Explore the vast range of titles available.

Computation instruction continues to be one of the most important aspects of the mathematics curricula. Students who fail to understand and master the foundational components of addition, subtraction, multiplication, and division are likely to experience mathematics difficulties in both their school and post-school lives. A balanced instructional approach that includes evidence-based practices related to the development of conceptual, procedural, and declarative knowledge increases the likelihood that students will understand the meaning of the computational operations and demonstrate the ability to solve problems with accuracy and fluency. (Contains 3 figures and 2 tables.)

For federal law to population changes, teacher preparation programs must not only respond to current trends but also reach out to develop educational partnerships with P-12 teachers and administrators. A review of recent educational changes prompted this viewpoint on how professional organizations like Delta Kappa Gamma can provide support, guidance, and a vision for education and, thus, for the preparation of teacher educators. Implications for teacher education as well as resources for teachers, families, and teacher educators are provided.

Service learning is increasingly used as a valid means of enhancing the learning and practice of teacher candidates at institutions of higher education. The purpose of this article is to describe a service-learning program that aims to help teacher candidates learn the social context of disabilities and its impact on such adults in real-world settings. The special-education teacher-certification program at this 4-year university has included a requirement of 30 service-learning hours for 10 years. The description of the service-learning piece is grounded in four components defined in the Serve America Act of 2009: (a) active participation that requires collaboration, (b) integration of academic curriculum, (c) use of pedagogy in real-world settings, and (d) reflection. The impact of service-learning experiences is demonstrated through the dispositions of teacher candidates in this program. [PUBLICATION ABSTRACT]

Students with disabilities face a difficult transition from high school to adult life. In the areas of employment and post secondary education students with disabilities have difficulty being successful (National Council on Disability, 2004; U.S. Census Bureau, 2004). The need for students with disabilities to be adequately prepared for the transition from school to adult life has been stated in government reports and research (Raskind, Goldberg, Higgins, & Herman, 1999; Wehmeyer, 1999; Field, Sarver, & Shaw, 2003, National Council on Disability, 2004; Reiff, 2004). The purpose of this study was to investigate the effects of the Possible Selves program (Hock, Schumaker, & Deshler, 2003) with a supplemental disability awareness lesson on perceptions related to self-awareness, self-advocacy, and goal setting among adolescents with disabilities, their teachers and their parents. Participants were 27 high school students with learning disabilities, two Learning Strategies Specialists, and 27 parents. A total of 10 intact classes were randomly assigned to either the treatment or control group. Both groups received a Disability Awareness Lesson . The treatment group received subsequent instruction using a Possible Selves program; whereas the control group received instruction in applied communication skills. The Student Rating Checklist, Student Rating by Teacher Checklist, and Student Rating by Parent Checklist were used to measure perceptions related to self-awareness, self-advocacy skills, and goal setting abilities. The Student Narrative Measurement was used to supplement these data. Using a one-way repeated measures ANOVA to analyze the data, all students' perceptions of their self-awareness, self-advocacy skills, and goal setting abilities significantly increased from pre-test to post-test with no significant difference between groups. Using a one-way between groups ANOVA to analyze the data, student perceptions related to self-awareness, self-advocacy skills, and goal setting skills at post-test were significantly higher than both teacher perceptions and parent perceptions of students' skills. Using descriptive statistical measures, the results of this study demonstrate that high school students can learn the Possible Selves program in 14 hours of instructional time.

We present a catalog of fundamental stellar properties for ∼7500 evolved stars, including stellar radii and masses, determined from the combination of spectroscopic observations from the Apache Point Observatory Galactic Evolution Experiment, part of the Sloan Digital Sky Survey IV, and asteroseismology from K2. The resulting APO-K2 catalog provides spectroscopically derived temperatures and metallicities, asteroseismic global parameters, evolutionary states, and asteroseismically derived masses and radii. Additionally, we include kinematic information from Gaia. We investigate the multidimensional space of abundance, stellar mass, and velocity with an eye toward applications in Galactic archaeology. The APO-K2 sample has a large population of low-metallicity stars (∼288 with [M/H] ≤ −1), and their asteroseismic masses are larger than astrophysical estimates. We argue that this may reflect offsets in the adopted fundamental temperature scale for metal-poor stars rather than metallicity-dependent issues with interpreting asteroseismic data. We characterize the kinematic properties of the population as a function of α enhancement and position in the disk and identify those stars in the sample that are candidate components of the Gaia-Enceladus merger. Importantly, we characterize the selection function for the APO-K2 sample as a function of metallicity, radius, mass, νmax , color, and magnitude referencing Galactic simulations and target selection criteria to enable robust statistical inferences with the catalog.

