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This article describes a study of how Chinese preservice teachers unpacked a learning goal pertaining to adding fractions and understanding the concepts underlying the operation. Based on work in the USA by Morris, Hiebert, and Spizter ("Journal for Research in Mathematics Education," 40(5), 491-529, 2009), 50 Chinese preservice teachers completed a task, "anticipating an ideal student response," in the context of four representations: (1) fraction pieces, (2) graph paper, (3) common denominator algorithm, and (4) pennies. Like the US-based study, this study shows that Chinese preservice teachers' ability to unpack a learning goal was highly influenced by how the problem was represented. The pennies and graph paper problems provided more supportive contexts for unpacking the learning goal; the algorithm problem provided the least supportive context. The main difference between the preservice teachers from these two countries was the US preservice teachers chose the pennies and graph paper problems as having the most potential for revealing students' understanding of the learning goal; while the Chinese preservice teachers chose the algorithm problem despite the problem's unsupportive context. Chinese preservice teachers' preference suggests that they privileged algorithmic/symbolic representations over pictorial/concrete representations. Based on our results, we argue that it is time for cross-cultural comparative research to refocus on the common barriers, challenges, and benefits as related to mathematics teacher preparation and professional development. A cooperative instead of competitive orientation will lead to richer and deeper dialogues among mathematics educators.

Purpose: Large population-based studies for the associations between dietary advanced glycation end products (dAGEs) intake and liver steatosis remain lacking. It is necessary to clarify the relationship of dAGEsintake with liver steatosis through the National Health and Nutrition Survey (NHANES). Methods: A total of 5856 participants in the NHANES 2017–2018 were included. The dietary AGEs intake, including ε-(carboxymethyl)lysine(CML), Nε-(1-carboxyethyl)lysine (CEL), and Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) were estimated using the combination of ultra-performance LC–tandem MS dietary AGEs database and two 24-h dietary recall interviews. Liver steatosis was assessed by controlled attenuation parameter via transient elastography. Logistic regression model was adopted to explore the relationships between dAGEs intake and hepatic steatosis. Results: Compared with individuals of total dAGEs, CML, MG-H1 in the lowest tertile, those in the highest tertile had highest risk of hepatic steatosis, and the corresponding odds radios(ORs) (95% confidence interval(CI)) were 1.37 (1.01, 1.84), 1.36 (1.04,1.78) and 1.40 (1.06, 1.85), respectively. Subgroups analysis found that the positive association between dAGEs, CML, CEL and MG-H1 and hepatic steatosis appeared stronger in subjects with obesity and those with abnormal waist circumference (WC). Conclusion: There was a positive correlation between dAGEs, CML, MG-H1, and hepatic steatosis, and this association mainly existed in subjects with obesity and those with abnormal WC. Dietary AGEs restriction might be of high priority for subjects with obesity for the prevention of fatty liver disease. Further longitudinal studies are required to confirm the causal associations and explore the potential mechanisms. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore urine caffeine metabolites in relation to cognitive performance among 2011-2014 National Health and Nutrition Examination Survey participants aged ≥60 years. We hypothesized that urine caffeine metabolites were positively associated with cognition in older adults. Caffeine and 14 of its metabolites were quantified in urine by use of high-performance liquid chromatography-electrospray ionization-tandem quadruple mass spectrometry with stable isotope labeled internal standards. Cognitive assessment was based on scores from the word learning and recall modules. Participants were categorized based on the quartiles of caffeine and its metabolites level. The association between caffeine metabolites and each cognitive dimension was analyzed using multiple logistic regression analysis in adjusted models. Stratification analyses by gender were also performed. For CERAD test, there was a significant association between 1-methyluric acid (OR=0.62, 95% CI: 0.42 to 0.92), 7-methylxanthine(OR=0.49, 95% CI: 0.27 to 0.89), theophylline (OR=0.52, 95% CI: 0.29 to 0.92), as well as paraxanthine (OR=0.49, 95% CI: 0.27 to 0.88) and cognitive function. For animal fluency test, there was a positive association between theophylline (TP) (OR=0.44, 95% CI: 0.22 to 0.89) and cognitive function. The trend that the risk of low cognitive function decreased with increasing concentration of 1-methylxanthine (P trend=0.0229) was also observed. Furthermore, the same trend existed for 3-methylxanthine (p trend = 0.0375) in men. In conclusion, there was a significant positive association between urine caffeine metabolites and cognitive performance in older adults, particularly for theophylline, paraxanthine and caffeine; and the association might be dependent on gender. We aimed to explore the relationship between urine caffeine metabolites and cognitive performance among 2011-2014 NHANES participants aged ≥60 years. There was a significant positive association between theophylline (TP) as well as paraxanthine (PX) and cognitive function. There was a trend towards a negative correlation between low cognitive function and 1-methylxanthine as well as theophylline. The same trend existed for 3-methylxanthine in men by performing stratification analyses. [Display omitted] [ABSTRACT FROM AUTHOR]

