Sharing learning outcomes in chemistry teaching at HE level: Beneficial or detrimental?

The sharing of explicit learning objectives and/or learning outcomes is considered to be good practice in schools, with OFSTED observation criteria indicating that this is a pre-requisite to a good or outstanding lesson1. Such practice does not appear to be widespread in chemistry teaching at HE level. Whilst a statement of aims/objectives/outcomes can normally be found in the documentation accompanying any given unit of teaching, these are typically in a less student-friendly format than those used in school, or are too vague to be useful. At the same time, many lecturers do communicate aims at the start of a lecture, but there may be scope for doing this in a more effective way. The extent to which students are exposed to „learning outcomes‟ varies greatly from institution to institution, discipline to discipline and from teacher to teacher, and as such it is difficult to discern the best approach.This article presents some background on developments at pre-university level that have influenced practice in this area, and outlines the findings of a research project carried out in the School of Chemistry at the University of Southampton. The project probed the views of staff and students regarding the usefulness of learning outcomes. Several different approaches to sharing learning outcomes with first year students were trialled and evaluated during the course of the 2010-11 academic year. This work is part of an on-going initiative which aims to identify effective methods to support students in becoming independent learners when making the transition to university, and to improve retention rates

Computational prediction of L_{3} EXAFS spectra of gold nanoparticles from classical molecular dynamics simulations

We present a computational approach for the simulation of extended x-ray absorption fine structure (EXAFS) spectra of nanoparticles directly from molecular dynamics simulations without fitting any of the structural parameters of the nanoparticle to experimental data. The calculation consists of two stages. First, a molecular dynamics simulation of the nanoparticle is performed and then the EXAFS spectrum is computed from “snapshots” of structures extracted from the simulation. A probability distribution function approach calculated directly from the molecular dynamics simulations is used to ensure a balanced sampling of photoabsorbing atoms and their surrounding scattering atoms while keeping the number of EXAFS calculations that need to be performed to a manageable level. The average spectrum from all configurations and photoabsorbing atoms is computed as an Au L3-edge EXAFS spectrum with the FEFF 8.4 package, which includes the self-consistent calculation of atomic potentials. We validate and apply this approach in simulations of EXAFS spectra of gold nanoparticles with sizes between 20 and 60 Å. We investigate the effect of size, structural anisotropy, and thermal motion on the gold nanoparticle EXAFS spectra and we find that our simulations closely reproduce the experimentally determined spectra

Fitting EXAFS data using molecular dynamics outputs and a histogram approach

The estimation of metal nanoparticle diameter by analysis of extended x-ray absorption fine structure (EXAFS) data from coordination numbers is nontrivial, particularly for particles <5 nm in diameter, for which the undercoordination of surface atoms becomes an increasingly significant contribution to the average coordination number. These undercoordinated atoms have increased degrees of freedom over those within the core of the particle, which results in an increase in the degree of structural disorder with decreasing particle size. This increase in disorder, however, is not accounted for by the standard means of EXAFS analysis, where each coordination shell is fitted with a single bond length and disorder term. In addition, the surface atoms of nanoparticles have been observed to undergo a greater contraction than those in the core, further increasing the range of bond distances. Failure to account for this structural change results in an increased disorder being measured, and therefore, a lower apparent coordination number and corresponding particle size are found. Here, we employ molecular dynamics (MD) simulations for a range of nanoparticle sizes to determine each of the nearest neighbor bond lengths, which were then binned into a histogram to construct a radial distribution function (RDF). Each bin from the histogram was considered to be a single scattering path and subsequently used in fitting the EXAFS data obtained for a series of carbon-supported platinum nanoparticles. These MD-based fits are compared with those obtained using a standard fitting model using Artemis and the standard model with the inclusion of higher cumulants, which has previously been used to account for the non-Gaussian distribution of neighboring atoms around the absorber. The results from all three fitting methods were converted to particle sizes and compared with those obtained from transmission electron microscopy (TEM) and x-ray diffraction (XRD) measurements. We find that the use of molecular dynamics simulations resulted in an improved fit over both the standard and cumulant models, in terms of both quality of fit and correlation with the known average particle size

