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Sustaining research capacity in UK paediatrics: insights from a survey of academic resident doctors
Get PDFAcceptability of a digital early years language support service for caregivers of children who have SLCN and/or are multilingual
Get PDFBackground: Parent-child interaction (PCI) interventions have the potential to mitigate early-identified risks of Speech, Language and Communication Needs (SLCN). PCI interventions can be delivered at Universal, Targeted and Specialist levels, but evidence for effectiveness at the Universal level is lacking, especially for some populations. We examine the acceptability of a universal PCI intervention for two underserved groups: children who have SLCN and/or are multilingual. For the former group we also explore acceptability of a supplementary, targeted intervention.Aim: This study aimed to: a) evaluate the acceptability of a digital early years PCI support service - comprising a universal text-message service delivering BBC Tiny Happy People videos and targeted speech and language therapy following the Early Language Identification Measure & Intervention (ELIM-I); b) establish the interest of families with children who have, or are at risk of, SLCN (N=61) and/or are multilingual (N=26) in utilising the service, and explore their perceptions regarding merits and drawbacks of the service, and elicit recommendations for improvements.Methods & Procedures: We employed a mixed-methods approach. Quantitative data were collected via questionnaires based on the Theoretical Framework of Acceptability. Qualitative data were gathered through semi-structured online interviews. Families of children with SLCN provided prospective acceptability data after reviewing three videos, indicating their view of receiving similar weekly video content via text message. Those who then opted to try the text service for a month provided retrospective acceptability data, with additional questions for participants who received the targeted online ELIM-I intervention. Multilingual families received the service for three months before providing retrospective acceptability data. Outcomes & Results: Quantitative analyses revealed that all acceptability ratings were high on average, though there was individual variability. Reflexive thematic analysis of caregivers’ qualitative data identified three central themes: 1) demand for trustworthy guidance to address uncertainty 2) positives including service suitability for busy family life, personalisation, human connection and reassurance, enjoyment and perceived efficacy 3) a need for inclusive content, especially for children with complex SLCN.Conclusions & Implications: There is a clear desire for early digital services to help caregivers support their children’s language development. Acceptability was generally high. Caregivers wanted to see their family represented in video content. This was largely successful for the multilingual group with content celebrating home languages. Caregivers of children with SLCN sometimes felt under-represented and recommended demonstrating support strategies appropriate for their child’s age and stage of development
Monosyndetic and bisyndetic conjunction in Gizey
Get PDFPrevious studies on Gizey (glottocode: gize1234, Masa < Chadic < Afroasiatic) have treated the monosyndetic and bisyndetic uses of the conjunction māj/mɛ̄j as semantically equivalent. This paper challenges that view, presenting novel evidence that these two forms of conjunction cannot always be equated. We argue that the distributional differences between monosyndetic and bisyndetic conjunction can be better understood by considering how they contribute to the coherence of the discourse that contain them. Using Segmented Discourse Representation Theory (SDRT), we show that monosyndetic and bisyndetic conjunction are compatible with coordinating discourse relations (e.g. RESULT, NARRATION, PARALLEL, CONTRAST) and are congruently incompatible with subordinating discourse relations (e.g. ELABORATION, EXPLANATION). Furthermore, whereas monosyndetic conjunction can appear with all coordinating relations, bisyndetic conjunction is restricted to the structural discourse relations, namely PARALLEL and CONTRAST
Development of efficient & reproducible perovskite absorbers for all-perovskite triple junction tandem solar cells
Get PDFThe development of efficient and reproducible perovskite absorbers for all-perovskite triple junction tandem solar cells is advanced by this thesis. Chapter 1 traces the energy advancements that have powered human development throughout history. The burning of fossil fuels since the Industrial Revolution has helped power extraordinary increases in economic development, life expectancy, and global population growth. However, rapid increases in greenhouse gas atmospheric concentrations from burning fossil fuels is raising global average surface temperatures and causing climate change dangerous to humanity today. Sunlight offers the greatest potential to meet our need for increased energy and decreased greenhouse gas emissions. Stable all-perovskite triple junction tandem solar cells offer the promise of higher efficiencies and lower costs than crystalline silicon, the dominant solar cell technology for 70 years, to help solve this challenge.Chapter 2 explains important physics principles for solar cells, including