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A measurement of the multi-strange Ξ− and Ω− baryons and their antiparticles by the ALICE experiment at the CERN Large Hadron Collider (LHC) is presented for inelastic proton–proton collisions at a centre-of-mass energy of 7 TeV. The transverse momentum (pT) distributions were studied at mid-rapidity (|y|<0.5) in the range of 0.6<pT<8.5 GeV/c for Ξ− and Ξ¯+ baryons, and in the range of 0.8<pT<5 GeV/c for Ω− and Ω¯+. Baryons and antibaryons were measured as separate particles and we find that the baryon to antibaryon ratio of both particle species is consistent with unity over the entire range of the measurement. The statistical precision of the current data has allowed us to measure a difference between the mean pT of Ξ− (Ξ¯+) and Ω− (Ω¯+). Particle yields, mean pT, and the spectra in the intermediate pT range are not well described by the PYTHIA Perugia 2011 tune Monte Carlo event generator, which has been tuned to reproduce the early LHC data. The discrepancy is largest for Ω− (Ω¯+). This PYTHIA tune approaches the pT spectra of Ξ− and Ξ¯+ baryons below pT<0.85 GeV/c and describes the Ξ− and Ξ¯+ spectra above pT>6.0 GeV/c. We also illustrate the difference between the experimental data and model by comparing the corresponding ratios of (Ω−+Ω¯+)/(Ξ−+Ξ¯+) as a function of transverse mass.
The ALICE Zero Degree Calorimeter system (ZDC) is composed of two identical sets of calorimeters, placed at opposite sides with respect to the interaction point, 114 meters away from it, complemented by two small forward electromagnetic calorimeters (ZEM). Each set of detectors consists of a neutron (ZN) and a proton (ZP) ZDC. They are placed at zero degrees with respect to the LHC axis and allow to detect particles emitted close to beam direction, in particular neutrons and protons emerging from hadronic heavy-ion collisions (spectator nucleons) and those emitted from electromagnetic processes. For neutrons emitted by these two processes, the ZN calorimeters have nearly 100% acceptance.
During the √sNN = 2.76 TeV Pb-Pb data-taking, the ALICE Collaboration studied forward neutron emission with a dedicated trigger, requiring a minimum energy deposition in at least one of the two ZN. By exploiting also the information of the two ZEM calorimeters it has been possible to separate the contributions of electromagnetic and hadronic processes and to study single neutron vs. multiple neutron emission.
The measured cross sections of single and mutual electromagnetic dissociation of Pb nuclei at √sNN = 2.76 TeV, with neutron emission, are σsingle EMD = 187:4 ± 0.2 (stat.)−11.2+13.2 (syst.) b and σmutual EMD = 5.7 ± 0.1 (stat.) ±0.4 (syst.) b, respectively [1]. This is the first measurement of electromagnetic dissociation of 208Pb nuclei at the LHC energies, allowing a test of electromagnetic dissociation theory in a new energy regime. The experimental results are compared to the predictions from a relativistic electromagnetic dissociation model.
The ALICE Collaboration has made the first measurement at the LHC of J/ψ photoproduction in ultra-peripheral Pb–Pb collisions at sNN=2.76 TeV. The J/ψ is identified via its dimuon decay in the forward rapidity region with the muon spectrometer for events where the hadronic activity is required to be minimal. The analysis is based on an event sample corresponding to an integrated luminosity of about 55 μb−1. The cross section for coherent J/ψ production in the rapidity interval −3.6<y<−2.6 is measured to be dσJ/ψcoh/dy=1.00±0.18(stat)−0.26+0.24(syst) mb. The result is compared to theoretical models for coherent J/ψ production and found to be in good agreement with those models which include nuclear gluon shadowing.
Long-range angular correlations on the near and away side in p–Pb collisions at √sNN=5.02 TeV
(2013)
Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p–Pb collisions at a nucleon–nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5<pT,assoc<pT,trig<4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and pT bins, and the widths show no significant evolution with event multiplicity or pT. These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge.
The inclusive charged particle transverse momentum distribution is measured in proton–proton collisions at s=900 GeV at the LHC using the ALICE detector. The measurement is performed in the central pseudorapidity region (|η|<0.8) over the transverse momentum range 0.15<pT<10 GeV/c. The correlation between transverse momentum and particle multiplicity is also studied. Results are presented for inelastic (INEL) and non-single-diffractive (NSD) events. The average transverse momentum for |η|<0.8 is 〈pT〉INEL=0.483±0.001 (stat.)±0.007 (syst.) GeV/c and 〈pT〉NSD=0.489±0.001 (stat.)±0.007 (syst.) GeV/c, respectively. The data exhibit a slightly larger 〈pT〉 than measurements in wider pseudorapidity intervals. The results are compared to simulations with the Monte Carlo event generators PYTHIA and PHOJET.
Background: The aim of this study was to evaluate post‐irradiation changes in the central nervous system (CNS) detected using magnetic resonance (MR) imaging.
Methods: Magnetic resonance images of 15 children with CNS tumors treated through whole‐brain irradiation over 10 years were reviewed retrospectively. Variables such as age at the time of irradiation, total radiation dose, treatment length, and time interval between irradiation and MR changes, were evaluated.
Results: All patients included in the study had imaging abnormalities of the CNS. Eight patients (53%) developed CNS abnormalities within a short period of time – only a few months after irradiation (mean 4.8 months). Seven patients (47%) developed CNS abnormalities within a long time interval after treatment (mean 4.6 years). In almost all patients, a T2 increase in supra‐ and infratentorial white matter was observed. Follow‐up examinations showed nine patients (60%) with cerebellar atrophy.
