4,017 research outputs found
Projections of Ebola outbreak size and duration with and without vaccine use in Équateur, Democratic Republic of Congo, as of May 27, 2018.
As of May 27, 2018, 6 suspected, 13 probable and 35 confirmed cases of Ebola virus disease (EVD) had been reported in Équateur Province, Democratic Republic of Congo. We used reported case counts and time series from prior outbreaks to estimate the total outbreak size and duration with and without vaccine use. We modeled Ebola virus transmission using a stochastic branching process model that included reproduction numbers from past Ebola outbreaks and a particle filtering method to generate a probabilistic projection of the outbreak size and duration conditioned on its reported trajectory to date; modeled using high (62%), low (44%), and zero (0%) estimates of vaccination coverage (after deployment). Additionally, we used the time series for 18 prior Ebola outbreaks from 1976 to 2016 to parameterize the Thiel-Sen regression model predicting the outbreak size from the number of observed cases from April 4 to May 27. We used these techniques on probable and confirmed case counts with and without inclusion of suspected cases. Probabilistic projections were scored against the actual outbreak size of 54 EVD cases, using a log-likelihood score. With the stochastic model, using high, low, and zero estimates of vaccination coverage, the median outbreak sizes for probable and confirmed cases were 82 cases (95% prediction interval [PI]: 55, 156), 104 cases (95% PI: 58, 271), and 213 cases (95% PI: 64, 1450), respectively. With the Thiel-Sen regression model, the median outbreak size was estimated to be 65.0 probable and confirmed cases (95% PI: 48.8, 119.7). Among our three mathematical models, the stochastic model with suspected cases and high vaccine coverage predicted total outbreak sizes closest to the true outcome. Relatively simple mathematical models updated in real time may inform outbreak response teams with projections of total outbreak size and duration
Accessing Nuclear Structure for Field Emission, in Lens, Scanning Electron Microscopy (FEISEM)
Scanning electron microscopy (SEM) has had a shorter time course in biology than conventional transmission electron microscopy (TEM) but has nevertheless produced a wealth of images that have significantly complemented our perception of biological structure and function from TEM information. By its nature, SEM is a surface imaging technology, and its impact at the subcellular level has been restricted by the considerably reduced resolution in conventional SEM in comparison to TEM. This restriction has been removed by the recent advent of high-brightness sources used in lensfield emission instruments (FEISEM) which have produced resolution of around 1 nanometre, which is not usually a limiting figure for biological material.
This communication reviews our findings in the use of FEISEM in the imaging of nuclear surfaces, then associated structures, such as nuclear pore complexes, and the relationships of these structures with cytoplasmic and nucleoplasmic elements. High resolution SEM allows the structurally orientated cell biologist to visualise, directly and in three dimensions, subcellular structure and its modulation with a view to understanding its functional significance. Clearly, intracellular surfaces require separation from surrounding structural elements in vivo to allow surface imaging, and we review a combination of biochemical and mechanical isolation methods for nuclear surfaces
Severe personality disorder in the secure estate: continuity and change
The Response to Offender Personality Disorder Consultation was released in October 2011. For some this is a welcome step in the right direction due to its therapeutic optimism, however for practitioners operating in the secure estate there are significant challenges ahead. This aim of this article is to discuss the increasing convergence of health and criminal justice and their inherent ideological and practical difficulties. It does so with reference to the consultation on offender personality disorder pathways and in particular the implications regarding multi-disciplinary and cross agency approaches to risk, public protection and personality disorder respectfully. It concludes that before embarking on a new wave of determining and responding to those with personality disorder, offender or otherwise, a more in-depth and empirically informed critical reflection is warranted
Subsystems of a finite quantum system and Bell-like inequalities
YesThe set of subsystems Sigma(m) of a finite quantum system Sigma(n) with variables in Z(n) together with logical connectives, is a Heyting algebra. The probabilities tau(m vertical bar rho(n)) Tr vertical bar B(m)rho(n)] (where B(m) is the projector to Sigma(m)) are compatible with associativity of the join in the Heyting algebra, only if the variables belong to the same chain. Consequently, contextuality in the present formalism, has the chains as contexts. Various Bell-like inequalities are discussed. They are violated, and this proves that quantum mechanics is a contextual theory
2D-infrared spectroscopy of proteins in water : using the solvent thermal response as an internal standard
