Jan Keller
Dados Biográficos
| ID | 3583670 |
|---|---|
| NOME | Jan Keller |
| PRENOMES | Jan |
| SOBRENOME | Keller |
| ASSINATURA | KELLER J |
| AFILIAÇÕES | Freie Universität Berlin |
| ORCID | 0000-0003-4660-6844 |
| VERIFICADO | Sim |
| TOTAL DE OBRAS | 20 |
| TOTAL DE CITAÇÕES | 21 |
| TOTAL COMO AUTOR | 20 |
| TOTAL COMO EDITOR | 0 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 1976 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 2025 |
| ÍNDICE H | 1 |
Planning a digital detox
In the recent years, studies on health consequences of smartphone usage time have increased, yet findings on the effectiveness of usage interventions remain unclear. This preregistered study investigates the effectiveness of a planning intervention to reduce total smartphone usage time. Additionally, it examines the interventions’ underlying mechanisms of self-efficacy, intention, action, and coping planning. A primary analysis of a randomized co…
The temporal dynamics of the association between daily physical activity and life satisfaction
PURPOSE: Life satisfaction (LS) is increasingly recognized as a crucial indicator and predictor of health and well-being across the lifespan. The impact of LS may be enhanced through physical activity (PA), although studies exploring the dynamic and bidirectional nature of the relationship are scarce. One principal goal of this project is to examine the dynamic, personalized interactions between LS and PA and exercise identity (the degree to whic…
Seropositivity and flight-associated risk factors for Sars-CoV-2 infection among asylum seekers arriving in Berlin, Germany – a cross-sectional study
Introduction: Refugees and asylum seekers might be at increased risk of SARS-CoV-2 infection due to precarious living conditions during flight. Methods: Between March 24th and June 15th 2021, we conducted a cross-sectional study among adult asylum seekers arriving in Berlin. Each participant was tested for acute SARS-CoV-2 infection with a nasopharyngeal swab using reverse transcriptase PCR (rt-PCR), and for anti-SARS-CoV-2-S1 IgG antibodies usin…
Developing habit-based health behaviour change interventions
OBJECTIVE: Habitual behaviours are triggered automatically, with little conscious forethought. Theory suggests that making healthy behaviours habitual, and breaking the habits that underpin many ingrained unhealthy behaviours, promotes long-term behaviour change. This has prompted interest in incorporating habit formation and disruption strategies into behaviour change interventions. Yet, notable research gaps limit understanding of how to harnes…
Handwashing adherence during the Covid-19 pandemic
Evaluating the Public Climate School—A School-Based Programme to Promote Climate Awareness and Action in Students
Introduction: School-based programmes may promote knowledge and skills required to address climate change and better health and well-being in adolescents, yet evidence of their effectiveness is limited. In preparation for evaluating the Public Climate School, a school-based intervention to promote climate awareness and action in adolescents, we conduct a pilot study intended to assess procedures for participant recruitment, retention, and data co…
What helps to form a healthy nutrition habit? Daily associations of intrinsic reward, anticipated regret, and self-efficacy with automaticity
Sars-CoV-2 Infection, Risk Perception, Behaviour and Preventive Measures at Schools in Berlin, Germany, during the Early Post-Lockdown Phase
Briefly before the first peak of the COVID-19 pandemic in Berlin, Germany, schools closed in mid-March 2020. Following re-opening, schools resumed operation at a reduced level for nine weeks. During this phase, we aimed at assessing, among students and teachers, infection status, symptoms, individual behaviour, and institutional infection prevention measures. Twenty-four primary and secondary school classes, randomly selected across Berlin, were …
The trajectory of Covid-19 pandemic and handwashing adherence
Clinical Trials.Gov, # NCT04367337
Digital detox
Smartphone use, e.g., on social network sites or instant messaging, can impair well-being and is related to clinical phenomena, like depression. Digital detox interventions have been suggested as a solution to reduce negative impacts from smartphone use on outcomes like well-being or social relationships. Digital detox is defined as timeouts from using electronic devices (e.g., smartphones), either completely or for specific subsets of smartphone…
Can individual, dyadic, or collaborative planning reduce sedentary behavior? A randomized controlled trial
