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Per- and polyfluoroalkyl substances (PFASs) from aqueous film forming foams (AFFFs) can hinder bioremediation of co-contaminants such as trichloroethene (TCE) and benzene, toluene, ethylbenzene, and xylene (BTEX). Anaerobic dechlorination can require bioaugmentation of Dehalococcoides, and for BTEX, oxygen is often sparged to stimulate in situ aerobic biodegradation. We tested PFAS inhibition to TCE and BTEX bioremediation by exposing an anaerobic TCE-dechlorinating coculture, an aerobic BTEX-degrading enrichment culture, and an anaerobic toluene-degrading enrichment culture to n-dimethyl perfluorohexane sulfonamido amine (AmPr-FHxSA), perfluorohexane sulfonamide (FHxSA), perfluorohexanesulfonic acid (PFHxS), or nonfluorinated surfactant sodium dodecyl sulfate (SDS). The anaerobic TCE-dechlorinating coculture was resistant to individual PFAS exposures but was inhibited by >1000× diluted AFFF. FHxSA and AmPr-FHxSA inhibited the aerobic BTEX-degrading enrichment. The anaerobic toluene-degrading enrichment was not inhibited by AFFF or individual PFASs. Increases in amino acids in the anaerobic TCE-dechlorinating coculture compared to the control indicated stress response, whereas the BTEX culture exhibited lower concentrations of all amino acids upon exposure to most surfactants (both fluorinated and nonfluorinated) compared to the control. These data suggest the main mechanisms of microbial toxicity are related to interactions with cell membrane synthesis as well as protein stress signaling.

Fungi and laccase mediator systems (LMSs) have a proven track record of oxidizing recalcitrant organic compounds. There has been considerable interest in applying LMSs to the treatment of perfluoroalkyl acids (PFAAs), a class of ubiquitous and persistent environmental contaminants. Some laboratory experiments have indicated modest losses of PFAAs over extended periods, but there have been no clear demonstrations of a transformation mechanism or the kinetics that would be needed for remediation applications. We set out to determine if this was a question of identifying and optimizing a rate-limiting step but discovered that observed losses of PFAAs were experimental artifacts. While unable to replicate the oxidation of PFAAs, we show that interactions of the PFAA compounds with laccase and laccase mediator mixtures could cause an artifact that mimics transformation (≲60%) of PFAAs. Furthermore, we employed a surrogate compound, carbamazepine (CBZ), and electron paramagnetic resonance spectroscopy to probe the formation of the radical species that had been proposed to be responsible for contaminant oxidation. We confirmed that under conditions where sufficient radical concentrations were produced to oxidize CBZ, no PFAA removal took place.

When students with the capacity to succeed in a 4-year college do not take a college admission test, this represents a potential loss of opportunity for students and colleges alike. However, the costs of testing--both pecuniary and nonpecuniary--may exceed the benefits for students who lack the interest in or qualifications for college attendance. In states like Virginia, access to admission tests varies markedly with district and family circumstances. We estimate that universal testing in Virginia could increase the number of high school graduates with test scores competitive for admission at broad-access universities in the state by as much as 40%--and at the most selective institutions by nearly 20%--with larger increases for low-income students. Alternative policies that encourage testing among students with strong demonstrated academic performance could realize nearly these increases without generating testing costs for students who are unlikely to attend a 4-year college.

LEGO® stop-motion animations were developed to engage first-year university students in the topics of matrices, vectors, linear geometry and linear transformations. LEGO® provided a versatile medium through which a wide range of concrete and abstract concepts could be physically demonstrated in both two and three dimensions. It was also familiar to most students, making the mathematics videos accessible and fun. When designed according to key principles around reducing cognitive load in multimedia learning, animations in education have been shown to increase learning compared to static images for concepts involving dynamic systems and processes. Multimodal approaches including video and narration have also been shown to be beneficial to students in terms of demonstrating mathematical problem solving. The videos created in this project were a mix of conceptual explanations and problem-solving examples, where the word problems were physically modelled before being converted to formal mathematical notation and then solved. Some animations were short clips that were integrated into online lecture recordings, others were stand-alone videos designed either as short introductions to topics or examples of common questions. This paper describes the theory underpinning the design of the animations.

