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1.
Sci Total Environ ; 663: 901-914, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30738269

RESUMO

The Mar Menor is the largest lagoon along the Spanish Mediterranean coast. It suffers from eutrophication and algal blooms associated with intensive agricultural activities and urban pressure in the surrounding Campo de Cartagena plain. A balanced discharge of groundwater, carrier of algal nutrients such as nitrate, is essential to ensure the integrity of the coastal lagoon and the availability of groundwater resources inland. We here present a 3D hydrogeological model of the unconfined Quaternary aquifer that discharges into the lagoon. The model couples both surface water balance and groundwater dynamics and has been calibrated to available data in the period 2000-2016. The calibrated model allows understanding of the current state of the aquifer and its link to the lagoon. The potential discharge has been quantified in both space and time and falls between 69.5 and 84.9 hm3/yr during dry and wet periods, respectively (with values of nitrate discharge of 11.4-11.8 Mkg/yr in the absence of aquifer sink terms, e.g., leakage to deeper aquifers and pumping from groundwater wells). The predictive capabilities of the calibrated model can be used to test the impact of different integrated management scenarios on the surface-groundwater dynamics of the catchment. Three plausible management scenarios are proposed that include localized and distributed groundwater pumping (drains and groundwater wells, respectively). Results show the effectiveness of the scenarios in reducing the groundwater and nitrate discharge into the lagoon. The disadvantages of the proposed scenarios, including potential seawater intrusion, need to be balanced with their relative merits for the sustainable development of the region and the survival of the Mar Menor ecosystem. The modelling approach proposed provides a valuable tool for the integrated and holistic management of the Campo de Cartagena-Mar Menor catchment and should be of great interest to similar hydrological systems with high ecological value.

2.
Med. interna Méx ; 34(6): 896-909, nov.-dic. 2018. tab, graf
Artigo em Espanhol | LILACS-Express | ID: biblio-990160

RESUMO

Resumen: El diagnóstico de un tumor primario desconocido suele ser difícil por su comportamiento clínico-patológico, su clínica emerge tardíamente de tal manera que la integración de un protocolo diagnóstico a partir de un síntoma o hallazgo clínico inespecífico condiciona el retraso de su abordaje. Las características propias de este tumor le confieren las herramientas mínimas necesarias para abandonar tempranamente su nicho de origen, diseminándose y alojándose distante al mismo, es decir, una metástasis temprana. El desarrollo de técnicas moleculares que sobrepasan la patología clásica ha sido una herramienta invaluable para su clasificación, teniendo la intención absoluta de separar los potencialmente sensibles a un tratamiento oncológico de los que no lo son. Sin rasgos distintivos que te permitan suponerlo, ante un clínico avezado la sospecha inicial de esta entidad es la mejor herramienta diagnóstica.


Abstract: The diagnosis of an unknown primary tumor is usually difficult due to its clinical-pathological behavior; its clinical manifestation is delayed so that the integration of a diagnostic protocol from a symptom or nonspecific clinical finding determines the delay of its approach. The characteristics of this tumor give it the minimum necessary tools to leave its niche of origin early, disseminating and staying distant from it, that is, an early metastasis. The development of molecular techniques that surpass the classic pathology has been an invaluable tool for its classification, having an absolute intention to separate those potentially sensitive to oncological treatment from those that are not. Without distinctive features that allow supposing it, before a seasoned clinician the initial suspicion of this entity is the best diagnostic tool.

3.
Sci Total Environ ; 630: 878-888, 2018 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-29499543

RESUMO

Paleolimnological studies in western South America, where meteorological stations are scarce, are critical to obtain more realistic and reliable regional reconstructions of past climate and environmental changes, including vegetation and water budget variability. However, climate and environmental geochemical indicators must be tested before they can be applied with confidence. Here we present a survey of lacustrine surface sediment (core top, 0 to ~1cm) biogeochemical proxies (total organic carbon [TOC], total nitrogen [TN], carbon/nitrogen ratio [C/N ratio] and bulk organic δ13C and total δ15N) from a suite of 72 lakes spanning the transition from a Mediterranean climate with a patchwork of cultivated vegetation, pastureland, and conifers in central Chile to a rainy temperate climate dominated by broadleaf deciduous and evergreen forest further south. Sedimentary data are compared to the latitudinal and orographic climatic trends of the region based on the climatology (precipitation and temperature) produced with Climate Forecast System Reanalysis (CFSR) data and the modern Southern Hemisphere Westerly Winds (SWW) location. The geochemical data show inflection points at ~42°S latitude and ~1500m elevation that are likely related to the northern limit of influence of the SWW and elevation of the snow line, respectively. Overall the organic proxies were able to mimic climatic trends (Mean Annual Precipitation [MAP] and temperature [MAT]), indicating that they are a useful tool to be included in paleoclimatological reconstruction of the region.

