The two video clips were each about 5 min long and were designed to evoke negative (fearful) or positive (happy) emotion, respectively. Another group of participants (n = 37) was asked to select the two most emotionally arousing (most touching or most fearful) scenes in each clip. The results of these questionnaire surveys were used as the ground-truth to evaluate whether the GFS could detect emotional highlights of both video clips. The emotional highlights estimated using the grand-averaged GFS waveforms of the first group were also compared with those evaluated from galvanic skin response, photoplethysmography, and multimedia content analysis, which are conventional methods used to estimate temporal changes in emotional arousal during video plays. From our results, we found that beta-band GFS values decreased during high emotional arousal, regardless of the type of emotional stimulus. Moreover, the emotional highlights estimated using the GFS waveforms coincided best with those found by the questionnaire surveys. These findings suggest that GFS might be applicable as a new index for tracking emotional arousal changes of a group of individuals during video watching, and is likely to be used to evaluate or edit movies, TV commercials, and other broadcast products.In the present study, we investigated whether global electroencephalography (EEG) synchronization can be a new promising index for tracking emotional arousal changes of a group of individuals during video watching. Global field synchronization (GFS), an index known to correlate with human cognitive processes, was evaluated; this index quantified the global temporal synchronization among multichannel EEG data recorded from a group of participants ( Understanding human emotional processes is an important research topic in neuroscience, since emotion plays a key role in the communications and interactions among people. A number of studies have aimed at estimating human emotional state using bio-signals. Traditionally, human emotional state has been robustly estimated by extracting features from facial expressions and speech sounds , have been most widely used to evaluate or recognize human emotional state using EEG , photoplethysmography (PPG), and multimedia content analysis (MCA).In this study, we focused on developing a new index by which temporal changes in emotional state of a group of individuals can be precisely estimated. To this end, we recorded and analyzed physiological responses of a number of participants while they were watching video clips designed to evoke contrasting emotions. Among the potential indices, we tested the feasibility of global EEG synchronization as an emotional state index. This choice was based on the observation that functional connectivity is generally increased during cognitive processing, whereas it is decreased during emotional processing, especially in the beta and gamma frequency bands  and the second group consisted of 37 participants . All participants had normal or corrected-to-normal vision and none had a previous history of neurological disease, psychiatric disease, or any other severe disease that could have affected the study results. Before the experiments, detailed written and verbal information on the experiments was given to all participants, who received monetary reimbursement for their participation in our study. This study was carried out in accordance with the recommendations of the Institutional Review Board (IRB) of Hanyang University with written informed consent from all subjects. All subjects gave written informed consent in accordance with the Declaration of Helsinki. The protocol was approved by the IRB of Hanyang University.http://youtu.be/5_v7QrIW0zY) as of 2016 and will hereafter be referred to as the “positive clip.” In the video, which is 5 min 13 s long, a man named Isaac surprises his girlfriend with the “world's first” live lip-dub marriage proposal. The other clip, which was used to elicit fearful emotion, had been edited from a horror movie entitled “The Grudge.” In this video, which is 4 min 36 s long, sudden appearances of ghosts made subjects feel fearful. This video clip will hereafter be referred to as the “negative clip.” A 17-inch LCD monitor was used to play the two video clips. The participants were seated in a comfortable armchair placed in front of the monitor, with the distance between the monitor and the participants set to 70 cm.Two short video clips were presented to the participants. One video clip, which was used to arouse happiness emotion, was a short video clip entitled “Isaac's Live Lip-Dub Proposal.” This clip had been watched by more than 30 million people on YouTube (n = 25) watched each video clip while EEG, GSR, and PPG signals were recorded from them. Figure Participants in the first group (n = 37), except that no EEG, GSR, and PPG signals were recorded. The study participants watched each video clip twice. For the first viewing, participants were asked simply to concentrate on the video. At the conclusion of each video clip, participants were asked to memorize the two most emotionally arousing (most touching or most fearful) scenes in each clip. They were asked to select two scenes in each video clip because participants had difficulty selecting more than two impressive scenes in such short video clips. Then, during the second viewing, the participants were asked to record these two-time points on a questionnaire. The elapsed time was included in the video clips during the second viewing so that the participants could record the exact time information. In our study, the two subject groups were separately enrolled in two independent experiments. This design allow us to investigate whether emotional arousal changes estimated from one group can be generally applied to other groups of individuals, by which the general applicability of the proposed index might be validated.To find the “ground-truth” about the temporal changes in emotional arousal of each video clip, the same video clips were presented to the participants of the second group  with a head-cap mounted with active electrodes arranged according to the international 10–20 system. E-Prime software  was used to accurately synchronize the video start times during EEG recording. EEG signals were recorded from 22 scalp positions . GSR and PPG data were recorded using the same system (ActiveTwo). Two GSR electrodes were adhered to each participant's left index and middle fingers, and a PPG sensor was attached to one's right index finger. Additionally, two electrodes were used to measure the horizontal and vertical electrooculograms (EOGs). One electrode was placed below the right eye for vertical EOG recording and the other electrode was placed at the outer canthus of the right eye for horizontal EOG recording. All data were recorded at a sampling rate of 2,048 Hz. The ground was composed of a feedback loop between the common mode sense (CMS) active electrode and the driven right leg (DRL) passive electrode, to which the closest approximation is a POz electrode.Raw EEG data were preprocessed to remove unwanted artifacts. All preprocessing procedures were conducted using Curry 7 Neuroimaging software . The raw EEG data were re-referenced with a common average reference. We removed DC components in all channels by subtracting the mean of time series of each channel, and then the data were bandpass-filtered at 1 and 55 Hz cutoff frequencies. EOG artifacts by eye blinks were removed using principal component analysis. Finally, the preprocessed EEG data were segmented into 2-s epochs with a 50% overlap to continuously evaluate beta-band (14–25 Hz) GFS values over time. The GFS time-series of each participant was averaged across all participants, and then the grand-averaged GFS time-series was filtered using a ten-point moving-average filter. Moving average filtering was used because it was difficult to recognize the peak positions in the GFS waveforms due to the high-frequency ripples present in the raw GFS waveforms.Global field synchronization, a method used to quantify the overall functional connectivity of the brain, has generally been used to investigate cognitive decline in patients with psychiatric disorders 1 and E(f)2 are the two eigenvalues obtained from principal component analysis at a given frequency, f. A GFS value close to 1 can be interpreted as increased overall functional connectivity. On the other hand, a GFS value close to 0 represents decreased overall functional connectivity. Lee et al.  was evaluated for each individual. We extracted time points of maximum peaks of all spikes in each PPG waveform and calculated peak to peak intervals (PPIs). The consecutive PPIs could be readily transformed to an HR time-series; each HR time-series were then grand-averaged across all participants. This grand averaged HR waveform was filtered using a ten-point moving-average filter.Multimedia content analysis (MCA) is used to automatically evaluate the semantic meanings of a multimedia document . Interestingly, the two-time points in each video clip at which the GFS values dropped below the lower horizontal line  matched well with the time points most frequently chosen as impressive or memorable by the participants in the second group. At N1, the sudden appearance of a ghost and a character covered with blood made the audience feel most fearful. At N2, the ghost rushed to the character and a close-up of the ghost's face was shown. At P1, a female received a marriage proposal from her boyfriend right after a sudden appearance of him. At P2, her boyfriend kissed her. Additional time points at which the GFS values suddenly dropped near the lower horizontal line  are also shown in Figure http://youtu.be/-fT_FYZ2Ceo–positive clip; http://youtu.be/N-dPAAtkhss–negative clip).The grand-averaged GFS waveforms of each video clip are shown in Figure t-test for all participants' data. This analysis revealed that the GFS levels over the two conditions were significantly different . The GFS waveforms displayed with standard errors are also included in the Supplementary Information File. In addition, to exclude the possibility that the GFS waveforms were affected by muscle artifacts generally contaminating EEG signals at temporal electrodes (T7 and T8), we first evaluated variations of beta-band power spectral densities (PSD) at T7 and T8, the results of which are presented in the Supplementary Information File .The mean GFS values exhibited small variability from individual to individual. The average GFS values for the positive and negative clips were 0.488 ± 0.026 and 0.470 ± 0.015, respectively. The standard deviations of both GFS values were much less than the dynamic ranges of the grand-averaged GFS waveforms Figure . The avep = 0.05). In the results of MCA, time intervals showing highest RMS energy, denoted by MCA N1 and MCA P1 for the negative and positive clips, respectively, coincided fairly well with the time periods most frequently chosen by the participants of the second group (see Figure We compared other emotional features evaluated using MCA, GSR, and PPG with the results of questionnaire survey and GFS in order to demonstrate the superiority of the GFS. Figure This study aimed to track continuous changes in emotional arousal in a group of individuals using GFS, a measure of global EEG synchronization. In support of our hypothesis, decreased GFS values were observed when stimuli eliciting high emotional arousal were presented. It is particularly noteworthy that decreased GFS values were observed regardless of the stimulus valence. This finding supports our hypothesis that emotional processing distracts from cognitive processing, and that the GFS value, an indicator of cognitive processing, decreases during emotional processing. The scenes identified as most impressionable/memorable matched fairly well with the grand-averaged GFS waveforms, suggesting that our study design can potentially be applied to practical applications, such as the evaluation of cultural content or broadcasting products.Only a few studies have attempted to track continuous changes in brain status while subjects watch videos (Dmochowski et al., A series of studies have demonstrated that cortical functional connectivity has strong positive correlations with cognitive load and cognitive ability. For example, the execution of specific mental tasks requiring a high cognitive load, such as working memory tasks, oddball tasks, and stroop tasks, resulted in significant increases of overall functional connectivity (Polich et al., In our study, we divided participants into two groups and only recorded EEG data from one group. We separated the “training” group from the “test” group in order to demonstrate the general applicability of our index. Similar experiments were conducted recently by Dmochowski et al. . In theiC-HH: wrote literature, completed literature review; performed analysis of MCA, GSR, and PPG; main contributing author. Ju-HL: wrote literature, analyzed EEG data; main contributing author. C-HI: final approval authority, guided overall study process, advanced concepts of this study; significant contribution to authorship. Je-HL: advised in fundamental concepts, assisted our experiment. Y-WK: assisted our experiment, advised about process of data analysis.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.


