41 research outputs found
Biomonitoring and risk assessment tools to manage impact of diesel oil in tropical coastal habitats
The papers III and IV of this thesis are not available in Munin.
Paper III: Sardi, A. E., Renaud, P. E., Morais, G. C., Martins, C. C., Lana, P. C., Camus, L.: “Effects of an in situ diesel oil spill on oxidative stress in the clam Anomalocardia flexuosa”. (Manuscript). Published version available in Environmental Pollution 2017, 230:891-901.
Paper IV: Sardi, A. E., Augustine, S., Morais, G. C., Olsen G. H., Camus, L.: “Exploring species sensitivity to a model hydrocarbon, 2–Methylnaphthalene, using a process–based model”. (Manuscript).The focus of this work is in developing biology–based tools for environmental monitoring
and risk assessment associated with diesel oil contamination in tropical coastal habitats.
Prediction of impacts is generally conducted via environmental monitoring, in which environmental
quality over time and space is assessed by repeated observations. Prediction of risk is included
within the risk assessment process, which is the procedure that estimates the likelihood or the
actual adverse effects caused by anthropogenic activities on ecosystems. During the past decades,
oil production has increased, and so has the risk of oil pollution, either through produced water
discharges, accidents, or other diffuse sources. This risk is notably high in tropical and
subtropical areas, which represent around 60% of total global oil production. Petroleum is composed
of a mixture of various mono– and polycyclic–aromatic hydrocarbons, toxic chemicals consisting of
two or more fused benzene rings. The mode of action of PAHs is classified as narcotic, meaning that
PAHs are expected to penetrate cell membranes and alter the lipid bilayer, ultimately disturbing
the normal function of cells. On average, nearly 85% of the total petrogenic PAH input to the
marine environment origins from petroleum consumption or diffuse sources. Among marine coastal
habitats, tropical and subtropical coastal regions are home to speciose and highly productive
ecosystems. Estuaries are among the most productive of marine ecosystems and are areas with high
economic and ecological importance. Being economic centers for coastal communities that harvest
biotic resources, tropical and subtropical estuarine intertidal environments (i.e. mangroves, salt
marshes, and unvegetated tidal flats) are particularly susceptible to anthropogenic disturbance.
Specifically, chronic diesel oil contamination that leaks from marine vessels poses a real risk to
the species inhabiting the Paranaguá Estuarine System (PES) in southern Brazil, which host the
third largest harbor of Brazil, and receives around 200 ships per month. Oil contamination from
such diffuse sources, is an untraceable chronic source of contamination that can occur anywhere a
ship travels and may have different effects, depending on the physical–chemical characteristics of
the environment into which the oil is released. Therefore, tools for biomonitoring the effects of
short and long–term exposure to diffuse oil contamination are much needed. The general objectives
of this work are to validate the use of antioxidant biomarkers as tools for biomonitoring coastal
estuarine habitats in Brazil, as also to compare the sensitivity and risk assessment metrics from
species distributed from subtropical, temperate and Arctic regions exposed to a toxic PAH.
Biomarkers are defined as measures of exposure or effect expressed at the sub–organism
level (i.e. biochemical, cellular, physiological or behavioral) in taxa under environmental stress.
We proposed the use of antioxidant biomarkers as sub-lethal measures of exposure at the
sub-organism level. Before implementing antioxidant biomarkers in biomonitoring programs, several
conceptual and methodological issues needed to be addressed. Namely, it is important to determine
their basal levels of activity, to select an appropriate sentinel species for their measurement,
and to determine the best group of biomarkers for a multi–biomarker approach. Also, it is necessary
to establish a correlation between the presence of diesel oil contamination and the activity of
selected biomarkers. This work addresses these points, first by conducting a seasonal baseline of
biomarker values, and then by performing experimental manipulations both in the lab and the field.
