202 research outputs found
Optimization in a Self-Stabilizing Service Discovery Framework for Large Scale Systems
Ability to find and get services is a key requirement in the development of large-scale distributed sys- tems. We consider dynamic and unstable environments, namely Peer-to-Peer (P2P) systems. In previous work, we designed a service discovery solution called Distributed Lexicographic Placement Table (DLPT), based on a hierar- chical overlay structure. A self-stabilizing version was given using the Propagation of Information with Feedback (PIF) paradigm. In this paper, we introduce the self-stabilizing COPIF (for Collaborative PIF) scheme. An algo- rithm is provided with its correctness proof. We use this approach to improve a distributed P2P framework designed for the services discovery. Significantly efficient experimental results are presented
Définition des centres experts en endométriose
OBJECTIVES: The Collège national des gynécologues obstétriciens français (CNGOF), in agreement with the Société de chirurgie gynécologique et pelvienne (SCGP), has set up a commission in 2017 to define endometriosis expert centres, with the aim of optimizing endometriosis care in France.
METHODS: The committee included members from university and general hospitals as well as private facilities, representing medical, surgical and radiological aspects of endometriosis care. Opinion of endometriosis patients\u27 associations was obtained prior to writing this work. The final text was presented and unanimously validated by the members of the CNGOF Board of Directors at its meeting of October 13, 2017.
RESULTS: Based on analysis of current management of endometriosis and the last ten years opportunities in France, the committee has been able to define the contours of endometriosis expert centres. The objectives, production specifications, mode of operation, missions and funding for these centres were described. The following missions have been specifically defined: territorial organization, global and referral care, communication and teaching as well as research and evaluation.
CONCLUSION: Because of its daily impact for women and its economic burden in France, endometriosis justifies launching of expert centres throughout the country with formal accreditation by health authorities, ideally as part of the National Health Plan
The definition of Endometriosis Expert Centres
Endometriosis is a common condition that causes pain and infertility. It can lead to absenteeism and also to multiple surgeries with a consequent risk of impaired fertility, and constitutes a major public health cost. Despite the existence of numerous national and international guidelines, the management of endometriosis remains suboptimal. To address this issue, the French College of Gynaecologists and Obstetricians (CNGOF) and the Society of Gynaecological and Pelvic Surgery (SCGP) convened a committee of experts tasked with defining the criteria for establishing a system of care networks, headed by Expert Centres, covering all of mainland France and its overseas territories. This document sets out the criteria for the designation of Expert Centres. It will serve as a guide for the authorities concerned, to ensure that the means are provided to adequately manage patients with endometriosis
Altered translation of GATA1 in Diamond-Blackfan anemia
Ribosomal protein haploinsufficiency occurs in diverse human diseases including Diamond-Blackfan anemia (DBA)[superscript 1, 2], congenital asplenia[superscript 3] and T cell leukemia[superscript 4]. Yet, how mutations in genes encoding ubiquitously expressed proteins such as these result in cell-type– and tissue-specific defects remains unknown[superscript 5]. Here, we identify mutations in GATA1, encoding the critical hematopoietic transcription factor GATA-binding protein-1, that reduce levels of full-length GATA1 protein and cause DBA in rare instances. We show that ribosomal protein haploinsufficiency, the more common cause of DBA, can lead to decreased GATA1 mRNA translation, possibly resulting from a higher threshold for initiation of translation of this mRNA in comparison with other mRNAs. In primary hematopoietic cells from patients with mutations in RPS19, encoding ribosomal protein S19, the amplitude of a transcriptional signature of GATA1 target genes was globally and specifically reduced, indicating that the activity, but not the mRNA level, of GATA1 is decreased in patients with DBA associated with mutations affecting ribosomal proteins. Moreover, the defective hematopoiesis observed in patients with DBA associated with ribosomal protein haploinsufficiency could be partially overcome by increasing GATA1 protein levels. Our results provide a paradigm by which selective defects in translation due to mutations affecting ubiquitous ribosomal proteins can result in human disease.National Institutes of Health (U.S.) (Grant P01 HL32262)National Institutes of Health (U.S.) (Grant U54 HG003067-09
IL-12Rβ1 Deficiency in Two of Fifty Children with Severe Tuberculosis from Iran, Morocco, and Turkey
