405 research outputs found

    Analyticity in a phenomenology of electro-weak structure of hadrons

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    The utility of an application of the analyticity in a phenomenology of electro-weak structure of hadrons is demonstrated in a number of obtained new and experimentally verifiable results. With this aim first the problem of an inconsistency of the asymptotic behavior of VMD model with the asymptotic behavior of form factors of baryons and nuclei is solved generally and a general approach for determination of the lowest normal and anomalous singularities of form factors from the corresponding Feynman diagrams is reviewed. Then many useful applications by making use of the analytic properties of electro-weak form factors and amplitudes of various electromagnetic processes of hadrons are carried out.Comment: 153 pages, Reviews&Tutorial

    Cyclooxygenase Inhibition Limits Blood-Brain Barrier Disruption following Intracerebral Injection of Tumor Necrosis Factor-alpha in the Rat

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    Increased permeability of the blood-brain barrier (BBB) is important in neurological disorders. Neuroinflammation is associated with increased BBB breakdown and brain injury. Tumor necrosis factor-alpha (TNF-a) is involved in BBB injury and edema formation through a mechanism involving matrix metalloproteinase (MMP) upregulation. There is emerging evidence indicating that cyclooxygenase (COX) inhibition limits BBB disruption following ischemic stroke and bacterial meningitis, but the mechanisms involved are not known. We used intracerebral injection of TNF-a to study the effect of COX inhibition on TNF-a-induced BBB breakdown, MMP expression/activity and oxidative stress. BBB disruption was evaluated by the uptake of 14C-sucrose into the brain and by magnetic resonance imaging (MRI) utilizing Gd-DTPA as a paramagnetic contrast agent. Using selective inhibitors of each COX isoform, we found that COX-1 activity is more important than COX-2 in BBB opening. TNF-a induced a significant upregulation of gelatinase B (MMP-9), stromelysin-1 (MMP-3) and COX-2. In addition, TNF-a significantly depleted glutathione as compared to saline. Indomethacin (10 mg/kg; i.p.), an inhibitor of COX-1 and COX-2, reduced BBB damage at 24 h. Indomethacin significantly attenuated MMP-9 and MMP-3 expression and activation, and prevented the loss of endogenous radical scavenging capacity following intracerebral injection of TNF-a. Our results show for the first time that BBB disruption during neuroinflammation can be significantly reduced by administration of COX inhibitors. Modulation of COX in brain injury by COX inhibitors or agents modulating prostaglandin E2 formation/signaling may be useful in clinical settings associated with BBB disruption

    Investigation of microwave transitions and nonlinear magneto-optical rotation in anti-relaxation-coated cells

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    Using laser optical pumping, widths and frequency shifts are determined for microwave transitions between ground-state hyperfine components of 85^{85}Rb and 87^{87}Rb atoms contained in vapor cells with alkane anti-relaxation coatings. The results are compared with data on Zeeman relaxation obtained in nonlinear magneto-optical rotation (NMOR) experiments, a comparison important for quantitative understanding of spin-relaxation mechanisms in coated cells. By comparing cells manufactured over a forty-year period we demonstrate the long-term stability of coated cells, an important property for atomic clocks and magnetometers

    Influencia de dosis y forma de aplicación de CPPU sobre la producción y calidad de fruta en poscosecha para arándano de arbusto alto