In humans, loss-of-function mutations in the UBE3A gene lead to the neurodevelopmental disorder Angelman syndrome (AS). AS patients have severe impairments in speech, learning and memory, and motor coordination, for which there is currently no treatment. In addition, UBE3A is duplicated in > 1-2% of patients with autism spectrum disorders-a further indication of the significant role it plays in brain development. Altered expression of UBE3A, an E3 ubiquitin ligase, is hypothesized to lead to impaired levels of its target proteins, but identifying the contribution of individual UBE3A targets to UBE3A-dependent deficits remains of critical importance. Ephexin5 is a putative UBE3A substrate that has restricted expression early in development, regulates synapse formation during hippocampal development, and is abnormally elevated in AS mice, modeled by maternally-derived Ube3a gene deletion. Here, we report that Ephexin5 can be directly ubiquitylated by UBE3A. Furthermore, removing Ephexin5 from AS mice specifically rescued hippocampus-dependent behaviors, CA1 physiology, and deficits in dendritic spine number. Our findings identify Ephexin5 as a key driver of hippocampal dysfunction and related behavioral deficits in AS mouse models. These results demonstrate the exciting potential of targeting Ephexin5, and possibly other UBE3A substrates, to improve symptoms of AS and other UBE3A-related developmental disorders.

A practice-based engineering degree, in which students worked on real-world, team-based projects from day one and throughout their course, was designed to address the need for employability skills in a rapidly changing world. Teaching mathematics in this way required a very different approach to the lecture-exam based model prevalent in most engineering degrees. In order to ensure all students developed the fundamental skills and knowledge required of engineers, a micro-credential based curriculum was developed where micro-credentials were mapped to projects and delivered "just-in-time". The curriculum contained forty-eight explicit mathematical micro-credentials in the areas of measurement and geometry, algebra, calculus, and statistics and probability as well as many more micro-credentials in other areas of curriculum that contain mathematical skills, from physics to project budgeting. Mathematical competencies were used as a framework in the design and analysis of the micro-credentials. This paper presents a description of, and reflection on the successes and challenges in implementing this model of teaching mathematics in engineering.

The Mariana crow ("Corvus kubaryi"), called Åga, is critically endangered and endemic to the Mariana Island of Rota. This study developed and implemented an avian-focused environmental education curriculum and evaluated the curriculum's influence on attitudes and knowledge using social science research methods. Fifth and sixth grade student identification of and attitudes toward Åga were measured; students in the treatment group improved their attitudes toward and ability to identify Åga. A longer-term student and teacher training component is recommended. The approaches used in this environmental education program development, implementation, and evaluation could be applied in other global settings.

Problem-based learning (PBL) has a history of producing strong educational results in engineering; however, global society is challenged by highly complex environmental, socio-political and technical problems summarised in the UN Sustainable Development Goals (SDGs). This obliges us to explore educational approaches that address complexity. Yet, confronting complexity is sometimes constrained within PBL structures. This conceptual paper posits practice-based education (PBE) as a whole-of-education approach embracing complexity. We present a PBE framework with three elements: (1) the context of an authentic engineering practice, (2) supporting learners' agency in the process of becoming professionals, and (3) opportunities to work and learn simultaneously. We make the case for innovative engineering education through the implementation of PBE using the case of the Engineering Practice Academy at Swinburne University of Technology. We detail innovations in student experience as a process of becoming, curriculum and assessment, and provide advice on the application of PBE elsewhere.

Objective: Covid-19 has resulted in changes to college students' daily lives due to recommendations to socially distance. Social distance is likely to affect youths' peer relationships at a time when these relationships remain important for development. Participants and Methods: The current study utilized survey data to examine perceived changes in peer relationships and the association with behavioral health among 275 college students (Mage = 18.69, SD =.72) during the fall/spring of 2020–2021. Results: Quantitative results indicated that participants reported significant perceived decreases in peer support but did not report significantly worse quality of closest friendships. Qualitative responses from an open-ended survey question supported these quantitative results suggesting that although many participants perceived decreases in quality of relationships, there was also the perception that friendships became closer. Participants who perceived decreased peer relationship support and quality were more likely to report depressive symptoms and loneliness when compared to participants who perceived no changes. [ABSTRACT FROM AUTHOR]