| 1. |
- Abt, I, et al.
(författare)
-
Inclusive V-0 production cross sections from 920 GeV fixed target proton-nucleus collisions
- 2003
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 29:2, s. 181-190
-
Tidskriftsartikel (refereegranskat)abstract
- Inclusive differential cross sections dsigma(pA)/dx(F) and dsigma(pA)/dp(t)(2) for the production of K-S(0), Lambda, and (&ULambda;) over bar particles are measured at HERA in proton-induced reactions on C, Al, Ti, and W targets. The incident beam energy is 920 GeV, corresponding to roots = 41.6 GeV in the proton-nucleon system. The ratios of differential cross sections dsigma(pA)(K-S(0))/dsigma(pA)(Lambda) and dsigma(pA)((&ULambda;) over bar)/dsigma(pA) (Lambda) are measured to be 6.2 +/- 0.5 and 0.66 +/- 0.07, respectively, for x(F) approximate to -0.06. No significant dependence upon the target material is observed. Within errors, the slopes of the transverse momentum distributions da,Ald t also show no significant dependence upon the target material. The dependence of the extrapolated total cross sections sigma(pA) on the atomic mass A of the target material is discussed, and the deduced cross sections per nucleon sigma(pN) are compared with results obtained at other energies.
|
|
| 2. |
- Abt, I, et al.
(författare)
-
Measurement of the b(b)over-bar production cross section in 920 GeV fixed-target proton-nucleus collisions
- 2003
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 26:3, s. 345-355
-
Tidskriftsartikel (refereegranskat)abstract
- Using the HERA-B detector, the b (b) over bar production cross section has been measured in 920 GeV proton collisions on carbon and titanium targets. The b (b) over bar production was tagged via inclusive bottom quark decays into J/psi by exploiting the longitudinal separation of J/psi --> l(+)l(-) decay vertices from the primary proton-nucleus interaction. Both e(+)e(-) and mu(+)mu(-) channels have been reconstructed and the combined analysis yields the cross section sigma(b (b) over bar) = 32(-12)(+14)(stat) (+6)(-7)(sys) nb/nucleon.
|
|
| 3. |
- Alcorn, J, et al.
(författare)
-
Basic instrumentation for Hall A at Jefferson Lab
- 2004
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 522:3, s. 294-346
-
Tidskriftsartikel (refereegranskat)abstract
- The instrumentation in Hall A at the Thomas Jefferson National Accelerator Facility was designed to study electro-and photo-induced reactions at very high luminosity and good momentum and angular resolution for at least one of the reaction products. The central components of Hall A are two identical high resolution spectrometers, which allow the vertical drift chambers in the focal plane to provide a momentum resolution of better than 2 x 10(-4). A variety of Cherenkov counters, scintillators and lead-glass calorimeters provide excellent particle identification. The facility has been operated successfully at a luminosity well in excess of 10(38) CM-2 s(-1). The research program is aimed at a variety of subjects, including nucleon structure functions, nucleon form factors and properties of the nuclear medium. (C) 2003 Elsevier B.V. All rights reserved.
|
|
| 4. |
- Ahmed, M., et al.
(författare)
-
Search for the lepton-family-number nonconserving decay μ +→e +γ
- 2002
-
Ingår i: Physical Review D. - : American Physical Society. - 1550-7998 .- 1550-2368. ; 65:11
-
Tidskriftsartikel (refereegranskat)abstract
- The MEGA experiment, which searched for the muon- and electron-number violating decay μ +→e + γ, is described. The spectrometer system, the calibrations, the data taking procedures, the data analysis, and the sensitivity of the experiment are discussed. The most stringent upper limit on the branching ratio, B(μ + →e + γ)<1.2×10 -11 with 90% confidence, is derived from a likelihood analysis.
|
|
| 5. |
- Dutta, D, et al.
(författare)
-
Nuclear transparency with the gamma n ->pi(-)p process in He-4
- 2003
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 68:2: 021001
-
Tidskriftsartikel (refereegranskat)abstract
- We have measured the nuclear transparency of the fundamental process gamman-->pi(-)p in He-4. These measurements were performed at Jefferson Lab in the photon energy range of 1.6-4.5 GeV and at theta(cm)(pi)=70degrees and 90degrees. These measurements are the first of their kind in the study of nuclear transparency in photoreactions. They also provide a benchmark test of Glauber calculations based on traditional models of nuclear physics. The transparency results suggest deviations from the traditional nuclear physics picture. The momentum transfer dependence of the measured nuclear transparency is consistent with Glauber calculations that include the quantum chromodynamics phenomenon of color transparency.
|
|
| 6. |
|
|
| 7. |
- Zhu, LY, et al.
