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The impact of margin trading and regulatory policy on IPO underpricing: evidence from Türkiye
No full textThis study examines the impact of margin loans and accompanying regulatory changes on the underpricing of initial public offerings (IPOs) in Türkiye, with a focus on the wave of IPOs from 2020 to 2023—a period during which the number of IPOs and proceeds from them reached record highs. Analyzing data from 154 IPOs, we find an average initial return of 35 percent, which shows significant underpricing, with an estimated $1.93 billion left on the table. Using multivariate regression models, we identify an inverse relationship between margin loans and abnormal initial returns, which indicates that higher margin trading is correlated with lower initial returns. Moreover, we find that restrictive margin loan policies positively affect initial returns, likely due to asymmetric information, such that underwriters adjust underpricing to attract retail investors with limited market experience. In addition, our results show that changes in policy that favor retail investor allocations positively impact on initial returns, as underwriters, who are limited with regard to accessing informed bidders, adjust prices to attract investors. This study offers new insights into the IPO and margin trading literature and has implications for policymakers and emerging markets.</p
Constructing queenship: Marguerite d’Angoulême and Marguerite de Valois in the Franco-Navarrese political sphere
No full textThroughout the sixteenth century, royal women gained and retained political power as queens regnant, regent, and consort. Those royal women not ruling as queens regnant often utilized their relationships with husbands and kin to influence their royal courts. This thesis looks at two such royal women, Marguerite d’Angoulême and Marguerite de Valois, and how they created and maintained political power within both France and Navarre during tumultuous periods of religious dissent and war. The comparative nature of this project directly questions a royal woman’s role in early modern France and Navarre. I broaden the scope of what political actions a princess might take, both before and after her marriage, through the study of her life-writing in the form of correspondence, poetry, and memoirs. This thesis is structured around four thematic chapters: ‘soft power’ and family ties, religion and dissent, patronage and court life, and diplomacy. These four chapters exhibit the diverse political questions into which both early modern royal women inserted themselves and discuss the strategies that they used to make their voices heard. Essential to this project is my analysis of their life-writing. Their life-writing reveals how Marguerite d’Angoulême and Marguerite de Valois conceptualized themselves as well as in how they attempted to exert influence on correspondents and readers. Ultimately, these two royal women saw themselves able mediators and willing counsellors, and attempted to prove themselves as such. I thus argue for their greater inclusion in studies of sixteenth-century French and Navarrese politics.</p
Robust μ-distortion constraints on primordial supermassive black holes from cubic (gNL) non-Gaussian perturbations
No full textWe make the first calculation of the spectral distortion constraints on the primordial curvature power spectrum in the limit of large cubic non-Gaussianity. This calculation involves computing a 2-loop integral, which we perform analytically. Despite being non-perturbatively non-Gaussian, we show that the constraints only change significantly from the case of Gaussian perturbations in the high-k tail, where spectral distortions become weak. We conclude that generating primordial supermassive black holes requires even more extreme forms of non-Gaussianity. We also argue why the μ-distortion constraint is unlikely to significantly change even in the presence of more extreme local non-Gaussianity.</p
Masked Divalent Reactivity of Heterobimetallic Lanthanide Isocarbonyl Complexes
No full textA new rare-earth reduction system is described in which trivalent yttrium and dysprosium react as though present in their unstable divalent oxidation state. This masked divalent reactivity is achieved using the isocarbonyl-bridged dimers [((Formula presented.) M)(μ-Fp)]2 (M=Y, 1Y; M=Dy, 1Dy; Cpttt=1,2,4-C5tBu3H2; Fp=CpFe(CO)2), where the reducing electrons originate from the bridging [Fp]− ligands. The reactivity of 1Y and 1Dy is showcased by reducing the N-heterocycles 2,2′-bipyridyl (bipy), phenazine (phnz) and hexaazatrinaphthylene (HAN) to give corresponding mono-, di- and tri-metallic rare-earth complexes, respectively, with the heterocyclic ligands present in their singly, doubly and triply reduced forms, respectively. The dynamic magnetic properties of the dysprosium compounds are described. Compound 1Dy is a single-molecule magnet (SMM) with an appreciable energy barrier of 449(17) cm−1, whereas [((Formula presented.) Dy)2(μ-phnz)] (3Dy) is not an SMM because of a strong, competing equatorial crystal field. Surprisingly, [((Formula presented.) Dy)3(HAN)] (4Dy) is also not an SMM, the origins of which are traced to the impact of the tert-butyl substituents on the dysprosium centre and its interaction with the radical [HAN]3− ligand.</p
Search for a light charged Higgs boson in t→H±b decays, with H±→cs, in pp collisions at s=13TeV with the ATLAS detector
No full textA search for a light charged Higgs boson produced in decays of the top quark, t→H±b with H±→cs, is presented. This search targets the production of top-quark pairs tt¯→WbH±b, with W→ℓν (ℓ=e,μ), resulting in a lepton-plus-jets final state characterised by an isolated electron or muon and at least four jets. The search exploits b-quark and c-quark identification techniques as well as multivariate methods to suppress the dominant tt¯ background. The data analysed correspond to 140fb-1 of pp collisions at s=13TeV recorded with the ATLAS detector at the LHC between 2015 and 2018. Observed (expected) 95% confidence-level upper limits on the branching fraction B(t→H±b), assuming B(t→Wb)+B(t→H±(→cs)b)=1.0, are set between 0.066% (0.077%) and 3.6% (2.3%) for a charged Higgs boson with a mass between 60 and 168 GeV.</p
Effects of a brief resonance frequency breathing exercise on heart rate variability and inhibitory control in the context of generalised anxiety disorder
