The welfare impacts of discriminatory price tariffs

This paper looks at the use of asymmetric tariffs as a regulatory instrument. We use a monopolistic market setup with two markets and we introduce price controls in one of the two. The purpose of the regulator is to maximise consumer welfare through this price discriminatory practice. We consider cases where the welfare of the consumers in the two markets is weighted equally and cases where it is not. In some cases we allow for the two markets to be linked through a monopsonistic input market. The paper focuses on the welfare implications of this regulatory approach, with the firm operating under a profit restriction. Results suggest that having only one price-controlled market is in certain cases a good option from a welfare perspective

Effect of axonal micro-tubules on the morphology of retinal nerve fibers studied by second-harmonic generation

Abstract. Many studies suggest that the degradation of microtubules in the retinal ganglion cells may be an early event in the progression of glaucoma. Because reflectance and birefringence of the retinal nerve fibers arise primarily from microtubules, the optical properties have been intensively studied for early detection of the disease. We previously reported a novel nonlinear optical signal from axonal microtubules for visualizing the retinal nerve fibers, namely second-harmonic generation (SHG). We demonstrate the use of axonal SHG to investigate the effect of microtubules on the morphology of the retinal nerve fiber bundles. Time-lapse SHG imaging of ex vivo rat retinal flat mounts was performed during pharmacological treatment of nocodazole, and the intensity of axonal SHG and the changes in nerve fiber bundle morphology were monitored. We found that the microtubule disruption does not lead to immediate modification in the morphology of the nerve fibers. Our results indicate that microtubular SHG may provide a useful means for sensitive detection of axonal injuries. Since the intrinsic radiation depends on the regular architecture of the cytoskeleton element as maintained by active cellular regulations, the intensity of signal reflects the health of the retinal ganglion cell axons

The "Heroic Journey" : managing the pedagogy and development of business studies teachers

This paper examines the use of the "Heroic Journey" framework from Joseph Campbell as a conceptual approach to manage the development of teaching skills of academic teachers in Business Education, through the teaching of tutorials in the Management Development Programme (MDP) of the University of Strathclyde. Tutors' development during their time spent in the MDP, their learning and their evolution into academic teachers is presented through the monomyth structure of the "Hero's Journey", as introduced by Campbell (2008). This paper offers insights, based on practitioner's perspective, and discussions and recommendations on the pedagogy of academic tutors in Business Education. Through the author's reflections, based on his experiences as Director of MDP during 2017-20, it is suggested that tutor development is a continuous process of learning, and a journey of discovery for anyone involved in it. The approach to manage the development of skills and knowledge-based competencies of teams can also be extended to other fields, to create a managerial tool

