Alpha and Beta Oscillations Differentially Support Word Production in a Rule-Switching Task

Research into the role of brain oscillations in basic perceptual and cognitive functions has suggested that the alpha rhythm reflects functional inhibition while the beta rhythm reflects neural ensemble (re)activation. However, little is known regarding the generalization of these proposed fundamental operations to linguistic processes, such as speech comprehension and production. Here, we recorded magnetoencephalography in participants performing a novel rule-switching paradigm. Specifically, Dutch native speakers had to produce an alternative exemplar from the same category or a feature of a given target word embedded in spoken sentences (e.g., for the word "tuna", an exemplar from the same category-"seafood"-would be "shrimp", and a feature would be "pink"). A cue indicated the task rule-exemplar or feature-either before (pre-cue) or after (retro-cue) listening to the sentence. Alpha power during the working memory delay was lower for retro-cue compared with that for pre-cue in the left hemispheric language-related regions. Critically, alpha power negatively correlated with reaction times, suggestive of alpha facilitating task performance by regulating inhibition in regions linked to lexical retrieval. Furthermore, we observed a different spatiotemporal pattern of beta activity for exemplars versus features in the right temporoparietal regions, in line with the proposed role of beta in recruiting neural networks for the encoding of distinct categories. Overall, our study provides evidence for the generalizability of the role of alpha and beta oscillations from perceptual to more "complex, linguistic processes" and offers a novel task to investigate links between rule-switching, working memory, and word production.

Do Storytelling and Processing Motivation Matter? Comparing Narratives and Exemplars in Promoting Hepatitis C Screening among College Students

Encouraging hepatitis C screening, particularly among young adults who are at increased risk of infection, is essential for eliminating viral hepatitis. A 3 (narrative vs. exemplar vs. informational message) × 2 (processing motivation: low vs. high) between-subjects experiment was conducted among college students to compare the effectiveness of different message strategies and examine the moderating role of processing motivation. Findings revealed that the narrative was perceived more favorably than the exemplar message, and both messages led to a greater screen intention than the informational message. The narrative persuaded by increasing transportation and identification and, then, enhancing message perceptions. However, these mediation paths did not explain the effects of the simple exemplar. Moreover, the effects of the narrative and the exemplar did not differ significantly depending on levels of processing motivation. The study advances a theoretical understanding of the differences between narratives and exemplars. It also offers practical suggestions for campaign message design.

How countries can reduce child stunting at scale: lessons from exemplar countries

BACKGROUND

Child stunting and linear growth faltering have declined over the past few decades and several countries have made exemplary progress.

OBJECTIVES

To synthesize findings from mixed methods studies of exemplar countries to provide guidance on how to accelerate reduction in child stunting.

METHODS

We did a qualitative and quantitative synthesis of findings from existing literature and 5 exemplar country studies (Nepal, Ethiopia, Peru, Kyrgyz Republic, Senegal). Methodology included 4 broad research activities: 1) a series of descriptive analyses of cross-sectional data from demographic and health surveys and multiple indicator cluster surveys; 2) multivariable analysis of quantitative drivers of change in linear growth; 3) interviews and focus groups with national experts and community stakeholders and mothers; and 4) a review of policy and program evolution related to nutrition.

RESULTS

Several countries have dramatically reduced child stunting prevalence, with or without closing geographical, economic, and other population inequalities. Countries made progress through interventions from within and outside the health sector, and despite significant heterogeneity and differences in context, contributions were comparable from health and nutrition sectors (40% of change) and other sectors (50%), previously called nutrition-specific and -sensitive strategies. Improvements in maternal education, maternal nutrition, maternal and newborn care, and reductions in fertility/reduced interpregnancy intervals were strong contributors to change. A roadmap to reducing child stunting at scale includes several steps related to diagnostics, stakeholder consultations, and implementing direct and indirect nutrition interventions related to the health sector and nonhealth sector .

CONCLUSIONS

Our results show that child stunting reduction is possible even in diverse and challenging contexts. We propose that our framework of organizing nutrition interventions as direct/indirect and inside/outside the health sector should be considered when mapping causal pathways of child stunting and planning interventions and strategies to accelerate stunting reduction to achieve the 2030 Sustainable Development Goals.

