Synechococcus dynamics in the Levantine basin shelf waters (northeastern Mediterranean)

The abundance of picoplanktonic marine cyanobacteria Synechococcus was measured at weekly intervals over a period of one year in the northern Levantine basin shelf waters. Synechococcuswas found more abundant during summer and early autumn and least during winter. Significant increases in abundances mostly occurred during very low nutrient concentrations either a week or two weeks after the nutrient enrichments. Cells were distributed homogenously in the water column due to intense mixing observed during winter. Despite the homogenous cell distribution attained during late autumn and winter, the magnitude of variation in cell abundances among depths was found greatest during August and September. Cell concentrations ranged from a minimum of 6.4 x 103 to a maximum of 9.2 x 104 cells ml-1 with an annual mean level of 2.5 x 104cells ml-1 at surface. Below the surface, it ranged from a minimum of 5.6 x 103 to a maximum of 8.0 x 104cells ml-1 with an annual mean level of 2.1 x 104 cells ml-1 at 25 m depth. Compared to surface and 25 m depth, lowest levels were attained at 50 m. At this depth, cell counts ranged from a minimum of 5.4 x 103to a maximum of 3.2 x 104 cells ml-1 with an annual mean level of 1.4 x 104 cells ml-1. Based on Pearson-product moment correlation analysis, a highly significant correlation between Synechococcusabundance and ambient temperature was observed

Regression on feature projections

Cataloged from PDF version of article.This paper describes a machine learning method, called Regression on Feature Projections (RFP), for predicting a real-valued target feature, given the values of multiple predictive features. In RFP training is based on simply storing the projections of the training instances on each feature separately. Prediction of the target value for a query point is obtained through two averaging procedures executed sequentially. The ®rst averaging process is to ®nd the individual predictions of features by using the K-Nearest Neighbor (KNN) algorithm. The second averaging process combines the predictions of all features. During the ®rst averaging step, each feature is associated with a weight in order to determine the prediction ability of the feature at the local query point. The weights, found for each local query point, are used in the second prediction step and enforce the method to have an adaptive or context-sensitive nature. We have compared RFP with KNN and the rule based-regression algorithms. Results on real data sets show that RFP achieves better or comparable accuracy and is faster than both KNN and Rule-based regression algorithms. (C)2000 Elsevier Science B.V. All rights reserved

Insights into mantle-type volatiles contribution from dissolved gases in artesian waters of the Great Artesian Basin, Australia

The geochemical features of the volatiles dissolved in artesian thermal waters discharged over three basins (Millungera, Galilee and Cooper basin) of the Australian Great Artesian Basin (GAB) consistently indicate the presence of fluids from multiple gas sources located in the crust (e.g. sediments, oil reservoirs, granites) as well as minor but detectable contributions of mantle/magma-derived fluids. The gases extracted from 19 water samples and analyzed for their chemical and isotopic composition exhibit amounts of CO up to about 340mlSTP/L marked by a δC (Total Dissolved Carbon) ranging from -16.9 to +0.18‰ vs PDB, while CH concentrations vary from 4.4×10 to 4.9mlSTP/L. Helium contents were between 9 and >2800 times higher than equilibrium with Air Saturated Water (ASW), with a maximum value of 0.12mlSTP/L. Helium isotopic composition was in the 0.02-0.21 Ra range (Ra = air-normalized He/He ratio). The three investigated basins differ from each other in terms of both chemical composition and isotopic signatures of the dissolved gases whose origin is attributed to both mantle and crustal volatiles. Mantle He is present in the west-central and hottest part of the GAB despite no evidence of recent volcanism. We found that the partial pressure of helium, significantly higher in crustal fluids than in mantle-type volatiles, enhances the crustal He signature in the dissolved gases, thus masking the original mantle contribution. Neotectonic activity involving deep lithospheric structures and magma intrusions, highlighted by recent geophysical investigations, is considered to be the drivers of mantle/magmatic volatiles towards the surface. The results, although pertaining to artesian waters from a vast area of >542,000km, provide new constraints on volatile injection, and show that fluids' geochemistry can provide additional and independent information on the geo-tectonic settings of the Great Artesian Basin and its geothermal potential

The podiform chromitites in the Dagküplü and Kavak mines, Eskisehir ophiolite (NW-Turkey) : genetic implications of mineralogical and geochemical data

Mantle tectonites from Eskisehir (NW-Turkey) include high-Cr chromitites with limited variation of Cr#, ranging from 65 to 82. Mg# ratios are between 54 and 72 and chromite grains contain up to 3.71 wt% Fe2O3 and 0.30 wt% TiO2. PGE contents are variable and range from 109 to 533 pbb. Chondrite-normalized PGE patterns are flat from Os to Rh and negatively sloping from Rh to Pd. Total PGE contents and low Pd/Ir ratios (from 0.07 to 0.41) of chromitites are consistent with typical ophiolitic chromitites. Chromite grains contain a great number of solid inclusions. They comprise mainly of highly magnesian (Mg# 95-98) mafic silicates (olivine, amphibole and clinopyroxene) and base-metal sulfide inclusions of millerite (NiS), godlevskite (Ni7S6), bornite (C5FeS4) with minor Ni arsenides of maucherite (Ni11As8) and orcelite (Ni5-xAs2), and unnamed Cu2FeS3 phases. Heazlewoodite, awaruite, pyrite, and rare putoranite (Cu9Fe,Ni9S16) were also detected in the matrix of chromite as secondary minerals. Laurite [(Ru,Os)S2] was the only platinum-group minerals found as primary inclusions in chromite. They occur as euhedral to subhedral crystals trapped within chromite grains and are believed to have formed in the high temperature magmatic stage during chromite crystallization. Laurite has limited compositional variation, range between Ru0.94Os0.03Ir0.02S1.95 and Ru0.64Os0.21Ir0.10S1.85, and contain up to 1.96 at% Rh and 3.67 at% As. Close association of some laurite grains with amphibole and clinopyroxene indicates crystallization from alkali rich fluid bearing melt in the suprasubduction environment. The lack of any IPGE alloys, as well as the low Os-content of laurite, assumes that the melt from which chromite and laurite were crystallized had relatively high fS2 but never reached the fS2 to crystallize the erlichmanite. The presence of millerite, as primary inclusions in chromite, reflects the increasing fS2 during the chromite crystallization

