Their expressions in the thymus, liver, and kidney were significant from 0 days post hatching (dph) to 45 dph, peaking at 45 dph in these three tissues. In situ hybridization detected high rag1 and rag2 expressions in the liver, kidney, and thymus of rice-field eel from 2 to 45 dph, suggesting that multiple tissues of rice-field eel contain lymphocyte lineage cells and undergo lymphopoiesis. Tissue morphology was used to observe lymphopoiesis development in these three tissues. The thymus primordium began to develop at 2 dph, while the kidney and liver have generated. Our findings verified that the thymus is the primary lymphopoietic tissue and suggested that, in rice-field eel, lymphocyte differentiation also occurs in the liver and kidney.In immature lymphocytes, recombination activating genes 1 and 2 are necessary for antigen receptor V (D) J recombination, representing immature lymphocyte biomarkers. Herein, we cloned and sequenced rice-field eel  Monopterus albus), belonging to the family Synbranchidae, is an important economic fish species in China [The rice-field eel  are DNA recombination activating genes, representing key genes of the vertebrate specific immune response [Rag genes encode recombinase proteins that can promote V (D) J rearrangement so as to change the antibody genotype and produce a new specific immune response [rag genes results in a variety of immunoglobulins and T cell receptor subtypes, enriches specific immunity, and affects the development and maturation of lymphocytes and the immune system [Rag1 can recognize and bind RSS alone, while rag2 can bind to DNA only in the presence of rag1. In addition, rag1 and rag2 genes can form complexes, which have higher specificity and stability and can be recognized more effectively [Rag genes, especially rag1, are widely used in the study of phylogeny because of their slow evolution and highly conserved sequences among different species [Xenopus laevis thymus was observed as the main site of rag1 and rag2 expressions, and both genes were expressed in the thymus and bone marrow of adult frogs of all ages [rag1 was continuously expressed until the thymus degenerated naturally after 12 months, with peak expression occurring in the thymus at 4.5 months [rag1 in rainbow trout was limited to immunoglobulin negative lymphocytes on the surface of thymus, while rag2 was expressed mainly in anterior kidney and thymus [rag1 was expressed in thymus and kidney at 4 dpf (days post fertilization), while rag2 was mainly expressed in the thymus [Rag1 of grass carp was expressed in the thymus at 4 dpf and rag2 expressed at 7 dpf, while the expressions of both genes persisted in the thymus during the first age [rag1 and rag2 genes in the lymphopoietic tissues of rice-field eel. Thus, rag1 and rag2 temporal and spatial expression patterns could be used to reveal the generation of lymphocyte in the rice-field eel.The recombination activating genes 1 and 2  staining was used to analyze morphological and structural characteristics and the changes in lymphopoiesis tissues during development.In this study, in situ hybridization and quantitative real-time reverse transcription PCR (qRT-PCR) were used to investigate Paralichthyidae and were closely related to the proteins from rainbow trout and zebrafish , while rag2 was mainly expressed in the thymus [Rag1 of grass carp was expressed in the thymus at 4 dpf and rag2 expressed at 7 dpf, while the expressions of both genes persisted in the thymus during the first age [rag1 and rag2 are mainly expressed in the thymus and kidney, as expected. Previous researchers found that, in the early development stage of Xenopus, rag1, and rag2, expression was mainly observed in the thymus, which was the site for T cell differentiation [Rag1 gene expressed at the surface of thymus and rag2 gene expressed in both thymus and head kidney, which indicated that thymus and head kidney was primitive lymphoid tissue in rainbow trout [Rag1 and rag2 genes were expressed in the head and body kidneys of Paralichthys olivaceus; therefore, the kidney was the lymphoid organ of Paralichthys olivaceus [Xenopus [rags induces V (D) J rearrangement during B cells development. In B cell development, rags transcriptions levels were higher in pro-B cells and pre-B cells and lower in lymphoid stem cells, immature B cells, naive B cells, and mature B cells [rags transcriptions might indicate the presence of pro-B cells and pre-B cells in the liver and kidney. Therefore, the liver and kidney were considered to be lymphopoiesis tissue. In addition, by analyzing the expression patterns of rag1 and rag2 in the kidney, liver, and thymus at different development stages, the development of these lymphopoiesis tissues in rice-field eel could be inferred.c tissue . Herein,ntiation ,26. In ze thymus . Rag1 ofirst age . The thyirst age  and the irst age . Similarntiation . Rag1 geow trout ,23. Rag1livaceus . Moreove[Xenopus ,31. The  B cells . In thisrag genes expressed at 4 dph, which suggested that the thymus appeared earlier than the differentiation of lymphocytes [Paralichthys olivaceus appeared at 10–15 dph [Rags signals positive immature lymphocytes were detected at the edge of the thymus at 10 dph and randomly on the surface and inside the thymus at 24 dph. At 45 dph, immature lymphocytes were intensively expressed in the outer thymus; meanwhile, the thymus of the rice-field eel showed internal and external divisions, and the mature thymus generated. However, the thymus of the rice-field eel did not show lobulation, which was different from