21 research outputs found

    Local inhibition of nitrogen fixation and nodule metabolism in drought-stressed soybean

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    Drought stress is a major factor limiting symbiotic nitrogen fixation (NF) in soybean crop production. However, the regulatory mechanisms involved in this inhibition are still controversial. Soybean plants were symbiotically grown in a split-root system (SRS), which allowed for half of the root system to be irrigated at field capacity while the other half remained water deprived. NF declined in the water-deprived root system while nitrogenase activity was maintained at control values in the well-watered half. Concomitantly, amino acids and ureides accumulated in the water-deprived belowground organs regardless of transpiration rates. Ureide accumulation was found to be related to the decline in their degradation activities rather than increased biosynthesis. Finally, proteomic analysis suggests that plant carbon metabolism, protein synthesis, amino acid metabolism, and cell growth are among the processes most altered in soybean nodules under drought stress. Results presented here support the hypothesis of a local regulation of NF taking place in soybean and downplay the role of ureides in the inhibition of NF

    International conference on the healthy effect of virgin olive oil

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    Ageing represents a great concern in developed countries because the number of people involved and the pathologies related with it, like atherosclerosis, morbus Parkinson, Alzheime's disease, vascular dementia, cognitive decline, diabetes and cancer. Epidemiological studies suggest that a Mediterranean diet (which is rich in virgin olive oil) decreases the risk of cardiovascular disease. The Mediterranean diet, rich in virgin olive oil, improves the major risk factors for cardiovascular disease, such as the lipoprotein profile, blood pressure, glucose metabolism and antithrombotic profile. Endothelial function, inflammation and oxidative stress are also positively modulated. Some of these effects are attributed to minor components of virgin olive oil. Therefore, the definition of the Mediterranean diet should include virgin olive oil. Different observational studies conducted in humans have shown that the intake of monounsaturated fat may be protective against age-related cognitive decline and Alzheimer's disease. Microconstituents from virgin olive oil are bioavailable in humans and have shown antioxidant properties and capacity to improve endothelial function. Furthermore they are also able to modify the haemostasis, showing antithrombotic properties. In countries where the populations fulfilled a typical Mediterranean diet, such as Spain, Greece and Italy, where virgin olive oil is the principal source of fat, cancer incidence rates are lower than in northern European countries. The protective effect of virgin olive oil can be most important in the first decades of life, which suggests that the dietetic benefit of virgin olive oil intake should be initiated before puberty, and maintained through life. The more recent studies consistently support that the Mediterranean diet, based in virgin olive oil, is compatible with a healthier ageing and increased longevity. However, despite the significant advances of the recent years, the final proof about the specific mechanisms and contributing role of the different components of virgin olive oil to its beneficial effects requires further investigations. © 2005 Blackwell Publishing Ltd

    First occurrence of <i>Panthera atrox</i> (Felidae, Pantherinae) in the Mexican state of Hidalgo and a review of the record of felids from the Pleistocene of Mexico