Drivers of stunting reduction in Peru: a country case study

BACKGROUND

Peru reduced its under-5 child stunting prevalence notably from 31.3% in 2000 to 13.1% in 2016.

OBJECTIVES

We aimed to study factors and key enablers of child stunting reduction in Peru from 2000-2016.

METHODS

Demographic and Health Surveys were used to conduct descriptive analyses [height-for-age z scores (HAZ) means and distributions, equity analysis, predicted child growth curves through polynomial regressions] and advanced regression analyses. An ecological (at department level) multilevel regression analysis was conducted to identify the major predictors of stunting decline from 2000 to 2016, and Oaxaca-Blinder decomposition was conducted to identify the relative contribution of each factor to child HAZ change. A systematic literature review, policy and program analysis, and interviews with relevant stakeholders were conducted to understand key drivers of stunting decline in Peru.

RESULTS

The distribution of HAZ scores showed a slight rightward shift from 2000 to 2007/2008, and a greater shift from 2007/2008 to 2016. Stunting reduction was higher in the lowest wealth quintile, in rural areas, and among children with the least educated mothers. Decomposing predicted changes showed that the most important factors were increased maternal BMI and maternal height, improved maternal and newborn health care, increased parental education, migration to urban areas, and reduced fertility. Key drivers included the advocacy role of civil society and political leadership around poverty and stunting reduction since the early 2000s. Key enablers included the economic growth and the consolidation of democracy since the early 2000s, and the acknowledgement that stunting reduction needs much more than food supplementation.

CONCLUSIONS

Peru reduced child stunting owing to improved socioeconomic determinants, sustained implementation of out-of-health-sector and within-health-sector changes, and implementation of health interventions. These efforts were driven through a multisectoral approach, strong civil society advocacy, and keen political leadership. Peru's experience offers useful lessons on how to tackle the problem of stunting under differing scenarios, with the participation of multiple sectors.

Understanding multifactorial drivers of child stunting reduction in Exemplar countries: a mixed-methods approach

BACKGROUND

Several countries have notably reduced childhood stunting relative to economic growth over the past 15-20 y. The Exemplars in Stunting Reduction project, or "Exemplars," studies success factors among these countries with a lens toward replicability.

OBJECTIVES

This paper details the standardized mixed-methods framework for studying determinants of childhood stunting reduction applied in Exemplars studies.

METHODS

An expert technical advisory group (TAG), criteria for identifying Exemplar countries, evidence-based frameworks, mixed methodologies (quantitative, qualitative, policy, literature review), effective research partnerships, case study process and timeline, and data triangulation and corroboration are presented.

RESULTS

Experts in health, nutrition, and evaluation methods were selected at the study outset to provide technical support to all phases of research (TAG). Exemplar countries were selected by the TAG, who considered quantitative data (e.g., annual rates of stunting change compared with economic growth, country population size) and qualitative insights (e.g., logistics of country work, political stability). Experienced country research partners were selected and an inception meeting with stakeholder consultations was held to launch research and garner support. Evidence-based conceptual frameworks underpinned all Exemplars research activities. A systematic review of published peer-reviewed and grey literature was undertaken, along with in-depth policy and program analysis of nutrition-specific and -sensitive investments. Both descriptive and advanced quantitative analysis was undertaken (e.g., equity analyses, difference-in-difference regression, Oaxaca-Blinder decomposition). Qualitative data collection using in-depth interviews and focus groups was conducted with national and community stakeholders (i.e., child care workers and mothers) to understand country experiences. The case study process was iterative, and all research outputs were triangulated to develop the stunting reduction narrative for each country. Findings were shared with country experts for weigh-in and corroboration through dissemination events.

CONCLUSIONS

Exemplars research uses a mixed-methods framework for studying positive outliers that can be applied across diverse health and development outcomes.

Drivers of stunting reduction in the Kyrgyz Republic: A country case study

BACKGROUND

Chronic malnutrition among infants and children continues to represent a global public health concern. The Kyrgyz Republic has achieved rapid declines in stunting over the last 20 y, despite modest increases in gross domestic product per capita.

OBJECTIVE

This study aimed to conduct a systematic, in-depth assessment of national, community, household, and individual drivers of nutrition change and stunting reduction, as well as nutrition-specific and -sensitive policies and programs, in the Kyrgyz Republic.

