In four experiments, we investigated how attention to local and global levels of hierarchical Navon figures affected the selection of diagnostic spatial scale information used in scene categorization. We explored this issue by asking observers to classify hybrid images  content of one image, and high spatial frequency (HSF) content from a second image) immediately following global and local Navon tasks. Hybrid images can be classified according to either their LSF, or HSF content; thus, making them ideal for investigating diagnostic spatial scale preference. Although observers were sensitive to both spatial scales (Experiment 1), they overwhelmingly preferred to classify hybrids based on LSF content (Experiment 2). In Experiment 3, we demonstrated that LSF based hybrid categorization was faster following global Navon tasks, suggesting that LSF processing associated with global Navon tasks primed the selection of LSFs in hybrid images. In Experiment 4, replicating Experiment 3 but suppressing the LSF information in Navon letters by contrast balancing the stimuli examined this hypothesis. Similar to Experiment 3, observers preferred to classify hybrids based on LSF content; however and in contrast, LSF based hybrid categorization was slower following global than local Navon tasks. The ability to perceive a scene under increased attentional load is often cited as evidence of pre-attentive scene perception. This evidence is typically indexed using dual-task paradigms in which a secondary scene categorization task is unaffected by a concurrent, cognitively demanding primary task. Researchers argue that scene perception is pre-attentive as it is immune to inattentional blindness . Navon  reportedFlevaris et al.'s  result sd prime (d′) was computed to measure observers' sensitivity to both LSFs, and HSFs. d′ values were above 1.5 in each condition, suggesting that both LSFs and HSFs are available in our hybrid images, at both short and long durations. Experiment 2 was a replication of Experiment 1, with the exception that we used an all-alternative forced choice paradigm in which observers were asked to choose the image category from a list of all possible target categories. Critically, this design allowed us to compute an objective measure of preferred diagnostic spatial scale. Results indicated that observers preferred to categorize hybrid images based on LSF content, at both short and long durations. Together with the results of Experiment 1, Experiment 2 demonstrated that our observers preferred to base categorization on LSF content, despite the fact that both LSFs, and HSFs were perceptually available.Experiment 1 was a probe design similar to Schyns and Oliva  in whichThe fact that our observers preferred to base hybrid categorization on LSF content suggests that attending globally facilitates scene categorization. A consequence of this prediction is that LSF-based hybrid categorization should be faster following global compared to local Navon tasks. In Experiment 3, we directly tested this hypothesis by asking observers to classify hybrid images immediately following global and local Navon tasks. Similar to Experiment 2, observers preferred to categorize hybrid images based on LSF content. Furthermore, and consistent with our hypothesis, LSF-based hybrid image categorization was faster following global Navon tasks. In Experiment 4, we directly tested whether this facilitation effect was the result of processing LSFs associated with a Navon figure's global structure. We thus replicated Experiment 3 with the exception that we contrast balanced the Navon stimuli in order to suppress their LSFs . Similar to Experiment 3, observers preferred to classify hybrid images based on LSF content, irrespective of the Navon task completed; however, and in contrast to Experiment 3, LSF-based hybrid image categorization was slower following global than local Navon tasks.The goal of Experiment 1 was to demonstrate the availability of both spatial frequencies in our hybrid images. We asked observers to complete a classification task in which they were required to indicate whether a cue word corresponded to a previously presented low-pass, high-pass, broadband, or hybrid image.Eight undergraduate students from Concordia University participated in this study in return for partial course credit. All observers self-reported normal or corrected-to-normal vision. The University Human Research Ethics Committee at Concordia University approved all experiments reported in this article and all observers provided written consent.Stimuli were presented on a 21-in. Viewsonic 225fb CRT monitor  controlled by a Dell Precision T3400 core2 quad processor running Microsoft Windows 7. Experiment Builder  was used to display the stimuli and record the responses. All participants were seated 60 cm away from the screen, and their head position was controlled using a table-mounted chinrest.RBG values = ; luminance of 52 cd/m2). These images were the same categories used by Schyns and Oliva , high-pass , or hybrid images. Hybrids were constructed by combining the low frequency components of one scene  with the high frequency components of another scene . Mathwork Matlab (ver. 2011b) was used to create the images. A total of 32,768 possible hybrid images were constructed by taking every possible combination of the four scene categories. All images were gray scaled, located in the center of the screen, and were 256 × 256 pixels.Stimuli were 128 natural images  taken from the Sun image database  and practice trials were not analyzed.d′ was calculated for each condition. Condition varied according to image type  and presentation duration (32 and 150 ms). Because hybrid images contained both low and HSF content, we further separated these trials into those on which the probe word matched the hybrid's low (Hybrid-LSF) and HSF content (Hybrid-HSF). As can be seen in Figure d′ values were high (d′ > 1.5) in all conditions, suggesting that observers were sensitive to all image types at both presentation durations. We entered d′ values into a 5 (image type) × 2 (presentation duration) repeated measures Analysis of Variance (ANOVA). There were significant main effects of image type, F = 8.09, p < 0.001, η2 = 0.54, and presentation duration, F = 34.47, p < 0.001, η2 = 0.83. The image type × presentation duration interaction was also significant, F = 4.65, p < 0.001, η2 = 0.39.The sensitivity measure, d′ values using a 3 (image type) × 2 (presentation duration) planned contrast. This contrast was not significant, suggesting that there was no statistical difference in spatial frequency processing as a function of presentation duration, F = 1.38, p > 0.279, η2 < 0.01. We then compared sensitivity between control images using a series of contrast comparisons. Specifically, we computed contrasts comparing d′ values between broadband images and high-pass (Ψ1) and low-pass (Ψ2) filtered images, respectively. d′ statistics and the results of these contrasts are displayed in Table M = 3.55; SD = 0.45) than both high-pass  and low-pass filtered images . Observers were equally sensitive to low-pass and high-pass filtered images (Ψ3). The effect size measures in Experiment 1 paralleled the significance results. The largest effect sizes were between broadband images and low-pass (η2 = 0.76) and high-pass (η2 = 0.47) filtered images. The effect size between low-pass and high-pass filtered images was relatively smaller in comparison (η2 = 0.26).Because Experiment 1 was designed to determine the availability of spatial frequencies in our hybrid images, we were particularly interested in comparisons between Hybrid-LSF and Hybrid-HSF trial types. However, before investigating the competing spatial scale information within hybrid images, we first compared performance between control images , to ensure that our observers were sensitive to all spatial scales. We first computed the planned comparison comparing Table 1d prime statistics for each image type at each presentation duration in Experiment 1.F = 0.137, p > 0.722, η2 < 0.01. We followed up this analysis by comparing sensitivity between hybrid trial types using a planned contrast, collapsing over presentation duration (Ψ4). Observers were more sensitive to hybrid-HSF image types  than hybrid-LSF image types . Furthermore, the associated effect size (η2 = 0.66) was similar to the effect sizes reported for the significant control contrasts, suggesting that observers were in fact more sensitive to HSFs than LSFs in the hybrid images.Following the control image type analysis, we computed the contrast comparing hybrid trial types (Hybrid—LSF and Hybrid—HSF) as a function of presentation duration. This was not statistically significant, d′ statistics, hybrid images were not separated further because target absent trials are the same between Hybrid—LSF and Hybrid—HSF trial types. The main effect of image type was significant, F = 3.29, p < 0.04, η2 = 0.3 However, the main effect of presentation duration and the image type × presentation duration interaction were not: F = 0.368, p > 0.563, η2 < 0.05 and F = 0.009, >0.899, η2 < 0.001.We calculated mean reaction time (RT) measures for each trial type as a function of presentation duration. These means are displayed in Figure M = 950.04; SD = 58.18) than both high-pass  (Ψ1) and low-pass filtered images  (Ψ2). There was no RT difference between low-pass and high-pass filtered images (Ψ3). Consistent with the sensitivity analysis, the largest effect size was between broadband images and low-pass filtered images (η2 = 0.52) followed by the effect size for the difference between broadband images and high-pass filtered images (η2 = 0.38). The effect size between low-pass and high-pass filtered images was negligible (η2 < 0.01).Similar to the sensitivity analysis, we were primarily interested in differences between Hybrid-HSF and Hybrid-LSF image types, but first report the results related to the control images. Specifically, we computed contrasts that paralleled the sensitivity comparisons. Reaction time statistics and mean difference contrasts are displayed in Table Table 2Reaction time statistics for each image type at each presentation duration in Experiment 1.F = 0.617, p > 0.458, η2 < 0.08. We then compared RTs between hybrid—LSF and hybrid—HSF image types, collapsing over presentation duration. This contrast was significant, F = 7.58, p < 0.028, η2 = 0.52. Observers were faster to respond to Hybrid—LSF image types  than Hybrid—HSF image types . This was a difference of approximately 54.81 ms . It is interesting to note that the associated effect size was similar to the effect size reported in the parallel sensitivity analysis (η2 = 0.66), suggesting that the effect of hybrid trial type is robust across dependent variables.Reaction times on target present trials were compared between Hybrid—LSF and Hybrid—HSF image types and are displayed in Figure d′ values were overall high, which is suggestive of weak masking effects. The most likely explanation for this result is that we constructed our masks so that their amplitude spectrum slope  would have a value of 0. Hansen and Loschky  × 4 (image type) repeated measures ANOVA. There were significant main effects of image type, F = 10.91, p < 0.001, η2 = 0.55, and presentation duration, F = 56.83, p < 0.001, η2 = 0.86. The image type × presentation duration interaction was not significant, F = 1.29, p > 0.299, η2 = 0.13. Observers were more sensitive at long  than short  durations, a difference of 0.73 . Although sensitivity was high in all conditions, the significant image type main effect appears to be driven by the fact that observers were less sensitive to hybrid images  than the other image types . This contrast (Ψ1) was statistically significant. Furthermore, the contrast comparing sensitivity between broadband images  and low-pass and high-pass filtered images  was not significant, corroborating our conclusion (Ψ2). Consistent with this conclusion, the effect size for Ψ1(η2 = 0.85) was higher than Ψ2(η2 = 0.31). d′ statistics and contrast analyses are displayed in Table nd Prins , which ae type, F, 27 = 10Table 3d prime statistics for each trial type at each presentation duration in Experiment 2.M = 0.20; SD = 0.07), t(9) = 1.87, p > 0.095 and was worse than chance at short durations , t(9) = 8.64, p < 0.001. As a result, we concentrated our analysis on trials on which hybrid categorization was based on LSF content. LSF-based hybrid categorization did not statistically significantly differ between short  and long  durations, t(9) = 1.78, p > 0.111, Cohen's d = 0.55, a difference of 0.04 .In order to examine diagnostic spatial scale preference, we separated hybrid trials into those on which categorization was based on low and HSF content, respectively. As can be seen in Figure F = 15.44, p < 0.001, η2 = 0.63. The main effect of presentation duration and the image type × presentation duration interaction were not significant, F = 0.033, p > 0.860, η2 = 0.01 and F = 1.77, p > 0.176, η2 = 0.16. Looking at Figure M = 1078.79; SD = 131.27) than any other