that of Epinephelus obliquus [Xenopus showed the division of the cortex and the medulla in the early stage of embryonic development [The thymus of teleosts is a paired organ, which is generally located at the back of the gill cavity and the upper dorsal horn at the junction of the operculum and the pharyngeal cavity. The thymus is covered by the operculum mucosa and is distributed symmetrically . The locphocytes . The thyphocytes , and thaphocytes , while, 0–15 dph , and the0–15 dph . The thy0–15 dph . In the obliquus  and Chinobliquus . Researcelopment , while iRag1 and rag2 signals were observed in the tubular epithelia at 2 dph and then distributed randomly in the hematopoietic tissues of kidney from 6 to 45 dph. It seems that the renal tubules might be transient lymphopoietic tissues before hematopoietic tissues generation in the rice-field eel. The expression of rags genes in the kidney varied among fish species. The expression of rag1 in rainbow trout was low in the head kidney [rag1 expressed in the head kidney [Rag1 in carp expressed in the kidney at 7 dph but was not detected in the kidney of 1-year-old carp, which proved that the head kidney of carp had a degraded immune function [Paralichthys olivaceus appears at the time of hatching stage [Paralichthys olivaceus and golden head snapper, lymphocytes appeared earlier in the thymus and lymphocytes migrate from the thymus to the head kidney [The kidney of teleost fish is usually divided into head, middle, and posterior kidneys. The middle kidney and posterior kidney are not only urinary organs but also hematopoietic tissue, which function urination, regulation of osmotic pressure, and hemopoiesis . Howeverd kidney , while id kidney . Rag1 infunction . The kidng stage . The heang stage . The devng stage . Zhong eng stage . The head kidney ,50.rag1 signals could be detected in the hematopoietic layer [rag1 and rag2 signals distributed in the entire tissues, indicating that the liver could be regarded as lymphopoietic tissues that function in the immune response. The livers of different fish have different development patterns. The liver rudiment of Epinephelus obliquus appeared about 3 dph, while liver cells formed hepatocyte clusters [Culter Alburnus, takes the central vein as the center, and the hepatocytes are arranged radially to form mutually consistent hepatocyte cords, and hepatic blood sinuses are formed between adjacent hepatocytes [The liver is one of the important digestive glands of teleost fish. It has the physiological functions of material metabolism, detoxification, hematopoiesis, and excretion. In addition, it is also the organ that can best reflect the physiological, pathological, and nutritional status of the body . In the ic layer . The livclusters . The livclusters . The ricclusters . The livatocytes . The resJuvenile fish are very fragile and easily affected by external environmental stimuli, thus their immune function is particularly important. It is generally believed that vertebrates rely on the lymphoid tissues and organs to produce immune activity, and the functional maturity of lymphocytes always occurs later than the development of lymphoid tissues and organs . TherefoParalichthys olivaceus. High rag1 and rag2 expression levels were used as a proxy to detect lymphocyte differentiation from 0 dph. The rag1 and rag2 spatial expression patterns suggested that, in addition to the thymus, the liver and kidney are also lymphopoietic tissues, which support lymphocyte receptor rearrangement in the rice-field eel.In conclusion, rice-field eel RAG1 and RAG2 are closely related to their homologs in The Animal Care and Use Committee of the Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, approved all the experimental procedures and animal handling.An experimental breeding base in Xiantao City, Hubei Province, provided the rice-field eels, which were all members of the same spawning batch. Fish were maintained in the laboratory at 25 °C. They were distributed in a 30 × 100 cm boxes with shading, and the water was changed once a day. The aerator was used to provide the oxygen needed by the rice-field eel. Fish were fed with red worm once a day. The tissues  were sampled at 0, 2, 6, 10, 17, 24, 30, and 45 days post hatching (dph). In total, 120 fish that were spawned at one time were used as an experiment. Every 40 fish were kept in the same tank, for a total of 3 tanks. At total of 5 fish were taken from each tank at each time point, and a total of 15 fish were used as a sample. We used three different batches of fish as biological replicates. The experiments were performed in triplicate as technical replicates. The experiments were performed in triplicate.The TRIzol reagent  was used to extract total RNA from the designated tissues, following the supplier’s instructions, which was stored at −80 °C before use. A cDNA Synthesis SuperMix kit  was used to reverse transcribe the RNA into cDNA, following the supplier’s instructions.The full length RAG1 and RAG2 proteins of rice-field eel were downloaded from the NCBI database, and their accession numbers were XP020470881 and XP020470878, respectively. The RAG1 and RAG2 protein sequences of various organisms were also downloaded from the NCBI database for homology analysis, and a multiple alignment of the amino acid sequences was carried out using the Clustal W 2.0.10 software  . PhylogeFollowing reverse transcription of mRNA from various tissues, the resultant cDNA was used as the template for the quantitative real-time PCR step of the qRT-PCR protocol using designed primers . The rearag1 and rag2 probes, following the supplier’s instructions. A digoxygenin (DIG) RNA-labeling kit  used SP6 RNA polymerase to synthesize the We used PBS to rehydrate the transverse serial sections of the kidney, liver, and thymus, followed by HE staining. Thereafter, the sections were dehydrated using an ethyl alcohol gradient, cleared using xylene, sealed using neutralized resin, and examined under light microscopy.ef1α was selected as the housekeeping gene [ef1α.The results for the three replicates of the qRT-PCR analysis of each sample were expressed as the mean (±the standard deviation (SD)). According to our previously published paper, ing gene . In each


