Genotoxicity evaluation of tilapia (Oreochromis niloticus) exposed to waters from two sites of Itajaí-Açu River (SC, Brazil)

The relationship between the genes and the effects attributed to them has been object of many studies, especially those seeking to establish the response of genes to environmental prod. The aim of this work was to establish a standard system to monitor effluents by using juvenile Nile tilapia (Oreochromis niloticus) as a bioindicator of genotoxicity, utilizing micronuclei test and comet assay. For this, the fish were exposed during 24, 48, 72 and 240 hours (10 days), to water samples collected at two sites of the Itajaí-Açú River: Ilhota and Blumenau, in the Santa Catarina State, Brazil. For positive control the herbicide 2,4-D (75 ppm) was utilized, and the negative control of each fish were the values obtained before the exposure to the river water, termed time zero (T0). Water samples from both sites of the Itajaí-Açú River showed significant genotoxic effects in erythrocytes of the exposed fishes. The comet assay was a more sensitive test to detect genotoxic damage in shorter exposure times (24 and 48 hours) than the micronuclei test.Key words: genotoxicity, comet assay, micronuclei test, Oreochromis niloticus, bioindicato

Creencias populares y enseñanza de la Biología

The existence of some popular beliefs has been referred to by several studies. A few of these popular beliefs, which seem to be also widespread in Portugal, are related to biological contents. Therefore, it can be expected that many students hold some of these beliefs when they come to the biology classes. Based on this suspicion, the authors decided to investigate: - The degree of adhesion shown by students with different biology backgrounds, to some popular beliefs. - The importance given by some biology textbooks to the popular beliefs

Quantum field theory solution for a short-range interacting SO(3) quantum spin-glass

We study the quenched disordered magnetic system, which is obtained from the 2D SO(3) quantum Heisenberg model, on a square lattice, with nearest neighbors interaction, by taking a Gaussian random distribution of couplings centered in an antiferromagnetic coupling, $\bar J>0$ and with a width $\Delta J$. Using coherent spin states we can integrate over the random variables and map the system onto a field theory, which is a generalization of the SO(3) nonlinear sigma model with different flavors corresponding to the replicas, coupling parameter proportional to $\bar J$ and having a quartic spin interaction proportional to the disorder ($\Delta J$). After deriving the CP$^1$ version of the system, we perform a calculation of the free energy density in the limit of zero replicas, which fully includes the quantum fluctuations of the CP$^1$ fields $z_i$. We, thereby obtain the phase diagram of the system in terms of ($T, \bar J, \Delta J$). This presents an ordered antiferromagnetic (AF) phase, a paramagnetic (PM) phase and a spin-glass (SG) phase. A critical curve separating the PM and SG phases ends at a quantum critical point located between the AF and SG phases, at T=0. The Edwards-Anderson order parameter, as well as the magnetic susceptibilities are explicitly obtained in each of the three phases as a function of the three control parameters. The magnetic susceptibilities show a Curie-type behavior at high temperatures and exhibit a clear cusp, characteristic of the SG transition, at the transition line. The thermodynamic stability of the phases is investigated by a careful analysis of the Hessian matrix of the free energy. We show that all principal minors of the Hessian are positive in the limit of zero replicas, implying in particular that the SG phase is stable.Comment: To appear in Nucl. Phys B [FS], 16 pages, 6 figure

Development of a method of robust rain gauge network optimization based on intensity-duration-frequency results

Based on rainfall intensity-duration-frequency (IDF) curves, fitted in several locations of a given area, a robust optimization approach is proposed to identify the best locations to install new rain gauges. The advantage of robust optimization is that the resulting design solutions yield networks which behave acceptably under hydrological variability. Robust optimization can overcome the problem of selecting representative rainfall events when building the optimization process. This paper reports an original approach based on Montana IDF model parameters. The latter are assumed to be geostatistical variables, and their spatial interdependence is taken into account through the adoption of cross-variograms in the kriging process. The problem of optimally locating a fixed number of new monitoring stations based on an existing rain gauge network is addressed. The objective function is based on the mean spatial kriging variance and rainfall variogram structure using a variance-reduction method. Hydrological variability was taken into account by considering and implementing several return periods to define the robust objective function. Variance minimization is performed using a simulated annealing algorithm. In addition, knowledge of the time horizon is needed for the computation of the robust objective function. A short- and a long-term horizon were studied, and optimal networks are identified for each. The method developed is applied to north Tunisia (area = 21 000 km2). Data inputs for the variogram analysis were IDF curves provided by the hydrological bureau and available for 14 tipping bucket type rain gauges. The recording period was from 1962 to 2001, depending on the station. The study concerns an imaginary network augmentation based on the network configuration in 1973, which is a very significant year in Tunisia because there was an exceptional regional flood event in March 1973. This network consisted of 13 stations and did not meet World Meteorological Organization (WMO) recommendations for the minimum spatial density. Therefore, it is proposed to augment it by 25, 50, 100 and 160% virtually, which is the rate that would meet WMO requirements. Results suggest that for a given augmentation robust networks remain stable overall for the two time horizons

