Ageing stereotypes influence the transmission of false memories in the social contagion paradigm

These experiments are the first to investigate the impact of confederate accuracy, age, and age stereotypes in the social contagion of memory paradigm. Across two experiments, younger participants recalled household scenes with an actual (Experiment 1) or virtual (Experiment 2), older or younger confederate who suggested different proportions (0%, 33% or 100%) of false items during collaboration. In Experiment 2, positive and negative age stereotypes were primed by providing bogus background information about our older confederate before collaboration. Across both experiments, if confederates suggested false items participants readily incorporated these into their own memory reports. In Experiment 1, when no age stereotype was primed, participants adopted similar proportions of false items from younger and older confederates. Importantly, in Experiment 2, when our older confederate was presented in terms of negative ageing stereotypes, participants reported less false items and were better able to correctly identify the source of those false items

Spike sorting for large, dense electrode arrays

Developments in microfabrication technology have enabled the production of neural electrode arrays with hundreds of closely spaced recording sites, and electrodes with thousands of sites are under development. These probes in principle allow the simultaneous recording of very large numbers of neurons. However, use of this technology requires the development of techniques for decoding the spike times of the recorded neurons from the raw data captured from the probes. Here we present a set of tools to solve this problem, implemented in a suite of practical, user-friendly, open-source software. We validate these methods on data from the cortex, hippocampus and thalamus of rat, mouse, macaque and marmoset, demonstrating error rates as low as 5%

Measles outbreak in South Africa, 2003 - 2005

Objectives. Measles was virtually eliminated in South Africa following control activities in 1996/7. However, from July 2003 to November 2005, 1 676 laboratory-confirmed measles cases were reported in South Africa. We investigated the outbreak’s cause and the role of HIV.Design. We traced laboratory-confirmed case-patients residingin the Johannesburg metropolitan (JBM) and O R Tambo districts. We interviewed laboratory- or epidemiologically confirmed case-patients or their caregivers to determine vaccination status and, in JBM, HIV status. We calculated vaccine effectiveness using the screening method.Setting. Household survey in JBM and O R Tambo districts.Outcome measures. Vaccine effectiveness, case-fatality rate, andhospitalisations. Results. In JBM, 109 case-patients were investigated. Of the 57 case-patients eligible for immunisation, 27 (47.4%) were vaccinated. Fourteen (12.8%) case-patients were HIV infected, 46 (42.2%) were HIV uninfected, and 49 (45.0%) had unknown HIV status. Among children aged 12 - 59 months, vaccine effectiveness was 85% (95% confidence interval (CI): 63, 94) for all children, 63% for HIV infected, 75% for HIV uninfected, and 96% for children with unknown HIV status. (Confidence intervals were not calculated for sub-groupsowing to small sample size.) In O R Tambo district, 157 casepatientswere investigated. Among the 138 case-patients eligible for  immunisation, 41 (29.7%) were vaccinated. Vaccine effectiveness was 89% (95% CI 77, 95).Conclusions. The outbreak’s primary cause was failure to vaccinate enough of the population to prevent endemic measles transmission. Although vaccine effectiveness might have been lower in HIV-infected than in uninfected children, population vaccine effectiveness remained high

Hospital case volume and outcomes for proximal femoral fractures in the USA: an observational study

Objective: To explore whether older adults with isolated hip fractures benefit from treatment in high-volume hospitals. Design: Population-based observational study. Setting: All acute hospitals in California, USA. Participants: All individuals aged >65 that underwent an operation for an isolated hip fracture in California between 2007 and 2011. Patients transferred between hospitals were excluded. Primary and secondary outcomes: Quality indicators (time to surgery) and patient outcomes (length of stay, in-hospital mortality, unplanned 30-day re-admission, and selected complications). Results: 91,401 individuals satisfied the inclusion criteria. Time to operation and length of stay were significantly prolonged in low volume hospitals, by 1.96 (95% CI 1.20-2.73) and 0.70 (0.38-1.03) days respectively. However, there were no differences in clinical outcomes, including in-hospital mortality, 30-day re-admission, and rates of pneumonia, pressure ulcers, and venous thromboembolism. Conclusion: These data suggest that there is no patient safety imperative to limit hip fracture care to high-volume hospitals

