| 1. |
- Schael, S, et al.
(author)
-
Precision electroweak measurements on the Z resonance
- 2006
-
In: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Research review (peer-reviewed)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. |
- Coustenis, A., et al.
(author)
-
TandEM : Titan and Enceladus mission
- 2009
-
In: Experimental astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 23:3, s. 893-946
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Journal article (peer-reviewed)abstract
- TandEM was proposed as an L-class (large) mission in response to ESA's Cosmic Vision 2015-2025 Call, and accepted for further studies, with the goal of exploring Titan and Enceladus. The mission concept is to perform in situ investigations of two worlds tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini-Huygens mission. These bodies still hold mysteries requiring a complete exploration using a variety of vehicles and instruments. TandEM is an ambitious mission because its targets are two of the most exciting and challenging bodies in the Solar System. It is designed to build on but exceed the scientific and technological accomplishments of the Cassini-Huygens mission, exploring Titan and Enceladus in ways that are not currently possible (full close-up and in situ coverage over long periods of time). In the current mission architecture, TandEM proposes to deliver two medium-sized spacecraft to the Saturnian system. One spacecraft would be an orbiter with a large host of instruments which would perform several Enceladus flybys and deliver penetrators to its surface before going into a dedicated orbit around Titan alone, while the other spacecraft would carry the Titan in situ investigation components, i.e. a hot-air balloon (MontgolfiSre) and possibly several landing probes to be delivered through the atmosphere.
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| 3. |
- Sarsour, M., et al.
(author)
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Measurement of the Absolute Differential Cross Section for np Elastic Scattering at 194 MeV
- 2006
-
In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 74:4, s. 044003-
-
Journal article (peer-reviewed)abstract
- A tagged medium-energy neutron beam was used in a precise measurement of the absolute differential cross section for np backscattering. The results resolve significant discrepancies within the np database concerning the angular dependence in this regime. The experiment has determined the absolute normalization with +/- 1.5% uncertainty, suitable to verify constraints of supposedly comparable precision that arise from the rest of the database in partial wave analyses. The analysis procedures, especially those associated with the evaluation of systematic errors in the experiment, are described in detail so that systematic uncertainties may be included in a reasonable way in subsequent partial wave analysis fits incorporating the present results.
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| 4. |
- Abbondanno, U, et al.
(author)
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The data acquisition system of the neutron time-of-flight facility n_TOF at CERN
- 2005
-
In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 538:1-3, s. 692-702
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Journal article (peer-reviewed)abstract
- The n_TOF facility at CERN has been designed for the measurement of neutron capture, fission and (n, xn) cross-sections with high accuracy. This requires a flexible and-due to the high instantaneous neutron flux-almost dead time free data acquisition system. A scalable and versatile data solution has been designed based on 8-bit flash-ADCs with sampling rates up to 2 GHz and 8 Mbyte memory buffer. The software is written in C and C++ and is running on PCs equipped with RedHat Linux.
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| 5. |
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| 6. |
- Newton-Cheh, Christopher, et al.
(author)
-
Genome-wide association study identifies eight loci associated with blood pressure
- 2009
-
In: Nature Genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 41:6, s. 666-676
-
Journal article (peer-reviewed)abstract
- Elevated blood pressure is a common, heritable cause of cardiovascular disease worldwide. To date, identification of common genetic variants influencing blood pressure has proven challenging. We tested 2.5 million genotyped and imputed SNPs for association with systolic and diastolic blood pressure in 34,433 subjects of European ancestry from the Global BPgen consortium and followed up findings with direct genotyping (N <= 71,225 European ancestry, N <= 12,889 Indian Asian ancestry) and in silico comparison (CHARGE consortium, N 29,136). We identified association between systolic or diastolic blood pressure and common variants in eight regions near the CYP17A1 (P = 7 x 10(-24)), CYP1A2 (P = 1 x 10(-23)), FGF5 (P = 1 x 10(-21)), SH2B3 (P = 3 x 10(-18)), MTHFR (P = 2 x 10(-13)), c10orf107 (P = 1 x 10(-9)), ZNF652 (P = 5 x 10(-9)) and PLCD3 (P = 1 x 10(-8)) genes. All variants associated with continuous blood pressure were associated with dichotomous hypertension. These associations between common variants and blood pressure and hypertension offer mechanistic insights into the regulation of blood pressure and may point to novel targets for interventions to prevent cardiovascular disease.
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| 7. |
- Paschke, K. D., et al.