Because the activity of antioxidant enzymes is involved in cell homeostasis, they are expected to
vary in relation to reproductive cycles, food availability, and environmental drivers. Thus an
initial screening in the activity of 5 different subtropical species was conducted at two seasons
(austral winter and austral summer) at two different locations that have different levels of
organic and PAH contamination. Then, experimental manipulations that tested the correlation between
the antioxidant response and diesel oil exposure were conducted. The first experiment characterized
the antioxidant biomarker response in two common species under laboratory conditions; while in the
second experiment, the antioxidant biomarker response in the clam species Anomalocardia flexuosa
was evaluated after chronic exposure to diesel oil in situ. The significant changes in the
biomarkers activities following exposure suggested a causal relationship between biomarkers and
diesel oil contamination, with the activities of GST and SOD being the most sensitive to
experimental manipulations. These cause–effect relationships indicate that it is possible to use
these biomarkers as tools in biomonitoring programs at PES. However, it was noticeable that natural
variability is a major confounding source of variation, which in our experiments was handled by
including appropriate control treatments for comparing the response from the experimental treatment
with that from natural conditions. As part of the outcomes of this work, a guiding framework for
selecting biomarkers and testing their causal relationship to contamination and specific
recommendations for designing experiments for biomonitoring purposes are provided. Briefly,
well–designed experiments have a clear hypothesis to test, for which the measurement of
environmental parameters at an adequate sampling intensity is feasible,
given financial and logistic constraints. The statistical power of the design must be
considered before starting sampling and the design should include spatial and temporal
variability. Regarding differences in risk assessment metrics following the exposure to 2–
Methylnaphthalene, our results indicate that No–Effect Concentration (NEC) values — concentration
thresholds use to assess species sensitivity to toxic exposure— were not significantly different
among the studied species and differences among regions were not identified. However, when defining
sensitivity as the time to observe an effect —a metric that includes the NEC and a toxicokinetic
parameter like the elimination rate— differences in sensitivity among regions were detected. In
summary, species from Arctic to subtropical regions have similar NEC thresholds, but the time they
need to reach that threshold varies, and this variation is related to taxonomy and trophic level.
Arctic species had on average shorter times for starting to show an effect, followed by subtropical
and finally temperate species. Our results suggest that assuming that species sensitivities from
Arctic, and temperate regions is sufficiently similar to those from subtropical regions might be
incorrect. We suggest that in in the search for metrics for safeguarding the marine ecosystem,
attention should not be given only to concentration thresholds. Concentration thresholds might be
providing assessors an inaccurate metric for species sensitivity, which
is ultimately underestimating the risk to marine and estuarine ecosystems
Non-pegmatitic beryl related to Carboniferous granitic magmatism, Velasco Range, Pampean Province, NW Argentina
The specialized leuco-monzogranite of the La Chinchilla Stock is a small Carboniferous stock located in the center of the Velasco Range, Pampean Province, La Rioja, Argentina. It is highly evolved and locally F- and Be-bearing, and has the potential for hosting U mineralization. Three different facies can be identified in the granitoid: border, porphyritic and equigranular facies. In all three facies the main minerals are quartz, microcline, plagioclase, biotite, and muscovite. Accessory minerals present in all facies include fluorite, zircon, and apatite. In addition, monazite, rutile, and uraninite occur as accessory minerals in the equigranular facies. Secondary minerals are muscovite, sericite, kaolinite, and opaque minerals. Secondary uranophane occurs in the equigranular and border facies. In localized areas, the equigranular facies contains small, green idiomorphic crystals of beryl (Be3Al2Si6O18) as accessory mineral. One of these beryl crystals was chemically analyzed for major and minor element contents using an electron microprobe and this information, along with fractional crystallization models and comparison with compositions of non-pegmatitic beryl from the literature, were used to understand the degree of evolution of the granitic melt. The chemical formula of beryl from the La Chinchilla Stock can be written as: C(Na0.014-0.033, K0.001-0.002, Ca0.001-0.004) T(2)(Be2.978-2.987, Li0.016-0.022) O(Al1.889-1.967, Fe0.045-0.103, Mg0.001-0.007, Mn0.001-0.007) T(1)(Si5.994-6.040O18). The alkali contents are low (Na2O6; FeOt<1.27 wt%). In a longitudinal geochemical profile, Al enrichment is observed at the border while the highest Na content is found in an internal point. In a transversal geochemical profile, the highest concentration of Al is seen in an internal point while Na remains almost invariable. Ferromagnesian elements vary randomly within the crystal. This indicates compositional changes in the magma for Al, ferromagnesian elements, and Na. The FeOt content of the analyzed beryl is within the compositional range of other disseminated beryl from granitoids but slightly higher than that of beryl from hydrothermal veins and greisens. It contains similar to slightly lower amounts of FeOt, MgO, and Na2O than beryl from medium to little evolved granitic pegmatites. Overall, the composition of beryl in the La Chinchilla Stock is quite similar to that from medium to poorly evolved granitic pegmatites of the nearby Velasco Pegmatite District. The formation of beryl in the La Chinchilla Stock is attributed to precipitation from a F-bearing, highly fractionated, Al- and Si-rich melt saturated in BeO. A fractional crystallization model using Rb and Ba suggests that the beryl-hosting rock crystallized from the parent melt after extreme fractionation and 75% crystallization. The occurrence of beryl as a magmatic accessory mineral in the equigranular facies of the La Chinchilla Stock is indicative of a very high degree of fractionation of the parental magma
Cuerpos universitarios, formación docente y ESI en el acontecimiento pandémico
La cruel pandemia que empezamos a transitar a principios del año 2020 en nuestro país transformó los modos en que, hasta ese momento, habíamos imaginado en que podían desarrollarse las prácticas de enseñanza y, específicamente, la formación docente. De manera inesperada, de una semana para la otra, como docentes universitarixs tuvimos que virtualizar las clases que estaban pensadas para desarrollarse de manera presencial y empezamos a transitar una experiencia excepcional y novedosa donde ya no nos encontrábamos en el espacio de la facultad y compartíamos intercambios presenciales entre estudiantes y docentes, entre compañerxs de cátedra, sino, por el contrario, todo se desarrollaba mediado por una pantalla.Centro Interdisciplinario de Investigaciones en GéneroFacultad de Humanidades y Ciencias de la Educació
Development of monoclonal antibodies against prM of Dengue virus 4
Introduction: dengue is a most common mosquito-borne viral disease in the Americas and tropical countries. Objective: in this work, mice were hyperimmunized with DENV 4 antigen to produce monoclonal antibodies (mAbs). Methodology: DENV 4 (GenBank KC806069) was inoculated in C6/36 cell monolayers cultivated in Leibovitz’s 15 medium supplemented with 5% fetal bovine serum and incubated at 28 C. The virus stock was submitted to concentration and ultracentrifugation and stored at -80 C until use (VC DENV 4). Balb/c mice were injected intraperitoneally with 50μg of DENV-4 and successive intraperitoneal injections of 25 μg of VC DENV 4 with Freund’s incomplete adjuvant were performed. The spleen cells were fused to SP2/0 myeloma cells with PEG 1540 and distributed in 96-well microplates with Iscove’s modified medium with Hipoxantina–Aminopterina–Timidina. Hybridoma screening by indirect ELISA showed positive results for six mAbs, and their characterization was performed by Western blotting and Indirect Immunofluorescence (IFI) techniques. Results: the six mAbs showed strong recognition of prM (24/29 kDa), and minor reaction to E protein (66 kDa), E/E protein dimer (105 kDa), and NS1 (49 kDa) protein in two mAbs. The use of mAbs anti-prM as a diagnostic tool using IFI has been demonstrated to detect DENV-4 antigen in infected cells or tissues. Conclusion: DENV 4 generate mAbs with strong reactivity to prM with potential use to confirm the presence of DENV 4 antigen in tissues or infected cells
