Universal inversion formulas for recovering a function from spherical means

The problem of reconstruction a function from spherical means is at the heart of several modern imaging modalities and other applications. In this paper we derive universal back-projection type reconstruction formulas for recovering a function in arbitrary dimension from averages over spheres centered on the boundary an arbitrarily shaped smooth convex domain. Provided that the unknown function is supported inside that domain, the derived formulas recover the unknown function up to an explicitly computed smoothing integral operator. For elliptical domains the integral operator is shown to vanish and hence we establish exact inversion formulas for recovering a function from spherical means centered on the boundary of elliptical domains in arbitrary dimension.Comment: [20 pages, 2 figures] Compared to the previous versions I corrected some typo

Self-adjusting multisegment, deployable, natural circulation radiator Patent

Development and characteristics of natural circulation radiator for use with nuclear power plants installed in lunar space station

I List the Trill in Golden Throat

https://digitalcommons.library.umaine.edu/mmb-vp/4611/thumbnail.jp

Model Estimation Within Planning and Learning

Risk and reward are fundamental concepts in the cooperative control of unmanned systems. In this research, we focus on developing a constructive relationship between cooperative planning and learning algorithms to mitigate the learning risk, while boosting system (planner & learner) asymptotic performance and guaranteeing the safety of agent behavior. Our framework is an instance of the intelligent cooperative control architecture (iCCA) where the learner incrementally improves on the output of a baseline planner through interaction and constrained exploration. We extend previous work by extracting the embedded parameterized transition model from within the cooperative planner and making it adaptable and accessible to all iCCA modules. We empirically demonstrate the advantage of using an adaptive model over a static model and pure learning approaches in an example GridWorld problem and a UAV mission planning scenario with 200 million possibilities. Finally we discuss two extensions to our approach to handle cases where the true model can not be captured exactly through the presumed functional form.United States. Air Force Office of Scientific Research (FA9550-09-1-0522)Natural Sciences and Engineering Research Council of CanadaUSAF (FA9550-09-1-0522

Ecosystem perspectives are needed to manage zoonotic risks under climate change

Climate change and biodiversity loss are among this century’s greatest threats to human health and are exposing people worldwide to increasing food and water insecurity, extreme weather, pollution, and infectious disease threats.1 2 Zoonotic infectious diseases are situated at this nexus between environmental change, ecosystems, and health. Zoonotic pathogens and parasites are maintained in an animal reservoir and regularly or sporadically spill over to cause disease in humans,3 sometimes leading to sustained human-to-human or vectorborne epidemics (eg, severe acute respiratory syndrome coronaviruses (SARS-CoV), Ebola, plague) but more commonly to endemic or sporadic disease (eg, leptospirosis, helminthiases, Lyme disease, hantavirus diseases)

Factors Associated with Smoking Cessation and Risk of Smoking Initiation in Bulgarian Youth

The goal of this project was to explore the factors associated with smoking behavior among Bulgarian adolescents. A sample recruited from 12 high schools in Bulgaria (N = 673, mean age = 16.52, 65% female), was used for the analyses in this paper. A series of logistic regressions were performed to explore the factors associated with smoking cessation and increased risk of smoking initiation. Based on self-reported smoking status participants completed different sets of questionnaires and were included in separate models exploring smoking cessation and increased risk of smoking initiation. Variables consistently associated with smoking like stress, coping strategies, peer influence, family influence, exposure to tobacco related marketing were included as predictor variables in both models. In addition each of the two models included the relevant constructs of decisional balance and temptations from the Transtheoretical Model (TTM). The final logistic model differentiating smokers/ex-smokers included age, parental smoking status, Temptation to smoke, and support for smoking bans in public places as variables, correctly classifying 82.3% of the sample. The final model among nonsmokers differentiating higher risk/lower risk of smoking initiation included the strength of the belief that smoking is harmful, Temptations to try smoking, Pros of being smoke-free, and support for smoking bans in public places, correctly classifying 72.7% of the sample. These results provide better understanding of the factors associated with smoking behavior in Bulgarian adolescents that can guide the development of smoking cessation and prevention programs for this population

The Western Design Revised: Death, Dissent, and Discontent on the Gloucester, 1654-1656

In December 1654 a large naval force departed from Portsmouth and sailed across the Atlantic. Its goal was to expand the English Commonwealth in the Caribbean at the expense of Spanish colonies. The Gloucester, a third-rate frigate recently constructed as part of Oliver Cromwell’s ambitious shipbuilding programme, was one of the largest and most heavily armed warships of the expedition. Combining analysis of courts martial accounts, inventories, journals, letters, sailing instructions, and wills, this article argues for the Gloucester’s importance as a case study and microcosm for understanding the economic, political, religious, and social problems that the navy and wider Protectorate faced. It revises traditional historiography about the topic that has underestimated the significance of the naval context to the Western Design. Crucial to this new history is that the extreme hardships and religious divisions created tensions that targeted the leadership of Admiral William Goodsonn. Of particular importance in this narrative is Benjamin Blake, captain of the Gloucester, who clashed with Goodsonn over key policies. By focusing on the Gloucester and exploring its crew’s experiences, this article shows that the English navy was a restricted and internally conflicted force when operating at the peripheries of the state network

Transcriptomic and proteomic analyses of Desulfovibrio vulgaris biofilms: carbon and energy flow contribute to the distinct biofilm growth state.

BackgroundDesulfovibrio vulgaris Hildenborough is a sulfate-reducing bacterium (SRB) that is intensively studied in the context of metal corrosion and heavy-metal bioremediation, and SRB populations are commonly observed in pipe and subsurface environments as surface-associated populations. In order to elucidate physiological changes associated with biofilm growth at both the transcript and protein level, transcriptomic and proteomic analyses were done on mature biofilm cells and compared to both batch and reactor planktonic populations. The biofilms were cultivated with lactate and sulfate in a continuously fed biofilm reactor, and compared to both batch and reactor planktonic populations.ResultsThe functional genomic analysis demonstrated that biofilm cells were different compared to planktonic cells, and the majority of altered abundances for genes and proteins were annotated as hypothetical (unknown function), energy conservation, amino acid metabolism, and signal transduction. Genes and proteins that showed similar trends in detected levels were particularly involved in energy conservation such as increases in an annotated ech hydrogenase, formate dehydrogenase, pyruvate:ferredoxin oxidoreductase, and rnf oxidoreductase, and the biofilm cells had elevated formate dehydrogenase activity. Several other hydrogenases and formate dehydrogenases also showed an increased protein level, while decreased transcript and protein levels were observed for putative coo hydrogenase as well as a lactate permease and hyp hydrogenases for biofilm cells. Genes annotated for amino acid synthesis and nitrogen utilization were also predominant changers within the biofilm state. Ribosomal transcripts and proteins were notably decreased within the biofilm cells compared to exponential-phase cells but were not as low as levels observed in planktonic, stationary-phase cells. Several putative, extracellular proteins (DVU1012, 1545) were also detected in the extracellular fraction from biofilm cells.ConclusionsEven though both the planktonic and biofilm cells were oxidizing lactate and reducing sulfate, the biofilm cells were physiologically distinct compared to planktonic growth states due to altered abundances of genes/proteins involved in carbon/energy flow and extracellular structures. In addition, average expression values for multiple rRNA transcripts and respiratory activity measurements indicated that biofilm cells were metabolically more similar to exponential-phase cells although biofilm cells are structured differently. The characterization of physiological advantages and constraints of the biofilm growth state for sulfate-reducing bacteria will provide insight into bioremediation applications as well as microbially-induced metal corrosion