122 research outputs found
Effect Of Xylitol Versus Sugar On Caries Risk
The effect of xylitol versus sugar on caries risk is a rising trend in caries prevention. The dominant explanation for this trend is explained by xylitol’s ability to significantly decrease caries rates in recent studies. To answer the question, in adult patients, what is the effect of xylitol versus sugar on caries risk, we compared previous studies in a literature review. The limitations of these findings include the many intrinsic and extrinsic factors that influence plaque accumulation that were not considered. Further research is needed to determine if xylitol alone has caries-prevention qualities.https://dune.une.edu/dh_studpost/1017/thumbnail.jp
Ten Simple Rules for Reproducible Research in Jupyter Notebooks
Reproducibility of computational studies is a hallmark of scientific
methodology. It enables researchers to build with confidence on the methods and
findings of others, reuse and extend computational pipelines, and thereby drive
scientific progress. Since many experimental studies rely on computational
analyses, biologists need guidance on how to set up and document reproducible
data analyses or simulations.
In this paper, we address several questions about reproducibility. For
example, what are the technical and non-technical barriers to reproducible
computational studies? What opportunities and challenges do computational
notebooks offer to overcome some of these barriers? What tools are available
and how can they be used effectively?
We have developed a set of rules to serve as a guide to scientists with a
specific focus on computational notebook systems, such as Jupyter Notebooks,
which have become a tool of choice for many applications. Notebooks combine
detailed workflows with narrative text and visualization of results. Combined
with software repositories and open source licensing, notebooks are powerful
tools for transparent, collaborative, reproducible, and reusable data analyses
Normalization and microbial differential abundance strategies depend upon data characteristics
BackgroundData from 16S ribosomal RNA (rRNA) amplicon sequencing present challenges to ecological and statistical interpretation. In particular, library sizes often vary over several ranges of magnitude, and the data contains many zeros. Although we are typically interested in comparing relative abundance of taxa in the ecosystem of two or more groups, we can only measure the taxon relative abundance in specimens obtained from the ecosystems. Because the comparison of taxon relative abundance in the specimen is not equivalent to the comparison of taxon relative abundance in the ecosystems, this presents a special challenge. Second, because the relative abundance of taxa in the specimen (as well as in the ecosystem) sum to 1, these are compositional data. Because the compositional data are constrained by the simplex (sum to 1) and are not unconstrained in the Euclidean space, many standard methods of analysis are not applicable. Here, we evaluate how these challenges impact the performance of existing normalization methods and differential abundance analyses.ResultsEffects on normalization: Most normalization methods enable successful clustering of samples according to biological origin when the groups differ substantially in their overall microbial composition. Rarefying more clearly clusters samples according to biological origin than other normalization techniques do for ordination metrics based on presence or absence. Alternate normalization measures are potentially vulnerable to artifacts due to library size. Effects on differential abundance testing: We build on a previous work to evaluate seven proposed statistical methods using rarefied as well as raw data. Our simulation studies suggest that the false discovery rates of many differential abundance-testing methods are not increased by rarefying itself, although of course rarefying results in a loss of sensitivity due to elimination of a portion of available data. For groups with large (~10×) differences in the average library size, rarefying lowers the false discovery rate. DESeq2, without addition of a constant, increased sensitivity on smaller datasets (<20 samples per group) but tends towards a higher false discovery rate with more samples, very uneven (~10×) library sizes, and/or compositional effects. For drawing inferences regarding taxon abundance in the ecosystem, analysis of composition of microbiomes (ANCOM) is not only very sensitive (for >20 samples per group) but also critically the only method tested that has a good control of false discovery rate.ConclusionsThese findings guide which normalization and differential abundance techniques to use based on the data characteristics of a given study
Aktivitas Antibakteri Ekstrak Dan Fraksi Karang Lunak Lobophytum SP. Terhadap Bakteri Escherichia Coli Dan Staphylococcus Aureus
