543 research outputs found
Exploring new Boundary Conditions for Extended Higher Spin Supergravity
In this paper, we present a candidate for extended higher
- spin supergravity with the most general boundary conditions discussed
by Grumiller and Riegler recently. We show that the asymptotic symmetry algebra
consists of two copies of the affine algebra in the
presence of the most general boundary conditions.Furthermore, we impose some
certain restrictions on gauge fields on the most general boundary conditions
and that leads us to the supersymmetric extension of the Brown - Henneaux
boundary conditions. We eventually see that the asymptotic symmetry algebra
reduces to two copies of the algebra for
extended higher - spin supergravity.Comment: 25 pages, no figures, LaTeX file, Sec.4 added, added references, a
few typos correcte
Vertex Operator Extension of Casimir W A(N) Algebras
We give an extension of Casimir of Casimir algebras including a
vertex operator which depends on non-simple roots of .Comment: 7 pages,no figures,TeX file,(to appear in Mod.Phys.Lett.A
Miura-Like Free Field Realization Of Fermionic Casimir WB(3) Algebras
Starting from the well-known quantum Miura-like transformation for the non
simply-laced Lie algebras B(3),we give an explicit construction of the Casimir
WB(3) algebras.We reserve the notation WB(N) for the Casimir W algebras of type
W(2,4,6,...,2N,N+1/2) which contains one fermionic field. It is seen that WB(3)
algebra is closed an associative for all values of the central element c.Comment: 7 pages,no figures,TeX fil
Unique pathogen peptidomes facilitate pathogen-specific selection and specialization of MHC alleles
A key component of pathogen-specific adaptive immunity in vertebrates is the presentation of pathogen-derived antigenic peptides by major histocompatibility complex (MHC) molecules. The excessive polymorphism observed at MHC genes is widely presumed to result from the need to recognize diverse pathogens, a process called pathogen-driven balancing selection. This process assumes that pathogens differ in their peptidomes—the pool of short peptides derived from the pathogen’s proteome—so that different pathogens select for different MHC variants with distinct peptide-binding properties. Here, we tested this assumption in a comprehensive data set of 51.9 Mio peptides, derived from the peptidomes of 36 representative human pathogens. Strikingly, we found that 39.7\% of the 630 pairwise comparisons among pathogens yielded not a single shared peptide and only 1.8\% of pathogen pairs shared more than 1\% of their peptides. Indeed, 98.8\% of all peptides were unique to a single pathogen species. Using computational binding prediction to characterize the binding specificities of 321 common human MHC class-I variants, we investigated quantitative differences among MHC variants with regard to binding peptides from distinct pathogens. Our analysis showed signatures of specialization toward specific pathogens especially by MHC variants with narrow peptide-binding repertoires. This supports the hypothesis that such fastidious MHC variants might be maintained in the population because they provide an advantage against particular pathogens. Overall, our results establish a key selection factor for the excessive allelic diversity at MHC genes observed in natural populations and illuminate the evolution of variable peptide-binding repertoires among MHC variants
Morphology, histology and phylogeny of Henneguya sinova sp. nov. (Myxobolidae: Myxozoa) infecting gills of Parablennius tentacularis in the Black Sea, Turkey
Myxosporeans of the genus Henneguya have a global distribution and infect organs and tissues of both marine and freshwater fishes. Here we describe the morphological, histological and molecular characteristics of Henneguya sinova sp. nov. parasitizing the gill arches of tenta-cled blenny Parablennius tentacularis (Perciformes: Blenniidae) collected from the coast of Sinop on the Black Sea in Turkey. Several oval whitish plasmodia of different sizes in the gill arches of fish were found. The mature spores were rounded oval in frontal view, with a mean (range) total length 57.5 (51.5-68.0) µm; the spore body was 11.7 (11.3-12.0) µm in length by 7.6 (7.3-8.3) µm in width and 6.7 (6.6-6.8) µm in thickness. The caudal appendages, measuring 46.0 (40.0-55.0) µm in length, were very thin at the tapered end. The prevalence of infection by H. sinova sp. nov. was 35.5%. Phylogenetic analysis of nuclear small subunit ribosomal DNA (SSU rDNA) clearly suggested H. sinova as a new species which is clustered within the marine Henneguya linÂeage. Pairwise nucleotide similarities and DNA distance values of SSU rDNA between H. sinova sp. nov. and other related Henneguya species also supported this suggestion
Minimal Scalar Sector of 3-3-1 Models without Exotic Electric Charges
We study the minimal set of Higgs scalars, for models based on the local
gauge group which do not contain
particles with exotic electric charges. We show that only two Higgs
triplets are needed in order to properly break the symmetry. The exact
tree-level scalar mass matrices resulting from symmetry breaking are calculated
at the minimum of the most general scalar potential, and the gauge bosons are
obtained, together with their couplings to the physical scalar fields. We show
how the scalar sector introduced is enough to produce masses for fermions in a
particular model which is an subgroup. By using experimental results we
constrain the scale of new physics to be above 1.3 TeV.Comment: LaTeX, 22 pages, 1 figure include
Generalized 11D supergravity equations from tri-vector deformations
In arXiv:2203.03372 we presented a modification of 11-dimensional
supergravity field equations which upon dimensional reduction yields
generalized supergravity equations in 10-dimensions. In this paper we provide
full technical details of that result which is based on SL(5) exceptional field
theory. The equations are obtained by making a non-unimodular tri-vector
Yang-Baxter deformation which breaks the initial GL(11) symmetry down to
GL(7)xGL(4). We also give some non-trivial solutions to these equations.Comment: v3, refs added, minor correction
How to determine an effective potential for a variable cosmological term
It is shown that if a variable cosmological term in the present Universe is
described by a scalar field with minimal coupling to gravity and with some
phenomenological self-interaction potential , then this potential
can be unambiguously determined from the following observational data: either
from the behaviour of density perturbations in dustlike matter component as a
function of redshift (given the Hubble constant additionally), or from the
luminosity distance as a function of redshift (given the present density of
dustlike matter in terms of the critical one).Comment: Latex, 7 pages, JETP Lett., in press, 199
Targeted analysis of polymorphic loci from low-coverage shotgun sequence data allows accurate genotyping of HLA genes in historical human populations
The highly polymorphic human leukocyte antigen (HLA) plays a crucial role in adaptive immunity and is associated with various complex diseases. Accurate analysis of HLA genes using ancient DNA (aDNA) data is crucial for understanding their role in human adaptation to pathogens. Here, we describe the TARGT pipeline for targeted analysis of polymorphic loci from low-coverage shotgun sequence data. The pipeline was successfully applied to medieval aDNA samples and validated using both simulated aDNA and modern empirical sequence data from the 1000 Genomes Project. Thus the TARGT pipeline enables accurate analysis of HLA polymorphisms in historical (and modern) human populations
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