54 research outputs found
Nuevas fuentes de antioxidantes naturales: caracterización de compuestos bioactivos en cinco frutos nativos de Chile.
Diferentes berries de la zona centro y sur de Chile fueron analizados con el fin de buscar fuentes promisorias de polifenoles con clara actividad sobre la salud humana. Se estudiaron cinco bayas nativas: arrayan, frutilla blanca, murtilla y calafate, y un berry tradicional (uva tintorera). Se determinó in vitro sus propiedades antioxidantes según el ensayo de polifenoles totales de Folin Ciocalteu, antocianinas por pH diferencial, capacidad antioxidante por medición de capacidad de reducción del radical libre 2.2-difenil-1picrilhidracilo (DPPH) y poder de reducción férrica (FRAP) y perfil químico por HPLC-DAD. De los cinco berries, calafate registró el valor más alto (1066,4 ± 24,9 mg GAE/100g de muestra) para polifenoles totales y antocianinas (1031,9 ± 48,1 mg de cianidina-3-glucósido/100g de muestra) seguido por uva tintorera. Calafate presentó excelente poder reductor (11279,2 ± 2027,4 umol Trolox/100g ensayo FRAP y 5235,0 ± 445,9, umol/100g en PPH). El perfil químico de antocianinas mostró delfinidina, cianidina, malvidina, petunidina, peonidina y pelargonidina en los cinco berries. Alrededor de 30 flavonoles derivados de quercetina, myricetina e isorhamnetina fueron identificados así cómo elagitaninos presentes en frutilla blanca, compuestos muy interesantes para estudios posteriores. Estos resultados contribuyen a destacar el uso potencial de estos berries como alimentos funcionales.Berries from central and southern Chile were analyzed in order to find promising sources of polyphenols with clear activity on human health. Five native fruits like arrayan, white strawberry, murtilla and calafate, and a traditional berry (grape called “tintorera”) were studied. Antioxidant properties were determined in vitro according to the total polyphenol assay of Folin Ciocalteu, anthocyanins by differential pH, antioxidant capacity by measuring the capacity of reduction of the free radical 2.2-diphenyl-1-picrylhydracil (DPPH) and iron reducing capacity (FRAP) and chemical profile by HPLC-DAD. Calafate showed the highest value (1066.4 ± 24.9 mg gallic acid / 100g sample) for total polyphenols and anthocyanins (1031.9 ± 48.1 mg of cyanidin-3-glucoside / 100g of sample) followed by blue grape. Calafate displayed excellent reducing power (11279.2 ± 2027.4 umol Trolox / 100g FRAP assay and 5235.0 ± 445.9, umol / 100g in DPPH), followed by grape. The chemical profile ofanthocyanins showed delphinidin, cyanidin, malvidin, petunidin, peonidin and pelargonidin in the five berries. Around 30 flavonols derived from quercetin, yricetin and sorhamnetin were identified as well as ellagitannins present in white trawberry, very interesting compounds for further studies. These results contribute to highlight the potential use of these berries as functional foods
DSM-V: modifying the postpartum-onset specifier to include hypomania
By failing to include it under the rubric of the postpartum-onset specifier, Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV-TR has ignored the clinical reality that childbirth is a potent trigger of hypomania. Given the serious and occasionally tragic consequences of misdiagnosis of bipolar II depression as unipolar depression in the postpartum period, it is argued that DSM-V should consider modifying the postpartum-onset specifier to include episodes of hypomania
Characterization of Microbialites and Microbial Mats of the Laguna Negra Hypersaline Lake (Puna of Catamarca, Argentina)
Microbial carbonates provide an invaluable tool to understand biogeochemical processes in aqueous systems, especially in lacustrine and marine environments. Lakes are strongly sensitive to climatically driven environmental changes, and microbialites have recently been shown to provide a record of these changes. Unraveling physicochemical and microbiological controls on carbonates textures and geochemistry is necessary to correctly interpret these signals and the microbial biosphere record within sedimentary carbonates. The Laguna Negra is a high-altitude hypersaline Andean lake (Puna of Catamarca, Argentina), where abundant carbonate precipitation takes place and makes this system an interesting example that preserves a spectrum of carbonate fabrics reflecting complex physical, chemical, and biological interactions. The extreme environmental conditions (high UV radiation, elevated salinity, and