Search

Amber is fossilized resin that preserves biological remains in exceptional detail, study of which has revolutionized understanding of past terrestrial organisms and habitats from the Early Cretaceous to the present day. Cretaceous amber outcrops are more abundant in the Northern Hemisphere and during an interval of about 54 million years, from the Barremian to the Campanian. The extensive resin production that generated this remarkable amber record may be attributed to the biology of coniferous resin producers, the growth of resiniferous forests in proximity to transitional sedimentary environments, and the dynamics of climate during the Cretaceous. Here we discuss the set of interrelated abiotic and biotic factors potentially involved in resin production during that time. We name this period of mass resin production by conifers during the late Mesozoic, fundamental as an archive of terrestrial life, the `Cretaceous Resinous Interval (CREI).

We study the bias induced by a weak (200 mT) external magnetic field on the preferred handedness of sodium chlorate crystals obtained by slow evaporation at ambient conditions of its saturated saline solution with 20 ppm of added racemic (dl) hydrophobic amino acids. By applying the Fisher test to pairs of experiments with opposing magnetic field orientation we conclude, with a confidence level of 99.7%, that at the water-air interface of this saline solution there is an enantioselective magnetic interaction that acts upon racemic mixtures of hydrophobic chiral amino acids. This interaction has been observed with the three tested racemic hydrophobic amino acids: dl-Phe, dl-Try and dl-Trp, at ambient conditions and in spite of the ubiquitous chiral organic contamination. This enantioselective magnetic dependence is not observed when there is only one handedness of added chiral amino-acid, if the added amino acid is not chiral or if there is no additive. This effect has been confirmed with a double blind test. This novel experimental observation may have implications for our view of plausible initial prebiotic scenarios and of the roles of the geomagnetic field in homochirality in the biosphere.

The idea of an autotrophic organism as the first living being on Earth leads to the hypothesis of a protometabolic, complex chemical system. In one of the main hypotheses, the first metabolic systems emerged from the interaction between sulfide minerals and/or soluble iron-sulfide complexes and fluids rich in inorganic precursors, which are reduced and derived from crustal or mantle activity. Within this context, the possible catalytic role of pyrrhotite, one of the most abundant sulfide minerals, in biomimetic redox and carbon fixation reactions was studied. Our results showed that pyrrhotite, under simulated hydrothermal conditions, could catalyze the pyruvate synthesis from lactate and that a dynamic system formed by coupling iron metal and iron-sulfur species in an electrochemical cell could promote carbon fixation from thioacetate esters.

The idea of an autotrophic organism as the first living being on Earth leads to the hypothesis of a protometabolic, complex chemical system. In one of the main hypotheses, the first metabolic systems emerged from the interaction between sulfide minerals and/or soluble iron-sulfide complexes and fluids rich in inorganic precursors, which are reduced and derived from crustal or mantle activity. Within this context, the possible catalytic role of pyrrhotite, one of the most abundant sulfide minerals, in biomimetic redox and carbon fixation reactions was studied. Our results showed that pyrrhotite, under simulated hydrothermal conditions, could catalyze the pyruvate synthesis from lactate and that a dynamic system formed by coupling iron metal and iron-sulfur species in an electrochemical cell could promote carbon fixation from thioacetate esters.

