541 research outputs found
Rent Seeking and the Unveiling of 'De Facto' Institutions: Development and Colonial Heritage within Brazil
This paper analyzes the roots of variation in de facto institutions, within a constant de jure institutional setting. We explore the role of rent-seeking episodes in colonial Brazil as determinants of the quality of current local institutions, and argue that this variation reveals a de facto dimension of institutional quality. We show that municipalities with origins tracing back to the sugar-cane colonial cycle -- characterized by a polarized and oligarchic socioeconomic structure -- display today more inequality in the distribution of land. Municipalities with origins tracing back to the gold colonial cycle -- characterized by an over-bureaucratic and heavily intervening presence of the Portuguese state -- display today worse governance practices and less access to justice. The colonial rent-seeking episodes are also correlated with lower provision of public goods and lower income per capita today, and the latter correlation seems to work partly through worse institutional quality at the local level.
Institutional Development and Colonial Heritage within Brazil
This paper analyzes the determinants of local institutions and distribution of political power within a constant 'macro-institutional' setting. We show that characteristics of Brazilian municipalities related to institutional quality and distribution of political power are partly inherited from the colonial histories experienced by different areas of the country. Municipalities with origins tracing back to the sugar-cane colonial cycle – characterized by a polarized and oligarchic socioeconomic structure – display today more inequality in the distribution of endowments (land). Municipalities with origins tracing back to the gold colonial cycle – characterized by a heavily inefficient presence of the Portuguese state – display today worse governance practices and less access to justice. The colonial rent-seeking episodes are also correlated with lower provision of public goods and lower income per capita.institutions, colonial heritage, rent-seeking, geography, Brazil
Weight–length relationships of four intertidal mollusc species from the northeastern Atlantic Ocean and their potential for conservation
Weight-length relationships (WLRs) are frequently used for the development of comparative
studies of life history, population dynamics, ecosystem modelling and estimation of the
production and biomass of populations among regions. WLRs provide information about
growth, wellbeing and fitness of a population in a marine environment. WLRs for four
topshells (Phorcus atratus, Phorcus lineatus, Phorcus mariae, Phorcus sauciatus) caught in
North-eastern Atlantic Ocean (Azores, Canaries, Cape Verde, Madeira and Mainland Portugal)
were established and their relative growth was assessed. The results showed that almost all
species exhibited a positive allometric growth. A comparative study on the effect of harvest
in the relative growth of P. sauciatus in the archipelago of Madeira showed that all the
populations from exploited areas exhibited a negative allometric growth in contrast to the
populations from the Marine Protected Areas (MPAs) which were predominantly isometric.
The present results indicate that the conservation measures established in the protected
areas promoted a positive effect in the protected populations and are valuable for
establishing a set of monitoring and management measures aiming at the sustainable
exploitation and conservation of these species. These results are important to demonstrate
the role of MPAs in the conservation of these keystone species in the north eastern Atlantic
Ocean rocky shore ecosystems.info:eu-repo/semantics/publishedVersio
Unravelling the effects of exploitation on the size–structure of the intertidal topshell Phorcus sauciatus in harvested and non-harvested Atlantic regions
Intertidal molluscs are keystone species often used as biological indicators of human-driven pertur bations. The increasing levels of harvesting pressure on these intertidal grazers, due to the expansion
of human population on coastal areas, is known to affect negatively the exploited populations by
altering population size–structure and decreasing abundances. A comparative study on the effect
of harvest on the size–structure of Phorcus sauciatus populations was conducted according to the
exploitation level, harvested and non-harvested, throughout the intertidal zone of mainland Portugal,
Azores, Madeira, and the Canaries. The comparative analysis of the size–structure of 10,480 individuals
of P. sauciatus showed that the largest individuals were recorded in the Azores and the smallest in
Madeira. In harvested populations, P. sauciatus showed to be under greater harvesting pressure in the
archipelago of Madeira, where the lowest mean size was observed. In the Canaries the harvesting is
regulated whilst in the mainland Portugal the regulation is scarce. The Azores showed no harvesting
pressure. Marine Protected Areas showed individuals with the highest mean sizes supporting their
effectiveness in preserving the size–structure of this species, regardless the ecoregion and thus,
the harvesting pressure. The present results highlight the importance of harvesting regulation of P.
sauciatus in Madeira, as well as the implementation of management measures aiming at the sustainable
exploitation and conservation of this species.info:eu-repo/semantics/publishedVersio
Thinking of fish population discrimination: population average phenotype vs. population phenotypes
The genetic polymorphism and phenotypic variation are key in ecology and evolution.
