7 research outputs found
Endogeneous magnetic reconnection and associated processes of relevance to fusion burning plasmas
No full textThe main characteristic of an endogenous magnetic reconnection process is that its driving
factor lays within the layer where a drastic change of magnetic field topology occurs. This
kind of process is shown to take place when a significant electron temperature gradient
is present in a magnetically confined plasma and when the evolving electron temperature
fluctuations are anisotropic r1s. Then r2s two classes of reconnecting modes are identified.
The localized class of mode involve a reconnected field B̃x of odd parity (as a function of
the radial variable), characteristic phase velocities and growth rates differently from the
commonly considered reconnecting modes associated with a finite effective resistivity. The
width of the reconnection layer remains significant even when large macroscopic distances
are considered. In view of the fact that there are plasmas in the Universe with considerable
electron thermal energy contents, the features of the considered modes can be relied upon
in order to produce generation or conversion of magnetic energy and high energy particle
populations through a sequence of mode-particle resonances r3s. With their excitation,
these modes acquire momentum in the direction of the main magnetic field component and
H
Tthe main body of the plasma column should recoil in the opposite direction r4s.
Endogenous modes associated with a finite electron temperature gradient are shown to be
sustained by the electron temperature heating rate due to the charged reaction products in
a fusion burning plasma r5s. In this case, the longitudinal thermal conductivity on selected
rational magnetic surfaces r5s is decreased, relative to its collisional value, by the effects of
reconnection.
The best agreement between theory and experiments concerning the onset of magnetic recon-
nection is (probably) represented by the theory of the resistive internal kink mode r6s. This
is reconsidered for regimes where the effects of local temperature gradients are important.
r1s B. Coppi and B. Basu, Phys. Lett. A, 382, 400 (2018).
r2s B. Coppi, Phys. Fluids, 8, 2273 (1965).
r3s B. Coppi et al., Nucl. Fus., 57, 7 (2017).
r4s B. Coppi, Nucl. Fus., 42, 1 (2002).
r5s B. Coppi et al., Nucl. Fus., 55, 053011 (2015).
r6s B. Coppi et al., Fiz. Plazmy, 2, 961 (1976)
Interaction of native and chimeric IF2 factors with archaeal and bacterial ribosomal subunits
No full text<p><b>Copyright information:</b></p><p>Taken from "Functional analysis of the translation factor aIF2/5B in the thermophilic archaeon "</p><p></p><p>Molecular Microbiology 2007;65(3):700-713.</p><p>Published online 01 Aug 2007</p><p>PMCID:PMC1976387.</p><p>© 2007 The Authors Journal compilation © 2007 Blackwell Publishing Ltd</p> The ribosome-bound fraction of the various proteins was determined as described in . Circle: recombinant aIF2/5B; diamond: recombinant IF2; triangle: BaSu1 chimera; square: BaSu2 chimera
Protection of fMet-tRNAi from alkaline hydrolysis in the presence of native and chimeric IF2 proteins
No full text<p><b>Copyright information:</b></p><p>Taken from "Functional analysis of the translation factor aIF2/5B in the thermophilic archaeon "</p><p></p><p>Molecular Microbiology 2007;65(3):700-713.</p><p>Published online 01 Aug 2007</p><p>PMCID:PMC1976387.</p><p>© 2007 The Authors Journal compilation © 2007 Blackwell Publishing Ltd</p> The extent of fMet-tRNAi protection was determined as described in . Closed circle: recombinant aIF2/5B; closed diamond; recombinant IF2; closed triangle: BaSu1 chimera; closed square: BaSu2 chimera; open triangle: SuBa chimera; open circle: no proteins added
ASD susceptibility CNV loci on human chromosome 22.
No full text<p>The number of individuals with duplications (green) and deletions (red) are plotted for both ASD cases (continuous lines) and controls (broken lines, on a log<sub>2</sub> scale) along human chromosome 22q11.21-13.33. RefSeq genes overlapping with these regions are depicted in blue rectangles. Genes that have been associated with ASD according to AutDB <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066707#pone.0066707-Basu1" target="_blank">[18]</a> are colored in orange. (<b>A</b>) The CNV locus on 22q11.21 contains primarily copy number gains (duplications). A black arrow indicates the peak in duplications count due to the CNV data from Glessner <i>et. al</i>. (<b>B</b>) The CNV locus on 22q13.32-13.33 contains primarily copy number losses (deletions).</p
Expression of nAChRs in CTLs from human and mice.
No full text<p>Purified RNA from human and mouse CD8 T cells were examined for nAChR subunits using PCR. A. PCR results (40 cycles, all PCR products were confirmed by sequencing). Memory OT-I cells were obtained as described in the text and as previously reported <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0068183#pone.0068183-Xiao2" target="_blank">[35]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0068183#pone.0068183-Basu1" target="_blank">[83]</a>. B–C. Quantitative PCR was performed on RNA from human CD8 T cells (B) or murine naive CD8 T cells (C). Expression of all subunits was relative to β2 (the highest expression) in murine naïve CTLs (C), which was designated as 1. D. Purified naïve OT-I cells were stimulated with 2SI or 3SI (2SI plus IL-12) for 3 days, and expression of nAChRs was compared relatively to β2 in each treatment (2SI and 3SI). E. The expression of 3 dominant nAChR subunits in 2SI and 3SI treatments was compared to naïve OT-I using the housekeeping gene GAPDH as internal control. Subunits α1, α7 and β3 were not detectable in D–E. F. CD8 OT-I cells were purified from naïve OT-I mice or OT-I mice treated with nicotine water at 200 µg/ml for 60 days to quantify the expression of nAChR subunits. Data are representatives of at least three experiments with similar results.</p
Some Contributions to the Theory of Sampling.