The particular mineralogy formed in the acidic conditions of the Río Tinto has proven to be a first-order analogue for the acid-sulfate aqueous environments of Mars. Therefore, studies about the formation and preservation of biosignatures in the Río Tinto will provide insights into equivalent processes on Mars. We characterized the biomolecular patterns recorded in samples of modern and old fluvial sediments along a segment of the river by means of an antibody microarray containing more than 200 antibodies (LDCHIP200, for Life Detector Chip) against whole microorganisms, universal biomolecules, or environmental extracts. Samples containing 0.3–0.5 g of solid material were automatically analyzed in situ by the Signs Of LIfe Detector instrument (SOLID2), and the results were corroborated by extensive analysis in the laboratory. Positive antigen-antibody reactions indicated the presence of microbial strains or high-molecular-weight biopolymers that originated from them. The LDCHIP200 results were quantified and subjected to a multivariate analysis for immunoprofiling. We associated similar immunopatterns, and biomolecular markers, to samples with similar sedimentary age. Phyllosilicate-rich samples from modern fluvial sediments gave strong positive reactions with antibodies against bacteria of the genus Acidithiobacillus and against biochemical extracts from Río Tinto sediments and biofilms. These samples contained high amounts of sugars (mostly polysaccharides) with monosaccharides like glucose, rhamnose, fucose, and so on. By contrast, the older deposits, which are a mix of clastic sands and evaporites, showed only a few positives with LDCHIP200, consistent with lower protein and sugar content. We conclude that LDCHIP200 results can establish a correlation between microenvironments, diagenetic stages, and age with the biomarker profile associated with a sample. Our results would help in the search for putative martian biomarkers in acidic deposits with similar diagen

The present invention relates to a novel method and to a device for obtaining crystals from a substance, comprising: (i) preparing a saturated dissolution of the substance to be crystallized in a suitable solvent in a reaction vessel; (ii) generating an aerosol in the reaction vessel; (iii) crystallizing the substance; and (iv) recovering the crystals at the bottom of the reaction vessel. The method is especially suitable for crystallizing substances which are typically difficult to crystallize and can lead to a chiral amplification result., La presente invención relaciona a un nuevo método y a un dispositivo para obtener los cristales de una sustancia, comprendiendo: (i) preparando una disolución saturada de la sustancia que se cristalizará en un disolvente adecuado en un recipiente de reacción (ii) generar un aerosol en el recipiente de reacción (iii) cristalizar la sustancia y (iv) recuperando los cristales en el fondo del recipiente de reacción. El método es especialmente adecuado para cristalizar las sustancias que el son típicamente difícil cristalizar y el bote conducen a un resultado de la amplificación del quiral.

[EN]: This contribution presents first results from the research on meteorite impact craters and events in Mauritania. Megabreccias from the remarkable (and controversial) Richat structure and materials from the Aoulloul impact crater were studied by the combination of transmitted and reflected light microscopy, XRD, SEM-EDX, ICP-MS, FT-IR and Raman spectroscopy. Quartz, analcime, goethite, haematite, calcite, dolomite and sulphides (pyrite) were identified as main minerals of the megabreccias. Their textures comprise collomorphous layers and aggregates, cloudy textures, infillings of veins and cracks and quartz recrystallization, and heterometric quartz grains showing corroded gulfs. Some samples from Richat show mosaicism in quartz and amorphized carbon. In general, the megabreccias are geochemically heterogeneous, displaying significant variations in some elements (mainly Na, K, Ti, Cr, V, Co, Cu, Sr, Ba y Ni). Intensely deformed rocks (quartz mosaicism), and iron rich and glass fragments from the Aouelloul impact crater were also studied., [ES]: Se presentan los primeros resultados de la campaña científica Mauritania’ 2007, en relación con la investigación de cráteres y eventos de impacto. Los estudios se centraron en la caracterización, mediante microscopía de luz transmitida y reflejada, DRX, SEM-EDX, ICP-MS, FT-IR y espectroscopia Raman, de las megabrechas de la espectacular (aunque controvertida) estructura de Richat y en el cráter meteorítico de Aouelloul. Los minerales identificados en las brechas son cuarzo, analcima, goethita, hematites, calcita, dolomita y sulfuros (pirita). Sus texturas incluyen bandeados y agregados colomorfos, texturas anubarradas, rellenos fisurales con recristalizaciones de cuarzo y fragmentos heterométricos de los granos/cristales de cuarzo con bordes y golfos de corrosión. En algunas muestras de Richat se ha observado mosaicismo de los granos de cuarzo y carbón amorfizado. Las brechas muestran heterogeneidad geoquímica con variaciones importantes de algunos elementos (principalmente Na, K, Ti, Cr, V, Co, Cu, Sr, Ba y Ni). En Aouelloul se han caracterizado las rocas intensamente deformadas del interior del cráter (se ha detectado mosaicismo) y los fragmentos ferruginizados (goethita y cuarzo) que aparecen dispersos alrededor de la estructura. También se ha realizado espectroscopia Raman de los fragmentos vítreos ricos en sílice, que muestran clara amorfización.

