Filamentous giant Beggiatoaceae from the Guaymas Basin are capable of both denitrification and dissimilatory nitrate reduction to ammonium

Filamentous large sulfur-oxidizing bacteria (FLSB) of the family Beggiatoaceae are globally distributed aquatic bacteria that can control geochemical fluxes from the sediment to the water column through their metabolic activity. FLSB mats from hydrothermal sediments of Guaymas Basin, Mexico, typically have a "fried-egg" appearance, with orange filaments dominating near the center and wider white filaments at the periphery, likely reflecting areas of higher and lower sulfide fluxes, respectively. These FLSB store large quantities of intracellular nitrate that they use to oxidize sulfide. By applying a combination of 15N-labeling techniques and genome sequence analysis, we demonstrate that the white FLSB filaments were capable of reducing their intracellular nitrate stores to both nitrogen gas and ammonium by denitrification and dissimilatory nitrate reduction to ammonium (DNRA), respectively. On the other hand, our combined results show that the orange filaments were primarily capable of DNRA. Microsensor profiles through a laboratory-incubated white FLSB mat revealed a 2- to 3-mm vertical separation between the oxic and sulfidic zones. Denitrification was most intense just below the oxic zone, as shown by the production of nitrous oxide following exposure to acetylene, which blocks nitrous oxide reduction to nitrogen gas. Below this zone, a local pH maximum coincided with sulfide oxidation, consistent with nitrate reduction by DNRA. The balance between internally and externally available electron acceptors (nitrate) and electron donors (reduced sulfur) likely controlled the end product of nitrate reduction both between orange and white FLSB mats and between different spatial and geochemical niches within the white FLSB mat

Interactions between temperature and energy supply drive microbial communities in hydrothermal sediment

Temperature and bioavailable energy control the distribution of life on Earth, and interact with each other due to the dependency of biological energy requirements on temperature. Here we analyze how temperature-energy interactions structure sediment microbial communities in two hydrothermally active areas of Guaymas Basin. Sites from one area experience advective input of thermogenically produced electron donors by seepage from deeper layers, whereas sites from the other area are diffusion-dominated and electron donor-depleted. In both locations, Archaea dominate at temperatures >45 °C and Bacteria at temperatures <10 °C. Yet, at the phylum level and below, there are clear differences. Hot seep sites have high proportions of typical hydrothermal vent and hot spring taxa. By contrast, high-temperature sites without seepage harbor mainly novel taxa belonging to phyla that are widespread in cold subseafloor sediment. Our results suggest that in hydrothermal sediments temperature determines domain-level dominance, whereas temperature-energy interactions structure microbial communities at the phylum-level and below

Evolution of the nuclear spin-orbit splitting explored via the ³²Si<i>(d,p)</i>³³Si reaction using SOLARIS

The spin-orbit splitting between neutron 1p orbitals at 33Si has been deduced using the single-neutron-adding (d,p) reaction in inverse kinematics with a beam of 32Si, a long-lived radioisotope. Reaction products were analyzed by the newly implemented SOLARIS spectrometer at the reaccelerated-beam facility at the National Superconducting Cyclotron Laboratory. The measurements show reasonable agreement with shell-model calculations that incorporate modern cross-shell interactions, but they contradict the prediction of proton density depletion based on relativistic mean-field theory. The evolution of the neutron 1p-shell orbitals is systematically studied using the present and existing data in the isotonic chains of = 17, 19, and 21. In each case, a smooth decrease in the separation of the - orbitals is seen as the respective p-orbitals approach zero binding, suggesting that the finite nuclear potential strongly influences the evolution of nuclear structure in this region

Depth-Related Differences in Organic Substrate Utilization by Major Microbial Groups in Intertidal Marine Sediment

Stable isotope probing of magnetic-bead-captured rRNA (Mag-SIP) indicated clear differences in in situ organic substrate utilization by major microbial groups between the more oxidized (0 to 2 cm) and sulfate-reducing (2 to 5 cm) horizons of marine intertidal sediment. We also showed that cyanobacteria and diatoms may survive by glucose utilization under dark anoxic conditions

