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In the context of persistent images of self-perpetuated technologies, we discuss the interplay of digital technologies and organisational dynamics against the backdrop of systems theory. Building on the case of an international corporation that, during an agile reorganisation, introduced an AI-based personnel management platform, we show how technical systems produce a form of algorithmic contingency that subsequently leads to the emergence of formal and informal interaction systems. Using the concept of datafication, we explain how these interactions are barriers to the self-perpetuation of data-based decision-making, making it possible to take into consideration further decision factors and complementing the output of the platform. The research was carried out within the scope of the research project ‘Organisational Implications of Digitalisation: The Development of (Post-)Bureaucratic Organisational Structures in the Context of Digital Transformation’ funded by the German Research Foundation (DFG).
Background: Following the rapid increase of asylum seekers arriving in the European Union in 2015/16, policymakers have invested heavily in improving their foresight and forecasting capabilities. A common method to elicit expert predictions are Delphi surveys. This approach has attracted concern in the literature, given the high uncertainty in experts’ predictions. However, there exists limited guidance on specific design choices for future-related Delphi surveys.
Objective: We test whether or not small adjustments to the Delphi survey can increase certainty (i.e., reduce variation) in expert predictions on immigration to the EU in 2030.
Methods: Based on a two-round Delphi survey with 178 migration experts, we compare variation and subjective confidence in expert predictions and assess whether additional context information (type of migration flow, sociopolitical context) promotes convergence among experts (i.e., less variation) and confidence in their own estimates.
Results: We find that additional context information does not reduce variation and does not increase confidence in expert predictions on migration.
Conclusions: The results reaffirm recent concerns regarding the limited scope for reducing uncertainty by manipulating the survey setup. Persistent uncertainty may be a result of the complexity of migration processes and limited agreement among migration experts regarding key drivers.
Contribution: We caution policymakers and academics on the use of Delphi surveys for eliciting expert predictions on immigration, even when conducted based on a large pool of experts and using specific scenarios. The potential of alternative approaches such as prediction markets should be further explored.
A circulatory loop
(2023)
In the digitalization debate, gender biases in digital technologies play a significant role because of their potential for social exclusion and inequality. It is therefore remarkable that organizations as drivers of digitalization and as places for social integration have been widely overlooked so far. Simultaneously, gender biases and digitalization have structurally immanent connections to organizations. Therefore, a look at the reciprocal relationship between organizations, digitalization, and gender is needed. The article provides answers to the question of whether and how organizations (re)produce, reinforce, or diminish gender‐specific inequalities during their digital transformations. On the one hand, gender inequalities emerge when organizations use post‐bureaucratic concepts through digitalization. On the other hand, gender inequalities are reproduced when organizations either program or implement digital technologies and fail to establish control structures that prevent gender biases. This article shows that digitalization can act as a catalyst for inequality‐producing mechanisms, but also has the potential to mitigate inequalities. We argue that organizations must be considered when discussing the potential of exclusion through digitalization.
In recent years, there have been a growing number of online and offline attacks linked to a loosely connected network of misogynist and antifeminist online communities called ‘the manosphere’. Since 2016, the ideas spread among and by groups of the manosphere have also become more closely aligned with those of other Far-Right online networks. In this commentary, I explore the role of what I term ‘evidence-based misogyny’ for mobilization and radicalization into the antifeminist and misogynist subcultures of the manosphere. Evidence-based misogyny is a discursive strategy, whereby members of the manosphere refer to (and misinterpret) knowledge in the form of statistics, studies, news items and pop-culture and mimic accepted methods of knowledge presentation to support their essentializing, polarizing views about gender relations in society. Evidence-based misogyny is a core aspect for manosphere-related mobilization as it provides a false sense of authority and forges a collective identity, which is framed as a supposed ‘alternative’ to mainstream gender knowledge. Due to its core function to justify and confirm the misogynist sentiments of users, evidence-based misogyny serves as connector between the manosphere and both mainstream conservative as well as other Far-Right and conspiratorial discourses.
Sven Siefken und Hilmar Rommetvedt (Hrsg.). 2021. Parliamentary committees in the policy process
(2023)
Never again?
(2023)
The Holocaust was the most terrible atrocity of the 20th century. In many ways, it was also unprecedented in the history of atrocities: for its comprehensiveness and systematic nature; for the fanaticism with which its perpetrators scoured an entire continent in their pursuit of Jews; for the awful potency of the Nazis’ insinuation that the victims represented a pernicious and existential threat. Collectively, we have spent decades—and published millions of words—trying to understand what happened and why.
Gender at the crossroads
(2023)
Since the early 2000s, the United Nations (UN) global counterterrorism architecture has seen significant changes towards increased multilateralism, a focus on prevention, and inter-institutional coordination across the UN’s three pillars of work. Throughout this reform process, gender aspects have increasingly become presented as a “cross-cutting” theme. In this article, I investigate the role of gender in the UN’s counterterrorism reform process at the humanitarian-development-peace nexus, or “triple nexus”, from a feminist institutionalist perspective. I conduct a feminist discourse analysis of the counterterrorism discourses of three UN entities, which represent the different UN pillars of peace and security (DPO), development (UNDP), and humanitarianism and human rights (OHCHR). The article examines the role of gender in the inter-institutional reform process by focusing on the changes, overlaps and differences in the discursive production of gender in the entities’ counterterrorism agendas over time and in two recent UN counterterrorism conferences. I find that gendered dynamics of nested newness and institutional layering have played an essential role both as a justification for the involvement of individual entities in counterterrorism and as a vehicle for inter-institutional cooperation and struggle for discursive power.
Introduction
(2023)
Several global governance initiatives launched in recent years have explicitly sought to integrate concern for gender equality and gendered harms into efforts to counter terrorism and violent extremism. As a result, commitments to gender-sensitivity and gender equality in international and regional counterterrorism and countering violent extremism (CT/CVE) initiatives, in national action plans, and at the level of civil society programming, have become a common aspect of the multilevel governance of terrorism and violent extremism. In light of these developments, aspects of our own research have turned in the past years to explore how concerns about gender are being incorporated in the governance of terrorism and violent extremism and how this development has affected (gendered) practices and power relations in CT policymaking and implementation. We were inspired by the growing literature on gender and CT/CVE, and critical scholarship on terrorism and political violence, to bring together a collection of new research addressing these questions.
This book brings together a variety of innovative perspectives on the inclusion of gender in the governance of (counter-)terrorism and violent extremism.
