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result(s) for
"Cobb, Rose E."
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Diversity of Marine-Derived Fungal Cultures Exposed by DNA Barcodes: The Algorithm Matters
by
Evans-Illidge, Elizabeth
,
Cobb, Rose E.
,
Gordon, Benjamin R.
in
Algorithms
,
Analysis
,
Animals
2015
Marine fungi are an understudied group of eukaryotic microorganisms characterized by unresolved genealogies and unstable classification. Whereas DNA barcoding via the nuclear ribosomal internal transcribed spacer (ITS) provides a robust and rapid tool for fungal species delineation, accurate classification of fungi is often arduous given the large number of partial or unknown barcodes and misidentified isolates deposited in public databases. This situation is perpetuated by a paucity of cultivable fungal strains available for phylogenetic research linked to these data sets. We analyze ITS barcodes produced from a subsample (290) of 1781 cultured isolates of marine-derived fungi in the Bioresources Library located at the Australian Institute of Marine Science (AIMS). Our analysis revealed high levels of under-explored fungal diversity. The majority of isolates were ascomycetes including representatives of the subclasses Eurotiomycetidae, Hypocreomycetidae, Sordariomycetidae, Pleosporomycetidae, Dothideomycetidae, Xylariomycetidae and Saccharomycetidae. The phylum Basidiomycota was represented by isolates affiliated with the genera Tritirachium and Tilletiopsis. BLAST searches revealed 26 unknown OTUs and 50 isolates corresponding to previously uncultured, unidentified fungal clones. This study makes a significant addition to the availability of barcoded, culturable marine-derived fungi for detailed future genomic and physiological studies. We also demonstrate the influence of commonly used alignment algorithms and genetic distance measures on the accuracy and comparability of estimating Operational Taxonomic Units (OTUs) by the automatic barcode gap finder (ABGD) method. Large scale biodiversity screening programs that combine datasets using algorithmic OTU delineation pipelines need to ensure compatible algorithms have been used because the algorithm matters.
Journal Article
Bacterial Community Dynamics in the Marine Sponge Rhopaloeides odorabile Under In Situ and Ex Situ Cultivation
by
Webster, Nicole S
,
Evans-Illidge, Elizabeth
,
Cobb, Rose E
in
Acidobacteria
,
Animals
,
Aquaculture
2011
Cultivation of sponges is being explored to supply biomaterial for the pharmaceutical and cosmetics industries. This study assesses the impact of various cultivation methods on the microbial community within the sponge Rhopaloeides odorabile during: (1) in situ cultivation under natural environmental conditions, (2) ex situ cultivation in small flow-through aquaria and (3) ex situ cultivation in large mesocosm systems. Principal components analysis of denaturing gradient gel electrophoresis profiles indicated a stable microbial community in sponges cultured in situ (grown in the wild) and in sponges cultured ex situ in small flow-through aquaria over 12 weeks. In contrast, a shift in the microbial community was detected in sponges cultivated ex situ in large mesocosm aquaria for 12 months. This shift included (1) a loss of some stable microbial inhabitants, including members of the Poribacteria, Chloroflexi and Acidobacteria and (2) the addition of new microbes not detected in the wild sponges. Many of these acquired bacteria had highest similarity to known sponge-associated microbes, indicating that the sponge may be capable of actively selecting its microbial community. Alternatively, long-term ex situ cultivation may cause a shift in the dominant microbes that facilitates the growth of the more rare species. The microbial community composition varied between sponges cultivated in mesocosm aquaria with different nutrient concentrations and seawater chemistry, suggesting that these variables play a role in structuring the sponge-associated microbes. The high growth and symbiont stability in R. odorabile cultured in situ confirm that this is the preferred method of aquaculture for this species at this time.
