2,128 research outputs found
Atom-molecule coherence in a one-dimensional system
We study a model of one-dimensional fermionic atoms that can bind in pairs to
form bosonic molecules. We show that at low energy, a coherence develops
between the molecule and fermion Luttinger liquids. At the same time, a gap
opens in the spin excitation spectrum. The coherence implies that the order
parameters for the molecular Bose-Einstein Condensation and the atomic BCS
pairing become identical. Moreover, both bosonic and fermionic charge density
wave correlations decay exponentially, in contrast with a usual Luttinger
liquid. We exhibit a Luther-Emery point where the systems can be described in
terms of noninteracting pseudofermions. At this point, we provide closed form
expressions for the density-density response functions.Comment: 5 pages, no figures, Revtex 4; (v2) added a reference to
cond-mat/0505681 where related results are reported; (v3) Expression of
correlation functions given in terms of generalized hypergeometric function
Hormone replacement therapy after surgery for stage 1 or 2 cutaneous melanoma
A total of 206 women were followed for a minimum of 5 years after primary melanoma surgery to establish if hormone replacement therapy (HRT) adversely affected prognosis. In all, 123 had no HRT and 22 have died of melanoma; 83 had HRT for varying periods and one has died of melanoma. After controlling for known prognostic factors, we conclude that HRT after melanoma does not adversely affect prognosis
International Council for Standardization in Haematology (ICSH) recommendations for laboratory measurement of ADAMTS13
This guidance document was prepared on behalf of the International Council for Standardization in Haematology (ICSH), by the ADAMTS13 Assay Working Group, which comprises an international group of both clinical and laboratory experts. The document provides recommendations on best practice for the performance of ADAMTS13 assays in clinical laboratories. ADAMTS13 assays support the differential diagnosis of thrombotic microangiopathies and have utility in the management of thrombotic thrombocytopenic purpura (TTP). There are three types of assay: activity, antigen and autoantibody/inhibitor assays. Methods for activity assays differ in terms of sensitivity, specificity, precision and turnaround time. The most widely used assays involve VWF peptide substrates and either chromogenic ELISA or FRET techniques, although chemiluminescence assays and rapid screening tests have recently become available. Tests for autoantibodies and inhibitors allow confirmation of acquired, immuneâmediated TTP, while antigen assays may be useful in congenital TTP and as prognostic markers. In this document, we have attempted to describe ADAMTS13 assays and the conditions that affect them, as well as: blood collection, sample processing, quality control, standardization and clinical utility; recognizing that laboratories in different parts of the world have varying levels of sophistication. The recommendations are based on expert opinion, published literature and good clinical laboratory practice
International Council for Standardization in Haematology (ICSH) recommendations for laboratory measurement of ADAMTS13
This guidance document was prepared on behalf of the International Council for Standardization in Haematology (ICSH), by the ADAMTS13 Assay Working Group, which comprises an international group of both clinical and laboratory experts. The document provides recommendations on best practice for the performance of ADAMTS13 assays in clinical laboratories. ADAMTS13 assays support the differential diagnosis of thrombotic microangiopathies and have utility in the management of thrombotic thrombocytopenic purpura (TTP). There are three types of assay: activity, antigen and autoantibody/inhibitor assays. Methods for activity assays differ in terms of sensitivity, specificity, precision and turnaround time. The most widely used assays involve VWF peptide substrates and either chromogenic ELISA or FRET techniques, although chemiluminescence assays and rapid screening tests have recently become available. Tests for autoantibodies and inhibitors allow confirmation of acquired, immuneâmediated TTP, while antigen assays may be useful in congenital TTP and as prognostic markers. In this document, we have attempted to describe ADAMTS13 assays and the conditions that affect them, as well as: blood collection, sample processing, quality control, standardization and clinical utility; recognizing that laboratories in different parts of the world have varying levels of sophistication. The recommendations are based on expert opinion, published literature and good clinical laboratory practice
Electrical conductivity of the Pampean Shallow Subduction Region of Argentina near 33 S: evidence for a slab window
We present a three-dimensional (3-D) interpretation of 117 long period (20â4096 s) magnetotelluric (MT) sites between 31°S and 35°S in western Argentina. They cover the most horizontal part of the Pampean shallow angle subduction of the Nazca Plate and extend south into the more steeply dipping region. Sixty-two 3-D inversions using various smoothing parameters and data misfit goals were done with a nonlinear conjugate gradient (NLCG) algorithm. A dominant feature of the mantle structure east of the horizontal slab is a conductive plume rising from near the top of the mantle transition zone at 410 km to the probable base of the lithosphere at 100 km depth. The subducted slab is known to descend to 190 km just west of the plume, but the Wadati-Benioff zone cannot be traced deeper. If the slab is extrapolated downdip it slices through the plume at 250 km depth. Removal of portions of the plume or blocking vertical current flow at 250 km depth significantly changes the predicted responses. This argues that the plume is not an artifact and that it is continuous. The simplest explanation is that there is a âwedgeâ-shaped slab window that has torn laterally and opens down to the east with its apex at the plume location. Stress within the slab and seismic tomography support this shape. Its northern edge likely explains why there is no deep seismicity south of 29°S.Fil: Burd, Aurora I.. University of Washington; Estados UnidosFil: Booker, John R.. University of Washington; Estados UnidosFil: Mackie, Randall. Land General Geophysics; ItaliaFil: Pomposiello, Maria Cristina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de GeocronologĂa y GeologĂa Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de GeocronologĂa y GeologĂa Isotopica; ArgentinaFil: Favetto, Alicia Beatriz. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de GeocronologĂa y GeologĂa Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de GeocronologĂa y GeologĂa Isotopica; Argentin
Superposition of macroscopic numbers of atoms and molecules
We theoretically examine photoassociation of a non-ideal Bose-Einstein
condensate, focusing on evidence for a macroscopic superposition of atoms and
molecules. This problem raises an interest because, rather than two states of a
given object, an atom-molecule system is a seemingly impossible macroscopic
superposition of different objects. Nevertheless, photoassociation enables
coherent intraparticle conversion, and we thereby propose a viable scheme for
creating a superposition of a macroscopic number of atoms with a macroscopic
number of molecules.Comment: 4 pages, 2 figs, to appear in Phys. Rev. Let
Linkage of people experiencing homeless using two consent models
Objectives
Administrative data linkage is relatively under-utilised as a way of generating evidence to guide homelessness policy and service delivery in the UK. Our objective is to contribute insight into the ethical, legal, and practical challenges of using data linkage with data from people experiencing homelessness (PEH).
Approach
We outline the data collection and linkage methodologies for two UK-based studies related to PEH. The first design aimed to explore the acceptability and feasibility of consented linkage of trial data (âMoving Onâ trial) to NHS Digital records in a cohort of recruited PEH in two English local authorities (n=50). The second design used administrative data originating from a local authority homelessness service in Wales (n=17,000 cases) to explore educational outcomes of children in homeless households. The resultant data linkage rates are contrasted and discussed in relation to the mechanisms for obtaining and linking personal data.
Results
The Moving On trial demonstrated high rates of consent for data linkage and the ability to collect sufficient personal identifiable data to increase the chance of successful matching. Aggregate match rates will be discussed. Of the roughly 17,000 cases included in the local authority administrative data, 75% could be linked to unique individuals using probabilistic matching and were therefor âuseableâ in linkage research. The proportion of useable cases rapidly decreased as the cut-off for matching quality was increased, to roughly 50% of cases being useable when a 99% match probability cut-off was used. Matching rates were higher amongst priority need homeless cases, possibly reflecting business need to identify and work closely with these people.
Conclusion
Where homelessness administrative data systems are not designed to enable data linkage, low matching rates can result, reducing study sample sizes and potentially leading to bias towards more extreme cases of homelessness if missed-matches are not random. Consented linkage within large-scale trials offers one possibility for generating long-term evidence
Anti-protein C antibodies and acquired protein C resistance in SLE: novel markers for thromboembolic events and disease activity?
OBJECTIVES: Risk factors for thromboembolism in SLE are poorly understood. We hypothesized a possible role for protein C, based on its dual activity in inflammation and haemostasis and on the evidence of an association between acquired activated protein C (APC) resistance (APCR) and high-avidity anti-protein C antibodies (anti-PC) with a severe thrombotic phenotype in venous thrombosis APS patients. METHODS: In a cross-sectional study of 156 SLE patients, the presence and avidity of IgG anti-PC was established by in house-ELISA, and APCR to exogenous recombinant human APC (rhAPC) and Protac (which activates endogenous protein C) was assessed by thrombin generation-based assays. Associations with aPL profile, thrombotic history and disease activity (BILAG and SLEDAI-2K) were also established. RESULTS: Anti-PC were detected in 54.5% of patients and APCR in 59%. Anti-PC positivity was associated with APCR to both rhAPC (PÂ <0.0001) and Protac (PÂ =0.0001). High-avidity anti-PC, detected in 26.3% of SLE patients, were associated with APCR in patients with thrombosis only (PÂ <0.05), and with the development of thrombosis over time (range: 0-52âyears; PÂ =0.014). High-avidity anti-PC levels correlated with SLEDAI-2K (PÂ =0.033) and total BILAG (PÂ =0.019); SLEDAI-2K correlated inversely with APCR to Protac (PÂ =0.004). CONCLUSION: Anti-PC occur in patients with SLE, independently of aPL profile, and are associated with APCR. High-avidity anti-PC are associated with thrombosis and with active disease and might prove a novel marker to monitor the risk of thrombosis and disease progression in SLE
Tenascin is associated with chondrogenic and osteogenic differentiation in vivo and promotes chondrogenesis in vitro.
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