80 research outputs found

    A computer program for the design and static analysis of single-point subsurface mooring systems : NOYFB

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    This report describes computer program NOYFB, a method of determining the static configuration of sub-surface oceanographic moorings for the purposes of system design and analysis of performance. The program is written in Fortran II for the W.H.O.I. Hewlett-Packard 2100 series shipboard computer systems. The user acts as computer operator in a decision-making capacity, specifying, evaluating and modifying the mooring composition and control and environmental parameters. Operating instructions and the program listing are included as appendices.Prepared for the Office of Naval Research under Contract N00014-66-C-0241; NR 083-004

    A study of CTD cables and lowering systems

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    This study first reviews both the electrical and mechanical modes and causes of failure of electromechanical (E/M) cables used to lower deep sea sensors, such as CTD instruments, from oceanographic ships. It then outlines measures or steps that could be taken to correct some of the deficiencies observed and improve the systems presently used. These measures include quality control, tests, operational limits, improved handling and maintenance, improved machinery. The study then surveys alternative cables for lowering the sensors and convey the information from the sensors back to the ship. These alternatives include strength members other than steel (Kevlar)and signal carriers other than conventional copper conductors (fiber optics). The final section - Conclusions - summarizes the recommendations, based on this study, for improving the reliability of present and future CTD lowering systems.Prepared for the Office of Naval Research under Contract N00014-7l6-C-0197; NR 083-400

    An acoustic navigation system

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    This report describes a system for underwater acoustic navigation developed, and in use, at the Woods Hole Oceanographic Institution. It includes a brief discussion of the electronic components, operation, mathematical analysis, and available computer programs. There is a series of supplementary Technical Memoranda containing more information on various aspects of the system. We believe that this kind of documentation is more flexible and better meets the needs of potential users than including all technical details in one large volume. These are not final or definitive reports; acoustic navigation capabilities will continue to evolve at W.H.O.I. for some time. Acoustic navigation provides a method of tracking a ship, and an underwater vehicle or instrument package (‘fish’), in the deep ocean. Acoustic devices attached to the ship and fish measure the length of time it takes a sound pulse to travel to acoustic transponders moored on the ocean floor. If the transponder positions and the average speed of sound are known, the ship or fish position can be found.Prepared for the Office of Naval Research under Contracts N00014-71-C0284; NR 293-008 N00014-70-C0205; NR 263-103 and the National Science Foundation/International Decade of Ocean Exploration Grant GX-36024 and the Applied Physics Laboratory of The Johns Hopkins University Contract 372111

    Observations of the Antarctic polar front during FDRAKE 76 : a cruise report

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    Figures 37 and 38 have been reduced from their original size for the purpose of scanning.During March/April 1976 the small-scale structure of the Antarctic Polar Front was observed in the Drake Passage. The observations were part of the International Southern Ocean Studies (ISOS) program called FDRAke 76. The purpose of the program was to obtain densely sampled measurements of temperature, salinity, dissolved oxygen, and chemical nutrients in the Polar Front Zone (PFZ) and pilot measurements of horizontal and vertical velocities in order to explain the above scalar variability. The PFZ is a region where Antarctic and sub-Antarctic waters intermingle and presumably mix to affect the properties of Antarctic Intermediate Water. A report on the third leg of Cruise 107 of the R. V. THOMPSON is presented as well as a description of the measurements and a preliminary report of the data. A feature of interest is the pinching off of a northward meander of the circumpolar current system into a cyclonic ring of Antarctic Waters.Prepared for the National Science Foundation, Office for the International Decade of Ocean Exploration, under Grant OCE75-14056 and the International Southern Ocean Studies (ISOS) Program

    Genomic-Bioinformatic Analysis of Transcripts Enriched in the Third-Stage Larva of the Parasitic Nematode Ascaris suum

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    Differential transcription in Ascaris suum was investigated using a genomic-bioinformatic approach. A cDNA archive enriched for molecules in the infective third-stage larva (L3) of A. suum was constructed by suppressive-subtractive hybridization (SSH), and a subset of cDNAs from 3075 clones subjected to microarray analysis using cDNA probes derived from RNA from different developmental stages of A. suum. The cDNAs (n = 498) shown by microarray analysis to be enriched in the L3 were sequenced and subjected to bioinformatic analyses using a semi-automated pipeline (ESTExplorer). Using gene ontology (GO), 235 of these molecules were assigned to ‘biological process’ (n = 68), ‘cellular component’ (n = 50), or ‘molecular function’ (n = 117). Of the 91 clusters assembled, 56 molecules (61.5%) had homologues/orthologues in the free-living nematodes Caenorhabditis elegans and C. briggsae and/or other organisms, whereas 35 (38.5%) had no significant similarity to any sequences available in current gene databases. Transcripts encoding protein kinases, protein phosphatases (and their precursors), and enolases were abundantly represented in the L3 of A. suum, as were molecules involved in cellular processes, such as ubiquitination and proteasome function, gene transcription, protein–protein interactions, and function. In silico analyses inferred the C. elegans orthologues/homologues (n = 50) to be involved in apoptosis and insulin signaling (2%), ATP synthesis (2%), carbon metabolism (6%), fatty acid biosynthesis (2%), gap junction (2%), glucose metabolism (6%), or porphyrin metabolism (2%), although 34 (68%) of them could not be mapped to a specific metabolic pathway. Small numbers of these 50 molecules were predicted to be secreted (10%), anchored (2%), and/or transmembrane (12%) proteins. Functionally, 17 (34%) of them were predicted to be associated with (non-wild-type) RNAi phenotypes in C. elegans, the majority being embryonic lethality (Emb) (13 types; 58.8%), larval arrest (Lva) (23.5%) and larval lethality (Lvl) (47%). A genetic interaction network was predicted for these 17 C. elegans orthologues, revealing highly significant interactions for nine molecules associated with embryonic and larval development (66.9%), information storage and processing (5.1%), cellular processing and signaling (15.2%), metabolism (6.1%), and unknown function (6.7%). The potential roles of these molecules in development are discussed in relation to the known roles of their homologues/orthologues in C. elegans and some other nematodes. The results of the present study provide a basis for future functional genomic studies to elucidate molecular aspects governing larval developmental processes in A. suum and/or the transition to parasitism

