61 research outputs found
TIC 168789840: A Sextuply-Eclipsing Sextuple Star System
We report the discovery of a sextuply-eclipsing sextuple star system from
TESS data, TIC 168789840, also known as TYC 7037-89-1, the first known sextuple
system consisting of three eclipsing binaries. The target was observed in
Sectors 4 and 5 during Cycle 1, with lightcurves extracted from TESS Full Frame
Image data. It was also previously observed by the WASP survey and ASAS-SN. The
system consists of three gravitationally-bound eclipsing binaries in a
hierarchical structure of an inner quadruple system with an outer binary
subsystem. Follow-up observations from several different observatories were
conducted as a means of determining additional parameters. The system was
resolved by speckle interferometry with a 0."42 separation between the inner
quadruple and outer binary, inferring an estimated outer period of ~2 kyr. It
was determined that the fainter of the two resolved components is an 8.217 day
eclipsing binary, which orbits the inner quadruple that contains two eclipsing
binaries with periods of 1.570 days and 1.306 days. MCMC analysis of the
stellar parameters has shown that the three binaries of TIC 168789840 are
"triplets", as each binary is quite similar to the others in terms of mass,
radius, and Teff. As a consequence of its rare composition, structure, and
orientation, this object can provide important new insight into the formation,
dynamics, and evolution of multiple star systems. Future observations could
reveal if the intermediate and outer orbital planes are all aligned with the
planes of the three inner eclipsing binaries
The L 98-59 System: Three Transiting, Terrestrial-size Planets Orbiting a Nearby M Dwarf
We report the Transiting Exoplanet Survey Satellite (TESS) discovery of three terrestrial-size planets transiting L 98-59 (TOI-175, TIC 307210830)âa bright M dwarf at a distance of 10.6 pc. Using the Gaia-measured distance and broadband photometry, we find that the host star is an M3 dwarf. Combined with the TESS transits from three sectors, the corresponding stellar parameters yield planet radii ranging from 0.8 R â to 1.6 R â. All three planets have short orbital periods, ranging from 2.25 to 7.45 days with the outer pair just wide of a 2:1 period resonance. Diagnostic tests produced by the TESS Data Validation Report and the vetting package DAVE rule out common false-positive sources. These analyses, along with dedicated follow-up and the multiplicity of the system, lend confidence that the observed signals are caused by planets transiting L 98-59 and are not associated with other sources in the field. The L 98-59 system is interesting for a number of reasons: the host star is bright (V = 11.7 mag, K = 7.1 mag) and the planets are prime targets for further follow-up observations including precision radial-velocity mass measurements and future transit spectroscopy with the James Webb Space Telescope; the near-resonant configuration makes the system a laboratory to study planetary system dynamical evolution; and three planets of relatively similar size in the same system present an opportunity to study terrestrial planets where other variables (age, metallicity, etc.) can be held constant. L 98-59 will be observed in four more TESS sectors, which will provide a wealth of information on the three currently known planets and have the potential to reveal additional planets in the system
Rare and low-frequency coding variants alter human adult height
Height is a highly heritable, classic polygenic trait with ~700 common associated variants identified so far through genome - wide association studies . Here , we report 83 height - associated coding variants with lower minor allele frequenc ies ( range of 0.1 - 4.8% ) and effects of up to 2 16 cm /allele ( e.g. in IHH , STC2 , AR and CRISPLD2 ) , >10 times the average effect of common variants . In functional follow - up studies, rare height - increasing alleles of STC2 (+1 - 2 cm/allele) compromise d proteolytic inhibition of PAPP - A and increased cleavage of IGFBP - 4 in vitro , resulting in higher bioavailability of insulin - like growth factors . The se 83 height - associated variants overlap genes mutated in monogenic growth disorders and highlight new biological candidates ( e.g. ADAMTS3, IL11RA, NOX4 ) and pathways ( e.g . proteoglycan/ glycosaminoglycan synthesis ) involved in growth . Our results demonstrate that sufficiently large sample sizes can uncover rare and low - frequency variants of moderate to large effect associated with polygenic human phenotypes , and that these variants implicate relevant genes and pathways
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
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Genome-wide analysis of 53,400 people with irritable bowel syndrome highlights shared genetic pathways with mood and anxiety disorders
