Affordability and subsidies in public urban transport : what do we mean, what can be done?

Subsidy policies on public urban transport have been adopted ubiquitously. In both developed and developing countries, subsidies are implemented to make transport more affordable. Despite their widespread implementation, there are virtually no quantitative assessments of their distributional incidence, making it impossible to determine if these instruments are pro-poor. This paper reviews the arguments used to justify subsidy policies in public urban transport. Using different tools to quantitatively evaluate the incidence and distributive impacts of subsidy policy options, the paper analyzes the findings of a series of researchpapers that study urban public transport subsidy policies in developed and developing countries. The available evidence indicates that current public urban transport subsidy policies do not make the poorest better off. Supply-side subsidies are, for the most part, neutral or regressive; while demand-side subsidies perform better-although many of them do not improve income distribution. Considering that the policy objective is to improve the welfare of the poorest, it is imperative to move away from supply-side subsidies towards demand-side subsidies and to integrate transport social concerns into wider poverty alleviation efforts, which include the possibility of channeling subsidies through monetary transfer systems or through other transfer instruments (food subsidies, health services and education for the poor). The general conclusion of the paper is that more effort should be devoted to improve the targeting properties of public urban transport subsidies using means-testing procedures to ensure a more pro-poor incidence of subsidies.Transport Economics Policy&Planning,Transport in Urban Areas,Urban Transport,Taxation&Subsidies,Economic Theory&Research

Enhanced Learning Using Mutimedia-Interactive Systems: An Experimental Study

The education field is in a process of change driven by new developments in multimedia technology, which is being used as a complementary alternative for teaching purposes. This paper describes a thesis project developed through an exploratory study comparing the effects of using three different teaching approaches: traditional teacher-led instruction, web page instruction and a multimedia-interactive system. The principal objective is to find out whether the use of a prototype multimedia-interactive delivers better outcomes in teaching complex subjects such as data structures, than web page and traditional teacher-led instruction approaches. Information Systems Design Theory was used to develop a multimediainteractive tool. Students were taught to use binary trees to compare the three teaching methods. Pilot test results show that there are significant differences in performance of students who used the multimedia-interactive tool. It is concluded that the multimedia-interactive system prototype can effectively be used to help students learn binary trees

Sense and sensitivity of double beta decay experiments

The search for neutrinoless double beta decay is a very active field in which the number of proposals for next-generation experiments has proliferated. In this paper we attempt to address both the sense and the sensitivity of such proposals. Sensitivity comes first, by means of proposing a simple and unambiguous statistical recipe to derive the sensitivity to a putative Majorana neutrino mass, m_bb. In order to make sense of how the different experimental approaches compare, we apply this recipe to a selection of proposals, comparing the resulting sensitivities. We also propose a "physics-motivated range" (PMR) of the nuclear matrix elements as a unifying criterium between the different nuclear models. The expected performance of the proposals is parametrized in terms of only four numbers: energy resolution, background rate (per unit time, isotope mass and energy), detection efficiency, and bb isotope mass. For each proposal, both a reference and an optimistic scenario for the experimental performance are studied. In the reference scenario we find that all the proposals will be able to partially explore the degenerate spectrum, without fully covering it, although four of them (KamLAND-Zen, CUORE, NEXT and EXO) will approach the 50 meV boundary. In the optimistic scenario, we find that CUORE and the xenon-based proposals (KamLAND-Zen, EXO and NEXT) will explore a significant fraction of the inverse hierarchy, with NEXT covering it almost fully. For the long term future, we argue that Xe-based experiments may provide the best case for a 1-ton scale experiment, given the potentially very low backgrounds achievable and the expected scalability to large isotope masses.Comment: 30 pages, 12 figures, 6 table

Unravelling mechanistic insights in the platinum-catalysed dihydroalkoxylation of allenes

The mechanism of the platinum-catalysed dihydroalkoxylation of allenes to give acetals has been studied experimentally and by computational methods. Our findings further explain divergent reactivity encountered for platinum- and gold-vinyl intermediates after the first nucleophilic attack onto the coordinated allene, as well as provide new details on the catalytic cycle with platinum, uncovering enol ethers as resting states of the catalytic cycle, a S(E)Ox process via Pt(V)-H as the final protodemetallation step after the second nucleophilic attack when neutral platinum complexes are used, and a fast acid promoted addition of methanol to enol ethers when cationic platinum complexes are employed

