1,116 research outputs found
The fundamental pro-groupoid of an affine 2-scheme
A natural question in the theory of Tannakian categories is: What if you
don't remember \Forget? Working over an arbitrary commutative ring , we
prove that an answer to this question is given by the functor represented by
the \'etale fundamental groupoid \pi_1(\spec(R)), i.e.\ the separable
absolute Galois group of when it is a field. This gives a new definition
for \'etale \pi_1(\spec(R)) in terms of the category of -modules rather
than the category of \'etale covers. More generally, we introduce a new notion
of "commutative 2-ring" that includes both Grothendieck topoi and symmetric
monoidal categories of modules, and define a notion of for the
corresponding "affine 2-schemes." These results help to simplify and clarify
some of the peculiarities of the \'etale fundamental group. For example,
\'etale fundamental groups are not "true" groups but only profinite groups, and
one cannot hope to recover more: the "Tannakian" functor represented by the
\'etale fundamental group of a scheme preserves finite products but not all
products.Comment: 46 pages + bibliography. Diagrams drawn in Tik
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Clades of huge phages from across Earth's ecosystems.
Bacteriophages typically have small genomes1 and depend on their bacterial hosts for replication2. Here we sequenced DNA from diverse ecosystems and found hundreds of phage genomes with lengths of more than 200 kilobases (kb), including a genome of 735 kb, which is-to our knowledge-the largest phage genome to be described to date. Thirty-five genomes were manually curated to completion (circular and no gaps). Expanded genetic repertoires include diverse and previously undescribed CRISPR-Cas systems, transfer RNAs (tRNAs), tRNA synthetases, tRNA-modification enzymes, translation-initiation and elongation factors, and ribosomal proteins. The CRISPR-Cas systems of phages have the capacity to silence host transcription factors and translational genes, potentially as part of a larger interaction network that intercepts translation to redirect biosynthesis to phage-encoded functions. In addition, some phages may repurpose bacterial CRISPR-Cas systems to eliminate competing phages. We phylogenetically define the major clades of huge phages from human and other animal microbiomes, as well as from oceans, lakes, sediments, soils and the built environment. We conclude that the large gene inventories of huge phages reflect a conserved biological strategy, and that the phages are distributed across a broad bacterial host range and across Earth's ecosystems
In vivo Recombinant Adenovirus-mediated p53 Gene Therapy in a Syngeneic Rat Model for Colorectal Cancer
The p53 gene has a significant role in controlling genomic stability of cancer. The purpose of this study was to evaluate the tumor response of allograft colorectal tumor treated with Ad5CMV-p53 in a syngeneic rat model. Two weeks after the inoculation of WB-2054-M5 tumor cells in the flank of rats, rats were randomly assigned by tumor size to one of three groups (n=18 in each): phosphate buffered saline (PBS), Ad5CMV, and Ad5CMV-p53. Recombinant adenovirus or PBS was administered through intratumoral injection at three divided doses every other day for 4 weeks. Apoptosis of the tumors was evaluated using TUNEL assay. After 2 and 4 weeks of treatment, the volume (cm3) of tumors in PBS, Ad5CMV, and Ad5CMV-p53 was as follows: 2 week: 1.66±0.43, 1.40±0.47, 0.75±0.26 (p<0.001), 4 week: 4.41±0.88, 3.93±1.86, 2.33±0.51 (p<0.001). Tumor growth showed no statistically significant difference between the PBS and Ad5CMV groups (6-week vol. p=0.32). The TUNEL assay results revealed more apparent apoptotic cells in Ad5CMV-p53-treated tumors than in other groups. Growth of allograft colorectal cancer in the syngeneic rat model was significantly suppressed by intratumoral Ad5CMV-p53 gene therapy. These results demonstrate that gene replacement therapy with p53 may provide a novel modality of treatment in conjunction with other present treatments for metastatic colorectal cancer
Status of Muon Collider Research and Development and Future Plans
The status of the research on muon colliders is discussed and plans are
outlined for future theoretical and experimental studies. Besides continued
work on the parameters of a 3-4 and 0.5 TeV center-of-mass (CoM) energy
collider, many studies are now concentrating on a machine near 0.1 TeV (CoM)
that could be a factory for the s-channel production of Higgs particles. We
discuss the research on the various components in such muon colliders, starting
from the proton accelerator needed to generate pions from a heavy-Z target and
proceeding through the phase rotation and decay ()
channel, muon cooling, acceleration, storage in a collider ring and the
collider detector. We also present theoretical and experimental R & D plans for
the next several years that should lead to a better understanding of the design
and feasibility issues for all of the components. This report is an update of
the progress on the R & D since the Feasibility Study of Muon Colliders
presented at the Snowmass'96 Workshop [R. B. Palmer, A. Sessler and A.