(author)
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Experimental determination of the complete spin structure for (p)over-barp ->(Lambda)over-bar Lambda at p((p)over-bar)=1.637 GeV/c
- 2006
-
In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 74:1, s. 015206-
-
Journal article (peer-reviewed)abstract
- The reaction (p) over barp -> (Lambda) over bar Lambda -> (p) over bar pi(+)p pi(-) has been measured with high statistics at a beam momentum of p((p) over bar)=1.637GeV/c. The use of a transversely polarized frozen-spin target combined with the self-analyzing property of Lambda/(Lambda) over bar decay allows access to unprecedented information on the spin structure of the interaction. The most general spin-scattering matrix can be written in terms of 11 real parameters for each bin of scattering angle; each of these parameters is determined with reasonable precision. From these results, all conceivable spin correlations are determined with inherent self-consistency. Good agreement is found with the few previously existing measurements of spin observables in (p) over barp ->(Lambda) over bar Lambda near this energy. Existing theoretical models do not give good predictions for those spin observables that had not been previously measured.
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| 8. |
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| 9. |
- Alkhazov, GD, et al.
(author)
-
SPES4-pi: installation for exclusive study of nuclear reactions
- 2005
-
In: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 551:2-3, s. 290-311
-
Journal article (peer-reviewed)abstract
- The paper describes the spectrometric system "SPES4-pi" used at the National Laboratory Saturne (CE Saclay, France) for the exclusive study of the baryon resonance excitation in inelastic alpha and d scattering on the proton, as well as coherent pion production in charge exchange reactions. The system consists of the magnetic spectrometer SPES4 and two wide-aperture position-sensitive detector arrays, equipped with wire chambers and scintillator hodoscopes, installed around a large-gap C-shape dipole magnet.
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| 10. |
- Amm, O., et al.
(author)
-
Towards understanding the electrodynamics of the 3-dimensional high-latitude ionosphere : present and future
- 2008
-
In: Annales Geophysicae. - : Copernicus GmbH. - 0992-7689 .- 1432-0576. ; 26:12, s. 3913-3932
-
Research review (peer-reviewed)abstract
- Traditionally, due to observational constraints, ionospheric modelling and data analysis techniques have been devised either in one dimension (e. g. along a single radar beam), or in two dimensions (e. g. over a network of magnetometers). With new upcoming missions like the Swarm ionospheric multi-satellite project, or the EISCAT 3-D project, the time has come to take into account variations in all three dimensions simultaneously, as they occur in the real ionosphere. The link between ionospheric electrodynamics and the neutral atmosphere circulation which has gained increasing interest in the recent years also intrinsically requires a truly 3-dimensional (3-D) description. In this paper, we identify five major science questions that need to be addressed by 3-D ionospheric modelling and data analysis. We briefly review what proceedings in the young field of 3-D ionospheric electrodynamics have been made in the past to address these selected question, and we outline how these issues can be addressed in the future with additional observations and/or improved data analysis and simulation techniques. Throughout the paper, we limit the discussion to high-latitude and mesoscale ionospheric electrodynamics, and to directly data-driven (not statistical) data analysis.
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| 11. |
- Buchert, Stephan, et al.
(author)
-
The Pedersen current carried by electrons : a non-linear response of the ionosphere to magnetospheric forcing
- 2008
-
In: Annales Geophysicae. - 0992-7689 .- 1432-0576. ; 26:9, s. 2837-2844
-
Journal article (peer-reviewed)abstract
- Observations by the EISCAT Svalbard radar show that electron temperatures T-e in the cusp electrojet reach up to about 4000 K. The heat is tapped and converted from plasma convection in the near Earth space by a Pedersen current that is carried by electrons due to the presence of irregularities and their demagnetising effect. The heat is transfered to the neutral gas by collisions. In order to enhance T-e to such high temperatures the maximally possible dissipation at 50% demagnetisation must nearly be reached. The effective Pedersen conductances are found to be enhanced by up to 60% compared to classical values. Conductivities and conductances respond significantly to variations of the electric field strength E, and "Ohm's law" for the ionosphere becomes non-linear for large E.
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| 12. |
- Cao, J., et al.
(author)
-
Spectral encoding and decoding of monolithic InP OCDMA encoder
- 2005
-
In: 31st European Conference on Optical Communications (ECOC 2005), 2005. - : Institution of Engineering and Technology. ; , s. 501-502
-
Conference paper (peer-reviewed)abstract
- We report the optical-coding operation of monolithic, ultra-compact optical-CDMA encoder and decoder pair, consisting of InP based integrated AWGs and phase modulators. The encoder and decoder successfully demonstrate eight-bit Walsh code based encoding and decoding.
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| 13. |
- Clark, Andrew G., et al.
