249 research outputs found
Heterogeneous contributions can jeopardize cooperation in the Public Goods Game
When studying social dilemma games, a crucial question arises regarding the
impact of general heterogeneity on cooperation, which has been shown to have
positive effects in numerous studies. Here, we demonstrate that heterogeneity
in the contribution value for the focal Public Goods Game can jeopardize
cooperation. We show that there is an optimal contribution value in the
homogeneous case that most benefits cooperation depending on the lattice. In a
heterogeneous scenario, where strategy and contribution coevolve, cooperators
making contributions higher than the optimal value end up harming those who
contribute lower. This effect is notably detrimental to cooperation in the
square lattice with von Neumann neighborhood, while it can have no impact in
others lattices. Furthermore, in parameter regions where a higher-contributing
cooperator cannot normally survive alone, the exploitation of lower value
contribution cooperators allows their survival, resembling a parasitic
behavior. To obtain these results, we employed various distributions for the
contribution values in the initial condition and conducted Monte Carlo
simulations
Rapid automated method for on-site determination of sulfadiazine in fish farming: a stainless steel veterinary syringe coated with a selective membrane of PVC serving as a potentiometric detector in a flow-injection-analysis system
Sulfadiazine is an antibiotic of the sulfonamide
group and is used as a veterinary drug in fish farming.
Monitoring it in the tanks is fundamental to control the
applied doses and avoid environmental dissemination.
Pursuing this goal, we included a novel potentiometric
design in a flow-injection assembly. The electrode body
was a stainless steel needle veterinary syringe of 0.8-mm
inner diameter. A selective membrane of PVC acted as a
sensory surface. Its composition, the length of the electrode,
and other flow variables were optimized. The best
performance was obtained for sensors of 1.5-cm length
and a membrane composition of 33% PVC, 66% onitrophenyloctyl
ether, 1% ion exchanger, and a small
amount of a cationic additive. It exhibited Nernstian slopes
of 61.0 mV decade-1 down to 1.0×10-5 mol L-1, with a limit
of detection of 3.1×10-6 mol L-1 in flowing media. All
necessary pH/ionic strength adjustments were performed
online by merging the sample plug with a buffer carrier of
4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, pH
4.9. The sensor exhibited the advantages of a fast response
time (less than 15 s), long operational lifetime (60 days),
and good selectivity for chloride, nitrite, acetate, tartrate,
citrate, and ascorbate. The flow setup was successfully
applied to the analysis of aquaculture waters. The analytical
results were validated against those obtained with liquid
chromatography–tandem mass spectrometry procedures.
The sampling rate was about 84 samples per hour and
recoveries ranged from 95.9 to 106.9%
Symbiotic behaviour in the Public Goods game with altruistic punishment
Finding ways to overcome the temptation to exploit one another is still a
challenge in behavioural sciences. In the framework of evolutionary game
theory, punishing strategies are frequently used to promote cooperation in
competitive environments. Here, we introduce altruistic punishers in the
spatial public goods game. This strategy acts as a cooperator in the absence of
defectors, otherwise it will punish all defectors in their vicinity while
bearing a cost to do so. We observe three distinct behaviours in our model: i)
in the absence of punishers, cooperators (who don't punish defectors) are
driven to extinction by defectors for most parameter values; ii) clusters of
punishers thrive by sharing the punishment costs when these are low iii) for
higher punishment costs, punishers, when alone, are subject to exploitation but
in the presence of cooperators can form a symbiotic spatial structure that
benefits both. This last observation is our main finding since neither
cooperation nor punishment alone can survive the defector strategy in this
parameter region and the specificity of the symbiotic spatial configuration
shows that lattice topology plays a central role in sustaining cooperation.
