Do algorithmic trading impact the quality of the United States financial market?

This paper aims to examine the effects of algorithmic trading on the market quality in the US market. Over the past decades, the introduction to sophisticated and complex algorithms into the financial sector has seduced many institutions and traders. Indeed, they are willing to pay large amount of money in research and development in order to improve their decision making of just some milliseconds. However, the rise of these new technologic tools came with some interrogations about its impact on the market quality. Many studies have been done all over the world without clearly agreeing on whether it was beneficial for the market or no. This study use aggregates values of 20 NYSE listed stocks to create a set of proxies for algorithmic trading such as the cancel-to-trade ratio, odd-lot volume ratio and trade-to-order volume ratio and analyse their relationships to another set of proxies representing the different measures of market quality (Liquidity, volatility, and price discovery). The analysis is made through a panel data regression and the findings concluded that AT proxies had a positive impact on the liquidity except for the Odd-lot volume ratio that was insignificant. The volatility in the opposite way is worsened and increased by the algorithmic trading activity. Finally, the results admit a strong positive relationship between odd-lot volume ratio and price discovery process and a strong inversely related correlation between trade-to-order volume ratio (negatively related to algorithmic trading activity) as AT proxy and the price discovery meaning that price efficiency was improved due to AT. This study draws the inference that algorithmic trading is beneficial for the market quality and its participants

Vehicle-to-vehicle communication: design, performance, and disruption mitigation in real-world environment

This thesis investigates the performance of 802.11p-based V2V communication in real-life scenarios, and explores potential practical applications such as GNSS correction data broadcasting to improve the positioning accuracy of nearby vehicles, and enhancing communication robustness by preemptively predicting potential disruptions with the assistance of Machine Learning (ML) models. A custom V2V On-board Unit (OBU) hardware platform was developed, and real- world multi-vehicle outdoor experiments were planned and carried out. The collected data was examined and used to train a number of ML models, and their performance was compared. The experiments revealed that the custom OBU was fully functional, and signal quality and communication range were observed to be affected by real-world imperfections. The GNSS correction data broadcasting was shown to notably increase the positioning accuracy of nearby vehicles, and the ML models trained from Key Performance Indicators (KPIs) demonstrated excellent prediction accuracy, allowing pre-emptive actions to be taken to reduce the downtime from communication disruption

Assessing the viability of Tenera oil palm shells as fine and coarse aggregates in structural lightweight concrete: microstructure and mechanical properties

Oil palm shells (OPS), a significant waste product of the oil palm industry, have raised environmental concerns due to their abundance and disposal challenges. Researchers have explored the potential use of OPS as coarse aggregates in structural lightweight concrete (SLWC) to address these issues. However, most studies lack specific OPS variety information, although indications by the thickness and accompanying figures point to the prevalent use of Dura OPS. The emergence of Tenera, a hybrid oil palm variety with thinner OPS, has significant implications, as it offers a 57% reduction in OPS thickness and a 30% increase in palm oil production compared to Dura OPS. Over 90% of oil palm farmers in Malaysia have already switched to the Tenera fruit, suggesting that the Dura variety may be phased out in the future. Concrete science acknowledges that changes to aggregate properties, such as size or thickness, can impact a concrete's mechanical property. Therefore, the primary focus of this study was to assess the mechanical properties of Tenera OPS when used individually as coarse and fine aggregates in SLWC, comparing them to normal weight concrete (NWC) of similar grade. Distinct mix designs and superplasticizers were employed, with a comprehensive analysis of density, permeable voids, and water absorption over time. Mechanical properties, including compressive strength, flexural tensile strength, modulus of elasticity, and drying shrinkage, were evaluated throughout a 365-day period in both cured and air-cured conditions. Microstructural analysis and ultrasonic pulse velocity testing were also performed. A key finding is that the use of Tenera OPS as coarse aggregates in OPS concrete (coarse OPSC) results in a notable reduction in compressive strength compared to Dura OPS under similar mix designs. However, Tenera OPS exhibits more promising outcomes when employed as fine-sized aggregates in concrete (fine OPSC). Microstructural analysis reveals fewer void spaces in fine OPSC, attributed to the swelling and shrinking characteristics of OPS when exposed to moisture and drying. The favourable shape of fine-sized OPS contributes to better performance and reduced cement consumption. By utilizing OPS in a saturated surface dry (SSD) state, both coarse and fine OPS in concrete facilitate internal curing. In terms of mix designs, fine OPSC demands 263% less cement content to achieve equivalent 28-day compressive strength compared to coarse OPSC, and only 14% more cement content than NWC, which showcases potential economic and environmental advantages. Despite its higher coarse aggregate content, the density of fine OPSC meets lightweight concrete (LWC) requirements and exhibits lower permeable voids and water absorption compared to coarse OPSC. This suggests enhanced durability. Fine OPSC also demonstrates early strength development superior to both NWC and coarse OPSC and maintains superior strength at 365 days. In contrast, coarse OPSC displays the lowest flexural tensile strength in cured conditions but excels in air-cured conditions, indicating susceptibility to moist environments, which is beneficial for continued cement hydration. Unexpectedly, the deterioration of coarse OPS, likely due to white-rot fungi, affects specific mechanical properties when exposed to curing regimes, a phenomenon not observed in fine OPSC. Furthermore, fine OPSC exhibits comparable dynamic and static modulus of elasticity (MOE) values to NWC, while coarse OPSC exhibits significantly lower MOE values. Drying shrinkage values for fine OPSC are similar to or slightly lower than NWC, whereas coarse OPSC displays significantly higher drying shrinkage values, almost three times that of NWC and fine OPSC. While drying shrinkage almost ceases after 365 days for NWC and fine OPSC, it continues at a significantly higher rate for coarse OPSC. This study offers critical insights and recommendations for future research, including strategies to mitigate OPS swelling and shrinking effects in concrete, refining mix designs, exploring additives to reduce cement content, examining performance under various environmental conditions, and conducting extended duration testing to further advance the utilization of OPS in sustainable construction practices