Parallelizing control flow in mixed imperative-SQL analytics using speculation

Η ανάλυση δεδομένων στις μέρες μας προχωρά με ιλιγγιώδη ταχύτητα, με έναν ολοένα αυξανόμενο αριθμό εταιρειών και οργανισμών να εγκαταλείπουν τις δομημένες γλώσσες ερωτημάτων υπέρ των μεικτών ροών εργασίας προστακτικού-SQL προγραμματισμού. Ωστόσο, τα συστήματα που εκτελούν αυτά τα μικτά προγράμματα δεν είναι επί του παρόντος ικανά να επιλύσουν τις εξαρτήσεις μεταξύ των ερωτημάτων-εντολών και των προστακτικών δομών (π.χ. εξαρτήσεις ροής ελέγχου), υιοθετώντας έτσι συνήθως έναν (σχεδόν) σειριακό τρόπο εκτέλεσης εντολών το οποίο περιορίζει σε μεγάλο βαθμό τον παραλληλισμό των έργων. Αντίθετα, οι διαθέσιμοι πόροι κατανέμονται προκειμένου να βελτιωθεί ο παραλληλισμός δεδομένων, ο οποίος μπορεί γρήγορα να οδηγήσει σε μειωμένες αποδόσεις ανάλογα με τη φύση της εργασίας που εκτελείται. Σε αυτή τη εργασία, προτείνουμε μια ενοποιημένη αρχιτεκτονική που γεφυρώνει την εκτέλεση προστακτικού κώδικα με τη μηχανή ανάλυσης των δεδομένων. Η συνέργεια μεταξύ αυτών των δύο συνιστωσών επιτρέπει στο σύστημα ανάλυσης δεδομένων (OLAP) να αποκτήσει γνώση του προγράμματος, ξεκλειδώνοντας έτσι πολλές ευκαιρίες παραλληλισμού ερωτημάτων-εντολών που διαφορετικά θα παρέμεναν ανεκμετάλλευτες. Βασιζόμενοι σε αυτήν την αρχιτεκτονική, αναπτύσσουμε ένα σκελετό επεξεργασίας που χαλαρώνει τις εξαρτήσεις ελέγχου-ροής και αυξάνει τον παραλληλισμό εργασιών, μια στρατηγική που δεν μπόρεσε να ευημερήσει με την τρέχουσα αρχιτεκτονική των αντίστοιχων συστημάτων.Data analysis in the present day is moving at breakneck speed, with an ever increasing amount of companies and organizations abandoning the structured query languages infavor of mixed imperative-SQL workflows. The engines that execute these mixed programs, however, are currently not capable of resolving dependencies between queries and the imperative constructs (e.g. control flow dependencies), thus commonly adopting an (almost) query-at-a-time execution fashion which heavily limits task-parallelism. Instead, the available resources are allocated in or-der to improve data parallelism, which can quickly lead to diminishing returns depending on the nature of the workflow being executed. In this thesis, we propose a unified architecture which bridges the code parsing and execution with the analytical processing engine. The synergy between these two componentsallows the OLAP engine to become code-aware, thus unlocking many opportunities of parallelizing queries that would otherwise remain unexploited. Building upon this architecture, we develop a paradigm that relaxes control-flow dependencies and increases task parallelism, a strategy that was not able to prosper with the current engine architecture

Electrocardiogram-gated single-photonemission computed tomography versus cardiacmagnetic resonance imaging for the assessmentof left ventricular volumes and ejection fraction A meta-analysis

AbstractObjectivesThe purpose of this study was to evaluate the accuracy of electrocardiogram (ECG)-gated single-photon emission computed tomography (SPECT) for assessment of left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) compared with the gold standard of cardiac magnetic resonance imaging (MRI).BackgroundSeveral comparisons of ECG-gated SPECT with cardiac MRI have been performed for evaluation of LV volumes and EF, but each has considered few subjects, thus leaving uncertainty about the frequency of discrepancies between the two methods.MethodsWe performed a meta-analysis of data on 164 subjects from nine studies comparing ECG-gated SPECT versus cardiac MRI. Data were pooled in correlation and regression analyses relating ECG-gated SPECT and cardiac MRI measurements. The frequency of discrepancies of at least 30 ml in EDV, 20 ml in ESV and 5% or 10% in EF and concordance for EF ≤40% versus >40% were determined.ResultsThere was an overall excellent correlation between ECG-gated SPECT and cardiac MRI for EDV (r = 0.89), ESV (r = 0.92) and EF (r = 0.87). However, rates of discrepancies for individual subjects were considerable (37% [95% confidence interval {CI}, 26% to 50%] for at least 30 ml in EDV; 35% [95% CI, 23% to 49%] for at least 20 ml in ESV; 52% [95% CI, 37% to 63%] for at least 5% in EF; and 23% [95% CI, 11% to 42%] for at least 10% in EF). The misclassification rate for the 40% EF cutoff was 11%.ConclusionsElectrocardiogram-gated SPECT measurements of EDV, ESV and EF show high correlation with cardiac MRI measurements, but substantial errors may occur in individual patients. Electrocardiogram-gated SPECT offers useful functional information, but cardiac MRI should be used when accurate measurement is required

Accessibility in digital health : virtual conversational agents and mental health services

