Understanding the fish pathogen flavobacterium psychrophilum diversity for the control of rainbow trout fry syndrome in the United Kingdom

Rainbow trout represents the most prominent species in freshwater farming in UK aquaculture. One of the common diseases constraining rainbow trout production and increasingly causing problems in Atlantic salmon (Salmo salar L.) hatcheries worldwide is rainbow trout fry syndrome (RTFS) or bacterial cold water disease (BCWD). During the last 20 years, the development of a commercial vaccine against RTFS has been hindered by the prevalence of a wide range of the fish pathogen F. psychrophilum, thus the current treatment of choice is the use of antibiotics. Studies involved in understanding the innate and adaptive immune response of vaccinated rainbow trout fry using inactivated whole cell are still lacking. Therefore, the aim of this thesis is to characterise the strain diversity and antibiotic susceptibility of UK F. psychrophilum isolates, evaluate the efficacy of a whole-cell formalin-killed polyvalent vaccine, which was developed based on the characterisation results of this study, and investigate the immune response in trout fry following the immersion vaccination via the changes in expression of relevant immune genes. A total of 315 F. psychrophilum isolates, 293 of which were collected within the UK, were characterised using four genotyping methods and a serotyping scheme. A high strain diversity was identified among the isolates with 54 pulsotypes, ten (GTG)5-PCR types, two 16S rRNA allele lineages, seven plasmid profiles and three serotypes. The predominant profile observed within the F. psychrophilum isolates examined was PFGE cluster II – (GTG)5-PCR type r1 – 16S rRNA lineage II – serotype Th (n= 70/156, 45%). The characterisation results not only revealed the wide distribution within the UK and the persistence within a site of predominant pulsotypes, but also the presence of unique genotypes in certain sites or countries. Co-existence of genetically and serologically heterogeneous isolates within each farm was detected, highlighting the reasons this disease is so difficult to control, especially by vaccination. The occurrence over time of F. psychrophilum pulsotypes within a site could provide important epidemiological data for farm management and the development of site-specific vaccines. The antimicrobial susceptibilities of 140 F. psychrophilum strains, 125 of which were from the UK, were evaluated by the broth microdilution (MIC) and disc diffusion methods. There was evidence of reduced susceptibilities to three of the main antimicrobials used in UK aquaculture. Broth microdilution testing showed that only 12% of 118 UK isolates tested were WT to oxolinic acid (MIC COWT 0.25 mg L-1), 42% were WT for oxytetracycline (MIC COWT 0.25 mg L-1), and 66% were WT for amoxicillin. In contrast, all the isolates tested were WT (MIC COWT 2 mg L-1) for florfenicol, the antimicrobial of choice for RTFS control in the UK. Despite the imprecision of disc diffusion-based COWT values due to high standard deviations, there was a high categorical agreement between the classification of the strains (into WT or NWT) by MIC and disc diffusion methods for florfenicol (100%), oxolinic acid (99%), amoxicillin (97%) and oxytetracycline (94%). In general, this study showed that the UK F. psychrophilum isolates examined remain susceptible to florfenicol and also stresses the importance of performing susceptibility testing using standardised methods and COWT values. Several statistically significant associations between genotypes and the reduced susceptibilities of F. psychrophilum strains were revealed. A whole-cell formalin killed polyvalent vaccine against RTFS/BCWD was developed by combining three genetically and serologically divergent strains, recently collected from UK farms. The efficacy of this polyvalent vaccine was evaluated after immersion vaccination in 5 g trout and bath challenge using hydrogen peroxide as a pre-stressor with a virulent heterologous isolate of F. psychrophilum strain. Significant protection was achieved with an RPS of 84%. The combination of exposure to hydrogen peroxide prior to bath challenge may be an alternative to an injection challenge with 12 g trout, although further standardisation and optimisation of the challenge model is required. Changes in the innate immune response of trout fry following the initial vaccination included the up-regulation of the interleukin 1 β (IL-1β) gene in head kidney at 4 h and the up-regulation of toll-like receptor-2 (TLR-2) in skin at day 2. While the expression levels of C3 was unchanged, the down regulation of CD8-α in head kidney and spleen and CD4-1 in spleen were documented. IgM and IgT transcripts were found to be up-regulated in hind-gut two days post-vaccination. Understanding the strain diversity and the antibiotic susceptibility of UK F. psychrophilum isolates could help improve the control strategies, such as preventing the spreading of pathogenic F. psychrophilum clones between fish farms, reducing the use of antibiotics in RTFS/BCWD treatment and monitoring the development of acquired antibiotic resistance mechanisms. Moreover, strain characterisation data of UK F. psychrophilum species has assisted in selecting suitable candidates for developing an effective RTFS vaccine

