L2 Speech Learning: perception, production & training

Adult L2 learners have difficulties in perceiving and producing L2 speech sounds. In analyzing learners’ L2 speech learning problems, this study provides research data from a series of studies on L2 speech perception, production, and training. Section 1 investigates how the L1 sound system influences L2 speech perception. A recent study shows that phonetic differences and distances between English and Mandarin consonants predicted the perceptual problems of Mandarin consonants by native English learners of Chinese. Section 2 explores the relationship between L2 speech perception and production and reports a subsequent study on Mandarin consonants that shows English learners of Chinese performed better in perception than production on Mandarin retroflex sounds but vice versa on palatal sounds. The lack of alignment between perception and production suggests the relationship between L2 speech perception and production is not straightforward. In Section 3, two training experiments are reported and compared to explore the effects of phonetic training on the learning of English vowel and Mandarin tone contrasts

Compreendendo mudanças no comportamento de risco moral médico em resposta a reforma governamental de cuidados à saúde

Doctor moral hazard has a significant effect on the doctor-patient relationship, increases the cost of healthcare, and introduces medical risks. It is a global concern. Doctor moral hazard behaviour is evolving in response to China’s healthcare reform program which was inaugurated in 2009.A scientific understanding of doctor behaviour would facilitate the prevention and control of doctor moral hazard behaviour. This study used the principles and methodology of Glaser and Strauss’s grounded theory. Theoretical and snowball samplings were used to identify 60 subjects. Semi-structured in-depth interviews were conducted with each subject. Themes were identified through substantial (open) coding and theoretical coding. Six types of doctor moral hazard behaviour were extracted from the data. A behavioural model was described and diagrammed to provide a conceptual framework of current doctor moral hazard behaviour. The conceptual model of doctor moral hazard behaviour can be used in several ways to correct or prevent undesirable actions. Rules governing hospital procedures can be strengthened and enforced by supervision and punishment; the asymmetry of information between doctor and patient can be reduced; patient participation in treatment decisions can be increased; the effectiveness of medical ethics education can be improved.Para un médico, el riesgo moral tiene un efecto significativo en la relación médico-paciente, incrementa el costo de la atención de salud e introduce riesgos en la salud. Se trata de una preocupación global. El riesgo moral del comportamiento médico ha evolucionado en respuesta al programa de reforma de atención de salud del gobierno de China, inaugurado en 2009. Un entendimiento científico del comportamiento de los médicos facilitaría la prevención y el control del riesgo moral. El presente estudio usa los principios y metodología de la teoría fundamentada de Glaser y Strauss. Se usaron muestras teóricas y multiplicativas para identificar 60 sujetos y realizar entrevistas semiestructuradas en profundidad. Los temas se identificaron mediante codificación sustancial abierta y teórica. De los datos se extrajeron seis tipos de riesgo moral del comportamiento médico. Se describió y diagramó un modelo de comportamiento para proporcionar una estructura conceptual del riesgo moral del comportamiento médico actual. El modelo conceptual de riesgo moral del comportamiento médico puede usarse de varias maneras para corregir o prevenir acciones no deseadas. Las normas procedimentales de los hospitales pueden fortalecerse y exigirse mediante supervisión y castigo; se puede reducir la asimetría de la información que se da entre el médico y el paciente, incrementar la participación del pacieRisco moral médico tem um efeito significativo na relação médico-paciente, aumenta o custo dos cuidados à saúde e introduz riscos médicos. É uma preocupação global. Comportamento de risco moral médico vem se desenvolvendo em resposta ao programa de reforma de cuidados à saúde da China, que se iniciou em 2009. Uma compreensão científica do comportamento médico facilitaria a prevenção e controle do comportamento de risco moral médico. Este estudo utilizou os princípios da metodologia da Teoria Fundamentada de Glaser e Strauss. Amostragem teóricas e por bola de neve foram utilizadas para identificar 60 participantes. Entrevistas detalhadas semi-estruturadas foram realizadas com cada participante. Temas foram identificados através de codificação (aberta) substancial e codificação teórica. Seis tipos de comportamento de risco moral médico foram obtidos dos dados. Um modelo comportamental foi descrito e diagramado de forma a fornecer um enquadre conceitual do comportamento de risco moral médico. O modelo conceitual de comportamento de risco moral médico pode ser utilizado de diversas formas para corrigir ou prevenir ações indesejáveis. Regras que governam procedimentos em hospitais podem ser fortalecidas e reforçadas por supervisão e punição; a assimetria de informações entre médicos e pacientes pode ser reduzida; a participação dos pacientes nas decisões sobre tratamento pode ser aumentada; e a efetividade da educação ética médica pode ser melhorada

