418 research outputs found

    A quantitative view on policymakers’ goal, institutions and tax evasion

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    We develop a general theoretical model to compare two different policymakers both facing tax evasion. Policymakers differs in that they aim to maximize either the fiscal revenues (T) as in a social-democracy as, e.g., Sweden, or the GDP as in a capitalistic country as, e.g., the USA. Both Bureaus can manoeuvre the tax rate and the share of tax receipts spent to fight the tax evasion rather than to increase the public capital. Our model merges the indications of two distinct, and sometimes conflicting, approaches to the analysis of tax evasion in that reconciling them. We also find that the feedbacks between the private and public sector are linked to some Laffer-type relationships usually unexplored by the existing literature. As compared to capitalistic systems, then, our results show that social-democracies end up imposing higher tax rates and, possibly, more pervasive regulations. Consequently, they are likely to suffer from larger tax-evasion-to-GDP ratios. This notwithstanding,social-democracies spend relatively more to contrast tax dodgers. On the other hand, T-maximizing governments have better institutional settings and greater employment rates. Whichever the preferred target, however, no policymaker is able to erase totally the tax evasion, which may explain why this latter is so pervasive and persistent even among the richest countries

    Bayesian estimation and entropy for economic dynamic stochastic models: An exploration of overconsumption

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    This paper examines psycho-induced overconsumption in a dynamic stochastic context. As emphasized by well-established psychological results, these psycho-distortions derive from a decision making based on simple rules-of-thumb, not on analytically sounded optimizations. To our end, we therefore compare two New Keynesian models. The first is populated by optimizing Muth-rational agents and acts as the normative benchmark. The other is a “psycho-perturbed” version of the benchmark that allows for the potential presence of overoptimism and, hence, of overconsumption. The parameters of these models are estimated through a Bayesian-type procedure, and performances are evaluated by employing an entropy measure. Such methodologies are particularly appropriate here since they take in full consideration the complexity generated by the randomness of the considered systems. In particular, they let to derive a not negligible information on the size and on the cyclical properties of the biases. In line with cognitive psychology suggestions our evidence shows that the overoptimism/overconsumption is: widespread—it is detected in nation-wide data; persistent—it emerges in full-sample estimations; it moves according to the expected cyclical behavior—larger in booms, and it disappears in crises. Moreover, by taking into account the effect of these psycho-biases, the model fits actual data better than the benchmark. All considered, then, enhancing the existing literature our findings: i) sustain the importance of inserting psychological distortions in macroeconomic models and ii) underline that system dynamics and psycho biases have statistically significant and economically important connections

    TINGKAT KEMAMPUAN PENYERAPAN TANAMAN HIAS DALAM MENURUNKAN POLUTAN KARBON MONOKSIDA

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    Most of the air pollution in large cities caused by motor vehicle. Increasing the number of motor vehicles in urban areas resulting in a net decrease in air quality due to emissions from fuel combustion. The research aims to determine the ability of plants to absorb carbon monoxide uses the lidah mertua plant (Sansevieria sp), lili paris plant (Spider plant), and sirih gading plant (Scindapsus aureus). Gaseous pollutants are presented tehadap test plants are pollutants derived from motor vehicle fumes. The research conducteted exposure to the lidah mertua plant (Sansevieria sp), lili paris plant (Spider plant) dan sirih gading pplant (Scindapsus aureus) with variaotions in the exhaust gas exposure during the 0,5 hour, 1 hour, and 1,5 hour conducted in house plants during for five days. The esult research showed lidah mertua plant (Sansevieria sp) with exposure time 1,5 hours contact at day five can absorb 46,21 %, lili paris plant (Spider plant) while absorbing 41,47 %, and sirih gading plant (Scindapsus aureus) absorbs 32,58 % carbon monoxide gas. Keyword: carbon monoxide, Sansevieria sp, Spider plant, Scindapsus aureu

    Periodontal evaluation of palatally impacted maxillary canines treated by closed approach with ultrasonic surgery and orthodontic treatment: a retrospective pilot study

