| 1. |
- 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
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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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| 2. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes
- 2008
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Ingår i: Autophagy. - : Landes Bioscience. - 1554-8627 .- 1554-8635. ; 4:2, s. 151-175
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Forskningsöversikt (refereegranskat)abstract
- Research in autophagy continues to accelerate,1 and as a result many new scientists are entering the field. Accordingly, it is important to establish a standard set of criteria for monitoring macroautophagy in different organisms. Recent reviews have described the range of assays that have been used for this purpose.2,3 There are many useful and convenient methods that can be used to monitor macroautophagy in yeast, but relatively few in other model systems, and there is much confusion regarding acceptable methods to measure macroautophagy in higher eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers of autophagosomes versus those that measure flux through the autophagy pathway; thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from fully functional autophagy that includes delivery to, and degradation within, lysosomes (in most higher eukaryotes) or the vacuole (in plants and fungi). Here, we present a set of guidelines for the selection and interpretation of the methods that can be used by investigators who are attempting to examine macroautophagy and related processes, as well as by reviewers who need to provide realistic and reasonable critiques of papers that investigate these processes. This set of guidelines is not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to verify an autophagic response.
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| 3. |
- Howe, B., et al.
(författare)
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Growth and physical properties of epitaxial metastable Hf1 - xAlxN alloys deposited on MgO(001) by ultrahigh vacuum reactive magnetron sputtering
- 2007
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Ingår i: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 202:4-7, s. 809-814
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Tidskriftsartikel (refereegranskat)abstract
- Epitaxial metastable Hf1 - xAlxN alloys with 0 ≤ x ≤ 0.50 were grown on MgO(001) substrates at 600 °C by ultrahigh vacuum reactive magnetron sputtering from Hf and Al targets in 90% Ar + 10% N2 discharges at 7 mTorr. X-Ray diffraction and cross-sectional transmission electron microscopy show that Hf1 - xAlxN alloys are single crystals with the B1-NaCl structure. Rutherford backscattering spectroscopy investigations reveal that all films are slightly overstochiometric with N / (Hf + Al) = 1.05 ± 0.05. The relaxed lattice parameter decreased linearly from 0.4519 nm with x = 0 to 0.4438 nm with x = 0.50, compared to 0.4320 nm expected from the linear Vegard's rule. We find a metastable single phase field that is remarkably broad given the large lattice mismatch (≃ 9%) between the two alloy components. Alloying HfN with AlN leads to an increase in hardness (≃ 30% to 32.4 ± 0.7 GPa), as well as nanostructured compositional modulations due to the onset of spinodal decomposition. © 2007 Elsevier B.V. All rights reserved.
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| 4. |
- Salem, Rany M., et al.
(författare)
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Chromogranin a polymorphisms are associated with hypertensive renal disease
- 2008
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Ingår i: Journal of the American Society of Nephrology. - 1046-6673 .- 1533-3450. ; 19:3, s. 600-614
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Tidskriftsartikel (refereegranskat)abstract
- Chromogranin A is released together with epinephrine and norepinephrine from catecholaminergic cells. Specific endopeptidases cleave chromogranin A into biologically active peptide fragments, including catestatin, which inhibits catecholamine release. Previous studies have suggested that a deficit in this sympathetic “braking” system might be an early event in the pathogenesis of human hypertension. Whether chromogranin A (CHGA) polymorphisms predict end-organ complications of hypertension, such as end-stage renal disease, is unknown. Among blacks, we studied common genetic variants spanning the CHGA locus in 2 independent case-control studies of hypertensive ESRD. Two haplotypes were significantly more frequent among subjects with hypertensive ESRD: 1) in the promoter (5′) region, G-462A→T-415C→C-89A, haplotype ATC (adjusted odds ratio = 2.65; P = 0.037), and 2) at the 3′-end, C11825T (3′-UTR, C+87T)→G12602C, haplotype TC (adjusted odds ratio = 2.73, P = 0.0196). Circulating levels of catestatin were lower among those with hypertensive ESRD than controls, an unexpected finding given that peptide levels are usually elevated in ESRD because of reduced renal elimination. We found that the 3′-UTR + 87T variant decreased reporter gene expression, providing a possible mechanistic explanation for diminished catestatin. In summary, common variants in chromogranin A associate with the risk of hypertensive ESRD in blacks.
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| 5. |
- Bjerketorp, J., et al.
