1. |
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1973. En träff med tidsandan
- 2008
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Ingår i: 1973. En träff med tidsandan. - Lund : Nordic Academic Press. - 9789189116979 ; , s. 11-21
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)
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2. |
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2002 års män och kvinnor : medborgare rapporterar om hemlöshet
- 2003
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- In 2002 a group of men and women, coming from different professions but sharing an interest in social issues, joined together in a Citizens' Study (medborgarundersökning) in the Swedish city of Malmö. They were inspired by a classic Swedish citizens' study "Men of 1912" (1912 års män) which was a clandestine field study of the deplorable conditions in Stockholm's hostels in 1912. This book is a compilation of the various reports written by the men and women of 2002. Over a period of several months they visited different places in Malmö where homeless people live and spend their lives. The reports provide us with different images of homelessness, from tent camps, hideouts in public parks, cheap hotels and shelters to overpopulated apartment buildings in the suburbs. It accounts for the City Council's expensive policy of solving the problems through putting up homeless in hotel rooms on a long-term basis. Striking in the reports is the frustration of the men and women of 2002 when they are confronted with access problems to shelters, and with the demeaning and contemptuous treatment of homeless people. As a method for social research the citizen's study does not have the theoretical and methodological consistency of the scientific study. However, it oversteps social borders and promotes social integration in a way that scientific studies were never able to do. The men and women of 2002 were drawn into the process, and formed private social relationships with homeless people and their places. Apart from the reports of the men and women of 2002, the book also includes a re-print of the edited version of the report of the men of 1912 published in Social Tidskrift 1913.
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3. |
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4. |
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5. |
- A, Lebedev, et al.
(författare)
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Direct photons in WA98.
- 2002
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Ingår i: Nuclear Physics A. ; 698, s. 135-135
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Tidskriftsartikel (refereegranskat)
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6. |
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7. |
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A Smorgasbord of Cognitive Science
- 2008
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- This book is intended as an introduction to the breadth of current research in cognitive science, with the research at Lund University Cognitive Science as our sample. The result is a smorgasbord for readers with some background in the neighbouring disciplines. Through the chapters we will follow some of the important cross-disciplinary issues in cognitive science. One is how the external world is represented, from cognitive maps in rats, to drawings made to enhance communication, or the organization of semantic knowledge. Another is to what extent such representations really are used: the world is often its own best model in areas from robotics to choice, and several chapters illustrate that even communication (despite its dependence on representations) is firmly situated in and constrained by its surroundings. In addition, many chapters emphasize the essentially dynamic relationship between mind and environment, in areas from development to interaction and learning. A third thread is how research concerning other animals= cognitive capacities, from pigeons to chimpanzees, has inspired research on human cognition, and how this comparative approach can be made to incorporate also non-animate fellow beings, such as robots and virtual characters. In sum, the book contains most of the areas we think are important in cognitive science today, and we hope that it will be of use for beginning researchers and advanced students in the area. Its production is part of the celebrations of Lund University Cognitive Science’s 20th anniversary. Our group hosts researchers with backgrounds in psychology, philosophy, computer science, linguistics, computational neuroscience, education, etc., and all of us have a multidisciplinary education. We encourage you to visit our web pages at www.lucs.lu.se to learn more about the activities of the group.
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8. |
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9. |
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10. |
- Aabenhus, Rune, et al.
(författare)
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First attempt to produce experimental Campylobacter concisus infection in mice
- 2008
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Ingår i: World Journal of Gastroenterology. - : Baishideng Publishing Group Inc.. - 1007-9327. ; 14:45, s. 6954-6959
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To infect mice with atypical Campylobacter concisus (C concisus) for the first time. METHODS: Three separate experiments were conducted in order to screen the ability of five clinical C concisus isolates of intestinal origin and the ATCC 33237 type strain of oral origin to colonize and produce infection in immunocompetent BALB/cA mice. The majority of the BALB/cA mice were treated with cyclophosphamide prior to C concisus inoculation to suppress immune functions. Inoculation of C concisus was performed by the gastric route. RESULTS: C concisus was isolated from the liver, ileum and jejunum of cyclophosphamide-treated mice in the first experiment. No C concisus strains were isolated in the two subsequent experiments. Mice infected with C concisus showed a significant loss of body weight from day two through to day five of infection but this decreased at the end of the first week. Histopathologicalexamination did not consistently find signs of inflammation in the gut, but occasionally microabscesses were found in the liver of infected animals. CONCLUSION: Transient colonization with C concisus was observed in mice with loss of body weight. Future studies should concentrate on the first few days after inoculation and in other strains of mice. (C) 2008 The WJG Press. All rights reserved.
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11. |
- Aabenhus, Rune, et al.
(författare)
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Lectin Typing of Campylobacter concisus
- 2002
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Ingår i: Journal of Clinical Microbiology. - 1098-660X. ; 40:2, s. 715-717
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Tidskriftsartikel (refereegranskat)abstract
- A total of 44 clinical isolates and the type strain of the putative pathogen Campylobacter concisus were grouped based on their reactions with plant lectins. The optimized lectin typing system used C. concisus strains proteolytically pretreated and subsequently typed by using a panel of four lectins. The system grouped all 45 strains into 13 lectin reaction patterns, leaving no strain untypeable due to autoagglutination. Lectin types were both stable and reproducible.
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12. |
- Aaby, Peter, et al.