Customer demands for product search are growing as a result of the recent growth of the e-commerce market. According to this trend, studies on object-centric retrieval using product images have emerged, but it is difficult to respond to complex user-environment scenarios and a search requires a vast amount of data. In this paper, we propose the Video E-commerce Retrieval Dataset (VERD), which utilizes user-perspective videos. In addition, a benchmark and additional experiments are presented to demonstrate the need for independent research on product-centered video-based retrieval. VERD is publicly accessible for academic research and can be downloaded by contacting the author by email. Image retrieval aims to search the database for images that are similar to a given query image. This technology has been used for automatic checkouts, which scan for products at supermarket cash registers. However, as a result of the recent expansion of the e-commerce market induced by the development of communication technology, research has been conducted to find similar items in online shopping malls.The goal of the offline datasets ,2,3,4,5 As previously stated, the growth of the e-commerce market has resulted in the emergence of online datasets ,7,8,9 usMultimodal online datasets ,11,12 haTo handle the limitations that existing datasets are not comparable to actual search environments and that multimodal datasets do not reduce search complexity, we propose a dataset named Video E-commerce Retrieval Dataset (VERD). Offline datasets are configured to perform tasks such as automatic payment or shop management in conventional grocery stores. Merler et al.  proposedOnline datasets, as opposed to offline datasets, comprise data acquired in a varied environment because they collect data uploaded to the e-commerce market. These online datasets can be broadly categorized into two types. The first type of online datasets is a single modality dataset comprising images. Song et al.  suggesteThe second type of online dataset is a multimodal dataset, mainly consisting of text and image data. Corbiere et al.  proposedTraditionally, image-based product retrieval studies ,18 were In addition, research is extending to include online shopping malls due to the expansion of the e-commerce market. These methods ,20,21 arThe majority of research on video-based retrieval focuses on video copy detection for video copy protection and verification, and also content-based video retrieval for video recommendation. These studies can be classified into two categories based on the similarity-calculating method.The first methods ,22,23 exThe second methods ,16 encodLN−iMAC . Shao etRecently, with the emergence of datasets that support various modalities, studies using various modality information have emerged. Shin et al.  proposedhttps://shopping.naver.com (accessed on 31 May 2022)).This section discusses the data collection procedure in the Video E-commerce Retrieval Dataset (VERD). We aimed to create a dataset with scenarios resembling those in which consumers look for objects in video. To accomplish this objective, VERD was collected using recently introduced video-based product reviews from online shopping malls ) was employed. Additionally, visually similar but nonidentical videos were deemed irrelevant and removed.The first step is to remove duplicate videos. Occasionally, the same video was reused for many reviews on the e-commerce platform. To eliminate these duplicate videos, Video Duplicate Finder , “life/health” (6327), “food” (5754), and “furniture/interior” (1240). Following that, the fashion-related category contains “fashion accessories”  and “fashion clothing” (7831), for a total of 18,114 videos. This demonstrates that the dataset is dispersed rather equally.VERD attempted to construct a dataset that simulates the scenario in which a user conducts an object search through a video. From this perspective, the data can be broadly separated into seller-centric data and user-centric data. In this part, we discuss in detail how user-centric data differ from seller-centric data in terms of the information they may provide.Differences in illumination and color: Lighting variance can be the most significant difference between the environment presented by the seller and the user. Complex backgrounds: Variety of viewpoints: The majority of the information on the page for product sales is taken from the front in order to make the product seem more attractive. However, users do not consider these factors when capturing the product. In order to address this issue, We illustrate numerous examples of the user-filmed environment by describing In this section, we propose a benchmark performance with several video retrieval systems. Among these methods, we conducted experiments on DML , ViSiL , and TCADue to the absence of available training datasets for object-centric