Molecular data reveal cryptic lineages within the northeastern Atlantic and Mediterranean small mussel drills of the Ocinebrina edwardsii complex (Mollusca: Gastropoda: Muricidae)

We used a molecular phylogenetic approach to investigate species delimitations and diversification in the mussel drills of the Ocinebrina edwardsii complex by means of a combination of nuclear (internal transcribed spacer 2, ITS2) and mitochondrial [cytochrome oxidase subunit I (COI) and 16S] sequences. Our sample included 243 specimens ascribed to seven currently accepted species from 51 sites. Five of the samples were from either the type locality of a nominal species or a close nearby locality (O. edwardsii from Corsica, O. carmelae and O. piantonii from the Kerkennah Islands, O. hispidula from the Gulf of Gabès and O. leukos from the Canary Islands), one from the inferred original locality (O. ingloria from Venice Lagoon), and specimens assigned in the recent literature to O. nicolai. We used a combination of distance‐ and tree‐based species delimitation methods to identify Molecular Operational Taxonomic Units (MOTUs) to compare with the a priori species identifications. The consensus tree obtained by BEAST on the COI alignment allows the recognition of several distinct clades supported by the three species delimitation methods employed. The eight‐MOTUs scenario, shared by the Automatic Barcode Gap Discovery (ABGD) and Generalized Mixed Yule‐Coalescent (GMYC) methods, comprises the following major clades: clade A contains the south Tunisian species Ocinebrina piantonii Cecalupo, Buzzurro & Mariani from which the sympatric taxon O. carmelae Cecalupo, Buzzurro & Mariani (new synonym) cannot be separated; clades B and C bring together all populations from the Aegean Sea and some from the Ionian Sea, respectively; clade D groups, on the one hand, the south Tunisian samples morphologically assigned to O. hispidula Pallary and, on the other, Atlantic and Alboran Sea samples (including the Canarian taxon O. leukos Houart); clade E includes a sample from the type locality of O. edwardsii and several samples from the Tyrrhenian Sea; clades F and G correspond to a few samples from the Venice Lagoon and the Tyrrhenian Sea, respectively; clade H groups the bulk of samples from the Adriatic Sea, including samples from the Venice Lagoon morphologically identified as Ocinebrina ingloria (Crosse), and some from the Ionian Sea. No final conclusions could be reached to reconcile the currently recognized morphological taxa with the clades suggested by the COI data. The geographical structure proposed by the mitochondrial markers is similar to that found in other marine invertebrates and partially corresponds to the species defined by shell characters. We propose here a framework for the revision of the Ocinebrina edwardsii species complex, suggesting a geographical pattern for the diversification of this group in the studied area. © 2013 The Linnean Society of London     

Monitoring the Interaction between β2-Microglobulin and the Molecular Chaperone αB-crystallin by NMR and Mass Spectrometry: αB-CRYSTALLIN DISSOCIATES β2-MICROGLOBULIN OLIGOMERS*

The interaction at neutral pH between wild-type and a variant form (R3A) of the amyloid fibril-forming protein β₂-microglobulin (β2m) and the molecular chaperone αB-crystallin was investigated by thioflavin T fluorescence, NMR spectroscopy, and mass spectrometry. Fibril formation of R3Aβ2m was potently prevented by αB-crystallin. αB-crystallin also prevented the unfolding and nonfibrillar aggregation of R3Aβ2m. From analysis of the NMR spectra collected at various R3Aβ2m to αB-crystallin molar subunit ratios, it is concluded that the structured β-sheet core and the apical loops of R3Aβ2m interact in a nonspecific manner with the αB-crystallin. Complementary information was derived from NMR diffusion coefficient measurements of wild-type β2m at a 100-fold concentration excess with respect to αB-crystallin. Mass spectrometry acquired in the native state showed that the onset of wild-type β2m oligomerization was effectively reduced by αB-crystallin. Furthermore, and most importantly, αB-crystallin reversibly dissociated β2m oligomers formed spontaneously in aged samples. These results, coupled with our previous studies, highlight the potent effectiveness of αB-crystallin in preventing β2m aggregation at the various stages of its aggregation pathway. Our findings are highly relevant to the emerging view that molecular chaperone action is intimately involved in the prevention of in vivo amyloid fibril formation.     

Regulating Near-Space Activities: Using the Precedent of the Exclusive Economic Zone as a Model?

Abstract

The deployment of high-altitude vehicles in near space with the purpose of providing Internet, communication, and other services represents the new frontier of aerospace activities. Near-space operations are attracting growing interest due to their mult-purpose nature and their anticipated high profitability. Despite such positive perceptions, near-space plans are, however, hampered by the uncertain international legal status of near space. Using the precedent of the exclusive economic zone (EEZ), this article suggests a new categorization of the near space as the exclusive utilization space (EUS) and a set of rules to manage its utilization.     