(author)
-
Evolution of genes and genomes on the Drosophila phylogeny
- 2007
-
In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 450:7167, s. 203-218
-
Journal article (peer-reviewed)abstract
- Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
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| 14. |
- Gilbert, M. Thomas P., et al.
(author)
-
Intraspecific phylogenetic analysis of Siberian woolly mammoths using complete mitochondrial genomes
- 2008
-
In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 105:24, s. 8327-8332
-
Journal article (peer-reviewed)abstract
- We report five new complete mitochondrial DNA (mtDNA) genomes of Siberian woolly mammoth (Mammuthus primigenius), sequenced with up to 73-fold coverage from DNA extracted from hair shaft material. Three of the sequences present the first complete mtDNA genomes of mammoth clade II. Analysis of these and 13 recently published mtDNA genomes demonstrates the existence of two apparently sympatric mtDNA clades that exhibit high interclade divergence. The analytical power afforded by the analysis of the complete mtDNA genomes reveals a surprisingly ancient coalescence age of the two clades, approximate to 1-2 million years, depending on the calibration technique. Furthermore, statistical analysis of the temporal distribution of the C-14 ages of these and previously identified members of the two mammoth clades suggests that clade II went extinct before clade I. Modeling of protein structures failed to indicate any important functional difference between genomes belonging to the two clades, suggesting that the loss of clade II more likely is due to genetic drift than a selective sweep.
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| 15. |
- Gilbert, M. Thomas P., et al.
(author)
-
Whole-genome shotgun sequencing of mitochondria from ancient hair shafts
- 2007
-
In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 317:5846, s. 1927-1930
-
Journal article (peer-reviewed)abstract
- Although the application of sequencing-by-synthesis techniques to DNA extracted from bones has revolutionized the study of ancient DNA, it has been plagued by large fractions of contaminating environmental DNA. The genetic analyses of hair shafts could be a solution: We present 10 previously unexamined Siberian mammoth (Mammuthus primigenius) mitochondrial genomes, sequenced with up to 48-fold coverage. The observed levels of damage-derived sequencing errors were lower than those observed in previously published frozen bone samples, even though one of the specimens was >50,000 14C years old and another had been stored for 200 years at room temperature. The method therefore sets the stage for molecular-genetic analysis of museum collections.
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| 16. |
- Kaeser, Stephan A., et al.
(author)
-
Cystatin C modulates cerebral beta-amyloidosis
- 2007
-
In: Nature Genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 39:12, s. 1437-1439
-
Journal article (peer-reviewed)abstract
- The CST3 Thr25 allele of CST3, which encodes cystatin C, leads to reduced cystatin C secretion and conveys susceptibility to Alzheimer's disease. Here we show that overexpression of human cystatin C in brains of APP-transgenic mice reduces cerebral amyloid-beta deposition and that cystatin C binds amyloid-beta and inhibits its fibril formation. Our results suggest that cystatin C concentrations modulate cerebral amyloidosis risk and provide an opportunity for genetic risk assessment and therapeutic interventions.
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| 17. |
- Kullen, A., et al.
(author)
-
Plasma transport along discrete auroral arcs and its contribution to the ionospheric plasma convection
- 2008
-
In: Annales Geophysicae. - : Copernicus GmbH. - 0992-7689 .- 1432-0576. ; 26:11, s. 3279-3293
-
Journal article (peer-reviewed)abstract
- The role of intense high-altitude electric field (E-field) peaks for large-scale plasma convection is investigated with the help of Cluster E-field, B-field and density data. The study covers 32 E-field events between 4 and 7 R-E geocentric distance, with E-field magnitudes in the range 500 1000 mV/m when mapped to ionospheric altitude. We focus on E-field structures above the ionosphere that are typically coupled to discrete auroral arcs and their return current region. Connected to such E-field peaks are rapid plasma flows directed along the discrete arcs in opposite directions on each side of the arc. Nearly all the E-field events occur during active times. A strong dependence on different substorm phases is found: a majority of intense E-field events appearing during substorm expansion or maximum phase are located on the night-side oval, while most recovery events occur on the dusk-to-dayside part of the oval. For most expansion and maximum phase cases, the average background plasma flow is in the sunward direction. For a majority of recovery events, the flow is in the anti-sunward direction. The net plasma flux connected to a strong E-field peak is in two thirds of the cases in the same direction as the background plasma flow. However, in only one third of the cases the strong flux caused by an E-field peak makes an important contribution to the plasma transport within the boundary plasma sheet. For a majority of events, the area covered by rapid plasma flows above discrete arcs is too small to have an effect on the global convection. This questions the role of discrete auroral arcs as major driver of plasma convection.
