2,051 research outputs found
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Amplification Of Dna-Polymerase Gene Fragments From Viruses Infecting Microalgae
No full textNested PCR with three highly degenerate primers was used for amplification and identification of DNA polymerase (pol) genes from viruses which infect three genera of microalgae. Group specific primers (AVS1 and AVS2) were designed on the basis of inferred amino acid sequences unique to the DNA pol genes of viruses (PBCV-1 and NY-2A) that infect an endosymbiotic Chlorella-like alga (Chlorophyceae) and a virus (MpV-SP1) which infects the photosynthetic flagellate Micromonas pusilla (Prasinophyceae). In addition, a nested primer (POL) was designed on the basis of the highly conserved amino acid sequence YGDTDS found in most B-family (alpha-like) DNA pol genes. These primers were used to amplify DNA from the three viruses, PBCV-1, NY-2A, and MpV-SP1, for which the primers were designed, as well as eight clonal isolates of genetically distinct viruses which infect M. pusilla and others which infect Chrysochromulina spp. (Prymnesiophyceae), suggesting that these are a group of related viruses. In contrast, no product resulted from using DNA from viruses which infect the marine brown algae Ectocarpus siliculosis and Feldmannia sp. (Phaeophyceae), suggesting that these viruses may not be closely related to those that infect microalgae. These primers were also used to amplify DNA from natural virus communities. Our results indicate that nested PCR, even under low-stringency conditions, can be used as a rapid method to verify the presence in seawater of a group of related viruses which infect microalgae. Sequence analysis of these fragments should provide information on the genetic diversity and potentially the phyletic relationships among these viruses. This is the first example of a PCR-based technique designed to detect viruses which infect eukaryotic algae.Marine Scienc
Without viruses we would not be alive
No full textThe novel coronavirus, SARS-CoV-2, is just the latest in what seems to be a never-ending war against the spread of viral diseases. But, did you know that we wouldn’t exist without viruses? Join 2019 Wall Scholar Curtis Suttle as he explains their central role in our evolution and survival.Science, Faculty ofBotany, Department ofEarth, Ocean and Atmospheric Sciences, Department ofMicrobiology and Immunology, Department ofOceans and Fisheries, Institute for theUnreviewedFacult
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Dynamics And Distribution Of Cyanophages And Their Effect On Marine Synechococcus Spp
No full textCyanophages infecting marine Synechococcus cells were frequently very abundant and were found in every seawater sample along a transect in the western Gulf of Mexico and during a 28-month period in Aransas Pass, Tex. In Aransas Pass their abundance varied seasonally, with the lowest concentrations coincident with cooler water and lower salinity. Along the transect, viruses infecting Synechococcus strains DC2 and SYN48 ranged in concentration from a few hundred per milliliter at 97 m deep and 83 km offshore to ca. 4 x 10(5) ml(-1) near the surface at stations within 18 km of the coast. The highest concentrations occurred at the surface, where salinity decreased from ca. 35.5 to 34 ppt and Synechococcus concentrations were greatest. Viruses infecting strains SNC1, SNC2, and 838BG were distributed in a similar manner but were much less abundant (<10 to >5 x 10(3) ml(-1)). When Synechococcus concentrations exceeded ca. 10(3) ml(-1), cyanophage concentrations increased markedly (ca. 10(2) to > 10(5) ml(-1)), suggesting that a minimum host density was required for efficient viral propagation. Data on the decay rate of viral infectivity d (per day), as a function of solar irradiance I (millimoles of quanta per square meter per second), were used to develop a relationship (d = 0.2610I-0.00718; r(2) = 0.69) for conservatively estimating the destruction of infectious viruses in the mixed layer of two offshore stations. Assuming that virus production balances losses and that the burst size is 250, ca. 5 to 7% of Synechococcus cells would be infected daily by viruses. Calculations based on contact rates between Synechococcus cells and infectious viruses produce similar results (5 to 14%). Moreover, balancing estimates of viral production with contact rates for the farthest offshore station required that most Synechococcus cells be susceptible to infection, that most contacts result in infection, and that the burst size be about 324 viruses per lytic event. In contrast, in nearshore waters, where ca. 80% of Synechococcus cells would be contacted daily by infectious cyanophages, only ca. 1% of the contacts would have to result in infection to balance the estimated virus removal rates. These results indicate that cyanophages are an abundant and dynamic component of marine planktonic communities and are probably responsible for lysing a small but significant portion of the Synechococcus population on a daily basis.National Science Foundation OCE-9018833U.S. Office of Naval Research N00014-92-J-1676Marine Scienc
