Stack semantics of type theory

We give a model of dependent type theory with one univalent universe and propositional truncation interpreting a type as a stack, generalising the groupoid model of type theory. As an application, we show that countable choice cannot be proved in dependent type theory with one univalent universe and propositional truncation

Constructive sheaf models of type theory

We generalise sheaf models of intuitionistic logic to univalent type theory over a small category with a Grothendieck topology. We use in a crucial way that we have constructive models of univalence, that can then be relativized to any presheaf models, and these sheaf models are obtained by localisation for a left exact modality. We provide first an abstract notion of descent data which can be thought of as a higher version of the notion of prenucleus on frames, from which can be generated a nucleus (left exact modality) by transfinite iteration. We then provide several examples.Comment: Simplified the definition of lex operation, simplified the encoding of the homotopy limit and remark that the homotopy descent data is a lex modality without using higher inductive type

Privacy-preserving data sharing infrastructures for medical research: systematization and comparison

Background: Data sharing is considered a crucial part of modern medical research. Unfortunately, despite its advantages, it often faces obstacles, especially data privacy challenges. As a result, various approaches and infrastructures have been developed that aim to ensure that patients and research participants remain anonymous when data is shared. However, privacy protection typically comes at a cost, e.g. restrictions regarding the types of analyses that can be performed on shared data. What is lacking is a systematization making the trade-offs taken by different approaches transparent. The aim of the work described in this paper was to develop a systematization for the degree of privacy protection provided and the trade-offs taken by different data sharing methods. Based on this contribution, we categorized popular data sharing approaches and identified research gaps by analyzing combinations of promising properties and features that are not yet supported by existing approaches. Methods: The systematization consists of different axes. Three axes relate to privacy protection aspects and were adopted from the popular Five Safes Framework: (1) safe data, addressing privacy at the input level, (2) safe settings, addressing privacy during shared processing, and (3) safe outputs, addressing privacy protection of analysis results. Three additional axes address the usefulness of approaches: (4) support for de-duplication, to enable the reconciliation of data belonging to the same individuals, (5) flexibility, to be able to adapt to different data analysis requirements, and (6) scalability, to maintain performance with increasing complexity of shared data or common analysis processes. Results: Using the systematization, we identified three different categories of approaches: distributed data analyses, which exchange anonymous aggregated data, secure multi-party computation protocols, which exchange encrypted data, and data enclaves, which store pooled individual-level data in secure environments for access for analysis purposes. We identified important research gaps, including a lack of approaches enabling the de-duplication of horizontally distributed data or providing a high degree of flexibility. Conclusions: There are fundamental differences between different data sharing approaches and several gaps in their functionality that may be interesting to investigate in future work. Our systematization can make the properties of privacy-preserving data sharing infrastructures more transparent and support decision makers and regulatory authorities with a better understanding of the trade-offs taken

Die kleine Fliege macht Kirschen sowie Produzenten und Produzentinnen sauer

Bei den Brenn- und Industriekirschenbetrieben ist die Stimmung im Keller. Nach mehreren Jahren mit Spätfrostereignissen und erheblichen Ernteausfällen war Ende Mai 2022 die Hoffnung auf eine gute Ernte gross. Es wurde jedoch die Rechnung ohne die Kirschessigfliege (KEF) gemacht, deren Entwicklung durch die warme und trockene Witterung der letzten Monate explosionsartig verlief

Kirschessigfliege macht Kirschenproduzenten sauer

Bei den Brenn- und Industriekirschenproduzent(innen) ist die Stimmung im Keller. Nach mehreren Jahren mit Spätfrostereignissen und erheblichen Ernteausfällen war Ende Mai 2022 die Hoffnung auf eine gute Ernte gross

Kleine Fliege macht auch Produzenten sauer

Bei den Brenn- und Industriekirschenproduzent(innen) ist die Stimmung im Keller. Nach mehreren Jahren mit Spätfrostereignissen und erheblichen Ernteausfällen war Ende Mai 2022 die Hoffnung auf eine gute Ernte gross

La petite mouche qui gâte les cerises et fâche les productrices et les producteurs

Le moral est au plus bas chez les producteurs de cerises de distillerie et d’industrie. Après plusieurs années marquées par des gels tardifs et d’énormes pertes de récoltes, à fin mai 2022 il y avait beaucoup d’espoir pour une bonne récolte. C’était sans compter avec la drosophile du cerisier (DC), qui s’est développée de manière explosive à cause du temps chaud et sec de ces derniers mois

The Influence of Grain Size Distribution on Mechanical Compaction and Compaction Localization in Porous Rocks

The modes of formation of clastic rocks result in a wide variety of microstructures, from poorly-sorted heterogeneous rocks to well-sorted and nominally homogeneous rocks. The mechanical behavior and failure mode of clastic rocks is known to vary with microstructural attributes such as porosity and grain size. However, the influence of the grain size distribution, in particular the degree of polydispersivity or modality of the distribution, is not yet fully understood, because it is difficult to study experimentally using natural rocks. To better understand the influence of grain size distribution on the mechanical behavior of porous rocks, we prepared suites of synthetic samples consisting of sintered glass beads with polydisperse grain size distributions. We performed hydrostatic compression experiments and found that, all else being equal, the onset of grain crushing occurs much more progressively and at lower pressure in polydisperse synthetic samples than in monodisperse samples. We conducted triaxial experiments in the regime of shear-enhanced compaction and found that the stress required to reach inelastic compaction was lower in polydisperse samples compared to monodisperse samples. Further, our microstructural observations show that compaction bands developed in monomodal polydisperse samples while delocalized cataclasis developed in bimodal polydisperse samples, where small grains were systematically crushed while largest grains remained intact. In detail, as the polydispersivity increases, microstructural deformation features appear to transition from localized to delocalized through a hybrid stage where a compaction front with diffuse bands propagates from both ends of the sample toward its center with increasing bulk strain