Box traps on an atom chip for one-dimensional quantum gases

We present the implementation of tailored trapping potentials for ultracold gases on an atom chip. We realize highly elongated traps with box-like confinement along the long, axial direction combined with conventional harmonic confinement along the two radial directions. The design, fabrication and characterization of the atom chip and the box traps is described. We load ultracold ($\lesssim1 \mu$K) clouds of $^{87}$Rb in a box trap, and demonstrate Bose-gas focusing as a means to characterize these atomic clouds in arbitrarily shaped potentials. Our results show that box-like axial potentials on atom chips are very promising for studies of one-dimensional quantum gases.Comment: 9 pages 4 figure

Yang-Yang thermodynamics on an atom chip

We investigate the behavior of a weakly interacting nearly one-dimensional (1D) trapped Bose gas at finite temperature. We perform in situ measurements of spatial density profiles and show that they are very well described by a model based on exact solutions obtained using the Yang-Yang thermodynamic formalism, in a regime where other, approximate theoretical approaches fail. We use Bose-gas focusing [Shvarchuck etal., Phys. Rev. Lett. 89, 270404 (2002)] to probe the axial momentum distribution of the gas, and find good agreement with the in situ results.Comment: extended introduction and conclusions, and minor changes throughout; accepted for publication in Phys. Rev. Let

Low-loss, low-confinement GaAs-AlGaAs DQW laser diode with optical trap layer for high-power operation

A low-confinement asymmetric GaAs-AlGaAs double-quantum-well molecular-beam-epitaxy grown laser diode structure with optical trap layer is characterized, The value of the internal absorption coefficient is as low as 1.4 cm-1, while keeping the series resistance at values comparable cm with symmetrical quantum-well gradient index structures in the same material system. Uncoated devices show COD values of 35 mW/µm. If coated, this should scale to about 90 mW/µm. The threshold current density is about 1000 A/cm2 for 2-mm-long devices and a considerable part of it is probably due to recombination in the optical trap layer. Fundamental mode operation is limited to 120-180 mW for 6.5-µm-wide ridge waveguide uncoated devices and to 200-300 mW for 13.5-µm-wide ones, because of thermal waveguiding effects. These values are measured under pulsed conditions, 10 µs/l m

The political dimension: added value for cross-cultural analysis:Nozawa and Smits, two CEO's and their public statements

Work-related cultural differences, which were familiarized by scholars such as Hall and Hofstede, offer important concepts to help us understand various forms of cooperation and communication. However, the predominant focus of cultural analysis on collectivistic harmony prevents us from gaining an understanding of strategy and conflict. In an attempt to grasp how conflicts are handled, a political analysis can provide new insights. This is illustrated by a comparative study of two CEOs who gave public statements concerning management failure: Shouhei Nozawa of Yamaichi and Paul Smits of KPN. Their statements were strikingly different in several ways, but the classical insights of cross-cultural analysis can only partly explain the differences. This is where political analysis comes in, focusing on interest relationships, responsibilities and virtues, tactics and strategy

Dimeric and polymeric IgA, but not monomeric IgA, enhance the production of IL-6 by human renal mesangial cells

Depositions of IgA in the renal glomerular mesangial area are a hallmark of IgA nephropathy, and are thought to be crucial for the onset of inflammation processes in IgA nephropathy. In this report we show that human mesangial cells (MC) in vitro bind IgA and that binding of IgA enhances the production of IL-6 by MC. Furthermore we show that the size of IgA is crucial in its capability to enhance IL-6 production. Monomeric IgA does not affect basic IL-6 production, whereas dimeric and polymeric IgA enhance IL-6 production up to 3- to 9-fold respectively. Additional studies demonstrate that enhanced IL-6 production by MC is not accompanied by increased proliferation of human mesangial cells, a finding which is distinct from that found with rat mesangial cells. Taken together, these fmdings suggest that deposition of dimeric and polymeric IgA in the mesangial area of human kidneys in IgA nephropathy may amplify local inflammation

Professional follow-up communication as an indicator of public value: Analyzing Dutch PSM’s Role in Public Debates Through Topic Modelling Newspaper Coverage

The legitimacy of public broadcasting has been under pressure for several decades. Attempts to repair and restore this legitimacy have led to an intensification of accountability instruments and measures. These instruments and measures tend to focus on consumption figures or cost-benefit analyses, requiring new ways of capturing public value. This article argues that, given the media’s persistent role as an interpreter and multiplier of news via traditional distribution channels and diverse new platforms providing information and opinions, professional follow-up communication is a relevant source for the examination of broadcasters’ contributions to public debate. The essay explores how the analysis of newspapers via computational methods can be used by public broadcasters to reflect on and demonstrate their role in public debates in contributing a diversity of topics and viewpoints

Public Broadcasting and Topic Diversity in The Netherlands: Mentions of Public Broadcasters’ Programming in Newspapers as Indicators of Pluralism

Following debates on media pluralism and decentralised public service media, this article discusses the contribution of Dutch public broadcasters to pluralism. While the Dutch system operates under the assumption that external pluralism of broadcasting associations contributes to diversity, here we empirically explored this relation with respect to topics within societal discourse. We argue that mentions of public broadcasters’ programming in newspapers can function as indicators of diversity. As such, we traced mentions of all television and radio programmes by eleven Dutch public broadcast associations in a collection of 263,476 Dutch newspaper articles published during the 2017–2018 TV and radio season. Employing Latent Dirichlet Allocation topic modelling, we thematically contextualised those mentions, which then allowed us to map the breadth of topics associated with programming by different public broadcast associations as well as the extent to which individual public broadcasting associations play a distinct role within a characteristic set of topics. The results of our exploratory analyses support the idea that the external pluralism of the Dutch system produces diversity in alignment with the intentions of the distributed system