Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that starts in early childhood and has a comprehensive impact on psychosocial activity and education as well as general health across the lifespan. Despite its prevalence, the current diagnostic criteria for ADHD are debated. Saccadic eye movements are easy to quantify and may be a quantitative biomarker for a wide variety of neurological and psychiatric disorders, including ADHD. The goal of this study was to examine whether children with ADHD exhibit abnormalities during a visually guided pro-saccadic eye-movement and to clarify the neurophysiological mechanisms associated with their behavioral impairments. Thirty-seven children with ADHD (aged 5–11 years) and 88 typically developing (TD) children (aged 5–11 years) were asked to perform a simple saccadic eye-movement task in which step and gap conditions were randomly interleaved. We evaluated the gap effect, which is the difference in the reaction time between the two conditions. Children with ADHD had a significantly longer reaction time than TD children (p < 0.01) and the gap effect was markedly attenuated (p < 0.01). These results suggest that the measurement of saccadic eye movements may provide a novel method for evaluating the behavioral symptoms and clinical features of ADHD, and that the gap effect is a potential biomarker for the diagnosis of ADHD in early childhood. Attention deficit hyperactivity disorder (ADHD) is one of the most common developmental disorders and is characterized by behavioral and cognitive symptoms such as inattention, impulsiveness, and hyperactivity –8. AlthoThere are relatively few studies of saccadic eye movements in children with ADHD , 23. HowA fundamental oculomotor behavior involves of a series of alternations between fixation and saccade guided by visual information, and this behavior occurs hundreds of thousands of times a day. Children with ADHD have problems with visual fixation and also exhibit several deficits in visually guided saccades, including a longer time to initiate saccades in response to the appearance of the target , 36–43. A wide variety of paradigms that challenge cognitive functions such as go/no-go behavioral inhibition , 37–40 aWe found that the gap effect was attenuated in children with ADHD compared with that in typically developing (TD) children. This is partly consistent with previous reports –39 showiThirty-seven children with ADHD  recruited from the Molecular Research Center for Children’s Mental Development at Osaka University Hospital and 88 TD children  without any visual, neurological, or psychiatric disorders participated in the study. The study was approved by the Internal Review Board of Osaka University Medical School Hospital, Suita, Japan . All participants and their parents provided written informed consent prior to participating.th edition, Home Version), which is based on the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), criteria for ADHD and is considered to be effective for diagnosis of this disorder [1/2-5) for children aged 18 months to 5 years and the school-age version (CBCL/6-18) for children aged 6 to 18 years, are available. The CBCL score can be subdivided into scores for eight symptoms: withdrawn, somatic complaints, anxious/depressed, social problems, thought problems, attention problems, delinquent behavior and aggressive behavior. We obtained CBCL profiles for children with ADHD and TD controls. Expert pediatricians yielded a definitive diagnosis of ADHD based on the DSM-IV criteria.All ADHD children underwent a semi-structured diagnostic interview for developmental disorders and a video-based behavioral investigation performed by senior expert pediatricians. The ADHD Rating Scale  appeared for 700 ms on a cathode-ray tube display placed 30 cm in front of the subject. This was followed by the appearance of a peripheral stimulus  to the left or right of the central fixation point at a visual angle of 16.4° for 700 ms. Children were instructed to initially maintain their eyes on the fixation point and to move their eyes toward the peripheral stimulus in response to its appearance as quickly and accurately as possible. The instructions were easily understood by participants regardless of their age and the severity of their clinical condition.The saccade paradigm was performed in two conditions that were randomly interleaved in each block of trials. In the step condition, the peripheral stimulus appeared at the same time as the fixation point disappeared. In the gap condition, the peripheral stimulus appeared 200 ms after the fixation point disappeared. Each participant completed three blocks of 40 trials, with a 30 s rest between consecutive blocks.Horizontal eye movements were detected using an infrared limbus detection eye-tracking device . The signal was sampled at 1 kHz and low-pass filtered at 100 Hz. Experiment Builder  was used to generate the visual stimuli, and LabView  was used to determine the exact time at which a visual stimulus appeared and disappeared  and to record continuous eye positions as digitally converted signals. Off-line analysis was performed using Matlab  software.The onset and end of each saccade were identified using radial eye velocity criteria . Detected saccades were analyzed if they satisfied the following criteria: amplitude >2°, peak velocity >50°/s, and duration >20 ms. Saccadic reaction time was defined as the time from the appearance of the peripheral stimulus to the initiation of the saccade. We also used an exclusion criteria for anticipatory saccade: reaction time <70 ms . Saccadevs. step; within-subject factor), subject groups , and age groups . The gap effect was quantified for each subject by subtracting the average reaction time for the gap condition from the average reaction time for the step condition. A two-way ANOVA was used to compare the gap effect across subject groups  and age groups . The variability in the reaction time was quantified for each subject using the coefficient of variation. A three-way ANOVA was used to compare the coefficient of variation across saccade conditions , subject groups , and age groups .A three-way analysis of variance (ANOVA) was used to compare the saccade reaction time across saccade conditions  and age groups . To examine the relationship between the gap effect and the behavioral symptoms of ADHD, the relationship between auROC and ADHD-RS scores with a fixing age analysis was evaluated using Spearman’s partial correlation coefficient.The gap effect was also evaluated using a receiver operating characteristic (ROC) analysis. The ROC value is the area under the ROC curve (auROC), and auROC >0.5 means that the reaction time for step trials was longer than for gap trials and indicates a different distribution of the reaction time in the gap and the step trials. A two-way ANOVA was used to compare auROC across subject groups  = 149.66, p < 0.0001), subject group (F(1) = 5.25, p < 0.05), and age group (F(6) = 11.07, p < 0.0001) on saccade reaction time and a significant two-way interaction between age group and saccade condition (F(6) = 3.09, p < 0.01). None of the other interactions were significant (p > 0.05). In both the gap and the step conditions, saccade reaction time decreased with age  = 2.51, p < 0.05) on gap effect but no effect of subject group (F(1) = 0.92, p > 0.3) and no interaction (F(6) = 0.99, p > 0.4). ANOVA also revealed a significant main effect of age group (F(6) = 5.21, p < 0.0005) on the coefficient of variation for reaction time and a significant two-way interaction between age group and subject group (F(6) = 2.19, p < 0.05). However, it is difficult to interpret the difference in the gap effect calculated as the difference in the average reaction time of the two conditions because the variance of reaction time is influenced by age and subject group, as shown in previous studies [The gap effect was calculated as the difference in the average reaction time in the two conditions. ANOVA revealed a significant main effect of age group  = 16.6, p < 0.0001) and the ADHD group (t(36) = 8.35, p < 0.0001), confirming the presence of a gap effect in both groups. However, the auROC was smaller in the ADHD group than in the TD group (two-sample t test: t(123) = 2.82, p < 0.01). ANOVA revealed a significant main effect of subject group on auROC (F(1) = 5.87, p < 0.05) but no significant effect of age group (F(6) = 0.4, p > 0.8) and no interaction (F(6) = 1.38, p > 0.2). These results demonstrate that the gap effect quantified using ROC analysis was attenuated in the ADHD group compared with the TD group, regardless of age.ROC analysis does not depend on the variance of reaction times and instead evaluates the distribution of the reaction times. There was no significant correlation between the auROC and the ADHD-RS score  or between the auROC and the T-score for any CBCL symptoms  in ADHD children . SimilarWe found that the gap effect was attenuated in children with ADHD compared with that in TD controls, regardless of age. The gap effect did not correlate with ADHD-RS or CBCL scores, suggesting that the gap effect may capture deficits that are not identified by these qualitative behavioral evaluations. In the following sections, we discuss the estimation of the gap effect, the mechanism underlying the attenuation of the gap effect in ADHD, and the application of this measure to clinical practice in the future.vs. TD). Therefore, we used ROC analyses to evaluate the difference in saccade reaction time between gap and step trials. In ROC analysis, the area under the curve represents the power of discrimination between gap and step trials, as shown in previous studies [The gap effect is normally quantified by subtracting the average reaction time in the gap condition from that in the step condition. This estimate decreases with age  and does studies –38.We adopted a gap-step task instead of another task to keep the behavioral paradigm as simple as possible. In our paradigm, the disappearance of the fixation point always indicated the appearance (in the step condition) or upcoming appearance (in the gap condition) of a target. Thus, we speculate that the disappearance of the central fixation point facilitated saccade initiation in all trials. By contrast, in behavioral paradigms that use overlap and gap conditions, the disappearance of the central fixation point can facilitate saccade initiation in only half of the trials.We designed this model to provide the simplest possible explanation for the saccade abnormalities observed in ADHD. Recently Watanabe et al. suggested that fixation saccades alter the gap effect, presumably by disrupting volitional saccade preparation . HoweverWe did not find significant correlations or trends between the gap effect or other eye-movement parameters and clinical features, except for the social problems domain of the CBCL . This maIn future studies we aim to assess the utility of eye-movement measures as a specific biomarker for the diagnosis of ADHD in early childhood and to evaluate the neurodevelopmental state related to cognitive and executive functions observed via social behaviors.


