893 research outputs found
The CSF in neurosarcoidosis contains consistent clonal expansion of CD8 T cells, but not CD4 T cells
The tissue-specific drivers of neurosarcoidosis remain poorly defined. To identify cerebrospinal fluid (CSF) specific, antigen-driven T and B cell responses, we performed single-cell RNA sequencing of CSF and blood cells from neurosarcoid participants coupled to T and B cell receptor sequencing. In contrast to pulmonary sarcoidosis, which is driven by CD4 T cells, we found CD8 T cell clonal expansion enriched in the neurosarcoid CSF. These CSF-enriched CD8 T cells were composed of two subsets with differential expression of EBI2, CXCR3, and CXCR4. Lastly, our data suggest that IFNγ signaling may distinguish neurosarcoidosis from other neurological disorders
Thirty-two Goldbach Variations
We give thirty-two diverse proofs of a small mathematical gem--the
fundamental Euler sum identity zeta(2,1)=zeta(3) =8zeta(\bar 2,1). We also
discuss various generalizations for multiple harmonic (Euler) sums and some of
their many connections, thereby illustrating both the wide variety of
techniques fruitfully used to study such sums and the attraction of their
study.Comment: v1: 34 pages AMSLaTeX. v2: 41 pages AMSLaTeX. New introductory
material added and material on inequalities, Hilbert matrix and Witten zeta
functions. Errors in the second section on Complex Line Integrals are
corrected. To appear in International Journal of Number Theory. Title change
Staggering effects in nuclear and molecular spectra
It is shown that the recently observed Delta J = 2 staggering effect (i.e.
the relative displacement of the levels with angular momenta J, J+4, J+8, ...,
relatively to the levels with angular momenta J+2, J+6, J+10, ...) seen in
superdeformed nuclear bands is also occurring in certain electronically excited
rotational bands of diatomic molecules (YD, CrD, CrH, CoH), in which it is
attributed to interband interactions (bandcrossings). In addition, the Delta J
= 1 staggering effect (i.e. the relative displacement of the levels with even
angular momentum J with respect to the levels of the same band with odd J) is
studied in molecular bands free from Delta J = 2 staggering (i.e. free from
interband interactions/bandcrossings). Bands of YD offer evidence for the
absence of any Delta J = 1 staggering effect due to the disparity of nuclear
masses, while bands of sextet electronic states of CrD demonstrate that Delta J
= 1 staggering is a sensitive probe of deviations from rotational behaviour,
due in this particular case to the spin-rotation and spin-spin interactions.Comment: LaTeX, 16 pages plus 30 figures given in separate .ps files. To
appear in the proceedings of the 4th European Workshop on Quantum Systems in
Chemistry and Physics (Marly-le-Roi, France, 1999), ed. J. Maruani et al.
(Kluwer, Dordrecht
Constraints on the circumstellar dust around KIC 8462852
© The Authors 2016. Published by Oxford University Press on behalf of The Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.We present millimetre (SMA) and sub-millimetre (SCUBA-2) continuum observations of the peculiar star KIC 8462852 which displayed several deep and aperiodic dips in brightness during the Kepler mission. Our observations are approximately confusion-limited at 850 m and are the deepest millimetre and sub-millimetre photometry of the star that has yet been carried out. No significant emission is detected towards KIC 8462852. We determine upper limits for dust between a few 10 M and 10 M for regions identified as the most likely to host occluding dust clumps and a total overall dust budget of 7.7 M within a radius of 200 AU. Such low limits for the inner system make the catastrophic planetary disruption hypothesis unlikely. Integrating over the Kepler lightcurve we determine that at least 10 M of dust is required to cause the observed Q16 dip. This is consistent with the currently most favoured cometary breakup hypothesis, but nevertheless implies the complete breakup of 30 Comet 1/P Halley type objects. Finally, in the wide SCUBA-2 field-of-view we identify another candidate debris disc system that is potentially the largest yet discovered.Peer reviewedFinal Published versio
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Sequencing and association analysis of the type 1 diabetes - linked region on chromosome 10p12-q11
