Towards a data-driven analysis of hadronic light-by-light scattering

The hadronic light-by-light contribution to the anomalous magnetic moment of the muon was recently analyzed in the framework of dispersion theory, providing a systematic formalism where all input quantities are expressed in terms of on-shell form factors and scattering amplitudes that are in principle accessible in experiment. We briefly review the main ideas behind this framework and discuss the various experimental ingredients needed for the evaluation of one- and two-pion intermediate states. In particular, we identify processes that in the absence of data for doubly-virtual pion–photon interactions can help constrain parameters in the dispersive reconstruction of the relevant input quantities, the pion transition form factor and the helicity partial waves for γ⁎γ⁎→ππ.

Probing the moduli dependence of refined topological amplitudes

With the aim of providing a worldsheet description of the refined topological string, we continue the study of a particular class of higher derivative couplings Fg,n in the type II string effective action compactified on a Calabi–Yau threefold. We analyse first order differential equations in the anti-holomorphic moduli of the theory, which relate the Fg,n to other component couplings. From the point of view of the topological theory, these equations describe the contribution of non-physical states to twisted correlation functions and encode an obstruction for interpreting the Fg,n as the free energy of the refined topological string theory. We investigate possibilities of lifting this obstruction by formulating conditions on the moduli dependence under which the differential equations simplify and take the form of generalised holomorphic anomaly equations. We further test this approach against explicit calculations in the dual heterotic theory.

Motion-insensitive determination of B1+ amplitudes based on the bloch-siegert shift in single voxels of moving organs including the human heart.

PURPOSE To reliably determine the amplitude of the transmit radiofrequency ( B1+) field in moving organs like the liver and heart, where most current techniques are usually not feasible. METHODS B1+ field measurement based on the Bloch-Siegert shift induced by a pair of Fermi pulses in a double-triggered modified Point RESolved Spectroscopy (PRESS) sequence with motion-compensated crusher gradients has been developed. Performance of the sequence was tested in moving phantoms and in muscle, liver, and heart of six healthy volunteers each, using different arrangements of transmit/receive coils. RESULTS B1+ determination in a moving phantom was almost independent of type and amplitude of the motion and agreed well with theory. In vivo, repeated measurements led to very small coefficients of variance (CV) if the amplitude of the Fermi pulse was chosen above an appropriate level (CV in muscle 0.6%, liver 1.6%, heart 2.3% with moderate amplitude of the Fermi pulses and 1.2% with stronger Fermi pulses). CONCLUSION The proposed sequence shows a very robust determination of B1+ in a single voxel even under challenging conditions (transmission with a surface coil or measurements in the heart without breath-hold). Magn Reson Med, 2015. © 2015 Wiley Periodicals, Inc.

Types and amplitudes of touch as reinforcing stimuli in operant conditioning of infant behavior

The reinforcing effects of diverse tactile stimuli were examined in this study. The study had two purposes. First, this study expanded on the Pelaez-Nogueras, Field, Gewirtz, Cigales, Gonzalez, Sanchez and Clasky (1997) finding that stroking increases infants' gaze duration, and smiling and vocalization frequencies more than tickling/poking. Instead of presenting poking and tickling as a single stimulus combination, this study separated poking and tickling in order to measure the effects of each component separately. Further, the effects of poking, tickling/tapping and stroking intensity (i.e., tactile pressure) were compared by having both mild and intense conditions. Second, this study compared the reinforcing efficacy of mother-delivered tactile stimulation to that of infant-originated tactile exploration. Twelve infants from 2- to 5-months of age participated in this study. The experiment was conducted using a repeated measures A-B-A-C-A-D reversal design. The A phases signified baselines and reversals. The B, C, and D phases consisted of alternating treatments (either mild stroking vs. mild poking vs. mild tickling/tapping, intense stroking vs. intense poking vs. intense tickling/tapping, or mother-delivered tactile stimulation vs. infant-originated tactile exploration). Three experimental hypotheses were assessed: (1) infant leg kick rate would be greater when it produced stroking or tickling/tapping (presumptive positive reinforcers), than when it produced poking (a possible punisher), regardless of tactile pressure; (2) infant leg kick rate would be greater when it produced a more intense level of stroking or tickling/tapping and lower when it produced intense poking compared to mild poking; (3) infant leg-kick rate would be greater for mother-delivered tactile stimulation than for infant-originated tactile exploration. Visual inspection and inferential statistical methods were used to analyze the results. The data supported the first two hypotheses. Mixed support emerged for the third hypothesis. This study made several important contributions to the field of psychology. First, this was the first study to quantify the pressure of tactile stimulation, via a pressure meter developed by the researcher. Additionally, the results of this study yielded valuable information about the effects of different modalities of touch. ^

Toward controlled growth of helicity-specific carbon nanotubes

The underlying mechanisms for the nucleation of carbon nanotubes as well as their helicity, remain elusive. Here, using van der Waals dispersion force calculations implemented within density functional theory, we study the cap formation, believed to be responsible for the chirality of surface-catalyzed carbon nanotubes. We find the energetics associated with growth along different facets to be independent of the surface orientation and that the growth across an edge along the axis of the metal particle leads to a perfect honeycomb lattice in a curved geometry. The formation of defects in the graphene matrix, which bend the carbon plane, requires that two or more graphene embryos with significantly different growth axis merge. Such scenario is only possible at the front- or back-end of the metal particle where growth symmetry is broken. The graphene embryos reconstruct their hexagonal structure into pentagons, heptagons, and octagons counterpart to accommodate the tube curvature.

Kinesiographic Study Of Masticatory Movements In Denture Wearers With Normal And Resorbed Denture-bearing Areas.

An unfavorable denture-bearing area could compromise denture retention and stability, limit mastication, and possibly alter masticatory motion. The purpose of this study was to evaluate the masticatory movements of denture wearers with normal and resorbed denture-bearing areas. Completely edentulous participants who received new complete dentures were selected and divided into 2 groups (n=15) according to the condition of their denture-bearing areas as classified by the Kapur method: a normal group (control) (mean age, 65.9 ± 7.8 years) and a resorbed group (mean age, 70.2 ± 7.6 years). Masticatory motion was recorded and analyzed with a kinesiographic device. The patients masticated peanuts and Optocal. The masticatory movements evaluated were the durations of opening, closing, and occlusion; duration of the masticatory cycle; maximum velocities and angles of opening and closing; total masticatory area; and amplitudes of the masticatory cycle. The data were analyzed by 2-way ANOVA and the Tukey honestly significant difference post hoc test (α=.05). The group with a resorbed denture-bearing area had a smaller total masticatory area in the frontal plane and shorter horizontal masticatory amplitude than the group with normal denture-bearing area (P<.05). Denture wearers with resorbed denture-bearing areas showed reduced jaw motion during mastication.

Analise cinematica da movimentação dos membros superiores e inferiores, tronco e cabeça durante a marcha de hemipareticos

Universidade Estadual de Campinas . Faculdade de Educação Física

As adaptações das curvaturas da coluna vertebral as atividades fisicas praticadas

Universidade Estadual de Campinas. Faculdade de Educação Física

Adaptações das curvas da coluna vertebral na marcha em função da altura dos saltos dos calçados

Universidade Estadual de Campinas. Faculdade de Educação Física

Análise do desempenho muscular do quadríceps e dos isquiotibiais em função da série temporal e da amplitude de movimento de atletas amadoras de futsal feminino = : Analysis of muscle performance of the quadriceps and hamstrings as a function of the times series and range of motion of amateurfemale futsal athletes

Universidade Estadual de Campinas . Faculdade de Educação Física