Synchronisation between Dengue Incidence in Bangkok and in the Rest of Thailand

<div><p>The incidence series are square root transformed, and all series are normalised.</p> <p>(A) Wavelet coherence computed based on the Morlet wavelet function between dengue incidence in Bangkok and in the rest of Thailand; colours as in <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0020106#pmed-0020106-g001" target="_blank">Figure 1</a>B. The white dashed lines show the α = 5% significance level computed based on 1,000 bootstrapped series.</p> <p>(B) Oscillating components computed with the wavelet transform in the 2–3-y period band (colours as in <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0020106#pmed-0020106-g001" target="_blank">Figure 1</a>A).</p> <p>(C) Oscillating components computed with the wavelet transform in the 0.8–1.2-y period band (colours as in <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0020106#pmed-0020106-g001" target="_blank">Figure 1</a>A).</p> <p>In (B) and (C) the black line shows the time evolution of the instantaneous time delay in months (Δ<i>T</i>) between the oscillating components of the two incidence time series.</p></div

Weekly raw incidence rates, filtered incidence and phase of four districts in Cambodia.

<p>The four districts are: district #306 (black), a rural district located around Kampong Cham; Phnom Penh (red); District #307 (green), a rural district located mid-way between #306 and Phnom Penh; District #104 (blue). (A) Weekly raw incidence rates (in number of cases declared per 100,000 people per week). (B) Annual component of incidence, obtained by filtering raw weekly incidence in the 0.8–1.2 year periodic band using wavelet analysis. (C) Phase of the annual component of incidence, computed in the 0.8–1.2 periodic band using wavelet analysis (see <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001957#s2" target="_blank">Methods</a>).</p

Results of the analysis of covariance and linear regressions (see methods).

1<p>Number of districts where an annual epidemic occurred according to the national threshold, along the Mekong River, the national road (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001957#pntd-0001957-g004" target="_blank">Figure 4A</a>), or, for the covariance analysis, both.</p>2<p>P-value of the regression slope estimate.</p>3<p>Inverse of the estimate of the regression slope β1, in km per week (see <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001957#s2" target="_blank">methods</a>).</p

Map of mean annual dengue fever incidence rates in districts of Cambodia.

<p>Mean annual incidence rates (in number of cases declared per 100,000 people per year) are calculated over 2002 to 2008, for districts with more than 20 people per km². Cambodia is surrounded by the Indian Ocean (bottom left), Thailand (West), Lao (North) and Vietnam (East and South-East). Phnom Penh, the capital, is represented by a circle, Siem Reap by a triangle, Kampong Cham by a square and Battambang by a lozenge. Blue lines represent the Mekong River, going north to south, and the Tonle Sap River linking the Tonle Sap central Lake to the Mekong River. Green lines represent national roads. Grey districts have less than 20 people per km².</p

Phases of the annual component of incidence for districts located along two geographic axes.

<p>Phases are computed in the 0.8–1.2 year periodic band. (A) Map of the two geographic areas chosen: the national road in blue, and the Mekong River in orange. (B) Phase of districts along the Mekong River (orange in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001957#pntd-0001957-g004" target="_blank">Figure 4A</a>), presented from the most southerly to the most northerly from bottom to top. (C) Phase of districts along the national road (blue in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001957#pntd-0001957-g004" target="_blank">Figure 4A</a>), presented from West to East from bottom to top. The arrows indicate districts: 1, #306; 2, Phnom Penh; 3, #805 (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001957#pntd-0001957-g004" target="_blank">Figure 4B</a>); 4, #104 (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001957#pntd-0001957-g004" target="_blank">Figure 4C</a>).</p

Scatterplot of mean annual temporal lags between epidemics against distances between districts.

<p>Temporal lags between epidemics and distances are computed relative to district #306. The lines show the linear regressions between the mean annual temporal lag of the annual epidemic in each district and the distance for 2002 (A), 2003 (B), 2004 (C), 2005 (D), 2006 (E) and 2007 (F). Colours represent the geographic localisation of each district, according to <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001957#pntd-0001957-g004" target="_blank">Figure 4A</a>. The number of districts included in the analysis changes every year, according to whether an epidemic occurred in the district (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001957#pntd-0001957-t001" target="_blank">Table 1</a>). Error bars represent the 95% C.I. associated with the mean. Normality and homoscedasticity of residuals were confirmed using the Shapiro-Wilks and the Bartlett tests respectively (alpha level of 0.05).</p

Apparent dengue haemorrhagic fever weekly incidence rates in the 135 most populous districts of Cambodia.

<p>Weekly incidence rates (cases per 100,000 people per week) were computed in each of the 135 districts where population density is higher than 20 people per km² in Cambodia. Districts are ranked by increasing distance to Phnom Penh from bottom to top.</p

Overall length, δ¹³C and δ¹⁵N values and C∶N mass ratio of fur seal whiskers from Crozet Islands.

<p>Values are means ± SD, with ranges in parentheses.</p>a<p>Fourteen samples were deleted because they corresponded to the suckling period of two females when they were pups, thus increasing the δ¹⁵N range (see text and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032916#pone-0032916-g004" target="_blank">Fig. 4</a>).</p

Periodicity in whisker δ¹³C and δ¹⁵N time series using wavelet analysis.

<p>Here we report the number of isotopic time series that exhibited significant cycles either all along the length of the whiskers (at least 80% of the cone of influence (COI), which is the region of the power spectrum that is not affected by the edge effects) or only in a smaller part of the series (between 50 and 80% of the COI). Growth rate was calculated assuming that cycles were annual (see text).</p

Mean δ¹³C and δ¹⁵N values (solid lines) and confidence intervals (dotted lines) of fur seal whiskers.

<p>Isotopic values were averaged by species (<i>A. gazella</i> (black) and <i>A. tropicalis</i> (grey)) and sex (males (left panels) and females (right panels)) over a time period of 4 consecutive years. Time zero that corresponds to the newly synthesized part of the whiskers appears on the right of plots.</p