318 research outputs found
Why did people pay taxes? Fiscal innovation in Portugal and state making in times of political struggle (1500-1680)
This paper considers growing fiscal capacity of the European early modern states as contingent to taxpayer’s consent in higher tax loads. It puts forward the hypothesis that war damages were the main factor guiding the taxpayer’s cost-benefit assessment of consenting or violently resisting to a fiscal innovation. To test the hypotheses, we consider data on Portugal in times of political struggle against the Habsburgs to restore and keep the political autonomy after 1640. The war was financed by an entirely new, universal income tax, remaining in the Portuguese fiscal system well until the liberal revolution in 1820, although enforced by a decentralized and nonspecialized administration. A model derives the optimal tax rate from the standpoint of the taxpayer as a function of war intensity, risk aversion, and awareness that evasion would enhance war damages. Data on damages, contemporary assessments of the tax base, and amounts enforced allow the model’s calibration. Results suggest the accuracy of the hypothesis and draw the conclusion that taxpayers’ utility in paying the new tax determined the efective tax rate (tax enforced). This paper claims that ultimately improvements in the fiscal capacity of states needed taxpayer’s perception of high levels of destruction, hence any political regime in early modern Europe must have found in war damages a persuasive argument to make efective a fiscal innovation. The other contribution of this case study is pointing out the advantage of the assignment of the tax collection to local, non-professional administration, for the endurance of a fiscal system, which incorporated an income tax that withstood the liberal revolution. It enhanced the role of peer monitoring and turned out to be an efective way of instilling social norms contributing to build up the taxpayer’s liability, which somehow the liberal state in 19th century exploited within a different technological environment.info:eu-repo/semantics/publishedVersio
Gene expression during regeneration of zebrafish (danio rerio) fins: relative expression levels of mineralization – related gla proteins
Most animals have the ability to regenerate epidermal injuries yet only a few can regenerate largely
severed appendages that comprise several different tissues. Nowadays zebrafish is one of the most used
metazoan models in regeneration studies in particular for investigation of molecular events during fin
regeneration process. Fin regeneration starts through the formation of a blastema, a set of heterogeneous
mesenchyma-like cells located between stump tissues and the wounded epidermis. This event,
denominated epimorphic regeneration, comprises strict growth control and cell reprogramming leading
to faithful restoration of the lost parts
A realistic simulation environment as a teaching aid in educational robotics
The experimental component is an essential method in Engineering education. Sometimes the availability of laboratories and components is compromised, and the COVID-19 pandemic worsened the situation. Resorting to an accurate simulation seems to help this process by allowing students to develop the work, program, test, and validate it. Moreover, it lowers the development time and cost of the prototyping stages of a robotics project. As a multidisciplinary area, robotics requires simulation environments with essential characteristics, such as dynamics, connection to hardware (embedded systems), and other applications. Thus, this paper presents the Simulation environment of SimTwo, emphasizing previous publications with models of sensors, actuators, and simulation scenes. The simulator can be used for free, and the source code is available to the community. Proposed scenes and examples can inspire the development of other simulation scenes to be used in electrical and mechanical Engineering projects. © 2022 IEEE.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support
through national funds FCT/MCTES (PIDDAC) to CeDRI
(UIDB/05757/2020 and UIDP/05757/2020) and SusTEC
(LA/P/0007/2021). Thadeu Brito was supported by FCT PhD
grant SFRH/BD/08598/2020 and Joao Braun received the ˜
support of a fellowship from ”la Caixa” Foundation (ID
100010434) with code LCF/BQ/DI20/11780028.info:eu-repo/semantics/publishedVersio
Proposta de uma solução inovadora e eco-eficiente para paredes divisórias
Neste trabalho pretende-se apresentar uma solução para paredes divisórias construídas com blocos de forma inovadora fabricados com um material compósito resultante a combinação de materiais considerados como subprodutos industriais. Pretende-se que os blocos possibilitem a colocação de instalações reduzindo os resíduos em obra, contribuindo para uma maior sustentabilidade na construção. São apresentados neste trabalho os detalhes da solução, do processo construtivo e da validação parcial do comportamento mecânico
Regeneration in Zebrafish (Danio rerio) fins: pattern of expression of mineralization–related Gla proteins
Teleost fishes have the exceptional ability to largely regenerate severed appendages
comprising several different tissues. Fin regeneration starts through the formation of
heterogeneous mesenchyma-like cells, named blastema, and located between stump
tissues and the wounded epidermis. This event, denominated epimorphic regeneration,
comprises strict growth control and cell reprogramming leading to faithful restoration
of the lost parts. Matrix Gla Protein (Mgp) and Bone Gla Protein (Bgp, osteocalcin)
are small extracellular matrix Gla proteins, members of the vitamin K-dependent
(VKD) family
Biogenic cloud nuclei in the central Amazon during the transition from wet to dry season