In vitro regeneration of ‘Feizixiao’ litchi (Litchi chinensis Sonn.)

A simple efficient in vitro plant regeneration system was developed by indirect somatic embryogenesis of ‘Feizixiao’ litchi (Litchi chinensis Sonn.). Pollen in the anther of monocytes was used to induce callus. Two auxins (naphthalene acetic acid [NAA] and 2,4-dichloriphenoxyacetic acid [2,4-D]), and two cytokines (kinetin [KT] and 6-benzyladenine [BA]) were tested to explore their influence on callus induction. MS medium supplemented with 2.22 μM BA, 2.69 μM NAA, 13.57 μM 2,4-D, and 0.4 g/L LH (lactalbumin hydrolysate) showed the highest callus induction frequency. The callus obtained from anther was subcultured in MS medium containing 4.52 μM 2,4-D to obtain synchronized friable embryogenic callus. Different developmental stages of SEs were obtained from the callus on MS medium containing 6% (w/v) sucrose and different PGRs (plant growth regulators). On MS medium containing 6% (w/v) sucrose and supplemented with 0.54 μM NAA, 23.23 μM KT, 0.4 g/L LH, 0.56 μM inositol, and 10% (w/v) CW (coconut water), a higher number of SEs (globular, heart, torpedo and cotyledonary embryos) was achieved than on other media. Plantlets were established onto half-strength MS medium containing 1.44 μM GA3 (gibberellic acid) followed by successful acclimatization in the greenhouse. With flow cytometry and chromosome counting, ploidy analysis of regenerated plants revealed that the regenerated plantlets were all diploid. This study is the first report on somatic embryogenesis of ‘Feizixiao litchi’, providing an opportunity to improve the cultivar by biotechnology methods.Keywords: litchi (Litchi chinensis Sonn.), anther culture, callus, regeneration, somatic embryogenesi

xCT increases tuberculosis susceptibility by regulating antimicrobial function and inflammation

The physiological functions of macrophage, which plays a central role in the pathogenesis of tuberculosis, depend on its redox state. System xc-, a cystine-glutamate transporter, which consists of xCT and CD98, influences many ROS-dependent pathways by regulating the production of the antioxidant glutathione. xCT\u27s ability to alter this critical host redox balance by increasing the glutathione synthesis aspect of phagocyte physiology suggested that it might influence tuberculosis pathogenesis. In this study, we found that the xCT expression was increased in peripheral blood monocyte of active tuberculosis. xCT expression in macrophage was induced by Mycobacterium tuberculosis (Mtb) through TLR2/Akt- and p38-dependent signaling pathway. Importantly, xCT deficiency conferred protection against tuberculosis, as xCT knock out mice displayed increased Mtb load and reduced pulmonary pathology in lung compared to wild type mice. xCT disruption enhanced the mycobateriacidal activity of macrophage through increasing the mycothiol oxidation. Importantly, chemical inhibition of xCT with sulfasalazine, a specific xCT inhibitor that is already approved by the FDA for treatment of inflammatory bowel disease, produces similar protective effects in vivo and in vitro, indicating xCT might be a novel and useful target for host-directed TB treatment strategy

