1,604 research outputs found
Landscape characteristics shape surface soil microbiomes in the Chihuahuan Desert
IntroductionSoil microbial communities, including biological soil crust microbiomes, play key roles in water, carbon and nitrogen cycling, biological weathering, and other nutrient releasing processes of desert ecosystems. However, our knowledge of microbial distribution patterns and ecological drivers is still poor, especially so for the Chihuahuan Desert.MethodsThis project investigated the effects of trampling disturbance on surface soil microbiomes, explored community composition and structure, and related patterns to abiotic and biotic landscape characteristics within the Chihuahuan Desert biome. Composite soil samples were collected in disturbed and undisturbed areas of 15 long-term ecological research plots in the Jornada Basin, New Mexico. Microbial diversity of cross-domain microbial groups (total Bacteria, Cyanobacteria, Archaea, and Fungi) was obtained via DNA amplicon metabarcode sequencing. Sequence data were related to landscape characteristics including vegetation type, landforms, ecological site and state as well as soil properties including gravel content, soil texture, pH, and electrical conductivity.ResultsFilamentous Cyanobacteria dominated the photoautotrophic community while Proteobacteria and Actinobacteria dominated among the heterotrophic bacteria. Thaumarchaeota were the most abundant Archaea and drought adapted taxa in Dothideomycetes and Agaricomycetes were most abundant fungi in the soil surface microbiomes. Apart from richness within Archaea (p = 0.0124), disturbed samples did not differ from undisturbed samples with respect to alpha diversity and community composition (p ≥ 0.05), possibly due to a lack of frequent or impactful disturbance. Vegetation type and landform showed differences in richness of Bacteria, Archaea, and Cyanobacteria but not in Fungi. Richness lacked strong relationships with soil variables. Landscape features including parent material, vegetation type, landform type, and ecological sites and states, exhibited stronger influence on relative abundances and microbial community composition than on alpha diversity, especially for Cyanobacteria and Fungi. Soil texture, moisture, pH, electrical conductivity, lichen cover, and perennial plant biomass correlated strongly with microbial community gradients detected in NMDS ordinations.DiscussionOur study provides first comprehensive insights into the relationships between landscape characteristics, associated soil properties, and cross-domain soil microbiomes in the Chihuahuan Desert. Our findings will inform land management and restoration efforts and aid in the understanding of processes such as desertification and state transitioning, which represent urgent ecological and economical challenges in drylands around the world
Insights into temperature controls on rockfall occurrence and cliff erosion
A variety of environmental triggers have been associated with the occurrence of rockfalls however their role and relative significance remains poorly constrained. This is in part due to the lack of concurrent data on rockfall occurrence and cliff face conditions at temporal resolutions that mirror the variability of environmental conditions, and over durations for large enough numbers of rockfall events to be captured. The aim of this thesis is to fill this data gap, and then to specifically focus on the role of temperature in triggering rockfall that this data illuminates. To achieve this, a long-term multiannual 3D rockfall dataset and contemporaneous Infrared Thermography (IRT) monitoring of cliff surface temperatures has been generated. The approaches used in this thesis are undertaken at East Cliff, Whitby, which is a coastal cliff located in North Yorkshire, UK. The monitored section is ~ 200 m wide and ~65 m high, with a total cliff face area of ~9,592 m². A method for the automated quantification of rockfall volumes is used to explore data collected between 2017–2019 and 2021, with the resulting inventory including > 8,300 rockfalls from 2017–2019 and > 4,100 rockfalls in 2021, totalling > 12,400 number of rockfalls.
The analysis of the inventory demonstrates that during dry conditions, increases in rockfall frequency are coincident with diurnal surface temperature fluctuations, notably at sunrise, noon and sunset in all seasons, leading to a marked diurnal pattern of rockfall. Statistically significant relationships are observed to link cliff temperature and rockfall, highlighting the response of rock slopes to absolute temperatures and changes in temperature. This research also shows that inclement weather constitutes the dominant control over the annual production of rockfalls but also quantifies the period when temperature controls are dominant. Temperature-controlled rockfall activity is shown to have an important erosional role, particularly in periods of iterative erosion dominated by small size rockfalls. As such, this thesis provides for the first high-resolution evidence of temperature controls on rockfall activity, cliff erosion and landform development
Frontiers of Humanity and Beyond: Towards new critical understandings of borders. Working Papers
UIDB/04666/2020
UIDP/04666/2020publishersversionpublishe
The European Experience: A Multi-Perspective History of Modern Europe, 1500–2000
The European Experience brings together the expertise of nearly a hundred historians from eight European universities to internationalise and diversify the study of modern European history, exploring a grand sweep of time from 1500 to 2000. Offering a valuable corrective to the Anglocentric narratives of previous English-language textbooks, scholars from all over Europe have pooled their knowledge on comparative themes such as identities, cultural encounters, power and citizenship, and economic development to reflect the complexity and heterogeneous nature of the European experience. Rather than another grand narrative, the international author teams offer a multifaceted and rich perspective on the history of the continent of the past 500 years. Each major theme is dissected through three chronological sub-chapters, revealing how major social, political and historical trends manifested themselves in different European settings during the early modern (1500–1800), modern (1800–1900) and contemporary period (1900–2000). This resource is of utmost relevance to today’s history students in the light of ongoing internationalisation strategies for higher education curricula, as it delivers one of the first multi-perspective and truly ‘European’ analyses of the continent’s past. Beyond the provision of historical content, this textbook equips students with the intellectual tools to interrogate prevailing accounts of European history, and enables them to seek out additional perspectives in a bid to further enrich the discipline
A War of Words: The Forms and Functions of Voice-Over in the American World War II Film — An Interdisciplinary Analysis
Aside from being American World War II films, what else do the following films have in common? The Big Red One; Hacksaw Ridge; Harts War; Mister Roberts; Stalag 17; and The Thin Red Line — all have voice-over in them. These, and hundreds of other war films have voice-overs that are sometimes the thoughts of a fearful soldier; the wry observations of a participant-observer; or the declarations of all-knowing authoritative figures. There are voice-overs blasted out through a ships PA system; as the reading of a heart-breaking letter; or as the words of a dead comrade, heard again in the mind of a haunted soldier. This thesis questions why is voice-over such a recurring phenomenon in these films? Why is it conveyed in so many different forms? What are the terms for those different forms? What are their narrative functions?
