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We present highlights from a series of hands-on physics lab modules developed for remote teaching. The labs were composed of multiple self-guided inquiry modules. Though the labs were developed from scratch, some modules that were central to the design process were borrowed from previous PDP sessions and the guiding PDP principles of mirroring authentic Science, Technology, Engineering, and Mathematics (STEM) practices (e.g., allowing students to raise questions and take ownership of decision making). One notable aspect of this work is that by sourcing and assembling low-cost ($25 per student) lab kits that were sent to each student, the majority of the modules were hands-on despite being fully online. Combining online resources and simulation tools with individual hardware kits and small lab groups allowed for a mix of synchronous and asynchronous exploration. This mixed lab mode was successful in promoting both inquiry exploration and community building. One example of a lab design choice aimed at overcoming online barriers was that in lieu of weekly lab write-ups, groups submitted video checkouts in which students were encouraged to reflect on the lab, self-assess their learning outcomes, and highlight unique aspects of their lab experience. This lab was specifically developed in response to the unforeseen challenges of online teaching; however, multiple aspects of the course will seamlessly transfer to an in-person lab setting.

The megalithic pillar sites found around Lake Turkana, Kenya, are monumental cemeteries built approximately 5000 years ago. Their construction coincides with the spread of pastoralism into the region during a period of profound climate change. Early work at the Jarigole pillar site suggested that these places were secondary burial grounds. Subsequent excavations at other pillar sites, however, have revealed planned mortuary cavities for predominantly primary burials, challenging the idea that all pillar sites belonged to a single 'Jarigole mortuary tradition'. Here, the authors report new findings from the Jarigole site that resolve long-standing questions about eastern Africa's earliest monuments and provide insight into the social lives, and deaths, of the region's first pastoralists. Keywords: Eastern Africa, megalithic architecture, funerary archaeology, mortuary practices, pastoralist society, Introduction The earliest evidence of monumentality in eastern Africa coincides with the initial spread of food production into sub-Saharan Africa during a period of profound climatic, economic and social change [...]

Common assumptions about the ephemeral archaeological signature of pastoralist settlements have limited the application of geophysical techniques in the investigation of past herding societies. Here, the authors present a geophysical survey of Luxmanda, Tanzania, the largest-known settlement documented for the Pastoral Neolithic era in eastern Africa (,c. 5000-1200 BP). The results demonstrate the value and potential of fluxgate gradiometry for the identification of magnetic anomalies relating to archaeological features, at a category of site where evidence for habitation was long thought to be undetectable. The study provides comparative data to enable archaeologists to identify loci for future investigations of mobile populations in eastern Africa and elsewhere. Keywords: Africa, Tanzania, geophysical survey, pastoralism, mobility, Introduction Archaeologists worldwide are now applying geochemical, biomolecular and ethnoarchaeological approaches to understand the long-term social and environmental histories of ancient pastoralism (Honeychurch & Makarewicz 2016). Common early assumptions held [...]

Using the Central Andean Chavín Phenomenon as a case study, this paper explores the middle ground between top-down (big data) and bottom-up (Bayesian modeling) approaches to archaeological radiocarbon data. Compiling radiocarbon dates associated with the Chavín Phenomenon addresses questions of chronology, demonstrating that the relevant phases at interacting sites are relatively brief and broadly contemporary. In addition, the definition of a discrete span of time associated with the Chavín Phenomenon makes it possible to explore the context for that period of heightened interaction. Juxtaposing that timespan with a compilation of Central Andean radiocarbon dates identifies contemporary non-participatory sites, enabling characterization of the sociopolitical milieu within which the Chavín Phenomenon emerged, flourished, and faded. The identification of that corpus of sites also highlights the importance of a shift in focus from identification of interaction to characterization of interaction. Bottom-up approaches to radiocarbon chronology will be a key element of that effort, while high-level summary of radiocarbon assemblages can identify where additional dating and Bayesian modeling can have the greatest interpretive impact. [ABSTRACT FROM AUTHOR]

The document titled "Corrigendum: Direct oral anticoagulants for the treatment of cerebral venous thrombosis – a protocol of an international phase IV study" in the journal Frontiers in Neurology outlines corrections made to the Statistical Analysis Plan. Changes include the addition of country income group as a confounder and the use of last observation carried forward approach for missing data. The study will analyze primary and secondary outcomes using propensity score inverse probability treatment weighting and sensitivity analyses. The authors emphasize that these corrections do not alter the scientific conclusions of the original article. [Extracted from the article]

