2% male, 48.8% female, age 59 ± 19 years). For 89 cases read by all readers, there was poor agreement for RT-PCR positive (Fleiss Score 0.36) and negative (Fleiss Score 0.46) exams. Agreement between two readers on 1638 cases was 54.2% (373/688) for RT-PCR positive cases and 71.4% (679/950) for negative cases. Agreement was highest for RT-PCR negative cases labeled as Normal (50.4%, n = 479). Reader performance did not improve with clinical history or time between CXR and RT-PCR result. CONCLUSION: At the time of presentation to the emergency department, emergency radiologist performance is non-specific for diagnosing COVID-19

The Implementation of Maryland's Bridge Plan for Academic Validation Policy in Anne Arundel County Public Schools

Maintaining the integrity and value of a high school diploma has been a fundamental reason for the establishment of state graduation requirements. The No Child Left Behind (NCLB) Act of 2001 heightened the need for standards-based accountability programs within states. Once annual measurable objectives have been set by the state, it is the responsibility of individual schools and districts to make sure students meet these standards. To ensure uniformity in student assessment, most states design and require standardized tests as the indicator of adequate student progress. A problem accompanying this high-stakes testing approach is the large number of students that are unable to pass the assessments. In response to this reality, some school districts and states have designed alternative pathways to graduation. In Maryland, one of these pathways is called the Bridge Plan for Academic Validation - a performance-based assessment for students to demonstrate their knowledge in English 10, Algebra 1 and Biology. The implementation of this program varies across school districts and even schools within the same district. Through interviews with 4 school district leaders, this study examined the origin and the implementation of the Bridge program in Anne Arundel County Public Schools (AACPS). A survey instrument administered to 334 teachers at 11 comprehensive high schools in the AACPS system measured perceptions about the impact of the Bridge program on both their teaching practices and student attitudes. Follow-up interviews were conducted with 36 school-based personnel to confirm and explore survey results in greater depth. Using a theoretical framework of public policy implementation, this study describes both the agreement and disagreement among the perceptions of district leaders and school-based employees. Major themes arising from this analysis include the appropriateness of Bridge as an alternative to the HSA, the support provided to schools for the implementation of Bridge, and the variability of implementation in schools across the district. The findings of this study should inform policymakers of the practical impacts of implementing the Bridge Program for Academic Validation. It is important to examine both the intended and unintended consequences of this policy as future alternatives to standardized testing are considered in Maryland

The Implementation of Maryland's Bridge Plan for Academic Validation Policy in Anne Arundel County Public Schools

Maintaining the integrity and value of a high school diploma has been a fundamental reason for the establishment of state graduation requirements. The No Child Left Behind (NCLB) Act of 2001 heightened the need for standards-based accountability programs within states. Once annual measurable objectives have been set by the state, it is the responsibility of individual schools and districts to make sure students meet these standards. To ensure uniformity in student assessment, most states design and require standardized tests as the indicator of adequate student progress. A problem accompanying this high-stakes testing approach is the large number of students that are unable to pass the assessments. In response to this reality, some school districts and states have designed alternative pathways to graduation. In Maryland, one of these pathways is called the Bridge Plan for Academic Validation - a performance-based assessment for students to demonstrate their knowledge in English 10, Algebra 1 and Biology. The implementation of this program varies across school districts and even schools within the same district. Through interviews with 4 school district leaders, this study examined the origin and the implementation of the Bridge program in Anne Arundel County Public Schools (AACPS). A survey instrument administered to 334 teachers at 11 comprehensive high schools in the AACPS system measured perceptions about the impact of the Bridge program on both their teaching practices and student attitudes. Follow-up interviews were conducted with 36 school-based personnel to confirm and explore survey results in greater depth. Using a theoretical framework of public policy implementation, this study describes both the agreement and disagreement among the perceptions of district leaders and school-based employees. Major themes arising from this analysis include the appropriateness of Bridge as an alternative to the HSA, the support provided to schools for the implementation of Bridge, and the variability of implementation in schools across the district. The findings of this study should inform policymakers of the practical impacts of implementing the Bridge Program for Academic Validation. It is important to examine both the intended and unintended consequences of this policy as future alternatives to standardized testing are considered in Maryland

Understanding the 1,3-Dipolar Cycloadditions of Allenes

Contains fulltext : 225091.pdf (publisher's version ) (Open Access

Understanding the 1,3‐Dipolar Cycloadditions of Allenes

Contains fulltext : 225091.pdf (publisher's version ) (Open Access

Improving the production and evaluation of structural models using a Delphi process

Bayes Nets (BNs) are extremely useful for causal and probabilistic modelling in many real-world applications, often built with information elicited from groups of domain experts. But their potential for reasoning and decision support has been limited by two major factors: the need for significant normative knowledge, and the lack of any validated methods or software supporting collaboration. Consequently, we have developed a web-based structured technique – Bayesian Argumentation via Delphi (BARD) – to enable groups of domain experts to receive minimal normative training and then collaborate effectively to produce high-quality BNs. BARD harnesses multiple perspectives on a problem, while minimising biases manifest in freely interacting groups, via a Delphi process: solutions are first produced individually, then shared, followed by an opportunity for individuals to revise their solutions. To test the hypothesis that BNs improve due to Delphi, we conducted an experiment whereby individuals with a little BN training and practice produced structural models using BARD for two Bayesian reasoning problems. Participants then received 6 other structural models for each problem, rated their quality on a 7-point scale, and revised their own models if they wished. Both top-rated and revised models were on average significantly better quality (scored against a gold-standard) than the initial models, with large and medium effect sizes. We conclude that Delphi – and BARD – improves the quality of BNs produced by groups. Further, although rating cannot create new models, rating seems quicker and easier than revision and yielded significantly better models – so, we suggest efficient BN amalgamation should include both