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In response to COVID-19, students in a first-year general engineering program rapidly transitioned from a highly interactive, hands-on model with large remote-controlled cars in the lobby to an asynchronous, online model without face-to-face student interaction. The instructors designed an assignment to encourage students to creatively express how the course interruption and transition online was affecting them. The assignment encouraged complete freedom of expression and choice of media. The intent was to keep a personal connection with students and to create a feedback opportunity to make up for the lost in-person informal connections and observations. The instructor of each section viewed submissions, and offered encouraging, individual feedback on each. Afterwards, instructors developed and applied a coding system for applicable media and moods to help understand overall student response. The instructors were left with the perception that the responses were very powerful, and successful at strengthening the recently weakened student-instructor bond. We found the assignment gave students a chance to express themselves more creatively than assignments such as reports. This paper will introduce the assignment and give an overview of student submissions. We believe similar assignments could be useful in any course where the instructor has an interest in the well-being of their students, and we ourselves plan to use this style of assignment to explore topics including students' desire to continue to pursue engineering, or comfort level during their first year of college.

Influenza A viruses encode their genomes across eight, negative sense RNA segments. The six largest segments produce mRNA transcripts that do not generally splice; however, the two smallest segments are actively spliced to produce the essential viral proteins NEP and M2. Thus, viral utilization of RNA splicing effectively expands the viral coding capacity without increasing the number of genomic segments. As a first step towards understanding why splicing is not more broadly utilized across genomic segments, we designed and inserted an artificial intron into the normally nonsplicing NA segment. This insertion was tolerated and, although viral mRNAs were incompletely spliced, we observed only minor effects on viral fitness. To take advantage of the unspliced viral RNAs, we encoded a reporter luciferase gene in frame with the viral ORF such that when the intron was not removed the reporter protein would be produced. This approach, which we also show can be applied to the NP encoding segment and in different viral genetic backgrounds, led to high levels of reporter protein expression with minimal effects on the kinetics of viral replication or the ability to cause disease in experimentally infected animals. These data together show that the influenza viral genome is more tolerant of splicing than previously appreciated and this knowledge can be leveraged to develop viral genetic platforms with utility for biotechnology applications. Author summary: Unlike most host mRNAs, many viral mRNAs encode multiple discrete, functional proteins. One method influenza A viruses use to increase the protein products from two of their eight RNA genome segments is splicing. Splicing requires host machinery to remove part of the viral mRNA, the intron, to generate a different mRNA product. Although only certain influenza viral segments naturally splice, we were interested in whether additional segments could splice to produce multiple proteins. We inserted artificial introns harboring reporter genes into otherwise nonsplicing genomic segments of an H1N1 influenza A virus and found that this modification was well tolerated by the virus. We further demonstrated that an unrelated H3N2 influenza A virus could similarly support splicing and express a reporter protein from an artificial intron. These findings have implications for our understanding of how viruses expand their coding capacity with a limited genome. Additionally, encoding reporter proteins in spliced intronic sequences also represents a new method of generating reporter viruses requiring limited manipulation of the viral RNA. [ABSTRACT FROM AUTHOR]

