The Horseshoe Estimator: Posterior Concentration around Nearly Black Vectors

We consider the horseshoe estimator due to Carvalho, Polson and Scott (2010) for the multivariate normal mean model in the situation that the mean vector is sparse in the nearly black sense. We assume the frequentist framework where the data is generated according to a fixed mean vector. We show that if the number of nonzero parameters of the mean vector is known, the horseshoe estimator attains the minimax $\ell_2$ risk, possibly up to a multiplicative constant. We provide conditions under which the horseshoe estimator combined with an empirical Bayes estimate of the number of nonzero means still yields the minimax risk. We furthermore prove an upper bound on the rate of contraction of the posterior distribution around the horseshoe estimator, and a lower bound on the posterior variance. These bounds indicate that the posterior distribution of the horseshoe prior may be more informative than that of other one-component priors, including the Lasso.Comment: This version differs from the final published version in pagination and typographical detail; Available at http://projecteuclid.org/euclid.ejs/141813426

De overheid als 'Change Agent' voor ISA

Onaangepaste en hoge snelheden zijn belangrijke factoren aangaande verkeersonveiligheid en leefbaarheid. Diverse maatregelen, zoals aanpassingen aan de infrastructuur, informatiecampagnes en handhaving worden reeds toegepast. Er wordt daarentegen nog nauwelijks gebruik gemaakt van in-car maatregelen zoals Intelligente Snelheids Aanpassing (ISA) voor het terugdringen van snelheid. De effecten van ISA blijken positief maar nog steeds is er weinig sprake van een coherente implementatie. Aangezien de effecten zich voornamelijk op het maatschappelijke vlak voordoen en veranderingen in de bestaande processen teweeg brengen is de overheid de meest aangewezen partij om als “Change Agent” op te treden in het realiseren van een gerichte implementatie. Stappen die de overheid zou moeten nemen zijn het creëren van de noodzakelijke voorwaarden, het onder de aandacht brengen van de positieve effecten van ISA bij de direct betrokkenen, en het bepalen van de wijze van implementatie

Representing their own? Ethnic minority women in the Dutch parliament

Ethnic minority women tend to be better represented in parliaments than ethnic minority men. What does this mean for their substantive representation? This article makes use of intersectional analysis to study how the relationship between descriptive and substantive representation differs within and between gender and ethnic groups. Drawing on written parliamentary questions and the committee memberships of MPs in seven parliamentary sessions (1995-2012) in the Netherlands, a strong link is found between descriptive and substantive representation. Female ethnic minority MPs more often sit on committees and table questions that address ethnic minority women's interests than male ethnic minority and female ethnic majority MPs. The link, however, is fragile as it is based on a small number of active MPs. This demonstrates the importance of an intersectional approach to understanding how representation works in increasingly diverse parliaments, which cannot be captured by focusing on gender or ethnicity alone

(F)actsheet: leiderschap en onzekerheid

The politics and administration of institutional chang

(F)actsheet: innovatievermogen in de Wmo-wijkteams

The politics and administration of institutional chang

Organizational rules and cognitive uncertainty among public professionals: a daily diary study

Although public management and human resource management research has extensively investigated the motivational effects of organizational rules, the original utility of organizational rules—uncertainty reduction—has remained overlooked. This study takes a cognitive perspective by examining how organizational rules relate to uncertainty experiences of public professionals. In this study, we provide a dynamic perspective on the relationship between organizational rules and uncertainty through a 2-week daily online diary study among 65 public professionals in the Netherlands. The results indicate that the amount and consistency of rules are related to professionals’ daily uncertainty experiences. Moreover, within-person experiences of rules and uncertainty are highly variable over time. We argue that a cognitive perspective of uncertainty reduction can broaden our understanding of the consequences of organizational rules in managing people, and that the dynamic nature of organizational rule experiences cannot be a mere footnote in future public administration and human resource management research.Public Health and primary carePrevention, Population and Disease management (PrePoD

(F)actsheet: Regels in de JMO-teams

The politics and administration of institutional chang

Type VII Collagen Expression in the Human Vitreoretinal Interface, Corpora Amylacea and Inner Retinal Layers

Type VII collagen, as a major component of anchoring fibrils found at basement membrane zones, is crucial in anchoring epithelial tissue layers to their underlying stroma. Recently, type VII collagen was discovered in the inner human retina by means of immunohistochemistry, while proteomic investigations demonstrated type VII collagen at the vitreoretinal interface of chicken. Because of its potential anchoring function at the vitreoretinal interface, we further assessed the presence of type VII collagen at this site. We evaluated the vitreoretinal interface of human donor eyes by means of immunohistochemistry, confocal microscopy, immunoelectron microscopy, and Western blotting. Firstly, type VII collagen was detected alongside vitreous fibers6 at the vitreoretinal interface. Because of its known anchoring function, it is likely that type VII collagen is involved in vitreoretinal attachment. Secondly, type VII collagen was found within cytoplasmic vesicles of inner retinal cells. These cells resided most frequently in the ganglion cell layer and inner plexiform layer. Thirdly, type VII collagen was found in astrocytic cytoplasmic inclusions, known as corpora amylacea. The intraretinal presence of type VII collagen was confirmed by Western blotting of homogenized retinal preparations. These data add to the understanding of vitreoretinal attachment, which is important for a better comprehension of common vitreoretinal attachment pathologies

A filter for syntactically incomparable parallel sentences

Massive automatic comparison of languages in parallel corpora will greatly speed up and enhance the development of a theoretical model of the syntactic properties all languages have in common and the range and limits of syntactic variation. When extracting syntactic differences from parallel corpora it is essential only to compare sentence pairs that are sufficiently similar syntactically. We explore four measures to automatically filter out syntactically incomparable sentence pairs: the Damerau-Levenshtein distance between POS- tags, the sentence-length ratio, the graph-edit distance between dependency parses, and a combination of the three in a logistic regression model. For all approaches we experiment with ignoring specific functional material and other parameters. We evaluate the filters on three labelled datasets consisting of sentence pairs that are and that are not syntactically comparable. Results suggest that the dependency-parse filter is the most stable throughout language pairs, while the combination filter achieves the best results.Theoretical and Experimental Linguistic