| 1. |
- Abazov, V. M., et al.
(författare)
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Improved determination of the width of the top quark
- 2012
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 85:9, s. 091104-
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Tidskriftsartikel (refereegranskat)abstract
- We present an improved determination of the total width of the top quark, Gamma(t), using 5.4 fb(-1) of integrated luminosity collected by the D0 Collaboration at the Tevatron p (p) over bar Collider. The total width Gamma(t) is extracted from the partial decay width Gamma(t -> Wb) and the branching fraction B(t -> Wb). Gamma(t -> Wb) is obtained from the t-channel single top-quark production cross section and B(t -> Wb) is measured in t (t) over bar events. For a top mass of 172.5 GeV, the resulting width is Gamma(t) = 2.00(-0.43)(+0.47) GeV. This translates to a top-quark lifetime of tau(t) = (3.29(-0.63)(+0.90)) x 10(-25) s. We also extract an improved direct limit on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix element 0.81 < vertical bar V-tb vertical bar <= 1 at 95% C.L. and a limit of vertical bar V-tb'vertical bar < 0.59 for a high-mass fourth-generation bottom quark assuming unitarity of the fourth-generation quark-mixing matrix.
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| 2. |
- Adrian-Martinez, S., et al.
(författare)
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A first search for coincident gravitational waves and high energy neutrinos using LIGO, Virgo and ANTARES data from 2007
- 2013
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :6
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Tidskriftsartikel (refereegranskat)abstract
- We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.
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| 3. |
- Lorenzen, Eline D., et al.
(författare)
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Species-specific responses of Late Quaternary megafauna to climate and humans
- 2011
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 479:7373, s. 359-364
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Tidskriftsartikel (refereegranskat)abstract
- Despite decades of research, the roles of climate and humans in driving the dramatic extinctions of large-bodied mammals during the Late Quaternary period remain contentious. Here we use ancient DNA, species distribution models and the human fossil record to elucidate how climate and humans shaped the demographic history of woolly rhinoceros, woolly mammoth, wild horse, reindeer, bison and musk ox. We show that climate has been a major driver of population change over the past 50,000 years. However, each species responds differently to the effects of climatic shifts, habitat redistribution and human encroachment. Although climate change alone can explain the extinction of some species, such as Eurasian musk ox and woolly rhinoceros, a combination of climatic and anthropogenic effects appears to be responsible for the extinction of others, including Eurasian steppe bison and wild horse. We find no genetic signature or any distinctive range dynamics distinguishing extinct from surviving species, emphasizing the challenges associated with predicting future responses of extant mammals to climate and human-mediated habitat change.
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| 4. |
- Ageron, M., et al.
(författare)
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ANTARES : The first undersea neutrino telescope
- 2011
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 656:1, s. 11-38
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Tidskriftsartikel (refereegranskat)abstract
- The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France. An illustration of the detector performance is given. (C) 2011 Elsevier B.V. All rights reserved.
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| 5. |
- Fogelström, Mikael, 1963, et al.
(författare)
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Point-contact spectroscopy in heavy-fermion superconductors
- 2010
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Ingår i: Physical Review B - Condensed Matter and Materials Physics. - 2469-9950 .- 2469-9969. ; 82:1
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Tidskriftsartikel (refereegranskat)abstract
- We develop a microscopic model to calculate point-contact spectra between a metallic tip and a superconducting heavy-fermion system. We apply our tunneling model to the heavy fermion CeCoIn5, both in the normal and superconducting states. In point contact and scanning tunneling spectroscopy many heavy-fermion materials, such as CeCoIn5, exhibit an asymmetric differential conductance, dI/dV, combined with a strongly suppressed Andreev reflection signal in the superconducting state. We argue that both features may be explained in terms of a multichannel tunneling model in the presence of localized states near the interface. We find that it is not sufficient to tunnel into two itinerant bands of light and heavy electrons to explain the Fano line shape of the differential conductance. Localized states in the bulk or near the interface are an essential component for quantum interference to occur when an electron tunnels from the metallic tip of the point contact into the heavy-fermion system.
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| 6. |
- Franck-Larsson, Karin, et al.
(författare)
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Physiological and structural anorectal abnormalities in patients with systemic sclerosis and fecal incontinence
- 2014
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 49:9, s. 1073-1083
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveFecal incontinence is common in systemic sclerosis (SSc), but the underlying mechanisms are not fully understood. The objectives of this study were to characterize anorectal physiological and morphological defects in SSc patients and to correlate the results with incontinence symptoms.Materials and methodsTwenty-five SSc patients underwent anorectal neurophysiological investigations, anal manometry, and ultrasound.ResultsEleven patients (44%) reported incontinence to solid or liquid feces, but no patient reported diarrhea. Increased fiber density (FD) was recorded in 78% of patients with and in 86% of patients without fecal incontinence not significant (NS). Incontinent patients had lower squeeze pressure (SP; median 49.5 mm Hg) in the high-pressure zone (HPZ) than continent patients (median 72 mm Hg; p = 0.01). In two of the incontinent patients, sonographic abnormalities of the internal anal sphincter (IAS) and the external anal sphincter (EAS) were present, whereas in another two patients isolated IAS abnormalities were seen. These four individuals had lower resting pressure at 1 cm and in the HPZ, and lower SP at 2 cm than patients with normal anorectal sonographic findings (p < 0.05).ConclusionLower voluntary SP in incontinent patients and EAS sonographic abnormalities only in patients with incontinence suggest that the EAS is more important in maintaining fecal continence in SSc patients than has previously been reported. The finding of increased FD in most patients further supports involvement of the EAS function in SSc and could indicate previous nerve injury with consequent incomplete reinnervation.