These results do not just help to explain the physiology underlying the disorder but open the door to future uses of these methodologies to monitor and evaluate patients with ADHD.The purpose of this work was to highlight the neurological differences between the MR resting state networks of a group of children with ADHD (pre-treatment) and an age-matched healthy group. Results were obtained using different image analysis techniques. A sample of n = 46 children with ages between 6 and 12 years were included in this study (23 per cohort). Resting state image analysis was performed using ReHo, ALFF and ICA techniques. ReHo and ICA represent connectivity analyses calculated with different mathematical approaches. ALFF represents an indirect measurement of brain activity. The ReHo and ICA analyses suggested differences between the two groups, while the ALFF analysis did not. The ReHo and ALFF analyses presented differences with respect to the results previously reported in the literature. ICA analysis showed that the same resting state networks that appear in healthy volunteers of adult age were obtained for both groups. In contrast, these networks were not identical when comparing the healthy and ADHD groups. These differences affected areas for all the networks except the Right Memory Function network. All techniques employed in this study were used to monitor different cerebral regions which participate in the phenomenological characterization of ADHD patients when compared to healthy controls. Results from our three analyses indicated that the cerebellum and mid-frontal lobe bilaterally for ReHo, the executive function regions in ICA, and the precuneus, cuneus and the clacarine fissure for ALFF, were the “hubs” in which the main  Attention deficit hyperactivity disorder (ADHD) is a common neuropsychiatric disorder in children and adolescents with a prevalence of 5.29% according to current meta-analysis studies There are several analytical approaches , as well as computing platforms  that can be used to study resting state networks. In this study three of these approaches were used: firstly, Regions of Homogeneity (ReHo). In this approach the BOLD time course of each voxel of the brain (excluding CSF and white matter) is filtered, retaining frequencies between 0.01 and 0.1 Hz. Kendall correlation coefficients (a non-parametric test for correlation) for each voxel are then calculated with respect to its closest 27 neighbors. These neighbors represent a cube in 3D around the given voxel http://fcon_1000.projects.nitrc.org/indi/adhd200/) has made available free resting state data sets of 747 volunteers . This project aims at differentially diagnosing ADHD patients (with their corresponding subtype) from healthy controls. It has been able to identify the illness with a maximum efficiency till now of 69.59% Several reviews One of the pre-existing hypotheses for ADHD is that a malfunction or subnormal performance of the dopaminergic and norepinephrinergic systems is the main source of the disorder. These problems affect primarily the prefrontal cortex which is responsible, amongst other things, for: inhibition, concentration, executive functions, motivation, memory, organizing, planning and problem solving Work on ADHD has been predominantly performed in young adults/adolescents  granted the necessary ethical approval for this study under the title “Técnicas avanzadas de Resonancia Magnética Funcional en población pediátrica con diagnóstico de TDAH” . This permission was obtained in June 2012, six months prior to the start of experiments which were performed over the first 6 months of 2013. When enrolling a volunteer to this study, an information session was first held, in which the task was explained to the volunteer and their legal guardian, and they were told what to expect from the experimental protocol, as well as its dangers. Secondly, they were asked to read at home the information sheets which repeated all of the information provided in the oral session. The language level of the oral sessions as well as the written information sheet was intended to be accessible for non-scientific or medically trained people. Finally, consent forms were signed by the legal guardians and handed to scientists in charge of the study. Twenty-seven (n = 27) ADHD patients together with 24 healthy volunteers (H from now on) were included in this study. One ADHD volunteer was excluded from the study as he could not remain in the scanner for the whole length of the protocol. Another four volunteers (three in the ADHD group and one in the control) were excluded as their head motion exceeded the motion threshold for this study (described below). All ADHD volunteers were diagnosed with the disorder after an interview performed before initiating imaging. For a patient to be diagnosed with ADHD, he/she should fulfil the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, (DSM-5). This was so for all the symptoms of inattentiveness, hyperactivity and impulsivity. On top of these requirements symptoms for ADHD infants were required to be present practically on each day of the week for the last six months. Also symptoms must have been inducing a dysfunction of the day to day normal activities. Finally, no other diagnosis should explain the symptoms. Once this was established in an interview two tests were always performed on patients: Conneŕs and ADHD rating scales (ADHD-RS). In some occasions the Wechsler  and the TOVA were also applied (data not presented here). All ADHD volunteers had never received medication for this disorder. Only volunteers with ADHD of the Inattentive and the Impulsivity-Hyperactivity subtypes were considered for this study. Controls were completely healthy at the time of the study, with no history of any previous psychological or mental disorder and no prior neurological interventions. No intelligence matching between groups was performed.The 46 infants finally involved in this study had an average age of 9.7±2.4 (6–12 years old), ), with the ADHD group (n = 23) being 9.3±2.8 (6–12 years old), and the H group (n = 23) 9.3±3.5 (6–11 years old) on average. There was a predominance of male subjects, as just 4 out of 46 volunteers were female (2 in the ADHD group and 2 in the H). ADHD patients of the inattentive subtype scored in the ADHD-RS scales 38.0±3.1 and in Conneŕs 66.1±2.8. ADHD patients of the mixed subtype scored in the ADHD-RS scales 38.3±4.0 and in Conneŕs 69.4±1.3. All patients were selected randomly from the population which checked in the Neurology department of the Hospital Infantil de México, Federico Gómez (Mexico). Due to the nature of the hospital being the public national reference in children care; volunteers belonged to all the social, economic and cultural backgrounds found in Mexican society. Nevertheless, no test or scale was used to support this fact.Experiments were performed on a 1.5 T Philips Intera-Achieva scanner , using an 8 channel SENSE head-coil. Gradient coils were NOVA .Protocol: Resting state scans were acquired immediately after standard setup of the scanner and patient, with the volunteer in a supine position with closed eyes . The resting state sequence was the first one to be run on all patients and lasted for a period of 7 minutes 25 seconds. Following this sequence a fast anatomical image was acquired which lasted for 3 minutes 10 seconds. Once these sequences were acquired patients were extracted from the scanner.in-plane resolution and 4 mm slice thickness (no gap between slices). Anatomical images were acquired with a T1-weighted gradient echo sequence . Sequences covered the same FOV with a 640×640 matrix which gave a 0.36×0.36 mm in-plane resolution and 4 mm slice thickness .Resting State: 150 whole brain volumes, comprising 35 axial slices covering the whole of the brain (including the cerebellum), were acquired with a fast-echo EPI sequence. TR = 2.9 s, TE = 50 ms, 90 degree flip angle, 64×64 matrix with a 3.6×3.6 mm http://www.restfmri.net), Resting-State fMRI Data Analysis Toolkit  and Group ICA of fMRI Toolbox . All software programs were run on a Statistical Parametric Mapping platform , based on the Matlab programming language .Resting state network data analysis was performed with: Data Processing Assistant for Resting State fMRI Advanced edition  showed that the number of volumes that should be eliminated due to motion at voxel level was 5.73±6.15 (mean ± standard deviation) for the control group and 9.32±8.25 for the ADHD group. As suspected the ADHD group had more movement than their control counterparts. Nevertheless this difference did not reach statistically significance  limiting the effect that motion could have on results for this study. Motion values of each individual during scanning were incorporated to the analysis further on, in the regression of nuisance covariates step. Anatomical and functional images of each volunteer were co-registered using interpolation and DARTEL methods Resting state network analysis began by converting all DICOM files obtained from the scanner into the ANALYZE format. In the process the first 7 volumes of functional data were discarded to avoid signal saturation problems (each subject had 143 useful sets of volumes). Slice timing correction followed on the 35 slices . It has been shown previously that spurious systematic correlations arise due to head motion during experimentation For ICA analysis, data was first preprocessed. All the data (H and ADHD groups) were analyzed together in these first steps. Slice time and motion correction of data was performed as in the resting state network analysis and was then normalized (estimated and written) to an EPI.nii template in MNI coordinates using SPM8 software. Normalization was performed with a tri-linear interpolation, a bounding box of -78-112-50 mm and voxel sizes of  mm. After this, data was filtered to retain frequencies between 0.01 and 0.1 Hz, and smoothed using a  mm kernel using DPARSFA software. To complete preprocessing, data was visually assessed using the “Check Registration” option in SPM8, and was fed to the GIFT software. At this point data was divided into three groups; one with ADHD subjects (description of ADHD with ICA), the other with the H volunteers (ICA results from the H group) and a mixed group . ICA analysis was performed for each of the three subgroups with the following parameters: regular analysis  with the Infomax algorithm and with 40 components. The number of components selected for ICA analysis is always controversial. This value was selected based on the work of Damoiseaux et al. which found 12 components in healthy patients. This would give our analysis 28 components more to show the possible appearance of new networks. All the analysis steps that this software follows were completed . Finally each individual component  was displayed on top of the EPI.nii template image. A threshold of Z>3.33 was used to eliminate random results. All 40 components were visually assessed. 