Background: Polybrominated diphenyl ethers (PBDEs) are chemical additives used as flame retardants in commercial products. PBDEs are bioaccumulative and persistent and have been linked to several ...adverse health outcomes. Objectives: This study leverages an ongoing pregnancy cohort to measure PBDEs and PBDE metabolites in serum collected from an understudied population of pregnant women late in their third trimester. A secondary objective was to determine whether the PBDEs or their metabolites were associated with maternal thyroid hormones. Methods: One hundred forty pregnant women > 34 weeks into their pregnancy were recruited into this study between 2008 and 2010. Blood samples were collected during a routine prenatal clinic visit. Serum was analyzed for a suite of PBDEs, three phenolic metabolites (i.e., containing an -OH moiety), and five thyroid hormones. Results: PBDEs were detected in all samples and ranged from 3.6 to 694 ng/g lipid. Two hydroxylated BDE congeners (4'-OH-BDE 49 and 6-OH-BDE 47) were detected in > 67% of the samples. BDEs 47, 99, and 100 were significantly and positively associated with free and total thyroxine (T₄) levels and with total triiodothyronine levels above the normal range. Associations between T₄ and PBDEs remained after controlling for smoking status, maternal age, race, gestational age, and parity. Conclusions: PBDEs and OH-BDEs are prevalent in this cohort, and levels are similar to those in the general population. Given their long half-lives, PBDEs may be affecting thyroid regulation throughout pregnancy. Further research is warranted to determine mechanisms through which PBDEs affect thyroid hormone levels in developing fetuses and newborn babies.
Restrictions on the use of polybrominated diphenyl ethers (PBDEs) have resulted in the increased use of alternate flame retardant chemicals to meet flammability standards. However, it has been ...difficult to determine which chemical formulations are currently being used in high volumes to meet flammability standards since the use of flame retardant formulations in consumer products is not transparent (i.e., not provided to customers). To investigate chemicals being used as replacements for PentaBDE in polyurethane foam, we analyzed foam samples from 26 different pieces of furniture purchased in the United States primarily between 2003 and 2009. Samples included foam from couches, chairs, mattress pads, pillows, and, in one case, foam from a sound-proofing system of a laboratory-grade dust sieve, and were analyzed using gas chromatography mass spectrometry. Fifteen of the foam samples contained the flame retardant tris(1,3-dichloro-2-propyl) phosphate (TDCPP; 1−5% by weight), four samples contained tris(1-chloro-2-propyl) phosphate (TCPP; 0.5 −2.2% by weight), one sample contained brominated chemicals found in a new flame retardant mixture called Firemaster 550 (4.2% by weight), and one foam sample collected from a futon likely purchased prior to 2004 contained PentaBDE (0.5% by weight). Due to the high frequency of detection of the chlorinated phosphate compounds in furniture foam, we analyzed extracts from 50 house dust samples collected between 2002 and 2007 in the Boston, MA area for TDCPP, TCPP, and another high volume use organophosphate-based flame retardant used in foam, triphenylphosphate (TPP). Detection frequencies for TDCPP and TPP in the dust samples were >96% and were log normally distributed, similar to observations for PBDEs. TCPP was positively detected in dust in only 24% of the samples, but detection was significantly limited by a coelution problem. The geometric mean concentrations for TCPP, TDCPP, and TPP in house dust were 570, 1890, and 7360 ng/g, respectively, and maximum values detected in dust were 5490, 56,080 and 1,798,000 ng/g, respectively. These data suggest that levels of these organophosphate flame retardants are comparable, or in some cases greater than, levels of PBDEs in house dust. The high prevalence of these chemicals in foam and the high concentrations measured in dust (as high as 1.8 mg/g) warrant further studies to evaluate potential health effects from dust exposure, particularly for children.