A qualitative exploration of attitudes to walking in the retirement life change

BACKGROUND: Walking is a simple activity that could help to reduce the prevalence of chronic diseases in all populations. Furthermore, an inverse dose–response relationship exists between steps taken and risk of premature death and cardiovascular events in middle-aged and older adults. There is a lack of information on how to effectively engage older adults around retirement age in walking. This qualitative study explored attitudes towards walking in older people with regard to habits, intensity, preferences and strategies for increasing walking behaviour. METHODS: In-depth qualitative interviews were conducted with 26 older adults who were either close to retirement or recently retired. An inductive thematic analysis was conducted. RESULTS: Three themes were identified from the data; 1) Engagement and perceived value of walking; was focused on the meaning of walking for the participant and the attributes they associate with their walking practice. 2) Integration and connectivity of walking; was focused on how participants integrate walking in their daily lives and whether walking can be practiced as a viable means of connectivity. 3) Strategies to increase walking; was focused on what factors motivate participants in their walking practice and what strategies they perceived to be beneficial to increase walking distance and intensity at an individual level. DISCUSSION: The views of walking in people of retirement age were represented within 3 key themes. The factors contained in these themes that may influence future walking practice are discussed with regard to future strategies to promote walking in the retirement life change. CONCLUSION: It may be beneficial to promote qualitative aspects of walking practice and strive for regularity rather than intensity of walking to accrue the social, psychological and intellectual benefits reported by individuals in the retirement life change. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-022-12853-2

Turn-taking in cooperative offspring care: by-product of individual provisioning behavior or active response rule?

ABSTRACT: For individuals collaborating to rear offspring, effective organization of resource delivery is difficult because each carer benefits when the others provide a greater share of the total investment required. When investment is provided in discrete events, one possible solution is to adopt a turn-taking strategy whereby each individual reduces its contribution rate after investing, only increasing its rate again once another carer contributes. To test whether turn-taking occurs in a natural cooperative care system, here we use a continuous time Markov model to deduce the provisioning behavior of the chestnut-crowned babbler (Pomatostomus ruficeps), a cooperatively breeding Australian bird with variable number of carers. Our analysis suggests that turn-taking occurs across a range of group sizes (2-6), with individual birds being more likely to visit following other individuals than to make repeat visits. We show using a randomization test that some of this apparent turn-taking arises as a by-product of the distribution of individual inter-visit intervals ("passive" turn-taking) but that individuals also respond actively to the investment of others over and above this effect ("active" turn-taking). We conclude that turn-taking in babblers is a consequence of both their individual provisioning behavior and deliberate response rules, with the former effect arising through a minimum interval required to forage and travel to and from the nest. Our results reinforce the importance of considering fine-scale investment dynamics when studying parental care and suggest that behavioral rules such as turn-taking may be more common than previously thought. SIGNIFICANCE STATEMENT: Caring for offspring is a crucial stage in the life histories of many animals and often involves conflict as each carer typically benefits when others contribute a greater share of the work required. One way to resolve this conflict is to monitor when other carers contribute and adopt a simple "turn-taking" rule to ensure fairness, but natural parental care has rarely been studied in sufficient detail to identify such rules. Our study investigates whether cooperatively breeding chestnut-crowned babblers "take turns" delivering food to offspring, and (if so) whether this a deliberate strategy or simply a by-product of independent care behavior. We find that babblers indeed take turns and conclude that part of the observed turn-taking is due to deliberate responsiveness, with the rest arising from the species' breeding ecology

Comparison of the spinels Co3O4 and NiCo2O4 as bifunctional oxygen catalysts in alkaline media

Data from experiments with both rotating disc electrodes (RDEs) and gas diffusion electrodes (GDEs) are used to investigate the properties of the spinels, Co3O4 and NiCo2O4, as bifunctional oxygen electrocatalysts. Emphasis is placed on catalyst compositions and electrode structures free of carbon. Oxygen evolution and reduction occur at surfaces where the transition metals are in different oxidation states but the surface can be repeatedly cycled between these two states without significant change. It is shown that carbon-free, NiCo2O4 catalysed GDEs can be fabricated using structures based on stainless steel cloth or nickel foam. Those based on nickel foam can be cycled extensively and allow both O2 evolution and reduction at current densities up to 100 mA cm?2