12 were regularly found in all groups and considered to be significant as they corresponded to networks reported by Damoiseaux et al. The other 28 components were considered to be noise (correlations in structures outside of the brain) or motion , and were discarded.Second-level analysis was used to compare the different components between the ADHD and H group. It was implemented using the statistical capabilities of SPM8, which were accessed through the utilities option in the GIFT software. Here, two sample Mann–Whitney U tests were performed between the same components of the ADHD and H mixed group. This way, component 9, for example, was the same for both the H and ADHD groups. Results of the comparison for each component were also thresholded at Z>3.33 and projected onto the EPI.nii template. For publication purposes, each significant component was displayed using the “View” option of the REST software (5×5 images with 7 mm separation between slices that covered the whole brain including cerebellum).All data studied failed normality tests; therefore non-parametric statistical tests were applied. When comparing voxel numbers and images, Mann–Whitney U tests were used with a threshold of p<0.001 (Z>3.33) corrected for multiple comparisons. For display purposes images were subject to a p<0.01 (Z>2.58) threshold , with the added requirement of at least 4 responding voxels lying together to consider the activation as a positive result The first objective of this study was to perform a comparison between resting state networks of ADHD patients and age matched healthy controls using the ReHo methodology. Results , top rowIn order to assess the differences between the ICA studies of the ADHD and H groups, Mann–Whitney U tests comparing the different networks were performed. As before, p values were thresholded at 0.001 after correction for multiple comparisons. In inter-group differences, except for the Right Memory Function network. In general the majority of these differences between networks were found in the frontal and temporal cortices, as well as cuneus, precuneus and the lingual regions.A list with the position in MNI coordinates, number of significant voxels as well as the names that correspond to these regions can be seen in In In this project the resting state networks of pre-treatment ADHD children (aged between 6 and 12 years old) and sex-matched controls were compared. The objective of this work was to highlight some of the physiological differences of the ADHD brain when compared to a healthy one. Different image analysis techniques were used for this study . The following major differences were found: ReHo and ICA analyses identified differences between the two groups while ALFF analysis did not. ReHo and ALFF analysis showed different regional recruitment in the ADHD group of this study when compared to previous work. ICA analysis showed that the same resting state networks that appear in healthy volunteers of adult age were obtained for both groups in this study. These networks were not identical and included changes such as the appearance of a third component of the Default network. When comparing healthy and ADHD groups, ICA analysis also showed differences in responding areas for all the networks except for the Right Memory Function network.When considering ReHo activations, which were greater for the H group compared to the ADHD patients, the following regions were statistically highlighted: cuneus, precuneus, occipital cortex, right putamen and right globus pallidus. The relevance of these findings is consistent with the difficulty that ADHD patients have to process visual and spatial inputs (precuneus), as well as to plan and organise movements (putamen & cerebellum). Also, the precuneus and cuneus are important nodes of the default mode network. The precuneus has been previously reported to have reduced connectivity for ADHD patients when compared to controls The putamen and globus pallidus, which form the lentiform nucleus with their high level of connectivity are involved in several functions such as reinforcement, learning, concept learning, motor function, etc. The globus pallidus controls, through its inhibitory function, the positive activity of the cerebellum in movement. It is also known that ADHD affects it as well as the putamen When considering which ReHo activations were greater for the ADHD patients when compared to the H, the following regions were statistically highlighted: cerebellum (crus and lobes 8 and 9) and mid-frontal cortex, bilaterally. The cerebellum is known to be involved in planning, organization and execution. It is also known to control the calibration of motor function and learning by inference. Both of these last two functions are altered in ADHD patients. The excess of coherence found in the cerebellum for the ADHD group indicates a neurological basis to this effect. This “dysfunction” of the cerebellum is accompanied by a reduction in its volume It is important to notice that ReHo correlations did appear in both groups in the same areas. Differences were driven exclusively by the strength or magnitude of the correlations, and not because of the lack or absence of a correlation in a given region.No new networks were found for the ICA analysis of ADHD patients when compared to healthy adult volunteers . TherefoThe Visual Cortex II network invaded medial structures of the occipital lobe that corresponded mainly to parietal cortex and its function as a convergence point between vision and proprioception. It also showed lower correlations in areas like Brodmann 18 and 19, which are secondary and tertiary regions related to image association. The Ventral Stream network showed new bilateral activations in the ADHD group in a region that corresponded to the frontal inferior orbital cortex (Brodmann area 47). Both of these findings supported previous studies in which ADHD children showed impaired early visual processing The Executive Function network of ADHD patients took up areas of the frontal cortex but did not reach the medial parts of this lobe as it did for healthy subjects. This region, which did not show up in the ICA analysis for ADHD patients, would correspond to Brodmann area 10, or equivalently, the frontopolar prefrontal cortex. This is a meaningful result as this region is known to be involved specifically in executive function . The lack of connectivity to this region may account for the problems ADHD patients have in planning or using working memory, or with their task flexibility.A new component for the Default network (Default 3) appeared in both healthy and ADHD groups. The regions involved  were areas which appeared in the two previous default networks found by Damoiseaux et al. Based on these two considerations it could be argued that this third component is just a manifestation of the different results obtained when using different image analysis methodologies .It is nevertheless of interest to highlight the difference in connectivity of the medial cingulate cortex, which in H was larger than in ADHD patients. It is known that damage to this region can induce mental disorders as well as affect information integration (cognitive and affective disorders), and our findings corroborate this.Differences between the networks of the two groups were broad and statistically significant (with the exception of the right memory function network).The visual networks  included eight regions which were involved in image processing in healthy subjects that did not appear for the ADHD patients. The most consistently observed regions amongst these eight were the calcarine sulcus, the precentral gyrus and areas in the occipital lobe. The calcarine sulcus is where primary visual cortex is located in the brain Lenz et al. Executive function is related to problem solving, planning, working memory, reasoning and task flexibility. When comparing controls to ADHD patients, the latter presented in ICA analysis a strong correlation in what would correspond to the paracentral lobule. This is a meaningful result as this region is known to have reduced connectivity in ADHD patients In this study no significant differences in ALFF activity was found between the two groups. This indicates that for the population of this study, ADHD did not affect the function of the different regions of the brain. This is in contrast with previous work comparing non-medicated ADHD patients to healthy ones, which showed larger activations for healthy in sensory motor cortex, frontal cortex and cerebellum ALFF analysis did show that regions in the brainstem (pons and medulla oblongata), which had previously been mentioned in literature for ADHD patients, were also active here. In contrast, a group of regions not previously reported were found to be active for both groups. These were the precuneus, cuneus and the calcarine fissure. Except for the calcarine fissure, all the other regions were also found in the ReHo analysis and were found in both groups at a similar magnitude. These results could be an indication that ADHD does not affect drastically the function of a region. It could be argued that it is the inter-regional connectivity, as well as the areas recruited for a given function, which are altered by the disorder.We believe that the main differences found between this study and previous work arise mainly because of the population used, and methodological issues.Even if the patient sample used here is in general larger than those used in the past, there are plenty of biological factors that might affect the results and produce differences, such as age, medication, subtype of ADHD, IQ, emotional situation of the patient, genetic origin, etc. As mentioned before, patients in this study had ages between 6 and 12, while the majority of previous studies were performed on patients with ages between 11 and 18 years old. There is a large difference in brain physiology of children and adolescents The methodological issues should also be considered . These are complicated computational analyses in which several (if not hundreds) of parameters have to be set by the researchers. It is impossible for the methods section of an article to present all of this information. Therefore differences between studies will appear due to this factor.In general, results from the three techniques indicated that the cerebellum and mid-frontal lobe bilaterally for ReHo, the executive function regions in ICA and the precuneus, cuneus and the clacarine fissure for ALFF, were the “hubs” through which ADHD affected brain function. Results from ReHo also showed that regions like the cuneus, precuneus, occipital cortex, right putamen and right globus pallidus were significantly important. In fact, ReHo correlations were always present for both groups in all regions and just presented different strengths, indicating different connectivity but not a complete malfunction of the region in question. ALFF results indicated that in general, function in every region was the same when comparing healthy controls and ADHD patients.Based on our results, the techniques used in this study could be considered part of the spectrum of techniques employed in the assessment of attentional disorders. The combination of them has shown that they are complementary and provide different views of the problem. This opens a door to more objective studies for ADHD diagnosis and the understanding of its physiopathology. In the near future the methodology used here could represent a helpful diagnostic tool to monitor the neurobiological changes of this disorder over time and during drug treatments. It was of great interest to observe how connectivity and dysfunction of several brain regions changed. This supported a context in which ADHD was a neurodevelopment disorder, and shows how early-stage intervention could help balance these intricate compensatory neuronal networks.Figure S1Default network components obtained from the ICA analysis of this study. In this image the three components into which the Default network was found to be divided in this study are presented. The first two are compared to the components obtained from Damoiseaux et al. (right panels), while the third stands alone. Data was thresholded between p<0.001 and p<0.0001, and a pseudo-colored bar indicates these differences.(TIF)Click here for additional data file.


