Calibration Challenges for Future Radio Telescopes

Instruments for radio astronomical observations have come a long way. While the first telescopes were based on very large dishes and 2-antenna interferometers, current instruments consist of dozens of steerable dishes, whereas future instruments will be even larger distributed sensor arrays with a hierarchy of phased array elements. For such arrays to provide meaningful output (images), accurate calibration is of critical importance. Calibration must solve for the unknown antenna gains and phases, as well as the unknown atmospheric and ionospheric disturbances. Future telescopes will have a large number of elements and a large field of view. In this case the parameters are strongly direction dependent, resulting in a large number of unknown parameters even if appropriately constrained physical or phenomenological descriptions are used. This makes calibration a daunting parameter estimation task, that is reviewed from a signal processing perspective in this article.Comment: 12 pages, 7 figures, 20 subfigures The title quoted in the meta-data is the title after release / final editing

Politics of religious diversity: toleration, religious freedom and visibility of religion in public space

In France, Germany and the Netherlands, a mix of secularisation, privatisation of religion, and immigration concerns have increased social and political anxiety about the visibility of religion and religious diversity in public space. Visibility in public space is a measure of sociability: expressions of identity in public space attest to a public recognition as well as integration of this identity into cultural transcendences. This visibility is historically intertwined with genealogies of early modern toleration (ca 1500-1789). This thesis compares trajectories in the development of toleration and religious freedom in France, Germany, and the Netherlands, arguing that common frames of reference to toleration – truth, outward unity, public order, economic benefit and trust – have transformed into substrata of constitutionalism. Is it possible to fully disentangle toleration from the structures of constitutional law? Toleration emerged in conjugation with the political imaginary of the corpus christianum, which relegated minorities primarily to private spaces, based on the assumption that one could separate spaces and personae. This thesis contends that the political imaginary of the nation replaced the imaginary of the corpus christianum, and that constitutionalisation was part of a new political order which constructed a different yet similar oneness of territory, people, and teleology. This nexus creates new categories of othering inside and outside the nation based on religion, race, and origin, or combinations of those. These new categories of othering obscure that belonging is about more than integration and outward conformity alone, and that immigrants still face structural racism, even when they have fully “integrated”. Moreover, the identification of common space with a shared political identity renders minorities vulnerable to political interpretations of public order in the context of the law. Parliamentary documentation and court cases on the full face veil, the burkini, and the hijab, demonstrate this vulnerability, in particular where religious otherness intersects with race and gender.Arts and Humanities Research Council Doctoral Training Programme Cambridge Trust Sint Geertruidslee

Intolerance unveiled? Burkini bans across France

This paper qualifies the unlawfulness of the 2016 “burkini bans” in France from the perspective of toleration. It asserts that they reveal a tendency towards intolerance, evaluating the legal texts and political expressions of mayors against specific factors of early modern toleration – truth, common good, (outward) unity, public peace ad order, and trust. Although higher courts in France and Europe tend to defend individual freedom in this and adjacent types of legal questions, local tendencies towards intolerance which target the visibility of otherness in the open space are profoundly concerning. Such tendencies might translate into variations of restrictive regulations, which indicate need to guard against regression in lieu of (individual) religious freedom.AHR

Verminderen diergeneesmiddelengebruik en antimicrobiele toevoegingsmiddelen in de vleesveehouderij

Overzicht van ziekteproblemen en aandachtspunten om het gebruik van diergeneesmiddelen en antimicrobiële toevoegingmiddelen te vermindere

Perspectiefvolle houderijsystemen van rosevlees tot jong rundvlees

Veel vleesveehouders zijn omgeschakeld naar de productie van rosévlees. Bij dit productiesysteem worden overwegend zwartbonte stierkalveren met een intensief rantsoen van krachtvoer, bijproducten en snijmaos gemest en op een leeftijd van circa 35 weken geslacht (karkasgewicht circa 185 kg)

Goede start kalf noodzaak voor minder medicijngebruik

Antibioticagebruik in de veehouderij wordt door de buitenwereld kritisch gevolgd