energy band theory and semiconductor properties. Theoretical and operational fundamentals of solar cells, semiconductor junctions, the operation and characterization of solar cells, and limits to their efficiency are explained. Advantages of perovskites are discussed, including the potential for all-perovskite tandem solar cells to be fabricated at costs 50% lower than crystalline silicon. For perovskites to deliver on the promise of more efficient and lower cost commercial solar cells, however, stability, efficiency, and scalability must improve. Chapter 3 details the experimental methods used to fabricate and characterize perovskite thin films and solar cells in this thesis. In Chapter 4, improvements to efficiency, reproducibility, and stability are investigated for a representative middle band gap 1.55 eV FA0.8Cs0.2PbI3 perovskite absorber relevant for all-perovskite triple junction tandem solar cells. A tandem-relevant C60/ALD SnO2/IZO/Au device stability stack increased solar cell reproducibility. EDAI2 surface passivation and excess PbI2 perovskite precursor stoichiometry improved the stability of 1.55 eV FA0.8Cs0.2PbI3 single junction perovskite solar cells using the tandem-relevant device stack under 85°C light aging. In Chapter 5, a novel DMF/DMAX crystallization method was developed to create efficient and reproducible solution-processed ~2 eV (1.97 eV) wide band gap perovskite absorbers and single junction solar cells. The novel 68 mol%:32 mol% stoichiometric mixture of dimethylammonium bromide (DMABr) and dimethylammonium iodide (DMAI) additive salts – DMAX – to a 1.97 eV FA0.9Cs0.1Pb(Br0.68I0.32)3 perovskite precursor solution in neat DMF solvent was created to replace DMSO solvent. Perovskite thin films crystallized using DMF/DMAX exhibit larger median apparent grain sizes, more homogeneous morphology, and longer carrier lifetimes. 1.97 eV perovskite single junction solar cells fabricated using DMF/DMAX improved solar cell efficiency, reproducibility, and operational stability compared to DMF/DMSO – achieving near-record 1.42 V open-circuit voltage and 13.7% maximum power point tracked efficiency. In Chapter 6, non-radiative recombination processes – rather than halide segregation – are shown to dominate VOC losses in the 1.97 eV wide band gap perovskite single junction solar cells. The 20 mV VOC loss from radiative recombination due to halide segregation (VOC, rad) measured is five times less than the published estimate of ~100 mV loss. These results indicate that, compared to previously published estimates, halide segregation had a less substantial effect on VOC loss mechanisms in the 1.97 eV perovskite solar cells fabricated using the DMF/DMAX crystallization method. In Chapter 7, all-perovskite triple junction tandem solar cells with 1.97 eV, 1.61 eV, and 1.25 eV band gap absorbers are optimized with a 0.9 M 1.97 eV perovskite precursor and unique device stack featuring an ICBA electron transport layer for the wide band gap subcell and IZO recombination layers and achieved higher efficiencies with improved steady-state VOC and JSC. The champion all-perovskite triple junction tandem solar cell achieved 27.3% maximum power point tracked efficiency at 1 cm2 area, the highest efficiency for any known all-perovskite triple junction tandem solar cell published to date and identical to the highest known reported efficiency of 27.3% for a single junction crystalline silicon solar cell. One of the all-perovskite triple junction tandem solar cells was stability tested and retained 99.3% of its initial efficiency after 120 minutes of continuous maximum power point tracking under 1-sun intensity AM 1.5G illumination. Chapter 8 summarizes improvements to efficiency, reproducibility, and stability that are investigated and achieved in this thesis for three principal areas: 1) representative middle band gap perovskite absorber relevant for all-perovskite triple junction tandem solar cells; 2) all-perovskite triple junction tandem solar cells using a novel crystallization method for the 1.97 eV wide band gap absorber layer involving dimethylammonium bromide and dimethylammonium iodide (DMAX); and 3) all-perovskite triple junction tandem solar cells using a unique device stack incorporating an ICBA electron transport layer and IZO recombination layers with the 1.97 eV wide band gap absorber layer. Future improvements are suggested to achieve all-perovskite triple junction tandem solar cell efficiencies exceeding 30%
Investigating the influence of maternal prenatal BMI and perinatal depressive symptoms on neonatal brain network dynamics