temperature extremes) make the Laguna Negra a good analogue to some Precambrian microbialites (e.g., Tumbiana Fm., Archean, Australia). In addition, the discovery of ancient evaporating playa-lake systems on Mars’ surface (e.g., ShalbatanaVallis, Noachian, Mars) highlights the potential of Laguna Negra to provide insight into biosignature preservation in similar environments, in both terrestrial and extraterrestrial settings, given that microbial processes in the Laguna Negra can be studied with remarkable detail.Fil: Boidi, Flavia Jaquelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Mlewski, Estela Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Gomez, Fernando Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Gérard, Emmanuelle. Centre National de la Recherche Scientifique; Franci
Study of pallial neurogenesis in shark embryos and the evolutionary origin of the subventricular zone
The dorsal part of the developing telencephalon is one of the brain areas that has suffered most drastic changes throughout vertebrate evolution. Its evolutionary increase in complexity was thought to be partly achieved by the appearance of a new neurogenic niche in the embryonic subventricular zone (SVZ). Here, a new kind of amplifying progenitors (basal progenitors) expressing Tbr2, undergo a second round of divisions, which is believed to have contributed to the expansion of the neocortex. Accordingly, the existence of a pallial SVZ has been classically considered exclusive of mammals. However, the lack of studies in ancient vertebrates precludes any clear conclusion about the evolutionary origin of the SVZ and the neurogenic mechanisms that rule pallial development. In this work, we explore pallial neurogenesis in a basal vertebrate, the shark Scyliorhinus canicula, through the study of the expression patterns of several neurogenic markers. We found that apical progenitors and radial migration are present in sharks, and therefore, their presence must be highly conserved throughout evolution. Surprisingly, we detected a subventricular band of ScTbr2-expressing cells, some of which also expressed mitotic markers, indicating that the existence of basal progenitors should be considered an ancestral condition rather than a novelty of mammals or amniotes. Finally, we report that the transcriptional program for the specification of glutamatergic pallial cells (Pax6, Tbr2, NeuroD, Tbr1) is also present in sharks. However, the segregation of these markers into different cell types is not clear yet, which may be linked to the lack of layering in anamniotesThis work was supported by the Spanish Ministerio de Economía y Competitividad-FEDER (BFU2014-5863-1P)S
Arsenic contamination of natural waters in San Juan and La Pampa, Argentina
Arsenic (As) speciation in surface and groundwater from two provinces in Argentina (San Juan and La Pampa) was investigated using solid phase extraction (SPE) cartridge methodology with comparison to total arsenic concentrations. A third province, Río Negro, was used as a control to the study. Strong cation exchange (SCX) and strong anion exchange (SAX) cartridges were utilised in series for the separation and preservation of arsenite (AsIII), arsenate (AsV), monomethylarsonic acid (MAV) and dimethylarsinic acid (DMAV). Samples were collected from a range of water outlets (rivers/streams, wells, untreated domestic taps, well water treatment works) to assess the relationship between total arsenic and arsenic species, water type and water parameters (pH, conductivity and total dissolved solids, TDS). Analysis of the waters for arsenic (total and species) was performed by inductively coupled plasma mass spectrometry (ICP-MS) in collision cell mode. Total arsenic concentrations in the surface and groundwater from Encon and the San José de Jáchal region of San Juan (north-west Argentina within the Cuyo region) ranged from 9 to 357 μg l−1 As. Groundwater from Eduardo Castex (EC) and Ingeniero Luiggi (LU) in La Pampa (central Argentina within the Chaco-Pampean Plain) ranged from 3 to 1326 μg l−1 As. The pH range for the provinces of San Juan (7.2–9.7) and La Pampa (7.0–9.9) are in agreement with other published literature. The highest total arsenic concentrations were found in La Pampa well waters (both rural farms and pre-treated urban sources), particularly where there was high pH (typically > 8.2), conductivity (>2,600 μS cm−1) and TDS (>1,400 mg l−1). Reverse osmosis (RO) treatment of well waters in La Pampa for domestic