4.
Mar Pollut Bull ; 126: 389-395, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29421116

RESUMO

Surface water samples from the environmental continuum spanning rivers (Petrohue, Cochamo, Puelo), fjord (Reloncaví), and the inner sea of Chiloé in Chilean Patagonia were analyzed to estimate concentration and distribution of dissolved Organochlorine pesticides (OCPs). High concentrations of HCHs, DDTs and endosulfan found in surface waters from rivers suggest that rivers are the major source of dissolved OCPs to coastal marine ecosystems. We interpret variations in the distribution and concentration as an apparent oscillation between rain and snow-scavenging processes that might determine the type of OCPs that can be preferentially deposited on mountains, glaciers, rivers, estuaries, and finally transferred to the marine realm. Predominance of α-HCH, γ-HCH, p,p'-DDE and α-endosulfan compounds suggest that the main deposition mechanism of OCPs to the Chilean Patagonia is rain scavenging. Snow and rain can be additional sources of OCPs that must be considered for future studies in fjord systems in Chilean Patagonia.


Assuntos
Endossulfano/análise , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Poluentes Químicos da Água/análise , Chile , Monitoramento Ambiental , Estuários , Chuva , Rios , Neve
5.
Mar Pollut Bull ; 95(1): 480-3, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25963572

RESUMO

PBDEs (10 congeners) were analyzed using GC-MS in superficial sediments and organisms of the Concepción Bay after the 2010 Tsunami. From all congeners analyzed PBDE-47, -99, -100 and -209 were the most frequently detected. Concentrations (ngg(-1) d.w.) in sediments for ΣPBDE-47, -99, -100 were low (0.02-0.09). However, PBDE-209 showed significantly higher values ∼20ngg(-1) d.w. This result were ∼10 times lower than those reported in a previous study of the 2010 Tsunami. The high result might be influenced by the massive urban debris dragged by the 2010 Tsunami. In organisms, concentrations of PBDE-47, -99, -100 (∼0.4ngg(-1) d.w.) were higher than those found in sediments (∼0.04ngg(-1) d.w.). Differences in PBDE pattern were also observed between different levels of the trophic food chain (primary and secondary consumers). This is the first attempt to assess the current status of Concepción Bay after the 2010 Tsunami.


Assuntos
Monitoramento Ambiental , Éteres Difenil Halogenados/análise , Tsunamis , Poluentes Químicos da Água/análise , Baías/química , Chile , Cromatografia Gasosa-Espectrometria de Massas
6.
Proc Natl Acad Sci U S A ; 110(47): 18994-9, 2013 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-24191043

RESUMO

Nitrogen (N) isotope ratios ((15)N/(14)N) provide integrative constraints on the N inventory of the modern ocean. Anaerobic ammonium oxidation (anammox), which converts ammonium and nitrite to dinitrogen gas (N2) and nitrate, is an important fixed N sink in marine ecosystems. We studied the so far unknown N isotope effects of anammox in batch culture experiments. Anammox preferentially removes (14)N from the ammonium pool with an isotope effect of +23.5‰ to +29.1‰, depending on factors controlling reversibility. The N isotope effects during the conversion of nitrite to N2 and nitrate are (i) inverse kinetic N isotope fractionation associated with the oxidation of nitrite to nitrate (-31.1 ± 3.9‰), (ii) normal kinetic N isotope fractionation during the reduction of nitrite to N2 (+16.0 ± 4.5‰), and (iii) an equilibrium N isotope effect between nitrate and nitrite (-60.5 ± 1.0‰), induced when anammox is exposed to environmental stress, leading to the superposition of N isotope exchange effects upon kinetic N isotope fractionation. Our findings indicate that anammox may be responsible for the unresolved large N isotope offsets between nitrate and nitrite in oceanic oxygen minimum zones. Irrespective of the extent of N isotope exchange between nitrate and nitrite, N removed from the combined nitrite and nitrate (NOx) pool is depleted in (15)N relative to NOx. This net N isotope effect by anammox is superimposed on the N isotope fractionation by the co-occurring reduction of nitrate to nitrite in suboxic waters, possibly enhancing the overall N isotope effect for N loss from oxygen minimum zones.