Importance and Basic Steps of Training Soft Skills to Children in Globalized World – An Overview of The Matter In Vietnam

Soft Skills fulfill an important role in shaping an individual’s personality, and should be introduced in the very early stages of childhood. In a competitive globalized world, the value of these skills is further enhanced. Soft Skills, especially life skills, help them know how to cope with daily situations as well as on more long-term choices. If children are well-equipped with Soft Skills, they will have the flexibility to manage their lives when they grow up. The field research in this paper was used to obtain a deeper understanding of how soft skills influent to children’ future as well as an overview of Vietnam on the matter. 

Using the best - worst scale to assess the relative impact of these behaviors on other passengers on the same flight: The disruptive passenger behavior

A method called the best-worst scaling method is proposed to overcome these problems by asking respondents to make tradeoffs among the variables being assessed. This paper raises issues in respect of supplementing and developing a block of disruptive behaviors exhibited by passengers during flights and assesses the impact of these behaviors on other passengers. To illustrate the proposed method and evaluate its performance, we surveyed 240 passengers, and data from 203 survey samples were analyzed. The data analysis results revealed three behaviors that were considered the most disruptive, including (1) Threatening and causing distress, (2) Harassment and disrupting public order, and (3) Creating unsanitary conditions. This can be considered a suitable explanation with the high safety requirements of the air transport service, and the context of high expectation of post-covid hygiene and epidemiology

Drought stress - related functional characterization of transcription factor GmNAC085 in soybean

Studies on soybean GmNAC085 transcription factor revealed that the gene expression in plants was induced by water shortage treatments and its overexpression in the model plant Arabidopsis displayed improved plant tolerance characteristics towards drought stress. In this study, we continued analyzing the biological functions of GmNAC085 using transgenic soybean system overexpressing GmNAC085 gene, by targeting at a number of plant physiological features and biochemical activities in response to limited water growing condition. Compared to the wild-type, the transgenic line demonstrated that it possessed stress tolerance characters, including enhanced elongation of taproot, minimized reduction of shoot growth, lower intracellular H2O2 content and stronger peroxidase enzyme activity under drought condition. The results of this study therefore suggest the transgenic plants had better drought tolerance and the GmNAC085 plays important role in aiding plants to cope with water deficit condition, probably via regulating the growth of roots and shoots, and activities of reactive-oxygen-species- scavenging enzymes

A Review Of Research On Professional Burnout Of Special Pedagogues In China

In order to provide references for further studies, this study attempts to summarize and present the current research situation regarding professional burnout among Chinese special education teachers on the basis of bibliometric analysis of academic articles about this topic in mainland China from 2007 to 2017. The findings are as follows: (1) there has been a significant increase in the number of articles and centralized distribution of research results; (2) limited research subjects and the lack of a research team are problems to be solved in the future; (3) there are limited research methods and constant expansion of the research content in the current research. According to the research situation, the following suggestions are proposed for follow-up research studies: (1) accelerating the construction of a research team and forming a stable research force; (2) expanding multidisciplinary and cross-system cooperation in research; (3) enriching research content and paying more attention to job burnout among special education staff in different areas and intervention strategies to improve the situation concerning SETs’ professional burnout

Challenges of Implementing Outcome-Based Assessment in Vietnamese Higher Education – A Qualitative Inquiry

This qualitative study investigates the key challenges faced by university lecturers in implementing outcome-based assessments (OBA) in higher education institutions in Vietnam, a country currently undergoing significant educational transformation. Utilizing a qualitative research design, the study conducted semi-structured interviews with 15 lecturers from diverse academic fields in a institution. The data were thematically coded and interpreted through the lenses of Constructivism, Institutional Theory, and Diffusion of Innovations Theory. Nine major challenges emerged from the findings, including pedagogical hurdles, lack of training and resources, institutional constraints, and technological limitations. These challenges are contextualized within the existing theoretical frameworks and related literature. The study offers critical insights that are deeply rooted in cultural, institutional, and structural variables. These findings are pertinent for educators, administrators, and policymakers in Vietnam and potentially for those in similar educational settings, and they hold broader implications for professional development, institutional policies, technological infrastructure, and cultural shifts within the educational landscape

In-action reflective teaching in Vietnam: A qualitative exploration of practices, influences and implications

