5,244 research outputs found
Low-temperature epitaxial growth of thin metal films
We present a different mechanism to explain the occurrence of long-lived oscillations in diffraction spot intensities during epitaxial growth of metal films on fcc (100) substrates at low temperature. Rather than rely on the common picture of cyclical nucleation and growth to produce the oscillations, the model invokes ‘‘downward funneling’’ deposition dynamics to fourfold-hollow adsorption sites
Living labs and co-production: university campuses as platforms for sustainability science
Living labs and co-production are increasingly popular strategies for universities to address sustainability challenges and yet the links between them remain largely implicit. This paper discusses the potential of living labs to provide a holistic and iterative framework for the co-production of knowledge. The University Living Lab initiative was launched in 2012 to transform the University of Manchester campus into a site for applied teaching and research around sustainability. Its goal was to provide a framework for students and academics to engage with the opportunities to work with Estates staff and their environmental consultants on applied sustainability challenges. This paper discusses the generation of living lab projects, the design of the campus as a living lab, and institutional visibility, identifying the key strengths of the living lab approach and the challenges of applying it more broadly
Senior Recital: Andrew Lastrapes, jazz guitar
This recital is presented in partial fulfillment of requirements for the degrees Bachelor of Music in Performance. Mr. Lastrapes studies jazz guitar with Trey Wright.https://digitalcommons.kennesaw.edu/musicprograms/1469/thumbnail.jp
A virulent strain of Deformed Wing Virus (DWV) of Honeybees (Apis mellifera) prevails after Varroa destructor-mediated, or in vitro, transmission
This work was supported by the Biotechnology and Biological Sciences Research Council, the Department for Environment, Food and Rural Affairs, the Natural Environment Research Council, the Scottish Government and the Wellcome Trust, under the Insect Pollinators Initiative (grant #BBI0008281, http://www.bbsrc.ac.uk/pollinators) and by University of Warwick HEIF5 Proof of Concept funding to DJE.The globally distributed ectoparasite Varroa destructor is a vector for viral pathogens of the Western honeybee (Apis mellifera), in particular the Iflavirus Deformed Wing Virus (DWV). In the absence of Varroa low levels DWV occur, generally causing asymptomatic infections. Conversely, Varroa-infested colonies show markedly elevated virus levels, increased overwintering colony losses, with impairment of pupal development and symptomatic workers. To determine whether changes in the virus population were due Varroa amplifying and introducing virulent virus strains and/or suppressing the host immune responses, we exposed Varroa-naive larvae to oral and Varroa-transmitted DWV. We monitored virus levels and diversity in developing pupae and associated Varroa, the resulting RNAi response and transcriptome changes in the host. Exposed pupae were stratified by Varroa association (presence/absence) and virus levels (low/high) into three groups. Varroa-free pupae all exhibited low levels of a highly diverse DWV population, with those exposed per os (group NV) exhibiting changes in the population composition. Varroa-associated pupae exhibited either low levels of a diverse DWV population (group VL) or high levels of a near-clonal virulent variant of DWV (group VH). These groups and unexposed controls (C) could be also discriminated by principal component analysis of the transcriptome changes observed, which included several genes involved in development and the immune response. All Varroa tested contained a diverse replicating DWV population implying the virulent variant present in group VH, and predominating in RNA-seq analysis of temporally and geographically separate Varroa-infested colonies, was selected upon transmission from Varroa, a conclusion supported by direct injection of pupae in vitro with mixed virus populations. Identification of a virulent variant of DWV, the role of Varroa in its transmission and the resulting host transcriptome changes furthers our understanding of this important viral pathogen of honeybees.Peer reviewe
Investigation of Magnesium Cation-proton Exchange with Transmembrane Electrostatically Localized Protons (TELP) at a Liquid-membrane Interface: Fundamental to Bioenergetics
The Lee transmembrane electrostatic proton localization (TELP) theory is a revolutionary scientific theory that has successfully explained decades long-standing quandary in the field of bioenergetics in regards to ATP synthesis in biological systems, specifically alkalophilic bacteria. This study provides experimental support for the TELP theory by further demonstrating evidence of a localized proton layer existing at the liquid-membrane interface in a simulated biological membrane apparatus. Whilst monovalent cations have been studied extensively, divalent cation exchange has not been studied experimentally.
