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  1. Communication of ideas involves the simultaneous efforts of verbal, physical and neurological processes (Sherr, 2008). In elementary classrooms where young students are in the process of developing their verbal capacities, gestures from both the teacher and students serve as a key component of communication of new ideas and the processing of social information (Foglia & Wilson, 2013). Thus far, research efforts to understand how students utilize gestures in the communication and understanding of ideas have focused primarily on mathematics and the physical sciences (see Nemirovsky & Ferrara, 2009; Nuñez, Edwards & Matos, 1999; Shapiro, 2014; Sherr, 2008). With the introduction of the Next Generation Science Standards (NGSS Lead States, 2013), students engineering is now included in K-12 instruction. Engineering education centers around designing and optimizing solutions to engineering challenges. The creation of a design solution differentiates engineering education from other classroom subject areas. Current work in engineering education focuses mostly on students’ words or drawings, leaving out gestures as an important component of students' communication of engineering designs. This study aimed to contribute to the general understanding of students’ use of gestures and manipulatives when discussing their engineering design solutions and is part of a larger NSF-funded project. Students participatedmore »in pre- and post-field trip classroom activities that extended learning done on an engineering-focused field trip to the local science center into the classroom. For this study, we focused on a module that challenged students to design a craft that either slowed the fall of a penny (classroom engineering design challenge) or hovered in a column of upward moving air (field trip engineering design challenge). We analyzed six videos (3 from the classroom and 3 from the field trip) of first-grade student explanations of their crafts to identify their use of gestures and prototyped craft design solutions in communicating. In this paper, we explore how student use of gestures and use of prototyped design solutions overlap and differentiate to understand how student sense-making can be understood through each.« less
  2. The plant pathogen Pseudomonas syringae secretes multiple effectors that modulate plant defenses. Some effectors trigger defenses due to specific recognition by plant immune complexes, whereas others can suppress the resulting immune responses. The HopZ3 effector of P. syringae pv. syringae B728a (PsyB728a) is an acetyltransferase that modifies not only components of plant immune complexes, but also the Psy effectors that activate these complexes. In Arabidopsis, HopZ3 acetylates the host RPM1 complex and the Psy effectors AvrRpm1 and AvrB3. This study focuses on the role of HopZ3 during tomato infection. In Psy-resistant tomato, the main immune complex includes PRF and PTO, a RIPK-family kinase that recognizes the AvrPto effector. HopZ3 acts as avirulence factor on tomato by suppressing AvrPto1Psy-triggered immunity. HopZ3acetylates AvrPto1Psy and the host proteins PTO, SlRIPK and SlRIN4s. Biochemical reconstruction and site-directed mutagenesis experiments suggest that acetylation acts in multiple ways to suppress immune signaling in tomato. First, acetylation disrupts the critical AvrPto1Psy-PTO interaction needed to initiate the immune response. Unmodified residues at the binding interface of both proteins and at other residues needed for binding are acetylated. Second, acetylation occurs at residues important for AvrPto1Psy function but not for binding to PTO. Finally, acetylation reduces specific phosphorylations neededmore »for promoting the immune-inducing activity of HopZ3’s targets such as AvrPto1Psy and PTO. In some cases, acetylation competes with phosphorylation. HopZ3-mediated acetylation suppresses the kinase activity of SlRIPK and the phosphorylation of its SlRIN4 substrate previously implicated in PTO-signaling. Thus, HopZ3 disrupts the functions of multiple immune components and the effectors that trigger them, leading to increased susceptibility to infection. Finally, mass 44 spectrometry used to map specific acetylated residues confirmed HopZ3’s unusual capacity to modify histidine in addition to serine, threonine and lysine residues.« less