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The microstructure of high-entropy alloys with refractory elements and Al as constituents can be considered to be analogous to superalloys. These so-termed refractory high-entropy superalloys (RHSAs) can show remarkable compressive strength up to temperatures exceeding 1200 °C. Here, we examine the microstructure and properties - compressive, tensile, and fracture toughness - of a precipitation-hardened, body-centered cubic, RHSA, Al0.5Nb1.25Ta1.25TiZr, at ambient temperature (RT) to 1200 °C. Two dual-phase microstructures comprising ordered B2 (brittle) and disordered A2 (ductile) phases were produced in this alloy - one with B2 as the matrix, the other with A2 - for evaluation of the mechanical properties. Under compression, both microstructures display RT compressive strengths above 1.5 GPa and considerable ductility exceeding 40% at elevated temperatures; the alloy with the A2 matrix has ∼15% compressive ductility even at RT. However, properties are very different under tensile loading; at all temperatures, both microstructures fail predominately in an intergranular mode in the elastic regime at a fracture stress less than 200 MPa and ductility below 0.15%. The microstructure with the A2 matrix has a KIc fracture toughness of ∼15 MPa√m at RT, although at all temperatures above 800 °C, measured KIc values for both dual-phase microstructures are less than 5 MPa√m. In this study, we investigate the microstructural origin of these mechanical properties, and emphasize the importance of evaluating these alloys in tension.

The purpose of this study is to provide the best possible learning environment for K-8 English Learners (ELs) in social studies content suggested by ESL teachers and school administrators in North Carolina. ESL teachers and school administrators share their perceptions of best practices and strategies that have been effective in addressing the needs of ELs in the K-8 social studies classroom. Authors propose multifaceted approaches to meeting the needs of ELs in the social studies classrooms: First, effective professional development activities train social studies content teachers to acquire research-based effective instructional models for ELs. Second, literacy strategies provide social studies teachers the necessary information to make pedagogical modifications. Third, collaboration among content teachers, ESL teachers, and school administrators creates open communication to take initiative in sharing effective strategies that can be easily implemented and challenges that can be addressed.

PURPOSE: We investigated a role of bone morphogenic protein 7 (BMP7), a member of the TGF-β superfamily on pathogenic mechanism of Graves orbitopathy (GO). The therapeutic effects of BMP7 on inflammation and fibrosis were evaluated in cultured Graves orbital fibroblasts. METHODS: Expression of BMP7 was compared in cultured orbital tissue explants from GO (n = 12) and normal control (n = 12) subjects using real-time PCR. Orbital fibroblasts were cultured from orbital connective tissues obtained from GO (n = 3) and normal control patients (n = 3). Cells were pretreated with recombinant human BMP7 (rhBMP7) before stimulation with TGF-β, IL-1β, and TNF-α. Fibrosis-related proteins and inflammatory cytokines were analyzed by Western blotting. The activation of signaling molecules in inflammation and fibrosis was also analyzed. RESULTS: The expressions of BMP7 mRNA were lower in GO orbital tissues than control. Fibrosis-related proteins, fibronectin, collagen 1α, and α-SMA induced by TGF-β were suppressed by treating rhBMP7, and rhBMP7 upregulated TGF-β induced SMAD1/5/8 protein expression, whereas downregulated SMAD2/3. Increased pro-inflammatory molecules, IL-6, IL-8, and intercellular adhesion molecule-1 (ICAM-1) by IL-1β or TNF-α were blocked by rhBMP7 treatment, and the expression of phosphorylated NFκB and Akt was suppressed by rhBMP7 treatment. CONCLUSIONS: BMP7 transcript levels were downregulated in Graves orbital tissues. Exogenous BMP7 treatment showed inhibitory effects on the production of profibrotic proteins and proinflammatory cytokines in orbital fibroblasts. Our results provide a molecular basis of BMP7 as a new potential therapeutic agent through the opposing mechanism of profibrotic TGF-β/SMAD signaling and proinflammatory cytokine production.

We compared the effects of different "mastery" criteria and doses on the acquisition and maintenance of sight words for 4 second graders with and without disabilities. First, we replicated Set Analysis and Operant Analysis conditions where participants were taught sight words in 20-trial (4 operants, 5 opportunities) sessions. Acquisition criteria were applied to a set of 4 operants or to individual operants, respectively. Second, we extended the literature by evaluating a lower dose of the Operant Analysis condition in a 12-trial session (4 operants, 3 opportunities). Thus, we compared 3 conditions--Set Analysis 5, Operant Analysis 5, and Operant Analysis 3. All participants acquired novel sight words fastest and required far fewer teaching trials to maintain each sight word under Operant Analysis 3 compared with Set Analysis 5 and Operant Analysis 5 conditions. Implications for arranging acquisition criteria and the interaction with trial-dosages are discussed.

We investigate when there is a partition of a positive integer nn, n=f(λ1)+f(λ2)+⋯+f(λℓ),n=f\left({\lambda }_{1})+f\left({\lambda }_{2})+\cdots +f\left({\lambda }_{\ell }), satisfying that 1=χp(λ1)λ1+χp(λ2)λ2+⋯+χp(λℓ)λℓ,1=\frac{{\chi }_{p}\left({\lambda }_{1})}{{\lambda }_{1}}+\frac{{\chi }_{p}\left({\lambda }_{2})}{{\lambda }_{2}}+\cdots +\frac{{\chi }_{p}\left({\lambda }_{\ell })}{{\lambda }_{\ell }}, where χp{\chi }_{p} is the Legendre symbol modulo prime pp and f(k)=kf\left(k)=k or the kkth mm-gonal number with m=3m=3, 4, or 5.