Ultrafast two-dimensional infrared (2D-IR) spectra can now be obtained in a matter of seconds, opening up the possibility of high-throughput screening applications of relevance to the biomedical and pharmaceutical sectors. Determining quantitative information from 2D-IR spectra recorded on different samples and different instruments is however made difficult by variations in beam alignment, laser intensity, and sample conditions. Recently, we demonstrated that 2D-IR spectroscopy of the protein amide I band can be performed in aqueous (H2O) rather than deuterated (D2O) solvents, and we now report a method that uses the magnitude of the associated thermal response of H2O as an internal normalization standard for 2D-IR spectra. Using the water response, which is temporally separated from the protein signal, to normalize the spectra allows significant reduction of the impact of measurement-to-measurement fluctuations on the data. We demonstrate that this normalization method enables creation of calibration curves for measurement of absolute protein concentrations and facilitates reproducible difference spectroscopy methodologies. These advances make significant progress toward the robust data handling strategies that will be essential for the realization of automated spectral analysis tools for large scale 2D-IR screening studies of protein-containing solutions and biofluids
From Service to Experience: Understanding and Defining the Hospitality Business
Failure adequately to define or understand hospitality as a commercial phenomenon has created a fragmented academic environment and a schizophrenia in the industry that has the potential to limit its development as a global industry. This article suggests that, by redefining hospitality as behaviour and experience, a new perspective emerges that has exciting implications for the management of hospitality businesses. A framework to describe hospitality in the commercial domain is proposed. This framework suggests a focus on the host–guest relationship, generosity, theatre and performance, ‘lots of little surprises’, and the security of strangers – a focus that provides guests with experiences that are personal, memorable and add value to their lives
Light Hadron Masses from Lattice QCD
This article reviews lattice QCD results for the light hadron spectrum. We
give an overview of different formulations of lattice QCD, with discussions on
the fermion doubling problem and improvement programs. We summarize recent
developments in algorithms and analysis techniques, that render calculations
with light, dynamical quarks feasible on present day computer resources.
Finally, we summarize spectrum results for ground state hadrons and resonances
using various actions.Comment: 53 pages, 24 figures, one table; Rev.Mod.Phys. (published version);
v2: corrected typ
Doing gender locally: The importance of ‘place’ in understanding marginalised masculinities and young men’s transitions to ‘safe’ and successful futures
Observable anxieties have been developing about the position of boys and young men in contemporary society in recent years. This is expressed as a crisis of masculinity, in which place is often implicitly implicated, but is rarely considered for its role in the shaping of young men’s practices, trajectories and aspirations. Drawing on research conducted with young people who accessed a range of social care support services, this article argues that transition means different things for young men in different locales and that local definitions of masculinity are required to better understand young men’s lives and the opportunities available to them. The authors argue that home life, street life, individual neighbourhoods, regions and nations all shaped the young men’s identities and the practices they (and the staff working with them) drew on in order to create successful futures and ‘safe’ forms of masculinity. It is suggested that this place-based approach has the potential to re-shape the ‘crisis’ discourse surrounding masculinity and the anxieties associated with young men
Synaptic Scaling Balances Learning in a Spiking Model of Neocortex
Learning in the brain requires complementary mechanisms: potentiation and
activity-dependent homeostatic scaling. We introduce synaptic scaling to a
biologically-realistic spiking model of neocortex which can learn changes in
oscillatory rhythms using STDP, and show that scaling is necessary to balance
both positive and negative changes in input from potentiation and atrophy. We
discuss some of the issues that arise when considering synaptic scaling in such
a model, and show that scaling regulates activity whilst allowing learning to
remain unaltered.Comment: 10 page
Majorana solutions to the two-electron problem
A review of the known different methods and results devised to study the
two-electron atom problem, appeared in the early years of quantum mechanics, is
given, with particular reference to the calculations of the ground state energy
of helium. This is supplemented by several, unpublished results obtained around
the same years by Ettore Majorana, which results did not convey in his
published papers on the argument, and thus remained unknown until now.
Particularly interesting, even for current research in atomic and nuclear
physics, is a general variant of the variational method, developed by Majorana
in order to take directly into account, already in the trial wavefunction, the
action of the full Hamiltonian operator of a given quantum system. Moreover,
notable calculations specialized to the study of the two-electron problem show
the introduction of the remarkable concept of an effective nuclear charge
different for the two electrons (thus generalizing previous known results), and
an application of the perturbative method, where the atomic number Z was
treated effectively as a continuous variable, contributions to the ground state
energy of an atom with given Z coming also from any other Z. Instead,
contributions relevant mainly for pedagogical reasons count simple broad range
estimates of the helium ionization potential, obtained by suitable choices for
the wavefunction, as well as a simple alternative to Hylleraas' method, which
led Majorana to first order calculations comparable in accuracy with well-known
order 11 results derived, in turn, by Hylleraas.Comment: amsart, 20 pages, no figure
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