1,074 research outputs found
The role of the left head of caudate in suppressing irrelevant words
Suppressing irrelevant words is essential to successful speech production and is expected to involve general control mechanisms that reduce interference from task-unrelated processing. To investigate the neural mechanisms that suppress visual word interference, we used fMRI and a Stroop task, using a block design with an event-related analysis. Participants indicated with a finger press whether a visual stimulus was colored pink or blue. The stimulus was either the written word "BLUE," the written word "PINK," or a string of four Xs, with word interference introduced when the meaning of the word and its color were "incongruent" (e.g., BLUE in pink hue) relative to congruent (e.g., BLUE in blue) or neutral (e.g., XXXX in pink). The participants also made color decisions in the presence of spatial interference rather than word interference (i.e., the Simon task). By blocking incongruent, congruent, and neutral trials, we identified activation related to the mechanisms that suppress interference as that which was greater at the end relative to the start of incongruency. This highlighted the role of the left head of caudate in the control of word interference but not spatial interference. The response in the left head of caudate contrasted to bilateral inferior frontal activation that was greater at the start than at the end of incongruency, and to the dorsal anterior cingulate gyrus which responded to a change in the motor response. Our study therefore provides novel insights into the role of the left head of caudate in the mechanisms that suppress word interference
STAT1 activation in association with JAK2 exon 12 mutations
La inclusiĂłn de la perspectiva de gĂ©nero en la actividad jurisdiccional es una demanda sostenida de los colectivos feministas y de mujeres, dado que las sentencias tienen un poder performativo y envĂan un mensaje a la sociedad: â[âŠ] tienen un poder individual y colectivo que impactan en la vida de las personas y conforman la identidad del poder judicial como un actor imprescindible en la construcciĂłn de un Estado democrĂĄtico de derechoâ (Suprema Corte de Justicia de la NaciĂłn, 2013:7). La incorporaciĂłn de la perspectiva de gĂ©nero viene a garantizar la igualdad de posiciones (Kessler, 2014) entre mujeres y varones como una meta, trascendiendo la mera igualdad de oportunidades que hasta el presente se ha demostrado insuficiente para que las mujeres consigamos una ciudadanĂa plena. Al momento de incorporar la perspectiva de gĂ©nero en las sentencias, quienes juzgan deben tener presente en primer lugar, el impacto diferenciado de las normas en base al sexo de las personas. En segundo lugar, la interpretaciĂłn y aplicaciĂłn de las leyes en relaciĂłn con (y en base a) estereotipos de gĂ©nero. Si, por ejemplo, quienes imparten justicia no tienen presentes los estereotipos de gĂ©nero vigentes detrĂĄs de las violaciones a los derechos humanos de las mujeres, si no los detectan ni cuestionan, entonces los reproducen. Tal como sostiene Scott (1996) el gĂ©nero es una categorĂa imprescindible para el anĂĄlisis social. En tercer lugar, al momento del juzgamiento, se deben tener en cuenta las exclusiones legitimadas por la ley por pensar el mundo en tĂ©rminos binarios y androcĂ©ntricos; en cuarto lugar, la distribuciĂłn no equitativa de recursos y poder que opera entre varones y mujeres en el marco de una organizaciĂłn social patriarcal, y, por Ășltimo, el trato diferenciado por gĂ©nero legitimado por las propias leyes.Eje 3: Tramas violentas y espacios de exclusiĂłn.Instituto de Cultura JurĂdic
Entropy of Lovelock Black Holes
A general formula for the entropy of stationary black holes in Lovelock
gravity theories is obtained by integrating the first law of black hole
mechanics, which is derived by Hamiltonian methods. The entropy is not simply
one quarter of the surface area of the horizon, but also includes a sum of
intrinsic curvature invariants integrated over a cross section of the horizon.Comment: 15 pages, plain Latex, NSF-ITP-93-4
Near-Threshold eta Meson Production in Proton-Proton Collisions
The production of eta mesons has been measured in the proton-proton
interaction close to the reaction threshold using the COSY-11 internal facility
at the cooler synchrotron COSY. Total cross sections were determined for eight
different excess energies in the range from 0.5 MeV to 5.4 MeV. The energy
dependence of the total cross section is well described by the available
phase-space volume weighted by FSI factors for the proton-proton and proton-eta
pairs.Comment: 9 pages, 1 table, 5 figure
