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Elementary and secondary district leaders seeking to recruit teachers and diversify their teaching workforce will find useful, research-based strategies in this brief from the Region 4 Comprehensive Center. The brief focuses on ways to develop work-based learning programs in secondary schools that engage students in considering teacher careers. Drawing on insights from 14 programs, this brief summarizes five useful strategies of teacher-focused work-based learning programs, including targeted courses, cohort model and peer supports, strategic counseling, dual enrollment, and field experiences. It also provides helpful background into the historic challenges around recruiting and retaining teachers of color.

Background: Type I X-Ray bursts (XRBs) are energetic stellar explosions that occur on the surface of a neutron star in an accreting binary system with a low-mass H/He-rich companion. The rate of the $^{34}$Ar($\alpha,p$)$^{37}$K reaction may influence features of the light curve that results from the underlying thermonuclear runaway, as shown in recent XRB stellar modelling studies. Purpose: In order to reduce the uncertainty of the rate of this reaction, properties of resonances in the compound nucleus $^{38}$Ca, such as resonance energies, spins, and particle widths, must be well constrained. Method: This work discusses a study of resonances in the $^{38}$Ca compound nucleus produced in the $^{34}$Ar($\alpha,p$) reaction. The experiment was performed at the National Superconducting Cyclotron Laboratory, with the ReA3 facility by measuring proton scattering using an unstable $^{37}$K beam. The kinematics were designed specifically to identify and characterize resonances in the Gamow energy window for the temperature regime relevant to XRBs. Results: The spins and proton widths of newly identified and previously known states in $^{38}$Ca in the energy region of interest for the $^{34}$Ar($\alpha,p$)$^{37}$K reaction have been constrained through an R-Matrix analysis of the scattering data. Conclusions: Using these constraints, a newly estimated rate is applied to an XRB model built using Modules for Experiments in Stellar Astrophysics (MESA), to examine its impact on observables, including the light curve. It is found that the newly determined reaction rate does not substantially affect the features of the light curve.

School leadership is a critical factor in school improvement. The Delaware Department of Education (DDOE) and Region 4 Comprehensive Center (R4CC) have strengthened school leadership through implementation of the Delaware Leadership Network and the Delaware Principal Supervisor Leadership Program. These two major efforts, collaboratively designed and delivered, have helped shift mindsets from principals as managers to principals as instructional leaders. DDOE, with R4CC support, clarified a statewide strategy for strengthening school leadership and is building off these two initial efforts. Read about this collaborative effort and its outcomes in "Strengthening School Leadership in Delaware: A Profile of Collaboration and Impact."

We present high-cadence photometric and spectroscopic observations of SN~2023axu, a classical Type II supernova with an absolute $V$-band peak magnitude of $-16.5 \pm 0.1$ mag. SN~2023axu was discovered by the Distance Less Than 40 Mpc (DLT40) survey within 1 day of the last non-detection in the nearby galaxy NGC 2283 at 13.7 Mpc. We modeled the early light curve using a recently updated shock cooling model that includes the effects of line blanketing and found the explosion epoch to be MJD 59971.48 $\pm$ 0.03 and the probable progenitor to be a red supergiant with a radius of 417 $\pm$ 28 $R_\odot$. The shock cooling model cannot match the rise of observed data in the $r$ and $i$ bands and underpredicts the overall UV data which points to possible interaction with circumstellar material. This interpretation is further supported by spectral behavior. We see a ledge feature around 4600 \AA\ in the very early spectra (+1.1 and +1.5 days after the explosion) which can be a sign of circumstellar interaction. The signs of circumstellar material are further bolstered by the presence of absorption features blueward of H$\alpha$ and H$\beta$ at day $>$40 which is also generally attributed to circumstellar interaction. Our analysis shows the need for high-cadence early photometric and spectroscopic data to decipher the mass-loss history of the progenitor., Comment: 18 pages, 12 figures, to be submitted to the AAS Journals

To ensure that students are prepared for the workforce, part of Maryland State Department of Education's (MSDE) vision for career and technical education (CTE) is for all students to have access and opportunities to engage in CTE programs of study that align to occupations that are high-wage, high-skill, and/or in-demand (MSDE, 2020). MSDE's Division of Career and College Readiness has been reviewing the state's CTE program offerings to ensure their alignment with this vision. To support this effort, the Region 4 Comprehensive Center evaluated the alignment between Maryland's high school CTE program offerings and the labor market by examining the following research questions: (1) In each workforce region of Maryland, do occupations that are high-wage, high-skill, and in-demand have an aligned CTE program of study offered?; (2) In each workforce region of Maryland, do CTE programs of study offered align with occupations that are high-wage, high-skill, and/or in-demand?; and (3) For the unaligned CTE programs of study, do any of them align to high-wage, high-skill, and in-demand occupations in other workforce regions in Maryland?

