Identifying preverbal children’s mathematical conceptions through bishop's reframed mathematical activities

Preverbal children demonstrate and develop mathematical conceptions as they engage with and investigate their environment. This engagement may involve navigating the environment or self-initiated play, neither of which includes an adult or educator interacting with the child. This paper applies Bishop’s (1988, 1991) mathematical activities, as reframed by Cooke and Jay (2021), to identify the mathematical conceptions preverbal children are engaging in during self-initiated play within their environment. Limitations of this approach are considered

Supporting undergraduate university students through instrumental mentoring

© 2020 Social Science Press. Student engagement and retention is a noted concern for universities and may be impacted by many different student factors such as difficulty transitioning to a university setting, inadequate skills or a sense of isolation. This study evaluated an instrumental mentoring program conducted at an Australian University in a program for pre service teachers. Twenty four undergraduate students were engaged as volunteer research assistants and worked with seven academic staff in meaningful writing and research tasks. Qualitative data was collected through focus groups, student journals, and follow up interviews. The data was analysed thematically. Results indicated that through their participation, students experienced and sustained an improved sense of belonging with more understanding and confidence regarding their academic writing and research skills. Implications for program practice, limitations, and future research directions are discussed

Comparative analysis of Salmonella susceptibility and tolerance to the biocide chlorhexidine identifies a complex cellular defense network

peer-reviewedChlorhexidine is one of the most widely used biocides in health and agricultural settings as well as in the modern food industry. It is a cationic biocide of the biguanide class. Details of its mechanism of action are largely unknown. The frequent use of chlorhexidine has been questioned recently, amidst concerns that an overuse of this compound may select for bacteria displaying an altered susceptibility to antimicrobials, including clinically important anti-bacterial agents. We generated a Salmonella enterica serovar Typhimurium isolate (ST24CHX) that exhibited a high-level tolerant phenotype to chlorhexidine, following several rounds of in vitro selection, using sub-lethal concentrations of the biocide. This mutant showed altered suceptibility to a panel of clinically important antimicrobial compounds. Here we describe a genomic, transcriptomic, proteomic, and phenotypic analysis of the chlorhexidine tolerant S. Typhimurium compared with its isogenic sensitive progenitor. Results from this study describe a chlorhexidine defense network that functions in both the reference chlorhexidine sensitive isolate and the tolerant mutant. The defense network involved multiple cell targets including those associated with the synthesis and modification of the cell wall, the SOS response, virulence, and a shift in cellular metabolism toward anoxic pathways, some of which were regulated by CreB and Fur. In addition, results indicated that chlorhexidine tolerance was associated with more extensive modifications of the same cellular processes involved in this proposed network, as well as a divergent defense response involving the up-regulation of additional targets such as the flagellar apparatus and an altered cellular phosphate metabolism. These data show that sub-lethal concentrations of chlorhexidine induce distinct changes in exposed Salmonella, and our findings provide insights into the mechanisms of action and tolerance to this biocidal agent.Department of Agriculture, Food and the Marin

Use of Ecotoxicological Tools to Evaluate the Health of New Bedford Harbor Sediments: A Microbial Biomarker Approach

We have been investigating microbial communities in sediments from New Bedford Harbor (NBH), Massachusetts, USA, for a number of years. NBH is a U.S. Environmental Protection Agency–designated Superfund site heavily contaminated with polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and heavy metals. Microorganisms are thought to contribute to the fate and distribution of contaminants in NBH through a variety of mechanisms, including direct transformations and formation of soluble and insoluble species. Our more recent research has focused on changes in microbial community structure and function in response to exposure to toxic contaminants, with the ultimate goal of using microbes as ecotoxicological tools. Microbial diversity, as measured by restriction fragment-length polymorphism analysis, changes along pollution gradients, with an apparent increase in diversity at the most contaminated sites, concomitant with an increase in genetic relatedness. Current work on microbial communities examines the presence of arsenic-resistance genes in NBH isolates. In collaboration with the Plymouth Environmental Research Center, Plymouth University, United Kingdom, we have also used more conventional ecotoxicological approaches to examine the health of the NBH biota

Proximity under threat: The role of physical distance in intergroup relations

Throughout human history, social groups have invested immense amounts of wealth and time to keep threatening out-groups at a distance. In the current research, we explored the relationship between intergroup threat, physical distance, and discrimination. Specifically, we examined how intergroup threat alters estimates of physical distance to out-groups and how physical proximity affects intergroup relations. Previous research has found that people judge threatening out-groups as physically close. In Studies 1 and 2, we examined ways to attenuate this bias. In Study 1 a secure (vs. permeable) US-Mexico border reduced the estimated proximity to Mexico City among Americans who felt threatened by Mexican immigration. In Study 2, intergroup apologies reduced estimates of physical proximity to a threatening cross-town rival university, but only among participants with cross-group friendships. In Study 3, New York Yankees fans who received an experimental induction of physical proximity to a threatening out-group (Boston Red Sox) had a stronger relationship between their collective identification with the New York Yankees and support for discriminatory policies toward members of the out-group (Red Sox fans) as well as how far they chose to sit from out-group members (Red Sox fans). Together, these studies suggest that intergroup threat alters judgment of physical properties, which has important implications for intergroup relations