We apply a novel statistical analysis to measurements of 16 elemental abundances in 34,410 Milky Way disk stars from the final data release (DR17) of APOGEE-2. Building on recent work, we fit median abundance ratio trends [X/Mg] versus [Mg/H] with a 2-process model, which decomposes abundance patterns into a “prompt” component tracing core-collapse supernovae and a “delayed” component tracing Type Ia supernovae. For each sample star, we fit the amplitudes of these two components, then compute the residuals Δ[X/H] from this two-parameter fit. The rms residuals range from ∼0.01–0.03 dex for the most precisely measured APOGEE abundances to ∼0.1 dex for Na, V, and Ce. The correlations of residuals reveal a complex underlying structure, including a correlated element group comprised of Ca, Na, Al, K, Cr, and Ce and a separate group comprised of Ni, V, Mn, and Co. Selecting stars poorly fit by the 2-process model reveals a rich variety of physical outliers and sometimes subtle measurement errors. Residual abundances allow for the comparison of populations controlled for differences in metallicity and [α/Fe]. Relative to the main disk (R = 3–13 kpc), we find nearly identical abundance patterns in the outer disk (R = 15–17 kpc), 0.05–0.2 dex depressions of multiple elements in LMC and Gaia Sausage/Enceladus stars, and wild deviations (0.4–1 dex) of multiple elements in ω Cen. The residual abundance analysis opens new opportunities for discovering chemically distinctive stars and stellar populations, for empirically constraining nucleosynthetic yields, and for testing chemical evolution models that include stochasticity in the production and redistribution of elements.

Stars that formed with an initial mass of over 50 M ⊙ are very rare today, but they are thought to be more common in the early Universe. The fates of those early, metal-poor, massive stars are highly uncertain. Most are expected to directly collapse to black holes, while some may explode as a result of rotationally powered engines or the pair-creation instability. We present the chemical abundances of J0931+0038, a nearby low-mass star identified in early follow-up of the SDSS-V Milky Way Mapper, which preserves the signature of unusual nucleosynthesis from a massive star in the early Universe. J0931+0038 has a relatively high metallicity ([Fe/H] = −1.76 ± 0.13) but an extreme odd–even abundance pattern, with some of the lowest known abundance ratios of [N/Fe], [Na/Fe], [K/Fe], [Sc/Fe], and [Ba/Fe]. The implication is that a majority of its metals originated in a single extremely metal-poor nucleosynthetic source. An extensive search through nucleosynthesis predictions finds a clear preference for progenitors with initial mass >50 M ⊙, making J0931+0038 one of the first observational constraints on nucleosynthesis in this mass range. However, the full abundance pattern is not matched by any models in the literature. J0931+0038 thus presents a challenge for the next generation of nucleosynthesis models and motivates the study of high-mass progenitor stars impacted by convection, rotation, jets, and/or binary companions. Though rare, more examples of unusual early nucleosynthesis in metal-poor stars should be found in upcoming large spectroscopic surveys.

We perform a detailed photometric and astrometric analysis of stars in the Jet stream using data from the first data release of the DECam Local Volume Exploration Survey DR1 and Gaia EDR3. We discover that the stream extends over ∼ 29° on the sky (increasing the known length by 18°), which is comparable to the kinematically cold Phoenix, ATLAS, and GD-1 streams. Using blue horizontal branch stars, we resolve a distance gradient along the Jet stream of 0.2 kpc deg−1, with distances ranging from D ⊙ ∼ 27–34 kpc. We use natural splines to simultaneously fit the stream track, width, and intensity to quantitatively characterize density variations in the Jet stream, including a large gap, and identify substructure off the main track of the stream. Furthermore, we report the first measurement of the proper motion of the Jet stream and find that it is well aligned with the stream track, suggesting the stream has likely not been significantly perturbed perpendicular to the line of sight. Finally, we fit the stream with a dynamical model and find that it is on a retrograde orbit, and is well fit by a gravitational potential including the Milky Way and Large Magellanic Cloud. These results indicate the Jet stream is an excellent candidate for future studies with deeper photometry, astrometry, and spectroscopy to study the potential of the Milky Way and probe perturbations from baryonic and dark matter substructure.

APOGEE is a high-resolution (R sim 22,000), near-infrared, multi-epoch, spectroscopic survey of the Milky Way. The second generation of the APOGEE project, APOGEE-2, includes an expansion of the survey to the Southern Hemisphere called APOGEE-2S. This expansion enabled APOGEE to perform a fully panoramic mapping of all the main regions of the Milky Way; in particular, by operating in the H-band, APOGEE is uniquely able to probe the dust-hidden inner regions of the Milky Way that are best accessed from the Southern Hemisphere. In this paper we present the targeting strategy of APOGEE-2S, with special attention to documenting modifications to the original, previously published plan. The motivation for these changes is explained as well as an assessment of their effectiveness in achieving their intended scientific objective. In anticipation of this being the last paper detailing APOGEE targeting, we present an accounting of all such information complete through the end of the APOGEE-2S project; this includes several main survey programs dedicated to exploration of major stellar populations and regions of the Milky Way, as well as a full list of programs contributing to the APOGEE database through allocations of observing time by the Chilean National Time Allocation Committee (CNTAC) and the Carnegie Institution for Science (CIS). This work was presented along with a companion article, R. Beaton et al. (submitted; AAS29028), presenting the final target selection strategy adopted for APOGEE-2 in the Northern Hemisphere.