Statistical Literacy Social Media Project for the Masses

This article examines a social media assignment used to teach and practice statistical literacy with over 400 students each semester in large-lecture traditional, fully online, and flipped sections of an introductory-level statistics course. Following the social media assignment, students completed a survey on how they approached the assignment. Drawing from the authors’ experiences with the project and the survey results, this article offers recommendations for developing social media assignments in large courses that focus on the interplay between the social media tool and the implications of assignment prompts

Exploring the Impacts of the COVID-19 Pandemic on the Number of Reported Missing Persons in Canada during 2020

The COVID-19 pandemic has resulted in notable social and economic impacts in many countries, including Canada. This study examines the impacts of the COVID-19 pandemic on the number of reported missing persons, adults and children, in Canada during 2020. Results indicate that there was a decrease in the number of reported missing persons cases during 2020 as compared to 2019 by 20.20%. All provinces and territories experienced a decrease, with the exception of New Brunswick. The pandemic had notable impacts specifically on the number of reported missing children, missing teenagers, and missing male individuals in general. This study provides a better understanding of how the restrictions of the pandemic affected missing persons numbers and the nature of who goes missing. These findings can also be used to inform strategies under similar future states to allow for effective response

UV and Visible Light Activated TiO2 Photocatalysis of 6-Hydroxymethyluracil, a Model Compound for the Potent Cyanotoxin Cylindrospermopsin

TiO2 photocatalyses of 6-hydroxymethyl uracil (6-HOMU) a model compound for the potent cyanotoxin, cylindrospermopsin (CYN), were carried out employing visible and UV irradiation using different non-metal doped TiO2 materials, nitrogen and fluorine-TiO2 (NF-TiO2), phosphorus and fluorine-TiO2 (PF-TiO2) and sulfur-TiO2 (S-TiO2). The model compound was readily degraded under UV TiO2 photocatalysis with pseudo-first-order rate constants (k) of 2.1, 1.0, and 0.44 h−1 for NF-TiO2, PF-TiO2 and S-TiO2, respectively. Under visible light activated (VLA), NF-TiO2 was the most active photocatalyst, PF-TiO2 was marginally active and S-TiO2 inactive. VLA NF-TiO2 was effective and increased the k with increasing pH from 3 to 9. The presence of humic acid (HA), Fe3+ and Cu2+ can enhance the degradation. However, at 20 ppm HA significant inhibition was observed, likely due to shadowing of the catalyst, quenching of ROS or blocking active sites of TiO2. We probed the roles of different reactive oxygen species (ROS) using specific scavengers and the results indicate that O2− plays an important role in VLA TiO2 photocatalysis. Our results demonstrate that NF-TiO2 photocatalysis is effective under UV and visible irradiation and over a range of water qualities. VLA NF-TiO2 photocatalysis is an attractive alternative technology for the CYN contaminated water treatment

UV and Visible Light-Driven Production of Hydroxyl Radicals by Reduced Forms of N, F, and P Codoped Titanium Dioxide

The photocatalytic activities of reduced titanium dioxide (TiO2) materials have been investigated by measuring their ability to produce hydroxyl radicals under UV and visible light irradiation. Degussa P25 TiO2 was doped with nitrogen (N), fluorine (F), and/or phosphorus (P) and then subjected to surface modification employing a thermo-physicochemical process in the presence of reducing agent sodium borohydride (NaBH4). The reduced TiO2 materials were characterized by a number of X-ray, spectroscopic and imaging methods. Surface doping of TiO2 was employed to modulate the band gap energies into the visible wavelength region for better overlap with the solar spectrum. Hydroxyl radical generation, central to TiO2 photocatalytic water purification applications, was quantitated using coumarin as a trap under UV and visible light irradiation of the reduced TiO2 materials. At 350 nm irradiation, the yield of hydroxyl radicals generated by the reduced forms of TiO2 was nearly 90% of hydroxyl radicals generated by the Degussa P25 TiO2. Hydroxyl radical generation by these reduced forms of TiO2 was also observed under visible light irradiation (419 and 450 nm). These results demonstrated that simple surface modification of doped TiO2 can lead to visible light activity, which is important for more economical solar-driven applications of TiO2 photocatalysis