Molecular phylogeny of the Piroplasmida: challenges from two potentially novel species found in the platypus (Ornithorhynchus anatinus)

The order Piroplasmida (Phylum: Apicomplexa) includes three main genera, Babesia, Theileria, and Cytauxzoon that are vector-borneprotozoan haemoparasites, some of which have clinical relevance both in humans and animals. With exceptions, Babesia is typically differentiated from Theileria based largely on morphology, serology, and several life-cycle peculiarities, within the tick vectors and vertebrate hosts. Despite these differences, and their global socio-economic importance, piroplasms often present conflicting or uncertain molecular classifications, nomenclature, and intergenic relationships. For instance, based on the small ribosomal subunit RNA gene (18S rDNA), the taxon Piroplasmida includes at least nine mono- and para-phyletic clades, which are sometimes populated by relatively distant members of the same genus, or by closely related species of different genera1 . As part of a study into the health and ecology of the platypus (Ornithorhynchus anatinus; Order: Monotremata), blood samples were collected for haematological and biochemical analysis, from wild-trapped individuals in Tasmania. Blood, together with ectoparasites removed from each individual, was also evaluated for piroplasm infections by blood film microscopy, and molecular analysis of the 18S rDNA. Moreover, phylogenetic analyses were performed on a subset of samples. Pleomorphic organisms with occasional tetrads and intra-leukocytic forms, thought to be Theileria schizonts, were observed by microscopy, and were phenotypically consistent with Theileria ornithorhynchi, a piroplasm of the platypus named in previous studies2 . However, molecularly, the parasite-derived DNA belonged to two potentially novel piroplasm species, forming one monophyletic clade, clearly separated from other known marsupial-derived Theileria spp.3 . The high prevalence (100%), apparent lack of clinical signs, and distinct phylogenetic position of the parasite, likely reflect the unique ecology and evolutionary history of its ancient vector-host system

"It doesn't all just stop at 18": Psychological adjustment and support needs of adults born with cleft lip and/or palate

© Copyright 2015 American Cleft Palate-Craniofacial Association. Background: Cleft in the lip and/or the palate (CL/P) is considered to be a lifelong condition, yet relatively little is known about the long-term outcomes for patients. Existing literature is largely outdated and conflicted, with an almost exclusive focus on medical aspects and deficits. Objective: To explore the psychological adjustment and possible support needs of a large number of adults born with CL/P from their own perspective. Design: Fifty-two individual telephone interviews eliciting qualitative data. Results: Qualitative analysis identified five themes. Participants reported a range of challenges in relation to discharge from the service, additional surgery as an adult, social and romantic relationships, higher education, vocational achievement, and access to psychological support. The findings imply that most adults with a cleft adjust well to these challenges and report many positive outcomes. For a minority of patients, issues attributed to the cleft may continue to cause distress in adulthood. Conclusions: Adults with CL/P may require psychological support, information about the heritability of cleft, signposting and referrals from nonspecialists, support regarding further treatment, and opportunities to take part in research and activities. New issues arising in adulthood, such as entering the workplace, forming long-term relationships, and starting a family, may warrant both further investigation and additional support. Further work is needed to identify the factors that contribute to psychological distress and resilience, as well as the timing of particular points of risk and opportunity for personal growth

Application of new thermodynamic data to grossular phase relations

Recent low temperature, adiabatic calorimetric heat capacity measurements for grossular have been combined with DSC measurements to give entropies up to 1000 K. In conjunction with enthalpy of solution values for grossular, these data have yielded Δ H f o (298.15K) and Δ G f o (298.15K) values of −1583.2 ± 3.5 and −1496.74 ± 3.7 kcal mol −1 respectively. For 15 reactions in the CaO-Al 2 O 3 -SiO 2 -H 2 O system, thermodynamically calculated P-T curves have been compared with experimental reversals and have shown good agreement in most cases. Calculations indicate that gehlenite is probably totally disordered. Estimates of zoisite and lawsonite entropies are consistent with the phase equilibrium and grossular data, but estimates of the entropies of pyrope and andradite show large discrepancies when compared with experimental reversals.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47323/1/410_2004_Article_BF00371508.pd