No full textGeneralised anxiety disorder (GAD) is associated with cognitive and physiological symptoms including uncontrollable worry, inhibitory control deficits, and low heart rate variability (HRV). Literature linking HRV and inhibition in GAD is predominantly correlational. The present experiment investigated whether HRV has a causal role in maintaining inhibitory control. Participants (N = 135, 111 female) aged 18–37 reporting high levels of symptoms associated with GAD (GAD-7 scores ≥ 10; Penn State Worry Questionnaire scores ≥ 56) were assigned to an experimental or active control condition and completed baseline measures of HRV, respiration rate, and inhibitory control. The experimental condition completed resonance frequency breathing (RFB) training, and the control condition practiced breathing at their mean breathing rate before repeating the inhibitory control assessment. Participants also completed the breathing training before a behavioural worry task. The experimental condition was predicted to show increased HRV, alongside improved inhibitory control and better ability to stop worrying as compared to the control condition. HRV increased during the experimental condition, as compared to the control condition. However, there were no significant effects of RFB on inhibitory control or worry, or on HRV during the inhibitory control tasks. In conclusion, RFB can increase HRV in high GAD scorers, but further research is required to determine whether there is a relationship between increased HRV and symptoms of GAD in a single session experiment.</p
Bio-inspired event-based looming object detection for automotive collision avoidance
No full textLow-latency sensory processing is a key requirement of collision avoidance systems for automated driving. Event-based cameras have been proposed and investigated as a new type of sensor for faster and more efficient collision detection. In this study, we investigate an insect vision-inspired network that detects looming objects in traffic situations using event-based camera data. As such, it represents a lightweight alternative to large neural networks applied in vision-based driving assistance systems. Using simulated driving accident scenarios, we find that our system can reliably detect colliding vehicles up to 1.3 s before the collision. Furthermore, we demonstrate the effectiveness of nonlinear radial motion opponency filtering in addressing the challenges of optical flow-based looming detection.</p
Competence assessment by stimulus matching (CASM): a novel approach to language assessment by chunk transcription
No full textThis thesis develops and evaluates Competence Assessment by Stimulus Matching (CASM) as an innovative approach to assessing individual’s competence in English as a second language, integrating chunking theory from cognitive science with elements of human-computer interaction. The research addresses the need for more efficient and effective methods to assess language competence. It explores the potential for extracting chunk signals from micro-behaviours observed during interactions in simple mouse-based tasks, as a reflection of language proficiency. The first step in the research was the development of a cognitive model utilizing the GOMS task analysis framework to inform the design of CASM. Following this, three empirical studies were conducted with eighty-nine participants who speak Arabic as their first language and English as their second, to test, refine and assess the effectiveness of the method. Chunk measures, such as pauses between clicks (pauses), the number of times a stimulus is viewed (view number), the duration of each view (view duration), and the duration of time spent clicking on answers between views (response duration) were collected and contrasted with independent measures of competence that included a language self-assessment, a vocabulary size test and an additional grammar test. The findings reveal a significant relationship between the dependant chunk measure and independent measures of language competence, demonstrating potential for using CASM for language assessment. This study highlights the value of exploring non-traditional ways of testing using technological advances to extract rich data. It also provides key considerations to assess competence using chunk signals across various domains.</p
‘We try to jump those hurdles’: Inter-agency dynamics of referral with self-neglect cases in England
No full textIn health and social care, disagreements over referrals involve professionals contesting between them the power to define the situation. An aspect of practice that commonly gives rise to such disagreements is self-neglect because of its high ambiguity for services. Self-neglect therefore provides a useful case to explore how professionals anticipate and respond to interagency barriers to referral when criteria and thresholds are only loosely defined, and collaboration is often ad hoc. To investigate the dynamics of interagency referral for self-neglect, we interviewed 69 practitioners: health and social care professionals; and fire and rescue, environmental health, and housing officers, all of whom regularly respond to both crisis and chronic situations of self-neglect. Dynamics that influence referrers and hinder coordination between interprofessional networks included uncertainties about the right route, perceived barriers to referral acceptance, and feeling unable to refer. These present barriers to the anticipatory labor needed to make interagency referrals land successfully with the receiving agency and may lead to a self-fulfilling cycle that discourages practitioners from thoughtful referral practice. Although referral failures are often treated in research on referral in safeguarding as a technical knowledge-deficit problem, the data show the significance of wider interagency relations, perceptions, and expectations in accounting for the barriers.</p
The vagus nerve as a gateway to body ownership: taVNS reduces susceptibility to a virtual version of the cardiac and tactile rubber hand illusion
No full textTranscutaneous auricular vagus nerve stimulation (taVNS) has been shown to influence cognitive and emotional function and enhance interoceptive awareness. This study investigates if taVNS effects extend to the experience of body ownership, as measured via susceptibility to the rubber hand illusion (RHI) in a virtual reality setting. The experiment involved 27 participants who underwent real and sham stimulation in two separate sessions while experiencing synchronous or asynchronous visuo-cardiac and visuo-tactile feedback on a virtual arm in place of their own. Results indicated that active compared to sham taVNS decreased sensitivity to the illusion in both cardiac and tactile trials. Specifically, a greater proprioceptive drift difference (PDD) toward the rubber hand was observed for synchronous compared to asynchronous trials only during sham (t(26) = −4.58, pbonf </p