Influenza A viruses (IAVs) encode their genome across eight, negative sense RNA segments. During viral assembly, the failure to package all eight segments, or packaging a mutated segment, renders the resulting virion incompletely infectious. It is known that the accumulation of these defective particles can limit viral disease by interfering with the spread of fully infectious particles. In order to harness this phenomenon therapeutically, we defined which viral packaging signals were amenable to duplication and developed a viral genetic platform which produced replication competent IAVs that require up to two additional artificial genome segments for full infectivity. The modified and artificial genome segments propagated by this approach are capable of acting as "decoy" segments that, when packaged by coinfecting wild-type viruses, lead to the production of non-infectious viral particles. Although IAVs which require 10 genomic segments for full infectivity are able to replicate themselves and spread in vivo, their genomic modifications render them avirulent in mice. Administration of these viruses, both prophylactically and therapeutically, was able to rescue animals from a lethal influenza virus challenge. Together, our results show that replicating IAVs designed to propagate and spread defective genomic segments represent a potent anti-influenza biological therapy that can target the conserved process of particle assembly to limit viral disease. Author summary: Influenza infections are best prevented via prophylactic vaccination. Vaccination, however, is incompletely efficacious, necessitating the use of anti-influenza therapeutics. To date, several different classes of anti-influenza therapeutics have been developed and used in order to combat these infections. Unfortunately, the incidence of influenza resistance to many of these therapeutics has begun to rise, necessitating the development of new strategies. One such strategy is to mimic the activity of naturally occurring viral particles that harbor defective genomes. These defective interfering particles have the ability to interfere with productive viral assembly, preventing the spread of influenza viruses across the respiratory tract. Furthermore, given the manner in which they target influenza segment packaging, a conserved feature of all influenza A viruses, resistance to this therapeutic strategy is unlikely. Here, we report the development of a genetic platform that allows the production of replicating influenza viruses which require 10 genomic segments to be fully infectious. These viruses are capable of amplifying themselves in isolation, but coinfection with a wild-type virus leads to segment exchange and compromises the spread of both viruses. This interference, while mechanistically distinct from naturally occurring defective particles, was able to target the same viral process and rescue animals exposed to an otherwise lethal viral infection. This viral-based approach may represent a cost effective and scalable method to generate effective anti-influenza therapeutics when vaccines or antiviral drugs become ineffective due to the acquisition of viral resistance mutations. [ABSTRACT FROM AUTHOR]

Intentional and unintentional openings in a building's envelope provide opportunities for unwanted pests to enter buildings. The brown marmorated stink bug, Halyomorpha halys (Stål), is one such pest, causing a significant domestic winter nuisance in many locations. One important means of pest control is exclusion, or blocking openings through which they can enter, although some openings are intentional and cannot be completely blocked without putting a building at risk. To help understand what size openings are relevant to entry, adult H. halys ready for overwintering were driven out of heated boxes through openings designed to limit passage by their lateral pronotal and dorsoventral dimensions. Pronotally limited holes of 8 mm wide were passed by only one female (3.3% of those tested), and no females and only one male (3.3%) passed through 7-mm-wide holes. For dorsoventrally limited slits, few (13%) of females passed through 4-mm-high slits, and no individuals passed through 3-mm-high slits. Dorsoventral heights and pronotal widths of 930 individuals collected in Virginia were measured. Females were consistently larger, with pronota averaging 8.33 mm wide to the males' 7.47 mm and heights at the point of leg movement restriction averaging 4.03 mm to the males' 3.50 mm. Based on experimental data and size data, we conclude that most H. halys individuals will be excluded by slits smaller than 3 mm and holes smaller than 7 mm. [ABSTRACT FROM AUTHOR]

Overwintering brown marmorated stink bugs (Halyomorpha halys) (Stål) are a notable domestic nuisance. In addition to disruptive activity, dead individuals remain in homes, sometimes in large numbers. To better understand the effects of these remains on overwintering behavior, adult H. halys were subjected to several experiments to test their responses to dead conspecifics. In non-tactile tests of individuals exposed to groups of dead conspecifics, H. halys did not respond to 1-yr-old desiccated dead conspecifics, but avoided corpses that were freshly killed. In tactile tests of individuals exposed to groups of dead conspecifics, H. halys joined those corpse aggregations significantly more often than not, and preferred corpses to cotton when given a choice. In tests of exposure of overwintering individuals to fresh dead conspecifics over the course of a winter, no necrophagy or evidence of survival advantage was observed, but overall females had higher survival rates than males. [ABSTRACT FROM AUTHOR]