Several global governance initiatives launched in recent years have explicitly sought to integrate concern for gender equality and gendered harms into efforts to counter terrorism and violent extremism (CT/CVE). As a result, commitments to gender-sensitivity and gender equality in international and regional CT/CVE initiatives, in national action plans and at the level of civil society programming, ´have become a common aspect of the multilevel governance of terrorism and violent extremism. In light of these developments, there is a need for more systematic analysis of how concerns about gender are being incorporated in the governance of (counter-)terrorism and violent extremism and how it has affected (gendered) practices and power relations in counterterrorism policy-making and implementation.
Ranging from the processes of global and regional integration of gender into the governance of terrorism, via the impact of the shift on government responses to the return of foreign fighters, to state and civil society-led CVE programming and academic discussions, the essays engage with the origins and dynamics behind recent shifts which bring gender to the forefront of the governance of terrorism. This book will be of great value to researchers and scholars interested in gender, governance and terrorism.
The chapters in this book were originally published in Critical Studies on Terrorism.
Atwood (2022) analyzes the effects of the 1963 U.S. measles vaccination on longrun labor market outcomes, using a generalized difference-in-differences approach. We reproduce the results of this paper and perform a battery of robustness checks. Overall, we confirm that the measles vaccination had positive labor market effects. While the negative effect on the likelihood of living in poverty and the positive effect on the probability of being employed are very robust across the different specifications, the headline estimate-the effect on earnings-is more sensitive to the exclusion of certain regions and survey years.
A room full of ‘views’
(2023)
Quantitative research into the effectiveness of the UN human rights treaty bodies (UNTBs) in eliciting remedial responses from states is impeded by a lack of usable data on how states respond to their decisions. The new Treaty Body Views Dataset (TBVD) aims to fill this gap. It comprises details on all published decisions in individual complaints cases issued by the UNTBs between 1979 and 2019 and matches these with information on their state of compliance. The TBVD can be used for research on the activities of the treaty bodies, the nature of the decisions themselves, or state behavior following a decision. An empirical application illustrates how the TBVD can advance knowledge about the factors that correlate with compliance with adverse UNTB decisions. Results show that the likelihood of implementation hinges critically on decision-level characteristics, and reveal differences and similarities between compliance with UNTB decisions and regional human rights court judgments.
Worldwide, companies are increasingly making claims about their current climate efforts and their future mitigation commitments. These claims tend to be underpinned by carbon credits issued in voluntary carbon markets to offset emissions. Corporate climate claims are largely unregulated which means that they are often (perceived to be) misleading and deceptive. As such, corporate climate claims risk undermining, rather than contributing to, global climate mitigation. This paper takes as its point of departure the proposition that a better understanding of corporate climate claims is needed to govern such claims in a manner that adequately addresses potential greenwashing risks. To that end, the paper reviews the nascent literature on corporate climate claims relying on the use of voluntary carbon credits. Drawing on the reviewed literature, three key dimensions of corporate climate claims as related to carbon credits are discussed: 1) the intended use of carbon credits: offsetting versus non-offsetting claims; 2) the framing and meaning of headline terms: net-zero versus carbon neutral claims; and 3) the status of the claim: future aspirational commitments versus stated achievements. The paper thereby offers a preliminary categorization of corporate climate claims and discusses risks associated with and governance implications for each of these categories.
The 2022 Kunming-Montreal Global Biodiversity Framework (GBF) and Paris Agreement (PA) are highly complementary agreements where each depends on the other’s success to be effective. The GBF offers a very specific framework of interim goals and targets that break down the objective of the Convention on Biodiversity (CBD) into a decade-spanning work plan. Comprised of 10 sections – including a 2050 vision and a 2030 mission, four overarching goals and 23 specific targets – the GBF is expected to guide biodiversity policy around the world in the coming years to decades. A similar set of global interim climate policy targets could translate the global temperature goal into concrete policy milestones that would provide policy makers and civil society with reference points for policy making and efforts to hold governments accountable. Beyond inspiring climate policy experts to convert temperature goals into policy milestones, GBF has the potential to strengthen the implementation of the PA at the nexus of biodiversity and climate (adaptation and mitigation) action. For example, the GBF can help to ensure that nature-based climate solutions are implemented with full consideration of biodiversity concerns, of the rights and interests of Indigenous Peoples and local communities, and with fair and transparent benefit sharing arrangements. In sum, the GBF should be mandatory reading for all climate policy makers.
The EU and its member countries have been laggards in using forest carbon to reduce EU emissions. The European Green Deal aims to change this. As part of its long-term emissions reductions, the EU aims to offset this by creating land-based carbon sinks, especially forest carbon sinks as well as carbon capture and storage. This chapter focuses on the role of forest carbon as part of the EU's climate policies towards achieving net-zero greenhouse gas emissions by 2050. It furthermore examines the European Commission's proposed forest strategy and its proposal for a revised LULUCF Regulation. The chapter shows that the logic of appropriateness dominates the European Commission's forest policies. Finally, the chapter makes policy recommendations on how the EU could credibly use long-term carbon sinks to achieve climate neutrality.
Long-term environmental policy remains a vexing puzzle of environmental policy. Following its definition, the author reviews the methods suitable for the study of long-term environmental policy and develops a typology of policy instruments to cope with these challenges. The concluding section offers five central research challenges to advance the study of long-term environmental policy.
Planned decommissioning of coal-fired plants in Europe requires innovative technical and economic strategies to support coal regions on their path towards a climate-resilient future. The repurposing of open pit mines into hybrid pumped hydro power storage (HPHS) of excess energy from the electric grid, and renewable sources will contribute to the EU Green Deal, increase the economic value, stabilize the regional job market and contribute to the EU energy supply security. This study aims to present a preliminary phase of a geospatial workflow used to evaluate land suitability by implementing a multi-criteria decision making (MCDM) technique with an advanced geographic information system (GIS) in the context of an interdisciplinary feasibility study on HPHS in the Kardia lignite open pit mine (Western Macedonia, Greece). The introduced geospatial analysis is based on the utilization of the constraints and ranking criteria within the boundaries of the abandoned mine regarding specific topographic and proximity criteria. The applied criteria were selected from the literature, while for their weights, the experts' judgement was introduced by implementing the analytic hierarchy process (AHP), in the framework of the ATLANTIS research program. According to the results, seven regions were recognized as suitable, with a potential energy storage capacity from 1.09 to 5.16 GWh. Particularly, the present study's results reveal that 9.27% (212,884 m(2)) of the area had a very low suitability, 15.83% (363,599 m(2)) had a low suitability, 23.99% (550,998 m(2)) had a moderate suitability, 24.99% (573,813 m(2)) had a high suitability, and 25.92% (595,125 m(2)) had a very high suitability for the construction of the upper reservoir. The proposed semi-automatic geospatial workflow introduces an innovative tool that can be applied to open pit mines globally to identify the optimum design for an HPHS system depending on the existing lower reservoir.
