Phylogenetic Relationships and Evolutionary Patterns of the Order Collodaria (Radiolaria)

Collodaria are the only group of Radiolaria that has a colonial lifestyle. This group is potentially the most important plankton in the oligotrophic ocean because of its large biomass and the high primary productivity associated with the numerous symbionts inside a cell or colony. The evolution of Collodaria could thus be related to the changes in paleo-productivity that have affected organic carbon fixation in the oligotrophic ocean. However, the fossil record of Collodaria is insufficient to trace their abundance through geological time, because most collodarians do not have silicified shells. Recently, molecular phylogeny based on nuclear small sub-unit ribosomal DNA (SSU rDNA) confirmed Collodaria to be one of five orders of Radiolaria, though the relationship among collodarians is still unresolved because of inadequate taxonomic sampling. Our phylogenetic analysis has revealed four novel collodarian sequences, on the basis of which collodarians can be divided into four clades that correspond to taxonomic grouping at the family level: Thalassicollidae, Collozoidae, Collosphaeridae, and Collophidae. Comparison of the results of our phylogenetic analyses with the morphological characteristics of each collodarian family suggests that the first ancestral collodarians had a solitary lifestyle and left no silica deposits. The timing of events estimated from molecular divergence calculations indicates that naked collodarian lineages first appeared around 45.6 million years (Ma) ago, coincident with the diversification of diatoms in the pelagic oceans. Colonial collodarians appeared after the formation of the present ocean circulation system and the development of oligotrophic conditions in the equatorial Pacific (ca. 33.4 Ma ago). The divergence of colonial collodarians probably caused a shift in the efficiency of primary production during this period

Amyloid Plaques Beyond Aβ: A Survey of the Diverse Modulators of Amyloid Aggregation

Aggregation of the amyloid-β (Aβ) peptide is strongly correlated with Alzheimer’s disease (AD). Recent research has improved our understanding of the kinetics of amyloid fibril assembly and revealed new details regarding different stages in plaque formation. Presently, interest is turning toward studying this process in a holistic context, focusing on cellular components which interact with the Aβ peptide at various junctures during aggregation, from monomer to cross-β amyloid fibrils. However, even in isolation, a multitude of factors including protein purity, pH, salt content, and agitation affect Aβ fibril formation and deposition, often producing complicated and conflicting results. The failure of numerous inhibitors in clinical trials for AD suggests that a detailed examination of the complex interactions that occur during plaque formation, including binding of carbohydrates, lipids, nucleic acids, and metal ions, is important for understanding the diversity of manifestations of the disease. Unraveling how a variety of key macromolecular modulators interact with the Aβ peptide and change its aggregation properties may provide opportunities for developing therapies. Since no protein acts in isolation, the interplay of these diverse molecules may differentiate disease onset, progression, and severity, and thus are worth careful consideration

Self-nucleation and kinetic behavior of nanocolloidal sodalite particles in highly caustic liquors

Sodium aluminosilicate (SAS) crystallization from supersaturated caustic liquors is of high industrial significance with regards to intractable heat exchanger precipitation fouling issues in Bayer process alumina refining and high level nuclear waste processing. In the present work, isothermal (65 °C) homogeneous nucleation behavior of nanocolloidal SAS particles in optically clear solutions as a function of time was investigated by dynamic light scattering (DLS). At a high SiO₂ relative supersaturation (σ) of 12, the solution was perennially metastable, reflecting a long nucleation induction time of 12 h. Upon ephemeral preheating at 100 °C, and/or a 25− 40% increase in σ, the DLS analysis showed that rapid nucleation and moderate particle growth occurred in the optically clear solutions. Furthermore, evolution uni-, bi-, and trimodal particle size distributions in the range of 20−1800 nm with time was observed, accompanied by significant time-dependent distribution broadening effects. For growth mechanisms, both nanoparticle aggregation and surface integration of ionic growth units are revealed, manifesting in polydispersed, low mass density-contrast agglomerates in optically clear liquors. The SAS solid product observed after prolonged crystallization was high carbonatesodalite crystals, comprising agglomerates of nanoparticles. The pivotal roles played by SiO₂ supersaturation and temperature in the early stages of sodalite nucleation and growth are demonstrated by the results.Jonas Addai-Mensah, Tatiana Khmeleva and John C. Thoma

Innovative technology for the production of macaroni products made of emmer wheat flour

Macaroni products as a product of mass consumption can serve as an object for enriching the human body with useful components by using non-traditional raw materials. The authors propose an innovative technology for the production of macaroni products made of a mixture of wheat and emmer wheat flour with the addition of wheat bran as a source of dietary fibers, which makes it possible to give functionality to the products and at the same time improve their quality

Benthic standing stock and metabolic activity in the bathyal Red Sea from 17°N to 27°N

To study the impact of the gradient of primary production between the southern, central, and northern Red Sea, benthic metabolism and standing stocks were investigated in the axial trough between 17°N and 27°N. Data on sediment chloroplastic pigments, macrofauna and meiofauna abundance, particulate adenylate, protein and carbohydrate biomass, as well as electron transport activity of the sediment community give evidence for an enhanced benthic standing stock and activity in the southern Red Sea south of 18°N; this is related to the increased primary productivity in the area south 16°N. Despite a large primary production only small benthic standing stocks were found in all areas investigated; they are much smaller than in other parts of the world's deep oceans with comparable primary production. The low benthic biomass is caused by two factors: a large proportion of particulate organic carbon is remineralized in the water column, while only a relatively small amount sediments to the sea floor; nearly all sedimented particulate organic matter is respired by the benthic community of the deep Red Sea and only a minute proportion is used for the production of benthic biomass