311 research outputs found

    Dengue epidemic in southern Vietnam, 1998.

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    A widespread epidemic of dengue hemorrhagic fever (DHF) occurred in southern Vietnam in 1998, with 438.98 cases/100,000 population and 342 deaths. The number of DHF cases and deaths per 100,000 population increased 152.4% and 151.8%, respectively, over a 1997 epidemic. Dengue viruses were isolated from 143 patient blood samples; DEN-3 virus was identified as the predominant serotype, although a resurgence of DEN-4 was noted

    Effectiveness of community outreach HIV prevention programs in Vietnam: A mixed methods evaluation

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    Background In 2014, Vietnam was the first Southeast Asian country to commit to achieving the World Health Organization’s 90–90-90 global HIV targets (90% know their HIV status, 90% on sustained treatment, and 90% virally suppressed) by 2020. This pledge represented further confirmation of Vietnam’s efforts to respond to the HIV epidemic, one feature of which has been close collaboration with the U.S. President’s Emergency Plan for AIDS Relief (PEPFAR). Starting in 2004, PEPFAR supported community outreach programs targeting high-risk populations (people who inject drugs, men who have sex with men, and sex workers). To provide early evidence on program impact, in 2007–2008 we conducted a nationwide evaluation of PEPFAR-supported outreach programs in Vietnam. The evaluation focused on assessing program effect on HIV knowledge, high-risk behaviors, and HIV testing among high-risk populations—results relevant to Vietnam’s push to meet global HIV goals. Methods We used a mixed-methods cross-sectional evaluation design. Data collection encompassed a quantitative survey of 2199 individuals, supplemented by 125 in-depth interviews. Participants were members of high-risk populations who reported recent contact with an outreach worker (intervention group) or no recent contact (comparison group). We assessed differences in HIV knowledge, risky behaviors, and HIV testing between groups, and between high-risk populations. Results Intervention participants knew significantly more about transmission, prevention, and treatment than comparison participants. We found low levels of injection drug-use-related risk behaviors and little evidence of program impact on such behaviors. In contrast, a significantly smaller proportion of intervention than comparison participants reported risky sexual behaviors generally and within each high-risk population. Intervention participants were also more likely to have undergone HIV testing (76.1% vs. 47.0%, p \u3c 0.0001) and to have received pre-test (78.0% vs. 33.7%, p \u3c 0.0001) and post-test counseling (80.9% vs. 60.5%, p \u3c 0.0001). Interviews supported evidence of high impact of outreach among all high-risk populations. Conclusions Outreach programs appear to have reduced risky sexual behaviors and increased use of HIV testing services among high-risk populations in Vietnam. These programs can play a key role in reducing gaps in the HIV care cascade, achieving the global 90–90-90 goals, and creating an AIDS-free generation

    Lowest-lying Tetra-Quark Hadrons in Anisotropic Lattice QCD

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    We present a detailed study of lowest-lying q2qˉ2q^{2}\bar{q}^{2} hadrons in quenched improved anisotropic lattice QCD. Using the ππ\pi\pi and diquark-antidiquark local and smeared operators, we attempt to isolate the signal for I(JP)=0(0+),2(0+)I(J^{P})=0(0^{+}), 2(0^{+}) and 1(1+)1(1^{+}) states in two flavour QCD. In the chiral limit of light-quark mass region, the lowest scalar 4q4q state is found to have a mass, m4qI=0=927(12)m^{I=0}_{4q}=927(12) MeV, which is slightly lower than the experimentally observed f0(980)f_{0}(980). The results from our variational analysis do not indicate a signature of a tetraquark resonance in I=1 and I=2 channels. After the chiral extrapolation the lowest 1(1+)1(1^{+}) state is found to have a mass, m4qI=1=1358(28)m^{I=1}_{4q}=1358(28) MeV. We analysed the static 4q4q potential extracted form a tetraquark Wilson loop and illustrated the behaviour of the 4q4q state as a bound state, unbinding at some critical diquark separation. From our analysis we conclude that scalar 4q4q system appears as a two-pion scattering state and that there is no spatially-localised 4q4q state in the light-quark mass region.Comment: 9 pages, 10 figure

    The Grand-Canonical Asymmetric Exclusion Process and the One-Transit Walk

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    The one-dimensional Asymmetric Exclusion Process (ASEP) is a paradigm for nonequilibrium dynamics, in particular driven diffusive processes. It is usually considered in a canonical ensemble in which the number of sites is fixed. We observe that the grand-canonical partition function for the ASEP is remarkably simple. It allows a simple direct derivation of the asymptotics of the canonical normalization in various phases and of the correspondence with One-Transit Walks recently observed by Brak et.al.Comment: Published versio

    Hamiltonian Study of Improved U(1U(1 Lattice Gauge Theory in Three Dimensions

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    A comprehensive analysis of the Symanzik improved anisotropic three-dimensional U(1) lattice gauge theory in the Hamiltonian limit is made. Monte Carlo techniques are used to obtain numerical results for the static potential, ratio of the renormalized and bare anisotropies, the string tension, lowest glueball masses and the mass ratio. Evidence that rotational symmetry is established more accurately for the Symanzik improved anisotropic action is presented. The discretization errors in the static potential and the renormalization of the bare anisotropy are found to be only a few percent compared to errors of about 20-25% for the unimproved gauge action. Evidence of scaling in the string tension, antisymmetric mass gap and the mass ratio is observed in the weak coupling region and the behaviour is tested against analytic and numerical results obtained in various other Hamiltonian studies of the theory. We find that more accurate determination of the scaling coefficients of the string tension and the antisymmetric mass gap has been achieved, and the agreement with various other Hamiltonian studies of the theory is excellent. The improved action is found to give faster convergence to the continuum limit. Very clear evidence is obtained that in the continuum limit the glueball ratio MS/MAM_{S}/M_{A} approaches exactly 2, as expected in a theory of free, massive bosons.Comment: 13 pages, 15 figures, submitted to Phys. Rev.