Acquisition of stabilized video is an important issue for various type of digital cameras. This paper presents an adaptive camera path estimation method using robust feature detection to remove shaky artifacts in a video. The proposed algorithm consists of three steps: (i) robust feature detection using particle keypoints between adjacent frames; (ii) camera path estimation and smoothing; and (iii) rendering to reconstruct a stabilized video. As a result, the proposed algorithm can estimate the optimal homography by redefining important feature points in the flat region using particle keypoints. In addition, stabilized frames with less holes can be generated from the optimal, adaptive camera path that minimizes a temporal total variation (TV). The proposed video stabilization method is suitable for enhancing the visual quality for various portable cameras and can be applied to robot vision, driving assistant systems, and visual surveillance systems. The demand for a compact, portable camera is rapidly growing because of popularized consumer hand-held cameras with easy handling and compact size such as mobile cameras, digital cameras, digital camcorders, drone cameras, and wearable cameras. With the advancement of cloud services, acquisition of high quality videos becomes more important to share contents without the barriers of time and space. However, video sequences are subject to undesired vibrations due to camera shaking caused by poor handling and/or a dynamic, unstable environment. To overcome this problem, various video stabilization methods have been developed to improve the visual quality of various hand-held cameras . A mechaAn image processing-based video stabilization method generally consists of two steps: (i) removing undesired motion by smoothing the camera path and (ii) rendering the stabilized frames . ExistinCurrently, 3D camera motions are estimated based on the image segmentation result to improve the quality of a video. Liu et al. proposed a 3D video stabilization method using structure from motion and spatial warping to preserve 3D structures . Zhou etTo solve these problems, this paper presents a novel video stabilization algorithm using a robust feature detection method to improve existing 2D methods instead of the less robust 3D methods. The proposed algorithm redefines important feature points using particle keypoints. The homography is accurately estimated by detecting robust particle keypoints. Undesired motions are removed by minimizing the temporal total-variation of the camera path. As a result, the proposed method provides a significantly increased visual quality of shaky video acquired by a handheld camera.This paper is organized as follows. Digital video stabilization plays an important role of a stabilized sensor in acquiring high-quality video with preserving information for visual perception. A portable or wearable camera produces jitter and an undesired camera path because of various unstable video acquisition environments with camera shaking. Specifically, we can observe the geometric distortion of the video due to the mislocation of the pixels as shown in The shaky video can be considered as a geometrically transformed version of the ideally stable video. The relationship between feature points in the original and the shaky frames is defined in the homogeneous coordinate asTo solve these problems, we extract robust feature points to estimate the optimal homography of the textureless region. By updating important feature points in flat regions using the particle keypoint, the proposed method can significantly remove undesirable jitter using the optimally estimated homography in the entire image. The proposed method can also improve the visual quality without expensive optical devices by reconstructing stable video with a significantly reduced perspective distortion.The proposed video stabilization method estimates the optimal camera path of a certain length of video by redefining robust feature points and it is an extended version of Jeon’s work . Figure Given a pair of input shaky video frames Conventional video stabilization methods enhance the quality of a consumer video by estimating and smoothing the global path. Existing video stabilization methods assumed that temporally adjacent frames are related by a homography, which is robust to camera transformation, and the global camera path can be easily estimated using the geometric transformation. The global camera path is estimated by matching feature points that are robust to a geometric transformation. However, existing methods fail to detect feature points in a flat region. In addition, an inaccurately estimated homography in a textureless region further degrades the stabilization performance. In order to solve this problem, the proposed method generates the flat region map and the optimal camera path by redefining important keypoints in a flat region.t-th original shaky frame and the corresponding flat region map.A textureless region is extracted using the flat region map. A spatially smoothed frames are obtained by convolving the shaky frames Matching of features between temporally adjacent frames is very important to understand the geometric relationship of two frames and detect specific objects in video ,21. Varin contiguous neighborhood pixels p is a corner, the decision tree classifier is trained using the iterative Dichotomiser 3 (ID3) algorithm. The keypoints p is defined asx represents the neighborhood that is selected by decision tree using the ID3 algorithm, and t the threshold for comparing intensity. We used t=0.2 for the experimentally best result. BRIEF identifies local feature points by comparing intensities of sampling pairs. The homography can be computed very efficiently because a binary string can be matched using the hamming distance by the XOR operation.The proposed method combines FAST and BRIEF for fast, accurate extraction of feature points. FAST extracts feature points by comparing intensities with 16 neighborhood pixels in the circle. We determine the corner if the intensity of the N particle keypoints μ and σ respectively represent the mean and standard deviation of the distribution. The descriptor matches the frames in the sense of the distance between particle keypoints and FAST and BRIEF keypoints. The descriptor t-th frame is defined asThe FAST keypoints are extracted between two adjacent video frames Final correspondences are matched using the sum of squared difference (SSD) of the descriptors of two frames. The descriptor is used to match robust keypoints in the flat region using particle keypoints. Finally, the optimal homography outliers . RANSAC Traditional video stabilization methods use a moving average of Gaussian filter to smooth the camera path. The moving average filter can smooth the camera path using the temporal mean of neighboring frames. The Gaussian kernel can remove undesired motion using the global transformation . HoweverA the temporal difference matrixλ represents the weight coefficient for smoothing. The first term of Equation =Pt−fined asE(Pt)=Pt−x-coordinates of the original camera path in the dotted curve and the smoothed path using the moving average filter in the solid curve. y-coordinates of the original camera path in the dotted curve and the smoothed path using the moving average filter in the solid curve. x-coordinates of the original camera path in the dotted curve and the smoothed path using the proposed method in the solid curve. y-coordinates of the original camera path in the dotted curve and the smoothed path using the proposed method in the solid curve. The proposed method can smooth the camera path without undesirable jitters and delay.The final step of video stabilization is to reconstruct geometrically transformed frames using the smoothed camera path. The smoothed homography As a result, the proposed video stabilization method can successfully generate a stabilized video by estimating the optimal homography.l1-norm error evaluation asThis section presents experimental results and compares the performance of the proposed and existing methods. The proposed method improves the video quality by estimating the optimal homography using the particle keypoint update. To verify the accuracy of the estimated homography  used in ,25, respTo evaluate the empty region caused by the process of frame registration for stabilization, we compared the results of the proposed stabilization method and YouTube stabilizer using the same test video as shown in As shown The difference between two successive frames is minimized since the proposed method reduces the noisy motions. To evaluate the objective performance, we used the peak signal to noise ratio (PSNR) values of the temporally adjacent frames. The PSNR is defined asFinally, we measured the perspective distortion for objective assessment of the proposed video stabilization method using Liu’s method . As mentUnstable videos with undesired camera motions have the limited performance of object detection and tracking. The final experiment is performed to demonstrate whether the proposed method can play a practical role of pre-processing in various video analysis systems. We used the Lucas-Kanade feature tracker (LKT) to demonstrate the performance of the object tracking on shaky and stabilized videos. The stabilized results used in The proposed video stabilization method removes unstable motions by estimating the optimal camera path using the robust keypoints extraction in the textureless region, and it smooths the shaky motions without frame delay using the variational optimization method. In addition, the proposed method is particularly suitable for hardware implementation in handheld cameras since it estimates the optimally camera path of shaky video using only four vertices in each frame. As a result, the proposed algorithm can successfully enhance the shaky video using an improved 2D stabilization method based on particle keypoints. The proposed method can be used for various video systems including mobile imaging devices, video surveillance systems, and vehicle imaging information systems. To overcome the vibration of the video acquired by vision-based mobile robots, the state of the art technology presents video stabilization system on a field programmable gate array (FPGA) based mobile robot system to apply to the single chip based embedded system for real-time video stream . The pro


