338 research outputs found
Feline T-Cell Receptor γ V- and J-Region Sequences Retrieved from the Trace Archive and from Transcriptome Analysis of Cats
The variable domains of antigen receptors are very diverse and assembled in a modular system from a number of V-, D-, and J-region genes. Here we describe additional variants of V- and J-region genes of the feline T-cell receptor γ (TRG) as well as the corresponding RSSs retrieved from Trace Archive of feline genomic sequences. Additionally, an unusually recombined TRGV-domain containing a partial inverted repeat of the included J-region and a short interspersed element of the CAN-SINE family located within the feline T-cell receptor γ locus are also described
Molecular characterization of the feline T-cell receptor γ alternate reading frame protein (TARP) ortholog
T-cell receptor γ alternate reading frame protein (TARP) is expressed by human
prostate epithelial, prostate cancer, and mammary cancer cells, but is not
found in normal mammary tissue. To date, this protein has only been described
in humans. Additionally, no animal model has been established to investigate
the potential merits of TARP as tumor marker or a target for adoptive tumor
immunotherapy. In this study conducted to characterize feline T-cell receptor
γ sequences, constructs very similar to human TARP transcripts were obtained
by RACE from the spleen and prostate gland of cats. Transcription of TARP in
normal, hyperplastic, and neoplastic feline mammary tissues was evaluated by
conventional RT-PCR. In felines similarly to the situation reported in humans,
a C-region encoding two open reading frames is spliced to a J-region gene. In
contrast to humans, the feline J-region gene was found to be a pseudogene
containing a deletion within its recombination signal sequence. Our findings
demonstrated that the feline TARP ortholog is transcribed in the prostate
gland and mammary tumors but not normal mammary tissues as is the case with
human TARP
Comparative analysis of primer sets for the assessment of clonality in feline lymphomas
IntroductionLymphomas are among the most important and common malignant tumors in cats. Differentiating lymphomas from reactive lymphoid proliferations can be challenging, so additional tools such as clonality assessment by PCR are important in diagnosis finding. Several PCR assays have been developed to assess clonality in feline lymphomas. For T-cell lymphomas TRG (T-cell receptor gamma) genes are the preferred target whereas for B-cell lymphomas most primer sets target immunoglobulin heavy chain (IGH) genes. Here we compare commonly used diagnostic primer sets for the assessment of clonality in feline lymphomas under controlled conditions (i.e., identical sample set, PCR setup, amplicon detection system).MethodsFormalin-fixed and paraffin-embedded samples from 31 feline T-cell lymphomas, 29 B-cell lymphomas, and 11 non-neoplastic controls were analyzed by PCR combined with capillary electrophoresis.Results and discussionWe show that the combination of the primer sets published by Weiss et al. and Mochizuki et al. provided the best results for T-cell clonality, i.e., correctly assigns most populations as clonal or polyclonal. For B-cell clonality, the combination of the primer sets by Mochizuki et al. and Rout et al. gave the best results when omitting the Kde gene rearrangement due to its low specificity. This study rigorously evaluated various primer sets under uniform experimental conditions to improve accuracy of lymphoma diagnostic and provides a recommendation for achieving the highest diagnostic precision in lymphoma clonality analysis
Localized qubits in curved spacetimes
We provide a systematic and self-contained exposition of the subject of
localized qubits in curved spacetimes. This research was motivated by a simple
experimental question: if we move a spatially localized qubit, initially in a
state |\psi_1>, along some spacetime path \Gamma from a spacetime point x_1 to
another point x_2, what will the final quantum state |\psi_2> be at point x_2?
This paper addresses this question for two physical realizations of the qubit:
spin of a massive fermion and polarization of a photon. Our starting point is
the Dirac and Maxwell equations that describe respectively the one-particle
states of localized massive fermions and photons. In the WKB limit we show how
one can isolate a two-dimensional quantum state which evolves unitarily along
\Gamma. The quantum states for these two realizations are represented by a
left-handed 2-spinor in the case of massive fermions and a four-component
complex polarization vector in the case of photons. In addition we show how to
obtain from this WKB approach a fully general relativistic description of
gravitationally induced phases. We use this formalism to describe the
gravitational shift in the COW 1975 experiment. In the non-relativistic weak
field limit our result reduces to the standard formula in the original paper.
We provide a concrete physical model for a Stern-Gerlach measurement of spin
and obtain a unique spin operator which can be determined given the orientation
and velocity of the Stern-Gerlach device and velocity of the massive fermion.
Finally, we consider multipartite states and generalize the formalism to
incorporate basic elements from quantum information theory such as quantum
entanglement, quantum teleportation, and identical particles. The resulting
formalism provides a basis for exploring precision quantum measurements of the
gravitational field using techniques from quantum information theory.Comment: 53 pages, 7 figures; v2: published version with further corrections.
v3: some references and equation typesetting fixe
Adventitious rooting declines with the vegetative to reproductive switch and involves a changed auxin homeostasis
Adventitious rooting, whereby roots form from non-root tissues, is critical to the forestry and horticultural industries that depend on propagating plants from cuttings. A major problem is that age of the tissue affects the ability of the cutting to form adventitious roots. Here, a model system has been developed using Pisum sativum to differentiate between different interpretations of ageing. It is shown that the decline in adventitious rooting is linked to the ontogenetic switch from vegetative to floral and is mainly attributed to the cutting base. Using rms mutants it is demonstrated that the decline is not a result of increased strigolactones inhibiting adventitious root formation. Monitoring endogenous levels of a range of other hormones including a range of cytokinins in the rooting zone revealed that a peak in jasmonic acid is delayed in cuttings from floral plants. Additionally, there is an early peak in indole-3-acetic acid levels 6h post excision in cuttings from vegetative plants, which is absent in cuttings from floral plants. These results were confirmed using DR5:GUS expression. Exogenous supplementation of young cuttings with either jasmonic acid or indole-3-acetic acid promoted adventitious rooting, but neither of these hormones was able to promote adventitious rooting in mature cuttings. DR5:GUS expression was observed to increase in juvenile cuttings with increasing auxin treatment but not in the mature cuttings. Therefore, it seems the vegetative to floral ontogenetic switch involves an alteration in the tissue’s auxin homeostasis that significantly reduces the indole-3-acetic acid pool and ultimately results in a decline in adventitious root formation
Dyson-Schwinger Equations: Density, Temperature and Continuum Strong QCD
Continuum strong QCD is the application of models and continuum quantum field
theory to the study of phenomena in hadronic physics, which includes; e.g., the
spectrum of QCD bound states and their interactions; and the transition to, and
properties of, a quark gluon plasma. We provide a contemporary perspective,
couched primarily in terms of the Dyson-Schwinger equations but also making
comparisons with other approaches and models. Our discourse provides a
practitioners' guide to features of the Dyson-Schwinger equations [such as
confinement and dynamical chiral symmetry breaking] and canvasses
phenomenological applications to light meson and baryon properties in cold,
sparse QCD. These provide the foundation for an extension to hot, dense QCD,
which is probed via the introduction of the intensive thermodynamic variables:
chemical potential and temperature. We describe order parameters whose
evolution signals deconfinement and chiral symmetry restoration, and chronicle
their use in demarcating the quark gluon plasma phase boundary and
characterising the plasma's properties. Hadron traits change in an equilibrated
plasma. We exemplify this and discuss putative signals of the effects. Finally,
since plasma formation is not an equilibrium process, we discuss recent
developments in kinetic theory and its application to describing the evolution
from a relativistic heavy ion collision to an equilibrated quark gluon plasma.Comment: 103 Pages, LaTeX, epsfig. To appear in Progress in Particle and
Nuclear Physics, Vol. 4
Agglomeration in counter-current spray drying towers. Part A: Particle growth and the effect of nozzle height
Agglomeration of particles and droplets is critical to the operation of spray dryers, however it remains relatively unexplored. This paper studies the effect of the nozzle height on product properties, wall deposits and dryer conditions in a counter-current spray drying tower of detergent with a swirling air flow. The process efficiency is driven by changes in particle agglomeration. To interpret the results and facilitate the study of swirl towers, it is useful to subdivide these units according to the sources of growth in (a) spray region(s), (b) concentrated near-wall region(s) and (c) wall deposits. The particles formed are very heterogeneous and show a size-dependent composition. In this case, particle properties are driven by the separation of solid and liquid phases during atomization and the formation of a heterogeneous set of droplets. Agglomeration serves to homogenise the product and create a distinct source of porosity. The capacity and energy consumption of the dryer are also determined by the evolution of the particle size, as fine powder is elutriated from the tower top and coarse particles are removed from the product. When the nozzle is moved to lower positions in the tower the increased temperature near the spray suppresses agglomeration, however the residence time is shortened and ultimately it leads to creation of wet, coarse granules. An optimum location is found high enough to maintain the drying efficiency but sufficiently far from the top exit to minimise the loss of fine particles. In this way, a capacity ratio (i.e. product vs spray dried powder) C > 90% can be obtained and energy efficiency maximised
The sustainability of habitability on terrestrial planets: Insights, questions, and needed measurements from Mars for understanding the evolution of Earth-like worlds
What allows a planet to be both within a potentially habitable zone and sustain habitability over long geologic time? With the advent of exoplanetary astronomy and the ongoing discovery of terrestrial-type planets around other stars, our own solar system becomes a key testing ground for ideas about what factors control planetary evolution. Mars provides the solar system's longest record of the interplay of the physical and chemical processes relevant to habitability on an accessible rocky planet with an atmosphere and hydrosphere. Here we review current understanding and update the timeline of key processes in early Mars history. We then draw on knowledge of exoplanets and the other solar system terrestrial planets to identify six broad questions of high importance to the development and sustaining of habitability (unprioritized): (1) Is small planetary size fatal? (2) How do magnetic fields influence atmospheric evolution? (3) To what extent does starting composition dictate subsequent evolution, including redox processes and the availability of water and organics? (4) Does early impact bombardment have a net deleterious or beneficial influence? (5) How do planetary climates respond to stellar evolution, e.g., sustaining early liquid water in spite of a faint young Sun? (6) How important are the timescales of climate forcing and their dynamical drivers? Finally, we suggest crucial types of Mars measurements (unprioritized) to address these questions: (1) in situ petrology at multiple units/sites; (2) continued quantification of volatile reservoirs and new isotopic measurements of H, C, N, O, S, Cl, and noble gases in rocks that sample multiple stratigraphic sections; (3) radiometric age dating of units in stratigraphic sections and from key volcanic and impact units; (4) higher-resolution measurements of heat flux, subsurface structure, and magnetic field anomalies coupled with absolute age dating. Understanding the evolution of early Mars will feed forward to understanding the factors driving the divergent evolutionary paths of the Earth, Venus, and thousands of small rocky extrasolar planets yet to be discovered
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