29 research outputs found

    Some aspects of the iodine metabolism of the giant kelp Macrocystis pyrifera (phaeophyceae)

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    We are grateful to the Total Foundation (Paris) and to the MASTS pooling initiative (Marine Alliance for Science and Technology for Scotland, funded by the Scottish Funding Council and contributing institutions; grant reference HR09011), both for their funding support to FCK. We thank Prof. Matt Edwards (SDSU department of Biology) and his students for help in collecting specimens and for the use of equipment.Peer reviewedPostprin

    Modified Laminar Bone in Ampelosaurus atacis and Other Titanosaurs (Sauropoda): Implications for Life History and Physiology

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    BACKGROUND: Long bone histology of the most derived Sauropoda, the Titanosauria suggests that titanosaurian long bone histology differs from the uniform bone histology of basal Sauropoda. Here we describe the long bone histology of the titanosaur Ampelosaurus atacis and compare it to that of basal neosauropods and other titanosaurs to clarify if a special titanosaur bone histology exists. METHODOLOGY/PRINCIPAL FINDINGS: Ampelosaurus retains the laminar vascular organization of basal Sauropoda, but throughout most of cortical growth, the scaffolding of the fibrolamellar bone, which usually is laid down as matrix of woven bone, is laid down as parallel-fibered or lamellar bone matrix instead. The remodeling process by secondary osteons is very extensive and overruns the periosteal bone deposition before skeletal maturity is reached. Thus, no EFS is identifiable. Compared to the atypical bone histology of Ampelosaurus, the large titanosaur Alamosaurus shows typical laminar fibrolamellar bone. The titanosaurs Phuwiangosaurus, Lirainosaurus, and Magyarosaurus, although differing in certain features, all show this same low amount or absence of woven bone from the scaffolding of the fibrolamellar bone, indicating a clear reduction in growth rate resulting in a higher bone tissue organization. To describe the peculiar primary cortical bone tissue of Phuwiangosaurus, Ampelosaurus, Lirainosaurus, and Magyarosaurus, we here introduce a new term, "modified laminar bone" (MLB). CONCLUSIONS/SIGNIFICANCE: Importantly, MLB is as yet not known from extant animals. At least in Lirainosaurus and Magyarosaurus the reduction of growth rate indicated by MLB is coupled with a drastic body size reduction and maybe also a reduction in metabolic rate, interpreted as a result of dwarfing on the European islands during the Late Cretaceous. Phuwiangosaurus and Ampelosaurus both show a similar reduction in growth rate but not in body size, possibly indicating also a reduced metabolic rate. The large titanosaur Alamosaurus, on the other hand, retained the plesiomorphic bone histology of basal neosauropods

    Emission of volatile halogenated compounds, speciation and localization of bromine and iodine in the brown algal genome model Ectocarpus siliculosus

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    This study explores key features of bromine and iodine metabolism in the filamentous brown alga and genomics model Ectocarpus siliculosus. Both elements are accumulated in Ectocarpus, albeit at much lower concentration factors (2-3 orders of magnitude for iodine, and < 1 order of magnitude for bromine) than e.g. in the kelp Laminaria digitata. Iodide competitively reduces the accumulation of bromide. Both iodide and bromide are accumulated in the cell wall (apoplast) of Ectocarpus, with minor amounts of bromine also detectable in the cytosol. Ectocarpus emits a range of volatile halogenated compounds, the most prominent of which by far is methyl iodide. Interestingly, biosynthesis of this compound cannot be accounted for by vanadium haloperoxidase since the latter have not been found to catalyze direct halogenation of an unactivated methyl group or hydrocarbon so a methyl halide transferase-type production mechanism is proposed

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Making a difference with Aviation Foreign Internal Defense

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    This thesis analyzes how U.S. Aviation Foreign Internal Defense (AvFID) proved itself to be a critical component in the successful campaign against the Hukbalahap (i.e., Huks) in the Philippines and the Farabundo Marti National Liberation Front (FMLN) in El Salvador. In addition, this thesis explores how AvFID was employed in Vietnam and why AvFID was not successful there. The overall argument is that airpower was not a decisive factor in the two successful counterinsurgency campaigns examined. However, airpower certainly played a critical role in quelling both insurgencies and without U.S. AvFID the air forces in the Philippines and El Salvador would not have been able to employ airpower as effectively as they did. In contrast, Vietnam offers a case study where AvFID failed; this thesis explores why. Ultimately, the reader should walk away with ideas about how to implement AvFID more effectively, and that if done right, can help ensure that AvFID can make a significant difference in a counterinsurgency campaign.http://archive.org/details/makingdifference1094527804Major, United States Air ForceApproved for public release; distribution is unlimited

    Design and Manufacturing of High Surface Area 3D-Printed Media for Moving Bed Bioreactors for Wastewater Treatment

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    The specific surface area and topology of a biofilter media carrier is one of the most important parameters that determines the performance and efficiency of the system. In this work, mathematical models and 3D printing technologies were used to design and fabricate complex media designs that provide high specific surface area and refugia to protect biofilm from premature sloughing. Several gyroid based designs were proposed with specific surface area well beyond 2300 m2/m3. However, wall thicknesses and pore sizes that are prone to clogging determined a design that yields 1168 m2/m3 (133% larger than the baseline commercial K1 Kaldnes). Several moving bed bioreactors were constructed for laboratory testing with inoculation provided by wastewater from a fisheries operation. Preliminary results indicate that the 3D printed media can withstand the prevalent conditions in moving bed bioreactors, and that the NH3 removal rate of gyroid media is comparable to that of K1 Kaldnes. This work establishes the feasibility of using 3D printing for bioreactor media fabrication and allows for future topology optimization for enhanced operation. Future work is needed to investigate how these complex media designs might stimulate novel microbial assemblages and community metabolism that translate into yield efficiency gains in reactor performance

    Design and Manufacturing of High Surface Area 3D‐Printed Media for Moving Bed Bioreactors for Wastewater Treatment

    No full text
    The specific surface area and topology of a biofilter media carrier is one of the most important parameters that determines the performance and efficiency of the system. In this work, mathematical models and 3D printing technologies were used to design and fabricate complex media designs that provide high specific surface area and refugia to protect biofilm from premature sloughing. Several gyroid based designs were proposed with specific surface area well beyond 2300 m2/m3. However, wall thicknesses and pore sizes that are prone to clogging determined a design that yields 1168 m2/m3 (133% larger than the baseline commercial K1 Kaldnes). Several moving bed bioreactors were constructed for laboratory testing with inoculation provided by wastewater from a fisheries operation. Preliminary results indicate that the 3D printed media can withstand the prevalent conditions in moving bed bioreactors, and that the NH3 removal rate of gyroid media is comparable to that of K1 Kaldnes. This work establishes the feasibility of using 3D printing for bioreactor media fabrication and allows for future topology optimization for enhanced operation. Future work is needed to investigate how these complex media designs might stimulate novel microbial assemblages and community metabolism that translate into yield efficiency gains in reactor performance
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