January 2016 saw the publication of proposed revisions to the UK’s lower risk drinking guidelines but no sustained promotional activity. This paper aims to explore the impact of publishing guidelines without sustained promotional activity on reported guideline exposure and determinants of behaviour  proposed by the COM-B model.Data were collected by a monthly repeat cross-sectional survey of adults (18+) resident in England over 15 months between November 2015 and January 2017 from a total of 16,779 drinkers, as part of the Alcohol Toolkit Study. Trends and associated 95% confidence intervals were described in the proportion of reported exposure to guidelines in the past month and measures of the capability, opportunity and motivation to consume alcohol within drinking guidelines.There was a rise in reported exposure to drinking guidelines in January 2016 (57.6–80.6%) which did not reoccur in January 2017. Following the increase in January 2016, reported exposure reduced slowly but remained significantly higher than in December 2015. In February 2016, there was an increase in measures of capability  and opportunity (84.0% perceived their lifestyle as conducive to drinking within guidelines). This change was not maintained in subsequent months. Other measures showed marginal changes between January and February 2016 with no evidence of change in subsequent months.Following the publication of revised drinking guideline in January 2016, there was a transient increase in exposure to guidelines, and capability and opportunity to drink within the guidelines that diminished over time. The transience and size of the changes indicate that behaviour change is unlikely. Well-designed, theory-based promotional campaigns may be required for drinking guidelines to be an effective public health intervention.The online version of this article (10.1186/s12889-018-5129-y) contains supplementary material, which is available to authorized users. In 2012, as part of the UK Government’s Alcohol Strategy, the country’s Chief Medical Officers were asked to oversee a review of their lower risk drinking guidelines. The review aimed to “support individuals to make informed choices about healthier and responsible drinking” (p. 4). Key milestones in the process of updating the guidelines are summarised in Table After publishing the proposed revisions in January, the new guidelines were subject to a public consultation until April 2016 which focused on whether the recommendations and reasoning behind them were clear and easy to understand [Guidelines, and their promotion, are prominent features of public health policy in the UK and beyond with governments or medical authorities publishing drinking guidelines in at least 37 countries . One limThere are a number of theoretical frameworks available to understand processes of behaviour change and the model used was chosen as it integrates core constructs present in many earlier theories . The modThis research aims to explore whether drinkers were exposed to the revised guidelines following their publication and promotion in January 2016 and whether capability, opportunity and motivation to drink within the revised guidelines changed.Data for this study were taken from the Alcohol Toolkit Study (ATS) which is a monthly repeat cross-sectional survey of approximately 1600 adults living in England. Data collected between November 2015 and January 2017 were included to provide a total sample size of 25,443. This timeframe includes two survey waves prior to the revised guideline publication and 13 subsequent waves. Data collection for January 2016 occurred in the week following publication of the proposed DGs. Since the Alcohol Toolkit Study was expanded for the purpose of evaluating the new low impact DGs in November 2015, data collection prior to this was not possible.The ATS uses a type of random location sampling in which 171,356 ‘output areas’, each of which holds around 300 households, are stratified based on geographic area and socioeconomic status. Sampled strata are then randomly allocated to interviewers who choose the houses to visit and conduct computer-assisted interviews with one member of each household. This process continues until quota targets, based on factors which influence the probability of being at home, are met. Data are then weighted using an iterative sequence of weighting adjustments to match nationally representative profiles based on age, sex, social-grade, region, working status and children in the household. The sampling method used is often considered to be superior to standard quota sampling as the choice of properties approached is significantly reduced. As interviewers choose houses within their allocated strata, there is no definite gross sample size and response/refusal rates cannot be meaningfully calculated. The full ATS methods are described in the study protocol .The first question of the AUDIT (Alcohol Use Disorders Identification Test) screening tool  was usedRespondents who reported that they were drinkers were asked: “Before this interview, have you ever heard of there being a recommended maximum number of alcohol units people should drink in a day or a week? This is sometimes known as a ‘drinking guideline’.” The response options were “Yes” or “No”. Those responding “No” were classified as ‘unexposed’ to the DGs while those responding “Yes” were asked: “In which of the following places, if any, have you seen, read or heard this drinking guideline figure mentioned in the last month?”. There were 12 possible responses to this question including the option “Have not seen it mentioned in any of these places”. Those responding that they had not seen it were also classified as ‘unexposed’ and those providing one or more place(s) that they had seen the guideline were classified as ‘exposed’.The main outcome measures were 10 questions with ordinal response scales designed to capture the capability, opportunity and motivation components of the COM-B model Table . The desResponses to these questions have been dichotomised into ‘positive’ and ‘negative’ groups as shown in Table n = 1443). The number excluded for the rest of the measures was between 243 and 191. The same approach was used to assess change in reported DG exposure for which 2131 participants were excluded due to missing data on their exposure status.Changes in responses to 10 COM-B measures over the 15 monthly datasets between November 2015 and January 2017 were examined using the 95% confidence intervals around the overall proportion of positive responses. December 2015 was used as a reference point to identify trends, since the draft guidelines were published in January 2016. All analyses were based on weighted survey data. Cases were excluded pairwise where the response to the question being analysed was ‘Don’t know’, ‘Refused’ or missing. The number of exclusions was highest for the first question, which related to knowledge of how many units it is safe to regularly consume  and seven point scales contained only two positive responses (instead of three). A further sensitivity analysis was conducted for item 1, in which participants who responded ‘Don’t know’ were included in the negative response group. All analyses were conducted in IBM SPSS Statistics version 23.Drinkers’ self-reported exposure to DGs in any location rose from 57.7% in December 2015 to 80.6% in January 2016  said that it was safe to regularly drink two or fewer units in December 2015. There was no clear trend in this proportion over time. The proportion of people who believed it was easy to drink less than three units a day and who tracked their units increased in February 2016 when compared with December 2015, although these improvements were modest (4.4 and 5.8%) and not maintained in the subsequent months  to 84.0% (81.8–86.2%) but the improvement was also not maintained.The second opportunity measure asked whether the respondent knew where to find information on cutting down their consumption of alcohol. There was no clear trend over time in positive responses to this see Fig. .Fig. 3TrThe first four questions designed to measure motivation  focus on different aspects of motivation. The first two ask about drinking more than is good for you, whether the respondent ‘want/s to’ avoid it and whether they’re ‘actively’ trying to avoid it. The next pair relate to respondents keeping their drinking within safe limits and respectively ask whether they ‘want to’ or ‘intend to’ do so. The questions which ask about whether participants ‘want to’ engage in the specified behaviour are designed to assess automatic motivation while their counterparts assess reflective motivation.The proportions of respondents who reported that they wanted to, or were actively trying to avoid drinking more than is good for them in December 2015 were lower (52.2 and 42.5%) than the proportions of people who wanted to, or intended to, keep their drinking within safe limits (77.0 and 77.0%). Trends in positive responses to these four measures were marginal between December and February.Lastly, automatic motivation was further assessed by question ten, which asked how concerned each respondent was about drinking more than is good for them. In December 2015 this proportion was 25.0% 22.4–27.6%). There was no clear change in the proportion of respondents who were concerned over time  and opportunity (proportion who perceived their lifestyle as conducive to drinking within guidelines). However, the change did not persist over subsequent months. Additionally, we observed some marginal changes in other measures.A key strength of this research is its use of a theory-based framework for studying behaviour change (COM-B) in order to explore the short term effects of promoting lower risk DG . FurtherAmong the key limitations are the potential confounding effects of December and January being traditionally heavy and light drinking months. However, data were collected over 15 months which facilitated comparison of results at guideline publication to those from the following year. Data collection was by self-report which is subject to known biases in studies on alcohol consumption; even though this study is not measuring consumption directly, issues such as social desirability may still have impacted responses , 17. SinAlthough previous evaluation of the efficacy of drinking guidelines to change behaviour is limited, this result is consistent with findings of low impact on those measures which have been explored , 8. A coThere was no difference in respondents’ knowledge of the number of units per day which it is safe to drink regularly over time


