5,703 research outputs found
Calculating Great Britains half-hourly electrical demand from publicly available data
Here we present a method to combine half-hourly publicly available electrical
generation and interconnector data to create a timeseries that approximates
Great Britains electrical demand. Publishing the method and the data provides a
resource to the wider community that can be further enhanced or adapted and
allows the method itself to be considered and critiqued. The method adds value
by combining transmission and distribution generation data into a single
dataset and adding ISO 8601 compatible datetimes to increase interoperability
with other data. The published data is therefore more useable by a wider group
of researchers and stakeholders interested in an example of the rapid
decarbonisation of a countries electrical system.Comment: 33 pages, 3 Figures, 6 table
Collective fields in the functional renormalization group for fermions, Ward identities, and the exact solution of the Tomonaga-Luttinger model
We develop a new formulation of the functional renormalization group (RG) for
interacting fermions. Our approach unifies the purely fermionic formulation
based on the Grassmannian functional integral, which has been used in recent
years by many authors, with the traditional Wilsonian RG approach to quantum
systems pioneered by Hertz [Phys. Rev. B 14, 1165 (1976)], which attempts to
describe the infrared behavior of the system in terms of an effective bosonic
theory associated with the soft modes of the underlying fermionic problem. In
our approach, we decouple the interaction by means of a suitable
Hubbard-Stratonovich transformation (following the Hertz-approach), but do not
eliminate the fermions; instead, we derive an exact hierarchy of RG flow
equations for the irreducible vertices of the resulting coupled field theory
involving both fermionic and bosonic fields. The freedom of choosing a momentum
transfer cutoff for the bosonic soft modes in addition to the usual band cutoff
for the fermions opens the possibility of new RG schemes. In particular, we
show how the exact solution of the Tomonaga-Luttinger model emerges from the
functional RG if one works with a momentum transfer cutoff. Then the Ward
identities associated with the local particle conservation at each Fermi point
are valid at every stage of the RG flow and provide a solution of an infinite
hierarchy of flow equations for the irreducible vertices. The RG flow equation
for the irreducible single-particle self-energy can then be closed and can be
reduced to a linear integro-differential equation, the solution of which yields
the result familiar from bosonization. We suggest new truncation schemes of the
exact hierarchy of flow equations, which might be useful even outside the weak
coupling regime.Comment: 27 pages, 15 figures; published version, some typos correcte
Elucidating the aetiology of human Campylobacter coli infections
Peer reviewedPublisher PD
Large-Scale Sequence Analysis of Hemagglutinin of Influenza A Virus Identifies Conserved Regions Suitable for Targeting an Anti-Viral Response
BACKGROUND: Influenza A viral surface protein, hemagglutinin, is the major target of neutralizing antibody response and hence a main constituent of all vaccine formulations. But due to its marked evolutionary variability, vaccines have to be reformulated so as to include the hemagglutinin protein from the emerging new viral strain. With the constant fear of a pandemic, there is critical need for the development of anti-viral strategies that can provide wider protection against any Influenza A pathogen. An anti-viral approach that is directed against the conserved regions of the hemaggutinin protein has a potential to protect against any current and new Influenza A virus and provide a solution to this ever-present threat to public health. METHODOLOGY/PRINCIPAL FINDINGS: Influenza A human hemagglutinin protein sequences available in the NCBI database, corresponding to H1, H2, H3 and H5 subtypes, were used to identify highly invariable regions of the protein. Nine such regions were identified and analyzed for structural properties like surface exposure, hydrophilicity and residue type to evaluate their suitability for targeting an anti-peptide antibody/anti-viral response. CONCLUSION/SIGNIFICANCE: This study has identified nine conserved regions in the hemagglutinin protein, five of which have the structural characteristics suitable for an anti-viral/anti-peptide response. This is a critical step in the design of efficient anti-peptide antibodies as novel anti-viral agents against any Influenza A pathogen. In addition, these anti-peptide antibodies will provide broadly cross-reactive immunological reagents and aid the rapid development of vaccines against new and emerging Influenza A strains
Interactions of Candida albicans with host epithelial surfaces
Candida albicans is an opportunistic, fungal pathogen of humans that frequently causes superficial infections
of oral and vaginal mucosal surfaces of debilitated and susceptible individuals. The organism is however,
commonly encountered as a commensal in healthy individuals where it is a component of the normal
microflora. The key determinant in the type of relationship that Candida has with its host is how it interacts
with the epithelial surface it colonises. A delicate balance clearly exists between the potentially damaging
effects of Candida virulence factors and the nature of the immune response elicited by the host. Frequently, it
is changes in host factors that lead to Candida seemingly changing from a commensal to pathogenic existence.