Examining the Links between Multi-Frequency Multibeam Backscatter Data and Sediment Grain Size

Publication history: Accepted - 13 April 2021Acoustic methods are routinely used to provide broad scale information on the geographical distribution of benthic marine habitats and sedimentary environments. Although single-frequency multibeam echosounder surveys have dominated seabed characterisation for decades, multifrequency approaches are now gaining favour in order to capture different frequency responses from the same seabed type. The aim of this study is to develop a robust modelling framework for testing the potential application and value of multifrequency (30, 95, and 300 kHz) multibeam backscatter responses to characterize sediments’ grain size in an area with strong geomorphological gradients and benthic ecological variability. We fit a generalized linear model on a multibeam backscatter and its derivatives to examine the explanatory power of single-frequency and multifrequency models with respect to the mean sediment grain size obtained from the grab samples. A strong and statistically significant (p < 0.05) correlation between the mean backscatter and the absolute values of the mean sediment grain size for the data was noted. The root mean squared error (RMSE) values identified the 30 kHz model as the best performing model responsible for explaining the most variation (84.3%) of the mean grain size at a statistically significant output (p < 0.05) with an adjusted r2 = 0.82. Overall, the single low-frequency sources showed a marginal gain on the multifrequency model, with the 30 kHz model driving the significance of this multifrequency model, and the inclusion of the higher frequencies diminished the level of agreement. We recommend further detailed and sufficient ground-truth data to better predict sediment properties and to discriminate benthic habitats to enhance the reliability of multifrequency backscatter data for the monitoring and management of marine protected areas.This research was funded by the Marine Institute under the Marine Research Programme by the Irish Government Cruise CE19007 Backscatter and Biodiversity of Shelf Sea Habitats (BaBioSSH) survey. Staffing was supported through the Marine Protected Area Monitoring and Management (MarPAMM) project, which is supported by the European Union’s INTERREG VA Programme, managed by the Special EU Programmes Body (SEUPM) with matching funding from the Government of Ireland, the Northern Ireland Executive, and the Scottish Government, as well as the PhD studentship through a Vice Chancellor Research Scholarship of Ulster University (U.K.)

Education Maintenance Allowance Pilots for Vulnerable Young People and Childcare Pilots : implementation and reported impacts in the first year

The Department for Education and Skills (DfES) commissioned the Centre for Research in Social Policy (CRSP), the National Centre for Social Research (NCSR) and the Institute for Employment Research (IER) to evaluate the Education Maintenance Allowance (EMA) Pilots for Vulnerable Young People and Childcare Pilots. This report focuses on the first year of the EMA Pilots for Vulnerable Young People and Childcare Pilots. The analysis of implementation of these pilots draws on interviews with implementation groups and key informants and stakeholders. Eligible young people and their significant others also provide evidence of the impact as well as difficulties involved in the EMA Pilot for Vulnerable Young People and Childcare Pilots. The integrated evaluation that follows discusses the degree of flexibility and level of effectiveness of EMA in relation to vulnerable young people

Surprisingly Strong K-band Emission Found in Low Luminosity Active Galactic Nuclei

We examine the near-infrared (NIR) emission from low-luminosity AGNs (LLAGNs). Our galaxy sample includes 15 objects with detected 2-10 keV X-ray emission, dynamical black hole mass estimates from the literature, and available Gemini/NIFS integral field spectroscopy (IFU) data. We find evidence for red continuum components at the center of most galaxies, consistent with the hot dust emission seen in higher luminosity AGN. We decompose the spectral data cubes into a stellar and continuum component, assuming the continuum component comes from thermal emission from hot dust. We detect nuclear thermal emission in 14 out of 15 objects. This emission causes weaker CO absorption lines and redder continuum ($2.05-2.28\:\mu$m) in our $K$-band data, as expected from hot dust around an AGN. The NIR emission is clearly correlated with the 2-10 keV X-ray flux, with a Spearman coefficient of $r_{spearman}=0.69$ suggesting a $>99\%$ significance of correlation, providing further evidence of an AGN origin. Our sample has typical X-ray and NIR fluxes $3-4$ orders of magnitude less luminous than previous work studying the NIR emission from AGN. We find that the ratio of NIR to X-ray emission increases towards lower Eddington ratios. The NIR emission in our sample is often brighter than the X-ray emission, with our $K$-band AGN luminosities comparable to or greater than the 2-10 keV X-ray luminosities in all objects with Eddington ratios below $0.01\%$. The nature of this LLAGN NIR emission remains unclear, with one possibility being an increased contribution from jet emission at these low luminosities. These observations suggest JWST will be a useful tool for detecting the lowest luminosity AGN.Comment: Submitted to ApJ, manuscript after resubmissio