Modelling Emergent Patterns of Dynamic Desert Ecosystems

In many desert ecosystems vegetation is both patchy and dynamic: vegetated areas are interspersed with patches of bare ground, and both the positioning and the species composition of the vegetated areas exhibit change through time. These characteristics lead to the emergence of multi-scale patterns in vegetation that arise from complex relationships between plants, soils and transport processes. Previous attempts to probe the causes of spatial complexity and predict responses of desert ecosystems tend to be limited in their focus: models of dynamics have been developed with no consideration of the inherent patchiness in the vegetation, or else models have been developed to generate patterns with no consideration of the dynamics. Here we develop a general modelling framework for the analysis of ecosystem change in deserts that is rooted in the concept of connectivity and is derived from a detailed process-based understanding. We explicitly consider spatial interactions among multiple vegetation types and multiple resources, and our model is formulated to predict responses to a variety of endogenous and exogenous disturbances. The model is implemented in the deserts of the American Southwest both to test hypotheses of the causes of the invasion of woody shrubs, and to test its ability to reproduce 16 observed spatial differences in response to drought in the twentieth century. The model’s performance leads us to argue that vertical and lateral connectivity are key emergent properties of the ecosystem, which both control its behaviour and provide indicators of its state. If this argument is shown to be compatible with field observations, the model presented here will provide a more certain approach towards preventing further degradation of semi-arid grasslands. http://www.esajournals.org/doi/pdf/10.1890/12-1253.

The cultural evolution of warfare practices: examining the roles of social structure, political complexity, and resource ecology with cross-cultural comparative analyses

This thesis investigates how forms of wartime violence changed with the scale and complexity of past human societies. Data on aspects of social and political structures, subsistence practices, and warfare were coded from ethnographic and secondary historical sources for a global sample of societies. Four studies are presented that examine variation in warfare cross-culturally and historically, specifically the prevalence of self-sacrificial actions for other group members, levels of indiscriminate killing of enemies, and the taking of enemy body parts as trophies. These behaviors were tested for relationships with social complexity and associated variables, including military formalization and reliance on agriculture. Overall, there was no evidence for any clear relationships. These efforts resulted in the creation of datasets representing archaeologically, historically, and ethnographically recorded societies and defined new variables for specific wartime behaviors which had not previously been the focus of quantitative comparative analyses. More broadly, it contributes to the growing area of cultural evolutionary research with comparative historical databases and to research on the evolution of warfare through human history

Tropes of Alterity in Soviet and Polish Science Fiction (1957-1992)

This dissertation examines Soviet and Polish science fiction from the 1960s to 1980s as a political genre that investigates power and society. The problem of alterity is central for this genre: it is ungovernable because it is incomprehensible. Science fiction of this kind explores the possibilities and impossibilities of living with the Other that can impact social organization dramatically and lethally while that Other cannot be impacted in return. Living peacefully with such alterity is the fundamental premise of pluralism as a principle of social organization, according to the conclusions of the study. The dissertation explores alterity in science fiction by Ivan Efremov (1908–1972), Arkady and Boris Strugatsky (1925–1991 and 1933–2012), Stanisław Lem (1921–2006), and Volodymyr Savchenko (1933–2005). My goal is to reveal in their works a transformative epistemological shift that had manifested itself through the tropes of alterity. Among these tropes the dissertation highlights aliens and alien civilizations, artificial intelligence, anisotropic universe, distant planets endowed with unique natural attributes, the more abstract unknown, and non-human elements running out-of-control within human species. I also examine specifically science-fictional notions such as the bull and progressor, which represent the intelligentsia’s relations with power and the masses. The analyzed literary worlds also represent their authors’ views of alternative societal organization, ruled by the powerful alterity such as a mega-computer or alien super-intelligence. Another important trope of alterity is based upon a simultaneous performance of contradictory competing logics that create an effect known as parallax: the reader may interpret the same characters and/or stories in multiple, mutually incompatible, ways. Beyond avoiding censorship, these tropes set the stage for the authors’ utopias, in which the Other appears as an impenetrable alterity that affects those who encounter it. For these writers, alterity serves as the tool for problematizing progress, as it was imagined after World War II by the majority of political elites under socialism and in the West. I suggest that their science fiction contributed, among many other factors, to the lexicon and the imaginary of a cohort of political dissidents and Communist Party functionaries alike who translated science-fictional themes into political science terms to shape Perestroika’s discourse. The dissertation, thus, establishes a historical connection between Soviet and Polish science fiction of the post-Stalin period and the ways in which democracy was discursively constructed in Russia, Ukraine, Poland, and other former socialist nations