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    Panthera atrox was a common large-sized cat in North America during the late Pleistocene. An isolated lower canine and a fifth metacarpal bone referable to this species were recovered from fluvial Quaternary deposits that outcrop in southeastern Hidalgo, central Mexico. Associated fossil material belonging to Bison indicates a Rancholabrean North American Land Mammal Age; the age assignment is corroborated by the presence of P. atrox. A comparative study with selected specimens of Panthera and Smilodon indicates that the Hidalgoan sample shares the following diagnostic features with P. atrox: a large, robust, and non-strongly curved lower canine; a large and relatively slender fifth metacarpal with a well-developed projection on the palmar side at the proximal end, narrow articulating surface for the unciform; a narrow notch on the articulating surface for the fourth metacarpal; and a diaphysis that at the middle is oval in cross section. The record supplements the evidence of P. atrox in central Mexico and represents the first reported occurrence of this cat species in the state of Hidalgo. By the same token, the known geographic distribution of P. atrox in the Mexican territory suggests that it was relatively common in temperate areas of central Mexico between 19 and 24° N at an altitudinal range from 1500 to 2250 m a.s.l. The large size (mean body mass of 300 kg) and hypercarnivorous adaptations of the American lion suggest it was the top predator of the mammalian community recorded at southeastern Hidalgo, displacing other members of the carnivore guild at the mesopredator level, such as the dire wolf (Canis dirus ), which has been also reported in the area. The high diversity of large herbivores recorded at southeastern Hidalgo, which in turn could represent potential prey of P. atrox, suggests that some areas that now are part of central Mexico were suitable hunting sites for this large-sized cat. A review of the Pleistocene record of Felidae from Mexico revealed that it encompasses 87.5 and 73.3 % of generic and specific diversity known for North America, respectively, including seven genera (Felis, Miracinonyx, Panthera, Puma, Lynx, Leopardus, and Smilodon) and 11 species (Felis rexroadensis, Miracinonyx inexpectatus, Panthera atrox, Panthera onca, Puma concolor, Puma yagouaroundi, Lynx rufus, Leopardus pardalis, Leopardus wiedii, Smilodon fatalis, and Smilodon gracilis). The majority of these taxa have been reported from numerous late Pleistocene localities; in particular, Panthera atrox was relatively common and widely distributed across the Mexican territory.</p

    Contamination in wells of the campina of Córdoba. II. Possible relation between contamination by E. Coli and some ions (chlorure, nitrite and amonia) concentration in water

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    The possible relation between chlorure, nitrite and ammonia ionic concentrations and qualitative-quantitative contamination by L. coli in water of wells located in the Campiña of Cordoba has been studied. No significative statistical differences between contaminated and non-contaminated water have been found.Se ha estudiado la posible relación entre la contaminación de cloruros, nitritos y amoniaco y la contaminación cuali-cuantitativa por coli en agua de pozos de hi zona de la Campiña de la Provincia de Córdoba, no habiéndose encontrado diferencias estadísticamente significativas entre aguas contaminadas y no contaminadas

    The Jaen Statement 2004: Consensus document of the International Conference on the healthy effects of virgin olive oil

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    Aging represents a great concern in developed countries because the number of people involved and the pathologies related with it, like atherosclerosis, Parkinson, Alzheimer, vascular dementia, cognitive decline, diabetes and cancer. Epidemiological studies suggest that a Mediterranean diet (which is rich in virgin olive oil) decreases the risk of cardiovascular disease. The Mediterranean diet, rich in virgin olive oil, improves the major risk factors for cardiovascular disease, such as the lipoprotein profile, blood pressure, glucose metabolism antiantithrombotic profile. Endothelial function, inflammation and oxidative stress are also positively modulated. Some of these effects are attributed to minor components of virgin olive oil. Therefore, the definition of the Mediterranean diet should include virgin olive oil. Different observational studies conducted in humans have shown that the intake of monounsaturated fat may be protective against age-related cognitive decline and Alzheimer's disease. Microconstituents from virgin olive oil are bioavailable in humans and have shown antioxidant properties and capacity to improve endothelial function. Furthermore, they are also able to modify the haemostasis, showing antithrombotic properties. In countries in which the populations fulfilled a typical Mediterranean diet, such as Spain, Greece, and Italy, where virgin olive oil is the principal source of fat, cancer incidence rates are lower than in Northern European countries. The protective effect of virgin olive oil can be most important in the first decades of life, which suggests that the dietetic benefit of virgin olive oil intake should be initiated before puberty, and maintained through life. The more recent studies consistently support that the Mediterranean diet, based in virgin olive oil, is compatible with a healthier aging and increased longevity. However, despite the significant advances of the recent years, the final proof about the specific mechanisms and contributing role of the different components of virgin olive oil to its beneficial effects requires further investigations
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