However, given the often reported heterogeneity in morphological and biochemical factors that exist between
Candida species and indeed strains of C. albicans, it may also be the fact that colonising strains differ in the
way they exploit resources to allow persistence at mucosal surfaces and as a consequence this too may affect
the way Candida interacts with epithelial cells. The aim of this review is to provide an overview of some of the
possible interactions that may occur between C. albicans and host epithelial surfaces that may in turn dictate
whether Candida removal, its commensal persistence or infection follows
Outbreak of pandemic influenza A/H1N1 2009 in Nepal
<p>Abstract</p> <p>Background</p> <p>The 2009 flu pandemic is a global outbreak of a new strain of H1N1 influenza virus. Pandemic influenza A (H1N1) 2009 has posed a serious public health challenge world-wide. Nepal has started Laboratory diagnosis of Pandemic influenza A/H1N1 from mid June 2009 though active screening of febrile travellers with respiratory symptoms was started from April 27, 2009.</p> <p>Results</p> <p>Out of 609 collected samples, 302 (49.6%) were Universal Influenza A positive. Among the influenza A positive samples, 172(28.3%) were positive for Pandemic influenza A/H1N1 and 130 (21.3%) were Seasonal influenza A. Most of the pandemic cases (53%) were found among young people with ≤ 20 years. Case Fatality Ratio for Pandemic influenza A/H1N1 in Nepal was 1.74%. Upon Molecular characterization, all the isolated pandemic influenza A/H1N1 2009 virus found in Nepal were antigenically and genetically related to the novel influenza A/CALIFORNIA/07/2009-LIKE (H1N1)v type.</p> <p>Conclusion</p> <p>The Pandemic 2009 influenza virus found in Nepal were antigenically and genetically related to the novel A/CALIFORNIA/07/2009-LIKE (H1N1)v type.</p
Effect of temperature and nucleotide on the binding of BiP chaperone to a protein substrate
BiP (immunoglobulin heavy-chain Binding Protein) is a Hsp70 monomeric ATPase motor that plays broad and crucial roles maintaining proteostasis inside the cell. Structurally, BiP is formed by two domains, a nucleotide-binding domain (NBD) with ATPase activity connected by a flexible hydrophobic linker to the substrate-binding domain (SBD). While the ATPase and substrate binding activities of BiP are allosterically coupled, the latter is also dependent on nucleotide binding. Recent structural studies have provided new insights into BiP's allostery; however, the influence of temperature on the coupling between substrate and nucleotide binding to BiP remains unexplored. Here we study BiP's binding to its substrate at the single molecule level using thermo-regulated optical tweezers which allows us to mechanically unfold the client protein and explore the effect of temperature and different nucleotides on BiP binding. Our results confirm that the affinity of BiP for its protein substrate relies on nucleotide binding, by mainly regulating the binding kinetics between BiP and its substrate. Interestingly, our findings also showed that the apparent affinity of BiP for its protein substrate in the presence of nucleotides remains invariable over a wide range of temperatures, suggesting that BiP may interact with its client proteins with similar affinities even when the temperature is not optimal. Thus, BiP could play a role as a "thermal buffer" in proteostasis. This article is protected by copyright. All rights reserved
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