The impact of civilian harm on strategic outcomes in war has been the subject of persistent debate. However, the literature has primarily focused on civilian casualties, thereby overlooking the targeting of civilian infrastructure, which is a recurrent phenomenon during war. This study fills this gap by examining the targeting of healthcare, one of the most indispensable infrastructures during war and peace time. We contend that attacks on medical facilities are distinct from direct violence against civilians. Because they are typically unrelated to military dynamics, the targeting of hospitals is a highly visible form and powerful signal of civilian victimization. To assess its effects, we analyze newly collected data on such attacks by pro-government forces and event data on combat activities in Northwest Syria (2017-2020). Applying a new approach for panel data analysis that combines matching methods with a difference-in-differences estimation, we examine the causal effect of counterinsurgent bombings on subsequent violent events. Distinguishing between regime-initiated and insurgent-initiated combat activities and their associated fatalities, we find that the targeting of hospitals increases insurgent violence. We supplement the quantitative analysis with unique qualitative evidence derived from interviews, which demonstrates that hospital bombings induce rebels to resist more fiercely through two mechanisms: intrinsic motivations and civilian pressure. The results have important implications for the effects of state-led violence and the strength of legal norms that protect noncombatants.
Public opinion polls have become vital and increasingly visible parts of election campaigns. Previous research has frequently demonstrated that polls can influence both citizens' voting intentions and political parties' campaign strategies. However, they are also fraught with uncertainty. Margins of error can reflect (parts of) this uncertainty. This paper investigates how citizens' voting intentions change due to whether polling estimates are presented with or without margins of error.
Using a vignette experiment (N=3224), we examine this question based on a real-world example in which different election polls were shown to nationally representative respondents ahead of the 2021 federal election in Germany. We manipulated the display of the margins of error, the interpretation of polls and the closeness of the electoral race.
The results indicate that margins of error can influence citizens' voting intentions. This effect is dependent on the actual closeness of the race and additional interpretative guidance provided to voters. More concretely, the results consistently show that margins of error increase citizens' inclination to vote for one of the two largest contesting parties if the polling gap between these parties is small, and an interpretation underlines this closeness.
The findings of this study are important for three reasons. First, they help to determine whether margins of error can assist citizens in making more informed (strategic) vote decisions. They shed light on whether depicting opinion-poll uncertainty affects the key features of representative democracy, such as democratic accountability. Second, the results stress the responsibility of the media. The way polls are interpreted and contextualized influences the effect of margins of error on voting behaviour. Third, the findings of this paper underscore the significance of including methodological details when communicating scientific research findings to the broader public.
Effect of magnesium salts with chaotropic anions on the swelling behavior of PNIPMAM thin films
(2023)
Poly(N-isopropylmethacrylamide) (PNIPMAM) is a stimuli responsive polymer, which in thin film geometry exhibits a volume-phase transition upon temperature increase in water vapor. The swelling behavior of PNIPMAM thin films containing magnesium salts in water vapor is investigated in view of their potential application as nanodevices. Both the extent and the kinetics of the swelling ratio as well as the water content are probed with in situ time-of-flight neutron reflectometry. Additionally, in situ Fourier-transform infrared (FTIR) spectroscopy provides information about the local solvation of the specific functional groups, while two-dimensional FTIR correlation analysis further elucidates the temporal sequence of solvation events. The addition of Mg(ClO4)2 or Mg(NO3)2 enhances the sensitivity of the polymer and therefore the responsiveness of switches and sensors based on PNIPMAM thin films. It is found that Mg(NO3)2 leads to a higher relative water uptake and therefore achieves the highest thickness gain in the swollen state.
Thermal electrons have gyroradii many orders of magnitude smaller than the finite width of a shock, thus need to be pre-accelerated before they can cross it and be accelerated by diffusive shock acceleration. One region where pre-acceleration may occur is the inner foreshock, which upstream electrons must pass through before any potential downstream crossing. In this paper, we perform a large-scale particle-in-cell simulation that generates a single shock with parameters motivated from supernova remnants. Within the foreshock, reflected electrons excite the oblique whistler instability and produce electromagnetic whistler waves, which comove with the upstream flow and as nonlinear structures eventually reach radii of up to 5 ion-gyroradii. We show that the inner electromagnetic configuration of the whistlers evolves into complex nonlinear structures bound by a strong magnetic field around four times the upstream value. Although these nonlinear structures do not in general interact with cospatial upstream electrons, they resonate with electrons that have been reflected at the shock. We show that they can scatter, or even trap, reflected electrons, confining around 0.8% of the total upstream electron population to the region close to the shock where they can undergo substantial pre-acceleration. This acceleration process is similar to, yet approximately three times more efficient than, stochastic shock drift acceleration.
Analyzing social wrongs
(2023)
Touching at a Distance
(2023)
Studies the capacity of Shakespeare’s plays to touch and think about touchBased on plays from all major genres: Hamlet, The Tempest, Richard III, Much Ado About Nothing and Troilus and CressidaCentres on creative, close readings of Shakespeare’s plays, which aim to generate critical impulses for the 21st century readerBrings Shakespeare Studies into touch with philosophers and theoreticians from a range of disciplinary areas – continental philosophy, literary criticism, psychoanalysis, sociology, phenomenology, law, linguistics: Friedrich Nietzsche, Maurice Blanchot, Jacques Lacan, Luce Irigaray, Jacques Derrida, Roland Barthes, Niklas Luhmann, Hans Blumenberg, Carl Schmitt, J. L. AustinTheatre has a remarkable capacity: it touches from a distance. The audience is affected, despite their physical separation from the stage. The spectators are moved, even though the fictional world presented to them will never come into direct touch with their real lives. Shakespeare is clearly one of the master practitioners of theatrical touch. As the study shows, his exceptional dramaturgic talent is intrinsically connected with being one of the great thinkers of touch. His plays fathom the complexity and power of a fascinating notion – touch as a productive proximity that is characterised by unbridgeable distance – which philosophers like Friedrich Nietzsche, Maurice Blanchot, Jacques Derrida, Luce Irigaray and Jean-Luc Nancy have written about, centuries later. By playing with touch and its metatheatrical implications, Shakespeare raises questions that make his theatrical art point towards modernity: how are communities to form when traditional institutions begin to crumble? What happens to selfhood when time speeds up, when oneness and timeless truth can no longer serve as reliable foundations? What is the role and the capacity of language in a world that has lost its seemingly unshakeable belief and trust in meaning? How are we to conceive of the unthinkable extremes of human existence – birth and death – when the religious orthodoxy slowly ceases to give satisfactory explanations? Shakespeare’s theatre not only prompts these questions, but provides us with answers. They are all related to touch, and they are all theatrical at their core: they are argued and performed by the striking experience of theatre’s capacities to touch – at a distance
We tested whether a brief self-affirmation writing intervention protected against identity-threats (i.e., stereotyping and discrimination) for adolescents' school-related adjustment. The longitudinal study followed 639 adolescents in Germany (65% of immigrant descent, 50% female, M-age = 12.35 years, SDage = .69) from 7(th) grade (pre-intervention at T1, five to six months post-intervention at T2) to the end of 8(th) grade (one-year follow-up at T3). We tested for direct and moderated (by heritage group, discrimination, classroom cultural diversity climate) effects using regression and latent change models. The self-affirmation intervention did not promote grades or math competence. However, in the short-term and for adolescents of immigrant descent, the intervention prevented a downward trajectory in mastery reactions to academic challenges for those experiencing greater discrimination. Further, it protected against a decline in behavioral school engagement for those in positive classroom cultural diversity climates. In the long-term and for all adolescents, the intervention lessened an upward trajectory in disruptive behavior. Overall, the self-affirmation intervention benefited some aspects of school-related adjustment for adolescents of immigrant and non-immigrant descent. The intervention context is important, with classroom cultural diversity climate acting as a psychological affordance enhancing affirmation effects. Our study supports the ongoing call for theorizing and empirically testing student and context heterogeneity to better understand for whom and under which conditions this intervention may work.
