| 1. |
- Adloff, C, et al.
(författare)
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A measurement of the t dependence of the helicity structure of diffractive rho meson electroproduction at HERA
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 539:1-2, s. 25-39
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Tidskriftsartikel (refereegranskat)abstract
- The helicity structure of the diffractive electroproduction of rho mesons, e + p --> e + rho + Y, is studied in a previously unexplored region of large four-momentum transfer squared at the proton vertex, t: 0 < t' < 3 GeV2, where t' = - min. The data used are collected with the HI detector at HERA in the kinematic domain 2.5 < Q(2) < 60 GeV2, 40 < W < 120 GeV No t dependence of the r(00)(04) spin density matrix element is found. A significant t dependent helicity non-conservation from the virtual photon to the rho meson is observed for the spin density matrix element combinations r(00)(5) + 2r(11)(5) and r(00)(1) + 2r(11)(1). These t dependences are consistently described by a perturbative QCD model based on the exchange of two gluons.
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| 2. |
- Adloff, C, et al.
(författare)
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Search for excited neutrinos at HERA
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 525:1-2, s. 9-16
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Tidskriftsartikel (refereegranskat)abstract
- We present a search for excited neutrinos using e(-) p data taken by the H1 experiment at HERA at a center-of-mass energy of 318 GeV with an integrated luminosity of 15 pb(-1). No evidence for excited neutrino production is found. Mass dependent exclusion limits are determined for the ratio of the coupling to the compositeness scale, f/Lambda, independently of the relative couplings to the SU(2) and U(1) gauge bosons. These limits extend the excluded region to higher masses than has been possible in previous searches at other colliders.
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| 3. |
- Adloff, C, et al.
(författare)
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Search for odderon-induced contributions to exclusive pi(0) photoproduction at HERA
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 544:1-2, s. 35-43
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Tidskriftsartikel (refereegranskat)abstract
- A search for contributions to the reaction ep --> epi(0)N* from photon-odderon fusion in the photoproduction regime at HERA is reported, at an average photon-proton centre-of-mass energy = 215 GeV. The measurement proceeds via detection of the pi(0) decay photons, a leading neutron from the N* decay, and the scattered electron. No pi(0) signal is observed and an upper limit on the cross section for the photon-odderon fusion process of sigma(gammap --> pi(0)N*) < 49 nb at the 95% confidence level is derived, integrated over the experimentally accessible range of the squared four-momentum transfer at the nucleon vertex 0.02 < < 0.3 GeV2. This excludes a recent prediction from a calculation based on a non-perturbative QCD model of a photon-odderon fusion cross section above 200 nb. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 4. |
- Adloff, C, et al.
(författare)
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Measurement of dijet cross sections in photoproduction at HERA
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 25:1, s. 13-23
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Tidskriftsartikel (refereegranskat)abstract
- Dijet cross sections as functions of several jet observables are measured in photoproduction using the HI detector at HERA. The data sample comprises e(+)p data with an integrated luminosity of 319 pb(-1). Jets are selected using the inclusive k(perpendicular to) algorithm with a minimum transverse energy of 25 GeV for the leading jet. The phase space covers longitudinal proton momentum fraction x(p) and photon longitudinal momentum fraction x(gamma) in the ranges 0.05 < x(p) < 0.6 and 0.1 < x(gamma) < 1. The predict ions of next-to-leading order perturbative QCD, including recent photon and proton parton densities, are found to be compatible with the data in a wide kinematical range.
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| 5. |
- Adloff, C, et al.
(författare)
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Energy flow and rapidity gaps between jets in photoproduction at HERA
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 24:4, s. 517-527
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Tidskriftsartikel (refereegranskat)abstract
- Dijet events in photon-proton collisions in which there is a large pseudorapidity separation, Deltaeta > 2.5 between the two highest E-T jets are studied with the H1 detector at HERA. The inclusive dijet cross sections are measured as functions of the longitudinal momentum fractions of the proton and photon which participate in the production of the jets, x(p)(jets) and x(gamma)(jets) respectively, Deltaeta, the pseudorapidity P separation between the two highest E-T jets, and E-T(gap), the total summed transverse energy between the jets. Rapidity gap events are defined as events in which E-T(gap) is less than E-T(cut), for E-T(cut) varied between jets 0.5 and 2.0 GeV. The fraction of dijet events with a rapidity gap is measured differentially in Deltaeta, x(p)(jets) and x(gamma)(jets). An excess of events with rapidity gaps at low values of E-T(cut) is observed above the expectation from standard photoproduction processes. This excess can be explained by the exchange of a strongly interacting colour singlet object between the jets.
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| 6. |
- Adloff, C, et al.
