Interaction Between Bacteria, Nannobacteria, and Mineral Precipitation in Hot Springs of Central Italy

A complex of inorganic and organic factors controls precipitation of carbonates in hot springs of Lazio, central Italy. A plot of data from this area shows that the main /norganic controls are temperature and Mg/Ca ratio of the spring waters. Virtually all springs with waters hotter than 400C precipitate aragonite, and cooler ones form calcite. Furthermore, even cold-water springs precipitate aragonite if the Mg/Ca ratio exceeds 1:1, except in two cases. To what extent is the precipitation of travertine inorganic vs. biochemical? Surely, conditions in diverse localities can vary between both end-points, but Le Zitelle springs, at the north flank of the caldera of Viterbo, provide a biochemical extreme. Waters are hot (600C), with Mg/Ca of .2, and are highly sulfurous. Carbonate precipitation rates can exceed 2 mm/day. /Vonetched samples of carbonate crusts, only minutes to a few hours old, exhibit aragonite, calcite, and 1- to 5- (im euhedral rhombs of probable dolomite. Aragonite forms spherical "pincushions" of radial needles, each needle tipped with a nannobacterial body of the same diameter as the needles, 0.1 to 0.4 jim. Each nannobacterium precipitated its own needle, and was propelled outward by needle growth. As little or no later "fattening" of the needle occurred, inorganic precipitation must have been insignificant here. fVonetched calcite crystals are composed of 0.05 (xm nannobacterial spheres that were incorporated into each layer of the crystal as it grew. No evidence of bacteria was found on the ?dolomite rhomb surfaces. Ironically, aragonite, calcite, and euhedral ?dolomite rhombs all grew within minutes to an hour of each other in the same solution under the same conditions, savaging all the rules exposed at the beginning they remain a baffling problem unresolved by chemistry, physics, or microbiology.Un ensemble de facteurs inorganiques et organiques sont à l'origine de la précipitation de carbonates dans les sources chaudes de Lazio. L'étude des données montre que les facteurs inorganiques principaux sont la température et le rapport Mg/Ca dans les eaux de source. Presque toutes les sources chaudes à plus de 400C font précipiter l'aragonite et les eaux plus froides, la calcite. De plus, même les sources froides font précipiter l'aragonite si le rapport Mg/Ca dépasse 1:1, sauf exceptions. Dans quelle mesure la précipitation du travertin est-elle inorganique plutôt que biochimique? Certes, les conditions varient d'un milieu à l'autre entre les deux extrémités, mais la source Le Zitelle constitue un extrême biochimique. Les eaux sont chaudes (60°C), avec un rapport de Mg/Ca de 0,2, et très sulfureuses. Les taux de précipitation de carbonates peuvent dépasser 2 mm/jour. Les échantillons de croûtes de carbonate non corrodées (par l'acide hydrochlorique), formées dans les minutes ou les heures précédentes, présentent de l'aragonite, de la calcite et des rhomboèdres automorphes de 1 à 5 fim probablement de dolomite. L'aragonite forme des « pelotes » sphériques, d'aiguilles radiales, dont chacun des bouts se termine par un corps nannobactériel de même diamètre, soit 0,1 à 0,4 p.m, Des cristaux non corrodés de calcite se composent de sphères de nannobactérie de 0,05 y.m incorporées dans chacune des couches de cristal au fur et à mesure du développement. Aucun signe de bactérie n'a été trouvé sur les surfaces de rhomboèdres de dolomite (?). Ironiquement, l'aragonite, la calcite et les rhomboèdres de dolomite (?) ont tous cru à peu près en même temps, dans la même solution soumise aux mêmes conditions, anéantissant ainsi toutes les règles déjà émises. Le problème persiste donc et n'a été résolu ni par la chimie, la physique ou la microbiologie.Ein vielschichtiges Zusammenspiel anorganischer und organischer Faktoren regelt die Ausscheidung von Karbonaten in den heiBen Quellen von Lazio, Zentralitalien. Daten von diesem Gebiet zeigen, daB die Temperatur und das Verhàltnis Mg/Ca in den Quell-wassern die hauptsâchlichen anorganischen Faktoren sind. Praktisch scheiden aile Quellen mit Wasser, das heiBer als 400C ist, Aragonit aus, wenn das Verhàltnis Mg/Ca 1:1 ùberschreitet, auBer in zwei Fallen. In welchem MaBe ist die Ausscheidung von Kalktuff eher anorganisch als biochemisch? Sicher kônnen die Bedingungen an verschie-denen Plâtzen zwischen den zwei End-punkten variieren, aber die Quellen Le Zitelle an der Nordflanke der caldera von Viterbo stellen ein biochemisches Extrem dar. Die Wasser sind heiB (6O0C) mit einem Mg/Ca Verhàltnis von 2 und sie sind sehr schwefel-haltig. Die Karbonat-Ausscheidungsrate kann 2 mm/Tag ùberschreiten. Proben nichtausgewaschener Karbonatkrusten, die nur Minuten bis zu wenige Stunden ait sind, zeigen Aragonit, Kalkspat und automorphe Rhomben von 1 bis 5 ^m, wahrscheinlich von Dolomit. Der Aragonit bildet kugelfôrmige "Nadelkissen" mit strahlenfôrmigen Nadeln, die in einem nannobakteriellen Kôrper vom selben Durchmesser wie die Nadel enden, 0.1 bis 0.4 ^m. Die nichausge-waschenen Kalkspatkristalle bestehen aus kugelfôrmigen Nannobakterien von 0.05jj.m, welche in jede Schicht des Kristalls wàhrend seines Wuchses aufgenommen wurden. Auf den Dolomit(?)-Rhombenoberflàchen wurde kein Hinweis auf Bakterien gefunden. SeIt-samerweise wuchsen Aragonit, Kalkspat und Dolomit(?)-Rhomben aile in einem Abstand von Minuten bis zu einer Stunde voneinander in derselben Losung unter denselben Bedingungen und haben so sâmtliche Regeln des ersten Absatzes umgestoBen; sie bleiben ein durch Chemie, Physik oder Mikrobiologie ungelôstes Problem

