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Hexafluoropropylene oxide dimer acid (HFPO-DA, ammonium salt with trade name: GenX) has been recently detected in river water worldwide. There are significant concerns about its persistence, and potential adverse effects to the biota. In this study, the degradability of GenX by typical advanced redox technologies (UV/persulfate and UV/sulfate) is investigated. Results demonstrate that <5% GenX is oxidized after 3 h in UV/persulfate system, which is much lower than ∼27% for PFOA. In comparison, GenX can be readily degraded and defluorinated by hydrated electron (e) generated by UV/sulfite system. Specifically, GenX is not detectable after 2 h, and >90% of fluoride ion is recovered 6 h later. This is attributed to the accumulation and subsequent degradation of CFCFCOOH and CFCOOH, which are stable intermediates of GenX degradation. Mechanistic investigations suggest that the etheric bond in the molecule is a favorable attack point for the e. Such finding is corroborated by quantum chemical calculations. The side CF- at the α-carbon probably acts as an effective barrier that prevents GenX from being cleaved by SO• or OH• at its most sensible point (i.e. the carboxyl group). This study illustrates that reduction by UV/sulfite might be a promising technology to remove GenX from contaminated water.

Psychological scientists have become increasingly concerned with issues related to methodology and replicability, and infancy researchers in particular face specific challenges related to replicability: For example, high-powered studies are difficult to conduct, testing conditions vary across labs, and different labs have access to different infant populations. Addressing these concerns, we report on a large-scale, multisite study aimed at (a) assessing the overall replicability of a single theoretically important phenomenon and (b) examining methodological, cultural, and developmental moderators. We focus on infants’ preference for infant-directed speech (IDS) over adult-directed speech (ADS). Stimuli of mothers speaking to their infants and to an adult in North American English were created using seminaturalistic laboratory-based audio recordings. Infants’ relative preference for IDS and ADS was assessed across 67 laboratories in North America, Europe, Australia, and Asia using the three common methods for measuring infants’ discrimination (head-turn preference, central fixation, and eye tracking). The overall meta-analytic effect size (Cohen’s d) was 0.35, 95% confidence interval = [0.29, 0.42], which was reliably above zero but smaller than the meta-analytic mean computed from previous literature (0.67). The IDS preference was significantly stronger in older children, in those children for whom the stimuli matched their native language and dialect, and in data from labs using the head-turn preference procedure. Together, these findings replicate the IDS preference but suggest that its magnitude is modulated by development, native-language experience, and testing procedure.

The current study explores how language experience may shape the correlation between lexical tone and musical pitch perception. A two domains (music and lexical tone) by two languages (tone, Mandarin Chinese and non-tone, Dutch) design is adopted. Participants were tested on their discrimination of Mandarin Chinese lexical tones, Montreal Battery of Evaluation of Amusia (MBEA), and Musical Ear Test (MET). The Chinese listeners outperformed the Dutch listeners on both MBEA and MET, but had comparable accuracies for the lexical tone discrimination. Importantly, a significant cross-domain correlation was only observed for the Dutch listeners but not for the Chinese listeners. For tone language listeners, once lexical tones have been acquired, native listeners perceive them as phonological categories, and split them from other pitch variations that do not play a phonemic role. Non-tone language listeners, on the other hand, perceive both lexical tones and musical pitch on a psycho-acoustical basis, hence exhibit a unified perception of pitch across the two domains.ARTICLE HISTORY

Purpose: Facing previous mixed findings between monolingual and bilingual infants’ phonetic development during perceptual reorganization, the current study aims at examining the perceptual development of a native vowel contrast (/I/-/i/) by Dutch monolingual and bilingual infants. Design: We tested 390 Dutch monolingual and bilingual infants from 5 to 15 months of age through a visual habituation paradigm. Data and analysis: Mixed-effect model analyses were conducted within 320 infants, with infants’ log10 transformed looking time as the dependent variable, age (4-level) and language background (2-level) as the fixed factors, and participant and order (2-level) as the random factors. Conclusions: All infants show weak initial sensitivity to the contrast regardless of language background(s), and sensitivity improves with age. By the second half of the first year, infants discriminate the contrast, indicating the emergence of the relevant vowel categories. In addition, a perceptual lead is observed in bilingual infants, probably due to: 1) a perceptual transfer from the close-category counterpart of the other native language; 2) heightened acoustic sensitivity in bilingual infants given their rich linguistic experience; and 3) a general bilingual cognitive advantage. The influences of contrast salience and bilingualism on language development are discussed. Originality: Overall, these findings constitute an extension of existing work on vowel perception and display a novel acceleration effect for the bilingual infants in phonetic perception. In addition, we propose a novel heightened acoustic sensitivity hypothesis, arguing that bilingual infants may pay more attention to acoustic details in the input than their monolingual peers. Significance: The observed progressive phonetic discrimination pattern of the native contrast contributes to our knowledge in infant language development, and specifically perceptual reorganization patterns, in the first year after birth. The observed acceleration effect, along with its explanations, provides new insights into the influence of bilingualism and potential bilingual advantages in infancy.