image type . This contrast was statistically significant (Ψ1). Furthermore, observers were faster to respond to broadband images  than low-pass and high-pass filtered images  (Ψ2). There was no significant difference in RTs between low-pass  and high-pass filtered  images (Ψ3). Similar to the previous experiments, effect size comparisons paralleled the significance results. The effect size associated with the non-significant difference between low-pass and high-pass filtered images was the smallest (η2 = 0.31), whereas the largest effect sizes were between broadband images and low-pass and high pass filtered images (η2 = 0.75) and between hybrid images and the other image types (η2 = 0.72). Reaction time statistics and contrast analyses are displayed in Table Reaction times were computed as described in the sensitivity analysis and are displayed in Figure Table 4Reaction time statistics for each trial type at each presentation duration in Experiment 2.t(9) = 2.98, p < 0.016, Cohen's d = 0.94, a difference of 108.21 ms .As with the sensitivity analysis, our main goal was to index differences relating to hybrid images. However, because HSF-based categorization was no better (or worse) than chance, we restricted our hybrid RT analysis to trials on which hybrid categorization was based on LSF content Figure . LSF-basExperiment 2 showed that observers preferred to categorize hybrid images based on LSF content, at both short and long durations. However, an interesting finding is that observers were significantly slower at categorizing hybrid images compared to the other image types. The most likely explanation for this result is that although the probability of a correct answer was greatest for hybrid images (50 vs. 25%) their categorization nevertheless led to greater interference effects because they contained competing sources of diagnostic information. Together with the fact that HSF-based hybrid categorization did not exceed chance performance, and these results corroborate the finding that although observers process information at multiple spatial scales, they nevertheless use a single spatial scale as the basis for categorization . The results of Experiments 1 and 2 thus serve as a baseline for Experiment 3 in which we examined whether we can influence diagnostic spatial selection by directing attention to either global, or local levels of hierarchical Navon figures.Experiment 3 was a replication of Experiment 2 with the exception that we asked observers to complete global and local Navon tasks prior to classifying hybrid images. Similar to Experiments 1 and 2, we included control images in order to properly understand how attending locally and globally affected the processing of LSFs and HSFs. Because observers preferred to base hybrid categorization on LSF content, we predicted that LSF-based hybrid categorization would be facilitated following global Navon tasks; that is, LSF-based hybrid categorization would be faster following global Navon tasks than local Navon tasks. Also, because there was no interaction between presentation duration and categorization performance in Experiments 1 and 2, we simplified our design by presenting images at only 32 ms.Fourteen naïve undergraduate students from Concordia University participated in this study in return for partial course credit. All observers self-reported normal or corrected-to-normal vision.Stimuli and apparatus were the same as in Experiment 1 with the following exceptions.RBG values, ; luminance of 102 cd/m2) presented on a gray background . The display consisted of two Navon letters, one in the left and one in the right visual field, located 1° from a centrally located fixation cross. The global and local features of the Navon stimuli were either consistent  or conflicting . The letters used were C, E, H, and T, in all their global and local combinations. Each local letter subtended 0.7° × 0.7° of visual angle whereas the global letter subtended 5.7° × 4° of visual angle.Stimuli used in the Navon task were white Navon letters  or the global  configurations of the Navon letters matched. We instructed observers to press the “1” key on the keyboard number pad if they believed that the two Navon letters matched; we instructed observers to press the “2” key if they believed that they did not. Responses were speeded, and no trial-by-trial feedback was provided.Each trial began with a fixation cross located in the center of the screen presented for 250 ms, followed by a single natural image presented for a display-to-mask SOA of 32 ms. A mask (the same white noise mask used in the previous experiments) followed image offset and was presented for 64 ms. The image was a broadband, low-pass, high-pass, or a hybrid image. Immediately following offset of the mask, observers were presented with a display screen in which they were asked to indicate the category of the image presented  by pressing the corresponding number of the category. The options were presented in the center of the screen and stayed visible until a response was made. Trial-to-trial feedback was not provided.Observers completed two phases: a local phase and a global phase. In both phases, observers completed both the Navon task and the scene categorization task on each experimental trial  of either the global, or local Navon task. Similar to the practice trials, the main purpose of this priming block was to minimize any interference effects from the previous block. Trials in this phase were not analyzed.The primary objective of Experiment 3 was to understand how attending to local and global levels of Navon figures affected the subsequent selection of diagnostic spatial scale information in subsequently presented hybrid images. However, and similar to Experiments 1 and 2, it was necessary that we first understood how attention to hierarchical level affected the processing of low and HSFs within our scenes. Accordingly, we first analyzed sensitivity and RT data between the control images.Sensitivity. Mean d′ values were computed for each trial type. Trial type varied according to image type and Navon processing. These means are displayed in Figure F = 40.15, p < 0.001, η2 = 0.75, but neither the main effect of Navon nor the image type × Navon interaction were significant, F = 0.851, p > 0.373, η2 = 0.06 and F = 0.027, p > 0.994, η2 = 0.02. Similar to Experiment 2, observers were less sensitive to hybrid images  than the other image types  (Ψ1). Furthermore, observers were more sensitive to broadband images  than low-pass and high-pass filtered images  (Ψ2). There was no difference in sensitivity between low-pass and high-pass filtered images (Ψ3). As in Experiment 2, the effect sizes associated with Ψ1(η2 = 0.88) and Ψ2(η2 = 0.73) were similar, replicating the result that observers were most sensitive to broadband images and least sensitive to hybrid images. The effect size between low-pass and high-pass filtered images was relatively smaller (η2 = 0.07). d′ statistics and contrast analyses are displayed in Table Table 5d prime statistics for each trial type in local and global conditions in Experiment 3.M = 0.22; SD = 0.02), t(13) = 1.61, p > 0.133, Cohen's d = 0.14, and worse than chance in the global condition , t(13) = 3.83, p < 0.001, Cohen's d = 0.51. Thus, we restricted our analysis to trials on which hybrid categorization was based on LSF content. LSF-based hybrid categorization was higher following global  than local Navon tasks , t(13) = 4.29, p < 0.001, Cohen's d = 1.14, a difference of 0.07 .The proportion of low- and HSF-based hybrid categorization is displayed in Figure Reaction time. Mean RTs were computed as in the sensitivity analysis and are displayed in Figure F = 16.15, p < 0.001, η2 = 0.55, and Navon, F = 98.55, p < 0.001, η2 = 0.88. The Navon × image type interaction was not significant, F = 2.07, p > 0.121, η2 = 0.14. Reaction times were overall faster following global  than local Navon tasks , a difference of 304.81 ms .M = 835.87; SD = 67.77) and the other image types  was significant (Ψ1). Furthermore, RTs were faster for broadband images  than low and high-pass filtered images , corroborating the result from Experiment 2 (Ψ2). There was no significant difference between low-pass  and high-pass filtered images  (Ψ3). As in the previous experiments, the associated effect sizes mirrored the statistical significance results. The largest effect sizes were for Ψ1(η2 = 0.81) and Ψ2(η2 = 0.35), corroborating the finding that observers were overall fastest to respond to broadband images and slowest to respond to hybrid images. Furthermore, and similar to the sensitivity analysis, the effect size for the comparison between low-pass and high pass filtered images was small (η2 < 0.01), corroborating the finding that there were no meaningful differences between these image types. Reaction time statistics and contrast analyses are displayed in Table As in Experiment 2, the significant image type main effect appears to be due to the fact that RTs were slower in response to hybrid images. The contrast comparing RTs between hybrid image types  = 6.71, p < 0.001, Cohen's d = 1.79, a difference of 322.32 ms .As in Experiment 2, we compared RTs between trials on which hybrids were classified according their LSF content Figure . LSF-basF = 2.25, p > 0.098, η2 = 0.15, and F = 0.126, p > 0.728, η2 = 0.01. Furthermore, the Navon × image type interaction was also not significant, F = 1.19, p > 0.326, η2 = 0.09.Mean accuracy was computed for the trial types described above. Overall, accuracy was above 90% in all conditions. We entered mean accuracy into a 2 (Navon) × 4 (image type) repeated measures ANOVA. The main effects of image type and Navon were not statistically significant, F = 6.88, p < 0.001, η2 = 0.35, and Navon, F = 56.28, p < 0.001, η2 = 0.81. The Navon × image type interaction was not significant, F = 0.449, p > 0.719, η2 = 0.03. Overall, global Navon tasks  were completed faster than local Navon tasks , This difference was approximately 187.34 ms  and corroborated the robust finding of the global precedence effect  and the other image trials  confirmed this interpretation, F = 59.14, p < 0.001, η2 = 0.42. This difference was approximately 57.31 ms . The contrast comparing Navon RTs between broadband image trials  and the combined mean of high-pass filtered image trials and hybrid image trials  was not significant, corroborating this conclusion, F = 4.17, p > 0.071, η2 = 0.24. This difference was approximately 26.54 ms .Mean RTs were computed as in the accuracy analysis and are displayed in Figure t Navon, . The maiGlobal Navon tasks were completed faster than local Navon tasks in Experiment 3, corroborating the global precedence effect Navon, . A critiExperiment 4 was a replication of Experiment 3 with the exception that Navon stimuli were contrast balanced to suppress LSF information in order to encourage observers to use HSFs to accomplish both local and global Navon tasks. We confirmed that LSFs were reduced in the stimuli used in Experiment 4, by calculating the log-power spectra and rotationally averaged log amplitude spectra of both the contrast balanced and original Navon stimuli. These analyses are described in the Appendix. We predicted that forcing observers to use HSFs to complete Navon tasks, irrespective of attended level, would eliminate the global advantage associated with scene categorization observed in Experiment 3.Fifteen naïve undergraduate students from Concordia University participated in this study in return for partial course credit. All observers self-reported normal or corrected-to-normal vision.Stimuli, apparatus, and procedure were the same as in Experiment 3, expect that Navon stimuli were contrast balanced, such that darker lines surrounded the white lines of the local letters.Sensitivity.d′ values were computed as in Experiment 3 and are displayed in Figure d′ means into a 2 (Navon) × 4 (image type) repeated measures ANOVA. There was a significant main effect of image type, F = 15.41, p < 0.001, η2 = 0.52, but neither the main effect of Navon nor the image type × Navon interaction was significant, F = 1.14, p > 0.304, η2 = 0.08 and F = 0.196, p > 0.898, η2 = 0.14. Similar to previous experiments, observers were less sensitive to hybrid images  than the other image types  (Ψ1). Furthermore, there was no difference in sensitivity between broadband images  and low-pass and high-pass filtered images  (Ψ2). Furthermore, the effect size measures mirrored the statistical significance results. The effect size for Ψ1(η2 = 0.79) was larger than the effect size for Ψ2(η2 = 0.09), corroborating the finding that observers were less sensitive to hybrid images and equally sensitive to all other image types in Experiment 4. d′ statistics and contrast analyses are displayed in Table Table 7d prime statistics for each image type in local and global conditions in Experiment 4.t(14) = 12.43, p < 0.001; and t(14) = 6.14, p < 0.001. In contrast to experiment 3, LSF-based hybrid categorization was higher following local than global Navon tasks, t(13) = 3.93, p < 0.001, Cohen's d = 1.07, a