(författare)
-
Cross-section measurement of charged-pion photoproduction from hydrogen and deuterium
- 2003
-
Ingår i: Physical Review Letters. - 1079-7114. ; 91:2: 022003
-
Tidskriftsartikel (refereegranskat)abstract
- We have measured the differential cross section for the gamman-->pi(-)p and gammap-->pi(+)n reactions at theta(c.m.)=90degrees in the photon energy range from 1.1 to 5.5 GeV at Jefferson Lab (JLab). The data at E(gamma)greater than or similar to3.3 GeV exhibit a global scaling behavior for both pi(-) and pi(+) photoproduction, consistent with the constituent counting rule and the existing pi(+) photoproduction data. Possible oscillations around the scaling value are suggested by these new data. The data show enhancement in the scaled cross section at a center-of-mass energy near 2.2 GeV. The cross section ratio of exclusive pi(-) to pi(+) photoproduction at high energy is consistent with the prediction based on one-hard-gluon-exchange diagrams.
|
|
| 8. |
- Ahrens, J., et al.
(författare)
-
Search for Extraterrestrial Point Sources of Neutrinos with AMANDA-II
- 2004
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 92:7, s. 711021-711025
-
Tidskriftsartikel (refereegranskat)abstract
- The results of a search for point sources of high energy neutrinos in the northern hemisphere were presented using AMANDA-II data collected in the year 2000. The results included the flux limits on several active-galactic-nuclei blazars, microquasars, magnetars, and other candidate neutrino sources. A search for excesses above a random background of cosmic ray induced atmospheric neutrinos and misreconstructed downgoing cosmic-rays muons, which revealed no statistically significant neutrino point sources was also presented. It was shown that AMANDA-II had achieved the sensitivity required to probe known TeV γ-ray sources such as the blazar Markarian 501 in its 1997 flaring state at a level where neutrino and γ-ray fluxes were equal.
|
|
| 9. |
- Andrés, E., et al.
(författare)
-
Observation of high-energy neutrinos using Čerenkov detectors embedded deep in Antarctic ice
- 2001
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 410:6827, s. 441-443
-
Tidskriftsartikel (refereegranskat)abstract
- Neutrinos are elementary particles that carry no electric charge and have little mass. As they interact only weakly with other particles, they can penetrate enormous amounts of matter, and therefore have the potential to directly convey astrophysical information from the edge of the Universe and from deep inside the most cataclysmic high-energy regions. The neutrino's great penetrating power, however, also makes this particle difficult to detect. Underground detectors have observed low-energy neutrinos from the Sun and a nearby supernova2, as well as neutrinos generated in the Earth's atmosphere. But the very low fluxes of high-energy neutrinos from cosmic sources can be observed only by much larger, expandable detectors in, for example, deep water3,4 or ice5. Here we report the detection of upwardly propagating atmospheric neutrinos by the ice-based Antarctic muon and neutrino detector array (AMANDA). These results establish a technology with which to build a kilometre-scale neutrino observatory necessary for astrophysical observations1.
|
|
| 10. |
- Andrés, E., et al.
(författare)
-
Recent results from AMANDA
- 2001
-
Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 16:1C, s. 1013-1015
-
Tidskriftsartikel (refereegranskat)abstract
- We present results based on data taken in 1997 with the 302-PMT Antarctic Muon and Neutrino Detector Array-B10 ("AMANDA-B10") array. Atmospheric neutrinos created in the northern hemisphere are observed indirectly through their charged current interactions which produce relativistic, Cherenkov-light-emitting upgoing muons in the South Pole ice cap. The reconstructed angular distribution of these events is in good agreement with expectation and demonstrates the viability of this ice-based device as a neutrino telescope.
|
|
| 11. |
- Andres, E., et al.
(författare)
-
Selected recent results from AMANDA
- 2001
-
Ingår i: ICHEP 2000. Proceedings of the 30th International Conference on High Energy Physics. - : World Scientific. ; , s. 965-968
-
Konferensbidrag (refereegranskat)abstract
- We present a selection of results based on data taken in 1997 with the 302-PMT Antarctic Muon and Neutrino Detector Array-B10 ("AMANDA-B10") array. Atmospheric neutrinos created in the northern hemisphere are observed indirectly through their charged current interactions which produce relativistic, Cherenkov-light-emitting upgoing muons in the South Pole ice cap. The reconstructed angular distribution of these events is in good agreement with expectation and demonstrates the viability of this ice-based device as a neutrino telescope. Studies of nearly vertical upgoing muons limit the available parameter space for WIMP dark matter under the assumption that WIMPS are trapped in the earth's gravitational potential well and annihilate with one another near the earth's center.
|
|
| 12. |
- Imanishi, T., et al.