Certain local atmospheric anomalies, such as the formation of unusually large ice conglomerations (megacryometeors), have been proposed to be a potential natural hazard for people and aviation, as well as geoindicators for fingerprinting larger-scale atmospheric environmental changes. On March 13th 2007, at approximately 10:15 am, an ice chunk weighing about 10 kg fell from the clear-sky and crashed through the roof (around 15 m) of an industrial storage house in Mejorada del Campo, a town located 20 km east from Madrid. The megacryometeor monitoring follow-up and the original investigation presented here includes, for the first time, both logistic and scientific collaboration between the Laboratory of the Environment, Criminalistic Service (SECRIM, the Spanish “Guardia Civil”) and academic and scientific institutions (universities and the Spanish National Research Council). We propose that the management procedure of the incident, along with the detailed scientific research and combination of analytical methodologies in different laboratories, can serve as a protocol model for other similar events

We report the synthesis of purine bases and other heterocycles and the formation of amino acids, hydroxy acids and dihydroxy compounds by the spark activation of an atmosphere of methane, nitrogen and hydrogen, in the presence of an aqueous aerosol. With the aid of the interface air–water, the organic material obtained shows greater amounts and diversity of molecules with biological interest than the products obtained in the absence of an aerosol. Our results support the suggestion that aerosols may have played a significant role in the prebiotic origin of molecular diversity and evolution.

It has been postulated that the oceans on early Earth had a salinity of 1.5 to 2 times the modern value and a pH between 4 and 10. Moreover, the presence of the banded iron formations shows that Fe(+2) was present in significant concentrations in the primitive oceans. Assuming the hypotheses above, in this work we explore the effects of Fe(+2) and other ions in the generation of biomolecules in prebiotic simulation experiments using spark discharges and aqueous aerosols. These aerosols have been prepared using different sources of Fe(+2), such as FeS, FeCl(2) and FeCO(3), and other salts (alkaline and alkaline earth chlorides and sodium bicarbonate at pH = 5.8). In all these experiments, we observed the formation of some amino acids, carboxylic acids and heterocycles, involved in biological processes. An interesting consequence of the presence of soluble Fe(+2) was the formation of Prussian Blue, Fe(4)[Fe(CN)(6)](3), which has been suggested as a possible reservoir of HCN in the initial prebiotic conditions on the Earth.

Ferrocyanide has been proposed as a potential prebiotic reagent by Arrhenius. The complex salt named Prussian Blue, Fe4[Fe(CN)6]3, [ferric hexacyaneferrate (II)], might be an important reservoir of hydrogen cyanide, HCN, in the early Earth. HCN is a major product of spark discharge experiments on various gas mixtures; it is considered the main precursor of amino acids and purine bases under prebiotic conditions. The presence of banded iron formations shows that dissolved iron (ferrous iron) was present in high quantities in the ocean water during Archean epoch. Recently, we observed the formation of Prussian Blue in spark discharge experiments using saline solutions of ferrous chloride, FeCl3. Using Prussian Blue as starting material in ammonium solutions at different values of pH, and carrying out the reactions under middle conditions of temperature and concentration, some organic compounds were formed. We detected urea, imidazole, substituted imidazoles, methyl hydantoines and other heterocycles containing nitrogen and some amino acids by GC-MS of their trimethylsilyl derivatives. These results seem to indicate that Prussian Blue could be a sink of HCN in the early Earth. Subsequent reactions, triggered by pH fluctuations, might lead to organic life precursors.