Recent advances in Artificial Intelligence have led changes to the operation, the capabilities and the performance of a number of industries. Provision of Mental Health Services is expected to experience a paradigm shift, with the introduction of Artificial Intelligence-driven Virtual Conversational Agents (VCAs). This is a conceptual paper, focusing on the use of Personalised Anthropomorphic VCAs (PAVCAs), which we introduce as a term. We suggest the use of PAVCAs to support people suffering from Prolonged Grief Disorder (PGD). For such an application to be able to drive meaningful change for the users and to deliver economic value and utility, we argue that the PAVCAs are configured to the known and public characteristics (e.g. personal linguistic peculiarities, moral principles, stated tastes and preferences across a range of themes) of the users beloved deceased ones. Such digital services aim to offer to service users solace, comfort and companion. We explore the options of having such applications personalized pre-mortem or post-mortem, and the source for information being affected by data limitations. Using two models, we suggest that the use of these platforms can comprise a reactive approach to the diagnosis of PGD; as well as a proactive approach, dealing with grief before PDG is manifested

Single breath-hold slice-following CSPAMM myocardial tagging

Myocardial tagging has shown to be a useful magnetic resonance modality for the assessment and quantification of local myocardial function. Many myocardial tagging techniques suffer from a rapid fading of the tags, restricting their application mainly to systolic phases of the cardiac cycle. However, left ventricular diastolic dysfunction has been increasingly appreciated as a major cause of heart failure. Subtraction based slice-following CSPAMM myocardial tagging has shown to overcome limitations such as fading of the tags. Remaining impediments, to this technique, however, are extensive scanning times (∼10 min), the requirement of repeated breath-holds using a coached breathing pattern, and the enhanced sensitivity of artifacts related to poor patient compliance or inconsistent depths of end-expiratory breath-holds. We therefore propose a combination of slice-following CSPAMM myocardial tagging with a segmented EPI imaging sequence. Together with an optimized RF excitation scheme, this enables to acquire as many as 20 systolic and diastolic grid-tagged images per cardiac cycle with a high tagging contrast during a short period of sustained respiratio

Coronary Angiography Breathhold Three-Dimensional Coronary Magnetic Resonance Angiography Using Real-Time Navigator Technology

The acquisition duration of most three-dimensional (30) coronary magnetic resonance angiography (MRA) techniques is considerably prolonged, thereby precluding breathholding as a mechanism to suppress respiratory motion artifacts. Splitting the acquired 30 volume into multiple subvolumes or slabs serves to shorten individual breathhold duration. Still, problems associated with misregistration due to inconsistent depths of expiration and diaphragmatic drift during sustained respiration remain to be resolved. Me propose the combination of an ultrafast 30 coronary MRA imaging sequence with prospective real-time navigator technology, which allows correction of the measured volume position. 30 volume splitting using prospective real-time navigator technology, was successfillly applied for3D coronary MRA in five healthy individuals. An ultrafast 30 interleaved hybrid gradient-echoplanar imaging sequence, including T2Prep for contrast enhancement, was used with the navigator localized at the basal anterior wall of the left ventricle. A 9-cm-thick volume, with in-plane spatial resolution of 1.1 X 2.2 mm, was acquired during five breathholds of 15-sec duration each. Consistently, no evidence of misregistration was observed in the images. Extensive contiguous segments of the left anterior descending coronary artery (48 2 18 mm) and the right coronary artery (75

The welfare impacts of discriminatory price tariffs

This paper examines the use of asymmetric tariffs as a regulatory instrument. A monopoly setup is adopted in which the firm sells in two markets but price controls are introduced in just one. The regulator’s objective is to increase consumer welfare through this price discriminatory practice, with the firm operating under a profit constraint. We consider cases where consumer welfare in the two markets is weighted both equally and unequally and also cases where the cost of supplying the two retail markets is determined in a monopsonistic input market. The results suggest that in certain situations controlling prices in only one market could be a desirable option from a welfare perspective