New methods of dosimetry in computed tomography (CT) X‐ray fields require the use of high‐resolution detectors instead of pencil‐type ionization chambers typically used for CT dose index (CTDI) measurements. This paper presents a study on the suitability of a wide range of ionization chambers, diodes, and a two‐dimensional detector array, used primarily in radiation therapy, for CT and cone‐beam CT dosimetry. Specifically, the energy dependence of these detectors from 50 kVp up to 125 kVp is reported. All measurements were performed in reference to a calibrated diode for use in this energy region. The radiation quality correction factors provided by the manufacturer were used, depending on the measured half‐value layer (HVL) for the particular X‐ray beam. Our study demonstrated the general usability of thimble ionization chambers. These thimble ionization chambers showed a maximum variation in energy response of 5%. Ionization chambers with even smaller sensitive volume, and which exhibit similar variation in energy dependence, can be used if higher spatial resolution is required. Furthermore, the investigated detectors are better suited for dosimetry at CT and CBCT units than conventional large volume or flat detectors, due to their rotational symmetry. Nevertheless, a flat detector can be used for certain measurement tasks, such as the acquisition of percent depth‐dose curves or beam profiles for nonrotating beams, which are important for beam characterization.PACS numbers: 87.57.uq, 87.56.Da, 87.57.Q‐ Dosimetry for CT devices is mostly limited to measurements of so‐called computed tomography dose index (CTDI) values and various dose conversion factors.CTDI100 is expressed as follows:nT is the total nominal collimation and D(z) the axial dose profile. The quantity CTDI100 serves as the primary dose descriptor for computed tomography.According to the international  and national codes of practice , the definition of the For new 256 slice CT scanners, the X‐ray cone beam already exceeds this integration length without even consideration of scattering.Additionally to the enlargement of the scanning beam, the routinely used scanning protocols are becoming more complex. Now common, tube current modulation (TCM) is utilized to ensure homogeneous image quality for scans of body regions with large variations in diameter, or to spare sensitive organs by reducing the tube current for certain arc segments within the tube rotation. These new technologies complicate the interpretation of the associated CTDI.Further dosimetry challenges result from the diversity in scanning techniques such as longitudinal and angular TCM, as well as variable pitch and z‐collimation like the new “rolling collimator”. The transfer of the CTDI concept also is problematic for scans without couch increment like perfusion studies or cone beam CTs in general. Therefore, new nonstandard measurement protocols for CTDI and CT dose profiles with small sensitive volume ionization chambers instead of pencil‐type ionization chambers in longer dosimetry phantoms were introduced.General X‐ray radiography ionization chambers, intended to measure incident doses, are usually plane parallel flat chambers with a relative large volume. In contrast, for dosimetry in CT fields, axially symmetric probes are needed and, especially for dose profile measurements, a small volume is required. Additional parameters needed for modeling X‐ray beams in Monte Carlo calculations, such as geometric efficiency, can only be determined using small volume detectors.60Co. Scandurra and LawfordIn previous studies, several ionization chambers designed primarily for dosimetry of megavoltage photon beams have been investigated in terms of their usability in X‐ray therapy.In this work, the usability of common dosimeters for megavoltage photon beams in diagnostic CT radiation fields is systematically evaluated. Additionally, the results complement the hitherto existing beam quality correction factors for several detectors in the energy range from 125 kVp down to 50 kVp with filtrations commonly used in modern CT scanners.An Oldelft Simulix MC X‐ray device  with a Hofmann Selector MD HV generator  and Varian G297 X‐ray tube in a Varian DO10 housing  was used for irradiation of all detectors. The X‐ray tube is mounted on a gantry in a focus‐isocenter‐distance of 100 cm with a collimator. This enables full control of focus‐surface distance, field size, and shape. Inherent filtering of the whole unit is 3.3 mm Al. Additional filters were used in a tray located 30 cm from focus, mounted at the collimator. The high voltage generator allows accelerating potentials ranging from 40 kVp up to 125 kVp.In order to evaluate the performance of various detectors in CT radiation fields, beam qualities similar to those common for CT devices were used. The total filtering was adjusted according to data provided by Siemens AG  with a mean value for the bowtie filter in a Siemens SOMATOM Sensation 64 CT unit. 20 cm×20 cm field in a focus distance of 100 cm. The manufacturer‐defined reference point of each detector was placed in this plane. Since the dose distribution of the radiation field is not completely uniform, a specific area of interest providing a flat homogeneous dose distribution was identified using the PTW 2D‐Array  were investigated. The specifications of all investigated detectors are listed in 1 cm3 when used for X‐ray dosimetry in this energy range. For CTDI measurements, only pencil‐type chambers are recommended.These detectors were chosen also by taking into consideration their general suitability according to DIN 6809‐4 and DIN 6809‐5, which state that the sensitive volume of parallel plate chambers or compact chambers should not exceed The PTW 60004 diode was used with a PTW DIADOS electrometer which was included in the original calibration process.x at a particular beam quality, E, was determined as follows:PQ(E)Ref is the air‐kerma beam quality correction factor (see M(E)Ref is the electrometer reading for the PTW 60004 reference diode, and M(E)x is the reading for the ionization chamber or diode under investigation. If the measured beam quality did not match the provided values, PQ(E)Ref was calculated using the two closest given qualities and a short range linear interpolation. Since all measured data were normalized to the reading at 70 kVp and taken in a close timely manner to their normalization readout, additional corrections like pressure and temperature correction were not applied, but monitored. This peak potential was chosen because the PTW 60004 reference diode was calibrated at this beam quality, and a correction factor has to be applied for every other quality. The maximum variation in energy response for this diode is 2.5% (The relative detector response (RDR) of an ionization chamber or dosimetry diode was determined according to the previously published method.ctor see  for the  is 2.5% .The RDR in air was measured with each detector listed in The uncertainties associated with a comparable measurement setup as used in this study have been analyzed by Hill et al.In order to evaluate the influence of the different phantom materials, a comparison measurement was performed with the PTW 31010 and PTW 31013 Semiflex chambers. For these chambers, the RDR was measured in water as well as in the Solid Water phantom. The difference in RDR was smaller than 2.6% for the PTW 31010 Semiflex chamber and smaller than 2.3% for the PTW 31013 Semiflex chamber, which is within the uncertainty of this measurement.The RDR calculated according to The RDR for the thimble ionization chambers were found to decrease with decreasing energy both in free air and in water , 3. This and IBA uses C552 plastic . Therefore, the PTW chambers are equipped with a lower Zmean, whereas the total wall density is higher than for IBA chambers. The ionization chambers with about 0.1 cm3 sensitive volume show the lowest variation in energy response. Especially the PTW 31010 Semiflex chamber (0.125 cm3) and IBA CC13, as well as IBA CC13‐S (0.13 cm3) Compact Chambers, all having nearly the same sensitive volume, showed very similar energy response variation in free air of 2.9%, 3.2%, 3.4%, respectively. This implies that the combination of lower Z and higher density in case of the PTW Semiflex chambers results in a similar photoelectric absorption for chambers of comparable volume. The results for the Semiflex chamber PTW 31013 are consistent with the results from the previous study by Hill et al.The two Semiflex chambers, PTW 31010 and PTW 31013, and the Compact Chambers IBA CC08, CC13, and CC13‐S  show a similar RDR due to their very similar design. Major differences for these chambers are the length of the sensitive volume and the wall material. The PTW chamber wall is made of PMMA Since the CTDI pencil‐type ionization chamber PTW 30009 is not waterproof and no suitable adapter for the Solid Water phantom was available, only measurement in free air was possible. A direct comparison to the manufacturer‐provided correction factors is not possible since the CTDI chamber was calibrated at a different energy. Nevertheless the variation in energy response of 2.3% found in this study is comparable to