Hydroxylamine oxidoreductase of Nitrosomonas catalyzes the dehydrogenation of NH2OH. It contains hemes c553, c559 and P460 in the ratio 5:2:1. At equilibrium four or five c hemes are reduced by NH2OH or NH2NH2, respectively. Heme P460 is the site of electron entry into the enzyme; electrons exit via P460 to O2 or H2O2 with rate constants of 30s−1. We report that hydroxylamine oxidoreductase has two categories of electron‐accepting sites: (a) heme P460, an H2O2‐sensitive site, which is reactive with NH2OH (2.2 hemes c 557 and 2 hemes c 559 are reduced) or NH2NH2 (3.3 heme c 553 and 2 heme c 559 are reduced) and (b)an H2O2‐insensitive site(s) which is reactive with H2O2 (∼0.15 heme c 553 is reduced): hydroquinone, pyrogallol, N‐methyl hydroxylamine, pyocyanine, and ascorbate (∼ 0.8 heme c 553 is reduced); or Na2S2O4 or EDTA‐photoreduction with proflavin, deazalumiflavin or acridine orange and methylviologen (all hemes are reduced). The rate constants at 19 °C for reduction by dithionite were: 0.7 heme c 553 (7s−1), 4.3 hemes c 553 (0.07s−1), 0.7 heme c 559 (0.8 s−1), 1.3 hemes c 559 (0.1 s−1), P460 (0.013 s−1). At 2 °C the rate constant for 0.8 heme c 559 was 1.7 s−1. The data indicate that one heme c 552 is reduced by dithionite at the same rate as mammalian cytochrome c; other hemes are reduced much more slowly and are possibly inaccessible to the solvent. The rate constants at 2 °C for reduction by NH2OH were: 1.8 hemes c 553 (30 s−1), 0.2 heme c 553 (2.4 s−1), 1.7 hemes c 559 (19s−1), 0.3 heme c 559 (1.4 s−1). For reduction by NH2NH2 the values were: 2.6 hemes c 553 (23 s−1), 0.7 heme c 553 (1.6 s−1), 1.3 hemes c 559 (22 s−1), 0.7 heme c 559 (4.2 s−1). Thus reduction by NH2OH at the substrate site was at least an order of magnitude faster than reduction of hydroxylamine oxidoreductase heme by Na2S2O4. Comparison of rates of heme‐heme electron transfer on the enzyme during reoxidation by O2 or H2O2, reduction by Na2S2O4 and reduction by NH2OH or NH2NH2 indicates that the enzyme can exist in distinct states which result in different rates of heme‐heme electron transfer. Comparison of the rate of substrate reduction of c hemes of hydroxylamine oxidoreductase (HAO) with the turnover of the enzyme in vivo is consistent with the electron path NH2OH → HAO P460 → HAO c hemes → biological electron acceptor.

What accounts for the survival and long‐term participation of activists in contentious movements under repression? I argue for the role of an important yet oft‐neglected factor: protective support by civilian bystanders. I propose that, mainly motivated by victim‐oriented sympathy, bystanders engage in high‐risk protection that helps activists to escape crackdowns and bolsters their dedication to the movement. To test my theoretical claims, I examine hard cases for activist survival at the height of state violence during military rule in Myanmar between 1988 and 2010, with an original qualitative data set consisting of oral history interviews and written accounts by more than 100 protest observers and former pro‐democracy activists. The data set presents an unprecedented number of voices from the average, non‐contentious general public, which are mostly missing in existing research on social movements. This approach generates a fresh perspective to better understand opportunities and constraints around movement entrepreneurs in hostile environments.

More than one year since its coup, the Myanmar military has neither established effective control of the territory nor crushed online dissent. What factors have enabled the resistance forces to deny the consolidation of military rule? We address this question by building a novel theoretical framework that incorporates the role of long-standing digitalized pro-democracy activism and by conducting a mixed methods analysis that includes an original, largely representative sample of public Facebook posts in post-coup Myanmar. We find that the development of online and hybrid pro-democracy activism against digital abuse and other illiberal policies under previous quasi-civilian governments enabled anti-coup resistance forces to thwart the military's attempt at authoritarian revival in 2021. Our research findings deepen understanding of Myanmar's post-coup contestation dynamics as well as other cases of unpopular autocratization in the digital age.

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Despite perennial hope in the democratic possibilities of the internet, the rise of digital authoritarianism threatens online and offline freedom across much of the world. Yet while critical data studies has expanded its geographic focus, limited work to date has examined digital mobilization in the agrarian communities that comprise much of the Global South. This article advances the concept of “organic online politics,” to demonstrate how digital mobilization grows from specific rural conditions, material concerns, and repertoires of resistance, within the constraints of authoritarian violence and internet control. To do so, we examine social media interaction in the wake of the 2021 military coup in Myanmar, an agrarian nation with recent, rapid digital connection that corresponded with a decade-long democratic turn. Analyzing an original archive of over 2000 Facebook posts collected from popular farming pages and groups, we find a massive drop-off in online activity after the military coup and analyze the shifting temporalities of digital mobilization. Crucially, we highlight the embeddedness of online interaction within the material concerns of farming communities, examining how social media become a key forum for negotiating political crisis in Myanmar's countryside. These findings call attention to rural digital subcultures as fertile sites of investigation and point toward the need for future scholarship on data practices that attends to rooted agrarian struggles.