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. 

Elucidating mechanisms of sulforaphane induced cell stress and death in the human lens

Purpose: Sulforaphane (SFN), derived from cruciferous vegetables, is an emerging therapeutic agent for many health conditions. Recently, SFN-induced cytotoxicity has been shown to have promise in preventing posterior capsule opacification (PCO) - a common lens disorder arising from undesirable cell proliferation and migration. However, no study in any models has elucidated the complete interplay and sequence of events contributing to the cytotoxicity. To address the gap in knowledge, this thesis, therefore, aimed to elucidate key processes and mechanisms linking SFN treatment to cell death in the human lens. Method: 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 qRT-PCR or Western blot. Mitochondrial networks and DNA damage were assessed by immunofluorescence. Mitochondrial membrane potential, ATF6 activity, GSH/GSSG ratio and glutathione reductase (GR) activity were measured using different light reporter assays. SFN metabolites were analysed by LC-MS/MS. Results: High concentrations of SFN triggered mitochondrial dysfunction, endoplasmic reticulum stress, DNA damage, autophagy and cell death in both models. The treatment of a ROS scavenger prevented all of these stress responses. SFN also significantly depleted glutathione (GSH), the major antioxidant in the eye, via conjugation since SFN-GSH was detected as the most abundant intracellular SFN metabolite. SFN also reduced GR activity. The supplementation of GSH protected lens cells from all SFN-induced stress responses and death. Conclusions: SFN depletes GSH levels in human lens epithelial cells through conjugation with GSH and inhibition of GR activity. This leads to ROS generation and oxidative stress that triggers mitochondrial dysfunction, ERS, autophagy and DNA damage leading to cell death. In summary, the work presented provides mechanistic understanding to support the therapeutic application of SFN for PCO and other conditions associated with GSH imbalance

Regulation of RNA Composition and Non-Coding RNA Decay in Mammalian Cells

Gene expression in eukaryotes is regulated at multiple levels. While transcription regulation plays an important role, the regulation of RNA stability and RNA localization are also key factors in controlling gene expression in response to stimuli. This thesis aims to 1) investigate the molecular mechanisms for how mRNAs are targeted to stress granules (SGs) and to 2) identify potential inhibitors for PARN, a deadenylase that is actively involved in regulating non-coding RNAs (ncRNAs) by removing their oligo(A) tails. 1) SGs are conserved cytoplasmic RNA-protein assemblies that form when translation initiation is inhibited. Although RNAs can differentially partition into SGs, the rules that dictate RNA partitioning into SGs are unknown. In this thesis, we demonstrated that SG-enriched NORAD RNA when added to the 3&rsquo; UTR of a SG-depleted reporter RNA can efficiently target the reporter RNA to SGs through the combined effects of multiple elements. Moreover, we observed that artificial tethering of SG RNA-binding proteins (RBPs), G3BP1, TIA1, or FMRP, can target mRNAs into SGs and SG transcriptome is largely unchanged in cell lines lacking the abundant SG RNA-binding proteins G3BP1 and G3BP2. The data suggest the targeting of ribonucleoproteins (RNPs) into SGs is due to a summation of multiple RNA-protein, protein-protein, and RNA-RNA interactions with no single interaction dominating RNP recruitment into SGs. 2) Poly(A)-specific ribonuclease (PARN) is a 3&rsquo;-5&rsquo; exoribonuclease that is shown removes poly(A) tails from the 3&rsquo; end of ncRNAs to enhance their stability by limiting the access of 3&rsquo; to 5&rsquo; exonucleases recruited by oligo(A) tails. Several PARN-regulated miRNAs target p53 mRNA, and PARN knockdown leads to an increase of p53 protein levels in human cells. Thus, PARN inhibitors might be used as a potential therapeutic treatment to repress tumor progression by inducing p53. Herein, we identified four compounds, including three novel compounds and GNF-7, previously shown to be a BcrAbl inhibitor, as PARN inhibitors using computational-based molecular docking and highthroughput screening (HTS). These inhibitors can be used as lead compounds for the development of improved PARN inhibitors.&nbsp;</p