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    54 p.Se ha comprobado que la aplicación de CPPU puede aumentar el peso en algunos cultivares de arándano de arbusto alto, pero hay escasa información sobre el efecto de CPPU sobre la vida de poscosecha de este tipo de arándano. Este ensayo se realizó en dos huertos comerciales de arándano. El primero está ubicado en Linares (Lat. Sur 35 º 52’14”; Long. Oriente 71 º 37’52’’), en plantas del cv. Duke de 8 años y cv. Brigitta de 10 años. El segundo está situado en Retiro (Lat. Sur 35º 57” 56’- Long. Oriente 71º 40’ 73’’), en plantas del cv. Elliott de 12 años. En esta investigación con un diseño completamente al azar (DCA), con 5 tratamientos y 5 repeticiones se probaron 4 tratamientos aplicados 10 DDPF (días después de plena flor): CPPU a 5 ppm y CPPU a 10 ppm aplicados con bomba de espalda, CPPU a 5 ppm y CPPU a 10 ppm aplicados con un pulverizador electrostático que ha tenido resultados en otras especies frutales, además de un tratamiento sin aplicación (control). Las cosechas se realizaron entre el 3 de diciembre de 2010 y el 31 de enero de 2011. Las evaluaciones se realizaron durante el crecimiento de la fruta, a cosecha y después de 40 días de almacenaje más 1 y 3 días a temperatura ambiente (40+1 y 40+3). Se evaluó crecimiento, rendimiento, calidad y condición de la fruta. La reacción de los distintos cv. fue variable frente a las diferentes aplicaciones. No hubo diferencias significativas en la evolución porcentual del diámetro frente a la medición anterior en cada fecha. Para los cv. Duke y Brigitta se encontraron alzas de rendimiento para las aplicaciones de CPPU: el primero respondió de mejor manera a una dosis de 5 ppm y el segundo, a 10 ppm, sin importar la forma de aplicación. `Elliott´ no presentó tratamientos que superaran al control en kilos cosechados, número de frutos y diámetro, entre otros. Aunque no hubo grandes diferencias para el peso por fruto, el análisis de segregación permite concluir que las aplicaciones de CPPU aumentan el porcentaje de fruta por sobre 1,8 g en Duke y Brigitta, y sobre 2,4 g para Elliott. Antes y después de almacenaje no se presentaron grandes diferencias entre los tratamientos para sólidos solubles, acidez titulable, firmeza, pudriciones, deshidratación y pérdida de peso. Palabras clave: Arándano, CPPU, Rendimiento, Calidad, Poscosecha./ABSTRACT:The application of CPPU can increase fruit weight in some cultivars of highbush blueberries, but little information is available on the impact of CPPU on the quality and postharvest life of blueberries. This investigation evaluated the effect of CPPU application on the fruit quality after 40 days of simulated maritime transport, plus 1 or 3 days at room temperature. The experiment was done in two commercial blueberry fields. The first one is located in Linares (South Lat. 35 º 52’14”; West Long. 71 º 37’52’’) where plants of cv. Duke (8 years) and Brigitta (10 years) were used. The second field is located in Retiro (South Lat. 35º 57” 56’- West Long. 71º 40’ 73’’) where 12-year-old plants of cv. Elliot were used. On each of the two fields, 5 treatments were established using 5 replicates of 2 plants each. Four treatments were applied 10 DAF (days after flowering): 5 ppm and 10 ppm CPPU using conventional backpack sprayer; 5 and 10 ppm, CPPU applied with an electrostatic sprayer. The fifth treatment was the control with no application . Fruit was harvested between December 3th, 2010 and January 31th, 2011. Evaluations were done at harvest, and after 40 days of cold storage (0-2º C) plus 1 and 3 days at room temperature (40+1 and 40+3) and were based on: fruit size, yield, and condition and quality of the berries. The experiment used a complete randomized design, with 5 treatments and 5 replications. Responses of the cv. under study was not always the same for the different treatments. No significant differences were found for the diameter. For cv. Duke and Brigitta yield increases were found with the application of CPPU: the first responded better to 5 ppm and the second to 10 ppm, regardless of the mode of application. On Elliott no differences were found for yield among treatments or the control. Results of this study showed that although there were no big differences for the average berry weight, the size segregation of the fruit indicates that the application of CPPU increased the percentage of fruit above 1,8 g in Duke and Brigitta, and above 2,4 g in Elliott. Finally, no significant differences were found between the treatments for soluble solids, titratable acidity, firmness, rotten fruit, dehydration and weight loss. Key words: Blueberry, CPPU, Yield, Quality, Postharvest

    Genome analysis of the necrotrophic fungal pathogens Sclerotinia sclerotiorum and Botrytis cinerea

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    Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38–39 Mb genomes include 11,860–14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared t

    Resonant nonlinear magneto-optical effects in atoms

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    In this article, we review the history, current status, physical mechanisms, experimental methods, and applications of nonlinear magneto-optical effects in atomic vapors. We begin by describing the pioneering work of Macaluso and Corbino over a century ago on linear magneto-optical effects (in which the properties of the medium do not depend on the light power) in the vicinity of atomic resonances, and contrast these effects with various nonlinear magneto-optical phenomena that have been studied both theoretically and experimentally since the late 1960s. In recent years, the field of nonlinear magneto-optics has experienced a revival of interest that has led to a number of developments, including the observation of ultra-narrow (1-Hz) magneto-optical resonances, applications in sensitive magnetometry, nonlinear magneto-optical tomography, and the possibility of a search for parity- and time-reversal-invariance violation in atoms.Comment: 51 pages, 23 figures, to appear in Rev. Mod. Phys. in Oct. 2002, Figure added, typos corrected, text edited for clarit

    Cooperation of cancer drivers with regulatory germline variants shapes clinical outcomes

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    Pediatric malignancies including Ewing sarcoma (EwS) feature a paucity of somatic alterations except for pathognomonic driver-mutations that cannot explain overt variations in clinical outcome. Here, we demonstrate in EwS how cooperation of dominant oncogenes and regulatory germline variants determine tumor growth, patient survival and drug response. Binding of the oncogenic EWSR1-FLI1 fusion transcription factor to a polymorphic enhancerlike DNA element controls expression of the transcription factor MYBL2 mediating these phenotypes. Whole-genome and RNA sequencing reveals that variability at this locus is inherited via the germline and is associated with variable inter-tumoral MYBL2 expression. High MYBL2 levels sensitize EwS cells for inhibition of its upstream activating kinase CDK2 in vitro and in vivo, suggesting MYBL2 as a putative biomarker for anti-CDK2-therapy. Collectively, we establish cooperation of somatic mutations and regulatory germline variants as a major determinant of tumor progression and highlight the importance of integrating the regulatory genome in precision medicine
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