Matrix factorizations for quantum complete intersections

We introduce twisted matrix factorizations for quantum complete intersections of codimension two. For such an algebra, we show that in a given dimension, almost all the indecomposable modules with bounded minimal projective resolutions correspond to such matrix factorizations.Comment: 13 page

Big data analyses reveal patterns and drivers of the movements of southern elephant seals

The growing number of large databases of animal tracking provides an opportunity for analyses of movement patterns at the scales of populations and even species. We used analytical approaches, developed to cope with big data, that require no a priori assumptions about the behaviour of the target agents, to analyse a pooled tracking dataset of 272 elephant seals (Mirounga leonina) in the Southern Ocean, that was comprised of >500,000 location estimates collected over more than a decade. Our analyses showed that the displacements of these seals were described by a truncated power law distribution across several spatial and temporal scales, with a clear signature of directed movement. This pattern was evident when analysing the aggregated tracks despite a wide diversity of individual trajectories. We also identified marine provinces that described the migratory and foraging habitats of these seals. Our analysis provides evidence for the presence of intrinsic drivers of movement, such as memory, that cannot be detected using common models of movement behaviour. These results highlight the potential for big data techniques to provide new insights into movement behaviour when applied to large datasets of animal tracking.Comment: 18 pages, 5 figures, 6 supplementary figure

Structure and Thermal Stability of Ceria Films Supported on YSZ(100) and α-Al\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e(0001)

The morphology and reducibility of vapor-deposited ceria films supported on yttria-stabilized zirconia (100) (YSZ(100)) and α-Al2O3(0001) single crystals were studied using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The results of this study show that the gas environment has a significant effect on the structure of the ceria films on both substrates. CeO2 films on α-Al2O3(0001) were found to be stable in a reducing environment at temperatures up to 1000K, but underwent agglomeration and reaction with the support to form CeAlO3 upon annealing at 1273 K in air. Heating CeO2/YSZ(100) in air at 1273 K caused the ceria thin film to agglomerate into bar-shaped features which were re-dispersed by subsequent annealing in vacuum. Interactions at the CeO2-YSZ interface were also found to dramatically enhance the reducibility of ceria films supported on YSZ(100)

Data for life cycle assessment of legume biorefining for alcohol

Benchmarking the environmental sustainability of alcohol produced from legume starch against alcohol produced from cereal grains requires considering of crop production, nutrient cycling and use of protein-rich co-products via life cycle assessment. This article describes the mass balance flows behind the life cycle inventories for gin produced from wheat and peas (Pisum sativum L.) in an associated article summarising the environmental footprints of wheat- and pea-gin [1], and also presents detailed supplementary results. Activity data were collected from interviews with actors along the entire gin value chain including a distillery manager and ingredient and packaging suppliers. Important fertiliserand animal-feed substitution effects of co-product use were derived using detailed information and models on nutrient flows and animal feed composition, along with linear optimisation modelling. Secondary data on environmental burdens of specific materials and processes were obtained from the Ecoinvent v3.4 life cycle assessment database. This article provides a basis for further quantitative evaluation of the environmental sustainability of legume-alcohol value chains

Just the tonic! Legume biorefining for alcohol has the potential to reduce Europe’s protein deficit and mitigate climate change

Industrialised agriculture is heavily reliant upon synthetic nitrogen fertilisers and imported protein feeds, posing environmental and food security challenges. Increasing the cultivation of leguminous crops that biologically fix nitrogen and provide high protein feed and food could help to address these challenges. We report on the innovative use of an important leguminous crop, pea (Pisum sativum L.), as a source of starch for alcohol (gin) production, yielding protein-rich animal feed as a co-product. We undertook life cycle assessment (LCA) to compare the environmental footprint of 1 L of packaged gin produced from either 1.43 kg of wheat grain or 2.42 kg of peas via fermentation and distillation into neutral spirit. Allocated environmental footprints for pea-gin were smaller than for wheat-gin across 12 of 14 environmental impact categories considered. Global warming, resource depletion, human toxicity, acidification and terrestrial eutrophication footprints were, respectively, 12%, 15%, 15%, 48% and 68% smaller, but direct land occupation was 112% greater, for pea-gin versus wheat-gin. Expansion of LCA boundaries indicated that co-products arising from the production of 1 L of wheat- or pea-gin could substitute up to 0.33 or 0.66 kg soybean animal feed, respectively, mitigating considerable greenhouse gas emissions associated with land clearing, cultivation, processing and transport of such feed. For pea-gin, this mitigation effect exceeds emissions from gin production and packaging, so that each L of bottled pea gin avoids 2.2 kg CO2 eq. There is great potential to scale the use of legume starches in production of alcoholic beverages and biofuels, reducing dependence on Latin American soybean associated with deforestation and offering considerable global mitigation potential in terms of climate change and nutrient leakage — estimated at circa 439 Tg CO2 eq. and 8.45 Tg N eq. annually