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| 18. |
- Miller, Webb, et al.
(author)
-
Sequencing the nuclear genome of the extinct woolly mammoth.
- 2008
-
In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 456:7220, s. 387-390
-
Journal article (peer-reviewed)abstract
- In 1994, two independent groups extracted DNA from several Pleistocene epoch mammoths and noted differences among individual specimens. Subsequently, DNA sequences have been published for a number of extinct species. However, such ancient DNA is often fragmented and damaged, and studies to date have typically focused on short mitochondrial sequences, never yielding more than a fraction of a per cent of any nuclear genome. Here we describe 4.17 billion bases (Gb) of sequence from several mammoth specimens, 3.3 billion (80%) of which are from the woolly mammoth (Mammuthus primigenius) genome and thus comprise an extensive set of genome-wide sequence from an extinct species. Our data support earlier reports that elephantid genomes exceed 4 Gb. The estimated divergence rate between mammoth and African elephant is half of that between human and chimpanzee. The observed number of nucleotide differences between two particular mammoths was approximately one-eighth of that between one of them and the African elephant, corresponding to a separation between the mammoths of 1.5-2.0 Myr. The estimated probability that orthologous elephant and mammoth amino acids differ is 0.002, corresponding to about one residue per protein. Differences were discovered between mammoth and African elephant in amino-acid positions that are otherwise invariant over several billion years of combined mammalian evolution. This study shows that nuclear genome sequencing of extinct species can reveal population differences not evident from the fossil record, and perhaps even discover genetic factors that affect extinction.
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| 19. |
- Ogawa, Y., et al.
(author)
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Coordinated EISCAT Svalbard radar and Reimei satellite observations of ion upflows and suprathermal ions
- 2008
-
In: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 113:A5, s. A05306-
-
Journal article (peer-reviewed)abstract
- The relationship between bulk ion upflows and suprathermal ions was investigated using data simultaneously obtained from the European Incoherent Scatter (EISCAT) Svalbard radar (ESR) and the Reimei satellite. Simultaneous observations were conducted in November 2005 and August 2006, and 14 conjunction data sets have been obtained at approximately 630 km in the dayside ionosphere. Suprathermal ions with energies of a few eV were present in the dayside cusp region, and the ion velocity distribution changed from an isotropic Maxwellian near the cusp region to tail heating at energies above a few eV in the cusp region. The velocity distribution of the suprathermal ions has a peak perpendicular or oblique to the geomagnetic field, and the temperature of the suprathermal ions was 0.9-1.4 eV. An increase in the phase space density (PSD) of the suprathermal ions, measured with the Reimei, was correlated with bulk ion upflow observed at the same altitude using EISCAT, and with the energy flux of precipitating electrons with energies of 50-500 eV. The PSD also has a good correlation with the electron temperature, which was increased by precipitation, but not with the ion temperature (0.1-0.3 eV) at the same altitude measured with EISCAT. These results suggest that plasma waves such as broadband extremely low frequency (BBELF) wavefields associated with precipitation are connected to the bulk ion upflows in the cusp and effectively cause the heating of suprathermal ions. The heating of suprathermal ions disagrees with anisotropic heating due to O+-O resonant charge exchange.
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| 20. |
- Ogawa, Y., et al.
(author)
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On the source of the polar wind in the polar topside ionosphere : First results from the EISCAT Svalbard radar
- 2009
-
In: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 36:24, s. L24103-
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Journal article (peer-reviewed)abstract
- We present quantitative radar observations of both hydrogen ion (H+) and oxygen ion (O+) upflow in the topside polar ionosphere using measurements that were recently carried out with the EISCAT Svalbard Radar and the Reimei satellite. H+ upflow was clearly observed equatorward of the cusp above 500 km altitude. Within the cusp the H+ density was very low, and the upflow was dominated by O+ ions, but on closed field lines the H+ became the larger contributor to the upward flux above about 550 km. The total flux seemed to be conserved, and so below 550 km altitude O+ (with a small upward velocity of similar to 50 m s(-1)) appeared to determine the upward flux which was then maintained by H+! in the topside ionosphere. We also found that the H+ density in the topside polar ionosphere was several times higher than current predictions of ionospheric models like IRI2001.
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| 21. |
- Pomp, Stephan, et al.