Viterbo Slime, TEM Revelations

Geological Science

Rates of niche and phenotype evolution lag behind diversification in a temperate radiation

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.Environmental change can create opportunities for increased rates of lineage diversification, but continued species accumulation has been hypothesized to lead to slowdowns via competitive exclusion and niche partitioning. Such density-dependent models imply tight linkages between diversification and trait evolution, but there are plausible alternative models. Little is known about the association between diversification and key ecological and phenotypic traits at broad phylogenetic and spatial scales. Do trait evolutionary rates coincide with rates of diversification, are there lags among these rates, or is diversification niche-neutral? To address these questions, we combine a deeply sampled phylogeny for a major flowering plant clade—Saxifragales—with phenotype and niche data to examine temporal patterns of evolutionary rates. The considerable phenotypic and habitat diversity of Saxifragales is greatest in temperate biomes. Global expansion of these habitats since the mid-Miocene provided ecological opportunities that, with density-dependent adaptive radiation, should result in simultaneous rate increases for diversification, niche, and phenotype, followed by decreases with habitat saturation. Instead, we find that these rates have significantly different timings, with increases in diversification occurring at the mid-Miocene Climatic Optimum (∼15 Mya), followed by increases in niche and phenotypic evolutionary rates by ∼5 Mya; all rates increase exponentially to the present. We attribute this surprising lack of temporal coincidence to initial niche-neutral diversification followed by ecological and phenotypic divergence coincident with more extreme cold and dry habitats that proliferated into the Pleistocene. A lack of density-dependence contrasts with investigations of other cosmopolitan lineages, suggesting alternative patterns may be common in the diversification of temperate lineages

Textural variations in Neogene pelagic carbonate ooze at DSDP Site 593, southern Tasman Sea, and their paleoceanographic implications

