2,104 research outputs found
Modeling Interjurisdictional Tax Competition in a Federal System
Interjurisdictional tax competition is a controversial theme little studied in an empirical approach in spite of the great advance in the theoretical debate at last decades. This paper aims to build a bridge between such theoretical issues and the empirical tools using an interregional general equilibrium model to evaluate the welfare effects of an experimental game of tax competition between two regional governments of the Brazilian federal system. The model recognizes the horizontal and vertical fiscal linkages underlying the Brazilian federalism. The results imply in a welfare-improving Nash equilibrium, in opposition with many theoretical issues. It can be seen that the fiscal externalities of tax competition does matter for such output not only due the mobility of the regional tax base but also because the substitution effect between regional goods and international goods since tax competition reduces the domestic prices. Additionally, the constitutional rules impose a rigid mechanism of fiscal transfers from central government to regional governments and contribute to alleviate the reduction pressures on the regional public goods because the increase in central government’s tax base also increase the regional government revenues. Then, interjurisdicional tax competition in the Brazilian federal system can be associated with gains in private consumption that overcome the reduction in regional public good provisions, reinforcing the welfare-improving equilibrium.
Phosphodiesterase Type 5 Inhibitors and Visual Side Effects: A Narrative Review
Phosphodiesterase type 5 inhibitors such as sildenafil citrate and tadalafil are well known for the treatment of erectile dysfunction. However, their use in the presence of pulmonary hypertension can cause ophthalmologic side effects, including non-arteritic optic ischemic neuropathy, chorioretinopathy, glaucoma, and optic atrophy. The present review aimed to identify these visual side effects and provide recommendations. We identified articles published from January 2000 to March 2019 on diseases arising from the management of sexual dysfunction in urology or pulmonary hypertension in pneumonia that could cause pathologic alterations in eye structure based on a literature search of the MEDLINE electronic database using keywords for the most common adverse effects and different kinds of phosphodiesterase 5 inhibitors. After applying the exclusion criteria, we selected 36 of the 77 articles initially identified to write the narrative review and added 20 additional articles to completely describe the pathological entities. Phosphodiesterase type 5 inhibitors can cause side effects in the eye including ocular surface abnormalities, increased intraocular pressure and glaucoma, uveitis, non-arteritic ischemic neuropathy, chorioretinopathy, retinal occlusion, and visual field changes. There is an increased need for well-performed studies to better understand these side effects, which are common due to the wide use of sildenafil
Inducing energy gaps in graphene monolayer and bilayer
In this paper we propose a mechanism for the induction of energy gaps in the
spectrum of graphene and its bilayer, when both these materials are covered
with water and ammonia molecules. The energy gaps obtained are within the range
20-30 meV, values compatible to those found in experimental studies of graphene
bilayer. We further show that the binding energies are large enough for the
adsorption of the molecules to be maintained even at room temperature
Life Cycle Assessment of Electrodialytic Technologies to Recover Raw Materials from Mine Tailings
UIDB/04085/2020
PD/BD/135170/2017Currently, the development of new sustainable technologies to recover raw materials from secondary resources has shown a lack of available data on the processes and supplies involved, as well as their environmental impacts. The present research has conducted a life cycle assessment of electrodialytic (ED) technologies to improve critical raw materials recovery in the Portuguese mining industry. To critically appraise the activities from the mining sector and gather data on technical and environmental issues, three waste management scenarios were considered: (1) ED treatment with a deep eutectic solvent as an adjuvant; (2) ED treatment with simultaneous H2 recovery; and (3) ED treatment with sodium chloride as an enhancement. The data presented were based on global databases, technical reports from official sources, and peer-reviewed published experimental outcomes. The estimated results indicated that one of the constraints in applying ED technologies is energy consumption and thus the impacts are highly dependent on energy source choices. On the other hand, as a consequence of the H2 inherently produced by ED technologies, there is a direct potential for energy recovery. Therefore, considering an upscale approach of the ED reactor based on bench scale experimental results, the H2 could be reused in the ED facility or stored. Additionally, according to experimental data, 22% of the tungsten from the fine mine tailings could be recovered. Finally, the possibility to remove 63% of arsenic from mine tailings could decrease contamination risks while creating additional marketable co-products.publishersversionpublishe
Cost-Effectiveness of Routine Screening for Cardiac Toxicity in Patients Treated with Imatinib in Brazil
AbstractWe performed a cost-effectiveness study of different strategies of screening for cardiotoxicity in patients receiving imatinib, the first strategy based on yearly echocardiograms in all patients and the second strategy based on yearly B-type natriuretic peptide level measurement, reserving echocardiograms for patients with an abnormal test result. Results are presented in terms of additional cost per diagnosis as compared with not performing any screening. From the Brazilian private sector’s perspective, strategies 1 and 2 resulted in additional costs of US 19,925.64 per diagnosis of cardiotoxicity, respectively. From the perspective of the Brazilian public health system, the same strategies generated additional costs of US 20,232.87 per diagnosis, respectively. In our study, systematic screening for cardiotoxicity in patients using imatinib has a high cost per diagnosis. If screening is to be adopted, a strategy based on B-type natriuretic peptide level measurement, reserving echocardiography for patients with abnormal results, results in lower costs per diagnosis in the private sector. From the public health system’s perspective, costs per diagnosis will greatly depend on the reimbursement values adopted for B-type natriuretic peptide level measurement