Patterns of Spatial Variation of Assemblages Associated with Intertidal Rocky Shores: A Global Perspective
Assemblages associated with intertidal rocky shores were examined for large scale distribution patterns with specific emphasis on identifying latitudinal trends of species richness and taxonomic distinctiveness. Seventy-two sites distributed around the globe were evaluated following the standardized sampling protocol of the Census of Marine Life NaGISA project (www.nagisa.coml.org). There were no clear patterns of standardized estimators of species richness along latitudinal gradients or among Large Marine Ecosystems (LMEs); however, a strong latitudinal gradient in taxonomic composition (i.e., proportion of different taxonomic groups in a given sample) was observed. Environmental variables related to natural influences were strongly related to the distribution patterns of the assemblages on the LME scale, particularly photoperiod, sea surface temperature (SST) and rainfall. In contrast, no environmental variables directly associated with human influences (with the exception of the inorganic pollution index) were related to assemblage patterns among LMEs. Correlations of the natural assemblages with either latitudinal gradients or environmental variables were equally strong suggesting that neither neutral models nor models based solely on environmental variables sufficiently explain spatial variation of these assemblages at a global scale. Despite the data shortcomings in this study (e.g., unbalanced sample distribution), we show the importance of generating biological global databases for the use in large-scale diversity comparisons of rocky intertidal assemblages to stimulate continued sampling and analyses
Pegmatitic beryl as indicator of melt evolution: example from the Velasco district, Pampeana Pegmatite Province, Argentina, and review of worldwide occurrences
Rare-element class, beryl type, beryl-columbite-phosphate subtype pegmatites of the Velasco district from the Pampeana Pegmatite Province, Argentina, contain varieties of green, yellow, and aquamarine beryl. The major and trace element chemistry and dimensions of the unit cell parameters of beryl from ten pegmatites from the Velasco district were used to identify differences among beryl types, determine chromophore elements, and determine the relative degree of fractionation of the pegmatites. Concentrations of Rb, Li, Cs, and Na in all beryls analyzed are among the lowest measured in pegmatitic beryl of similar colors worldwide. Within and among individual pegmatites, an increase in Li and Cs contents and decrease in Na/Li ratios in the order green beryl → yellow beryl → aquamarine suggest that green beryl formed in the early stages of crystallization of the pegmatites while yellow beryl and aquamarine formed from more evolved fluids in the late stages of crystallization. The chemical variations from green beryl to yellow beryl to aquamarine reflect crystallization during melt fractionation and/or crystallization of Fe-Mn phosphate minerals. Beryl from the El Bolsoncito and El Principio pegmatites, with the highest Li and Cs and some of the lowest Fe + Mg contents in the studied beryl, reflects the highest degree of evolution among the Velasco pegmatites. Within individual pegmatites Cr contents in beryl decrease in the order green beryl → yellow beryl, and green beryl → aquamarine, consistent with Cr being a chromophore element for green beryl. Niobium contents increase from green to yellow beryl, and from green beryl to aquamarine, indicating that Nb tends to concentrate in late forms of beryl. The absence of a systematic change in the size of unit cell parameters a and c with varying compositions and the small size of the c parameter reflect the extremely limited incorporation of Li, Na, and Cs in the mineral. A compilation of beryl compositions worldwide shows the highest degree of fractionation for the Tanco, Koktokay No. 3, Minas Gerais, Kaatiala, Namivo, Bikita, Czech Republic, and Greer Lake pegmatites.Fil: Sardi, Fernando Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto Superior de Correlación Geológica; ArgentinaFil: Heimann, Adriana. East Carolina University; Estados Unido
Local geology and accesory mineralogy of beryl-pegmatites and granitic rocks of the Velasco district, pampeana pegmatite province, northwestern Argentina.