Local laws on urban policy, i.e., ordinances directly affect our daily life in various ways (health, business etc.), yet in practice, for many citizens they remain impervious and complex. This article focuses on an approach to make urban policy more accessible and comprehensible to the general public and to government officials, while also addressing pertinent social media postings. Due to the intricacies of the natural language, ranging from complex legalese in ordinances to informal lingo in tweets, it is practical to harness human judgment here. To this end, we mine ordinances and tweets via reasoning based on commonsense knowledge so as to better account for pragmatics and semantics in the text. Ours is pioneering work in ordinance mining, and thus there is no prior labeled training data available for learning. This gap is filled by commonsense knowledge, a prudent choice in situations involving a lack of adequate training data. The ordinance mining can be beneficial to the public in fathoming policies and to officials in assessing policy effectiveness based on public reactions. This work contributes to smart governance, leveraging transparency in governing processes via public involvement. We focus significantly on ordinances contributing to smart cities, hence an important goal is to assess how well an urban region heads towards a smart city as per its policies mapping with smart city characteristics, and the corresponding public satisfaction.
FicucariconeD (1) and its 4 '-demethyl congener 2 are isoflavones isolated from fruits of Ficus carica that share a 5,7-dimethoxy-6-prenyl-substituted A-ring. Both naturalproducts were, for the first time, obtained by chemical synthesisin six steps, starting from 2,4,6-trihydroxyacetophenone. Key stepsare a microwave-promoted tandem sequence of Claisen- and Cope-rearrangementsto install the 6-prenyl substituent and a Suzuki-Miyaura crosscoupling for installing the B-ring. By using various boronic acids,non-natural analogues become conveniently available. All compoundswere tested for cytotoxicity against drug-sensitive and drug-resistanthuman leukemia cell lines, but were found to be inactive. The compoundswere also tested for antimicrobial activities against a panel of eightGram-negative and two Gram-positive bacterial strains. Addition ofthe efflux pump inhibitor phenylalanine-arginine-beta-naphthylamide(PA beta N) significantly improved the antibiotic activity in mostcases, with MIC values as low as 2.5 mu M and activity improvementfactors as high as 128-fold.
Introduction:
Decision making results not only from logical analyses, but seems to be further guided by the ability to perceive somatic information (interoceptive accuracy). Relations between interoceptive accuracy and decision making have been exclusively studied in adults and with regard to complex, uncertain situations (as measured by the Iowa Gambling Task, IGT).
Methods:
In the present study, 1454 children (6-11 years) were examined at two time points (approximately 1 year apart) using an IGT as well as a delay-of-gratification task for sweets-items and toy-items. Interoceptive accuracy was measured using a child-adapted version of the Heartbeat Perception Task.
Results:
The present results revealed that children with higher, as compared to lower, interoceptive accuracy showed more advantageous choices in the IGT and delayed more sweets-items, but not toy-items, in a delay-of-gratification task at time point 2 but not at time point 1. However, no longitudinal relation between interoceptive accuracy and decision making 1 year later could be shown.
Discussion:
Results indicate that interoceptive accuracy relates to decision-making abilities in situations of varying complexity already in middle childhood, and that this link might consolidate across the examined 1-year period. Furthermore, the association of interoceptive accuracy and the delay of sweets-items might have implications for the regulation of body weight at a later age.
Weathering the storm?
(2023)
Democratization scholars are currently debating if we are indeed witnessing a third wave of autocratization. While this has led to an extensive debate about the future of the liberal international order, we still know relatively little about the consequences of autocratization for international organizations (IOs). In this article, we explore to what extent autocratization has led to changes in the composition of IO membership. We propose three different ways of conceptualizing autocratization of IO membership. We argue that we should move away from a dichotomous understanding of regime type and regime change, but rather focus on composition of subregime types to understand current developments. We build on updated membership data for 73 IOs through 2020 to map membership configurations based on the V-Dem Electoral Democracy Index. Contrary to current debates on the crisis of the liberal order, we find that many IOs are not (yet) affected by broad autocratization of their membership that would endanger democratic majorities or overall democratic densities. However, we also observe the disappearance of formerly homogenous democratic clubs due to democratic backsliding in a number of European and Latin American IO member states, as well as a return of autocratic clubs in Southeast Asia and Southern Africa. These findings have important implications for the broader research agenda on international democracy promotion and human right protection as well as the study of legitimacy and the effectiveness of international organizations.
The analysis of event time series is in general challenging. Most time series analysis tools are limited for the analysis of this kind of data. Recurrence analysis, a powerful concept from nonlinear time series analysis, provides several opportunities to work with event data and even for the most challenging task of comparing event time series with continuous time series. Here, the basic concept is introduced, the challenges are discussed, and the future perspectives are summarized.
International institutions are an essential driving force of contemporary policies to combat gender-based violence but remain toothless if political actors do not implement them in domestic policies. How can scholars conceptualise the transposition of international gender-based violence norms into domestic policies? I argue that discourse network analysis provides a powerful conceptual and methodological extension of critical frame analysis to understand how frames shape the meaning of gender-based violence norms in multi-level institutional contexts. Frames’ normative and cognitive network structure invites combining discourse network and frame analysis techniques that locate frames’ power in their ability to connect different institutional spheres temporally and spatially. I outline a multi-level research agenda that traces the framing processes of international norms and their domestic implementation through gender-based violence policies in the Council of Europe’s Istanbul Convention. This agenda includes avenues to study how complex transnational policy frameworks like the Istanbul Convention play out in domestic policy implementation.