(författare)
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Vaccinia scars associated with better survival for adults. An observational study from Guinea-Bissau
- 2006
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Ingår i: Vaccine. - : Elsevier BV. - 1873-2518 .- 0264-410X. ; 24:29-30, s. 5718-5718
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Live vaccines including BCG and measles may have non-targeted beneficial effects on childhood survival in areas with high mortality. The authors therefore undertook a survey of vaccinia scars to evaluate subsequent mortality. SUBJECTS: Based on a population census, a cohort of 1893 adults in urban Guinea-Bissau was examined in 1998 and followed until 2002. MAIN OUTCOME MEASURE: All cause mortality, excluding accidents. RESULTS: The median age of vaccinia vaccinations had been 16-18 years. Adults with a vaccinia scar had a mortality ratio (MR) of 0.60 (0.41-0.87) compared to those without any scar. The effect was stronger for women. Mortality decreased with each additional vaccinia scar (MR=0.73 (0.56-0.95)). Among 502 individuals with information on HIV infection, the age-adjusted HIV-2 prevalence was 2.45 (1.06-5.65) for those with a vaccinia scar. Control for district, ethnic group, schooling, place of birth, quality of housing and HIV status had little effect on the estimate. Since vaccinia and BCG scars could have been confused, mortality for adults with vaccinia and/or BCG scar was compared to those without, the MR being 0.61 (0.41-0.89). CONCLUSION: Known cultural or socio-economic factors possibly associated with access to vaccination had no influence on the mortality ratio for having a vaccinia scar. Hence, vaccinia vaccination may have a prolonged beneficial effect on adult survival.
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13. |
- Aad, G., et al.
(författare)
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The ATLAS Experiment at the CERN Large Hadron Collider
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08003
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Forskningsöversikt (refereegranskat)abstract
- The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.
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14. |
- Aalamian, M, et al.
(författare)
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Inhibition of dendropoiesis by tumor derived and purified prostate specific antigen
- 2003
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Ingår i: Journal of Urology. - : Ovid Technologies (Wolters Kluwer Health). - 1527-3792 .- 0022-5347. ; 170:5, s. 2026-2030
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Prostate specific antigen (PSA) is a serine protease produced by the prostate gland at high concentrations. Serum PSA may be significantly elevated in prostate cancer and benign prostatic diseases. It has recently become evident that, in addition to being a tissue and/or serum marker, PSA may also have biological effects. Despite the voluminous literature on this biomarker in the diagnosis of prostatic diseases relatively few reports have addressed the issue of the physiological function, biological role and immune effects of PSA in the context of prostate cancer development and progression. Materials and Methods: Human dendritic cell (DC) cultures were generated from CD34+ hematopoietic precursors in the presence of PSA. The DC phenotype was assessed by flow cytometry and DC ability to induce T-cell proliferation was detected by allogeneic mixed lymphocyte reaction assay. DCs were also generated in co-cultures with LNCaP cells in the presence of antiPSA antibodies. The concentrations of PSA in cultures were determined by the AXSYM System (Abbott Laboratories, Wiesbaden, Germany). Results: We noted that purified and LNCaP derived PSA inhibited the generation and maturation of DC (dendropoiesis) in vitro, which might have a crucial role in the induction and regulation of specific antitumor immune responses. The addition of active PSA to DC cultures significantly inhibited the generation and maturation of DC, as assessed by the levels of expression of CD83, CD80, CD86 and HLA DR. The ability of DC to induce T-cell proliferation, which depends on the expression of co-stimulatory and major histocompatibility complex molecules, was also suppressed in PSA treated DC cultures. Conclusions: The antidendropoietic effect of PSA in vitro suggests a new mechanism of prostate cancer induced immunosuppression and tumor escape, and provides novel evidence of the immunoregulatory properties of PSA.
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15. |
- Aalto, Kristina, et al.
(författare)
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The Nordic swan
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)
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16. |
- Aaltonen, Emil
(författare)
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Prokaryotic Arsenic Resistance - Studies in Bacillus subtilis
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Arsenic is a toxic metalloid which is found all over the globe. Due to its toxicity and wide abundance, all living organisms have evolved intrinsic arsenic resistance systems. In this study, three proteins that provide arsenic resistance in the Gram-positive bacterium Bacillus subtilis have been investigated. Acr3 is a trans-membrane protein that extrudes arsenite to the cell exterior. It belongs to the ACR family of arsenite transporters. Experimental data on the topology of Acr3, the first ever for a member of the ACR family, is provided and show that Acr3 has 10 trans-membrane helices. Both the N- and C-terminal ends of Acr3 are located to the cytoplasm and the protein has unusually short loops connecting its helices. ArsR is an arsenite sensitive transcription regulator that controls the expression of genes encoding arsenic resistance proteins. Experiments show that the operator site for ArsR from B. subtilis consists of a 6-6-6 inverted repeat and that DNA binding by ArsR involves formation of higher order multimers of the protein. The ArsK (former YqcK) protein has an unknown function. The present study shows that the arsK gene contributes to resistance towards both arsenite and arsenate. The results indicate that the function of ArsK is important in an aerobic environment and that it decreases the inhibitory effect that arsenite has on the sporulation efficiency of B. subtilis. A function of ArsK that involves an enzymatic addition of low molecular weight thiols to arsenic is proposed.
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17. |
- Aaltonen, Emil, et al.
(författare)
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Transmembrane topology of the Acr3 family arsenite transporter from Bacillus subtilis.
- 2008
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Ingår i: Biochimica et Biophysica Acta - Biomembranes. - : Elsevier BV. - 0005-2736. ; 1778:4, s. 963-973
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Tidskriftsartikel (refereegranskat)abstract
- The transmembrane topology of the Acr3 family arsenite transporter Acr3 from Bacillus subtilis was analysed experimentally using translational fusions with alkaline phosphatase and green fluorescent protein and in silico by topology modelling. Initial topology prediction resulted in two models with 9 and 10 TM helices respectively. 32 fusion constructs were made between truncated forms of acr3 and the reporter genes at 17 different sites throughout the acr3 sequence to discriminate between these models. Nine strong reporter protein signals provided information about the majority of the locations of the cytoplasmic and extracellular loops of Acr3 and showed that both the N- and the C-termini are located in the cytoplasm. Two ambiguous data points indicated the possibility of an alternative 8 helix topology. This possibility was investigated using another 10 fusion variants, but no experimental support for the 8 TM topology was obtained. We therefore conclude that Acr3 has 10 transmembrane helices. Overall, the loops which connect the membrane spanning segments are short, with cytoplasmic loops being somewhat longer than the extracellular loops. The study provides the first ever experimentally derived structural information on a protein of the Acr3 family which constitutes one of the largest classes of arsenite transporters.