Tollestrup, Proceedings of the 1996 DPF/DPB Summer Study on High-Energy Physics
(Stanford Linear Accelerator Center, Menlo Park, CA, 1997)].Comment: 95 pages, 75 figures. Submitted to Physical Review Special Topics,
Accelerators and Beam
Scrambling for access: availability, accessibility, acceptability and quality of healthcare for lesbian, gay, bisexual and transgender people in South Africa
BACKGROUND: Sexual orientation and gender identity are social determinants of health for people identifying as lesbian, gay, bisexual and transgender (LGBT), and health disparities among sexual and gender minority populations are increasingly well understood. Although the South African constitution guarantees sexual and gender minority people the right to non-discrimination and the right to access to healthcare, homo- and transphobia in society abound. Little is known about LGBT people's healthcare experiences in South Africa, but anecdotal evidence suggests significant barriers to accessing care. Using the framework of the UN International Covenant on Economic, Social and Cultural Rights General Comment 14, this study analyses the experiences of LGBT health service users using South African public sector healthcare, including access to HIV counselling, testing and treatment. METHODS: A qualitative study comprised of 16 semi-structured interviews and two focus group discussions with LGBT health service users, and 14 individual interviews with representatives of LGBT organisations. Data were thematically analysed within the framework of the UN International Covenant on Economic, Social and Cultural Rights General Comment 14, focusing on availability, accessibility, acceptability and quality of care. RESULTS: All interviewees reported experiences of discrimination by healthcare providers based on their sexual orientation and/or gender identity. Participants recounted violations of all four elements of the UN General Comment 14: 1) Availability: Lack of public health facilities and services, both for general and LGBT-specific concerns; 2) Accessibility: Healthcare providers' refusal to provide care to LGBT patients; 3) Acceptability: Articulation of moral judgment and disapproval of LGBT patients' identity, and forced subjection of patients to religious practices; 4) Quality: Lack of knowledge about LGBT identities and health needs, leading to poor-quality care. Participants had delayed or avoided seeking healthcare in the past, and none had sought out accountability or complaint mechanisms within the health system. CONCLUSION: Sexual orientation and gender identity are important categories of analysis for health equity, and lead to disparities in all four dimensions of healthcare access as defined by General Comment 14. Discriminatory and prejudicial attitudes by healthcare providers, combined with a lack of competency and knowledge are key reasons for these disparities in South Africa
The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in
operation since July 2014. This paper describes the second data release from
this phase, and the fourteenth from SDSS overall (making this, Data Release
Fourteen or DR14). This release makes public data taken by SDSS-IV in its first
two years of operation (July 2014-2016). Like all previous SDSS releases, DR14
is cumulative, including the most recent reductions and calibrations of all
data taken by SDSS since the first phase began operations in 2000. New in DR14
is the first public release of data from the extended Baryon Oscillation
Spectroscopic Survey (eBOSS); the first data from the second phase of the
Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2),
including stellar parameter estimates from an innovative data driven machine
learning algorithm known as "The Cannon"; and almost twice as many data cubes
from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous
release (N = 2812 in total). This paper describes the location and format of
the publicly available data from SDSS-IV surveys. We provide references to the
important technical papers describing how these data have been taken (both
targeting and observation details) and processed for scientific use. The SDSS
website (www.sdss.org) has been updated for this release, and provides links to
data downloads, as well as tutorials and examples of data use. SDSS-IV is
planning to continue to collect astronomical data until 2020, and will be
followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14
happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov
2017 (this is the "post-print" and "post-proofs" version; minor corrections
only from v1, and most of errors found in proofs corrected
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
Concerns About Exercise Are Related to Walk Test Results in Pulmonary Rehabilitation for Patients with COPD
# The Author(s). This article is published with open access at Springerlink.com 2010 Background Although international guidelines on pulmonary rehabilitation acknowledge that psychological factors contribute to exercise intolerance in patients with chronic obstructive pulmonary disease (COPD), the few empirical studies investigating this association have found inconsistent results. Purpose The purpose of this study is to investigate whether negative affect and beliefs about exercise of patients with COPD would be related to baseline 6-min walk (6-MW) test results in a pulmonary rehabilitation setting, after correction for physical variables (sex, age, height, weight, and lung function). A second aim was to examine whethe
INVENTORY OF MOSQUITOES (DIPTERA: CULICIDAE) IN CONSERVATION UNITS IN BRAZILIAN TROPICAL DRY FORESTS
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