What makes a good action plan? Characteristics and enactment of fruit and vegetable plans
Augmenting fruit and vegetable consumption by an online intervention
Which characteristics of planning matter? Individual and dyadic physical activity plans and their effects on plan enactment
Neue Soziale Risiken und Soziale Arbeit in der Transformationsgesellschaft
Neue soziale Risiken und Soziale Arbeit in der Transformationsgesellschaft
Resolution scaling in STED microscopy
We undertake a comprehensive study of the inverse square root dependence of spatial resolution on the saturation factor in stimulated emission depletion (STED) microscopy and generalize it to account for various focal depletion patterns. We used an experimental platform featuring a high quality depletion pattern which results in operation close to the optimal optical performance. Its superior image brightness and uniform effective resolution <25 …
Jak sociologie přichází o společnost [How Sociology Is Abandoning Society]
The article analyses the development and the current situation in sociology in relation to the transformations that contemporary society is going through. The author explores some basic sociological questions in an examination of the character of institutions and forms of social stratifi cation, showing how deeply these questions are connected with the character of 'organised modernity'. He analyses the transformations of society since the 1970s …
The Czech Republic
This article discusses some aspects of developments in the Czech Republic during the 15 years since the downfall of the Communist regime. At the level of social structures, the dominant trend has been a rapid growth of inequality, which has blocked the development of a middle-class society. At the political level, the most salient tendency is the growth of a 'silent majority', not least due to the murky methods of privatization and the manifest c…
Time of Transition
Digital detox
Smartphone use, e.g., on social network sites or instant messaging, can impair well-being and is related to clinical phenomena, like depression. Digital detox interventions have been suggested as a solution to reduce negative impacts from smartphone use on outcomes like well-being or social relationships. Digital detox is defined as timeouts from using electronic devices (e.g., smartphones), either completely or for specific subsets of smartphone…
Can individual, dyadic, or collaborative planning reduce sedentary behavior? A randomized controlled trial
Augmenting fruit and vegetable consumption by an online intervention
Which characteristics of planning matter? Individual and dyadic physical activity plans and their effects on plan enactment
Time of Transition
The Czech Republic
This article discusses some aspects of developments in the Czech Republic during the 15 years since the downfall of the Communist regime. At the level of social structures, the dominant trend has been a rapid growth of inequality, which has blocked the development of a middle-class society. At the political level, the most salient tendency is the growth of a 'silent majority', not least due to the murky methods of privatization and the manifest c…
Resolution scaling in STED microscopy
We undertake a comprehensive study of the inverse square root dependence of spatial resolution on the saturation factor in stimulated emission depletion (STED) microscopy and generalize it to account for various focal depletion patterns. We used an experimental platform featuring a high quality depletion pattern which results in operation close to the optimal optical performance. Its superior image brightness and uniform effective resolution <25 …
Jak sociologie přichází o společnost [How Sociology Is Abandoning Society]
The article analyses the development and the current situation in sociology in relation to the transformations that contemporary society is going through. The author explores some basic sociological questions in an examination of the character of institutions and forms of social stratifi cation, showing how deeply these questions are connected with the character of 'organised modernity'. He analyses the transformations of society since the 1970s …
Neue Soziale Risiken und Soziale Arbeit in der Transformationsgesellschaft
Neue soziale Risiken und Soziale Arbeit in der Transformationsgesellschaft
Which characteristics of planning matter? Individual and dyadic physical activity plans and their effects on plan enactment
Augmenting fruit and vegetable consumption by an online intervention