(författare)
-
Integrative annotation of 21,037 human genes validated by full-length cDNA clones
- 2004
-
Ingår i: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 2:6, s. 856-875
-
Tidskriftsartikel (refereegranskat)abstract
- The human genome sequence defines our inherent biological potential; the realization of the biology encoded therein requires knowledge of the function of each gene. Currently, our knowledge in this area is still limited. Several lines of investigation have been used to elucidate the structure and function of the genes in the human genome. Even so, gene prediction remains a difficult task, as the varieties of transcripts of a gene may vary to a great extent. We thus performed an exhaustive integrative characterization of 41,118 full-length cDNAs that capture the gene transcripts as complete functional cassettes, providing an unequivocal report of structural and functional diversity at the gene level. Our international collaboration has validated 21,037 human gene candidates by analysis of high-quality full-length cDNA clones through curation using unified criteria. This led to the identification of 5,155 new gene candidates. It also manifested the most reliable way to control the quality of the cDNA clones. We have developed a human gene database, called the H-Invitational Database (H-InvDB; http://www.h-invitational.jp/). It provides the following: integrative annotation of human genes, description of gene structures, details of novel alternative splicing isoforms, non-protein-coding RNAs, functional domains, subcellular localizations, metabolic pathways, predictions of protein three-dimensional structure, mapping of known single nucleotide polymorphisms (SNPs), identification of polymorphic microsatellite repeats within human genes, and comparative results with mouse full-length cDNAs. The H-InvDB analysis has shown that up to 4% of the human genome sequence (National Center for Biotechnology Information build 34 assembly) may contain misassembled or missing regions. We found that 6.5% of the human gene candidates (1,377 loci) did not have a good protein-coding open reading frame, of which 296 loci are strong candidates for non-protein-coding RNA genes. In addition, among 72,027 uniquely mapped SNPs and insertions/deletions localized within human genes, 13,215 nonsynonymous SNPs, 315 nonsense SNPs, and 452 indels occurred in coding regions. Together with 25 polymorphic microsatellite repeats present in coding regions, they may alter protein structure, causing phenotypic effects or resulting in disease. The H-InvDB platform represents a substantial contribution to resources needed for the exploration of human biology and pathology.
|
|
| 13. |
- Karle, A., et al.
(författare)
-
Observation of high energy atmospheric neutrinos with AMANDA
- 2000
-
Ingår i: AIP Conference Proceedings. - : American Institute of Physics (AIP). ; , s. 823-827
-
Konferensbidrag (refereegranskat)abstract
- In 1997 the Antarctic Muon and Neutrino Detector Array (AMANDA) started operating with 10 strings. In an analysis of data taken during the first year of operation 188 atmospheric neutrino candidates were found. Their zenith angle distribution agrees with expectations based on Monte Carlo simulations. A preliminary upper limit is given on a diffuse flux of high energy neutrinos of astrophysical origin.
|
|
| 14. |
- Liu, T. B., et al.
(författare)
-
Synthesis, structures and electrochemical properties of nitro- and amino-functionalized diiron azadithiolates as active site models of Fe-only hydrogenases
- 2004
-
Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 10:18, s. 4474-4479
-
Tidskriftsartikel (refereegranskat)abstract
- Complex [{(mu-SCH2)(2)N(4-NO2C6H4)}Fe-2(CO)(6)] (4) was prepared by the reaction of the dianionic intermediate [(mu-S)(2)Fe-2(CO)(6)](2-) and N,N-bis(chloromethyl)-4-nitroaniline as a biomimetic model of the active site of Fe-only hydrogenase. The reduction of 4 by Pd-C/H-2 under a neutral condition afforded complex [{(mu-SCH2)(2)N(4-NH2C6H4)}Fe-2(CO)(6)] (5) in 67% yield. Both complexes were characterized by IR, H-1 and C-13 NMR spectroscopy and MS spectrometry. The molecular structure of 4, as determined by X-ray analysis, has a butterfly 2Fe2S core and the aryl group on the bridged-N atom slants to the Fe(2) site. Cyclic voltammograms of 4 and 5 were studied to evaluate their redox properties. It was found that complex 4 catalyzed electrochemical proton reduction in the presence of acetic acid. A plausible mechanism of the electrocatalytic proton reduction is discussed.
|
|
| 15. |
- Niessen, Peter, et al.
(författare)
-
Recent results from the amanda experiment
- 2003
-
Ingår i: Proceedings of 38th Rencontres de Moriond on Electroweak Interactions and Unified Theories 15-22 Mar 2003. Les Arcs, France.
-
Konferensbidrag (refereegranskat)abstract
- AMANDA (Antarctic Muon And Neutrino Detector Array) is a neutrino telescope built under the southern polar icecap and its scope is to explore the possibility to detect high energy cosmic neutrinos. This should generate insight into the powerful celestial objects where acceleration mechanisms can bring up to 10 20 eV. We describe the achievements and results from the AMANDA-B10 prototype and the preliminary results from the current AMANDA-II detector which show dramatic increase in sensitivity.
|
|
| 16. |
- Polyakov, A. Y., et al.