the manufacturer‐provided value of 3%.3 in this group this chamber shows the properties similar to the small volume chambers discussed later.The largest variation in RDR in this detector group was found for the Compact Chamber IBA CC08. With the smallest sensitive volume of 0.08 cm10×10 cm2 in Li et al, 6 cm diameter in Hill et al., and 20×20 cm2 in our study), as well as in SSD , and spectral composition  of the 100 kVp beam: 2.43 mm in Li et al., 3.9 mm in Hill et al., and 8.5 mm in our study).In this study, an increasing RDR in free air of 19% variation for the PTW 23343 Markus chamber and 15.4% for the PTW 34001 Roos chamber , Table 3The Roos type chamber was only used by Hill and colleagues and showed a similar behavior like the Markus chamber which could be confirmed here. The Hill study showed already the accuracy of the percent depth‐dose curves measured with both the Markus and Roos type chambers.Both investigated dosimetry diodes PTW 60008 and PTW 60012 showed stronger energy dependence in free air as well as in water than the air cavity based detectors. This may be due to the optimization of the construction for high MeV beams, like the introduction of additional guarding electrodes.Comparison between the small volume ionization chambers IBA CC01, CC04, PTW 31006, 31014, 31015, and 31016 with the larger thimble chambers shows in general a larger RDR variation for the smaller chambers. This is caused by the increasing ratio of high‐Z materials like Al or C in the electrodes compared to the small air cavity and, thus, more energy deposition through photoelectric effect. Additionally, the overall design of the chamber has a large impact on the results due to the limited size of the chamber, and may lead to an opposite effect.The largest energy dependency in this group of detectors was found for the pinpoint chambers PTW 31006  and IBA CC01 . This is attributed to the steel central electrode in these chambers, perturbing the radiation field due to the increased photoelectric cross section. The pinpoint chambers PTW 31014, PTW 31016 and especially the PTW 31015 and IBA CC04, which have larger sensitive volumes and are equipped with Al central electrodes, do not contain as much high‐Z material. Therefore, a lower overresponse for low‐energy beams compared to the steel electrode pinpoint chambers IBA CC01 and PTW 310006 is expected and was found in free air , as wellThe PTW 31016 showed the greatest variation of relative detector response. Based on the manufacturer's data, this chamber is optimized for a 3D response in small MV beams. In the intended application fields described in this work, this seems not to be advantageous.The PTW 2D‐Array seven29 showed a larger RDR variation than the single ionization chambers with comparable volume . This may be due to the copper‐based electrode matrix, which is used as electrode in this detector. However, the RDR of the 2D‐Array with 15% variation is comparable to 8%–12% variations for the single chambers in the whole investigated energy region. The disadvantage of the PTW 2D‐Array is its nonrotational symmetric design of the single chambers. Nevertheless, the 2D‐Array can be very useful in nonrotating radiation fields, such as the overview scan before a CT examination or for measurements in service mode with a fixed X‐ray tube. It enables the acquisition of the whole two‐dimensional beam profiles in a single measurement, similar to radiographic films.It has been demonstrated that the thimble ionization chambers PTW 31010 and PTW 31013, as well as the IBA Compact Chambers of comparable sensitive volume IBA CC13 and IBA CC13S, with a maximum variation in RDR in free air of 5% are well suited for dosimetry in X‐ray fields of computed tomography and CBCT units, such as those integrated to linear accelerators for image‐guided radiation therapy. If higher spatial resolution is needed, Compact Chamber IBA CC04 or PTW 31015 or PTW 31016 PinPoint chambers with Al central electrodes can also be used. Energy response of these detectors has been analyzed by the method proposed by Li et al.Dosimetry diodes PTW 60008 and PTW 60012 are of limited use in this low‐energy range due to their optimization in designs for high MV beams.Parallel plate chambers PTW 23343 and PTW 34001 showed a similar RDR to previous studies. In addition to these chambers, the PTW 10024 2D‐Array was investigated and a comparable variation in detector response in this energy range was found. Therefore, it is worthwhile to investigate the application potential of such 2D‐Arrays for nonrotating irradiations.www.helmholtz‐muenchen.de/kvsf/ for further information.This study was funded by the Bundesministerium fuer Bildung und Forschung through the grant 03NUK008A. See Supplementary MaterialClick here for additional data file.


RCD often occurs in a delayed manner and is initiated in the context of adaptive responses that unsuccessfully attempt to restore cellular homeostasis. It is important to mention that the term RCD includes both physiological instances of death, referred to as ‘programmed cell death’, but also death processes that occur in pathological contexts. Our comprehension of cell death subroutines has progressed significantly, as the main molecular events underlying these mechanisms have been elucidated.Ppif gene. At present, CyPD is the unique genetically confirmed component of the permeability transition pore complex (PTPC) in the mammalian system,3 a supramolecular complex operating at the junctions between the inner and outer mitochondrial membranes that may cause the ‘mitochondrial permeability transition’ (MPT), an abrupt increase in the permeability of the inner membrane to small solutes, triggered by cytosolic Ca2+ overload and/or oxidative stress.4 The importance of CyPD for MPT has been recognized for a long time in mammalian systems, mostly due to the consistent cytoprotective effects mediated in vitro and in vivo by Cyclosporin A (CsA), an immunosuppresive undecapeptide that acts as a CyP inhibitor.4 Moreover, both the administration of CsA and the genetic ablation of the Ppif gene in a knockout mice model (known as Ppif−/− mice) have been shown to limit necrotic cell death, in vitro as well as in vivo, in a variety of pathophysiological settings, including ischemia−reperfusion injuries of the heart, brain and kidney . Once MPT has been established, it seals the cell fate independently of caspase activation. ‘MPT-driven RCD’ should be used for cell death instances whose course can be influenced by the genetic or pharmacological inhibition of CyPD. Perhaps, CyPD's central role in MPT-driven RCD reflects its ability to control the Ca2+ buffering capacity of the mitochondrial network, although this hypothesis has not been yet fully addressed.1A variant of RCD that often manifests with necrotic morphotype critically relies on Cyclophilin D (CyPD), a mitochondrial matrix peptidyl-prolyl isomerase, which is encoded by the A lot of research has been done in mammals, but still very little is known for protozoan parasites, one of the most ancient phylogenic branches of unicellular eukaryotes. Although the benefits of RCD in unicellular organisms are less evident than in mammalian tissues, there are increasing numbers of reports that describe that some unicellular organisms undergo RCD under certain conditions. A more precise description of unicellular death would be informative in the comprehension of how cell death has evolved in higher eukaryotes.Moreover, as Cyclosporin A and its non-immunosuppresive analogs are known to exhibit anti-parasitic effects on a wide range of organisms, including several protozoan parasites of medical importance, a profound knowledge of their cyclophilin repertoire and the possibility of the MPT-driven RCD pathway present in these organisms represents a challenging field to be explored.Trypanosoma cruzi, where we observed that parasites grown in an oxidative stress environment with H2O2 underwent cell death, showing typical features such as DNA degradation, ROS production, cytochrome c release into the cytosol after induction and sensitivity to CsA inhibition, suggesting that a T. cruzi mitochondrial cyclophilin could be present in a MPT-like structure in this protozoan parasite.5The response of the RCD phenotype to various stimuli has been measured in protozoan parasites. In T. cruzi is a unicellular protozoan parasite that infects 7–8 million people in South America as well as in other parts of the world through migrations from endemic areas.6 The T. cruzi infection can evolve into Chagas disease, a potential life-threatening illness.7 Our research group has described the T. cruzi CyP gene family and reported the expression of several parasite cyclophilins that exhibited enzymatic PPIase activity, inhibited by CsA.8Cell Death Discovery, we identified that a homolog of mammalian CyPD is expressed in T. cruzi, named TcCyP22. This protein was localized to the parasite mitochondrion in the three stages of the parasite life cycle, as expected. Interestingly, in parasites overexpressing TcCyP22, an increased susceptibility to hydrogen peroxide effects was observed, demonstrating that this protein is directly involved in parasite RCD.9In a report published in To our knowledge, this was the first identification of a homolog of a CyPD in a protozoan parasite and shows that the MPT-driven RCD could be an evolutionarily well-conserved pathway from this ancient eukaryote. However, whether CyPD homologs are also present in the other protozoan parasites remains to be elucidated.The study of parasitic protozoa during infections in the insect and mammalian hosts could provide useful information about natural cell death. These insights could ultimately lead to the identification of key regulatory or executioner molecules that are central to RCD. Such discoveries would potentially provide the basis of novel therapeutic strategies. Further study of protozoan parasites' death process will be of significance in a greater understanding of the interaction between the parasite and its host, and also cell death mechanism in general.