(författare)
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Rapid lab-on-a-chip profiling of human gut bacteria
- 2008
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Ingår i: Journal of Microbiological Methods. - : Elsevier BV. - 0167-7012 .- 1872-8359. ; 72:1, s. 82-90
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Tidskriftsartikel (refereegranskat)abstract
- The human gut microbiota has a substantial impact on human health. Different factors such as disease, diet and drug use can have significant impacts on the gut microbiota. Therefore, it is of interest to have simple, rapid methods for analysis of the composition of the gut microbiota for clinical diagnostic purposes. Since only a minor fraction of the gastrointestinal bacterial community is presently possible to cultivate, molecular approaches are currently the best suited to investigate its composition. However, most of these molecular approaches require technical expertise and expensive equipment to run and they are not routinely available. Ideally, the analyses should be point-of-care options that can be run on a chip. In this study, an existing lab-on-chip (LOC) system for sizing/quantifying DNA was combined with length heterogeneity PCR (LH-PCR), a PCR-based profiling method targeting bacterial 16S rRNA gene sequences, to develop a fast, straightforward, reproducible, and economical method for profiling bacterial communities. The LOC LH-PCR method was first evaluated using a standardized gut cocktail containing genomic DNA from eight different bacterial species representing different genera of relevance for human health. The method was also tested on DNA that was directly extracted from human faecal samples and it was consistently capable of detecting alterations in the bacterial samples before and after antibiotic treatment. Although the resolution of the method needs improvement, this study represents the first step towards development of a diagnostic LOC for profiling gut bacterial communities.
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| 6. |
- Dong, C. L., et al.
(författare)
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Electronic structure and surface structure of Cu2S nanorods from polarization dependent X-ray absorption spectroscopy
- 2006
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Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 151:1, s. 64-70
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Tidskriftsartikel (refereegranskat)abstract
- Highly aligned CuS nanorods have been studied by polarization dependent X-ray absorption spectroscopy. In contrast to bulk Cu2S, strong s, p, and d hybridization is found in the nanorods. The polarization dependence shows a predominant d(z2) character of Cu 3d states. Ab initio multiple-scattering calculations confirm the strong hybridization, and reveal that CuS nanorods are grown along the z-axis of chalcocite structure with Cu-7 and Cu-10 sites being the main building blocks. The hybridized absorption peak in the nanorods is shifted towards lower energies for smaller diameter of nanorods, which is attributed to surface reconstruction due to strong Cu-Cu interactions on the Cu-rich surface of the nanorods.
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| 7. |
- Jiang, Q. H., et al.
(författare)
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Magnetoelectric composites of nickel ferrite and lead zirconnate titanate prepared by spark plasma sintering
- 2007
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Ingår i: Journal of the European Ceramic Society. - : Elsevier BV. - 0955-2219 .- 1873-619X. ; 27:1, s. 279-284
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Tidskriftsartikel (refereegranskat)abstract
- Magnetoelectric (ME) bulk composites of ferrite and lead zirconnate titanate (PZT) were prepared by spark plasma sintering (SPS) of mechanically mixed ferrites. BaFe2O4 or NiFe2O4 and a soft lead zirconnate titanate, PZT-5A, powders. The feasibility of retarding possible reactions occurring between the ferrite and lead zirconnate titanate was approved by applying such a dynamic process as SPS. It was further revealed that nickel ferrite and PZT-5A is a more favorable combination that underwent no obvious reactions up to 1050 degrees C. Efforts were made to optimize the SPS processing parameters in order to produce immiscible composites with high electrical resistivity, low dielectric loss and better magnetoelectric response.
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| 8. |
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| 9. |
- Agustin, Sanchez-Arcilla, et al.
(författare)
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Introduction
- 2008
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Ingår i: Journal of Hydraulic Research. - 0022-1686. ; 46:2, s. 179-182
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 10. |
- Ben-Akiva, M., et al.
(författare)
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Towards Disaggregate Dynamic Travel Forecasting Models
- 2007
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Ingår i: Tsinghua Science and Technology. - 1007-0214. ; 12:2, s. 115-130
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Tidskriftsartikel (refereegranskat)abstract
- The authors argue that travel forecasting models should be dynamic and disaggregate in their representation of demand, supply, and supply-demand interactions, and propose a framework for such models. The proposed framework consists of disaggregate activity-based representation of travel choices of individual motorists on the demand side integrated with disaggregate dynamic modeling of network performance, through vehicle-based traffic simulation models on the supply side. The demand model generates individual members of the population and assigns to them socioeconomic characteristics. The generated motorists maintain these characteristics when they are loaded on the network by the supply model. In an equilibrium setting, the framework lends itself to a fixed-point formulation to represent and resolve demand-supply interactions. The paper discusses some of the remaining development challenges and presents an example of an existing travel forecasting model system that incorporates many of the proposed elements.
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