(författare)
-
Electrical and luminescent properties and the spectra of deep centers in GaMnN/InGaN light-emitting diodes
- 2004
-
Ingår i: Journal of Electronic Materials. - : Springer Science and Business Media LLC. - 0361-5235 .- 1543-186X. ; 33:3, s. 241-247
-
Tidskriftsartikel (refereegranskat)abstract
- Electrical and electroluminescent properties were studied for GaN/InGaN light-emitting diodes (LEDs) with the n-GaN layer up and with the top portion of the n layer made of undoped GaMnN to allow polarization modulation by applying an external magnetic field (so-called -spin-LEDs-). The contact annealing temperature was kept to 750°C, which is the thermal stability limit for retaining room-temperature magnetic ordering in the GaMnN layer. Measurable electroluminescence (EL) was obtained in these structures at threshold voltages of ∼15 V, with a lower EL signal compared to control LEDs without Mn. This is related to the existence of two parasitic junctions between the metal and the lower contact p-type layer and between the GaMnN and the n-GaN in the top contact layer.
|
|
| 17. |
- Ahrens, J., et al.
(författare)
-
Initial results from AMANDA
- 2001
-
Ingår i: 21st Rencontres de Moriond Workshop on Very High-Energy Phenomena in the Universe.
-
Konferensbidrag (refereegranskat)
|
|
| 18. |
- Ahrens, J., et al.
(författare)
-
Limits to the muon flux from WIMP annihilation in the center of the Earth with the AMANDA detector
- 2002
-
Ingår i: Physical Review D. - : American Physical Society. - 1550-7998 .- 1550-2368. ; 66:3, s. 032006-
-
Tidskriftsartikel (refereegranskat)abstract
- A search for nearly vertical up-going muon-neutrinos from neutralino annihilations in the center of the Earth has been performed with the AMANDA-B10 neutrino detector. The data collected in 130.1 days of live time in 1997, ∼10 9 events, have been analyzed for this search. No excess over the expected atmospheric neutrino background has been observed. An upper limit at 90% confidence level has been obtained on the annihilation rate of neutralinos in the center of the Earth, as well as the corresponding muon flux limit, both as a function of the neutralino mass in the range 100 GeV-5000 GeV. © 2002 The American Physical Society.
|
|
| 19. |
- Ahrens, J., et al.
(författare)
-
Observation of high energy atmospheric neutrinos with the Antarctic muon and neutrino detector array
- 2002
-
Ingår i: Physical Review D. - : American Physical Society. - 1550-7998 .- 1550-2368. ; 66:1, s. 120051-1200520
-
Tidskriftsartikel (refereegranskat)abstract
- The Antarctic muon and neutrino detector array (AMANDA) began collecting data with ten strings in 1997. Results from the first year of operation are presented. Neutrinos coming through the Earth from the Northern Hemisphere are identified by secondary muons moving upward through the array. Cosmic rays in the atmosphere generate a background of downward moving muons, which are about 106 times more abundant than the upward moving muons. Over 130 days of exposure, we observed a total of about 300 neutrino events. In the same period, a background of 1.05 × 109 cosmic ray muon events was recorded. The observed neutrino flux is consistent with atmospheric neutrino predictions. Monte Carlo simulations indicate that 90% of these events lie in the energy range 66 GeV to 3.4 TeV. The observation of atmospheric neutrinos consistent with expectations establishes AMANDA-B10 as a working neutrino telescope.
|
|
| 20. |
- Ahrens, J., et al.
(författare)
-
Results from AMANDA
- 2001
-
Ingår i: Proceedings, 9th International Workshop, Venice, Italy, March 6-9, 2001. Vol. 1, 2. ; , s. 569-580
-
Konferensbidrag (refereegranskat)
|
|
| 21. |
- Ahrens, J., et al.
(författare)
-
Results from the Antarctic muon and nuetrino detector array
- 2003
-
Ingår i: Nuclear physics B, Proceedings supplements. - : Elsevier. - 0920-5632 .- 1873-3832. ; 118, s. 371-379
-
Tidskriftsartikel (refereegranskat)abstract
- We show new results from both the older and newer incarnations of AMANDA (AMANDA-B10 and AMANDA-II, respectively). These results demonstrate that AMANDA is a functioning, multipurpose detector with significant physics and astrophysics reach. They include a new higher-statistics measurement of the atmospheric muon neutrino flux and preliminary results from searches for a variety of sources of ultrahigh energy neutrinos: generic point sources, gamma-ray bursters and diffuse sources producing muons in the detector, and diffuse sources producing electromagnetic or hadronic showers in or near the detector.
|
|
| 22. |
- Ahrens, J., et al.