difference of 0.06 . It is interesting to note that the effect size was consistent with the value reported in Experiment 3 (Cohen's d = 1.14), but is in the opposite direction, suggesting a complete reversal of the effect.Similar to the previous experiments, observers preferred to categorize hybrid images based on LSF content in both local and global conditions Figure . FurtherReaction time. Mean reaction time was computed as in Experiment 3 and is displayed in Figure F = 23.56, p < 0.001, η2 = 0.63 and F = 20.99, p < 0.001, η2 = 0.60. The Navon × image type interaction was not statistically significant, F = 0.942, p > 0.429, η2 = 0.06. In contrast to Experiment 3, RTs were overall faster following local  than global  Navon tasks, a difference of 245.84 ms . As in the previous experiments, observers were slower to respond to hybrid image types  than the other image types  (Ψ1). Observers were also faster to respond to broadband images  than low-pass and high-pass filtered images  (Ψ2). In contrast to previous experiments, observers were faster to respond to high-pass filtered images  than low-pass filtered images  (Ψ3).1(η2 = 0.80), corroborating previous experiments that observers were slowest to respond to hybrid images. Furthermore, the effect size for Ψ2(η2 = 0.36) was similar to the previous experiments, corroborating the finding that observers were fastest to respond to broadband images. However an interesting finding is that the effect size for Ψ3(η2 = 0.59) was relatively higher than those reported in previous experiments, suggesting that whereas there was no difference in RTs between low-pass and high-pass filtered images in Experiments 1–3, observers took longer to respond to high-pass filtered images than low-pass filtered images in Experiment 4. Reaction time statistics and contrast analyses are displayed in Table The largest effect size in Experiment 4 was for Ψ1η2 = 0.0, corrobTable 8Reaction time statistics for each image type in local and global conditions in Experiment 4.t(14) = 3.21, p < 0.006, Cohen's d = 0.91, a difference of 229.62 . Furthermore, the associated effect size was relatively smaller than in Experiment 3 (Cohen's d = 1.79), suggesting that although the effect in Experiment 4 reversed direction, its magnitude is smaller.As in previous experiments, we compared LSF-based hybrid categorization RTs between local and global conditions Figure . In contF = 0.736, p > 0.405, η2 = 0.05 and F = 0.628, p > 0.601, η2 = 0.04. The Navon × image type interaction was also not significant, F = 0.301, p > 0.825, η2 = 0.02.Mean accuracy was computed as in Experiment 3 and replicated the overall high accuracy observed in the previous experiment (>90%). We compared accuracy by computing a 2 (Navon) × 4 (image type) repeated measures ANOVA. The main effects of Navon and image type were not significant, F = 1.15, p > 0.226, η2 = 0.1 and F = 0.924, p > 0.353, η2 = 0.06. Further, the Navon × image type interaction was not significant, F = 1.52, p > 0.223, η2 = 0.10.Mean RTs were computed as in the accuracy analysis and are displayed in Figure Experiment 4 was a replication of Experiment 3 with the exception that Navon stimuli were contrast balanced. There was no RT difference between Navon tasks, corroborating the previous finding that contrast balancing Navon stimuli eliminates the global precedence effect  or fine (conveyed by a hybrid's HSFs) content. We showed that although observers were sensitive to both types of information (Experiment 1) they overwhelming preferred to base hybrid image categorization on LSF content (Experiments 2–4). When hybrid image categorization was not based on LSF content, HSF-based hybrid image categorization was no better (and often worse) than chance. In Experiment 3, we directly examined how attending to global and local levels of hierarchical Navon figures affected LSF-based hybrid categorization, and found that LSF- based hybrid image categorization was faster following global Navon tasks. This corroborates Flevaris et al.  suggestiAn interesting finding from the present set of studies is that our observers preferred to categorize hybrid images based LSF information in Experiments 2–4, despite the fact that they were sensitive to both spatial frequencies in Experiment 1. One possible explanation is that our masking procedure weakened the signal from HSFs more than the signal from LSFs. Such an explanation suggests that our observers preferred to base hybrid image categorization on the spatial frequency with the strongest signal. Consistent with this hypothesis, Losada and Mullen  showed td′ values in Experiments 2–4 were calculated by transforming proportion correct as described by Kingdom and Prins , the main purpose of including these results was to demonstrate the availability and sensitivity to different spatial scales in isolation. According to DeCarlo , the larA comparison between the present work and the apparent automaticity of scene perception under dual task conditions is particularly relevant. Cohen et al.  suggesteOne issue the present study was unable to resolve is why scene categorization was faster following local Navon tasks in Experiment 4. This is particularly true for hybrid images, as it is unclear how attending locally would facilitate categorization based on LSF content. If LSFs associated with global Navon tasks facilitated LSF-based hybrid categorization in Experiment 3, then removing that information should have eliminated the global benefit, but should not have resulted in a benefit following local Navon tasks. The fact that it did suggests that observers were using different types of information within a hybrid image's LSF content as the basis for categorization in Experiments 3 and 4, respectively. This conclusion is consistent with Oliva and Schyns'  suggestiAnother interesting question arising from the present results is whether a hybrid image's HSFs were encoded in Experiments 2–4. Although observers preferred to categorize hybrids based on LSFs in Experiments 2–4, the results of Experiment 1 suggest that both spatial scales were perceptually available. This suggestion is consistent with Oliva and Schyns  found thThe question relating to the role of attention in scene categorization is currently a major source of debate in psychology. Traditionally, this question is addressed by examining the automaticity of scene perception, and whether or not conscious scene perception can occur in the absence of attention. The present article addressed this question from a different angle. It examined how attention facilitates the selection of diagnostic information used in scene categorization. Along the same lines, Larson et al.  showed tThe primary purpose of the present experiments was to address how attention to local and global levels of Navon figures affects the selection of diagnostic spatial scale information used in scene categorization. This investigation was largely based on the connection between the Navon task spatial scale and the diagnostic spatial scale used for scene categorization. As such, it is reasonable to assume that the categorization of different scene types could also differentially affect the completion of the Navon task. The results of Experiments 3 and 4 allude to this possibility. Whereas Navon processing was slowest when completed in conjunction with low-pass filtered images in Experiment 3, there was no difference in Navon task RTs as a function of scene type in Experiment 4. Although we can only speculate as to the reason for this difference, it appears to be related to the amount of LSFs in the Navon stimuli. Navon stimuli in Experiment 4 were contrast balanced, such that their LSF content was suppressed compared to the Navon stimuli used in Experiment 3. Combined with the fact that LSFs were the preferred diagnostic spatial scale in all experiments, this suggests that the observed Navon slowing in Experiment 3 following low-pass scene categorization was due, in part, to an increased use of LSFs in Experiment 3 compared to Experiment 4.In conclusion, the present set of experiments demonstrates that attending locally and globally affects the selection of diagnostic spatial scale information used for rapid scene categorization. The present results also converge with previous research in suggesting that LSF information is important in rapid scene categorization (Schyns and Oliva, The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


We report a rare case of combined hepatocellular carcinoma and fibrolamellar carcinoma arising in a noncirrhotic liver, in a 14-year-old boy who underwent right hepatectomy. We discuss the clinicopathological and immunohistochemical features and the clinical outcome in this unusual tumor. Hepatocellular carcinoma of adult type (HCC) and fibrolamellar carcinoma (FLC) are two distinct entities unique in their clinical, histological, and biological aspects . There hA 14-year-old boy presented with history of right sided abdominal pain for 2 months. On examination there was an irregular, firm, swelling palpable in the liver extending up to 7 cm below the right costal margin. Computed tomography (CT) of the abdomen showed a large 9.6 × 10.2 × 10.5 cm well-defined, heterogeneously enhancing mass in the right lobe of liver in segments 6 and 5 and another lobulated 9.8 × 6.7 cm mass with homogenous enhancement in segments 8 and 7 suggestive of malignant liver masses with intrahepatic metastases. Investigations showed no elevation of serum alphafetoprotein (AFP), beta human chorionic gonadotrophin, or carcinoembryonic antigen. Hepatitis B surface antigen, hepatitis C antibody, and human immunodeficiency virus antibody were negative. Liver function tests at the time of admission showed total serum bilirubin level of 0.4 mg/dL, direct 0.2 mg/dL, total protein 8.2 g/dL, albumin 3.8 g/dL, aspartate aminotransferase (AST) 289 U/L, alanine aminotransferase (ALT) 99 U/L and alkaline phosphatase (ALP) 143 U/L, and INR of 0.96. There was no history of parasitic infestation or known exposure to environmental toxins. A wedge biopsy from the liver mass revealed a moderately differentiated hepatocellular carcinoma following which the patient underwent right hepatectomy.Histopathological findings: grossly, the right lobe of the liver weighed 1000 g. The external surface was focally nodular and on sectioning revealed a circumscribed tumor measuring 10 × 8 × 12 cm with solid brown cut surface almost reaching the capsular surface. Adjoining this tumor was another nodular lesion measuring 8 × 9 × 9 cm with lobulated grey white cut surface . Also seMicroscopic examination of the larger brown tumor and the small nodules showed large polygonal cells arranged in pseudoglandular and trabecular pattern  separateImmunohistochemistry revealed tumor cells of HCC with diffuse positivity for Hep Par1  and focaThe patient was given chemotherapy which included cisplatin, carboplatin, and adriamycin, which he tolerated well, completed the course, and was on followup. Four months after surgery, S. bilirubin, total was 0.5 mg/dL, S. protein 7.5 g/dL, S. albumin 4.4 g/dL, AST 22 U/L, ALT 11 U/L and ALP 290 U/L.Two years after surgery, new lesions were detected in the liver, on ultrasonography. Subsequent CT scan showed a heterogeneous mass in the porta, between the hepatic artery and inferior vena cava, fairly well-defined measuring approximately 9.7 × 4.6 × 4.6 cm with a lobulated contour and calcification on its inferior aspect, likely to represent a nodal mass. Considering disease recurrence and inoperability, the patient was put on Sorafenib treatment from March 2012. Presently, till the writing of this paper, he has survived and is on palliative care.FLC is an uncommon tumor which occurs in adolescents and young adults and is rare in the Asian population . It is qThere are occasional reports of FLC coexistent with or admixed with HCC , 4, 5. TWe report the first case of synchronous FLC and HCC, presenting as 2 adjacent, but separate, well-defined gross and microscopic lesions in a 14-year-old boy from India. Typical HCC with fibrous stroma can resemble FLC but these cases should not be mistaken for mixed HCC and FLC. Immunohistochemistry is useful in resolving these cases. The tumor cells of FLC show strong positivity for CK7, which is focal in HCC, as seen in our case. A recent study has shown strong positivity for CD68 in FLC with 96% sensitivity and 80% specificity, with 98% negative predictive value . These aMutations in the beta catenin gene have been reported in all categories of hepatocellular neoplasm but not in FLC and there was no nuclear staining for beta catenin by immunohistochemistry . We did Most of the earlier case reports –4, 8, 9 The presence of CK7 and/or CK19 has been suggested to represent evidence of hepatic progenitor cell origin . The celAFP levels are typically normal in FLC . So raisThe occurrence of two morphologically distinct types of liver tumor in the same patient raises the possibility that they could have arisen from prehepatocytic cancer stem cell. This may be worth investigating further in the future.