History & Mathematics: Trends and Cycles

The present yearbook (which is the fourth in the series) is subtitled Trends & Cycles. It is devoted to cyclical and trend dynamics in society and nature; special attention is paid to economic and demographic aspects, in particular to the mathematical modeling of the Malthusian and post-Malthusian traps' dynamics. An increasingly important role is played by new directions in historical research that study long-term dynamic processes and quantitative changes. This kind of history can hardly develop without the application of mathematical methods. There is a tendency to study history as a system of various processes, within which one can detect waves and cycles of different lengths – from a few years to several centuries, or even millennia. The contributions to this yearbook present a qualitative and quantitative analysis of global historical, political, economic and demographic processes, as well as their mathematical models. This issue of the yearbook consists of three main sections: (I) Long-Term Trends in Nature and Society; (II) Cyclical Processes in Pre-industrial Societies; (III) Contemporary History and Processes. We hope that this issue of the yearbook will be interesting and useful both for historians and mathematicians, as well as for all those dealing with various social and natural science

Applications of stability theory to ecological problems

The goal of ecology is to investigate the interactions among organisms and their environment. However, ecological systems often exhibit complex dynamics. The application of mathematics to ecological problems has made tremendous progress over the years and many mathematical methods and tools have been developed for the exploration, whether analytical or numerical, of these dynamics. Mathematicians often study ecological systems by modelling them with partial differential equations (PDEs). Calculating the stability of solutions to these PDE systems is a classical question. This thesis first explores the concept of stability in the context of predator-prey invasions. Many ecological systems exhibit multi-year cycles. In such systems, invasions have a complicated spatiotemporal structure. In particular, it is common for unstable steady states to exist as long-term transients behind the invasion front, a phenomenon known as dynamical stabilisation. We combine absolute stability theory and computation to predict how the width of the stabilised region depends on parameter values. We develop our calculations in the context of a model for a cyclic predator-prey system, in which the invasion front and spatiotemporal oscillations of predators and prey are separated by a region in which the coexistence steady state is dynamically stabilised. Vegetation pattern formation in water-limited environments is another topic where stability theory plays a key role; indeed in mathematical models, these patterns are often the results of the dynamics that arise from perturbations to an unstable homogeneous steady state. Vegetation patterns are widespread in semi-deserts and aerial photographs of arid and semi-arid ecosystems have shown several kilometers square of these patterns. On hillsides in particular, vegetation is organised into banded spatial patterns. We first choose a domain in parameter space and calculate the boundary of the region in parameter space where pattern solutions exist. Finally we conclude with investigating how changes in the mean annual rainfall affect the properties of pattern solutions. Our work also highlights the importance of research on the calculation of the absolute spectrum for non-constant solutions

Entre coopération et répression : la défense des droits humains en Union soviétique sous Brejnev : étude du Groupe Helsinki de Moscou

Ce mémoire porte sur le Groupe Helsinki de Moscou et son évolution au sein de l’Union soviétique dans les années 1970 et 1980. Celui-ci y est présenté en tant qu’association dissidente originale de par son pouvoir de convergence parmi les sources d’opposition et son succès à mobiliser les instances étrangères à la cause des droits humains en URSS. L’étude se penche plus spécifiquement sur la portée de ses activités à la fois sur la conduite du gouvernement à l’intérieur du pays et sur la création d’un réseau d’activisme au-delà des frontières du régime. En maintenant une approche orientée selon ces deux perspectives, à savoir celle de la politique intérieure de l’URSS et celle de l’évolution du contexte international, il s’agit de mettre en évidence la contribution du groupe à la montée d’une opposition au régime soviétique et à ses pratiques humainitaires, mais également d’en souligner les limites. À travers cette narrative, se révèleront donc les contours du régime soviétique sous Léonid Brejnev, sa nature, ses priorités et son caractère répressif.This thesis focuses on the Moscow Helsinki Group and its evolution in the Soviet Union during the 1970s and 1980s. The Group’s work is presented as an original form of dissidence due to its ability to converge the sources of opposition and its success in mobilizing foreign advocacy groups to the cause of human rights in the USSR. This study deals more specifically with the influence of its activities both on the government’s course of behavior domestically as well as on the creation of an activism network beyond the borders of the regime. By focusing on these two perspectives, namely on the USSR’s internal politics and on the shifting international context, the research highlights the Group’s contribution to the growing opposition to the Soviet regime and its humanitarian practices, but also emphasises the limits of this strategy. This thesis hence uses these perspectives as a framework to reveal the outlines of the regime under Leonid Brezhnev, its nature, its priorities and its inclination towards repression

