Time-frequency characterization of femtosecond extreme ultraviolet pulses

A measurement of chirp and pulse duration of fifth harmonic of a frequency-doubled Ti:sapphire laser was presented. The photoelectron signal due to cross correlation of harmonics generated by 400 nm blue light and an 800 nm infrared probe pulse, was measured using energy resolved cross-correlation method. Results demonstrated that the technique could be used to characterize the time-frequency behavior of much higher-order harmonics

Personality or role? Comparisons of Turkish leaders across different institutional positions

Personality approaches to politics are often criticized for not examining the effect that institutional role constraints have on individual beliefs and preferences. When leaders appear to change their stance when they change roles, it is assumed that roles have a determining influence. Modern personality theory and contemporary sociological role theory, however, view the effects of roles as interacting with agents’ personalities. In this article, we investigate this question by comparing personality profiles of three Turkish leaders (Özal, Demirel, and Gül) during their tenure as prime minister and during their subsequent time as president. For Gül, we perform an additional comparison during his time as foreign minister. The personality profiles are in the form of quantitative scores generated from machine-coded content analysis of leaders’ words using the Leadership Trait Analysis method. We hypothesize that different leaders will be more susceptible to changing role contexts, depending on core personality traits, and that different traits are more likely to change with new roles. Overall, our results suggest that leaders’ traits are fairly resistant to changes across roles and that task orientation is the most likely trait to change as leaders adapt to different role demands and expectations. This study makes a contribution to our understanding of the interaction between personality and political contexts by offering specific theoretically derived hypotheses and by empirically and statistically examining a preliminary set of expectations that could be applied more broadly to other leaders. © 2016 International Society of Political Psycholog

Control of high-order harmonic emission using attosecond pulse trains

We show that attosecond pulse trains are a natural tool to control strong field processes such as high-order harmonic generation. Coherently combining an attosecond pulse train with an IR driving field, we predict and experimentally confirm enhancement and spectral narrowing of the harmonic yield at photon energies around 90 eV. The use of an attosecond pulse train to seed the harmonic generation process replaces tunneling ionization with a single-photon ionization step, therefore permitting the manipulation of the time–frequency properties of high-order harmonic generation already at the single-atom level. © 2006 Taylor & Francis Group, LLC

Measurement and control of the frequency chirp rate of high-order harmonic pulses

The chirp rate of harmonics 13 to 23 in argon was measured by cross correlation with a 12 femtosecond probe pulse. The negative chirp was directly measured under low ionization conditions due to the atomic dipole phase. It was showed that the additional chirp on the pump pulse was transferred to the qth harmonic as q times the fundamental chirp. The attosecond pulse trains synthesized from these harmonics had a pulse spacing that increased linearly with time

Attitudes towards medication non-adherence in elderly kidney transplant patients: A Q methodology study

Background. Non-adherence to the post-transplant regime is a common problem in kidney transplant patients and may lead to rejection or even graft failure. This study investigated attitudes towards the post-transplant regime of immunosuppressive medication among the ever growing population of elderly kidney recipients.Methods. Q methodology was used to explore attitude profiles. Participants (> 65 years) were asked to rank-order opinion statements on issues associated with (non-)adherence. The rankings were subject to by-person factor analysis, and the resulting factors were interpreted and described as attitudes.Results. Twenty-six elderly renal transplant recipients participated in the study. All passed the Mini-Mental

Quantum modeling of semiconductor gain materials and vertical-external-cavity surface-emitting laser systems

This article gives an,overview of the microscopic theory,theory used to quantitatively model a wide range of semiconductor laser gain materials. As a snapshot of the current state of research, applications to a variety of actual quantum-well systems are presented. Detailed theory experiment comparisons are shown and it is analyze how the theory can be used to extract poorly known material parameters. The intrinsic laser loss processes due to radiative and nonradiative Auger recombination are evaluated microscopically. The results are used for realistic simulations of vertical-external-cavity surface-emitting laser systems. To account for nonequilibrium effects, a simplified model is presented using pre-computed microscopic scattering and dephasing rates. Prominent deviations from quasi-equilibrium carrier distributions are obtained under strong in-well pumping conditions

Objective and subjective measures of sleep among preschoolers: Disentangling attachment security and dependency

Many scholars have proposed that parent-child attachment security should favor child sleep. Research has yet, however, to provide convincing support for this hypothesis. The current study used objective measures of sleep and attachment to assess the longitudinal links between mother-child attachment security and subsequent sleep, controlling for child dependency. Sixty-two middle-class families (30 girls) were met twice, when children were 15 months (Wave 1; W1) and 2 years of age (Wave 2; W2). At W1, mother-child attachment was assessed with the observer version of the Attachment Q-Sort. At W2, children wore an actigraph monitor for 72 hours. Results indicated that children more securely attached to their mothers subsequently slept more at night and had higher sleep efficiency, and these predictions were not confounded by child dependency. These findings suggest a unique role for secure attachment relationships in the development of young children’s sleep regulation, while addressing methodological issues that have long precluded consensus in this literature

Remarks on Exact RG Equations

Exact RG equations are discussed with emphasis on the role of the anomalous dimension $\eta$. For the Polchinski equation this may be introduced as a free parameter reflecting the freedom of such equations up to contributions which vanish in the functional integral. The exact value of $\eta$ is only determined by the requirement that there should exist a well defined non trivial limit at a IR fixed point. The determination of $\eta$ is related to the existence of an exact marginal operator, for which an explicit form is given. The results are extended to the exact Wetterich RG equation for the one particle irreducible action $\Gamma$ by a Legendre transformation. An alternative derivation of the derivative expansion is described. An application to $\N=2$ supersymmetric theories in three dimensions is described where if an IR fixed point exists then $\eta$ is not small.Comment: version 2: minor correction