720 research outputs found

    Automatic Integral Reduction for Higher Order Perturbative Calculations

    Get PDF
    We present a program for the reduction of large systems of integrals to master integrals. The algorithm was first proposed by Laporta; in this paper, we implement it in MAPLE. We also develop two new features which keep the size of intermediate expressions relatively small throughout the calculation. The program requires modest input information from the user and can be used for generic calculations in perturbation theory.Comment: 23 page

    Fibrometabolism-An emerging therapeutic frontier in pulmonary fibrosis

    Get PDF
    Fibrosis is the final pathological outcome and major cause of morbidity and mortality in many common and chronic inflammatory, immune-mediated, and metabolic diseases. Despite the growing incidence of fibrotic diseases and extensive research efforts, there remains a lack of effective therapies that improve survival. The application of omics technologies has revolutionized our approach to identifying previously unknown therapeutic targets and potential disease biomarkers. The application of metabolomics, in particular, has improved our understanding of disease pathomechanisms and garnered a wave of scientific interest in the role of metabolism in the biology of myofibroblasts, the key effector cells of the fibrogenic response. Emerging evidence suggests that alterations in metabolism not only are a feature of but also may play an influential role in the pathogenesis of fibrosis, most notably in idiopathic pulmonary fibrosis (IPF), the most rapidly progressive and fatal of all fibrotic conditions. This review will detail the role of key metabolic pathways, their alterations in myofibroblasts, and the potential this new knowledge offers for the development of antifibrotic therapeutic strategies

    Use of calcareous fly ash in SCC

    Get PDF
    Abstract The robustness of self-compacting concrete (SCC) mixtures is usually sensitive to alterations in the mixture constituents, which is also the case when using high volumes of calcareous fly ash as binder. In the present report, calcareous fly ash was used as 30% and 50% by mass of the total binder without changing the water to binder ratio. The expected loss of workability due to the increased water demand of calcareous fly ash was compensated by adjusting the dosages of the admixtures (superplasticizer and viscosity modifying agent). Slump flow, L-Box and segregation resistance tests were carried out on the fresh mixtures, showing that robust SCC can be produced with the addition of high volumes of calcareous fly ash. Mechanical characteristics of the test mixtures were also measured, showing adequate strength development, comparable to that of the reference concrete, while shrinkage deformations were reduced when higher volumes of calcareous fly ash were used.

    Analytic Results for Virtual QCD Corrections to Higgs Production and Decay

    Get PDF
    We consider the production of a Higgs boson via gluon-fusion and its decay into two photons. We compute the NLO virtual QCD corrections to these processes in a general framework in which the coupling of the Higgs boson to the external particles is mediated by a colored fermion and a colored scalar. We present compact analytic results for these two-loop corrections that are expressed in terms of Harmonic Polylogarithms. The expansion of these corrections in the low and high Higgs mass regimes, as well as the expression of the new Master Integrals which appear in the reduction of the two-loop amplitudes, are also provided. For the fermionic contribution, we provide an independent check of the results already present in the literature concerning the Higgs boson and the production and decay of a pseudoscalar particle.Comment: 19 pages, 3 figures, version accepted by JHE

    Towards Higgs boson production in gluon fusion to NNLO in the MSSM

    Full text link
    We consider the Higgs boson production in the gluon-fusion channel to next-to-next-to-leading order within the Minimal Supersymmetric Standard Model. In particular, we present analytical results for the matching coefficient of the effective theory and study its influence on the total production cross section in the limit where the masses of all MSSM particles coincide. For supersymmetric masses below 500 GeV it is possible to find parameters leading to a significant enhancement of the Standard Model cross section, the KK-factors, however, change only marginally.Comment: 20 pages; v2: modification of discussion of numerical effect, version to appear in EPJC; v3: eq.(18) corrected, minor correction

    Two-Loop Helicity Amplitudes for Quark-Gluon Scattering in QCD and Gluino-Gluon Scattering in Supersymmetric Yang-Mills Theory