As the bio-distribution and radiation dose of PET tracers in human research are important for estimating the relative risks and benefits, a study was conducted to obtain this information on florbetapir.Florbetapir is one of several Nine cognitively normal subjects  received an intravenous bolus injection of 395 ± 27.9 MBq of florbetapir, and whole-body emission scans were performed over approximately 6 h. Computed tomography scans were acquired for attenuation correction. Volumes of interest (VOIs) for source organs including the brain, liver, lung, heart wall, and vertebrae were defined on the PET images. The VOIs of the gallbladder, urinary bladder, and large and small intestines were also defined. Using reference man organ volumes (ICRP 30), total activity was calculated per organ for each time point. The resultant time-activity curves (TACs) were fitted with constrained exponentials. Kinetic data were entered into OLINDA/EXM software to calculate dose estimates; the dynamic urinary bladder and ICRP 30 GI tract models were employed. The effective dose (ED) for each subject was estimated from the acquired data using the adult model.The mean ED determined for nine healthy volunteers was 18.60 ± 4.26 μSv/MBq or 6.88 mSv for a 370-MBq dose. The organs that received the highest radiation absorbed doses were the gallbladder, upper large intestine, small intestine, liver, and urinary bladder at 143.0 ± 80.20, 74.50 ± 34.20, 65.50 ± 29.60, 64.40 ± 22.10, and 27.10 ± 11.70 μSv/MBq, respectively.The ED for florbetapir has been calculated for nine healthy volunteers. At a dose of 370 MBq florbetapir, the total average ED is approximately 6.88 mSv. When applied at tracer concentrations, florbetapir labels Aβ plaques in sections from patients with pathologically confirmed Alzheimer's disease (AD) , florbetaben [18F-BAY94-9172], 18F-FDG, and 11C-PIB are summarized in Table The present findings are very similar to the results of a preliminary study  that cale et al.  and O'Ketion 106 , presentd Segall , Deloar d Segall , and Meid Segall . The ret18F-labeled amyloid imaging agent florbetapir has been calculated in nine healthy volunteers and results in an effective radiation dose of 18.60 ± 4.26 μSv/MBq or 6.88 mSv for 370 MBq.The radiation dosimetry for the Abhinay D. Joshi, Michael J. Pontecorvo, Alan P. Carpenter, Mark A. Mintun, and Daniel M. Skovronsky are employees of Avid Radiopharmaceuticals, Inc. Lee P. Adler has no relevant financial disclosures other than the clinical study contract with Avid for this work. Michael G. Stabin has no relevant financial disclosures other than a consultant with Avid for this work.ADJ participated in the study design, image analysis, and data interpretation and drafted the manuscript. MJP was responsible for the study concept and design, data interpretation and review of the manuscript. LA carried out the data acquisition and participated in the scientific review. MGS performed the dosimetry analysis. APC was responsible for the administrative and material support, data interpretation and critical review of the manuscript. DMS supervised the study, provided administrative or material support and participated in the critical review. MAM participated in the data interpretation and critical review of the manuscript. All authors read and approved the final manuscript.


Diabetes mellitus (DM) is a frequently encountered disease with important morbidity and mortality. The aim of this study is to document the importance of 1,5-anhydroglucitol  for the diagnosis of prediabetes and DM, as well as to compare the 1,5-AG with other glycemic markers in order to understand which one is the better diagnostic tool. Between April 2012 and December 2012, 128 participants enrolled in the study. Participants were split into five groups that are IFG, IGT, IFG+IGT, diabetic and control groups by their OGTT results. The diagnostic value of markers was compared by ROC (receiver operating characteristic) method. The mean serum 1,5-AG levels in the diabetic group (33.38 nmol/ml) were lower than, IFG (59.83 nmol/ml), IGT (54.44 nmol/ml), IFG+IGT (51.98 nmol/ml) and control groups (73.24 nmol/ml). When analyzed in the total study population serum 1,5-AG levels did not differ by gender significantly. When analyzed in the total study population, 1,5-AG correlates inversely with age significantly (p = 0.036). In subgroup analysis, in the control group, serum 1,5-AG level was also inversely correlated with age (p = 0.087). The best marker for the diagnosis of prediabetes and DM was fasting plasma glucose (FPG). 1,5-AG was not found to be effective for the diagnosis of DM. This study, contributes to our knowledge of the efficiency and cut-off values of 1,5-AG for the diagnosis of prediabetes and DM. In future, there is a need for larger studies with more standardized and commonly used measurement methods for 1,5-AG, in order to evaluate the efficiency of 1,5-AG for the diagnosis of prediabetes and DM. Diabetes mellitus (DM) is a syndrome which insulin function or secretion or both impaired , liver disease, malabsorption syndromes, usage of steroids, polygala, tenuifolia, senega, alpha-glucosidase inhibitors, anemia, DM diagnosis before, usage of antidiabetic drugs and history of gastrectomy. This study is a cross-sectional analysis of an observational study. Ufuk University ethical board approval has been received. All participants gave informed consent. All of the ethical considerations have been strictly followed in accordance with the Helsinki declaration. All of the measurements were performed within a few days after the indication for OGTT. Participants who agreed to attend study gave blood samples between hours 08.00–09.00 after minimum 10 h of fasting. 75 g OGTT was performed and the patients were divided into 5 groups according to OGTT World Health Organization (WHO) criteria which were IFG, IGT, IFG+IGT, DM and control groups. From fasting glucose samples Glycated hemoglobin, fructosamine, total cholesterol, LDL, HDL, trigliseride, BUN, creatinine, CBC, AST, ALT, albumine, total protein, sedimentation, fasting insulin, fasting c-peptide levels were detected. Blood samples from each patient taken for 1,5-AG levels had stored at −83 cantigrat degree for the analysis day with ELISA method. Each patients arterial blood pressure were measured and demographic data were recorded. Waist circumference measurement executed from half of distance between inferior costa and spina iliaca anterior superior. Body mass index and HOMA-IR (fasting plasma glucose (FPG) (mg/dl) × fasting plasma insulin (μ/ml)/405) were calculated for each participant. The pancreas B cell function were calculated with the formula of 360 × fasting plasma insulin (μ/ml)/FPG (mg/dl) −63 %. The analysis of blood samples were performed at Ufuk University Dr. Rıdvan Ege Hospital Biochemistry Department Laboratuary. Glycated hemoglobin was measured with “Agilent 1100 Series” with “High Pressure Likid Chromatography” method whereas fructosamine was measured with “Cobas Integra 400 Plus” with spectrophotometric method. BUN, creatinine, HDL, LDL, trigliseride, total cholesterol, albumine, total proteine blood samples were detected with “Cobas Integra 800” with spectrophotometric method. The analysis of plasma samples for glucose levels were executed with hexocinase method by “Cobas Integra 800”. 1,5-AG is measured with “Cusabio Human 1,5-anhydroglucitol ELISA Kit” by “DSX Automated Elisa System” machine.T Test methods and results were presented as mean ± standard deviation. The dual comparison of the data which showed normal distrubution, TUKEY method was used. Data which did not show normal pattern were analyzed with Cruscal-Wallis or Mann–Whitney U methode and results were presented as mean and 95 % confidence interval. Dual comparison of data which do not showed normal pattern executed with “Bonferroni corrected Mann–Whitney U” methode. Spearman corelation analyzes performed to investigate serum 1,5-AG and other variables. In the comparison of the power of the diagnostic tools, ROC (Receiver Operating Characteristics) curve is used. Threshold level of the diagnostic tools determined as the point in the ROC curve which is closest to sensitivity value 100 % and false positive value 0 %. HOMA-IR calculated as “FPG (mg/dl) × fasting insulin (μU/ml)/405” and HOMA-B calculated as “360 x fasting insulin (μU/ml)/(FPG (mg/dl)-63)”. Statistical significance point set to p < 0.05.Statistical analyzis executed with “IBM SPSS Statistics 20” programme. Firstly the distribution type of data analyzed. Data which showed normal distribution patern analyzed with ANOVA or Between April 2012 and December 2012, 128 participants who applied to endocrinology or internal medicine clinics of Ufuk University Dr. Rıdvan Ege Hospital, enrolled in this study. All participants had indication for 75 g OGTT and gave informed consent. Mean age of participants were 53.0 ± 12.2. 48 participant (37.5 %) were male, 80 participant (62.5 %) were female. IFG, IGT, IFG+IGT groups together evaluated as “prediabetic group”. Control group has the most participant with 38 people. Mean age of participants was highest in diabetic group. Distribution of participant according to gender was not significantly different between groups. Data of participants were described in Table Early diagnosis in prediabetes and DM can reduce the mortality and morbidity of the disease. The reference test for the diagnosis of prediabetes and DM is OGTT according to the WHO recommendations. For screeening of glucose intolerance, 2 h post-OGTT glucose level is used. Fasting condition of the patient is needed for the OGTT and FPG tests. For this reason application of these methods can be challenging for doctor and patient. Also if the patient is not in fasting condition, it is required to come to hospital for a second time, thus making the situation tiring and expensive. Therefore, alternative diagnostic tools which do not reguire fasting condition, may be preferred. Glycated hemoglobin, fructosamine, 1,5-AG are diagnostic tools which do not reguire fasting (Shah et al. In many reports, it is found that there is a statistically significant inverse relationship between plasma 1,5-AG level and post OGTT second hour plasma glucose (Yamanouchi et al. To conclude, although there are several studies in the literature about the relationship between 1,5-AG and DM diagnosis; our study is the first study about this issue that is demonstrated in our country. Also, this is first study about in our country that is performed clinically and prospectively. In respect to this, our study may represent the threshold values of 1,5-AG in our country that can be referred by other studies that will be conducted future. The limitations of our study was the relatively small patient cohort compared to wide distribution range of 1,5-AG.