The influences of different types of surfactants and Cl− species on the size and morphology were investigated. A possible formation mechanism was also proposed on the basis of time-dependent experiments. The photoresponse properties show that the conductivity of Bi2S3 micro-flowers is significantly enhanced and the photocurrent is approximately two orders of magnitude larger than the dark current. The response and decay times are estimated to be 142 and 151 ms, respectively. It is expected that hierarchical architectures Bi2S3 may provide a new pathway to develop advanced nanomaterial for high-speed and high-sensitivity photoelectrical switches and photodetecting devices.A solvothermal method has been employed to synthesize bismuth sulfide (Bi The light current increased by 1.1 times upon exposure to the simulated sunlight. The signal-to-noise ratio (SNR) of the photodetectors was probably too low [2S3 hierarchical architectures reported by Xiao et al. had their response time and decay time of 0.5 and 0.8 s, respectively [2S3 hierarchical architectures, with a fast response time of ~50 ms via a hydrothermal method [2 (AM 1.5), which may be too low for high-performance photodetectors. Therefore, fast and high response photodetectors based on Bi2S3 are still a challenge for practical applications. To improve the crystal quality and morphology of Bi2S3, nanostructures may be a good route to enhance their photodetecting properties. It has been reported that chloride ion (Cl−) could monitor the crystal growth of Cu2O [− could retard the nucleation and growth and reduce the surface energy by binding strongly to seeds. Thus it is reasonable to conjecture that the Cl− could affect the crystallinity and growth of 3D hierarchical Bi2S3 considering the similar crystalline structure and growth behavior of Bi2S3 and Cu2O. However, there is no report to prepare Bi2S3 nanostructures by introducing Cl− to monitor the morphology of Bi2S3 during solvothermal process. Moreover, the influence of surfactants on the morphologies of 3D hierarchical Bi2S3 has not been investigated systematically. For example, Jiang et al. reported that they had synthesized flower-like Bi2S3 by an ionic liquid-assisted templating route [2S3 had been synthesized via a hydrothermal method by Tang et al [2S3 had also been obtained by Wang et al. via the same hydrothermal method and assembled into the dye-sensitized solar cells with a good performance [2S3 nanosheets via an organometallic synthetic route [Bismuth sulfide , sodium dodecyl sulfate (SDS), and centrimonium bromide (CTAB) were employed in the synthesis of Bi2S3 nanostructures, and PVP shows more manifest effects on the morphologies than the other two surfactants. The potassium chloride was added first in the solution to investigate the influence of chloride ions on 3D hierarchical Bi2S3 during solvothermal process. Our results demonstrate that Cl− plays a critical role on monitoring the shapes of Bi2S3 nanostructures. A possible formation mechanism of 3D Bi2S3 hierarchical nanostructures is proposed. Furthermore, a photodetector has been constructed based on as-prepared 3D Bi2S3 hierarchical nanostructures. The results show that the photocurrent is enhanced by two orders of magnitude compared with the dark current and the response time and decay time are estimated to be 142 and 151 ms, respectively, indicating promising applications of the as-prepared 3D hierarchical Bi2S3 for photodetecting and photoelectric switches.In this paper, we report a facile synthetic route to synthesize 3D hierarchical flower-like Bi3)•5H2O, thiourea (TU), polyvinylpyrrolidone (PVP), and ethylene glycol (EG) were purchased from Sinopharm Chemical Reagent Co., Ltd., (Shanghai) without further purification.Bi(NO3)•5H2O, 0.3 g TU, and 0.1 g PVP were added successively into 40 mL EG. The resulting mixture was sonicated to obtain a clear, yellow solution, which was then transferred into a 100-mL Teflon-lined autoclave and heated at 60 °C for 24 h. Finally, the sample was collected and washed with distilled water and ethanol for three times, and then dried at 60 °C for 12 h in a vacuum oven. This final sample was designated as V-Bi2S3.In a typical procedure, 0.6 g Bi and centrimonium bromide (CTAB) were selected. Moreover, potassium chloride with different amounts was added to investigate the effects of chloride ions on the final morphologies. Each control experiment was performed in the same conditions except the change of the surfactants and chloride concentrations.To investigate the influence of surfactants on the morphologies of the Biλ = 0.15418 nm). X-ray photoelectron spectra (XPS) were characterized with Kratos AXIS Ultra DLD-600W X-ray photo electron spectroscopy.The morphologies, structures, and compositions were characterized by field emission scanning electron microscopy  and transmission electron microscopy . X-ray powder diffraction (XRD) characterization was performed on Shimadzu XRD-7000s diffractometer equipped with Cu Kα radiation  on Al2O3 substrates were cleaned by distilled water, ethanol, and acetone successively for 15 min, respectively. And then 10 μL of suspension was dropped on the Au electrodes. Finally, the devices were put in an oven at 30 °C for 12 h. Electrical property measurements and photo-sensing tests were conducted in ambient condition by a semiconductor characterization system (Keithley 2420) and a solar simulator (Newport 91160-1000) in the dark and under simulated AM 1 and 1.5 illumination.The photodetectors were fabricated by a simple drop-casting method. Typically, 10 mg V-Bi2S3 phase (JCPDS no. 17-0320), and no characteristic peaks of any other phases and impurities are observed. In another investigation, the average crystalline size was derived from Scherrer formula as shown below:Figure D is the average crystalline size, k is a constant whose value is typically 0.9 of non-spherical crystals, B is the full width at half maximum (FWHM) of the diffraction peak (in radians) that has the maximum intensity in the diffraction pattern, λ is the wavelength of incident X-ray beam (0.154184 nm), and θ is diffraction angle or Bragg angle. From this formula, the average crystalline size of Bi2S3 was calculated 12.27 nm. The full spectrum of XPS shows four distinct peaks corresponding to bismuth, carbon, sulfur, and oxygen, respectively  Fig. 8 which is expected at 228 eV, and SOx species [x < 3 , are typically at ~230 eV. Metal sulfites are typically found at ~230 eV. S8 is a byproduct of the reaction that is difficult to remove during purification.where ely Fig. . The peaely Fig.  are assi162.4 eV , 34. The species , where x2S3 nanostructures are produced. The flower-like Bi2S3 nanostructures are composed of numerous nanowires with diameters of about 12 nm and length up to 1 μm. TEM images further reveal that the petals burst forth. The HRTEM image  of pyrrolidone from the PVP molecules and Bi3+, resulting in selective absorption and growth of various crystallographic planes of Bi2S3 [2S3 consisting of nanowires [2S3 nanoparticles could reduce total surface energy of the reaction system; as a consequence, flower-like Bi2S3 assembled by nanowires is produced.It had been reported that surfactants have a very important influence on the morphologies of the products via solvothermal reaction –38. Hereanowires . PVP mol2S3 nanostructures, a series of time-dependent experiments was performed. Figure 2S3 microspheres with a diameter of 500 nm were produced  atoms of pyrrolidone units of PVP chemically interact with the newly formed nuclei, thus the nuclei were stabilized.The bismuth–thiourea system has been well-developed to prepare bismuth sulfide in various forms , 41. It − has an important effect on the final morphologies of final Bi2S3. When the KCl was added, the flower-like Bi2S3 had changed their morphologies immediately, as suggested by Fig. 2S3 began to assemble into a sphere-like structure. More KCl (Fig. 2S3 microspheres consisted of quantities of individual nanowires were obtained. The wire-like petals had a diameter and length of 12 nm and 1 μm, respectively. However, too much KCl (Fig. 2S3. In addition, these Cl− species can prevent the microspheres from aggregating by providing electrostatic repulsion between the microspheres [Besides, it is found that the ClKCl Fig.  was addeKCl Fig.  would leospheres , 29.Fig.2S3 as a representative micro- and nanomaterial to evaluate the potential application in photodetectors. The schematic illustration of Bi2S3 micro-flower-based photodetector is shown in the inset of Fig. I-V curve (Fig. 2S3 have an excellent photovoltaic response upon light illumination. The photocurrent increases with bias voltage increases, showing that the separation of photo-generated electrons and holes is more efficient at a high bias voltage. In addition, the photocurrent significantly increases by ca. two orders of magnitude compared with the dark state (Fig. 2S3; Fig. 2S3 micro-flowers respond quickly to the light. Such on–off cycles were repeated several times, and no detectable degradation was found, showing its excellent stability and reproducible behavior. It is generally defined that the response time as the time needed to recover to 10 % of the maximum photocurrent equal to the calculated response and recovery time for our photodetector is calculated to be 142 and 151 ms at a bias of 5 V. The above results indicate that the photodetector based on Bi2S3 micro-flowers has a good stability and responds quickly to light, suggesting promising applications of Bi2S3 micro-flower in photodetector and photoelectrical switches. More importantly, the Bi2S3 micro-flowers as well as the relevant photosensitive devices presented in this paper were very easy and do not need complex equipment and procedures, thus offering probability for low-cost and large-scale circuit integration.Photodetectors and optical switches are indispensable elements in memory storage and optoelectronic circuits in imaging techniques and light-wave communications . Unforturve Fig.  for bothate Fig.  which in2S3 nanowires with a diameter of 12 nm and axial dimension of up to 1 μm. The influences of surfactant, KCl, and time on the final morphologies of Bi2S3 nanostructures have been investigated, and the growth mechanism is proposed. The capping effect of the PVP and chloride ions and the specific amount of Cl− species seem to be the most pivotal factors in guiding the formation of Bi2S3 micro-flowers and microspheres. A high efficient photodetector was constructed based on Bi2S3 micro-flowers. The photoresponse properties show that the conductivity of Bi2S3 micro-flowers is significantly enhanced and the photocurrent is approximately two orders of magnitude larger than the dark current. The response and decay times are estimated to be 142 and 151 ms, respectively, suggesting promising applications in photodetectors.In summary, a facile solvothermal procedure has been developed for large-scale production of 3D micro-structures consisted of ultra-long Bi