A core component of this thesis is a new taxonomy of the six distinct forms of voice-over: acousmatic, audioemic, epistolary, objective, omniscient, and subjective. However, the project is more than a structuralist taxonomy that merely serves to identify, and define those forms. It is also a close examination of their narrative functions beyond the unimaginative trope that voice-over in war films is simply a convenient storytelling device. Through interdisciplinarity — combined with a realist framework — I probe the correlations between: the conditions, codification, and suppression of speech within the U.S. military, and the manifestations of that experience through the cinematic device, and genre convention of voice-over.
In addition, I present a radically new interpretation of the voice-overs in The Thin Red Line (Terrence Malick, 1998) as being both a choric meta-memorial to James Jones; and a Greek tragedy — with its replication of the stagecraft of Aeschylus, in its use of the cosmic frame, and the inclusion of a collective character, which I have named ‘The Chorus of Unknown Soldiers’.
The overall result is a more logical, and nuanced explanation of the forms, functions, and prevalent use of voice-over in the American World War II film
To the Last Drop: Affective Economies of Extraction and Sentimentality
The romance of extraction underlies and partly defines Western modernity and our cultural imaginaries. Combining affect studies and environmental humanities, this volume analyzes societies' devotion to extraction and fossil resources. This devotion is shaped by a nostalgic view on settler colonialism as well as by contemporary "affective economies" (Sara Ahmed). The contributors examine the links between forms of extractivism and gendered discourses of sentimentality and the ways in which cultural narratives and practices deploy the sentimental mode (in plots of attachment, sacrifice, and suffering) to promote or challenge extractivism
Welcome to Mitchell’s Plain
Under the apartheid regime, South Africa’s Mitchell’s Plain, situated close to Cape Town, was devised as a “model township.” A cutting-edge urban planning scheme would provide middle-class Coloured people—evacuated from their homes by racialised rehousing programmes—with exemplary living conditions. This flagship for the regime was inaugurated with fanfare in 1976, and heavily publicised not just within South Africa but also in the international press. Cohorts of political leaders and journalists were invited to admire first-hand how racial segregation could be paired with progressive social planning. A documentary film was commissioned for worldwide distribution: Mitchells Plain (1980). Like other well-laid plans, however, Mitchell’s Plain would foil the designs of its architects. The vaunted utopian township was, for its inhabitants, deeply flawed: essential facilities such as schools and transport were thoroughly inadequate to the population’s needs. These sources of frustration generated a groundswell of civic activism. While the government had banked on separating the Coloured population from the national liberation movement, in 1983, Mitchell’s plain acquired important symbolic status as the birthplace of the United Democratic Front, an umbrella organisation of anti-apartheid associations. This event marked a turning point in the history of South Africa’s struggle for freedom. This study chronicles the fortunes of Mitchell’s Plain: its conception and role as propaganda for the apartheid regime. It draws on official documentary sources, but also on interviews with the various social actors whose life-experience conveys a very different image of the process, to reconstitute from a critical and historical perspective, the ill-fated window-dressing efforts of the National Party government during its declining years
Geoarchaeological Approaches to Pictish Settlement Sites: Assessing Heritage at Risk
Due to the poor preservation of Pictish period buildings and the occupation deposits within them, very little is known of daily life in early medieval Scotland. In lowland and coastal areas, Pictish buildings are generally truncated by deep ploughing, coastal erosion, or urban development, while those uncovered in upland areas seem to have no preserved floor deposits for reasons that remain poorly understood. Geoarchaeological techniques are particularly effective in clarifying site formation processes and understanding post-depositional transformations. They are also a powerful research tool for identifying floor deposits, distinguishing their composition, and linking this to daily activities. However, archaeologists are often reluctant to apply geoarchaeological methods if they suspect preservation is poor or stratigraphy is not visible in the field.
This study therefore employs an innovative suite of geoarchaeological techniques to evaluate the preservation of Pictish period buildings and the potential that fragmentary buildings have to reconstruct daily life in early medieval Scotland. Alongside literature analysis and a desk-based comparison with national soil datasets, over 400 sediment samples from three key settlement sites were subjected to integrated soil micromorphology, x-ray fluorescence, magnetic susceptibility, loss-on-ignition, pH, electrical conductivity and microrefuse analysis. The combined data were successful in generating new information about the depositional and post-depositional history of the sites, preservation conditions of the occupation deposits, and activity areas within domestic dwellings. Most significantly, the integrated approach demonstrated that ephemeral and fragmented occupation surfaces retain surviving characteristics of the use of space, even if floors are not preserved well enough to be clearly defined in the field or in thin-section. A partnership with Historic Environment Scotland has channelled this work into research-led guidelines aimed at communicating geoarchaeological methods and principles to a wider audience
Subduction Zone Dynamics and Forearc Tectonostratigraphic Evolution: Talara Basin, northwestern Peru
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