21 research outputs found
Genetic landscape of autism spectrum disorder in Vietnamese children
Autism spectrum disorder (ASD) is a complex disorder with an unclear aetiology and an estimated global prevalence of 1%. However, studies of ASD in the Vietnamese population are limited. Here, we first conducted whole exome sequencing (WES) of 100 children with ASD and their unaffected parents. Our stringent analysis pipeline was able to detect 18 unique variants (8 de novo and 10 ×-linked, all validated), including 12 newly discovered variants. Interestingly, a notable number of X-linked variants were detected (56%), and all of them were found in affected males but not in affected females. We uncovered 17 genes from our ASD cohort in which CHD8, DYRK1A, GRIN2B, SCN2A, OFD1 and MDB5 have been previously identified as ASD risk genes, suggesting the universal aetiology of ASD for these genes. In addition, we identified six genes that have not been previously reported in any autism database: CHM, ENPP1, IGF1, LAS1L, SYP and TBX22. Gene ontology and phenotype-genotype analysis suggested that variants in IGF1, SYP and LAS1L could plausibly confer risk for ASD. Taken together, this study adds to the genetic heterogeneity of ASD and is the first report elucidating the genetic landscape of ASD in Vietnamese children
Carbon assurance: Does it have an impact on credit ratings?
This paper examines the impact of firm-level carbon assurance on credit ratings among U.S. publicly traded firms. The findings reveal a positive relationship, indicating that carbon assurance enhances credit ratings by reducing information asymmetry and attracting analyst following. These results are robust to alternative measures of variables, model specifications, and endogeneity tests. U.S. firms with higher carbon assurance benefit from improved creditworthiness, particularly in competitive markets and Democratic-leaning states. These findings support signalling theory and show the strategic importance of carbon assurance in credit assessments and corporate sustainability.fals
Long-tenured CEOs and firm performance: too much of a good thing? Evidence from New Zealand
Purpose: This study aims to investigate the association between chief executive officer (CEO) tenure and firm performance. Extended CEO tenure offers the potential for organizational stability, sustained operational coherence and heightened insights into business intricacies. However, longer tenure concurrently fosters complacency and impedes innovation by engendering resistance to change and a deficiency in novel perspectives. The authors’ inquiry seeks to discern the prevailing influence between these contrasting perspectives.
Design/methodology/approach: This study uses unbalanced panel data for a unique hand-collected dataset from listed firms in New Zealand (2000–2020) – a country that adopts the principles-based corporate governance regime. The authors perform ordinary least squares, two-stage least squares and propensity score matching tests to examine the relationship between CEO tenure and firm performance.
Findings: The authors document a significant positive impact of CEO tenure on firm performance, implying the benefits of long tenure. However, this study further reveals a significant inverted U-shaped relationship between CEO tenure and firm performance, suggesting that such a positive impact can hold up to a certain threshold; after that, long CEO tenure can hinder firm performance. The finding is robust to alternative measures and endogeneity tests and offers important implications for corporate governance policies and practices.
Practical implications: The findings highlight the importance of balancing the benefits of long CEO tenure. Practically, firms should prioritize regular evaluation of CEO performance and tenure, emphasize succession planning and foster a culture of innovation to sustain organizational success in the long term.
Originality/value: This research offers valuable insights by examining the intricate relationship between CEO tenure and firm performance within the distinct setting of New Zealand. By uncovering both the benefits and drawbacks of long CEO tenure, this study contributes to a nuanced understanding of corporate governance dynamics.fals
Catalytic CO2 hydrogenation to formic acid over carbon nanotube-graphene supported PdNi alloy catalysts
Pure formic acid was successfully produced via CO2 hydrogenation for the first time over a heterogeneous catalyst of PdNi alloy on a carbon nanotube-graphene (CNT-GR) support in water as an eco-friendly solvent without a base additive. The highest formic acid yield obtained was 1.92 mmol with a turnover number of 6.4 and a turnover frequency of 1.2 x 10(-4) s(-1) under mild reaction conditions of 40 degrees C and 50 bar. Alloying Pd with Ni brought a significant enhancement in catalytic activity compared to the monometallic Pd catalyst. In addition, the CNT-GR composite as a catalytic support improved the dispersion of Pd-Ni alloy particles, which exhibited good stability under the reaction conditions.1126sciescopu
Dengue in Vietnamese infants - Results of infection-enhancement assays correlate with age-related disease epidemiology, and cellular immune responses correlate with disease severity
The pathogenesis of severe dengue is not well understood. Maternally derived subneutralizing levels of dengue virus-reactive IgG are postulated to be a critical risk factor for severe dengue during infancy. In this study, we found that, in healthy Vietnamese infants, there was a strong temporal association between the Fc-dependent, dengue virus infection-enhancing activity of neat plasma and the age-related epidemiology of severe dengue. We then postulated that disease severity in infants with primary infections would be associated with a robust immune response, possibly as a consequence of higher viral burdens in vivo. Accordingly, in infants hospitalized with acute dengue, the activation phenotype of peripheral-blood NK cells and CD8+ and CD4+ T cells correlated with overall disease severity, but HLA-A*1101-restricted NS3(133-142)-specific CD8+ T cells were not measurable until early convalescence. Plasma levels of cytokines/chemokines were generally higher in infants with dengue shock syndrome. Collectively, these data support a model of dengue pathogenesis in infants whereby antibody-dependent enhancement of infection explains the age-related case epidemiology and could account for antigen-driven immune activation and its association with disease severity. These results also highlight potential risks in the use of live attenuated dengue vaccines in infants in countries where dengue is endemic
The protective effect of green space on heat-related respiratory hospitalization among children under 5 years of age in Hanoi, Vietnam.