    Multi-Target Prediction: A Unifying View on Problems and Methods

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    Multi-target prediction (MTP) is concerned with the simultaneous prediction of multiple target variables of diverse type. Due to its enormous application potential, it has developed into an active and rapidly expanding research field that combines several subfields of machine learning, including multivariate regression, multi-label classification, multi-task learning, dyadic prediction, zero-shot learning, network inference, and matrix completion. In this paper, we present a unifying view on MTP problems and methods. First, we formally discuss commonalities and differences between existing MTP problems. To this end, we introduce a general framework that covers the above subfields as special cases. As a second contribution, we provide a structured overview of MTP methods. This is accomplished by identifying a number of key properties, which distinguish such methods and determine their suitability for different types of problems. Finally, we also discuss a few challenges for future research

    Pure-glue hidden valleys through the Higgs portal

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    We consider the possibility that the Higgs boson can act as a link to a hidden sector in the context of pure-glue hidden valley models. In these models the standard model is weakly coupled, through loops of heavy messengers fields, to a hidden sector whose low energy dynamics is described by a pure-Yang-Mills theory. Such a hidden sector contains several metastable hidden glueballs. In this work we shall extend earlier results on hidden valleys to include couplings of the messengers to the standard model Higgs sector. The effective interactions at one-loop couple the hidden gluons to the standard model particles through the Higgs sector. These couplings in turn induce hidden glueball decays to fermion pairs, or cascade decays with multiple Higgs emission. The presence of effective operators of different mass dimensions, often competing with each other, together with a great diversity of states, leads to a great variability in the lifetimes and decay modes of the hidden glueballs. We find that most of the operators considered in this paper are not heavily constrained by precision electroweak physics, therefore leaving plenty of room in the parameter space to be explored by the future experiments at the LHC.Comment: 44 pages, 16 figures. Major revision for JHEP, corrected an error in Eq. 5.1, comments adde

    Financial Inclusion and Macroeconomic Stability in Emerging and Frontier Markets

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    Financial inclusion, being considered as a key enabler to reducing poverty and boosting prosperity in emerging and frontier markets such as Vietnam, is the process in which individuals and small businesses are provided with an access to useful and affordable financial products and services. The extant literature on the empirical evidence regarding the contribution of financial inclusion to macroeconomic stability is mixed. This paper investigates the linkages between financial inclusion and macroeconomic stability, which has not yet been thoroughly examined in the literature, for 22 emerging and frontier economies from 2008 to 2015, with particular focus on a potential optimal level. Using the panel threshold estimation technique, the empirical findings show that financial inclusion, as approximated by the growth rate in the number of bank branches over 100,000 account holders, is found to enhance financial stability under a certain threshold. Financial inclusion is also found to be of benefit to maintaining stable inflation and output growth. Policy implications are also discussed on the basis of the important empirical findings

    Nonlinear Diffusion Through Large Complex Networks Containing Regular Subgraphs

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    Transport through generalized trees is considered. Trees contain the simple nodes and supernodes, either well-structured regular subgraphs or those with many triangles. We observe a superdiffusion for the highly connected nodes while it is Brownian for the rest of the nodes. Transport within a supernode is affected by the finite size effects vanishing as N.N\to\infty. For the even dimensions of space, d=2,4,6,...d=2,4,6,..., the finite size effects break down the perturbation theory at small scales and can be regularized by using the heat-kernel expansion.Comment: 21 pages, 2 figures include

    Constraints on the Clustering, Biasing and Redshift Distribution of Radio Sources

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    We discuss how different theoretical predictions for the variance σ2\sigma^2 of the distribution of radio sources can be matched to measurements from the FIRST survey at different flux limits. The predictions are given by the integration of models for the angular correlation function w(θ)w(\theta) for three different functional forms of the redshift distribution N(z)N(z), different spatial correlation functions and by different evolutions of the bias b(z)b(z) with redshift. We also consider the two cases of open and flat Universes. Although the predicted w(θ)w(\theta) show substantial differences due to differences in the N(z)N(z)'s, these differences are not significant compared to the uncertainties in the current observations. It turns out that the best fit is provided by models with constant biasing at all times, although the difference between models with epoch-independent bias and models with bias that evolves linearly with redshift is not very large. All models with strong evolution of bias with epoch are ruled out. As a further step we directly calculated wobs(θ)w_{obs}(\theta) at 3mJy from the catalogue and matched it with our models for the angular correlation function in the hypothesis that the clustering signal comes from two different populations, namely AGN-powered sources and starbursting galaxies. The results are consistent with a scenario for hierarchical clustering where the fainter starbursting galaxies trace the mass at all epochs, while brighter AGN's are strongly biased, with b(z)b(z) evolving linearly with redshift, as suggested by some theories of galaxy formation and evolution.Comment: 14 pages, 12 figures, version to appear on MNRA
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