Background: In an effort to locate susceptibility genes for type I diabetes (TID) several genome-wide linkage scans have been undertaken. A chromosomal region designated IDDM10 retained genome-wide significance in a combined analysis of the main linkage scans. Here, we studied sequence polymorphisms in 23 Mb on chromosome 10p12-q11, including the putative IDDM10 region, to identify genes associated with TID. Results: Initially, we resequenced the functional candidate genes, CREM and SDF1, located in this region, genotyped 13 tag single nucleotide polymorphisms (SNPs) and found no association with TID. We then undertook analysis of the whole 23 Mb region. We constructed and sequenced a contig tile path from two bacterial artificial clone libraries. By comparison with a clone library from an unrelated person used in the Human Genome Project, we identified 12,058 SNPs. We genotyped 303 SNPs and 25 polymorphic microsatellite markers in 765 multiplex TID families and followed up 22 associated polymorphisms in up to 2,857 families. We found nominal evidence of association in six loci (P = 0.05-0.0026), located near the PAPDI gene. Therefore, we resequenced 38.8 kb in this region, found 147 SNPs and genotyped 84 of them in the TID families. We also tested 13 polymorphisms in the PAPDI gene and in five other loci in 1,612 TID patients and 1,828 controls from the UK. Overall, only the D10S193 microsatellite marker located 28 kb downstream of PAPDI showed nominal evidence of association in both TID families and in the case-control sample (P = 0.037 and 0.03, respectively). Conclusion: We conclude that polymorphisms in the CREM and SDFI genes have no major effect on TID. The weak TID association that we detected in the association scan near the PAPDI gene may be either false or due to a small genuine effect, and cannot explain linkage at the IDDM10 region
Acoustic-Friction Networks and the Evolution of Precursory Rupture Fronts in Laboratory Earthquakes
We show that the mesoscopic and transport characteristics of networks follow
the same trends for the same type of the shear ruptures in terms of rupture
speed while also comparing the results of three different friction
experiments.The classified fronts obtained from a saw cut Westerly granite
fault regarding friction network parameters show a clear separation into two
groups indicating two different rupture fronts. With respect to the scaling of
local ruptures durations with the networks parameters we show that the gap is
related to the possibility of a separation between slow and regular fronts
Global Warming on Triton
Triton, Neptune's largest moon, has been predicted to undergo significant seasonal changes that would reveal themselves as changes in its mean frost temperature. But whether this temperature should at the present time be increasing, decreasing or constant depends on a number of parameters (such as the thermal properties of the surface, and frost migration patterns) that are unknown. Here we report observations of a recent stellar occultation by Triton which, when combined with earlier results, show that Triton has undergone a period of global warming since 1989. Our most conservative estimates of the rate of temperature and surface-pressure increase during this period imply that the atmosphere is doubling in bulk every 10 years, significantly faster than predicted by any published frost model for Triton. Our result suggests that permanent polar caps on Triton play a c dominant role in regulating seasonal atmospheric changes. Similar processes should also be active on Pluto
Nucleosome-coupled expression differences in closely-related species
<p>Abstract</p> <p>Background</p> <p>Genome-wide nucleosome occupancy is negatively related to the average level of transcription factor motif binding based on studies in yeast and several other model organisms. The degree to which nucleosome-motif interactions relate to phenotypic changes across species is, however, unknown.</p> <p>Results</p> <p>We address this challenge by generating nucleosome positioning and cell cycle expression data for <it>Saccharomyces bayanus </it>and show that differences in nucleosome occupancy reflect cell cycle expression divergence between two yeast species, <it>S. bayanus </it>and <it>S. cerevisiae</it>. Specifically, genes with nucleosome-depleted MBP1 motifs upstream of their coding sequence show periodic expression during the cell cycle, whereas genes with nucleosome-shielded motifs do not. In addition, conserved cell cycle regulatory motifs across these two species are more nucleosome-depleted compared to those that are not conserved, suggesting that the degree of conservation of regulatory sites varies, and is reflected by nucleosome occupancy patterns. Finally, many changes in cell cycle gene expression patterns across species can be correlated to changes in nucleosome occupancy on motifs (rather than to the presence or absence of motifs).</p> <p>Conclusions</p> <p>Our observations suggest that alteration of nucleosome occupancy is a previously uncharacterized feature related to the divergence of cell cycle expression between species.</p
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