10 research outputs found

    Chemical and stable isotope composition (18O/16O, 2H/1H) of formation waters from the Carabobo Oilfield, Venezuela

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    In this short note, we present the first data on stable isotope composition of the oilfield waters from Carabobo area of the Faja Petrolífera del Orinoco “Hugo Chávez” (Orinoco Oil Belt). From a chemical point of view, the formation waters show a main Na-Cl level (TDS up to 30g/l) with a dilution trend toward Na-HCO3 composition (down to 1g/l). Until now, such a clear net chemical compositional trend was ascribed to a meteoric dilution (fresh/ brackish bicarbonate) of the seawater endmember (the saltiest chloride). The isotope results of this study reveal that the seawater mother water was modified during a high-temperature thrusting event (120–125°C), forming 18O-enriched diagenetic water (up to +4‰), which was diluted in recent times by glacial meltwater and presentday meteoric water. The hypothetical presence of flood by a meteoric paleo-water also offers new hints to explain the low API gravity (<10°API biodegraded, extra heavy oil) and composition of the local crude

    Chemical and stable isotope composition (18O/16O, 2H/1H) of formation waters from the Carabobo Oilfield, Venezuela

    Get PDF
    In this short note, we present the first data on stable isotope composition of the oilfield waters from Carabobo area of the Faja Petrolífera del Orinoco "Hugo Chávez" (Orinoco Oil Belt). From a chemical point of view, the formation waters show a main Na-Cl level (TDS up to 30g/l) with a dilution trend toward Na-HCO3 composition (down to 1g/l). Until now, such a clear net chemical compositional trend was ascribed to a meteoric dilution (fresh/ brackish bicarbonate) of the seawater endmember (the saltiest chloride). The isotope results of this study reveal that the seawater mother water was modified during a high-temperature thrusting event (120-125°C), forming 18O-enriched diagenetic water (up to +4‰), which was diluted in recent times by glacial meltwater and presentday meteoric water. The hypothetical presence of flood by a meteoric paleo-water also offers new hints to explain the low API gravity (<10°API biodegraded, extra heavy oil) and composition of the local crude

    Can the intake of antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?

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    Background: Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites (Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon), unicellular flagellate protozoans (Trypanosoma) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load. Results: We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general antiparasitic properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests. Conclusions: The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates

    Chemical and stable isotope composition (18O/16O, 2H/1H) of formation waters from the Carabobo Oilfield, Venezuela.

    Get PDF
    In this short note, we present the first data on stable isotope composition of the oilfield waters from Carabobo area of the Faja Petrolífera del Orinoco “Hugo Chávez” (Orinoco Oil Belt). From a chemical point of view, the formation waters show a main Na-Cl level (TDS up to 30g/l) with a dilution trend toward Na-HCO3 composition (down to 1g/l). Until now, such a clear net chemical compositional trend was ascribed to a meteoric dilution (fresh/ brackish bicarbonate) of the seawater endmember (the saltiest chloride). The isotope results of this study reveal that the seawater mother water was modified during a high-temperature thrusting event (120–125°C), forming 18O-enriched diagenetic water (up to +4‰), which was diluted in recent times by glacial meltwater and presentday meteoric water. The hypothetical presence of flood by a meteoric paleo-water also offers new hints to explain the low API gravity (&lt;10°API biodegraded, extra heavy oil) and composition of the local crude

    Chemical and stable isotope composition (18O/16O, 2H/1H) of formation waters from the Carabobo Oilfield, Venezuela

    No full text
    In this short note, we present the first data on stable isotope composition of the oilfield waters from Carabobo area of the Faja Petrolífera del Orinoco "Hugo Chávez" (Orinoco Oil Belt). From a chemical point of view, the formation waters show a main Na-Cl level (TDS up to 30g/l) with a dilution trend toward Na-HCO3 composition (down to 1g/l). Until now, such a clear net chemical compositional trend was ascribed to a meteoric dilution (fresh/ brackish bicarbonate) of the seawater endmember (the saltiest chloride). The isotope results of this study reveal that the seawater mother water was modified during a high-temperature thrusting event (120-125°C), forming 18O-enriched diagenetic water (up to +4‰), which was diluted in recent times by glacial meltwater and presentday meteoric water. The hypothetical presence of flood by a meteoric paleo-water also offers new hints to explain the low API gravity (<10°API biodegraded, extra heavy oil) and composition of the local crude

    Hidatidosis retroperitoneal secundaria a quiste hidatĂ­dico de localizaciĂłn hepĂĄtica

