514 research outputs found
Homi Jehangir Bhabha as a Knowledge Generating System: A Longitudinal Cognition Study
Quantitative analysis of the events of synchronous references in the research papers followed throughout the publishing career of an individual scientist revealed interesting highlights on the knowledge-generating-system. In the case study of Homi Jehangir Bhabha first quinquennium and fifth quinquennium of his research career had low Self-references; third quinquennium and fourth quinquennium had moderate Self-references; whereas second quinquennium had highest Self-references. The two major clusters of Self-references occurring during the second and third quinquennium were indicators of active periods of knowledgegenerating and faster communications
Hesitancy for COVID-19 Vaccines and Its Implications for Routine Immunisation
Vaccine hesitancy is a continuum, conditional on confidence (on vaccine or healthcare authorities), complacency, structural or psychological constraints, calculation or evaluation, vaccination convenience, and aspects pertaining to collective responsibility. The present chapter documents hesitancy to COVID-19 vaccination; and elaborates on factors that contribute to both hesitancy (barriers and concerns) and acceptance (enablers) rates, disaggregated by populations. We also discuss the multimodal nature of the COVID-19 pandemic and its vaccine hesitancy-related implications on routine immunisation. The pandemic and related movement restrictions or other mitigation measures, partial or complete suspension of vaccination clinics or fear of COVID-19, stress, anxiety, and depression may have limited parents’ access to avail routine immunisation vaccines for their children. Also, the impact of COVID-19 vaccine hesitancy is not limited to pandemic vaccines but may continue to extend to routinely recommended vaccines
OL-038 Efficiency of RD-1 antigen-specific interferon-γ release assays (IGRAs) blood-based tests for the diagnosis of Mycobacterium tuberculosis infection in Pott's disease at a tertiary care hospital
Mouse prion protein polymorphism Phe-108/Val-189 affects the kinetics of fibril formation and the response to seeding: evidence for a two-step nucleation polymerization mechanism
Prion diseases are fatal neurodegenerative disorders associated with the polymerization of the cellular form of prion protein (PrP(C)) into an amyloidogenic β-sheet infectious form (PrP(Sc)). The sequence of host PrP is the major determinant of host prion disease susceptibility. In mice, the presence of allele a (Prnp(a), encoding the polymorphism Leu-108/Thr-189) or b (Prnp(b), Phe-108/Val-189) is associated with short or long incubation times, respectively, following infection with PrP(Sc). The molecular bases linking PrP sequence, infection susceptibility, and convertibility of PrP(C) into PrP(Sc) remain unclear. Here we show that recombinant PrP(a) and PrP(b) aggregate and respond to seeding differently in vitro. Our kinetic studies reveal differences during the nucleation phase of the aggregation process, where PrP(b) exhibits a longer lag phase that cannot be completely eliminated by seeding the reaction with preformed fibrils. Additionally, PrP(b) is more prone to propagate features of the seeds, as demonstrated by conformational stability and electron microscopy studies of the formed fibrils. We propose a model of polymerization to explain how the polymorphisms at positions 108 and 189 produce the phenotypes seen in vivo. This model also provides insight into phenomena such as species barrier and prion strain generation, two phenomena also influenced by the primary structure of PrP.FWN – Publicaties zonder aanstelling Universiteit Leide
Use of Quadrupolar Nuclei for Quantum Information processing by Nuclear Magnetic Resonance: Implementation of a Quantum Algorithm
Physical implementation of Quantum Information Processing (QIP) by
liquid-state Nuclear Magnetic Resonance (NMR), using weakly coupled spin-1/2
nuclei of a molecule, is well established. Nuclei with spin1/2 oriented in
liquid crystalline matrices is another possibility. Such systems have multiple
qubits per nuclei and large quadrupolar couplings resulting in well separated
lines in the spectrum. So far, creation of pseudopure states and logic gates
have been demonstrated in such systems using transition selective
radio-frequency pulses. In this paper we report two novel developments. First,
we implement a quantum algorithm which needs coherent superposition of states.
Second, we use evolution under quadrupolar coupling to implement multi qubit
gates. We implement Deutsch-Jozsa algorithm on a spin-3/2 (2 qubit) system. The
controlled-not operation needed to implement this algorithm has been
implemented here by evolution under the quadrupolar Hamiltonian. This method
has been implemented for the first time in quadrupolar systems. Since the
quadrupolar coupling is several orders of magnitude greater than the coupling
in weakly coupled spin-1/2 nuclei, the gate time decreases, increasing the
clock speed of the quantum computer.Comment: 16 pages, 3 figure
Real and Virtual Compton Scattering off the Nucleon
A review is given of the very recent developments in the fields of real and
virtual Compton scattering off the nucleon. Both real and virtual Compton
scattering reactions are discussed at low outgoing photon energy where one
accesses polarizabilities of the nucleon. The real Compton scattering at large
momentum transfer is discussed which is asymptotically a tool to obtain
information on the valence quark wave function of the nucleon. The rapid
developments in deeply virtual Compton scattering and associated meson
electroproduction reactions at high energy, high photon virtuality and small
momentum transfer to the nucleon are discussed. A unified theoretical
description of those processes has emerged over the last few years, which gives
access to new, generalized parton distributions. The experimental status and
perspectives in these fields are also discussed.Comment: 25 pages, 17 figure
Are randomly grown graphs really random?