Obesity is a risk factor for inadequate receipt of recommended preventive care services. The objective of this study was to assess the relationship between increasing body mass index and receipt of influenza and pneumococcal vaccinations. A systematic review of the PubMed, Embase, and Web of Science databases was conducted from January 1966 to May 2015 for cohort and cross-sectional studies that assessed the relationship between body mass index and the receipt of vaccinations for influenza and pneumococcus. Separate meta-analyses by obesity classification were performed using a random effects model.2) patients. When the outcome was reported by obesity class, combined odds ratios of influenza vaccination were 1.13 (95 % CI 1.02–1.24) for Class I (30–34.9 kg/m2) obesity, 1.21 (95 % CI 1.05–1.37) for Class II obesity (35–39.9 kg/m2), and 1.19 (95 % CI 0.95–1.42) for Class III obesity (≥40 kg/m2) patients. Compared to normal weight patients, combined odds ratio of pneumococcal vaccination were 1.20 (95 % CI 1.13–1.27) for obese patients. When the outcome was reported by obesity class, combined odds ratios were 1.08 (95 % CI 1.04–1.13) for Class I obesity patients, 1.13 (95 % CI 1.10–1.16) for Class II obesity patients, and 1.26 (95 % CI 1.15–1.38) for Class III obesity patients for pneumococcal vaccination.Six cross-sectional and three cohort studies were included. Average vaccine uptake was 50.4 % for influenza vaccination and 34.6 % for pneumococcal vaccination. Compared to normal weight patients, combined odds ratio  for influenza vaccination was 1.11 (95 % CI 0.97–1.25) for obese  contains supplementary material, which is available to authorized users. The World Health Organization (WHO) Strategic Advisory Group of Experts (SAGE) on Immunization and the US Centers for Disease and Control and Prevention (CDC) recommends vaccination of eligible adults for influenza virus and streptococcus pneumoniae bacteria. Influenza vaccination is recommended yearly for adults with few contraindications –3. For iDespite the many benefits of vaccination and their strong endorsement from major national professional organizations, vaccine uptake is lower than desired. For example, in the US, the median vaccination rate is 60.7 % for influenza and 70.0 % for pneumococcal vaccination among adults in 2011, compared to US Healthy People 2020 goals for influenza (70 %) and pneumococcal 90 %) vaccination of eligible adults , 9. Many0 % vacciAs with many other chronic diseases, obesity is associated with increased mortality from both influenza and pneumococcal infections –15. ObesWe adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Guidelines for Meta-Analyses and Systematic Reviews of Observational Studies  using a template defining inclusion and exclusion criteria. The inclusion criteria for the first screening were: a population including comparison of non-obese and obese adults, the receipt of vaccination for influenza or pneumococcus as a recorded outcome and identification as a cohort or cross-sectional study. The inclusion criteria for the full-text, second screening used the same inclusion criteria as the first. Discrepancies in any of the reviews were adjudicated by consensus.The same two independent reviewers examined the full text of the study, assessing for the protocol inclusion and exclusion criteria. Human papilloma virus was included in the search terms, but no studies met inclusion criteria; we are therefore unable to include this vaccine in the analysis. The study team reviewed all studies meeting criteria for relevant information and results were extracted using a data collection template. Abstracted data included detailed information about the study objectives, design, participants, covariates, outcomes, statistical methods, and a quality assessment.We assessed methodological quality using the US National Institute of Health National Heart, Lung, and Blood Institute Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies . This to2, obesity BMI ≥ 30 kg/m2, class I obesity BMI 30–34.9 kg/m2, Class II obesity BMI 35–39.9 kg/m2, Class III obesity BMI >40 kg/m2) or between normal weight and obesity ≥30 kg/m2 if that was the only comparison reported.We created tables to summarize the study populations, inclusion and exclusion criteria, vaccination type, and outcomes. The principal summary measure was odds ratios. We performed a meta-analysis in studies that reported body mass index in the categories defined by the World Health Organization and the National Institutes of Health  18.5–24.9 kg/m2 statistic to test for heterogeneity, and the Begg’s test and visual inspection of the funnel plot to assess for the possibility of publication. We used STATA 13.0  for all analyses. The study was deemed exempt by The University of Michigan Medical Institutional Review Board (HUM00097519).We used random-effects (DerSimonian and Laird) models to calculate odds ratios and 95 % confidence intervals for pneumococcal and influenza vaccination . For stuOf 342 titles identified in the full search of three databases and hand searching, nine articles met inclusion criteria Fig. .Fig. 1St2), healthy weight (BMI 18.5–24.9 kg/m2), overweight (BMI 25–29.9 kg/m2), obese (BMI ≥30 kg/m2) [2), healthy weight (BMI 18.5–24.9 kg/m2), overweight (BMI 25–29.9 kg/m2), obesity Class I (BMI 30–34.9), obesity Class II (BMI 35–39.9 kg/m2), obesity Class III (BMI ≥40 kg/m2) [2 or waist circumference >102 cm in men and >88 cm in women [Among included studies, obesity was most frequently measured by BMI, which was most often defined as underweight (BMI < 18.5 kg/m0 kg/m2) , 24–27 o0 kg/m2) –32. A siin women . The refin women .Influenza vaccination was defined most often as receiving vaccination within the past 12 months or past year. Single studies defined influenza vaccination as receipt within the past 2 years or 4 out of the past 5 years (and at least 8 months apart) , 32. PneStudy populations involved one of two groups: 1) adults aged 18 or older (commonly for influenza vaccination studies) and 2 adults aged 65 years or older . All studies examined both men and women in population-based (between 3000 and 1 million participants) national or international settings. Six studies were cross-sectional, three were cohort studies, and all studies included data for was from population-based surveys, including the Behavioral Risk Factor Surveillance System, Medical Expenditure Panel Survey, Health and Retirement Study, Medicare Current Beneficiary Survey, and the Survey of Health, Aging, and Retirement in Europe. BMI and vaccination information was generally self-reported except for studies using Veteran’s Health Administration (VA) populations, where these data represent measure biometric indices and vaccination variables abstracted from the electronic medical record , 32.Using the United States National Institute of Health (NIH) National Heart, Lung and Blood Institute (NHLBI) Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies, we rated 4 studies at a “good” quality rating and 5 studies at a “fair” quality rating. The studies all used well-designed surveys except studies using VA or Medicare administrative datasets. The number and type of covariates differed widely among the studies; use of a more complete list of model covariates was a key differentiating characteristic of studies rated “good”.Most studies included a wide variety of covariates in their regression models. Common covariates included age, sex, race, ethnicity, education level, tobacco and drug use. Measures of prior healthcare utilization were included in five studies , 30, 31.The full study characteristics are presented in Table Among the three studies with NIH NHLBI Quality Assessment Tool “good” ratings, where model covariates included measures of outpatient utilization, one study each that found a positive or negative association, and two studies found a statistically insignificant association between receipt of vaccination and increasing body mass index , 27, 31.Among studies that measured pneumococcal vaccination, three of four studies noted a positive association between receipt of vaccination and increasing body mass index , 30, 32.P = 0.04 and P = 0.04)  to 96.4 % (high heterogeneity between studies) depending on the vaccination type and obesity comparison. The wide confidence intervals observed in our meta-analysis are attributable to effect size variations in the included studies. Varied study designs , and differences in sample selection, measurement of vaccine receipt, and adjustment for possible confounding explains much of heterogeneity in effect direction as well as the broad confidence intervals noted in this meta-analysis.In addition to heterogeneity in study populations, the included studies’ models vary significantly in the selection of covariates used to control for confounding. Beyond the importance of age, sex, and race for reasons noted above, controlling for health care utilization is important. Three of the nine studies controlled for medical care utilization . Increasing body mass index is associated with increased utilization of medical services , 46. IncIn summary, the receipt of vaccination for pneumococcus and influenza is an important health care quality indicator. While obese patients are associated with higher levels of vaccination, the overall levels of vaccination are low in all populations. Our findings highlight the importance of continued efforts to improve patient access to and utilization of recommended adult vaccinations. Persons with comorbidities like obesity are particularly vulnerable to morbidity from vaccine-preventable illnesses, and future research is needed to better identify patient-level and systems-level predictors of vaccine uptake in this group.The study was deemed exempt from human subject research approval by The University of Michigan Medical Institutional Review Board (HUM00097519). The study did not involve human or animal tissue.Not applicablehttps://zenodo.org/record/47856.The data compiled and used for meta-analysis is available at