Changes in Neogene sediment texture in pelagic carbonate-rich oozes on the Challenger Plateau, southern Tasman Sea, are used to infer changes in depositional paleocurrent velocities. The most obvious record of textural change is in the mud:sand ratio. Increases in the sand content are inferred to indicate a general up-core trend towards increasing winnowing of sediments resulting from increasing flow velocity of Southern Component Intermediate Water (SCIW), the forerunner of Antarctic Intermediate Water. In particular, the intervals c. 19-14.5 Ma, c. 9.5-8 Ma, and after 5 Ma are suggested to be times of increased SCIW velocity and strong sediment winnowing. Within the mud fraction, the fine silt to coarse clay sizes from 15.6 to 2 µm make the greatest contribution to the sediments and are composed of nannofossil plates. During extreme winnowing events it is the fine silt to very coarse clay material (13-3 µm) within this range that is preferentially removed, suggesting the 10 µm cohesive silt boundary reported for siliciclastic sediments does not apply to calcitic skeletal grains. The winnowed sediment comprises coccolithophore placoliths and spheres, represented by a mode at 4-7 µm. Further support for seafloor winnowing is gained from the presence in Hole 593 of a condensed sedimentary section from c. 18 to 14 Ma where the sand content increases to c. 20% of the bulk sample. Associated with the condensed section is a 6 m thick orange unit representing sediments subjected to particularly oxygen-rich, late early to early middle Miocene SCIW. Together these are inferred to indicate increased SCIW velocity resulting in winnowed sediment associated with faster arrival of oxygen-rich surface water subducted to form SCIW. Glacial development of Antarctica has been recorded from many deep-sea sites, with extreme glacials providing the mechanism to increase watermass flow. Miocene glacial zones Mi1b-Mi6 are identified in an associated oxygen isotope record from Hole 593, and correspond with times of particularly invigorated paleocirculation, bottom winnowing, and sediment textural changes

The relationship between eruptive activity, flank collapse, and sea level at volcanic islands: A long-term (>1 Ma) record offshore Montserrat, Lesser Antilles

Hole U1395B, drilled southeast of Montserrat during Integrated Ocean Drilling Program Expedition 340, provides a long (>1 Ma) and detailed record of eruptive and mass-wasting events (>130 discrete events). This record can be used to explore the temporal evolution in volcanic activity and landslides at an arc volcano. Analysis of tephra fall and volcaniclastic turbidite deposits in the drill cores reveals three heightened periods of volcanic activity on the island of Montserrat (?930 ka to ?900 ka, ?810 ka to ?760 ka, and ?190 ka to ?120 ka) that coincide with periods of increased volcano instability and mass-wasting. The youngest of these periods marks the peak in activity at the Soufrière Hills volcano. The largest flank collapse of this volcano (?130 ka) occurred towards the end of this period, and two younger landslides also occurred during a period of relatively elevated volcanism. These three landslides represent the only large (>0.3 km3) flank collapses of the Soufrière Hills edifice, and their timing also coincides with periods of rapid sea-level rise (>5 m/ka). Available age data from other island arc volcanoes suggests a general correlation between the timing of large landslides and periods of rapid sea-level rise, but this is not observed for volcanoes in intra-plate ocean settings. We thus infer that rapid sea-level rise may modulate the timing of collapse at island arc volcanoes, but not in larger ocean-island settings

A framework for the development of a global standardised marine taxon reference image database (SMarTaR-ID) to support image-based analyses

Video and image data are regularly used in the field of benthic ecology to document biodiversity. However, their use is subject to a number of challenges, principally the identification of taxa within the images without associated physical specimens. The challenge of applying traditional taxonomic keys to the identification of fauna from images has led to the development of personal, group, or institution level reference image catalogues of operational taxonomic units (OTUs) or morphospecies. Lack of standardisation among these reference catalogues has led to problems with observer bias and the inability to combine datasets across studies. In addition, lack of a common reference standard is stifling efforts in the application of artificial intelligence to taxon identification. Using the North Atlantic deep sea as a case study, we propose a database structure to facilitate standardisation of morphospecies image catalogues between research groups and support future use in multiple front-end applications. We also propose a framework for coordination of international efforts to develop reference guides for the identification of marine species from images. The proposed structure maps to the Darwin Core standard to allow integration with existing databases. We suggest a management framework where high-level taxonomic groups are curated by a regional team, consisting of both end users and taxonomic experts. We identify a mechanism by which overall quality of data within a common reference guide could be raised over the next decade. Finally, we discuss the role of a common reference standard in advancing marine ecology and supporting sustainable use of this ecosystem

The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age  6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score  652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

Clay Minerals and Italy – the Nannobacterial Connection

A continuation of research started by Dr. Folk and the late Dr. F. Leo Lynch seeking to demonstrate a biological origin for many clay mineralsGeological Science