Is it possible to enhance face recognition skills? The effect of transcranial direct current stimulation (tDCS) and image-variability training

Face recognition ability is important for social interaction that occurs in our everyday lives. Given the importance of faces in social interactions, losing the ability to recognize faces may produce devastating consequences for an individual’s social life. Improvement of face recognition ability is important not only for individuals with facial recognition deficits, but also for national security. Thus, the main aim of this thesis is to examine the effect of transcranial direct current stimulation (tDCS) and cognitive training on own- and other-race face recognition. Chapter two focuses on examining the role of the occipital face area (OFA) and the fusiform face area (FFA) in the recognition of individual facial features and whole faces using multifocal tDCS. The results indicated that multifocal tDCS applied to the FFA led to increased efficiency for facial feature recognition while no effect of OFA stimulation on either facial feature or whole face recognition was found. Chapter three investigated how anodal and cathodal tDCS could affect the recognition of own- and other-race faces. In the course of this study, we created and evaluated a new Asian version of the Cambridge Face Memory Test (CFMT) (i.e., CFMT – Chinese Malaysian (CFMT-MY)). Our evaluation of the CFMT-MY showed high consistency and high reliability and therefore exhibits potential utility in facilitating the diagnosis of individuals with difficulty in face recognition in clinical settings, the measurement of individual differences in face recognition ability and the measurement of the other-race effect. However, we found no effect of a-tDCS and c-tDCS on either own- or other-race face recognition. Chapter four focuses on the benefits of learning identity via multiple high variation exposure on own- and other-race faces. The findings showed enhanced own-race face learning (i.e., face recognition and face-name association) for identities learned in high variability condition compared to low variability condition. However, identities learned in high variability condition only benefited other-race face recognition, but not face-name association. Finally, chapter five aims to examine if the benefits of learning identity via high variation multiple exposure could be applied to individuals with prosopagnosia. We found no effect of variability on face learning for either suspected developmental prosopagnosics (DP) or neurotypical participants. Overall, our results showed that tDCS improved facial feature recognition but not own- and other-race whole face recognition. Thus, tDCS might have limited effects on improving face recognition. Additionally, our results showed enhanced own- and other-race face recognition for identities learned with multiple exposure in high variation settings. However, this effect was not found for suspected DPs and neurotypical participants. This discrepancy in results could be due to the low sample size of suspected DPs and neurotypical participants in Experiment 5

Replacement of animal models of cardiac arrest and resuscitation strategies using a computer simulation