We analyze a minimal model of a growing network. At each time step, a new
vertex is added; then, with probability delta, two vertices are chosen
uniformly at random and joined by an undirected edge. This process is repeated
for t time steps. In the limit of large t, the resulting graph displays
surprisingly rich characteristics. In particular, a giant component emerges in
an infinite-order phase transition at delta = 1/8. At the transition, the
average component size jumps discontinuously but remains finite. In contrast, a
static random graph with the same degree distribution exhibits a second-order
phase transition at delta = 1/4, and the average component size diverges there.
These dramatic differences between grown and static random graphs stem from a
positive correlation between the degrees of connected vertices in the grown
graph--older vertices tend to have higher degree, and to link with other
high-degree vertices, merely by virtue of their age. We conclude that grown
graphs, however randomly they are constructed, are fundamentally different from
their static random graph counterparts.Comment: 8 pages, 5 figure
Cost-effectiveness of closed incision negative pressure wound therapy in preventing surgical site infection among obese women giving birth by caesarean section: An economic evaluation (DRESSING trial)
First published: 18 May 2023.
OnlinePublBackground: There is growing evidence regarding the potential of closed incision negative pressure wound therapy (ci-NPWT) to prevent surgical site infections (SSIs) in healing wounds by primary closure following a caesarean section (CS). Aim: To assess the cost-effectiveness of ci-NPWT compared to standard dressings for prevention of SSI in obese women giving birth by CS. Materials and Methods: Cost-effectiveness and cost-utility analyses from a health service perspective were undertaken alongside a multicentre pragmatic randomised controlled trial, which recruited women with a pre-pregnancy body mass index ≥30 kg/m2 giving birth by elective/semi-urgent CS who received ci-NPWT (n = 1017) or standard dressings (n = 1018). Resource use and health-related quality of life (SF-12v2) collected during admission and for four weeks post-discharge were used to derive costs and quality-adjusted life years (QALYs). Results: ci-NPWT was associated with AUD170 to 12 849 (95%CI −133 378) per SSI avoided. There was no detectable difference in QALYs between groups; however, there are high levels of uncertainty around both cost and QALY estimates. There is a 20% likelihood that ci-NPWT would be considered cost-effective at a willingness-to- pay threshold of $50 000 per QALY. Per protocol and complete case analyses gave similar results, suggesting that findings are robust to protocol deviators and adjustments for missing data. Conclusions: ci-NPWT for the prevention of SSI in obese women undergoing CS is unlikely to be cost-effective in terms of health service resources and is currently unjustified for routine use for this purpose.Jennifer A. Whitty, Adam P. Wagner, Evelyn Kang, David Ellwood, Wendy Chaboyer, Sailesh Kumar, Vicki L. Clifton, Lukman Thalib and Brigid M. Gillespi
The social predictors of paternal antenatal mental health and their associations with maternal mental health in the Queensland Family Cohort prospective study
OnlinePublAntenatal depression (AND) affects 1 in 10 fathers, potentially negatively impacting maternal mental health and well-being during and after the transition to parenthood. However, few studies have assessed the social predictors of paternal AND or their possible associations with maternal mental health. We analysed data from 180 couples participating in the Queensland Family Cohort longitudinal study. Both parents completed surveys measuring mental health, relationship quality, social support, and sleep quality at 24 weeks of pregnancy. Mothers also completed the same surveys 6 weeks’ postpartum. Antenatal depression, stress, and anxiety were highest among fathers reporting lower social support and higher sleep impairment. Maternal AND, stress, and anxiety were higher among mothers reporting higher physical pain and poor sleep quality. Postnatally, mothers reporting lower social support also reported higher depression, anxiety, stress, and psycho-social well-being. While there were no significant associations between AND among fathers and maternal antenatal or postnatal depression, an exploratory analysis revealed that mothers whose partners reported lower antenatal social support also reported lower postnatal social support and higher postnatal depression. Our findings highlight the importance of including data among fathers to achieve a whole family approach to well-being during the transition to parenthood.Barnaby J. W. Dixson, Danielle Borg, Kym M. Rae, Koa Whittingha, Brenda Gannon, Steven M. McPhail, Hannah E. Carter, Karen M. Moritz, Roslyn N. Boyd, Samudragupta Bora, Sailesh Kumar, Julanne Frater, Daniel Schweitzer, Paul Miller, Divya Mehter, Vicki L. Clifto
Search for Higgs bosons decaying to tautau pairs in ppbar collisions at sqrt(s) = 1.96 TeV
We present a search for the production of neutral Higgs bosons decaying into
tautau pairs in ppbar collisions at a center-of-mass energy of 1.96 TeV. The
data, corresponding to an integrated luminosity of 5.4 fb-1, were collected by
the D0 experiment at the Fermilab Tevatron Collider. We set upper limits at the
95% C.L. on the product of production cross section and branching ratio for a
scalar resonance decaying into tautau pairs, and we then interpret these limits
as limits on the production of Higgs bosons in the minimal supersymmetric
standard model (MSSM) and as constraints in the MSSM parameter space.Comment: 7 pages, 5 figures, submitted to PL
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