161 research outputs found

    The Role of Phonological Awareness and Phonetic Radical Awareness in Acquiring Chinese Literacy Skills in Learners of Chinese as a Second Language

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    There is much research into the roles of phonological awareness and phonetic radical awareness in the development of Chinese character reading and writing skills in native-speaking children, but there is comparatively little work on the relationship between such metalinguistic skills and character literacy skills in adult learners of Chinese a second language (CSL). In this study, we explored this issue with 83 Arabic and English CSL learners who had studied Chinese in their home country. Their knowledge of phonological awareness, phonetic radical awareness, and Chinese character reading and writing was measured. There were two main findings. Firstly, the learners’ phonological awareness, but not their phonetic radical awareness, predicted the acquisition of character reading and writing skills directly or indirectly. Secondly, phonetic radical awareness did not mediate the effect of phonological awareness on character reading and writing skills. The results point to the different roles that phonological awareness and phonetic radical awareness play in the development of character literacy skills, and the still unclear relationship between phonological awareness and phonetic radical awareness. These findings are important for understanding the contribution of phonological awareness and phonetic radical awareness to the acquisition of character literacy skills for CSL learners

    Selection for efficient translation initiation biases codon usage at second amino acid position in secretory proteins

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    The definition of a typical sec-dependent bacterial signal peptide contains a positive charge at the N-terminus, thought to be required for membrane association. In this study the amino acid distribution of all Escherichia coli secretory proteins were analysed. This revealed that there was a statistically significant bias for lysine at the second codon position (P2), consistent with a role for the positive charge in secretion. Removal of the positively charged residue P2 in two different model systems revealed that a positive charge is not required for protein export. A well-characterized feature of large amino acids like lysine at P2 is inhibition of N-terminal methionine removal by methionyl amino-peptidase (MAP). Substitution of lysine at P2 for other large or small amino acids did not affect protein export. Analysis of codon usage revealed that there was a bias for the AAA lysine codon at P2, suggesting that a non-coding function for the AAA codon may be responsible for the strong bias for lysine at P2 of secretory signal sequences. We conclude that the selection for high translation initiation efficiency maybe the selective pressure that has led to codon and consequent amino acid usage at P2 of secretory proteins

    Option Pricing Kernels and the ICAPM

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    We estimate the parameters of pricing kernels that depend on both aggregate wealth and state variables that describe the investment opportunity set, using FTSE 100 and S&P 500 index option returns as the returns to be priced. The coefficients of the state variables are highly significant and remarkably consistent across specifications of the pricing kernel, and across the two markets. The results provide further evidence that, consistent with Merton's (1973) Intertemporal Capital Asset Pricing Model, state variables in addition to market risk are priced

    Red hot frogs:Identifying the Australian frogs most at risk of extinction

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    More than a third of the world’s amphibian species are listed as Threatened or Extinct, with a recent assessment identifying 45 Australian frogs (18.4% of the currently recognised species) as ‘Threatened’ based on IUCN criteria. We applied structured expert elicitation to 26 frogs assessed as Critically Endangered and Endangered to estimate their probability of extinction by 2040. We also investigated whether participant experience (measured as a self-assigned categorical score, i.e. ‘expert’ or ‘non-expert’) influenced the estimates. Collation and analysis of participant opinion indicated that eight species are at high risk (>50% chance) of becoming extinct by 2040, with the disease chytridiomycosis identified as the primary threat. A further five species are at moderate–high risk (30–50% chance), primarily due to climate change. Fourteen of the 26 frog species are endemic to Queensland, with many species restricted to small geographic ranges that are susceptible to stochastic events (e.g. a severe heatwave or a large bushfire). Experts were more likely to rate extinction probability higher for poorly known species (those with <10 experts), while non-experts were more likely to rate extinction probability higher for better-known species. However, scores converged following discussion, indicating that there was greater consensus in the estimates of extinction probability. Increased resourcing and management intervention are urgently needed to avert future extinctions of Australia’s frogs. Key priorities include developing and supporting captive management and establishing or extending in-situ population refuges to alleviate the impacts of disease and climate change