This brief is the third of a four-part series that focuses on bilingual education, bilingual educators, and addressing the bilingual teacher shortage in contexts across the United States. This research was commissioned by the New Jersey State Department of Education, which is committed to providing quality bilingual education to its linguistically diverse student population. More than half of U.S. states are experiencing bilingual teacher shortages, with shortages most acute in states that provide bilingual education to the greatest numbers of English learners (ELs) and those that require teachers to obtain specific bilingual endorsements (for more information on the term "English learner," please refer to our previous brief, Bilingual Education Across the United States). These states experience a persistent tension between: (1) requiring educators to comply with certification requirements and (2) meeting the increasing demand for bilingual teachers, driven by the growing population of ELs and the increasing popularity of dual language programs. States have created various policy solutions to broaden their bilingual teacher pool by diversifying the ways in which teachers may gain certification. In this brief, we share strategies that state education agencies may use to provide more flexibility in teacher certification policies and thereby mitigate bilingual teacher shortages, including: (1) providing educators multiple pathways to certification; (2) offering prospective teachers a menu of certification requirements; (3) allowing educators to earn probationary certifications; and (4) creating flexible reciprocity policies.

This brief is the fourth of a four-part series that focuses on bilingual education, bilingual educators, and addressing the bilingual teacher shortage in contexts across the United States. This research was commissioned by the New Jersey State Department of Education, which is committed to providing quality bilingual education to its linguistically diverse student population. In this brief, we describe Washington state's approach to bilingual education and detail the ways in which state leaders have leveraged policy and funding to expand access to it. We also offer specific policy considerations for strengthening bilingual education and developing bilingual educators in states across the country.

This brief is the second of a four-part series that focuses on bilingual education, bilingual educators, and addressing the bilingual teacher shortage in contexts across the United States. This research was commissioned by the New Jersey State Department of Education, which is committed to providing quality bilingual education to its linguistically diverse student population. Many specialized subject areas face shortages of teachers who can fill positions, and bilingual education is no exception. More than half of states nationwide are experiencing bilingual teacher shortages, and the states with the most acute shortages are those that provide bilingual education to the greatest numbers of English learners. In this brief, we share strategies that can help mitigate bilingual teacher shortages and provide considerations for state and district leaders who are interested in addressing these shortages.

This brief is the first of a four-part series that focuses on bilingual education, bilingual educators, and addressing the bilingual teacher shortage in contexts across the United States. This research was commissioned by the New Jersey State Department of Education, which is committed to providing quality bilingual education to its linguistically diverse student population. Multilingual learners and students classified as English learners (ELs), a growing population nationwide, come to school with tremendous assets, among which are proficiency in a language other than English and the potential to become bilingual. Yet without school-based opportunities to develop biliteracy--that is, literacy in both their home language and English--their linguistic potential can remain underdeveloped. Many states recognize these students' multilingual potential and have prioritized bilingual education: Some states require bilingual education, while others encourage or allow it in certain contexts. In this brief, we define some of the key terms in bilingual education and then provide an overview of the different state policies for the provision of bilingual education to English learners.

We analyze data from the Hydrogen Epoch of Reionization Array. This is the third in a series of papers on the closure phase delay-spectrum technique designed to detect the HI 21cm emission from cosmic reionization. We present the details of the data and models employed in the power spectral analysis, and discuss limitations to the process. We compare images and visibility spectra made with HERA data, to parallel quantities generated from sky models based on the GLEAM survey, incorporating the HERA telescope model. We find reasonable agreement between images made from HERA data, with those generated from the models, down to the confusion level. For the visibility spectra, there is broad agreement between model and data across the full band of $\sim 80$MHz. However, models with only GLEAM sources do not reproduce a roughly sinusoidal spectral structure at the tens of percent level seen in the observed visibility spectra on scales $\sim 10$ MHz on 29 m baselines. We find that this structure is likely due to diffuse Galactic emission, predominantly the Galactic plane, filling the far sidelobes of the antenna primary beam. We show that our current knowledge of the frequency dependence of the diffuse sky radio emission, and the primary beam at large zenith angles, is inadequate to provide an accurate reproduction of the diffuse structure in the models. We discuss implications due to this missing structure in the models, including calibration, and in the search for the HI 21cm signal, as well as possible mitigation techniques., Comment: 17 pages, 10 figures, accepted for the ApJ Supplement

