Frameworks to Develop Integrated STEM Curricula

Research-based frameworks can help K-12 schools develop integrated STEM curricula. Two frameworks are presented that describe the characteristics of effective integrated STEM lessons and effective engineering education. The second framework is a modification of the first. Modifications were made to align the framework to a school that was new to integrated STEM. The frameworks have promise for K-12 schools who wish to develop and implement an integrated STEM curriculum that may have different levels of experience and different types of support

The Multiple Usages of Thinking With Algebra

Thinking With Algebra (TWA) is a National Science Foundation Project (DUE 2021414) to develop a post-secondary curriculum for intermediate algebra. TWA focuses on six elements that align with building algebraic fluency with conceptual understanding, a mixed review approach, small-group work, and whole-class discussion (Feikes, et al., 2021). Using an equity lens (Oppland-Cordell et al., 2023), TWA is designed for students, including underrepresented students, who need additional mathematical supports at the college level. Seventeen college math instructors attended a workshop on the lessons and pedagogy in order to use TWA in their college courses. Feedback from instructors participating in the TWA first-year faculty workshop indicated that the curriculum was used in many different ways to help prepare students for college algebra and other STEM courses

Students\u27 Perspectives of Thinking With Algebra

Thinking With Algebra (TWA) is a curriculum development project for college students needing introductory/intermediate algebra. Unique guiding principles of the project are a focus on algebraic structure, mixed review, equity, and a classroom approach emphasizing small-group work and whole-class discussion (Feikes et al., 2022). Results are derived from a survey given to one class of fifteen students taking an intermediate algebra summer course. The paper shares both Likert and open-ended responses. Data demonstrates that the students believed that the TWA curriculum was beneficial

Applying a Sociopolitical Equity Framework to a Developmental Algebra Curriculum

The Thinking With Algebra (TWA) curriculum, a National Science Foundation Project (DUE 2021414), applies a sociopolitical equity framework (Gutiérrez, 2012) to strengthen student participants’ mathematics achievement outcomes and mathematics identity development. Instructor and student data indicate improvements in these two dimensions. This project also expands knowledge about creating equitable math learning environments that support underrepresented students’ mathematical success

Highly Sideophile Element Abundance Constraints on the Nature of the Late Accretionary Histories of Earth, Moon and Mars

The highly siderophile elements (HSE) include Re, Os, Ir, Ru, Pt and Pd. These elements are initially nearly-quantitatively stripped from planetary silicate mantles during core segregation. They then may be re-enriched in mantles via continued accretion sans continued core segregation. This suite of elements and its included long-lived radiogenic isotopes systems (Re-187 (right arrow) Os-187; Pt-190 (right arrow) Os-186) can potentially be used to fingerprint the characteristics of late accreted materials. The fingerprints may ultimately be useful to constrain the prior nebular history of the dominant late accreted materials, and to compare the proportion and genesis of late accretionary materials added to the inner planets. The past ten years have seen considerable accumulation of isotopic and compositional data for HSE present in the Earth's mantle, lunar mantle and impact melt breccias, and Martian meteorites. Here we review some of these data and consider the broader implications of the compiled data

Characteristics of two outstanding elementary teachers of mathematics: Implications for teacher education

This study identifies characteristics of two “outstanding” elementary teachers of mathematics who were different in style and who taught in different settings. The intent is to determine what characteristics make these different teachers outstanding in hopes of helping preservice teachers improve their teaching of mathematics. Preliminary findings indicate that both teachers were (1) focused on children’s learning of mathematics; (2) focused on the mathematical solution methods used by students; (3) believed that all of their students could learn mathematics; (4) were enthusiastic and dedicated to the profession of teaching; and (5) cared deeply about their students and emphasized the necessity of building relationships with them

The possible existence of Hs in nature from a geochemical point of view

A hypothesis of the existence of a long-lived isotope 271Hs in natural molybdenites and osmirides is considered from a geochemical point of view. It is shown that the presence of Hs in these minerals can be explained only by making an additional ad hoc assumption on the existence of an isobaric pair of 271Bh-271Hs. This assumption could be tested by mass-spectrometric measurements of U, Pb, Kr, Xe, and Zr isotopic shifts.Comment: 5 pages, no figures. Physics of Particles and Nuclei Letters, 2006, Vol. 3, No. 3, pp. 165-168 in pres