Identification of freshwater Phycodnaviridae and their potential phytoplankton hosts, using DNA pol sequence fragments and a genetic-distance analysis
No full textViruses that infect phytoplankton are an important component of aquatic ecosystems, yet in lakes they remain largely unstudied. In order to investigate viruses (Phycodnaviridae) infecting eukaryotic phytoplankton in lakes and to estimate the number of potential host species, samples were collected from four lakes at the Experimental Lakes Area in Ontario, Canada, during the ice-free period (mid-May to mid-October) of 2004. From each lake, Phycodnaviridae DNA polymerase (pol) gene fragments were amplified using algal-virus-specific primers and separated by denaturing gradient gel electrophoresis; 20 bands were extracted from the gels and sequenced. Phylogenetic analysis indicated that freshwater environmental phycodnavirus sequences belong to distinct phylogenetic groups. An analysis of the genetic distances "within" and "between" monophyletic groups of phycodnavirus isolates indicated that DNA pol sequences that differed by more than 7% at the inferred amino acid level were from viruses that infect different host species. Application of this threshold to phylogenies of environmental sequences indicated that the DNA pol sequences from these lakes came from viruses that infect at least nine different phytoplankton species. A multivariate statistical analysis suggested that potential freshwater hosts included Mallomonas sp., Monoraphidium sp., and Cyclotella sp. This approach should help to unravel the relationships between viruses in the environment and the phytoplankton hosts they infect.final article publishedphytoplanktonChlorophytadiatomsFresh WaterPhycodnavirida
In researching the history of rum and rum cocktails, author Wayne Curtis bought
No full textIn researching the history of rum and rum cocktails, author Wayne Curtis bought an out-of-print copy of Trader Vic\u27s Book of Food & Drink that once belonged to Maine author Kenneth Roberts (1885-1957). On a blank page, Curtis discovered Roberts\u27 well-crafted description of inventing a recipe, with scratched out and recast words
Curtis Blanton, Mountain Humorist
No full textAuthor Curtis Blanton has a wonderful sense of humor. Herewith, listen to this interview from 2009 about how he came to publish the stories he heard the old timers tell when he was a kid
Trip account
No full textTrip account - AMs, 15 pp.
“I am attempting to give you some account of a recent vacation trip which we were privileged to enjoy - Rose, Mother and I…” As the account of the trip to view the eclipse is unsigned, we can’t say for sure but as the author states “Rose, Mother and I” one could logically assume that the author is a sibling of T. Rose Curtis
Curtis Wilkie Letter and Map
No full textA nine-page letter from journalist and author Curtis Wilkie, written to his parents, containing a first-hand account of the integration of the University of Mississippi. Wilkie was a student at the university at the time. Included is a hand-drawn map showing the places on campus where various events occurred during the riots
Program for the Curtis Picture Musicale
No full textPrinted on title page: Edward S. Curtis. Author of "The North American Indian". Music composed by Henry F. Gilbert.
The program for Edward Curtis's "musicale" or "picture-opera" featuring a foreward by Curtis, dissolving slide shows, motion pictures and music. The music was composed by Henry Gilbert and based on the wax cylinder recordings Curtis had made of Native American music with his photographic subjects. This program which toured the country during the winter of 1911-1912 included such productions as "Dream of the Ancient Red Man", and "Evening in Hopi Land".
Also in PH Coll 484.AD
[Letter] 1859 December 12, Roxberg / George William Curtis.
No full textCurtis thanks the sender for the little book, stating that it makes him wish and hope that the fraternity of good thinking will not be dissolved. An author and an orator who spent two years at the utopian Brook Farm community, Curtis published novels like _Trumps_ [1861] as well as delivering addresses on William Cullen Bryant, Robert Burns, Washington Irving, and James Russell Lowell. He befriended Emerson, edited _Putnam\u27s Monthly_ , actively wrote about New York and national politics in periodicals like _Harper\u27s Magazine_ , and wrote travel narratives
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