video studies, K-fold cross-validation was applied as the evaluation approach. We fixed query videos in the dataset and set K to 5 to split the database. In order to ensure that a sufficient quantity of data is used in the search, the experiment was constructed so that while one fold was used for learning, the remaining fold was used for evaluation.Benchmark performance was obtained by separating the product category and the fashion category. This is due to the fact that the two categories have different visual qualities. As a result, items in the fashion category have varied shapes based on whether or not they are worn by humans, whereas the visual aspects of products change based on location but the shape of the item does not change. Therefore, the overall performance of the fashion category was deemed to be inferior to that of the product category.On the other hand, it is noticeable that the performance, in general, is insufficient. This demonstrates that the existing video-to-video retrieval model did not acquire the properties required by object-centric video datasets such as VERD, as it was mainly researched using incident-centric videos. Consequently, the experimental result shows the need for future independent object-centric video retrieval study.Most video retrieval methods use frame-level features or video-level features to calculate video similarities. The frame-level feature calculates the similarity between each frame to determine the similarity of the video, while the video-level feature compresses the feature representation of the video to determine the similarity.To demonstrate that video clips have a higher volume for visual representation than images, analysis was conducted to compare the performance of image-based and video-based retrieval in The experiment employed the same K-fold cross-validation as Using the method of , a simplObject-centric retrieval in the user environment is a major task that can be handled in the expanding e-commerce industry. According to this trend, research on single and multimodal search based on product images emerged, but the challenge was that it was difficult to respond to complex scenarios or that the quantity of data required for a search was massive. Therefore, we propose the Video E-commerce Retrieval Dataset (VERD), comprising videos that have not been utilized in previous studies. We present benchmark performance experiments applying the proposed dataset to existing video search methodologies, and additional experiments indicate the better performance of videos relative to images, demonstrating the need for video-based research.


OCD = 43; nhealthy = 24) and BDD . In individuals with OCD, the left ventrolateral prefrontal cortex, a node of the arbitration system, exhibited more inhibitory causal influence over the left posterolateral putamen, a node of the habitual system, compared with controls. Inhibitory causal influence in this connection showed a trend for a similar pattern in individuals with BDD compared with controls. Those with stronger negative connectivity had lower obsession and compulsion severity in both those with OCD and those with BDD. These relationships were not evident within the habitual or goal-directed circuits, nor were they associated with depressive or anxious symptomatology. These results suggest that abnormalities in the arbitration system may represent a shared neural phenotype across these two related disorders that is specific to obsessive–compulsive symptoms. In addition to nosological implications, these results identify potential targets for novel, circuit-specific treatments.Obsessions and compulsions are central components of obsessive–compulsive disorder (OCD) and obsessive–compulsive related disorders such as body dysmorphic disorder (BDD). Compulsive behaviours may result from an imbalance of habitual and goal-directed decision-making strategies. The relationship between these symptoms and the neural circuitry underlying habitual and goal-directed decision-making, and the arbitration between these strategies, remains unknown. This study examined resting state effective connectivity between nodes of these systems in two cohorts with obsessions and compulsions, each compared with their own corresponding healthy controls: OCD (n The central behavioural phenotypes in OCRD patients are (i) obsessions – recurrent, intrusive thoughts that cause significant distress – and (ii) compulsions – repetitive, stereotyped behaviours aimed at preventing or reducing distress. Although there is support for this grouping on the behavioural and symptom level, much less neurobiological evidence exists for this nosology. Decision-making perspectives of OCD have theorized that compulsive behaviours are the result of an imbalance of habitual and goal-directed decision-making strategies . ConvergFurther studies have identified the existence of a separate mechanism that monitors the reliability of both the goal-directed and habitual systems and gates which system should control behaviour . This “aDespite emerging evidence, no studies have specifically examined to what extent abnormalities exist in the directed, causal relationships between the arbitration and habitual systems in OCRD disorders. These causal relationships can be inferred using functional magnetic resonance imaging (fMRI) data and effective connectivity analysis techniques based on, for example, Granger causality  or dynamshared phenotype across different OCRDs. Additionally, because anxiety and depression symptoms are commonly present in individuals