The news about Jo’s passing only reached me today and I am very sad to read this. I first met Jo when I came to the University of Surrey in 2006 as an Erasmus exchange student and was immediately impressed by her presence. I will always remember chatting to her in that corner office, after a presentation or on our way to the EBRS conference in Strasbourg. Her presentations were fascinating and fun and I found conversations with Jo interesting and encouraging, which was very valuable as a junior researcher. The atmosphere she helped to create is certainly one of the reasons that I returned to Surrey to do my PhD and that I still have fond memories of that time. My sincere condolences go out to Jo’s loved ones, friends and (former) colleagues and collaborators and I wish them much strength in dealing with this loss. Sophie Wehrens (Netherlands) …

I am very sorry to hear that Jo Arendt has passed away. Ever since I became active in chronobiological research, she has been a leading figure in my scientific life. She has played a very important role in my career, both with her important publications on melatonin, sleep and chronobiology in particular, but also through her supportive presence at conferences. I also enjoyed her presentations and the discussions with her after my presentations. She was such a kind person, respectful to everybody, especially to young, starting students. I am very grateful to her for the invitation to give the Stockgrand lecture at the EBRS in Amsterdam in 2017. I still remember a wonderful part of a presentation of hers in which she discussed that melatonin would have an anti-aging function and she emphasized that with two pictures of herself showing that she herself did not age at all….. That humour combined with so much knowledge is how I will remember her. In addition, she was an example to me in setting up a science-driven company that aims to bring chronobiological knowledge to society and supports research. I will continue to do so and continue to run melatonin analyses while …

I’m really sad to hear that Jo has left us.  I first saw her (with Norm) on the TV circa 1990 in a documentary about light and circadian rhythms.  The first time in the flesh was at a meeting for lighting industry professionals.  With more courage than I knew I had I took her to task for using the term “full spectrum light”.  Pipsqueak that I was (a newly started circadian lightbox company).  Much harrumphing, but then a brief discussion afterwards. Then a year or so later at Clock Club she said “broad spectrum light” and stared at me, eyebrows raised meaning “is that ok?”  The serious point, for Jo, no matter where it comes from, facts are facts, the science is what it is. Years later, I got on the Ryanair to Copenhagen, found my seat, the senior woman next to me evidently not happy to have some big bloke in shorts alongside.  Then she expostulates “Oh Steve” and we chatted away all the way to the meeting hotel. I really liked her.  And she looked just like my Granny.  And although she did age, (despite the daily melatonin as she pointed out), she matured beautifully …

The sad news of Jo’s passing just reached me today, and I think of all whose lives she enriched with her passion, intellect, and kindness. She was a role model and a source of inspiration for many, myself included. As I think of Jo, my heart goes out to her close collaborators and former trainees as well – they will carry on her legacy and for that we can all be grateful. May she rest in peace. – Hans …

The first time I met Jo was at an EBRS conference. I was a Ph.D. student, and it marked my inaugural oral presentation at this conference. My presentation revolved around data on melatonin (DLMO) from patients with delayed sleep-wake phase. Jo was incredibly kind and provided me with remarkably constructive feedback, accompanied by warm words of encouragement. I was elated and deeply honored to receive her comments. She must have been an incredible mentor, and without a doubt, she was an inspirational figure, particularly for emerging researchers and women in the field of science as a whole! Cátia Reis (Portugal) …

Although we all know that our lives are limited, death nevertheless comes as a surprise and fills us with sadness. Even more so when an eminent colleague and dear friend passes away. Jo has always been an inspiration and a great role model for my scientific career. Dear Jo, you shall always be remembered. Thank you for all that I owe to you. Stephan …

Chère Jo, C’est en 1977, à Jérusalem, que je t’ai rencontrée pour la première fois. Et durant ces plus de 55 ans, nous nous sommes rencontrées souvent, aux quatre coins du monde, au gré des colloques et congrès. Nous avons partagé de nombreux moments très heureux qui m’ont marquée. Comme durant les 3 – 4 jours que tu es venue passer à Strasbourg avec Helena il y a quelques années. Nous nous sommes vues pour la dernière fois en janvier, à Strasbourg, où la grande scientifique que tu étais a donné deux belles conférences. Et comme toujours, tu as fait preuve de beaucoup d’attention pour chacun et bien sûr d’humour et de perspicacité. Tu faisais partie de notre vie. Tu fais et fera partie de notre vie. Je pense fort à toi …

I was so sorry to hear of Jo’s death. She was a pioneer in the field of chronobiology and in particular the role of melatonin. Jo was such an inspiration to many and was a great advocate for many young scientists. Her work was intellectually rigorous and she was a fabulous, engaging speaker at conferences who always held your attention. Jo was great fun to be around at meetings. Her impact on the field was immense and the legacy she leaves behind is testament to her ability in championing others to succeed.  …

Ma chère Jo, Tu nous as quitté brutalement et c’est un choc immense. Nous nous connaissons depuis si longtemps (en fait depuis 1973) que ton absence crée en moi un immense vide. Je ne peux oublier que, dans tes années à Genève tu as mis au point un dosage radioimmunologique de la mélatonine (le premier) qui a révolutionné notre discipline. A partir de cette date la mélatonine, une substance mystérieuse originaire d’une structure énigmatique (l’épiphyse), est devenue une hormone respectée et l’épiphyse une glande endocrine reconnue (la glande pinéale). Avec le temps tu es devenue une spécialiste incontestée de la pinéale et tes travaux sur la mélatonine chez l’Homme t’ont donné une grande notoriété. Tu as participé directement à la structuration de notre discipline. Personnellement, ce dont je me souviens le plus, c’est le long chemin commun dans la vie de la maintenant « European Biological Society ». Le « European Pineal study group » a été crée en 1977 et des 1981 tu as intégré le conseil de cette société jusqu’à en devenir la Présidente, une Présidente active et forte. Tu as donc été impliquée directement, et souvent comme force motrice, dans les changements qui ont suivi les progrès de nos connaissances …