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| 7. |
- Frank, Matthias, et al.
(författare)
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Femtosecond X-ray diffraction from two-dimensional protein crystals
- 2014
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Ingår i: IUCrJ. - 2052-2525. ; 1:2, s. 95-100
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Tidskriftsartikel (refereegranskat)abstract
- X-ray diffraction patterns from two-dimensional (2-D) protein crystals obtained using femtosecond X-ray pulses from an X-ray free-electron laser (XFEL) are presented. To date, it has not been possible to acquire transmission X-ray diffraction patterns from individual 2-D protein crystals due to radiation damage. However, the intense and ultrafast pulses generated by an XFEL permit a new method of collecting diffraction data before the sample is destroyed. Utilizing a diffract-before-destroy approach at the Linac Coherent Light Source, Bragg diffraction was acquired to better than 8.5 Å resolution for two different 2-D protein crystal samples each less than 10 nm thick and maintained at room temperature. These proof-of-principle results show promise for structural analysis of both soluble and membrane proteins arranged as 2-D crystals without requiring cryogenic conditions or the formation of three-dimensional crystals.
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| 8. |
- Hunter, Mark S, et al.
(författare)
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Fixed-target protein serial microcrystallography with an x-ray free electron laser.
- 2014
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 4, s. 6026-
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Tidskriftsartikel (refereegranskat)abstract
- We present results from experiments at the Linac Coherent Light Source (LCLS) demonstrating that serial femtosecond crystallography (SFX) can be performed to high resolution (~2.5 Å) using protein microcrystals deposited on an ultra-thin silicon nitride membrane and embedded in a preservation medium at room temperature. Data can be acquired at a high acquisition rate using x-ray free electron laser sources to overcome radiation damage, while sample consumption is dramatically reduced compared to flowing jet methods. We achieved a peak data acquisition rate of 10 Hz with a hit rate of ~38%, indicating that a complete data set could be acquired in about one 12-hour LCLS shift using the setup described here, or in even less time using hardware optimized for fixed target SFX. This demonstration opens the door to ultra low sample consumption SFX using the technique of diffraction-before-destruction on proteins that exist in only small quantities and/or do not produce the copious quantities of microcrystals required for flowing jet methods.
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| 9. |
- Karnouskos, Stamatis, et al.
(författare)
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The IMC-AESOP architecture for cloud-based industrial Cyber-physical Systems
- 2014
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Ingår i: Industrial Cloud-Based Cyber-Physical Systems. - Cham : Encyclopedia of Global Archaeology/Springer Verlag. - 9783319056234 - 9783319056241 ; , s. 49-88
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Bokkapitel (refereegranskat)abstract
- A coherent architectural framework is needed to be able to cope with the imposed requirements and realise the vision for the industrial automation domain. Future factories will rely on multi-system interactions and collaborative cross-layer management and automation approaches. The service-oriented architecture paradigm empowered by virtualisation of resources acts as a lighthouse. More specifically by integrating Web services, Internet technologies, Cloud systems and the power of the Internet of Things, we can create a framework that has the possibility of empowering seamless integration and interaction among the heterogeneous stakeholders in the future industrial automation domain. We propose here a service architecture that attempts to cover the basic needs for monitoring, management, data handling, integration, etc., by taking into consideration the disruptive technologies and concepts that could empower future industrial systems
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| 10. |
- Raghavan, Maanasa, et al.
(författare)
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Upper Palaeolithic Siberian genome reveals dual ancestry of Native Americans
- 2014
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 505:7481, s. 87-
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Tidskriftsartikel (refereegranskat)abstract
- The origins of the First Americans remain contentious. Although Native Americans seem to be genetically most closely related to east Asians(1-3), there is no consensus with regard to which specific Old World populations they are closest to(4-8). Here we sequence the draft genome of an approximately 24,000-year-old individual (MA-1), from Mal'ta in south-central Siberia(9), to an average depth of 1x. To our knowledge this is the oldest anatomically modern human genome reported to date. The MA-1 mitochondrial genome belongs to haplogroup U, which has also been found at high frequency among Upper Palaeolithic and Mesolithic European hunter-gatherers(10-12), and the Y chromosome of MA-1 is basal to modern-day western Eurasians and near the root of most Native American lineages(5). Similarly, we find autosomal evidence that MA-1 is basal to modern-day western Eurasians and genetically closely related to modern-day Native Americans, with no close affinity to east Asians. This suggests that populations related to contemporary western Eurasians had a more north-easterly distribution 24,000 years ago than commonly thought. Furthermore, we estimate that 14 to 38% of Native American ancestry may originate through gene flow from this ancient population. This is likely to have occurred after the divergence of Native American ancestors from east Asian ancestors, but before the diversification of Native American populations in the New World. Gene flow from the MA-1 lineage into Native American ancestors could explain why several crania from the First Americans have been reported as bearing morphological characteristics that do not resemble those of east Asians(2,13). Sequencing of another south-central Siberian, Afontova Gora-2 dating to approximately 17,000 years ago(14), revealed similar autosomal genetic signatures as MA-1, suggesting that the region was continuously occupied by humans throughout the Last Glacial Maximum. Our findings reveal that western Eurasian genetic signatures in modern-day Native Americans derive not only from post-Columbian admixture, as commonly thought, but also from a mixed ancestry of the First Americans.
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