202 research outputs found
Centimeter-wave continuum radiation from the rho Ophiuchi molecular cloud
The rho Oph molecular cloud is undergoing intermediate-mass star formation.
UV radiation from its hottest young stars heats and dissociates exposed layers,
but does not ionize hydrogen. Only faint radiation from the Rayleigh-Jeans tail
of ~10-100K dust is expected at wavelengths longwards of 3mm. Yet Cosmic
Background Imager (CBI) observations reveal that the rho Oph W
photo-dissociation region (PDR) is surprisingly bright at centimetre
wavelengths. We searched for interpretations consistent with the WMAP radio
spectrum, new ISO-LWS parallel mode images and archival Spitzer data.
Dust-related emission mechanisms at 1 cm, as proposed by Draine & Lazarian, are
a possibility. But a magnetic enhancement of the grain opacity at 1cm is
inconsistent with the morphology of the dust column maps Nd and the lack of
detected polarization. Spinning dust, or electric-dipole radiation from
spinning very small grains (VSGs), comfortably explains the radio spectrum,
although not the conspicuous absence from the CBI data of the infrared
circumstellar nebulae around the B-type stars S1 and SR~3. Allowing for VSG
depletion can marginally reconcile spinning dust with the data. As an
alternative interpretation we consider the continuum from residual charges in
rho Oph W, where most of carbon should be photoionised by the close binary
HD147889 (B2IV, B3IV). Electron densities of ~100 cm^{-3}, or H-nucleus
densities n_H > 1E6 cm^{-3}, are required to interpret rho Oph W as the CII
Stromgren sphere of HD147889. However the observed steep and positive
low-frequency spectral index would then require optically thick emission from
an hitherto unobserved ensemble of dense clumps or sheets with a filling factor
~1E-4 and n_H ~ 1E7 cm^{-3}.Comment: accepted for publication in MNRA
Mixed-state quasiparticle transport in high-T_c cuprates: localization by magnetic field
Theory of quasiparticle transport in the mixed state of a d-wave
superconductor is developed under the assumption of disordered vortex array. A
novel universal regime is identified at fields above H*= c*H_{c2}(T/T_c)^2,
characterized by a field-independent longitudinal thermal conductivity. It is
argued that this behavior is responsible for the high-field plateau in the
thermal conductivity experimentally observed in cuprates by Krishana, Ong and
co-workers.Comment: 4 pages REVTeX + 1 PostScript figure. Final version to appear in PRL.
Several changes in response to referee comments. For related work and info
visit http://www.pha.jhu.edu/~fran
β2M Signals Monocytes Through Non-Canonical TGFβ Receptor Signal Transduction.
Rationale: Circulating monocytes can have pro-inflammatory or pro-reparative phenotypes. The
endogenous signaling molecules and pathways that regulate monocyte polarization in vivo are poorly
understood. We have shown that platelet derived beta-2 microglobulin (β2M) and transforming growth
factor beta (TGFβ) have opposing effects on monocytes by inducing inflammatory and reparative
phenotypes respectively, but each bind and signal through the same receptor. We now define the signaling
pathways involved.
Objective: To determine the molecular mechanisms and signal transduction pathways by which β2M and
TGFβ regulate monocyte responses both in vitro and in vivo.
Methods and Results: Wild-type (WT) and platelet specific β2M knockout (Plt-β2M-/-) mice were treated
intravenously with either β2M or TGFβ to increase plasma concentrations to those in cardiovascular
diseases. Elevated plasma β2M increased pro-inflammatory monocytes, while increased plasma TGFβ
increased pro-reparative monocytes. TGFβ receptor (TGFβR) inhibition blunted monocyte responses to
both β2M and TGFβ in vivo. Using imaging flow cytometry, we found that β2M decreased monocyte
SMAD2/3 nuclear localization, while TGFβ promoted SMAD nuclear translocation, but decreased noncanonical/
inflammatory (JNK and NFκB nuclear localization). This was confirmed in vitro using both
imaging flow cytometry and immunoblots. β2M, but not TGFβ, promoted ubiquitination of SMAD3 and
SMAD4, that inhibited their nuclear trafficking. Inhibition of ubiquitin ligase activity blocked noncanonical
SMAD-independent monocyte signaling and skewed monocytes towards a pro-reparative
monocyte response.
