97 research outputs found
Ho Chi Minh Ville : de la migration à l'emploi
L'agglomération de Ho Chi Minh Ville est le principal pôle de développement du Viêtnam. La politique de libéralisation économique mise en oeuvre depuis 1986 est en train de bouleverser l'économie de la ville, ce qui entraîne notamment une forte croissance économique, un accroissement des disparités ville-campagne, une augmentation des flux migratoires, un développement du secteur privé, un élargissement des disparités sociales en ville. Parallèlement, le contrôle de l'immigration en ville, depuis longtemps strict, avec l'instauration d'un permis de résidence, est devenu beaucoup plus lâche. Dans ce contexte, les principales caractéristiques de la migration et de l'emploi en ville sont analysées à partir des résultats d'une enquête menée en 1994. Certaines données sont semblables à ce que l'on rencontre dans d'autres pays de l'Asie du Sud-Est, telle que la prépondérance des femmes parmi les migrants. D'autres résultats sont plus originaux, comme l'éducation assez élevée du migrant, le maintien du chômage à un niveau inférieur à ce qu'on aurait pu craindre, l'insertion limitée du migrant dans le secteur informel, le revenu relativement élevé du migrant... Cependant, l'évolution en cours laisse présager une modification très rapide de la situation avec une très forte croissance urbaine à venir, même si les données démographiques récentes manquent cruellement, le dernier recensement datant de 1989. Cette urbanisation sera très difficile à maîtriser et ses conséquences risquent d'être négatives à terme. Une des solutions serait le développement des centres urbains secondaires destinés à faire "tampon" sur les axes de migration de la campagne vers la grande ville. (Résumé d'auteur
Effects of palladium on the optical and hydrogen sensing characteristics of Pd-doped ZnO nanoparticles
Abstract The effect of palladium doping of zinc oxide nanoparticles on the photoluminescence (PL) properties and hydrogen sensing characteristics of gas sensors is investigated. The PL intensity shows that the carrier dynamics coincides with the buildup of the Pd-related green emission. The comparison between the deep level emission and the gas sensing response characteristics allows us to suggest that the dissociation of hydrogen takes place at Pd Zn -vacancies ([Pd 2+ (4d 9 )]). The design of this sensor allows for a continuous monitoring in the range of 0-100% LEL H 2 concentration with high sensitivity and selectivity. 126
Genetic characterization of an H5N1 avian influenza virus from a vaccinated duck flock in Vietnam
This study reports the genetic characterization of a highly pathogenic avian influenza virus subtype H5N1 isolated from a moribund domestic duck in central Vietnam during 2012. In the moribund duck’s flock, within 6 days after vaccination with a commercial H5N1 vaccine (Re-5) to 59-day-old birds, 120 out of 2,000 ducks died. Genetic analysis revealed a substantial number of mutations in the HA gene of the isolate in comparison with the vaccine strains, Re-1 and Re-5. Similar mutations were also found in selected Vietnamese H5N1 strains isolated since 2009. Mutations in the HA gene involved positions at antigenic sites associated with antibody binding and also neutralizing epitopes, with some of the mutations resulting in the modification of N-linked glycosylation of the HA. Those mutations may be related to the escape of virus from antibody binding and the infection of poultry, interpretations which may be confirmed through a reverse genetics approach. The virus also carried an amino acid substitution in the M2, which conferred a reduced susceptibility to amantadine, but no neuraminidase inhibitor resistance markers were found in the viral NA gene. Additional information including vaccination history in the farm and the surrounding area is needed to fully understand the background of this outbreak. Such understanding and expanded monitoring of the H5N1 influenza viruses circulating in Vietnam is an urgent need to provide updated information to improve effective vaccine strain selection and vaccination protocols, aiding disease control, and biosecurity to prevent H5N1 infection in both poultry and humans.Japan Society for the Promotion of Science. Grant-in-Aid for the Bilateral Joint ProjectsHeiwa Nakajima FoundationNational Institute of Allergy and Infectious Diseases (U.S.) (Contract HHSN2662007000010C
