Filtering by
- All Subjects: tobacco
- All Subjects: PRIMARY CHARGE SEPARATION
- Creators: Redding, Kevin E
- Creators: Lodha, Pratishtha
- Creators: Pearson, Jennifer
- Creators: Wachter, Rebekka M.
The PsaA-A684N mutants exhibited increased ET on the B-branch as compared to the A-branch in both in vivo and in vitro conditions. The transient electron paramagnetic resonance (EPR) spectroscopy revealed the formation of increased B-side radical pair (RP) at ambient and cryogenic temperatures. The ultrafast transient absorption spectroscopy and fluorescence decay measurement of the PsaA-A684N and PsaB-A664N showed a slight deceleration of energy trapping. Thus making mutations near ec2 on each branch resulted into modulation of the charge separation process. In the second set of mutants, where ec2 cofactor was target by substitution of PsaA-Asn604 or PsaB-Asn591 to other amino acids, a drop in energy trapping was observed. The quantum yield of CS decreases in Asn to Leu and His mutants on the respective branch. The P700 triplet state was not observed at room and cryogenic temperature for these mutants, nor was a rapid decay of P700+ in the nanosecond timescale, indicating that the mutations do not cause a blockage of electron transfer from the ec3 Chl. Time-resolved fluorescence results showed a decrease in the lifetime of the energy trapping. We interpret this decrease in lifetime as a new channel of excitation energy decay, in which the untrapped energy dissipates as heat through a fast internal conversion process. Thus, a variety of spectroscopic measurements of PSI with point mutations near the ec2 cofactor further support that the ec2 cofactor is involved in energy trapping process.
Due to the COVID-19 pandemic, declared in March of 2020, there have been many lifestyle changes which have likely influenced tobacco smoking behavior. Such lifestyle changes include lockdowns, stay at home orders, reduction in social cues related to smoking, increased stress, and boredom among other things. This study utilized a cross-sectional survey which looked into these behaviors, primarily perceived risk to COVID-19, and determined if there is an association between perceived risk and education level/race. Education level is a proxy for income and material resources, therefore making it more likely that people with lower levels of education have fewer resources and higher perceived risk to negative effects of COVID-19. Additionally, people of color are often marginalized in the medical community along with being the target of heavy advertising by tobacco companies which have likely impacted risk to COVID-19 as well.