Search results for "Cone"
showing 10 items of 772 documents
Off-forward Matrix Elements in Light-front Hamiltonian QCD
2002
We investigate the off-forward matrix element of the light cone vector operator for a dressed quark state in light-front Hamiltonian perturbation theory. We obtain the corresponding splitting functions in a straightforward way. We show that the end point singularity is canceled by the contribution from the normalization of state. Considering mixing with the gluon operator, we verify the helicity sum rule in perturbation theory. We show that the quark mass effects are suppressed in the plus component of the matrix element but in the transverse component, they are not suppressed. We emphasize that this is a particularity of the off-forward matrix element and is absent in the forward case.
Massive quarks in NLO dipole factorization for DIS : Longitudinal photon
2021
In this work, we will present the first complete calculation of the one-loop longitudinal photon-to-quark-antiquark light cone wave function, with massive quarks. The quark masses are renormalized in the pole mass scheme. The result is used to calculate the next-to-leading order correction to the high energy Deep Inelastic Scattering longitudinal structure function on a dense target in the dipole factorization framework. For massless quarks the next-to-leading order correction was already known to be sizeable, and our result makes it possible to evaluate it also for massive quarks.
Dipole picture and the nonrelativistic expansion
2022
We study exclusive quarkonium production in the dipole picture at next-to-leading order (NLO) accuracy, using the non-relativistic expansion for the quarkonium wavefunction. This process offers one of the best ways to obtain information about gluon distributions at small $x$, in ultraperipheral heavy ion collisions and in deep inelastic scattering. The quarkonium light cone wave functions needed in the dipole picture have typically been available only at tree level, either in phenomenological models or in the nonrelativistic limit. In this paper, we discuss the compatibility of the dipole approach and the non-relativistic expansion and compute NLO relativistic corrections to the quarkonium …
Women's connective action: Analysis of the mobilization of the #ParoInternacionalDeMujeres of March 8, 2017
2020
Este artículo presenta un análisis del modo de manifestarse y de las percepciones de las/ os participantes en el #ParoInternacionalDeMujeres que tuvo lugar el 8 de marzo de 2017 en Argentina. Su hipótesis sostiene que la movilización mostró una lógica de acción conectiva híbrida. La investigación que sustenta este trabajo consistió en la realización de una encuesta en el momento y lugar de la movilización, a un total de 365 personas, con el propósito de capturar la percepción de las/os participantes y no simplemente de las/os impulsoras/es. Los datos resultantes de la encuesta se interpretaron considerando cinco dimensiones analíticas creadas a partir del concepto de acción conectiva: carác…
5,11,17,23-Tetranitro-25,26,27,28-tetrapentyloxycalix[4]arene
2005
The molecule of the title compound, C48H60N4O12, is located on a crystallographic twofold rotation axis. It is found in the typical pinched cone conformation. The dihedral angles between the reference plane (defined by the C atoms of the methylene bridges) and the benzene rings are 83.33 (6) and 141.61 (5)°.
PRCD is concentrated at the base of photoreceptor outer segments and is involved in outer segment disc formation.
2019
Abstract Mutations of the PRCD gene are associated with rod-cone degeneration in both dogs and humans. Prcd is expressed in the mouse eye as early as embryonic day 14. In the adult mouse retina PRCD is expressed in the outer segments of both rod and cone photoreceptors. Immunoelectron microscopy revealed that PRCD is located at the outer segment rim, and that it is highly concentrated at the base of the outer segment. Prcd-knockout mice present with progressive retinal degeneration, starting at 20 weeks of age and onwards. This process is reflected by a significant and progressive reduction of both scotopic and photopic electroretinographic responses, and by thinning of the retina, and spec…
Vesicle transport and photoreceptor death: fishing for molecular links.
2013
Intracellular vesicle transport defects can induce retinal degeneration and photoreceptor cell death, but the molecular connections between these processes remains poorly understood. Reporting in Developmental Cell, Nishiwaki et al. (2013) suggest that a vesicle fusion cis-SNARE complex component translates vesicular transport defects into photoreceptor cell apoptosis.
Phosphodiesterase inhibition induces retinal degeneration, oxidative stress and inflammation in cone-enriched cultures of porcine retina.
2013
nherited retinal degenerations affecting both rod and cone photoreceptors constitute one of the causes 74 of incurable blindness in the developed world. Cyclic guanosine monophosphate (cGMP) is crucial in the 75 phototransduction and, mutations in genes related to its metabolism are responsible for different retinal 76 dystrophies. cGMP-degrading phosphodiesterase 6 (PDE6) mutations cause around 4e5% of the retinitis 77 pigmentosa, a rare form of retinal degeneration. The aim of this study was to evaluate whether phar- 78 macological PDE6 inhibition induced retinal degeneration in cone-enriched cultures of porcine retina 79 similar to that found in murine models. PDE6 inhibition was induced…
Some substrates and inhibitors of cytosolic epoxide hydrolase induce sister-chromatid exchanges in mammalian cells, but do not induce gene mutations …
1993
Abstract Trans -stilbene oxide, trans -β-methylstyrene, 7,8-oxide, trans -β-ethylstyrene, 7,8-oxide, trans -β-propylstyrene 7,8-oxide and 4-fluorochalcone oxide were investigated for genotoxic activity in bacterial and mammalian cells, in the absence of external xenobiotic-metabolising systems. All compounds strongly enhanced the frequency of sister-chromatid exchanges (SCE) in cultured human lymphocytes. None of them was mutagenic in Salmonella typhimurium (reversion of the his − strains TA98, TA100 and TA104). The limit of detection was 1 20,000 to 1 10 6 of the activity of the positive control, benzo[ a ]pyrene 4,5-oxide, depending on the compound and the bacterial strain. Trans -β-methy…
Ex vivo measurement reliability using two different cbct scanners for orthodontic purposes
2012
Background There are many cone beam computed tomography (CBCT) scanners available on the market: detector technology, algorithm precision, and scanner settings influence image quality. The aim of this study was to compare the accuracy of linear measurements made on images of the same sample obtained using two different CBCT scanners. Methods Twenty-eight linear measurements between orthodontic anatomical landmarks that were marked with gutta-percha points on a fresh sacrificed lamb head were taken three times. The head was scanned with two CBCT scanners using different scanning parameters. Digital Imaging and Communications in Medicine (DICOM) images were reconstructed and the same measurem…