(författare)
-
Search for neutrino-induced cascades with the AMANDA detector
- 2003
-
Ingår i: Physical Review D. - : American Physical Society (APS). - 1550-7998 .- 1550-2368. ; 67:1, s. 012003-
-
Tidskriftsartikel (refereegranskat)abstract
- We report on a search for electromagnetic and/or hadronic showers (cascades) induced by a diffuse flux of neutrinos with energies between 5 TeV and 300 TeV from extraterrestrial sources. Cascades may be produced by matter interactions of all flavors of neutrinos, and contained cascades have better energy resolution and afford better background rejection than throughgoing νμ-induced muons. Data taken in 1997 with the AMANDA detector were searched for events with a high-energy cascadelike signature. The observed events are consistent with expected backgrounds from atmospheric neutrinos and catastrophic energy losses from atmospheric muons. Effective volumes for all flavors of neutrinos, which allow the calculation of limits for any neutrino flux model, are presented. The limit on cascades from a diffuse flux of νe+ νμ + ντ+ ν̄e + ν̄μ+ ν̄τ is E2(dΦ/dE)<9.8×10-6 GeV cm-2 s-1 sr-1, assuming a neutrino flavor flux ratio of 1:1:1 at the detector. The limit on cascades from a diffuse flux of νe+ν̄e is E2(dΦ/dE)<6. 5×10-6 GeV cm-2 s-1 sr-1, independent of the assumed neutrino flavor flux ratio. © 2003 The American Physical Society.
|
|
| 23. |
- Ahrens, J., et al.
(författare)
-
Search for supernova neutrino bursts with the AMANDA detector
- 2001
-
Ingår i: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 16:4, s. 345-359
-
Tidskriftsartikel (refereegranskat)abstract
- The core collapse of a massive star in the Milky Way will produce a neutrino burst, intense enough to be detected by existing underground detectors. The AMANDA neutrino telescope located deep in the South Pole ice can detect MeV neutrinos by a collective rate increase in all photo-multipliers on top of dark noise. The main source of light comes from positrons produced in the CC reaction of anti-electron neutrinos on free protons ve + p → e+ + n. This paper describes the first supernova search performed on the full sets of data taken during 1997 and 1998 (215 days of live time) with 302 of the detector's optical modules. No candidate events resulted from this search. The performance of the detector is calculated, yielding a 70% coverage of the galaxy with one background fake per year with 90% efficiency for the detector configuration under study. An upper limit at the 90% c.l. on the rate of stellar collapses in the Milky Way is derived, yielding 4.3 events per year. A trigger algorithm is presented and its performance estimated. Possible improvements of the detector hardware are reviewed.
|
|
| 24. |
- Bai, X., et al.
(författare)
-
Status of the Neutrino Telescope AMANDA : Monopoles and WIMPS
- 2001
-
Ingår i: Dark Matter in Astro- and Particle Physics. - Berlin, Heidelberg : Springer. - 9783642626081 ; , s. 699-706
-
Konferensbidrag (refereegranskat)abstract
- The neutrino telescope AMANDA has been set up at the geographical South Pole as first step to a neutrino telescope of the scale of one cubic kilometer, which is the canonical size for a detector sensitive to neutrinos from Active Galactic Nuclei (AGN), Gamma Ray Bursts (GRB) and Topological Defects (TD). The location and depth in which the detector is installed is given by the requirement to detect neutrinos by the Cherenkov light produced by their reaction products and to keep the background due to atmospheric muons as small as possible. However, a detector optimized for this purpose is also capable to detect the bright Cherenkov light from relativistic Monopoles and neutrino signals from regions with high gravitational potential, where WIMPS are accumulated and possibly annihilate. Both hypothetical particles might contribute to the amount of dark matter. Therefore here a report about the status of the experiment (autumn 2000) and about the status of the search for these particles with the AMANDA B10 sub-detector is given.
|
|
| 25. |
|
|
| 26. |
- Carpten, JD, et al.