(författare)
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Measurement of D*(+/-) meson production and F-2(c) in deep-inelastic scattering at HERA
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 528:3-4, s. 199-214
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Tidskriftsartikel (refereegranskat)abstract
- The inclusive production of D*+/-(2010) mesons in deep-inelastic scattering is studied with the HI detector at HERA. In the kinematic region 1 < Q(2) < 100 GeV2 and 0.05 < y < 0.7 an e(+) p cross section for inclusive D*+/- meson production of 8.50 +/- 0.42(stat.)(-100)(+1.21)(syst.) nb is measured in the visible range p(tD*) > 1.5 GeV and eta(D*) < 1.5. Single and double differential inclusive D*+/- meson cross sections are compared to perturbative QCD calculations in two different evolution schemes, The charm contribution to the proton structure, F-c(2)(x, Q(2)), is determined by extrapolating the visible charm cross section to the full phase space. This contribution is found to rise from about 10% at Q(2) = 1.5 GeV2 to more than 25% at Q(2) = 60 GeV2 corresponding to x values ranging from 5 x 10(-5) to 3 x 10(-3). (C) 2002 Elsevier Science B.V. All rights reserved.
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| 7. |
- Adloff, C, et al.
(författare)
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Measurement of dijet electroproduction at small jet separation
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 24:1, s. 33-41
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Tidskriftsartikel (refereegranskat)abstract
- Deep-inelastic scattering data in the range 150 < Q(2) < 35000 GeV2 are used to investigate the minimum jet separation necessary to allow accurate description of the rate of dijet production using next-to-leading order perturbative QCD calculations. The required jet separation is found to be small, allowing about 1/3 of DIS data to be classified as dijet, as opposed to approximately 1/10 with more typical jet analyses. A number of precision measurements made using this dijet sample are well described by the calculations. The data are also described by the combination of leading order matrix elements and parton showers, as implemented in the QCD based Monte Carlo model RAPGAP.
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| 8. |
- Neusser, A, et al.
(författare)
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Superdeformed band at very high spin in Nd-140
- 2004
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 70:6
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Tidskriftsartikel (refereegranskat)abstract
- A new high-spin superdeformed band has been discovered in Nd-140(60)80. It was populated in the Zr-96(Ca-48,4n) reaction and investigated using the EUROBALL gamma-ray spectrometer array. The band is observed in the approximate spin range of I=36 to 66. It is associated with shell gaps around Z=60 and at N=80 at large deformation. These gaps produce a pronounced minimum in the calculated total Routhian surfaces at a quadrupole deformation of epsilon(2)=0.45. The new band which lies between the high-deformation bands in the Aapproximate to130 region and the superdeformed bands in Aapproximate to150 nuclei provides insight into the development of the deformation between these two regions. Two possible configurations are suggested involving four neutrons of i(13/2) origin (nu6(4)) and either six protons of h(11/2)/h(9/2) origin (pi5(6)) or five protons of h(11/2)/h(9/2) and one of i(13/2) origin (pi5(5)6(1)).
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| 9. |
- Sehgal, B. R., et al.
(författare)
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Assessment of reactor vessel integrity (ARVI)
- 2003
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Ingår i: Nuclear Engineering and Design. - 0029-5493 .- 1872-759X. ; 221:03-jan, s. 23-53
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Tidskriftsartikel (refereegranskat)abstract
- The cost-shared project ARVI (assessment of reactor vessel integrity) involves a total of nine organisations from Europe and USA. The objective of the ARVI Project is to resolve the safety issues that remain unresolved for the melt vessel interaction phase of the in-vessel progression of a severe accident. The work consists of experiments and analysis development. Four tests were performed in the EC-FOREVER Programme, in which failure was achieved in-vessels employing the French pressure vessel steel. The tests were analysed with the commercial code ANSYS-Multiphysics, and the codes SYSTUS+ and PASULA, and quite good agreement was achieved for the failure location. Natural convection experiments in stratified pools have been performed in the SIMECO and the COPO facilities, which showed that much greater heat is transferred downwards for immiscible layers or before layers mix. A model for gap cooling and a set of simplified models for the system codes have been developed. MVITA code calculations have been performed for the Czech and Hungarian VVERs, towards evaluation of the in-vessel melt retention accident management scheme. Tests have been performed at the ULPU facility with organised flow for vessel external cooling. Considerable enhancement of the critical heat flux (CHF) was obtained. The ARVI Project has reached the halfway stage. This paper presents the results obtained thus far from the project.
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| 10. |
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| 11. |
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| 12. |
- Burger, AM, et al.
