Aprendizaje de la lengua portuguesa y acceso al capital: un estudio sobre estudiantes universitarios de Macao

This paper reports on an inquiry into a group of students’ Portuguese language learning with a focus on their access to economic, social, and cultural capital. The inquiry problematizes the traditional uncritical assumption of a shared pursuit of linguistic competence among students. Drawing on individual in-depth interviews with 14 participants at a university in Macau, this article illustrates how local and mainland Chinese students related their Portuguese language learning to the acquisition of different forms of capital, respectively. Specifically, our analysis reveals that economic capital dominated in the local participants’ pursuits, with cultural and social capital being less influential, whereas among mainland Chinese participants the influence of economic capital was weak and unsustainable, with a balanced distribution of cultural and social capital. The findings also suggest that the participants’ family contexts and social networks shaped their pursuits of different forms of capital in Portuguese learning, implying that educational institutions and teachers need to reframe their learning resources and pedagogical strategies for Portuguese language learners in Macau, placing greater emphasis on reinforcing students’ social connections with Portuguese or local Macanese communities.Este estudio investiga el aprendizaje de la lengua portuguesa de un grupo de estudiantes con un enfoque en su acceso al capital económico, social y cultural. La investigación cuestiona la tradicional suposición acrítica de la búsqueda compartida de la competencia lingüística entre los estudiantes. Basándose en entrevistas individuales a profundidad con 14 participantes en una universidad de Macao, este estudio ilustra cómo los estudiantes locales y los de China continental relacionaron su aprendizaje del idioma portugués con la adquisición de diferentes formas de capital. En concreto, nuestro análisis revela que los participantes buscaron principalmente el capital económico, siendo el capital cultural y social menos influyente, mientras que, entre los participantes de China continental, la influencia del capital económico fue débil e insostenible, con una distribución equilibrada de capital cultural y social. Los resultados también sugieren que los contextos familiares y las redes sociales de los participantes determinaron su búsqueda de diferentes formas de capital en el aprendizaje del portugués, lo que implica que las instituciones educativas y los docentes deben reestructurar sus recursos de aprendizaje y estrategias pedagógicas para los estudiantes de lengua portuguesa en Macao, poniendo mayor énfasis en el refuerzo de las conexiones sociales de los estudiantes con las comunidades portuguesas o macaenses locales

Characterization and cytotoxicity of PAHs in PM2.5 emitted from residential solid fuel burning in the Guanzhong Plain, China

The emission factors (EFs) of polycyclic aromatic hydrocarbons (PAHs) in PM2.5 were measured from commonly used stoves and fuels in the rural Guanzhong Plain, China. The toxicity of the PM2.5 also was measured using in vitro cellular tests. EFs of PAHs varied from 0.18 mg kg(-1) (maize straw charcoal burning in a clean stove) to 83.3 mg kg(-1) (maize straw burning in Heated Kang). The two largest influencing factors on PAH EFs were air supply and volatile matter proportion in fuel. Improvements in these two factors could decrease not only EFs of PAHs but also the proportion of 3-ring to 5-ring PAHs. Exposure to PM2.5 extracts caused a concentration-dependent decline in cell viability but an increase in reactive oxygen species (ROS), tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6). PM2.5 emitted from maize burning in Heated Kang showed the highest cytotoxicity, and EFs of ROS and inflammatory factors were the highest as well. In comparison, maize straw charcoal burning in a clean stove showed the lowest cytotoxicity, which indicated a clean stove and fuel treatment were both efficient methods for reducing cytotoxicity of primary PM2.5. The production of these bioreactive factors were highly correlated with 3-ring and 4-ring PAHs. Specifically, pyrene, anthracene and benzo(a)anthracene had the highest correlations with ROS production (R = 0.85, 0.81 and 0.80, respectively). This study shows that all tested stoves emitted PM2.5 that was cytotoxic to human cells; thus, there may be no safe levels of exposure to PM2,5 emissions from cooking and heating stoves using solid fuels. The study may also provide a new approach for evaluating the cytotoxicity of primary emitted PM2.5 from solid fuel burning as well as other PM2.5 sources. (C) 2018 Elsevier Ltd. All rights reserved

