1,767 research outputs found
2-(1,4-Dioxo-1,4-dihydro-2-naphthyl)-2-methylpropanoic acid
The sterically crowded title compound, C₁₄H₁₂O₄, crystallizes as centrosymmetric hydrogen-bonded dimers involving the carboxyl groups. The naphthoquinone ring system is folded by 11.5 (1)° about a vector joining the 1,4-C atoms, and the quinone O atoms are displaced from the ring plane, presumably because of steric interactions with the bulky substituent
Supply-side determinants of Energy Consumption and Efficiency (ECE) innovations
This paper empirically analyses the supply-side determinants of eco-innovations related to Energy Consumption or Efficiency (ECE) for electricity and other energy sources. Using preliminary firm-level data from a 2010 survey of innovation activity in Tasmania (a regional economy and state of Australia), a multinomial discrete choice model is employed to test the research hypotheses. The analysis shows the positive association between technological and organisational capabilities and ECE outcomes in electricity and other energy sources, with a specific effect from investment in external R&D. We also find differences in sectoral technological opportunities for ECE innovation and a positive effect for firm structure and size. Our contribution is to show the importance of supply-side factors on ECE innovation outcomes and draw attention to their potential policy relevance.<br
Absence of evidence for pentaquarks on the lattice
We study the question of whether or not QCD predicts a pentaquark state. We
use the improved, fixed point lattice QCD action which has very little
sensitivity to the lattice spacing and also allows us to reach light quark
masses. The analysis was performed on a single volume of size with lattice spacing of fm. We use the
correlation matrix method to identify the ground and excited states in the
isospin 0, negative parity channel. In the quenched approximation where
dynamical quark effects are omitted, we do not find any evidence for a
pentaquark resonance in QCD.Comment: 17 pages, 5 figures replaced with revised versio
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The relationship between Indian monsoon rainfall and low-pressure systems
Indian summer monsoon precipitation is significantly modulated by synoptic-scale tropical low pressure areas (LPAs), the strongest of which are known as monsoon depressions (MDs). Despite their apparent importance, previous studies attempting to constrain the fraction of monsoon precipitation for which such systems are responsible have yielded an unsatisfyingly wide range of estimates.
Here, a variant of the DBSCAN algorithm is implemented to identify nontrivial, coherent rainfall structures in TRMM-3B42 precipitation data. Using theoretical considerations and an idealised model, an effective capture radius is computed to be 200 km, providing upper-bound attribution fractions of 57% (17%) for LPAs (MDs) over the monsoon core zone and 44% (12%) over all India. These results are also placed in the context of simpler attribution techniques. A climatology of these clusters suggests that the central Bay of Bengal (BoB) is the region of strongest synoptic organisation.
A k-means clustering technique is used to identify four distinct partitions of LPA (and two of MD) track, and their regional contributions to monsoon precipitation are assessed. Most synoptic rainfall over India is attributable to short-lived LPAs originating at the head of the BoB, though longer-lived systems are required to bring rain to west India and east Pakistan. Secondary contributions from systems originating in the Arabian Sea and south BoB are shown to be important for west Pakistan and Sri Lanka respectively.
Finally, a database of precipitating-event types is used to show that small-scale deep convection happens independently of MDs, whereas the density of larger-scale convective and stratiform events are sensitive to their presence - justifying the use of a noise-rejecting algorithm
Temporal trend in the transfer of Sellafield-derived 14C into different size fractions of the carbonate component of NE Irish Sea sediment
From 1994 onwards, 14C discharges from the Sellafield nuclear fuel reprocessing plant have been made largely to the Northeast Irish Sea. They represent the largest contributor to UK and European populations of the collective dose commitment derived from the entire nuclear industry discharges. Consequently, it is important to understand the long-term fate of 14C in the marine environment. Research undertaken in 2000 suggested that the carbonate component of Northeast Irish Sea sediments would increase in 14C activity as mollusc shells, which have become enriched in Sellafield-derived 14C, are broken down by physical processes including wave action and incorporated into intertidal and sub-tidal sediments. The current study, undertaken in 2011, tested this hypothesis. The results demonstrate significant increases in 14C enrichments found in whole mussel shells compared to those measured in 2000. Additionally, in 2000, there was an enrichment above ambient background within only the largest size fraction (>500 μm) of the intertidal inorganic sediment at Nethertown and Flimby (north of Sellafield). In comparison, the present study has demonstrated 14C enrichments above ambient background in most size fractions at sites up to 40 km north of Sellafield, confirming the hypothesis set out more than a decade ago
The CD4+ T cell methylome contributes to a distinct CD4+ T cell transcriptional signature in Mycobacterium bovis-infected cattle
peer-reviewedWe hypothesised that epigenetic regulation of CD4+ T lymphocytes contributes to a shift toward a dysfunctional T cell phenotype which may impact on their ability to clear mycobacterial infection. Combined RNA-seq transcriptomic profiling and Reduced Representation Bisulfite Sequencing identified 193 significantly differentially expressed genes and 760 differentially methylated regions (DMRs), between CD4+ T cells from M. bovis infected and healthy cattle. 196 DMRs were located within 10 kb of annotated genes, including GATA3 and RORC, both of which encode transcription factors that promote TH2 and TH17 T helper cell subsets respectively. Gene-specific DNA methylation and gene expression levels for the TNFRSF4 and Interferon-γ genes were significantly negatively correlated suggesting a regulatory relationship. Pathway analysis of DMRs identified enrichment of genes involved in the anti-proliferative TGF-β signaling pathway and TGFB1 expression was significantly increased in peripheral blood leukocytes from TB-infected cattle. This first analysis of the bovine CD4+ T cell methylome suggests that DNA methylation directly contributes to a distinct gene expression signature in CD4+ T cells from cattle infected with M. bovis. Specific methylation changes proximal to key inflammatory gene loci may be critical to the emergence of a non-protective CD4+ T cell response during mycobacterial infection in cattle
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