MicroRNA gga-miR-200a-3p modulates immune response via MAPK signaling pathway in chicken afflicted with necrotic enteritis
International audienceAbstractMicroRNAs (miRNAs) are small non-coding RNAs that contribute to host immune response as post-transcriptional regulation. The current study investigated the biological role of the chicken (Gallus gallus) microRNA-200a-3p (gga-miR-200a-3p), using 2 necrotic enteritis (NE) afflicted genetically disparate chicken lines, 6.3 and 7.2, as well as the mechanisms underlying the fundamental signaling pathways in chicken. The expression of gga-miR-200a-3p in the intestinal mucosal layer of NE-induced chickens, was found to be upregulated during NE infection in the disease-susceptible chicken line 7.2. To validate the target genes, we performed an overexpression analysis of gga-miR-200a-3p using chemically synthesized oligonucleotides identical to gga-miR-200a-3p, reporter gene analysis including luciferase reporter assay, and a dual fluorescence reporter assay in cultured HD11 chicken macrophage cell lines. Gga-miR-200a-3p was observed to be a direct transcriptional repressor of ZAK, MAP2K4, and TGFβ2 that are involved in mitogen-activated protein kinase (MAPK) pathway by targeting the 3′-UTR of their transcripts. Besides, gga-miR-200a-3p may indirectly affect the expression of protein kinases including p38 and ERK1/2 at both transcriptional and translational levels, suggesting that this miRNA may function as an important regulator of the MAPK signaling pathway. Proinflammatory cytokines consisting of IL-1β, IFN-γ, IL-12p40, IL-17A, and LITAF belonging to Th1 and Th17-type cytokines, were upregulated upon gga-miR-200a-3p overexpression. These findings have enhanced our knowledge of the immune function of gga-miR-200a-3p mediating the chicken immune response via regulation of the MAPK signaling pathway and indicate that this miRNA may serve as an important biomarker of diseases in domestic animals
MicroRNA expression profiling in the lungs of genetically different Ri chicken lines against the highly pathogenic avian influenza H5N1 virus
The highly pathogenic avian influenza (HPAI) virus triggers infectious diseases, resulting in pulmonary damage and high mortality in domestic poultry worldwide. This study aimed to analyze miRNA expression profiles after infection with the HPAI H5N1 virus in resistant and susceptible lines of Ri chickens.For this purpose, resistant and susceptible lines of Vietnamese Ri chicken were used based on the A/G allele of Mx and BF2 genes. These genes are responsible for innate antiviral activity and were selected to determine differentially expressed (DE) miRNAs in HPAI-infected chicken lines using small RNA sequencing. A total of 44 miRNAs were DE after 3 days of infection with the H5N1 virus. Computational program analysis indicated the candidate target genes for DE miRNAs to possess significant functions related to cytokines, chemokines, MAPK signaling pathway, ErBb signaling pathway, and Wnt signaling pathway. Several DE miRNA-mRNA matches were suggested to play crucial roles in mediating immune functions against viral evasion. These results revealed the potential regulatory roles of miRNAs in the immune response of the two Ri chicken lines against HPAI H5N1 virus infection in the lungs
ẢNH HƯỞNG CỦA CÔNG NGHỆ THỰC TẾ ẢO TĂNG CƯỜNG ĐẾN Ý ĐỊNH MUA HÀNG TRỰC TUYẾN CỦA NGƯỜI TIÊU DÙNG