About 15 years ago, the first Massive Open Online Courses (MOOCs) appeared and revolutionized online education with more interactive and engaging course designs. Yet, keeping learners motivated and ensuring high satisfaction is one of the challenges today's course designers face. Therefore, many MOOC providers employed gamification elements that only boost extrinsic motivation briefly and are limited to platform support. In this article, we introduce and evaluate a gameful learning design we used in several iterations on computer science education courses. For each of the courses on the fundamentals of the Java programming language, we developed a self-contained, continuous story that accompanies learners through their learning journey and helps visualize key concepts. Furthermore, we share our approach to creating the surrounding story in our MOOCs and provide a guideline for educators to develop their own stories. Our data and the long-term evaluation spanning over four Java courses between 2017 and 2021 indicates the openness of learners toward storified programming courses in general and highlights those elements that had the highest impact. While only a few learners did not like the story at all, most learners consumed the additional story elements we provided. However, learners' interest in influencing the story through majority voting was negligible and did not show a considerable positive impact, so we continued with a fixed story instead. We did not find evidence that learners just participated in the narrative because they worked on all materials. Instead, for 10-16% of learners, the story was their main course motivation. We also investigated differences in the presentation format and concluded that several longer audio-book style videos were most preferred by learners in comparison to animated videos or different textual formats. Surprisingly, the availability of a coherent story embedding examples and providing a context for the practical programming exercises also led to a slightly higher ranking in the perceived quality of the learning material (by 4%). With our research in the context of storified MOOCs, we advance gameful learning designs, foster learner engagement and satisfaction in online courses, and help educators ease knowledge transfer for their learners.
Sanctions are critical to the Security Council's efforts to fight terrorism. What is striking is that the Council's sanctions regimes are subject to detailed sets of rules and decision criteria. The scholarship on human rights in counterterrorism assumes that rights advocacy and court litigation have prompted this development. The article complements this literature by highlighting an unexplored internal driver of legal-regulatory decision-making and explores how mixed-motive interest constellations among Security Council members have affected the extent of committee regulations and the content of decisions taken by sanctions committees. Based on internal documents and diplomatic cables, a comparative analysis of the Iraq sanctions regime and the counterterrorism sanctions regime demonstrates that mixed-motive interest constellations among Security Council members provide incentives to elaborate rules to guide decision-making resulting in legal-regulatory sanctions governance, even if the human rights of targeted individuals are not at stake. For comparative leverage and to assess the limits of the proposed mechanism, the analysis is briefly extended to other sanctions regimes targeting individuals (Democratic Republic of the Congo and Sudan). The findings have implications for this essential tool of the Security Council to react to threats to peace as diverse as counterterrorism, nonproliferation, and internal armed conflict.
Background: The worldwide prevalence of diabetes has been increasing in recent years, with a projected prevalence of 700 million patients by 2045, leading to economic burdens on societies. Type 2 diabetes mellitus (T2DM), representing more than 95% of all diabetes cases, is a multifactorial metabolic disorder characterized by insulin resistance leading to an imbalance between insulin requirements and supply. Overweight and obesity are the main risk factors for developing type 2 diabetes mellitus. The lifestyle modification of following a healthy diet and physical activity are the primary successful treatment and prevention methods for type 2 diabetes mellitus. Problems may exist with patients not achieving recommended levels of physical activity. Electrical muscle stimulation (EMS) is an increasingly popular training method and has become in the focus of research in recent years. It involves the external application of an electric field to muscles, which can lead to muscle contraction. Positive effects of EMS training have been found in healthy individuals as well as in various patient groups. New EMS devices offer a wide range of mobile applications for whole-body electrical muscle stimulation (WB-EMS) training, e.g., the intensification of dynamic low-intensity endurance exercises through WB-EMS. This dissertation project aims to investigate whether WB-EMS is suitable for intensifying low-intensive dynamic exercises such as walking and Nordic walking.
Methods: Two independent studies were conducted. The first study aimed to investigate the reliability of exercise parameters during the 10-meter Incremental Shuttle Walk Test (10MISWT) using superimposed WB-EMS (research question 1, sub-question a) and the difference in exercise intensity compared to conventional walking (CON-W, research question 1, sub-question b). The second study aimed to compare differences in exercise parameters between superimposed WB-EMS (WB-EMS-W) and conventional walking (CON-W), as well as between superimposed WB-EMS (WB-EMS-NW) and conventional Nordic walking (CON-NW) on a treadmill (research question 2). Both studies took place in participant groups of healthy, moderately active men aged 35-70 years. During all measurements, the Easy Motion Skin® WB-EMS low frequency stimulation device with adjustable intensities for eight muscle groups was used. The current intensity was individually adjusted for each participant at each trial to ensure safety, avoiding pain and muscle cramps. In study 1, thirteen individuals were included for each sub question. A randomized cross-over design with three measurement appointments used was to avoid confounding factors such as delayed onset muscle soreness. The 10MISWT was performed until the participants no longer met the criteria of the test and recording five outcome measures: peak oxygen uptake (VO2peak), relative VO2peak (rel.VO2peak), maximum walk distance (MWD), blood lactate concentration, and the rate of perceived exertion (RPE).
Eleven participants were included in study 2. A randomized cross-over design in a study with four measurement appointments was used to avoid confounding factors. A treadmill test protocol at constant velocity (6.5 m/s) was developed to compare exercise intensities. Oxygen uptake (VO2), relative VO2 (rel.VO2) blood lactate, and the RPE were used as outcome variables. Test-retest reliability between measurements was determined using a compilation of absolute and relative measures of reliability. Outcome measures in study 2 were studied using multifactorial analyses of variances.
Results: Reliability analysis showed good reliability for VO2peak, rel.VO2peak, MWD and RPE with no statistically significant difference for WB-EMS-W during 10WISWT. However, differences compared to conventional walking in outcome variables were not found. The analysis of the treadmill tests showed significant effects for the factors CON/WB-EMS and W/NW for the outcome variables VO2, rel.VO2 and lactate, with both factors leading to higher results. However, the difference in VO2 and relative VO2 is within the range of biological variability of ± 12%. The factor combination EMS∗W/NW is statistically non-significant for all three variables. WB-EMS resulted in the higher RPE values, RPE differences for W/NW and EMS∗W/NW were not significant.
