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Enteroaggregative Escherichia coli (EAEC) strains including those of serogroup O111 are important causes of diarrhea in children. In the Czech Republic, no information is available on the etiological role of EAEC in pediatric diarrhea due to the lack of their targeted surveillance. To fill this gap, we determined the proportion of EAEC among E. coli O111 isolates from children with gastrointestinal disorders ≤ 2 years of age submitted to the National Reference Laboratory for E. coli and Shigella during 2013–2022. EAEC accounted for 177 of 384 (46.1 %) E. coli O111 isolates, being the second most frequent E. coli O111 pathotype. Most of them (75.7 %) were typical EAEC that carried aggR , usually with aaiC and aatA marker genes; the remaining 24.3 % were atypical EAEC that lacked aggR but carried aaiC and/or aatA. Whole genome sequencing of 11 typical and two atypical EAEC O111 strains demonstrated differences in serotypes, sequence types (ST), virulence gene profiles, and the core genomes between these two groups. Typical EAEC O111:H21/ST40 strains resembled by their virulence profiles including the presence of the aggregative adherence fimbriae V (AAF/V)-encoding cluster to such strains from other countries and clustered with them in the core genome multilocus sequence typing (cgMLST). Atypical EAEC O111:H12/ST10 strains lacked virulence genes of typical EAEC and differed from them in cgMLST. All tested EAEC O111 strains displayed stacked-brick aggregative adherence to human intestinal epithelial cells. The AAF/V-encoding cluster was located on a plasmid of 95,749 bp or 93,286 bp (pAA O111) which also carried aggR , aap , aar , sepA , and aat cluster. EAEC O111 strains were resistant to antibiotics, in particular to aminopenicillins and cephalosporins; 88.3 % produced AmpC β-lactamase, and 4.1 % extended spectrum β-lactamase. We conclude that EAEC are frequent among E. coli O111 strains isolated from children with gastrointestinal disorders in the Czech Republic. To reliably assess the etiological role of EAEC in pediatric diarrhea, a serotype-independent, PCR-based pathotype surveillance system needs to be implemented in the future. [ABSTRACT FROM AUTHOR]

Abstract We conducted a meta-analysis of 33 independent samples (N = 2924) to address whether adding anthropomorphic faces to multimedia graphics and/or adding pleasant colors are effective emotional design approaches. We found significant positive meta-analytic effects for retention (k = 18, d + = 0.387), comprehension (k = 14, d + = 0.317), and transfer (k = 27, d + = 0.327) under a random-effects model. Effects for affective-motivational variables were mixed, with a robust effect for intrinsic motivation (k = 23, d + = 0.255), a weaker effect for liking/enjoyment (k = 20, d + = 0.109), and a marginal effect for positive affect (k = 15, d + = 0.113). The manipulations did not significantly (ps >.227) influence perceptions of learning (k = 11, d + = 0.097) or effort (k = 20, d + = 0.051), but reduced perceptions of difficulty (k = 14, d + = −0.208). Four of the outcome variables (retention, transfer, intrinsic motivation, and perceived effort) were sufficiently heterogeneous. There was no major issue with publication bias, influential cases, or outliers. With one exception, there was no evidence of moderation by experimental contrast, dynamicity of materials, age, language/culture, prior mood, time-on-task, and publication type after adjusting for multiple comparisons. There was provisional evidence that age moderated the effect of the manipulations on intrinsic motivation, such that larger effects were revealed for children compared to older learners. Altogether, anthropomorphisms/colors appear to be useful design principles. Highlights • Anthropomorphisms and pleasant colors should enhance multimedia learning. • We test this hypothesis using a meta-analysis of 33 independent samples. • Anthropomorphisms/colors consistently increased learning outcomes. • Their effects on affective-motivational states were weaker and less robust. • Anthropomorphisms/colors are beneficial, but the mechanism is unclear. [ABSTRACT FROM AUTHOR]

Composing instructional texts in multimedia learning materials in a conversational style rather than a formal style can facilitate learning. We investigated whether a specific language/cultural background could present a boundary condition for this effect. In four experiments with a Czech sample ( N = 278), we replicated a seminal experiment conducted on a US sample (with a short animation on the topic of lightning formation), which demonstrated a large effect size in favor of the instructional texts in the conversational style. In our four experiments, we varied between two types of audiences (a college and a high school audience) and two types of short animations (the original one and a complementary one). Instructional texts in a conversational style brought no overall advantage for the Czech audience (η p 2 = .00; the high school audience: d = 0.48, 0.22; the college audience: d = −0.45, −0.04). Twenty-nine percent of participants who received the conversational instructional texts expressed explicit reservations regarding the style of the language. In the fifth supplementary experiment, Czech participants ( N = 138) had to rate preferences on computer tutor’s printed statements. Direct rather than polite statements were preferred. Limited benefits of conversational/polite instructional texts for Czech learners are probably related to the generally more formal approach to education in the Czech Republic compared to the US schooling system. We also failed to find a link between several affective variables and learning outcomes; with the exception of a relationship of generalized positive affect, levels of flow and perceived difficulty to some of the learning outcomes. [ABSTRACT FROM AUTHOR]

There is increased interest in augmenting multimedia instructional materials to elevate learners’ positive affective-motivational states in order to improve learning. However, these efforts have only been partly successful and mediational effects of positive affective-motivational states have not always been established. In this study, university students ( N = 65) from the Czech Republic, a country where beer brewing is a source of national pride, were informed that they would either study how to brew beer (high intrinsic motivation condition) or how to prepare a citrate substrate (low intrinsic motivation condition). The 90-min simulation environment used for learning was about beer brewing in both cases, with superficial changes to instructions and graphics to disguise the topic manipulation. Generalized positive affect, overall enjoyment, flow, and learning involvement were higher in the beer brewing condition (Cohen’s d = 0.44–0.87) as were learning gains when measured immediately (retention: d = 0.48; transfer: d = 0.46) and a month later (retention: d = 0.66; transfer: d = 0.62). However, only learning involvement and flow positively mediated the influence of the topic manipulation on immediate learning outcomes; there were no mediation effects on delayed learning outcomes after co-varying out immediate learning. The findings corroborate results from extant studies on the importance of topic interest in learning from instructional texts. They also indicate that affective-motivational mediation is one, but not the only, mechanism by which topic-based intrinsic motivation manipulations influence learning and that induced positive affective-motivational states can be differentially related or unrelated to learning. [ABSTRACT FROM AUTHOR]