The study shows the effects of factors affecting consumers' purchase intention after experiencing Virtual Try-on (VTO) in Vietnam. The study is carried out by quantitative method through data from 408 subjects of different ages in Hanoi and Northern provinces. The findings of the study demonstrate that perceived usefulness, perceived ease of use, perceived enjoyment, and perceived privacy risk, have a significant impact on users' attitudes toward Virtual Try-On (VTO). Consequently, these factors increase their influence on customers' purchase intentions. Based on these results, the research group recommends that, in practical settings, enterprises concentrate on providing high-quality services, promoting their products to augment the aforementioned factors, and simultaneously addressing users' attitudes to enhance the overall customer experience. Therefore, this study provides valuable insights into the factors that influence customers' attitudes toward VTO technology, thereby contributing to the existing literature on the topic.Nghiên cứu chỉ ra những tác động của các nhân tố ảnh hưởng tới ý định mua hàng của người tiêu dùng qua hành vi sử dụng công nghệ trải nghiệm sản phẩm trực tuyến (Virtual Try-on - VTO) tại Việt Nam. Phương pháp định lượng được sử dụng để phân tích dữ liệu từ 408 đối tượng trong nhiều độ tuổi khác nhau trên địa bàn thành phố Hà Nội và các tỉnh thành phố miền Bắc. Kết quả cho thấy rằng các nhân tố như cảm nhận tính hữu ích, cảm nhận tính dễ sử dụng, cảm nhận tính thích thú, và cảm nhận rủi ro về quyền riêng tư có tác động đến thái độ của người dùng với công nghệ VTO từ đó gia tăng ảnh hưởng tới ý định mua sắm của khách hàng. Nhóm nghiên cứu đề xuất rằng, trong bối cảnh thực tiễn, doanh nghiệp cần tập trung vào cung cấp dịch vụ chất lượng, quảng bá sản phẩm để nâng cao các yếu tố đã được đề cập, đồng thời quan tâm đến thái độ của người dùng để cải thiện trải nghiệm tích cực cho khách hàng
Chicken novel leukocyte immunoglobulin-like receptor subfamilies B1 and B3 are transcriptional regulators of major histocompatibility complex class I genes and signaling pathways
Objective The inhibitory leukocyte immunoglobulin-like receptors (LILRBs) play an important role in innate immunity. The present study represents the first description of the cloning and structural and functional analysis of LILRB1 and LILRB3 isolated from two genetically disparate chicken lines. Methods Chicken LILRB1-3 genes were identified by bioinformatics approach. Expression studies were performed by transfection, quantitative polymerase chain reaction. Signal transduction was analyzed by western blots, immunoprecipitation and flow cytometric. Cytokine levels were determined by enzyme-linked immunosorbent assay. Results Amino acid homology and phylogenetic analyses showed that the homologies of LILRB1 and LILRB3 in the chicken line 6.3 to those proteins in the chicken line 7.2 ranged between 97%–99%, while homologies between chicken and mammal proteins ranged between 13%–19%, and 13%–69%, respectively. Our findings indicate that LILRB1 and LILRB3 subdivided into two groups based on the immunoreceptor tyrosine-based inhibitory motifs (ITIM) present in the transmembrane domain. Chicken line 6.3 has two ITIM motifs of the sequence LxYxxL and SxYxxV while line 7.2 has two ITIM motifs of the sequences LxYxxL and LxYxxV. These motifs bind to SHP-2 (protein tyrosine phosphatase, non-receptor type 11) that plays a regulatory role in immune functions. Moreover, our data indicate that LILRB1 and LILRB3 associated with and activated major histocompatibility complex (MHC) class I and β2-microglobulin and induced the expression of transporters associated with antigen processing, which are essential for MHC class I antigen presentation. This suggests that LILRB1 and LILRB3 are transcriptional regulators, modulating the expression of components in the MHC class I pathway and thereby regulating immune responses. Furthermore, LILRB1 and LILRB3 activated Janus kinase2/tyrosine kinase 2 (JAK2/TYK2); signal transducer and activator of transcription1/3 (STAT1/3), and suppressor of cytokine signaling 1 genes expressed in Macrophage (HD11) cells, which induced Th1, Th2, and Th17 cytokines. Conclusion These data indicate that LILRB1 and LILRB3 are innate immune receptors associated with SHP-2, MHC class I, β2-microglobulin, and they activate the Janus kinase/signal transducer and activator of transcription signaling pathway. Thus, our study provides novel insights into the regulation of immunity and immunopathology