Funder: Kennedy Trust Rheumatology Research Prize StudentshipFunder: DFG Cluster of Excellence âPrecision Medicine in Chronic In-flammationâ (PMI; ID: EXC2167)Funder: EC | EC Seventh Framework Programm | FP7 Ideas: European Research Council (FP7-IDEAS-ERC - Specific Programme: âIdeasâ Implementing the Seventh Framework Programme of the European Community for Research, Technological Development and Demonstration Activities (2007 to 2013)); doi: https://doi.org/10.13039/100011199; Grant(s): 715772Funder: NWO-VIDI grant 016.178.056, the Netherlands Heart Foundation CVON grant 2018-27, and NWO Gravitation grant ExposomeNLFunder: Li Ka Shing Foundation (Li Ka Shing Foundation Limited); doi: https://doi.org/10.13039/100007421Abstract: Irritable bowel syndrome (IBS) results from disordered brainâgut interactions. Identifying susceptibility genes could highlight the underlying pathophysiological mechanisms. We designed a digestive health questionnaire for UK Biobank and combined identified cases with IBS with independent cohorts. We conducted a genome-wide association study with 53,400 cases and 433,201 controls and replicated significant associations in a 23andMe panel (205,252 cases and 1,384,055 controls). Our study identified and confirmed six genetic susceptibility loci for IBS. Implicated genes included NCAM1, CADM2, PHF2/FAM120A, DOCK9, CKAP2/TPTE2P3 and BAG6. The first four are associated with mood and anxiety disorders, expressed in the nervous system, or both. Mirroring this, we also found strong genome-wide correlation between the risk of IBS and anxiety, neuroticism and depression (rg > 0.5). Additional analyses suggested this arises due to shared pathogenic pathways rather than, for example, anxiety causing abdominal symptoms. Implicated mechanisms require further exploration to help understand the altered brainâgut interactions underlying IBS
The Somatic Genomic Landscape of Glioblastoma
We describe the landscape of somatic genomic alterations based on multi-dimensional and comprehensive characterization of more than 500 glioblastoma tumors (GBMs). We identify several novel mutated genes as well as complex rearrangements of signature receptors including EGFR and PDGFRA. TERT promoter mutations are shown to correlate with elevated mRNA expression, supporting a role in telomerase reactivation. Correlative analyses confirm that the survival advantage of the proneural subtype is conferred by the G-CIMP phenotype, and MGMT DNA methylation may be a predictive biomarker for treatment response only in classical subtype GBM. Integrative analysis of genomic and proteomic profiles challenges the notion of therapeutic inhibition of a pathway as an alternative to inhibition of the target itself. These data will facilitate the discovery of therapeutic and diagnostic target candidates, the validation of research and clinical observations and the generation of unanticipated hypotheses that can advance our molecular understanding of this lethal cancer
Coccidia of Gerbils from Mongolia
In this study, gerbils collected in the Mongolia over the summers of 2009-2012 were examined for coccidia. In total, 171 gerbils of three species from 22 localities were examined for coccidia. Coccidian oocysts were identified from 21 gerbils, but those found in 1 of those gerbils were probably pseudoparasites of the host from which they were recovered. From the remaining 20 gerbils, 7 morphotypes of Eimeria and 1 morphotype of Isospora were identified. Four of the 7 morphotypes of Eimeria were attributed to new species which were described in this study. In addition, 10 previously described species of Eimeria were recommended to be considered junior synonyms or species inquirendae. Phylogenetic analyses of the species of Eimeria identified in this study based on 9 continuous and 12 categorical morphological characters were then performed. The anaylsis which produced the highest consistency index (CI = 0.6667, excluding uninformative characters) used all data with unweighted character states and produced 3 equally parsimonious trees. However, the tree score distribution for this analysis was only weakly skewed right with a g1 value of â0.25439, indicating a lack of phylogenetic information. The analysis which produced the most strongly right skewed tree score distribution (g1 = â0.4950) used only categorical data with characters weighted inversely to the number of states and produced seven equally parsimonious trees. In order to predict the spatial distribution of Eimeria spp. occurring in gerbils in Mongolia and identify any apparent ecological trends, ecological niche models (ENMâs) were produced using both GARP and Maxent, and chi-squared tests were performed to identify correlations between infection with species of Eimeria or Isospora and host species, sex, infection with helminths, and year and month of capture. ENMâs produced with GARP predicted that Eimeria spp. occur in 28.63% of Mongolia, while the model produced with Maxent predicted the Eimeria spp. occur in 28.70% of Mongolia. The environmental variables with the greatest percent contribution to the ENM predicting the distribution of Eimeria spp. created with Maxent were Normalized Differential Vegitative Index (NDVI), mean precipitation of the driest month, and aspect. The only significant (α=0.10) correlation found using a chi-squared test was that between host species and infection by Eimeria spp. (p=.07); oocysts of Eimeria spp. were recovered from 5% of hosts of Meriones meridianus and 14% of hosts of Meriones unguiculatus. The additions and revisions to the taxonomy of the coccidia of gerbils in this study contribute to the knowledge base of host-parasite associations which may serve as a foundation for future studies in a wide variety of fields, and while the distributions predicted and phylogenies produced in this study are tentative, they may serve as a starting point for future investigators.
Advisor: Scott L. Gardne
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