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18. |
- Aaltonen, Kirsimari, et al.
(författare)
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Cyclin D1 expression is associated with poor prognostic features in estrogen receptor positive breast cancer
- 2009
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Ingår i: Breast Cancer Research and Treatment. - : Springer Science and Business Media LLC. - 1573-7217 .- 0167-6806. ; 113:1, s. 75-82
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Tidskriftsartikel (refereegranskat)abstract
- Cyclins D1 and E play an important role in breast carcinogenesis. High cyclin E expression is common in hormone receptor negative and high grade aggressive breast cancer, whereas cyclin D1 in hormone receptor positive and low grade breast cancer. Experimental data has suggested that cyclin D1 and E mediate cell proliferation by different mechanisms in estrogen receptor (ER) positive and negative breast cancer. To test this hypotheses in large breast cancer material and to clarify the histopathological correlations of cyclin E and D1, especially the association with proliferation, we analyzed cyclin E and D1 immunohistochemical expression on breast tumour microarrays consisting of 1348 invasive breast cancers. High cyclin D1 expression was associated with high grade (P < 0.0005), high cyclin A (P < 0.0005) and Ki67 (P < 0.0005) expression among ER positive but with low grade (P = 0.05) and low Ki67 (P = 0.01) expression among ER negative breast cancers. Cyclin E and D1 expression correlated positively in ER positive (P < 0.0005) but had a negative correlation in ER negative tumours (P = 0.004). Cyclin E associated with high grade among all tumours (P < 0.0005). In conclusion, the findings of this study show that cyclin D1 has separate roles, and proliferation is driven by different mechanisms in ER positive and negative breast cancers.
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19. |
- Aaltonen, Kristina
(författare)
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Mating system evolution and self-incompatibility in the wild plant species Brassica cretica
- 2008
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Compared to animals like ourselves, plants have a very flexible sexual life. Most plants are, for example, hermaphrodites with the potential capacity for reproduction by self-fertilization (or selfing). While selfing can provide several definite advantages for the individual plant, there is a downside; mainly the severe reduction in fitness due to inbreeding depression. To avoid the negative consequences of selfing, many hermaphrodite plant species have evolved an intricate self-recognition – or self-incompatibility (SI) – system that prevents fertilization by cognate pollen. SI is in the majority of cases genetically controlled by a narrowly delimited region of the genome, called the S locus. The S locus contains several tightly linked genes, two of which – SRK and SCR – determine the pistil (female) and pollen (male) SI recognition type. One of the best-characterized SI systems is found in the Brassicaceae family, which includes the model plant Arabidopsis thaliana and a number of economically important crop species of the Brassica genus, e.g. rape seed, cabbage, and turnip. For evolutionary biologists, SI have long been a prominent and fascinating example of Darwinian natural selection acting in a frequency-dependent manner, i.e. the rarer a genetic variant becomes, the more favoured by natural selection it is. For the S locus, this means that a very large number of variants – or haplotypes – are expected to be maintained in a population and that the DNA sequences of different haplotypes will be very divergent. However, until recently there has been a shortage of empirical studies from natural plant populations to test these, and other, theoretical predictions of S locus evolutionary dynamics. In this thesis, I have produced the largest SRK and SCR DNA sequence data set from a wild Brassica species available to date. These data have allowed me to explore, in more detail than previously possible, the population genetic properties and the evolutionary history of the Brassica S locus. Moreover, accompanying studies of the pattern of inheritance of S locus variants and the occurrence of self-fertilization in natural B. cretica population have added novel information of great value to the understanding of how plants produce offspring in nature.
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20. |
- Aaltonen, Kristina, et al.
(författare)
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Molecular Population Genetics of the SRK and SCR Self-incompatibility Genes in the Wild Plant Species Brassica cretica (Brassicaceae).
- 2009
-
Ingår i: Genetics. - : Oxford University Press (OUP). - 0016-6731 .- 1943-2631. ; 181:3, s. 985-995
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Tidskriftsartikel (refereegranskat)abstract
- Self-incompatibility (SI) in plants is a classic example of a trait evolving under strong frequency-dependent selection. As a consequence, population genetic theory predicts that the S locus, which controls SI, should maintain numerous alleles, display a high level of nucleotide diversity, and, in structured populations, show a lower level of among-population differentiation compared to neutral loci. Population-level investigations of DNA sequence variation at the S locus have recently been carried out in the genus Arabidopsis, largely confirming results from theoretical models of S-locus evolutionary dynamics, but no comparable studies have been done in wild Brassica species. In this study, we sequenced parts of the S-locus genes SRK and SCR, two tightly linked genes that are directly involved in the determination of SI specificity, in samples from four natural populations of the wild species Brassica cretica. The amount and distribution of nucleotide diversity, as well as the frequency spectrum of putative functional haplotypes, observed at the S locus in B. cretica fit very well with expectations from theoretical models, providing strong evidence for frequency-dependent selection acting on the S locus in a wild Brassica species.
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21. |
- Aaltonen, Kristina, et al.