Clinical Differences between Younger and Older Adults with HIV/AIDS Starting Antiretroviral Therapy in Uganda and Zimbabwe: A Secondary Analysis of the DART Trial

Objective: Clinical and immunological data about HIV in older adults from low and middle income countries is scarce. We aimed to describe differences between younger and older adults with HIV starting antiretroviral therapy in two low–income African countries. Methods: Setting:: HIV clinics in Uganda and Zimbabwe. Design:: Secondary exploratory cross-sectional analysis of the DART randomized controlled trial. Outcome Measures: Clinical and laboratory characteristics were compared between adults aged 18-49 years (younger) and ≥ 50 years (older), using two exploratory multivariable logistic regression models, one with HIV viral load (measured in a subset pre-ART) and one without. Results: A total of 3316 eligible participants enrolled in DART were available for analysis; 219 (7%) were ≥ 50 years and 1160 (35%) were male. Across the two adjusted regression models, older adults had significantly higher systolic blood pressure, lower creatinine clearance and were consistently less likely to be females compared to younger adults with HIV. Paradoxically, the models separately suggested that older adults had statistically significant (but not clinically important) higher CD4+ cell counts and higher plasma HIV–1 viral copies at initiation. Crude associations between older age and higher baseline hemoglobin, body mass index, diastolic blood pressure and lower WHO clinical stage were not sustained in the adjusted analysis. Conclusions: Our study found clinical and immunological differences between younger and older adults, in a cohort of Africans starting antiretroviral therapy. Further investigations should explore how these differences could be used to ensure equity in service delivery and affect outcomes of antiretroviral therapy

An Evolutionary Reduction Principle for Mutation Rates at Multiple Loci

A model of mutation rate evolution for multiple loci under arbitrary selection is analyzed. Results are obtained using techniques from Karlin (1982) that overcome the weak selection constraints needed for tractability in prior studies of multilocus event models. A multivariate form of the reduction principle is found: reduction results at individual loci combine topologically to produce a surface of mutation rate alterations that are neutral for a new modifier allele. New mutation rates survive if and only if they fall below this surface - a generalization of the hyperplane found by Zhivotovsky et al. (1994) for a multilocus recombination modifier. Increases in mutation rates at some loci may evolve if compensated for by decreases at other loci. The strength of selection on the modifier scales in proportion to the number of germline cell divisions, and increases with the number of loci affected. Loci that do not make a difference to marginal fitnesses at equilibrium are not subject to the reduction principle, and under fine tuning of mutation rates would be expected to have higher mutation rates than loci in mutation-selection balance. Other results include the nonexistence of 'viability analogous, Hardy-Weinberg' modifier polymorphisms under multiplicative mutation, and the sufficiency of average transmission rates to encapsulate the effect of modifier polymorphisms on the transmission of loci under selection. A conjecture is offered regarding situations, like recombination in the presence of mutation, that exhibit departures from the reduction principle. Constraints for tractability are: tight linkage of all loci, initial fixation at the modifier locus, and mutation distributions comprising transition probabilities of reversible Markov chains.Comment: v3: Final corrections. v2: Revised title, reworked and expanded introductory and discussion sections, added corollaries, new results on modifier polymorphisms, minor corrections. 49 pages, 64 reference

First observations with SuperCam and future plans

Supercam is a 345 GHz, 64-pixel heterodyne imaging array for the Heinrich Hertz Submillimeter Telescope (HHSMT). By integrating SIS mixer devices with Low Noise Ampliers (LNAs) in 8 - 1x8 pixel modules, the size needed for the cryostat and the complexity of internal wiring is signicantly reduced. All subsystems including the optics, cryostat, bias system, IF boxes, and spectrometer have been integrated for all 64 pixels. In the spring of 2012, SuperCam was installed on the HHSMT for an engineering run where it underwent system level tests and performed rst light observations. In the fall of 2012 SuperCam will begin a 500 square degree survey of the Galactic Plane in ^(12)CO J=3-2. This large-scale survey will help answer fundamental questions about the formation, physical conditions, and energetics of molecular clouds within the Milky Way. The data set will be available via the web to all interested researchers