The Diverse Solar Phase Curves of Distant Icy Bodies. II. The Cause of the Opposition Surges and Their Correlations

We collect well-measured opposition surge properties for many icy bodies orbiting the Sun (mostly from our own observations) plus for many icy moons, resulting in a data base of surface and orbital properties for 52 icy bodies. (1) We put forward four criteria for determining whether the surge is being dominated by shadow hiding (SH) or coherent backscattering (CB) based on readily measured quantities. The CB surge mechanism dominates if the surge is color dependent, the phase curve is steeper than 0.04 mag/deg, the phase curve shape matches the CB model of Hapke, or if the albedo is higher than roughly 40%. (2) We find that virtually all of our sample have their phase curves dominated by CB at low phase angles. (3) We present a graphical method to determine the Hapke surge parameters B_C0 and h_C. (4) The Kuiper Belt Objects (KBOs) and Centaurs have relatively high surge amplitudes, B_C0 > ~0.5 and widths with h_C ~ 3 deg. (5) We find highly significant but loose correlations between surge properties and the colors, albedos, and inclinations. We interpret this as young surfaces tending to have low surge slopes, high albedo, and gray colors. (6) Nereid has its surface properties similar to other icy moons and greatly different from KBOs and Centaurs, so we conclude that Nereid is likely a nearly-ejected inner Neptunian moon rather than a captured KBO.Comment: Astronomical Journal, in press, 41 pages, 5 figure

The Structure-Function Linkage Database

The Structure–Function Linkage Database (SFLD, http://sfld.rbvi.ucsf.edu/) is a manually curated classification resource describing structure–function relationships for functionally diverse enzyme superfamilies. Members of such superfamilies are diverse in their overall reactions yet share a common ancestor and some conserved active site features associated with conserved functional attributes such as a partial reaction. Thus, despite their different functions, members of these superfamilies ‘look alike’, making them easy to misannotate. To address this complexity and enable rational transfer of functional features to unknowns only for those members for which we have sufficient functional information, we subdivide superfamily members into subgroups using sequence information, and lastly into families, sets of enzymes known to catalyze the same reaction using the same mechanistic strategy. Browsing and searching options in the SFLD provide access to all of these levels. The SFLD offers manually curated as well as automatically classified superfamily sets, both accompanied by search and download options for all hierarchical levels. Additional information includes multiple sequence alignments, tab-separated files of functional and other attributes, and sequence similarity networks. The latter provide a new and intuitively powerful way to visualize functional trends mapped to the context of sequence similarity

Self-organizing actin networks drive sequential endocytic protein recruitment and vesicle release on synthetic lipid bilayers

UNLABELLED: Forces generated by actin assembly assist membrane invagination during clathrin-mediated endocytosis (CME). The sequential recruitment of core endocytic proteins and regulatory proteins, and assembly of the actin network, are well documented in live cells and are highly conserved from yeasts to humans. However, understanding of CME protein self-organization, as well as the biochemical and mechanical principles that underlie actin’s role in CME, is lacking. Here, we show that supported lipid bilayers coated with purified yeast WASP, an endocytic actin assembly regulator, and incubated in cytoplasmic yeast extracts, recruit downstream endocytic proteins and assemble actin tails. Time-lapse imaging of WASP-coated bilayers revealed sequential recruitment of proteins from different endocytic modules, faithfully replicating in vivo behavior. Reconstituted actin networks assemble in a WASP-dependent manner and deform lipid bilayers, as seen by electron microscopy. Time-lapse imaging revealed that vesicles are released from the lipid bilayers with a burst of actin assembly. Actin networks pushing on membranes have previously been reconstituted; here, we have reconstituted a biologically important variation of these actin networks that self-organize on bilayers and produce pulling forces sufficient to bud off membrane vesicles. We propose that actin-driven vesicle generation may represent an ancient evolutionary precursor to diverse vesicle forming processes adapted for a wide array of cellular environments and applications. SIGNIFICANCE STATEMENT: Actin filament assembly participates in many vesicle-forming processes. However, the underlying principles for how assembly is initiated and organized to effectively harness assembly forces remain elusive. To address this gap, we report a novel reconstitution of actin-driven vesicle release from supported lipid bilayers. Using real-time imaging, we observe sequential recruitment of endocytic proteins and, following a burst of actin assembly, vesicle release from bilayers. Given the absence of cargo or upstream endocytic regulatory proteins on the bilayers, and the participation of actin in many vesicle-forming processes, we posit that this mode of vesicle formation represents an early evolutionary precursor for multiple trafficking pathways. We expect that this assay will be of great use for future investigations of actin-mediated vesicle-forming processes

Sub-national consumer ethnocentrism and the importance of the origin of food products: An exploratory analysis

Purpose This study’s main objective is to analyse the role of the consumer’s ethnocentrism as a potential segmentation basis and to detect product origin-sensitive groups. The relationship between the consumer’s regional ethnocentrism, local and regional identity and corresponding valuation and purchase of food products from a region is also examined. Design/methodology/approach The responses of 358 consumers residing in two Spanish regions are analysed by means of a mediation analysis and a cluster analysis. Findings The results suggest the convenience of considering ethnocentric consumer tendencies, also at the regional level, when studying attitudes, valuation, information search and effective purchase of foods of diverse categories and origins. Originality The main contributions of this work derive from the assessment of consumer ethnocentrism at a sub-national level (which is much less present in the literature) and the evidence of its usefulness for segmenting the market and detecting groups of origin-sensitive consumers, which can be useful to companies that produce and market food products in different regions.publishe

Juegos y mecánicas de juegos en la educación contable: gamificación. Una revisión de la literatura

