Spatial Analysis and Actor-Network Theory: A multi-scalar analytical study of the Chumash rock art of South-Central California

The aim of this research is to provide a more holistic approach to study Chumash rock art throughout their entire geographic region within South-Central California by applying geographic information systems (GIS), incorporating ethnohistoric and ethnographic data and utilising associated archaeological material under an Actor-Network Theory (ANT) framework. Through a review of past Chumash archaeological and rock art studies, I discuss where previous research is lacking and how that research was fragmentary due to focusing only on specific geographic areas or linguistic regions. As rock art is an artefact fixed within the terrain, I further argue it has a potential connection to the topography--particularly its relationship to Chumash landscapes and taskscapes by applying both formal and informed methodologies at multiple scales. By modifying the tenets of ANT to create a framework that uses the rock art data to define space, analyse its heterogeneity and connectivity and study its topographic entrenchment, this research conceptualises rock art’s networks. To conduct this research, I collated a large body of spatial and descriptive information for 254 rock art sites and associated archaeology. Spatial analyses were performed at multiple scales using GIS as a heuristic to conceptualise site clustering, landscape entrenchment and anisotropic movement for the collated data. While the rock art sites were used to define the multi-scalar spaces, results show that the identity of the sites change throughout space and time where rock art itself is a network and not exclusive to one specific Chumash network. Analysis of the data shows that the topographic setting entrenches the rock art and begins to represent the dynamic assembly of its heterogeneous network relations. Movement through the landscape reflects how the sites were connected or structured within their landscapes and taskscapes. Overall it reflects rock art’s interrelationships to the networked economic, social, ideological and political organisations of the Chumash and their rich ceremonial practices. Therefore, the Chumash rock art networks were as complex, dynamic, variable and heterogeneous as Chumash society and the rock art panels themselves

Resources for Teaching and Assessing the Vision and Change Biology Core Concepts

The Vision and Change report called for the biology community to mobilize around teaching the core concepts of biology. This essay describes a collection of resources developed by several different groups that can be used to respond to the report’s call to transform undergraduate education at both the individual course and departmental levels. First, we present two frameworks that help articulate the Vision and Change core concepts, the BioCore Guide and the Conceptual Elements (CE) Framework, which can be used in mapping the core concepts onto existing curricula and designing new curricula that teach the biology core concepts. Second, we describe how the BioCore Guide and the CE Framework can be used alongside the Partnership for Undergraduate Life Sciences Education curricular rubric as a way for departments to self-assess their teaching of the core concepts. Finally, we highlight three sets of instruments that can be used to directly assess student learning of the core concepts: the Biology Card Sorting Task, the Biology Core Concept Instruments, and the Biology—Measuring Achievement and Progression in Science instruments. Approaches to using these resources independently and synergistically are discussed

Reconciliation of essential process parameters for an enhanced predictability of Arctic stratospheric ozone loss and its climate interactions

Significant reductions in stratospheric ozone occur inside the polar vortices each spring when chlorine radicals produced by heterogeneous reactions on cold particle surfaces in winter destroy ozone mainly in two catalytic cycles, the ClO dimer cycle and the ClO/BrO cycle. Chlorofluorocarbons (CFCs), which are responsible for most of the chlorine currently present in the stratosphere, have been banned by the Montreal Protocol and its amendments, and the ozone layer is predicted to recover to 1980 levels within the next few decades. During the same period, however, climate change is expected to alter the temperature, circulation patterns and chemical composition in the stratosphere, and possible geo-engineering ventures to mitigate climate change may lead to additional changes. To realistically predict the response of the ozone layer to such influences requires the correct representation of all relevant processes. The European project RECONCILE has comprehensively addressed remaining questions in the context of polar ozone depletion, with the objective to quantify the rates of some of the most relevant, yet still uncertain physical and chemical processes. To this end RECONCILE used a broad approach of laboratory experiments, two field missions in the Arctic winter 2009/10 employing the high altitude research aircraft M55-Geophysica and an extensive match ozone sonde campaign, as well as microphysical and chemical transport modelling and data assimilation. Some of the main outcomes of RECONCILE are as follows: (1) vortex meteorology: the 2009/10 Arctic winter was unusually cold at stratospheric levels during the six-week period from mid-December 2009 until the end of January 2010, with reduced transport and mixing across the polar vortex edge; polar vortex stability and how it is influenced by dynamic processes in the troposphere has led to unprecedented, synoptic-scale stratospheric regions with temperatures below the frost point; in these regions stratospheric ice clouds have been observed, extending over >106km2 during more than 3 weeks. (2) Particle microphysics: heterogeneous nucleation of nitric acid trihydrate (NAT) particles in the absence of ice has been unambiguously demonstrated; conversely, the synoptic scale ice clouds also appear to nucleate heterogeneously; a variety of possible heterogeneous nuclei has been characterised by chemical analysis of the non-volatile fraction of the background aerosol; substantial formation of solid particles and denitrification via their sedimentation has been observed and model parameterizations have been improved. (3) Chemistry: strong evidence has been found for significant chlorine activation not only on polar stratospheric clouds (PSCs) but also on cold binary aerosol; laboratory experiments and field data on the ClOOCl photolysis rate and other kinetic parameters have been shown to be consistent with an adequate degree of certainty; no evidence has been found that would support the existence of yet unknown chemical mechanisms making a significant contribution to polar ozone loss. (4) Global modelling: results from process studies have been implemented in a prognostic chemistry climate model (CCM); simulations with improved parameterisations of processes relevant for polar ozone depletion are evaluated against satellite data and other long term records using data assimilation and detrended fluctuation analysis. Finally, measurements and process studies within RECONCILE were also applied to the winter 2010/11, when special meteorological conditions led to the highest chemical ozone loss ever observed in the Arctic. In addition to quantifying the 2010/11 ozone loss and to understand its causes including possible connections to climate change, its impacts were addressed, such as changes in surface ultraviolet (UV) radiation in the densely populated northern mid-latitudes