(författare)
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The breast cancer-associated gene Di12 has oncogenic activity
- 2003
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Ingår i: Anticancer research. - 1791-7530. ; 23:3A, s. 2027-2033
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Tidskriftsartikel (refereegranskat)abstract
- The breast cancer-associated gene Di12 encodes a novel protein, which was found overexpressed in invasive ductal carcinomas of the breast. In experiments designed to assess the role of the Di12 gene in oncogenesis, the overexpression of 339 N-terminal amino acids of this gene in NIH3T3 cells resulted in cellular transformation and in vivo tumorigenesis. NIH3T3-Di12 tumor cell growth was partly reversible upon Di12 antisense treatment. In addition, transfortnation of the ER + human breast cancer cell line MCF- 7 resulted in hormone independent growth of these tumors in nude mice. Di12 expression in NIH3T3 and MCF-7 tumor cells was confirmed by RT-PCR and mabDi12 immunostaining. Immunohistochemistry using mabDi12 on an arrayed collection of 106 invasive breast tumors further underlined the expression of the gene in over 75% of advanced stage breast cancers. Our data indicate that Di12 expression is oncogenic in in vitro transformation and in vivo tumorigenic assays.
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| 13. |
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| 14. |
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| 15. |
- Eslamboli, A, et al.
(författare)
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Recombinant adeno-associated viral vector (rAAV) delivery of GDNF provides protection against 6-OHDA lesion in the common marmoset monkey (Callithrix jacchus)
- 2003
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Ingår i: Experimental Neurology. - : Elsevier BV. - 0014-4886. ; 184:1, s. 536-548
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Tidskriftsartikel (refereegranskat)abstract
- Glial cell line-derived neurotrophic factor (GDNF) has shown potential as a treatment for Parkinson's disease. Recombinant adeno-associated viral vectors expressing the GDNF protein (rAAV-GDNF) have been used in rodent models of Parkinson's disease to promote functional regeneration after 6-OHDA lesions of the nigrostriatal system. The goal of the present study was to assess the anatomical and functional efficacy of rAAV-GDNF in the common marmoset monkey (Callithrix jacchus). rAAV-GDNF was injected into the striatum and substantia nigra 4 weeks prior to a unilateral 6-OHDA lesion of the nigrostriatal bundle. Forty percent of the dopamine cells in the lesioned substantia nigra of the rAAV-GDNF-treated monkeys survived, compared with 21% in the untreated monkeys. Fine dopaminergic fibres were observed microscopically in the injected striatum of some rAAV-GDNF-treated monkeys, suggesting that rAAV-GDNF treatment may have prevented, at least in part, the loss of dopaminergic innervation of the striatum. Protection of dopamine cells and striatal fibre innervation was associated with amelioration of the lesion-induced behavioural deficits. rAAV-GDNF-treated monkeys showed partial or complete protection not only in the amphetamine and apomorphine rotation but also in head position and the parkinsonian disability rating scale. Therefore, our study provides evidence for the behavioural and anatomical efficacy of GDNF delivered via an rAAV vector as a possible treatment for Parkinson's disease. (C) 2003 Elsevier Inc. All rights reserved.
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| 16. |
- Seth, A, et al.
(författare)
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Gene expression profiling of ductal carcinomas in situ and invasive breast tumors
- 2003
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Ingår i: Anticancer research. - 1791-7530. ; 23:3A, s. 2043-2051
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Tidskriftsartikel (refereegranskat)abstract
- Comparative and functional genomics are powerful tools to advance the understanding of the molecular basis of cancer. It is believed that genes are epigenetically regulated and, thus, each tumor type and stage will be characterized by a gene expression fingerprint. In this study we identified genes that are differentially expressed in ductal carcinoma in situ and invasive ductal carcinoma of the breast. To isolate genes that are associated with progression of breast cancer we performed differential display and subtractive cloning procedures using matched RNA from normal and tumor tissue. cDNA microarray analysis generated gene expression profiles typical of the transition front in situ to invasive breast cancer when we used mRAA extracted from a case of low-to intermediate-grade DCIS and a case of high-grade DC1S/IDC. cDNAs from these samples were the probes in a cDNA microarray hybridization to 9183 unique cDAAs representing 8507 genes. Signals from both transcriptomes were obtained for 8083 genes, and the balanced differential expression values between pure DCIS and DCIS/invasive tumors revealed 303 distinct cDNAs with a ratio of > 2. Interferon inducible genes were found to be expressed at the highest level in the pure DCIS sample. Genes most abundantly expressed in the invasive tumor were immunoglobulin heavy constant gamma 3 and calgranulin B. Further analysis of RNA and protein expression in breast tumor cell lines and patient tissue samples revealed that: IGFBP-rP1 is down-regulated in invasive tumors whereas cyclin I protein is regulated by ubiquitination and is associated with ER-negative breast cancers. Conclusion: The known and novel genes discussed here represent targets for molecular characterization during breast cancer development as well as,for designing novel strategies for diagnosis and treatment.
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