What makes a good action plan? Characteristics and enactment of fruit and vegetable plans
Sars-CoV-2 Infection, Risk Perception, Behaviour and Preventive Measures at Schools in Berlin, Germany, during the Early Post-Lockdown Phase
Briefly before the first peak of the COVID-19 pandemic in Berlin, Germany, schools closed in mid-March 2020. Following re-opening, schools resumed operation at a reduced level for nine weeks. During this phase, we aimed at assessing, among students and teachers, infection status, symptoms, individual behaviour, and institutional infection prevention measures. Twenty-four primary and secondary school classes, randomly selected across Berlin, were …
The trajectory of Covid-19 pandemic and handwashing adherence
Clinical Trials.Gov, # NCT04367337
Digital detox
Smartphone use, e.g., on social network sites or instant messaging, can impair well-being and is related to clinical phenomena, like depression. Digital detox interventions have been suggested as a solution to reduce negative impacts from smartphone use on outcomes like well-being or social relationships. Digital detox is defined as timeouts from using electronic devices (e.g., smartphones), either completely or for specific subsets of smartphone…
Can individual, dyadic, or collaborative planning reduce sedentary behavior? A randomized controlled trial
Evaluating the Public Climate School—A School-Based Programme to Promote Climate Awareness and Action in Students
Introduction: School-based programmes may promote knowledge and skills required to address climate change and better health and well-being in adolescents, yet evidence of their effectiveness is limited. In preparation for evaluating the Public Climate School, a school-based intervention to promote climate awareness and action in adolescents, we conduct a pilot study intended to assess procedures for participant recruitment, retention, and data co…
What helps to form a healthy nutrition habit? Daily associations of intrinsic reward, anticipated regret, and self-efficacy with automaticity
Seropositivity and flight-associated risk factors for Sars-CoV-2 infection among asylum seekers arriving in Berlin, Germany – a cross-sectional study
Introduction: Refugees and asylum seekers might be at increased risk of SARS-CoV-2 infection due to precarious living conditions during flight. Methods: Between March 24th and June 15th 2021, we conducted a cross-sectional study among adult asylum seekers arriving in Berlin. Each participant was tested for acute SARS-CoV-2 infection with a nasopharyngeal swab using reverse transcriptase PCR (rt-PCR), and for anti-SARS-CoV-2-S1 IgG antibodies usin…
Developing habit-based health behaviour change interventions
OBJECTIVE: Habitual behaviours are triggered automatically, with little conscious forethought. Theory suggests that making healthy behaviours habitual, and breaking the habits that underpin many ingrained unhealthy behaviours, promotes long-term behaviour change. This has prompted interest in incorporating habit formation and disruption strategies into behaviour change interventions. Yet, notable research gaps limit understanding of how to harnes…
Handwashing adherence during the Covid-19 pandemic
Planning a digital detox
In the recent years, studies on health consequences of smartphone usage time have increased, yet findings on the effectiveness of usage interventions remain unclear. This preregistered study investigates the effectiveness of a planning intervention to reduce total smartphone usage time. Additionally, it examines the interventions’ underlying mechanisms of self-efficacy, intention, action, and coping planning. A primary analysis of a randomized co…
The temporal dynamics of the association between daily physical activity and life satisfaction
PURPOSE: Life satisfaction (LS) is increasingly recognized as a crucial indicator and predictor of health and well-being across the lifespan. The impact of LS may be enhanced through physical activity (PA), although studies exploring the dynamic and bidirectional nature of the relationship are scarce. One principal goal of this project is to examine the dynamic, personalized interactions between LS and PA and exercise identity (the degree to whic…
Medicine (11 obras) · Psychology (11 obras) · Behavioral Health and Interventions (9 obras) · Computer Science (5 obras) · COVID-19 and Mental Health (5 obras) · Physical Activity and Health (5 obras) · Political science (5 obras) · Psychiatry (5 obras) · Psychological intervention (5 obras) · Social Psychology (5 obras)