(författare)
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Nuclear and chloroplast microsatellites reveal extreme population differentiation and limited gene flow in the Aegean endemic Brassica cretica (Brassicaceae)
- 2007
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Ingår i: Molecular Ecology. - 0962-1083. ; 16:23, s. 4972-4983
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Tidskriftsartikel (refereegranskat)abstract
- Nuclear and chloroplast microsatellite markers were used to study population structure and gene flow among seven Cretan populations of the Aegean endemic plant species Brassica cretica (Brassicaceae). Both nuclear and chloroplast markers revealed exceptionally high levels of population differentiation (overall FST = 0.628 and 1.000, respectively) and relatively little within-population diversity (overall HS = 0.211 and 0.000, respectively). Maximum-likelihood estimates of directional migration rates were low among all pairs of populations (average Nm = 0.286). There was no evidence that differences in flower colour between populations had any influence on historical levels of gene flow. In addition, a haplotype network showed that all five chloroplast haplotypes found in the sample were closely related. Together, these results suggest that current patterns of diversification in B. cretica are mainly a result of genetic drift during the last half million years. The main conclusions from the present study are consistent with the prevailing hypothesis that plant diversification in the Aegean region is driven by random rather than adaptive differentiation among isolated populations.
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22. |
- Aaltonen, Kristina, et al.
(författare)
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The Evolution and Diversification of S-locus Haplotypes in the Brassicaceae Family.
- 2009
-
Ingår i: Genetics. - : Oxford University Press (OUP). - 0016-6731 .- 1943-2631. ; 181:3, s. 977-984
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Tidskriftsartikel (refereegranskat)abstract
- Self-incompatibility (SI) in the Brassicaceae plant family is controlled by the SRK and SCR genes situated at the S locus. A large number of S haplotypes have been identified, mainly in cultivated species of the Brassica and Raphanus genera, but recently also in wild Arabidopsis species. Here, we used DNA sequences from the SRK and SCR genes of the wild Brassica species B. cretica, together with publicly available sequence data from other Brassicaceae species, to investigate the evolutionary relationships between S haplotypes in the Brassicaceae family. The results reveal that wild and cultivated Brassica species have similar levels of SRK diversity indicating that domestication has had but a minor effect on S-locus diversity in Brassica. Our results also show that a common set of S haplotypes were present in the ancestor of the Brassica and Arabidopsis genera, that only a small number of haplotypes survived in the Brassica lineage after its separation from Arabidopsis, and that diversification within the two Brassica dominance classes occurred after the split between the two lineages. We also find indications that recombination may have occurred between the kinase domain of SRK and the SCR gene in Brassica.
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23. |
- Aaltonen, Kristina, et al.
(författare)
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Unequal segregation of SRK alleles at the S locus in Brassica cretica.
- 2008
-
Ingår i: Genetical Research. - 1469-5073. ; 90:3, s. 223-228
-
Tidskriftsartikel (refereegranskat)abstract
- In the Brassicaceae plant family, which includes the Arabidopsis and Brassica genera, self-incompatibility (SI) is controlled by genes at the S locus. Using experimental crosses, we studied the pattern of inheritance of S-locus alleles in the wild species Brassica cretica. Four full-sib families were established and unequal segregation of alleles at the SRK SI gene was found in one family. The segregation distortion acted in favour of a recessive (class II) allele and was best explained by some form of gametic-level selection. Our findings are discussed in the light of theoretical predictions of differential accumulation of deleterious mutations among S-locus alleles.
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24. |
- Aamodt, K., et al.
(författare)
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The ALICE experiment at the CERN LHC
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
-
Forskningsöversikt (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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25. |
- Aanæs, Henrik, et al.
(författare)
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Camera Resectioning from a Box
- 2009
-
Ingår i: Lecture Notes in Computer Science. - 0302-9743 .- 1611-3349.
-
Konferensbidrag (refereegranskat)abstract
- In this paper we describe how we can do camera resectioning from a box with unknown dimensions, i.e. determine the camera model, assuming that image pixels are square. This assumption is equivalent to assuming that the camera as an aspect ratio of one and zero skew, and holds for most - if not all - digital cameras. Our proposed method works by first deriving 9 linear constraints on the projective camera matrix from the box, leaving a 3 dimensional subspace in which the projective camera matrix can lye. A single solution in this 3D subspace is then found via a method by Triggs in 1999, which uses the squared pixel assumption to set up a 4th degree polynomial to which the solution is the desired model. This approach is, however, numerically challenging, and we use several means to combat this issue. Lastly the solution is refined in an iterative manner, i.e. using bundle adjustment.
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26. |
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27. |
- Aanæs, Henrik, et al.
(författare)
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Factorization with erroneous data
- 2002
-
Konferensbidrag (refereegranskat)abstract
- Factorization algorithms for recovering structure and motion from an image stream have many advantages, but traditionally requires a set of well tracked feature points. This limits the usability since, correctly tracked feature points are not available in general. There is thus a need to make factorization algorithms deal successfully with incorrectly tracked feature points. We propose a new computationally efficient algorithm for applying an arbitrary error function in the factorization scheme, and thereby enable the use of robust statistical techniques and arbitrary noise models for individual feature points. These techniques and models effectively deal with feature point noise as well as feature mismatch and missing features. Furthermore, the algorithm includes a new method for Euclidean reconstruction that experimentally shows a significant improvement in convergence of the factorization algorithms. The proposed algorithm has been implemented in the Christy–Horaud factorization scheme and the results clearly illustrate a considerable increase in error tolerance.
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28. |
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29. |
- Aanaes, H, et al.
(författare)
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Robust factorization
- 2002
-
Ingår i: IEEE Transactions on Pattern Analysis and Machine Intelligence. - 1939-3539. ; 24:9, s. 1215-1225
-
Tidskriftsartikel (refereegranskat)abstract
- Factorization algorithms for recovering structure and motion from an image stream have many advantages, but they usually require a set of well-tracked features. Such a set is in generally not available in practical applications. There is thus a need for making factorization algorithms deal effectively with errors in the tracked features. We propose a new and computationally efficient algorithm for applying an arbitrary errorfunction in the factorization scheme. This algorithm enables the use of robust statistical techniques and arbitrary noise models for the individual features. These techniques and models enable the factorization scheme to deal effectively with mismatched features, missing features, and noise on the individual features. The proposed approach further includes a new method for Euclidean reconstruction that significantly improves convergence of the factorization algorithms. The proposed algorithm has been implemented as a modification of the Christy-Horaud factorization scheme, which yields a perspective reconstruction. Based on this implementation, a considerable increase in error tolerance is demonstrated on real and synthetic data. The proposed scheme can, however, be applied to most other factorization algorithms.
