22 research outputs found

    Quantum Hall effect on odd spheres

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    We solve the Landau problem for charged particles on odd dimensional spheres S2k-1 in the background of constant SO(2k - 1) gauge fields carrying the irreducible representation (I/2,I/2, . . . , I/2). We determine the spectrum of the Hamiltonian, the degeneracy of the Landau levels and give the eigenstates in terms of the Wigner D-functions, and for odd values of I, the explicit local form of the wave functions in the lowest Landau level (LLL). The spectrum of the Dirac operator on S2k-1 in the same gauge field background together with its degeneracies is also determined, and in particular, its number of zero modes is found. We show how the essential differential geometric structure of the Landau problem on the equatorial S2k-2 is captured by constructing the relevant projective modules. For the Landau problem on S-5, we demonstrate an exact correspondence between the union of Hilbert spaces of LLLs, with I ranging from 0 to I-max = 2K or I-max = 2K or I-max = 2K + 1 to the Hilbert spaces of the fuzzy CP3 or that of winding number +/- 1 line bundles over CP3 at level K, respectively

    Efectos del secado al aire y solar sobre la calidad nutricional del aceite, las semillas y pieles de las uvas Muscat Hamburg

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    Grape pomace is an agro-industrial by-product from the production of must (grape juice) by pressing whole grapes. In order to evaluate the seeds and skins of the grape pomace, it must first be dried and then separated in a screen machine. The drying of pomace is an important and necessary process for the optimum separation of seeds. The main purpose of this study was to determine the optimum drying process for obtaining high-quality grape seed oil. In this research, open air and solar energy drying methods were compared in terms of water activity, total bacterial and mold-yeast count, along with the chemical and fatty acid compositions of pressed grape residues. Oleic acid and linoleic acid contents ranged from 16.56-16.96% and 71.45-71.96%, respectively. Antioxidant activities ranged from 2.33-2.80 μmol trolox/g. The results showed that the drying methods did not decrease the nutritional quality of grape residues and prevented microbial growth by decreasing water activity to below 0.60.El orujo de uva es un subproducto agroindustrial de la producción de mosto (jugo de uva) al prensar las uvas enteras. Para poder evaluar las semillas y las pieles del orujo de uva, primero debe secarse y luego separarse mediante una máquina de tamizado. El secado del orujo es un proceso importante y necesario para una separación óptima de las semillas. El objetivo principal de este estudio fue determinar el proceso de secado óptimo para obtener aceites de semillas de uva de alta calidad. En este trabajo, los métodos de secado al aire libre y la energía solar de los residuos de uva prensados se compararon en términos de actividad de agua, recuento total de bacterias y moho, así como la composición de ácidos grasos. Los contenidos de ácido oleico y linoleico variaron entre 16,56-16,96% y 71,45-71,96%, respectivamente. Las actividades antioxidantes variaron entre 2,33-2,80 μmol trolox/g. Los resultados mostraron que los métodos de secado no disminuyeron la calidad nutricional de los residuos de la uva y evitaron el crecimiento microbiano al disminuir la actividad del agua por debajo de 0,60

    The effectiveness of a multidisciplinary intervention strategy for the treatment of symptomatic joint hypermobility in childhood:A randomised, single Centre parallel group trial (The Bendy Study)

