Gauge field theories with covariant star-product

A noncommutative gauge theory is developed using a covariant star-product between differential forms defined on a symplectic manifold, considered as the space-time. It is proven that the field strength two-form is gauge covariant and satisfies a deformed Bianchi identity. The noncommutative Yang-Mills action is defined using a gauge covariant metric on the space-time and its gauge invariance is proven up to the second order in the noncommutativity parameter.Comment: Dedicated to Ioan Gottlieb on the occasion of his 80th birthday anniversary. 12 page

Dissociative electron attachment to the H2O molecule. II. Nuclear dynamics on coupled electronic surfaces within the local complex potential model

We report the results of a first-principles study of dissociative electron attachment to H2O. The cross sections are obtained from nuclear dynamics calculations carried out in full dimensionality within the local complex potential model by using the multi-configuration time-dependent Hartree method. The calculations employ our previously obtained global, complex-valued, potential-energy surfaces for the three (doublet B1, doublet A1, and doublet B2) electronic Feshbach resonances involved in this process. These three metastable states of H2O- undergo several degeneracies, and we incorporate both the Renner-Teller coupling between the B1 and A1 states as well as the conical intersection between the A1 and B2 states into our treatment. The nuclear dynamics are inherently multidimensional and involve branching between different final product arrangements as well as extensive excitation of the diatomic fragment. Our results successfully mirror the qualitative features of the major fragment channels observed, but are less successful in reproducing the available results for some of the minor channels. We comment on the applicability of the local complex potential model to such a complicated resonant system.Comment: Corrected version of Phys Rev A 75, 012711 (2007

Noncommutative Differential Forms on the kappa-deformed Space

We construct a differential algebra of forms on the kappa-deformed space. For a given realization of the noncommutative coordinates as formal power series in the Weyl algebra we find an infinite family of one-forms and nilpotent exterior derivatives. We derive explicit expressions for the exterior derivative and one-forms in covariant and noncovariant realizations. We also introduce higher-order forms and show that the exterior derivative satisfies the graded Leibniz rule. The differential forms are generally not graded-commutative, but they satisfy the graded Jacobi identity. We also consider the star-product of classical differential forms. The star-product is well-defined if the commutator between the noncommutative coordinates and one-forms is closed in the space of one-forms alone. In addition, we show that in certain realizations the exterior derivative acting on the star-product satisfies the undeformed Leibniz rule.Comment: to appear in J. Phys. A: Math. Theo

Risk of Cesarean scar defect following single- vs double-layer uterine closure: systematic review and meta-analysis of randomized controlled trials

OBJECTIVE: There is a growing body of evidence that suggests that the surgical technique for uterine closure following Cesarean delivery influences the healing of the Cesarean scar, but there is still no consensus on the optimal technique. The aim of this systematic review and meta-analysis was to compare the effect of single- vs double-layer uterine closure on the risk of uterine scar defect. METHODS: MEDLINE, Scopus, ClinicalTrials.gov, PROSPERO, EMBASE and the Cochrane Central Register of Controlled Trials were searched from inception of each database until May 2016. All randomized controlled trials (RCTs) evaluating the effect of single- vs double-layer uterine closure following low transverse Cesarean section on the risk of uterine scar defect were included. The primary outcome was the incidence of uterine scar defects detected on ultrasound. Secondary outcomes were residual myometrial thickness evaluated by ultrasound and the incidence of uterine dehiscence and/or rupture in subsequent pregnancy. Summary measures were reported as relative risk (RR) or mean difference (MD), with 95% CIs. Quality of the evidence was assessed using the GRADE approach. RESULTS: Nine RCTs (3969 participants) were included in the meta-analysis. The overall risk of bias of the included trials was low. Statistical heterogeneity within the studies was low, with no inconsistency in the primary and secondary outcomes. Women who received single-layer uterine closure had a similar incidence of uterine scar defects as did women who received double-layer closure (25% vs 43%; RR, 0.77 (95% CI, 0.36-1.64); five trials; 350 participants; low quality of evidence). Compared with double-layer uterine closure, women who received single-layer closure had a significantly thinner residual myometrium on ultrasound (MD, -2.19 mm (95% CI, -2.80 to -1.57 mm); four trials; 374 participants; low quality of evidence). No difference was found in the incidence of uterine dehiscence (0.4% vs 0.2%; RR, 1.34 (95% CI, 0.24-4.82); three trials; 3421 participants; low quality of evidence) or uterine rupture (0.1% vs 0.1%; RR, 0.52 (95% CI, 0.05-5.53); one trial; 3234 participants; low quality of evidence) in a subsequent pregnancy. CONCLUSIONS: Single- and double-layer closure of the uterine incision following Cesarean delivery are associated with a similar incidence of Cesarean scar defects, as well as uterine dehiscence and rupture in a subsequent pregnancy. However, the quality level of summary estimates, as assessed by GRADE, was low, indicating that the true effect may be, or is even likely to be, substantially different from the estimate of the effect

