32,588 research outputs found
Summer snow extent heralding of the winter North Atlantic Oscillation
[1] Winter climate over the North Atlantic and European sector is modulated by the North Atlantic Oscillation (NAO). We find that the summer extent of snow cover over northern North America and northern Eurasia is linked significantly (p < 0.01) to the upcoming winter NAO state. Summers with high/low snow extent precede winters of low/high NAO index phase. We suggest the linkage arises from the summer snow-associated formation of anomalous longitudinal differences in surface air temperature with the subpolar North Atlantic. Our findings indicate the seasonal predictability of North Atlantic winter climate may be higher and extend to longer leads than thought previously
Institutional vehicles for place-shaping in remote Australia
© 2015 Taylor & Francis. Some communities in remote Australia represent the most impoverished people in the country, with the problem especially acute amongst Aboriginal and Torres Strait Islanders. Effective remedial intervention is often undermined by the absence of democratically elected, local government institutions. Place-shaping as a developmental process enables local people to become agents of change, and thereby self-determine and shape their places for the future. This paper considers the different institutional structures which could underpin place-shaping in remote settlements. Drawing on a range of governance structures, an emphasis on less traditional entities and polity-forming bodies may better serve the interests of remote people
Expressing Measurement Uncertainty in OCL/UML Datatypes
Uncertainty is an inherent property of any measure or estimation performed in any physical setting, and therefore it needs to
be considered when modeling systems that manage real data. Although several modeling languages permit the representation of measurement uncertainty for describing certain system attributes, these aspects are not normally incorporated into their type systems. Thus, operating with uncertain values and propagating uncertainty are normally cumbersome processes, di cult to achieve at the model level. This paper proposes an extension of OCL and UML datatypes to incorporate data uncertainty coming from physical measurements or user estimations into the models, along with the set of operations de ned for the values of these types.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
A Role of Myocardin Related Transcription Factor-A (MRTF-A) in Scleroderma Related Fibrosis.
In scleroderma (systemic sclerosis, SSc), persistent activation of myofibroblast leads to severe skin and organ fibrosis resistant to therapy. Increased mechanical stiffness in the involved fibrotic tissues is a hallmark clinical feature and a cause of disabling symptoms. Myocardin Related Transcription Factor-A (MRTF-A) is a transcriptional co-activator that is sequestered in the cytoplasm and translocates to the nucleus under mechanical stress or growth factor stimulation. Our objective was to determine if MRTF-A is activated in the disease microenvironment to produce more extracellular matrix in progressive SSc. Immunohistochemistry studies demonstrate that nuclear translocation of MRTF-A in scleroderma tissues occurs in keratinocytes, endothelial cells, infiltrating inflammatory cells, and dermal fibroblasts, consistent with enhanced signaling in multiple cell lineages exposed to the stiff extracellular matrix. Inhibition of MRTF-A nuclear translocation or knockdown of MRTF-A synthesis abolishes the SSc myofibroblast enhanced basal contractility and synthesis of type I collagen and inhibits the matricellular profibrotic protein, connective tissue growth factor (CCN2/CTGF). In MRTF-A null mice, basal skin and lung stiffness was abnormally reduced and associated with altered fibrillar collagen. MRTF-A has a role in SSc fibrosis acting as a central regulator linking mechanical cues to adverse remodeling of the extracellular matrix
Exhaustive generation of -critical -free graphs
We describe an algorithm for generating all -critical -free
graphs, based on a method of Ho\`{a}ng et al. Using this algorithm, we prove
that there are only finitely many -critical -free graphs, for
both and . We also show that there are only finitely many
-critical graphs -free graphs. For each case of these cases we
also give the complete lists of critical graphs and vertex-critical graphs.
These results generalize previous work by Hell and Huang, and yield certifying
algorithms for the -colorability problem in the respective classes.
Moreover, we prove that for every , the class of 4-critical planar
-free graphs is finite. We also determine all 27 4-critical planar
-free graphs.