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30. |
- Aanen, M C, et al.
(författare)
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A detailed analysis of sodium removal by peritoneal dialysis: comparison with predictions from the three-pore model of membrane function
- 2005
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Ingår i: Nephrology Dialysis Transplantation. - : Oxford University Press (OUP). - 1460-2385 .- 0931-0509. ; 20:6, s. 1192-1200
-
Tidskriftsartikel (refereegranskat)abstract
- Background. The development of fluid and salt retention is a potential problem for all peritoneal dialysis (PD) patients. Sodium removal by the peritoneum is predominantly determined by convective fluid loss but influenced by diffusion and sieving due to free water transport as predicted by the three-pore model (TPM). The aim of the study was to establish the effect of transport status, dwell length and glucose concentration on observed ultrafiltration (UF), dialysate sodium concentration ([Na+](D)) and removal, and compare this with that predicted by a computer program based on the principles of the TPM. Methods. This was a cross-sectional study of UF and [Na+](D) collected prospectively from dwells classified by length, glucose concentration and membrane transport characteristics. Solute transport, converted to area parameter and UF capacity, was measured on each occasion by the peritoneal equilibration test. These parameters, along with plasma [Na+], were entered into the computer model. Fixed values for other parameters, e.g. hydraulic conductance and lymphatic absorption and sump volume, were used. Results. A total of 1853 dwells from 182 patients [10% were on automated PD (APD)] were analysed. There was a high degree of correlation (r=0.83-95, P<0.001) between the observed and predicted values for UF, [Na+](D) and sodium removal across the full range of dwell categories. The model overpredicted UF as the net volume increased with increasing glucose concentration, independently of solute transport. This bias was not fully explained by the preferential use of hypertonic dialysate by patients with reduced UF capacity. The prediction of [Na+](D) described sodium sieving, which was overestimated in a small number of patients with UF failure. There were no discrepancies between continous ambulatory PD (CAPD) and APD patients. Conclusion. This analysis endorses the TPM as a description of membrane function, particularly in relation to sodium sieving and removal. The relationship between dialysate glucose concentration and achieved UF appears to be more complex; even accounting for extended time on treatment and reduction in the osmotic conductance in patients preferentially using hypertonic exchanges, further adjustments may be needed to account for the tendency to overestimate UF.
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31. |
- Aapro, M, et al.
(författare)
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Guidance on the use of bisphosphonates in solid tumours: recommendations of an international expert panel
- 2008
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Ingår i: Annals of Oncology. - : Elsevier BV. - 1569-8041 .- 0923-7534. ; 19:3, s. 420-432
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Tidskriftsartikel (refereegranskat)abstract
- Bisphosphonates (BP) prevent, reduce, and delay cancer-related skeletal complications in patients, and have substantially decreased the prevalence of such events since their introduction. Today, a broad range of BP with differences in potency, efficacy, dosing, and administration as well as approved indications is available. In addition, results of clinical trials investigating the efficacy of BP in cancer treatment-induced bone loss (CTIBL) have been recently published. The purpose of this paper is to review the current evidence on the use of BP in solid tumours and provide clinical recommendations. An interdisciplinary expert panel of clinical oncologists and of specialists in metabolic bone diseases assessed the widespread evidence and information on the efficacy of BP in the metastatic and nonmetastatic setting, as well as ongoing research on the adjuvant use of BP. Based on available evidence, the panel recommends amino-bisphosphonates for patients with metastatic bone disease from breast cancer and zoledronic acid for patients with other solid tumours as primary disease. Dosing of BP should follow approved indications with adjustments if necessary. While i.v. administration is most often preferable, oral administration (clodronate, IBA) may be considered for breast cancer patients who cannot or do not need to attend regular hospital care. Early-stage cancer patients at risk of developing CTIBL should be considered for preventative BP treatment. The strongest evidence in this setting is now available for ZOL. Overall, BP are well-tolerated, and most common adverse events are influenza-like syndrome, arthralgia, and when used orally, gastrointestinal symptoms. The dose of BP may need to be adapted to renal function and initial creatinine clearance calculation is mandatory according to the panel for use of any BP. Subsequent monitoring is recommended for ZOL and PAM, as described by the regulatory authority guidelines. Patients scheduled to receive BP (mainly every 3-4 weeks i.v.) should have a dental examination and be advised on appropriate measures for reducing the risk of jaw osteonecrosis. BP are well established as supportive therapy to reduce the frequency and severity of skeletal complications in patients with bone metastases from different cancers.
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32. |
- Aaris-Sorensen, K, et al.