with these disorders, an important consideration is whether any identified neural abnormalities are specific to OCRD symptoms. Answering these questions will contribute to the refinement of the field’s neurobiological and nosological understanding of these conditions, including their shared and distinct etiology.It remains unclear if dysfunction of these neural systems could represent a https://aspredicted.org/675hy.pdf, https://aspredicted.org/w8hj7.pdf) we predicted that: (i) these connections would be significantly attenuated and less variable relative to controls; (ii) within OCRD participants, stronger inhibitory connectivity would be associated with lower symptom severity. We also predicted that these associations would be specifically associated with obsessive–compulsive severity and not symptoms of depression or anxiety. Additional exploratory analyses tested for abnormalities within the habitual system  and within the goal-directed system (left/right caudate → OFC).To this end, this study examines resting state effective connectivity in two cohorts of individuals with OCRD: OCD and BDD. Based on regions of interest (ROIs) identified in previous studies , we exam22.1Two sets of data, collected independently, one of OCD participants  and anotThe OCD participants were those who met eligibility criteria, including a primary diagnosis of OCD. The BDD participants were those who met eligibility criteria, including a primary diagnosis of BDD. OCD participants could be unmedicated or medicated, provided they had no changes in medication for at least 12 weeks prior to recruitment. BDD participants currently on psychotropic medications were excluded. For full inclusion/exclusion criteria, please see the 2.2Obsessive compulsive symptomology in the OCD group was assessed using the YBOCS . BDD parDepressive symptomology was measured using the Montgomery-Asberg Depression Rating Scale  sequence. Pulse sequences between these datasets differed, most significantly in TR , which has been shown to affect estimates of effective connectivity . Therefo2.4Structural and functional images from both datasets were processed using FMRIPREP . We incl2.5https://www.nitrc.org/projects/rshrf).Multiple fMRI , simulatDeconvolved timeseries were sampled from key connections of the habitual, arbitration and goal-directed systems , using sFinally, measures of DEC were estimated by employing Kalman-filter based time-varying Granger causality on the timeseries . Effectiwithin the habitual  and within the goal-directed systems . The results of analyses for the remaining 27 directed connections are included in We analyzed three directed connections in the arbitration system: L vlPFC → L posterolateral putamen A, R vlPFC → L posterolateral putamen B, R FPC → R posterolateral putamen . These c2.6Omnibus group differences in the mean and variability of DEC were assessed using a one-factor MANCOVA that included the three directed arbitration connections as the dependent variables, group as the independent variable and age, gender, and motion  as covariates. Separate tests were performed for the mean and variability of DEC. Separate MANCOVAs were also conducted for the within-habitual and within-goal-directed connections.P-values for post-hoc models were subject to Bonferroni correction. Cohen’s d was also computed to compare effect sizes across the two datasets.Separate models were fit for the OCD and BDD datasets. If a significant group difference was detected, post-hoc linear regressions examining group differences were fit, one for each connection. p-values for each connection were Bonferroni corrected for the three arbitration connections. Separate models were also fit for the within-habitual and within-goal-directed connections. Pearson correlation coefficients for significantly associated connections were computed to allow us to compare effect sizes across the two datasets. We also examined associations with MADRS and HAM-A scores.Associations between DEC measures and obsessive–compulsive symptomology (YBOCS) were examined using multiple linear regression, including all three arbitration connections as regressors. As a follow-up, As a post-hoc analysis, we explored potential moderating effects of psychotropic medication in symptom-connectivity relationships. For this, we tested a linear model that included an interaction term between DEC measures and medication status (expressed as a binary variable: medicated with any psychotropic medications OR unmedicated). We generated a model for every connection that exhibited significant association with symptom severity. These analyses were only conducted for the OCD dataset, since all BDD participants were unmedicated.2.7aspredicted.org (https://aspredicted.org/675hy.pdf and https://aspredicted.org/w8hj7.pdf) prior to analysis. Exploratory analyses of the within-habitual and within-goal-directed connections and the post-hoc analysis of medication effects were not preregistered. All code for preprocessing and analysis is available on GitHub (https://github.com/dseok/ocd_bdd_arbitration_rsfmri).Hypotheses and methods for the regions/connections of interest were preregistered through 3For the OCD dataset, 45 OCD participants and 25 healthy controls were enrolled. One participant was not included in the analyses due to a change in medication status immediately prior to the study. Additionally, we excluded one OCD participant’s and one healthy control’s data due to excessive head motion (DVARS > two standard deviations of the mean), leaving 43 OCD and 24 healthy control