Statistical learning of novel graphotactic constraints in children and adults

The current study explored statistical learning processes in the acquisition of orthographic knowledge in school-aged children and skilled adults. Learning of novel graphotactic constraints on the position and context of letter distributions was induced by means of a two-phase learning task adapted from Onishi, Chambers, and Fisher (Cognition, 83 (2002) B13–B23). Following incidental exposure to pattern-embedding stimuli in Phase 1, participants’ learning generalization was tested in Phase 2 with legality judgments about novel conforming/nonconforming word-like strings. Test phase performance was above chance, suggesting that both types of constraints were reliably learned even after relatively brief exposure. As hypothesized, signal detection theory d′ analyses confirmed that learning permissible letter positions (d′ = 0.97) was easier than permissible neighboring letter contexts (d′ = 0.19). Adults were more accurate than children in all but a strict analysis of the contextual constraints condition. Consistent with the statistical learning perspective in literacy, our results suggest that statistical learning mechanisms contribute to children’s and adults’ acquisition of knowledge about graphotactic constraints similar to those existing in their orthography

Artificial Grammar Learning in Dyslexic and Nondyslexic Adults: Implications for Orthographic Learning

Potential implicit orthographic learning deficits were investigated in adults with dyslexia. An artificial grammar learning paradigm served to assess dyslexic and typical readers’ ability to exploit information about chunk frequency, letter-position patterns, and specific string similarity, all of which have analogous constructs in real orthographies. We also investigated whether implicit learning deficits in dyslexia held for letter strings (Experiment 1) and symbol strings (Experiment 2). Experiment 1 results indicated that dyslexic adults were mildly impaired in memorizing letter strings, although this finding proved inconclusive in a more stringent analysis of the data across experiments. There were no signs of difficulty during symbol string memorization in Experiment 2. In each experiment, dyslexic and nondyslexic readers were comparably sensitive to chunk frequencies and showed reliable sensitivity to letter and shape position patterns and string similarities. These findings challenge the claim that a general learning deficit contributes to literacy difficulties in dyslexia

Statistical learning and spelling: Evidence from an incidental learning experiment with children

Statistical learning processes–akin to those seen in spoken language acquisition (Saffran et al., 1996)–may be important for the development of literacy, particularly spelling development. One previous study provides direct evidence for this process: Samara and Caravolas (2014) demonstrated that 7-year-olds generalize over permissible letter contexts (graphotactics) in novel word-like stimuli under incidental learning conditions. However, unlike in actual orthography, conditioning contexts in Samara and Caravolas’ (2014) stimuli comprised perfectly correlated, redundant cues in both word-initial and word-final positions. The current study explores whether 7-year-olds can extract such constraints in the absence of redundant cues. Since theories of literacy development predict greater sensitivity to restrictions within word-final units, we also contrast learning in word-initial and word-final units. We demonstrate that–for 7-year-old learners in two linguistic contexts (English and Turkish)–there is substantial evidence for the learning of both types of restriction

Semantic cues in language learning: an artificial language study with adult and child learners

Grammatical regularities may correlate with semantics; e.g., grammatical gender is often partially predictable from the noun’s semantics. We explore whether learners generalise over semantic cues, and whether extent of exposure (1 versus 4 sessions) and number of exemplars for each semantic class (type-frequency) affect this. Six-year-olds and adults were exposed to semi-artificial languages where nouns co-occurred with novel particles, with particle usage fully or partially determined by the semantics of nouns. Both adults and children generalised to novel nouns when semantic cues were fully consistent. Adults (but not children) also generalised when cues were partially consistent. Generalisation increased with exposure, however there was no evidence that increasing type-frequency (i.e. more nouns per semantic class) increased generalisation. Post-experiment interviews also suggested that successful generalisation depended on explicit awareness. These results suggest that semantic cues are particularly difficult for children to exploit during the early stages of language acquisition

Seasonal and diurnal changes in inorganic ions, carbonaceous matter and mass in ambient aerosol particles in an urban, background area

Concentration and composition of the fine particulate matter (PM) was measured using various online methods for 13 months in an urban, background area in Helsinki, Finland. Seasonal differences were found for ions and carbonaceous compounds. Biomass burning was found to increase inorganic ion and elemental carbon (EC) concentrations in winter, whereas organic carbon (OC) contribution was highest during summer due to secondary aerosol formation. Diurnal cycles, with maxima between 06:00 and 09:00, were recorded for EC and nitrate due to traffic emissions. In addition, the concentrations measured with the online and offline PM sampling devices were compared using regression analysis. In general, a good agreement (r(2) = 0.60-0.95) was found. During the year-long measurements, on average 65% of PM2.5 was identified by submicron chemical analyses (ions, OC, EC). As compared with filter measurements, the high resolution measurements provided important data on short pollution plumes and diurnal changes.Peer reviewe

Trends in energy intake in U.S. between 1977 and 1996: Similar shifts seen across age groups

