Adolescents' Drinking Behavior Off- and Online: Disentangling Exposure Effects and Selective Exposure in Networked Communication Structures.

This article applies a network approach to better understand the often-demonstrated link between adolescents' drinking behavior and their exposure to alcohol-related content on social media. Focusing on social dynamics among adolescents and their peers, we investigate the causes and consequences of exposure to individual peers who share alcohol-related content online. Drawing on social network literature and the perspective of networked communication online, we distinguish between exposure effects and selective exposure as the two core dynamics that can explain the association between drinking behavior and exposure to alcohol-related content online. Based on a two-wave network survey among adolescents aged 14 to 17 (n = 277), we applied a longitudinal network analysis to test both dynamics simultaneously. The findings indicate no exposure effects but robust evidence for selective exposure. This means that drinking adolescents are more likely to become exposed to peers who post alcohol-related content. The stochastic actor-oriented model hereby controls for rivaling explanations, such as the tendency to be exposed to friends, classmates, and peers of the same gender. In addition to these empirical findings, we discuss the value of the network approach, outlining the implications for future research and prevention strategies.

The guanine nucleotide exchange factor Rin-like controls Tfh cell differentiation via CD28 signaling.

T follicular helper (Tfh) cells are essential for the development of germinal center B cells and high-affinity antibody-producing B cells in humans and mice. Here, we identify the guanine nucleotide exchange factor (GEF) Rin-like (Rinl) as a negative regulator of Tfh generation. Loss of Rinl leads to an increase of Tfh in aging, upon in vivo immunization and acute LCMV Armstrong infection in mice, and in human CD4+ T cell in vitro cultures. Mechanistically, adoptive transfer experiments using WT and Rinl-KO naïve CD4+ T cells unraveled T cell-intrinsic GEF-dependent functions of Rinl. Further, Rinl regulates CD28 internalization and signaling, thereby shaping CD4+ T cell activation and differentiation. Thus, our results identify the GEF Rinl as a negative regulator of global Tfh differentiation in an immunological context and species-independent manner, and furthermore, connect Rinl with CD28 internalization and signaling pathways in CD4+ T cells, demonstrating for the first time the importance of endocytic processes for Tfh differentiation.

A multi-omics based anti-inflammatory immune signature characterizes long COVID-19 syndrome.

To investigate long COVID-19 syndrome (LCS) pathophysiology, we performed an exploratory study with blood plasma derived from three groups: 1) healthy vaccinated individuals without SARS-CoV-2 exposure; 2) asymptomatic recovered patients at least three months after SARS-CoV-2 infection and; 3) symptomatic patients at least 3 months after SARS-CoV-2 infection with chronic fatigue syndrome or similar symptoms, here designated as patients with long COVID-19 syndrome (LCS). Multiplex cytokine profiling indicated slightly elevated pro-inflammatory cytokine levels in recovered individuals in contrast to patients with LCS. Plasma proteomics demonstrated low levels of acute phase proteins and macrophage-derived secreted proteins in LCS. High levels of anti-inflammatory oxylipins including omega-3 fatty acids in LCS were detected by eicosadomics, whereas targeted metabolic profiling indicated high levels of anti-inflammatory osmolytes taurine and hypaphorine, but low amino acid and triglyceride levels and deregulated acylcarnitines. A model considering alternatively polarized macrophages as a major contributor to these molecular alterations is presented.

Preclinical Establishment of a Divalent Vaccine against SARS-CoV-2.

First-generation vaccines against SARS-CoV-2 do not provide adequate immune protection. Therefore, we engineered a divalent gene construct combining the receptor-binding domain (RBD) of the spike protein and the immunodominant region of the viral nucleocapsid. This fusion protein was produced in either E. coli or a recombinant baculovirus system. Subsequently, the fusion protein was mixed with adjuvant and administered to mice in a prime-booster mode. Mice (72%) produced an IgG response against both proteins (titer: 10-4-10-5) 14 days after the first booster injection, which was increased to 100% by a second booster. Comparable IgG responses were detected against the delta, gamma and omicron variants of the RBD region. Durability testing revealed IgGs beyond 90 days. In addition, cytolytic effector cell molecules were increased in lymphocytes isolated from peripheral blood. Ex vivo stimulation of T cells by nucleocapsid and RBD peptides showed antigen-specific upregulation of CD44 among the CD4+ and CD8+ T cells of vaccinated mice. No side effect was documented in the central nervous system. Cumulatively, these data represent a proof-of-principle approach alternative to existing mRNA vaccination strategies.

Effectiveness of a tailored web app on sun protection intentions and its implications for skin cancer prevention: A randomized controlled trial.

Skin cancers related to sunexposure are rising globally, yet largely preventable. Digital solutions enable individually tailored prevention and may play a crucial role in reducing disease burden. We developed SUNsitive, a theory-guided web app to facilitate sun protection and skin cancer prevention. The app collected relevant information through a questionnaire and provided tailored feedback on personal risk, adequate sun protection, skin cancer prevention, and overall skin health. SUNsitive's effect on sun protection intentions and a set of secondary outcomes was evaluated with a two-arm randomized controlled trial (n = 244). At 2 weeks post-intervention, we did not find any statistical evidence for the intervention's effect on the primary outcome or any of the secondary outcomes. However, both groups reported improved intentions to sun protect compared to their baseline values. Furthermore, our process outcomes suggest that approaching sun protection and skin cancer prevention with a digital tailored "questionnaire-feedback" format is feasible, well-perceived, and well accepted. Trial registration: Protocol registration: ISRCTN registry (ISRCTN10581468).

Social Media Use in the Context of Drinking Onset: The Mutual Influences of Social Media Effects and Selectivity.

The article aims to provide a profound understanding of the multifaceted role of adolescents' social media use in the context of drinking onset. It differentiates between exposure and sharing effects from social media content on drinking behavior and, conversely, exposure to and sharing of alcohol-related content due to drinking in the initiation phase of regular alcohol consumption. We tested our hypotheses based on a two-wave survey among adolescents aged 13 to 17 and focused on those who had not yet been regular drinkers at the first wave of data collection (n = 406). Based on a cross-lagged panel model, we found that exposure to alcohol-related content (exposure effect) as well as the sharing of such content (sharing effect) affected drinking behavior, and that drinking behavior resulted in the sharing of alcohol-related content on social media (selective sharing). We discuss a self-concept verification spiral at the individual level and a social influence spiral at the social level to assess possible risk-reinforcing dynamics.

Transport through a strongly coupled graphene quantum dot in perpendicular magnetic field.

We present transport measurements on a strongly coupled graphene quantum dot in a perpendicular magnetic field. The device consists of an etched single-layer graphene flake with two narrow constrictions separating a 140 nm diameter island from source and drain graphene contacts. Lateral graphene gates are used to electrostatically tune the device. Measurements of Coulomb resonances, including constriction resonances and Coulomb diamonds prove the functionality of the graphene quantum dot with a charging energy of approximately 4.5 meV. We show the evolution of Coulomb resonances as a function of perpendicular magnetic field, which provides indications of the formation of the graphene specific 0th Landau level. Finally, we demonstrate that the complex pattern superimposing the quantum dot energy spectra is due to the formation of additional localized states with increasing magnetic field.