participants for the OCD dataset.For the BDD dataset, 24 BDD participants and 20 healthy controls were recruited. Three BDD and three healthy control participants were excluded due to excessive head motion and one healthy participant due to poor image registration to template space. This left 21 BDD participants and 16 healthy controls for the BDD dataset.p > 0.15), depression (p > 0.8) or anxiety (p > 0.4).Demographic information for all analyzed participants is presented in Please see 3.1F = 2.880, p = 0.043). Post-hoc analyses revealed that mean DEC for the L vlPFC → L posterolateral putamen connection was significantly more negative in OCD participants compared to healthy controls  = -2.908, correctedp = 0.015, Cohen’s d [95% CI] = 0.74 ). OCD participants and healthy controls did not significantly differ in DEC variability (p > 0.5). Neither MANCOVA for the within-habitual (p > 0.7) nor within-goal-directed connections (p > 0.7) was significant.MANCOVA analyses detected a significant difference in mean DEC for connections involving the arbitration system between OCD participants and healthy controls  or DEC variability (p > 0.5) for the arbitration system connections in the BDD dataset. However, exploring the mean DEC of the L vlPFC → L posterolateral putamen connection, there was a group difference trending in the same direction as in OCD dataset  = -1.595, uncorrectedp = 0.121, Cohen’s d [95% CI] = 0.53 ). A post-hoc power analysis for this connection suggested that the BDD dataset (n = 37) was underpowered to detect a group difference of the same magnitude as the OCD dataset (n = 48 required for 85% power for one-sided test). As in OCD, neither MANCOVA for the within-habitual (p > 0.75) nor within-goal-directed connections (p > 0.7) was significant.The MANCOVA revealed no significant group differences in mean DEC  = 2.561, correctedp = 0.042, Pearson correlation [95% CI] = 0.328 ). No other connections in the arbitration set exhibited significant associations (see correctedp > 0.4) or within-goal-directed (correctedp > 0.2) connections exhibited significant associations. DEC variability across all connections was not significantly associated with YBOCS.In the OCD dataset the L vlPFC → L posterolateral putamen connection was positively associated with YBOCS  = 1.583, uncorrectedp = 0.132). The bivariate correlation between this connection and YBOCS was positive  positive association in the same direction as in the OCD dataset (p = 0.203) or BDD  datasets. Similarly, HAM-A scores were not significantly correlated with mean DEC in this connection in either the OCD  or BDD  datasets.MADRS scores were not significant correlated with mean DEC in the L vlPFC → L posterolateral putamen connection in either the OCD  and BDD-YBOCS (BDD) for both datasets are shown in 3.3p = 0.021), whereas unmedicated participants did not .There was a significant interaction between medication status and mean DEC of the L vlPFC → L posterolateral putamen connection  = 2.300, p = 0.027; 4The goals of this study were to investigate associations between the neural substrates of decision-making and obsessive-compulsion related symptomatology across OCD and BDD. Within arbitration circuitry, the L vlPFC → L posterolateral putamen connection exhibited more negative effective connectivity compared to healthy controls as well as positive associations with obsessive–compulsive symptom severity. These results suggest that abnormalities in effective connectivity between the arbitration and habitual systems may represent a common neural phenotype across these two OCRD disorders. Importantly, this association may be specific to both the arbitration system and OCRD symptoms: connectivity within the habitual and goal-directed systems was not significantly associated with group or OCRD symptom severity, and the L vlPFC → L posterolateral putamen connection was not associated with either depression or anxiety symptoms.relative difference between healthy controls and OCRD participants may be a key finding. This result could reflect that individuals with OCRD may experience greater tonic load on their arbitration system, which needs to exert more frequent inhibitory control to compensate for a hyperactive habitual system. Alternatively, the results could represent a state effect in which OCRD individuals may be more likely than controls to engage their arbitration system within the scanner to resist urges to perform compulsions. The latter explanation would appear less likely due to the heterogenous nature of OCD symptoms such that some individuals experience spontaneous intrusive thoughts and urges to perform compulsions whereas for others this occurs primarily when being triggered by external stimuli. Larger studies, especially those studying individuals with BDD, are necessary to confirm this finding.While we predicted that OCRD participants would exhibit an attenuated (less inhibitory) arbitration system, we observed the opposite: OCD participants exhibited more negative DEC in the L vlPFC → L posterolateral putamen compared to controls, and BDD participants had a trend in the same direction . We observed that, in the resting state, healthy controls generally exhibited positive DEC while the mean of OCD and BDD participants was closer to zero, which seems contrary to previous task-based fMRI results identifying an inhibitory connection . HoweverAs predicted, stronger inhibitory connectivity between the arbitration and habitual systems was associated with less severe obsessive–compulsive symptoms in both OCD and BDD