(författare)
-
HRPT2, encoding parafibromin, is mutated in hyperparathyroidism-jaw tumor syndrome
- 2002
-
Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 32:4, s. 676-680
-
Tidskriftsartikel (refereegranskat)abstract
- We report here the identification of a gene associated with the hyperparathyroidism-jaw tumor (HPT-JT) syndrome. A single locus associated with HPT-JT (HRPT2) was previously mapped to chromosomal region 1q25-q32. We refined this region to a critical interval of 12 cM by genotyping in 26 affected kindreds. Using a positional candidate approach, we identified thirteen different heterozygous, germline, inactivating mutations in a single gene in fourteen families with HPT-JT. The proposed role of HRPT2 as a tumor suppressor was supported by mutation screening in 48 parathyroid adenomas with cystic features, which identified three somatic inactivating mutations, all located in exon 1. None of these mutations were detected in normal controls, and all were predicted to cause deficient or impaired protein function. HRPT2 is a ubiquitously expressed, evolutionarily conserved gene encoding a predicted protein of 531 amino acids, for which we propose the name parafibromin. Our findings suggest that HRPT2 is a tumor-suppressor gene, the inactivation of which is directly involved in predisposition to HPT-JT and in development of some sporadic parathyroid tumors.
|
|
| 27. |
- Edsjö, Joakim, et al.
(författare)
-
WIMP searches with AMANDA-B10
- 2001
-
Ingår i: The Identification Of Dark Matter. - : World Scientific. - 9789810246020 ; , s. 499-505
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
|
|
| 28. |
|
|
| 29. |
- Hedenfalk, I, et al.
(författare)
-
Gene-expression profiles in hereditary breast cancer
- 2001
-
Ingår i: New England Journal of Medicine. - 0028-4793. ; 344:8, s. 48-539
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Many cases of hereditary breast cancer are due to mutations in either the BRCA1 or the BRCA2 gene. The histopathological changes in these cancers are often characteristic of the mutant gene. We hypothesized that the genes expressed by these two types of tumors are also distinctive, perhaps allowing us to identify cases of hereditary breast cancer on the basis of gene-expression profiles.METHODS: RNA from samples of primary tumor from seven carriers of the BRCA1 mutation, seven carriers of the BRCA2 mutation, and seven patients with sporadic cases of breast cancer was compared with a microarray of 6512 complementary DNA clones of 5361 genes. Statistical analyses were used to identify a set of genes that could distinguish the BRCA1 genotype from the BRCA2 genotype.RESULTS: Permutation analysis of multivariate classification functions established that the gene-expression profiles of tumors with BRCA1 mutations, tumors with BRCA2 mutations, and sporadic tumors differed significantly from each other. An analysis of variance between the levels of gene expression and the genotype of the samples identified 176 genes that were differentially expressed in tumors with BRCA1 mutations and tumors with BRCA2 mutations. Given the known properties of some of the genes in this panel, our findings indicate that there are functional differences between breast tumors with BRCA1 mutations and those with BRCA2 mutations.CONCLUSIONS: Significantly different groups of genes are expressed by breast cancers with BRCA1 mutations and breast cancers with BRCA2 mutations. Our results suggest that a heritable mutation influences the gene-expression profile of the cancer.
|
|
| 30. |
|
|
| 31. |
- Kowalski, Marek, et al.
(författare)
-
Physics results from the AMANDA neutrino detector
- 2001
-
Ingår i: Proceedings of Science. - 1824-8039. ; HEP2001
-
Tidskriftsartikel (refereegranskat)abstract
- In the winter season of 2000, the AMANDA (Antarctic Muon And NeutrinoDetector Array) detector was completed to its nal state. We report on major physicsresults obtained from the AMANDA-B10 detector, as well as initial results of the fullAMANDA-II detector.
|
|
| 32. |
|
|
| 33. |
|
|
| 34. |
|
|
| 35. |
- Ma, C. B., et al.
(författare)
-
Great framework variation of polymers in the manganese(II) maleate/alpha,alpha' - Diimine system : Syntheses, structures, and magneto-structural correlation
- 2003
-
Ingår i: European Journal of Inorganic Chemistry. - : Wiley. - 1434-1948 .- 1099-1948 .- 1099-0682. ; :15, s. 2872-2879
-
Tidskriftsartikel (refereegranskat)abstract
- Three novel manganese(II) coordination polymers, [Mn (maleate)(phen)](n) (1; phen = 1,10-phenanthroline), [Mn-(maleate)(phen)](n).nH(2)O (2), and [Mn(maleate)(bpy)](n) (3; bpy = 2,2'-bipyridine), have been synthesized by treatment of Mn2+ with maleic acid with participation of chelate diimine ligands, and have been identified by single-crystal, X-ray diffraction to have either one-dimensional (1D) zigzag chain structures (1 and 2) or a two-dimensional (2D) sinuous layer structure (3). Each maleate dianion coordinates to three Mn centers, in different bridging modes (syn-anti in 1 and 2, syn-syn and anti-anti in 3). These compounds represent an interesting example of structural topology variation from 1D to 2D mediated by chemically similar auxiliary chelate ligands. Variable-temperature magnetic susceptibility measurements show weak anti-ferromagnetic exchange interactions between the adjacent Mn-II ions, with J = -0.06 cm(-1) (2) and J = -1.3 cm(-1), zJ' = -0.27 cm(-1) (3). The differences in the magnitudes of these coupling interactions agree well with the nature of the carb oxylate-bridging coordination of maleate.
|
|
| 36. |
- Muthu, D. V S, et al.
