A tunable approach to induce the formation of flexible nanofilms from small (3 nm) gold nanoparticles at oil/water interfaces

type of work: Research Articlepublication status: This is the accepted version of a research article. The final version of the article is available here: https://doi.org/10.1021/acs.jpcb.3c0727

Photosynthetic adaptations of polar phytoplankton to extreme low light

Polar phytoplankton are vital to global aquatic ecosystems, driving primary production, biogeochemical cycling, carbon sequestration, biodiversity, and climate regulation. Polar phytoplankton’s slow but significant productivity at exceptionally low light suggests possible adaptations for low-light photosynthesis. We hypothesized that maintaining photosynthesis under extremely low light involves suppressing energetically wasteful charge recombinations in Photosystem II. These recombinations desynchronize the four-step cycle of Photosystem II oxygen evolution. We used single turnover variable chlorophyll fluorescence to detect changes in recombination in polar diatoms and green algae in response to temperature and photon delivery spacing. Prolonged synchronous cycling indicates fewer wasteful recombination reactions and, thus, more efficient photosynthetic energy conversion under low light. We observed that higher photon delivery rates and colder temperatures result in less recombination within taxa. Further, polar taxa synchronized cycles for longer durations than temperate taxa under comparable conditions. Our findings support our hypothesis that diverse polar phytoplankton have evolved capacities to suppress energetically wasteful charge recombinations and sustain photosynthesis under extremely low light. This research challenges the conventional understanding of the limits on photosynthesis under light limitation, helping unravel polar ecosystem dynamics and predict their ecosystem responses to climate change

Testing the energy resolution capabilities of the Compton And Two Photons Spectrometer

The nuclear equation of state describes the properties and formation of large astrophysical objects, notably neutron stars. It can be constrained with the density dependence of the symmetry energy, which is modelled to have a linear correlation with neutron skin thickness. Neutron skin thickness can be studied with parity-violating electron scattering experiments, which have a systematic error that can be constrained by measuring beam-normal single-spin asymmetries. Experimental measurements of such asymmetries agree with theoretical values, but the theoretical values have an error of 20% due to a poorly known Compton form factor, which is a function of the energy deposited into the target in elastic Compton scattering. Because of this, it is necessary to separate elastic and inelastic Compton scattering events. CATSis alarge NaI(Tl) scintillating detector that will be used to study the Compton form factor at the A2 Collaboration in Mainz, Germany. Two Geant4 simulations of CATS were built, and using results from Ref. [Wis94], efficiency and contamination were calculated for a range of energies with one of these simulations. This was done by estimating the ratio of elastic to inelastic photons produced at a variety of energies for Compton scattering off of a 12C target. Then, based on the estimated ratio, photons at energies associated with elastic and inelastic Compton scattering off of a 12C target were fired into the core of the CATS simulation. Additionally, CATS was used for the first time in years to collect cosmic ray data for an overnight run in Mainz in July of 2022 for testing purposes

Job Autonomy and Resilience as Predictors of Well-Being and Organizational Outcomes: A Comparison Between Remote and On-Site Employees

The COVID-19 pandemic has precipitated momentous changes in the modern workplace environment, with a greater number of employees now working from home. As such, the current study sought to determine how job autonomy and resilience contribute to job satisfaction, turnover intention, and burnout among participants working on-site, remote, and hybrid. A sample of 158 Canadian employees between the ages of 18 to 70 years (M = 41.49, SD = 15.10) completed a series of questions about their workplace experiences. The results indicated that these three groups significantly differed in their level of job autonomy, with this variable being a stronger predictor of individual and organizational outcomes than resilience. These findings suggest that job-related factors like job autonomy may be a valuable tool to all employees, irrespective of where and how they work. Future research should investigate ways of implementing job autonomy across various work environment

Sexual Health Education and Attitudes Toward Gender and Sexual Minorities in New Brunswick

Gender and sexual minorities experience an increased risk for stigma and poor sexual health outcomes compared to their cisgender heterosexual peers. Despite national and international recommendations for comprehensive and inclusive school-based sexual health education, research has shown inconsistencies and lack of gender and sexual minority content in New Brunswick’s curricula. The current study examined if adult participants’ experiences of New Brunswick’s sexual health education within the last 10 years included gender and sexual minority specific content and how perceptions of their sexual health education correlated with attitudes toward gender and sexual minorities. A total of 623 participants who attended sexual health education in New Brunswick between grades 6 to 12 completed an online survey. The survey measured sources of sexual health education, perceived quality of sexual health education, and homophobia, biphobia, and transphobia. Participants of all identities and orientations reported low scores for the quality of their school-based sexual health education. Gender and sexual minority participants reported their education was not inclusive of their identities, which differed significantly from cisgender heterosexual participants’ experiences. Unexpectedly, higher perceived quality and inclusivity of school-based sexual health education significantly correlated with higher scores of homophobia, biphobia, and transphobia. However, since most people reported low quality, the education itself was inadequate, but those who perceived it as higher quality were more likely to endorse stigma against sexual and gender minorities. Overall, this study highlights opportunities to improve the explicit and comprehensive inclusion of gender and sexual minority content in New Brunswick’s sexual health education curricul

The Effect of Rejection Resiliency Education on University Students’ Experiences of Sexual Rejection