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• SVMs and SVM-DA models forced with limited climate variables can forecast CGWLs up to 3 months lead time. • Performance of SVM model can be influenced by the local climate variables. • Addition of GRACE information can further improve the prediction of change in groundwater levels based on SVM-DA model. Groundwater (GW) is a vital resource for human consumption, agriculture, environmental sustainability, and socio-economic development in different parts of the world. Besides, GW plays a crucial role in minimizing the impacts during extreme drought events. However, there is a fast decline in groundwater resources due to increased sectoral water demand compounded by reduced rainfall and rising temperature. Therefore, it is essential to develop appropriate tools to study spatio-temporal dynamics and predict groundwater levels to improve water resource management, especially during drought events. In this study, we applied machine learning algorithms based on support vector machines (SVMs), combined with data assimilation (DA) technique to predict the change in groundwater levels (CGWLs) at 1 to 3-month time scales for 46 GW wells located at the northeast United States. The in-situ climate variables and the Gravity Recovery and Climate Experiment (GRACE) mission-informed groundwater anomalies data (GWA) are used to develop the models. The results suggest that SVMs (SVM-DA) models forced with limited climate variables (i.e., precipitation, solar radiation, air temperature, infrared surface temperature) can forecast the CGWLs up to 3-month lead times at most of the locations. The addition of GRACE data as a forcing variable can improve the performance of SVMs at most of the stations, where a strong relationship exists between the CGWLs and the GWA. The SVM-DA model comparatively performed better than SVMs at most of the stations. [ABSTRACT FROM AUTHOR]

The unprecedented urbanization that is occurring worldwide brings with it a vast amount of solid waste, leading to a rapid increase in study of municipal waste management (MWM) worldwide. This mini-review assessed this body of research both quantitatively and qualitatively. The data for the review were 9711 publications indexed by the Science Citation Index Expanded and the Social Sciences Citation Index for the period 2000-2019. The analysis showed that developed countries, the United States in particular, led trends in research during the first part of the period, and developing countries made substantial contributions to the literature more recently. For all years since 2009 except for 2014, China produced more research than the United States, becoming the most productive country in the study of MWM. Home to five of the ten most productive global research institutes on this subject, China is also a hub for collaboration among countries and institutes, as is the United States. Using content analysis and keyword visualization, this study characterized two decades of study of MWM. This study found that the keywords "sustainability," "waste-to-energy," "life-cycle assessment," and "China" exhibited an upward trend in research. This study seeks the pathway to successful scientific research, helping guide researchers as they innovate in and contribute to the field, and proposes pathways that governments can take to build sustainable MWM systems.

Porcine reproductive and respiratory syndrome virus (PRRSV), an important pathogen that affects the pig industry, is a highly genetically diverse RNA virus. However, the phylogenetic and genomic recombination properties of this virus have not been completely elucidated. In this study, comparative analyses of all available genomic sequences of North American (NA)-type PRRSVs ( n  = 355, including 138 PRRSV genomes sequenced in this study) in China and the United States during 2014-2018 revealed a high frequency of interlineage recombination hot spots in nonstructural protein 9 (NSP9) and the GP2 to GP3 regions. Lineage 1 (L1) PRRSV was found to be susceptible to recombination among PRRSVs both in China and the United States. The recombinant major parent between the 1991-2013 data and the 2014-2018 data showed a trend from complex to simple. The major recombination pattern changed from an L8 to L1 backbone during 2014-2018 for Chinese PRRSVs, whereas L1 was always the major backbone for US PRRSVs. Intralineage recombination hot spots were not as concentrated as interlineage recombination hot spots. In the two main clades with differential diversity in L1, NADC30-like PRRSVs are undergoing a decrease in population genetic diversity, NADC34-like PRRSVs have been relatively stable in population genetic diversity for years. Systematic analyses of insertion and deletion (indel) polymorphisms of NSP2 divided PRRSVs into 25 patterns, which could generate novel references for the classification of PRRSVs. The results of this study contribute to a deeper understanding of the recombination of PRRSVs and indicate the need for coordinated epidemiological investigations among countries. IMPORTANCE Porcine reproductive and respiratory syndrome (PRRS) is one of the most significant swine diseases. However, the phylogenetic and genomic recombination properties of the PRRS virus (PRRSV) have not been completely elucidated. In this study, we systematically compared differences in the lineage distribution, recombination, NSP2 polymorphisms, and evolutionary dynamics between North American (NA)-type PRRSVs in China and in the United States. Strikingly, we found high frequency of interlineage recombination hot spots in nonstructural protein 9 (NSP9) and in the GP2 to GP3 region. Also, intralineage recombination hot spots were scattered across the genome between Chinese and US strains. Furthermore, we proposed novel methods based on NSP2 indel patterns for the classification of PRRSVs. Evolutionary dynamics analysis revealed that NADC30-like PRRSVs are undergoing a decrease in population genetic diversity, suggesting that a dominant population may occur and cause an outbreak. Our findings offer important insights into the recombination of PRRSVs and suggest the need for coordinated international epidemiological investigations., (Copyright © 2020 American Society for Microbiology.)