Journal Article
Temperature thresholds for bacterial symbiosis with a sponge
2008
The impact of elevated seawater temperature on bacterial communities within the marine sponge
Rhopaloeides odorabile
was assessed. Sponges were exposed to temperatures ranging between 27 and 33 °C. No differences in bacterial community composition or sponge health were detected in treatments between 27 and 31 °C. In contrast, sponges exposed to 33 °C exhibited a complete loss of the primary cultivated symbiont within 24 h and cellular necrosis after 3 days. Furthermore, denaturing gradient gel electrophoresis (DGGE) and clone sequence analysis detected a dramatic shift in bacterial community composition between 31 and 33 °C. Within the first 24 h most of the DGGE bands detected in samples from 27 to 31 °C were absent from the 33 °C sponges whereas eight bands were detected exclusively in the 33 °C sponges. The 16S rRNA sequencing revealed that most of the microbes from sponges exposed to 27–31 °C had highest homology to known sponge-associated bacteria. In contrast, many of the microbes from sponges exposed to 33 °C were similar to sequences previously retrieved from diseased and bleached corals. The 16S rRNA clone library analysis also detected a significant shift in bacterial community structure. The 27 °C library was composed of
Proteobacteria
,
Actinobacteria
,
Nitrospira
,
Acidobacteria
and
Chloroflexi
whereas the 33 °C library contained sequences from the
Proteobacteria
,
Bacteroidetes
and
Firmicutes
. The clear shifts in community composition at elevated temperatures can be attributed to the loss of symbionts and to the establishment of alien microbial populations including potential pathogens. Breakdown of symbioses and stress in the sponge occurred at temperatures identical to those reported for coral bleaching, indicating that sponges may be similarly threatened by climate change.
Journal Article
Diversity of Marine-Derived Fungal Cultures Exposed by DNA Barcodes: The Algorithm Matters: e0136130
2015
Marine fungi are an understudied group of eukaryotic microorganisms characterized by unresolved genealogies and unstable classification. Whereas DNA barcoding via the nuclear ribosomal internal transcribed spacer (ITS) provides a robust and rapid tool for fungal species delineation, accurate classification of fungi is often arduous given the large number of partial or unknown barcodes and misidentified isolates deposited in public databases. This situation is perpetuated by a paucity of cultivable fungal strains available for phylogenetic research linked to these data sets. We analyze ITS barcodes produced from a subsample (290) of 1781 cultured isolates of marine-derived fungi in the Bioresources Library located at the Australian Institute of Marine Science (AIMS). Our analysis revealed high levels of under-explored fungal diversity. The majority of isolates were ascomycetes including representatives of the subclasses Eurotiomycetidae, Hypocreomycetidae, Sordariomycetidae, Pleosporomycetidae, Dothideomycetidae, Xylariomycetidae and Saccharomycetidae. The phylum Basidiomycota was represented by isolates affiliated with the genera Tritirachium and Tilletiopsis. BLAST searches revealed 26 unknown OTUs and 50 isolates corresponding to previously uncultured, unidentified fungal clones. This study makes a significant addition to the availability of barcoded, culturable marine-derived fungi for detailed future genomic and physiological studies. We also demonstrate the influence of commonly used alignment algorithms and genetic distance measures on the accuracy and comparability of estimating Operational Taxonomic Units (OTUs) by the automatic barcode gap finder (ABGD) method. Large scale biodiversity screening programs that combine datasets using algorithmic OTU delineation pipelines need to ensure compatible algorithms have been used because the algorithm matters.
Journal Article
Evaluation of the feasibility, diagnostic yield, and clinical utility of rapid genome sequencing in infantile epilepsy (Gene-STEPS): an international, multicentre, pilot cohort study
2023
Most neonatal and infantile-onset epilepsies have presumed genetic aetiologies, and early genetic diagnoses have the potential to inform clinical management and improve outcomes. We therefore aimed to determine the feasibility, diagnostic yield, and clinical utility of rapid genome sequencing in this population.
We conducted an international, multicentre, cohort study (Gene-STEPS), which is a pilot study of the International Precision Child Health Partnership (IPCHiP). IPCHiP is a consortium of four paediatric centres with tertiary-level subspecialty services in Australia, Canada, the UK, and the USA. We recruited infants with new-onset epilepsy or complex febrile seizures from IPCHiP centres, who were younger than 12 months at seizure onset. We excluded infants with simple febrile seizures, acute provoked seizures, known acquired cause, or known genetic cause. Blood samples were collected from probands and available biological parents. Clinical data were collected from medical records, treating clinicians, and parents. Trio genome sequencing was done when both parents were available, and duo or singleton genome sequencing was done when one or neither parent was available. Site-specific protocols were used for DNA extraction and library preparation. Rapid genome sequencing and analysis was done at clinically accredited laboratories, and results were returned to families. We analysed summary statistics for cohort demographic and clinical characteristics and the timing, diagnostic yield, and clinical impact of rapid genome sequencing.