Whether visual processing deficits are common in reading disorders (RD), and related to reading ability in general, has been debated for decades. The type of visual processing affected also is debated, although visual discrimination and short-term memory (STM) may be more commonly related to reading ability. Reading disorders are frequently comorbid with ADHD, and children with ADHD often have subclinical reading problems. Hence, children with ADHD were used as a comparison group in this study. ADHD and RD may be dissociated in terms of visual processing. Whereas RD may be associated with deficits in visual discrimination and STM for order, ADHD is associated with deficits in visual-spatial processing. Thus, we hypothesized that children with RD would perform worse than controls and children with ADHD only on a measure of visual discrimination and a measure of visual STM that requires memory for order. We expected all groups would perform comparably on the measure of visual STM that does not require sequential processing. We found children with RD or ADHD were commensurate to controls on measures of visual discrimination and visual STM that do not require sequential processing. In contrast, both RD groups  performed worse than controls on the measure of visual STM that requires memory for order, and children with comorbid RD/ADHD performed worse than those with ADHD. In addition, of the three visual measures, only sequential visual STM predicted reading ability. Hence, our findings suggest there is a deficit in visual sequential STM that is specific to RD and is related to basic reading ability. The source of this deficit is worthy of further research, but it may include both reduced memory for order and poorer verbal mediation. How much visual processing contributes to reading disorders, and to reading performance in general, has been a topic of debate for decades. Whereas some early theorists suggested reduced sensory-perceptual processing plays a pivotal role in reading disability (RD)/developmental dyslexia (DD) Kephart, , others Multiple researchers have found various deficits in visual processing in DD recently. These deficits include reduced multi-character processing/visual attention for briefly presented stimuli , a test of visual STM that does not require memory for order  and a test of sequential visual STM. As visual-spatial processing/coding requirements were limited in these tasks, individuals with ADHD were not expected to be affected and were used as a comparison group. We hypothesized that children with reading disorders  would perform worse than controls and children with ADHD on the measures of discrimination and sequential STM. We thought the Visual Memory task, which presents one geometric figure per trial, would be intact for both the RD and ADHD groups as it did not require a great deal of spatial processing nor memory for order. We also were interested in whether visual processing predicts basic reading ability after controlling for phonological processing (awareness) or orthographic processing. It was hypothesized that discrimination and sequential STM would predict basic reading ability when phonological processing was controlled but not when orthographic processing was controlled, as visual processing may be related to orthographic ability in particular.t(128) = −0.21, p = 0.83; Hyperactivity/Impulsivity: t(128) = −0.08, p = 0.94]. This sample included children with ADHD Predominantly Inattentive and Combined subtypes. ADHD Hyperactive/Impulsive type was not included as its validity after the preschool/early childhood years is debated  and a SLD discrepancy definition following the guidelines of Pennington , as therOur participants were from a community sample, and many were recruited as part of grant funded projects (see Section Acknowledgments). Parents brought their children to the first author's laboratory for the study. Children attended public or private schools or were homeschooled. Most children with RD had a history of intervention including remedial services, special education services, and/or tutoring. Some children with ADHD were diagnosed prior to our testing and were treated with stimulant medication, but none were on medication during testing.In order to control for intellectual ability, the Wechsler Intelligence Scale for Children . When using One-way ANOVA groups were comparable in age, maternal education, and handedness (ps > 0.10) but not FSIQ (p < 0.001). Because FSIQ includes measures that rely on visual processing, it was decided to use the VCI as the IQ covariate. Groups differed in VCI when using One-way ANOVA, p < 0.001. See Table To ensure groups were comparable on variables that may affect our findings, the four groups were compared on age, SES , handedness laterality (Edinburgh), and Full-Scale IQ (FSIQ). There were no differences in ethnicity and gender when using chi-square ps > 0.0. When uTo verify groups were comparable and disparate in functioning where expected based on diagnosis, groups were compared on basic reading measures, inattention, and hyperactivity using One-way ANOVA. Groups differed where expected see Table F = 3.84, p < 0.001, F = 13.88, p < 0.001, Post-hoc comparisons using SIDAK revealed that on both Visual Discrimination (p = 0.02) and Visual Memory (p = 0.003), the comorbid group performed worse than controls, whereas no other groups differed significantly from one another (ps > 0.10). On Visual Sequential Memory, both the comorbid (p < 0.001) and RD (p = 0.03) groups performed worse than controls, whereas the ADHD group did not differ from controls (p > 0.10). Furthermore, although the RD and comorbid groups were not significantly different (p = 0.07), the comorbid group scored significantly lower than the ADHD group (p = 0.001). See Table A MANCOVA was used to compare the four groups  on the three TVPS-R measures, using VCI as the covariate. Groups differed on the visual processing measures  such that children with phonological awareness deficits  performed better than those without phonological awareness deficits  on Visual Sequential Memory. In children without RD the t-test also was significant ; however, those with phonological awareness deficits  also performed worse on Visual Sequential Memory than those without phonological awareness deficits . The interaction approached significance  despite the small n of those with phonological awareness deficits using this definition.Prior research has suggested that visual processing and phonological processing may independently contribute to reading ability  performed worse than controls, and children with comorbid RD/ADHD performed worse than children with ADHD.Our findings did not fully support our first hypothesis in that both visual discrimination and visual STM for complex geometric figures presented singularly were comparable to controls for the RD group. We expected that visual STM for the complex figures would be intact but not visual discrimination based upon the literature reviewed , but it was significantly correlated with Attention Problems . TVPS-R Visual Memory was correlated with Picture Completion , but it had a larger correlation with Attention Problems . Furthermore, all four groups were comparable on Picture Completion , but they differed on Attention Problems , with children with comorbid ADHD/RD performing worse than controls and RD. Thus, it is likely that attention problems were related to the visual processing weaknesses found in the comorbid group. Future research should examine alternate measures of visual processing and attention problems to determine if these relations will hold.In contrast to the RD group, children with comorbid RD and ADHD (RD/ADHD) had worse performance than controls on both visual discrimination and visual memory, along with worse performance on STM for order, displaying more global problems. As it is believed that ours is the first study to contrast comorbid RD/ADHD to both RD and ADHD alone on these measures; this is a novel finding and worthy of further study. There are at least two potential sources of this more global deficit: poor visual processing in the comorbid group and/or worse focused attention/concentration in the comorbid group that affected their performance on the visual measures. Prior research on RD/ADHD has suggested that having comorbid RD and ADHD is additive, such that having both disorders could lead to worse deficits in the areas affected by either disorder , but it is less likely to cause additional deficits unique to RD/ADHD . Given the trend found, it is worthy of further study. Visual Sequential Memory measures memory for order, as the participant must select the item choice that presents the shapes in the correct order. In addition, this task may tap linguistic skills as some children may enhance their performance by using verbal labels to help remember the shape order. Thus, a deficit in memory for order and/or linguistic processing in the RD groups may be driving this finding. Majerus et al. have demonstrated that deficits in memory for order are separable from deficits in memory for item in RD using verbal tasks and that deficits in memory for order are related to reading ability  as was a verbal measure of memory for order, Sentence Memory, which requires verbatim repetition . Thus, both linguistic deficits  and memory for order/sequential processing deficits may be playing a role in the deficit found on Sequential Memory. The specificity of the sequential STM weakness to RD helps to explain why some children have RD but not ADHD despite the relatively high comorbidity between the two disorders. There are other deficits that are specific to RD as well, such as poor phonological processing , but the ADHD group did not. Moreover, the comorbid group also performed significantly worse than the ADHD group, demonstrating that the weakness was specific to RD. Nonetheless, there may be slight additive effects in that the RD/ADHD tended to perform worse than the RD group, although this was not significant  of reading ability when the sample was comprised solely of children with RD/ADHD and only the three TVPS-R measures were entered. Hence, untimed discrimination does not appear to be a good predictor of reading ability when one is using a community sample.Contrary to the second hypothesis, visual discrimination did not predict basic reading ability when phonological processing was controlled. It also did not predict basic reading ability when orthographic processing was controlled. Our null findings on discrimination could be due to two factors. The first is that untimed discrimination may not be affected, and thus not contribute much to reading variability, when most individuals in the sample have deficits specific to RD and/or ADHD or have neither disorder. The other is that we controlled verbal intellect (VCI), and Kavale and Forness  noted thWe conducted an exploratory analysis to determine whether children with RD but not phonological awareness problems performed worse than children with RD and phonological awareness problems on sequential STM. It was believed that this may be the case based upon articles which suggested that dyslexia could arise from either phonological awareness problems or visual processing problems  for this study, which facilitates direct comparisons amongst the measures as their scores were based on the same normative sample. In addition, we were only able to administer three subtests of the TVPS-R for time reasons. Our battery for the larger studies from which this one was drawn was quite extensive, requiring us to focus on what we believed to be the most crucial measures. As visual discrimination and visual STM were processes that Boder  originalper se. Deficits in sequential STM were specific to reading disorders, with weaknesses being found in both the RD group and the comorbid RD/ADHD group. Moreover, sequential STM was modestly related to basic reading performance even after controlling for orthographic and phonological processing skills, but discrimination and visual STM were not. Further research is needed to determine whether the findings related to Visual Sequential Memory were due to sequential processing deficits in the RD group, such as poor memory for order, and/or reduced verbal mediation of the task by the RD group due to linguistic weaknesses. Based upon our exploratory analyses, we believe it to be due, at least in part, to both weaknesses. Our study is among the first to show that reduced memory for order using a visual task is specific to RD, with the comorbid group being particularly affected. Thus, replication of this finding is warranted, using both verbal and visual STM tasks, to determine if there are effects specific to modality.In summary, visual processing may be intact in RD and ADHD when measured with tasks of untimed discrimination and visual STM that do not require sequential processing or allow easy labeling. Although more general visual processing deficits were found in the comorbid group, it is likely these were due to worse focused attention/concentration caused by the additive effects of having both RD and ADHD rather than additional visual processing problems unique to this group 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.