Nigella sativa L. (family Ranunculaceae) is an annual herb of immense medicinal properties because of its major active components , thymohydroquinone (THQ), and thymol (THY)). Plant tissue culture techniques like elicitation, Agrobacterium mediated transformation, hairy root culture, and so on, are applied for substantial metabolite production. This study enumerates the antibacterial and antioxidant potentials of N. sativa epicotyl suspension cultures under biotic and abiotic elicitation along with concentration optimization of the elicitors for enhanced TQ and THY production. Cultures under different concentrations of pectin and manganese chloride (MnCl2) elicitation  showed that the control, MnCl2 10 mg/L, and pectin 15 mg/L suspension extracts greatly inhibited the growth of E. coli, S. typhimurium, and S. aureus . Elicitation decreased SOD enzyme activity whereas CAT enzyme activity increased remarkably under MnCl2 elicitation. MnCl2 10 mg/L and pectin 15 mg/L elicitation enhanced the DPPH radical inhibition ability, but ferric scavenging activity was comparable to the control. TQ and THY were quantified by LC-MS/MS in the cultures with high bioactive properties revealing maximum content under MnCl2 10 mg/L elicitation. Therefore, MnCl2 elicitation can be undertaken on large scale for sustainable metabolite production. Nigella sativa L. (family Ranunculaceae) has emerged as a miraculous herb with a wide spectrum of pharmacological activities. N. sativa seeds are most extensively studied, both phytochemically and pharmacologically. Both seeds and oils are known to possess various health properties like antitumour activity [ N. sativa have shown effectiveness against multiantibiotic resistance bacterial isolates [ in vitro free radical scavengers which are correlated well with its total content of polyunsaturated fatty acids, unsaponifiables, phospholipids, and phytoconstituents as well as the initial peroxide values of crude oil [ N. sativa are due to the rich presence of chemically varied bioactive compounds.The use of spices as food additives, flavouring agents, and also digestive stimulant tonic has been practiced widely since ancient times. These attributes, largely empirical, nevertheless efficacious, have earned them pharmacological applications in the indigenous systems of medicine. Among various medicinal spicesactivity , antioxiactivity , anti-inactivity , antibacactivity , and a sactivity  because isolates . Black sisolates . Furtherrude oil . These s Digitalis lanata [ Calendula officinalis [Techniques of plant tissue culture have proved to be the best alternatives in supplementing traditional agriculture for the industrial production of medicinal plant derived metabolites . Among ts lanata . Furthericinalis . The acc N. sativa epicotyl suspension cultures under the effect of different concentrations of biotic (pectin) and abiotic elicitor (MnCl2). Further, the effect of elicitation on cell growth, thymoquinone (TQ) and thymol (THY) production from the cell suspension cultures of N. sativa was examined.The present study was conducted to demonstrate the antioxidant and antibacterial efficacy against different Gram positive and Gram negative bacteria of the2, methanol, toluene, chloroform, ethanol, diethyl ether, benzene, streptomycin, ciprofloxacin, doxycycline, ampicillin, ofloxacin, dimethyl sulfoxide, DPPH , sodium acetate, glacial acetic acid, hydrochloric acid, TPTZ , ferrous sulphate, ferric chloride, nitro blue tetrazolium, ethylenediaminetetraacetic acid (EDTA), riboflavin, hydrogen peroxide, methionine, dipotassium phosphate, monopotassium phosphate, and thymol (THY) were purchased from HIMEDIA; thymoquinone (TQ) was purchased from Sigma Aldrich.Murashige and Skoog (MS) medium, kinetin, naphthalene acetic acid, pectin, MnCl N. sativa were procured from a local grocery store in Lucknow, India, and authenticated at the National Botanical Research Institute, Lucknow. Seeds were surface-sterilized by washing thoroughly under tap water containing few drops of Tween-20 and then rinsed with 70% ethanol for 30 seconds followed by washing with sterile water twice. They were then immersed in 0.2% mercuric chloride solution for 5 min after which they were rinsed with sterile water twice, were allowed to grow in glass petri plates having threefold of damp blotting paper in distilled water at 25 ± 2°C under aseptic condition in dark for three days till sprouting, and, thereafter, were exposed to light , where complete germination with leaf, epicotyl, hypocotyl, and root took eleven days [Seeds ofven days .Explants leaves (40–50) and segments (0.5 cm) of epicotyl, hypocotyl, and root from the 11th day seedling were surface-sterilized and cultured in triplicate on solidified Murashige and Skoog (MS) medium supplemented with kinetin (Kn) 2 mg/L + naphthalene acetic acid (NAA) 1 mg/L . Culture2, that is, 5 mg/L, 10 mg/L, and 15 mg/L  [A cell biomass of 50–75 mg from the stock culture was transferred into Erlenmeyer flasks of separate groups, containing 100 mL medium with Kn 2 mg/L + NAA 1 mg/L in triplicate under three different concentrations of pectin and MnClµm), and concentrated at 45°C up to 5 mL. Extracts were stored at −20°C for further use.Cells from different suspension cultures were ground in 100% of methanol using pestle and mortar at room temperature with periodical mixing on shaker overnight, filtrated using Whatman Grade number 1 filter paper, medium particle retention  . Briefly2+-tripyridyltriazine compound from the colorless oxidized ferric Fe3+ forms by the action of electron donating antioxidants [3·6H2O in the ratio of 10 : 1 : 1. For the standard curve FeSO4 solution dilution from 0.2 mM to 1.6 mM concentration was prepared from the stock and processed in similar way. Results of percentage scavenging were compared with those of BHT, ascorbic acid, quercetin, and catechin:The FRAP assay measures the change in absorbance at 593 nm owing to the formation of a blue colored ferrous; Feoxidants . The FRA2PO4/K2HPO4) pH 7.0, containing 0.1 mM Na2EDTA and 0.1 g of polyvinylpyrrolidone (PVP), was added to them. The homogenate was filtered through Whatman filter and centrifuged at 15000 ×g for 10 min at 4°C; supernatant was recentrifuged at 18000 ×g for 10 min; the supernatant was stored at 4°C for enzyme assay.The samples were prepared as described by Mukherjee and Choudhuri  with somSOD activity was measured in a reaction solution (3 mL) according to the method of Giannopolitis and Ries . SOD act2O2 consumed [CAT activity was assayed by the method of Aebi  in a reaconsumed . Escherichia coli (NCIM 2065), Staphylococcus aureus (NCIM 2099), Klebsiella pneumoniae (NCIM 2957), Salmonella typhimurium (NCIM 2501), and Bacillus cereus (NCIM 2156), were procured from NCIM, Pune, India.Pure cultures of five test pathogenic bacteria isolates, namely,6 cfu mL−1 [Active cultures for each bacterial species were prepared by transferring a loopful of cells from the stock cultures to nutrient broth, incubated without agitation for 24 hrs at 37°C; further the cultures were diluted with fresh nutrient broth to achieve optical densities corresponding to 10μL bacterial cultures in 10 mL NB which contained 105 cfu of bacteria). Gradually increasing concentrations of the extracts were added to test tubes containing the bacterial cultures. The tubes were incubated at 37°C for 18–24 hours. Visible turbidity and optical density of cultures were determined at 620 nm using NB as control to elucidate MIC [Modified broth dilution technique was used to determine the minimum inhibitory concentration (MIC) values. Log phase cultures of bacteria were diluted 100-fold in NB (100 date MIC .μL/well) were used. Standard antibiotics, streptomycin (30 μg), ciprofloxacin (10 μg), doxycycline (30 μg), ampicillin (10 μg), and ofloxacin (5 μg), were used as positive control and dimethyl sulfoxide (75 μL/well) was used as negative control. A 100 μL (105 cfu) of diluted microbial suspension was swabbed on nutrient agar plates. Extracts and positive control were added separately to each well and allowed to diffuse at room temperature for 15–20 min. Plates were incubated at 37°C for 24 h after which they were examined for zones of growth inhibition and the diameter of these zones was measured. The assay was repeated three times for each extract. The antimicrobial effects were recorded as the mean diameter of the resulting inhibition zones of growth in millimeter.Agar well diffusion method was used to test the antibacterial effect of different suspension culture crude extracts , 27. MedExtraction from different suspension cultures was done in 100% of HPLC grade methanol using mortar and pestle with periodical mixing on shaker overnight and centrifuged at 5000 ×g for 10 min, and then the supernatant (5 mL) was collected for analysis.µL, and run time 2 min. All acquisitions were performed under positive ionization mode with a capillary voltage of 3500 V. Data acquisition and processing were done using the software version Analyst 1.6.Analysis was performed using Triple Quadrupole LC-MS/MS Mass Spectrometer  turbo spray interface. The separation was carried out in Acquity UPLC BEH apparatus with an autosampler equipped with C18 column dimension—2.1 × 50 mm. Column temperature was kept ambient, mobile phase methanol and water in ratio of 90 : 10, source temperature 200.0°C at set point, injection volume 10.0 1MS total chromatogram was run at positive mode and the nebulizer gas , heater gas , temperature , declustering potential (DP), entrance potential , collision energy (CE), and collision exit potential  of the compounds were optimized. CXP gave the daughter ion of the parent ion. Multiple Reaction Monitoring (MRM) of the compound's daughter ion was developed. The chromatogram developed gave separate peaks of different area for two compounds which was used to quantify the two compounds in the samples against the standard thymol and thymoquinone in terms of μg/gm. Best peak of thymoquinone was developed at 151.100/109.100  and best peak of thymol was developed 165.100/137.100 .Qn = 3). p values (≤0.05) were considered as significant compared to the respective controls.Data were statistically analyzed and the results were expressed as means (±SD) of average of three replicates , epicotyl segments (0.5 cm long) gave the best and fast callusing response with creamish white friable callus. The stock suspension cultures were initiated by these epicotyl calluses which were subcultured every week. A sigmoidal growth curve was obtained with all five growth phases, that is, lag, exponential, linear, stationary, and progressive decline. Maximum growth and longest stationary phase were achieved in suspension culture supplemented with Kn (2 mg/L) + NAA (1 mg/L) combination.Plant tissue culture techniques are of immense importance for the production of myriad of useful secondary metabolites as compared to the whole plant or microbial system , 29. In N. sativa epicotyl suspension cultures were subjected to three different concentrations of biotic and abiotic elicitors. Growth pattern under elicitation was determined, where cultures under pectin and MnCl2 reported early cell death which was due to the deleterious effect of elicitation. Maximum growth inhibition caused by both the elicitors, that is, pectin and MnCl2, was recorded in the cultures under 15 mg/L of elicitation having growth index of 2.533 and 2.403, respectively  on culture growth are in accordance with the results of Ghorpade et al. [ Boswellia serrata callus cultures which showed a deleterious effect of increasing concentration of the abiotic elicitors on the biomass accumulation.Pectin elicitation used in the present study clearly supports the facts of the previous findings that elicitation facilitates growth and enhances metabolite production. Pectin elicitation showed a dose-dependent effect on the cell growth and biomass accumulation of thea et al. . Furthere et al.  conducteRf values 0.76 and 0.82 similar to the standards used for THY and TQ, respectively, were recorded in all three cultures with a more prominent band in cultures