A kinematically complete quasi-free $(p,pn)$ experiment in inverse kinematics was performed to study the structure of the Borromean nucleus $^{17}$B, which had long been considered to have neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for $1s_{1/2}$ and $0d_{5/2}$ orbitals, and a surprisingly small percentage of 9(2)$\%$ was determined for $1s_{1/2}$. Our finding of such a small $1s_{1/2}$ component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in $^{17}$B. The present work gives the smallest $s$- or $p$-orbital component among known nuclei exhibiting halo features, and implies that the dominant occupation of $s$ or $p$ orbitals is not a prerequisite for the occurrence of neutron halo., Comment: Accepted for publication in Physical Review Letters,8 pages, 4 figures

Sagittarius A* (Sgr A*) is the variable radio, near-infrared (NIR), and X-ray source associated with accretion onto the Galactic center black hole. We have analyzed a comprehensive submillimeter (including new observations simultaneous with NIR monitoring), NIR, and 2-8 keV dataset. Submillimeter variations tend to lag those in the NIR by $\sim$30 minutes. An approximate Bayesian computation (ABC) fit to the X-ray first-order structure function shows significantly less power at short timescales in the X-rays than in the NIR. Less X-ray variability at short timescales combined with the observed NIR-X-ray correlations means the variability can be described as the result of two strictly correlated stochastic processes, the X-ray process being the low-pass-filtered version of the NIR process. The NIR--X-ray linkage suggests a simple radiative model: a compact, self-absorbed synchrotron sphere with high-frequency cutoff close to NIR frequencies plus a synchrotron self-Compton scattering component at higher frequencies. This model, with parameters fit to the submillimeter, NIR, and X-ray structure functions, reproduces the observed flux densities at all wavelengths, the statistical properties of all light curves, and the time lags between bands. The fit also gives reasonable values for physical parameters such as magnetic flux density $B\approx13$ G, source size $L \approx2.2R_{S}$, and high-energy electron density $n_{e}\approx4\times10^{7}$ cm$^{-3}$. An animation illustrates typical light curves, and we make public the parameter chain of our Bayesian analysis, the model implementation, and the visualization code., Comment: Accepted by ApJS, June 3, 2021. The journal version of figure 21 is animated. The animation can also be found here: https://doi.org/10.17617/1.kctx3s25. This version (version 2) has been revised according to the referee's suggestions and includes optimized figures and some changes and corrections of the text; no scientific conclusions have changed

Collisions that induce melting and vaporization can have a substantial effect on the thermal and geochemical evolution of planets. However, the thermodynamics of major minerals are not well known at the extreme conditions attained during planet formation. We obtained new data at the Sandia Z Machine and use published thermodynamic data for the major mineral forsterite (Mg$_2$SiO$_4$) to calculate the specific entropy in the liquid region of the principal Hugoniot. We use our calculated specific entropy of shocked forsterite, and revised entropies for shocked silica, to determine the critical impact velocities for melting or vaporization upon decompression from the shocked state to 1 bar and the triple points, which are near the pressures of the solar nebula. We also demonstrate the importance of the initial temperature on the criteria for vaporization. Applying these results to $N$-body simulations of terrestrial planet formation, we find that up to 20 to 40% of the total system mass is processed through collisions with velocities that exceed the criteria for incipient vaporization at the triple point. Vaporizing collisions between small bodies are an important component of terrestrial planet formation., Comment: 15 pages, 8 figures, Accepted for publication in JGR: Planets

Exclusive photoproduction cross sections have been measured for the process $\gamma p \rightarrow p\pi^0(e^+e^-(\gamma))$ with the Dalitz decay final state using tagged photon energies in the range of $E_{\gamma} = 1.275-5.425$ GeV. The complete angular distribution of the final state $\pi^0$, for the entire photon energy range up to large values of $t$ and $u$, has been measured for the first time. The data obtained show that the cross section $d\sigma/dt$, at mid to large angles, decreases with energy as $s^{-6.89\pm 0.26} $. This is in agreement with the perturbative QCD quark counting rule prediction of $s^{-7} $. Paradoxically, the size of angular distribution of measured cross sections is greatly underestimated by the QCD based Generalized Parton Distribution mechanism at highest available invariant energy $s=11$ GeV$^2$. At the same time, the Regge exchange based models for $\pi^0$ photoproduction are more consistent with experimental data., Comment: 7 pages, 6 figures