War and Veterans : An Introduction

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Thinning mechanisms of heterogeneous continental lithosphere

The mechanisms responsible for the formation of extremely thinned continental crust (<10 km thick) and lithosphere during rifting remains debated. Observations from present-day and fossil passive margins highlight the role of deep-seated deformation, likely controlled by heterogeneities within the continental lithosphere, such as changing lithologies, mechanical anisotropies and inherited structures. We investigate the mechanisms of lithospheric thinning by exploring the role of pre-existing heterogeneities on the architecture and evolution of rifted margins. We estimate pre-rift pressure conditions (P0) vs. depth diagrams of crustal to lithospheric sections, to quantify rift-related modifications on inherited lithostatic pressure gradients. Two field examples from the Alpine Tethys margins in the Eastern and Southern Alps (SE Switzerland and N Italy) were selected to characterize: (1) the pre-rift architecture of the continental lithosphere; (2) the localization of rift-related deformation in distinct portions of the lithosphere; and (3) the interaction between pre-existing heterogeneities of the lithosphere and rift-related structures. These observations are compared with high-resolution, two-dimensional thermo-mechanical numerical models. The design of the models takes into account pre-existing mechanical heterogeneities representing the initial pre-rift architecture of the continental lithosphere. Extensional structures consist of high-angle and low-angle normal faults, anastomosing shear-zones and decoupling horizons. Such structures accommodate the lateral extraction of mechanically stronger levels derived from the middle to lower crust. As a result, the extremely thinned continental crust in Tethyan passive margins represents the juxtaposition and amalgamation of distinct strong levels of the crust separated by major extensional structures identified by sharp pressure gradients. Future work should determine the applicability of these results to other present-day and fossil rifted margins

Bayesian and frequentist analysis of an Austrian genome-wide association study of colorectal cancer and advanced adenomas

Most genome-wide association studies (GWAS) were analyzed using single marker tests in combination with stringent correction procedures for multiple testing. Thus, a substantial proportion of associated single nucleotide polymorphisms (SNPs) remained undetected and may account for missing heritability in complex traits. Model selection procedures present a powerful alternative to identify associated SNPs in high-dimensional settings. In this GWAS including 1060 colorectal cancer cases, 689 cases of advanced colorectal adenomas and 4367 controls we pursued a dual approach to investigate genome-wide associations with disease risk applying both, single marker analysis and model selection based on the modified Bayesian information criterion, mBIC2, implemented in the software package MOSGWA. For different case-control comparisons, we report models including between 1-14 candidate SNPs. A genome-wide significant association of rs17659990 (P=5.43x10(-9), DOCK3, chromosome 3p21.2) with colorectal cancer risk was observed. Furthermore, 56 SNPs known to influence susceptibility to colorectal cancer and advanced adenoma were tested in a hypothesis-driven approach and several of them were found to be relevant in our Austrian cohort. After correction for multiple testing (alpha=8.9x10(-4)), the most significant associations were observed for SNPs rs10505477 (P=6.08x10(-4)) and rs6983267 (P=7.35x10(-4)) of CASC8, rs3802842 (P=8.98x10(-5), COLCA1,2), and rs12953717 (P=4.64x10(-4), SMAD7). All previously unreported SNPs demand replication in additional samples. Reanalysis of existing GWAS datasets using model selection as tool to detect SNPs associated with a complex trait may present a promising resource to identify further genetic risk variants not only for colorectal cancer

Zusammenhänge erkennen, konzeptuelles Denken entwickeln: Konzept eines Lehr-Lern-Modells für den Sachunterricht

Besonders im Sachunterricht ist es aufgrund seiner diversen Bezugsdisziplinen herausfordernd, eine Basis für Anschlussfähigkeit zur nächsten Bildungsstufe zu schaffen. Die Schwierigkeit liegt vordringlich darin, gleichsam das Wesen des Sachunterrichts, mit seinem Anspruch der ganzheitlichen Welterschließung, und die fachlich orientierten Anforderungen der Sekundarstufe zu berücksichtigen. Das Verbindende dieser beiden Ansätze sind zentrale Konzepte diverser Inhalte aus den Bezugsdisziplinen. Die Fähigkeit, Inhalte auf diese Weise zu vernetzen, ist jedoch anspruchsvoll und muss erlernt werden. Dazu fehlt es an Theorien mit Vorschlägen zu konkreten Handlungsideen. Dieser Artikel skizziert ein Lehr-Lern-Modell für den Sachunterricht, das diese Problematik aufgreift und zu lösen sucht. Es zeigt einen theoretischen Ansatz zum verstehensorientierten und konzeptbezogenen Lernen, verknüpft mit fachdidaktischen Tools zur unterrichtlichen Planung, Gestaltung und Umsetzung kompetenzorientierten Sachunterrichts. Ausgehend von der Entwicklung des Lehr-Lern-Modells werden theoretische Hintergründe erläutert, bevor das Modell selbst und seine Einbeziehung in die Unterrichtspraxis vorgestellt werden