Bridging Knowledge Gaps in the Management of Acute Coronary Syndromes

Contexte L’occlusion d’une artère du cœur cause un syndrome coronarien aigu (SCA) soit avec une élévation du segment ST (IAMEST) ou sans élévation du segment ST (1). Le traitement des patients avec un IAMEST requiert soit une intervention coronarienne d’urgence (ICP primaire) ou une thérapie fibrinolytique (FL). La thérapie FL peut être administrée soit dans un contexte pré-hospitalier (PHL) ou à l’hôpital. Une prise en charge précoce des patients avec SCA peut être améliorée par un simple indice de risque. Objectifs Les objectifs de cette thèse étaient de : 1) comparer l’ICP primaire et la thérapie FL (2); décrire plusieurs systèmes internationaux de PHL; (3) développer et valider un indice de risque simplifié pour une stratification précoce des patients avec SCA. Méthodes Nous complétons des méta-analyses, de type hiérarchique Bayésiennes portant sur l’effet de la randomisation, d’études randomisées et observationnelles; complétons également un sondage sur des systèmes internationaux de PHL; développons et validons un nouvel indice de risque pour ACS (le C-ACS). Résultats Dans les études observationnelles, l’ICP primaire, comparée à la thérapie FL, est associée à une plus grande réduction de la mortalité à court-terme; mais ce sans bénéfices concluants à long terme. La FL pré-hospitalière peut être administrée par des professionnels de la santé possédant diverses expertises. Le C-ACS a des bonnes propriétés discriminatoires et pourrait être utilisé dans la stratification des patients avec SCA. Conclusion Nous avons comblé plusieurs lacunes importantes au niveau de la connaissance actuelle. Cette thèse de doctorat contribuera à améliorer l’accès à des soins de qualité élevée pour les patients ayant un SCA.Background Acute occlusion of an artery of the heart results in acute coronary syndromes (ACS), either with ST-segment elevation (STEMI) or without ST-segment elevation (1). STEMI requires urgent treatment to restore coronary artery flow either by primary percutaneous coronary intervention (PCI) or fibrinolytic therapy (FL) (2). Although several randomized controlled trials (RCTs) demonstrate the superiority of primary PCI in reducing mortality compared to FL (2), the benefit of primary PCI over FL remains uncertain in unselected “real-life” patients (3,4). FL can be administered either in the pre-hospital setting (i.e., pre-hospital FL (PHL)) or at the hospital. PHL is rarely available outside Europe (5,6). Insights into the organization of PHL systems of care may promote more widespread use of PHL. Risk stratification of ACS patients should be prompt to ensure timely PCI for high-risk patients and to avoid unnecessary intervention in low-risk patients (7). Despite the availability of numerous ACS risk scores, there is still no simple risk score that can be easily applied in the initial management of ACS patients (8). Objectives The objectives of this doctoral dissertation were to address these current knowledge gaps in the optimal management of ACS. The objectives were to: 1) evaluate the efficacy, effectiveness, and safety of primary PCI and FL, (2) describe the infrastructure, processes and outcomes of several international PHL systems; and (3) develop and validate a novel clinical risk score for early risk stratification of ACS patients. Methods To address these objectives, I completed Bayesian hierarchical random-effects meta-analyses of published RCTs and observational studies which compare primary PCI and FL in patients with STEMI. I undertook a survey of the infrastructure, processes and outcomes of PHL in several European and North American pre-hospital emergency systems. Finally, I developed and validated an ACS risk score called the Canadian ACS (C-ACS). Results Primary PCI was superior to FL in reducing short-term mortality in RCTs and observational studies. However, the long-term survival benefit of primary PCI was noted only in RCTs, and not in the observational studies. PHL can be effectively delivered by health care professionals with variable levels of expertise. The new risk score, C-ACS, has good discriminant properties for short- and long-term mortality in patients with ACS. Conclusions The first manuscript of this dissertation has been recognized as one of the most valuable recent publications in STEMI management and has contributed to reorganization of STEMI care in Ontario. The other two manuscripts in this dissertation provide practical information and tools for health professionals caring for patients with ACS. In summary, this doctoral dissertation has and will continue to contribute to improve access to high quality care for patients with ACS

Factors affecting customers’ decisions to purchase medicines in Ho Chi Minh City: A quantitative study