under 15 mg/L elicitation though of less intensity as compared to the control cultures showing clearly that higher amount of pectin elicitation facilitated the production of TQ and THY. Bands of other metabolites of Rf values, that is, 0.97, 0.73, 0.60, and 0.43, were also recorded in the THY TLC. The TQ TLC results also showed the presence of two more bands of Rf values 0.95 and 0.68.The pectin elicited cultures were preliminarily demonstrated for production of TQ and THY by TLC. The accumulation of TQ and THY showed dose-dependent response as in the case of both the metabolites band intensity and color increased with the increasing concentration of the elicitor . Bands o2 elicitation reported the production of THY along with four other metabolites with Rf values 0.76, 0.97, 0.73, 0.60, and 0.43, respectively  also comparable to the standard ascorbic acid used over a value of 16.44 IC50  showed increased levels of antioxidant metabolites, that is, TQ and THY, which contributed to reducing the stress generated in these circumstances. The observed high levels of DPPH radical scavenging capacity in the MnClchilling  and saltchilling . The pre.8 mg/mL . The val50 value of 27.8, whereas MnCl2 10 mg/L elicited cultures showed higher reducing ability than the pectin elicitation, epicotyl explant extract, and the cultures without elicitation (control suspension culture) at an EC50 value of 23.46 which was comparable to the standard used, that is, FeSO4 (Results of Fe (III) reduction demonstrated that all the tissue culture generated extracts had lower reducing ability than the radical scavenging activity . Pectin s, FeSO4 . The che N. sativa [The protective effects of plant are ascribed because of their several components; correspondingly the metabolites like thymoquinone, carvacrol, thymol, cymene, t-anethole, and 4-terpineol confer major antioxidant properties to. sativa , 41. Res2 (10 mg/L) proved to be the best inducer . Pectin 10 mg/L and MnClactivity . The con in vitro conditions in different plants, including heavy metals, such as Al, Cd, Mn, Cr, and Cu, salt, and drought [Plant products are rich sources of phytochemicals as is the extract of this study and have been found to possess a variety of biological activities including antioxidant, cytotoxic, and hepatoprotective potentials. They are excellent reducing agents and reverse oxidation by donating electrons and/or hydrogen ions . Increas drought –48. E. coli and B. cereus, that is, inhibiting the growth of both Gram positive and Gram negative bacteria  with MIC value 2.35 ± 0.8 µg mL−1 at lowest dose of 25 µL (25 mg sample)  and E. coli (30 ± 0.2) (µg mL−1 (µL (25 mg sample). Further, MnCl2 15 mg/L elicited culture recorded least inhibitory activity followed by epicotyl, with maximum inhibitions against E. coli 18 ± 0.2, MIC 4.15 ± 0.3 µg mL−1; 22 ± 0.3, MIC 3.61 ± 0.5, respectively. Results of the in vitro generated extracts were far better when compared with standard antibiotics used as positive control.Among the biotic and abiotic elicitation, control cultures, and the sample) . Likewis0 ± 0.2)  with MIC(µg mL−1 , respectN. sativa is known to have very strong antibacterial background mainly due to lethal effects of its active components, that is, TQ and THY, towards the microbial growth [2, CoCl2, cellulose, and pectin elicited epicotyl callus extracts showed remarkable antibacterial properties [ N. sativa against the bacterial strains where maximum inhibition was marked by MnCl2 10 mg/L elicited epicotyl followed by pectin 15 mg/L elicited culture extracts.l growth –52. Antil growth  and Kamal growth , as the l growth . Findingoperties . Therefoµg/gm and THY 1.08 ± 0.27 µg/gm (Figures µg/gm and THY 1.99 ± 0.21 µg/gm (Figures 2 10 mg/L elicitation marked the highest presence of the metabolites, that is, TQ 2.90 ± 0.33 µg/gm and THY 1.86 ± 0.29 µg/gm, showing the positive effect of abiotic elicitation followed by pectin elicitation of 15 mg/L TQ 2.64 ± 0.27 µg/gm and THY 1.72 ± 0.5 µg/gm (Figures Suspension cultures which marked the prominent presence of thymoquinone and thymol in the TLC analysis and also proved to be potent inhibitors towards the pathogenic bacterial isolates and different reactive free radicals were further quantified for the presence of TQ and THY in them. Quantitative analysis of the epicotyl explant showed a total content of TQ 1.843 ± 0.34  Figures , whereas Figures . In cont Figures .The higher degree of antioxidant and antibacterial activities demonstrated by the suspension extracts was in regard to the enhanced production of the two very important metabolites, that is, TQ and THY, along with other terpenoids which is comparable to the quantification results of TQ in oil and extracts cited by Iqbal et al. and Solati et al. , 56. N. sativa epicotyl suspension culture for thymoquinone and thymol production and their efficacy as potent antioxidants and antibacterial agents. Therefore, this is a first report on response of growth and metabolite production in epicotyl suspension cultures of N. sativa under the effect of biotic and abiotic elicitation. Results showed that MnCl2 elicitation enhanced the production of thymoquinone and thymol; further, these extracts demonstrated strong antioxidant and antibacterial properties against Gram positive and Gram negative bacteria due to increased phytochemical accumulation. Henceforth, it could be concluded that these elite cell lines can be used for sustainable production of thymoquinone and thymol which will be helpful in understanding the biosynthetic mechanism of these metabolites under in vitro conditions.The present study was carried out to exploit the potential of


To determine appropriate timing of an adaptive radiation therapy (ART) replan by evaluating anatomic and dosimetric changes of target volumes and organs at risk (OARs) during intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC).Nineteen NPC patients were recruited. Each patient had repeat computed tomography (CT) scans after each five fractions and at treatment completion. Automatic re-contouring the targets and OARs by using deformable registration algorithm was conducted through CT-CT fusion. Anatomic changes were assessed by comparing the initial CT and repeated CT. Hybrid plans with re-contouring were generated and the dose-volume histograms (DVH) of the hybrid plan and the original plan were compared.Progressive volume reductions in gross target volume for primary disease (GTVnx), gross target volume for involved lymph nodes (GTVnd), and parotids were observed over time. Comparing with the original plan, each hybrid plan had no significant difference in homogeneity index (HI) for all the targets. Some parameters for planning target volumes for primary disease and high-risk clinical target volume  improved significantly, notably starting from the 10th fraction. These parameters included mean dose (Dmean), dose to 95 % of the volume (D95), percentage of the volume receiving 95 % of the prescription dose (V95), and conformity index (CI) for PTVnx, and Dmean, D95, and CI for PTV1. The dosimetric parameters for PTVnd remained the same in general except for D95 and V95 which had significant improvement at specific time points; whereas for PTV2, similar trend of dosimetric changes was also observed. Dose to some OARs increased significantly at some time points.There were significant anatomic and dosimetric changes in the targets and OARs. The target dose coverage in the hybrid plans did not get worse, but overdose occurred in some critical structures. Significant dosimetric changes should be considered as a trigger point at which ART replanning is indicated. D95/V95/CI for PTV2, Dmax for the brain stem, spinal cord, right eyeball and left lens, and Dmean/V30 for the parotids and glottis were taken into account for predicting the need for ART. Two replans at the 5th and 15th fractions were suggested. Radiation therapy (RT) is considered a main treatment approach in the management of nasopharyngeal carcinoma (NPC). Intensity-modulated radiation therapy (IMRT), formally introduced in clinical practice since early 1990s, has now replaced conventional radiation therapy (CRT) and three-dimensional radiation therapy (3D-CRT) and become a standard treatment for NPC. This technique provides adequate target coverage while maintaining steep dose gradients at the border between the target and adjacent normal tissues, through which dose escalation for the targets may be achieved without delivering excessive dose to the organs at risk (OARs) –6.However, NPC patients may experience significant anatomical changes throughout the entire treatment course. These changes include the shrinkage of the primary disease and metastatic lymph nodes, external contour because of significant weight loss, and displacement/size of the normal structures. As a consequence of the anatomic changes, significant difference between the actual delivered dose and the initial planned dose would be anticipated, which may ultimately result in underdose to the targets and/or overdose to the critical structures. Wang et al.  comparedIt is suggested that the initial planning based on pretreatment condition may not truly reflect the dosimetric variations during the course of IMRT. Thus adaptive radiation therapy (ART), a plan modification and implementation according to tumor response and anatomic changes of normal structures, becomes particularly important. In recent years, many studies have focused on ART for NPC patients, however, the optimal timing and frequency of ART remains unanswered –19. In tPatients with histologically proven NPC and treated with curative IMRT were enrolled into this prospective study. Inclusion criteria were as follows: age ≥18 years; Eastern Cooperative Oncology Group (ECOG) Performance Status 0–2; stages I-IVb according to the 2010 AJCC Staging System. Patients diagnosed with, or treated for other malignances, or treated with non-IMRT techniques were excluded in the study. Written informed consent was obtained for all patients. The study was approved by the Institutional Review Board (IRB) .3, version 9.2).All patients were immobilized in a supine position with the head in a neutral position with a tailored thermoplastic mask covering the head, neck, and shoulders. Intravenous contrast-enhanced CT using 2 mm slice from the vertex to the manubriosternal joint was performed for planning. The CT data were imported to the a treatment planning system  and the involved cervical lymphadenopathy (GTVnd) included all known gross disease as determined by the imaging, clinical, and endoscopic findings. The high-risk clinical target volume (CTV1) was defined as GTVnx plus 5-mm margin and entire nasopharyngeal mucosa plus 5-mm submucosal volume. The low-risk clinical target volume (CTV2) covered CTV1, entire nasopharynx, parapharyngeal space, pterygopalatine fossa, posterior third of the nasal cavity and maxillary sinuses, inferior sphenoid sinus, posterior ethmoid sinus, skull base, and anterior half of the clivus. CTV2 also covered elective neck nodal regions, including