The Kazhdan-Lusztig conjecture for finite W-algebras

We study the representation theory of finite W-algebras. After introducing parabolic subalgebras to describe the structure of W-algebras, we define the Verma modules and give a conjecture for the Kac determinant. This allows us to find the completely degenerate representations of the finite W-algebras. To extract the irreducible representations we analyse the structure of singular and subsingular vectors, and find that for W-algebras, in general the maximal submodule of a Verma module is not generated by singular vectors only. Surprisingly, the role of the (sub)singular vectors can be encapsulated in terms of a `dual' analogue of the Kazhdan-Lusztig theorem for simple Lie algebras. These involve dual relative Kazhdan-Lusztig polynomials. We support our conjectures with some examples, and briefly discuss applications and the generalisation to infinite W-algebras.Comment: 11 page

Unravelling lactate-acetate and sugar conversion into butyrate by intestinal Anaerobutyricum and Anaerostipes species by comparative proteogenomics

Thed- andl-forms of lactate are important fermentation metabolites produced by intestinal bacteria but are found to negatively affect mucosal barrier function and human health. Both enantiomers of lactate can be converted with acetate into the presumed beneficial butyrate by a phylogenetically related group of anaerobes, includingAnaerobutyricumandAnaerostipesspp. This is a low energy yielding process with a partially unknown pathway inAnaerobutyricumandAnaerostipesspp. and hence, we sought to address this via a comparative genomics, proteomics and physiology approach. We compared growth ofAnaerobutyricum soehngeniion lactate with that on sucrose and sorbitol. Comparative proteomics revealed complete pathway of butyrate formation from sucrose, sorbitol and lactate. Notably, a gene cluster,lctABCDEFwas abundantly expressed when grown on lactate. This gene cluster encodes a lactate dehydrogenase (lctD), electron transport proteins A and B (lctCB), nickel-dependent racemase (lctE), lactate permease (lctF) and short-chain acyl-CoA dehydrogenase (lctG). Investigation of available genomes of intestinal bacteria revealed this new gene cluster to be highly conserved in onlyAnaerobutyricumandAnaerostipesspp. Present study demonstrates thatA. soehngeniiand several relatedAnaerobutyricumandAnaerostipesspp. are highly adapted for a lifestyle involving lactate plus acetate utilization in the human intestinal tract.Peer reviewe

A systematic review of the energy and climate impacts of teleworking

Information and communication technologies (ICTs) increasingly enable employees to work from home and other locations (‘teleworking’). This study explores the extent to which teleworking reduces the need to travel to work and the consequent impacts on economy-wide energy consumption. Methods/Design: The paper provides a systematic review of the current state of knowledge of the energy impacts of teleworking. This includes the energy savings from reduced commuter travel and the indirect impacts on energy consumption associated with changes in non-work travel and home energy consumption. The aim is to identify the conditions under which teleworking leads to a net reduction in economy-wide energy consumption, and the circumstances where benefits may be outweighed by unintended impacts. The paper synthesises the results of 39 empirical studies, identified through a comprehensive search of 9,000 published articles. Review results/Synthesis: Twenty six of the 39 studies suggest that teleworking reduces energy use, and only eight studies suggest that teleworking increases, or has a neutral impact on energy use. However, differences in the methodology, scope and assumptions of the different studies make it difficult to estimate ‘average’ energy savings. The main source of savings is the reduced distance travelled for commuting, potentially with an additional contribution from lower office energy consumption. However, the more rigorous studies that include a wider range of impacts (e.g. non-work travel or home energy use) generally find smaller savings. Discussion: Despite the generally positive verdict on teleworking as an energy-saving practice, there are numerous uncertainties and ambiguities about its actual or potential benefits. These relate to the extent to which teleworking may lead to unpredictable increases in non-work travel and home energy use that may outweigh the gains from reduced work travel. The available evidence suggests that economy-wide energy savings are typically modest, and in many circumstances could be negative or non-existent

New <i>Methyloceanibacter</i> diversity from North Sea sediments includes methanotroph containing solely the soluble methane monooxygenase