Serial measurement of the circulating levels of tumour necrosis factor and its soluble receptors 1 and 2 for monitoring leprosy patients during multidrug treatment

Leprosy is an infectious and contagious spectral disease accompanied by a series of immunological events triggered by the host response to the aetiologic agent, Mycobacterium leprae . The induction and maintenance of the immune/inflammatory response in leprosy are linked to multiple cell interactions and soluble factors, primarily through the action of cytokines. The purpose of the present study was to evaluate the serum levels of tumour necrosis factor (TNF)-α and its soluble receptors (sTNF-R1 and sTNF-R2) in leprosy patients at different stages of multidrug treatment (MDT) in comparison with non-infected individuals and to determine their role as putative biomarkers of the severity of leprosy or the treatment response. ELISA was used to measure the levels of these molecules in 30 healthy controls and 37 leprosy patients at the time of diagnosis and during and after MDT. Our results showed increases in the serum levels of TNF-α and sTNF-R2 in infected individuals in comparison with controls. The levels of TNF-α, but not sTNF-R2, decreased with treatment. The current results corroborate previous reports of elevated serum levels of TNF-α in leprosy and suggest a role for sTNF-R2 in the control of this cytokine during MDT.     

Exploration of the Genomic Diversity and Core Genome of the Bifidobacterium adolescentis Phylogenetic Group by Means of a Polyphasic Approach

In the current work, we describe genome diversity and core genome sequences among representatives of three bifidobacterial species, i.e., Bifidobacterium adolescentis, Bifidobacterium catenulatum, and Bifidobacterium pseudocatenulatum, by employing a polyphasic approach involving analysis of 16S rRNA gene and 16S-23S internal transcribed spacer (ITS) sequences, pulsed-field gel electrophoresis (PFGE), and comparative genomic hybridization (CGH) assays.     

Fast Two-Dimensional Bubble Analysis of Biopolymer Filamentous Networks Pore Size from Confocal Microscopy Thin Data Stacks

The average pore size ξ₀ of filamentous networks assembled from biological macromolecules is one of the most important physical parameters affecting their biological functions. Modern optical methods, such as confocal microscopy, can noninvasively image such networks, but extracting a quantitative estimate of ξ₀ is a nontrivial task. We present here a fast and simple method based on a two-dimensional bubble approach, which works by analyzing one by one the (thresholded) images of a series of three-dimensional thin data stacks. No skeletonization or reconstruction of the full geometry of the entire network is required. The method was validated by using many isotropic in silico generated networks of different structures, morphologies, and concentrations. For each type of network, the method provides accurate estimates (a few percent) of the average and the standard deviation of the three-dimensional distribution of the pore sizes, defined as the diameters of the largest spheres that can be fit into the pore zones of the entire gel volume. When applied to the analysis of real confocal microscopy images taken on fibrin gels, the method provides an estimate of ξ₀ consistent with results from elastic light scattering data.     

The role of procalcitonin in neonatal intensive care unit patients with candidemia

Candidemia is a major infectious complication in neonatal patients. The isolation of yeasts from blood is still the ??gold standard?? for its diagnosis, but other laboratory markers (i.e., circulating antigens) have been studied with varying specificities and sensitivities. The aim of this study was to evaluate the role of procalcitonin for the diagnosis of candidemia in neonatal patients at high risk. To verify if the use of different commercial methods can highlight dissimilar results of sensitivity and/or specificity, the determination of procalcitonin serum levels was estimated by two systems. Overall, 90 patients from a Neonatal Intensive Care Units were enrolled, of whom six developed Candida bloodstream infection. Four of six infants with candidemia had slight increase of procalcitonin values (0.5?C1?ng/mL). Only one baby showed very high levels but he had fungal and bacterial sepsis at the same time, while no elevation was observed in the sixth patient. No statistically significant difference was observed between two different methods at the time of monitoring (p?>?0.643). Both methods showed a sensitivity of 83.3?% at diagnosis, while the specificity was 73.8 and 63.1?% by methods A and B, respectively. In the light of the low sensibility and specificity of this assay, we can assume that the determination of procalcitonin would not seem to play a significant role in the diagnosis of fungal infection in neonatal patients.     

Phenological and aeropalynological survey in an olive orchard in Umbria (Central Italy)

The olive tree Olea europaea L. is a resource of notable value from an economic and landscape point of view in Central Italy. This study examined two cultivars (Giarraffa and Ascolana) grown in an associative stand in an experimental olive orchard, to verify the possibility of introducing new olive cultivars into Umbria. The analyses were carried out at three different altitudes in the olive orchard following criteria used for non-homogeneous samplings in order to minimize the effect due to steepness. Since the number of trees of the two cultivars is different, the sample sizes were different for the two cultivars. Phenological observations of the above mentioned cultivars and the evaluation of the pollen flow, done by using a portable pollen trap inside the olive orchard, were carried out over two seasons (1998-1999). The start of initial phenological phases differed in the two cultivars, but the differences became less evident during phases of anthesis. In aeropalynological respect, it appears that, in a hill species such as the olive tree, the flowering is correlated with altitude. Comparing the aeropalynological data from the distant pollen trap and those collected in the olive orchard, it is clear that the periods of pollen release are very similar in the two cultivars, and there is a clear synchronism in the peak pollen release. It is concluded that in Central Italy the pollen grains of Giarraffa cultivar are well compatible with the Ascolana cultivar from a phenological and aeropalynological point of view.