(author)
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Neutron-induced light-ion production from Fe, Pb and U at 96 MeV
- 2007
-
In: Radiation Protection Dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 126:1-4, s. 123-125
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Journal article (peer-reviewed)abstract
- Double-differential cross-sections for light-ion production (up to A = 4) induced by 96 MeV neutrons have been measured for Fe, Pb and U. The experiments have been performed at The Svedberg Laboratory in Uppsala, using two independent devices, MEDLEY and SCANDAL. The recorded data cover a wide angular range (20 degrees-160 degrees) with low energy thresholds. The data have been normalised to obtain cross-sections using up elastic scattering events. The latter have been recorded with the same setup, and results for this measurement are reported. The work was performed within the HINDAS collaboration with the primary aim of improving the database for three of the most important nuclei for incineration of nuclear waste with accelerator-driven systems. The obtained cross-section data are of particular interest for the understanding of the so-called pre-equilibrium stage in a nuclear reaction and will be compared with model calculations.
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| 22. |
- Rosenqvist, Lisa, et al.
(author)
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Modulated reconnection rate and energy conversion at the magnetopause under steady IMF conditions
- 2008
-
In: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 35:8
-
Journal article (peer-reviewed)abstract
- We use the multi-spacecraft mission Cluster to make observational estimates of the local energy conversion across the dayside high-latitude magnetopause. The energy conversion is estimated during eleven complete magnetopause crossings under steady south-dawnward interplanetary magnetic field (IMF). We describe a new method to determine the reconnection rate from the magnitude of the local energy conversion. The reconnection rate as well as the energy conversion varies during the course of the eleven crossings and is typically much higher for the outbound crossings. This supports the previous interpretation that reconnection is continuous but its rate is modulated.
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| 23. |
- Smits, Edsger C. P., et al.
(author)
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Bottom-up organic integrated circuits
- 2008
-
In: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 455:7215, s. 956-959
-
Journal article (peer-reviewed)abstract
- Self- assembly - the autonomous organization of components into patterns and structures(1) - is a promising technology for the mass production of organic electronics. Making integrated circuits using a bottom- up approach involving self- assembling molecules was proposed(2) in the 1970s. The basic building block of such an integrated circuit is the self- assembled- monolayer field- effect transistor ( SAMFET), where the semiconductor is a monolayer spontaneously formed on the gate dielectric. In the SAMFETs fabricated so far, current modulation has only been observed in submicrometre channels(3-5), the lack of efficient charge transport in longer channels being due to defects and the limited intermolecular pi-pi coupling between the molecules in the self-assembled monolayers. Low field- effect carrier mobility, low yield and poor reproducibility have prohibited the realization of bottom- up integrated circuits. Here we demonstrate SAMFETs with long- range intermolecular pi - pi coupling in the monolayer. We achieve dense packing by using liquid- crystalline molecules consisting of a pi- conjugated mesogenic core separated by a long aliphatic chain from a monofunctionalized anchor group. The resulting SAMFETs exhibit a bulk- like carrier mobility, large current modulation and high reproducibility. As a first step towards functional circuits, we combine the SAMFETs into logic gates as inverters; the small parameter spread then allows us to combine the inverters into ring oscillators. We demonstrate real logic functionality by constructing a 15- bit code generator in which hundreds of SAMFETs are addressed simultaneously. Bridging the gap between discrete monolayer transistors and functional self-assembled integrated circuits puts bottom- up electronics in a new perspective.
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| 24. |
- Treebak, Jonas T, et al.
(author)
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AMPK-mediated AS160 phosphorylation in skeletal muscle is dependent on AMPK catalytic and regulatory subunits.
- 2006
-
In: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 55:7, s. 2051-2058
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Journal article (peer-reviewed)abstract
- AMP-activated protein kinase (AMPK) is a heterotrimeric protein that regulates glucose transport mediated by cellular stress or pharmacological agonists such as 5-aminoimidazole-4-carboxamide 1 beta-D-ribonucleoside (AICAR). AS160, a Rab GTPase-activating protein, provides a mechanism linking AMPK signaling to glucose uptake. We show that AICAR increases AMPK, acetyl-CoA carboxylase, and AS160 phosphorylation by insulin-independent mechanisms in isolated skeletal muscle. Recombinant AMPK heterotrimeric complexes (alpha 1 beta 1 gamma l and alpha 2 beta 2 gamma 1) phosphorylate AS160 in a cell-free assay. In mice deficient in AMPK signaling (alpha 2 AMPK knockout [KO], alpha 2 AMPK kinase dead [KD], and gamma 3 AMPK KO), AICAR effects on AS160 phosphorylation were severely blunted, highlighting that complexes containing alpha 2 and gamma 3 are necessary for AICAR-stimulated AS160 phosphorylation in intact skeletal muscle. Contraction-mediated AS160 phosphorylation was also impaired in alpha 2 AMPK KO and KD but not gamma 3 AMPK KO mice. Our results implicate AS160 as a downstream target of AMPK.
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