The Youth Collaborative Mental Health Survey: A Community-Based Participatory Research Approach Using Constructivism With Majority Hispanic Youth

Youth today face novel mental health challenges compared to youth of previous generations. Youth voice in research is necessary to better understand and alleviate this national youth mental health crisis, but current U.S. nationally representative datasets on youth mental health lack youth voice in their survey designs. The academic team collaborated with 19 high school students to design a comprehensive youth mental health survey called the Youth Collaborative Mental Health Survey (YCMHS). The youth co-investigators represented the diversity of San Antonio, Texas, and were majority Hispanic. The constructivism pedagogy in education, which empowers youth voice in the learning process, was utilized to facilitate the youth-led creation of the YCMHS. During eight 2-hour meetings, the youth co-investigators designed the YCMHS with 20 domains and 195 questions. The YCMHS embraced respondent flexibility and voice and included 42 conditional response questions and 29 free-text response questions. The youth co-investigators led the survey administration at five schools during the 2020–2021 school year. The youth-led research design also strengthened collaboration between community and school partners. Takeaways from the academic team include the importance of being flexible and patient and advocating for the youth collaborators. Takeaways from the youth co-investigators include the importance of being open-minded, asking honest questions related to youth mental health, and being persistent. Future work will strengthen the scientific rigor of the YCMHS and highlight preliminary survey results

Dynamic Regulation of H3K27 Trimethylation during Arabidopsis Differentiation

During growth of multicellular organisms, identities of stem cells and differentiated cells need to be maintained. Cell fate is epigenetically controlled by the conserved Polycomb-group (Pc-G) proteins that repress their target genes by catalyzing histone H3 lysine 27 trimethylation (H3K27me3). Although H3K27me3 is associated with mitotically stable gene repression, a large fraction of H3K27me3 target genes are tissue-specifically activated during differentiation processes. However, in plants it is currently unclear whether H3K27me3 is already present in undifferentiated cells and dynamically regulated to permit tissue-specific gene repression or activation. We used whole-genome tiling arrays to identify the H3K27me3 target genes in undifferentiated cells of the shoot apical meristem and in differentiated leaf cells. Hundreds of genes gain or lose H3K27me3 upon differentiation, demonstrating dynamic regulation of an epigenetic modification in plants. H3K27me3 is correlated with gene repression, and its release preferentially results in tissue-specific gene activation, both during differentiation and in Pc-G mutants. We further reveal meristem- and leaf-specific targeting of individual gene families including known but also likely novel regulators of differentiation and stem cell regulation. Interestingly, H3K27me3 directly represses only specific transcription factor families, but indirectly activates others through H3K27me3-mediated silencing of microRNA genes. Furthermore, H3K27me3 targeting of genes involved in biosynthesis, transport, perception, and signal transduction of the phytohormone auxin demonstrates control of an entire signaling pathway. Based on these and previous analyses, we propose that H3K27me3 is one of the major determinants of tissue-specific expression patterns in plants, which restricts expression of its direct targets and promotes gene expression indirectly by repressing miRNA genes

An empirical investigation of volatility dynamics in the cryptocurrency market

By employing an asymmetric Diagonal BEKK model, this paper examines volatility dynamics of five major cryptocurrencies, namely Bitcoin, Ether, Ripple, Litecoin, and Stellar Lumen. It is shown that the conditional variances of all the five cryptocurrencies are significantly affected by both previous squared errors and past conditional volatility. Moreover, in the case of Bitcoin, Ether, Ripple, and Litecoin, asymmetric past shocks have a significant effect in the current conditional variance. Similar results are obtained for the cryptocurrencies' conditional covariances, which are significantly affected by cross products of previous error terms and past covariance terms while capturing asymmetric effects of past shocks accordingly. It is also shown that time-varying conditional correlations exist and are mostly positive. Finally, the cryptocurrencies' volatility dynamics are found to be responsive to major news, with Bitcoin and Litecoin exhibiting one structural breakpoint each in the conditional variance. The results improve our understanding of interdependencies between cryptocurrencies as well as of the events that affect their volatility dynamics and thus have important implications for both cryptocurrency users and investors

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements