4,857 research outputs found
Playing the odds in clinical decision making: lessons from berry aneurysms undetected by magnetic resonance angiography
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MORPHOLOGICAL AND FUNCTIONAL STUDIES OF FETAL THYMUS TRANSPLANTS IN MICE
The fetal thymus at 13 days of gestation withstands transplantation and develops normally under the renal capsule of a syngenic host. Distinct differences were observed between the fetal thymus grafts and grafts from neonatal or adult thymus donors. The fetal thymus graft did not undergo the rapid and severe necrosis observed when adult thymus was grafted. Furthermore, when thymuses were transplanted into allogenic recipients, rejection was delayed. The fetal thymus was as effective as the adult thymus in restoring syngenic neonatally thymectomized mice and far superior to adult thymus when grafted into allogenic recipients. These observations seem relevant to clinical efforts to restore immunocompetence in patients with congenital absence of the thymus
Learning from FITS: Limitations in use in modern astronomical research
The Flexible Image Transport System (FITS) standard has been a great boon to astronomy, allowing observatories, scientists and the public to exchange astronomical information easily. The FITS standard, however, is showing its age. Developed in the late 1970s, the FITS authors made a number of implementation choices that, while common at the time, are now seen to limit its utility with modern data. The authors of the FITS standard could not anticipate the challenges which we are facing today in astronomical computing. Difficulties we now face include, but are not limited to, addressing the need to handle an expanded range of specialized data product types (data models), being more conducive to the networked exchange and storage of data, handling very large datasets, and capturing significantly more complex metadata and data relationships.
There are members of the community today who find some or all of these limitations unworkable, and have decided to move ahead with storing data in other formats. If this fragmentation continues, we risk abandoning the advantages of broad interoperability, and ready archivability, that the FITS format provides for astronomy. In this paper we detail some selected important problems which exist within the FITS standard today. These problems may provide insight into deeper underlying issues which reside in the format and we provide a discussion of some lessons learned. It is not our intention here to prescribe specific remedies to these issues; rather, it is to call attention of the FITS and greater astronomical computing communities to these problems in the hope that it will spur action to address them
Adaptable-radius, time-orbiting magnetic ring trap for Bose-Einstein condensates
We theoretically investigate an adjustable-radius magnetic storage ring for
laser-cooled and Bose-condensed atoms. Additionally, we discuss a novel
time-dependent variant of this and other ring traps. Time-orbiting ring traps
provide a high optical access method for spin-flip loss prevention near a
storage ring's circular magnetic field zero. Our scalable storage ring will
allow one to probe the fundamental limits of condensate Sagnac interferometry.Comment: 5 pages, 3 figures. accepted in J Phys
Reappraising David Livingstone's The Geographical Tradition:A Quarter of a Century On
The information, practices and views in this article are those of the author(s) and do not necessarily reflect the opinion of the Royal Geographical Society (with IBG). © 2019 Royal Geographical Society (with the Institute of British Geographers). The quarter of a century since the publication of David Livingstone's The Geographical Tradition in 1992 provides an apt moment to reflect on the book's theses, lacunae, and legacies, and to take stock of the ways in which its provocations and reception might instruct the wider project of rendering the discipline's history. In framing this themed intervention, we engage the assertion that contextualisers need contextualising; there exists scope to heighten awareness of the location within time, space and culture from which contextualist historiographies of geography are written. We call attention to the meaning and implications of the particular and situated contextualist methodology mobilised and executed in The Geographical Tradition
A Novel Method for Rapid and Quantitative Mechanical Assessment of Soft Tissue for Diagnostic Purposes: A Computational Study
Cross Helicity of the November 2018 Magnetic Cloud Observed by the Parker Solar Probe
Magnetic clouds are large-scale transient structures in the solar wind with
low plasma , low-amplitude magnetic field fluctuations, and twisted
field lines with both ends often connected to the Sun. Their inertial-range
turbulent properties have not been examined in detail. In this Letter, we
analyze the normalized cross helicity, , and residual energy,
, of plasma fluctuations in the November 2018 magnetic cloud observed
at 0.25 au by the Parker Solar Probe. A low value of was present
in the cloud core, indicating that wave power parallel and anti-parallel to the
mean field was approximately balanced, while the cloud's outer layers displayed
larger amplitude Alfv\'enic fluctuations with high values and
. These properties are discussed in terms of the cloud's solar
connectivity and local interaction with the solar wind. We suggest that low
is likely a common feature of magnetic clouds given their
typically closed field structure. Anti-sunward fluctuations propagating
immediately upstream of the cloud had strongly negative values.Comment: 9 pages, 4 figures; accepted for publication in the Astrophysical
Journal Letters 2020 August 1
Seminal plasma as a source of prostate cancer peptide biomarker candidates for detection of indolent and advanced disease
Background:Extensive prostate specific antigen screening for prostate cancer generates a high number of unnecessary biopsies and over-treatment due to insufficient differentiation between indolent and aggressive tumours. We hypothesized that seminal plasma is a robust source of novel prostate cancer (PCa) biomarkers with the potential to improve primary diagnosis of and to distinguish advanced from indolent disease.
<br>Methodology/Principal Findings: In an open-label case/control study 125 patients (70 PCa, 21 benign prostate hyperplasia, 25 chronic prostatitis, 9 healthy controls) were enrolled in 3 centres. Biomarker panels a) for PCa diagnosis (comparison of PCa patients versus benign controls) and b) for advanced disease (comparison of patients with post surgery Gleason score <7 versus Gleason score >>7) were sought. Independent cohorts were used for proteomic biomarker discovery and testing the performance of the identified biomarker profiles. Seminal plasma was profiled using capillary electrophoresis mass spectrometry. Pre-analytical stability and analytical precision of the proteome analysis were determined. Support vector machine learning was used for classification. Stepwise application of two biomarker signatures with 21 and 5 biomarkers provided 83% sensitivity and 67% specificity for PCa detection in a test set of samples. A panel of 11 biomarkers for advanced disease discriminated between patients with Gleason score 7 and organ-confined (<pT3a) or advanced (≥pT3a) disease with 80% sensitivity and 82% specificity in a preliminary validation setting. Seminal profiles showed excellent pre-analytical stability. Eight biomarkers were identified as fragments of N-acetyllactosaminide beta-1,3-N-acetylglucosaminyltransferase​,prostatic acid phosphatase, stabilin-2, GTPase IMAP family member 6, semenogelin-1 and -2. Restricted sample size was the major limitation of the study.</br>
<br>Conclusions/Significance: Seminal plasma represents a robust source of potential peptide makers for primary PCa diagnosis. Our findings warrant further prospective validation to confirm the diagnostic potential of identified seminal biomarker candidates.</br>
Synthetic RNA Silencing of Actinorhodin Biosynthesis in Streptomyces coelicolor A3(2)
We demonstrate the first application of synthetic RNA gene silencers in Streptomyces coelicolor A3(2). Peptide nucleic acid and expressed antisense RNA silencers successfully inhibited actinorhodin production. Synthetic RNA silencing was target-specific and is a new tool for gene regulation and metabolic engineering studies in Streptomyces.Peer reviewe
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