(författare)
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Late Pleistocene remains of giant deer (Megaloceros giganteus Blumenbach) in Scandinavia: chronology and environment
- 2004
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Ingår i: Boreas. - : Wiley. - 1502-3885 .- 0300-9483. ; 33:1, s. 61-73
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Tidskriftsartikel (refereegranskat)abstract
- This article presents new data on the Late Pleistocene giant deer, Megaloceros giganteus (Blumenbach), describing its distribution in time and space, geographical and sexual variation and general biology. Twenty-three south Scandinavian fossils found in situ in lacustrine sediments or redeposited in glaciofluvial material form the basis of this investigation. Fourteen C-14 dates show that the giant deer inhabited southern Scandinavia in the ice-free late Middle Weichselian from c. 40000 to 28000 BP (the Sandnes Interstadial) and again in the Late Weichselian from c. 12000 to 10700 BP (Older Dryas, Allerod and early Younger Dryas Chronozones), corresponding to a calibrated range from c. 14300 to 12400 cal. yr BP. Osteometric analyses show that the Scandinavian giant deer belonged to the upper size range of the lateglacial Irish population and that a marked sexual dimorphism existed, the males being 10-11% larger than the females. Investigations furthermore point at an antler cycle similar to that among extant northern cervids, and subsequently at a rutting season in autumn. The skeletal remains also prove the occurrence of twin delivery and the possibility of reaching an ontogenetic age of at least 23 years. During both occurrences the Scandinavian giant deer population was part of the northernmost distribution of the species in Europe and the palaeogeographical settings and palaeoenvironmental conditions of the two periods show striking similarities. Clearly, the giant deer were able to colonize and survive in a landscape dominated by grasses and sedges with scattered shrubs and dwarf shrubs. They came as close as 200-250 km to the ice front and their distribution included coastal areas along a cold sea with drifting icebergs. They were present in the area at least from March until November. However, the pure arctic conditions created during the early phase of the Younger Dryas event led to a new local extinction around 10700 C-14 yr BP. This was the beginning of a total Eurasian extinction which, at least in Europe, was completed before the Pleistocene/Holocene transition.
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33. |
- Aarnio, Harri, et al.
(författare)
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Recombination studies in a polyfluorene copolymer for photovoltaic applications
- 2005
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Ingår i: Synthetic Metals. - : Elsevier BV. - 0379-6779. ; 155:2, s. 299-302
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Tidskriftsartikel (refereegranskat)abstract
- We present detailed continuous wave (cw) and transient photoinduced absorption (PA) measurements in thin films of a novel alternating polyfluorene copolymer, poly[2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4',7'-di-2-thienyl-2',1',3-benzo-thiadiazole)] (DiO-PFDTBT), and its blends with the sol. fullerene deriv. [6,6]-phenyl-C61-butyric acid Me ester (PCBM) in wt. ratios of 1:0, 4:1 and 1:4. We measure the frequency, intensity and temp. dependence of the PA signal in the frequency domain, and compare with the results obtained from the transient PA decay measurements in the time domain. In all blends, the PA spectrum shows a broad high energy PA band ranging from .apprx.1 eV to 2 eV as well as a low energy band peaking at .apprx.0.35 eV. We attribute the low energy band to the P1 transition of polarons and part of the high energy band to the correlated P2 transition of polarons. Both frequency and time domain measurements show that the high energy band has two decay components, a faster component in the microsecond time regime and a slower component in the millisecond time regime. The slow component is strongly dispersive, whereas the fast component is practically non-dispersive. [on SciFinder (R)]
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34. |
- Aaron, F. D., et al.
(författare)
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A general search for new phenomena at HERA
- 2009
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 674:4-5, s. 257-268
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Tidskriftsartikel (refereegranskat)abstract
- A model-independent search for deviations from the Standard Model prediction is performed using the full e(+/-) p data sample collected by the H1 experiment at HERA. All event topologies involving isolated electrons, photons, muons, neutrinos and jets with transverse momenta above 20 GeV are investigated in a single analysis. Events are assigned to exclusive classes according to their final state. A dedicated algorithm is used to search for deviations from the Standard Model in the distributions of the scalar sum of transverse momenta or the invariant mass of final state particles and to quantify their significance. Variables related to angular distributions and energy sharing between final state particles are also introduced to study the final state topologies. No significant deviation from the Standard Model expectation is observed in the phase space covered by this analysis. (C) 2009 Elsevier B.V. All rights reserved.
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35. |
- Aaron, F. D., et al.
(författare)
-
A precision measurement of the inclusive ep scattering cross section at HERA
- 2009
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 64:4, s. 561-587
-
Tidskriftsartikel (refereegranskat)abstract
- A measurement of the inclusive deep inelastic neutral current e(+) p scattering cross section is reported in the region of four-momentum transfer squared, 12GeV(2) <= Q(2) <= 150 GeV2, and Bjorken x, 2 x 10(-4) <= x <= 0.1. The results are based on data collected by the H1 Collaboration at the ep collider HERA at positron and proton beam energies of E-e = 27.6 GeV and E-p = 920 GeV, respectively. The data are combined with previously published data, taken at E-p = 820 GeV. The accuracy of the combined measurement is typically in the range of 1.3-2%. A QCD analysis at next-to-leading order is performed to determine the parton distributions in the proton based on H1 data.
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36. |
- Aaron, F. D., et al.
(författare)
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A search for excited neutrinos in e(-) p collisions at HERA
- 2008
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 663:5, s. 382-389
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Tidskriftsartikel (refereegranskat)abstract
- A search for first generation excited neutrinos is performed using the full e(-) p data sample collected by the HI experiment at HERA at a centre-of-mass energy of 319 GeV, corresponding to a total luminosity of 184 pb(-1). The electroweak decays of excited neutrinos nu* -> nu gamma, v* -> nu Z and nu* -> eW with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for excited neutrino production is found. Mass dependent exclusion limits on nu* production cross sections and on the ratio of the coupling to the compositeness scale f/boolean AND are derived within gauge mediated models. A limit on f/boolean AND A, independent of the relative couplings to the SU(2) and U(1) gauge bosons, is also determined. These limits extend the excluded region to higher masses than has been possible in previous excited neutrino searches. (c) 2008 Elsevier B.V. All rights reserved.
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37. |
- Aaron, F.D., et al.
(författare)
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Charged particle production in high Q^2 deep-inelastic scattering at HERA
- 2007
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 654:5-6, s. 148-159
-
Tidskriftsartikel (refereegranskat)abstract
- The average charged track multiplicity and the normalised distribution of the scaled momentum, xp, of charged final state hadrons are measured in deep-inelastic ep scattering at high Q2 in the Breit frame of reference. The analysis covers the range of photon virtuality Click to view the MathML source. Compared with previous results presented by HERA experiments this analysis has a significantly higher statistical precision and extends the phase space to higher Q2 and to the full range of xp. The results are compared with e+e− annihilation data and with various calculations based on perturbative QCD using different models of the hadronisation process.