Not Good Enough: Ironic Efficiency in Automated-Aided Signal-Detection

During applied signal-detection (e.g., airport-baggage screening) human operators can be assisted in their decision-making process by automated devices. Automation implementation is aimed at increasing performance relative to unaided levels. Generally, this intended effect is empirically observed. However, operators consistently fall short of optimal levels of aided performance, indicating suboptimal aid-use efficiency. Previous research suggests aid-use efficiency might vary depending on the sensitivity levels of each agent in the human + automation team. In the present research we manipulated Task Difficulty (easy vs. difficult) and Aid Reliability (low vs high) to examine how measures of sensitivity and aid-use efficiency vary across these factors. Participants completed a numerical signal-detection task with automated-support manipulated within-subjects. Bayesian inference analyses suggested higher sensitivity gains were achieved at higher levels of difficulty and aid reliability. Interestingly, however, aid-use efficiency was lower at these conditions. These findings replicate and expand previously observed ironic patterns of aided performance where operators fall shorter of optimal levels in conditions where empirical and potential levels of aid-benefit are higher. These findings provide valuable insight for system designers and highlight the need to better understand factors contributing to suboptimal human-automation interaction during aided signal-detection to procure safety and efficiency in naturalistic settings

Unveiling Ethereum's Hidden Centralization Incentives: Does Connectivity Impact Performance?

Modern public blockchains like Ethereum rely on p2p networks to run distributed and censorship-resistant applications. With its wide adoption, it operates as a highly critical public ledger. On its transition to become more scalable and sustainable, shifting to PoS without sacrificing the security and resilience of PoW, Ethereum offers a range of consensus clients to participate in the network. In this paper, we present a methodology to measure the performance of the consensus clients based on the latency to receive messages from the p2p network. The paper includes a study that identifies the incentives and limitations that the network experiences, presenting insights about the latency impact derived from running the software in different locations.Comment: THE FIFTH INTERNATIONAL CONFERENCE ON BLOCKCHAIN COMPUTING AND APPLICATIONS (BCCA 2023

Case Report: Neurologic Presentation of West Nile Virus: Difficult Diagnosis

West Nile virus infections have surged across the globe. South Texas, located on the path of bird migration, with Culex quinquefasciatus and other Culex species, and biotic primers that predispose the area to epidemics (floods, amplifying hosts, and lack of mosquito control and prevention) remains a highly endemic area for arbovirus spread. West Nile virus infection ranges from mild febrile illness to severe central nervous system involvement. The purpose of this report is to highlight complex presentations of WNV and how confounding presenting symptoms delay diagnosis. The secondary goal is to describe how pandemics, such as SARS-CoV-2, can overwhelm the system and result in medical decision bias errors

Prevention and management of acute reactions to intravenous iron in surgical patients

Absolute or functional iron deficiency is the most prevalent cause of anaemia in surgical patients, and its correction is a fundamental strategy within "Patient Blood Management" programmes. Offering perioperative oral iron for treating iron deficiency anaemia is still recommended, but intravenous iron has been demonstrated to be superior in most cases. However, the long-standing prejudice against intravenous iron administration, which is thought to induce anaphylaxis, hypotension and shock, still persists. With currently available intravenous iron formulations, minor infusion reactions are not common. These self-limited reactions are due to labile iron and not hypersensitivity. Aggressively treating infusion reactions with H 1 -antihistamines or vasopressors should be avoided. Self-limited hypotension during intravenous iron infusion could be considered to be due to hypersensitivity or vascular reaction to labile iron. Acute hypersensitivity reactions to current intravenous iron formulation are believed to be caused by complement activation-related pseudo-allergy. However, though exceedingly rare (<1:250,000 administrations), they should not be ignored, and intravenous iron should be administered only at facilities where staff is trained to evaluate and manage these reactions. As preventive measures, prior to the infusion, staff should inform all patients about infusion reactions and identify those patients with increased risk of hypersensitivity or contraindications for intravenous iron. Infusion should be started at a low rate for a few minutes. In the event of a reaction, the very first intervention should be the immediate cessation of the infusion, followed by evaluation of severity and treatment. An algorithm to scale the intensity of treatment to the clinical picture and/or response to therapy is presented