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- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 2. |
- Carninci, P, et al.
(författare)
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The transcriptional landscape of the mammalian genome
- 2005
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Ingår i: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 309:5740, s. 1559-1563
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Tidskriftsartikel (refereegranskat)abstract
- This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5′ and 3′ boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development.
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| 3. |
- Jagarlamudi, Krishna Rao, 1980-
(författare)
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The functional roles of the intra-oocyte phosphatidylinositol 3-kinase (PI3K) signaling in controlling follicular development in mice
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The key functions of the mammalian ovary are the production of fertilizable oocytes and thesecretion of steroid hormones. At the time of birth the human ovary is composed of basic unitstermed primordial follicles. Primordial follicles are long-lived structures in the ovary and some ofthem last until the woman reaches menopause. However, the intra-oocyte signaling pathways thatactivate primordial follicles and early follicular development are largely unknown. In this thesis, the functional roles that the phosphatidylinositol 3-kinase (PI3K) signaling pathwayplays in follicular development were investigated. In vivo approaches using genetically modifiedmouse models were used to determine the functions of several members of the PI3K signalingpathway in oocytes and in follicles. The function of Foxo3a, a substrate of Akt, was investigatedby expressing Foxo3a constitutively in oocytes of primary follicles. We found that continuouslyactive Foxo3a in mouse oocytes caused retardation of oocyte growth, resulting in arrest offollicular development. The functions of p27kip1 (p27) were studied using p27-deficient (p27-/-)mice. It was found that p27 suppresses follicle endowment/formation and activation, and that itinduces follicle atresia. The functions of PI3K signaling in oocytes during follicular activationwere also investigated using conditional mutant mice, by disrupting the Pten in oocytes ofprimordial follicles. We found that, all primordial follicles were prematurely activated due toovergrowth of oocytes and these follicles were depleted in young adulthood, causing prematureovarian failure (POF). At the same time, disruption of the Pten from oocytes of primary follicleshad no effect on activation of primordial follicles, and the follicles developed and maturednormally. The results clearly show that the PI3K pathway in the mammalian oocyte plays a keyrole in follicular activation through control of initiation of oocyte growth and folliculardevelopment.
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| 8. |
- Liu, Ming, 1982-
(författare)
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A High-end Reconfigurable Computation Platform for Particle Physics Experiments
- 2008
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Modern nuclear and particle physics experiments run at a very high reaction rate and are able to deliver a data rate of up to hundred GBytes/s. This data rate is far beyond the storage and on-line analysis capability. Fortunately physicists have only interest in a very small proportion among the huge amounts of data. Therefore in order to select the interesting data and reject the background by sophisticated pattern recognition processing, it is essential to realize an efficient data acquisition and trigger system which results in a reduced data rate by several orders of magnitude. Motivated by the requirements from multiple experiment applications, we are developing a high-end reconfigurable computation platform for data acquisition and triggering. The system consists of a scalable number of compute nodes, which are fully interconnected by high-speed communication channels. Each compute node features 5 Xilinx Virtex-4 FX60 FPGAs and up to 10 GBytesDDR2 memory. A hardware/software co-design approach is proposed to develop custom applications on the platform, partitioning performance-critical calculation to the FPGA hardware fabric while leaving flexible and slow controls to the embedded CPU plus the operating system. The system is expected to be high-performance and general-purpose for various applications especially in the physics experiment domain. As a case study, the particle track reconstruction algorithm for HADES has been developed and implemented on the computation platform in the format of processing engines. The Tracking Processing Unit (TPU) recognizes peak bins on the projection plane and reconstructs particle tracks in realtime. Implementation results demonstrate its acceptable resource utilization and the feasibility to implement the module together with the sys-tem design on the FPGA. Experimental results show that the online track reconstruction computation achieves 10.8 - 24.3 times performance acceleration per TPU module when compared to the software solution on a Xeon2.4 GHz commodity server.
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| 10. |
- Rajareddy, Singareddy, 1977-
(författare)
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Studies of phosphatidylinositol 3 kinase (PI3K) signaling pathway in mammalian ovarian follicle activation and development
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The intra-oocyte signaling pathways that control oocyte growth and early follicular development are largely unknown. The aim of this thesis was to investigate the regulation and functions of phosphatidylinositol 3 kinase (PI3K) pathway in the oocyte, focusing in the roles of Foxo3a, p27, and Pten (phosphatase and tensin homolog deleted on chromosome ten). The physiological significance of Foxo3a in oocytes had been investigated by generating a transgenic mouse, whereby constitutively active Foxo3a is maintained in oocytes using the oocyte-specific ZP3 (Zona pellucida) promoter. The expression of the constantly active “negative” molecule Foxo3a in mouse oocytes was found to cause retardation of oocyte growth, resulting in a significant reduction in oocyte volume in secondary follicles. The transgenic mice also showed arrested follicular development and were infertile. In addition, when Foxo3a was overexpressed in oocytes of primary follicles, oocyte growth and follicular development were retarded. One of the causes of this phenotype may be the retained expression of the cyclin-dependent kinase (Cdk) inhibitor 1B (Cdkn1b), commonly known as p27kip1 or p27, in the nuclei of oocytes. The role and related mechanisms of p27 in controlling early follicular development and oocyte growth were then investigated using wild-type and p27-deficient (p27-/-) mice, and we demonstrated that (i) p27 suppresses follicle endowment/formation and activation, (ii) p27 induces follicle atresia that occurs prior to sexual maturity, and (iii) the overactivated follicles in p27-/- ovaries are depleted in early adulthood, causing premature ovarian failure (POF). In this thesis, we also provide genetic evidence that in mice with conditional deletion of Pten a major negative regulator of PI3K in oocytes, the entire pool of primordial follicles becomes activated, and subsequently all activated follicles are depleted in young adulthood, causing POF. Further mechanistic studies revealed that loss of Pten in oocytes resulted in elevated Akt signaling, which led to upregulation of both expression and activation of ribosomal protein S6 (rpS6) in oocytes. The results thus show that the mammalian oocyte serves as the headquarters of programming of the occurrence of follicle activation, and that the PI3K pathway of the oocyte governs follicle activation through control of initiation of oocyte growth.
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