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38. |
- Aaron, F. D., et al.
(författare)
-
Deeply virtual Compton scattering and its beam charge asymmetry in e(+/-)p collisions at HERA
- 2009
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 681:5, s. 391-399
-
Tidskriftsartikel (refereegranskat)abstract
- A measurement of elastic deeply virtual Compton scattering gamma*p --> gamma p using e(+) p and e(-) p collision data recorded with the HI detector at HERA is presented. The analysed data sample corresponds to an integrated luminosity of 306 pb(-1), almost equally shared between both beam charges. The cross section is measured as a function of the virtuality Q(2) of the exchanged photon and the centre-of-mass energy W of the gamma*p system in the kinematic domain 6.5 < Q(2) < 80 GeV2, 30 < W < 140 GeV and |t| < 1 GeV2, where t denotes the squared momentum transfer at the proton vertex. The cross section is determined differentially in t for different Q(2) and W values and exponential t-slope parameters are derived. Using e(+) p and e(-) p data samples, a beam charge asymmetry is extracted for the first time in the low Biorken x kinematic domain. The observed asymmetry is attributed to the interference between Bethe-Heitler and deeply virtual Compton scattering processes. Experimental results are discussed in the context of two different models, one based on generalised parton distributions and one based on the dipole approach. (C) 2009 Elsevier B.V. All rights reserved.
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39. |
- Aaron, F. D., et al.
(författare)
-
Events with isolated leptons and missing transverse momentum and measurement of W production at HERA
- 2009
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 64:2, s. 251-271
-
Tidskriftsartikel (refereegranskat)abstract
- Events with high energy isolated electrons, muons or tau leptons and missing transverse momentum are studied using the full e(+/-)p data sample collected by the H1 experiment at HERA, corresponding to an integrated luminosity of 474 pb(-1). Within the Standard Model, events with isolated leptons and missing transverse momentum mainly originate from the production of single W bosons. The total single W boson production cross section is measured as 1.14 +/- 0.25 (stat.) +/- 0.14 (sys.) pb, in agreement with the Standard Model expectation. The data are also used to establish limits on the WW gamma gauge couplings and for a measurement of the W boson polarisation.
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40. |
- Aaron, F. D., et al.
(författare)
-
Inclusive photoproduction of rho(0), K*(0) and phi mesons at HERA H1 Collaboration
- 2009
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 673:2, s. 119-126
-
Tidskriftsartikel (refereegranskat)abstract
- Inclusive non-diffractive photoproduction of rho(770)(0), K*(892)(0) and phi(1020) mesons is investigated with the H1 detector in ep collisions at HERA. The corresponding average gamma p centre-of-mass energy is 210 GeV. The mesons are measured in the transverse momentum range 0.5 < p(T) < 7 GeV and the rapidity range vertical bar y(lab)vertical bar < 1. Differential cross sections are presented as a function of transverse momentum and rapidity, and are compared to the predictions of hadroproduction models. (C) 2009 Elsevier B.V. All rights reserved.
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41. |
- Aaron, F. D., et al.
(författare)
-
Measurement of diffractive scattering of photons with large momentum transfer at HERA
- 2009
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 672:3, s. 219-226
-
Tidskriftsartikel (refereegranskat)abstract
- The first measurement of diffractive scattering of quasi-real photons with large momentum transfer gamma p -> gamma Y, where Y is the proton dissociative system, is made using the H1 detector at HERA. The measurement is performed for initial photon virtualities Q(2) < 0.01 GeV2. Single differential cross sections are Measured as a function of W, the incident photon-proton centre of mass energy, and t, the square of the four-momentum transferred at the proton vertex, in the range 175 < W < 247 GeV and 4 < |t| < 36 GeV2. The W dependence is well described by a model based on perturbative QCD using a leading logarithmic approximation of the BFKL evolution. The measured |t| dependence is harder than that predicted by the model and those observed in exclusive vector meson production. (C) 2009 Published by Elsevier B.V.
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42. |
- Aaron, F. D., et al.
(författare)
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Measurement of isolated photon production in deep-inelastic scattering at HERA
- 2008
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 54:3, s. 371-387
-
Tidskriftsartikel (refereegranskat)abstract
- The production of isolated photons in deep-inelastic scattering ep -> e gamma X is measured with the H1 detector at HERA. The measurement is performed in the kinematic range of negative four-momentum transfer squared 4 < Q(2)< 150 GeV2 and a mass of the hadronic system W-X > 50 GeV. The analysis is based on a total integrated luminosity of 227 pb(-1). The production cross section of isolated photons with a transverse energy in the range 3 < E-T(gamma)< 10 GeV and pseudorapidity range -1.2
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43. |
- Aaron, F. D., et al.
(författare)
-
Measurement of the inclusive ep scattering cross section at low Q (2) and x at HERA
- 2009
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 63:4, s. 625-678
-
Tidskriftsartikel (refereegranskat)abstract
- A measurement of the inclusive ep scattering cross section is presented in the region of low momentum transfers, 0.2 GeV2 a parts per thousand currency signQ (2)a parts per thousand currency sign12 GeV2, and low Bjorken x, 5a <...10(-6)a parts per thousand currency signxa parts per thousand currency sign0.02. The result is based on two data sets collected in dedicated runs by the H1 Collaboration at HERA at beam energies of 27.6 GeV and 920 GeV for positrons and protons, respectively. A combination with data previously published by H1 leads to a cross section measurement of a few percent accuracy. A kinematic reconstruction method exploiting radiative ep events extends the measurement to lower Q (2) and larger x. The data are compared with theoretical models which apply to the transition region from photoproduction to deep inelastic scattering.
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44. |
- Aaron, F. D., et al.