Open a GLAM lab

Defining a GLAM Lab: A Galleries, Libraries, Archives and Museums (GLAM) Lab is a place for experimenting with digital collections and data. It is where researchers, artists, entrepreneurs, educators and the interested public can collaborate with an engaged group of partners to create new collections, tools, and services that will help transform the future ways in which knowledge and culture are disseminated. The exchanges and experimentation in a Lab are open, iterative and shared widely. This book describes why and how to open a GLAM Lab and encourages participation in a movement that can transform organisations and the communities they partner with. Building a GLAM Lab: Building a GLAM Lab involves defining its core values to guide future work, fostering a culture that is open, transparent, generous, collaborative, creative, inclusive, bold, ethical, accessible and encourages a mindset of exploration. The Lab should be grounded in user-centred and participatory design processes and its staff should be able to clearly communicate what the Lab is about. It's important to think big but start small and establish quick wins to get up and running. GLAM Lab teams: There are recommendations for the qualities and skills to look for in Labs teams, how to go about finding allies within and outside the institution, and ideas on how to create a nurturing environment for teams to thrive in. Labs teams have no optimal size or composition, and its team members can come from all walks of life. Teams need a healthy culture to ensure a well-functioning Lab which might be augmented intermittently by fellows, interns or researchers-inresidence. For a Lab to have lasting impact it must be integrated into the parent organisation and have the support of staff at all levels. User communities: GLAM Labs will need to engage and connect with potential users and partners. This means rethinking these relationships to help establish clear and targeted messages for specific communities. In turn, this enables Labs to adjust their tools, services and collections to establish deeper partnerships based on co-creation, and open and equal dialogue. Rethinking collections and Data: The book discusses the digital collections which are an integral part of Labs. It provides insights on how to share the collections as data, and how to identify, assess, describe, access, and reuse the collections. In addition, there is information about messy and curated data, digitisation, metadata, rights and preservation. Transformation: Experimentation is the critical core of the Lab's process. Insights about how to transform tools into operational services are demonstrated. It shows that experimentation can prepare the organisational culture and services for transformation. There is an examination of funding and the advantages and disadvantages of various models through discussion of the different mechanisms and options that an organisation can apply to Lab set-ups. Funding and Sustainability: We share insights on how to plan for a Lab's sustainability as well as a step-by-step guide for when an organisation is retiring or decommissioning a Lab. Labs have a pivotal role in the transformation of GLAMs and the book highlights the critical importance of Labs in changing the future of digital cultural heritage.Funded by UCL Qatar (Mmember of Qatar Foundation) and Qatar University Library. There has also been support from the British Library Labs, and the Library of Congress Labs

A study of the TEX86 paleothermometer in the water column and sediments of the Santa Barbara Basin, California

Particulate organic matter collected during a 2-year period, as part of an ongoing sediment trap study, and a high-resolution sediment record from 1850 to 1987 A.D. from the Santa Barbara Basin were analyzed for TEX86, a temperature proxy based on marine crenarchaeotal membrane lipids. Highest fluxes of crenarchaeotal lipids in the water column were found in May-June 1996 and from October 1996 to January 1997 and, in general, showed a good correlation with mass fluxes. TEX86 reconstructed temperatures from the sediment trap series ranged from 8 to 11°C and were usually substantially lower than sea surface temperatures (SST), indicating that unlike in previous studies, the TEX86 corresponds to subsurface temperatures, likely between 100 and 150 m. TEX86 temperature variations observed in trap samples were not coupled to changes in SST or deep-water temperatures and only to some degree with crenarchaeotal lipid fluxes. This suggests that a complex combination of different depth origins and seasonal growth periods of Crenarchaeota contributed to the variations in TEX86 signal during the annual cycle. TEX86 temperatures in the two sediment cores studied (8-13°C) were also substantially lower than those of instrumental SST records (14-17.5°C) confirming that TEX86 records a subsurface temperature signal in the Santa Barbara Basin. This result highlights the importance of performing calibration studies using sediment traps and core tops before applying the TEX86 temperature proxy in a given study area

Reconstruction of sea surface temperature variations in the Arabian Sea over the last 23 kyr using organic proxies (TEX86 and U37K')