Between Sept 1, 2021, and Aug 31, 2022, we enrolled 100 infants with new-onset epilepsy, of whom 41 (41%) were girls and 59 (59%) were boys. Median age of seizure onset was 128 days (IQR 46–192). For 43 (43% [binomial distribution 95% CI 33–53]) of 100 infants, we identified genetic diagnoses, with a median time from seizure onset to rapid genome sequencing result of 37 days (IQR 25–59). Genetic diagnosis was associated with neonatal seizure onset versus infantile seizure onset (14 [74%] of 19 vs 29 [36%] of 81; p=0·0027), referral setting (12 [71%] of 17 for intensive care, 19 [44%] of 43 non-intensive care inpatient, and 12 [30%] of 40 outpatient; p=0·0178), and epilepsy syndrome (13 [87%] of 15 for self-limited epilepsies, 18 [35%] of 51 for developmental and epileptic encephalopathies, 12 [35%] of 34 for other syndromes; p=0·001). Rapid genome sequencing revealed genetic heterogeneity, with 34 unique genes or genomic regions implicated. Genetic diagnoses had immediate clinical utility, informing treatment (24 [56%] of 43), additional evaluation (28 [65%]), prognosis (37 [86%]), and recurrence risk counselling (all cases).
Our findings support the feasibility of implementation of rapid genome sequencing in the clinical care of infants with new-onset epilepsy. Longitudinal follow-up is needed to further assess the role of rapid genetic diagnosis in improving clinical, quality-of-life, and economic outcomes.
American Academy of Pediatrics, Boston Children's Hospital Children's Rare Disease Cohorts Initiative, Canadian Institutes of Health Research, Epilepsy Canada, Feiga Bresver Academic Foundation, Great Ormond Street Hospital Charity, Medical Research Council, Murdoch Children's Research Institute, National Institute of Child Health and Human Development, National Institute for Health and Care Research Great Ormond Street Hospital Biomedical Research Centre, One8 Foundation, Ontario Brain Institute, Robinson Family Initiative for Transformational Research, The Royal Children's Hospital Foundation, University of Toronto McLaughlin Centre.
Journal Article
Influence of Electronic Cigarette Characteristics on Susceptibility, Perceptions, and Abuse Liability Indices among Combustible Tobacco Cigarette Smokers and Non-Smokers
2019
This study assessed how electronic cigarette (ECIG) characteristics amenable to regulation—namely nicotine content, flavor, and modified risk messages—impact ECIG use susceptibility, harm/addiction perceptions, and abuse liability indices among combustible tobacco cigarette (CTC) smokers and non-smokers. CTC smokers and non-smokers varying in ECIG use recruited via Amazon Mechanical Turk (MTurk) completed an online survey in 2016 (analytic n = 706). Participants were randomly assigned to one of eight conditions differing in ECIG characteristics: nicotine content (no, low, high), flavor (menthol, tobacco, fruit), or modified risk message (reduced harm, reduced carcinogen exposure). Regressions assessed ECIG susceptibility, harm/addiction perceptions, and abuse liability indices (purchase task measures of breakpoint/intensity) within each regulatory domain (nicotine content, flavor, message) and their interactions with CTC/ECIG status. Differential effects on ECIG susceptibility, harm/addiction perceptions, and abuse liability indices were observed by regulatory domain with many effects moderated by CTC/ECIG status. ECIG nicotine content and flavor conditions were the most influential across outcomes. Greater nicotine content, tobacco-flavored and reduced carcinogen exposure ECIGs were more highly preferred by CTC smokers with some differing preferences for non-users. Findings reinforce consideration of discrete ECIG preferences across tobacco use status to improve regulatory efficacy.
Journal Article
Dense genotyping of immune-related disease regions identifies 14 new susceptibility loci for juvenile idiopathic arthritis
2013
Anne Hinks and colleagues identify 14 new susceptibility loci for juvenile idiopathic arthritis through targeted analyses of genomic regions implicated in immune function. Their study implicates several pathways, including IL-2 signaling, in the pathogenesis of this common childhood autoimmune disease.