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    Aim of this study is the evaluation of the periodontal status of impacted canines treated by closed approach with ultrasonic surgery and orthodontic treatment compared with contralateral spontaneously erupted teeth. The periodontal conditions of the teeth adjacent to the canines (lateral incisors and first premolar) were also considered. 17 patients (9 females and 8 males; mean age: 15.2 years) with unilateral palatal impaction of maxillary canine were selected. All patients were treated by closed-flap surgery with ultrasonic instruments. Periodontal status was evaluated by assessing probing depth (PD), gingival recession and width of keratinized tissue (KT) 4.6 months after the end of the orthodontic treatment, on average. Test group was composed by impacted elements and adjacent teeth and control group by contralateral spontaneously erupted canines and adjacent teeth. Student's t-test was used to compare test and control group values of PD and width of KT. Significance threshold for Student's t-test was set at p < 0.05. The average probing depth values show no significant clinical differences between the test and control groups. Probing depths recorded at the mesiovestibular and distopalatal sides of the impacted canine were statistically significant compared to the control elements (p < 0.05). No gingival recession was detected on the treated canines. The measurement of KT did not differ significantly between the test and the control groups. In conclusion, the ultrasonic surgery for disinclusion associated with a closed approach and orthodontic traction allows the alignment of an impacted palatal canine without damaging the periodontium

    Genetic analysis for sooty mold resistance and heart of palm yield in Archontophoenix.

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    Palmeiras do gênero Archontophoenix, utilizadas tanto como ornamentais quanto produtoras de palmito de qualidade, são susceptíveis à fumagina, doença associada à infestação por pulgões, que afeta a fotossíntese, o crescimento e a aparência das plantas. Foram avaliados a campo a resistência à fumagina conjuntamente com três caracteres associados ao crescimento em 24 famílias de meios-irmãos, 28 meses após o plantio, a fim de identificar a variabilidade genética para os caracteres resistência à fumagina, altura, diâmetro e número de folhas; estimar as correlações genotípicas e fenotípicas envolvendo esses quatro caracteres; e aplicar a estratégia de seleção usando o índice multiefeitos. Houve diferenças entre as famílias para os caracteres avaliados, sugerindo a possibilidade de seleção. O baixo coeficiente de variação observado para resistência à fumagina (9,48%) indica que o método de avaliação adotado, baseado em escala de notas após observação visual, foi eficiente e prático para comparar níveis de infestação do complexo fungo+pulgão em palmeiras do gênero Archontophoenix. As estimativas da herdabilidade no sentido restrito foram baixas a médias para os caracteres relacionados ao crescimento (0,10, 0,26 e 0,26 para número de folhas, diâmetro e altura da planta, respectivamente) e muito altas (0,91) para resistência à fumagina. Correlação genética positiva foi observada entre resistência à fumagina e altura da planta, indicando que a eliminação de plantas muito susceptíveis pode ser feita sem interferência na seleção indireta para produção de palmito. A estratégia de seleção pelo índice multiefeitos (com ganhos genéticos esperados variando de 6,23 a 11,83%) mostrou-se adequada para melhorar simultaneamente caracteres relacionados ao crescimento e à produção de palmito

    Characterization of kinetic and kinematic parameters for wearable robotics

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    The design process of a wearable robotic device for human assistance requires the characterization of both kinetic and kinematic parameters (KKP) of the human joints. The first step in this process is to extract the KKP from different gait analyses studies. This work is based on the human lower limb considering the following activities of daily living (ADL): walking over ground, stairs ascending/descending, ramp ascending/descending and chair standing up. The usage of different gait analyses in the characterization process, causes the data to have great variations from one study to another. Therefore, the data is graphically represented using Matlab® and Excel® to facilitate its assessment. Finally, the characterization of the KKP performed was proved to be useful in assessing the data reliability by directly comparing all the studies between each other; providing guidelines for the selection of actuator capacities depending on the end application; and highlighting optimization opportunities such as the implementation of agonist-antagonist actuators for particular human joints

    Stealth silica nanoparticles for theranostic applications

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    Silica nanoparticles (SNPs) are a promising carrier system for medical applications. They can be conveniently tailored with different moieties in order to obtain peculiar capabilities. SNPs surface is successfully modified in order to obtain a specific targeting ability through Boletus Edulis Lectin (BEL) bioconjugation, a lectin that specifically recognize overexpressed tumor markers. Moreover, stealthing abilities are imparted with a one-step cocondensation of silanated poly(ethylene) glycol monomethyl ether. Herein we present the preliminary results of these studies

    Nutrição mineral do urucueiro. I. Curva de crescimento de duas cultivares de urucueiro (Bixa orellana L.), em fase de viveiro.

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    Parte da tese apresentada à Escola Superior de Agricultura de lavras (ESAL), pelo primeiro autor, para obtenção do grau de Mestre em agronomia na área de Solos e Nutrição de Plantas
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