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. 2009 Jul 31;75(18):5893–5909. doi: 10.1128/AEM.02757-08

TABLE 3.

Continuous independent variables for isolation of Listeria spp. from the environmenta

Variable group and variable Listeria absent
Listeria present
P value
Median 25th % 75th % Median 25th % 75th %
Spatial location
    Position
        Northing (103) 4,702 4,670 4,711 4,693 4,670 4,707 0.036
    Soil properties
        Slope.gradient 6.00 2.80 10.00 12.00 5.00 20.00 0.000
        Water.depth 31.00 0.00 38.00 31.00 0.00 54.00 0.007
        Water.storage.50 5.42 4.78 6.65 6.60 5.42 8.05 0.000
        Water.storage.100 7.76 5.78 10.10 8.10 6.78 11.35 0.003
        Water.storage.150 7.78 6.78 11.35 8.96 7.22 11.83 0.005
    Precipitation
        Precipitation.2 0.00 0.00 0.00 0.00 0.00 2.41 0.006
        Precipitation.0_3 0.38 0.00 1.84 0.95 0.19 2.03 0.048
        Precipitation.0_6 1.09 0.18 3.63 1.16 0.22 4.35 0.002
    Temp
        Temperature.a.0_2 9.82 6.30 17.41 14.63 7.22 21.30 0.003
        Temperature.a.0_3 8.33 5.97 17.78 15.14 8.06 20.28 0.000
        Temperature.a.0_4 9.44 6.11 18.78 14.33 7.11 20.56 0.000
        Temperature.a.0_5 9.63 5.56 19.44 13.70 6.57 20.56 0.000
        Temperature.a.0_6 8.41 6.19 19.52 13.10 6.51 21.43 0.001
        Temperature.a.0_7 7.43 6.67 19.44 13.06 6.46 22.01 0.008
        Temperature.a.0_8 8.15 6.70 19.14 13.02 6.54 22.28 0.011
        Temperature.a.0_9 8.28 6.50 19.22 13.22 7.28 22.33 0.006
        Temperature.L.0_6 3.49 1.03 12.62 6.59 2.78 14.84 0.000
        Temperature.L.0_7 2.57 2.15 12.43 6.60 2.29 15.00 0.003
        Temperature.L.0_8 3.09 2.01 12.65 6.85 1.67 15.19 0.010
    Freeze-thaw cycle
        Temperature.a.3 15.56 2.22 20.56 17.22 8.89 20.56 0.011
        Temperature.L.0 5.56 −0.56 12.78 9.44 2.78 15.00 0.000
        Temperature.L.3 8.89 −1.67 13.33 11.11 2.78 14.44 0.007
        Temperature.L.0_1 4.17 0.56 10.83 7.78 3.19 14.86 0.000
    PCA scores
        PC.temperature 1.90 −3.04 3.75 −0.81 −3.97 2.85 0.000
        PC.rain 0.56 −0.36 1.19 0.33 −0.36 1.15 0.004
Soil layer
    Position
        Easting (103) 495.5 353.1 550.4 363.1 352.7 511.6 0.012
    Soil property
        Water.depth 31.00 0.00 48.00 41.00 20.00 54.00 0.045
    Precipitation
        Precipitation.0 0.00 0.00 0.25 0.00 0.00 4.06 0.011
        Precipitation.2 0.00 0.00 0.00 0.00 0.00 8.13 0.004
    Freeze-thaw cycle
        Temperature.L.0_1 5.00 0.56 14.72 7.78 5.00 11.67 0.041
    PCA score
        PC.freeze.thaw −0.27 −0.84 0.26 −0.03 −0.31 0.15 0.045
Vegetation layer
    Position
        Northing (103) 4,694 4,680 4,711 4,693 4,669 4,707 0.047
    Precipitation
        Precipitation.2 0.00 0.00 0.00 0.00 0.00 2.41 0.024
    Temperature
        Temperature.a.0_2 9.82 6.30 17.41 16.67 9.82 21.48 0.000
        Temperature.a.0_3 9.10 5.97 18.19 17.36 8.33 21.25 0.000
        Temperature.a.0_4 9.44 6.11 18.44 18.11 7.69 21.64 0.000
        Temperature.a.0_5 9.63 5.56 18.89 18.06 7.34 21.67 0.000
        Temperature.a.0_6 8.41 6.19 19.52 17.78 7.22 22.08 0.000
        Temperature.a.0_7 7.43 6.46 19.44 17.78 7.29 22.17 0.000
        Temperature.a.0_8 8.15 6.54 19.14 17.84 7.07 22.38 0.001
        Temperature.a.0_9 8.28 6.50 19.22 17.44 7.51 22.92 0.001
        Temperature.L.0_6 3.49 1.03 12.06 10.79 2.96 15.97 0.000
        Temperature.L.0_7 2.57 2.15 12.43 10.83 2.41 16.25 0.000
        Temperature.L.0_8 3.09 1.67 12.65 10.93 2.49 16.48 0.000
    Freeze-thaw cycle
        Temperature.a.3 15.56 2.22 20.56 18.33 10.00 21.11 0.000
        Temperature.L.0 5.56 −0.56 11.67 10.00 3.33 15.00 0.000
        Temperature.L.3 8.89 −1.67 13.33 12.22 3.33 15.56 0.000
        Temperature.L.0_1 4.17 0.35 10.83 8.89 5.00 15.00 0.000
        Temperature.H.3 17.78 6.11 26.67 23.89 17.22 27.22 0.005
    PCA score
        PC.temperature 2.10 −2.81 3.97 −2.36 −4.37 2.82 0.000
Water layer
    Position
        Northing (103) 4,706 4,668 4,711 4,691 4,670 4,693 0.022
    Soil properties
        Slope.gradient 6 1.9 9 12 5.75 20 0.000
        Water.storage.50 5.2 4.78 6.6 6.6 5.795 8.05 0.000
        Water.storage.100 6.42 5.57 10.09 9.98 7.91 12.54 0.000
        Water.storage.150 7.22 6.5 11.35 9.98 7.943 15.57 0.001
    Precipitation
        Precipitation.0 0 0 0.254 0.127 0 0.762 0.011
        Precipitation.0_4 0.76 0.20 1.89 0.81 0.46 5.08 0.022
        Precipitation.0_5 0.85 0.17 1.64 1.21 0.85 4.23 0.008
        Precipitation.0_6 1.07 0.18 3.63 3.63 1.09 4.35 0.001
    PCA score
        PC.rain 0.69 −0.08 1.46 0.31 −0.35 0.99 0.045
a

PC.rain, PC.temperature, and PC.freeze.thaw denote component scores predicted from PCA.rain, PCA.temperature, and PCA.freeze.thaw, respectively; other variables are defined in Table 1. 25th % and 75th % indicate 25th percentile and 75th percentile, respectively.