groups, suggesting that utilization of the arbitration system may be instrumental in successful resisting of compulsive behaviours. Further, confidence intervals for this association were highly overlapping across OCD and BDD, suggesting that the strength of this effect is similar across these two populations. It should be noted, however, that the confidence intervals for both estimates are large, which may be due to limited sample size. Effective connectivity in this connection was not significantly associated with depressive or anxious symptomology, highlighting the potential specificity of this association with obsessive–compulsive symptoms. However, given the sample sizes, non-significance of associations of connectivity with these symptoms is weak support for specificity. Future larger studies are necessary to confirm the generalizability and specificity of these phenotypes.Connectivity strengths within the habitual and goal-directed systems were neither significantly different between OCRD groups and healthy controls nor significantly associated with OCRD symptom severity. Thus, the findings in the OCD and BDD groups in the arbitration system suggest that abnormalities in this system may be a primary feature of OCRD pathophysiology. However, non-significance does not necessarily imply that the habitual and goal-directed systems are not implicated in the pathophysiology of OCRD, particularly given the small set of connections (two connections each) tested within these systems and the fact that this study examined connections in the resting state rather than during a task.A previous study in OCD provided evidence that deficits in goal-directed planning and general cognitive control may underlie OCD psychopathology and symptom severity , as oppoThese findings have potential clinical implications. Given current evidence for its role in arbitration circuitry relevant to obsessions and compulsions and its accessible location on the cortex, the L vlPFC presents a prime target for neuromodulatory techniques like repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS). Previous studies in OCD have targeted other brain regions that also have roles in decision-making, such as the OFC , SMA Go and dorsAnalyses of medication effects in the OCD dataset revealed that only medicated participants exhibited a positive relationship between effective connectivity in the left vlPFC → L posterolateral putamen connection and obsessions/compulsions. The limited sample size of medicated OCD participants (n = 14) precludes definitive conclusions about if or how medication status influences connectivity and how relationships with symptoms compare across groups. Further, because this is a cross-sectional study, we cannot make definitive conclusions about causality. For example, medication could potentially have a direct or interactive effect on connectivity or, alternatively, separate inherent factors could have contributed to one subgroup pursuing and receiving treatment with medication. Addressing the question of the medication status is challenging and will likely involve larger, longitudinal studies that are outside of the scope of the current investigation. Nonetheless, the observation of a similarly positive trend between connectivity and symptom severity in the (entirely) unmedicated BDD cohort suggests that this mechanism may have some independence from medication status.4.1r range = ), and the magnitudes of the group difference and correlation with BDD-YBOCS were comparable after resampling (Several other limitations should be considered. Most notably, these data were collected from two separate studies; thus, differences in scanners and acquisition protocols may have affected results. For example, participants in the OCD study were instructed to keep their eyes closed during the scan while participants in the BDD study were instructed to keep their eyes open. While studies have identified differences in visual and auditory system connectivity based on eyes-open and eyes-closed protocols, none have identified significant differences in default mode or cognitive control regions . Our anasampling . AnotherSome ROIs, particularly the left and right putamen seeds, exhibited high levels of white matter in many participants . This rea priori due to their associations with decision-making processes, only future task-based studies can definitively draw the links between aberrant arbitration behaviors, abnormalities in the left vlPFC → L posterolateral putamen connection and OCRD symptoms.Finally, participants were evaluated with resting-state scans, so it remains unclear whether these associations truly reflect neurobehavioral deficits in decision-making arbitration or are related to other functions of the vlPFC and posterolateral putamen. While this hypothesis-driven study selected these connections 4.2This represents the first study to investigate, and provide evidence for, transdiagnostic abnormalities in the arbitration system across OCRD disorders. Heightened inhibitory influence of the arbitration system on the habitual system may operate to downregulate compulsive behaviours in both OCD and BDD. These results have nosological implications for understanding the neurobiological relationships between specific OCRDs and could potentially be utilized in future studies to test the effects of neuromodulatory interventions that target the arbitration and habit systems.The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: JF has received consultant fees from NOCD, Inc. All other authors have nothing to disclose.