Marine methylotrophs play a key role in the global carbon cycle by metabolizing reduced one-carbon compounds that are found in high concentrations in marine environments. Genome, physiology and diversity studies have been greatly facilitated by the numerous model organisms brought into culture. However, the availability of marine representatives remains poor. Here, we report the isolation of four novel species from North Sea sediment enrichments closely related to the Alphaproteobacterium Methyloceanibacter caenitepidi. Each of the newly isolated Methyloceanibacter species exhibited a clear genome sequence divergence which was reflected in physiological differences. Notably one strain R-67174 was capable of oxidizing methane as sole source of carbon and energy using solely a soluble methane monooxygenase and represents the first marine Alphaproteobacterial methanotroph brought into culture. Differences in maximum cell density of >1.5 orders of magnitude were observed. Furthermore, three strains were capable of producing nitrous oxide from nitrate. Together, these findings highlight the metabolic and physiologic variability within closely related Methyloceanibacter species and provide a new understanding of the physiological basis of marine methylotrophy

Physics Behind Precision

This document provides a writeup of contributions to the FCC-ee mini-workshop on "Physics behind precision" held at CERN, on 2-3 February 2016.Comment: https://indico.cern.ch/event/469561

<i>Vibrio communis</i> sp. nov., isolated from the marine animals <i>Mussismilia hispida, Phyllogorgia dilatata, Palythoa caribaeorum, Palythoa variabilis</i> and <i>Litopenaeus vannamei</i>

Eight Vibrio isolates originating from the marine corals Mussismilia hispida and Phyllogorgia dilatata and the zoanthids Palythoa caribaeorum and Palythoa variabilis in Brazil and the Pacific white shrimp (Litopenaeus vannamei) in Ecuador were studied by means of a polyphasic approach. The novel isolates formed a tight monophyletic group in the genus Vibrio and were closely related to species of the Vibrio harveyi group, to which they showed more than 99?% 16S rRNA gene sequence similarity. Analysis based on concatenated sequences of the following seven genes, 16S rRNA, gyrB, recA, rpoA, topA, pyrH and mreB (5633 bp in length), showed clear separation between the isolates and species of the V. harveyi group. Amplified fragment length polymorphism (AFLP) analysis, performed previously, revealed that a representative isolate of this group, LMG 20370, was clearly separate from known Vibrio species (it belonged to the so-called AFLP cluster A31). DNA–DNA hybridization (DDH) experiments with representative isolates and type strains of the V. harveyi species group revealed high DDH between the novel isolates (more than 74?%) and less than 70?% DDH towards type strains of related Vibrio species, proving the novel species status of the isolates. Phenotypically, the novel species belongs to the arginine dihydrolase (A)-negative, lysine decarboxylase (L)-positive and ornithine decarboxylase (O)-positive (A-/L+/O+) cluster reported previously. Most species of the V. harveyi group (i.e. Vibrio rotiferianus, V. harveyi, V. parahaemolyticus and V. alginolyticus) also belong to this A-/L+/O+ cluster. However, several phenotypic features can be used for the identification of the novel species. In contrast to its closest phylogenetic neighbours, the novel species exhibits esterase (C4) and N-acetyl-ß-glucosaminidase activities, but it does not produce acetoin, does not use citrate, a-ketoglutaric acid or propionic acid and does not ferment melibiose. The novel species can also be differentiated on the basis of the presence of the fatty acids C17?:?0, C17?:?1?8c, iso-C17?:?0 and iso-C13?:?0 and the absence of the fatty acid C18?:?0. The name Vibrio communis sp. nov. is proposed for this taxon. Strain R-40496T (=LMG 25430T =CAIM 1816T) is the type strain

Intense field stabilization in circular polarization: 3D time-dependent dynamics

We investigate the stabilization of a hydrogen atom in circularly polarized laser fields. We use a time-dependent, fully three dimensional approach to study the quantum dynamics of the hydrogen atom subject to high intensity, short wavelength laser pulses. We find enhanced survival probability as the field is increased under fixed envelope conditions. We also confirm wavepacket dynamics seen in prior time-dependent computations restricted to two dimensions.Comment: 4 pages, 3 figures, submitte

Chytrid epidemics may increase genetic diversity of a diatom spring-bloom

Contrary to expectation, populations of clonal organisms are often genetically highly diverse. In phytoplankton, this diversity is maintained throughout periods of high population growth (that is, blooms), even though competitive exclusion among genotypes should hypothetically lead to the dominance of a few superior genotypes. Genotype-specific parasitism may be one mechanism that helps maintain such high-genotypic diversity of clonal organisms. Here, we present a comparison of population genetic similarity by estimating the beta-dispersion among genotypes of early and peak bloom populations of the diatom Asterionella formosa for three spring-blooms under high or low parasite pressure. The Asterionella population showed greater beta-dispersion at peak bloom than early bloom in the 2 years with high parasite pressure, whereas the within group dispersion did not change under low parasite pressure. Our findings support that high prevalence parasitism can promote genetic diversification of natural populations of clonal hosts