Solving the woolly mammoth conundrum: amino acid 15N-enrichment suggests a distinct forage or habitat

Understanding woolly mammoth ecology is key to understanding Pleistocene community dynamics and evaluating the roles of human hunting and climate change in late Quaternary megafaunal extinctions. Previous isotopic studies of mammoths’ diet and physiology have been hampered by the ‘mammoth conundrum’: woolly mammoths have anomalously high collagen δ15N values, which are more similar to coeval carnivores than herbivores and which could imply a distinct diet and (or) habitat, or a physiological adaptation. We analyzed individual amino acids from collagen of adult woolly mammoths and coeval species and discovered greater  15N enrichment in source amino acids of woolly mammoths than in most other herbivores or carnivores. Woolly mammoths consumed an isotopically distinct food source, reflective of extreme aridity, dung fertilization and (or) plant selection. This dietary signal suggests that woolly mammoths occupied a distinct habitat or forage niche relative to other Pleistocene herbivores

Kinetic and economic analysis of reactive capture of dilute carbon dioxide with Grignard reagents

Carbon Dioxide Utilisation (CDU) processes face significant challenges, especially in the energetic cost of carbon capture from flue gas and the uphill energy gradient for CO2 reduction. Both of these stumbling blocks can be addressed by using alkaline earth metal compounds, such as Grignard reagents, as sacrificial capture agents. We have investigated the performance of these reagents in their ability to both capture and activate CO2 directly from dried flue gas (essentially avoiding the costly capture process entirely) at room temperature and ambient pressures with high yield and selectivity. Naturally, to make the process sustainable, these reagents must then be recycled and regenerated. This would potentially be carried out using existing industrial processes and renewable electricity. This offers the possibility of creating a closed loop system whereby alcohols and certain hydrocarbons may be carboxylated with CO2 and renewable electricity to create higher-value products containing captured carbon. A preliminary Techno-Economic Analysis (TEA) of an example looped process has been carried out to identify the electrical and raw material supply demands and hence determine production costs. These have compared broadly favourably with existing market values

From Traditional Farming in Morocco to Early Urban Agroecology in Northern Mesopotamia: Combining Present-day Arable Weed Surveys and Crop Isotope Analysis to Reconstruct Past Agrosystems in (Semi-)arid Regions

Published by Informa UK Limited, trading as Taylor & Francis GroupWe integrate functional weed ecology with crop stable carbon and nitrogen isotope analysis to assess their combined potential for inferring arable land management practices in (semi-)arid regions from archaeobotanical assemblages. Weed and GIS survey of 60 cereal and pulse fields in Morocco are combined with crop sampling for stable isotope analysis to frame assessment of agricultural labour intensity in terms of manuring, irrigation, tillage and hand-weeding. Under low management intensity weed variation primarily reflects geographical differences, whereas under high management intensity fields in disparate regions have similar weed flora. Manured and irrigated oasis barley fields are clearly discriminated from less intensively manured rain-fed barley terraces in southern Morocco; when fields in northern and southern Morocco are considered together, climatic differences are superimposed on the agronomic intensity gradient. Barley δ13C and δ15N values clearly distinguish among the Moroccan regimes. An integrated approach combines crop isotope values with weed ecological discrimination of low- and high-intensity regimes across multiple studies (in southern Morocco and southern Europe). Analysis of archaeobotanical samples from EBA Tell Brak, Syria suggests that this early city was sustained through extensive (low-intensity, large-scale) cereal farming

Debates of the European Parliament. Report of Proceedings of 8 March 1982. No. 1-286. 1981-1982 Session. March 1982