    Evaluation of the Berlin polytrauma definition:A Dutch nationwide observational study

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    BACKGROUND The Berlin polytrauma definition (BPD) was established to identify multiple injury patients with a high risk of mortality. The definition includes injuries with an Abbreviated Injury Scale score of >= 3 in >= 2 body regions (2AIS >= 3) combined with the presence of >= 1 physiological risk factors (PRFs). The PRFs are based on age, Glasgow Coma Scale, hypotension, acidosis, and coagulopathy at specific cutoff values. This study evaluates and compares the BPD with two other multiple injury definitions used to identify patients with high resource utilization and mortality risk, using data from the Dutch National Trauma Register (DNTR). METHODS The evaluation was performed based on 2015 to 2018 DNTR data. First, patient characteristics for 2AIS >= 3, Injury Severity Score (ISS) of >= 16, and BPD patients were compared. Second, the PRFs prevalence and odds ratios of mortality for 2AIS >= 3 patients were compared with those from the Deutsche Gesellschaft fur Unfallchirurgie Trauma Register. Subsequently, the association between PRF and mortality was assessed for 2AIS >= 3-DNTR patients and compared with those with an ISS of >= 16. RESULTS The DNTR recorded 300,649 acute trauma admissions. A total of 15,711 patients sustained an ISS of >= 16, and 6,263 patients had suffered a 2AIS >= 3 injury. All individual PRFs were associated with a mortality of >30% in 2AIS >= 3-DNTR patients. The increase in PRFs was associated with a significant increase in mortality for both 2AIS >= 3 and ISS >= 16 patients. A total of 4,264 patients met the BPDs criteria. Overall mortality (27.2%), intensive care unit admission (71.2%), and length of stay were the highest for the BPD group. CONCLUSION This study confirms that the BPD identifies high-risk patients in a population-based registry. The addition of PRFs to the anatomical injury scores improves the identification of severely injured patients with a high risk of mortality. Compared with the ISS >= 16 and 2AIS >= 3 multiple injury definitions, the BPD showed to improve the accuracy of capturing patients with a high medical resource need and mortality rate

    Missing effects of zinc in a porcine model of recurrent endotoxemia

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    BACKGROUND: Chronic human sepsis often is characterised by the compensatory anti-inflammatory response syndrome (CARS). During CARS, anti-inflammatory cytokines depress the inflammatory response leading to secondary and opportunistic infections. Proved in vitro as well as in vivo, zinc's pro-inflammatory effect might overcome this depression. METHODS: We used the model of porcine LPS-induced endotoxemia established by Klosterhalfen et al. 10 pigs were divided into two groups (n = 5). Endotoxemia was induced by recurrent intravenous LPS-application (1.0 μg/kg E. coli WO 111:B4) at hours 0, 5, and 12. At hour 10, each group received an intravenous treatment (group I = saline, group II = 5.0 mg/kg elementary zinc). Monitoring included hemodynamics, blood gas analysis, and the thermal dilution technique for the measurement of extravascular lung water and intrapulmonary shunt. Plasma concentrations of IL-6 and TNF-alpha were measured by ELISA. Morphology included weight of the lungs, width of the alveolar septae, and rate of paracentral liver necrosis. RESULTS: Zinc's application only trended to partly improve the pulmonary function. Compared to saline, significant differences were very rare. IL-6 and TNF-alpha were predominately measured higher in the zinc group. Again, significance was only reached sporadically. Hemodynamics and morphology revealed no significant differences at all. CONCLUSION: The application of zinc in this model of recurrent endotoxemia is feasible and without harmful effects. However, a protection or restoration of clinical relevance is not evident in our setting. The pulmonary function just trends to improve, cytokine liberation is only partly activated, hemodynamics and morphology were not influenced. Further pre-clinical studies have to define zinc's role as a therapeutic tool during CARS
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