The test-retest reliability of the primary PIPR outcome parameter was very high, both between day-to-day assessments (Intraclass Correlation Coefficient (ICC) = 0.85), as well as between winter and summer assessments (ICC = 0.83). Compared to the PIPR obtained with the use of mydriatics and 160 µW/cm2 blue light exposure, the method with intensified light without mydriatics showed almost zero bias according to Bland-Altman plots and had moderate to strong reliability (ICC = 0.67). In conclusion, for PIPR assessments, increasing the light intensity is a feasible and reliable alternative to pupil dilation to relieve the participant’s burden and to allow for performance outside the ophthalmological clinic.Melanopsin-containing retinal ganglion cells play an important role in the non-image forming effects of light, through their direct projections on brain circuits involved in circadian rhythms, mood and alertness. Individual differences in the functionality of the melanopsin-signaling circuitry can be reliably quantified using the maximum post-illumination pupil response (PIPR) after blue light. Previous protocols for acquiring PIPR relied on the use of mydriatics to dilate the light-exposed eye. However, pharmacological pupil dilation is uncomfortable for the participants and requires ophthalmological expertise. Hence, we here investigated whether an individual’s maximum PIPR can be validly obtained in a protocol that does not use mydriatics but rather increases the intensity of the light stimulus. In 18 participants  we evaluated the PIPR after exposure to intensified blue light (550 µW/cm The suprachiasmatic nucleus (SCN) in the hypothalamus encompasses the endogenous biological clock, which drives physiological, endocrine, and behavioral rhythms with a periodicity of about 24 h . The daiBesides circadian photoentrainment, ipRGCs are also involved in the regulation of mood , alertneAccordingly, we have previously developed a reliable and robust method to assess individual differences in the maximum PIPR  and showPrevious studies have presented reliable PIPR measurements without pharmacological mydriasis ,29. The A total of 18 volunteers : 34.6 ± 13.6 (22–69) years) were enrolled. Volunteers were assessed at two different locations with different experimenters and the same equipment: the Netherlands Institute for Neuroscience in Amsterdam  and PsyQ Expertise Center Adult ADHD in The Hague . All participants were informed about the procedure, signed informed consent, and did not receive any incentive. None of the participants had a self-claimed history of ocular pathology and none reported to use any medication known to influence the PLR. According to Nagel anomaloscope tests, none of the participants had a color vision deficiency. The study was approved by the Medical Ethical Committee of the VU University Medical Center Amsterdam (protocol NL43319.029.13) and adhered to the tenets of the Declaration of Helsinki.The previously established pupillometry procedures have been described elsewhere . In brie2 . In order to assess whether increasing the intensity of the light stimulus may compensate for the possible reduced PIPR in the absence of pharmacological mydriasis the previously used saturating PIPR assessment condition was also compared to the condition in which the light intensity was increased, 550 µW/cm2 during blue light and the illuminated pupil was kept in its natural undilated state (550My−). In view of comments from participants in a previous pilot study, reporting major discomfort during exposure to a stimulus of such intensity with tropicamide application, we refrained from assessing the PIPR after intensified blue light with pharmacological mydriasis. Light intensities were calibrated using a spectrometer . The light stimuli activate all photoreceptors, the effect on each photoreceptor during each light stimulus are shown in The previously established protocol to assess the PIPR involved a blue light stimulus with an irradiance level of 160 µW/cm2  and the For both PIPR-mm and PIPR-%, differences between 160My+ and 160My− and differences between 160My+ and 550My− were visually inspected using Bland-Altman plots . To evalThe values for baseline and post-blue pupil diameter, PIPR-mm and PIPR-%, are shown in The Bland-Altman plots indicated almost zero bias between 160My+ and 550My− for PIPR-mm and PIPR-%  indicatiDuring baseline dark there was an almost perfect agreement between 160My+ and 160My− (ICC = 0.88) and also between 160My + and 550My− (ICC = 0.92). Bland-Altman biases also indicated this high similarity .Fifteen : 36.4 ± 14.3 (23–70) years) out of the 18 participants returned to the lab for two consecutive summer assessments, one day apart. Bland-Altman plots indicated almost zero bias between the outcome measures of the 550My− protocol for PIPR-mm and PIPR-% , indicatThe Bland-Altman plots also indicated almost zero bias between 550My− winter and 550My− summer measurements for PIPR-mm and PIPR-% , indicatIn order to allow for a wide application of assessing the functionality of the melanopsin-signaling circuitry, we here examined whether an individual’s maximum PIPR can be validly assessed without mydriatics by instead increasing the intensity of the light exposure. In our previously established paradigm, with mydriatics, the 5-min duration of the blue light stimulus was expected to saturate the ipRGCs ,37,40, l2, evoked a reduced PIPR when the pupil was kept in its natural dynamic state compared to the condition with the use of mydriatics. This indicates that dilation of the pupil or intensifying the light is required to evoke a maximum PIPR.The previously established blue light stimulus with an irradiance of 160 µW/cmThe retinal illuminance during blue light was over four times higher for the previously established protocol with mydriatics compared to the condition with intensified blue light without mydriatics. In spite of this fourfold difference, the PIPR did not systematically differ between these conditions. This suggests that during both conditions the ipRGCs response was saturated and a maximum PIPR was generated, since there was no further increase in PIPR even though the blue-light retinal illuminance was higher in the previously established protocol.2 blue light with mydriatics protocol and the alternative protocol with intensified blue light with a natural pupil indicates that both approaches are valid for eliciting the maximum PIPR. However, there can be individual variation between the results obtained with these two approaches, indicating that they should not be used interchangeably.The moderate to strong agreement between the previously established 160 µW/cm2 blue light and mydriatics . This indicates that although the pupil is dynamic and the amount of light reaching the retina has a larger variation in the protocol with intensified blue light without mydriatics, this does not seem to affect the reliability of this protocol, suggesting saturation of the response at a certain intensity.The within-subject test-retest of the protocol with intensified blue light with a natural pupil showed a very high agreement for both PIPR-mm and PIPR-%, approaching the reliability of our formerly established protocol with 160 µW/cmPrevious research showed that the post-illumination contraction amplitude following blue light was larger in summer compared to winter . HoweverIn patients with retinal diseases pharmacological pupil dilation may not be without risk since dilation can lead to a rise in intraocular pressure . With ipA limitation of the study is the unequal gender distribution, there were more females included than males, which may have confounded our PIPR results. Accordingly, some parameters of the PLR were shown to be mildly affected by gender . Future The aim of the present study was to evaluate an accessible PIPR assessment protocol without mydriatics to relieve the participant’s burden and to allow for a wide application of safe PIPR measurements. This protocol was an adaption of an established reliable pupillometry paradigm, which was designed to evoke a maximum PIPR in order to estimate functionality of the intrinsic melanopsin-dependent circuitry . In spit


Scientific Reports7: Article number: 4466710.1038/srep44667; published online: 03202017; updated: 04192017The original version of this Article contained an incorrect affiliation list. The correct affiliations are listed below:Affiliation 1Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas, 77030, USA.Sangeetha Mahadevan, Khalied Kaskar & Ignatia B. Van den VeyverAffiliation 2Jan and Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, 77030, USA.Sangeetha Mahadevan & Ignatia B. Van den VeyverAffiliation 3Century Scholars Program, Rice University, Houston, Texas, 77005, USA.Varsha SathappanAffiliation 4Shared Equipment Authority, Rice University, Houston, Texas, 77005, USA.Budi UtamaAffiliation 5Department of Molecular Human Genetics, Baylor College of Medicine, Houston, Texas, 77030, USA.Isabel Lorenzo & Ignatia B. Van den VeyverAffiliation 6Interdepartmental Graduate Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, Texas, 77030, USA.Sangeetha MahadevanThese errors have now been corrected in the PDF and HTML versions of this Article.


