4,074 research outputs found
The Pendulum Has Swung: How Do We Ensure a Life Course Approach to Immunisation in Australia?
Rather than concentrating primarily on children and adolescents, there has been a shift in the discourse around immunisation to encompass a whole-of-life approach. Despite this acknowledgement and ongoing high burdens of vaccine preventable diseases in adults, coverage for some adult risk groups remains sub-optimal. This study aimed to explore key informant's and stakeholder's perceptions of factors impacting provision of immunisation programs for Australian adults and to identify strategies to promote acceptance and uptake. Semi-structured telephone interviews were undertaken with people involved in adult immunisation program delivery, advocacy, policy or research between September 2020 and June 2021. Transcripts were inductively analysed, with the resulting themes categorised into the five influences on vaccination gaps that have informed program planning in other countries: Access, Affordability, Awareness, Acceptance and Activation. Participants spoke of improvements in the provision of vaccines to adults, however, ongoing challenges persisted. Participants agreed that the focus or emphasis of policies and the promotion/communication strategies has been on childhood vaccination in Australia, however there is a sense that the “pendulum has swung.” These included understanding of eligibility amongst the Australian population and the reluctance of some health providers to dedicate time to exploring immunisation needs with adult patients. In comparison to the childhood vaccination program, there has been a lack of data available on coverage for adult vaccines on the national immunisation program. This has contributed to the ongoing challenges of identifying and promoting certain vaccines. At a government level, questions were raised about why the Australian government has never set an aspirational target for adult vaccination (i.e., influenza or pneumococcal) coverage. While significant improvements have been made in adult immunisation uptake, there are still gaps across the program. While the system remains under stress because of the COVID-19 pandemic, it is not appropriate to implement any additional programs. There needs to be strong commitment to establish the value of adult vaccination in the eyes of community members, policy makers and healthcare professionals. Having a national adult immunisation strategic plan would help advance action
The Holographic Universe
We present a holographic description of four-dimensional single-scalar
inflationary universes in terms of a three-dimensional quantum field theory.
The holographic description correctly reproduces standard inflationary
predictions in their regime of applicability. In the opposite case, wherein
gravity is strongly coupled at early times, we propose a holographic
description in terms of perturbative QFT and present models capable of
satisfying the current observational constraints while exhibiting a
phenomenology distinct from standard inflation. This provides a qualitatively
new method for generating a nearly scale-invariant spectrum of primordial
cosmological perturbations.Comment: 20 pages, 5 figs; extended version of arXiv:0907.5542 including
background material and detailed derivations. To appear in Proceedings of 1st
Mediterranean Conference on Classical and Quantum Gravit
High Strain Rate Superplasticity in Microcrystalline and Nanocrystalline Materials
Superplasticity has evolved to become a significant industrial forming process. The phenomenon of superplasticity is explored at high strain rates where it is economically more attractive. True tensile superplasticity has been demonstrated in nanocrystalline materials. The difference in the details of superplasticity between the nanocrystalline and microcrystalline state is emphasised
Probability distribution of the maximum of a smooth temporal signal
We present an approximate calculation for the distribution of the maximum of
a smooth stationary temporal signal X(t). As an application, we compute the
persistence exponent associated to the probability that the process remains
below a non-zero level M. When X(t) is a Gaussian process, our results are
expressed explicitly in terms of the two-time correlation function,
f(t)=.Comment: Final version (1 major typo corrected; better introduction). Accepted
in Phys. Rev. Let
Integrating Kinetic Model of E. coli with Genome Scale Metabolic Fluxes Overcomes Its Open System Problem and Reveals Bistability in Central Metabolism
An understanding of the dynamics of the metabolic profile of a bacterial cell is sought from a dynamical systems analysis of kinetic models. This modelling formalism relies on a deterministic mathematical description of enzyme kinetics and their metabolite regulation. However, it is severely impeded by the lack of available kinetic information, limiting the size of the system that can be modelled. Furthermore, the subsystem of the metabolic network whose dynamics can be modelled is faced with three problems: how to parameterize the model with mostly incomplete steady state data, how to close what is now an inherently open system, and how to account for the impact on growth. In this study we address these challenges of kinetic modelling by capitalizing on multi-omics steady state data and a genome-scale metabolic network model. We use these to generate parameters that integrate knowledge embedded in the genome-scale metabolic network model, into the most comprehensive kinetic model of the central carbon metabolism of E. coli realized to date. As an application, we performed a dynamical systems analysis of the resulting enriched model. This revealed bistability of the central carbon metabolism and thus its potential to express two distinct metabolic states. Furthermore, since our model-informing technique ensures both stable states are constrained by the same thermodynamically feasible steady state growth rate, the ensuing bistability represents a temporal coexistence of the two states, and by extension, reveals the emergence of a phenotypically heterogeneous population
Universality of Cluster Dynamics
We have studied the kinetics of cluster formation for dynamical systems of
dimensions up to interacting through elastic collisions or coalescence.
These systems could serve as possible models for gas kinetics, polymerization
and self-assembly. In the case of elastic collisions, we found that the cluster
size probability distribution undergoes a phase transition at a critical time
which can be predicted from the average time between collisions. This enables
forecasting of rare events based on limited statistical sampling of the
collision dynamics over short time windows. The analysis was extended to
L-normed spaces () to allow for some amount of
interpenetration or volume exclusion. The results for the elastic collisions
are consistent with previously published low-dimensional results in that a
power law is observed for the empirical cluster size distribution at the
critical time. We found that the same power law also exists for all dimensions
, 2D L norms, and even for coalescing collisions in 2D. This
broad universality in behavior may be indicative of a more fundamental process
governing the growth of clusters
Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I
We have embarked on a project, under the aegis of the Nearby Stars (NStars)/
Space Interferometry Mission Preparatory Science Program to obtain spectra,
spectral types, and, where feasible, basic physical parameters for the 3600
dwarf and giant stars earlier than M0 within 40 parsecs of the sun. In this
paper we report on the results of this project for the first 664 stars in the
northern hemisphere. These results include precise, homogeneous spectral types,
basic physical parameters (including the effective temperature, surface gravity
and the overall metallicity, [M/H]) and measures of the chromospheric activity
of our program stars. Observed and derived data presented in this paper are
also available on the project's website at http://stellar.phys.appstate.edu/
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