    Full text link
    We present the two-loop QCD helicity amplitudes for quark-gluon scattering, and for quark-antiquark annihilation into two gluons. These amplitudes are relevant for next-to-next-to-leading order corrections to (polarized) jet production at hadron colliders. We give the results in the `t Hooft-Veltman and four-dimensional helicity (FDH) variants of dimensional regularization. The transition rules for converting the amplitudes between the different variants are much more intricate than for the previously discussed case of gluon-gluon scattering. Summing our two-loop expressions over helicities and colors, and converting to conventional dimensional regularization, gives results in complete agreement with those of Anastasiou, Glover, Oleari and Tejeda-Yeomans. We describe the amplitudes for 2 to 2 scattering in pure N=1 supersymmetric Yang-Mills theory, obtained from the QCD amplitudes by modifying the color representation and multiplicities, and verify supersymmetry Ward identities in the FDH scheme.Comment: 77 pages. v2: corrected errors in eqs. (3.7) and (3.8) for one-loop assembly; remaining results unaffecte

    Neurological and neurourological complications of electrical injuries

    Get PDF
    Electrical injury can affect any system and organ. Central nervous system (CNS) complications are especially well recognised, causing an increased risk of morbidity, while peripheral nervous system (PNS) complications, neurourological and cognitive and psychological abnormalities are less predictable after electrical injuries.PubMed was searched for English language clinical observational, retrospective, review and case studies published in the last 30 years using the key words: electrical injury, electrocution, complications, sequelae, neurological, cognitive, psychological, urological, neuropsychological, neurourological, neurogenic, and bladder.In this review, the broad spectrum of neurological, cognitive, psychological and neurourological consequences of electrical trauma are discussed, and clinical features characteristic of an underlying neurological, psychological or neurourological disorder are identified. The latest information about the most recently discovered forms of nervous system disorders secondary to electrical trauma, such as the presentation of neurological sequelae years after electrocution, in other words long-term sequelae, are presented. Unexpected central nervous system or muscular complications such as hydrocephalus, brain venous thrombosis, and amyotrophic lateral sclerosis are described. Common and uncommon neuropsychological syndromes after electrical trauma are defined. Neurourological sequelae secondary to spinal cord or brain trauma or as independent consequences of electrical shock are also highlighted

    High-precision QCD at hadron colliders: electroweak gauge boson rapidity distributions at NNLO

    Full text link
    We compute the rapidity distributions of W and Z bosons produced at the Tevatron and the LHC through next-to-next-to leading order in QCD. Our results demonstrate remarkable stability with respect to variations of the factorization and renormalization scales for all values of rapidity accessible in current and future experiments. These processes are therefore ``gold-plated'': current theoretical knowledge yields QCD predictions accurate to better than one percent. These results strengthen the proposal to use W and Z production to determine parton-parton luminosities and constrain parton distribution functions at the LHC. For example, LHC data should easily be able to distinguish the central parton distribution fit obtained by MRST from that obtained by Alekhin.Comment: 47 pages, 17 figures. Minor typos, 1 reference correcte

    Reversible Cortical Blindness as a Prominent Manifestation of Cerebral Embolism due to Infective Endocarditis

    Get PDF
    Introduction. Infective endocarditis in the left heart may be complicated by stroke, due to embolisation from infectious valvular vegetations. Infarction of both occipital lobes, which are supplied by the posterior cerebral arteries, is infrequent, and is the cause of cortical blindness from lesion of the visual cortex. Cortical blindness is characterized by intact pupillary reflexes, a normal fundoscopy, and, rarely, denial of visual loss. Case Presentation. We report the case of a 58-year-old woman, recipient of a mechanical aortic valve, who presented with fever, multiple organ dysfunction, and cortical blindness. Transesophageal echocardiography and blood cultures confirmed the diagnosis of infective endocarditis caused by methicillin-sensitive Staphylococcus aureus. Computed tomography of the brain without contrast revealed the presence of infarctions in both occipital lobes. It is noteworthy that the visual loss resolved after treatment of endocarditis. Conclusions. A stroke occurring in a patient presenting with fever and a history of valvular heart disease strongly suggests the presence of infective endocarditis. Bilateral thromboembolic infarcts of the occipital lobes cause cortical blindness, that can resolve after treatment of endocarditis
    • …
    corecore