No full textThe work Presented here had originated from a pioneering paper by Basu1 and is essentially an extension of his ideas to different problem in sample surveys. The whole word mainly consists in deriving estimators uniformly better than those usually adopted in with replacement schemes.in with replacement sampling schemes, the \u27order-statistic\u27 (distinct sample unite arranged in an ascending order of their unit-indices) forms a sufficient statistic. Therefore, if any estimator (e.g., say of the population man) does not depend on the \u27order-statistic\u27, it can be uniformly improved by the use of the Rao-blalckwell theorem. The author has not hesitated to use this powerful theorem to derive improved estimators- It T is a sufficient statistic, for any convex (downwards_ lose function, an estimator uniformly better than g(S) (where g(S) is some estimator based on the sample S) is given by E[g(S)1T]=S\u3eΣT g(S) p(S)/ S\u3eΣ T p(S)The whole theais ie divided into eight chapter and two ppendioen. Che pter II hau been davoted to the problen of finting moente of dietinet uni te that appear in a aple, thie chapber haa teen very helprul in getting now roulte in subeequent ehaptere whieh vould haw been, othervia, dieioult te obtain. It may te podntod out shat it we thie ohnpter vhiah ultiantely led the uthar te write don the theute. It hae been the authorte endeavour to prent selfcontadned trea tamt of the problens dinouneod haredn. N ia for thia and for the purpoee of completens that soe problene already oonaidered y other authom, ae alno given in a stapli fied fam. TheProblems with which have been dnly oonermel, are the entdmetion of the poulatton ana ? (or total), ste aqure nd the population varianoe. The problan of finting unbiaaed entinstor of the saqure of the population mean arone whi le finding undad varianoe entiantore of the eatiatore af . The following teahnique for finding waldaad varianoe eetimtore hae been uaed- if ia an unhdased catian tor of , an unbiaaed estigtor of v(4) ie givenly
156. The immunological response to COVID-19 vaccination in patients with ANCA-associated vasculitis treated with rituximab
No full textBackground: Landmark clinical trials have demonstrated efficacy of SARS-CoV-2 vaccination in preventing severe COVID-19, however most participants in these trials were healthy volunteers. In particular, vaccine performance in immunosuppressed individuals, such as those with ANCA-associated vasculitis (AAV) is unknown. Rituximab (RTX) has become an important treatment for AAV, however this B cell depleting agent has previously evidenced impaired humoral response following influenza vaccines and now there are similar concerns regarding reduced immunogenicity to SARS-CoV-2 vaccines. In this study, we aimed to characterise the immune response of the ChAdOx1 (Astra Zeneca) vaccine in RTX treated AAV patients. (1)
Methods: The OCTAVE trial was a UK based, multi-centre, multi-disease prospective cohort study designed to assess the immune response to SARS-CoV-2 vaccination in immunosuppressed individuals, including patients with AAV treated with RTX within the prior 12 months. Peripheral blood samples were taken for quantitative IgG response to SARS-CoV-2 spike antigen (anti-S) and IFN T cell responses to SARS-CoV-2 antigens at baseline (where possible), immediately prior to second SARS-CoV-2 vaccine dose and 28 days post-second dose. Results were compared to a group of healthy controls from the UK PITCH (Protective Immunity from T cells in Healthcare workers) study.
Results: Of 455 cases recruited for full immune response analysis, 29 had AAV and 93 were healthy controls. Baseline demographics were described (Table 1). At 4 weeks post-second SARS-CoV-2 vaccine dose 27.6% (8/29) AAV patients demonstrated anti-S seroconversion, compared to 100% (93/93) healthy controls. Further, 89.7% of AAV patients had an anti-S antibody response that was less that the lowest titre achieved in the healthy control group. When compared to other OCTAVE disease cohorts, AAV patients had the lowest serological conversion rate and lowest median anti-S titre. The median SARS-CoV-2 specific T cell response in the AAV group was 98 (IQR: 40-178) IFN secreting T cells / 106 peripheral blood
mononuclear cells (PBMC), while the equivalent result in the healthy control group was 60 (IQR: 20-136) (Table 1).
Conclusions: Early analysis indicates that individuals with AAV have a substantially blunted antibody response to SARS-CoV-2 compared to a healthy population, but a comparable T-cell response. This may suggest that AAV patients have some degree of protection from SARS-CoV-2 vaccination, but clinical evaluation of this population is awaited. Analyses of additional immunological parameters, such as neutralising antibody responses and broader immunoglobulin analysis, are ongoing.
Disclosures: None relevant to this study.
Table 1: Demographics and anti-Spike seroconversion at 4 weeks in healthy controls and AAV patients
Healthy controls
AAV
N (whole cohort)
231
30
Age; N (%)
18 – 40
186 (81%)
10 (33%)
50 – 64
37 (16%)
12 (40%)
65 +
7 (3%)
8 (27%)
Missing data
1 (0%)
0 (0%)
Sex; N (%)
Female (%)
156 (68%)
16 (53%)
N (full immune response at 4 weeks)
93
29
Anti-S seroconversion; N (%)
93 (100%)
8 (27.6%)
Anti-S titre; U/ml [Median(IQR)]
11,514
(3,324-23,302)
0.4
(0.4-24.5)
IFN secreting T cells; per 106 PBMC [Median(IQR)]
60
(20-136).
98
(40-178
