4,384 research outputs found
Experience-related reductions of myelin and axon diameter in adulthood
The production of new myelin has been highlighted as an underappreciated mechanism of brain plasticity, but whether plastic decreases in myelin also happen in the adult brain has been largely unexplored. Recently, Sinclair et al. (Sinclair JS, Fischl MJ, Alexandrova O, Heß M, Grothe B, Leibold C, and Kopp-Scheinpflug C. J Neurosci 37: 8239–8255, 2017) have shown that auditory deprivation can lead to decrease in myelination and axon caliber even in healthy adulthood. These findings show that activity-regulated myelination is more complex than previously thought and expand our knowledge of how adult brain plasticity could operate on a cellular level
Observation of Scaling Violations in Scaled Momentum Distributions at HERA
Charged particle production has been measured in deep inelastic scattering
(DIS) events over a large range of and using the ZEUS detector. The
evolution of the scaled momentum, , with in the range 10 to 1280
, has been investigated in the current fragmentation region of the Breit
frame. The results show clear evidence, in a single experiment, for scaling
violations in scaled momenta as a function of .Comment: 21 pages including 4 figures, to be published in Physics Letters B.
Two references adde
Matrix Elements with Vetoes in the CASCADE Monte Carlo Event Generator
We illustrate a study based on a veto technique to match parton showers and
matrix elements in the Cascade Monte Carlo event generator, and present a
numerical application to gluon matrix elements for jet production.Comment: Published in DIS 2012 proceeding
Parton shower contributions to jets from high rapidities at the LHC
We discuss current issues associated with the dependence of jet distributions
at the LHC on the behavior of QCD parton showers for high rapidities.Comment: Contribution at DIS2012, Univ. of Bonn, March 201
Forward Physics at the LHC
The CMS/TOTEM and ATLAS collaborations carry out a program of forward physics
with several near-beam detectors extending their coverage to high
pseudorapidities. This instrumentation includes calorimeters (CASTOR and ZDC),
tracking devices (TOTEM T1 and T2), proton taggers (Roman Pots and FP420), and
instrumentation dedicated to luminosity monitoring and normalisation. A rich
physics program is accessible, including soft QCD interactions, Diffraction,
photon-induced physics and luminosity measurements.Comment: Proceedings of the XLIIIrd Rencontres de Moriond on QCD and High
Energy Interactions, La Thuile, March 200
Forward Proton Detectors at High Luminosity at the LHC
We discuss the special challenges posed by measuring diffractive and forward
physics at the LHC at high luminosity and the solutions proposed by the FP420
R&D collaboration.Comment: 5 pages, no pictures, contribution to the proceedings of ICHEP0
The architecture of amyloid-like peptide fibrils revealed by X-ray scattering, diffraction and electron microscopy
Structural analysis of protein fibrillation is inherently challenging. Given the crucial role of fibrils in amyloid diseases, method advancement is urgently needed. A hybrid modelling approach is presented enabling detailed analysis of a highly ordered and hierarchically organized fibril of the GNNQQNY peptide fragment of a yeast prion protein. Data from small-angle X-ray solution scattering, fibre diffraction and electron microscopy are combined with existing high-resolution X-ray crystallographic structures to investigate the fibrillation process and the hierarchical fibril structure of the peptide fragment. The elongation of these fibrils proceeds without the accumulation of any detectable amount of intermediate oligomeric species, as is otherwise reported for, for example, glucagon, insulin and [alpha]-synuclein. Ribbons constituted of linearly arranged protofilaments are formed. An additional hierarchical layer is generated via the pairing of ribbons during fibril maturation. Based on the complementary data, a quasi-atomic resolution model of the protofilament peptide arrangement is suggested. The peptide structure appears in a [beta]-sheet arrangement reminiscent of the [beta]-zipper structures evident from high-resolution crystal structures, with specific differences in the relative peptide orientation. The complexity of protein fibrillation and structure emphasizes the need to use multiple complementary methods
On the low x behaviour of nuclear shadowing
We calculate the x dependence of nuclear shadowing at moderate values of Q^2
by using HERA diffractive data and, for consistency, F2 parameterization of
ZEUS. We show that no decrease of shadowing occurs down to very low x (x =
10^-4).Comment: 9 pages, submitted on june for publicatio
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A model of emotional influence on memory processing.
To survive in a complex environment, agents must be able to encode information about the utility value of the objects they meet. We propose a neuroscience-based model aiming to explain how a new memory is associated to an emotional response. The same theoretical framework also explains the effects of emotion on memory recall. The originality of our approach is to postulate the presence of two central processing units (CPUs): one computing only emotional information, and the other mainly concerned with cognitive processing. The emotional CPU, which is phylogenetically older, is assumed to modulate the cognitive CPU, which is more recent. The article first deals with the cognitive part of the model by highlighting the set of processes underlying memory recognition and storage. Then, building on this theoretical background, the emotional part highlights how the emotional response is computed and stored. The last section describes the interplay between the cognitive and emotional systems
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