Assuntos
Compostos de Amônio/metabolismo , Bactérias Anaeróbias/metabolismo , Isótopos de Nitrogênio/metabolismo , Água do Mar/análise , Cinética , Modelos Biológicos , Oceanos e Mares , Água do Mar/microbiologia
7.
Proc Natl Acad Sci U S A ; 110(45): 18098-103, 2013 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-24145422

RESUMO

The coupling of subseafloor microbial life to oceanographic and atmospheric conditions is poorly understood. We examined diagenetic imprints and lipid biomarkers of past subseafloor microbial activity to evaluate its response to glacial-interglacial cycles in a sedimentary section drilled on the Peruvian shelf (Ocean Drilling Program Leg 201, Site 1229). Multiple and distinct layers of diagenetic barite and dolomite, i.e., minerals that typically form at the sulfate-methane transition (SMT), occur at much shallower burial depth than the present SMT around 30 meters below seafloor. These shallow layers co-occur with peaks of (13)C-depleted archaeol, a molecular fossil of anaerobic methane-oxidizing Archaea. Present-day, non-steady state distributions of dissolved sulfate also suggest that the SMT is highly sensitive to variations in organic carbon flux to the surface shelf sediments that may lead to shoaling of the SMT. Reaction-transport modeling substantiates our hypothesis that shallow SMTs occur in response to cyclic sediment deposition with a high organic carbon flux during interglacials and a low organic carbon flux during glacial stages. Long diffusion distances expectedly dampen the response of deeply buried microbial communities to changes in sediment deposition and other oceanographic drivers over relatively short geological time scales, e.g., glacial-interglacial periods. However, our study demonstrates how dynamically sediment biogeochemistry of the Peru Margin has responded to glacial-interglacial change and how these changes are now preserved in the geological record. Such changes in subsurface biogeochemical zonation need to be taken into account to assess the role of the subseafloor biosphere in global element and redox cycling.


Assuntos
Sedimentos Geológicos/química , Fenômenos Geológicos , Metano/análise , Modelos Químicos , Oceanografia/métodos , Sulfato de Bário/análise , Biomarcadores/análise , Carbonato de Cálcio/análise , Isótopos de Carbono/análise , Lipídeos/análise , Magnésio/análise , Metano/metabolismo , Oxirredução , Oceano Pacífico , Peru , Fatores de Tempo
8.
PLoS One ; 8(8): e68661, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23990875

RESUMO

In Eastern Boundary Upwelling Systems nutrient-rich waters are transported to the ocean surface, fuelling high photoautotrophic primary production. Subsequent heterotrophic decomposition of the produced biomass increases the oxygen-depletion at intermediate water depths, which can result in the formation of oxygen minimum zones (OMZ). OMZs can sporadically accumulate hydrogen sulfide (H2S), which is toxic to most multicellular organisms and has been implicated in massive fish kills. During a cruise to the OMZ off Peru in January 2009 we found a sulfidic plume in continental shelf waters, covering an area >5500 km(2), which contained ∼2.2×10(4) tons of H2S. This was the first time that H2S was measured in the Peruvian OMZ and with ∼440 km(3) the largest plume ever reported for oceanic waters. We assessed the phylogenetic and functional diversity of the inhabiting microbial community by high-throughput sequencing of DNA and RNA, while its metabolic activity was determined with rate measurements of carbon fixation and nitrogen transformation processes. The waters were dominated by several distinct γ-, δ- and ε-proteobacterial taxa associated with either sulfur oxidation or sulfate reduction. Our results suggest that these chemolithoautotrophic bacteria utilized several oxidants (oxygen, nitrate, nitrite, nitric oxide and nitrous oxide) to detoxify the sulfidic waters well below the oxic surface. The chemolithoautotrophic activity at our sampling site led to high rates of dark carbon fixation. Assuming that these chemolithoautotrophic rates were maintained throughout the sulfidic waters, they could be representing as much as ∼30% of the photoautotrophic carbon fixation. Postulated changes such as eutrophication and global warming, which lead to an expansion and intensification of OMZs, might also increase the frequency of sulfidic waters. We suggest that the chemolithoautotrophically fixed carbon may be involved in a negative feedback loop that could fuel further sulfate reduction and potentially stabilize the sulfidic OMZ waters.