Featured Application: Navigation of autonomous agents without a source of complete and global knowledge of the environment, such as Global Positioning Systems. When autonomous agents are deployed in an unknown environment, obstacle-avoiding movement and navigation are required basic skills, all the more so when agents are limited by partial-observability constraints. This paper addresses the problem of autonomous agent navigation under partial-observability constraints by using a novel approach: Artificial Potential Fields (APF) assisted by heuristics. The well-known problem of local minima is addressed by providing the agents with the ability to make individual choices that can be exploited in a swarm. We propose a new potential function, which provides precise control of the potential field's reach and intensity, and the use of auxiliary heuristics provides temporary target points while the agent explores, in search of the position of the real intended target. Artificial Potential Fields, together with auxiliary search heuristics, are integrated into a novel navigation model for autonomous agents who have limited or no knowledge of their environment. Experimental results are shown in 2D scenarios that pose challenging situations with multiple obstacles, local minima conditions and partial-observability constraints, clearly showing that an agent driven using the proposed model is capable of completing the navigation task, even under the partial-observability constraints. [ABSTRACT FROM AUTHOR]

Artifacts made from Quispisisa obsidian are widely disseminated in the Peruvian Andes, but the geological source of the Quispisisa geochemical type was only recently located in southern Ayacucho. Following the positive identification of the source in 1999 by Richard Burger and colleagues, we found evidence of broad quarrying activities in unexplored portions of the source area. We describe 34 quarry pits, some as large as 80 m across, together with evidence of early- stage lithic reduction at the source. We encountered high concentrations of reduction debris associated with more extensive knapping in two localities, but our preliminary evaluation of surface evidence suggests that much of the material quarried was removed from the area as intact nodules or after minimal reduction at the source area.Los estudios geoquímicos de la obsidiana en los Andes Centrales han demostrado que la gran mayoría de los artefactos prehispánicos hechos de obsidiana se produjeron utilizando materia prima de ocho fuentes, cada una de las cuales es distinta en términos de composición geoquímica. De las ocho fuentes, material de Alca, Chivay, y Quispisisa predomina en las colecciones de todas las épocas prehispánicas. El tipo geoquímico de obsidiana llamado Quispisisa ocupa una posición importante en la historia del Perú prehispánico, pues herramientas hechas de este material se han encontrado en muchos sitios de la costa y sierra de la parte norcentral del país. Esos sitios se caracterizan por encontrarse dispersos en un amplio marco espacial y temporal, pues algunos se ubican en lugares distantes de la fuente y corresponden a épocas diversas, inclusive, algunas de ellas tan antiguas como el Precerámico Temprano. A pesar de esa importancia evidente, hasta la fecha solo se había ubicado la fuente, y faltaba cualquier exploración y registro detallado de los afloramientos de obsidiana y de los rasgos de explotación humana de la zona. A partir del año 2007 Tripcevich y Contreras visitaron la fuente ubicada por Richard Burger y sus colegas en la zona de Huanca Sancos, Ayacucho; posteriormente en el año 2009 los autores, con el apoyo de unas colegas, ampliaban las investigaciones y como producto de ello han revelado que el área geográfica que abarca la fuente de obsidiana tipo Quispisisa es mucho más extensa de lo que se había pensado. Asimismo, han logrado documentar la existencia de varios rasgos de explotación de la fuente tales como: pozos de cantera, lascas de reducción inicial de material, y caminos, los mismos que evidencian la presencia de la actividad de la cantería de obsidiana a una escala única en los Andes.

This paper is based on a multiple case study of schools which have been identified as improving their performance for about a decade. We proposed different criteria by which to characterize and study these improvement processes and, by applying them to our sample, we elaborated a typology of school improvement trajectories: we identified 4 different trajectories of school improvement. We called the first type "restricted improvement" because at its center is the management of processes that mainly target academic achievement tests; the second is "incipient improvement," which is based on changes that restructure the school processes; the third identified trajectory are cases where school improvement is "moving toward institutionalization," while the last are those cases where improvement has been already "institutionalized" and the schools have achieved high levels of educational effectiveness. We identified challenges that schools face at different stages of school improvement and discussed some related policy issues.

Con el objetivo de analizar la relación entre turismo culinario y patrimonio histórico se desarrolló un estudio de caso con enfoque cualitativo, que aborda el análisis de una comunidad productora de una sal milenaria en el centro de México. Las categorías de análisis fueron los actores sociales, el producto alimentario y el territorio. Los resultados muestran que la actividad turística presenta efectos ambivalentes hacia la reproducción social de un bien patrimonial alimentario con fuertes vínculos históricos. Se concluye que es necesaria una revisión de los retos y oportunidades que enfrenta el campo mexicano frente a la inserción del turismo rural como una estrategia de desarrollo.