Autistic students are particularly vulnerable to stressors within a university environment and are more likely to experience poor mental health than their non-autistic peers. Students' experiences of ...stigma from staff and peers, and the masking behaviors they deploy to minimize it, can also result in worsening mental health. Despite these concerns, there is a lack of tailored support for autistic students at university. The current project assesses a co-created training course for university staff focused on debunking stereotypes, educating about the autistic experience at university, mental health presentation among autistic individuals, and practical strategies to improve interactions with autistic students.
The Autism Stigma and Knowledge Questionnaire ASK-Q was administered before and after the training, to examine changes in trainees' understanding and acceptance of autism and autistic people. Post-training interviews and surveys were also conducted with trainees, covering the impact the training has had on their perceptions of autism, the strategies they found beneficial, and how they will use the materials in future.
There were no statistically significant differences between pre- and post-training scores on the ASK-Q, likely due to ceiling effects as pre-training scores were high. Thematic analysis of interviews identified five themes: value of lived experience; developing nuanced, in-depth knowledge of autism; training as acceptable and feasible; links to professional practice; and systemic barriers.
Although ceiling effects meant there were no changes to participant's knowledge about autism and autistic people statistically, the qualitative data reveals the extensive benefits they gained from taking part in the training programs. Scoring highly on the ASK-Q did not mean that people could not learn important new information and benefit from the course. This more nuanced understanding of autism led to practical changes in their practice. Listening to and learning from autistic people was seen as particularly important, highlighting the value of co-production. Our results also emphasize the need for varied approaches to evaluating training effectiveness, as reliance on quantitative data alone would have missed the subtler, but impactful, changes our participants experienced. This has important implications for professional practice, both within higher education and more broadly.
This paper develops an approach to thinking about young children, digital technologies and learning, drawing on research literature that relates children’s learning to the use of books, and on ...literature that discusses the nature of interaction between adults and children and its relationship to children’s learning. An analysis is given of parents and children using devices marketed as supporting young children’s learning, identifying, within the interactions that take place, the adult’s conception of appropriate use, and showing how this influences the nature of adult–child interaction. The findings are then related to literature on social interaction and learning, and discussed in relation to the assumptions that underpin the design of the devices used. The paper suggests that the artefact can influence adult–child interaction via a conception of appropriate use, which relates to traditions or practices with which the adult is familiar but also to the design features of the artefact. It suggests that it may be time to rethink the design of technologies to support young children’s learning.
► This study analyses adult–child interaction during the use of digital technologies. ► Adults showed, or supported, the child in ‘the right way’ of using the technology. ► Children made contributions which the adults did not attend to nor take up. ► Shared use of digital technologies did not foster exploration or development of the child’s meaning-making.
Background: Polybrominated diphenyl ethers (PBDEs) are persistent, bioaccumulative, and endocrine-disrupting chemicals. Objectives: We used handwipes to estimate exposure to PBDEs in house dust among ...toddlers and examined sex, age, breast-feeding, race, and parents' education as predictors of serum PBDEs. Methods: Eighty-three children from 12 to 36 months of age were enrolled in North Carolina between May 2009 and November 2010. Blood, handwipe, and house dust samples were collected and analyzed for PBDEs. A questionnaire was administered to collect demographic data. Results: PBDEs were detected in all serum samples (geometric mean for ΣpentaBDE in serum was 43.3 ng/g lipid), 98% of the handwipe samples, and 100% of the dust samples. Serum ΣpentaBDEs were significantly correlated with both handwipe and house dust ΣpentaBDE levels, but were more strongly associated with handwipe levels (r = 0.57; p < 0.001 vs. r = 0.35; p < 0.01). Multivariate model estimates revealed that handwipe levels, child's sex, child's age, and father's education accounted for 39% of the variation in serum ΣBDE₃ levels (sum of BDEs 47, 99, and 100). In contrast, age, handwipe levels, and breast-feeding duration explained 39% of the variation in serum BDE 153. Conclusions: Our study suggests that hand-to-mouth activity may be a significant source of exposure to PBDEs. Furthermore, age, socioeconomic status, and breast-feeding were significant predictors of exposure, but associations varied by congener. Specifically, serum ΣBDE₃ was inversely associated with socioeconomic status, whereas serum BDE-153 was positively associated with duration of breast-feeding and mother's education.
