49 research outputs found

    The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

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    The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

    Prognostic value of thumb pain sensation in birth brachial plexopathy

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    OBJECTIVE: To evaluate the prognostic value of absent thumb pain sensation in newborns and young infants with birth brachial plexopathy. METHODS: We evaluated 131 patients with birth brachial plexopathy with less than two months of age. Pain sensation was evoked by thumb nail bed compression to evaluate sensory fibers of the upper trunk (C6). The patients were followed-up monthly. Patients with less than antigravity elbow flexion at six months of age were considered to have a poor outcome. RESULTS: Thirty patients had absent thumb pain sensation, from which 26 showed a poor outcome. Sensitivity of the test was 65% and specificity was 96%. CONCLUSION: Evaluation of thumb pain sensation should be included in the clinical assessment of infants with birth brachial plexopathy

    Botulinum toxin for treatment of cocontractions related to obstetrical brachial plexopathy Toxina botulínica para tratamento das co-contrações relacionadas à plexopatia braquial obstétrica

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    Botulinum toxin type A was recently introduced for treatment of biceps - triceps muscle cocontraction, which compromises elbow function in children with obstetrical brachial plexopathy. This is our preliminary experience with this new approach. Eight children were treated with 2 - 3 U/kg of botulinum toxin injected in the triceps (4 patients) and biceps (4 patients) muscle, divided in 2 or 3 sites. All patients submitted to triceps injections showed a long-lasting improvement of active elbow flexion and none required new injections, after a follow-up of 3 to 18 months. Three of the patients submitted to biceps injections showed some improvement of elbow extension, but none developed anti-gravitational strength for elbow extension and the effect lasted only three to five months. One patient showed no response to triceps injections. Our data suggest that botulinum toxin can be useful in some children that have persistent disability secondary to obstetrical brachial plexopathy.A toxina botulínica do tipo A foi introduzida recentemente para o tratamento das co-contrações entre os músculos biceps e triceps, que comprometem a função do cotovelo nas crianças com plexopatia braquial obstétrica. Apresentamos nossa experiência preliminar com esta abordagem. Oito crianças foram tratadas com 2 - 3 U/kg de toxina botulínica injetada nos músculos triceps (4 pacientes) e biceps (4 pacientes), divididas em 2 ou 3 sítios. Todos os pacientes submetidos a injeções no triceps apresentaram melhora persistente da flexão do cotovelo e nenhum precisou de novas aplicações após seguimento de 3 a 18 meses. Três pacientes submetidos a aplicações no biceps apresentaram melhora na extensão do cotovelo, mas nenhum adquiriu força antigravitacional e o efeito durou apenas 3 a 5 meses. Um paciente não respondeu às injeções. Nossos dados sugerem que a toxina botulínica pode ser útil no tratamento de algumas crianças com seqüelas de plexopatia braquial obstétrica

    Motor Nerve-Conduction Studies in Obstetric Brachial Plexopathy for a Selection of Patients with a Poor Outcome

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    Background: The criteria and timing for nerve surgery in infants with obstetric brachial plexopathy remain controversial. Our aim was to develop a new method for early prognostic assessment to assist this decision process. Methods: Fifty-four patients with unilateral obstetric brachial plexopathy who were ten to sixty days old underwent bilateral motor-nerve-conduction studies of the axillary, musculocutaneous, proximal radial, distal radial, median, and ulnar nerves. The ratio between the amplitude of the compound muscle action potential of the affected limb and that of the healthy side was called the axonal viability index. The patients were followed and classified in three groups according to the clinical outcome. We analyzed the receiver operating characteristic curve of each index to define the best cutoff point to detect patients with a poor recovery. Results: The best cutoff points on the axonal viability index for each nerve (and its sensitivity and specificity) were <10% (88% and 89%, respectively) for the axillary nerve, 0% (88% and 73%) for the musculocutaneous nerve, <20% (82% and 97%) for the proximal radial nerve, <50% (82% and 97%) for the distal radial nerve, and <50% (59% and 97%) for the ulnar nerve. The indices from the proximal radial, distal radial, and ulnar nerves had better specificities compared with the most frequently used clinical criterion: absence of biceps function at three months of age. Conclusions: The axonal viability index yields an earlier and more specific prognostic estimation of obstetric brachial plexopathy than does the clinical criterion of biceps function, and we believe it may be useful in determining surgical indications in these patients
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