Conclusions: Our findings indicate that elevated plasma β2M and TGFβ dichotomously polarize
monocytes. Furthermore, these immune molecules share a common receptor, but induce SMAD-dependent
canonical signaling (TGFβ) versus non-canonical SMAD-independent signaling (β2M) in a ubiquitin ligase
dependent manner. This work has broad implications as β2M is increased in several inflammatory
conditions, while TGFβ is increased in fibrotic diseases.pre-print3451 K
Nonmonotonous Magnetic Field Dependence and Scaling of the Thermal Conductivity for Superconductors with Nodes of the Order Parameter
We show that there is a new mechanism for nonmonotonous behavior of magnetic
field dependence of the electronic thermal conductivity of clean
superconductors with nodes of the order parameter on the Fermi surface. In
particular, for unitary scatterers the nonmonotony of relaxation time takes
place. Contribution from the intervortex space turns out to be essential for
this effect even at low temperatures. Our results are in a qualitative
agreement with recent experimental data for superconducting UPt_3. For
E_{2u}-type of pairing we find approximately the scaling of the thermal
conductivity in clean limit with a single parameter x=T/T_c\sqrt{B_{c2}/B} at
low fields and low temperatures, as well as weak low-temperature dependence of
the anisotropy ratio K_{zz}/K_{yy} in zero field. For E_{1g}-type of pairing
deviations from the scaling are more noticeable and the anisotropy ratio is
essentially temperature dependent.Comment: 37 pages, 8 Postscript figures, REVTE
Recommendations on clinical trial design for treatment of Mucopolysaccharidosis Type III
Abstract Background Mucopolysaccharidosis type III is a progressive, neurodegenerative lysosomal storage disorder for which there is currently no effective therapy. Though numerous potential therapies are in development, there are several challenges to conducting clinical research in this area. We seek to make recommendations on the approach to clinical research in MPS III, including the selection of outcome measures and trial endpoints, in order to improve the quality and impact of research in this area. Results An international workshop involving academic researchers, clinical experts and industry groups was held in June 2015, with presentations and discussions on disease pathophysiology, biomarkers, potential therapies and clinical outcome measures. A set of recommendations was subsequently prepared by a working group and reviewed by all delegates. We present a series of 11 recommendations regarding the conduct of clinical research, outcome measures and management of natural history data in Mucopolysaccharidosis type III. Conclusions Improving the quality of clinical research in Mucopolysaccharidosis type III will require an open, collaborative and systematic approach between academic researchers, clinicians and industry. Natural history data should be published as soon as possible and ideally collated in a central repository. There should be agreement on outcome measures and instruments for evaluation of clinical outcomes to maximise the effectiveness of current and future clinical research
A Fully Integrated Real-Time Detection, Diagnosis, and Control of Community Diarrheal Disease Clusters and Outbreaks (the INTEGRATE Project):Protocol for an Enhanced Surveillance System
BACKGROUND:Diarrheal disease, which affects 1 in 4 people in the United Kingdom annually, is the most common cause of outbreaks in community and health care settings. Traditional surveillance methods tend to detect point-source outbreaks of diarrhea and vomiting; they are less effective at identifying low-level and intermittent food supply contamination. Furthermore, it can take up to 9 weeks for infections to be confirmed, reducing slow-burn outbreak recognition, potentially impacting hundreds or thousands of people over wide geographical areas. There is a need to address fundamental problems in traditional diarrheal disease surveillance because of underreporting and subsequent unconfirmed infection by patients and general practitioners (GPs); varying submission practices and selective testing of samples in laboratories; limitations in traditional microbiological diagnostics, meaning that the timeliness of sample testing and etiology of most cases remains unknown; and poorly integrated human and animal surveillance systems, meaning that identification of zoonoses is delayed or missed. OBJECTIVE:This study aims to detect anomalous patterns in the incidence of gastrointestinal disease in the (human) community; to target sampling; to test traditional diagnostic methods against rapid, modern, and sensitive molecular and genomic microbiology methods that identify and characterize responsible pathogens rapidly and more completely; and to determine the cost-effectiveness of rapid, modern, sensitive molecular and genomic microbiology methods. METHODS:Syndromic surveillance will be used to aid identification of anomalous patterns in microbiological events based on temporal associations, demographic similarities among patients and animals, and changes in trends in acute gastroenteritis cases using a point process statistical model. Stool samples will be obtained from patients' consulting GPs, to improve the timeliness of cluster detection and characterize the pathogens responsible, allowing health protection professionals to investigate and control outbreaks quickly, limiting their size and impact. The cost-effectiveness of the proposed system will be examined using formal cost-utility analysis to inform decisions on national implementation. RESULTS:The project commenced on April 1, 2013. Favorable approval was obtained from the Research Ethics Committee on June 15, 2015, and the first patient was recruited on October 13, 2015, with 1407 patients recruited and samples processed using traditional laboratory techniques as of March 2017. CONCLUSIONS:The overall aim of this study is to create a new One Health paradigm for detecting and investigating diarrhea and vomiting in the community in near-real time, shifting from passive human surveillance and management of laboratory-confirmed infection toward an integrated, interdisciplinary enhanced surveillance system including management of people with symptoms. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID):DERR1-10.2196/13941
Quasi-Classical Calculation of the Mixed-State Thermal Conductivity in s-Wave and d-Wave Superconductors
To see how superconducting gap structures affect the longitudinal component
of mixed-state thermal conductivity kappa_{xx}(B), the magnetic-field
dependences of kappa_{xx}(B) in s-wave and d-wave superconductors are
investigated. Calculations are performed on the basis of the quasi-classical
theory of superconductivity by fully taking account of the spatial variation of
the normal Green's function, neglected in previous works, by the
Brandt-Pesch-Tewordt approximation. On the basis of our result, we discuss the
possibility of kappa_{xx}(B) measurement as a method of probing the gap
structure.Comment: To appear in J. Phys. Soc. Jp
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Sepsis promotes splenic production of a protective platelet pool with high CD40 ligand expression.