Get PDFBackgroundElevated pre-pregnancy body mass index (BMI) and perinatal depressive symptoms have been linked to neonatal alterations in brain structure and function. This study examined associations between neonatal functional brain dynamics, maternal BMI, and perinatal depressive symptoms measured by the Edinburgh Postnatal Depression Scale (EPDS) in a community-based, largely low-risk cohort.MethodsFuncitonal MRI and Leading Eigenvector Analysis (LEiDA) were applied in a neonatal cohort (N = 437; 236 males; mean gestational age 39.6 weeks) from the developing Human Connectome Project. We assessed whether neonatal brain-state probabilities related to maternal BMI and EPDS scores (M = 5.6, SD = 4.3), testing main effects and, separately, their interaction. The sample included 291 healthy-weight (BMI < 25), 98 overweight (25 BMI < 30), and 48 obese (BMI 30) mothers.ResultsEPDS scores were low in this cohort and did not demonstrate associations with brain states or a significant BMI × EPDS interaction. Higher maternal pre-pregnancy BMI was negatively associated with the stability of a functional network encompassing superior frontal, superior parietal, and temporal regions (ß = -0.129, p = 0.006).ConclusionAs this network is normally recruited more with age, reduced stability suggests slowed maturation of fronto-parieto-temporal systems and may signal early risk for later behavioral challenges.ImpactHigher maternal pre-pregnancy BMI is associated with reduced stability in a neonatal frontoparietal brain state, characterized by coordinated activity in frontal, parietal, and temporal regions. This state is one of six distinct dynamic connectivity patterns identified, reflecting core neonatal resting-state networks. The association was robust across multiple analytic models and clustering solutions. No significant effects were found for maternal depressive symptoms. These findings underscore the selective impact of maternal metabolic health on early brain organization, suggesting prenatal influences on the functional architecture of the newborn brain that may shape long-term neurodevelopmental trajectories
Machine learning elucidates associations between oral microbiota and the decline of sweet taste perception during aging
Get PDFAging-induced deterioration in taste perception can result in loss of appetite and malnutrition in the elderly, posing a substantial challenge to healthy aging. In oral cavity, the oral microbiota, food particles, and taste receptors interact extensively under the flow of saliva. Although it has been hypothesized that oral microbiota may influence taste perception, evidence remains limited. Here we justified this hypothesis and further proposed that specific oral bacterial genera exhibited significant associations with age-related alterations in sweet taste perception. Notable age-related changes in taste perception were observed: the elderly presented significantly higher detection and recognition thresholds for sweet taste acuity compared to the youth. Linking back to the oral microbiota, we identified key bacteria genera Haemophilus, Lachnoanaerobaculum, Fusobacterium, Aggregatibacter and Oribacterium associated with sweet taste perception via machine learning. Correspondingly, we found several volatile compounds in the oral exhaled breath, especially the endogenous compound isoprene, that significantly correlated with oral bacteria genera and sweet taste sensitivity. Our findings in sweet taste perception-associated bacteria and metabolites can be potential biomarkers of early aging, which provides timely fresh clues for the well-being of the aging population
Quality of life in patients with pheochromocytoma and paraganglioma: influence of tumor type, genetics and surgical resection
Get PDFContext: Pheochromocytomas and paragangliomas (PPGL) are rare endocrine tumors with high heritability. Carriers of pathogenic variants (PVs) in susceptibility genes face a lifelong risk of recurrence or metastatic disease. Quality of life (QoL) in patients with PPGL, a history of PPGL and PV carriers, remains insufficiently studied. Methods: We assessed patient-reported QoL in patients with PPGL before and after surgery and in carriers of susceptibility PVs for the development of PPGLs within the prospective ProsPheo study. QoL was evaluated using standardized questionnaires (SF-12, PHQ-D, and GAD-7). Results: A total of 202 participants were analyzed. SF-12 physical component summary scores (PCS) differed significantly across subgroups (P = .006), with the lowest PCS scores in patients with metastatic PPGL (40.3) and unresected head and neck paragangliomas (HNPGL) (40.0), compared with PV carriers after curative PPGL resection (50.2). Within metastatic disease, hormonally active tumors showed lower PCS scores than inactive tumors (36.9 vs 46.2; P = .03). Perceived physical health in carriers of a PV without history of a PPGL was significantly lower compared to the age-matched general population. Mental health was not significantly impaired across all subgroups. Clinically relevant anxiety was reported in 15.2% of PV carriers and 21.7% of patients with unresected HNPGLs, compared with about 5.9% in the general population. Conclusions: Patient-reported physical health was reduced in patients with metastatic PPGLs, unresected HNPGLs, and PV carriers without prior PPGL, whereas patients after curative PPGL resection reported QoL comparable to the general population, regardless of PV status, suggesting that annual follow-up has minimal impact on QoL
Graphical sequences and plane trees
Get PDFBalister, the second author, Groenland, Johnston, and Scott recently showed that there are asymptotically many unordered sequences that occur as degree sequences of graphs with vertices. Combining limit theory for infinitely divisible distributions with a new connection between a class of random walk trajectories and a subset counting formula from additive number theory, we describe in terms of Walkup’s number of rooted plane trees. The bijection is related to an instance of the Lévy–Khintchine formula. Our main result complements a result of Stanley, that ordered graphical sequences are related to quasi-forests