GET WELL: an automated surveillance system for gaining new epidemiological knowledge

<p>Abstract</p> <p>Background</p> <p>The assumption behind the presented work is that the information people search for on the internet reflects the disease status in society. By having access to this source of information, epidemiologists can get a valuable complement to the traditional surveillance and potentially get new and timely epidemiological insights. For this purpose, the Swedish Institute for Infectious Disease Control collaborates with a medical web site in Sweden.</p> <p>Methods</p> <p>We built an application consisting of two conceptual parts. One part allows for trends, based on user specified requests, to be extracted from anonymous web query data from a Swedish medical web site. The second conceptual part permits tailored analyses of particular diseases, where more complex statistical methods are applied to the data. To evaluate the epidemiological relevance of the output, we compared Google search data and search data from the medical web site.</p> <p>Results</p> <p>In the paper, we give concrete examples of the output from the web query-based system. We also present results from the comparison between data from the search engine Google and search data from the national medical web site.</p> <p>Conclusions</p> <p>The application is in regular use at the Swedish Institute for Infectious Disease Control. A system based on web queries is flexible in that it can be adapted to any disease; we get information on other individuals than those who seek medical care; and the data do not suffer from reporting delays. Although Google data are based on a substantially larger search volume, search patterns obtained from the medical web site may still convey more information from an epidemiological perspective. Furthermore we can see advantages with having full access to the raw data.</p

Detection of Infectious Disease Outbreaks From Laboratory Data With Reporting Delays

Many statistical surveillance systems for the timely detection of outbreaks of infectious disease operate on laboratory data. Such data typically incur reporting delays between the time at which a specimen is collected for diagnostic purposes, and the time at which the results of the laboratory analysis become available. Statistical surveillance systems currently in use usually make some ad hoc adjustment for such delays, or use counts by time of report. We propose a new statistical approach that takes account of the delays explicitly, by monitoring the number of specimens identified in the current and past m time units, where m is a tuning parameter. Values expected in the absence of an outbreak are estimated from counts observed in recent years (typically 5 years). We study the method in the context of an outbreak detection system used in the United Kingdom and several other European countries. We propose a suitable test statistic for the null hypothesis that no outbreak is currently occurring. We derive its null variance, incorporating uncertainty about the estimated delay distribution. Simulations and applications to some test datasets suggest the method works well, and can improve performance over ad hoc methods in current use. Supplementary materials for this article are available online

Charmed quark component of the photon wave function

We determine the c-anti-c component of the photon wave function on the basis of (i) the data on the transitions e+ e- -> J/psi(3096), psi(3686), psi(4040), psi(4415), (ii) partial widths of the two-photon decays eta_{c0}(2979), chi_{c0}(3415), chi_{c2}(3556) -> gamma-gamma, and (iii) wave functions of the charmonium states obtained by solving the Bethe-Salpeter equation for the c-anti-c system. Using the obtained c-anti-c component of the photon wave function we calculate the gamma-gamma decay partial widths for radial excitation 2S state, eta_{c0}(3594) -> gamma-gamma, and 2P states chi_{c0}(3849), chi_{c2}(3950) -> gamma-gamma.Comment: 20 pages, 8 figure

Quark--antiquark states and their radiative transitions in terms of the spectral integral equation. {\Huge III.} Light mesons

We continue the investigation of mesons in terms of the spectral integral equation initiated before [hep-ph/0510410, hep-ph/0511005] for the $b\bar b$ and $c\bar c$ systems: in this paper we consider the light-quark ($u, d,s$) mesons with masses $M\le 3$ GeV. The calculations have been performed for the mesons lying on linear trajectories in the $(n,M^2)$-planes, where $n$ is the radial quantum number. Our consideration relates to the $q\bar q$ states with one component in the flavor space, with the quark and antiquark masses equal to each other, such as $\pi(0^{-+})$, $\rho(1^{--})$, $\omega(1^{--})$, $\phi(1^{--})$, $a_0(0^{++})$, $a_1(1^{++})$, $a_2(2^{++})$, $b_1(1^{+-})$, $f_2(2^{++})$, $\pi_2(2^{-+})$, $\rho_3(3^{--})$, $\omega_3(3^{--})$, $\phi_3(3^{--})$, $\pi_4(4^{-+})$ at $n\le 6$. We obtained the wave functions and mass values of mesons lying on these trajectories. The corresponding trajectories are linear, in agreement with data. We have calculated the two-photon decays $\pi\to \gamma\gamma$, $a_0(980)\to \gamma\gamma$, $a_2(1320)\to \gamma\gamma$, $f_2(1285)\to \gamma\gamma$, $f_2(1525)\to \gamma\gamma$ and radiative transitions $\rho\to\gamma\pi$, $\omega\to\gamma\pi$, that agree qualitatively with the experiment. On this basis, we extract the singular part of the interaction amplitude, which corresponds to the so-called "confinement interaction". The description of the data requires the presence of the strong $t$-channel singularities for both scalar and vector exchanges.Comment: 48 pages, 24 figure

Quark--antiquark states and their radiative transitions in terms of the spectral integral equation. {\Huge II.} Charmonia