METHODS

This mixed methods study employed 4 inquiry methods, including: 1) a systematic scoping literature review; 2) retrospective quantitative data analyses, including linear regression multivariable hierarchical modeling, difference-in-difference analysis, and Oaxaca-Blinder decomposition; 3) qualitative data collection and analysis; and 4) analysis of key nutrition-specific and -sensitive policies and programs.

RESULTS

Stunting prevalence has decreased in the Kyrgyz Republic, however, subnational variations and inequities persist. Child growth Victora curves show improvements in height-for-age z-scores (HAZ) for children in the Kyrgyz Republic between 1997 and 2014, indicating increased intrauterine growth and population health improvements. The decomposition analysis explained 88.9% (0.637 SD increase) of the predicted change in HAZ for children under 3 y (1997-2012). Key factors included poverty (61%), maternal nutrition (14%), paternal education (6%), fertility (6%), maternal age (3%), and wealth accumulation (2%). Qualitative analysis revealed poverty reduction, increased migration and remittances, food security, and maternal nutrition as key drivers of stunting decline. Systematic scoping literature review findings supported quantitative and qualitative results, and indicated that land reforms and improved food security represented important factors. Key nutrition-specific and -sensitive policies and programs implemented involved breastfeeding promotion, social protection schemes, and land and health sector reforms.

CONCLUSIONS

Improvements in stunting were achieved amidst political and economic changes. Multilevel enablers, including poverty reduction, improved food security, and introduction of land and health reforms have contributed to improvements in health, nutrition, and stunting among children in the Kyrgyz Republic.

Drivers of stunting reduction in Ethiopia: a country case study

BACKGROUND

Chronic undernutrition in children continues to be a global public health concern. Ethiopia has documented a significant decline in the prevalence of childhood stunting, a measure of chronic undernutrition, over the last 20 y.

OBJECTIVES

The aim of this research was to conduct a systematic assessment of the determinants that have driven child stunting reduction in Ethiopia from 2000 to 2016, focused on the national, community, household, and individual level.

METHODS

This study employed both quantitative and qualitative methods. Specifically, a systematic literature review, retrospective quantitative data analysis using Demographic and Health Surveys from 2000-2016, qualitative data collection and analysis, and analyses of key nutrition-specific and -sensitive policies and programs were undertaken.

RESULTS

National stunting prevalence improved from 51% in 2000 to 32% in 2016. Regional variations exist, as do pro-rich, pro-urban, and pro-educated inequalities. Child height-for-age z score (HAZ) decomposition explained >100% of predicted change in mean HAZ between 2000 and 2016, with key factors including increases in total consumable crop yield (32% of change), increased number of health workers (28%), reduction in open defecation (13%), parental education (10%), maternal nutrition (5%), economic improvement (4%), and reduced diarrhea incidence (4%). Policies and programs that were key to stunting decline focused on promoting rural agriculture to improve food security; decentralization of the health system, incorporating health extension workers to improve rural access to health services and reduce open defecation; multisectoral poverty reduction strategies; and a commitment to improving girls' education. Interviews with national and regional stakeholders and mothers in communities presented improvements in health service access, women and girls' education, improved agricultural production, and improved sanitation and child care practices as drivers of stunting reduction.

CONCLUSIONS

Ethiopia's stunting decline was driven by both nutrition-specific and -sensitive sectors, with particular focus on the agriculture sector, health care access, sanitation, and education.

Drivers of stunting reduction in Senegal: a country case study

BACKGROUND

Senegal has been an exemplar country in the West African region, reducing child stunting prevalence by 17.9% from 1992 to 2017.

OBJECTIVES

In this study, we aimed to conduct a systematic in-depth assessment of factors at the national, community, household, and individual levels to determine the key enablers of Senegal's success in reducing stunting in children <5 y old between 1992/93 and 2017.

METHODS

A mixed methods approach was implemented, comprising quantitative data analysis, a systematic literature review, creation of a timeline of nutrition-related programs, and qualitative interviews with national and regional stakeholders and mothers in communities. Demographic and Health Surveys and Multiple Indicator Cluster Surveys were used to explore stunting inequalities and factors related to the change in height-for-age z-score (HAZ) using difference-in-difference linear regression and the Oaxaca-Blinder decomposition method.