This doctoral thesis explores cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) from a multidisciplinary perspective, with a focus on three main objectives: enhancing the Interdisciplinary Collaboration in Systems Medicine (ICSM) simulation suite, investigating the pathophysiology of CA, and proposing an alternative to animal models in CA and CPR research. The ICSM simulation suite was significantly improved, with additions such as a thoracic model for chest compressions, multiple organ tissue compartments, a vasculature equation accounting for resistance changes, circulatory transport delays, retrograded blood flow during CPR, and respiratory and cardiovascular control mechanisms. Utilizing the enhanced ICSM simulation suite, a series of studies were conducted to examine various aspects of CPR strategies, all with the aim of improving resuscitation outcomes. These studies encompassed investigations into the impact of positive end-expiratory pressure (PEEP) on cardiac output during CPR, the effects of chest compression rate, depth, and duty cycle, the influence of the precipitating aetiology on CPR strategy optimization, and the comparison of personalized CPR strategies to current guidelines. The research also quantitatively identified the effect of CPR parameters on cardiac output, with end compression force and positive end expiratory pressure emerging as significant contributors. The validation of the ICSM simulation suite thoracic model using individual haemodynamic recordings of a patient undergoing CPR demonstrated its capacity to simulate individualized patient data for retrospective identification of optimized CPR protocols. These outcomes collectively emphasize the potential of computational models, particularly the ICSM simulation suite, to revolutionize CA and CPR research by providing humane, informative, and personalized alternatives to traditional animal models. The findings of this research suggest that the ICSM simulation suite offers a valuable alternative to animal models in the study of CA and CPR. This computational model allows for the simulation and investigation of personalized CPR strategies, which can be tailored to individual patients' need

Machine Learning Systems as Integrative Objects: Towards a Generic Epistemology of Predictive Systems

This thesis is concerned with machine learning, focusing in particular on high-stakes implementations of predictive systems that have been increasingly recognized as leading to social harm and deepening discrimination. The expanding range of machine learning applications, including examples such as predictive policing, the primary case study in this thesis, means that these technologies are no longer predominantly within the purview of computer science, and a wide range of critical scholarship is now also invested in discussing their societal impact. However, the resulting research landscape remains fragmented, and efforts to combine critical and computational perspectives in order to address problems with predictive systems often culminate in reductive metrics for ‘fairness’ or ‘bias’. Drawing on generic epistemology, an approach developed primarily by philosopher Anne-Françoise Schmid, this project proposes a framing of machine learning systems as ‘integrative objects’, meaning objects which exceed the productive capacities of singular disciplines as well as their synthesis. Generic epistemology posits that when faced with integrative objects, the operative logics and priorities of distinct disciplines often lead to an impasse in interdisciplinary work. Schmid and her collaborators advocate a more heterogeneous approach, where fragments of disciplinary knowledge can be used in new contexts without the wholesale import of the epistemic machinery of their source domains, in order to enable new conceptual formations. To this end, this thesis explores some of the limitations of the perspectives on machine learning produced by critical theory and computer science, and proposes an engagement with theories of induction (principally John D. Norton’s material theory of induction), with the philosophy of models in science (focusing on the tension between prediction and explanation, and the role of idealization in scientific models), and with theories of causality (in particular the interventionist approach to causation as advanced by Judea Pearl and James Woodward), as conceptual material capable of illuminating crucial parameters of high-stakes predictions. I argue that recognizing machine learning systems as integrative objects and adopting the research paradigm of generic epistemology can offer a more nuanced approach to contesting problematic uses of these technologies

AdvantAGE: a start-up of recruitment service for mature talent

Malaysia is expected to become an aged society by 2044 with 14% of the population aged above 65. Only 45.2% of people aged 55-64 are employed, which is lower than other high-income economies. This aging trend would bring unique challenges to the nation especially in areas of employment, income security and aged care. The main aim of this start-up is to assist retirees in Malaysia in gaining access to a wide variety of job opportunities while allowing them to embrace active ageing. A survey was conducted through questionnaire to ascertain the employers' acceptance towards hiring of senior citizens in their organization, the willingness of retirees to return to the workforce. Internal and external analysis using PESTLE, Porter’s Five Forces, SWOT, TOWS, VRIO theories were conducted. Findings from primary research data show strong intention of working post-retirement among participants aged 50 and above. The result also shows participants’ acceptance of our platforms offering. Sales forecast and projection indicated the feasibility of the idea, and it is worthwhile exploring further

Does AI-based recruitment influence an employer’s attractiveness to potential employees?