Reflective teaching plays a crucial role in the field of education though its intricacies in particular cultural contexts like Vietnam are still little understood. This study aims to investigate reflective teaching practices in more detail within the context of Vietnamese education.  This study used a qualitative methodology and semi-structured interviews with twelve Vietnamese teachers, each representing a different stage of their careers to shed light on the many forms of in-action reflective practices and their implementation, benefits, drawbacks and even cultural influences. The results of this in-depth investigation provided an overview of the wide range of in-action reflective practices that are actively used in the classroom.  The enhancement of adaptive teaching methodologies and the bolstering of student engagement are prominent among the many advantages that were noted.  Teaching in the Vietnamese context also presents unique challenges. Teachers often struggle with the demands of multitasking, the complexities of navigating uncertainties in real-time classroom scenarios   and the predominant challenge of managing large class sizes. Moreover, it was surprising to learn how many Vietnamese cultural, social   and educational factors influenced teacher understanding and use of in-action reflection.  The understanding of reflective teaching practices is enhanced by the research findings which also have broad implications for areas such as instructional strategies, teacher preparation programmes, academic research perspectives and even the development of educational policies.  The study strongly emphasizes the pressing need for more context-specific investigations into reflective teaching and underscores the indispensable role of reflection in fostering an environment conducive to effective teaching and learning

Multi-faceted identities of teacher assessors: A qualitative study in the Vietnamese educational context

Within the educational landscape of Vietnam, the professional identity of teachers when acting as assessors remains a comparatively uncharted domain and requires further explorations. Consequently, this qualitative investigation was initiated to delve deeper into the intricate identities Vietnamese teachers adopt in their capacities as assessors. Relying upon frameworks such as Constructivist Grounded Theory and Identity Theory, the study meticulously analyzed self-reported narratives from 15 tertiary lecturers based in Vietnam. Through this rigorous analysis, a spectrum of fifteen distinct identities was uncovered. These identities included “Gatekeepers of Knowledge and Competency”, “Nurturers”, “Diplomatists”, “Auditors”, “Confusian Sages”, “Innovators”, “Social Justice Advocators”, “Cultural Mediators”, “Emotional Anchors”, “Scalfolders”, “Technological Navigators”, “Lifelong Learners”, “Community Builders”, “Ethical Guardians”, and “Democratic Facilitators.” Intriguingly, these identities were not merely seen as additional layers to their professional duties; instead, they emerged as foundational components of teachers’ professional self-image. The forces molding these roles are diverse, encompassing deep-seated cultural values, prevailing educational paradigms, and personal lived experiences of educators. Unraveling these identities offers consequential implications for the broader educational sector. It underscores the imperative to holistically re-envision teacher training programs and assessment design, ensuring they resonate with the multifaceted roles educators play in steering both academic achievements and wider societal outcomes

GSH Levels Serve As a Biological Redox Switch Regulating Sulforaphane-Induced Cell Fate in Human Lens Cells

Purpose: Sulforaphane (SFN) is a therapeutic phytochemical agent for many health conditions. SFN-induced cytotoxicity is shown to have promise in preventing posterior capsule opacification (PCO). In the current study, we aimed to elucidate key processes and mechanisms linking SFN treatment to lens cell death. Methods: The human lens epithelial cell line FHL124 and central anterior epithelium were used as experimental models. Cell death was assessed by microscopic observation and cell damage/viability assays. Gene or protein levels were assessed by TaqMan RT-PCR or immunoblotting. Mitochondrial networks and DNA damage were assessed by immunofluorescence. Mitochondrial membrane potential, activating transcription factor 6 (ATF6) activity, ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG), and glutathione reductase (GR) activity were measured using different light reporter assays. SFN metabolites were analyzed by LC-MS/MS. Results: Treatment with N-acetylcysteine (NAC), a reactive oxygen species scavenger, prevented SFN-induced cell death in both models. NAC also significantly protected FHL124 cells from SFN-induced mitochondrial dysfunctions, endoplasmic reticulum stress (ERS), DNA damage and autophagy. SFN significantly depleted GSH, the major antioxidant in the eye, and reduced GR activity, despite doubling its protein levels. The most abundant SFN conjugate detected in lens cells following SFN application was SFN–GSH. The addition of GSH protected lens cells from all SFN-induced cellular events. Conclusions: SFN depletes GSH levels in lens cells through conjugation and inhibition of GR activity. This leads to increased reactive oxygen species and oxidative stress that trigger mitochondrial dysfunction, ERS, autophagy, and DNA damage, leading to cell death. In summary, the work presented provides a mechanistic understanding to support the therapeutic application of SFN for PCO and other disorders