Reconciliation of essential process parameters for an enhanced predictability of Arctic stratospheric ozone loss and its climate interactions : (RECONCILE) ; activities and results

The international research project RECONCILE has addressed central questions regarding polar ozone depletion, with the objective to quantify some of the most relevant yet still uncertain physical and chemical processes and thereby improve prognostic modelling capabilities to realistically predict the response of the ozone layer to climate change. This overview paper outlines the scope and the general approach of RECONCILE, and it provides a summary of observations and modelling in 2010 and 2011 that have generated an in many respects unprecedented dataset to study processes in the Arctic winter stratosphere. Principally, it summarises important outcomes of RECONCILE including (i) better constraints and enhanced consistency on the set of parameters governing catalytic ozone destruction cycles, (ii) a better understanding of the role of cold binary aerosols in heterogeneous chlorine activation, (iii) an improved scheme of polar stratospheric cloud (PSC) processes that includes heterogeneous nucleation of nitric acid trihydrate (NAT) and ice on non-volatile background aerosol leading to better model parameterisations with respect to denitrification, and (iv) long transient simulations with a chemistry-climate model (CCM) updated based on the results of RECONCILE that better reproduce past ozone trends in Antarctica and are deemed to produce more reliable predictions of future ozone trends. The process studies and the global simulations conducted in RECONCILE show that in the Arctic, ozone depletion uncertainties in the chemical and microphysical processes are now clearly smaller than the sensitivity to dynamic variability

Household networks and emergent territory: a GIS study of Chumash households, villages and rock-art in South-Central California

Elite households of the Californian Chumash have been studied in order to understand the development of Late Holocene hunter-gatherer alliance networks. Equally, models of what has been termed ‘tribelet territories’ have been used to describe land ownership within larger Californian concepts. Surprisingly little research has explicitly addressed issues of how such territories may have developed. In this article, we turn to DeLanda’s philosophy of social complexity to consider how Chumash households may have underpinned the development of tribelet territories and the political implications for their articulation with wider alliances. Importantly, utilizing Geographic Information Systems (GIS), we analyse potential mobility patterns in relation to households, villages and rock-art locales in a case from the Emigdiano Chumash. The results suggest that the painting of rock art was imbricated within processes of territorialization, and that the local placement of art reflects which villages were home to particularly high-status households

GIS in Rock Art Studies

In recent years, geographic information system (GIS) and spatial analysis in rock art studies has become a more prominent means of studying rock art and its association with the Indigenous landscape. Recent approaches integrate theoretical dimensions of GIS analysis with a diverse range of methods, each of which requires comprehensive consideration of its strengths and limitations. Insight into Indigenous peoples’ landscape perceptions through multiscalar, theoretical analyses can be gleaned through the application of GIS within rock art research. A holistic review is presented here to understand the methodologies that have been utilized in rock art research, not only for conservation and preservation, but also to further understand the integration of rock art within the landscape through statistical and spatial interrogation

Rapid ozone depletion after humidification of the stratosphere by the Hunga Tonga Eruption

International audienceThe eruption of the Hunga Tonga–Hunga Ha’apai volcano on 15 January 2022 offered a good opportunity to explore the early impacts of tropical volcanic eruptions on stratospheric composition. Balloon-borne observations near Réunion Island revealed the unprecedented amount of water vapor injected by the volcano. The enhanced stratospheric humidity, radiative cooling, and expanded aerosol surface area in the volcanic plume created the ideal conditions for swift ozone depletion of 5% in the tropical stratosphere in just 1 week. The decrease in hydrogen chloride by 0.4 parts per million by volume (ppbv) and the increase in chlorine monoxide by 0.4 ppbv provided compelling evidence for chlorine activation within the volcanic plume. This study enhances our understanding of the effect of this unusual volcanic eruption on stratospheric chemistry and provides insights into possible chemistry changes that may occur in a changing climate

A GIS-investigation of Four Early Anglo-Saxon Cemeteries: Riply’s K-Function analysis of spatial groupings amongst graves

Archaeologists have often used their ‘‘eye’’ to interpret spatial patterns within cemetery sites. In this article, we will use Ripley’s K-function analysis to determine the proximity of statistically significant clusters within four early Anglo-Saxon cemetery sites: Wakerley, Norton, Berinsfield, and Lechlade. Using spatial and statistical methods supported by ArcGIS 10 we will explore the kernel density estimates of graves at the point of significance to discuss the organization of cemeteries as part of their chronological and social development. As a result of this investigation we will conclude that these sites were not organized into small clusters of nuclear family graves but large plots that contained the remains of varied, multivocational households