AKTIVITAS ANTIBAKTERI EKSTRAK DAN FRAKSI KARANG LUNAK Lobophytum sp. TERHADAP BAKTERI Escherichia coli DAN Staphylococcus aureus Queen Novika Hermina Loing1), Defny Silvia Wewengkang1), Jemmy Abidjulu 1) 1)Program Studi Farmasi FMIPA UNSRAT Manado ABSTRACT Indonesia is a tropical country which is have so many abundant biodiversity, and one of them is soft coral. This research aims to test the antibacterial activity of soft coral Lobophytum sp. fractions against the Escherichia coli and Staphylococcus aureus. Extraction was done by maceration and fractionation using n-hexane, chloroform, methanol and water as a solvent. The test of antibacterial activity was done by using agar diffusion method. The result shows that extract and fractions have an antibacterial activity. The results conclude that the extract and fractions of Lobophytum sp. effectively inhibit the Escherichia coli and Staphylococcus aureus, in medium and strong category. The Strong inhibitory capacity showed by chloroform fraction. Key words : Lobophytum sp, antibacterial activity, Escherichia coli, Staphylococcus aureus, fractionation, agar diffusion. ABSTRAK Indonesia merupakan negara tropis, yang mempunyai keanekaragaman hayati berlimpah salah satunya ialah karang lunak. Penelitian ini bertujuan untuk menguji aktivitas antibakteri fraksi karang lunak Lobophytum sp. terhadap bakteri Escherichia coli dan Stapylococcus aureus. Ekstraksi menggunakan metode maserasi dengan pelarut etanol dan fraksinasi menggunakan pelarut n-heksan, kloroform, metanol dan air. Pengujian antibakteri mengunakan metode difusi agar. Hasil penelitian menunjukkan ekstrak dan fraksi uji memiliki aktivitas sebagai antibakteri. Berdasarkan hasil penelitian, disimpulkan bahwa ekstrak dan fraksi karang lunak Lobophytum sp efektif dalam menghambat pertumbuhan bakteri Escherichia coli serta bakteri Staphylococus aureus dengan kategori sedang dan kuat. Daya hambat terbesar ditunjukkan oleh fraksi kloroform
Combinatorial CRISPR-Cas9 screens for de novo mapping of genetic interactions.
We developed a systematic approach to map human genetic networks by combinatorial CRISPR-Cas9 perturbations coupled to robust analysis of growth kinetics. We targeted all pairs of 73 cancer genes with dual guide RNAs in three cell lines, comprising 141,912 tests of interaction. Numerous therapeutically relevant interactions were identified, and these patterns replicated with combinatorial drugs at 75% precision. From these results, we anticipate that cellular context will be critical to synthetic-lethal therapies
PyCogent: a toolkit for making sense from sequence
The COmparative GENomic Toolkit, a framework for probabilistic analyses of biological sequences, devising workflows and generating publication quality graphics, has been implemented in Python
Circumstellar Disk Candidates Identified in NGC 2264
We present an optical and near-infrared study of a 45' × 45' field in NGC 2264, which includes both S Mon and the Cone Nebula. We report photometry at optical (UBVRCIC) and near-infrared (JHK) wavelengths for ~5600 stars and spectroscopic classifications for ~400 of these stars. We identify circumstellar disk candidates using three techniques: excess ultraviolet (U-V) emission, excess near-IR (I-K and H-K) emission, and Hα emission-line equivalent widths for those stars with spectra. We find generally good correlation between disk indicators thought to originate from different physical processes. We find little if any evolution of disk fraction with stellar age or mass. However, when we derive mass accretion rates () from the excess emission at U, we find that decreases with age over the age range spanned by our data, ~0.1–5 Myr, and increases with mass over the range ~0.25–1 M⊙. These findings are comparable to results found previously by us in the Orion Nebula cluster flanking fields
Statistical methods for analysis of high-throughput RNA interference screens
RNA interference (RNAi) has become a powerful technique for reverse genetics and drug discovery, and in both of these areas large-scale high-throughput RNAi screens are commonly performed. The statistical techniques used to analyze these screens are frequently borrowed directly from small-molecule screening; however, small-molecule and RNAi data characteristics differ in meaningful ways. We examine the similarities and differences between RNAi and small-molecule screens, highlighting particular characteristics of RNAi screen data that must be addressed during analysis. Additionally, we provide guidance on selection of analysis techniques in the context of a sample workflow
Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study
Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
‘Oh you pretty thing!’: How David Bowie ‘unlocked everybody’s inner queen’ in spite of the music press
The 1967 Sexual Offence Act decriminalised homosexual acts between men allowing gay men to discuss their sexuality in public. Few prominent popular musicians came-out until 1972 when David Bowie claimed that he was bisexual in an interview with Melody Maker. Music papers and Bowie had substantial cultural power: Bowie was a rising star and music papers recruited journalists who discussed and perpetuated social change. The subsequent conversation, however, reinforced negative stereotypes in constructing the queer subject and tried to safeguard commercial concerns due to the assumption that the market for popular music avoided queer music. This undermined arguments that associate permissive legislation with a permissive media and society, but, to some, representation alone empowered people and destabilised preconceptions about queer identity.Published versio
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