Discussion: The present project found good reliability for measuring VO2peak, rel. VO2peak, MWD and RPE during 10MISWT during WB-EMS-W, confirming prior research of the test. The test appears technically limited rather than physiologically in healthy, moderately active men. However, it is unsuitable for investigating differences in exercise intensities using WB-EMS-W compared to CON-W due to different perceptions of current intensity between exercise and rest. A treadmill test with constant walking speed was conducted to adjust individual maximum tolerable current intensity for the second part of the project. The treadmill test showed a significant increase in metabolic demands during WB-EMS-W and WB-EMS-NW by an increased VO2 and blood lactate concentration. However, the clinical relevance of these findings remains debatable. The study also found that WB-EMS superimposed exercises are perceived as more strenuous than conventional exercise. While in parts comparable studies lead to higher results for VO2, our results are in line with those of other studies using the same frequency. Due to the minor clinical relevance the use of WB-EMS as exercise intensification tool during walking and Nordic walking is limited. High device cost should be considered. Habituation to WB-EMS could increase current intensity tolerance and VO2 and make it a meaningful method in the treatment of T2DM. Recent figures show that WB-EMS is used in obese people to achieve health and weight goals. The supposed benefit should be further investigated scientifically.
In nowadays production, fluctuations in demand, shortening product life-cycles, and highly configurable products require an adaptive and robust control approach to maintain competitiveness. This approach must not only optimise desired production objectives but also cope with unforeseen machine failures, rush orders, and changes in short-term demand. Previous control approaches were often implemented using a single operations layer and a standalone deep learning approach, which may not adequately address the complex organisational demands of modern manufacturing systems. To address this challenge, we propose a hyper-heuristics control model within a semi-heterarchical production system, in which multiple manufacturing and distribution agents are spread across pre-defined modules. The agents employ a deep reinforcement learning algorithm to learn a policy for selecting low-level heuristics in a situation-specific manner, thereby leveraging system performance and adaptability. We tested our approach in simulation and transferred it to a hybrid production environment. By that, we were able to demonstrate its multi-objective optimisation capabilities compared to conventional approaches in terms of mean throughput time, tardiness, and processing of prioritised orders in a multi-layered production system. The modular design is promising in reducing the overall system complexity and facilitates a quick and seamless integration into other scenarios.
In nowadays production, fluctuations in demand, shortening product life-cycles, and highly configurable products require an adaptive and robust control approach to maintain competitiveness. This approach must not only optimise desired production objectives but also cope with unforeseen machine failures, rush orders, and changes in short-term demand. Previous control approaches were often implemented using a single operations layer and a standalone deep learning approach, which may not adequately address the complex organisational demands of modern manufacturing systems. To address this challenge, we propose a hyper-heuristics control model within a semi-heterarchical production system, in which multiple manufacturing and distribution agents are spread across pre-defined modules. The agents employ a deep reinforcement learning algorithm to learn a policy for selecting low-level heuristics in a situation-specific manner, thereby leveraging system performance and adaptability. We tested our approach in simulation and transferred it to a hybrid production environment. By that, we were able to demonstrate its multi-objective optimisation capabilities compared to conventional approaches in terms of mean throughput time, tardiness, and processing of prioritised orders in a multi-layered production system. The modular design is promising in reducing the overall system complexity and facilitates a quick and seamless integration into other scenarios.
Our study applies legitimacy theorizing to service research, zooming in on co-prosumption service business models, which reside on significant direct contacts among provider-actors and customers as well as fellow customers in the service space. Our findings are based on a longitudinal flexible pattern matching method on 17 coworking spaces. The service cocreation nuances the double role of customers as evaluators and cocreators of legitimacy. This is because customers can have immediate perceptions of the actions and values of the services in their legitimacy evaluation while cocreating the service. Legitimacy shaped via social and recursive processes occurs in three stages: provisional, calibrated, and affirmed legitimacy. Findings inform four trajectory mechanisms of value-in-use pattern provenance, emergent Business Model development adaptive to the spatial context and loyal customers, visible trances as well as inside-out and outside-in identification processes. Further, the processes in the micro-ecosystem of an interstitial service space can develop a superordinate logic which overlays the potentially present coopetive and heterogenous institutional logics and interests of service customers.
Purpose – Design thinking has become an omnipresent process to foster innovativeness in various fields. Due to its popularity in both practice and theory, the number of publications has been growing rapidly. The authors aim to develop a research framework that reflects the current state of research and allows for the identification of research gaps.
Design/methodology/approach – The authors conduct a systematic literature review based on 164 scholarly articles on design thinking.
Findings – This study proposes a framework, which identifies individual and organizational context factors, the stages of a typical design thinking process with its underlying principles and tools, and the individual as well as organizational outcomes of a design thinking project.
Originality/value – Whereas previous reviews focused on particular aspects of design thinking, such as its characteristics, the organizational culture as a context factor or its role on new product development, the authors provide a holistic overview of the current state of research.
Strategic social media use positively influences organizational goals such as the long-term accrual of social capital, and thus social media information governance has become an increasingly important organizational objective. It is particularly important for humanitarian nongovernmental organizations (HNGOs), whose work relies on accurate and timely information regarding socially altruistic behavior (donations, volunteerism, etc.). Despite the potential of social media for increasing social capital, tensions in governing social media information across an organization's different operational levels (regional, intermediate, and national) pose a difficult challenge. Prominent governance frameworks offer little guidance, as their focus on control and incremental policymaking is largely incompatible with the processes, roles, standards, and metrics needed for managing self-governing social media. This study offers a notion of dynamic and co-evolutionary process management of multi-level organizations as a means of conceptualizing social media information governance for the accrual of organizational social capital. Based on interviews with members of HNGOs, this study reveals tensions that emerge within eight focus areas of accruing social capital in multi-level organizations, explains how dynamic process management can ease those tensions, and proposes corresponding strategy recommendations.
Many international organisations (IOs) are currently challenged, yet are they also in decline? Despite much debate on the crisis of liberal international order, con-testation, loss of legitimacy, gridlock, pathologies and exiting member states, there is little research on IO decline. This article seeks to clarify this concept and argues that decline can be considered in absolute and relative terms. Absolute decline involves a decrease in the number of IOs and their authority, member-ship and output, whereas relative decline concerns a decrease in the centrality of IOs in international relations. Reviewing a wide range of indicators, this article argues that, whereas there is limited decline in absolute terms since 1945, there may well be important decline in relative terms. Relative decline is more difficult to measure, but to probe its significance this article presents data from speeches during the United Nations General Assembly General Debate. It shows that IOs were most often mentioned in 1996 and that there has been a decline since. These findings indicate that, whereas IOs might survive as institutions, they are decreasingly central to international relations.