Optical source profiles of brown carbon in size-resolved particulate matter from typical domestic biofuel burning over Guanzhong Plain, China

In this study, both PM2.5 and size-resolved source samples were collected from a "heated kang" and an advanced stove to investigate the optical properties of brown carbon (BrC). The light-absorption coefficient (babs), the absorption Angstrom exponent (AAE), and the mass absorption cross-section (MAC) of both water and methanol-extracted BrC were investigated. The methanol-extracted BrC (BrCmethanol) had higher light absorption than water-extracted BrC (BrCwater). The value of PM2.5 babs of BrCmethanol at 365 nm(b(abs365),methanol) dramatically decreased from 64,669.8Mm(-1) for straw burning in the "heated kang" to 1169.2 Mm(-1) formaize straw briquettes burning in the advanced stove at the same burning rate. The value of PM2.5 MAC for BrCmethanol at 365 nm (MAC(365), methanol) decreased from 1.8 m(2) g(-1) in the "heated kang" to 1.3 m(2) g-1 in the advanced stove. For smoldering burning in the "heated kang", babs365, methanol, MAC365, methanol, and K+ showed a unimodal distribution that peaked at sizes < 0.4 mu m. However, the babs365, methanol and MAC(365), methanol size distributions of the briquette burning in the advanced stove showed a bimodal pattern, with a large peak at sizes < 0.4 mu m and a minor peak in the size range of 4.7-5.8 mu m. The babs365, methanol value for sizes < 0.4 mu m (277.4 Mm(-1)) was only 12.3% compared to those obtained from the "heated kang". The burning rate did not influence the size distribution pattern of either the "heated kang" or the advanced stove. Results from a radiative model show that biomass burning is an important factor for light absorptivity, and the use of an advanced stove can reduce the simple forcing efficiency value by nearly 20% in UV bands compared to the "heated kang". Our results indicate that changing the combustion style from maize straw smoldering to briquette burning in an advanced stove can effectively reduce BrC emissions during heating seasons in rural areas of Guanzhong Plain. (C) 2017 Elsevier B.V. All rights reserved

miR-423-5p Inhibits Osteosarcoma Proliferation and Invasion Through Directly Targeting STMN1

Background/Aims: Increasing evidences suggest that dysregulated expression of miRNAs contributes to the progression of various tumors. However, the underlying function of miR-423-5p in osteosarcoma remains unexplored. Methods: The expression of miR-423-5p and STMN1 were determined in osteosarcoma samples and cell lines via quantitative real-time PCR. Colony formation and Cell Counting Kit-8 (CCK-8) assays were performed to measure cell proliferation ability and transwell analysis was used to detect cell invasion, and dual luciferase reporter assay was perform to analysis the interaction between the miR-423-5p and STMN1. Results: The expression levels of miR-423-5p and STMN1 in the osteosarcoma tissues and cell lines were measured by qRT-PCR. Cell viability was determined using the clone formation and CCK-8 assays. A dual-luciferase reporter and Western blot were performed to stdudy the target gene of miR-423-5p. Here, we showed that miR-423-5p expression was downregulated in osteosarcoma tissues and cell lines. However, the expression of stathmin1 (STMN1) was downregulated in osteosarcoma tissues and cell lines. Moreover, STMN1 expression level was negatively correlated with the miR-423-5p expression in the osteosarcoma tissues. We identified STMN1 was a direct target gene of miR-423-5p in osteosarcoma cell. Overexpression of miR-423-5p inhibited osteosarcoma cell proliferation, colony formation and invasion. Furthermore, we demonstrated that STMN1 was involved in miR-423-5p-mediated cell behavior such as cell proliferation, colony formation and invasion in the osteosarcoma cell. Conclusion: Our present study indicated that miR-423-5p acted as a tumor suppressor gene in osteosarcoma partly through inhibiting STMN1 expression