This research investigates the key factors, specifically the new AI-based Recruitment Process which can affect the Employer’s Attractiveness and Joining Intentions from potential candidate’s perspective in Malaysia. Kaplan and Haenlein (2019) describes AI recruiting as a tech-advanced procedure which helps firms in their recruitment and selection processes. It uses a system’s capability to infer the external data accurately to implement the knowledge gained to attain determined goals with its adaptability. Firms using new, innovative and cutting-edge technologies such as AI, Machine Learning, Deep learning technologies etc. are deemed to be attractive as they have great capabilities to widen the reach of realtime engagements for businesses with its stakeholders and offer business continuity even during challenging times like the pandemic (Watters,2023). AI-tools are highly attractive in the recruitment industry as they offer higher speed, superior business insights, reduce human errors, automate tedious repetitive tasks, provides efficiency gains by increases productivity, candidate experience and is also time and cost saving. Hence, it has emerged as a valued asset over traditional recruitment practices(VanEsch and Black, 2019). Other studies like Gartner, InfoTech Research Group report also suggests that AI and other modern technologies are gaining popularity. HR Managers and Firms thus, need to understand the needs of its potential employees when strategically approaching the job market for competitive advantage and to attract skilled talents to join them. In this study, Berthon’s EmpAt scale (Sivertzen et.al, 2013) was used as a basis to create a conceptual model since it’s renowned and its reliability is proved by many scholars for Brand Reputation and Employer Attractiveness leading to Intention to Join a firm. Besides investigating the new proposed concept of AI-based Recruitment process, other key factors like Firm’s Attributes such as Symbolic, Instrumental and P.E Fit as identified through literatures were also studied. The research was conducted by means of a quantitative survey and 275 responses were gathered out of which 220 responses were used for the study using SPSS software for analysis. The target sample comprised of Working Professionals, recent Graduates and Full Time, Part-time students enrolled in Post-Graduate and UnderGraduate Programs in Malaysian Universities who are looking for a new job or a career change. Structural Equation Modelling (SEM) technique using SmartPLS4 was then used to analyse the findings of the research critically to understand the main factors specifically AI-based Recruitment Process affecting the Employer’s Attractiveness and Brand Reputation. And its influence on Joining Intentions from a potential candidate’s perspective in Malaysia. The results showed that both AI-based recruitment and Firm’s Attributes(Symbolic Attributes(FAS),Instrumental Attributes- (FAI) and Person-Environment (P.E) Fit) directly affects the Brand Reputation and Employer’s Attractiveness which leads to positively influencing the Joining Intentions of the prospective candidates in Malaysia.AI-Based Recruitment also has an effect on increasing the Brand Reputation which results in influencing the Joining decisions of the potential employees

The impact of zinc levels on taste change and hair loss following bariatric surgery and reporting of dietary compliance to weight loss interventions

