66 research outputs found
Performance of the CMS Regional Calorimeter Trigger
The CMS Regional Calorimeter Trigger (RCT) receives eight-bit energies and a data quality bit from the HCAL and ECAL Trigger Primitive Generators (TPGs). The RCT uses these trigger primitives to find e/Îł candidates and calculate regional calorimeter sums that are sent to the Global Calorimeter Trigger (GCT) for sorting and further processing. The RCT hardware consists of one clock distribution crate and 18 double-sided crates containing custom boards, ASICs, and backplanes. The RCT electronics have been completely installed since 2007. The RCT has been integrated into the CMS Level-1 Trigger chain. Regular runs, triggering on cosmic rays, prepare the CMS detector for the restart of the LHC. During this running, the RCT control is handled centrally by CMS Run Control and Monitor System communicating with the Trigger Supervisor. Online Data Quality Monitoring (DQM) evaluates the performance of the RCT during these runs. Offline DQM allows more detailed studies, including trigger efficiencies. These and other results from cosmicray data taking with the RCT will be presented
Unusual heavy-mass nearly ferromagnetic state with a surprisingly large Wilson ratio in the double layered ruthenates (SrCa)RuO
We report an unusual nearly ferromagnetic, heavy-mass state with a
surprisingly large Wilson ratio (e.g.,
700 for 0.2) in double layered ruthenates
(SrCa)RuO with 0.08 0.4. This state
does not evolve into a long-range ferromagnetically ordered state despite
considerably strong ferromagnetic correlations, but freezes into a
cluster-spin-glass at low temperatures. In addition, evidence of non-Fermi
liquid behavior is observed as the spin freezing temperature of the
cluster-spin-glass approaches zero near 0.1. We discuss the origin
of this unique magnetic state from the Fermi surface information probed by Hall
effect measurements.Comment: 4 pages, 4 figures; to be published in Physical Review B Rapid
Communication; solve the problem with Fig.
Tunable Emergent Heterostructures in a Prototypical Correlated Metal
At the interface between two distinct materials desirable properties, such as
superconductivity, can be greatly enhanced, or entirely new functionalities may
emerge. Similar to in artificially engineered heterostructures, clean
functional interfaces alternatively exist in electronically textured bulk
materials. Electronic textures emerge spontaneously due to competing
atomic-scale interactions, the control of which, would enable a top-down
approach for designing tunable intrinsic heterostructures. This is particularly
attractive for correlated electron materials, where spontaneous
heterostructures strongly affect the interplay between charge and spin degrees
of freedom. Here we report high-resolution neutron spectroscopy on the
prototypical strongly-correlated metal CeRhIn5, revealing competition between
magnetic frustration and easy-axis anisotropy -- a well-established mechanism
for generating spontaneous superstructures. Because the observed easy-axis
anisotropy is field-induced and anomalously large, it can be controlled
efficiently with small magnetic fields. The resulting field-controlled magnetic
superstructure is closely tied to the formation of superconducting and
electronic nematic textures in CeRhIn5, suggesting that in-situ tunable
heterostructures can be realized in correlated electron materials
Processing of Plasmodium falciparum Merozoite Surface Protein MSP1 activates a Spectrin-binding function enabling parasite egress from RBCs
The malaria parasite Plasmodium falciparum replicates within erythrocytes, producing progeny merozoites that are released from infected cells via a poorly understood process called egress. The most abundant merozoite surface protein, MSP1, is synthesized as a large precursor that undergoes proteolytic maturation by the parasite protease SUB1 just prior to egress. The function of MSP1 and its processing are unknown. Here we show that SUB1-mediated processing of MSP1 is important for parasite viability. Processing modifies the secondary structure of MSP1 and activates its capacity to bind spectrin, a molecular scaffold protein that is the major component of the host erythrocyte cytoskeleton. Parasites expressing an inefficiently processed MSP1 mutant show delayed egress, and merozoites lacking surface-bound MSP1 display a severe egress defect. Our results indicate that interactions between SUB1-processed merozoite surface MSP1 and the spectrin network of the erythrocyte cytoskeleton facilitate host erythrocyte rupture to enable parasite egress
From (pi, 0) magnetic order to superconductivity with (pi, pi) magnetic resonance in Fe1.02(Te1-xSex)
The iron chalcogenide Fe1+y(Te1-xSex) is structurally the simplest of the
Fe-based superconductors. Although the Fermi surface is similar to iron
pnictides, the parent compound Fe1+yTe exhibits antiferromagnetic order with
in-plane magnetic wave-vector (pi, 0). This contrasts the pnictide parent
compounds where the magnetic order has an in-plane magnetic wave-vector (pi,
pi) that connects hole and electron parts of the Fermi surface. Despite these
differences, both the pnictide and chalcogenide Fe-superconductors exhibit
superconducting spin resonances around (pi, pi), suggesting a common symmetry
for their superconducting order parameter. A central question in this
burgeoning field is therefore how (pi, pi) superconductivity can emerge from a
(pi, 0) magnetic instability. Here, we report that the magnetic soft mode
evolving from the (pi, 0)-type magnetic long-range order is associated with
weak charge carrier localization. Bulk superconductivity occurs only as the
magnetic mode at (pi, pi) becomes dominant upon doping. Our results suggest a
common magnetic origin for superconductivity in iron chalcogenide and pnictide
superconductors.Comment: 17 pages, 4 figure
Does Presentation Format Influence Visual Size Discrimination in Tufted Capuchin Monkeys (Sapajus spp.)?
Most experimental paradigms to study visual cognition in humans and non-human species are based on discrimination tasks involving the choice between two or more visual stimuli. To this end, different types of stimuli and procedures for stimuli presentation are used, which highlights the necessity to compare data obtained with different methods. The present study assessed whether, and to what extent, capuchin monkeys\u27 ability to solve a size discrimination problem is influenced by the type of procedure used to present the problem. Capuchins\u27 ability to generalise knowledge across different tasks was also evaluated. We trained eight adult tufted capuchin monkeys to select the larger of two stimuli of the same shape and different sizes by using pairs of food items (Experiment 1), computer images (Experiment 1) and objects (Experiment 2). Our results indicated that monkeys achieved the learning criterion faster with food stimuli compared to both images and objects. They also required consistently fewer trials with objects than with images. Moreover, female capuchins had higher levels of acquisition accuracy with food stimuli than with images. Finally, capuchins did not immediately transfer the solution of the problem acquired in one task condition to the other conditions. Overall, these findings suggest that - even in relatively simple visual discrimination problems where a single perceptual dimension (i.e., size) has to be judged - learning speed strongly depends on the mode of presentation
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