(författare)
-
Pressure-induced phase transitions in α-ZrMo2O8
- 2002
-
Ingår i: Physical Review B (Condensed Matter). - 0163-1829. ; 65:6, s. 641011-641015
-
Tidskriftsartikel (refereegranskat)abstract
- We report high-pressure Raman, infrared (IR), and optical-absorption spectra of α-ZrMo2O8 (trigonal) up to 38 GPa at room temperature. The spectroscopic studies are consistent with diffraction results that show that α-ZrMo2O8 transforms into δ-ZrMo2O8 (monoclinic) at about 1 GPa and the δ phase converts to the ε phase (triclinic) at about 2.0 GPa. Optical-absorption measurements give an estimate of the band gap of about 0.6 eV at the lowest pressure. Band-gap changes with pressure are confirmed with visual observations. ZrMo2O8 changes from transparent at 5 GPa to yellow at 10 GPa, red at 18 GPa, and at about 30 GPa it becomes opaque.
|
|
| 37. |
|
|
| 38. |
|
|
| 39. |
- Schulte, EC, et al.
(författare)
-
High energy angular distribution measurements of the exclusive deuteron photodisintegration reaction
- 2002
-
Ingår i: Physical Review C (Nuclear Physics). - : American Physical Society. - 0556-2813 .- 1089-490X. ; 66:4
-
Tidskriftsartikel (refereegranskat)abstract
- The first complete measurements of the angular distributions of the two-body deuteron photodisintegration differential cross section at photon energies above 1.6 GeV were performed at the Thomas Jefferson National Accelerator Facility. The results show a persistent forward-backward asymmetry up to E-gamma=2.4 GeV, the highest-energy measured in this experiment. The Hard Rescattering and the Quark-Gluon string models are in fair agreement with the results.
|
|
| 40. |
- Strauch, S, et al.
(författare)
-
Polarization transfer in the He-4((e)over-right-arrow,e '(p)over-right-arrow)H-3 reaction up to Q(2)=2.6 (GeV/c)(2)
- 2003
-
Ingår i: Physical Review Letters. - 1079-7114. ; 91:5: 052301
-
Tidskriftsartikel (refereegranskat)abstract
- We have measured the proton recoil polarization in the He-4((e) over right arrow ,e(')(p) over right arrow)H-4 reaction at Q(2)=0.5, 1.0, 1.6, and 2.6 (GeV/c)(2). The measured ratio of polarization transfer coefficients differs from a fully relativistic calculation, favoring the inclusion of a medium modification of the proton form factors predicted by a quark-meson coupling model. In addition, the measured induced polarizations agree reasonably well with the fully relativistic calculation indicating that the treatment of final-state interactions is under control.
|
|
| 41. |
- Wiebusch, C., et al.
(författare)
-
Results from AMANDA
- 2002
-
Ingår i: Modern Physics Letters A. - : Institution of Electrical Engineers (IEE). - 0217-7323 .- 1793-6632. ; 17:31, s. 2019-2037
-
Tidskriftsartikel (refereegranskat)abstract
- The Antarctic Muon and Neutrino Detector Array (AMANDA) is a high-energy neutrino telescope operating at the geographic South Pole. It is a lattice of photomultiplier tubes buried deep in the polar ice. The primary goal of this detector is to discover astrophysical sources of high energy neutrinos. We describe the detector methods of operation and present results from the AMANDA-B10 prototype. We demonstrate the improved sensitivity of the current AMANDA-II detector. We conclude with an outlook to the envisioned sensitivity of the future IceCube detector.
|
|
| 42. |
- Wijesooriya, K, et al.
(författare)
-
Polarization measurements in high-energy deuteron photodisintegration
- 2001
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 86:14, s. 2975-2979
-
Tidskriftsartikel (refereegranskat)abstract
- We present measurements of the recoil proton polarization for the d(γ⃗,p⃗)n reaction at θc.m. = 90° for photon energies up to 2.4 GeV. These are the first data in this reaction for polarization transfer with circularly polarized photons. The induced polarization py vanishes above 1 GeV, contrary to meson-baryon model expectations, in which resonances lead to large polarizations. However, the polarization transfer Cx does not vanish above 1 GeV, inconsistent with hadron helicity conservation. Thus, we show that the scaling behavior observed in the d(γ,p)ncross sections is not a result of perturbative QCD. These data should provide important tests of new nonperturbative calculations in the intermediate energy regime.
|
|
| 43. |
- Wijesooriya, K, et al.