drinking water in EC and LU significantly reduced total arsenic concentrations from a range of 216–224 μg l−1 As to 0.3–0.8 μg l−1 As. Arsenic species for both provinces were predominantly AsIII and AsV. AsIII and AsV concentrations in San Juan ranged from 4–138 μg l−1 to <0.02–22 μg l−1 for surface waters (in the San José de Jáchal region) and 23–346 μg l−1 and 0.04–76 μg l−1 for groundwater, respectively. This translates to a relative AsIII abundance of 69–100% of the total arsenic in surface waters and 32–100% in groundwater. This is unexpected because it is typically thought that in oxidising conditions (surface waters), the dominant arsenic species is AsV. However, data from the SPE methodology suggests that AsIII is the prevalent species in San Juan, indicating a greater influence from reductive processes. La Pampa groundwater had AsIII and AsV concentrations of 5–1,332 μg l−1 and 0.09–592 μg l−1 for EC and 32–242 μg l−1 and 30–277 μg l−1 As for LU, respectively. Detectable levels of MAV were reported in both provinces up to a concentration of 79 μg l−1 (equating to up to 33% of the total arsenic). Previously published literature has focused primarily on the inorganic arsenic species, however this study highlights the potentially significant concentrations of organoarsenicals present in natural waters. The potential for separating and preserving individual arsenic species in the field to avoid transformation during transport to the laboratory, enabling an accurate assessment of in situ arsenic speciation in water supplies is discussed
Complete Characterization of Stratified Ecosystems of the Salar de Llamara (Atacama Desert)
Salar de Llamara is situated in the north of the Atacama Desert, which is the driest desert and one of the most irradiated places on Earth. Besides, its subterranean hypersaline waters contain a high content of arsenic, among other compounds such as heavy metals that are poisonous to life in the concentrations present. Despite these extreme conditions, diverse microbial communities flourish in gypsum stratified ecosystems (microbial mats and evaporitic domes).Here, we reviewed all the analysis carried out in these communities, involving taxonomic and functional studies by culture-independent techniques, analysis of the physicochemical parameters of the water and its relation with the microbial ecosystems, together with pigments, mineralogy, and the microscopic view.Regarding taxonomy, the major points analyzed were: (1) the taxonomic trends at phylum level showed that Proteobacteria and Bacteroidetes were the major components of these communities. (2) A low proportion of sequences associated with the phylum Cyanobacteria were detected in all the studied samples. (3) The increased proportion of sequences that could not be affiliated with any taxonomic group that is deposited in the databases. (4) The large amount of rare phyla represented by candidate phyla, such as OD1, OP1, OD8, Hyd24-12, and NKB19.The functional analysis, carried out in these gypsum evaporite systems, revealed that there was only a minor presence of oxygenic photosynthesizers in the community, and anoxygenic photosynthesis appears as an alternative for primary production. Since the Calvin?Benson cycle was scant, the low abundance of oxygenic photosynthesizers was also related to unusual carbon fixation pathways.Regarding physicochemical parameters of the water, the most interesting results were: (1) a huge amount of arsenic; (2) high salinity; (3) low nutrients and high levels of some ions, such as sodium, sulfate, and calcium. The low dissolved oxygen in most of the set points was low, which was consistent with the low proportion of oxygenic photosynthesizers in all the samples studied.Regarding the mineralogy, gypsum mainly compounded all the evaporitic domes, and the microbial mats present halite as the main mineral component.Fil: Rasuk, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Contreras Leiva, Manuel. Centro de Ecología Aplicada; ChileFil: Kurth, Daniel German. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentin
Autoregulation of the Synthesis of the MobM Relaxase Encoded by the Promiscuous Plasmid pMV158
Growth Response and Modifications of Organic Nitrogen Compounds in Pure and Mixed Cultures of Lactic Acid Bacteria from Wine
Arsenic and Its Biological Role: From Early Earth to Current Andean Microbial Ecosystems
