The use of phase change material as an actuator in linkage fabric structures

Linkage fabric structures show potential as assistive technology that can provide support and assistance for individuals with specific mobility and disability needs. The core functionality of these fabrics is the ability to passively and actively control the mechanics of each link producing a structure with variable and adjustable stiffness. Current actuators have shown limited ability to produce active stiffening within a fabric structure without the addition of a continuous energy supply to the structure, therefore, limiting its use as wearable assistive technology. Here, we address the energy supply problem and show the novel use of sodium acetate trihydrate (SAT) in the linkage structures to induce mechanical stiffening through a phase change induced by an electric impulse. We find that a SAT aqueous concentration of 55 wt% is optimum to achieve a stable supercooled liquid (to ambient temperature) and effective electrical nucleation from liquid to solid, which provides robust locking mechanism of individual linkages able to withstand mechanical torsion up to 200 mNm. We demonstrate proof of principle through the integration of SAT into one- and two-dimensional linkage structures and their nearly instantaneous stiffening within each link by enabling electrically controlled actuation

Learning histology – dental and medical students' study strategies

PurposeHistology, the science of cells and tissues at the microscopic level, is an integral component of most dental and medical curricula and is often taught using both traditional and novel computer‐based didactic approaches. The purpose of this study was to analyse the strategies used by dental and medical students when studying this very visual and challenging subject.MethodsData were collected from 75 dental and 143 medical students, who had almost identical histology learning resources at their disposal.ResultsWhen compared with their medical counterparts, dental students view histology as a more difficult subject and as less relevant for their future career. Whereas dental students, who are required to attend class unlike medical students, made more use of in‐classroom learning opportunities, they did not take as much advantage of out‐of‐classroom resources. In addition, dental students reported a significantly higher tendency than medical students to work together, rather than to study alone.DiscussionSmall differences in the dental versus the medical learning environment associate with several observed differences in learning strategies that are adopted by dental and medical students.ConclusionsThese differences should be considered when teaching the subject of histology to dental or to medical students.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111121/1/eje12104.pd

The impact and effectiveness of the general public wearing masks to reduce the spread of pandemics in the UK: a multidisciplinary comparison of single-use masks versus reusable face masks

During the coronavirus (COVID-19) pandemic, the UK government mandated the use of face masks in various public settings and recommended the use of reusable masks to combat shortages of medically graded single-use masks in healthcare. To assist decision-making on the choice of masks for future pandemics, where shortages may not be a contributing factor, the University College London (UCL) Plastic Waste Innovation Hub has carried out a multidisciplinary comparison between single-use and reusable masks based on their anatomy, standalone effectiveness, behavioural considerations, environmental impact and costs. Although current single-use masks have a higher standalone effectiveness against bacteria and viruses, studies show that reusable masks have adequate performance in slowing infection rates of respiratory viruses. Material flow analysis (MFA), life cycle assessment (LCA) and cost comparison show that reusable masks have a lower environmental and economic impact than single-use masks. If every person in the UK uses one single-use mask each day for a year, it will create a total of 124,000 tonnes of waste, 66,000 tonnes of which would be unrecyclable contaminated plastic waste (the masks), with the rest being the recyclable packaging typically used for transportation and distribution of masks. Using reusable masks creates >85% less waste, generates 3.5 times lower impact on climate change and incurs 3.7 times lower costs. Further behavioural research is necessary to understand the extent and current practices of mask use; and how these practices affect mask effectiveness in reducing infection rates. Wearing single-use masks may be preferred over reusable masks due to perceptions of increased hygiene and convenience. Understanding behaviour towards the regular machine-washing of reusable masks for their effective reuse is key to maximise their public health benefits and minimise environmental and economic costs

The Levellers, political literacy and contemporary citizenship education in England

This paper analyses the concept of political literacy (as introduced in the 1998 Crick Report) in relation to Citizenship in the English National Curriculum. It argues that political literacy has not been sufficiently emphasised or facilitated within this foundation subject and that the concept is particularly important for students at a time of considerable political and social conflict in England (and elsewhere). The authors state that engagement with the ideas and practices of the Levellers (a political group writing and agitating at the time of the Civil Wars) could enable students and teachers to explore political literacy (especially the implications of social media) by looking at a political group who utilised mass pamphlettering as a form of political communication. The paper will also investigate the context of Citizenship within the English National Curriculum and some of the philosophical concerns around Citizenship education. It contains a section placing the Levellers in their contemporary and historiographical contexts

CCP4 Cloud for structure determination and project management in macromolecular crystallography

Nowadays, progress in the determination of three-dimensional macromolecular structures from diffraction images is achieved partly at the cost of increasing data volumes. This is due to the deployment of modern high-speed, high-resolution detectors, the increased complexity and variety of crystallographic software, the use of extensive databases and high-performance computing. This limits what can be accomplished with personal, offline, computing equipment in terms of both productivity and maintainability. There is also an issue of long-term data maintenance and availability of structure-solution projects as the links between experimental observations and the final results deposited in the PDB. In this article, CCP4 Cloud, a new front-end of the CCP4 software suite, is presented which mitigates these effects by providing an online, cloud-based environment for crystallographic computation. CCP4 Cloud was developed for the efficient delivery of computing power, database services and seamless integration with web resources. It provides a rich graphical user interface that allows project sharing and long-term storage for structure-solution projects, and can be linked to data-producing facilities. The system is distributed with the CCP4 software suite version 7.1 and higher, and an online publicly available instance of CCP4 Cloud is provided by CCP4.The following funding is acknowledged: Biotechnology and Biological Sciences Research Council (grant No. BB/L007037/1; grant No. BB/S007040/1; grant No. BB/S007083/1; grant No. BB/S005099/1; grant No. BB/S007105/1; award No. BBF020384/1); Medical Research Council (grant No.MC_UP_A025_1012; grant No. MC_U105184325); Ro¨ntgenA˚ ngstro¨m Cluster (grant No. 349-2013-597); Nederlandse Wetenschappelijke Organisatie (grant No. TKI 16219)

Mechanism of the Very Efficient Quenching of Tryptophan Fluorescence in Human γD- and γS-Crystallins: The γ-Crystallin Fold May Have Evolved To Protect Tryptophan Residues from Ultraviolet Photodamage†

Proteins exposed to UV radiation are subject to irreversible photodamage through covalent modification of tryptophans (Trps) and other UV-absorbing amino acids. Crystallins, the major protein components of the vertebrate eye lens that maintain lens transparency, are exposed to ambient UV radiation throughout life. The duplicated β-sheet Greek key domains of β- and γ-crystallins in humans and all other vertebrates each have two conserved buried Trps. Experiments and computation showed that the fluorescence of these Trps in human γD-crystallin is very efficiently quenched in the native state by electrostatically enabled electron transfer to a backbone amide [Chen et al. (2006) Biochemistry 45, 11552−11563]. This dispersal of the excited state energy would be expected to minimize protein damage from covalent scission of the excited Trp ring. We report here both experiments and computation showing that the same fast electron transfer mechanism is operating in a different crystallin, human γS-crystallin. Examination of solved structures of other crystallins reveals that the Trp conformation, as well as favorably oriented bound waters, and the proximity of the backbone carbonyl oxygen of the n − 3 residues before the quenched Trps (residue n), are conserved in most crystallins. These results indicate that fast charge transfer quenching is an evolved property of this protein fold, probably protecting it from UV-induced photodamage. This UV resistance may have contributed to the selection of the Greek key fold as the major lens protein in all vertebrates.National Eye Institute (Grant EY 015834