Bartonella spp. from 275 rats purchased in food markets (n=150) and trapped in different ecosystems  (n=125) was carried out during October, 2012–March, 2013, in the Mekong Delta of Vietnam. The overall Bartonella spp. prevalence detected by culture and PCR in blood was 14.9% (10.7–19.1%), the highest corresponding to Rattus tanezumi (49.2%), followed by Rattus norvegicus (20.7%). Trapped rats were also investigated for the presence and type of chiggers (larvae of trombiculid mites), and Bartonella spp. were investigated on chigger pools collected from each rat by RT-PCR. A total of five Bartonella spp. were identified in rats, three of which  are known zoonotic pathogens. Among trapped rats, factors independently associated with increased prevalence of Bartonella spp. included: (1) Rat species (R. tanezumi); (2) the number of Trombiculini–Blankaartia and Schoengastiini–Ascoschoengastia mites found on rats; and (3) the habitat of the rat . The prevalence of Bartonella infection among chiggers from Bartonella spp.–positive R. tanezumi rats was 5/25 (25%), compared with 1/27 (3.7%) among Bartonella spp.–negative R. tanezumi rats . The finding of Bartonella spp.–positive chiggers on Bartonella spp.–negative rats is strongly suggestive of a transovarial transmission cycle. Rats are ubiquitous in areas of human activity and farms in the Mekong Delta; in addition, trapping and trading of rats for food is common. To correctly assess the human risks due to rat trapping, marketing, and carcass dressing, further studies are needed to establish the routes of transmission and cycle of infection. The widespread presence of these zoonotic pathogens in rats and the abundance of human—rat interactions suggest that surveillance efforts should be enhanced to detect any human cases of Bartonella infection that may arise.A survey of  Infections with Bartonella spp. are associated with a remarkable variety of clinical symptoms, ranging from transitory febrile disease, to severe vascular dysfunction and endocarditis . The life cycle of trombiculid mites consists of three active stages—larvae (chiggers), nymphs, and adults. The nymph and adult stages are free-living, whereas the larvae are parasitic on a wide range of animals, including rats, squirrels, shrews, and birds  characterize the burden and species of chiggers in rats and the prevalence of Bartonella spp. in the chiggers themselves; and (3) investigate variables associated with prevalence of Bartonella spp. .The prevalence of i.e., nine sources) located in five provinces of the Mekong Delta  (∼30 per province) during October of 2012. Rat trapping was carried out in different locations in the province of Dong Thap during March, 2013. A total of 30 lines (one per location) of 10 live cage metal tomahawk traps were set up, checked for rats trapped, and reset over 10 subsequent mornings . Traps were placed in farm sites where poultry and pigs were kept (n=20), as well as in crop fields (rice) and forest locations (n=10). Traps with a rat inside were brought back to the laboratory and were replaced by a new trap. On the day of purchase/catching, the following procedures were carried out on all rats: (1) Humane culling by overdose of inhalant anesthetic (isoflurane) following American Veterinary Medical Association (AVMA) guidelines ; (2) measurement of main biological and morphometric parameters  to allow species identification; (3) postmortem aseptic collection of 1–3 mL of whole blood by cardiac puncture; and (4) collection of one ear from each animal, by cutting it from the base and placing into a 5-mL universal tube with 70°C ethanol. Detailed methods for sample collection are described elsewhere  using PCR followed by molecular sequencing of the product and blasting using the RatSEA barcoding tool (www.ceropath.org/barcoding_tool/ratsea).The rat species identification was carried out on the basis of morphological characteristics. One rat representative of each batch (markets) and two to three of each species identified were confirmed by amplification of a conserved housekeeping gene  after being removed using a fine needle. Chiggers were washed several times with distilled water to remove alcohol. Chiggers were then submerged in a drop of mounting fluid  that had previously been placed on a glass slide. Slides were dried overnight using an incubator at 40°C and were then sealed with nail polish. Chiggers were examined using a phase-contrast microscope at 400×magnification. At least five chiggers from each ear were identified morphologically. The chigger mites were identified down to the subfamily–tribe–genus–subgenus based on published guidelines on Southeast Asian chiggers  (Nadchatram and Dohany Bartonella spp. in accordance with the Centers for Disease Control and Prevention (CDC) procedures  plates containing 5% fresh sheep blood previously screened to ensure absence of Bartonella spp. Plates were incubated at 35°C in an atmosphere of 5% CO2 for up to 4 weeks. Plates were examined once per week for bacterial growth. Bacterial colonies were selected on the basis of colony morphology, size and shape, and Gram-staining characteristics, and were subcultured from initial plates and subsequent passages until a pure culture was obtained.Blood was cultured for ® DNA Mini Kit, cat. no. 51304, Qiagen, The Netherlands). Primers BhCS871.p and BhCS1137.n for amplification product of 379 of the citrate synthase (gltA) gene of Bartonella were used. The PCR was carried out in a Techne 512 Thermal Cycler  following program parameters—an initial denaturing at 95°C for 5 min, and 35 cycles at 95°C for 1 min, 56°C for 1 min, and 72°C for 1 min. The PCR products were analyzed for the presence of amplicons of the correct size by electrophoresis in 1.5% agarose gels containing ethidium bromide.DNA extractions were performed on whole bacterial cells using a DNA extraction kit . Chiggers were placed in a 1.5-mL microcentrifuge tube and punctured with a fine needle. Ninety microliters of ATL tissue lysis buffer were added, and the sample was either processed immediately or stored at −70°C. Ten microliters of Proteinase K solution (20 mg/mL) were added, and the sample was incubated at 56°C for 3 h. Subsequently, 100 μL of AL buffer was added, and the sample was mixed by pulse-vortexing for 15 s, followed by incubation at 70°C for 10 min. Then 100 μL of absolute ethanol was added, and the sample was mixed by pulse-vortexing for 15 s. The sample was applied to a QIAamp spin column, and DNA was eluted in 50 μL of AE buffer and stored at −20°C until amplification. Detection of Bartonella in chiggers was performed by RT-PCR following a previously published protocol using Bartonella specific primers targeting the transfer-mRNA gene (ssrA)  to determine consensus of sequences for the amplified region of the Bartonella spp. prevalence comparisons were performed using chi-squared tests. For trapped rats, the association between Bartonella spp. and the species, body length, type of habitat (farm vs. field/forest), and number of chiggers (log-transformed) was explored by multivariable logistic regression modeling. Body length was transformed into a binary variable  based on a cutoff determined by the 50% quantile for each species. Multivariable model building was carried out in a stepwise forward fashion starting with variables with the lowest p value in univariable analyses .Rattus argentiventer (n=104), Bandicota indica (n=65), R. tanezumi (n=61), R. norvegicus (n=29), and R. exulans (n=16). All rat species were present in both collections, except for R. exulans, which was not represented in the market collection. R. argentiventer was more represented in the market collection (58.7%) than among trapped rats (12.8%). In contrast, R. tanezumi was the most commonly trapped rat species (41.6%), but represented only 6% of market rats. A total of 41 Bartonella strains were identified by culture and further confirmed by PCR. We did not observe any evidence of colonies of different morphology indicative for co-infection by different Bartonella species in the same rat.A total of 275 rats were examined, of which 150 were purchased in markets and 125 were trapped. Five different rat species were identified: Bartonella spp. prevalence in rats was 14.9% . The prevalence in rats purchased in markets was 8.7% compared with a prevalence of 22.4% among trapped rats . The highest prevalence corresponded to R. tanezumi (49.2%), followed by R. norvegicus (20.7%). B. indica and R. argentiventer rats had <5% Bartonella spp. prevalence, and all 16 R. exulans rats were Bartonella spp.–negative. For R. tanezumi, the Bartonella spp. prevalence was highest among rats trapped in fields/forests habitats (63.6%), and lowest among rats trapped on farms (21.0%)  .Bartonella spp. was successfully determined for 32/41 Bartonella isolates . B. rattimassiliensis and B. coopersplainensis were found only in R. tanezumi, whereas all other Bartonella spp. were found at least in two different host species (The species of isolates . In four species .R. exulans) contained at least one chigger in their ears. The main trombiculid species identified corresponded to (tribe–genus–subgenus): Gahrliepiini–Gahrliepia–Walchia (GGW), Schoengastiini–Ascoschoengastia (SA), Trombiculini–Blankaartia (TB), Schoengastiini–Schoengastia (SS), and Trombiculini–Leptotrombidium–Leptotrombidium (TLL). Overall counts were similar for all rat species (median six to eight). R. argentiventer rats had the highest chigger counts , followed by R. tanezumi , whereas R. exulans had the lowest  (All rats investigated except one (6.0–6.0) .Bartonella spp. A total of 6/28 (21.4%) chigger pools from Bartonella spp.–positive rats tested positive, compared with 7/96 (7.3%) pools from Bartonella spp.–negative rats . The prevalence of Bartonella spp. in chiggers from Bartonella spp.–positive R. tanezumi rats was 5/25 (25%), compared with 1/27 (3.7%) among Bartonella spp.–negative R. tanezumi rats (3.7%) .Thirteen chigger pools of 124 (10.5%) tested positive for Bartonella spp. prevalence in rats were: (1) Rat species (R. tanezumi vs. other) (odds ratio [OR]=7.68); (2) presence of SA and TB chiggers (log-transformed) ; and (3) type of habitat (rat trapped in field/ forest vs. trapped in a farm) (OR=3.20). Large rats (relative to the median for each species) had a higher risk of positivity (OR=2.55), although it was not significant (p=0.103) and was therefore excluded from the model. Interaction terms between main effects were not significant (p>0.05) (Factors independently associated with (p>0.05) .R. tanezumi, there was a statistically significant association between body length and the probability of testing positive for Bartonella spp.   than for Bartonella spp.