Currently, there is significant interest in the effective treatment of obesity, particularly the implementation of a very low-calorie diet (VLCD) and the use of bariatric surgery (BS) which is a well-established long-term treatment. However, much of the contemporary research has noted that patients who have undergone bariatric surgery have reported unexplained side effects, such as a change in their sense of taste which may impact dietary compliance post-surgery. Additionally, there is limited research concerning long-term compliance with a very low-calorie diet which is a crucial aspect of pre-and post-bariatric surgery eating requirement. This thesis is divided into two sections: the first section investigates the links between taste change and zinc following BS, and the second section examines patients’ compliance with a VLCD. The over-arching theme of the thesis focuses on the speculative association of taste and hair loss following bariatric surgery with decreased circulating zinc levels, which might affect compliance to post-surgery eating requirements and the reporting of compliance to significant calorie restriction. In the initial part of the first section, a systematic review was conducted to collect evidence regarding the role of zinc in the development of taste disorders among patients who had undergone bariatric surgery and those who had not. This study used PRISMA guidelines to conduct systematic reviews of several electronic bibliographical databases, including EMBASE, PubMed, AMED, and MEDLINE, for studies concerning the effects of BS on taste, the effects of BS on zinc levels, and the effect of zinc replacement on taste. The results from this systematic review demonstrated that, according to the findings of qualitative research (conducted via questionnaires), taste change was observed in the majority of patients within a year following bariatric surgery. However, experimental investigations did not yield statistically significant evidence of taste alteration. A total of twelve investigations were conducted to examine the occurrence of zinc deficiency following bariatric surgery (BS), which revealed a notable reduction in zinc levels that persisted for six months post-surgery. The administration of zinc sulphate was found to be efficacious in enhancing taste perception in patients, apart from those with a cancer diagnosis who did not exhibit any improvement in taste following the dispensation of zinc supplements. Given that zinc deficiency and taste disorders occur in repeated cases at approximately the same time, this study hypothesises the existence of a potential relationship between these two factors. Therefore, the subsequent section of this work examines the connection between zinc and taste change following sleeve gastrectomy (SG) and gastric bypass (GB) via a single-centre, prospective cohort study conducted at King Abdullah Medical City (KAMC) in Saudi Arabia (Makkah). Forty-three patients were selected, consisting of eighteen gastric bypass patients and twenty-five patients who had undergone sleeve gastrectomy (SG). The duration of the follow-up period spanned a length of six months. The assessment of taste alteration was conducted via the utilisation of a validated questionnaire and implementation of the taste strips technique. Additionally, the study involved the measurement of serum zinc levels and salivary flow rate for all of the participants. Following the administration of the questionnaire, the results of this study demonstrate that patients who had undergone gastric bypass (GB) surgery exhibited a higher prevalence of hypogeusia (at the three-month mark) when compared with those who underwent sleeve gastrectomy (SG), with percentages of 72.0% and 36.0% respectively (p=0.03). However, no significant difference in hypogeusia prevalence was discovered between the two groups at the six-month mark, with percentages of 56.0% for GB and 45.0% for SG patients (p=0.74). However, when taste strips were utilised, there was no notable disparity in the occurrence of hypogeusia between patients with GB and SG at the three-month point (44.4% versus 36.0%, p=0.75). Nevertheless, at six months, a higher proportion of patients with GB reported experiencing hypogeusia compared to SG patients (44.0% vs. 11.0%, p=0.052). The study observed a significant decrease in zinc levels among GB patients, from the initial measurement of 85.6±16.9μgm /dl to the six-month measurement of 67.5±9.2μgm/dl. Conversely, SG patients reported an increase in zinc levels from the baseline measurement of 76.9±11.4 to the six-month measurement of 84.9±21.7μgm/dl. A decrease in the salivary flow rate was noted in 66.0% and 72.0% of individuals with GB and SG, respectively, after 3 months, and in 47.0% and 70.0%, respectively, after 6 months. Hair loss was noted as an additional side-effect following BS; however, the underlying causes and factors of this condition remain unidentified. Therefore, a subsequent section investigates the potential association between hair loss and decreased circulating zinc levels following BS and the differences between SG and GB patients. The findings of the study revealed that the prevalence of hair loss among patients who underwent GB was double that of SG. Specifically, at three months post-surgery, the percentage of hair loss was 66.6% in the GB group and 32% in the SG group, indicating a significant difference between the two groups (P = 0.025). Furthermore, at six months post-surgery, the percentage of hair loss increased to 75% among GB patients, while it decreased to 20% among SG patients. The findings also indicated a statistically significant difference between the groups, with a p-value of 0.001. This research established that individuals who had undergone bariatric surgery and experienced subsequent hair loss displayed reduced zinc levels compared to the established reference value and that, in this patient population, females were more susceptible to hair loss than males. These findings suggest that hair loss is a frequently observed adverse outcome that can occur following both types of surgeries; however, it has been shown that GB patients are inclined to experience a higher degree of hair loss, which has been linked to lower levels of zinc in their blood. In the final part of this section, a study assessed the effective zinc doses for taste disorder treatment to inform future clinical guidelines and studies regarding the use of zinc as a remedy for taste disorders following BS. A systematic review and meta-analysis were conducted regarding the effectiveness of zinc supplementation in taste disorder treatment following the guidelines outlined in the PRISMA Statement. A comprehensive search of four electronic bibliographic databases (Ovid MEDLINE, Ovid Embase, Ovid AMAD, and PubMed) was conducted. This review has been duly recorded with PROSPERO and assigned the unique identification number CRD42021228461. The results demonstrate that zinc supplementation, when administered at high dosages ranging from 68 to 86.7 mg/d for a duration of up to six months, is an efficacious intervention for taste abnormalities in individuals with zinc deficiency, idiopathic taste disorders, and those with taste disorders resulting from chronic renal failure. The second section of this thesis concerns a clinical study involving thirty-five, healthy, middle-aged male volunteers and is designed to investigate and document the consumption of an extra calorie allowance derived from conventional foods or only from vegetables and nuts (up to 200kcal/day). Additionally, this study employed two distinct evaluation methodologies to analyse the macronutrient composition of these dietary additions to evaluate VLCD compliance for up to six weeks. The results revealed that patients following a very low-calorie diet (VLCD) who are provided with an additional food allowance from traditional sources or have their food intake confined to vegetables and nuts, frequently consume more calories than the prescribed daily limit. How compliance is reported exhibits substantial variation depending on the method of monitoring employed. The data presented in the conclusion of this thesis suggest that: firstly, decreased circulating zinc level following bariatric surgery is directly correlated to taste change, low salivary flow and hair loss, and that high doses of zinc supplementation are an effective remedy for taste change; and, secondly, patients fail to strictly adhere to VLCD. Additionally, the data presented by this thesis suggests that future research concerning the effectiveness of zinc supplementation in taste disorder treatment (following bariatric surgery), and additional studies concerning long-term compliance with a very low-calorie diet, are required