Primary Molar Pulpotomies with Different Hemorrhage Control Agents and Base Materials: A Randomized Clinical Trial

Objective: To evaluate the clinical and radiographical success of primary molar pulpotomies which used 15.5% ferric sulfate (FS) or 1.25% sodium hypochlorite (NaOCl) for hemostasis and zinc oxide-eugenol (ZOE) and calcium hydroxide (CH) pastes as base materials. Methods: In 29 healthy children, 80 primary molars were randomly allocated to one of the study groups: Group 1: FS-ZOE, Group 2: FS-CH, Group 3: NaOCl-ZOE, and Group 4: NaOCl-CH. After hemostasis with the respective solutions, pulp stumps and floor of the pulp chambers were covered with either ZOE or CH pastes. All teeth were restored with stainless steel crowns. Follow-up examinations were carried out at 1, 3, 6, and 12 months. Results: One tooth in Group 1 and two teeth in Group 4 were extracted because of pain and periapial pathosis at sixth month. After 12 months, clinical success rates of pulpotomies in Groups 1-4 were 95%, 100%, 100%, and 89.5%, respectively. The differences were not significant (P = 0.548). Radiographic success rates for Groups 1-4 were 80%, 88.9%, 78.9%, and 84.2%, respectively. No statistically significant difference was found (P = 0.968). Pain on percussion was the most observed clinical finding. However, internal root resorption was the most common radiological finding and it was observed significantly more in mandibular primary molars (P \u3c 0.05). Conclusion: Both ZOE and CH can be preferred as base materials after hemostasis achieved by the use of 15.5% FS or 1.25% NaOCl in primary tooth pulpotomy

Peptidylarginine Deiminase Isozyme-Specific PAD2, PAD3 and PAD4 Inhibitors Differentially Modulate Extracellular Vesicle Signatures and Cell Invasion in Two Glioblastoma Multiforme Cell Lines

Glioblastoma multiforme (GBM) is an aggressive adult brain tumour with poor prognosis. Roles for peptidylarginine deiminases (PADs) in GBM have recently been highlighted. Here, two GBM cell lines were treated with PAD2, PAD3 and PAD4 isozyme-specific inhibitors. Effects were assessed on extracellular vesicle (EV) signatures, including EV-microRNA cargo (miR21, miR126 and miR210), and on changes in cellular protein expression relevant for mitochondrial housekeeping (prohibitin (PHB)) and cancer progression (stromal interaction molecule 1 (STIM-1) and moesin), as well as assessing cell invasion. Overall, GBM cell-line specific differences for the three PAD isozyme-specific inhibitors were observed on modulation of EV-signatures, PHB, STIM-1 and moesin protein levels, as well as on cell invasion. The PAD3 inhibitor was most effective in modulating EVs to anti-oncogenic signatures (reduced miR21 and miR210, and elevated miR126), to reduce cell invasion and to modulate protein expression of pro-GBM proteins in LN229 cells, while the PAD2 and PAD4 inhibitors were more effective in LN18 cells. Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways for deiminated proteins relating to cancer, metabolism and inflammation differed between the two GBM cell lines. Our findings highlight roles for the different PAD isozymes in the heterogeneity of GBM tumours and the potential for tailored PAD-isozyme specific treatment

Effects of ions on the liquid crystalline mesophase of transition-metal salt: Surfactant (CnEOm)

The transition-metal aqua complex salts [M(H2O) x]Y2 (where M is some of the first- and second-row transitionmetal ions and Y is Cl-, NO3-, and ClO4- counteranions) form liquid crystalline (LC) mesophases with oligo(ethylene oxide) nonionic surfactants (CnH 2n+1(CH2CH2O)mOH, denoted as C nEOm). The structure of the [M(H2O) x]Y2:CnEOm mesophase is usually 2D hexagonal in nitrate systems, cubic in perchlorate systems, and absent in the chloride systems. The solubility of the metal aqua complex salt follows the Hofmeister series in a [M(H2O)x]Y2:C nEOm mesophase. However, the nitrate ion interacts with the metal center as a bidentate and/or unidentate ligand, therefore reducing the ion density (and/or ionic strength) of the LC medium and further enhancing the solubility of nitrate salt in the LC systems. The cobalt chloride salt is the only soluble chloride salt that undergoes ligand-exchange reactions in the [Co(H2O)6]Cl2:CnEOm system. In an LC mesophase, anions have a greater influence on the hydrophilicity of nonionic surfactants than do cations. The structure and stability of the LC mesophase can be controlled by controlling either the hydrophilicity of the nonionic surfactant (by choosing the right anion type) or the ion density of the medium (by either influencing the equilibrium between the free and coordinated anions or balancing between the coordinating and noncoordinating anions in the medium)