We used the Immunochip array to analyze 2,816 individuals with juvenile idiopathic arthritis (JIA), comprising the most common subtypes (oligoarticular and rheumatoid factor–negative polyarticular JIA), and 13,056 controls. We confirmed association of 3 known JIA risk loci (the human leukocyte antigen (HLA) region,
PTPN22
and
PTPN2
) and identified 14 loci reaching genome-wide significance (
P
< 5 × 10
−8
) for the first time. Eleven additional new regions showed suggestive evidence of association with JIA (
P
< 1 × 10
−6
). Dense mapping of loci along with bioinformatics analysis refined the associations to one gene in each of eight regions, highlighting crucial pathways, including the interleukin (IL)-2 pathway, in JIA disease pathogenesis. The entire Immunochip content, the HLA region and the top 27 loci (
P
< 1 × 10
−6
) explain an estimated 18, 13 and 6% of the risk of JIA, respectively. In summary, this is the largest collection of JIA cases investigated so far and provides new insight into the genetic basis of this childhood autoimmune disease.
Journal Article
Triangulating abuse liability assessment for flavoured cigar products using physiological, behavioural economic and subjective assessments: a within-subjects clinical laboratory protocol
by
Hoetger, Cosima
,
Lipato, Thokozeni
,
Guy, Mignonne C
in
Cigars
,
Electronic cigarettes
,
Federal regulation
2018
IntroductionIn the USA, Food and Drug Administration regulations prohibit the sale of flavoured cigarettes, with menthol being the exception. However, the manufacture, advertisement and sale of flavoured cigar products are permitted. Such flavourings influence positive perceptions of tobacco products and are linked to increased use. Flavourings may mask the taste of tobacco and enhance smoke inhalation, influencing toxicant exposure and abuse liability among novice tobacco users. Using clinical laboratory methods, this study investigates how flavour availability affects measures of abuse liability in young adult cigarette smokers. The specific aims are to evaluate the effect of cigar flavours on nicotine exposure, and behavioural and subjective measures of abuse liability.Methods and analysesParticipants (projected n=25) are healthy smokers of five or more cigarettes per day over the past 3 months, 18–25 years old, naive to cigar use (lifetime use of 50 or fewer cigar products and no more than 10 cigars smoked in the past 30 days) and without a desire to quit cigarette smoking in the next 30 days. Participants complete five laboratory sessions in a Latin square design with either their own brand cigarette or a session-specific Black & Mild cigar differing in flavour (apple, cream, original and wine). Participants are single-blinded to cigar flavours. Each session consists of two 10-puff smoking bouts (30 s interpuff interval) separated by 1 hour. Primary outcomes include saliva nicotine concentration, behavioural economic task performance and response to various questionnaire items assessing subjective effects predictive of abuse liability. Differences in outcomes across own brand cigarette and flavoured cigar conditions will be tested using linear mixed models.Ethics and disseminationThe Virginia Commonwealth University Institutional Review Board approved the study (VCU IRB: HM20007848). Dissemination channels for study findings include scientific journals, scientific meetings, and policy briefs.Trial registration number NCT02937051.
Journal Article
Short Notices
1992
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Suzanne Desan, Reclaiming the Sacred: Lay Religion and Popular Politics in Revolutionary France (1990), xviii + 262 (Cornell University Press, Ithaca, NY, $33.50).
Michael Knieriem (ed.),Die Herkunft des Friedrich Engels. Briefeaus der Verwandschaft 1791-1847 (1991), 829 (Schriften aus dem Karl Marx Haus, Trier, DM98.
Jane Lewis, Women and Social Action in Victorian and Edwardian England (1991), vii + 338 (Edward Elgar, Aldershot, Hants, £39,95).
David Vincent, Poor Citizens, The State and the Poor in Twentieth Century Britain (1991), viii and 258 (Longman, £19.99, paperback £8.99).
Panikos Panayi, The Enemy in our Midst: Germans in Britain during the First World War (1991), xii + 312 (Berg, Oxford, £35.00).
Timothy Mitchell, Blood Sport. A Social History of Spanish Bullfighting (1991), xv + 244 (University of Pennsylvania Press, Philadelphia, £25.60, paperback £9.95).
Keith Jenkins, Rethinking History (1991), 77 (Routledge, £5.99).
Journal Article