Disease-specific, neurosphere-derived cells as models for brain disorders

There is a pressing need for patient-derived cell models of brain diseases that are relevant and robust enough to produce the large quantities of cells required for molecular and functional analyses. We describe here a new cell model based on patient-derived cells from the human olfactory mucosa, the organ of smell, which regenerates throughout life from neural stem cells. Olfactory mucosa biopsies were obtained from healthy controls and patients with either schizophrenia, a neurodevelopmental psychiatric disorder, or Parkinson's disease, a neurodegenerative disease. Biopsies were dissociated and grown as neurospheres in defined medium. Neurosphere-derived cell lines were grown in serum-containing medium as adherent monolayers and stored frozen. By comparing 42 patient and control cell lines we demonstrated significant disease-specific alterations in gene expression, protein expression and cell function, including dysregulated neurodevelopmental pathways in schizophrenia and dysregulated mitochondrial function, oxidative stress and xenobiotic metabolism in Parkinson's disease. The study has identified new candidate genes and cell pathways for future investigation. Fibroblasts from schizophrenia patients did not show these differences. Olfactory neurosphere-derived cells have many advantages over embryonic stem cells and induced pluripotent stem cells as models for brain diseases. They do not require genetic reprogramming and they can be obtained from adults with complex genetic diseases. They will be useful for understanding disease aetiology, for diagnostics and for drug discovery

Resonance Lifetimes from Complex Densities

The ab-initio calculation of resonance lifetimes of metastable anions challenges modern quantum-chemical methods. The exact lifetime of the lowest-energy resonance is encoded into a complex "density" that can be obtained via complex-coordinate scaling. We illustrate this with one-electron examples and show how the lifetime can be extracted from the complex density in much the same way as the ground-state energy of bound systems is extracted from its ground-state density

The dynamical Green's function and an exact optical potential for electron-molecule scattering including nuclear dynamics

We derive a rigorous optical potential for electron-molecule scattering including the effects of nuclear dynamics by extending the common many-body Green's function approach to optical potentials beyond the fixed-nuclei limit for molecular targets. Our formalism treats the projectile electron and the nuclear motion of the target molecule on the same footing whereby the dynamical optical potential rigorously accounts for the complex many-body nature of the scattering target. One central result of the present work is that the common fixed-nuclei optical potential is a valid adiabatic approximation to the dynamical optical potential even when projectile and nuclear motion are (nonadiabatically) coupled as long as the scattering energy is well below the electronic excitation thresholds of the target. For extremely low projectile velocities, however, when the cross sections are most sensitive to the scattering potential, we expect the influences of the nuclear dynamics on the optical potential to become relevant. For these cases, a systematic way to improve the adiabatic approximation to the dynamical optical potential is presented that yields non-local operators with respect to the nuclear coordinates.Comment: 22 pages, no figures, accepted for publ., Phys. Rev.

Neutropenia in Barth syndrome:characteristics, risks, and management

PURPOSE OF REVIEW: Barth syndrome (BTHS) is an X-linked disease characterized by defective remodeling of phospholipid side chains in mitochondrial membranes. Major features include neutropenia, dilated cardiomyopathy, motor delay and proximal myopathy, feeding problems, and constitutional growth delay. We conducted this review of neutropenia in BTHS to aid in the diagnosis of this disease, and to improve understanding of both the consequences of neutropenia and the benefits of treatment with granulocyte colony-stimulating factor (G-CSF). RECENT FINDINGS: In 88 patients with BTHS, neutropenia, that is, at least one count below 1.5 × 10/l, was detected in 74 (84%) and 44% had severe chronic neutropenia, with multiple counts below 0.5 × 10/l. The pattern of neutropenia varied between intermittent and unpredictable, chronic and severe, or cyclical with mathematically regular oscillations. Monocytosis, that is, monocytes more than 1.0 × 10/l, was observed at least once in 64 of 85 (75%) patients. G-CSF was administered to 39 of 88 patients (44%). Weekly average G-CSF doses ranged from 0.12 to 10.92 μg/kg/day (mean 1.16 μg/kg/day, median 1.16 μg/kg/day). Antibiotic prophylaxis was additionally employed in 21 of 26 neutropenic patients. Pretreatment bone marrow evaluations predominantly showed reduced myeloid maturation which normalized on G-CSF therapy in seven of 13 examined. Consistent clinical improvement, with reduced signs and symptoms of infections, was observed in response to prophylactic G-CSF ± prophylactic antibiotics. However, despite G-CSF and antibiotics, one adult patient died with multiple infections related to indwelling medical devices and gastrostomy site infection after 15.5 years on G-CSF and a pediatric patient required gastrostomy removal for recurrent abdominal wall cellulitis. SUMMARY: BTHS should be considered in any men with neutropenia accompanied by any of the characteristic features of this syndrome. Prophylaxis with G-CSF ± antibiotics prevents serious bacterial infections in the more severe neutropenic patients although infections remain a threat even in patients who are very compliant with therapy, especially in those with indwelling devices

Media events and cosmopolitan fandom:"Playful nationalism' in the Eurovision Song Contest

Academic literature on media events is increasingly concerned with their global dimensions and the applicability of Dayan and Katz's (1992) theoretical concept in a post-national context. This paper contributes to this debate by exploring the Eurovision Song Contest as a global media event. In particular, we employ a perspective from 'inside the media event', drawing upon empirical material collected during the 2014 Eurovision final in Copenhagen and focusing on the experiences of fans attending the contest. We argue that the ESC as a media event is experienced by its fans as a cosmopolitan space, open and diverse, whereas national belonging is expressed in a playful way tied to the overall visual aesthetics of the contest. However, the bounded and narrow character of participation render this cosmopolitan space rather limited