104 research outputs found
N=2 supersymmetric Yang-Mills theory and the superparticle: twistor transform and kappa-symmetry
Lagrangian and Hamiltonian dynamics of de Azcarraga-Lukierski N=2 massive
superparticle is considered in the framework of twistor-like Lorentz-harmonic
approach. The emphasis is on the study of the interaction with external Abelian
gauge superfield. The requirement of preservation of all gauge symmetries of
the free model including kappa-symmetry yields correct expressions for the
superfield strength constraints and determines the form of nonminimal
interaction. We also show that for de Azcarraga-Lukierski N=2 massive
superparticle the pullback of field strength 2-superform to the superworld line
is not integrable in contrast to the massless superparticle.Comment: 16 pages, LaTe
Anti- Schistosomular Activity of Human Monocytes/Macrophages in Response to Interleukin-3 and Granulocyte-Macrophage Colonystimulating Factor Stimulation
Human monocytes, co-incubated for 7 days in culture with GM-CSF or
IL-3 but not with IFN-γ, exerted a variable
schistosotnulicidal effect on Schistosoma mansoni
parasites when grown in 96-well round-bottomed plates but not in
flat-bottomed plates. Addition of LPS or IFN-γ or both, for
the last 48 h did not enhance the cidal effect. Addition of LPS but
not IFN-γ to the pre-incubated cells with GM-CSF or IL-3
markedly stimulated TNF-α production by the cells but not
their cidal activity. The variable cidal effects obtained with the
monocytes/macrophages from different donors suggest that these
effects may be genetically predetermined and are possibly linked to
blood group markers or to MHC class I or II antigens
Weyl-Conformally-Invariant Lightlike p-Brane Theories: New Aspects in Black Hole Physics and Kaluza-Klein Dynamics
We introduce and study in some detail the properties of a novel class of
Weyl-conformally invariant p-brane theories which describe intrinsically
lightlike branes for any odd world-volume dimension. Their dynamics
significantly differs from that of the ordinary (conformally non-invariant)
Nambu-Goto p-branes. We present explicit solutions of the Weyl-invariant
lightlike brane- (WILL-brane) equations of motion in various gravitational
models of physical relevance exhibiting various new phenomena. In D=4 the
WILL-membrane serves as a material and charged source for gravity and
electromagnetism in the coupled Einstein-Maxwell-WILL-membrane system; it
automatically positions itself on (``straddles'') the common event horizon of
the corresponding matching black hole solutions, thus providing an explicit
dynamical realization of the membrane paradigm in black hole physics. In
product spaces of interest in Kaluza-Klein theories the WILL-brane wraps
non-trivially around the compact (internal)dimensions and still describes
massless mode dynamics in the non-compact (space-time) dimensions. Due to
nontrivial variable size of the internal compact dimensions we find new types
of physically interesting solutions describing massless brane modes trapped on
bounded planar circular orbits with non-trivial angular momentum, and with
linear dependence between energy and angular momentum.Comment: 28 pages, published versio
Genome Sequence of Stenotrophomonas maltophilia PML168, Which Displays Baeyer-Villiger Monooxygenase Activity
Stenotrophomonas maltophilia PML168 was isolated from Wembury Beach on the English Coast from a rock pool following growth and selection on agar plates. Here we present the permanent draft genome sequence, which has allowed prediction of function for several genes encoding enzymes relevant to industrial biotechnology, including a novel flavoprotein monooxygenase
Negative Even Grade mKdV Hierarchy and its Soliton Solutions
In this paper we provide an algebraic construction for the negative even mKdV
hierarchy which gives rise to time evolutions associated to even graded Lie
algebraic structure. We propose a modification of the dressing method, in order
to incorporate a non-trivial vacuum configuration and construct a deformed
vertex operator for , that enable us to obtain explicit and
systematic solutions for the whole negative even grade equations
Reconstructing SARS-CoV-2 lineages from mixed wastewater sequencing data
Wastewater surveillance of SARS-CoV-2 has emerged as a critical tool for tracking the spread of COVID-19. In addition to estimating the relative case numbers using quantitative PCR, SARS-CoV-2 genomic RNA can be extracted from wastewater and sequenced. There are many existing techniques for using the sequenced RNA to determine the relative abundance of known lineages in a sample. However, it is very challenging to predict novel lineages from wastewater data due to its mixed composition and unreliable genomic coverage. In this work, we present a novel technique based on non-negative matrix factorization which is able to reconstruct lineage definitions by analyzing data from across different samples. We test the method both on synthetic and real wastewater sequencing data. We show that the technique is able to determine major lineages such as Omicron and Delta as well as sub-lineages such as BA.5.2.1. We provide a method for determining emerging lineages in wastewater without the need for genomic data from clinical samples. This could be used for routine monitoring of SARS-CoV-2 as well as other emerging viral pathogens in wastewater. Additionally, it may be used to determine more full-genome sequences for viruses with fewer available genomes
Hiding and Confining Charges via "Tube-like" Wormholes
We describe two interesting effects in wormhole physics. First, we find that
a genuinely charged matter source may appear neutral to an external observer -
a phenomenon opposite to the famous Misner-Wheeler "charge without charge"
effect. This phenomenon takes place when coupling a bulk
gravity/nonlinear-gauge-field system to a charged lightlike brane as a matter
source. The "charge-hiding" effect occurs in a wormhole solution which connects
a non-compact "universe", comprising the exterior region of
Schwarzschild-(anti-)de-Sitter (SdS) or purely Schwarzschild black hole beyond
the Schwarzschild horizon, to a Levi-Civita-Bertotti-Robinson-type (LCBR)
"tube-like" "universe" via a wormhole "throat" occupied by the brane. In this
solution the whole electric flux produced by the brane is expelled into the
"tube-like" "universe" and the brane is detected as neutral by an observer in
the non-compact "universe". Next, we find a truly charge-confining wormhole
solution when we couple the bulk gravity/nonlinear-gauge-field system to two
oppositely charged lightlike branes. The latter system possesses a "two-throat"
wormhole solution, where the "left-most" and the "right-most" "universes" are
two identical copies of the exterior region of SdS black hole beyond the
Schwarzschild horizon, whereas the "middle" "universe" is of LCBR "tube-like"
form with geometry dS_2 x S^2. It comprises the finite-extent intermediate
region of dS_2 between its two horizons. Both "throats" are occupied by the two
oppositely charged lightlike branes and the whole electric flux produced by the
latter is confined entirely within the middle "tube-like" "universe". A crucial
ingredient is the special form of the nonlinear gauge field action, which
contains both the standard Maxwell term as well as a square root of the latter.
This theory was previously shown to produce a QCD-like confining dynamics in
flat space-time.Comment: 26 pages, 2 figures; v.2 several references added, missing constant
factors in few equations inserted, acknowledgement added, results unchanged;
v.3 28 pages, several clarifying remarks, references and acknowledgements
added, version to appear in International Journal of Modern Physics
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