Divergent mathematical treatments in utility theory

In this paper I study how divergent mathematical treatments affect mathematical modelling, with a special focus on utility theory. In particular I examine recent work on the ranking of information states and the discounting of future utilities, in order to show how, by replacing the standard analytical treatment of the models involved with one based on the framework of Nonstandard Analysis, diametrically opposite results are obtained. In both cases, the choice between the standard and nonstandard treatment amounts to a selection of set-theoretical parameters that cannot be made on purely empirical grounds. The analysis of this phenomenon gives rise to a simple logical account of the relativity of impossibility theorems in economic theory, which concludes the paper

Hospitalization and Alzheimer's Disease: Results from a Community-Based Study

Background. Prior studies offer conflicting findings on whether Alzheimer's disease (AD) is associated with an increased risk of hospitalization. Methods. We investigated AD and hospitalization in the Washington Heights-Inwood Columbia Aging Project (WHICAP), a community-based study of 2,334 elders in New York City. In 1996, an electronic medical records system was established that allows an e-mail alert to be sent to the research team whenever WHICAP subjects are admitted to Columbia-Presbyterian Medical Center (CPMC), the site of hospital care for the majority of subjects. Results. Of the WHICAP cohort, 13.1% was admitted to CPMC in 21 months of follow-up; 17.5% of AD patients and 11.9% of unaffected subjects were admitted (p < .01). Multivariate logistic regression models showed that more advanced AD (Clinical Dementia Rating scale 3+) was a significant risk factor for hospitalization independently of age, gender, education, comorbid medical conditions, and death in the follow-up period (OR 2.3; 95% CI: 1.1,4.6); subjects with mild or moderate AD did not show a significantly elevated risk. The prevalence of psychiatric symptoms did not differ between AD subjects who were hospitalized in the reporting period and AD subjects who were not hospitalized. Infectious disease was a more common discharge diagnosis for subjects with AD (p < .05). Conclusions. In this community-based cohort, subjects with severe AD were more likely to be hospitalized than unaffected subjects. The increased use of hospital care by these AD patients appears to be specific to AD but is not a result of psychiatric morbidity or end-of-life care. Rather, a greater risk of medical complications that require hospital care, especially infections, appears to be characteristic of severe AD

Productivity patterns in the Equatorial Pacific over the last 30,000 years

The equatorial Pacific traverses a number of productivity regimes, from the highly productive coastal upwelling along Peru to the near gyre-like productivity lows along the international dateline, making it an ideal target for investigating how biogeochemical systems respond to changing oceanographic conditions over time. However, conflicting reconstructions of productivity during periods of rapid climate change, like the last deglaciation, render the spatiotemporal response of equatorial Pacific productivity ambiguous. In this study, surface productivity since the last glacial period (30,000 years ago) is reconstructed from seven cores near the Line Islands, central equatorial Pacific, and integrated with productivity records from across the equatorial Pacific. Three coherent deglacial patterns in productivity are identified: (1) a monotonic glacial-Holocene increase in productivity, primarily along the Equator, associated with increasing nutrient concentrations over time; (2) a deglacial peak in productivity ~15,000 years ago due to transient entrainment of nutrient rich southern-sourced deep waters; and (3) possible precessional cycles in productivity in the eastern equatorial Pacific that may be related to Intertropical Convergence Zone migration and potential interactions with El Niño–Southern Oscillation dynamics. These findings suggest that productivity was generally lower during the glacial period, a trend observed zonally across the equatorial Pacific, while deglacial peaks in productivity may be prominent only in the east

A review of solar thermochemical CO2 splitting using ceria-based ceramics with designed morphologies and microstructures

ABSTRACT: This review explores the advances in the synthesis of ceria materials with specific morphologies or porous macro- and microstructures for the solar-driven production of carbon monoxide (CO) from carbon dioxide (CO2). As the demand for renewable energy and fuels continues to grow, there is a great deal of interest in solar thermochemical fuel production (STFP), with the use of concentrated solar light to power the splitting of carbon dioxide. This can be achieved in a two-step cycle, involving the reduction of CeO2 at high temperatures, followed by oxidation at lower temperatures with CO2, splitting it to produce CO, driven by concentrated solar radiation obtained with concentrating solar technologies (CST) to provide the high reaction temperatures of typically up to 1,500 degrees C. Since cerium oxide was first explored as a solar-driven redox material in 2006, and to specifically split CO2 in 2010, there has been an increasing interest in this material. The solar-to-fuel conversion efficiency is influenced by the material composition itself, but also by the material morphology that mostly determines the available surface area for solid/gas reactions (the material oxidation mechanism is mainly governed by surface reaction). The diffusion length and specific surface area affect, respectively, the reduction and oxidation steps. They both depend on the reactive material morphology that also substantially affects the reaction kinetics and heat and mass transport in the material. Accordingly, the main relevant options for materials shaping are summarized. We explore the effects of microstructure and porosity, and the exploitation of designed structures such as fibers, 3-DOM (three-dimensionally ordered macroporous) materials, reticulated and replicated foams, and the new area of biomimetic/biomorphous porous ceria redox materials produced from natural and sustainable templates such as wood or cork, also known as ecoceramics.info:eu-repo/semantics/publishedVersio

3DOM ceria ecoceramics from sustainable cork templates for solar thermochemical CO2 splitting

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