Over de boeg van een akkoord

Dit essay beschrijft een praktijk van lokaal klimaatbeleid, waarin beleid in de vorm van een klimaatakkoord met ruim 100 partijen tot stand komt. In plaats van dat de gemeente beleid afkondigt, maken partijen dit samen. Werkt dat, hoe werkt dat en wat kunnen we ervan leren? We gingen op zoek naar de kracht van de aanpak en hoe partijen die kracht hebben gevonden. De volgende vraag was daarbij leidend: _‘Wat zijn de opbrengsten van de werkwijze rond het Rotterdams Klimaatakkoord, welke dilemma’s deden zich voor en welke lessen kan een initiërende gemeente (als Rotterdam) daaruit trekken?’

Weak instances of class group action based cryptography via self-pairings

In this paper we study non-trivial self-pairings with cyclic domains that are compatible with isogenies between elliptic curves oriented by an imaginary quadratic order $\mathcal{O}$. We prove that the order $m$ of such a self-pairing necessarily satisfies $m \mid \Delta_\mathcal{O}$ (and even $2m \mid \Delta_\mathcal{O}$ if $4 \mid \Delta_\mathcal{O}$ and $4m \mid \Delta_\mathcal{O}$ if $8 \mid \Delta_\mathcal{O}$) and is not a multiple of the field characteristic. Conversely, for each $m$ satisfying these necessary conditions, we construct a family of non-trivial cyclic self-pairings of order $m$ that are compatible with oriented isogenies, based on generalized Weil and Tate pairings. As an application, we identify weak instances of class group actions on elliptic curves assuming the degree of the secret isogeny is known. More in detail, we show that if $m^2 \mid \Delta_\mathcal{O}$ for some prime power $m$ then given two primitively $\mathcal{O}$-oriented elliptic curves $(E, \iota)$ and $(E\u27,\iota\u27) = [\mathfrak{a}] (E,\iota)$ connected by an unknown invertible ideal $\mathfrak{a} \subseteq \mathcal{O}$, we can recover $\mathfrak{a}$ essentially at the cost of a discrete logarithm computation in a group of order $m^2$, assuming the norm of $\mathfrak{a}$ is given and is smaller than $m^2$. We give concrete instances, involving ordinary elliptic curves over finite fields, where this turns into a polynomial time attack. Finally, we show that these self-pairings simplify known results on the decisional Diffie-Hellman problem for class group actions on oriented elliptic curves

Signatures of mutational processes in human cancer.

All cancers are caused by somatic mutations; however, understanding of the biological processes generating these mutations is limited. The catalogue of somatic mutations from a cancer genome bears the signatures of the mutational processes that have been operative. Here we analysed 4,938,362 mutations from 7,042 cancers and extracted more than 20 distinct mutational signatures. Some are present in many cancer types, notably a signature attributed to the APOBEC family of cytidine deaminases, whereas others are confined to a single cancer class. Certain signatures are associated with age of the patient at cancer diagnosis, known mutagenic exposures or defects in DNA maintenance, but many are of cryptic origin. In addition to these genome-wide mutational signatures, hypermutation localized to small genomic regions, 'kataegis', is found in many cancer types. The results reveal the diversity of mutational processes underlying the development of cancer, with potential implications for understanding of cancer aetiology, prevention and therapy

High-throughput epitope discovery reveals frequent recognition of neo-antigens by CD4(+) T cells in human melanoma

Tumor-specific neo-antigens that arise as a consequence of mutations(1,2) are thought to be important for the therapeutic efficacy of cancer immunotherapies(3-5). Accumulating evidence suggests that neo-antigens may be commonly recognized by intratumoral CD8(+) T cells(3-7), but it is unclear whether neoantigen-specific CD4(+) T cells also frequently reside within human tumors. In view of the accepted role of tumor-specific CD4(+) T-cell responses in tumor control(8-10), we addressed whether neo-antigen-specific CD4(+) T-cell reactivity is a common property in human melanom