Search results for "Polarization"

On the Determinants of Distribution Dynamics

2013

n this paper we propose a novel approach to identify the impact of growth determinants on the distribution dynamics of productivit y. Our approach integrates counterfactual analysis with the estima tion of stochastic kernels. The counterfactuals are constructed from a semi-parametric growth regression, in which the cross-section heterogeneity in the growth determinants is removed. The methodology also allows us to test for potential distributional effects in the residuals. We illustrate the usefulness of the proposed methodology by an application to a cross-section of countries, which highlights the significant impact on inequality and polarization in the world productivity distribution of …

Radio polarization maps of shell-type SNRs II. Sedov models with evolution of turbulent magnetic field

2017

Polarized radio emission has been mapped with great detail in several Galactic supernova remnants (SNRs), but has not yet been exploited to the extent it deserves. We have developed a method to model maps of the Stokes parameters for shell-like SNRs during their Sedov evolution phase. At first, 3-dimensional structure of a SNR has been computed, by modeling the distribution of the magnetohydrodynamic parameters and of the accelerated particles. The generation and dissipation of the turbulent component of magnetic field everywhere in SNR are also considered taking into account its interaction with accelerated particles. Then, in order to model the emission, we have used a generalization of t…

Flip angle considerations in (3)helium-MRI.

2000

3Helium-MRI ((3)He-MRI) can be used for analysis of lung function, e. g. dynamic imaging of ventilation and gas diffusion within the lung, assessment of intrapulmonary oxygen concentrations and their time course. During imaging, the irreversible signal loss due to depolarizing radio frequency excitations can be described using the flip angle (FA) alpha. This parameter has to be quantified in order to account for it during quantitative assessment of the (3)helium signal intensity and its temporal development. This technical report reviews two different methods to determine alpha. Limitations and possible error sources of each method are discussed.

Probing the radio emission from air showers with polarization measurements

2014

The emission of radio waves from air showers has been attributed to the so-called geomagnetic emission process. At frequencies around 50 MHz this process leads to coherent radiation which can be observed with rather simple setups. The direction of the electric field induced by this emission process depends only on the local magnetic field vector and on the incoming direction of the air shower. We report on measurements of the electric field vector where, in addition to this geomagnetic component, another component has been observed which cannot be described by the geomagnetic emission process. The data provide strong evidence that the other electric field component is polarized radially wit…

Polarization Insensitive Wavelength Conversion in a Low-Birefringence SiGe Waveguide

2016

We report the first demonstration of a single-pass dual-orthogonal-pump four-wave mixing-based wavelength conversion scheme in a silicon-based waveguide. The silicon germanium waveguide used was designed to exhibit strong TE/TM mode similarity across a broad wavelength range as well as a large nonlinear coefficient. A polarization-dependent loss of just 0.42 dB was measured, and the conversion of 40-Gb/s differential phase-shift keying signals was demonstrated with 1.5-dB power penalty at a bit error ratio of $10^{-9}$ .

PSA-based phase regeneration of DPSK signals in a silicon germanium waveguide

2015

We demonstrate a polarization-assisted PSA-based phase regenerator in a passive low-birefringence SiGe waveguide at low CW pump power. A PSER of 28.6-dB enables a six-fold reduction in phase-error and BER improvement of approximately 2-dB in the regenerated signal.

Polarization is first and foremost a categorical phenomenon: a comment on Kiers

2002

Hate Speech as an Indicator for the State of the Society

2022

Abstract. Previous research indicates that user comments serve as exemplars and thus have an effect on perceived public opinion. Moreover, they also shape the attitudes of their readers. However, studies almost exclusively focus on controversial issues if they explore the consequences of user comments for attitudes and perceived public opinion. The current study wants to find out if hate speech attacking social groups due to characteristics such as religion or sexual orientation also has an effect on the way people think about these groups and how they think society perceives them. Moreover, we also investigated the effects of hate speech on prejudiced attitudes. To explore the hypotheses a…

Spanish Adaptation of the Left-Wing Authoritarianism Index

2021

Notwithstanding long-simmering controversies around the construct, several studies have gathered consistent evidence of authoritarian attitudes among left-wing voters and activists. Recently, Costello et al. (Clarifying the structure and nature of left-wing authoritarianism. Journal of Personality and Social Psychology, 2021) validated, in the English-speaking context, a three-factor scale to measure left-wing authoritarianism, as well as two shortened versions of the same scale (Costello & Patrick, Development and initial validation of two brief measures of left-wing authoritarianism: A machine learning approach, 2021; composed of 39, 25 and 13 items, respectively). In this article, we use…

Kinetic Properties of Cl−Uptake Mediated by Na+-Dependent K+-2Cl−Cotransport in Immature Rat Neocortical Neurons

2007

GABA, the main inhibitory neurotransmitter in the adult nervous system, evokes depolarizing membrane responses in immature neurons, which are crucial for the generation of early network activity. Although it is well accepted that depolarizing GABA actions are caused by an elevated intracellular Cl−concentration ([Cl−]i), the mechanisms of Cl−accumulation in immature neurons are still a matter of debate. Using patch-clamp, microfluorimetric, immunohistochemical, and molecular biological approaches, we studied the mechanism of Cl−uptake in Cajal-Retzius (CR) cells of immature [postnatal day 0 (P0) to P3] rat neocortex. Gramicidin-perforated patch-clamp and 6-methoxy-N-ethylquinolinium-microfl…