Sexual and romantic rejection have been shown to have clear connections to increased aggressive and manipulative responses, including physical and sexual assault. Sexual education programs have attempted to target this through evidence-based consent education curriculum; however, to date, no research has been done on the efficacy of education directly targeting rejection resiliency. The current study aimed to create a rejection resiliency program to decrease negative reactions to sexual rejection. Participants (N = 114) were university students assigned to receive either rejection resiliency education or a program on transitioning to university. Participants in both conditions completed a survey before the education session, immediately after, and three months after. Prior to the education, participants who reported more aggression, manipulation, and sexism also reported poor reactions to rejection, which is consistent with past research. Participants in the rejection resiliency condition reported feeling better able to handle rejection and more comfortable saying no to a sexual advance immediately after completing training. Contrary to expectations, participants who received the rejection resiliency training did not report significantly lower responses of aggression and manipulation compared to their initial responses nor the control group. Qualitative responses did support the importance of fostering open discussion about reacting to rejection and implied that more research should be done on effective education programming. Quantitatively assessing behaviour change in rejection resiliency may be challenging to do since many of the behaviours may be affected by social desirability bias. Participants may be reluctant to report their negative behaviours

The effect of source credibility and similarity to participants on susceptibility to misinformation

Previous research exploring misinformation has established that source credibility and source similarity to the information recipient are factors that can increase a source’s ability to mislead someone (Chaiken & Maheswaran, 1994; Traberg and van der Linden, 2022). The purpose of the present study is to investigate how people judge the veracity of factual information and misinformation coming from sources varying in these qualities. The hypotheses were: (1) misinformation from high-credibility sources will be most endorsed; (2) misinformation from similar sources will be more endorsed than from dissimilar sources; and (3) factual information from low-credibility, dissimilar sources will be dismissed. Participants (N = 93) were recruited from a small undergraduate university. They viewed and rated the perceived truthfulness of 40 fabricated Instagram posts, including sixteen posts related to sexual violence whose sources varied in ideology (feminist versus non-feminist) and credibility (high versus low credibility). Participants completed a measure of feminist attitudes and were classified as being high-feminist or low-feminist. Results indicated participants generally endorsed misinformation more from high-credibility sources, and that both high- and low-feminist participants preferred similar sources, being generally more willing to endorse misinformation from ideologically similar sources. However, in an unexpected finding, participants endorsed misinformation from non-feminist, low-credibility sources more than other sources, even those participants with a high degree of feminist attitudes. Limitations and future considerations are discussed

Study of normalization techniques using low and high energy x-ray fluorescence excitation beams with standard samples

X-Ray fluorescence is gaining popularity in the scientific community as it is portable, non-invasive, and inexpensive to operate. Rigorous method analysis is needed to accurately assess health and mineral conditions in people or crops through concentrations of various elements. The current study examines the role of the 6.4keV X-ray fluorescence (XRF) excitation beam in the analysis of low atomic number (Z) elements and its comparison to the 17.48keV excitation beam for these elements. Fifty okra samples were analyzed using XRF and results were compared to inductively coupled plasma mass spectrometry (ICP-MS) values through linear correlation plots. The correlations for calcium, potassium, and phosphorus, revealed that the 6.4keV excitation beam, was better suited for elements up to but not including chromium. The low energy beam had an average R2 value of 0.74 whereas the high energy beam had an R2 of 0.52 for the okra samples. The same procedure was used to examine standard caprine horn samples where only calcium was examined. These supported the use of the low energy beam for low Z elements with an average R2 value of 0.45 compared to the high energy R2 value of 0.26. Normalization of the data was required and four methods, Region of Interest (ROI), Molybdenum or Iron, Scatter Peak, and total area ratio (TAR) were created and tested to determine which produced normalized counts with the best correlation to ICP-MS. Linear correlations of the okra samples indicated the ROI method was most promising for studying low Z elements while using the low energy X-ray fluorescence excitation beam. The goat horn samples indicated the Fe method provided the best correlations though all R2 were similar and the relative uncertainties were twice the okra. More research is needed to determine the potential of the ROI normalization method with higher atomic number elements

Legacy impacts of historical gold mines on the cladocera assemblages of two Nova Scotian lakes

Historical gold mines in Nova Scotia released toxic tailings into nearby environments from the 1860s to ~1945. Tailings high in contaminants, such as arsenic and mercury, were disposed of, untreated, into nearby surface waters, which can negatively impact ecosystems and biota. There are now ~360 inactive gold mines from 64 mining districts throughout Nova Scotia and little is known regarding the long-term ecological harm historical mining has caused. I used a paleolimnological approach for two Nova Scotia lakes located downstream of historical gold mines, to investigate contaminant levels within sediment cores before, during and after the mining periods. I then examined Cladocera assemblages to determine the bioindicator responses to environmental changes associated with mining, as well as post-mining stressors such as urbanization and climate change. Changes in contaminant concentrations and zooplankton assemblages were more pronounced at deep and oligotrophic Lake Thomas, as opposed to shallow and dystrophic Gegogan Lake. Cladoceran assemblages showed statistically significant (P < 0.05) differences between the pre-mining, mining, and post-mining periods at both study lakes. Sedimentary mercury levels peaked at ~6 and 65 times Canadian Council of Ministers of the Environment (CCME) guidelines, and ~165 and 58 times for arsenic, at Gegogan Lake and Lake Thomas, respectively. While geochemical recovery is underway, my findings can inform decisions regarding development of areas near historical mines and management of aquatic ecosystems impacted by mining contaminant