520 research outputs found
Cepstral analysis based on the Glimpse proportion measure for improving the intelligibility of HMM-based synthetic speech in noise
In this paper we introduce a new cepstral coefficient extraction method based on an intelligibility measure for speech in noise, the Glimpse Proportion measure. This new method aims to increase the intelligibility of speech in noise by modifying the clean speech, and has applications in scenarios such as public announcement and car navigation systems. We first explain how the Glimpse Proportion measure operates and further show how we approximated it to integrate it into an existing spectral envelope parameter extraction method commonly used in the HMM-based speech synthesis framework. We then demonstrate how this new method changes the modelled spectrum according to the characteristics of the noise and show results for a listening test with vocoded and HMM-based synthetic speech. The test indicates that the proposed method can significantly improve intelligibility of synthetic speech in speech shaped noise. Index Terms — cepstral coefficient extraction, objective measure for speech intelligibility, Lombard speech, HMM-based speech synthesis 1
Collective action in networks: communication, cooperation and redistribution
PhDA person's friends, neighbours and other social relationships can
have a large impact on their economic outcomes. We examine three
important ways that networks can affect people's lives: when networks
describe who they communicate with, who they can trust, and who
benefits from their public good provision. We analyse information
transmission in networks in a new, intuitive way which removes the
problematic redundancy of double counting the signals that travel
through more than one walk between nodes. Two-connectedness and
cycles of length four play an important role in whether players are
`visible', which means that other players can communicate about
them.
Next, using this approach to network communication, we investigate
cooperation and punishment in a society where information flows
about cheating are determined by an arbitrary fixed network. We
identify which players can trust and cooperate with each other in a
repeated game where members of a community are randomly matched
in pairs. Our model shows how two aspects of trust depend on players'
network position: they are `trusting' if they are more likely to receive
information about other players' types; and they are `trusted' if others
can communicate about them, giving them strong incentives not to
deviate.
Lastly, in networks with private provision of public goods, we show
that a `neutral' policy corresponds to a switch in the direction of
the impact of income redistribution. Where redistribution is non-
neutral, we can identify the welfare effects of transfers, including
whether or not Pareto-improving transfers are possible. If not, we
find the implicit welfare weights of the original equilibrium. In this
setting, we also identify a transfer paradox, where, counter-intuitively,
a transfer of wealth between economic agents can result in the giver
being better off at the new Nash equilibrium, while the recipient is
worse off .Queen Mary, University of Londo
Constrained public goods in networks
This paper analyses the private provision of public goods where agents interact within a fixed network structure and may benefit only from their direct neighbours’ provisions. We generalise the public goods in networks model of Bramoullé and Kranton (2007) to allow for constrained provision. In so doing, we characterise Nash equilibria with no intermediate contributors
The tidal tails of NGC 2298
We present an implementation of the matched-filter technique to detect tidal
tails of globular clusters. The method was tested using SDSS data for the
globular cluster Palomar 5 revealing its well known tidal tails. We also ran a
simulation of a globular cluster with a tidal tail where we successfully
recover the tails for a cluster at the same position and with the same
characteristics of NGC 2298. Based on the simulation we estimate that the
matched-filter increases the contrast of the tail relative to the background of
stars by a factor of 2.5 for the case of NGC 2298. We also present the
photometry of the globular cluster NGC 2298 using the MOSAIC2 camera installed
on the CTIO 4m telescope. The photometry covers ~ 3deg2 reaching V ~ 23. A fit
of a King profile to the radial density profile of NGC 2298 shows that this
cluster has a tidal radius of 15.91' \pm 1.07' which is twice as in the
literature. The application of the matched-filter to NGC 2298 reveals several
extra-tidal structures, including a leading and trailing tail. We also find
that NGC 2298 has extra-tidal structures stretching towards and against the
Galactic disk, suggesting strong tidal interaction. Finally, we assess how the
matched-filter performs when applied to a globular cluster with and without
mass segregation taken into account. We find that disregarding the effects of
mass segregation may significantly reduce the detection limit of the
matched-filter.Comment: 11 pages, 9 figures, 1 table. Accepted for publication on MNRAS main
journa
Introgression of Aegilops speltoides segments in Triticum aestivum and the effect of the gametocidal genes
• Background and Aims Bread wheat (Triticum aestivum) has been through a severe genetic bottleneck as a result of its evolution and domestication. It is therefore essential that new sources of genetic variation are generated and utilized. This study aimed to generate genome-wide introgressed segments from Aegilops speltoides. Introgressions generated from this research will be made available for phenotypic analysis.
