73 research outputs found
Towards a genealogy of migrant struggles and rescue. The memory of solidarity at the Alpine border
This article advances a genealogy of migrant struggles and citizens solidarity practices, with a focus on the French-Italian migrant passage. It contends that scholarship has mainly mobilised a spatial approach to migrant struggles, while the temporality of solidarity and the collective memory of struggles have remained under-theorised. Then, the article moves on by focusing on the French-Italian Alpine border and it analyses the longstanding history of migrants’ passages there and, jointly, the mobilisations that took place in that area over the last decades exploring how these sedimented a citizen collective memory of solidarity practices. The final section deals with the history of mountain rescue at the French-Italian Alpine border and shows how migrants were saved by volunteers. The piece concludes by arguing that an insight into the memory of migrant struggles and solidarity practices enables foregrounding the transversal alliances which have been built between migrants and citizens and unsettling binary opposition between the former and the latter
BLUF Domain Function Does Not Require a Metastable Radical Intermediate State
BLUF
(blue light using flavin) domain proteins are an important
family of blue light-sensing proteins which control a wide variety
of functions in cells. The primary light-activated step in the BLUF
domain is not yet established. A number of experimental and theoretical
studies points to a role for photoinduced electron transfer (PET)
between a highly conserved tyrosine and the flavin chromophore to
form a radical intermediate state. Here we investigate the role of
PET in three different BLUF proteins, using ultrafast broadband transient
infrared spectroscopy. We characterize and identify infrared active
marker modes for excited and ground state species and use them to
record photochemical dynamics in the proteins. We also generate mutants
which unambiguously show PET and, through isotope labeling of the
protein and the chromophore, are able to assign modes characteristic
of both flavin and protein radical states. We find that these radical
intermediates are not observed in two of the three BLUF domains studied,
casting doubt on the importance of the formation of a population of
radical intermediates in the BLUF photocycle. Further, unnatural amino
acid mutagenesis is used to replace the conserved tyrosine with fluorotyrosines,
thus modifying the driving force for the proposed electron transfer
reaction; the rate changes observed are also not consistent with a
PET mechanism. Thus, while intermediates of PET reactions can be observed
in BLUF proteins they are not correlated with photoactivity, suggesting
that radical intermediates are not central to their operation. Alternative
nonradical pathways including a keto–enol tautomerization induced
by electronic excitation of the flavin ring are considered
Minor Keywords of Political Theory: Migration as a Critical Standpoint. A collaborative project of collective writing
Coordinated and Edited by:
N De Genova, M Tazzioli
Co-Authored by:
Claudia Aradau, Brenna Bhandar, Manuela Bojadzijev, Josue David Cisneros, N De Genova, Julia Eckert, Elena Fontanari, Tanya Golash-Boza, Jef Huysmans, Shahram Khosravi, Clara Lecadet, Patrisia MacĂas-Rojas, Federica Mazzara, Anne McNevin, Peter Nyers, Stephan Scheel, Nandita Sharma, Maurice Stierl, Vicki Squire, M Tazzioli, Huub van Baar and William Walter
- …