Multimodal Bayesian Network for Artificial Perception
In order to make machines perceive their external environment coherently, multiple sources of sensory information derived from several different modalities can be used (e.g. cameras, LIDAR, stereo, RGB-D, and radars). All these different sources of information can be efficiently merged to form a robust perception of the environment. Some of the mechanisms that underlie this merging of the sensor information are highlighted in this chapter, showing that depending on the type of information, different combination and integration strategies can be used and that prior knowledge are often required for interpreting the sensory signals efficiently. The notion that perception involves Bayesian inference is an increasingly popular position taken by a considerable number of researchers. Bayesian models have provided insights into many perceptual phenomena, showing that they are a valid approach to deal with real-world uncertainties and for robust classification, including classification in time-dependent problems. This chapter addresses the use of Bayesian networks applied to sensory perception in the following areas: mobile robotics, autonomous driving systems, advanced driver assistance systems, sensor fusion for object detection, and EEG-based mental states classification
Cross-domain MLP and CNN Transfer Learning for Biological Signal Processing: EEG and EMG
In this work, we show the success of unsupervised transfer learning between Electroencephalographic (brainwave) classification and Electromyographic (muscular wave) domains with both MLP and CNN methods. To achieve this, signals are measured from both the brain and forearm muscles and EMG data is gathered from a 4-class gesture classification experiment via the Myo Armband, and a 3-class mental state EEG dataset is acquired via the Muse EEG Headband. A hyperheuristic multi-objective evolutionary search method is used to find the best network hyperparameters. We then use this optimised topology of deep neural network to classify both EMG and EEG signals, attaining results of 84.76% and 62.37% accuracy, respectively. Next, when pre-trained weights from the EMG classification model are used for initial distribution rather than random weight initialisation for EEG classification, 93.82%(+29.95) accuracy is reached. When EEG pre-trained weights are used for initial weight distribution for EMG, 85.12% (+0.36) accuracy is achieved. When the EMG network attempts to classify EEG, it outperforms the EEG network even without any training (+30.25% to 82.39% at epoch 0), and similarly the EEG network attempting to classify EMG data outperforms the EMG network (+2.38% at epoch 0). All transfer networks achieve higher pre-training abilities, curves, and asymptotes, indicating that knowledge transfer is possible between the two signal domains. In a second experiment with CNN transfer learning, the same datasets are projected as 2D images and the same learning process is carried out. In the CNN experiment, EMG to EEG transfer learning is found to be successful but not vice-versa, although EEG to EMG transfer learning did exhibit a higher starting classification accuracy. The significance of this work is due to the successful transfer of ability between models trained on two different biological signal domains, reducing the need for building more computationally complex models in future research
A review and comparison of methodologies
Funding Information: This work received national funds through Fundação para a Ciência e Tecnologia (FCT) through the Research units CENSE “Center for Environmental and Sustainability Research”, (PTDC/CTA-AMB/6587/2020) and LAQV/REQUIMTE (UID/QUI/ 50006/2020). FCT is also acknowledged for J. Brinco (UI/BD/150867/2021) fellowship, and P. Guedes Contract established under Individual Call to Scientific Employment Stimulus (CEECIND/01969/2020). This research is anchored at RESOLUTION LAB, an infrastructure at NOVA School of Science and Technology. Funding Information: This work received national funds through Fundação para a Ciência e Tecnologia (FCT) through the Research units CENSE “Center for Environmental and Sustainability Research”, (PTDC/CTA-AMB/6587/2020) and LAQV/REQUIMTE (UID/QUI/ 50006/2020). FCT is also acknowledged for J. Brinco (UI/BD/150867/2021) fellowship, and P. Guedes Contract established under Individual Call to Scientific Employment Stimulus (CEECIND/01969/2020). This research is anchored at RESOLUTION LAB, an infrastructure at NOVA School of Science and Technology. Publisher Copyright: © 2023 The Author(s)This work reviews recently developed methodologies for multiclass pesticide residue analysis in soil and evaluates them under the focus of Green Analytical Chemistry principles, cost and time. Different extraction, clean-up and determination techniques are highlighted. QuEChERS was found to be the dominant form of extraction reported, although extractions using pressurized fluid, ultrasound and simple solid–liquid partitioning are still widely employed. GC–MS and LC-MS remain the standard analytical techniques, with the latter becoming more prevalent due to its greater versatility in analysing different chemical classes of pesticide residues, namely poorly volatile compounds. A selection of twelve representative methods was compared using the analytical eco-scale and AGREE metrics, as well as in terms of instrumental and operational cost, and time. The analysis shows that the choice of reagents and other operational parameters are more important towards the greenness of a method than the extraction and determination techniques used, but cost and time are more dependent on the techniques themselves.publishersversionpublishe
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