(författare)
-
Measurement of the proton structure function F-L(x, Q(2)) at low x
- 2008
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 665:4, s. 139-146
-
Tidskriftsartikel (refereegranskat)abstract
- A first measurement is reported of the longitudinal proton structure function FL(X, Q(2)) at the ep collider HERA. It is based on inclusive deep inelastic e(+)p scattering cross section measurements with a positron beam energy of 27.5 GeV and proton beam energies of 920, 575 and 460 GeV. Employing the energy dependence of the cross section, FL is measured in a range of squared four-momentum transfers 12 <= Q2 <=, 90 GeV2 and low Bjorken x 0.00024 <= x <= 0.0036. The F-L values agree with higher order QCD calculations based on parton densities obtained using cross section data previously measured at HERA. (C) 2008 Elsevier B.V. All rights reserved.
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45. |
- Aaron, F. D., et al.
(författare)
-
Multi-lepton production at high transverse momenta in ep collisions at HERA
- 2008
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 668:4, s. 268-276
-
Tidskriftsartikel (refereegranskat)abstract
- Processes leading to a final state with at least two high transverse momentum leptons (electrons or muons) are studied using the full e(+/-) p data sample collected by the H1 experiment at HERA. The data correspond to an integrated luminosity of 463 pb(-1). Di-lepton and tri-lepton event classes are investigated. Cross sections of the production of e(+)e(-) and mu(+)mu(-) pairs are derived in a restricted phase space dominated by photon-photon collisions. In general, good agreement is found with Standard Model predictions. Events are observed with a total scalar sum of lepton transverse momenta above 100 GeV where the Standard Model expectation is low. In this region, combining di-lepton and tri-lepton classes, five events are observed in e(+) p collisions, compared to a Standard Model expectation of 0.96 +/- 0.12, while no such event is observed in e(-) p data for 0.64 +/- 0.09 expected. (C) 2008 Elsevier B.V. All rights reserved.
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46. |
- Aaron, F. D., et al.
(författare)
-
Multi-leptons with high transverse momentum at HERA
- 2009
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Ingår i: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479. ; :10
-
Tidskriftsartikel (refereegranskat)abstract
- Events with at least two high transverse momentum leptons (electrons or muons) are studied using the H1 and ZEUS detectors at HERA with an integrated luminosity of 0.94 fb(-1). The observed numbers of events are in general agreement with the Standard Model predictions. Seven di- and tri-lepton events are observed in e(+)p collision data with a scalar sum of the lepton transverse momenta above 100 GeV while 1.94 +/- 0.17 events are expected. Such events are not observed in e(-)p collisions for which 1.19 +/- 0.12 are predicted. Total visible and differential di-electron and di-muon photoproduction cross sections are extracted in a restricted phase space dominated by photon-photon collisions.
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47. |
- Aaron, F. D., et al.
(författare)
-
Observation of the hadronic final state charge asymmetry in high Q(2) deep-inelastic scattering at HERA
- 2009
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 681:2, s. 125-133
-
Tidskriftsartikel (refereegranskat)abstract
- A first measurement is presented of the charge asymmetry in the hadronic final state from the hard interaction in deep-inelastic ep neutral current scattering at HERA. The measurement is performed in the range of negative squared four momentum transfer 100 < Q(2) < 8000 GeV2. The difference between the event normalised distributions of the scaled momentum, x(p), for positively and negatively charged particles, measured in the current region of the Breit frame, is studied together with its evolution as a function of Q. The results are compared to Monte Carlo models at the hadron and parton levels. (C) 2009 Elsevier B.V. All rights reserved.
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48. |
- Aaron, F. D., et al.
(författare)
-
Search for excited electrons in ep collisions at HERA
- 2008
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 666:2, s. 131-139
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Tidskriftsartikel (refereegranskat)abstract
- A search for excited electrons is performed using the full e(+/-) p data sample collected by the HI experiment at HERA, corresponding to a total luminosity of 475 pb(-1). The electroweak decays of excited electrons e* -> e gamma, e* -> eZ and e* -> vW with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for excited electron production is found. Mass dependent exclusion limits on e* production cross sections and on the ratio f/Lambda of the coupling to the compositeness scale are derived within gauge mediated models. These limits extend the excluded region compared to previous excited electron searches. The e* production via contact interactions is also addressed for the first time in ep collisions. (C) 2008 Elsevier B.V. All rights reserved.
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49. |
- Aaron, F. D., et al.
(författare)
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Search for excited quarks in ep collisions at HERA
- 2009
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 678:4, s. 335-343
-
Tidskriftsartikel (refereegranskat)abstract
- A search for excited quarks is performed using the full e(+/-)p data sample collected by the HI experiment at HERA, corresponding to a total integrated luminosity of 475 pb(-1). The electroweak decays of excited quarks q* -> q gamma. q* -> qZ and q* - qW with Subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for first generation excited quark production is found. Mass dependent exclusion limits on q* production cross sections and on the ratio f/Lambda of the coupling to the compositeness scale are derived Within gauge mediated models. These limits extend the excluded region compared to previous excited quark searches. (C) 2009 Elsevier B.V. All rights reserved.
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50. |
- Aaron, F. D., et al.
(författare)
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Search for single top quark production at HERA
- 2009
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 678:5, s. 450-458
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Tidskriftsartikel (refereegranskat)abstract
- A search for single top quark production is performed in the full e(+/-)p data sample collected by the H1 experiment at HERA, corresponding to an integrated luminosity of 474 pb(-1). Decays of top quarks into a b quark and a W boson with Subsequent leptonic or hadronic decay of the W are investigated. A multivariate analysis is performed to discriminate top quark production from Standard Model background processes. An upper limit on the top quark production cross section via flavour changing neutral current processes sigma(ep -> et X) < 0.25 pb is established at 95% CL. Limits on the anomalous coupling K-tu gamma are derived. (C) 2009 Elsevier B.V. All rights reserved.
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