3,435 research outputs found
Circulating Vaccine Derived Poliovirus and the polio eradication endgame
No Abstract. Key words: Polio, polio eradication, vaccine derived poliovirus, Oral polio vaccine, inactivated polio vaccine, surveillanc
Segmenting consumers’ reasons for and against ethical consumption
© Emerald Group Publishing Limited. Purpose - This paper aims to quantify the relative importance of reasons used to explain consumers’ selection and rejection of ethical products, accounting for differences in ethical orientations across consumers. Design/methodology/approach - Reviewing previous literature and drawing on in-depth interviews, a taxonomy of reasons for and against ethical purchasing is developed. An online survey incorporating best-worst scaling (BWS) determines which reasons feature more in shaping ethical consumerism. Cluster analysis and multinomial regression are used to identify and profile segments. Findings - Positively orientated consumers (42 per cent of respondents) purchase ethical products more so because of reasons relating to impact, health, personal relevance, and quality. Negatively orientated consumers (34 per cent of respondents) reject ethical alternatives based on reasons relating to indifference, expense, confusion and scepticism. A third segment is ambivalent in their behaviour and reasoning; they perceive ethical purchasing to be effective and relevant, but are confused and sceptical under what conditions this can occur. Research limitations/implications - Preferences were elicited using an online survey rather than using real market data. Though the task instructions and methods used attempted to minimise social-desirability bias, the experiment might still be subject to its effects. Practical implications - Competitive positioning strategies can be better designed knowing which barriers to ethical purchasing are more relevant. The paper challenges the benefits in altruistic-based positioning and outlines shortcomings in communication about ethical products, including those relating to product labelling. Social implications - Through their purchase behaviours across a number of categories, ethical consumers aim to minimise theharmand exploitation of humans, animals and the natural environment. This research provides insights into the potential reasonswhythe uptake of ethical products is not being achieved and how it can be addressed to make improvements in making this movement more mainstream. Originality/value - This research examines an extensive list of reasons for and against ethical purchasing used by a general population of consumers. By forcing respondents to make trade-offs, this is the first study quantifying the relative importance of reasons utilised by consumers. It also highlights the value in using cluster analysis on best-worst scores to identify underlying segments
Statistical Evaluation of NDE Reliability in the Aerospace Industry
The goal of this paper is to review the statistical methods used in the aerospace industries to evaluate NDE reliability. The techniques presented are consistent with the damage tolerant design and structural maintenance philosophies of the aerospace industry. The first part of this paper establishes the evaluation criteria and discusses the history of NDE reliability evaluations. The second part describes the state-of-the-art analysis methods through examples from the retirement for cause (RFC) inspection system evaluation. The last part of the paper discusses some techniques used to rate operator performance and deal with false calls
Impact of inactivated poliovirus vaccine on mucosal immunity: implications for the polio eradication endgame.
The polio eradication endgame aims to bring transmission of all polioviruses to a halt. To achieve this aim, it is essential to block viral replication in individuals via induction of a robust mucosal immune response. Although it has long been recognized that inactivated poliovirus vaccine (IPV) is incapable of inducing a strong mucosal response on its own, it has recently become clear that IPV may boost immunity in the intestinal mucosa among individuals previously immunized with oral poliovirus vaccine. Indeed, mucosal protection appears to be stronger following a booster dose of IPV than oral poliovirus vaccine, especially in older children. Here, we review the available evidence regarding the impact of IPV on mucosal immunity, and consider the implications of this evidence for the polio eradication endgame. We conclude that the implementation of IPV in both routine and supplementary immunization activities has the potential to play a key role in halting poliovirus transmission, and thereby hasten the eradication of polio
Commentary: Providing Versus Packaging Support for Bereaved Parents After Perinatal Loss
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73421/1/j.1523-536X.1992.tb00384.x.pd
Molecular astronomy of cool stars and sub-stellar objects
The optical and infrared spectra of a wide variety of `cool' astronomical
objects including the Sun, sunspots, K-, M- and S-type stars, carbon stars,
brown dwarfs and extrasolar planets are reviewed. The review provides the
necessary astronomical background for chemical physicists to understand and