Se realiza un estudio de la estructura interna de las pegmatitas y del contenido mineralógico de las pegmatitas y rocas asociadas del Distrito Velasco de la Provincia Pegmatítica Pampeana, Argentina. Las pegmatitas pertenecen a la clase de Elementos Raros, tipo berilo, subtipo berilo-columbita-fosfato, y tienen relación espacial y genética con los granitos post-orogénicos de edad Carbonífera inferior, los que presentan características de granito tipo-A. Las pegmatitas tienen formas elipsoidales, alargadas y semi-circulares, siendo la relación del eje mayor/eje menor variable, entre aproximadamente 1 y 4,7. El rumbo del eje mayor de las pegmatitas tiene rumbo variable para cada pegmatita. La zonación es simple, desde la parte externa hacia el interior de las pegmatitas, se observa una zona de borde de naturaleza netamente granítica, con escasa a nula biotita; una zona intermedia, con sub-zonas de acuerdo al mineral de feldespato predominante; y finalmente, un núcleo de cuarzo. El microclino gráfico y pertítico de la zona intermedia presenta en algunas pegmatitas un reemplazamiento por plagioclasa. La mineralogía accesoria de los granitos parentales incluye: biotita, muscovita, apatita, fluorita, circón, ilmenita, magnetita, uraninita y xenotima; en el borde de las pegmatitas, muscovita, biotita, apatita, circón, monacita, fluorita, columbita-tantalita, ilmenita, rutilo, pirita, calcopirita, thorita; y en la zona intermedia, muscovita, biotita, berilo, apatita, triplita, turmalina, granate.A study of the internal structure of the pegmatites and its mineralogy and associated granitic rocks from the Velasco district of the Pampean Pegmatite Province (Argentina) is presented. The pegmatites belong to the Rare Elements class, beryl type, beryl-columbite-phosphate subtype. They have spatial and genetic relationship to Carboniferous A-type granites. The pegmatites have ellipsoidal, elongated and semi-circular morphologies, being the major axis/minor axis ratio between 1 and 4.7. The direction of the major axis is variable for each pegmatite. The zoning is simple. From the outside inwards, the following internal zones could be recognized in the pegmatites: border zone, intermediate zone and quartz core. The graphic and pertitic microcline of the intermediate zone is replaced by plagioclase in some pegmatites. The accessory mineralogy is: for the parental granites, biotite, muscovite, apatite, fluorite, zircon, ilmenite, magnetite, uraninite and xenotime; for the border of the pegmatites, muscovite, biotite, apatite, zircon, monazite, fluorite, columbite-tantalite, ilmenite, rutile, pyrite, chalcopyrite, thorite; and for the intermediate zone, muscovite, biotite, beryl, apatite, triplite, tourmaline, garnet.Fil: Sardi, Fernando Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; ArgentinaFil: Heimann, Adriana. East Carolina University; Estados UnidosFil: Sarapura Martinez, Janet Ivanna. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentin
Baseline levels of oxidative stress biomarkers in species from a subtropical estuarine system (Paranaguá Bay, southern Brazil)
Offshore petroleum exploration has increased the risks of oil spills in coastal tropical and subtropical habitats. Monitoring tools are needed to assess and protect environmental health. We determined baseline values of antioxidant biomarkers (CAT, SOD, GPx, GST, MDA) for five ecologically relevant species in a subtropical system in southern Brazil. Regional baseline levels are compared with literature data as a basis to eventually test their efficacy as post-spill monitoring tools. Differences in the antioxidant response among species, contamination, and seasons were tested using univariate and multivariate analyses. The bivalves Anomalocardia flexuosa and Crassostrea rhizophorae and the catfish Genidens genidens emerge as suitable sentinel species. Seasonality is the main factor accounting for biomarkers variability, and not background background contamination level. However, interactions between season and contamination level are also significant, indicating that biomarkers respond to complex environmental settings, a fact that needs to be fully understood for designing proper monitoring programs
Non-pegmatitic beryl related to Carboniferous granitic magmatism, Velasco Range, Pampean Province, NW Argentina