(författare)
-
Polarization measurements in neutral pion photoproduction
- 2002
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 66:3
-
Tidskriftsartikel (refereegranskat)abstract
- We present measurements of the recoil proton polarization for the H-1((γ) over right arrow,(p) over right arrow)pi(0) reaction for theta(c.m.)(pi) = 60degrees-135degrees and for photon energies up to 4.1 GeV. These are the first data in this reaction for polarization transfer with circularly polarized photons. Various theoretical models are compared with the results. No evidence for hadron helicity conservation is observed. Models that employ factorization are not favored. It appears from the strong angular dependence of the induced polarization at photon energies of 2.5 and 3.1 GeV that a relatively high spin resonance or background amplitude might exist in this energy region.
|
|
| 44. |
|
|
| 45. |
|
|
| 46. |
- Arver, B, et al.
(författare)
-
Hereditary breast cancer: a review
- 2000
-
Ingår i: Seminars in cancer biology. - : Elsevier BV. - 1044-579X. ; 10:4, s. 271-288
-
Tidskriftsartikel (refereegranskat)
|
|
| 47. |
- Bomprezzi, R, et al.
(författare)
-
Gene expression profile in multiple sclerosis patients and healthy controls: identifying pathways relevant to disease
- 2003
-
Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 12:17, s. 2191-2199
-
Tidskriftsartikel (refereegranskat)abstract
- Multiple sclerosis (MS) and other T cell-mediated autoimmune diseases develop in individuals carrying a complex susceptibility trait, probably following exposure to various environmental triggers. Owing to the presumed weak influence of single genes on disease predisposition and the recognized genetic heterogeneity of autoimmune disorders in humans, candidate gene searches in MS have been difficult. In an attempt to identify molecular markers indicative of disease status rather than susceptibility genes for MS, we show that gene expression profiling of peripheral blood mononuclear cells by cDNA microarrays can distinguish MS patients from healthy controls. Our findings support the concept that the activation of autoreactive T cells is of primary importance for this complex organ-specific disorder and prompt further investigations on gene expression in peripheral blood cells aimed at characterizing disease phenotypes.
|
|
| 48. |
|
|
| 49. |
- Boyce, SW, et al.
(författare)
-
Impact of sodium-hydrogen exchange inhibition by cariporide on death or myocardial infarction in high-risk CABG surgery patients: Results of the CABG surgery cohort of the GUARDIAN study
- 2003
-
Ingår i: Journal of Thoracic and Cardiovascular Surgery. - 1097-685X. ; 126:2, s. 420-427
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: To evaluate the effects of cariporide on all-cause mortality or myocardial infarction at 36 days in patients at risk,of myocardial necrosis after coronary artery bypass graft surgery. Methods: In the coronary artery bypass graft cohort of the GUARD During Ischemia Against Necrosis trial, patients greater than or equal to 18 years who required urgent coronary artery bypass graft, repeat coronary artery bypass graft, or had a history of unstable angina and 2 :2 risk factors (age >65 years, female gender, diabetes mellitus, ejection fraction <35%, or left main or 3-vessel disease) were randomized to placebo (n = 743) or cariporide 20 mg (n = 736), 80 mg (n = 705), or 120 mg (n = 734). A 1-hour intravenous infusion was initiated shortly before surgery and administered every 8 hours for 2 to 7 days. Patients were followed up for 6 months. A nonparametric covariance analysis was used to calculate the primary efficacy endpoint. Results: Baseline characteristics were similar between treatment groups. The cariporide 20- and 80-mg groups had event rates similar to placebo. The endpoint of all-cause mortality or myocardial infarction at day 36 was significant with cariporide 120 mg versus placebo (event rate 12.2% vs 16.2%; P = .027). The risk reduction was evident on postoperative day 1 (3.3% vs 6.5%; P = .005) and was maintained at 6 months (event rate 15.0% vs 18.6%; P = .033). Cariporide was well tolerated, and most adverse events were mild and transient in this high-risk population. Conclusions: Clinical benefit with cariporide 120 mg was observed early after treatment initiation and continued for 6 months postsurgery, suggesting that sodium-hydrogen exchange inhibition with cariporide is cardioprotective in patients undergoing high-risk coronary artery bypass graft surgery.
|
|
| 50. |
- Burghart, Armin, et al.
(författare)
-
Energy transfer cassettes based on BODIPY® dyes
- 2000
-
Ingår i: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1359-7345 .- 1364-548X. ; :2203-4
-
Tidskriftsartikel (refereegranskat)abstract
- The donor–acceptor dye cassettes 1–4 were designed to capture energy at a single wavelength and to convert it to well-resolved, intense fluorescence emissions; in practice, Stokes shifts of 40–148 nm, quantum yields of 0.12–0.60, and efficient energy transfer was demonstrated.
|
|