Archaeological Perspectives on Conflict and Warfare in Australia and the Pacific

When James Boswell famously lamented the irrationality of war in 1777, he noted the universality of conflict across history and across space – even reaching what he described as the gentle and benign southern ocean nations. This volume discusses archaeological evidence of conflict from those southern oceans, from Palau and Guam, to Australia, Vanuatu and Tonga, the Marquesas, Easter Island and New Zealand. The evidence for conflict and warfare encompasses defensive earthworks on Palau, fortifications on Tonga, and intricate pa sites in New Zealand. It reports evidence of reciprocal sacrifice to appease deities in several island nations, and skirmishes and smaller scale conflicts, including in Easter Island. This volume traces aspects of colonial-era conflict in Australia and frontier battles in Vanuatu, and discusses depictions of World War II materiel in the rock art of Arnhem Land. Among the causes and motives discussed in these papers are pressure on resources, the ebb and flow of significant climate events, and the significant association of conflict with culture contact. The volume, necessarily selective, eclectic and wide-ranging, includes an incisive introduction that situates the evidence persuasively in the broader scholarship addressing the history of human warfare

Programs as Diagrams: From Categorical Computability to Computable Categories

This is a draft of the textbook/monograph that presents computability theory using string diagrams. The introductory chapters have been taught as graduate and undergraduate courses and evolved through 8 years of lecture notes. The later chapters contain new ideas and results about categorical computability and some first steps into computable category theory. The underlying categorical view of computation is based on monoidal categories with program evaluators, called *monoidal computers*. This categorical structure can be viewed as a single-instruction diagrammatic programming language called Run, whose only instruction is called RUN. This version: improved text, moved the final chapter to the next volume. (The final version will continue lots of exercises and workouts, but already this version has severely degraded graphics to meet the size bounds.)Comment: 150 pages, 81 figure

Archaeological Perpsectives on Conflict and Warfare in Australia and the Pacific

When James Boswell famously lamented the irrationality of war in 1777, he noted the universality of conflict across history and across space – even reaching what he described as the gentle and benign southern ocean nations. This volume discusses archaeological evidence of conflict from those southern oceans, from Palau and Guam, to Australia, Vanuatu and Tonga, the Marquesas, Easter Island and New Zealand. The evidence for conflict and warfare encompasses defensive earthworks on Palau, fortifications on Tonga, and intricate pa sites in New Zealand. It reports evidence of reciprocal sacrifice to appease deities in several island nations, and skirmishes and smaller scale conflicts, including in Easter Island. This volume traces aspects of colonial-era conflict in Australia and frontier battles in Vanuatu, and discusses depictions of World War II materiel in the rock art of Arnhem Land. Among the causes and motives discussed in these papers are pressure on resources, the ebb and flow of significant climate events, and the significant association of conflict with culture contact. The volume, necessarily selective, eclectic and wide-ranging, includes an incisive introduction that situates the evidence persuasively in the broader scholarship addressing the history of human warfare

Central and Eastern European Literary Theory and the West

The twentieth century saw intensive intellectual exchange between Eastern and Central Europe and the West. Yet political and linguistic obstacles meant that many important trends in East and Central European thought and knowledge hardly registered in Western Europe and the US. This book uncovers the hidden westward movements of Eastern European literary theory and its influence on Western scholarship