Governance abhors a vacuum
(2023)
International organisations have become increasingly contested resulting in worries about their decline and termination. While international organisation termination is indeed a regular event in international relations, this article shows that other institutions carry the legacy of terminated international organisations. We develop the novel concept of international organisation afterlife and suggest indicators to systematically assess it. Our analysis of 26 major terminated international organisations reveals legal-institutional and asset continuity in 21 cases. To further illustrate this point, the article zooms in on the afterlife of the International Institute of Agriculture in the Food and Agriculture Organization, the International Refugee Organization in the United Nations High Commissioner for Refugees, and the Western European Union in the European Union. In these three cases, international organisation afterlife inspired and structured the design of their successor institutions. While specific international organisations might be terminated, international cooperation therefore often lives on in other institutions.
The synthesis and the crystal structure of the double cluster compound [Nb6Cl14(MeCN)(4)][Nb6Cl14(pyz)(4)]middot6CH(3)CN are described. The synthesis is based on a partial ligand exchange reaction, which proceeds upon dissolving [Nb6Cl14(pyz)(4)]middot2CH(2)Cl(2) in acetonitrile. The compound is built up of two discrete neutral cluster units, which consist of octahedra of Nb-6 atoms coordinated by 12 edge-bridging chlorido and two terminal chlorido ligands, and four acetonitrile ligands on one and four pyrazine ligands on the other cluster unit. Co-crystallized acetonitrile molecules are also present. The single-crystal structure determination has revealed a cluster arrangement in which the [Nb6Cl14(pyz)(4)] units are connected by (halogen) lone-pair-(pyrazine) pi interactions. These lead to chains of [Nb6Cl14(pyz)(4)] clusters. These chains are further connected to cluster layers by (nitrile-halogen) dipole-dipole interactions, in which the [Nb6Cl14(MeCN)(4)] and co-crystallized MeCN molecules are also involved. These cluster layers are arranged parallel to the crystallographic {011} plane.
Design thinking is a well-established practical and educational approach to fostering high-level creativity and innovation, which has been refined since the 1950s with the participation of experts like Joy Paul Guilford and Abraham Maslow. Through real-world projects, trainees learn to optimize their creative outcomes by developing and practicing creative cognition and metacognition. This paper provides a holistic perspective on creativity, enabling the formulation of a comprehensive theoretical framework of creative metacognition. It focuses on the design thinking approach to creativity and explores the role of metacognition in four areas of creativity expertise: Products, Processes, People, and Places. The analysis includes task-outcome relationships (product metacognition), the monitoring of strategy effectiveness (process metacognition), an understanding of individual or group strengths and weaknesses (people metacognition), and an examination of the mutual impact between environments and creativity (place metacognition). It also reviews measures taken in design thinking education, including a distribution of cognition and metacognition, to support students in their development of creative mastery. On these grounds, we propose extended methods for measuring creative metacognition with the goal of enhancing comprehensive assessments of the phenomenon. Proposed methodological advancements include accuracy sub-scales, experimental tasks where examinees explore problem and solution spaces, combinations of naturalistic observations with capability testing, as well as physiological assessments as indirect measures of creative metacognition.
Case report
(2023)
The increasing prevalence of Long COVID is an imminent public health disaster, and established approaches have not provided adequate diagnostics or treatments. Recently, anesthetic blockade of the stellate ganglion was reported to improve Long COVID symptoms in a small case series, purportedly by "rebooting" the autonomic nervous system. Here, we present a novel diagnostic approach based on the Adaptive Force (AF), and report sustained positive outcome for one severely affected Long COVID patient using individualized pulsed electromagnetic field (PEMF) at the area C7/T1. AF reflects the capacity of the neuromuscular system to adapt adequately to external forces in an isometric holding manner. In case, maximal isometric AF (AFiso(max)) is exceeded, the muscle merges into eccentric muscle action. Thereby, the force usually increases further until maximal AF (AFmax) is reached. In case adaptation is optimal, AFiso(max) is similar to 99-100% of AFmax. This holding capacity (AFiso(max)) was found to be vulnerable to disruption by unpleasant stimulus and, hence, was regarded as functional parameter. AF was assessed by an objectified manual muscle test using a handheld device. Prior to treatment, AFiso(max) was considerably lower than AFmax for hip flexors (62 N = similar to 28% AFmax) and elbow flexors (71 N = similar to 44% AFmax); i.e., maximal holding capacity was significantly reduced, indicating dysfunctional motor control. We tested PEMF at C7/T1, identified a frequency that improved neuromuscular function, and applied it for similar to 15 min. Immediately post-treatment, AFiso(max) increased to similar to 210 N (similar to 100% AFmax) at hip and 184 N (similar to 100% AFmax) at elbow. Subjective Long COVID symptoms resolved the following day. At 4 weeks post-treatment, maximal holding capacity was still on a similarly high level as for immediately post-treatment (similar to 100% AFmax) and patient was symptom-free. At 6 months the patient's Long COVID symptoms have not returned. This case report suggests (1) AF could be a promising diagnostic for post-infectious illness, (2) AF can be used to test effective treatments for post-infectious illness, and (3) individualized PEMF may resolve post-infectious symptoms.
We conduct a laboratory experiment to study how locus of control operates through people's preferences and beliefs to influence their decisions. Using the principal-agent setting of the delegation game, we test four key channels that conceptually link locus of control to decision-making: (i) preference for agency; (ii) optimism and (iii) confidence regarding the return to effort; and (iv) illusion of control. Knowing the return and cost of stated effort, principals either retain or delegate the right to make an investment decision that generates payoffs for themselves and their agents. Extending the game to the context in which the return to stated effort is unknown allows us to explicitly study the relationship between locus of control and beliefs about the return to effort. We find that internal locus of control is linked to the preference for agency, an effect that is driven by women. We find no evidence that locus of control influences optimism and confidence about the return to stated effort, or that it operates through an illusion of control.
Paid parental leave schemes have been shown to increase women’s employment rates but to decrease their wages in case of extended leave duration. In view of these potential trade-offs, many countries are discussing the optimal design of parental leave policies. We analyze the impact of a major parental leave reform on mothers’ long-term earnings. The 2007 German parental leave reform replaced a means-tested benefit with a more generous earnings-related benefit that is granted for a shorter period of time. Additionally, a ”daddy quota” of two months was introduced. To identify the causal effect of this policy mix on long-run earnings of mothers, we use a difference-in-differences approach that compares labor market outcomes of mothers who gave birth just before and right after the reform and nets out seasonal effects by including the year before. Using administrative social security data, we confirm previous findings and show that the average duration of employment interruptions increased for mothers with high pre-birth earnings. Nevertheless, we find a positive long-run effect on earnings for mothers in this group. This effect cannot be explained by changes in the selection of working mothers, working hours or changes in employer stability. Descriptive evidence suggests that the stronger involvement of fathers, incentivized by the ”daddy months”, could have facilitated mothers’ re-entry into the labor market and thereby increased earnings. For mothers with low pre-birth earnings, however, we do not find beneficial long-run effects of this parental leave reform.
