2,025 research outputs found
Diversity and distribution of Symbiodiniaceae detected on coral reefs of Lombok, Indonesia using environmental DNA metabarcoding
Background
Dinoflagellates of family Symbiodiniaceae are important to coral reef ecosystems because of their contribution to coral health and growth; however, only a few studies have investigated the function and distribution of Symbiodiniaceae in Indonesia. Understanding the distribution of different kinds of Symbiodiniaceae can improve forecasting of future responses of various coral reef systems to climate change. This study aimed to determine the diversity of Symbiodiniaceae around Lombok using environmental DNA (eDNA).
Methods
Seawater and sediment samples were collected from 18 locations and filtered to obtain fractions of 0.4â12 and \u3e12 Âľm. After extraction, molecular barcoding polymerase chain reaction was conducted to amplify the primary V9-SSU 18S rRNA gene, followed by sequencing (Illumina MiSeq). BLAST, NaĂŻve-fit-Bayes, and maximum likelihood routines were used for classification and phylogenetic reconstruction. We compared results across sampling sites, sample types (seawater/sediment), and filter pore sizes (fraction).
Results
Phylogenetic analyses resolved the amplicon sequence variants into 16 subclades comprising six Symbiodiniaceae genera (or genera-equivalent clades) as follows: Symbiodinium, Breviolum, Cladocopium, Durusdinium, Foraminifera Clade G, and Halluxium. Comparative analyses showed that the three distinct lineages within Cladocopium, Durusdinium, and Foraminifera Clade G were the most common. Most of the recovered sequences appeared to be distinctive of different sampling locations, supporting the possibility that eDNA may resolve regional and local differences among Symbiodiniaceae genera and species.
Conclusions
eDNA surveys offer a rapid proxy for evaluating Symbiodiniaceae species on coral reefs and are a potentially useful approach to revealing diversity and relative ecological dominance of certain Symbiodiniaceae organisms. Moreover, Symbiodiniaceae eDNA analysis shows potential in monitoring the local and regional stability of coralâalgal mutualisms
Catheter ablation and lower risk of incident dementia and mortality in older adults with atrial fibrillation.
Background Atrial fibrillation (AF) has consistently been associated with a higher risk of incident dementia. Observational evidence has suggested catheter ablation may be associated with a lower risk of dementia in patients with AF, but further research is needed. The objectives of this study were to use a global health research network to examine associations between catheter ablation, incident dementia and mortality in older adults with AF, and amongst subgroups by age, sex, co-morbidity status, and oral anticoagulant use.Methods The research network primarily included healthcare organizations in the United States. This network was searched on 28th September 2022 for patients aged âĽ65âyears with a diagnosis of AF received at least 5âyears prior to the search date. Cox proportional hazard models were run on propensity-score matched cohorts. Results After propensity score matching, 20,746 participants (mean age 68âyears; 59% male) were included in each cohort with and without catheter ablation. The cohorts were well balanced for age, sex, ethnicity, co-morbidities, and cardiovascular medications received. The risk of dementia was significantly lower in the catheter ablation cohort (Hazard Ratio 0.52, 95% confidence interval: 0.45-0.61). The catheter ablation cohort also had a lower risk of all-cause mortality (Hazard Ratio 0.58, 95% confidence interval: 0.55-0.61). These associations remained in subgroup analyses in individuals aged 65-79âyears, âĽ80âyears, males, females, participants who received OACs during follow-up, participants with paroxysmal and non-paroxysmal AF, and participants with and without hypertension, diabetes mellitus, ischemic stroke, chronic kidney disease and heart failure, including heart failure with preserved ejection fraction and heart failure with reduced ejection fraction.Conclusion The observed lower risk of dementia and mortality with catheter ablation could be an important consideration when determining appropriate patient-centered rhythm control strategies for patients with AF. Further studies including data on the success of ablation are required
Universal Parametric Correlations of Conductance Peaks in Quantum Dots
We compute the parametric correlation function of the conductance peaks in
chaotic and weakly disordered quantum dots in the Coulomb blockade regime and
demonstrate its universality upon an appropriate scaling of the parameter. For
a symmetric dot we show that this correlation function is affected by breaking
time-reversal symmetry but is independent of the details of the channels in the
external leads. We derive a new scaling which depends on the eigenfunctions
alone and can be extracted directly from the conductance peak heights. Our
results are in excellent agreement with model simulations of a disordered
quantum dot.Comment: 12 pages, RevTex, 2 Postscript figure
Pattern Transfer of Sub-10 nm Features via Tin-Containing Block Copolymers
Tin-containing block copolymers were investigated as materials for nanolithographic applications. Poly(4-trimethylstannylstyrene-block-styrene) (PSnS-PS) and poly(4-trimethylstannylstyrene-block-4-methoxystyrene) (PSnS-PMOST) synthesized by reversible additionâfragmentation chain transfer polymerization form lamellar domains with periodicities ranging from 18 to 34 nm. Thin film orientation control was achieved by thermal annealing between a neutral surface treatment and a top coat. Incorporation of tin into one block facilitates pattern transfer into SiO_2 via a two-step etch process utilizing oxidative and fluorine-based etch chemistries
Australian Sphingidae â DNA Barcodes Challenge Current Species Boundaries and Distributions
Š 2014 Rougerie et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article
Corynebacterium marinum sp. nov. isolated from coastal sediment
A taxonomic study was performed on strain D7015T, which was isolated from coastal sediment close to a coal-fired power station in Qingdao, China. Strain D7015T comprised Gram-positive, non-motile diphtheroid rods, which grew in the presence of 0-8% (w/v) NaCl and at 4-37°C, with optimum growth at 1% (w/v) NaCl and 30-32°C. The G+C content was 65.0 mol%. The major fatty acids were C18:1Ď9c (56.18%), C16:0 (38.02%), C16:1Ď7c (4.45%), C18:0 (1.0%) and C14:0 (0.35%). On the basis of the morphological, physiological and phylogenetic characteristics, strain D7015T was classified in the genus Corynebacterium. It exhibited a 16S rRNA gene sequence similarity of 95.9% and a DNA:DNA relatedness value of 20.4% with Corynebacterium halotolerans DSM 44683T. Strain D7015T was sufficiently different from hitherto described Corynebacterium species to be considered as a novel species. The name Corynebacterium marinum sp. nov. is proposed, with strain D7015T (=CGMCC 1.6998T =NRRL B-24779T) as the type strain
Long-lived photoexcited states in polydiacetylenes with different molecular and supramolecular organization
With the aim of determining the importance of the molecular and supramolecular organization on the excited states of polydiacetylenes, we have studied the photoinduced absorption spectra of the red form of poly[1,6-bis(3,6-didodecyl-N-carbazolyl)-2,4-hexadiyne] (polyDCHD-S) and the results compared with those of the blue form of the same polymer. An interpretation of the data is given in terms of both the conjugation length and the interbackbone separation also in relation to the photoinduced absorption spectra of both blue and red forms of poly[1,6-bis(N-carbazolyl)-2,4-hexadiyne] (polyDCHD), which does not carry the alkyl substituents on the carbazolyl side groups. Information on the above properties is derived from the analysis of the absorption and Raman spectra of this class of polydiacetylenes
One-Loop Renormalization of Lorentz-Violating Electrodynamics
We show that the general Lorentz- and CPT-violating extension of quantum
electrodynamics is one-loop renormalizable. The one-loop Lorentz-violating beta
functions are obtained, and the running of the coefficients for Lorentz and CPT
violation is determined. Some implications for theory and experiment are
discussed.Comment: 12 pages, accepted for publication in Physical Review
Standalone vertex ďŹnding in the ATLAS muon spectrometer
A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at âs = 7 TeV collected with the ATLAS detector at the LHC during 2011
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