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Full-Text Articles in Physical Sciences and Mathematics

These Are Not The K-Mers You Are Looking For: Efficient Online K-Mer Counting Using A Probabilistic Data Structure, Qingpeng Zhang, Jason Pell, Rosangela Canino-Koning, Adina Chuang Howe, C. Titus Brown Jul 2014

These Are Not The K-Mers You Are Looking For: Efficient Online K-Mer Counting Using A Probabilistic Data Structure, Qingpeng Zhang, Jason Pell, Rosangela Canino-Koning, Adina Chuang Howe, C. Titus Brown

Adina Howe

K-mer abundance analysis is widely used for many purposes in nucleotide sequence analysis, including data preprocessing for de novo assembly, repeat detection, and sequencing coverage estimation. We present the khmer software package for fast and memory efficient online counting of k-mers in sequencing data sets. Unlike previous methods based on data structures such as hash tables, suffix arrays, and trie structures, khmer relies entirely on a simple probabilistic data structure, a Count-Min Sketch. The Count-Min Sketch permits online updating and retrieval of k-mer counts in memory which is necessary to support online k-mer analysis algorithms. On sparse data sets this …


Revealing The Bacterial Butyrate Synthesis Pathways By Analyzing (Meta)Genomic Data, Marius Vital, Adina Chuang Howe, James M. Tiedje Apr 2014

Revealing The Bacterial Butyrate Synthesis Pathways By Analyzing (Meta)Genomic Data, Marius Vital, Adina Chuang Howe, James M. Tiedje

Adina Howe

Butyrate-producing bacteria have recently gained attention, since they are important for a healthy colon and when altered contribute to emerging diseases, such as ulcerative colitis and type II diabetes. This guild is polyphyletic and cannot be accurately detected by 16S rRNA gene sequencing. Consequently, approaches targeting the terminal genes of the main butyrate-producing pathway have been developed. However, since additional pathways exist and alternative, newly recognized enzymes catalyzing the terminal reaction have been described, previous investigations are often incomplete. We undertook a broad analysis of butyrate-producing pathways and individual genes by screening 3,184 sequenced bacterial genomes from the Integrated Microbial …


The Genome And Developmental Transcriptome Of The Strongylid Nematode Haemonchus Contortus, Erich M. Schwarz, Pasi K. Korhonen, Bronwyn E. Campbell, Neil D. Young, Aaron R. Jex, Abdul Jabbar, Ross S. Hall, Alinda Mondal, Adina C. Howe, Jason Pell, Andreas Hofmann, Peter R. Boag, Xing-Quan Zhu, T. Ryan Gregory, Alex Loukas, Brian A. Williams, Igor Antoshechkin, C. Titus Brown, Paul W. Sternberg, Robin B. Gasser Aug 2013

The Genome And Developmental Transcriptome Of The Strongylid Nematode Haemonchus Contortus, Erich M. Schwarz, Pasi K. Korhonen, Bronwyn E. Campbell, Neil D. Young, Aaron R. Jex, Abdul Jabbar, Ross S. Hall, Alinda Mondal, Adina C. Howe, Jason Pell, Andreas Hofmann, Peter R. Boag, Xing-Quan Zhu, T. Ryan Gregory, Alex Loukas, Brian A. Williams, Igor Antoshechkin, C. Titus Brown, Paul W. Sternberg, Robin B. Gasser

Adina Howe

Background The barber's pole worm, Haemonchus contortus, is one of the most economically important parasites of small ruminants worldwide. Although this parasite can be controlled using anthelmintic drugs, resistance against most drugs in common use has become a widespread problem. We provide a draft of the genome and the transcriptomes of all key developmental stages of H. contortus to support biological and biotechnological research areas of this and related parasites. Results The draft genome of H. contortus is 320 Mb in size and encodes 23,610 protein-coding genes. On a fundamental level, we elucidate transcriptional alterations taking place throughout the life …


Management Strategies To Improve Yield And Nitrogen Use Of Spring Wheat And Field Pea In The Semi-Arid Northern Great Plains Usa, Andrew W. Lenssen, Brett Allen, Upendra Sainju, Thecan Caesar, Robert Lartey, Robert Evans Jan 2010

Management Strategies To Improve Yield And Nitrogen Use Of Spring Wheat And Field Pea In The Semi-Arid Northern Great Plains Usa, Andrew W. Lenssen, Brett Allen, Upendra Sainju, Thecan Caesar, Robert Lartey, Robert Evans

Andrew W. Lenssen

Available water and N fertility are primary constraints to crop production in the northern Great Plains of the USA. A field trial was initiated in 2004 to compare four crop rotations in a complete factorial of two tillage and two management systems. Rotations were continuous spring wheat (SW), pea-SW, barley hay-pea-SW, and barley hay-corn-pea-SW. Tillage systems were no till and field cultivator tillage, while management systems were conventional and ecological. Conventional management included broadcast nitrogen fertilizer, standard seeding rates, and short stubble height. Ecological management practices varied by crop, and included banded nitrogen fertilizer for cereals, increased seeding rate, delayed …


Microbial Development In Distillers Wet Grains Produced During Fuel Ethanol Production From Corn (Zea Mays), R. Michael Lehman, Kurt A. Rosentrater Jan 2007

Microbial Development In Distillers Wet Grains Produced During Fuel Ethanol Production From Corn (Zea Mays), R. Michael Lehman, Kurt A. Rosentrater

Kurt A. Rosentrater

Distillers grains are coproduced with ethanol and carbon dioxide during the production of fuel ethanol from the dry milling and fermentation of corn grain, yet there is little basic microbiological information on these materials. We undertook a replicated field study of the microbiology of distillers wet grains (DWG) over a 9 day period following their production at an industrial fuel ethanol plant. Freshly produced DWG had a pH of about 4.4, a moisture content of about 53.5% (wet mass basis), and 4 x 10(5) total yeast cells/g dry mass, of which about 0.1% were viable. Total bacterial cells were initially …