Isolation rearing impairs novel object recognition and attentional set shifting performance in female rats

YesIt has been suggested that the isolation rearing paradigm models certain aspects of schizophrenia symptomatology. This study aimed to investigate whether isolation rearing impairs rats’ performance in two models of cognition: the novel object recognition (NOR) and attentional set-shifting tasks, tests of episodic memory and executive function, respectively. Two cohorts of female Hooded-Lister rats were used in these experiments. Animals were housed in social isolation or in groups of five from weaning, post-natal day 28. The first cohort was tested in the NOR test with inter-trial intervals (ITIs) of 1 min up to 6 h. The second cohort was trained and tested in the attentional set-shifting task. In the NOR test, isolates were only able to discriminate between the novel and familiar objects up to 1-h ITI, whereas socially reared animals remembered the familiar object up to a 4-h ITI. In the attentional set-shifting task, isolates were significantly and selectively impaired in the extra-dimensional shift phase of the task (P < 0.01). Rats reared in isolation show impaired episodic memory in the NOR task and reduced ability to shift attention between stimulus dimensions in the attentional set-shifting task. Because schizophrenic patients show similar deficits in performance in these cognitive domains, these data further support isolation rearing as a putative preclinical model of the cognitive deficits associated with schizophrenia

A biophysical model of cell adhesion mediated by immunoadhesin drugs and antibodies

A promising direction in drug development is to exploit the ability of natural killer cells to kill antibody-labeled target cells. Monoclonal antibodies and drugs designed to elicit this effect typically bind cell-surface epitopes that are overexpressed on target cells but also present on other cells. Thus it is important to understand adhesion of cells by antibodies and similar molecules. We present an equilibrium model of such adhesion, incorporating heterogeneity in target cell epitope density and epitope immobility. We compare with experiments on the adhesion of Jurkat T cells to bilayers containing the relevant natural killer cell receptor, with adhesion mediated by the drug alefacept. We show that a model in which all target cell epitopes are mobile and available is inconsistent with the data, suggesting that more complex mechanisms are at work. We hypothesize that the immobile epitope fraction may change with cell adhesion, and we find that such a model is more consistent with the data. We also quantitatively describe the parameter space in which binding occurs. Our results point toward mechanisms relating epitope immobility to cell adhesion and offer insight into the activity of an important class of drugs.Comment: 13 pages, 5 figure

Barriers to participation in a placebo-surgical trial for lumbar spinal stenosis

© 2019 Background: Placebo-controlled trials are an important tool when assessing the efficacy of spinal surgical procedures. The most common spinal surgical procedure in older adults is decompression for lumbar spinal stenosis. Before conducting a placebo-surgical trial on decompression surgery, an investigation of patients’ willingness to participate in a placebo-controlled trial of decompression surgery and barriers to participation were explored. Materials: An online survey. Methods: Descriptive analyses of demographic and clinical data, and participants' willingness to participate in a placebo-surgical trial. Logistic regression was used to examine potential predictors of willingness to participate. Two independent researchers performed a coded framework analysis of patients’ barriers to participation. Results: 68 patients were invited and 63 participants completed the survey (91.3% response, mean (SD) age 69.5 (10.9) years, 52% females), 71% suffered from moderate to very severe pain. Ten participants (15.9%) were willing to participate in a placebo-controlled trial. Being married was associated with decreased odds of participating (OR: 0.2; 95% CI, 0.05 to 0.8; P = 0.03), while the main barriers were a lack of information about the procedure, reassurance of a positive outcome with participation, and concerns about the risks and benefits of placebo surgery. Conclusions: A minority of patients with lumbar spinal stenosis were willing to participate in a placebo-controlled trial of surgery. The identified barriers indicate that educating eligible patients about: the need for placebo-surgical trials, the personal risks and benefits of participation, and the importance and potential benefits of placebo trials to others, may be crucial to ensure adequate recruitment into the placebo-controlled surgical trial. Conclusions should be read cautiously however, given the small sample size present in this study