–negative individuals (168.5 mm) .Among p=0.003) . In contBartonella spp. prevalence in rats (14.9%) was comparable with a previous study in Vietnam (19.2%)  corresponding to R. tanezumi. Studies in the Southeast Asian region and China have confirmed high levels of Bartonella spp. infection among R. tanezumi  have previously been identified in rats from the region  are phylogenetically close and belong to the B. elizabethae complex sensu lato as an assemblage of genospecies and strains associated with Old World rats   have been associated with human febrile illness in Thailand and have been linked epidemiologically to exposure to rats . The reason was a low sensitivity of detection of Bartonella spp. in chiggers based on gltA gene testing (data not shown).We observed a statistical association between Bartonella spp. to the rat host would only be theoretically possible if transovarial transmission occurs. The finding of Bartonella spp.–positive chiggers on noninfected rats is strongly suggestive of transovarial transmission.These results should be interpreted with caution and should be followed by relevant studies to investigate the mites' vector competence and to establish the cycle of transmission . Trombiculid chiggers are thought to feed after attaching themselves firmly to their hosts' skin by a feeding tube (stylostome). Therefore, transmission of R. tanezumi, and to a lesser extent R. norvegicus, which are common in areas of human dwelling may therefore represent the greatest risk.Because a number of trombiculid species have been reported to feed on humans (Shatrov and Kudryashova Bartonella spp. infections have been detected in patients in Vietnam. This is in part likely to be the result of limited awareness of this infection among the medical community, partly as a result of a diffuse, nonspecific clinical picture. We suggest that Bartonella spp. infections may be more common than previously thought in Vietnam given the widespread presence of rats in close proximity to human habitats, of which a fraction are infected with pathogenic Bartonella spp., as well as rat trade–related practices that may facilitate human contact with vectors of Bartonella spp. infection.To date no


In a feasibility analysis, the intervention was judged to be a suitable treatment option for 94.5 % of all individuals with a primary diagnosis of ADHD at an outpatient psychiatric clinic. In total, 43 out of 51 allocated individuals with ADHD (84.3 %) completed the intervention. The corresponding figures for their significant others were 42 out of 57 (73.7 %). Knowledge about ADHD increased, and both the quality of relationships and psychological well-being improved from baseline to post-intervention in all participants. The significant others reported a reduction in the subjective burden of care, such as worry and guilt. The objective burden of care  did not change. The findings support the potential value of psychoeducation for adults with ADHD and their significant others. An ongoing randomized controlled trial will generate further evidence concerning the PEGASUS program.The aim of this pilot study was to investigate the feasibility and effectiveness of a new psychoeducative intervention program (PEGASUS) for adults with ADHD and their significant others in a psychiatric outpatient context. At three outpatient psychiatric clinics, adults with ADHD and their significant others took part in PEGASUS, a psychoeducational program based on theories from cognitive behavioral therapy, neuropsychology, and cross-disciplinary evidence regarding ADHD. In total, 108 adults were allocated to treatment (51 with ADHD and their 57 significant others). Feasibility was evaluated regarding suitability of the intervention at a psychiatric outpatient clinic and treatment completion. Preliminary efficacy was evaluated  Attention deficit hyperactivity disorder (ADHD) is an early-onset neurodevelopmental disorder characterized by profound difficulties with inattention, hyperactivity, and impulsivity   and one outpatient psychiatric clinic . The study was approved by the Regional Ethics Committee of Stockholm (2009/824-31/3).Participants were recruited from the patient base of the three psychiatric clinics involved in the study. The ADHD diagnostic assessment was performed before the participant entered the study and was based on clinical practice in Stockholm County Council clinics at the time of the study. Multiple sources of information were combined to constitute a consensus between the clinicians involved in the assessment. A clinical interview based on the DSM-IV-TR criteria  diagnosis; age of 18 years or older; possibility to participate with at least one adult significant other. The exclusion criteria were as follows: current substance abuse (during the previous 3 months); mental retardation (IQ ≤ 70); organic brain injury; autism spectrum disorder; suicidality; any other severe psychiatric disorders ; or adverse psychosocial circumstances , thus making successful participation unlikely or impossible. Ongoing pharmacological treatment was not a reason for exclusion.The first contact with the ADHD participants was established by sending out study information letters. Thereafter, they were invited to visit the clinic in small groups for further information and for judging the inclusion criteria individually. All participants gave their written informed consent before completing the questionnaires. An experienced clinician  conducted individual interviews and studied case files in order to further assess eligibility. Participants with ADHD were instructed to participate with at least one significant other with whom they had a relationship in their everyday lives. The significant others completed the questionnaires at home after having received a written rationale and instructions.The PEGASUS program for adults with ADHD and their significant others is a highly structured manualized psychoeducational intervention designed to constitute a first nonpharmacological intervention after the establishment of an ADHD diagnosis at adult age ) in order to reduce the burden of care on the participating significant others, to increase acceptance of the ADHD diagnosis, to promote belief in finding relief, and to improve the quality of life of the participants.The program is based on general principles taken from CBT, neuropsychology, and cross-disciplinary clinical evidence pertaining to ADHD. Several experienced psychologists, psychiatrists, and occupational therapist have contributed to the contents of the program. Following training in the general principles of the intervention, the group leaders were responsible for the staging of the course at the participating clinics. The group leaders were provided with a preliminary version of the workbook  is stressed. Negative experiences, such as school failure or past substance abuse, should be validated while rumination and dwelling on the past are avoided , at post-treatment of 1–2 weeks after the last session (T2), and at follow-up of 6 months after the intervention had ended (T3).Treatment satisfaction was evaluated for the entire psychoeducational program, using a modified version of the patient evaluation form  the psychoeducative program should be regarded as a suitable intervention for at least 90 % of all individuals assessed with ADHD, as judged in a consecutive cohort from one of the participating clinics by a senior clinical psychologist involved in the project (EW); and (2) a dropout rate of <25 % . All participants completed the ADHD 20 Questions, a knowledge quiz with 20 true/false scored items, reflecting knowledge about ADHD and modified for this study from a corresponding scale  Scale   missing T2 but having T3 (follow-up at 6 months), we imputed the T3 score instead of the missing T2. Thus, the main statistical analyses were performed on all participants who (1) completed the treatment, i.e., were present at at least 4 out of 8 sessions and (2) had T2 or T3 data. Among these individuals (n = 81), baseline data were missing for four cases on the ADHD 20 Questions and one case on the PSS. The treatment mean imputation (TMI)  for efficacy-related measures and was interpreted using the guidelines proposed by Cohen: 0.01 = small effect size, 0.06 = moderate effect size, and 0.14 = large effect size . The results were similar using nonparametric versus parametric statistical methods and, for the sake of brevity, we chose to report results from the parametric methods only. Outliers were screened for using boxplots. One of the three clinics/sites was not able to perform the T3 assessments due to changes in staffing. In conjunction with individuals not reached for T3 measurements at the other sites, the T3 data were missing for one third of the study groups. Therefore, the data were only analyzed from T1 (baseline) to T2 (post-intervention). For cases  of the individuals in this consecutive cohort.The flowchart for the present study group is presented in Fig. p = 0.007) and “I would attend a similar course in the future” (p = 0.03). The rating of the whole course according to the school grading system did not differ between the groups . The feedback on each course occasion was summarized in writing for the purpose of further development of the PEGASUS program.The mean scores (±1 standard error) on the patient evaluation form are shown in Fig. all participants at baseline as well as post-intervention are depicted in Table F = 19.91, η2 = 0.06, p < 0.05).The mean values and standard deviations for questionnaires administered to adults with ADHD, a trend toward improvement of self-esteem was observed in RSE  = 3.75, η2 = 0.09, p = 0.06), while the increase in the AaQoL score did not reach statistical significance or trend .In questionnaires completed by the significant others, a significant decrease was observed in the subjective burden (p < 0.01), while no changes occurred in the objective burden from baseline to post-intervention , completed by the on Table .Table 5RA new manualized psychoeducational program for adults with ADHD and their significant others, PEGASUS . Moreover, treatment completion was better among adults with ADHD (84.3 %) than among their significant others (73.7 %). Therefore, the acceptability of the program for both groups was judged to be one of the main focuses for further development of the PEGASUS program.One of the main goals of the intervention is to provide the participants with evidence- based knowledge concerning ADHD in order to reduce stigma, prejudices, and discrimination  should also be increased among psychologists (ibid). This may be especially true regarding psychological treatments for adults with ADHD, since early studies  and floor effects (measures of depression and anxiety among significant others) on some of the outcome measures. Bearing these limitations in mind, the overall pattern in the results indicated promising effects of participation in the PEGASUS program and encouraged us to continue with the project and initiate a randomized controlled trial. However, before entering the RCT phase, the treatment materials were subjected to a thorough adaptation based on feedback from the participants as well as the involved course coordinators.Due to the open study design, the results from the efficacy-related measures should be considered to be preliminary and interpreted cautiously. In an open study, the conventional alpha level of In summary, a new manualized psychoeducational program for adults with ADHD and their significant others, PEGASUS (Hirvikoski et al.