• Methods Aegilops speltoides was crossed as the male parent to T. aestivum ‘Paragon’. The interspecific hybrids were then backcrossed to Paragon. Introgressions were detected and characterized using the Affymetrix Axiom Array and genomic in situ hybridization (GISH).
• Key Results Recombination in the gametes of the F₁ hybrids was at a level where it was possible to generate a genetic linkage map of Ae. speltoides. This was used to identify 294 wheat/Ae. speltoides introgressions. Introgressions from all seven linkage groups of Ae. speltoides were found, including both large and small segments. Comparative analysis showed that overall macro-synteny is conserved between Ae. speltoides and T. aestivum, but that Ae. speltoides does not contain the 4A/5A/7B translocations present in wheat. Aegilops speltoides has been reported to carry gametocidal genes, i.e. genes that ensure their transmission through the gametes to the next generation. Transmission rates of the seven Ae. speltoides linkage groups introgressed into wheat varied. A 100 % transmission rate of linkage group 2 demonstrates the presence of the gametocidal genes on this chromosome.
• Conclusions A high level of recombination occurs between the chromosomes of wheat and Ae. speltoides, leading to the generation of large numbers of introgressions with the potential for exploitation in breeding programmes. Due to the gametocidal genes, all germplasm developed will always contain a segment from Ae. speltoides linkage group 2S, in addition to an introgression from any other linkage group
Separating the spindle, checkpoint, and timer functions of BubR1
The BubR1 kinase domain controls spindle attachment to the kinetochores, whereas the KEN domain regulates activation of the spindle assembly checkpoint
Prediction of climate change effects on the runoff regime of a forested catchment in northern Iran
One Health – an Ecological and Evolutionary Framework for tackling Neglected Zoonotic Diseases
Understanding the complex population biology and transmission ecology of multihost parasites has been declared as one of the major challenges of biomedical sciences for the 21st century and the Neglected Zoonotic Diseases (NZDs) are perhaps the most neglected of all the Neglected Tropical Diseases (NTDs). Here we consider how multihost parasite transmission and evolutionary dynamics may affect the success of human and animal disease control programmes, particularly neglected diseases of the developing world. We review the different types of zoonotic interactions that occur, both ecological and evolutionary, their potential relevance for current human control activities, and make suggestions for the development of an empirical evidence base and theoretical framework to better understand and predict the outcome of such interactions. In particular, we consider whether preventive chemotherapy, the current mainstay of NTD control, can be successful without a One Health approach. Transmission within and between animal reservoirs and humans can have important ecological and evolutionary consequences, driving the evolution and establishment of drug resistance, as well as providing selective pressures for spill‐over, host switching, hybridizations and introgressions between animal and human parasites. Our aim here is to highlight the importance of both elucidating disease ecology, including identifying key hosts and tailoring control effort accordingly, and understanding parasite evolution, such as precisely how infectious agents may respond and adapt to anthropogenic change. Both elements are essential if we are to alleviate disease risks from NZDs in humans, domestic animals and wildlife
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Competitive Equilibrium and Trading Networks: A Network Flow Approach
Under full substitutability of preferences, it has been shown that a competitive equilibrium exists in trading networks, and is equivalent (after a restriction to equilibrium trades) to (chain) stable outcomes. In this paper, we formulate the problem of finding an efficient outcome as a generalized submodular flow problem on a suitable network. Equivalence with seemingly weaker notions of stability follows directly from the optimality conditions, in particular the absence of improvement cycles in the flow problem. Our formulation yields strongly polynomial algorithms for finding competitive equilibria in trading networks, and testing (chain) stability
- …