S-wave eta'-proton FSI; phenomenological analysis of near-threshold production of pi0, eta, and eta' mesons in proton-proton collisions
We describe a novel technique for comparing total cross sections for the
reactions pp --> pp pi(0), pp --> pp eta, and pp --> pp eta' close to
threshold. The initial and final state proton-proton interactions are factored
out of the total cross section, and the dependence of this reduced cross
section on the volume of phase space is discussed. Different models of the
proton-proton interaction are compared. We argue that the scattering length of
the S-wave eta'-proton interaction is of the order of 0.1 fm.Comment: 10 pages, 5 figure
CMOS Active Pixel Sensors as energy-range detectors for proton Computed Tomography
Since the first proof of concept in the early 70s, a number of technologies has been proposed to perform proton CT (pCT), as a means of mapping tissue stopping power for accurate treatment planning in proton therapy. Previous prototypes of energy-range detectors for pCT have been mainly based on the use of scintillator-based calorimeters, to measure proton residual energy after passing through the patient. However, such an approach is limited by the need for only a single proton passing through the energy-range detector in a read-out cycle. A novel approach to this problem could be the use of pixelated detectors, where the independent read-out of each pixel allows to measure simultaneously the residual energy of a number of protons in the same read-out cycle, facilitating a faster and more efficient pCT scan.
This paper investigates the suitability of CMOS Active Pixel Sensors (APSs) to track indi- vidual protons as they go through a number of CMOS layers, forming an energy-range telescope. Measurements performed at the iThemba Laboratories will be presented and analysed in terms of correlation, to confirm capability of proton tracking for CMOS APSs
A 15.7-minAMâCVn binary discovered in K2
We present the discovery of SDSSâJ135154.46â064309.0, a short-period variable observed using 30-mincadence photometry in K2 Campaign 6. Follow-up spectroscopy and high-speed photometry support a classification as a new member of the rare class of ultracompact accreting binaries known as AMâCVn stars. The spectroscopic orbital period of 15.65 ± 0.12âmin makes this system the fourth-shortest-period AMâCVn known, and the second system of this type to be discovered by the Kepler spacecraft. The K2 data show photometric periods at 15.7306 ± 0.0003âmin, 16.1121 ± 0.0004âmin, and 664.82 ± 0.06âmin, which we identify as the orbital period, superhump period, and disc precession period, respectively. From the superhump and orbital periods we estimate the binary mass ratio q = M2/M1= 0.111 ± 0.005, though this method of mass ratio determination may not be well calibrated for helium-dominated binaries. This system is likely to be a bright foreground source of gravitational waves in the frequency range detectable by Laser Interferometer Space Antenna, and may be of use as a calibration source if future studies are able to constrain the masses of its stellar components
A probabilistic model for gene content evolution with duplication, loss, and horizontal transfer
We introduce a Markov model for the evolution of a gene family along a
phylogeny. The model includes parameters for the rates of horizontal gene
transfer, gene duplication, and gene loss, in addition to branch lengths in the
phylogeny. The likelihood for the changes in the size of a gene family across
different organisms can be calculated in O(N+hM^2) time and O(N+M^2) space,
where N is the number of organisms, is the height of the phylogeny, and M
is the sum of family sizes. We apply the model to the evolution of gene content
in Preoteobacteria using the gene families in the COG (Clusters of Orthologous
Groups) database
Energy Dependence of the Near-Threshold Total Cross-Section for the pp --> pp eta' Reaction
Total cross sections for the pp --> pp eta' reaction have been measured in
the excess energy range from Q = 1.53 MeV to Q = 23.64 MeV. The experiment has
been performed at the internal installation COSY-11 using a stochastically
cooled proton beam of the COoler SYnchrotron COSY and a hydrogen cluster
target. The determined energy dependence of the total cross section weakens the
hypothesis of the S-wave repulsive interaction between the eta' meson and the
proton. New data agree well with predictions based on the phase-space
distribution modified by the proton-proton final-state-interaction (FSI) only.Comment: 12 pages, 1 table, 4 figure
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