Near-threshold neutral pion electroproduction at high momentum transfers and generalized form factors

We report the measurement of near-threshold neutral pion electroproduction cross sections and the extraction of the associated structure functions on the proton in the kinematic range Q(2) from 2 to 4.5 GeV2 and W from 1.08 to 1.16 GeV. These measurements allow us to access the dominant pion-nucleon s-wave multipoles E0+ and S0+ in the near-threshold region. In the light-cone sum-rule framework (LCSR), these multipoles are related to the generalized form factors G(1)(pi 0p) (Q(2)) and G(2)(pi 0p) (Q(2)). The data are compared to these generalized form factors and the results for G(1)(pi 0p) (Q(2)) are found to be in good agreement with the LCSR predictions, but the level of agreement with G(2)(pi 0p) (Q(2)) is poor. DOI: 10.1103/PhysRevC.87.04520

First measurement of the polarization observable E in the (p)over-right-arrow((gamma)over-right-arrow, pi(+))n reaction up to 2.25 GeV

First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E, for the reaction (p) over right arrow((gamma) over right arrow, pi( + ))n, has been measured using a circularly polarized tagged-photon beam, with energies from 0.35 to 2.37 GeV. The final-state pions were detected with the CEBAF Large Acceptance Spectrometer in Hall B at the Thomas Jefferson National Accelerator Facility. These polarization data agree fairly well with previous partial-wave analyses at low photon energies. Over much of the covered energy range, however, significant deviations are observed, particularly in the high-energy region where high-L multipoles contribute. The data have been included in new multipole analyses resulting in updated nucleon resonance parameters. We report updated fits from the Bonn-Gatchina, Jfilich-Bonn, and SAID groups. (C) 2015 The Authors. Published by Elsevier B.V

Fossil evidence for a pharyngeal origin of the vertebrate pectoral girdle

The origin of vertebrate paired appendages is one of the most investigated and debated examples of evolutionary novelty. Paired appendages are widely considered key innovations that allowed new opportunities for controlled swimming and gill ventilation and were prerequisites for the eventual transition from water to land. The last 150 years of debate has been shaped by two contentious theories: the ventrolateral fin-fold hypothesis and the archipterygium hypothesis. The latter proposes that fins and girdles evolved from an ancestral gill arch. Although tantalizing developmental evidence has revived interest in this idea, it is apparently unsupported by fossil evidence. Here we present fossil evidence of a pharyngeal basis for the vertebrate shoulder girdle. We use CT scanning to reveal details of the braincase of Kolymaspis sibirica, a placoderm fish from the Early Devonian of Siberia that suggests a pharyngeal component of the shoulder. We combine these findings with refreshed comparative anatomy of placoderms and jawless outgroups to place the origin of the shoulder girdle on the sixth branchial arch. These findings provide a novel framework for understanding the origin of the pectoral girdle. Our new evidence clarifies the location of the presumptive head-trunk interface in jawless fishes and explains the constraint on branchial arch number in gnathostomes. The results revive a key aspect of the archipterygium hypothesis, but also reconciles it with the ventrolateral fin fold model

Exclusive πᵒ Electroproduction at W \u3e 2 GeV with CLAS

Exclusive neutral-pion electroproduction (ep → e\u27p\u27π0 was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections d4σ/dtdQ2dxBdΦπ and structure functions σT+ ϵσL, σTT, and σLT as functions of t were obtained over a wide range of Q2 and xB. The data are compared with Regge and handbag theoretical calculations. Analyses in both frameworks find that a large dominance of transverse processes is necessary to explain the experimental results. For the Regge analysis it is found that the inclusion of vector meson rescattering processes is necessary to bring the magnitude of the calculated and measured structure functions into rough agreement. In the handbag framework, there are two independent calculations, both of which appear to roughly explain the magnitude of the structure functions in terms of transversity generalized parton distributions

Emphysematous cystitis and emphysematous pyelitis: A clinically misleading association

We present a rare case of emphysematous cystitis associated with an emphysematous pyelonephritis in a diabetic Arab man who was admitted ina confusional state. A 60-year-old man was admitted to the emergency department with confusion and hypogastric mass. The Clinical examinationfound comatose patient with a mass in the tympanic hypogastric percussion. The pelvic computed tomography (CT) demonstrated intramural gas in the urinarytract, which suggested a diagnosis of emphysematous cystitis and emphysematous pyelitis. The treatment was based on an antibiotics  associated with a bladder drainage and diabetes stabilization. The evolution was uneventful. Every diabetic patient with a urinary tract infection who seems to be severely ill should have an abdominal X-ray as a minimal screening tool to detect emphysematous complications. The rarity and the association with an emphysematous pyelitis, which is rarely reported in the literature, are two remarkable characteristics described in this case report

Mise en place d’un projet de préparation des Kits de radiologie au sein de la pharmacie de l’Institut National d’Oncologie.

Introduction : La dispensation nominative des produits de santé est une pratique recommandée sur l’échelle nationale et  internationale .L’objectif de ce travail est de décrire le projet  de mise en place d’une unité de préparation et de dispensation des kits de radiologie au sein de la pharmacie de l’institut national d’oncologie.Matériel et méthode : Nous avons préparé en concertation avec le service de radiologie trois types de kits, deux pour le scanner contenant comme produit de contraste l’Ultravist® 50 ml ou 100 ml et le troisième pour l’imagerie par résonance magnétique (IRM)  contenant  le Gadovist®. Les kits contiennent  aussi les dispositifs médicaux nécessaires pour l’administration des produits de contraste. La traçabilité et le suivi de la consommation ont été assurés tout au long de la mise en place du projet.Résultats : Durant le premier mois suivant la mise en place de ce système de dispensation, nous avons préparé 288 kits IRM, 184 kits scanner 100 ml et 60 kits scanner 50ml. La traçabilité des kits IRM montre une consommation de 154, le  sexe ratio des patients est de 1.53, 69% des patients étaient ramedistes, 64% sont des patients de l’institut national d’oncologie.Conclusion : La mise en place du projet de préparation des kits  de radiologie permet  une  standardisation de la pratique, une meilleure traçabilité des produits pharmaceutiques et un gain économique pour l’hôpital, d’où l’intérêt de maintenir ce projet et le développer

Measurement of the Q(2) Dependence of the Deuteron Spin Structure Function g(1) and Its Moments at Low Q(2) with CLAS

We measured the g1 spin structure function of the deuteron at low Q2, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W ≈ 1.9  GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γd1 and the spin polarizability γ0d are precisely determined down to a minimum Q2 of 0.02  GeV2 for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first in a program of benchmark measurements of polarization observables in the χPT domain. We measured the g1 spin structure function of the deuteron at low Q2, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W ≈1.9  GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γ_{1}^{d} and the spin polarizability γ_{0}^{d} are precisely determined down to a minimum Q2 of 0.02  GeV2 for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first in a program of benchmark measurements of polarization observables in the χPT domain

Cross Sections for the Exclusive Photon Electroproduction on the Proton and Generalized Parton Distributions

Unpolarized and beam-polarized fourfold cross sections (d4σ/dQ2dxBdtdϕ) for the ep → e\u27p\u27γ reaction were measured using the CLAS detector and the 5.75-GeV polarized electron beam of the Jefferson Lab accelerator, for 110 (Q2;xB;t) bins over the widest phase space ever explored in the valence-quark region. Several models of generalized parton distributions (GPDs) describe the data well at most of our kinematics. This increases our confidence that we understand the GPD H, expected to be the dominant contributor to these observables. Through a leading-twist extraction of Compton form factors, these results support the model predictions of a larger nucleon size at lower quark-momentum fraction xB