Whether parental supply of alcohol affects the likelihood of later adolescent risky drinking remains unclear. We conducted a systematic review and meta-analysis to synthesize findings from longitudinal studies investigating this association. We searched eight electronic databases up to 10 September 2016 for relevant terms and included only original English language peer-reviewed journal articles with a prospective design. Two reviewers independently screened articles, extracted data and assessed risk of bias. Seven articles met inclusion criteria, six of which used analytic methods allowing for meta-analysis. In all seven studies, the follow-up period was ≥12 months and attrition ranged from 3% to 15%. Parental supply of alcohol was associated with subsequent risky drinking ; however, there was substantial risk of confounding bias and publication bias. In all studies, measurement of exposure was problematic given the lack of distinction between parental supply of sips of alcohol versus whole drinks. In conclusion, parental supply of alcohol in childhood is associated with an increased likelihood of risky drinking later in adolescence. However, methodological limitations preclude a causal inference. More robust longitudinal studies are needed, with particular attention to distinguishing sips from whole drinks, measurement of likely confounders, and multivariable adjustment. Risky consumption of alcohol is a leading threat to adolescent health globally because of its role in the aetiology of intentional and unintentional injury, mental disorders, and sexually transmitted infection ,2. RiskyIn addition to illegal sales, sources of alcohol for adolescent  drinking include parents, other relatives, and peers . ParentsResearch regarding the impact of parental supply of alcohol on adolescent risky drinking has produced conflicting results. A 2014 narrative review of the literature found that parental supply of alcohol was associated with heavy episodic drinking and higher risk of alcohol-related harm in 10 studies; but seven studies found it to be protective against such harm . Some stThere have been no reviews synthesizing longitudinal studies to examine associations between prospectively measured parental supply of alcohol and later adolescent risky drinking. We sought to critically examine longitudinal studies with prospective measurement of exposures, and to conduct a meta-analysis to determine whether parental supply of alcohol is associated with later risky drinking.We used the PRISMA   guidelinOnly prospective longitudinal studies  were eligible for inclusion; cross-sectional and retrospective studies being excluded. We included estimates based on assessment of outcome 12 months, or as close to 12 months as possible, after assessment of exposure. Articles analysing parental supply based on adolescent-, parent-, or both adolescent- and parent-report were eligible for inclusion. Only peer-reviewed journal articles published in English were included and there were no exclusion criteria regarding year of publication.Eight electronic databases were searched  with the last search carried out on 10 September 2016. We searched for the following terms: parental provision, social hosting, parental source of alcohol, youth, student, teenage, underage, minor, risky drinking, excessive drinking, and binge drinking. We modified and used appropriate mesh terms in the databases with the assistance of the health librarian at the University of Newcastle. Two authors (S.S. and M.K.) extracted information  using the Cochrane Public Health Group Data Extraction and Assessment Template  to tabulmetan command, specifying random, in Stata 13 [2 and I2 statistics [p < 0.05 were interpreted as significant. We conducted a sensitivity analysis by examining change in the overall estimate after removing each study in turn, excluding the weaker studies, and excluding those studies that assessed both parent and child report. We assessed publication bias using funnel plots, contour-enhanced funnel plots, and both Begg’s [For articles that reported suitable statistics, a meta-analysis with a random effects model was conducted , using tStata 13 . There wStata 13  reportedatistics . Analyseh Begg’s  and Eggeh Begg’s  tests.Two studies were conducted in Sweden, two in the USA, one in The Netherlands, one in Australia and one each in the USA and Australia . The folParental supply of alcohol was defined in different ways across studies, including alcohol being supplied at home, direct offers of alcohol by parents to their children in different drinking contexts , and alcohol consumption at home on weekdays versus weekends. Outcomes included a range of definitions such as heavy episodic drinking (≥5 drinks on a single occasion) , problemThe study results are summarised in Two studies focused explicitly on drinking at home as an exposure. In a study of Australian adolescents , Degenhardt and colleagues found that drinking at home with family in mid-adolescence was associated with a higher risk of drinking in a range of unsupervised settings, and of becoming a risky drinker in late adolescence . In a DuIn a USA cohort, Warner and White  found thp < 0.05) [In a comparison of cohorts in the USA state of Washington, and the Australian state of Victoria, alcohol use among 14 year-olds under adult supervision either “at parties” or “at dinner or a special occasion” was found to be associated with higher levels of alcohol-related harm a year later  . In a study of USA children, parental supply of alcohol at age 12 years was associated with an increasing trajectory of drunkenness and risky drinking . In a SwOur search revealed a small number of prospective cohort studies from four high income countries with traditionally restrictive approaches to alcohol . It is pThe exposures of interest were ascertained from child report in four studies ,33,36,38There is evidence to suggest that parents are not a reliable source of information about whether they supply their children with alcohol. In a study involving an anonymous survey of New Zealand school children aged 13–17 years, and a telephone  survey of their parents, 36% of children reported that their parents had given them alcohol to drink in unsupervised settings in the preceding month, while only 2% of parents reported that they had supplied alcohol to their children for unsupervised drinking in the same period . It is uThe effects on estimates of systematic misreporting of the outcome are also difficult to assess and depend on whether misreporting varies as a function of exposure status . MethodoStudies involved parental consent ,37,38,44Several studies ,36,37,38Rates of loss-to-follow-up ranged from 3% to 15%, suggesting a low overall potential for attrition bias. The median duration of follow-up was ≥12 months, a period probably long enough for outcomes to occur if parental supply were a causal factor.I2 = 26.4%; p = 0.218). The I2 statistic indicates that the estimates are consistent across the studies. We found the effect estimates from sensitivity analyses were consistent with the effect estimate from the primary analysis  and Egger’s test results (p = 0.689) do not confirm this observation; however, they are limited by the small number of studies.The funnel plot  is asymmThe results of this systematic review and meta-analysis suggest the possibility that parental supply of alcohol in childhood increases the odds of later adolescent risky drinking; however, a causal inference is limited by a high likelihood that estimates are inflated by a lack of control for confounders, and a risk of publication bias. If the findings do reflect a true effect, the following aspects of parental supply are implicated: direct supply of alcohol by parents, offers of alcohol by parents, adolescent drinking under parental supervision, adolescent drinking at home, and adolescent drinking in family gatherings.We included only prospective cohort studies providing the basis for establishing that parental supply preceded the outcome of adolescent risky drinking, excluding simple reverse causality as an explanation for the association. However, we cannot exclude more complex competing explanations for the findings. For example, parental supply may initially facilitate moderate drinking in early or mid-adolescence which in turn potentiates heavier drinking and thereby demands on parents or peers to supply alcohol in the larger amounts necessary for risky drinking. Testing such explanations requires assessment at multiple time points and analytic approaches  that caStrengths of the review include the comprehensive search strategy, independent screening, study identification and coding, and the risk of bias assessment. The use of meta-analysis increased the precision of the key point estimate, and formal assessment of publication bias has helped to qualify that estimate. Some studies were judged to be high in risk of bias, particular concerns being unreliable measurement of exposure, and lack of adjustment for confounding variables. It is possible that the literature is biased by non-publication of small studies with null findings or findings suggesting that parental supply is protective against adolescent risky drinking.d to lnOR) may have introduced error producing wider confidence intervals for estimates. We standardized effect estimates for the purpose of comparison. The transformations we performed  measured when children were around 13 years-old, was not associated with risky drinking (>4 drinks in a single episode in the preceding year) up to three years later, after adjustment for parental drinking, access to alcohol without parents knowing, alcohol-specific rules, monitoring, family factors, family alcohol problems, child factors, and peer factors . ImportaProspective cohort studies suggest that parental supply of alcohol in childhood increases the likelihood of risky drinking later in adolescence but the potential for bias in this literature is judged to be high. Further longitudinal studies are needed, with particular attention to distinguishing parental supply of sips versus whole drinks, the meaning of supervised drinking, measurement of likely confounders, and adjustment for them in multivariable models. Studies are needed in cultures with traditionally low restrictions on youth drinking , and in