Children and adolescents with ADHD present behaviors such as impulsiveness, inattention, and difficulties with personal organization that represent an overload for parents. Moreover, it also increases their level of stress and leads them to resort to inadequate educational strategies. The present study verifies associations between inadequate parenting practices and behavioral profiles of children and adolescents with ADHD. The sample was composed of 22 children with ADHD (age range 6–16 years) and their mothers. Spearman correlation analyses were made with the scores of Parenting Style Inventory (PSI) and Child Behavior Checklist for ages 6–18 (CBCL/6–18). Results indicate statistically significant associations between behavioral problems and the use of punishment practices and negligence. When assessing a child with ADHD, it is important to verify the predominant types of parenting practices that can influence both immediate interventions and the prognosis of the disorder.  Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by a persistent pattern of inattention and/or hyperactivity-impulsiveness that affects significantly the social and academic functioning of the child . InadequAccording to parental perception, children with ADHD, when compared to children without the disorder, demand more efforts to be managed and directed to the acquisition of adjusted behavioral repertoires and present less capacity to regulate their behaviors , 5. TheyParents of children with ADHD more often report family conflicts ; disorgaAnother situation that can aggravate behavioral problems is the lack of or delay in providing proper intervention for children with a psychiatric disorder such as ADHD. In Latin American countries such as Mexico, in population cohorts of adolescents aged 12 to 17 years, it was verified that 1 out of 7 individuals with psychiatric disorders (including ADHD) did not have access to mental health services . In deveThe sample was selected from a neuropsychological, behavioral, and clinical assessment protocol involving children and adolescents with complaint of inattention and hyperactivity, which was carried out by a national reference center that identifies signs compatible with ADHD in the community . The proThe inventory assesses seven parenting practices, two of them positive  and five negative . It consists of 42 items to be responded by parents about strategies adopted to orient the child . For thiThe inventory was responded by parents considering the behavior of their children in the previous six months. It is composed of 136 items and is divided into two parts. The first part assesses social competence/adaptive functioning, and the second part identifies behavioral problems grouped in the syndromes scales, DSM-oriented scales, internalizing, externalizing, and total behavior problems scales. This study considered only behavioral problems of syndromes, externalizing, internalizing, and total problems scales , 33.Spearman correlation analyses were made with the scores from both instruments to verify associations between parenting practices  and behavioral problems in children with ADHD.Results of correlation analyses among the studied variables can be seen in Individuals who suffer physical abuse and those who present symptoms of ADHD are alike in some aspects of behavioral expression. Both present tendency to externalizing behavioral problems, such as aggressiveness and opposition, and to internalizing problems, such as social withdrawal and peer rejection. Children with ADHD who suffer physical abuse are perceived by parents, teachers, and peers as excessively aggressive . Some itOther behavioral problems of the Rule-Breaking Behavior scale (CBCL/6–18), such as “does not seem to feel guilty after misbehaving,” “lying or cheating,” “disobedient at home, school, or other places,” and “steals outside the home,” present positive correlation with abuse and physical maltreatment. In the sphere of internalizing problems, physical abuse was also correlated to items of Thought Problems scale, such as “nervous movements, twitching,” “cannot get his/her mind off certain thoughts; obsessions,” “repeats certain actions over and over,” and “strange behavior.” These problems could be exacerbated by the influence of several factors, including the use of parenting abusive practices, as shown by previous studies , 40.The perception of mothers about the academic competences of their children has also presented statistically significant associations with behavioral problems, as it was the case with inadequate parenting practices. The School scale of CBCL  had a neThe findings of the present study indicate that the parents of the 22 assessed children keep an expressive use of parenting practices characterized by punishment and negligence. Such strategies are associated with several patterns of behavioral problems, including those typical of ADHD, but also with other emotional and behavioral problems, mainly of the externalizing type. Children and adolescents with ADHD often find themselves under immediate effect of several adverse factors that can aggravate the behavioral symptoms of the disorder as well as favoring the onset of other psychiatric problems and symptoms. Some examples are excessive use of physical punishment, yelling, absence of parents performing the role of caregiver, and lack of positive parenting practices, that is, adequate use of rules and instructions, establishment of routine, and positive stimulation of adequate behaviors. Other variables that could potentially work as intermediate factors of inadequate parenting practices, such as the caregiver's mental health, were not controlled.Correlation studies indicate associations among variables, but not their cause and effect relationships. The way a child behaves can influence the adoption of a certain parenting style as well as certain parenting practices that, in their turn, can have short- and long-term negative influence on the child's behavior. This phenomenon is described as a vicious cycle between behavioral problems and parenting practices. The present results suggest that the general clinical assessment of children and adolescents with ADHD should consider parenting practices to better understand mental health problems among this population. We highlight the importance of including the parents of children with ADHD in the intervention process, in order to provide orientation on the management of behavioral problems and thus attempt to minimize the aforementioned vicious cycle.


Since the beginning of clinical attachment research in the mid-1980s the number of research projects in this area has been continuously increasing. The research questions so far can be allocated to numerous medical disciplines such as psychosomatic medicine, adult psychiatry or child and adolescent psychiatry. Recently, children with ADHD and their families have also become subjects of this branch of research. Their specific behavioral characteristics from early childhood on constitute unique challenges on the parent-child interaction. If these interactions develop in a suboptimal way, children may develop an insecure or even a disorganized attachment quality. The latter represents a risk factor for a clinically significant psychopathological development.This article initially presents basic principles of attachment theory and discusses the relevance of the cardinal symptoms of ADHD for clinical attachment research. Subsequently, it outlines and discusses the main results of existing research regarding attachment and ADHD. It concludes with a perspective on research questions that need to be addressed in the future with regard to a transgenerational model that highlights the importance of parental attachment representations to the development of children’s attachment quality. Attachment theory as developed by Bowlby –3 is a mAttachment research initially focused on childhood and the first assessment procedure – the Strange Situation – was developed to evaluate attachment qualities in 11–20 months old infants . Subsequ2 = 114.83, p < 0.001). It has to be noted that these studies encompassed a great diversity of samples [Since these inventories were introduced into attachment research, numerous studies were carried out concerning the prevalence of the various attachment representations in normative and in clinical samples. A meta-analytical evaluation of these studies by van IJzendoorn and Bakermans-Kranenburg  resulted samples . The aut samples .Besides the question of the distribution of attachment representation in adults, attachment research dealt with the transgenerational transmission of parental attachment experiences. The correlations between parental attachment representation and the attachment quality of the child, meanwhile established in numerous studies, are regarded as evidence for the intergenerational transmission of attachment –33. SummSince its introduction as a diagnosis, attention deficit hyperactivity disorder (ADHD) has increasingly become a term used to describe a wide range of behavior problems in children. There is considerable disagreement both with regard to the etiology as well as suitable therapy for ADHD . The ICDOverall, this clearly demonstrates that a plethora of different symptom types is combined with each other in the entire picture of ADHD, and that the expressions of this disorder must be considered in a differentiated manner. Although the new features in DSM-5 consider a multifactorial genesis of ADHD, they still do not allow for any new assumptions about a specific etiology. Over the last decades, research has increased which, alongside neuropsychological and cognitive deficits, could also identify factors in the family context of the affected child , 39. In It can be assumed that from their first years, children with ADHD present a major challenge to everyday family life. Their inattention, their hyperactivity and their impulsivity impede the primary caregivers in their approach to these children’s signals. Since the caregivers sensitivity in dealing with the childrens signals represents the basis of forming a secure attachment, the requirements for the development of a secure attachment appear to be less favorable than in children in unaffected control groups.Moreover, it could be demonstrated that insecurely attached individuals are more susceptible to problems with emotional regulation and behavior regulation . ProblemIn addition, literature suggests that attachment security has a positive effect on certain areas of competency children with ADHD have difficulties with . Secure In contrast, disorganized attachment in early childhood shows a strong connection with a later abnormality or psychopathology , 55. AltIn a sample of 100 8½ year old children, Thorell et al.  demonstrn = 89) of 6–10 year olds and a short narrative story stem technique, likewise found significantly stronger expressions of ADHD in disorganized children than in children who were securely attached. This connection could not be accounted for either by the overlap between ADHD symptoms with externalizing behavior problems or by cognitive deficits. These latest results may suggest a specific connection especially between attachment disorganization and ADHD. However, the particular quality of this tie is not understood or even characterized yet.The latest study on this topic by Scholtens et al. , using aEven though individual research projects were able to underpin some theoretical considerations empirically in recent years – mostly within the connection of disorganized attachment and ADHD – results are very heterogeneous. Hence, the link between attachment and ADHD is still not demonstrated. One weakness of previous research on this topic lies in the general consideration of the construct ADHD. The various phenotypic expressions of this disorder are not taken into account, but are rather conceived as a global clinical construct. The resultant heterogeneity of the specific samples allows only poorly differentiated and inconsistent assertions about the relationship to other constructs. Instead, individual aspects of the disorder should first be considered separately in order to link specific symptom classes with respective constructs.In the above mentioned paper, Erdman  suggestsOne important variable that might affect the specific parent-child relationship is the parents’ own attachment representation. As discussed above, these representations play a major role in the intergenerational transmission of attachment. The contextual model of van IJzendoorn and Bakermans-Kranenburg  may idenAccording to these preliminary considerations, from an attachment perspective, there are two major aspects research should focus on. One should address the role of transgenerational transmission of attachment in the development of ADHD in the child. The second one should investigate whether attachment representations of children with ADHD differ from those of children without ADHD. If that is the case, the specific behaviors within the construct of ADHD that contribute to that difference need to be identified, since some behaviors might be the adequate contextual response to an impaired relationship with the parent. In doing so, it is important to keep possible mediating and moderating factors in mind that might also account for the relation between these two constructs. All these considerations are of great importance in the investigation of ADHD and attachment and can help to provide a more detailed and differentiated perspective on the extent of their mutual influence.