The effects of the traditional pedagogy in accounting have contributed to a passive role of students in the teaching-learning process; this impedes an effective internalization and understanding of the contents (learning objectives); hence, it is necessary to review alternative pedagogical approaches, such as gamification, that may motivate students to take active roles in their educational process. This text is the result of a scientific literature review about gamification in accounting education. The main objective of this study permitted to gather theoretically and methodologically other author’s developments in the field of gamification and its implementation on accounting education; eventually, the conclusion presents it as an effective and valid pedagogy to enhance student´s learning.Los efectos de pedagogía tradicional en la contabilidad han propiciado que el educando ejerza un papel pasivo dentro del proceso de enseñanza-aprendizaje, impidiendo que la interiorización y aprehensión de los contenidos sea efectiva, por lo que es necesario revisar los métodos alternativos de enseñanza con el fin de que el educando pueda jugar un papel activo en su proceso de formación. Es por eso que se plantea la gamificación como uno de los métodos alternativos para tal fin. Así, este texto es el resultado de una revisión de literatura sobre el uso de juegos y mecánicas de juegos o gamificación en la educación contable. El principal objetivo fue recopilar teórica y metodológicamente los aportes de los autores que han desarrollado sus investigaciones en torno a la gamificación y su aplicación en la educación contable en el área financiera, llegando a la conclusión de que se trata de una pedagogía válida y efectiva para mejorar el aprendizaje del estudiante dentro del aula

12 Museum Theorists at Play

Introduction by Lauren Appel1. Learning by Do-weyan, by Marian Howard, with Nicole Ferrin2: Dewey Defines Himself and Education, by David Vining 3. Benjamin Ives Gilman: Arts in People’s Lives, by Katherine Hillman 4. John Cotton Dana: The Social Construction of Museums, by Marissa Corwin 5. Piaget in the Art Museum: Constructing Knowledge Through Active Engagement, by Berry Stein 6. Lev Vygotsky: The Social Aspects of Learning, by Nicole Keller 7. Paulo Freire: Literacy, Democracy, and Context, by Nicole Keller 8. Maxine Greene: Aesthetic Education, by Lauren Appel 9. Howard Gardner and Multiple Intelligence Theory: A Practical Application of Entry Points in Museum Programming, by Bill Elliston 10. Mihaly Csikszentmihalyi: Finding the Flow, by David Bowles 11. George Hein: Metaconstructivist, by Lauren Appel 12. David Carr: A Poetics of Questions, by Tiffany Reedy 13. David Sobel: Please in My Backyard, by Kathryn Eliza Harris 14. Connecting the Dots, by Liat Olenickhttps://educate.bankstreet.edu/faculty-staff/1009/thumbnail.jp

The formation of Encke meteoroids and dust trail

We observed comet 2P/Encke with the Infrared Space Observatory ISOCAM on July 14, 1997 from a particularly favorable viewing geometry above the comet's orbital plane and at a distance of 0.25 AU. A structured coma was observed, along with a long, straight dust trail. For the first time, we are able to observe the path of particles as they evolve from the nucleus to the trail. The particles that produce the infrared coma are large, with a radiation to gravitational force ratio betamm-sized particles). The dust trail follows the orbit of the comet across our image, with a central core that is 20,000 km wide, composed of particles with beta<1e-5 (size $\sim 5$ cm) from previous apparitions. The abundant large particles near the comet pose a significant hazard to spacecraft. There is no evidence of a classical cometary dust tail due to small particles with beta>0.001, in marked contrast to other comets like P/Halley or C/Hale-Bopp. The structure of the coma requires anisotropic emission and that the spin axis of the nucleus to be nearly parallel to the orbital plane, resulting in strong seasonal variations of the particle emission. While most of the infrared coma emission is due to dust produced during the 1997 apparition, the core of the dust trail requires emissions from previous apparitions. The total mass lost during the 1997 apparition is estimated to be 2-6e13 g. Comparing to the gas mass loss from ultraviolet observations, the dust-to-gas mass ratio is 10-30, much higher than has ever been suggested from visual light observations. Using the recently-measured nuclear diameter, we find that Encke can only last 3000-10,000 rhoN yr (where rhoN is the nuclear density in g/cc) at its present mass loss rate.Comment: manuscript in TeX, 10 figures (6 ps, 4 jpg); accepted by Icarus July 3, 200

Remote assessment of ADHD in children and adolescents: recommendations from the European ADHD Guidelines Group following the clinical experience during the COVID-19 pandemic

The COVID-19 pandemic led ADHD services to modify the clinical practice to reduce in-person contact as much as possible to minimise viral spread. This had far-reaching effects on day-to-day clinical practice as remote assessments were widely adopted. Despite the attenuation of the acute threat from COVID, many clinical services are retaining some remote practices. The lack of clear evidence-based guidance about the most appropriate way to conduct remote assessments meant that these changes were typically implemented in a localised, ad hoc, and un-coordinated way. Here, the European ADHD Guidelines Group (EAGG) discusses the strengths and weaknesses of remote assessment methods of children and adolescents with ADHD in a narrative review based on available data and expert opinions to highlight key recommendations for future studies and clinical practice. We conclude that going forward, despite remote working in clinical services functioning adequately during the pandemic, all required components of ADHD assessment should still be completed following national/international guidelines; however, the process may need adaptation. Social restrictions, including changes in education provision, can either mask or exacerbate features associated with ADHD and therefore assessment should carefully chart symptom profile and impairment prior to, as well as during an ongoing pandemic. While remote assessments are valuable in allowing clinical services to continue despite restrictions and may have benefits for routine care in the post-pandemic world, particular attention must be paid to those who may be at high risk but not be able to use/access remote technologies and prioritize these groups for conventional face-to-face assessments