New Insights into the Mechanism of Visible Light Photocatalysis

ABSTRACT: In recent years, the area of developing visible-lightactive photocatalysts based on titanium dioxide has been enormously investigated due to its wide range of applications in energy and environment related fields. Various strategies have been designed to efficiently utilize the solar radiation and to enhance the efficiency of photocatalytic processes. Building on the fundamental strategies to improve the visible light activity of TiO2-based photocatalysts, this Perspective aims to give an insight into many contemporary developments in the field of visible-light-active photocatalysis. Various examples of advanced TiO2 composites have been discussed in relation to their visible light induced photoconversion efficiency, dynamics of electron− hole separation, and decomposition of organic and inorganic pollutants, which suggest the critical need for further development of these types of materials for energy conversion and environmental remediation purposes

Solar photocatalysis for water disinfection: Materials and reactor design

As of 2010, access to clean drinking water is a human right according to UN regulations. Nevertheless, the number of people living in areas without safe drinking water is predicted to increase by three billion by the end of this decade. Several recent cases of E. coli and Cryptosporidium contamination in drinking water are also reported in a number of advanced countries. Therefore ensuring the potability of drinking water is urgent, but highly challenging to both the developing and developed world in the future. A combination of solar disinfection and photocatalysis technology offers real possibilities for removing lethal pathogenic microroganisms from drinking water. The time taken for the conventional SODIS process can be greatly reduced by semiconductor (e.g. TiO2, ZnO, nano-heterojunctions) based photocatalysis. This review addresses the fundamental reaction mechanism, advances in materials synthesis and selection and recent developments in the reactor design for solar energy driven photocatalysis using titanium dioxide. The major advantage of using photo-reactors is that they enhance disinfection by increasing photon flux into the photocatalyst. Other major factors affecting such efficiency of solar-based photocatalysis such as the illuminated volume/total volume ratio, catalyst load and flow rate, are discussed in detail. The significance of using immobilised catalysts over the catalyst powder in slurries is also highlighted. It is noted that, despite encouraging early field studies, the commercialisation and mass production of solar photocatalysis systems remains highly challenging. Recommendations for future directions for addressing issues such as mass transfer, requirement of a standard test method, photo-reactors design and visible light absorption by TiO2 coatings are also discussed

Water-soluble bis(1,10-phenanthroline) Octanedioate Cu2+ and Mn2+ Complexes with Unprecedented Nano and Picomolar in Vitro Cytotoxicity: Promising Leads for Chemotherapeutic Drug Development

Dinuclear CuII and MnII bis-phenanthroline octanedioate complexes exhibit rapid, unprecedented nano and picomolar in vitro cytotoxicity against colorectal cancer lines and are less toxic than cisplatin when examined in vivo. The complexes are potent generators of cellular reactive oxygen species, avid DNA binders and induce O2 dependent cleavage of DNA. The Cu(II) complex was found to have self-cleaving nuclease activity

Understanding a Low Vitamin D State in the Context of COVID-19

While a low vitamin D state has been associated with an increased risk of infection by SARS-CoV-2 in addition to an increased severity of COVID-19 disease, a causal role is not yet established. Here, we review the evidence relating to i) vitamin D and its role in SARS-CoV-2 infection and COVID-19 disease ii) the vitamin D status in the Irish adult population iii) the use of supplemental vitamin D to treat a deficient status and iv) the application of the Bradford-Hill causation criteria. We conclude that reverse causality probably makes a minimal contribution to the presence of low vitamin D states in the setting of COVID-19. Applying the Bradford-Hill criteria, however, the collective literature supports a causal association between low vitamin D status, SARS-CoV-2 infection, and severe COVID-19 (respiratory failure, requirement for ventilation and mortality). A biologically plausible rationale exists for these findings, given vitamin D’s role in immune regulation. The thresholds which define low, deficient, and replete vitamin D states vary according to the disease studied, underscoring the complexities for determining the goals for supplementation. All are currently unknown in the setting of COVID-19. The design of vitamin D randomised controlled trials is notoriously problematic and these trials commonly fail for a number of behavioural and methodological reasons. In Ireland, as in most other countries, low vitamin D status is common in older adults, adults in institutions, and with obesity, dark skin, low UVB exposure, diabetes and low socio-economic status. Physiological vitamin D levels for optimal immune function are considerably higher than those that can be achieved from food and sunlight exposure alone in Ireland. A window exists in which a significant number of adults could benefit from vitamin D supplementation, not least because of recent data demonstrating an association between vitamin D status and COVID-19. During the COVID pandemic, we believe that supplementation with 20-25ug (800–1000 IU)/day or more may be required for adults with apparently normal immune systems to improve immunity against SARS-CoV-2. We expect that higher monitored doses of 37.5–50 ug (1,500–2,000)/day may be needed for vulnerable groups (e.g., those with obesity, darker skin, diabetes mellitus and older adults). Such doses are within the safe daily intakes cited by international advisory agencies