440 research outputs found

    Differences in decision-making behavior between elite and amateur team-handball players in a near-game test situation

    Get PDF
    Athletic features distinguishing experts from non-experts in team sports are relevant for performance analyses, talent identification and successful training. In this respect, perceptual-cognitive factors like decision making have been proposed to be important predictor of talent but, however, assessing decision making in team sports remains a challenging endeavor. In particular, it is now known that decisions expressed by verbal reports or micro-movements in the laboratory differ from those actually made in on-field situations in play. To address this point, our study compared elite and amateur players' decision-making behavior in a near-game test environment including sport-specific sensorimotor responses. Team-handball players (N = 44) were asked to respond as quickly as possible to representative, temporally occluded attack sequences in a team-handball specific defense environment on a contact plate system. Specifically, participants had to choose and perform the most appropriate out of four prespecified, defense response actions. The frequency of responses and decision time were used as dependent variables representing decision-making behavior. We found that elite players responded significantly more often with offensive responses (p < 0.05, odds ratios: 2.76-3.00) in left-handed attack sequences. Decision time decreased with increasing visual information, but no expertise effect was found. We suppose that expertise-related knowledge and processing of kinematic information led to distinct decision-making behavior between elite and amateur players, evoked in a domain-specific and near-game test setting. Results also indicate that the quality of a decision might be of higher relevance than the required time to decide. Findings illustrate application opportunities in the context of performance analyses and talent identification processes

    Momentum-resolved charge excitations in high-Tc cuprates studied by resonant inelastic x-ray scattering

    Full text link
    We report a Cu K-edge resonant inelastic x-ray scattering (RIXS) study of high-Tc cuprates. Momentum-resolved charge excitations in the CuO2 plane are examined from parent Mott insulators to carrier-doped superconductors. The Mott gap excitation in undoped insulators is found to commonly show a larger dispersion along the [pi,pi] direction than the [pi,0] direction. On the other hand, the resonance condition displays material dependence. Upon hole doping, the dispersion of the Mott gap excitation becomes weaker and an intraband excitation appears as a continuum intensity below the gap at the same time. In the case of electron doping, the Mott gap excitation is prominent at the zone center and a dispersive intraband excitation is observed at finite momentum transfer

    Risk-cost optimization of buried pipelines using subset simulation

    Get PDF
    On the basis of time-dependent reliability analysis, a computational framework called subset simulation (SS) has been applied for risk-cost optimization of flexible underground pipeline networks. SS can provide better resolution for rare failure events that are commonly encountered in pipeline engineering applications. Attention in this work is devoted to scrutinize the robustness of SS in risk-cost optimization of pipelines. SS is first employed to estimate the reliability of flexible underground pipes subjected to externally applied loading and material corrosion. Then SS is extended to determine the intervention year for maintenance and to identify the most appropriate renewal solution and renewal priority by minimizing the risk of failure and whole life-cycle cost. The efficiency of SS compared to genetic algorithm has been demonstrated by numerical studies with a view to prevent unexpected failure of flexible pipes at minimal cost by prioritizing maintenance based on failure severity and system reliability. This paper shows that SS is a more robust method in the decision-making process of reliability-based management for underground pipeline networks

    Inhibition of DNA replication fork progression and mutagenic potential of 1, N6-ethenoadenine and 8-oxoguanine in human cell extracts

    Get PDF
    Comparative mutagenesis of 1,N6-ethenoadenine (εA) and 8-oxoguanine (8-oxoG), two endogenous DNA lesions that are also formed by exogenous DNA damaging agents, have been evaluated in HeLa and xeroderma pigmentosum variant (XPV) cell extracts. Two-dimensional gel electrophoresis of the duplex M13mp2SV vector containing these lesions established that there was significant inhibition of replication fork movement past εA, whereas 8-oxoG caused only minor stalling of fork progression. In extracts of HeLa cells, εA was weakly mutagenic inducing all three base substitutions in approximately equal frequency, whereas 8-oxoG was 10-fold more mutagenic inducing primarily G→T transversions. These data suggest that 8-oxoG is a miscoding lesion that presents a minimal, if any, block to DNA replication in human cells. We hypothesized that bypass of εA proceeded principally by an error-free mechanism in which the undamaged strand was used as a template, since this lesion strongly blocked fork progression. To examine this, we determined the sequence of replication products derived from templates in which a G was placed across from the εA. Consistent with our hypothesis, 93% of the progeny were derived from replication of the undamaged strand. When translesion synthesis occurred, εA→T mutations increased 3-fold in products derived from the mismatched εA: G construct compared with those derived from the εA: T construct. More efficient repair of εA in the εA: T construct may have been responsible for lower mutation frequency. Primer extension studies with purified pol η have shown that this polymerase is highly error-prone when bypassing εA. To examine if pol η is the primary mutagenic translesion polymerase in human cells, we determined the lesion bypass characteristics of extracts derived from XPV cells, which lack this polymerase. The εA: T construct induced εA→G and εA→C mutant frequencies that were approximately the same as those observed using the HeLa extracts. However, εA→T events were increased 5-fold relative to HeLa extracts. These data support a model in which pol η-mediated translesion synthesis past this adduct is error-free in the context of semiconservative replication in the presence of fidelity factors such as PCNA