Teacher cognition in teaching intercultural communicative competence: A qualitative study on preservice Chinese language teachers in Hong Kong SAR, China

The purpose of this study is to examine preservice Chinese language teachers’ cognition in teaching intercultural communicative competence. In the study we collected data through in-depth interviews with seven preservice teachers in a Master of Education program (Teaching Chinese as a Second Language, TCSL) at a university in Hong Kong SAR, China. The findings indicated that the participants had a relatively positive attitude and inclination toward the development of students’ intercultural communicative competence, while their conceptualizations of culture tended to be static and ambiguous. In addition, the participants’ objectives in teaching intercultural communicative competence were found to be more attitude-than knowledge- or skill-oriented. The study offers valuable insights that preservice language teachers’ cognition plays a crucial role in their future professional development and calls for curricular innovations with intercultural aims in teacher education programs

Evaluation of Metformin on Cognitive Improvement in Patients With Non-dementia Vascular Cognitive Impairment and Abnormal Glucose Metabolism

Objective: Recent studies have suggested that metformin can penetrate the blood–brain barrier, protecting neurons via anti-inflammatory action and improvement of brain energy metabolism. In this study, we aim to investigate the effect of metformin on cognitive function in patients with abnormal glucose metabolism and non-dementia vascular cognitive impairment (NDVCI).Methods: One hundred patients with NDVCI and abnormal glucose metabolism were randomly allocated into two groups: metformin and donepezil (n = 50) or acarbose and donepezil (n = 50). The neuropsychological status, glucose metabolism, and common carotid arteries intima–media thickness (CCA-IMT) before and after a year of treatment, were measured and compared between the groups.Results: Ninety four patients completed all the assessment and follow-up. After a year of treatment, there was a decrease in Alzheimer’s disease Assessment Scale-Cognitive Subscale scores and the duration of the Trail Making Test in the metformin-donepezil group. Furthermore, these patients showed a significant increase in World Health Organization–University of California–Los Angeles Auditory Verbal Learning Test scores after treatment (all P < 0.05). However, there was no obvious improvement in cognitive function in the acarbose-donepezil group. We also observed a significant decrease in the level of fasting insulin and insulin resistance (IR) index in the metformin-donepezil group, with a lower CCA-IMT value than that in the acarbose-donepezil group after a year of treatment (P < 0.05).Conclusion: We conclude that metformin can improve cognitive function in patients with NDVCI and abnormal glucose metabolism, especially in terms of performance function. Improved cognitive function may be related to improvement of IR and the attenuated progression of IMT.Trial Registration:ChiCTR-IPR-17011855

Interactions between depositional regime and climate proxies in the northern South China Sea since the Last Glacial Maximum

Sedimentary deposits from the northern South China Sea (SCS) can provide important constraints on past changes in ocean currents and the East Asian summer monsoon (EASM) in this region. However, the interpretation of such records spanning the last deglaciation is complicated because sea-level change may also have influenced the depositional processes and patterns. Here, we present new records of grain size, clay mineralogy, and magnetic mineralogy spanning the past 24 kyr from both shallow and deep-water sediment cores in the northern SCS. Our multi-proxy comparison among multiple cores helps constrain the influence of sea-level change, providing confidence in interpreting the regional climate-forced signals. After accounting for the influence of sea-level change, we find that these multi-proxy records reflect a combination of changes in (a) the strength of the North Pacific Intermediate Water inflow, (b) the EASM strength, and (c) the Kuroshio Current extent. Overall, this study provides new insights into the roles of varying terrestrial weathering and oceanographic processes in controlling the depositional record on the northern SCS margin in response to climate and sea-level fluctuations