The field of infancy research faces a difficult challenge: Some questions require samples that are simply too large for any 1 lab to recruit and test. ManyBabies aims to address this problem by forming large-scale collaborations on key theoretical questions in developmental science, while promoting the uptake of Open Science practices. Here, we look back on the first project completed under the ManyBabies umbrella-ManyBabies 1-which tested the development of infant-directed speech preference. Our goal is to share the lessons learned over the course of the project and to articulate our vision for the role of large-scale collaborations in the field. First, we consider the decisions made in scaling up experimental research for a collaboration involving 100ϩ researchers and 70ϩ labs. Next, we discuss

This paper examines the ability of bilingual infants who were learning Dutch and another non-tone language to discriminate tonal contrasts. All infants from 5 to 18 months of age succeeded in discriminating a tonal contrast of Mandarin Chinese (Tone 1 versus Tone 4) and showed a U-shaped pattern when facing a less acoustically salient manipulated version (contracted) of the aforementioned contrast. Specifically, infants showed initial sensitivity to the contracted contrast during their early months, followed by a loss of sensitivity at the stage where tonal perceptual reorganization typically occurs, and a sensitivity rebound by the end of the first year after birth. Compared to a previous studying of ours testing monolingual Dutch infants (Liu & Kager, 2014), the discrimination patterns of bilingual infants revealed both similarities and differences. On one hand, as with monolinguals, non-tone-learning bilingual infants’ tonal perception presented plasticity influenced by contrast acoustic salience along the trajectory of perceptual reorganization; as well as a general U-shaped perceptual pattern when discriminating non-native tones. On the other hand, bilingual infants appeared to regain sensitivity to the contracted tonal contrast at an earlier age (11–12 months) in comparison with monolinguals infants (17–18 months). We provide several explanations, stemming from the simultaneous exposure to two languages, to account for the 6-month bilingual perceptual plasticity from linguistic and cognitive perspectives. The overall outcomes of the study offer insights into the infant perceptual reorganization and language development trajectory, expand on the differences between monolingual and bilingual language development, and broaden our understanding of the influence of bilingual exposure to the perception of non-native contrasts in infancy from linguistic and cognitive perspectives.

Background In recent years, the widespread presence of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in the environment and the related exposures and adverse health effects has received increasing attention. However, PFASs are not routinely monitored in drinking water in many parts of the world, including China. PFAS data are mainly generated by research studies. This paper provides an overview of the available research studies on PFASs in Chinese drinking water to better understand the current status of PFAS contamination and the potential for exposure. Results The available studies provided PFAS data from 526 drinking water samples across 66 cities in China with a total of approximately 452 million inhabitants. We mapped the risk distribution associated with PFAS-contaminated drinking water in China by comparing the measured levels with recent international guidelines. The PFAS concentrations reported in more than 20% of the studied cities, likely affecting 98.5 million people, were above the maximum contaminant level issued by Vermont in 2019. Furthermore, we also investigated the human exposure to PFASs in drinking water by estimating total daily intakes based on Exposure Factors Handbook of Chinese Population. This study revealed that East China and the Southwest regions posed a relatively higher risk to the Chinese population and some cities in the Yangtze River basin such as Zigong, Jiujiang, Lianyungang and a considerable share of other cities have exceeded the health-based guidelines issued by EU and US agencies. Conclusion Drinking water in many cities and regions in China is contaminated with PFASs at levels of concern. PFAS elimination of PFASs from drinking water in contaminated cities and affected regions in China is urgently needed. PFAS releases from industries and other sources need better control and reduction. Further monitoring in remote Chinese regions is needed to overcome the knowledge gaps for a more comprehensive understanding of population exposure. The current risk assessment of PFASs in China should be re-evaluated considering the most recent toxicological studies, to clarify if the guidelines need to be lowered as recently done in Europe and the United States. This is necessary to have the best national base for risk assessment and a science-based driver for countermeasures.