appreciate the unique molecular environments found in astronomy. The
calculation of molecular opacities needed to simulate the observed spectral
energy distributions is discussed
Direct Observation of the Superfluid Phase Transition in Ultracold Fermi Gases
Water freezes into ice, atomic spins spontaneously align in a magnet, liquid
helium becomes superfluid: Phase transitions are dramatic phenomena. However,
despite the drastic change in the system's behaviour, observing the transition
can sometimes be subtle. The hallmark of Bose-Einstein condensation (BEC) and
superfluidity in trapped, weakly interacting Bose gases is the sudden
appearance of a dense central core inside a thermal cloud. In strongly
interacting gases, such as the recently observed fermionic superfluids, this
clear separation between the superfluid and the normal parts of the cloud is no
longer given. Condensates of fermion pairs could be detected only using
magnetic field sweeps into the weakly interacting regime. The quantitative
description of these sweeps presents a major theoretical challenge. Here we
demonstrate that the superfluid phase transition can be directly observed by
sudden changes in the shape of the clouds, in complete analogy to the case of
weakly interacting Bose gases. By preparing unequal mixtures of the two spin
components involved in the pairing, we greatly enhance the contrast between the
superfluid core and the normal component. Furthermore, the non-interacting
wings of excess atoms serve as a direct and reliable thermometer. Even in the
normal state, strong interactions significantly deform the density profile of
the majority spin component. We show that it is these interactions which drive
the normal-to-superfluid transition at the critical population imbalance of
70(5)%.Comment: 16 pages (incl. Supplemental Material), 5 figure
Mapping gene associations in human mitochondria using clinical disease phenotypes
Nuclear genes encode most mitochondrial proteins, and their mutations cause diverse and debilitating clinical disorders. To date, 1,200 of these mitochondrial genes have been recorded, while no standardized catalog exists of the associated clinical phenotypes. Such a catalog would be useful to develop methods to analyze human phenotypic data, to determine genotype-phenotype relations among many genes and diseases, and to support the clinical diagnosis of mitochondrial disorders. Here we establish a clinical phenotype catalog of 174 mitochondrial disease genes and study associations of diseases and genes. Phenotypic features such as clinical signs and symptoms were manually annotated from full-text medical articles and classified based on the hierarchical MeSH ontology. This classification of phenotypic features of each gene allowed for the comparison of diseases between different genes. In turn, we were then able to measure the phenotypic associations of disease genes for which we calculated a quantitative value that is based on their shared phenotypic features. The results showed that genes sharing more similar phenotypes have a stronger tendency for functional interactions, proving the usefulness of phenotype similarity values in disease gene network analysis. We then constructed a functional network of mitochondrial genes and discovered a higher connectivity for non-disease than for disease genes, and a tendency of disease genes to interact with each other. Utilizing these differences, we propose 168 candidate genes that resemble the characteristic interaction patterns of mitochondrial disease genes. Through their network associations, the candidates are further prioritized for the study of specific disorders such as optic neuropathies and Parkinson disease. Most mitochondrial disease phenotypes involve several clinical categories including neurologic, metabolic, and gastrointestinal disorders, which might indicate the effects of gene defects within the mitochondrial system. The accompanying knowledgebase (http://www.mitophenome.org/) supports the study of clinical diseases and associated genes
Breakdown of the adiabatic limit in low dimensional gapless systems
It is generally believed that a generic system can be reversibly transformed
from one state into another by sufficiently slow change of parameters. A
standard argument favoring this assertion is based on a possibility to expand
the energy or the entropy of the system into the Taylor series in the ramp
speed. Here we show that this argumentation is only valid in high enough
dimensions and can break down in low-dimensional gapless systems. We identify
three generic regimes of a system response to a slow ramp: (A) mean-field, (B)
non-analytic, and (C) non-adiabatic. In the last regime the limits of the ramp
speed going to zero and the system size going to infinity do not commute and
the adiabatic process does not exist in the thermodynamic limit. We support our
results by numerical simulations. Our findings can be relevant to
condensed-matter, atomic physics, quantum computing, quantum optics, cosmology
and others.Comment: 11 pages, 5 figures, to appear in Nature Physics (originally
submitted version
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