Conclusions: In this sample of pediatric patients who underwent whole‐brain irradiation, the time receiving irradiation was not related to the severity of the MR changes. A correlation between the age of the child or the length of the radiotherapy and the extent of the changes could not be confirmed. However, we observed a trend towards stronger brain parenchymal degeneration with cystic changes in the younger age group of children in our sample. Older children who received irradiation seem to be more susceptible to vascular dysplasia with cavernous hemangiomas and microbleeding.
Um weltweit die Wasser- und die Sanitärversorgung zu sichern, muss zeitnah in großem Umfang in neue Trinkwasser- bzw. Abwassersysteme investiert werden. Nicht nur die Länder des globalen Südens stehen im Wassersektor vor erheblichen Herausforderungen, auch die meisten Industrieländer haben Nachholbedarf und massive Investitionserfordernisse. Angesichts des globalen Investitionsbedarfes ist mit einem rasant wachsenden Markt für Wasser- und Abwassertechnologien zu rechnen, der auch der deutschen Industrie gute Absatzchancen bietet. Die vorhandenen Stärken der deutschen Wasserwirtschaft auszubauen und deren Innovationsfähigkeit zu fördern, ist daher eine zentrale politische und gesellschaftliche Aufgabe. Dafür muss die derzeitige Forschungs- und Entwicklungsförderung intensiviert und neu justiert werden, wobei auf sehr guten Vorarbeiten aufgebaut werden kann.
Die Nutzung der natürlichen Ressourcen ist zur Sicherung gesellschaftlichen Aktivitäten unverzichtbar, gleichwohl stehen ihrer nachhaltigen Bewirtschaftung immer neue Veränderungsprozesse und damit einhergehende Herausforderungen gegenüber. In Anbetracht von wirtschaftlichen Konzentrationsprozessen, sozio-strukturellen und demographischen Entwicklungen, technischen Innovationen, globalem Wandel und neuen Erkenntnissen zu Risiken stoßen etablierte klassische Verfahren des Planungsdenkens zunehmend an ihre Grenzen. Vor diesem Hintergrund wurden neue und innovative Ansätze zur Ressourcensicherung entwickelt, die vereinzelt auch bereits in der Praxis realisiert wurden. Sie greifen die Herausforderung gegenwärtiger Veränderungsprozesse konzeptionell auf und überführen sie in angepasste Strukturen und Verfahren. Die vorliegende Arbeit beschreibt diesen Übergang zu einem neuen, angepassten Planungsdenken. In seinem Mittelpunkt steht der Begriff der „sozial-ökologischen Ressourcenregulation“. Am Beispiel der Bewirtschaftung der Wasserressourcen werden aktuelle Entwicklungen vorgestellt und exemplarisch anhand von zwei Fallbeispielen vertieft: dem Fuhrberger Feld und dem Hessische Ried unter den spezifischen Gesichtspunkten von Wassergüte und Wassermenge. Die Entwicklungen in beiden Regionen werden zunächst anhand der Anforderungen an eine sozial-ökologische Regulation bewertet. In einem weiteren Schritt werden verallgemeinerte Schlussfolgerungen für eine verbesserte Ressourcenbewirtschaftung und deren Regulation sowohl hinsichtlich der Wassergüte als auch der Wassermenge gezogen. Es zeigt sich hierbei die große Bedeutung der Entstehung adaptiver Strukturen durch Rückkopplungen und den Einbezug der relevanten gesellschaftlichen Akteure; so ist langfristig auch eine Koexistenz von tendenziell konfligierenden Ressourcennutzungen und deren nachhaltige Entwicklung möglich.
Rain- and floodwater harvesting (RFWH) technologies and water reuse are ideal and generalpurpose technologies to improve water security and to contribute to climate adaptation – in particular for semi-arid regions. These technologies are part of a multi-resources mix within an integrated water resources management (IWRM). They create capacities to buffer water fluctuations and alleviate water scarcity. In this way, they reduce the pressure on existing resources, and can stimulate local economies. However, in order to be sustainable, these technologies need to be adapted to the local context – through suitable design, adapted operation requirements, and a back-up by training users and operators accordingly.
Wasserbedarfsprognosen sind für Wasserversorger eine wichtige Entscheidungsgrundlage für zukünftige Maßnahmen in der wirtschaftlichen und technischen Betriebsführung sowie beim Ressourcenmanagement. In den letzten zwei Jahrzehnten sanken in Deutschland die spezifischen Wasserbedarfe aufgrund von Technik- und Verhaltensinnovationen. Für Regionen mit Wirtschafts- und Bevölkerungswachstum ist aber das Zusammenspiel dieser für den zukünftigen Bedarf konträren Entwicklungen von besonderem Interesse. Auch die Metropolregion Hamburg ist von diesen Entwicklungen betroffen.
Im Auftrag des Wasserversorgers HAMBURG WASSER aktualisierte das ISOE (Forschungsschwerpunkt Wasserressourcen und Landnutzung) in Kooperation mit dem ifo Institut München seine mittel- und langfristige Wasserbedarfsprognose aus dem Jahr 2007 für das Versorgungsgebiet des Auftraggebers. In einem innovativen Konzept wurden dafür Forschungsmethoden aus Natur-, Wirtschafts-, Planungs- und Sozialwissenschaften kombiniert. Mit dem gewählten transdisziplinären Forschungsmodus war das Projekt darauf angelegt, im laufenden Forschungsprozess gemeinsam mit den wissenschaftlichen und außerwissenschaftlichen Projektpartnern das Prognosekonzept weiterzuentwickeln. Der vorliegende Studientext basiert auf dem Projektbericht an HAMBURG WASSER und fasst Prognosekonzept, Modellentwicklung, Prognoseergebnissen und Schlussfolgerungen zusammen.