Evolution in cluster cores since z~1

A large fraction of the stellar mass in galaxy clusters is thought to be contained in the diffuse low surface brightness intracluster light (ICL). Being bound to the gravitational potential of the cluster rather than any individual galaxy, the ICL contains much information about the evolution of its host cluster and the interactions between the galaxies within. However due its low surface brightness it is notoriously difficult to study. We present the first detection and measurement of the flux contained in the ICL at z~1. We find that the fraction of the total cluster light contained in the ICL may have increased by factors of 2-4 since z~1, in contrast to recent findings for the lack of mass and scale size evolution found for brightest cluster galaxies. Our results suggest that late time buildup in cluster cores may occur more through stripping than merging and we discuss the implications of our results for hierarchical simulations.Comment: To appear in the Proceedings of IAU Symposium 295 - The intriguing life of massive galaxie

Estimation of country-level basic reproductive ratios for novel Coronavirus (SARS-CoV-2/COVID-19) using synthetic contact matrices

The 2019-2020 pandemic of atypical pneumonia (COVID-19) caused by the virus SARS-CoV-2 has spread globally and has the potential to infect large numbers of people in every country. Estimating the country-specific basic reproductive ratio is a vital first step in public-health planning. The basic reproductive ratio (R0) is determined by both the nature of pathogen and the network of human contacts through which the disease can spread, which is itself dependent on population age structure and household composition. Here we introduce a transmission model combining age-stratified contact frequencies with age-dependent susceptibility, probability of clinical symptoms, and transmission from asymptomatic (or mild) cases, which we use to estimate the country-specific basic reproductive ratio of COVID-19 for 152 countries. Using early outbreak data from China and a synthetic contact matrix, we estimate an age-stratified transmission structure which can then be extrapolated to 151 other countries for which synthetic contact matrices also exist. This defines a set of country-specific transmission structures from which we can calculate the basic reproductive ratio for each country. Our predicted R0 is critically sensitive to the intensity of transmission from asymptomatic cases; with low asymptomatic transmission the highest values are predicted across Eastern Europe and Japan and the lowest across Africa, Central America and South-Western Asia. This pattern is largely driven by the ratio of children to older adults in each country and the observed propensity of clinical cases in the elderly. If asymptomatic cases have comparable transmission to detected cases, the pattern is reversed. Our results demonstrate the importance of age-specific heterogeneities going beyond contact structure to the spread of COVID-19. These heterogeneities give COVID-19 the capacity to spread particularly quickly in countries with older populations, and that intensive control measures are likely to be necessary to impede its progress in these countries

Temperament and early word learning:the effect of shyness on referent selection and retention

The current thesis examined individual differences that can impact on the disambiguation and learning of novel word meanings, focusing on the effects of shyness, defined as an aversion to novelty in social situations (Putnam, Gartstein & Rothbart, 2006). A systematic pattern of attention during labeling is crucial in supporting children's novel word disambiguation (Halberda, 2006), and in determining whether these novel word meanings will be learned (Axelsson, Churchley & Horst, 2012). This thesis hypothesized that shyness affects novel word disambiguation and learning by modulating attention during labeling. This thesis showed that shy children did not reliably select a novel object as the referent of a novel label, while less-shy children did. Crucially, only less-shy children showed evidence of learning the novel label-referent mappings (Paper 1). However, these differences were only apparent in an unfamiliar environment (Paper 2), likely because shy children attended much more to features of the unfamiliar environment than lessshy children, which reduced their attention to the objects during labeling. Examination of children's eye-gaze during novel object labeling supported the conclusion that shyness exerts an effect on word learning via attention. Shy children did not demonstrate robust disengagement from the novel object during labeling (Paper 3), which meant that competitor objects could not be ruled out as referents, a critical process in determining whether a novel word-referent mapping will be formed (Mather & Plunkett, 2009). Furthermore, shy children's bias to attend to faces (Brunet et al., 2009) reduced their attention to potential referents during labeling (Paper 4). This thesis thus argues that shyness impacts on word disambiguation and learning by modulating the attentional processes that support these abilities, clearly demonstrating that shyness affects one of the earliest stages of language development: word learning

