The Massachusetts and Utah Health Insurance Exchanges: Lessons Learned

Examines the quality and choice of plans, affordability, and ease of enrollment in existing state-run exchanges. Outlines lessons learned, including the need for ongoing refinement, consideration of broader market interactions, and public outreach

Can Musicians Tell Sharp From Flat?

A musician’s awareness of intonation (i.e. “being in tune”) is an important skill. While musicians are highly sensitive to “out of tune” notes, research suggests that this sensitivity is categorical rather than absolute (Siegel & Siegel, 1977). If intonation is heard “categorically,” musicians’ classification of intonation errors (both magnitude and direction), would be expected to be poor. This experiment was designed to determine whether or not musicians could categorically perceive mistuned musical intervals, as well as to investigate the relative limits of absolute intonation perception. Ten undergraduate music students were tested on their ability to identify intonation errors within an 3AFC paradigm. The results found that while participants were able to identify mistuned intervals, they struggled to correctly identify the directionality of these intonation errors. The results are consistent with the hypothesis that musicians perceive intonation “categorically,” and more specifically, that they struggle to hear the difference between sharp and flat intervals

Identification of three new proto-Planetary Nebulae exhibiting the unidentified feature at 21 um

Among its great findings, the IRAS mission showed the existence of an unidentified mid-IR feature around 21 um. Since its discovery, this feature has been detected in all C-rich proto-PNe of intermediate spectral type (A-G) and - weakly - in a few PNe and AGB stars, but the nature of its carriers remains unknown. In this paper, we show the detection of this feature in the spectra of three new stars transiting from the AGB to the PN stage obtained with the Spitzer Space Telescope. Following a recent suggestion, we try to model the SEDs of our targets with amorphous carbon and FeO, which might be responsible for the unidentified feature. The fit thus obtained is not completely satisfactory, since the shape of the feature is not well matched. In the attempt to relate the unidentified feature to other dust features, we retrieved mid-IR spectra of all the 21-um sources currently known from ISO and Spitzer on-line archives and noticed a correlation between the flux emitted in the 21-um feature and that emitted at 7 and 11 um (PAH bands and HAC broad emission). Such a correlation may point to a common nature of the carriers.Comment: Accepted for publication in Ap

Characterization of the visit-to-visit Stability of the GR700XD Wavelength Calibration for NIRISS/SOSS Observations

When utilizing the NIRISS/SOSS mode on JWST, the pupil wheel (tasked with orienting the GR700XD grism into the optical path) does not consistently settle into its commanded position resulting in a minor misalignment with deviations of a few fractions of a degree. These small offsets subsequently introduce noticeable changes in the trace positions of the NIRISS SOSS spectral orders between visits. This inconsistency, in turn, can lead to variations of the wavelength solution. In this report, we present the visit-to-visit characterization of the NIRISS GR700XD Wavelength Calibration for spectral orders 1 and 2. Employing data from Calibration Program 1512 (PI: Espinoza), which intentionally and randomly sampled assorted pupil wheel positions during observations of the A-star BD+60-1753, as well as data from preceding commissioning and calibration activities to model this effect, we demonstrate that the wavelength solution can fluctuate in a predictable fashion between visits by up to a few pixels. We show that via two independent polynomial regression models for spectral orders 1 and 2, respectively, using the measured x-pixel positions of known Hydrogen absorption features in the A-star spectra and pupil wheel positions as regressors, we can accurately predict the wavelength solution for a particular visit with an RMS error within a few tenths of a pixel. We incorporate these models in PASTASOSS, a Python package for predicting the GR700XD spectral traces, which now allows to accurately predict spectral trace positions and their associated wavelengths for any NIRISS/SOSS observation.Comment: 12 pages, package to predict wavelength solution for NIRISS/SOSS: https://github.com/spacetelescope/pastasos

Characterization of the visit-to-visit Stability of the GR700XD Spectral Traces for NIRISS/SOSS Observations

In this report, we present the results of our analysis of trace position changes during NIRISS/SOSS observations. We examine the visit-to-visit impact of the GR700XD pupil wheel (PW) position alignment on trace positions for spectral orders 1 and 2 using the data obtained to date. Our goal is to improve the wavelength solution by correlating the trace positions on the detector with the PW position angle. We find that there is a one-to-one correspondence between PW position and spectral trace rotation for both orders. This allowed us in turn to find an analytic model that is able to predict a trace position/shape as a function of PW position with sub-pixel accuracy of about ~0.1 pixels. Such a function can be used to predict the trace position in low signal-to-noise ratio cases, and/or as a template to track trace position changes as function of time in Time Series Observations (TSOs).Comment: 9 pages, package to predict spectral traces for NIRISS/SOSS: https://github.com/spacetelescope/pastasos

Centering the Marginalized: The Impact of the Pandemic on Online Student Retention

During the pandemic, much of the focus of administrators and scholars has been on its impact on residential students and the sudden shift to online instruction. While justified, researchers have yet to focus on online students—who often represent marginalized communities in higher education—to ask whether they were impacted by factors related to the pandemic other than the modality shift. In this study, we examined how the first-year retention of online students was affected during the pandemic, and whether it differed from first-year residential students who transitioned online. We examined records of two student cohorts (Fall 2017 and Fall 2019) from a university to determine each cohort’s retention rate by modality. Holding other relevant factors constant, we found the COVID cohort of students were less likely to persist to the following Fall regardless of modality, although residential students were still much more likely to be retained overall. However, Black and Hispanic students were less likely to be retained across both modalities, and even Black residential students were more vulnerable to not returning than their White counterparts, suggesting that racial inequalities persist across learning modalities. We conclude by suggesting how one retention tool—financial aid—could be used to address the particular needs of online students to improve their retention

Genomic Structure and Chromosomal Location of the Rat Gene Encoding the Zinc Finger Transcription Factor Kid-1

We have previously cloned and sequenced a novel zinc finger cDNA, Kid-1 , from the rat. Because of its developmentally regulated expression pattern and its suppression after renal injury, as well as its kindey-predominant expression, we propose that Kid-1 is likely to play an important role in renal gene regulation. Kid-1 encodes a predicted protein with 13 zinc fingers at the carboxy end and Krüppel-associated box (KRAB) A and B regions at the amino terminus. Expression of a Kid-1-GAL4 chimeric protein results in strong transcriptional repression of cotransfected constructs containing GAL4 binding sites and a chloramphenicol acetyl transferase gene driven by either a minimal promoter or a SV40 enhancer. We now report the cloning, structural organization, and chromosomal localization of the Kid-1 gene. The Kid-1 gene is composed of four exons and three introns, closely reflecting the organization of the Kid-1 protein. The KRAB A and B regions are encoded by the second and third exons, respectively. The entire zinc finger region is encoded by the fourth exon. Using a combination of linkage analysis and somatic cell hybrid analysis, Kid-1was mapped to rat chromosome (RNO) 10. Kid-1, Il3, and Sparc form a tight linkage group on RNO10. Regional sublocalization to RNO10q21.3-q22 was established by fluorescence in situ hybridization.