The morphological variability of the contour of fish otoliths has been extensively used for
the delimitation of stocks. These studies are conventionally based on average phenotype
using elliptic Fourier analysis and lineal discriminant analysis as classifier. Considering new
analytical options, such as the wavelet transformand non-parametric algorithms, we here
analyzed the otolith shape of Trachurus picturatus (blue jack mackerel) from mainland
Portugal, Madeira, and the Canaries. We explore the phenotypic variation throughout
a latitudinal gradient, establish a hypothesis to explain this variability based on the
reaction norms, and determine how the use of average phenotype and/or morphotypes
influences in the delimitation of stocks. Four morphotypes were identified in all regions,
with an increase of phenotypes in warmer waters. The findings demonstrated that stocks
were clearly separated with classification rates over 90%. The use of morphotypes,
revealed seasonal variations in their frequencies and per region. The presence of shared
phenotypes in different proportions among fishing grounds may open new management
approaches in migratory species. These results show the importance of the phenotypic
diversity in fisheries management.Preprin
Biofilm phenotype potentiates virulence transduction in Acinetobacter baumannii
Portuguese Foundation for Science and Technology (FCT) under the scope of the
strategic funding UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-
FEDER-006684) and the Project PTDC/BBB-BSS/6471/2014 (POCI-
01-0145-FEDER-016678). This work was also supported by BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Ana Rita Costa acknowledges FCT for grant SFRH/BPD/94648/2013info:eu-repo/semantics/publishedVersio
The role of prophages on virulence transduction in Acinetobacter baumannii biofilms
Recent years have observed an alarming increase on bacterial resistance
to antibiotics. Many factors contribute to this, mainly antibiotics misuse
but also an intrinsic capacity of bacteria to trade genetic material. These
exchanges are emphasized in biofilms due to bacteria proximity, and
involve several mechanisms including prophage-mediated transduction.
Prophages are bacteriophages that incorporate into the bacterial
genome, being able to excise and enter other bacteria. They are found in
many bacterial species, being particularly frequent in Acinetobacter
baumannii. This bacterial species is emerging as an important
nosocomial pathogen worldwide especially due to a rapid acquisition of
antibiotic resistance, in which prophage-mediated transduction may play
a key role.The aim of this work was to evaluate the role of prophages on
virulence transduction in A. baumannii biofilms. For this, an A. baumannii
strain (ANC 4097) enclosing a prophage codifying a beta-lactam
resistance gene and a receptor A. baumannii strain (NIPH 146) were
selected based on biofilm-forming capacity. Strain susceptibility was
tested for selecting a beta-lactam antibiotic to assess transduction. Both
strains were genetically modified to follow transduction by fluorescence
microscopy (mCherry inserted in the prophage and gfp in 146) and 146
was further modified to allow strain distinction on plate (lacZ). Levels of
transduction were evaluated in mixed biofilms under different stress
conditions (sub-MIC, light, and temperature).This work provides new
insights into the importance of prophage transduction in virulence
acquisition in mixed A. baumannii biofilms
Sustainable fully printed UV sensors on cork using zinc oxide/ethylcellulose inks
SFRH/BD/121679/2016 SFRH/BD/139225/2018 ERC-StG-2014, GA 640598 H2020-TWINN-2015, GA 692373 UID/CTM/50025/2019 PTDC/CTM-NAN/5172/2014 PTDC/CTMBIO/6178/2014.Low-cost and large-scale production techniques for flexible electronics have evolved greatly in recent years, having great impact in applications such as wearable technology and the internet of things. In this work, we demonstrate fully screen-printed UV photodetectors, successfully fabricated at a low temperature on a cork substrate, using as the active layer a mixture of zinc oxide nanoparticles and ethylcellulose. The photoresponse under irradiation with a UV lamp with peak emission at 302 nm exhibited a quasi-quadratic behavior directly proportional to the applied voltage, with a photocurrent of about 5.5 and 20 μA when applying 1.5 V and 5 V, respectively. The dark current stayed below 150 nA, while the rise and falling times were, respectively, below 5 and 2 s for both applied voltages. The performance was stable over continuous operation and showed a degradation of only 9% after 100 bending cycles in a 45 mm radius test cylinder. These are promising results regarding the use of this type of sensor in wearable applications such as cork hats, bracelets, or bags.publishersversionpublishe
Motorway tidal flow lane control
The expansion of road infrastructure, in spite of increasing congestion levels, faces severe restrictions from all sorts: economical, environmental, social, or technical. An efficient and, usually, less expensive alternative to improve mobility and the use of available infrastructure is the adoption of traffic management. A particular case of interest occurs when inbound and outbound traffic on a given facility is unbalanced throughout the day. This scenario may benefit of a lane management strategy called tidal flow (or reversible) lane control, in which case the direction of one or more contraflow buffer lanes is reversed according to the needs of each direction. This paper proposes a simple and practical real-time strategy for efficient motorway tidal flow lane control. A state-feedback switching policy based on the triangular fundamental diagram, that requires only aggregated measurements of density, is adopted. A theoretical analysis based on the kinematic wave theory shows that the strategy provides a Pareto-optimal solution. Microsimulations using empirical data from the A38(M) Aston Expressway in Birmingham, UK, are used to demonstrate the operation of the proposed strategy. The robustness of the switching policy to parameter variations is demonstrated by parametric sensitivity analysis. Simulation results confirm an increase of motorway throughput and a smooth operation for the simulated scenarios
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