The specialized leuco-monzogranite of the La Chinchilla Stock is a small Carboniferous stock located in the center of the Velasco Range, Pampean Province, La Rioja, Argentina. It is highly evolved and locally F- and Be-bearing, and has the potential for hosting U mineralization. Three different facies can be identified in the granitoid: border, porphyritic and equigranular facies. In all three facies the main minerals are quartz, microcline, plagioclase, biotite, and muscovite. Accessory minerals present in all facies include fluorite, zircon, and apatite. In addition, monazite, rutile, and uraninite occur as accessory minerals in the equigranular facies. Secondary minerals are muscovite, sericite, kaolinite, and opaque minerals. Secondary uranophane occurs in the equigranular and border facies. In localized areas, the equigranular facies contains small, green idiomorphic crystals of beryl (Be3Al2Si6O18) as accessory mineral. One of these beryl crystals was chemically analyzed for major and minor element contents using an electron microprobe and this information, along with fractional crystallization models and comparison with compositions of non-pegmatitic beryl from the literature, were used to understand the degree of evolution of the granitic melt. The chemical formula of beryl from the La Chinchilla Stock can be written as: C(Na0.014-0.033, K0.001-0.002, Ca0.001-0.004) T(2)(Be2.978-2.987, Li0.016-0.022) O(Al1.889-1.967, Fe0.045-0.103, Mg0.001-0.007, Mn0.001-0.007) T(1)(Si5.994-6.040O18). The alkali contents are low (Na2O6; FeOt<1.27 wt%). In a longitudinal geochemical profile, Al enrichment is observed at the border while the highest Na content is found in an internal point. In a transversal geochemical profile, the highest concentration of Al is seen in an internal point while Na remains almost invariable. Ferromagnesian elements vary randomly within the crystal. This indicates compositional changes in the magma for Al, ferromagnesian elements, and Na. The FeOt content of the analyzed beryl is within the compositional range of other disseminated beryl from granitoids but slightly higher than that of beryl from hydrothermal veins and greisens. It contains similar to slightly lower amounts of FeOt, MgO, and Na2O than beryl from medium to little evolved granitic pegmatites. Overall, the composition of beryl in the La Chinchilla Stock is quite similar to that from medium to poorly evolved granitic pegmatites of the nearby Velasco Pegmatite District. The formation of beryl in the La Chinchilla Stock is attributed to precipitation from a F-bearing, highly fractionated, Al- and Si-rich melt saturated in BeO. A fractional crystallization model using Rb and Ba suggests that the beryl-hosting rock crystallized from the parent melt after extreme fractionation and 75% crystallization. The occurrence of beryl as a magmatic accessory mineral in the equigranular facies of the La Chinchilla Stock is indicative of a very high degree of fractionation of the parental magma
Temperature and feeding frequency impact the survival, growth, and metamorphosis success of Solea solea larvae.
Human-induced climate change impacts the oceans, increasing their temperature, changing their circulation and chemical properties, and affecting marine ecosystems. Like most marine species, sole has a biphasic life cycle, where one planktonic larval stage and juvenile/adult stages occur in a different ecological niche. The year-class strength, usually quantified by the end of the larvae stage, is crucial for explaining the species' recruitment. We implemented an experimental system for rearing larvae under laboratory conditions and experimentally investigated the effects of temperature and feeding frequencies on survival, development (growth), and metamorphosis success of S. solea larvae. Specific questions addressed in this work include: what are the effects of feeding regimes on larvae development? How does temperature impact larvae development? Our results highlight that survival depends on the first feeding, that the onset of metamorphosis varies according to rearing temperature and that poorly fed larvae take significantly longer to start (if they do) metamorphosing. Moreover, larvae reared at the higher temperature (a +4°C scenario) showed a higher incidence in metamorphosis defects. We discuss the implications of our results in an ecological context, notably in terms of recruitment and settlement. Understanding the processes that regulate the abundance of wild populations is of primary importance, especially if these populations are living resources exploited by humans