Influenza virus infections are responsible for more than 250,000 deaths annually. Influenza virus isolation, propagation, and characterization protocols are critical for completing reproducible basic research studies and for generating vaccine seed stocks. Detailed protocols for the isolation and identification of influenza virus have been recently reported (Eisfeld et al., 2014). However, there are few standardized protocols focused on the propagation and characterization of viral isolates, and as a result, viruses propagated in different conditions in different laboratories often have distinct in vitro and in vivo characteristics. Here, we focus on influenza A virus propagation and characterization in the laboratory taking into consideration the overall quality and composition of the virus stock to achieve consistency in virus yield, virulence, and immunostimulatory activity. [ABSTRACT FROM AUTHOR]

Graphene oxide flakes were successfully fabricated and deposited as a film onto a silicon substrate. A series of these samples were annealed at various temperatures under a low pressure argon environment. The valence structure of the surface is examined using ultraviolet photoelectron spectroscopy whilst the chemical nature of the surface is examined using X-ray photoelectron spectroscopy. The sheet resistance was measured to document the performance changes with variation in electronic and chemical nature of the surface. It was found that increasing the annealing temperature increased the 2p π content leading to a better conductivity and reduction in sheet resistance. [ABSTRACT FROM AUTHOR]

Viral infections are a major cause of human disease, but many require molecular assays for conclusive diagnosis. Current assays typically rely on RT-PCR or ELISA; however, these tests often have limited speed, sensitivity or specificity. Here, we demonstrate that rapid RNA FISH is a viable alternative method that could improve upon these limitations. We describe a platform beginning with software to generate RNA FISH probes both for distinguishing related strains of virus (even those different by a single base) and for capturing large numbers of strains simultaneously. Next, we present a simple fluidic device for reliably performing RNA FISH assays in an automated fashion. Finally, we describe an automated image processing pipeline to robustly identify uninfected and infected samples. Together, our results establish RNA FISH as a methodology with potential for viral point-of-care diagnostics. [ABSTRACT FROM AUTHOR]

Summary Influenza vaccines must be updated regularly because influenza viruses continuously acquire mutations in antibody binding sites of hemagglutinin (HA). The majority of H3N2 strains circulating in the Northern Hemisphere during the 2014–2015 season are antigenically mismatched to the A/Texas/50/2012 H3N2 vaccine strain. Recent H3N2 strains possess several new HA mutations, and it is unknown which of these mutations contribute to the 2014–2015 vaccine mismatch. Here, we use reverse genetics to demonstrate that mutations in HA antigenic site B are primarily responsible for the current mismatch. Sera isolated from vaccinated humans and infected ferrets and sheep had reduced hemagglutination inhibition and in vitro neutralization titers against reverse-genetics-derived viruses possessing mutations in the HA antigenic site B. These data provide an antigenic explanation for the low influenza vaccine efficacy observed during the 2014–2015 influenza season. Furthermore, our data support the World Health Organization’s decision to update the H3N2 component of future vaccine formulations. [ABSTRACT FROM AUTHOR]

Prior to serological testing, influenza viruses are typically propagated in eggs or cell culture. Recent human H3N2 strains bind to cells with low avidity. Here, we isolated nine primary H3N2 viral isolates from respiratory secretions of children. Upon propagation in vitro, five of these isolates acquired hemagglutinin or neuraminidase mutations that increased virus binding to cell surfaces. These mutations can potentially confound serological assays commonly used to identify antigenically novel influenza viruses. [ABSTRACT FROM AUTHOR]