bilateral retropharyngeal lymph nodes and ipsilateral levels II, III, and Va for node-negative neck, or full length of ipsilateral neck for node-positive neck. Level Ib was not routinely irradiated unless there was confirmed lymphadenopathy in level Ib, or large metastatic node size (≥3 cm)/extracapsular spread was present in level IIa. PTVnx, PTVnd, PTV1, and PTV2 were generated by adding 5-mm margin to GTVnx, GTVnd, CTV1, and CTV2, respectively. Care was taken to ensure at least 5-mm gap was present between the PTVs and the skin. The contoured critical structures included the brain stem, chiasm, optic nerves, spinal cord, eyes, lens, parotid glands, oral cavity, larynx, mandible, and temporomandibular joints.The plans were designed and optimized using the Pinnacle inverse planning system. The prescribed radiation dose was 69.76 Gy at 2.18 Gy per fraction delivered to the PTVnx and PTVnd, and 60.8 Gy at 1.9 Gy per fraction delivered to the PTV1. The PTV2 was treated to 54.4 Gy at 1.7 Gy per fractions. All patients were treated once daily, five fractions weekly. Dose constrains to the critical structures were within the tolerance according to the RTOG 0225 protocol, and efforts were made to meet the criteria as closely as possible. IMRT was delivered via seven fixed-gantry angles with an Elekta Synergy Linear Accelerator (Elekta Ltd.) with step-and-shoot treatment techniques.Repeat CT scans were acquired for each patient with the same mask and isocenter as the initial simulation CT scan after each five fractions and at the end of the full treatment course using a 24-slice CT scanner . The datasets were denoted as CT-1, CT-2, CT-3, CT-4, CT-5, and CT-6, respectively. Each new CT dataset was registered with the initial planning CT dataset through VoxAlign Deformation Engine provided by the MiM Maestro software. Auto-propagating the planning contours on the new CT was conducted and manual modification was performed if needed. Changes in the volume of GTVnx, GTVnd, and parotid and shift of the parotid centroid were calculated by comparing the new CT and the planning CT.A hybrid IMRT plan was generated by superimposing the initial treatment plan (Plan-0) to each repeated new CT image. After recalculation of the dose distribution on the new CT images, the dose delivered by the hybrid plans to the redelineated target volumes and OARs were recorded and analyzed .T-test or Wilcoxon rank-sum test was chosen based on the data types. The correlation between weight loss and parameters associated with anatomic changes was estimated using Pearson’s correlation. Analysis of variance (ANOVA) was performed to determine significant dosimetric changes at any time point (trigger point) of the entire treatment course. A probability value less than 0.05 was considered significant. Analyses were performed using SPSS 19.0 software .The Kolmogorov-Smirnov test was used to test data for normality. Mean ± standard deviation was used for data with normal distribution; whereas median (interquartile range) was used for data with skewed distribution. A paired sample Between August 2012 and December 2013, a total of 19 patients diagnosed with undifferentiated non-keratinizing NPC were enrolled into this study. There were 11 men and 8 women with median age of 46 years . Stage distributions according to the 2010 AJCC Staging System were as follows: stages II, 3 patients; stage III, 13 patients; and stage IV, 3 patients. Concurrent platinum-based chemotherapy was given to 17 patients, and no chemotherapy to 2 patients. The characteristics of the patient cohort are listed in Table p = 0.001 and 0.046), corresponding to a reduction rate of 17.3 ± 10.4 %/week and 22.2 ± 15.0 %/week, respectively.Steady volume reduction in GTVnx and GTVnd was observed over time. Compared with the baseline, the volumes of GTVnx and GTVnd at the end of IMRT were decreased significantly by 65.6 ± 13.3 % and 72.7 ± 13.3 % (p = 0.016) and 14.4 ± 7.6 % (p = 0.003) for the left and right parotids, respectively.At the treatment completion, the volume of the left parotid decreased by 38.0 ± 15.3 %, corresponding to a reduction rate of 7.9 ± 9.6 %/week; whereas for the right parotid, the volume reduction was 39.2 ± 14.7 %, corresponding to a reduction rate of 7.8 ± 11.3 %/week. The most significant volume reduction occurred at the third week, with its value of 15.8 ± 6.8 % (p = 0.001 and 0.018). While for the right parotid, the displacements of its centroid were 0.31 ± 0.19 cm, 0.01 ± 0.21 cm, and 0.03 ± 0.20 cm in the RL, AP, and SI directions, respectively. Significant shift occurred in the AP direction (p < 0.001). The centroid displacement for the parotids is illustrated in Fig. The displacements of the centroid for the left parotid were −0.27 ± 0.25 cm, 0.04 ± 0.12 cm, and 0.14 ± 0.20 cm in the right-left (RL), anterior-posterior (AP), and superior-inferior (SI) directions, respectively. Significant shifts were noticed in the RL and AP directions (p < 0.001), 2.5 ± 1.9 % (p < 0.001), 3.9 ± 2.2 % (p < 0.001), 4.8 ± 2.8 % (p < 0.001), 6.2 ± 3.3 % (p < 0.001), and 8.3 ± 5.1 % (p < 0.001), respectively.Gradual weight loss was observed during the course of IMRT, with an average loss of 1.5 ± 2.2 %/week. Compared with the baseline, the percentages of weight loss after the 1st, 2nd, 3rd, 4th, and 5th weeks and at the completion of treatment were 1.7 ± 1.5 %  for all the targets between the original plan and the hybrid plan. Some parameters for PTVnx and PTV1 improved significantly as treatment continued, notably starting from the 10th fraction. These parameters included mean dose (Dmean), dose to 95 % of the volume (D95), percentage of the volume receiving 95 % of the prescription dose (V95), and conformity index (CI) for PTVnx, and Dmean, D95, and CI for PTV1. Other parameters including percentage of the volume receiving >110 % of the prescription dose (V110) for PTVnx, and V95 and V110 for PTV1 changed less or not significantly. The dosimetric parameters for PTVnd remained the same in general except for D95 which had significant improvement at the 15th and 25th fraction, and for V95 which had significant improvement starting from the 10th fraction to 25th fraction; whereas for PTV2, a similar trend of dosimetric changes was also observed Table .Table 3DDmean for the brain stem and spinal cord increased significantly over the IMRT course, occurring as early as at the 15th and 5th fractions, respectively. Dmean and V30 for the left and right parotids increased significantly, beginning at the fifteenth and twentieth fraction, respectively. For the glottis, right eye, and left lens, significant increase in Dmax or Dmean was found in some time point (s) during the treatment. Table It is reasonable to postulate that any anatomic changes during the treatment course may not certainly result in marked dosimetric changes. So ART may not be necessary for a patient who has no significant dosimetric changes at some time point even if statistical anatomic changes exist at the same time. Based on this concept, we considered a trigger point at which significant dosimetric variation for a specific parameter was present as an indicator for ART replanning. First of all, dosimetric parameters in Plan-0 were compared with those in the following hybrid plans separately until statistical differences were found. For example, if significant difference was found in the target dose coverage or overdose to the OARs between Plan-0 and Plan-1, adaptive replanning would be initiated after the 5th fraction (here the 5th fraction was considered a trigger point). Then parameters in Plan-1 were compared with those in the following hybrid plans until another trigger point was found, and so on. In this way, the trigger points for each selected parameter throughout the treatment course could be identified. Table 3. On the last day of treatment, the median volume loss of the initial GTV was 69.5 % . This was consistent with our findings. In the present study, progressive tumor regression for GTVnx and GTVnd was observed over time. The volumes of GTVnx and GTVnd at the end of IMRT were decreased significantly by 65.6 ± 13.3 % and 72.7 ± 13.3 % (p = 0.001 and 0.046), corresponding to reduction rates of 17.3 ± 10.4 %/week and 22.2 ± 15.0 %/week, respectively.Similar to other head-and-neck cancers, patients with NPC disease also experience marked changes during IMRT. These changes include shrinkage of the primary disease and involved lymph nodes, weight loss, and geometric/volumetric variations of the OARs. Fung et al.  acquiredWeight loss is a common event for head-and-neck cancer patients when RT is given with or without concurrent chemotherapy. Ng et al.  found thThe parotids are the most frequently changed organs in NPC patients throughout the treatment course, both in the volume and in the displacement. Wang et al.  showed aIt has been reported that shrinkage of the parotid and shift of its centroid are correlated with weight loss. Barker et al.  found thSignificant anatomic changes during the treatment course in NPC patients may affect the dose distribution. The initial plan based on pretreatment CT images that are only snapshots of the patient’s anatomy at a static time point do not precisely reflect the actual dose distribution during fractionated IMRT. Fung et al.  created Determining an appropriate time point at which ART is intervened in a timely manner is critical to ensure that the planned dose to the targets and OARs can be delivered faithfully throughout the entire IMRT course. Workflow for ART includes re-simulating, re-contouring, and treatment re-designing, which is a time-consuming and heavy workload process. Thus daily ART is not always applicable in many cancer centers. Many reports in recent years suggested that mid-to-late phase of the treatment course was appropriate timing for ART. Lu et al.  recommenIt should be noted that all patients in the present study were treated with the original plan. The repeat CT scans during IMRT were only used for research, and no ART replanning was prepared for patient treatment. Whether ART replanning can transfer into dosimetric or clinical benefits remains unknown. To answer these questions, a further study is underway to investigate the impact of ART on dosimetric parameters and clinical outcomes.In summary, there were significant anatomic and dosimetric changes in the targets and OARs during the course of IMRT. Weight loss significantly correlated with the shrinkage of parotids and their centroid shift towards the medial direction. The target dose coverage in the hybrid plans did not get worse, comparing with the original plan, but overdose occurred in some critical structures. Significant dosimetric changes should be considered as a trigger point at which ART replanning would be initiated. Based on the dosimetric analysis, D95/V95/CI for PTV2, Dmax for the brain stem, spinal cord, right eyeball and left lens, and Dmean/V30 for the parotids and glottis were taken into account for predicting the need for ART. Two replans at the 5th and 15th fractions were suggested for performing ART.