BACKGROUND AND OBJECTIVES: In the last decade, autosomal recessive IL-12Rβ1 deficiency has been diagnosed in four children with severe tuberculosis from three unrelated families from Morocco, Spain, and Turkey, providing proof-of-principle that tuberculosis in otherwise healthy children may result from single-gene inborn errors of immunity. We aimed to estimate the fraction of children developing severe tuberculosis due to IL-12Rβ1 deficiency in areas endemic for tuberculosis and where parental consanguinity is common. METHODS AND PRINCIPAL FINDINGS: We searched for IL12RB1 mutations in a series of 50 children from Iran, Morocco, and Turkey. All children had established severe pulmonary and/or disseminated tuberculosis requiring hospitalization and were otherwise normally resistant to weakly virulent BCG vaccines and environmental mycobacteria. In one child from Iran and another from Morocco, homozygosity for loss-of-function IL12RB1 alleles was documented, resulting in complete IL-12Rβ1 deficiency. Despite the small sample studied, our findings suggest that IL-12Rβ1 deficiency is not a very rare cause of pediatric tuberculosis in these countries, where it should be considered in selected children with severe disease. SIGNIFICANCE: This finding may have important medical implications, as recombinant IFN-γ is an effective treatment for mycobacterial infections in IL-12Rβ1-deficient patients. It also provides additional support for the view that severe tuberculosis in childhood may result from a collection of single-gene inborn errors of immunity
Modeling of Intermediate Structures and Chain Conformation in Silica-Latex Nanocomposites Observed by SANS During Annealing
The evolution of the polymer structure during nanocomposite formation and
annealing of silica-latex nanocomposites is studied using contrast-variation
small angle neutron scattering. The experimental system is made of silica
nanoparticles (Rsi \approx 8 nm) and a mixture of purpose-synthesized
hydrogenated and deuterated nanolatex (Rlatex \approx 12.5 nm). The progressive
disappearance of the latex beads by chain interdiffusion and release in the
nanocomposites is analyzed quantitatively with a model for the scattered
intensity of hairy latex beads and an RPA description of the free chains. In
silica-free matrices and nanocomposites of low silica content (7%v), the
annealing procedure over weeks at up to Tg + 85 K results in a molecular
dispersion of chains, the radius of gyration of which is reported. At higher
silica content (20%v), chain interdiffusion seems to be slowed down on
time-scales of weeks, reaching a molecular dispersion only at the strongest
annealing. Chain radii of gyration are found to be unaffected by the presence
of the silica filler
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Biomineralisation by earthworms: an investigation into the stability and distribution of amorphous calcium carbonate
Background
Many biominerals form from amorphous calcium carbonate (ACC), but this phase is highly unstable when synthesised in its pure form inorganically. Several species of earthworm secrete calcium carbonate granules which contain highly stable ACC. We analysed the milky fluid from which granules form and solid granules for amino acid (by liquid chromatography) and functional group (by Fourier transform infrared (FTIR) spectroscopy) compositions. Granule elemental composition was determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES) and electron microprobe analysis (EMPA). Mass of ACC present in solid granules was quantified using FTIR and compared to granule elemental and amino acid compositions. Bulk analysis of granules was of powdered bulk material. Spatially resolved analysis was of thin sections of granules using synchrotron-based μ-FTIR and EMPA electron microprobe analysis.
Results
The milky fluid from which granules form is amino acid-rich (≤ 136 ± 3 nmol mg−1 (n = 3; ± std dev) per individual amino acid); the CaCO3 phase present is ACC. Even four years after production, granules contain ACC. No correlation exists between mass of ACC present and granule elemental composition. Granule amino acid concentrations correlate well with ACC content (r ≥ 0.7, p ≤ 0.05) consistent with a role for amino acids (or the proteins they make up) in ACC stabilisation. Intra-granule variation in ACC (RSD = 16%) and amino acid concentration (RSD = 22–35%) was high for granules produced by the same earthworm. Maps of ACC distribution produced using synchrotron-based μ-FTIR mapping of granule thin sections and the relative intensity of the ν2: ν4 peak ratio, cluster analysis and component regression using ACC and calcite standards showed similar spatial distributions of likely ACC-rich and calcite-rich areas. We could not identify organic peaks in the μ-FTIR spectra and thus could not determine whether ACC-rich domains also had relatively high amino acid concentrations. No correlation exists between ACC distribution and elemental concentrations determined by EMPA.
Conclusions
ACC present in earthworm CaCO3 granules is highly stable. Our results suggest a role for amino acids (or proteins) in this stability. We see no evidence for stabilisation of ACC by incorporation of inorganic components
Inborn errors of type I IFN immunity in patients with life-threatening COVID-19.
Clinical outcome upon infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ranges from silent infection to lethal coronavirus disease 2019 (COVID-19). We have found an enrichment in rare variants predicted to be loss-of-function (LOF) at the 13 human loci known to govern Toll-like receptor 3 (TLR3)- and interferon regulatory factor 7 (IRF7)-dependent type I interferon (IFN) immunity to influenza virus in 659 patients with life-threatening COVID-19 pneumonia relative to 534 subjects with asymptomatic or benign infection. By testing these and other rare variants at these 13 loci, we experimentally defined LOF variants underlying autosomal-recessive or autosomal-dominant deficiencies in 23 patients (3.5%) 17 to 77 years of age. We show that human fibroblasts with mutations affecting this circuit are vulnerable to SARS-CoV-2. Inborn errors of TLR3- and IRF7-dependent type I IFN immunity can underlie life-threatening COVID-19 pneumonia in patients with no prior severe infection
Autoantibodies against type I IFNs in patients with life-threatening COVID-19
Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-w (IFN-w) (13 patients), against the 13 types of IFN-a (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men
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