Assuntos
Bactérias/genética , Crescimento Quimioautotrófico/fisiologia , Sulfeto de Hidrogênio/química , Oxigênio/química , Água do Mar/química , Bactérias/isolamento & purificação , Bactérias/metabolismo , Biomassa , Ciclo do Carbono , Dióxido de Carbono/química , Análise por Conglomerados , Coloides/química , Ecossistema , Citometria de Fluxo/métodos , Genoma Bacteriano , Nitrogênio/química , Oceano Pacífico , Peru , Filogenia , Análise de Sequência de DNA , Análise de Sequência de RNA , Sulfetos/química , Microbiologia da Água
9.
Mar Pollut Bull ; 73(1): 154-60, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23773949

RESUMO

A simple and rapid method for the detection and extraction of oxolinic acid, flumequine, florfenicol and oxytetracycline from marine sediments was developed and validated. The analytes were extracted from the marine sediment using a solution of oxalic acid diluted in methanol with sonication before detection by HPLC using a diode-array detector (florfenicol and oxytetracycline) and fluorescence (oxolinic acid and flumequine). The quantification limits (QL) were 100 ng/g for oxytetracycline and florfenicol and 5 ng/g for oxolinic acid and flumequine. The coefficients of variation of the repeatability and intermediate precision were less than 10% in all of the analytes. The calibration curves were linear between 50 and 500 ng/ml for oxytetracycline and florfenicol and 1 and 20 ng/ml for oxolinic acid and flumequine. The recuperation rate for the analytes was above 86%.


Assuntos
Fracionamento Químico/métodos , Fluoroquinolonas/análise , Sedimentos Geológicos/química , Ácido Oxolínico/análise , Oxitetraciclina/análise , Tianfenicol/análogos & derivados , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Tianfenicol/análise
10.
Plant Cell Environ ; 35(6): 1026-39, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22146000

RESUMO

We investigated whether stand structure modulates the long-term physiological performance and growth of Pinus halepensis Mill. in a semiarid Mediterranean ecosystem. Tree radial growth and carbon and oxygen stable isotope composition of latewood (δ(13)C(LW) and δ(18)O(LW), respectively) from 1967 to 2007 were measured in P. halepensis trees from two sharply contrasting stand types: open woodlands with widely scattered trees versus dense afforested stands. In both stand types, tree radial growth, δ(13)C(LW) and δ(18)O(LW) were strongly correlated with annual rainfall, thus indicating that tree performance in this semiarid environment is largely determined by inter-annual changes in water availability. However, trees in dense afforested stands showed consistently higher δ(18)O(LW) and similar δ(13)C(LW) values compared with those in neighbouring open woodlands, indicating lower stomatal conductance and photosynthesis rates in the former, but little difference in water use efficiency between stand types. Trees in dense afforested stands were more water stressed and showed lower radial growth, overall suggesting greater vulnerability to drought and climate aridification compared with trees in open woodlands. In this semiarid ecosystem, the negative impacts of intense inter-tree competition for water on P. halepensis performance clearly outweigh potential benefits derived from enhanced infiltration and reduced run-off losses in dense afforested stands.


Assuntos
Clima , Secas , Ecossistema , Pinus/crescimento & desenvolvimento , Pinus/fisiologia , Isótopos de Carbono/análise , Região do Mediterrâneo , Isótopos de Oxigênio/análise , Chuva , Espanha , Árvores/crescimento & desenvolvimento , Árvores/fisiologia , Água/fisiologia
11.
Vaccine ; 29(15): 2810-20, 2011 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-21320542

RESUMO

Sea lice (Copepoda, Caligidae) are the most widely distributed marine pathogens in the salmon industry in the last 30 years. Caligus rogercresseyi is the most important species affecting Chile's salmon industry. Vaccines against caligid copepods have the potential to be a cost-effective means of controlling the infestation and avoid many of the disadvantages of medicine treatments. However, research in the development of such vaccines has begun only recently and approaches used thus far have met with little or no success. In the present study, we characterized a novel gene (denoted as my32) from C. rogercresseyi which has the highest identity with the Lepeophtheirus salmonis gene akirin-2. To assess the function of the gene an RNA interference experiment was developed and a reduction in the number of ectoparasites on fish in the my32-dsRNA treated group was observed. The recombinant my32 protein was used in a vaccination-challenge trial to evaluate its ability to protect against sea lice infestations. A significant reduction in the number of parasites per fish was observed at 24 days post-challenge. These results, together with the delay observed in the development of parasites from the vaccinated group suggest that the major effect of immunization was on the second parasite generation. The results of these experiments suggest that the my32 protein may be a promising target for vaccine development to control sea lice infestations in fish.