RESULTS

Population-wide gains in average child HAZ and stunting prevalence have occurred from 1992/93 to 2017. Stunting prevalence reduction varied by geographical region and prevalence gaps were reduced slightly between wealth quintiles, maternal education groups, and urban compared with rural residence. Statistical determinants of change included improvements in maternal and newborn health (27.8%), economic improvement (19.5%), increases in parental education (14.9%), and better piped water access (8.1%). Key effective nutrition programs used a community-based approach, including the Community Nutrition Program and the Nutrition Enhancement Program. Stakeholders felt sustained political will and multisectoral collaboration along with improvements in poverty, women's education, hygiene practices, and accessibility to health services at the community level reduced the burden of stunting.

CONCLUSIONS

Senegal's success in the stunting decline is largely attributed to the country's political stability, the government's prioritization of nutrition and execution of nutrition efforts using a multisectoral approach, improvements in the availability of health services and maternal education, access to piped water and sanitation facilities, and poverty reduction. Further efforts in the health, water and sanitation, and agriculture sectors will support continued success.

When imitating successful others fails: Accidentally successful exemplars inspire risky decisions and can hamper performance

We examined the impact of viewing exemplars on people's behaviour in risky decision-making environments. Specifically, we tested if people disproportionally choose to view and then imitate the behaviour of successful (vs. unsuccessful) others, which in the case of risky decision-making increases risk-taking and can hamper performance. In doing so, our research tested how a fundamental social psychological process (social influence) interacts with a fundamental statistical phenomenon (regression to the mean) to produce biases in decision-making. Experiment 1 (N = 96) showed that people indeed model their own behaviour after that of a successful exemplar, resulting in more risky behaviour and poorer outcomes. Experiment 2 (N = 208) indicated that people disproportionately choose to examine and then imitate most successful versus least successful exemplars. Experiment 3 (N = 381) replicated Experiment 2 in a context where participants were offered the freedom to examine any possible exemplar, or no exemplar whatsoever, and across different incentive conditions. The results have implications for decision-making in a broad range of social contexts, such as education, health, and finances where risk-taking can have detrimental outcomes, and they may be particularly helpful to understand the role of social influence in gambling behaviour.

The indispensability of labelled groups to vulnerability in bioethics

Regarding the determination of vulnerability, the bioethics community has univocally jettisoned "labelled groups", groups whose membership confers a context-invariant "vulnerable" status to their members. While the usual reasons against the sole use of labelled groups to determine the vulnerability of individuals are sound, labelled groups as exemplars of vulnerability can play indispensable roles in bioethical reasoning. In this article, I argue against the wholesale jettisoning of labelled groups by showing how they can be useful.

On Computing Breakpoint Distances for Genomes with Duplicate Genes

A fundamental problem in comparative genomics is to compute the distance between two genomes in terms of its higher level organization (given by genes or syntenic blocks). For two genomes without duplicate genes, we can easily define (and almost always efficiently compute) a variety of distance measures, but the problem is NP-hard under most models when genomes contain duplicate genes. To tackle duplicate genes, three formulations (exemplar, maximum matching, and any matching) have been proposed, all of which aim to build a matching between homologous genes so as to minimize some distance measure. Of the many distance measures, the breakpoint distance (the number of nonconserved adjacencies) was the first one to be studied and remains of significant interest because of its simplicity and model-free property. The three breakpoint distance problems corresponding to the three formulations have been widely studied. Although we provided last year a solution for the exemplar problem that runs very fast on full genomes, computing optimal solutions for the other two problems has remained challenging. In this article, we describe very fast, exact algorithms for these two problems. Our algorithms rely on a compact integer-linear program that we further simplify by developing an algorithm to remove variables, based on new results on the structure of adjacencies and matchings. Through extensive experiments using both simulations and biological data sets, we show that our algorithms run very fast (in seconds) on mammalian genomes and scale well beyond. We also apply these algorithms (as well as the classic orthology tool MSOAR) to create orthology assignment, then compare their quality in terms of both accuracy and coverage. We find that our algorithm for the "any matching" formulation significantly outperforms other methods in terms of accuracy while achieving nearly maximum coverage.