Odontomachus chelifer. Five subterranean nests were excavated; one of them filled with liquid cement for extraction of casts of chambers, shafts and tunnels. All nests were found in a woodland area, with Dystrophic Red Latosol soil, associated with roots of large trees and, differently from the pattern currently described for this subfamily, presented a complex structure with multiple entrances and more than one vertical shaft connected by tunnels to relatively horizontal chambers. The number of chambers varied from 24 to 77, with mean volume ranging from 200.09 cm3 to 363.79 cm3, and maximum depth of 134 cm. Worker population varied between 304 and 864 individuals with on average 8.28 cm2 of area per worker. All nests had at least one Hall, which is a relatively larger chamber serving as a distribution centre of the nest, and to our knowledge, there is no record of Ponerinae species building similar structure. All nests had chambers "paved" with pieces of decaying plant material and on the floor of some of them, we found a fungus whose identification and function are being investigated. Thus, our findings provide evidence to suggest that nests of O. chelifer can be considered complex, due to the great number and organization of chambers, shafts and connections, compared to those currently described for Ponerinae species.In social insects, nests are very important structures built to provide a protected microhabitat for immature development and food storage and are the places where most interactions between all members of a colony occur. Considering that nest architecture is an important behavioural trait that can clarify essential points of the social level of the species, here we describe the architectural model of the Ponerinae ant  Nests are the places where most interactions between members of colonies of social insects occur and their main function is to provide a protected microhabitat for immature development and food storage . MaintaiAnt nests consist of two main elements, vertical shafts connected by tunnels to relatively horizontal chambers . The varDinoponera quadriceps Kempf 1971 which build nests near or associated with trees, branches or fallen trunks, with few chambers and maximum depth of 1.2 m [Dinoponera lucida Emery 1901 whose nests present chambers following the axis of tree roots on litterfall and reach maximum depth of 35 cm [Dinoponera australis Emery 1901 featuring nests with few chambers arranged along a helicoidal axis [Pachycondyla striata Smith 1858 whose nests are poorly elaborated with chambers and tunnels near the ground surface [Harpegnathos saltator Jerdon 1851, which uses a papery material to build their nests and have the upper chamber protected by a particular vaulted roof on the outside of which there is an intervening space that isolates the chambers from the ground conferring protection against flooding [There are few studies that describe nest architecture of Ponerinae ants, which generally present nests with small number of chambers, without branches, often built by modifying and increasing natural cavities ,14,15. Aof 1.2 m , and somof 1.2 m ; Dinoponof 35 cm ; Dinopondal axis ; Pachyco surface , among oOdontomachus Latreille 1804 have several forms of nesting. Odontomachus hastatus Fabricius 1804 are arboreal ants and build their nests occupying spaces between roots of epiphytic bromeliads; therefore, these nests do not have a system of chambers and tunnels [Odontomachus bauri Emery 1892 uses natural refuges, such as spaces under rocks and hollow trunks to house the colony, thus building superficial nests [Odontomachus brunneus Patton 1894, on the other hand, consist of a single vertical shaft connecting simple relatively horizontal chambers, ranging from 18 to 184 cm deep [Species of the genus  tunnels . Odontomal nests ,20. Nest cm deep . TherefoOdontomachus chelifer Latreille 1802 and demonstrate that they are more complex than the ones of the majority of Ponerinae ants currently described.Considering that nest architecture is an important behavioural trait and can clarify relevant points of the social level of the species and that there are still few studies on building patterns of subterranean ant nests, especially of Ponerinae species, here we describe the nest architecture of O. chelifer from April 2016 to March 2017, in the municipality of Dourados-MS . One of them was filled with liquid cement for extraction of casts of the chambers, shafts and tunnels. All colonies were nested in a woodland area with Dystrophic Red Latosol soil [We excavated 5 subterranean nests of sol soil . Field pThe subterranean nests were excavated according to the methodology proposed by . InitialWhenever possible, from each nest we recorded the following data: number of individuals; maximum depth (MD); number of shafts (NS), each vertical system connecting chambers one relatively below the other was called “shaft”; number of chambers (NC); number of entrance orifices (NE), diameter in length (the longer two edges) and width (the shorter two edges) of each entrance orifice ,22. In aWe also performed Pearson’s Correlation tests to assess whether there is correlation between total volume of chambers and number of chambers; total area of chambers and number of chambers; total volume of chambers and number of workers and total area of chambers and number of workers. In order to put the area per worker into the perspective of ant size, ants collected from the nests were measured for body length with and without mandibles, head width between the eyes, gaster width at the largest part, thorax width at the largest part and lateral extension of femur of the second pair of legs. These data were used to calculate the area of the dorsal silhouette of ants with and without the legs modified from .To obtain the 3D cast, we choose a relatively small nest, with few entrance orifices (n = 3) and close to a young tree, so there were fewer roots facilitating the pouring of cement. We poured a mixture of 16 kg of cement for 80 l of water with addition of two measures of lime substitute additive according to the manufacturer’s guidance on all entrances until the content overflowed, indicating that all volume had been filled, following the methodology used by ,24,25. A3 to 363.79 cm3 and total volume between 4700.05 cm3 and 20 676.08 cm3. The mean depth was 97.70 ± 21.35 cm, and maximum 134 cm  and connections when compared with other species of the group. Even within the genus Odontomachus, these nests deviate from the pattern described so far, since nests of O. brunneus have only one vertical shaft and maximum of 17 chambers [O. chelifer in Paraguay described that they were highly associated with nests of A. sexdens rubropilosa Linnaeus 1758 and discussed that the minimal excavation effort required by O. chelifer and the mandibular shape of these ants indicate that they are poor excavators, but we did not find any case of this association despite the presence of colonies of Atta Fabricius 1804 in the same area. In addition, the complex structure, great number and area of chambers, tunnels and connections described here indicate that despite their mandible shape these ants might actually excavate very well.Subterranean nests of poneromorph ants are generally considered simple structures consisting of a single vertical shaft with few chambers, and even nests with 16 chambers are considered relatively complex, as is the case of chambers  studyingO. chelifer have maximum depth, number of chambers, and area per worker increased according to the number of individuals of the colony. Moreover, the total area and volume of chambers are intimately related to the number of chambers, which indicates that nest size grows almost entirely by adding more chambers of a standard size, so that total area and volume remain tightly related to the number of ants. Generally, ants that nest in the soil increase the number of chambers according to the increase in colony’s population, as already described for E. vizottoi [D. quadriceps [O. brunneus [O. brunneus, whose nests are moderately more bottom-heavy than top-heavy [Nests of vizottoi , D. quadadriceps  and O. bbrunneus . Nests oop-heavy .O. chelifer have on average 8.28 ± 1.75 cm2 of area per worker, with the ant’s dorsal silhouette without legs and mandibles occupying on average 1.21% of the available area, and 6.50% with legs. Different from nests of O. brunneus whose area available per worker is approximately 2 cm2 regardless of nest size, with ant bodies without legs occupying on average 4.8% of the area available, and 15% with legs [O. chelifer is about 4 times larger than the observed in O. brunneus. Nests of Pogonomyrmex badius Latreille 1802 feature on average 1.4 cm2 per worker of which worker bodies without legs occupy about 18%, and nests of Camponotus socius Roger 1863 have on average 1.1 cm2 per worker of which worker bodies without legs occupy a mean of 16% [Nests of E. vizottoi, for chambers that have a similar function. This structure acts as a central where there are several tunnels giving access to chambers located both on the same shaft as in different ones. So far, there is no record of Ponerinae species building similar structures to the one described in this study. This system of multiple entrances, chambers and connections, and various sectors of the nest can be related to airflow to maintain its internal conditions, in a pattern similar to that of nests of Atta [In all the nests of this species there is at least one chamber with larger dimensions relative to all the others, called “Hall”, as suggested by , studyin of Atta ,37,38,39Ectatomma edentatum Roger 1863, E. opaciventre, E. brunneum, E. vizottoi, D. quadriceps and D. australis [Atta in which the last chambers also contain garbage and probably have the ability to maintain constant temperature throughout the year because of the production of heat and carbon dioxide by bacterial fermentation [Atta which are usually larger than the superficial ones, in O. chelifer nests these structures usually have smaller dimensions than the other chambers.Specific garbage storage chambers were commonly found in the deepest portions of each shaft, as well as in ustralis ,30,31. Sentation ,14. HoweO. chelifer do not allocate their immature neither in specific chambers nor according to the developmental stages in a single chamber, since we did not find any pattern of immature distribution and it was possible to find all the stages, eggs, larvae and pupae in the same chamber on more than one occasion. The same seems to happen in E. brunneum whose immature are generally found all in a single chamber without any preference as to disposal, depth or volume of chambers [P. striata it is often observed a differentiated allocation of pupae relative to larvae and eggs, which may be a derived feature [Apparently, chambers . On the  feature . However feature ,13,40; oP. striata within which there are chambers with immature paved with termite wings. In addition, along with this plant material we sometimes found a fungus developing on the chambers’ floor. The species of this fungus and its function are being investigated, since it is recurrent in all nests. Fungi can affect both workers and immature and if their presence is expected by the ants there must be some mechanism that prevents their proliferation and problems for the population of the colony. Fungus-growing species such as Atta and Acromyrmex Mayr 1865 for example use antibiotic-producing bacteria that are carried upon the ants’ cuticle to control garden parasites and defend young workers against a fungal entomopathogen [O. chelifer and D. quadriceps with colonies of the fungus-growing ant A. sexdens rubropilosa and the presence of a fungus inside O. chelifer nests might suggest some level of co-evolution between these species [Pavement with plant material found in some chambers containing immature may be related to control of temperature and humidity, as suggested by  for nestpathogen ,42. Inte species ,36. HoweO. chelifer are cohabitated by several other animals. The use of subterranean ant nests by other animals, mostly arthropods, is well documented in several poneromorph species. As well as in this study, termite nests have also been found associated with nests of many other species, suggesting that this relationship might be widespread in the group [Nests of he group . The prehe group ,44 howevhe group , the useO. chelifer can be considered complex, compared to those currently described for other Ponerinae species, mainly from the same genus. The system of multiple entrances connected directly or indirectly to the Halls, which link various parts of the nest, suggests a complex air circulation system for maintenance of internal conditions.Nests of