    The Evolution of Host Specialization in the Vertebrate Gut Symbiont Lactobacillus reuteri

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    Recent research has provided mechanistic insight into the important contributions of the gut microbiota to vertebrate biology, but questions remain about the evolutionary processes that have shaped this symbiosis. In the present study, we showed in experiments with gnotobiotic mice that the evolution of Lactobacillus reuteri with rodents resulted in the emergence of host specialization. To identify genomic events marking adaptations to the murine host, we compared the genome of the rodent isolate L. reuteri 100-23 with that of the human isolate L. reuteri F275, and we identified hundreds of genes that were specific to each strain. In order to differentiate true host-specific genome content from strain-level differences, comparative genome hybridizations were performed to query 57 L. reuteri strains originating from six different vertebrate hosts in combination with genome sequence comparisons of nine strains encompassing five phylogenetic lineages of the species. This approach revealed that rodent strains, although showing a high degree of genomic plasticity, possessed a specific genome inventory that was rare or absent in strains from other vertebrate hosts. The distinct genome content of L. reuteri lineages reflected the niche characteristics in the gastrointestinal tracts of their respective hosts, and inactivation of seven out of eight representative rodent-specific genes in L. reuteri 100-23 resulted in impaired ecological performance in the gut of mice. The comparative genomic analyses suggested fundamentally different trends of genome evolution in rodent and human L. reuteri populations, with the former possessing a large and adaptable pan-genome while the latter being subjected to a process of reductive evolution. In conclusion, this study provided experimental evidence and a molecular basis for the evolution of host specificity in a vertebrate gut symbiont, and it identified genomic events that have shaped this process

    Inheritance of quantitative expression of erythrocyte glucose-6-phosphate dehydrogenase activity in the Negro—a twin study

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    Studies have been conducted on eight sets of monozygous and nine sets of dizygous female Negro twins, both members of whom were heterozygous for G-6-PD deficiency. Twins were studied both by assay of erythrocytic G-6-PD activity and by the methemoglobin elution test (MET). The MET is a procedure which identifies histochemically cells with appreciable G-6-PD activity and permits accurate determination of the percentage of such cells in heterozygotes. Monozygous twins showed significantly less “within-pair” variation than dizygous twins with both the MET and G-6-PD assay.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44115/1/10528_2004_Article_BF00487735.pd

    East Coast Fever Caused by Theileria parva Is Characterized by Macrophage Activation Associated with Vasculitis and Respiratory Failure

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    Respiratory failure and death in East Coast Fever (ECF), a clinical syndrome of African cattle caused by the apicomplexan parasite Theileria parva, has historically been attributed to pulmonary infiltration by infected lymphocytes. However, immunohistochemical staining of tissue from T. parva infected cattle revealed large numbers of CD3- and CD20-negative intralesional mononuclear cells. Due to this finding, we hypothesized that macrophages play an important role in Theileria parva disease pathogenesis. Data presented here demonstrates that terminal ECF in both Holstein and Boran cattle is largely due to multisystemic histiocytic responses and resultant tissue damage. Furthermore, the combination of these histologic changes with the clinical findings, including lymphadenopathy, prolonged pyrexia, multi-lineage leukopenia, and thrombocytopenia is consistent with macrophage activation syndrome. All animals that succumbed to infection exhibited lymphohistiocytic vasculitis of small to medium caliber blood and lymphatic vessels. In pulmonary, lymphoid, splenic and hepatic tissues from Holstein cattle, the majority of intralesional macrophages were positive for CD163, and often expressed large amounts of IL-17. These data define a terminal ECF pathogenesis in which parasite-driven lymphoproliferation leads to secondary systemic macrophage activation syndrome, mononuclear vasculitis, pulmonary edema, respiratory failure and death. The accompanying macrophage phenotype defined by CD163 and IL-17 is presented in the context of this pathogenesis
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