Platelets have a wide range of functions including critical roles in hemostasis, thrombosis, and immunity. We hypothesized that during acute inflammation, such as in life-threatening sepsis, there are fundamental changes in the sites of platelet production and phenotypes of resultant platelets. Here, we showed during sepsis that the spleen was a major site of megakaryopoiesis and platelet production. Sepsis provoked an adrenergic-dependent mobilization of megakaryocyte-erythrocyte progenitors (MEPs) from the bone marrow to the spleen, where IL-3 induced their differentiation into megakaryocytes (MKs). In the spleen, immune-skewed MKs produced a CD40 ligandhi platelet population with potent immunomodulatory functions. Transfusions of post-sepsis platelets enriched from splenic production enhanced immune responses and reduced overall mortality in sepsis-challenged animals. These findings identify a spleen-derived protective platelet population that may be broadly immunomodulatory in acute inflammatory states such as sepsis.NHS Blood and Transplant
European Union's Horizon 2020 (ERC-2014-CoG-648765)
MRC-AMED (MR/V005421/1
Primary and malignant cholangiocytes undergo CD40 mediated Fas dependent Apoptosis, but are insensitive to direct activation with exogenous fas ligand
Introduction
Cholangiocarcinoma is a rare malignancy of the biliary tract, the incidence of which is rising, but the pathogenesis of which remains uncertain. No common genetic defects have been described but it is accepted that chronic inflammation is an important contributing factor. We have shown that primary human cholangiocyte and hepatocyte survival is tightly regulated via co-operative interactions between two tumour necrosis family (TNF) receptor family members; CD40 and Fas (CD95). Functional deficiency of CD154, the ligand for CD40, leads to a failure of clearance of biliary tract infections and a predisposition to cholangiocarcinoma implying a direct link between TNF receptor-mediated apoptosis and the development of cholangiocarcinoma.
Aims
To determine whether malignant cholangiocytes display defects in CD40 mediated apoptosis. By comparing CD40 and Fas-mediated apoptosis and intracellular signalling in primary human cholangiocytes and three cholangiocyte cell lines.
Results
Primary cholangiocytes and cholangiocyte cell lines were relatively insensitive to direct Fas-mediated killing with exogenous FasL when compared with Jurkat cells, which readily underwent Fas-mediated apoptosis, but were extremely sensitive to CD154 stimulation. The sensitivity of cells to CD40 activation was similar in magnitude in both primary and malignant cells and was STAT-3 and AP-1 dependent in both.
Conclusions
1) Both primary and malignant cholangiocytes are relatively resistant to Fas–mediated killing but show exquisite sensitivity to CD154, suggesting that the CD40 pathway is intact and fully functional in both primary and malignant cholangiocytes 2) The relative insensitivity of cholangiocytes to Fas activation demonstrates the importance of CD40 augmentation of Fas dependent death in these cells. Agonistic therapies which target CD40 and associated intracellular signalling pathways may be effective in promoting apoptosis of malignant cholangiocytes
The Atacama Cosmology Telescope: Extragalactic Sources at 148 GHz in the 2008 Survey
We report on extragalactic sources detected in a 455 square-degree map of the
southern sky made with data at a frequency of 148 GHz from the Atacama
Cosmology Telescope 2008 observing season. We provide a catalog of 157 sources
with flux densities spanning two orders of magnitude: from 15 to 1500 mJy.
Comparison to other catalogs shows that 98% of the ACT detections correspond to
sources detected at lower radio frequencies. Three of the sources appear to be
associated with the brightest cluster galaxies of low redshift X-ray selected
galaxy clusters. Estimates of the radio to mm-wave spectral indices and
differential counts of the sources further bolster the hypothesis that they are
nearly all radio sources, and that their emission is not dominated by
re-emission from warm dust. In a bright (>50 mJy) 148 GHz-selected sample with
complete cross-identifications from the Australia Telescope 20 GHz survey, we
observe an average steepening of the spectra between 5, 20, and 148 GHz with
median spectral indices of , , and . When the
measured spectral indices are taken into account, the 148 GHz differential
source counts are consistent with previous measurements at 30 GHz in the
context of a source count model dominated by radio sources. Extrapolating with
an appropriately rescaled model for the radio source counts, the Poisson
contribution to the spatial power spectrum from synchrotron-dominated sources
with flux density less than 20 mJy is C^{\rm Sync} = (2.8 \pm 0.3) \times
10^{-6} \micro\kelvin^2.Comment: Accepted to Ap
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