Predicting entrepreneurial development based on individual and business-related characteristics is a key objective of entrepreneurship research. In this context, we investigate whether the motives of becoming an entrepreneur influence the subsequent entrepreneurial development. In our analysis, we examine a broad range of business outcomes including survival and income, as well as job creation, and expansion and innovation activities for up to 40 months after business formation. Using the self-determination theory as conceptual background, we aggregate the start-up motives into a continuous motivational index. We show – based on a unique dataset of German start-ups from unemployment and non-unemployment – that the later business performance is better, the higher they score on this index. Effects are particularly strong for growth-oriented outcomes like innovation and expansion activities. In a next step, we examine three underlying motivational categories that we term opportunity, career ambition, and necessity. We show that individuals driven by opportunity motives perform better in terms of innovation and business expansion activities, while career ambition is positively associated with survival, income, and the probability of hiring employees. All effects are robust to the inclusion of a large battery of covariates that are proven to be important determinants of entrepreneurial performance.
Objective:
Following a life course perspective, this study examines the link between partnership trajectories and three dimensions of psychological well-being: psychological health, overall sense of self-worth and quality of life.
Background:
Assuming that life outcomes are the result of prior decisions, experiences and events, partnership histories can be seen as a resource for psychological well-being. Furthermore, advantages or disadvantages from living with or without a partner should accumulate over time. While previous cross-sectional research has mainly focused on the influence of partnership status or a status change on well-being, prior longitudinal studies could not control for reverse causality of well-being and partnership trajectories. This research addresses the question of how different patterns of partnership biographies are related to a person's well-being in middle adulthood. Selection effects of pre-trajectory well-being as well as current life conditions are also taken into account.
Method:
Using data from the German LifE Study, the partnership trajectories between ages of 16 and 45 are classified by sequence and cluster analysis. OLS regression is then used to examine the link between types of partnership trajectories and depression, self-esteem and overall life satisfaction at age 45.
Results:
For women, well-being declined when experiencing unstable non-cohabitational union trajectories or divorce followed by unpartnered post-marital trajectories. Men suffered most from being long-term single. The results could not be explained by selection effects of pre-trajectory well-being.
Conclusion:
While women seem to 'recover' from most of the negative effects of unstable partnership trajectories through a new partnership, for men it was shown that being mainly unpartnered has long-lasting effects on their psychological well-being.
Carbon nitride semiconductors: properties and application as photocatalysts in organic synthesis
(2023)
Graphitic carbon nitrides (g-CNs) are represented by melon-type g-CN, poly(heptazine imides) (PHIs), triazine-based g-CN and poly(triazine imide) with intercalated LiCl (PTI/Li+Cl‒). These materials are composed of sp2-hybridized carbon and nitrogen atoms; C:N ratio is close to 3:4; the building unit is 1,3,5-triazine or tri-s-triazine; the building units are interconnected covalently via sp2-hybridized nitrogen atoms or NH-moieties; the layers are assembled into a stack via weak van der Waals forces as in graphite. Due to medium band gap (~2.7 eV) g-CNs, such as melon-type g-CN and PHIs, are excited by photons with wavelength ≤ 460 nm. Since 2009 g-CNs have been actively studied as photocatalysts in evolution of hydrogen and oxygen – two half-reactions of full water splitting, by employing corresponding sacrificial agents. At the same time application of g-CNs as photocatalysts in organic synthesis has been remaining limited to few reactions only. Cumulative Habilitation summarizes research work conducted by the group ‘Innovative Heterogeneous Photocatalysis’ between 2017-2023 in the field of carbon nitride organic photocatalysis, which is led by Dr. Oleksandr Savatieiev.
g-CN photocatalysts activate molecules, i.e. generate their more reactive open-shell intermediates, via three modes: i) Photoinduced electron transfer (PET); ii) Excited state proton-coupled electron transfer (ES-PCET) or direct hydrogen atom transfer (dHAT); iii) Energy transfer (EnT). The scope of reactions that proceed via oxidative PET, i.e. one-electron oxidation of a substrate to the corresponding radical cation, are represented by synthesis of sulfonylchlorides from S-acetylthiophenols. The scope of reactions that proceed via reductive PET, i.e. one-electron reduction of a substrate to the corresponding radical anion, are represented by synthesis of γ,γ-dichloroketones from the enones and chloroform.
Due to abundance of sp2-hybridized nitrogen atoms in the structure of g-CN materials, they are able to cleave X-H bonds in organic molecules and store temporary hydrogen atom. ES-PCET or dHAT mode of organic molecules activation to the corresponding radicals is implemented for substrates featuring relatively acidic X-H bonds and those that are characterized by low bond dissociation energy, such as C-H bond next to the heteroelements. On the other hand, reductively quenched g-CN carrying hydrogen atom reduces a carbonyl compound to the ketyl radical via PCET that is thermodynamically more favorable pathway compared to the electron transfer. The scope of these reactions is represented by cyclodimerization of α,β-unsaturated ketones to cyclopentanoles.
g-CN excited state demonstrates complex dynamics with the initial formation of singlet excited state, which upon intersystem crossing produces triplet excited state that is characterized by the lifetime > 2 μs. Due to long lifetime, g-CN activate organic molecules via EnT. For example, g-CN sensitizes singlet oxygen, which is the key intermediate in the dehydrogenation of aldoximes to nitrileoxides. The transient nitrileoxide undergoes [3+2]-cycloaddition to nitriles and gives oxadiazoles-1,2,4.
PET, ES-PCET and EnT are fundamental phenomena that are applied beyond organic photocatalysis. Hybrid composite is formed by combining conductive polymers, such as poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) with potassium poly(heptazine imide) (K-PHI). Upon PET, K-PHI modulated population of polarons and therefore conductivity of PEDOT:PSS. The initial state of PEDOT:PSS is recovered upon material exposure to O2. K-PHI:PEDOT:PSS may be applied in O2 sensing.
In the presence of electron donors, such as tertiary amines and alcohols, and irradiation with light, K-PHI undergoes photocharging – the g-CN material accumulates electrons and charge-compensating cations. Such photocharged state is stable under anaerobic conditions for weeks, but at the same time it is a strong reductant. This feature allows decoupling in time light harvesting and energy storage in the form of electron-proton couples from utilization in organic synthesis. The photocharged state of K-PHI reduces nitrobenzene to aniline, and enables dimerization of α,β-unsaturated ketones to hexadienones in dark.