Results were obtained by means of Monte Carlo simulations on a square lattice
and subsequently confirmed by a pairwise comparison of different strategies'
payoffs in diverse group compositions, leading to a phase diagram of the
possible states
Structure Characterization of Materials by Association of the Raman Spectra and X-Ray Diffraction Data
Perspectives For Sustainable Aviation Biofuels In Brazil
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The aviation industry has set ambitious goals to reduce carbon emissions in coming decades. The strategy involves the use of sustainable biofuels, aiming to achieve benefits from environmental, social, and economic perspectives. In this context, Brazilian conditions are favorable, with a mature agroindustry that regularly produces automotive biofuel largely adopted by Brazilian road vehicles, while air transportation has been growing at an accelerating pace and a modern aircraft industry is in place. This paper presents the main conclusions and recommendations from a broad assessment of the technological, economic, and sustainability challenges and opportunities associated with the development of drop-in aviation biofuels in Brazil. It was written by a research team that prepared the initial reports and conducted eight workshops with the active participation of more than 30 stakeholders encompassing the private sector, government institutions, NGOs, and academia. The main outcome was a set of guidelines for establishing a new biofuels industry, including recommendations for (a) filling the identified research and development knowledge gaps in the production of sustainable feedstock; (b) overcoming the barriers in conversion technology, including scaling-up issues; (c) promoting greater involvement and interaction between private and government stakeholders; and (d) creating a national strategy to promote the development of aviation biofuels.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)BoeingEmbraerFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2012/50009-1
Perspectives for sustainable aviation biofuels in Brazil
The aviation industry has set ambitious goals to reduce carbon emissions in coming decades. The strategy involves the use of sustainable biofuels, aiming to achieve benefits from environmental, social, and economic perspectives. In this context, Brazilian conditions are favorable, with a mature agroindustry that regularly produces automotive biofuel largely adopted by Brazilian road vehicles, while air transportation has been growing at an accelerating pace and a modern aircraft industry is in place. This paper presents the main conclusions and recommendations from a broad assessment of the technological, economic, and sustainability challenges and opportunities associated with the development of drop-in aviation biofuels in Brazil. It was written by a research team that prepared the initial reports and conducted eight workshops with the active participation of more than 30 stakeholders encompassing the private sector, government institutions, NGOs, and academia. The main outcome was a set of guidelines for establishing a new biofuels industry, including recommendations for (a) filling the identified research and development knowledge gaps in the production of sustainable feedstock; (b) overcoming the barriers in conversion technology, including scaling-up issues; (c) promoting greater involvement and interaction between private and government stakeholders; and (d) creating a national strategy to promote the development of aviation biofuels2015FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2012/50009-
FORESAM—FOG paradigm-based resource allocation mechanism for vehicular clouds
The Intelligent Transport Systems (ITS) has the objective quality of transportation improvement through transportation system monitoring and management and makes the trip more comfortable and safer for drivers and passengers. The mobile clouds can assist the ITS in handling the resource management problem. However, resource allocation management in an ITS is challenging due to vehicular network characteristics, such as high mobility and dynamic topology. With that in mind, we propose the FORESAM, a mechanism for resources management and allocation based on a set of FOGs which control vehicular cloud resources in the urban environment. The mechanism is based on a more accurate mathematical model (Multiple Attribute Decision), which aims to assist the allocation decision of resources set that meets the period requested service. The simulation results have shown that the proposed solution allows a higher number of services, reducing the number of locks of services with its accuracy. Furthermore, its resource allocation is more balanced the provided a smaller amount of discarded services
Projetos voltados aos jovens em instituições sociais: atividades fragmentadas e desresponsabilização do poder público
Stress and psychological health: testing the mediating role of cognitive appraisal
This study tested the mediating role of primary (e.g., threat and challenge perceptions) and secondary (e.g., coping potential and control perception) cognitive appraisal in the relationship between occupational stress and psychological health. This mediation was tested using a cross-sectional study based on self-reported measures. The total sample consisted of 2,302 nurses, 1,895 females (82.3%) and 407 males (17.7%), who completed an evaluation protocol with measures of occupational stress, cognitive appraisal, and psychological health. To test the mediating role of cognitive appraisal in the relationship between cognitive appraisal and psychological health, we used Structural Equation Modeling (SEM). The results confirmed that primary and secondary cognitive appraisals partially mediated the relationship between occupational stress and psychological health; however, the direct effects of stress on psychological health cannot be ignored. The findings indicated that cognitive appraisal is an important underlying mechanism in explaining adaptation at work.This study was conducted at Psychology Research Centre (UID/PSI/01662/2013), University of MInho, and supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, Technology and Higher Education through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653)
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