161 research outputs found
ALICE pp physics programme
The physics programme of the ALICE experiment at CERN-LHC comprises besides
studies of high-energy heavy-ion collisions measurements of proton-proton
interactions at unprecedented energies, too. This paper focuses on the global
event characterisation in terms of the multiplicity distribution of charged
hadrons and mean transverse momentum. These bulk observables become accessible
because the detector features excellent track reconstruction, especially at low
transverse momenta. The measurement of strange hadrons is of particular
interest since the strange-particle phase-space was found to be suppressed
beyond canonical reduction at lower center-of-mass energies and the production
mechanism of soft particles is not yet fully understood. Here we benefit in
particular from particle identification down to very low transverse momentum,
i.e. 100 - 300 MeV/c, giving access to spectra and integrated yields of
identified hadrons.
Equipped with these features, ALICE will play a complementary role w.r.t.
other LHC experiments. New interest in the soft part of pp collisions arose
recently and new insights in the physics of the underlying event are expected
from both, theory and experiment.Comment: 7 pages, 5 figures, proceedings of XLVII International Winter Meeting
on Nuclear Physics, Bormio (Italy
Ecological Importance of Alkaline Phosphatase Activity in Changing Marine Environmental Conditions
The effects of changing hydrological and climatic conditions on the dynamics of phosphorus (P) were studied in the Northern Adriatic Sea (NA), a coastal system currently affected by these changes. P limitation is one of the key stresses in the NA and it is a globally important phenomenon in aquatic ecosystems. Therefore, the response to P stress by inducing alkaline phosphatase activity (APA) was studied in characteristic water types in the NA, formed by the changing freshwater input in different thermic conditions. APA was important in providing P for microbial growth in upper waters dominated by assimilation during the warmer part of the year in stratified conditions. Contrarily, APA was not important during mixing in the colder part of the year, as well as in waters dominated by regeneration. In waters influenced by freshwater, temperature had no effect on APA, while in high-salinity waters, temperature was an important factor for APA increase. The highest APA occurred during riverine nutrients supply, indicating that the alteration of anthropogenic nutrient loads might strongly change P status in this coastal system. Furthermore, predicted increases in winter sea temperature and summer Po River discharge could delay the water column mixing, prolonging periods of P limitation
Task-based functional connectivity reveals aberrance with the salience network during emotional interference in late-life depression
Objectives
Late-life depression (LLD) is a common and debilitating disorder. Previously, resting-state studies have revealed abnormal functional connectivity (FC) of brain networks in LLD. Since LLD is associated with emotional-cognitive control deficits, the aim of this study was to compare FC of large-scale brain networks in older adults with and without a history of LLD during a cognitive control task with emotional stimuli.
Methods
Cross-sectional case-control study. Twenty participants diagnosed with LLD and 37 never-depressed adults 60–88 years of age underwent functional magnetic resonance imaging during an emotional Stroop task. Network-region-to-region FC was assessed with seed regions in the default mode, the frontoparietal, the dorsal attention, and the salience networks.
Results
FC between salience and sensorimotor network regions and between salience and dorsal attention network regions were reduced in LLD patients compared to controls during the processing of incongruent emotional stimuli. The normally positive FC between these networks were negative in LLD patients and inversely correlated with vascular risk and white matter hyperintensities.
Conclusions
Emotional-cognitive control in LLD is associated with aberrant functional coupling between salience and other networks. This expands on the network-based LLD model and proposes the salience network as a target for future interventions.publishedVersio
System size and centrality dependence of the balance function in A+A collisions at sqrt[sNN]=17.2 GeV
Electric charge correlations were studied for p+p, C+C, Si+Si, and centrality selected Pb+Pb collisions at sqrt[sNN]=17.2 GeV with the NA49 large acceptance detector at the CERN SPS. In particular, long-range pseudorapidity correlations of oppositely charged particles were measured using the balance function method. The width of the balance function decreases with increasing system size and centrality of the reactions. This decrease could be related to an increasing delay of hadronization in central Pb+Pb collisions
System size and centrality dependence of the balance function in A + A collisions at sqrt s NN = 17.2 GeV
Electric charge correlations were studied for p+p, C+C, Si+Si and centrality selected Pb+Pb collisions at sqrt s_NN = 17.2$ GeV with the NA49 large acceptance detector at the CERN-SPS. In particular, long range pseudo-rapidity correlations of oppositely charged particles were measured using the Balance Function method. The width of the Balance Function decreases with increasing system size and centrality of the reactions. This decrease could be related to an increasing delay of hadronization in central Pb+Pb collisions
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