Objective: To determine the trends in locations and food sources of Americans stratified by age group for both total energy and the meal and snack subcomponents. Research Methods and Procedures: Nationally representative data was taken from the 1977 to 1978 Nationwide Food Consumption Survey and the 1989 to 1991 and 1994 to 1996 (and 1998 for children age 2 through 9) Continuing Surveys of Food Intake by Individuals. The sample consisted of 63,380 individuals, age 2 and up. For each survey year, the percentage of total energy intake from meals and snacks was calculated separately for 2‐ to 18‐year‐olds, 19‐ to 39‐year‐olds, 40‐ to 59‐year‐olds, and those 60 years and older. The percentage of energy intake by location (at‐home consumption or preparation, vending, store eaten out, restaurant/fast‐food, and school) and by specific food group was computed for all age groups separately. Results: The trends in location and food sources were almost identical for all age groups. Key dietary behavior shifts included greater away‐from‐home consumption; large increases in total energy from salty snacks, soft drinks, and pizza; and large decreases in energy from low‐ and medium‐fat milk and medium‐ and high‐fat beef and pork. Discussion: Total energy intake has increased over the past 20 years, with shifts away from meals to snacks and from at‐home to away‐from‐home consumption. The similarity of changes across all age groups furthers the assertion that broad‐based environmental changes are needed to improve the diets of Americans

Expression of pattern recognition receptors in liver biopsy specimens of children chronically infected with HBV and HCV

Pattern recognition receptors (PRRs) constitute a pivotal arm of innate immunity. Their distribution is widespread and not limited to cells of the immune system. Following our previous findings concerning the expression of Toll-like receptors (TLRs) 2, 3 and 4 in chronic viral hepatitis C of children, we wished to search for other PRRs, including other TLRs, NOD-like receptors (NLRs) and RIG-1-like helicase receptors (RLR) in infected hepatocytes. Liver biopsy fragments from ten children with chronic hepatitis B and C were used and two others in which hepatotropic virus infection was excluded. Frozen sections of liver samples were subjected to ABC immunohistochemistry (IHC) following incubation with a set of antibodies. Results of IHC findings were screened for correlation with clinical/laboratory data of patients. It was found that several PRRs could be shown in affected hepatocytes, but the incidence was higher in hepatitis C than in B. In hepatitis C, TLR1, 2, 4, NALP and RIG-1 helicase showed the most marked expression. In hepatitis B, TLR1, 3, 9, NOD1 and NALP expression were the most conspicuous. Expression PRRs in liver from hepatitis of unknown origin was much lower. It was also the case in cytospins from human hepatoma cell line. Several correlations between PRRs expression and clinical findings in patients could be shown by statistical exploration. In conclusion, this data suggests some role for PRRs in the pathogenesis of chronic viral hepatitis. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 3, pp. 410–416

Validation of the Surgical Outcome Risk Tool (SORT) and SORT v2 for Predicting Postoperative Mortality in Patients with Pancreatic Cancer Undergoing Surgery

BACKGROUND: Pancreatic cancer surgery is related to significant mortality, thus necessitating the accurate assessment of perioperative risk to enhance treatment decision making. A Surgical Outcome Risk Tool (SORT) and SORT v2 have been developed to provide enhanced risk stratification. Our aim was to validate the accuracy of SORT and SORT v2 in pancreatic cancer surgery. METHOD: Two hundred and twelve patients were included and underwent pancreatic surgery for cancer. The surgeries were performed by a single surgical team in a single tertiary hospital (2016-2022). We assessed a total of four risk models: SORT, SORT v2, POSSUM (Physiology and Operative Severity Score for the enumeration of Mortality and Morbidity), and P-POSSUM (Portsmouth-POSSUM). The accuracy of the model was evaluated using an observed-to-expected (O:E) ratio and the area under the curve (AUC). RESULTS: The 30-day mortality rate was 3.3% (7 patients). Both SORT and SORT v2 demonstrated excellent discrimination traits (AUC: 0.98 and AUC: 0.98, respectively) and provided the best-performing calibration in the total analysis. However, both tools underestimated the 30-day mortality. Furthermore, both reported a high level of calibration and discrimination in the subgroup of patients undergoing pancreaticoduodenectomy, with previous ERCP, and CA19-9 ≥ 500 U/mL. CONCLUSIONS: SORT and SORT v2 are efficient risk-assessment tools that should be adopted in the perioperative pathway, shared decision-making (SDM) process, and counseling of patients with pancreatic cancer undergoing surgery

Non-canonical BIM-regulated energy metabolism determines drug-induced liver necrosis.

Paracetamol (acetaminophen, APAP) overdose severely damages mitochondria and triggers several apoptotic processes in hepatocytes, but the final outcome is fulminant necrotic cell death, resulting in acute liver failure and mortality. Here, we studied this switch of cell death modes and demonstrate a non-canonical role of the apoptosis-regulating BCL-2 homolog BIM/Bcl2l11 in promoting necrosis by regulating cellular bioenergetics. BIM deficiency enhanced total ATP production and shifted the bioenergetic profile towards glycolysis, resulting in persistent protection from APAP-induced liver injury. Modulation of glucose levels and deletion of Mitofusins confirmed that severe APAP toxicity occurs only in cells dependent on oxidative phosphorylation. Glycolytic hepatocytes maintained elevated ATP levels and reduced ROS, which enabled lysosomal recycling of damaged mitochondria by mitophagy. The present study highlights how metabolism and bioenergetics affect drug-induced liver toxicity, and identifies BIM as important regulator of glycolysis, mitochondrial respiration, and oxidative stress signaling