In the precedent paper of the authors (hep-ph/0510410), the $b\bar b$ states were treated in the framework of the spectral integral equation, together with simultaneous calculations of radiative decays of the considered bottomonia. In the present paper, such a study is carried out for the charmonium $(c\bar c)$ states. We reconstruct the interaction in the $c\bar c$-sector on the basis of data for the charmonium levels with $J^{PC}=0^{-+}$, $1^{--}$, $0^{++}$, $1^{++}$, $2^{++}$, $1^{+-}$ and radiative transitions $\psi(2S)\to\gamma\chi_{c0}(1P)$, $\gamma\chi_{c1}(1P)$, $\gamma\chi_{c2}(1P)$, $\gamma\eta_{c}(1S)$ and $\chi_{c0}(1P)$, $\chi_{c1}(1P)$, $\chi_{c2}(1P)\to\gamma J/\psi$. The $c\bar c$ levels and their wave functions are calculated for the radial excitations with $n\le 6$. Also, we determine the $c\bar c$ component of the photon wave function using the $e^+e^-$ annihilation data: $e^+e^- \to J/\psi(3097)$, $\psi(3686)$, $\psi(3770)$, $\psi(4040)$, $\psi(4160)$, $\psi(4415)$ and perform the calculations of the partial widths of the two-photon decays for the $n=1$ states: $\eta_{c0}(1S)$, $\chi_{c0}(1P)$, $\chi_{c2}(1P)\to\gamma\gamma$, and $n=2$ states: $\eta_{c0}(2S)\to\gamma\gamma$, $\chi_{c0}(2P)$, $\chi_{c2}(2P)\to \gamma\gamma$. We discuss the status of the recently observed $c\bar c$ states X(3872) and Y(3941): according to our results, the X(3872) can be either $\chi_{c1}(2P)$ or $\eta_{c2}(1D)$, while Y(3941) is $\chi_{c2}(2P)$.Comment: 24 pages, 9 figure

Optical Properties of Deep Ice at the South Pole - Absorption

We discuss recent measurements of the wavelength-dependent absorption coefficients in deep South Pole ice. The method uses transit time distributions of pulses from a variable-frequency laser sent between emitters and receivers embedded in the ice. At depths of 800 to 1000 m scattering is dominated by residual air bubbles, whereas absorption occurs both in ice itself and in insoluble impurities. The absorption coefficient increases approximately exponentially with wavelength in the measured interval 410 to 610 nm. At the shortest wavelength our value is about a factor 20 below previous values obtained for laboratory ice and lake ice; with increasing wavelength the discrepancy with previous measurements decreases. At around 415 to 500 nm the experimental uncertainties are small enough for us to resolve an extrinsic contribution to absorption in ice: submicron dust particles contribute by an amount that increases with depth and corresponds well with the expected increase seen near the Last Glacial Maximum in Vostok and Dome C ice cores. The laser pulse method allows remote mapping of gross structure in dust concentration as a function of depth in glacial ice.Comment: 26 pages, LaTex, Accepted for publication in Applied Optics. 9 figures, not included, available on request from [email protected]

The rho -> gamma pi and omega -> gamma pi decays in quark-model approach and estimation of coupling for pion emission by quark

In the framework of the relativistic and gauge invariant spectral integral technique, we calculate radiative decays rho(770)-> gamma pi(140) and omega(780)-> gamma pi(140) supposing all mesons (pi, rho and omega) to be quark-antiquark states. The q anti-q wave functions found for mesons and photon lead to a reasonably good description of data ($\Gamma^{(exp)}_{\rho^{\pm} \to\gamma\pi^{\pm}}=68\pm 30$ keV, $\Gamma^{(exp)}_{\rho^{0}\to\gamma\pi^0}=77\pm 28$ keV, $\Gamma^{(exp)}_{\omega\to\gamma\pi^0}=776\pm 45$ keV) that makes it possible to estimate the coupling for the bremsstrahlung emission of pion by quarks $g_\pi\equiv g_\pi (u\to d \pi)$. We have found two values for the pion bremsstrahlung coupling: $|g_\pi|=16.7 \pm 0.3 ^{+0.1}_{-2.3}$ (Solution I) and $|g_\pi|=3.0 \pm 0.3 ^{+0.1}_{-2.1}$ (Solution II). Within SU(6)-symmetry for nucleons, Solution I gives us for pi NN coupling the value $16.4 \le g_{\pi NN}^2/(4\pi) \le 23.2$ that is in qualitative agreement with the pi N scattering data, $g_{\pi NN}^2/(4\pi)\simeq 14$. For excited states, we have estimated the partial widths in Solution I as follows: $\Gamma (\rho_{2S}^\pm\to \gamma\pi)\simeq 10 - 130$ keV, $\Gamma (\rho_{2S}^0\to \gamma\pi)\simeq 10 -130$ keV, $\Gamma (\omega_{2S}\to \gamma\pi)\simeq 60 - 1080$ keV. The large uncertainties emphasise the necessity to carry out measurements of the meson radiative processes in the region of large masses.Comment: 23 pages in IOP forma

Inheritance patterns in citation networks reveal scientific memes

Memes are the cultural equivalent of genes that spread across human culture by means of imitation. What makes a meme and what distinguishes it from other forms of information, however, is still poorly understood. Our analysis of memes in the scientific literature reveals that they are governed by a surprisingly simple relationship between frequency of occurrence and the degree to which they propagate along the citation graph. We propose a simple formalization of this pattern and we validate it with data from close to 50 million publication records from the Web of Science, PubMed Central, and the American Physical Society. Evaluations relying on human annotators, citation network randomizations, and comparisons with several alternative approaches confirm that our formula is accurate and effective, without a dependence on linguistic or ontological knowledge and without the application of arbitrary thresholds or filters.Comment: 8 two-column pages, 5 figures; accepted for publication in Physical Review

The AMANDA Neutrino Telescope and the Indirect Search for Dark Matter

With an effective telescope area of order 10^4 m^2, a threshold of ~50 GeV and a pointing accuracy of 2.5 degrees, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe its performance, focussing on the capability to detect halo dark matter particles via their annihilation into neutrinos.Comment: Latex2.09, 16 pages, uses epsf.sty to place 15 postscript figures. Talk presented at the 3rd International Symposium on Sources and Detection of Dark Matter in the Universe (DM98), Santa Monica, California, Feb. 199