Assuntos
Copépodes/genética , Copépodes/parasitologia , Ectoparasitoses/veterinária , Doenças dos Peixes/prevenção & controle , Doenças Parasitárias em Animais/prevenção & controle , Vacinação/métodos , Animais , Copépodes/imunologia , Ectoparasitoses/imunologia , Ectoparasitoses/prevenção & controle , Doenças dos Peixes/imunologia , Inativação Gênica , Dados de Sequência Molecular , Doenças Parasitárias em Animais/imunologia , Análise de Sequência de DNA , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
12.
PLoS One ; 6(12): e29299, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22216239

RESUMO

Nutrient measurements indicate that 30-50% of the total nitrogen (N) loss in the ocean occurs in oxygen minimum zones (OMZs). This pelagic N-removal takes place within only ~0.1% of the ocean volume, hence moderate variations in the extent of OMZs due to global warming may have a large impact on the global N-cycle. We examined the effect of oxygen (O(2)) on anammox, NH(3) oxidation and NO(3)(-) reduction in (15)N-labeling experiments with varying O(2) concentrations (0-25 µmol L(-1)) in the Namibian and Peruvian OMZs. Our results show that O(2) is a major controlling factor for anammox activity in OMZ waters. Based on our O(2) assays we estimate the upper limit for anammox to be ~20 µmol L(-1). In contrast, NH(3) oxidation to NO(2)(-) and NO(3)(-) reduction to NO(2)(-) as the main NH(4)(+) and NO(2)(-) sources for anammox were only moderately affected by changing O(2) concentrations. Intriguingly, aerobic NH(3) oxidation was active at non-detectable concentrations of O(2), while anaerobic NO(3)(-) reduction was fully active up to at least 25 µmol L(-1) O(2). Hence, aerobic and anaerobic N-cycle pathways in OMZs can co-occur over a larger range of O(2) concentrations than previously assumed. The zone where N-loss can occur is primarily controlled by the O(2)-sensitivity of anammox itself, and not by any effects of O(2) on the tightly coupled pathways of aerobic NH(3) oxidation and NO(3)(-) reduction. With anammox bacteria in the marine environment being active at O(2) levels ~20 times higher than those known to inhibit their cultured counterparts, the oceanic volume potentially acting as a N-sink increases tenfold. The predicted expansion of OMZs may enlarge this volume even further. Our study provides the first robust estimates of O(2) sensitivities for processes directly and indirectly connected with N-loss. These are essential to assess the effects of ocean de-oxygenation on oceanic N-cycling.


Assuntos
Nitrogênio/química , Oxigênio/química , Compostos de Amônio Quaternário/química , Oxirredução
13.
Environ Monit Assess ; 90(1-3): 89-99, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15887365

RESUMO

Liquid wastes from the fish meal and oil processing industries produce serious environmental impacts in coastal embayments on the coasts of Chile and Peru. This article presents an analysis of an environmental monitoring program at Lota Bay, a shallow coastal indentation in central Chile (37 degrees S) exposed to industrial fishing activity. The study of the environmental impact produced by waste effluents permitted making an evaluation of the bay's capacity for seasonal recovery from this impact. Seasonal cruises were carried out during 1994 and in 1996, 1997, and 1998. Variables analyzed included salinity, temperature, dissolved oxygen, ammonium concentration and surface oil and grease. The hydrographic regime of Lota Bay follows a seasonal pattern, where, typical of most SE pacific embayments, waters from subsuperficial oxygen minimum zones moved into the bay. The percentages of dissolved oxygen were critical in the area of organic waste discharge. The impact of wastewater is related to the type and status of the fishery, including: (i) overloads of plant production lines, (ii) maintenance and cleaning of installations, and (iii) degree of shipboard fishing conservation. Major alterations were observed in summer, when the highest discharge of organic load occurred. In winter, an improvement in the re-aeration conditions reduced the impact. Remedial measures implemented beginning in 1997 arose from the monitoring program and had to be separated into two recovery factors including (a) internal management of plants and (b) treatment of plant effluents.


Assuntos
Monitoramento Ambiental , Pesqueiros , Resíduos Industriais , Eliminação de Resíduos Líquidos , Poluentes da Água/análise , Animais , Chile , Óleos Industriais/análise , Oceanos e Mares , Oxigênio/análise , Peru , Compostos de Amônio Quaternário/análise , Estações do Ano , Cloreto de Sódio/análise , Temperatura Ambiente , Gerenciamento de Resíduos
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