Climatic and Physiographic Variables to Evaluate Culex pipiens s.l. Risk and Habitat

This article belongs to the Special Issue on Environmental Management Information SystemsUsing a geographic information system (GIS), the relations between a georeferenced data set of Culex pipiens s.l . collected in Portugal mainland during seven years (2006-2012) and meteorological and physiographic parameters are evaluated. This work is one of the results of a long-term surveillance program of pernicious insects that act as vectors of various diseases; its focus is on the possibility of prevention that can be achieved with abundance data. The focus on Culex pipiens is justified by its abundance and its competence as a vector for numerous health issues. The cumulative distribution of monthly captures by each meteorological parameter allows to compute thresholds corresponding to mosquito massive presence related to 90% of the captures. Using the weather parameters measured in the network of weather stations across the country, a monthly average of each parameter of interest (temperature, humidity, etc.) is computed and an interpolation of the results is made to produce raster maps corresponding to each month. The previously obtained thresholds are applied to each map, producing spatial masks with the relevant zones for each parameter. The intersection of the various masks for each month shows the most densely populated area of Culex, and the ensemble allows us to observe the evolution of mosquito presence through the critical season, which is from May to October at these latitudes. In parallel, mosquito abundance data are related to physiographic parameters. The relative distribution of female mosquitoes across land cover types in each month allows identifying which classes and seasons are most relevant. Orthometric altitude related to the presence of 90% of the catches shows the limits reached by mosquitoes in each month. The results are applied to the previously obtained climate envelopes, delimiting critical areas where the level of risk of transmission of the pathogens for which Culex pipiens is a competent vector is high and countermeasures should be concentrated, allowing its planning, and targeting on a monthly basis. The described procedure can be used with other relevant vectors in any region of the world, whenever abundance data is available.We acknowledge financial support through national funds to Project PTDC/SAU-SAP/119199/2010, and CESAM by FCT/MCTES [UIDP/50017/2020 + UIDB/50017/2020 + LA/P/0094/2020], to MARE by FCT/MCTES (UIDB/04292/2020) and ARNET (LA/P/0069/2020)info:eu-repo/semantics/publishedVersio

Beatus Manuscripts under the microscope: The Alcobaça Beatus and the Iberian Cistercian Tradition revisited

SFRH/BPD/70305/2010The Alcobaça Beatus (Lisbon, National Library, Alc. 247) is one of the few extant unillustrated copies of the eighth-century Commentary on the Apocalypse attributed to the Iberian monk Beatus of Liébana. It has traditionally been considered that this Beatus was produced at the Cistercian Portuguese abbey of Santa Maria de Alcobaça and that its model was the Lorvão Beatus (Lisbon, Arquivo Nacional da Torre do Tombo, Ordem de Cister, Mosteiro de Santa Maria de Lorvão, Liv. 44). This article provides the first in-depth examination of the Alcobaça Beatus, carried out by a multidisciplinary team using combined methods from the natural and human sciences. The technical data provided by the analysis of the decoration, molecular palette and bookbinding support the theory of its production at the scriptorium of the Portuguese monastery of Alcobaça, whereas the analysis of the textual structure and content reveals that the Alcobaça Beatus and the Lorvão Beatus show a different sequence of texts and that the Alcobaça copy contains later notes that evidence its use in the monastic reading practice, especially the liturgical readings of the Divine Office. This set of results turns this manuscript, which had received minimal scholarly attention to date, into a significant case study since it reveals itself as the basis to further investigate the corpus of extant Beatus copies and question the importance of such a work within the Cistercian order, thus provoking new questions within the debate on Cistercians and their identity around the year 1200.authorsversionpublishe

Espécies florestais nativas e exóticas: comportamento silvicultural no planalto do Tapajós - Pará.

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