Post-transcriptional regulation of the Pqs Quorum Sensing System in Pseudomonas aeruginosa

Pseudomonas aeruginosa is a leading cause of morbidity in patients with respiratory diseases and is a very frequent pathogen in medical device-associated infections. The adaptability and potent virulence of this pathogen are mainly attributed to virulence coordination at the population level by the three Quorum Sensing (QS) systems Las, Rhl, and Pqs, in conjunction with small, regulatory non-coding RNAs (sRNA). Regulation by sRNAs provides quick responses to environmental cues by altering gene expression at the post-transcriptional level, aiding to swift adaptation to new environments. In the present study, the expression of the sRNA PqsX in P. aeruginosa PAO1-L was explored. In the first results chapter, the construction of an aptamer-based reporter and a bioluminescent reporter fusion to the pqsX promoter were attempted. Although the aptamer reporter was marred by technical difficulties, the bioluminescence reporter showed that pqsX was under the control of the Las and the Rhl QS systems, as well as underscored PqsE as a significant inducer of this gene in both static and aerobic conditions. Northern Blot analysis revealed the presence of at least two forms of PqsX of less than 300 nt each, and these two forms could be detected from late exponential growth phase. The lack of longer PqsX transcripts that would run into pqsA was not due to steric inhibition of transcription by PqsR binding downstream of pqsX. In silico analysis of PqsX pointed towards two major stem loops and two probable RNase E recognition sites which might be important for PqsX maturation and function. The second results chapter was focused on the potential roles of PqsX. PqsX could not be confirmed to control any of the QS systems under aerobic conditions, in contrast to a previously reported positive regulation of lasR in surface-attached cells. To reveal candidate RNA targets of PqsX, GRIL-Seq was employed. As PqsX was not known to bind RNAs or proteins, PhrS was chosen as positive control of the process. Both sRNAs were ligated to multiple different mRNA targets, including lasB, rsaL, mRNAs of aromatic amino acid catabolic enzymes, phzS, arcD, and bfrB, spanning a broad range of metabolic pathways and virulence determinants. They were also bound to other sRNAs, with PqsX binding to PhrS, CrcZ, and ErsA, while PhrS was found to bind to ErsA, expanding their regulatory roles. A selection of target genes were explored in vitro and phenotypically in chapter 3. PqsX interacted with RNAs of rsaL, clpX, bfrB, mvaT, CrcZ, and PhrS in vitro, and PhrS with ErsA, CrcZ, and phzS. Although no interaction was seen between PqsX and phzS mRNA, deletion of pqsX resulted in reduced pyocyanin production compared with the wild type. The PqsX-CrcZ interaction prompted investigation on the connection of PqsX in the presence of non-preferred carbon sources. PqsX was more abundant and expressed in stationary phase of growth in presence of mannitol than in glucose or succinate where it was found in exponential phase. This upregulation was dependent on the presence of rhlR. Considering the extensive regulome of PqsX, the final step was to identify the effect of this sRNA on the whole transcriptome by means of RNA-Seq. Overexpression of pqsX in microaerophilic conditions did not have any significant impact on the PAO1-L transcriptome. However, in aerobic conditions, pqsX overexpression led to downregulation of the pyochelin biosynthesis genes but increase in pyoverdine biosynthetic genes as well as genes involved in iron uptake and signalling in low iron environments. Employing the bioluminescent reporter fusion of pqsX, the activity of the promoter was inversely related to the iron concentration in the media, peaking at 0.15 μΜ FeCl3. A pqsX mutant produced less pyoverdine in iron-rich media than the wild type, and the opposite effect was observed in iron scarcity. Comparison of RNA-Seq and Gril-Seq revealed one common target, bfrB, leading to hypothesise that the effect on iron scavenging seen in the RNA-Seq is an indirect result of bfrB translational repression by PqsX. This study uncovered the broad functions of the sRNA PqsX in connection with the virulence and response to low iron of the multi-drug resistant P. aeruginosa. Furthermore, it showed that sRNAs may interact with each other adding a new layer in the regulation of gene expression. These results will help understand how this pathogen adapts in the host environment and design novel antimicrobial therapies against P. aeruginosa