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  1. Murphy, Beth (Ed.)
    This article briefly describes the design of the five Quander games and the game world in which the games are situated. It described the rational for the game design and includes brief descriptions of all 5 games and the reward system. 
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  2. ABSTRACT

    The 1D power spectrum P1D of the Ly α forest provides important information about cosmological and astrophysical parameters, including constraints on warm dark matter models, the sum of the masses of the three neutrino species, and the thermal state of the intergalactic medium. We present the first measurement of P1D with the quadratic maximum likelihood estimator (QMLE) from the Dark Energy Spectroscopic Instrument (DESI) survey early data sample. This early sample of 54 600 quasars is already comparable in size to the largest previous studies, and we conduct a thorough investigation of numerous instrumental and analysis systematic errors to evaluate their impact on DESI data with QMLE. We demonstrate the excellent performance of the spectroscopic pipeline noise estimation and the impressive accuracy of the spectrograph resolution matrix with 2D image simulations of raw DESI images that we processed with the DESI spectroscopic pipeline. We also study metal line contamination and noise calibration systematics with quasar spectra on the red side of the Ly α emission line. In a companion paper, we present a similar analysis based on the Fast Fourier Transform estimate of the power spectrum. We conclude with a comparison of these two approaches and discuss the key sources of systematic error that we need to address with the upcoming DESI Year 1 analysis.

     
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  3. null (Ed.)
    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 participated 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. 
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  4. null (Ed.)
    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 needed 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. 
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  5. ABSTRACT

    We present a study of photometric flares on 154 low-mass (≤0.2 M⊙) objects observed by the SPECULOOS-South Observatory from 2018 June 1 to 2020 March 23. In this sample, we identify 85 flaring objects, ranging in spectral type from M4 to L0. We detect 234 flares in this sample, with energies between 1029.2 and 1032.7 erg, using both automated and manual methods. With this work, we present the largest photometric sample of flares on late-M and ultra-cool dwarfs to date. By extending previous M dwarf flare studies into the ultra-cool regime, we find M5–M7 stars are more likely to flare than both earlier, and later, M dwarfs. By performing artificial flare injection-recovery tests, we demonstrate that we can detect a significant proportion of flares down to an amplitude of 1 per cent, and we are most sensitive to flares on the coolest stars. Our results reveal an absence of high-energy flares on the reddest dwarfs. To probe the relations between rotation and activity for fully convective stars, we extract rotation periods for fast rotators and lower-bound period estimates of slow rotators. These rotation periods span from 2.2 h to 65 d, and we find that the proportion of flaring stars increases for the most fastest rotators. Finally, we discuss the impact of our flare sample on planets orbiting ultra-cool stars. As stars become cooler, they flare less frequently; therefore, it is unlikely that planets around the most reddest dwarfs would enter the ‘abiogenesis’ zone or drive visible-light photosynthesis through flares alone.

     
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  6. null (Ed.)
  7. null (Ed.)