© Author(s) 2016. This work is distributed under the Creative Commons Attribution 3.0 License. Whitehead, J. D., Darbyshire, E., Brito, J., Barbosa, H. M. J., Crawford, I., Stern, R., Gallagher, M. W., Kaye, P. H., Allan, J. D., Coe, H., Artaxo, P., and McFiggans, G.: Biogenic cloud nuclei in the central Amazon during the transition from wet to dry season, Atmos. Chem. Phys., 16, 9727-9743, doi:10.5194/acp-16-9727-2016, 2016.The Amazon basin is a vast continental area in which atmospheric composition is relatively unaffected by anthropogenic aerosol particles. Understanding the proper- ties of the natural biogenic aerosol particles over the Ama- zon rainforest is key to understanding their influence on re- gional and global climate. While there have been a number of studies during the wet season, and of biomass burning par- ticles in the dry season, there has been relatively little work on the transition period – the start of the dry season in the absence of biomass burning. As part of the Brazil–UK Net- work for Investigation of Amazonian Atmospheric Composi- tion and Impacts on Climate (BUNIAACIC) project, aerosol measurements, focussing on unpolluted biogenic air masses, were conducted at a remote rainforest site in the central Ama- zon during the transition from wet to dry season in July 2013. This period marks the start of the dry season but before sig- nificant biomass burning occurs in the region. Median particle number concentrations were 266 cm−3, with size distributions dominated by an accumulation mode of 130–150 nm. During periods of low particle counts, a smaller Aitken mode could also be seen around 80 nm. While the concentrations were similar in magnitude to those seen during the wet season, the size distributions suggest an en- hancement in the accumulation mode compared to the wet season, but not yet to the extent seen later in the dry sea- son, when significant biomass burning takes place. Submi- cron nonrefractory aerosol composition, as measured by an aerosol chemical speciation monitor (ACSM), was domi- nated by organic material (around 81 %). Aerosol hygro- scopicity was probed using measurements from a hygro- scopicity tandem differential mobility analyser (HTDMA), and a quasi-monodisperse cloud condensation nuclei counter (CCNc). The hygroscopicity parameter, κ , was found to be low, ranging from 0.12 for Aitken-mode particles to 0.18 for accumulation-mode particles. This was consistent with pre- vious studies in the region, but lower than similar measure- ments conducted in Borneo, where κ ranged 0.17–0.37. A wide issue bioaerosol sensor (WIBS-3M) was deployed at ground level to probe the coarse mode, detecting pri- mary biological aerosol by fluorescence (fluorescent biolog- ical aerosol particles, or FBAPs). The mean FBAP number concentration was 400 ± 242 L−1; however, this ranged from around 200 L−1 during the day to as much as 1200 L−1 at night. FBAPs dominated the coarse-mode particles, compris- ing between 55 and 75 % of particles during the day to more than 90 % at night. Non-FBAPs did not show a strong diur- nal pattern. Comparison with previous FBAP measurements above canopy at the same location suggests there is a strong vertical gradient in FBAP concentrations through the canopy. Cluster analysis of the data suggests that FBAPs were dom- inated (around 70 %) by fungal spores. Further, long-term measurements will be required in order to fully examine the seasonal variability and distribution of primary biological aerosol particles through the canopy. This is the first time that such a suite of measurements has been deployed at this site to investigate the chemical compo- sition and properties of the biogenic contributions to Ama- zonian aerosol during the transition period from the wet to the dry season, and thus provides a unique comparison to the aerosol properties observed during the wet season in previ- ous similar campaigns. This was also the first deployment of a WIBS in the Amazon rainforest to study coarse-mode parti- cles, particularly primary biological aerosol particles, which are likely to play an important role as ice nuclei in the region.Peer reviewe
Stationary solutions for the parity-even sector of the CPT-even and Lorentz-covariance-violating term of the standard model extension
In this work, we focus on some properties of the parity-even sector of the
CPT-even electrodynamics of the standard model extension. We analyze how the
six non-birefringent terms belonging to this sector modify the static and
stationary classical solutions of the usual Maxwell theory. We observe that the
parity-even terms do not couple the electric and magnetic sectors (at least in
the stationary regime). The Green's method is used to obtain solutions for the
field strengths E and B at first order in the Lorentz- covariance-violating
parameters. Explicit solutions are attained for point-like and spatially
extended sources, for which a dipolar expansion is achieved. Finally, it is
presented an Earth-based experiment that can lead (in principle) to an upper
bound on the anisotropic coefficients as stringent as
Comment: 8 pages, revtex style, revised published version, to appear in EPJC
(2009
Combining experiences of race gaming and natural driving affects gaze location strategy in simulated context
Isoprene photochemistry over the Amazon rainforest
Isoprene photooxidation is a major driver of atmospheric chemistry over forested regions. Isoprene reacts with hydroxyl radicals (OH) and molecular oxygen to produce isoprene peroxy radicals (ISOPOO). These radicals can react with hydroperoxyl radicals (HO_2) to dominantly produce hydroxyhydroperoxides (ISOPOOH). They can also react with nitric oxide (NO) to largely produce methyl vinyl ketone (MVK) and methacrolein (MACR). Unimolecular isomerization and bimolecular reactions with organic peroxy radicals are also possible. There is uncertainty about the relative importance of each of these pathways in the atmosphere and possible changes because of anthropogenic pollution. Herein, measurements of ISOPOOH and MVK + MACR concentrations are reported over the central region of the Amazon basin during the wet season. The research site, downwind of an urban region, intercepted both background and polluted air masses during the GoAmazon2014/5 Experiment. Under background conditions, the confidence interval for the ratio of the ISOPOOH concentration to that of MVK + MACR spanned 0.4–0.6. This result implies a ratio of the reaction rate of ISOPOO with HO_2 to that with NO of approximately unity. A value of unity is significantly smaller than simulated at present by global chemical transport models for this important, nominally low-NO, forested region of Earth. Under polluted conditions, when the concentrations of reactive nitrogen compounds were high (>1 ppb), ISOPOOH concentrations dropped below the instrumental detection limit (<60 ppt). This abrupt shift in isoprene photooxidation, sparked by human activities, speaks to ongoing and possible future changes in the photochemistry active over the Amazon rainforest
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