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    Introduction: Joint hypermobility is common in childhood and can be associated with musculoskeletal pain and dysfunction. Current management is delivered by a multidisciplinary team, but evidence of effectiveness is limited. This clinical trial aimed to determine whether a structured multidisciplinary, multisite intervention resulted in improved clinical outcomes compared with standard care. Method: A prospective randomised, single centre parallel group trial comparing an 8-week individualised multidisciplinary intervention programme (bespoke physiotherapy and occupational therapy in the clinical, home and school environment) with current standard management (advice, information and therapy referral if deemed necessary). The primary endpoint of the study was between group difference in child reported pain from baseline to 12 months as assessed using the Wong Baker faces pain scale. Secondary endpoints were parent reported pain (100 mm visual analogue scale), parent reported function (child health assessment questionnaire), child reported quality of life (child health utility 9-dimensional assessment), coordination (movement assessment battery for children version 2) and grip strength (handheld dynamometer). Results: 119 children aged 5 to 16 years, with symptomatic hypermobility were randomised to receive an individualised multidisciplinary intervention (I) (n = 59) or standard management (S) (n = 60). Of these, 105 completed follow up at 12 months. No additional significant benefit could be shown from the intervention compared to standard management. However, there was a statistically significant improvement in child and parent reported pain, coordination and grip strength in both groups. The response was independent of the degree of hypermobility. Conclusion: This is the first randomised controlled trial to compare a structured multidisciplinary, multisite intervention with standard care in symptomatic childhood hypermobility. For the majority, the provision of education and positive interventions aimed at promoting healthy exercise and self-management was associated with significant benefit without the need for more complex interventions. Trial registration: The trial was registered prospectively with the national database at the Clinical Research Network (UKCRN Portfolio 9366). The trial was registered retrospectively with ISRCTN (ISRCTN86573140)

    Protective effect of the N-methyl-D-aspartate receptor antagonists, MK-801 and CPP on cold-induced brain oedema

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    Cold injury model in rat was used to determine the effect of treatment with the competitive NMDA antagonists CPP and the noncompetitive NMDA antagonist MK-801 in cerebral oedema. MK-801 was applied in doses of 1 mg/kg and CPP of 10 mg/kg, 15 min. after injury. Control animals received 1 mi saline at the same time interval after injury. Tissue samples from the core and periphery of the lesion of the injured hemisphere and from the symmetrical location of the undamaged contralateral hemisphere were removed 24 hours after injury. Blood brain barrier permeability, brain water content and tissue specific gravity values were determined. MK-801 was found beneficial for reducing the oedema and restore the blood brain barrier permeability at the penumbral zone of the lesion, whereas both MK-801 and CPP were found ineffective for prevention of oedema accumulation at the core of the lesion

    Superoxide dismutase activity and the effects of NBQX and CPP on lipid peroxidation in experimental spinal cord injury

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    The endogenous activity of the neuroprotective enzyme superoxide dismutase (SOD) and the amount of lipid peroxidation in the early phase of experimental spinal cord injury, together with the effects of N-methyl-D-aspartate (NMDA) antagonist CPP and non-NMDA antagonist NBQX on lipid peroxidation were evaluated. The clip compression model was used for the production of a standardized spinal cord trauma. SOD activity and malondialdehyde (MDA) levels - as an indicator of lipid peroxidation - were determined in the injured segment of the spinal cord 30 and 60 min after injury. SOD activity did not change in this period, whereas MDA levels at 30 and 60 min after trauma were significantly elevated. Intrathecal administration of CPP or NBQX 15 min after injury produced statistically significant reductions in MDA elevation 60 min after injury. NBQX was found to be more effective than CPP. These results demonstrated that intrathecal local application of excitatory amino acid receptor antagonists can protect the spinal cord from secondary damage caused by the generation of lipid peroxides in experimental spinal cord injury

    Quadrupole magnet design, manufacturing and the acceptance tests for METU-defocusing beamline

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    Middle East Technical University Defocusing Beam Line (METU-DBL) performs the Single Event Effects (SEEs) radiation tests with protons in the range of 15 MeV to 30 MeV kinetic energy at Turkish Atomic Energy Authority Proton Accelerator Facility (TENMAK NÜKEN-PAF) for space and nuclear applications. The most critical beam transfer elements in the METU-DBL are three quadrupole magnets, which are used for defocusing the beam like optical lenses. The first two quadrupole magnets were purchased commercially, and the third quadrupole magnet was designed by the METU-DBL project team and manufactured by Sönmez Transformer Inc. in Turkey. Electronic, mechanic and magnetic capability tests of this custom-designed magnet were conducted both at TUBITAK and CERN facilities. After passing the acceptance tests, the magnet was certified by CERN and then installed to METU-DBL as a third quadrupole magnet. In this paper, we present details of the design, production and performed tests of the quadrupole magnet
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