Understanding customer behavior and the factors influencing decisions to purchase medicines is crucial for businesses. This study aimed to examine the factors influencing customers’ decisions to purchase medicines in Ho Chi Minh City (HCM). This quantitative study used a self-administered questionnaire. A convenience quota sample of 599 participants was recruited online and offline, and data were collected from July to October 2022. The questionnaire included 8 items on personal characteristics, 6 on customers’ medicine use characteristics, 13 on factors determining where to buy medicine, and 17 on factors influencing customers’ decision to buy medicine. A two-step cluster analysis method was used to identify three distinct customer clusters based on common characteristics. Statistical significance was set at p<0.05, with a 95% confidence interval. Of the 632 distributed questionnaires, 599 were returned and analyzed, resulting in a response rate of 94.78%. When making decisions about purchasing medicines, customers expressed the highest level of concern regarding the therapeutic effects of medicines (mean = 4.40 ± 0.77) and the least interest in advertisements (mean = 3.29 ± 1.19). Offering a wide range of products from different brands provides customers with more choices, which attracts them to drugstores. It is recommended that companies minimize their efforts to advertise medicines in Vietnam

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

Pik3r1 Is Required for Glucocorticoid-Induced Perilipin 1 Phosphorylation in Lipid Droplet for Adipocyte Lipolysis.

Glucocorticoids promote lipolysis in white adipose tissue (WAT) to adapt to energy demands under stress, whereas superfluous lipolysis causes metabolic disorders, including dyslipidemia and hepatic steatosis. Glucocorticoid-induced lipolysis requires the phosphorylation of cytosolic hormone-sensitive lipase (HSL) and perilipin 1 (Plin1) in the lipid droplet by protein kinase A (PKA). We previously identified Pik3r1 (also called p85α) as a glucocorticoid receptor target gene. Here, we found that glucocorticoids increased HSL phosphorylation, but not Plin1 phosphorylation, in adipose tissue-specific Pik3r1-null (AKO) mice. Furthermore, in lipid droplets, the phosphorylation of HSL and Plin1 and the levels of catalytic and regulatory subunits of PKA were increased by glucocorticoids in wild-type mice. However, these effects were attenuated in AKO mice. In agreement with reduced WAT lipolysis, glucocorticoid- initiated hepatic steatosis and hypertriglyceridemia were improved in AKO mice. Our data demonstrated a novel role of Pik3r1 that was independent of the regulatory function of phosphoinositide 3-kinase in mediating the metabolic action of glucocorticoids. Thus, the inhibition of Pik3r1 in adipocytes could alleviate lipid disorders caused by excess glucocorticoid exposure

Seawater desalination using air gap membrane distillation-an experimental study on membrane scaling and cleaning

The connection between operating temperature and membrane scaling/cleaning during an air gap membrane distillation (AGMD) process of seawater has been systematically elucidated in this study. Experimental and mathematically simulated data demonstrate the profound influences of feed salinity and membrane scaling on water flux at various operating temperatures. Feed salinity exerted significant impacts on water flux at high operating temperatures because of aggravated polarization effects. Membrane scaling and the subsequent membrane cleaning efficiency were also strongly affected by operating temperatures. Indeed, membrane scaling was more severe and occurred at a lower water recovery when operating at 60-50 °C (feed-coolant temperature) compared to that at 35-25 °C. Moreover, membrane cleaning with fresh water and vinegar was less effective for the membrane scaled at 60-50 °C compared to 35-25 °C. Finally, membrane cleaning using vinegar was much more efficient than fresh water. Given the availability of vinegar at household level, vinegar cleaning can potentially be a low cost and readily accessible approach for MD maintenance for small scale seawater desalination applications in remote coastal communities

Complete Genomic Sequences of Three Salmonella enterica subsp. enterica Serovar Muenchen Strains from an Orchard in San Joaquin County, California.

We present here the complete genome sequences of three Salmonella enterica subsp. enterica serovar Muenchen strains, LG24, LG25, and LG26. All three strains were isolated from almond drupes grown in an orchard in San Joaquin County, California, in 2016. These genomic sequences are nonidentical and will contribute to our understanding of S. enterica genomics