Randomness invalidates criminal smart contracts

A smart contract enforces specific performance on anonymous users without centralization. It facilitates payment equity in commerce by providing irreversible transactions. Smart contracts are also used for illegal activities such as money laundering and ransomware. Such contracts include criminal smart contracts (CSCs), proposed in CCS’16, that can be efficiently implemented in existing scripting languages. This aggravates concerns about the dangers of CSCs. However, PublicLeaks, a CSC for leaking private data, is conditionally implemented as it is influenced by various factors. For example, PublicLeaks does not necessarily reach a desirable terminal state for a criminal leaking private information, and other possible terminal states may invalidate the CSC. In this study, we propose a CSC based on PublicLeaks by formulating random factors such as the donation ratio. Our contract forks into five terminal states, including a unique one in PublicLeaks due to randomness. We simulated the maximal probabilities of these terminal states and found that the desirable terminal state in PublicLeaks is reachable with low probabilities (lower than 25%). The terminal state where the criminal fails to leak private information is attained with relatively high probabilities (over 65%). Therefore, our simulations show that CSCs are not always as powerful as expected, and the risk posed by them can be mitigated

Melatonin Supplementation, a Strategy to Prevent Neurological Diseases through Maintaining Integrity of Blood Brain Barrier in Old People

Blood brain barrier (BBB) plays a crucial role in maintaining homeostasis of microenvironment that is essential to neural function of the central nervous system (CNS). When facing various extrinsic or intrinsic stimuli, BBB is damaged which is an early event in pathogenesis of a variety of neurological diseases in old patients including acute and chronic cerebral ischemia, Alzheimer’s disease and etc. Treatments that could maintain the integrity of BBB may prevent neurological diseases following various stimuli. Old people often face a common stress of sepsis, during which lipopolysaccharide (LPS) is released into circulation and the integrity of BBB is damaged. Of note, there is a significant decrease of melatonin level in old people and animal. Melatonin has been shown to preserves BBB integrity and permeability via a variety of pathways: inhibition of matrix metalloproteinase-9 (MMP-9), inhibition of NADPH oxidase-2, and impact on silent information regulator 1 (SIRT1) and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome. More important, a recent study showed that melatonin supplementation alleviates LPS-induced BBB damage in old mice through activating AMP-activated protein kinase (AMPK) and inhibiting gp91phox, suggesting that melatonin supplementation may help prevent neurological diseases through maintaining the integrity of BBB in old people

Mediating Roles of Gratitude and Social Support in the Relation Between Survivor Guilt and Posttraumatic Stress Disorder, Posttraumatic Growth Among Adolescents After the Ya’an Earthquake

Objective: This study aims to examine the mediating roles of gratitude and social support in the relationship between survivor guilt and posttraumatic stress disorder (PTSD) as well as the relationship between survivor guilt and posttraumatic growth (PTG).Methods: The current study used self-report questionnaires to investigate 706 adolescent survivors of Lushan county three and a half years after the Ya’an earthquake. The structural equation model was used to evaluate the relations between survivor guilt, gratitude and social support in PTSD and PTG.Results: The results indicated that survivor guilt had a positive effect on both PTSD and PTG. Gratitude partly mediated the relation between survivor guilt and both PTSD and PTG; social support partly mediated the relation between survivor guilt and PTG but not PTSD as well as the relation between gratitude and PTG.Conclusion: Survivor guilt has a double-edged sword effect. Survivor guilt affects PTSD and PTG through gratitude, and it could affect PTG but not PTSD through social support. Gratitude decreases PTSD and increases PTG, whereas social support only increases PTG

Characterization of Soybean Protein Adhesives Modified by Xanthan Gum

The aim of this study was to provide a basis for the preparation of medical adhesives from soybean protein sources. Soybean protein (SP) adhesives mixed with different concentrations of xanthan gum (XG) were prepared. Their adhesive features were evaluated by physicochemical parameters and an in vitro bone adhesion assay. The results showed that the maximal adhesion strength was achieved in 5% SP adhesive with 0.5% XG addition, which was 2.6-fold higher than the SP alone. The addition of XG significantly increased the hydrogen bond and viscosity, as well as increased the β-sheet content but decreased the α-helix content in the second structure of protein. X-ray diffraction data showed significant interactions between SP molecules and XG. Scanning electron microscopy observations showed that the surface of SP adhesive modified by XG was more viscous and compact, which were favorable for the adhesion between the adhesive and bone. In summary, XG modification caused an increase in the hydrogen bonding and zero-shear viscosity of SP adhesives, leading to a significant increase in the bond strength of SP adhesives onto porcine bones