Untangling Linguistic Salience

The concept of linguistic salience is broadly used within sociolinguistics to account for processes as diverse as language change (Kerswill & Williams, 2002) and language acquisition (Ellis, 2016) in that salient forms are e.g. more likely to undergo change, or are often acquired earlier than other features. However, the meaning of salience is “notoriously difficult to quantify” (Hickey, 2000, p. 57) and definitions of the term given in the literature often differ to such a degree that one could dispute whether the concept of salience has explanatory value (cf. Rácz, 2013). Accordingly, what makes a particular linguistic feature salient is contested: some argue that salience can be defined by linguistic traits such as loudness, high word-frequency, or a greater articulatory effort, whereas others argue that salience is a result of associations with social factors (cf. Kerswill & Williams, 2002). In a pilot study, we used eye-tracking to collect pupil dilation data while participants listened to spoken samples that were hypothesized to be either salient or not. These differences in salience were based on notions taken from the literature and included traits such as acoustical prominence, gender violations, loudness and differing realizations of the consonants /r/ and /v/. We were able to show that pupil size increased significantly for salient variables in the categories acoustic prominence, gender and loudness, pointing towards an increase in brain activity for these variables. In this poster, we propose to untangle how the concept is used. To those ends, we conducted a review of the literature on salience and identified different ways of operationalizing it. We conclude by discussing how salience could be decomposed in terms of other notions such as frequency, surprisal and markedness. We then propose a series of experiments using eye-tracking and ERP experiments

You Can Have Your Pudding: A Service-Oriented Approach to Process Standardization

Since the emergence of the Theory of Scientific Management, a key dimension against which business processes have been judged is by their repeatability, consistency and efficiency. Transformational “manufacturing” processes have been designed with emphasis on controlling both the process in action (sequence), and the outcome (product). Conventional process standardization focuses on the avoidance of and control of exceptions in the name of quality. However, when dealing with service delivery, in which delivery quality is impacted by the ability to accommodate exceptions rather than by avoidance, a new approach to process standardization is needed, one that ensures that process services provided are performed consistently, while embracing the flexibility in delivery sequence and product composition required in service delivery. In this paper, using an analytic model we illustrate the limitations of the conventional process standardization approach vary with both the number of service providers and the amount of provided services

Taking their eye off the ball:How shyness affects children’s attention during word learning

The current study tests the hypothesis that shy children's reduced word learning is partly due to an effect of shyness on attention during object labeling. A sample of 20- and 26-month-old children (N = 32) took part in a looking-while-listening task in which they saw sets of familiar and novel objects while hearing familiar or novel labels. Overall, children increased attention to familiar objects when hearing their labels, and they divided their attention equally between the target and competitors when hearing novel labels. Critically, shyness reduced attention to the target object regardless of whether the heard label was novel or familiar. When children's retention of the novel word–object mappings was tested after a delay, it was found that children who showed increased attention to novel objects during labeling showed better retention. Taken together, these findings suggest that shyer children perform less well than their less shy peers on measures of word learning because their attention to the target object is dampened. Thus, this work presents evidence that shyness modulates the low-level processes of visual attention that unfold during word learning

Face time:Effects of shyness and attention to faces on early word learning

Previous research has shown that shyness affects children’s attention during the fast-mapping of novel words via disambiguation. The current study examined whether shyness also affects children’s attention when eye-gaze cues to novel word meanings are present. 20- to 26-month-old children’s (N = 31) gaze was recorded as they viewed videos in which an onscreen actor sat at a table on which one novel and two familiar objects appeared. The actor looked at and labeled one of the objects, using a novel word if the target object was novel. Overall, shyness was associated with a stronger preference for looking at the actor’s face, and less time looking at the object being labeled. These effects did not differ when the target object was novel or familiar, suggesting that shyness is related to attentional differences during object labeling generally, rather than specific processes involved in the disambiguation of novel words. No evidence was found of a relation between retention and shyness or attention during labeling