    Coping with an Advanced Stage Lung Cancer Diagnosis: Patient, Caregiver, and Provider Perspectives on the Role of the Health Care System

    Get PDF
    Although lung cancer is the leading cause of cancer death in the USA, there have been few studies on patient-centered advanced lung cancer treatment practices. As part of a larger research study on how to use a patient-inclusive approach in late-stage lung cancer treatment, this present study describes patient, caregiver, and provider perspectives on the role of the health care system in helping patients cope with an advanced stage lung cancer diagnosis. Four focus group sessions were conducted with six to eleven participants per group for a total of 36 participants. Two focus groups were held with patients and family members/caregivers and two with physicians and nurses. A major theme that emerged concerned coping with an advanced lung cancer diagnosis, which is the subject of this paper. The patients, caregivers, and providers spoke passionately about interactions with the health care system and volunteered examples of supportive and non-supportive relationships between patients and clinicians. They advocated for better patient-provider communication practices as well as the expanded use of patient navigation and new patient orientation programs. This study contributes additional knowledge by including the perspectives of caregivers and providers who live and work closely with patients with advanced lung cancer. The findings can inform the development of comprehensive patient-centered care plans for patients living with an advanced lung cancer diagnosis

    A combined XAS and XRD Study of the High-Pressure Behaviour of GaAsO4 Berlinite

    Full text link
    Combined X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) experiments have been carried out on GaAsO4 (berlinite structure) at high pressure and room temperature. XAS measurements indicate four-fold to six-fold coordination changes for both cations. The two local coordination transformations occur at different rates but appear to be coupled. A reversible transition to a high pressure crystalline form occurs around 8 GPa. At a pressure of about 12 GPa, the system mainly consists of octahedral gallium atoms and a mixture of arsenic in four-fold and six-fold coordinations. A second transition to a highly disordered material with both cations in six-fold coordination occurs at higher pressures and is irreversible.Comment: 8 pages, 5 figures, LaTeX2

    Control of magnetic anisotropy by orbital hybridization in (La0.67Sr0.33MnO3)n/(SrTiO3)n superlattice

    Full text link
    The asymmetry of chemical nature at the hetero-structural interface offers an unique opportunity to design desirable electronic structure by controlling charge transfer and orbital hybridization across the interface. However, the control of hetero-interface remains a daunting task. Here, we report the modulation of interfacial coupling of (La0.67Sr0.33MnO3)n/(SrTiO3)n superlattices by manipulating the periodic thickness with n unit cells of SrTiO3 and n unit cells La0.67Sr0.33MnO3. The easy axis of magnetic anisotropy rotates from in-plane (n = 10) to out-of-plane (n = 2) orientation at 150 K. Transmission electron microscopy reveals enlarged tetragonal ratio > 1 with breaking of volume conservation around the (La0.67Sr0.33MnO3)n/(SrTiO3)n interface, and electronic charge transfer from Mn to Ti 3d orbitals across the interface. Orbital hybridization accompanying the charge transfer results in preferred occupancy of 3d3z2-r2 orbital at the interface, which induces a stronger electronic hopping integral along the out-of-plane direction and corresponding out-of-plane magnetic easy axis for n = 2. We demonstrate that interfacial orbital hybridization in superlattices of strongly correlated oxides may be a promising approach to tailor electronic and magnetic properties in device applications

    On the stability of 2 \sqrt{2} x 2 \sqrt{2} oxygen ordered superstructures in YBa2Cu3O6+x

    Full text link
    We have compared the ground-state energy of several observed or proposed " 2 \sqrt{2} x 2 \sqrt{2} oxygen (O) ordered superstructures " (from now on HS), with those of "chain superstructures" (CS) (in which the O atoms of the basal plane are ordered in chains), for different compositions x in YBa2Cu3O6+x. The model Hamiltonian contains i) the Madelung energy, ii) a term linear in the difference between Cu and O hole occupancies which controls charge transfer, and iii) covalency effects based on known results for tJt-J models in one and two dimensions. The optimum distribution of charge is determined minimizing the total energy, and depends on two parameters which are determined from known results for x=1 and x=0.5. We obtain that on the O lean side, only CS are stable, while for x=7/8, a HS with regularly spaced O vacancies added to the x=1 structure is more stable than the corresponding CS for the same x. We find that the detailed positions of the atoms in the structure, and long-range Coulomb interactions, are crucial for the electronic structure, the mechanism of charge transfer, the stability of the different phases, and the possibility of phase separation.Comment: 24 text pages, Latex, one fig. included as ps file, to be publisheb in Phys. Rev.
    corecore