The Transfer of Object Learning after Training with Multiple Exemplars

Object recognition improves with training. This training effect only partially generalizes to untrained images of the trained objects (new exemplars, orientation,…). The aim of this study is to investigate whether and to what extent the learning transfer improves when participants are trained with more exemplars of an object. Participants were trained to recognize two sets of stimuli using a backward masking paradigm. During training with the first set, only one exemplar of each object was presented. The second set was trained using four exemplars of each object. After 3 days of training, participants were tested on all the trained exemplars and a completely new exemplar of the same objects. In addition, recognition performance was compared to a set of completely new objects. For the objects of which four exemplars were used during training, participants showed more generalization toward new exemplars compared to when they were only trained with one exemplar. Part of the generalization effect extended to completely new objects. In conclusion, more variation during training leads to more generalization toward new visual stimuli.

The influence of celebrity exemplars on college students' smoking

OBJECTIVE

This study examined the effect of celebrity smoking exemplars in health news on college students' perceptions of smoking-related health risks and smoking intentions.

PARTICIPANTS AND METHODS

The data were collected using a Web-based survey of 219 undergraduate students at a large midwestern university in March 2011. Separate analyses of covariance were conducted.

RESULTS

The influence of negative exemplars of celebrity smoking on perceptions of smoking-related health risks and smoking intentions varied according to smoking status. Ever-smokers who read smoking news with negative exemplars of celebrity smoking were more likely than ever-smokers who read the same news absent any exemplar to report higher levels of perceptions of smoking-related health risks and lower levels of smoking intentions. However, these patterns were not found in never-smokers.

CONCLUSIONS

Exemplification theory enhanced by the celebrity element may be effectively applied as a strategy to change health behavior in college students.

A Dynamic Programming Algorithm For (1,2)-Exemplar Breakpoint Distance

The exemplar breakpoint distance problem is motivated by finding conserved sets of genes between two genomes. It asks to find respective exemplars in two genomes to minimize the breakpoint distance between them. If one genome has no repeated gene (called trivial genome) and the other has genes repeating at most twice, it is referred to as the (1, 2)-exemplar breakpoint distance problem, EBD(1, 2) for short. Little has been done on algorithm design for this problem by now. In this article, we propose a parameter to describe the maximum physical span between two copies of a gene in a genome, and based on it, design a fixed-parameter algorithm for EBD(1, 2). Using a dynamic programming approach, our algorithm can take O(4(s)n(2)) time and O(4(s)n) space to solve an EBD(1, 2) instance that has two genomes of n genes where the second genome has each two copies of a gene spanning at most s copies of the genes. Our algorithm can also be used to compute the maximum adjacencies between two genomes. The algorithm has been implemented in C++. Simulations on randomly generated data have verified the effectiveness of our algorithm. The software package is available from the authors.

Racial and mental illness stereotypes and discrimination: an identity-based analysis of the Virginia Tech and Columbine shootings

The Virginia Tech and Columbine High shootings are 2 of the deadliest school massacres in the United States. The present study investigates in a nationally representative sample how White Americans' causal attributions of these shooting moderate their attitudes toward the shooter's race. White Americans shown a vignette based on the Virginia Tech shooting were more likely to espouse negative beliefs about Korean American men and distance themselves from this group the more they believed that the shooter's race caused the shooting. Among those who were shown a vignette based on the Columbine High shooting, believing that mental illness caused the shooting was associated with weaker negative beliefs about White American men. White Americans in a third condition who were given the Virginia Tech vignette and prompted to subtype the shooter according to his race were less likely to possess negative beliefs about Korean American men the more they believed that mental illness caused the shooting. There was no evidence for the ultimate attribution error. Theoretical accounts based on the stereotype and in-group-out-group bias literature are presented. The current findings have important implications for media depictions of minority group behavior and intergroup relations.

Narrative Health Communication and Behavior Change: The Influence of Exemplars in the News on Intention to Quit Smoking

This study investigated psychological mechanisms underlying the effect of narrative health communication on behavioral intention. Specifically, the study examined how exemplification in news about successful smoking cessation affects recipients' narrative engagement, thereby changing their intention to quit smoking. Nationally representative samples of U.S. adult smokers participated in 2 experiments. The results from the 2 experiments consistently showed that smokers reading a news article with an exemplar experienced greater narrative engagement compared to those reading an article without an exemplar. Those who reported more engagement were in turn more likely to report greater smoking cessation intentions.