Combined effects of global warming and rapid urbanization replace green spaces with urban facilities. Children in urban areas are at a higher risk of heat-related adverse health effects. Our study aimed to examine the protective effect of urban green space on heat-related respiratory hospitalization among children under 5 years of age in Hanoi, the capital city of Vietnam. We estimated district-specific meteorological conditions from 2010 to 2014 by using a dynamic downscaling approach with a fine-resolution numerical climate model. The green space in each district was calculated using satellite data. The attributable fraction of heat-related respiratory hospitalization was estimated using a two-stage model, including a distributed lag non-linear model (DLNM) coupled with multivariate meta-analysis. The association between heat-related respiratory hospitalization and green spaces at the district level was explored using a linear regression model. The central districts were more crowded and hotter, with less green spaces than the outer districts. At temperatures > 34 °C (extreme heat threshold), the hospitalizations in the central districts increased significantly; however, in the outer districts, the hospitalization rate was insignificant. On average, extreme heat attributed 0.33% to citywide hospitalization, 0.35% in the center, and 0.32% in the outer region. Every 1% increase in the green space fraction will reduce heat-related respiratory hospitalization risk by 3.8%. Heat significantly increased the risk of respiratory hospitalization among children under 5 years in Hanoi, Vietnam. These findings are valuable for authorities to consider strategies to protect children's health against the effects of heat, including increasing green space
A Composite Based on Pd Nanoparticles Incorporated into a Zirconium-Based Metal–Organic Frameworks Zr–AzoBDC and Its Electrocatalytic Activity for Hydrogen Evolution Reaction
Natural infection of Neotropical bats with hantavirus in Brazil
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Processo FAPESP: 11/06810-9Processo FAPESP: 16/02568-2Processo FAPESP: 11/22663-6Processo FAPESP: 13/06380-0Processo FAPESP: 12/03700-0Processo FAPESP: 12/24150-9Processo FAPESP: 15/06142-7Processo FAPESP: 12/04096-0Processo FAPESP: 15/05354-0Processo FAPESP: 11/19897-5Processo FAPESP: 14/02438-6FAPEMIG: APQ-00606-14Bats (Order: Chiroptera) harbor a high diversity of emerging pathogens presumably because their ability to fly and social behavior favor the maintenance, evolution, and dissemination of these pathogens. Until 2012, there was only one report of the presence of Hantavirus in bats. Historically, it was thought that these viruses were harbored primarily by rodent and insectivore small mammals. Recently, new species of hantaviruses have been identified in bats from Africa and Asia continents expanding the potential reservoirs and range of these viruses. To assess the potential of Neotropical bats as hosts for hantaviruses and its transmission dynamics in nature, we tested 53 bats for active hantaviral infection from specimens collected in Southeastern Brazil. Part of the hantaviral S segment was amplified from the frugivorous Carollia perspicillata and the common vampire bat Desmodus rotundus. DNA sequencing showed high similarity with the genome of Araraquara orthohantavirus (ARQV), which belongs to one of the more lethal hantavirus clades (Andes orthohantavirus). ARQV-like infection was detected in the blood, urine, and organs of D. rotundus. Therefore, we describe a systemic infection in Neotropical bats by a human pathogenic Hantavirus. We also propose here a schematic transmission dynamics of hantavirus in the study region. Our results give insights to new, under-appreciated questions that need to be addressed in future studies to clarify hantavirus transmission in nature and avoid hantavirus outbreaks
Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial
Background: Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods: AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings: Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation: Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke. Funding: National Health and Medical Research Council of Australia
