56 research outputs found
A New Genus of Gigantopterid from the Middle Permian of the United States and China and Its Relevance to the Gigantopterid Concept
Late Paleozoic continental warming of a cold tropical basin and floristic change in western Pangea
Gut Microbiome Dysbiosis in Antibiotic-Treated COVID-19 Patients is Associated with Microbial Translocation and Bacteremia
Although microbial populations in the gut microbiome are associated with COVID-19 severity, a causal impact on patient health has not been established. Here we provide evidence that gut microbiome dysbiosis is associated with translocation of bacteria into the blood during COVID-19, causing life-threatening secondary infections. We first demonstrate SARS-CoV-2 infection induces gut microbiome dysbiosis in mice, which correlated with alterations to Paneth cells and goblet cells, and markers of barrier permeability. Samples collected from 96 COVID-19 patients at two different clinical sites also revealed substantial gut microbiome dysbiosis, including blooms of opportunistic pathogenic bacterial genera known to include antimicrobial-resistant species. Analysis of blood culture results testing for secondary microbial bloodstream infections with paired microbiome data indicates that bacteria may translocate from the gut into the systemic circulation of COVID-19 patients. These results are consistent with a direct role for gut microbiome dysbiosis in enabling dangerous secondary infections during COVID-19
The James Webb Space Telescope Mission: Optical Telescope Element Design, Development, and Performance
The James Webb Space Telescope (JWST) is a large, infrared space telescope
that has recently started its science program which will enable breakthroughs
in astrophysics and planetary science. Notably, JWST will provide the very
first observations of the earliest luminous objects in the Universe and start a
new era of exoplanet atmospheric characterization. This transformative science
is enabled by a 6.6 m telescope that is passively cooled with a 5-layer
sunshield. The primary mirror is comprised of 18 controllable, low areal
density hexagonal segments, that were aligned and phased relative to each other
in orbit using innovative image-based wavefront sensing and control algorithms.
This revolutionary telescope took more than two decades to develop with a
widely distributed team across engineering disciplines. We present an overview
of the telescope requirements, architecture, development, superb on-orbit
performance, and lessons learned. JWST successfully demonstrates a segmented
aperture space telescope and establishes a path to building even larger space
telescopes.Comment: accepted by PASP for JWST Overview Special Issue; 34 pages, 25
figure
Localization of type 1 diabetes susceptibility to the MHC class I genes HLA-B and HLA-A
The major histocompatibility complex (MHC) on chromosome 6 is associated with susceptibility to more common diseases than any other region of the human genome, including almost all disorders classified as autoimmune. In type 1 diabetes the major genetic susceptibility determinants have been mapped to the MHC class II genes HLA-DQB1 and HLA-DRB1 (refs 1-3), but these genes cannot completely explain the association between type 1 diabetes and the MHC region. Owing to the region's extreme gene density, the multiplicity of disease-associated alleles, strong associations between alleles, limited genotyping capability, and inadequate statistical approaches and sample sizes, which, and how many, loci within the MHC determine susceptibility remains unclear. Here, in several large type 1 diabetes data sets, we analyse a combined total of 1,729 polymorphisms, and apply statistical methods - recursive partitioning and regression - to pinpoint disease susceptibility to the MHC class I genes HLA-B and HLA-A (risk ratios >1.5; Pcombined = 2.01 × 10-19 and 2.35 × 10-13, respectively) in addition to the established associations of the MHC class II genes. Other loci with smaller and/or rarer effects might also be involved, but to find these, future searches must take into account both the HLA class II and class I genes and use even larger samples. Taken together with previous studies, we conclude that MHC-class-I-mediated events, principally involving HLA-B*39, contribute to the aetiology of type 1 diabetes. ©2007 Nature Publishing Group
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
Utvärdering av BRIS Internetbaserade stödkontakter
I denna utvärdering av BRIS Internetbaserade stödjande kontakter har de barn som kontaktat BRIS via mejl eller chatt ombetts besvara ett antal frågor om hur de upplever sitt mående, den svårighet som är anledningen till att de kontaktar BRIS och hur de upplever att de blivit bemötta av BRIS. Dessa frågor har ställts före den stödjande kontakten, direkt efter kontakten och därefter 10 dagar efter att barnen mejlat eller chattat med BRIS. Därutöver har en förfrågan om att delta i en enkätstudie gått ut till alla barn som varit aktiva på BRIS diskussionsforum, där de tillfrågats om hur ofta de besökerforumet, vilka funktioner de uppskattar med forumet och hur de upplever den hjälp de får i forumet. Barnen har fått skatta sitt mående på en skala mellan 1 och 9, där 1 motsvarar ”jättedåligt” och 9 ”jättebra”. Undersökningen har designats efter den kvasiexperimentella studie som gjorts av holländska Kindertelefoon (Fukkink & Herrmanns 2007). Den teoretiska utgångspunkten för frågorna i undersökningen har varit KASAM (Antonovsky 1991) och BRISsamtalsmetod (Iwarsson 2007). In this evaluation, children who contacted BRIS via email or chat were asked to answer a few questions concerning their perceived well- being, the difficulties leading up to the contact, and how they feel they have been treated by BRIS. These questions were asked immediately before and after the contact, as well as 10 days later. In addition, a request to participate in a questionnaire study went out to all children who had been active on the BRIS discussion forums, where they were asked how often they visit the forum, what features they appreciate in the community and how they perceive the help they get in the forum. The children have estimated their well-being on a scale from 1 to 9, where 1 represents "Very poor" and 9 "Great". A total of 6,193 children were asked to participate in the evaluation. 925 responses were submitted during the period April 1st to June 7th (email & chat) and May 24th - August 17th (discussion forum). The internal loss is low, 5.05% for the entire study. Complete series in which the child has answered all three questionnaires in the email and chat amounts to only 51, however, between 220 and 432 questionnaires has been submitted by the different occasions. A total of 245 questionnaires have been submitted to the evaluation of the discussion forum. The children report that their well-being increases immediately after the contact with BRIS, regardless of modality. This however declines in the last follow-up. In general however, they still produce a higher value than at the first measurement. The children reported that they feel listened to and that they feel that BRIS is taking them seriously. The children who contact BRIS through discussion forums are even more satisfied with the assistance they receive than the children who use chat and email. Above all, the discussion forum helps kids to feel they are not alone in their situation. The children who use the discussion forum also very much appreciate the answers from other children and the opportunity to help other children by answering others postings. A small group of children, indicate that they feel worse after contac- ting BRIS. An analysis of their answers describe either a dissatis- faction with the provided advice or an incapacity to follow the provided advice despite them being perceived relevant
AN EARLY PERMIAN FLORA WITH LATE PERMIAN AND MESOZOIC AFFINITIES FROM NORTH-CENTRAL TEXAS
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