A previous study determined equilibrium constant for Na+ and K+ to exchange with localized H+ layer to be (5.07 ± 0.46) x 10-8 and (6.93 ± 0.91) x 10-8 respectively. We discovered that an equilibrium exchange occurs at 0.85 mM Mg2+ concentration. The findings here contributed to the successful determination of the equilibrium constant between Mg2+ and the localized H+ layer to be (1.56 ± 0.46) x 10-5. The equilibrium constant, much smaller than one, thus provides support for Lee’s TELP model since so many more Mg2+ in the bulk liquid phase that are required to even partially delocalize just a single H+ at the liquid-membrane interface. These results are relevant to further understand how water can act as a proton conductor for proton coupling energy transduction and the implications of different biological organisms’ salinity tolerance.https://digitalcommons.odu.edu/gradposters2022_sciences/1012/thumbnail.jp
The Neon Abundance in the Ejecta of QU Vul From Late-Epoch IR Spectra
We present ground-based SpectroCam-10 mid-infrared, MMT optical, and Spitzer
Space Telescope IRS mid-infrared spectra taken 7.62, 18.75, and 19.38 years
respectively after the outburst of the old classical nova QU Vulpeculae (Nova
Vul 1984 #2). The spectra of the ejecta are dominated by forbidden line
emission from neon and oxygen. Our analysis shows that neon was, at the first
and last epochs respectively, more than 76 and 168 times overabundant by number
with respect to hydrogen compared to the solar value. These high lower limits
to the neon abundance confirm that QU Vul involved a thermonuclear runaway on
an ONeMg white dwarf and approach the yields predicted by models of the
nucleosynthesis in such events.Comment: ApJ 2007 accepted, 18 pages, including 5 figures, 1 tabl
Smart and Sustainable Cities? Pipedreams, Practicalities and Possibilities
Smart and Sustainable Cities? Pipedreams, Practicalities and Possibilities provides one of the first examinations of how smart cities relate to environmental and social issues. It addresses the gap between the ambitious visions of smart cities and the actual practices on the ground by focusing on the social and environmental dimensions of real smart city initiatives as well as the possibilities they hold for creating more equitable and progressive cities. Through detailed analyses of case studies in the United States, Australia, the United Kingdom, Japan, Germany, India and China, the contributors describe the various ways that social and environmental issues are interpreted and integrated into smart city initiatives and actions. The findings point towards the need for more intentional engagement and collaboration with all urban stakeholders in the design, development and maintenance of smart cities to ensure that everyone benefits from the increasingly digitalised urban environments of the twenty-first century
Similarity in Programs
An overview of the concept of program similarity is presented. It divides
similarity into two types - syntactic and semantic - and provides a review
of eight categories of methods that may be used to measure program
similarity. A summary of some applications of these methods is included.
The paper is intended to be a starting point for a more comprehensive
analysis of the subject of similarity in programs, which is critical to
understand if progress is to be made in fields such as clone detection
A highly conserved complete accessory Escherichia coli type III secretion system 2 is widespread in bloodstream isolates of the ST69 lineage
The work was funded by the Scottish Executive via the Chief Scientists Office through the provision of a grant to establish the Scottish Healthcare Associated Infection Prevention Institute (SHAIPI). The funders had no role in the study design, data collection and interpretation, or the decision to submit the work for publication.Bacterial type III secretion systems (T3SSs) play an important role in pathogenesis of Gram-negative infections. Enteropathogenic and enterohemorrhagic Escherichia coli contain a well-defined T3SS but in addition a second T3SS termed E. coli T3SS 2 (ETT2) has been described in a number of strains of E. coli. The majority of pathogenic E. coli contain elements of a genetic locus encoding ETT2, but which has undergone significant mutational attrition rendering it without predicted function. Only a very few strains have been reported to contain an intact ETT2 locus. To investigate the occurrence of the ETT2 locus in strains of human pathogenic E. coli, we carried out genomic sequencing of 162 isolates obtained from patient blood cultures in Scotland. We found that 22 of 26 sequence type (ST) 69 isolates from this collection contained an intact ETT2 together with an associated eip locus which encodes putative secreted ETT2 effectors as well as eilA, a gene encoding a putative transcriptional regulator of ETT2 associated genes. Using a reporter gene for eilA activation, we defined conditions under which this gene was differentially activated. Analysis of published E. coli genomes with worldwide representation showed that ST69 contained an intact ETT2 in these strains as well. The conservation of the genes encoding ETT2 in human pathogenic ST69 strains strongly suggests it has importance in infection, although its exact functional role remains obscure.Publisher PDFPeer reviewe
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