Arsenic (As) is present in the Earth's crust and is widely distributed in the environment. It is frequently a component of sulfidic ores in the form of arsenides of nickel, cobalt, copper, and iron. The main sources of As are natural, mostly associated with volcanic areas and hydrothermal vents; further, it can also originate as a result of human activities: mining, waste treatment, and industrial activities, among others.Arsenic is a redox-active metalloid and exists in nature in four oxidation states: arsine [As(-III)], elemental [As(0)], arsenate [As(V)], and arsenite [As(III)]. These states vary according to changes in pH and the redox environment. The first two forms are relatively rare; naturally, As is found as As(V) or As(III). As(V) is predominant in oxygenated aqueous environments, while As(III) is found in reduced or anoxic conditions. Arsenic is a highly dangerous element, as As(III) is 100 times more toxic than As(V). Its greatest toxicity is due to the fact that it can bind to sulfhydryl groups, affecting the correct functioning of many enzymes and proteins. As(V), on the other hand, is a chemical analog of phosphate, so it can interact and eventually replace it in early steps in different ways. On our planet, there are environments with a high arsenic content.Our research group has worked in bioprospecting in Andean microbial ecosystems (AMEs) in the Atacama Desert, Bolivian Altiplano, and Argentine Puna (the so-called Puna?High Andes region). In all of these places, there are hypersaline lakes at altitudes higher than 3000 m above sea level (asl). These lakes share the common characteristic of high concentrations of arsenic, normally ranging between 12 and 230 mg L−1. This range of As concentrations is one of the highest ranges reported for hypersaline lakes.Fil: Saona Acuña, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Soria, Mariana Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Villafañe, Patricio Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Stepanenko, Tatiana Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentin
Integral Prospection of Andean Microbial Ecosystem Project
When microbial ecosystems first started to be reported 10 years ago, nobody reallyhad a notion of the relevance they would have in the Central Andean region.Consequently, the heritage of the microbialites reported in El Peinado, LagunaNegra, Laguna Pozo Bravo, Laguna La Brava, etc. promises to position the Andes asreservoirs of the most relevant modern microbialites on the planet (Table 17.1,Fig. 17.1). Furthermore, the number of different ecosystems is worth paying closeattention to, as it gives rise to questions such as: What favors the development ofthese ecosystems? What are the conditions that influence the precipitation of a carbonaceousor a gypsum system at such a short distance and under similar environmentalconditions, such as at the Atacama salt flat? Why are oncolites distributed so? Untilnow, it has been possible only to survey the systems and to carry out more in-depthstudies in some of them to try to achieve their preservation. Throughout the prospection of the Andean microbial ecosystems (AMEs), some shared characteristics have beenfound from the geological, physical, and chemical points of view [(1) active volcanicincidence: all of the microbial ecosystems that have been found are in some way connectedto areas where active volcanoes are present; (2) underground water input;(3) mixed zones with different salinities: underground low-conductivitywater andsalar thalassic water; (4) two kinds of microbialites found: oncolites (at LagunaNegra, Tres Quebradas, Las Quinoas, etc.) or domes with thrombolites at the bottomand stromatolites at the top surface (at La Brava, Pozo Bravo, Ojos Bravos, and ElPeinado)] and from the biological point of view [(5) predominance of diatoms, themain component in all studied systems; (6) predominance of anaerobic over aerobicphotosynthetic microorganisms; (7) microbial rhodopsin as the main system for producing adenosine triphosphate (ATP); (8) arsenicresistance and bioenergetic mechanisms;and (9) predominance of Carbon fixation pathways other than the Calvincycle]. The biological aspects of these are being studied thoroughly in our lab and arebriefly discussed below.Fil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Villafañe, Patricio Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Lencina, Agustina Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Catamarca. Universidad Nacional de Catamarca. Centro de Investigaciones y Transferencia de Catamarca; Argentin
- …