Abstract: Solution processed CdTe layers are a potentially low-cost alternative for use in thin-film solar cells. We have recently reported the use of such nanocrystalline layers within ITO/CdTe/ZnO/Al device architectures. One key concern with this type of device structure is the possibility of atomic scale interdiffusion between the ITO and CdTe layers, which can result in deleterious n-type doping of the CdTe layer. Rutherford Backscattering has been used to study the chemical composition across the ITO/CdTe interface as a function of thermal annealing temperature. Through these measurements we verify that interdiffusion is observed across the interface for annealing temperatures above 200°C, and the extent of interdiffusion increases with temperature. Ultra-thin alumina, zirconia and titania layers deposited between the ITO and CdTe layers have been studied for their potential to act as a diffusion barrier. All investigated barriers successfully suppress interdiffusion. The outcomes of these compositional studies are directly compared to solar cells fabricated under analogous processing conditions, demonstrating improved cell performance. [Copyright &y& Elsevier]

The combination of ultraviolet photoelectron spectroscopy and metastable helium induced electron spectroscopy is used to determine the density of states of the inner and outer coaxial carbon nanotubes. Ultraviolet photoelectron spectroscopy typically measures the density of states across the entire carbon nanotube, while metastable helium induced electron spectroscopy measures the density of states of the outermost layer alone. The use of double-walled carbon nanotubes in electronic devices allows for the outer wall to be functionalised whilst the inner wall remains defect free and the density of states is kept intact for electron transport. Separating the information of the inner and outer walls enables development of double-walled carbon nanotubes to be independent, such that the charge transport of the inner wall is maintained and confirmed whilst the outer wall is modified for functional purposes. [ABSTRACT FROM AUTHOR]

Analysis of stainless steel 316 as a containment material in the presence of a phase change material (PCM) cycled at high temperature was carried out through a combination of X-ray photoelectron spectroscopy and X-ray diffraction methods. In this work, stainless steel tokens were half-immersed in a chloride carbonate-based PCM, which were then thermally cycled in an air or a nitrogen environment up to 500 times, allowing the PCM to repeatedly transform between solid and liquid phases. Spectroscopy and diffraction methods were applied on the tokens, as well as the cycled PCM, to investigate the extent and nature of corrosion in such steel alloys. With varying sputtering conditions, the oxidation state at different depths of token surfaces was quantified. From the outermost corroded layer through to the bulk, this study shows a gradual change in distribution in both Cr and oxidation of Fe, while Cr was specifically found to have depleted and migrated into the PCM. The oxidation and depletion have been found to increase with increasing exposure time to PCM while sigma-phase structure embrittled in the corrosion layer. [Display omitted] • Chemical degradation of thermal cycled SS 316 with PCM was analysed. • X-ray photoelectron spectroscopy methods were applied to analyse corrosion layers. • Chloride carbonate based PCM in air and nitrogen environment was studied. • With varying sputtering conditions, oxidation state of steel was quantified. [ABSTRACT FROM AUTHOR]

The formation and mechanism that drive corrosion in stainless steel as a containment material in the presence of phase change materials is of importance in solar thermal energy storage systems. In our work, half-immersed stainless steel 316 tokens in a carbonate-based phase change material (PCM 638) have been investigated. The samples were thermally cycled in air and Nitrogen environment up to 500 times within a high-temperature range, allowing the PCM to transform between solid and liquid states repeatedly. As a consequence of thermal cycling, severe thickness loss on steel token was observed, indicating a degree of oxidation occurring, which depleted the uncorroded steel. Cross-sectional microstructural analysis was carried out to determine the elemental distribution and structural morphology along the corrosion layers. This study shows that thermal cycling of SS 316 in PCM results in active Ni and Cr migration to the surface, leading to a significant depletion of Cr from steel moving into the PCM. Cr and Fe on the surface are found to oxidise with varying degrees, with respect to the exposure time. The depletion of Cr was found to be higher in SS 316 immersed in PCM, while also increasing with exposure time. [Display omitted] • Degradation of stainless steel as a containment material at high temperature is studied. • Corrosion of steel against PCM at accelerated thermal cycling is explained. • The degree of oxidation in corrosion layers due to reactions with PCM is explained. • Structural morphology along with active Ni and Cr migration of steel is found. • Relationship between elemental depletion and exposure time is explained. [ABSTRACT FROM AUTHOR]