Two sediment cores from the western Arabian Sea, NIOP905 and 74KL, were analyzed to determine sea surface temperature (SST) variations over the last 23 kyr. Two organic molecular SST proxies were used, the well-established U37K' based on long-chain unsaturated ketones synthesized by haptophyte algae and the newly proposed TEX86 derived from the membrane lipids of Crenarchaeota. Comparison of NIOP905 and 74KL core top data with present-day SST (0-10 m) values indicates that both proxies yield temperatures similar to local annual mean SSTs. However, TEX86 and U37K' SST down-core records derived from the same cores differ in magnitude and phasing. The alkenone SST record of NIOP905 shows small changes in SST (∼0.5°C) over the last 23 kyr, while that of core 74KL shows a ∼2°C increase from the Last Glacial Maximum (LGM) (23-19 calendar (cal) kyr B.P.) through the Holocene (the last 11.5 cal kyr B.P.) synchronous with changes in the Northern Hemisphere. In contrast, the TEX86 records of both cores show a large increase in SST from 22°-23°C in the LGM to 28°-30°C during Termination I (19-11.5 cal kyr B.P.), decreasing to present-day annual means of ∼26°C. A cold phase between 14.5 and 12 cal kyr B.P. that may correspond to the Antarctic cold reversal is also observed. This implies a Southern Hemisphere control on tropical SST reconstructed by the TEX86, possibly related to SW monsoon. Our results suggest that the application of both TEX86 and U37K' give different but complementary information on SST developments in past marine environments

Coherent millennial-scale patterns in Uk'37 and TEX86H temperature records during the penultimate interglacial-to-glacial cycle in the western Mediterranean

The TEX86H temperature proxy is a relatively new proxy based on crenarchaeotal lipids and has rarely been applied together with other temperature proxies. In this study, we applied the TEX86H on a sediment core from the Alboran Sea (western Mediterranean, core ODP-977A) covering the penultimate climate cycle, that is, from 244 to 130 ka, and compared this with previously published sea surface temperatures derived from the U37k' of alkenones of haptophyta and Mg/Ca records of planktonic foraminifera. The TEX86H temperature record shows remarkably similar stadial-interstadial patterns and abrupt temperature changes to those observed with the U37k' palaeothermometer. Absolute TEX86H temperature estimates are generally higher than those of U37k', though this difference (<3°C in 81% of the data points) is mainly within the temperature calibration error for both proxies, suggesting that crenarchaeota and haptophyta experienced similar temperature variations. During occasional events (<5% of the analyzed time span), however, the TEX86H exhibits considerably higher absolute temperature estimates than the U37k'. Comparison with Mg/Ca records of planktonic foraminifera as well as other Mediterranean TEX86 and U37k' records suggests that part of this divergence may be attributed to seasonal differences, that is, with TEX86H reflecting mainly the warm summer season while U37k' would show annual mean. Biases in the global calibration of both proxies or specific biases in the Mediterranean are an alternative, though less likely, explanation. Despite differences between absolute TEX86H and U37k' temperatures, the correlation between the two proxies (r2 = 0.59, 95% significance) provides support for the occurrence of abrupt temperature variations in the western Mediterranean during the penultimate interglacial-to-glacial cycle

Pathways of Carbon Assimilation and Ammonia Oxidation Suggested by Environmental Genomic Analyses of Marine Crenarchaeota

Marine Crenarchaeota represent an abundant component of oceanic microbiota with potential to significantly influence biogeochemical cycling in marine ecosystems. Prior studies using specific archaeal lipid biomarkers and isotopic analyses indicated that planktonic Crenarchaeota have the capacity for autotrophic growth, and more recent cultivation studies support an ammonia-based chemolithoautotrophic energy metabolism. We report here analysis of fosmid sequences derived from the uncultivated marine crenarchaeote, Cenarchaeum symbiosum, focused on the reconstruction of carbon and energy metabolism. Genes predicted to encode multiple components of a modified 3-hydroxypropionate cycle of autotrophic carbon assimilation were identified, consistent with utilization of carbon dioxide as a carbon source. Additionally, genes predicted to encode a near complete oxidative tricarboxylic acid cycle were also identified, consistent with the consumption of organic carbon and in the production of intermediates for amino acid and cofactor biosynthesis. Therefore, C. symbiosum has the potential to function either as a strict autotroph, or as a mixotroph utilizing both carbon dioxide and organic material as carbon sources. From the standpoint of energy metabolism, genes predicted to encode ammonia monooxygenase subunits, ammonia permease, urease, and urea transporters were identified, consistent with the use of reduced nitrogen compounds as energy sources fueling autotrophic metabolism. Homologues of these genes, recovered from ocean waters worldwide, demonstrate the conservation and ubiquity of crenarchaeal pathways for carbon assimilation and ammonia oxidation. These findings further substantiate the likely global metabolic importance of Crenarchaeota with respect to key steps in the biogeochemical transformation of carbon and nitrogen in marine ecosystems