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This article reports on analyses of the instructional practices of six middle- and high-school science teachers in the United States who participated in a research-practice partnership that aims to support reform science education goals at scale. All six teachers were well qualified, experienced, and locally successful--respected by students, parents, colleagues, and administrators--but they differed in their success in supporting students' three-dimensional learning. Our goal is to understand how the teachers' instructional practices contributed to their similarities in achieving local success and to differences in enabling students' learning, and to consider the implications of these findings for research-practice partnerships. Data sources included classroom videos supplemented by interviews with teachers and focus students and examples of student work. We also compared students' learning gains by teacher using pre-post assessments that elicited three-dimensional performances. Analyses of classroom videos showed how all six teachers achieved local success--they led effectively managed classrooms, covered the curriculum by teaching almost all unit activities, and assessed students' work in fair and efficient ways. There were important differences, however, in how teachers engaged students in science practices. Teachers in classrooms where students achieved lower learning gains followed a pattern of practice we describe as "activity-based teaching," in which students completed investigations and hands-on activities with few opportunities for sensemaking discussions or three-dimensional science performances. Teachers whose students achieved higher learning gains combined the social stability characteristic of local classroom success with more demanding instructional practices associated with "scientific sensemaking" and "cognitive apprenticeship." We conclude with a discussion of implications for research-practice partnerships, highlighting how partnerships need to support all teachers in achieving both local and standards-based success.

Questions: How does the grass layer affect seedlings across large environmental gradients in savannas? Location: Savanna sites in Argentina, Tanzania, and South Africa. Methods: We carried out a joint analysis of three grass removal experiments in which seedlings of various Fabaceae species were transplanted into plots with native grass and companion plots where grass had been removed. First, we estimated the effect of grasses on tree seedling mortality and seedling growth rate at each site. Then, we used the resulting coefficient estimates from site‐level models to examine the impact of two climate (monthly precipitation and aridity index) and two soil (soil organic carbon content and clay content) variables on the direction and magnitude of the grass effects. Results: Grasses increased the risk of mortality, but there was no evidence for a global effect of grasses on tree seedling rate of height growth. The best model fit indicated a high mortality risk of tree seedlings in response to grasses at intermediate aridity index values. No other climate or soil variable influenced tree seedling survival or growth (monthly precipitation, soil organic carbon content and clay content). Conclusions: Our results support the notion that the grass layer consistently creates a bottleneck to tree seedling establishment in African and South American savannas beyond climate and soil conditions, mainly by affecting tree seedling survival. The negative effect of grasses on seedling survival was lower in dry conditions compared to intermediate aridity levels. These results suggest that grass–seedling interaction is less intense in drier conditions, possibly due to reduced total grass biomass, which leads to decreased site evapotranspiration and improved soil water retention capacity. [ABSTRACT FROM AUTHOR]

We previously reported that deletion of a 44-nucleotide element in the 3′ untranslated region (UTR) of the Chikungunya virus (CHIKV) genome enhances the virulence of CHIKV infection in mice. Here, we find that while this 44-nucleotide deletion enhances CHIKV fitness in murine embryonic fibroblasts in a manner independent of the type I interferon response, the same mutation decreases viral fitness in C6/36 mosquito cells. Further, the fitness advantage conferred by the UTR deletion in mammalian cells is maintained in vivo in a mouse model of CHIKV dissemination. Finally, SHAPE-MaP analysis of the CHIKV 3′ UTR revealed this 44-nucleotide element forms a distinctive two-stem-loop structure that is ablated in the mutant 3′ UTR without altering additional 3′ UTR RNA secondary structures. [ABSTRACT FROM AUTHOR]

Dual antiplatelet therapy (DAPT) is standard treatment for endoluminal stent insertion, and complete resistance to DAPT is rare. A case of in-stent thrombosis occurring 3 hours after stent-assisted coiling of internal carotid artery aneurysm is presented despite compliance with DAPT. Platelet function tests (PFTs) revealed complete clopidogrel and prasugrel resistance. [ABSTRACT FROM AUTHOR]

Chikungunya virus (CHIKV) is an arbovirus capable of causing a severe and often debilitating rheumatic syndrome in humans. CHIKV replicates in a wide variety of cell types in mammals, which has made attributing pathologic outcomes to replication at specific sites difficult. To assess the contribution of CHIKV replication in skeletal muscle cells to pathogenesis, we engineered a CHIKV strain exhibiting restricted replication in these cells via incorporation of target sequences for skeletal muscle cell-specific miR-206. This virus, which we term SKE, displayed diminished replication in skeletal muscle cells in a mouse model of CHIKV disease. Mice infected with SKE developed less severe disease signs, including diminished swelling in the inoculated foot and less necrosis and inflammation in the interosseous muscles. SKE infection was associated with diminished infiltration of T cells into the interosseous muscle as well as decreased production of Il1b, Il6, Ip10, and Tnfa transcripts. Importantly, blockade of the IL-6 receptor led to diminished swelling of a control CHIKV strain capable of replication in skeletal muscle, reducing swelling to levels observed in mice infected with SKE. These data implicate replication in skeletal muscle cells and release of IL-6 as important mediators of CHIKV disease., Introduction Viral cell and tissue tropism is an important determinant of viral pathogenesis. The capacity to replicate in a particular cell or tissue is often an essential precursor to the [...]

This article reports on a design-based implementation research (DBIR) project that addresses the question: "How can classrooms be supported at scale to achieve the three-dimensional learning goals of the Next Generation Science Standards?" Inherent in this question are three key design challenges: (i) "three-dimensional learning"--the multidimensional changes in curriculum, assessment, and instruction required for three-dimensional learning; (ii) "scale"--the necessity of change at multiple scales in educational systems; and (iii) "diversity"--achieving rigor in our expectations with responsiveness to the enduring diversity of our students, classrooms, and schools. We discuss findings from the "Carbon TIME" project, which focuses on teaching carbon cycling and energy transformations at multiple scales. Findings focus on design and knowledge building in three interconnected contexts. (i) "Assessment"--understanding and assessing students' three-dimensional learning. Learning progression frameworks provide insight into students' reasoning and the basis for efficient and reliable classroom and large-scale assessments that have used automated scoring of constructed responses for over 80,000 tests. (ii) "Classrooms"--classroom discourse and learning communities. Six "Carbon TIME" units are based on an instructional model that scaffolds students' engagement with phenomena as questioners, investigators, and explainers. The units support substantial learning and reduce the achievement gap between high-pretest and low-pretest students, but with substantial differences among teachers. (iii) "Professional communities"--a professional development course of study and research-practice partnerships address issues of organizational resources, conflicting norms and obligations, and building practical knowledge in schools and districts. Project results show continuing advantages for schools with more organizational resources. Overall, results provide evidence that it is possible to measure and achieve three-dimensional learning at scale. However, this accomplishment requires substantial investments in the material, human, and social resources of educational communities of practice.