41 research outputs found

    Feasibility studies for the measurement of time-like proton electromagnetic form factors from p¯ p→ μ+μ- at P ¯ ANDA at FAIR

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    This paper reports on Monte Carlo simulation results for future measurements of the moduli of time-like proton electromagnetic form factors, | GE| and | GM| , using the p¯ p→ μ+μ- reaction at P ¯ ANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at P ¯ ANDA , using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is p¯ p→ π+π-, due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented

    Acute myeloid leukemias expressing lymphoid-associated antigens: diagnostic incidence and prognostic significance

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    A portion of patients with acute myeloid leukemia also display surface antigens associated with lymphoid development (Ly+AML). The incidence of Ly+AML varies considerably between independent studies, both overall and with regard to individual antigens. On average, lymphoid-associated antigen expression is relatively low in AML. The reasons for some striking differences between conflicting reports are not clear, but are most probably due to various technical aspects including several arbitrary parameters. The data accumulated from the literature lead to the following conclusions: (i) use of different reagents against the CD surface antigens, different positive/negative cut-off levels, analysis of fresh or frozen cell material and variable sensitivities of the analytical instruments (expression of lymphoid-associated antigens was commonly weaker than myeloid-associated markers) seriously influence the results; (ii) most antigens (CD1, CD2, CD3, CD5, CD8, CD10, CD19, CD20, CD21, CD22) were expressed on less than 10% of AML cases; (iii) the CD4 and CD7 antigens, also found on normal monocytic and immature myeloid progenitor cells, were detected in 24% and 15% of AML cases, and their expression correlated with FAB M4/M5 and M1/M2 morphology, respectively; (iv) differences between pediatric and adult Ly+AML were restricted to CD4 and CD19 expression being detected more often in childhood cases; (v) there is no cytogenetic anomaly specific for Ly+AML; anomalies exclusively associated with lymphoid malignancies were not seen; aberrations involving 11q23, 14q32, and the 9;22 translocation seem to be increased; (vi) in most studies, expression of lymphoid-associated antigens (with the exception of CD7) on AML blasts lacked prognostic significance; CD7+AML appears to be a particular subset of malignant myeloid progenitors. In summary, these findings suggest that in general, Ly+AML may not represent a biologically distinct form of leukemia as these cases have similar clinical features and respond to therapy in a comparable manner

    BIO-C-FLUX. Biologischer Kohlenstofffluss in der bodennahen Wasserschicht des kuestenfernen Ozeans Schlussbericht

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    This report presents the results of biological investigations in the near-bottom water layer in the deep sea of the Northeast Atlantic. The scientific framework of BIO-C-FLUX is closely associated with the international JGOFS (Joint Global Ocean Flux Study) program which deals, on a global scale, with the biological aspects of the marine carbon cycle, concentrating mainly on the carbon flux in the upper mixed layer of the open ocean. BIO-C-FLUX studied the following main topics: - The biological turnover of sedimented POC by the benthopelagic and benthic faunas. The benthopelagic fauna included bacteria, zooplankton, nekton, and megafauna. The benthic studies covered bacteria, nano-, meio- and macrofauna. - The quantity and quality of sedimented POC. - The temporal and spatial variability of composition, standing stocks and turnover of POC in various faunal groups within the subsystems (benthopelagos, benthos) studied. The main research site was the BIOTRANS area in the Westeuropean Basin at 47 N/20 W (water depth 3850-4550 m). Comparative studies were made along the 20 W meridian at 59 N (Iceland Basin, 2900 m) and at 34 N (Madeira Abyssal Plain, 5120 m). These three locations represented different production regimes with increasing primary productivity from south to north. (orig./HK)Available from TIB Hannover: RN 3292(280)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

    Surgical management of tennis elbow

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    Skeletal ciliopathies are a heterogeneous group of autosomal recessive osteochondrodysplasias caused by defects in formation, maintenance and function of the primary cilium. Mutations in the underlying genes affect the molecular motors, intraflagellar transport complexes (IFT), or the basal body. The more severe phenotypes are caused by defects of genes of the dynein-2 complex, where mutations in DYNC2H1, WDR34 and WDR60 have been identified. In a patient with a Jeune-like phenotype we performed exome sequencing and identified compound heterozygous missense and nonsense mutations in DYNC2LI1 segregating with the phenotype. DYNC2LI1 is ubiquitously expressed and interacts with DYNC2H1 to form the dynein-2 complex important for retrograde IFT. Using DYNC2LI1 siRNA knockdown in fibroblasts we identified a significantly reduced cilia length proposed to affect cilia function. In addition, depletion of DYNC2LI1 induced altered cilia morphology with broadened ciliary tips and accumulation of IFT-B complex proteins in accordance with retrograde IFT defects. Our results expand the clinical spectrum of ciliopathies caused by defects of the dynein-2 complex

    Mutations in the pericentrin (PCNT) gene cause primordial dwarfism.

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    Contains fulltext : 70830.pdf (publisher's version ) (Closed access)Fundamental processes influencing human growth can be revealed by studying extreme short stature. Using genetic linkage analysis, we find that biallelic loss-of-function mutations in the centrosomal pericentrin (PCNT) gene on chromosome 21q22.3 cause microcephalic osteodysplastic primordial dwarfism type II (MOPD II) in 25 patients. Adults with this rare inherited condition have an average height of 100 centimeters and a brain size comparable to that of a 3-month-old baby, but are of near-normal intelligence. Absence of PCNT results in disorganized mitotic spindles and missegregation of chromosomes. Mutations in related genes are known to cause primary microcephaly (MCPH1, CDK5RAP2, ASPM, and CENPJ)
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