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    La hidatidosis es una enfermedad de distribuciĂłn mundial, producida por un platelminto parĂĄsito del gĂ©nero Echinococcus. El caso que se presenta corresponde a una paciente con una tumoraciĂłn fluctuante en el espacio retroperitoneal lumbar, secundaria a un quiste hepĂĄtico. El diagnĂłstico inicial de certeza fue dado por el hallazgo de ganchos rostelares de protoescĂłlices en el lĂ­quido aspirado de un absceso. Este trabajo describe el cuadro clĂ­nico, el diagnĂłstico y el tratamiento mĂ©dico-quirĂșrgico de esta paciente. Se analiza cĂłmo la elaboraciĂłn de un diagnĂłstico certero requiere de un anĂĄlisis adecuado de los antecedentes epidemiolĂłgicos, las manifestaciones clĂ­nicas, los estudios de imĂĄgenes y las pruebas de laboratorio, ya que el conjunto de estos datos confirman el caso.Retroperitoneal hydatidosis secondary to hepatic hydatid cyst. Hydatid disease is a worldwide zoonosis. It is caused by a parasitic platyhelminth of the genus Echinococcus. We present a patient with a fluctuating lumbar tumor in the retroperitoneal space, secondary to a hepatic cyst. The initial diagnosis was made by identification of rostellar hooks from protoscoleces in the fluid aspirated from the abscess. We herein describe the clinical manifestations, diagnosis and medical and surgical treatment of this unusual case and conclude that the development of an accurate diagnosis requires a proper analysis of the patient’s epidemiological history, clinical manifestations, imaging studies and laboratory tests. A multidisciplinary approach and differential diagnosis is paramount to be able to establish a cause of the disease to deliver appropriate treatment

    Hidatidosis retroperitoneal secundaria a quiste hidatĂ­dico de localizaciĂłn hepĂĄtica Retroperitoneal hydatidosis secondary to hepatic hydatid cyst

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    La hidatidosis es una enfermedad de distribuciĂłn mundial, producida por un platelminto parĂĄsito del gĂ©nero Echinococcus. El caso que se presenta corresponde a una paciente con una tumoraciĂłn fluctuante en el espacio retroperitoneal lumbar, secundaria a un quiste hepĂĄtico. El diagnĂłstico inicial de certeza fue dado por el hallazgo de ganchos rostelares de protoescĂłlices en el lĂ­quido aspirado de un absceso. Este trabajo describe el cuadro clĂ­nico, el diagnĂłstico y el tratamiento mĂ©dico-quirĂșrgico de esta paciente. Se analiza cĂłmo la elaboraciĂłn de un diagnĂłstico certero requiere de un anĂĄlisis adecuado de los antecedentes epidemiolĂłgicos, las manifestaciones clĂ­nicas, los estudios de imĂĄgenes y las pruebas de laboratorio, ya que el conjunto de estos datos confirman el caso.<br>Hydatid disease in a worldwide zoonosis. It is caused by a parasitic platyhelminth of the genus Echinococcus. We present a patient with a fluctuating lumbar tumor in the retroperitoneal space, secondary to a hepatic cyst. The initial diagnosis was made by identification of rostellar hooks from protoscoleces in the fluid aspirated from the abscess. We herein describe the clinical manifestations, diagnosis and medical and surgical treatment of this unusual case and conclude that the development of an accurate diagnosis required a proper analysis of the patient's epidemiological history, clinical manifestations, imaging studies and laboratory tests. A multidisciplinary approach and differential diagnosis is paramount to be able to establish a cause of the disease to deliver appropriate treatment

    Can the intake of antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?

    No full text
    © 2018 The Author(s).Background: Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated t

    Ezetimibe added to statin therapy after acute coronary syndromes

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    BACKGROUND: Statin therapy reduces low-density lipoprotein (LDL) cholesterol levels and the risk of cardiovascular events, but whether the addition of ezetimibe, a nonstatin drug that reduces intestinal cholesterol absorption, can reduce the rate of cardiovascular events further is not known. METHODS: We conducted a double-blind, randomized trial involving 18,144 patients who had been hospitalized for an acute coronary syndrome within the preceding 10 days and had LDL cholesterol levels of 50 to 100 mg per deciliter (1.3 to 2.6 mmol per liter) if they were receiving lipid-lowering therapy or 50 to 125 mg per deciliter (1.3 to 3.2 mmol per liter) if they were not receiving lipid-lowering therapy. The combination of simvastatin (40 mg) and ezetimibe (10 mg) (simvastatin-ezetimibe) was compared with simvastatin (40 mg) and placebo (simvastatin monotherapy). The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, unstable angina requiring rehospitalization, coronary revascularization ( 6530 days after randomization), or nonfatal stroke. The median follow-up was 6 years. RESULTS: The median time-weighted average LDL cholesterol level during the study was 53.7 mg per deciliter (1.4 mmol per liter) in the simvastatin-ezetimibe group, as compared with 69.5 mg per deciliter (1.8 mmol per liter) in the simvastatin-monotherapy group (P<0.001). The Kaplan-Meier event rate for the primary end point at 7 years was 32.7% in the simvastatin-ezetimibe group, as compared with 34.7% in the simvastatin-monotherapy group (absolute risk difference, 2.0 percentage points; hazard ratio, 0.936; 95% confidence interval, 0.89 to 0.99; P = 0.016). Rates of pre-specified muscle, gallbladder, and hepatic adverse effects and cancer were similar in the two groups. CONCLUSIONS: When added to statin therapy, ezetimibe resulted in incremental lowering of LDL cholesterol levels and improved cardiovascular outcomes. Moreover, lowering LDL cholesterol to levels below previous targets provided additional benefit

    Can the intake of antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?

    No full text
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