We also prove that every -free graph of girth at least five is
3-colorable, and determine the smallest 4-chromatic -free graph of
girth five. Moreover, we show that every -free graph of girth at least
six and every -free graph of girth at least seven is 3-colorable. This
strengthens results of Golovach et al.Comment: 17 pages, improved girth results. arXiv admin note: text overlap with
arXiv:1504.0697
In defense of Bacillus thuringiensis, the safest and most successful microbial insecticide available to humanity – a response to EFSA
This is the author accepted manuscript. The final version is available from Oxford University Press via the DOI in this record.The Bacillus cereus group contains vertebrate pathogens such as Bacillus anthracis and Bacillus cereus and the invertebrate pathogen Bacillus thuringiensis. Microbial biopesticides based on B. thuringiensis (Bt) are widely recognized as being among the safest and least environmentally damaging insecticidal products available. Nevertheless, a recent food poisoning incident prompted a European Food Safety Authority review which argued that B. thuringiensis poses a health risk equivalent to B. cereus, a causative agent of diarrhoea. However, a critical examination of available data, and this latest incident, provide no solid evidence that B. thuringiensis causes diarrhoea. Although relatively high levels of B. cereus-like spores can occur in foods, genotyping demonstrates that these are predominantly naturally-occurring strains rather than biopesticides. Moreover, MLST genotyping of >2000 isolates show that biopesticidegenotypes have never been isolated from any clinical infection. MLST data demonstratethat Bacillus cereus group is heterogeneous and formed of distinct clades withsubstantial differences in biology, ecology and host association. The group posing the greatest risk (the anthracis clade) is distantly related to the clade containing allbiopesticides. These recent data support the long-held view that B. thuringiensis, andespecially the strains used in Bt biopesticides, are very safe for humans.BR has received support from NERC, BBSRC and the Leverhulme Trust for funding his research on Bt
The role of stoichiometric vacancy periodicity in pressure-induced amorphization of the Ga2SeTe2 semiconductor alloy
We observe that pressure-induced amorphization of Ga2SeTe2 (a III-VI
semiconductor) is directly influenced by the periodicity of its intrinsic
defect structures. Specimens with periodic and semi-periodic two-dimensional
vacancy structures become amorphous around 10-11 GPa in contrast to those with
aperiodic structures, which amorphize around 7-8 GPa. The result is a notable
instance of altering material phase-change properties via rearrangement of
stoichiometric vacancies as opposed to adjusting their concentrations. Based on
our experimental findings, we posit that periodic two-dimensional vacancy
structures in Ga2SeTe2 provide an energetically preferred crystal lattice that
is less prone to collapse under applied pressure. This is corroborated through
first-principles electronic structure calculations, which demonstrate that the
energy stability of III-VI structures under hydrostatic pressure is highly
dependent on the configuration of intrinsic vacancies
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Design Principles for High-Capacity Mn-Based Cation-Disordered Rocksalt Cathodes
Mn-based Li-excess cation-disordered rocksalt (DRX) oxyfluorides are promising candidates for next-generation rechargeable battery cathodes owing to their large energy densities, the earth abundance, and low cost of Mn. In this work, we synthesized and electrochemically tested four representative compositions in the Li-Mn-O-F DRX chemical space with various Li and F content. While all compositions achieve higher than 200 mAh g−1 initial capacity and good cyclability, we show that the Li-site distribution plays a more important role than the metal-redox capacity in determining the initial capacity, whereas the metal-redox capacity is more closely related to the cyclability of the materials. We apply these insights and generate a capacity map of the Li-Mn-O-F chemical space, LixMn2-xO2-yFy (1.167 ≤ x ≤ 1.333, 0 ≤ y ≤ 0.667), which predicts both accessible Li capacity and Mn-redox capacity. This map allows the design of compounds that balance high capacity with good cyclability
Accelerating exhaustive pairwise metagenomic comparisons
In this manuscript, we present an optimized and parallel version of our previous work IMSAME, an exhaustive gapped aligner for the pairwise and accurate comparison of metagenomes. Parallelization strategies are applied to take advantage of modern multiprocessor architectures. In addition, sequential optimizations in CPU time and memory consumption are provided. These algorithmic and computational enhancements enable IMSAME to calculate near optimal alignments which are used to directly assess similarity between metagenomes without requiring reference databases. We show that the overall efficiency of the parallel implementation is superior to 80% while retaining scalability as the number of parallel cores used increases. Moreover, we also show thats equential optimizations yield up to 8x speedup for scenarios with larger data.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
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Understanding the relative importance of vertical and horizontal flow in ice-wedge polygons
Ice-wedge polygons are common Arctic landforms. The future of these landforms in a warming climate depends on the bidirectional feedback between the rate of ice-wedge degradation and changes in hydrological characteristics. This work aims to better understand the relative roles of vertical and horizontal water fluxes in the subsurface of polygonal landscapes, providing new insights and data to test and calibrate hydrological models. Field-scale investigations were conducted at an intensively instrumented location on the Barrow Environmental Observatory (BEO) near Utqiagvik, AK, USA. Using a conservative tracer, we examined controls of microtopography and the frost table on subsurface flow and transport within a low-centered and a high-centered polygon. Bromide tracer was applied at both polygons in July 2015 and transport was monitored through two thaw seasons. Sampler arrays placed in polygon centers, rims, and troughs were used to monitor tracer concentrations. In both polygons, the tracer first infiltrated vertically until encountering the frost table and was then transported horizontally. Horizontal flow occurred in more locations and at higher velocities in the low-centered polygon than in the high-centered polygon. Preferential flow, influenced by frost table topography, was significant between polygon centers and troughs. Estimates of horizontal hydraulic conductivity were within the range of previous estimates of vertical conductivity, highlighting the importance of horizontal flow in these systems. This work forms a basis for understanding complexity of flow in polygonal landscapes
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