Background: Lower thoracic esophageal cancer (LTEC) with celiac node metastasis and upper thoracic esophageal cancer (UTEC) with supraclavicular node metastasis were previously categorized as M1a diseases. Our study aimed to investigate whether the clinical significance of supraclavicular and celiac lymph node metastasis should be reevaluated in thoracic esophageal cancer., Methods: A total of 6178 patients with thoracic esophageal cancer were identified from the Surveillance, Epidemiology, and End Results (SEER) database during 2004-2015. Treatment strategies and outcomes (OS, overall survival; CSS, cancer-specific survival) of patients with different nodal status were reviewed. The Cox proportional hazards regression model was applied to evaluate the prognostic factors. Statistical analyses were performed in all subgroups., Results: Multivariate analysis identified supraclavicular node metastasis but not celiac node metastasis as an independent predictor of both OS and CSS in LTEC. However, metastasis to supraclavicular or celiac nodes was not an independent predictor of OS and CSS in UTEC. Surgery was not associated with increased OS and CSS for UTEC with celiac or supraclavicular node metastasis but was favored as a predictor of better OS and CSS for LTEC with celiac or supraclavicular node metastasis. Radiotherapy benefited OS and CSS in LTEC involving celiac or supraclavicular nodes and in UTEC involving celiac nodes, while only OS benefited from radiotherapy in UTEC involving supraclavicular nodes., Conclusions: These results provide preliminary evidence that the clinical significance of supraclavicular and celiac lymph node metastasis should be reevaluated in thoracic esophageal cancer with different prognostic information according to the primary sites., (© 2019 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.)

Purpose/Objective(s): Treatments for superior sulcus non-small cell lung cancer (SS-NSCLC) have evolved, but adequate treatments of T4 disease have not been found. The aim of our study was to evaluate the prognostic factors and optimal treatment strategy for patients with T4 SS-NSCLC. Materials/Methods: We utilized the Surveillance, Epidemiology, and End Results (SEER) database (1973-2015) to identify patients diagnosed with T4 stage SS-NSCLC (according to the 7th edition American Joint Committee on Cancer (AJCC) staging system) from 2004 to 2015; those with M1 disease were excluded. Propensity score matching (PSM) with Kaplan-Meier and Cox proportional hazards' models was performed to estimate prognosis. Results: A total of 384 patients were included. The majority was male (59.4%) at stage IIIB (56.6%), with N2 accounting for 45.3%. A total of 47 patients underwent cancer-directed surgery, while radiotherapy alone was received by 60.2% of patients. Median overall survival (OS) and lung cancer-specific survival (LCSS) were 12 and 17 months, respectively, and the 5-year OS and LCSS rates were 15.8 and 25.4%, respectively. In the matched population, the median survival outcomes were better following surgery (OS: 25 compared with 9.0 months, P <0.001; LCSS: not available (NA) compared with 11.0 months, P <0.001). Multivariate Cox analysis showed that ages ≥ 66 years (hazard ratio (HR) = 1.639, P =0.001), unmarried status (HR = 1.356, P =0.034), and tumor size ≥ 6.0 cm (HR = 1.694, P <0.001) were associated with inferior OS. Cancer-directed surgery (HR = 0.537, P =0.009) and radiotherapy (HR = 0.644, P =0.006) were independent prognostic factors for patients with T4 SS-NSCLC. Conversely, in the subgroup analysis, favorable impacts of radiotherapy were observed for nonsurgical patients (OS: HR = 0.58, P <0.001; LCSS: HR = 0.55, P <0.001). Conclusion: Our study showed that T4 stage SS-NSCLC patients had a poor prognosis. Surgical resection remains the best option for those with resectable disease. For nonsurgical T4 SS-NSCLC patients, radiotherapy should be actively considered., (© 2019 The Author(s).)