Questo lavoro introduce STELLAR, la Rete di Eccellenza nel settore del Technology Enhanced Learning (TEL) finanziata nell’ambito del 7° Programma Quadro, ed illustra i suoi obiettivi. Inoltre ...l’articolo descrive come STELLAR ha affrontato la sfida del lavoro interdisciplinare e delinea i principali risultati della Rete in termini di sviluppo di una visione strategica per la ricerca nel TEL in Europa. Infine fornisce esempi di aree di ricerca che andrebbero considerate nei futuri programmi di ricerca del TEL.
This thesis is concerned with the potential for interactive digital technologies to support young children's learning within the context of family life. The perspective taken is a sociocultural one. ...learning is understood as meaning-making, which is inseparable from the activity of others. Designed physical artefacts may be understood as reifications of the activity of others; but the meaning that a learner makes of the artefact, and of its use, arises in the course of social experience relating to that artefact and the contexts of its use. Thus, one approach to investigating meaning-making of young children in relation to artefacts is to study the nature of social interaction in relation to their use. In this thesis, a framework is developed for the analysis of social interaction in relation to physical artefacts, which is then applied to activity between young children and parents during the use of interactive digital artefacts in the home. The focus is on the child's agency in the use of interactive digital artefacts and design features of the artefacts themselves. Drawing on interviews and visits to four families, a description is given of the arrangements for children to participate in the use of interactive digital technologies. 1brough a comparison of opportunities for children's observation of others' use, for their solo play, and for use in conjunction with another person, the diversity in the nature of young children's experience of interactive digital artefacts is illustrated, demonstrating the complex interrelations between the practices and priorities of families and the nature of interactive artefacts that ace used.. The interactions between adults and children involving digital artefacts that ace analysed in this thesis ace taken from video made by the families. Each family provided video recordings of occasions when the child used interactive digital technologies with another person; the technologies included both those which were and those which were not designed for young children's use. The analysis showed that the nature of interaction was generally oriented towards parents' interpretations of their design features, which reflected the designer's conception of what the artefact was supposed to be, do, or enable; this carried implicit expectations for the child's agency in determining the nature of the activity, for the overall characterisation of the activity between adult and child, and for the nature of interactions between them. In the light of these findings, the thesis ends by discussing the design features of technologies, and the aspects of cultural practice, that might be considered when seeking to develop artefacts that support more exploratory activity between adults and young children.
Karst aquifers are productive groundwater systems around the world, supplying approximately 25% of the world's drinking water. However, they are highly vulnerable to contamination due to rapid ...groundwater transit in the transmission zone (KWI 2006). The epikarst, also known as the subcutaneous zone, is an interface between the soil overburden and the transmission zone. The epikarst is considered a critical zone as it can control hydrologic and geochemical characteristics of recharge to the underlying karst aquifer. The overall goal of this thesis is to utilize time series hydrologic and geochemical data collected at James Cave, Virginia, to examine the influence of epikarst on the quantity, quality, and rates of recharge to aquifers in Appalachian karst.
Results of this study indicate a strong seasonality of both the hydrology and geochemistry of recharge. The conceptual model of the epikarst developed in this study identifies three hydrologic seasons: recharge, recession, and baseflow. Seasonality of recharge geochemistry coincides with these three hydrologic seasons. These results have implications for management of karst aquifers. First, recharge to Appalachian karst aquifers is seasonal, reaching a maximum during the winter-early spring; the onset of recharge depends on antecedent climatic conditions. Second, water that infiltrates into the epikarst will have seasonally variable residence times due to changes in hydrologic storage; these variations in attenuation affect geochemical reactions in the epikarst, which can influence recharge quality. Overall, these results point to the complex influence of epikarst on karst recharge, which necessitates collection of long-term and high resolution datasets.
Master of Science
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