Building the bench: developing the leadership capacity of assistant principals

Our disquisition is founded in both the leadership literature and empirical data from four North Carolina school districts. Our work and the literature suggest that support is needed for assistant principals to develop their leadership capacity and prepare them for the principalship (Chan, Webb, & Bowen, 2003; Leithwood, Louis, Anderson, & Wahlstrom, 2004). We utilized improvement science methods to identify a problem of practice to be addressed with an improvement initiative (Bryk, Gomez, Grunow, LeMaheiu, 2016). Our improvement initiative was employed through a combined framework of succession planning (Lynn, 2001; Peters, 2011) and social justice leadership theory (Theoharis, 2007; 2009). Called the Assistant Principal Professional Leadership Experience (APPLE), our implementation consisted of three components including an orientation session, monthly professional development sessions, and shadowing experiences. Utilizing a PDSA (Plan-Do-Study-Act) approach, we collected data throughout the initiative to make decisions. Using both qualitative (interviews, focus groups)and quantitative instruments (surveys), we analyzed the pre-initiative and post-initiative data to find statistically significant growth in several leadership areas, including: equity, student assessment, teacher evaluation, teacher remediation, data-driven decision making, studentdecision making, and school safety. The data showed mean increases in assistant principalcreated goals as well as increases in the pre- and post-measurements of the North CarolinaStandards for School Executives. The qualitative and quantitative shadowing data showed positive findings that acknowledged the success of the experience.Keywords: leadership, assistant principals, administrator support, shadowing, professional development, orientation, succession planning model, social justice leadershi

Biobutanol as Fuel for Direct Alcohol Fuel Cells-Investigation of Sn-Modified Pt Catalyst for Butanol Electro-oxidation

Direct alcohol fuel cells (DAFCs) mostly use low molecular weight alcohols such as methanol and ethanol as fuels. However, short-chain alcohol molecules have a relative high membrane crossover rate in DAFCs and a low energy density. Long chain alcohols such as butanol have a higher energy density, as well as a lower membrane crossover rate compared to methanol and ethanol. Although a significant number of studies have been dedicated to low molecular weight alcohols in DAFCs, very few studies are available for longer chain alcohols such as butanol. A significant development in the production of biobutanol and its proposed application as an alternative fuel to gasoline in the past decade makes butanol an interesting candidate fuel for fuel cells. Different butanol isomers were compared in this study on various Pt and PtSn bimetallic catalysts for their electro-oxidation activities in acidic media. Clear distinctive behaviors were observed for each of the different butanol isomers using cyclic voltammetry (CV), indicating a difference in activity and the mechanism of oxidation. The voltammograms of both n-butanol and iso-butanol showed similar characteristic features, indicating a similar reaction mechanism, whereas 2-butanol showed completely different features; for example, it did not show any indication of poisoning. Ter-butanol was found to be inactive for oxidation on Pt. In situ FTIR and CV analysis showed that OHads was essential for the oxidation of primary butanol isomers which only forms at high potentials on Pt. In order to enhance the water oxidation and produce OHads at lower potentials, Pt was modified by the oxophilic metal Sn and the bimetallic PtSn was studied for the oxidation of butanol isomers. A significant enhancement in the oxidation of the 1° butanol isomers was observed on addition of Sn to the Pt, resulting in an oxidation peak at a potential ?520 mV lower than that found on pure Pt. The higher activity of PtSn was attributed to the bifunctional mechanism on PtSn catalyst. The positive influence of Sn was also confirmed in the PtSn nanoparticle catalyst prepared by the modification of commercial Pt/C nanoparticle and a higher activity was observed for PtSn (3:1) composition. The temperature-dependent data showed that the activation energy for butanol oxidation reaction over PtSn/C is lower than that over Pt/C

Identification of tidal trapping of microplastics in a temperate salt marsh system using sea surface microlayer sampling

Microplastics are contaminants of increasing global environmental concern. Estuaries are a major transport pathway for land-derived plastics to the open ocean but are relatively understudied compared to coastal and open marine environments. The role of the “estuarine filter”, by which the supply of sediments and contaminants to the sea is moderated by processes including vegetative trapping and particle flocculation, remains poorly defined for microplastics land to sea transfer. Here, we focus on the sea surface microlayer (SML) as a vector for microplastics, and use SML sampling to assess microplastic trapping in a temperate marsh system in Southampton Water, UK. The SML is known to concentrate microplastics relative to the underlying water and is the first part of rising tidal waters to traverse intertidal and upper tidal surfaces. Sampling a salt marsh creek at high temporal resolution allowed assessment of microplastics in-wash and outflow from the salt marsh, and its relationship with tidal state and bulk suspended sediment concentrations (SSC), over spring and neap tides. A statistically significant decrease in microplastics abundance from the flood tide to the ebb tide was found, and a weak positive relationship with SSC observed

In situ XAFS of acid-resilient iridate pyrochlore oxygen evolution electrocatalysts under operating conditions

Pyrochlore iridates (Na,Ca)2-xIr2O6?H2O are acid-stable electrocatalysts that are candidates for use in electrolysers and fuel cells. Ir LIII-edge X-ray absorption fine structure spectroscopy in 1 M H2SO4 at oxygen evolution conditions suggests the involvement of the electrons from the conduction band of the metallic particles, rather than just surface iridium reacting