Background:Angiosarcomas may develop as primary tumours of unknown cause or as secondary tumours, most commonly following radiotherapy to the involved field. The different causative agents may be linked to alternate tumorigenesis, which led us to investigate the genetic profiles of morphologically indistinguishable primary and secondary angiosarcomas.Methods:Whole-genome (18k) c-DNA-mediated annealing, selection, extension and ligation analysis was used to genetically profile 26 primary and 29 secondary angiosarcomas. Key findings were thereafter validated using RT-qPCR, immunohistochemistry and validation of the gene signature to an external data set.Results:In total, 103 genes were significantly deregulated between primary and secondary angiosarcomas. Secondary angiosarcomas showed upregulation of MYC, KIT and RET and downregulation of CDKN2C. Functional annotation analysis identified multiple target genes in the receptor protein tyrosine kinase pathway. The results were validated using RT-qPCR and immunohistochemistry. Further, the gene signature was applied to an external data set and, herein, distinguished primary from secondary angiosarcomas.Conclusions:Upregulation of MYC, KIT and RET and downregulation of CDKN2C characterise secondary angiosarcoma, which implies possibilities for diagnostic application and a mechanistic basis for therapeutic evaluation of RET-kinase-inhibitors in these highly aggressive tumours

Electron Transfer from Cyt b559 and Tyrosine-D to the S2 and S3 states of the water oxidizing complex in Photosystem II at Cryogenic Temperatures

The Mn4CaO5 cluster of photosystem II (PSII) catalyzes the oxidation of water to molecular oxygen through the light-driven redox S-cycle. The water oxidizing complex (WOC) forms a triad with Tyrosine(Z) and P-680, which mediates electrons from water towards the acceptor side of PSII. Under certain conditions two other redox-active components, Tyrosine(D) (Y-D) and Cytochrome b (559) (Cyt b (559)) can also interact with the S-states. In the present work we investigate the electron transfer from Cyt b (559) and Y-D to the S-2 and S-3 states at 195 K. First, Y-D (aEuro cent) and Cyt b (559) were chemically reduced. The S-2 and S-3 states were then achieved by application of one or two laser flashes, respectively, on samples stabilized in the S-1 state. EPR signals of the WOC (the S-2-state multiline signal, ML-S-2), Y-D (aEuro cent) and oxidized Cyt b (559) were simultaneously detected during a prolonged dark incubation at 195 K. During 163 days of incubation a large fraction of the S-2 population decayed to S-1 in the S-2 samples by following a single exponential decay. Differently, S-3 samples showed an initial increase in the ML-S-2 intensity (due to S-3 to S-2 conversion) and a subsequent slow decay due to S-2 to S-1 conversion. In both cases, only a minor oxidation of Y-D was observed. In contrast, the signal intensity of the oxidized Cyt b (559) showed a two-fold increase in both the S-2 and S-3 samples. The electron donation from Cyt b (559) was much more efficient to the S-2 state than to the S-3 state

Challenges facing an understanding of the nature of low-energy excited states in photosynthesis

© 2016 Elsevier B.V. While the majority of the photochemical states and pathways related to the biological capture of solar energy are now well understood and provide paradigms for artificial device design, additional low-energy states have been discovered in many systems with obscure origins and significance. However, as low-energy states are naively expected to be critical to function, these observations pose important challenges. A review of known properties of low energy states covering eight photochemical systems, and options for their interpretation, are presented. A concerted experimental and theoretical research strategy is suggested and outlined, this being aimed at providing a fully comprehensive understanding

Interpreting ancient food practices:Stable isotope and molecular analyses of visible and absorbed residues from a year-long cooking experiment

Chemical analyses of carbonized and absorbed organic residues from archaeological ceramic cooking vessels can provide a unique window into the culinary cultures of ancient people, resource use, and environmental effects by identifying ingredients used in ancient meals. However, it remains uncertain whether recovered organic residues represent only the final foodstuffs prepared or are the accumulation of various cooking events within the same vessel. To assess this, we cooked seven mixtures of C3 and C4 foodstuffs in unglazed pots once per week for one year, then changed recipes between pots for the final cooking events. We conducted bulk stable-isotope analysis and lipid residue analysis on the charred food macro-remains, carbonized thin layer organic patina residues and absorbed lipids over the course of the experiment. Our results indicate that: (1) the composition of charred macro-remains represent the final foodstuffs cooked within vessels, (2) thin-layer patina residues represent a mixture of previous cooking events with bias towards the final product(s) cooked in the pot, and (3) absorbed lipid residues are developed over a number of cooking events and are replaced slowly over time, with little evidence of the final recipe ingredients