COPPER HEXACYANOFERRATE (II): SYNTHESIS, CHARACTERIZATION, AND CESIUM, STRONTIUM ADSORBENT APPLICATION
Low-cost nanoscale copper hexacyanoferrate (CuHF), a good selective adsorbent for cesium (Cs+) removal, was prepared using the chemical co-precipitation method. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and high-resolution transmission electron microscopy (HR-TEM) were conducted to determine the CuHF morphology. Copper hexacyanoferrate, Cu13[Fe(CN)6]14.(2K).10H2O, has a cubic structure (space group F-43m) in the range of 10-30 nm and a Brunauer-Emmett-Teller (BET) surface area of 462.42 m2/g. The removal of Cs+ and Sr2+ is dependent on pH; the maximum adsorption capacity (qmax) of CuHF is achieved at a pH = 6. From the Langmuir model, qmax = 143.95 mg/g for Cs+ and 79.26 mg/g for Sr2+, respectively. At high concentrations, Na+, Ca2+, and K+ ions have very little effect on Cs+ removal, and Na+ and K+ ions have a higher affinity for removing Sr2+ than Ca2+ at all concentrations. CuHF has a high affinity for alkaline cations in the order: Cs+ > K+ > Na+ > Ca2+ > Sr2+, as proposed and discussed
Age-time-specific transmission of hand-foot-and-mouth disease enterovirus serotypes in Vietnam: a catalytic model with maternal immunity
Hand, foot and mouth disease (HFMD) is highly prevalent in the Asia Pacific region, particularly in Vietnam. To develop effective interventions and efficient vaccination programs, we inferred the age-time-specific transmission patterns of HFMD serotypes enterovirus A71 (EV-A71), coxsackievirus A6 (CV-A6), coxsackievirus A10 (CV-A10), coxsackievirus A16 (CV-A16) in Ho Chi Minh City, Vietnam from a case data collected during 2013–2018 and a serological survey data collected in 2015 and 2017. We proposed a catalytic model framework with good adaptability to incorporate maternal immunity using various mathematical functions. Our results indicate the high-level transmission of CV-A6 and CV-A10 which is not obvious in the case data, due to the variation of disease severity across serotypes. Our results provide statistical evidence supporting the strong association between severe illness and CV-A6 and EV-A71 infections. The HFMD dynamic pattern presents a cyclical pattern with large outbreaks followed by a decline in subsequent years. Additionally, we identify the age group with highest risk of infection as 1-2 years and emphasise the risk of future outbreaks as over 50% of children aged 6-7 years were estimated to be susceptible to CV-A16 and EV-A71. Our study highlights the importance of multivalent vaccines and active surveillance for different serotypes, supports early vaccination prior to 1 year old, and points out the potential utility for vaccinating children older than 5 years old in Vietnam
Pharmacists’ Perspectives on the Use of Telepharmacy in Response to COVID-19 Pandemic in Ho Chi Minh City, Vietnam
Introduction: Telepharmacy, the application of information and communication technologies in healthcare services, has been adopted in many countries to provide patients with pharmaceutical care. However, it has yet to be widely used in Vietnam. This study was conducted to assess the current status of use and the factors associated with the willingness to use telepharmacy of pharmacists in Vietnam. Methods: A descriptive cross-sectional study was conducted from February to July 2021; 414 pharmacists were recruited to fill in an online survey. Results: Overall, 86.7% of participants have used telepharmacy application and 87.2% of them were willing to apply telepharmacy in pharmacy practice. According to our multivariate analysis, the level of readiness was associated with positive attitude (odds ratio [OR] = 4.67; 95% confidence interval [CI]: 2.26-9.66), and a good behavior (OR = 11.34; 95% CI: 3.84-33.45). Discussion: Developing a telepharmacy system with appropriate features is essential to meet the requirements of pharmacy practice amid the spread of the COVID-19 pandemic
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