Psychological theories consider autonomic arousal to be a reinforcer for problem gambling. Structural characteristics such as near-misses, which are non-win events that come close to a real win, have been shown to elicit win-like responses while increasing motivation and gambling persistence. This study investigated the autonomic and subjective responses of young adults to different gambling outcomes. This study also investigated sex differences in autonomic and subjective responses to different gambling outcomes.Participants from Sweden (n = 270) performed a computerized slot machine task that produced wins, near-misses (before and after payline) and full-misses. Phasic measurements of heart rate (HR) and skin conductance responses (SCR) were recorded during gambling performance and ratings of perceived chance of winning, pleasure and motivation to play were collected following each gambling outcome.Autonomic responses differed across slot machine outcomes as indicated by HR and SCR. Compared with other gambling outcomes, near-misses elicited the largest HR accelerations, and they also elicited larger HR decelerations and SCRs relative to full-misses. Near-misses before and after payline elicited differential psychophysiological responses and subjective reports, suggesting different emotional processing of near-miss subtypes. Females showed increased SCRs and motivation following win outcomes compared with males.In conclusion, wins, near-misses and full-misses generate differential physiological and subjective responses among young adults. Autonomic responses to wins differed between male and female players, emphasizing the need to consider sex differences when investigating the role of autonomic arousal in gambling. Diagnostic and Statistical Manual of Mental Disorders  have proved to be reliable indexes of event-related responses to winning and losing outcomes in gambling  in relation to sex may offer important contributions to the psychophysiological research on gambling. Furthermore, improving reproducibility and the inclusion of large sample sizes are important concerns, and have received increased recognition especially within the field of psychology and neuroscience  generated by win, near-miss and full-miss outcomes in a slot machine task, focusing on the differential effects of two subtypes of near-misses characterized by their position before or after the payline. A secondary aim was to investigate whether near-miss and full-miss outcomes are processed differently by male and female players with regard to physiological and subjective responses, using a large sample of young adults.This study reports data from an extensive project that included several experimental tasks. Participants were drawn from a large cohort study of Swedish young adults born in 1997 and 1999 . Participants were recruited from the cohort wave 2 (n = 1644) . Cohortp = 0.690 and p = 0.893, respectively). All participants provided informed consent, and this study was approved by the Ethical Review Board of Uppsala (dnr 2016/569), with an extended approval (dnr: 2019 − 01368).Participants were invited to an experimental gambling session at the SALVe Science lab, Västmanland Hospital Västerås, Sweden. In the case of any previous history of gambling disorder participants would have been excluded from participation to avoid the risk of increasing the severity of gambling problems. Upon direct questioning, none of the participants reported a history of gambling disorder. There were no differences in socio-economic status (parents’ monthly income) or origin (parents born in/outside Scandinavia) between the participants in this study and the cohort  attached to the thenar and hypothenar eminences of the non-dominant hand. Electrode sites were cleaned using a dry cloth prior to the application. To facilitate recording of the EDA signal, 0.05 M NaCl electrolyte paste GEL101 was used. The signal was transformed into microsiemens (µS) in Acqknowledge. The ECG was recorded with three disposable grounded Ag–AgCl electrodes  attached to the right shoulder and grounded to the eighth rib on the left and right side. The electrodes contained liquid hydrogel (4% NaCl). The ECG data were converted into HR in Acqknowledge. Although room temperature and humidity were regulated, because of seasonal changes, the temperature ranged from 20 to 32 °C (M = 25.5 °C) and the humidity ranged from 20 to 58% (M = 41%) across the sessions.This study reports data from one of several tasks that participants performed during the same experimental session, including a battery of questionnaires on gambling, gaming, personality traits, sleep habits, sensory processing sensitivity, and positive/negative affect; four computerized cognition tasks; two interviews on substance and behavioural addictions; and three computerized gambling tasks. Psychophysiological responding was recorded throughout the session. Participants received a gift card of 1000 SEK (≈ 100 €) for participation in the entire session, with the possibility of additional 600 SEK  depending on their performance on the gambling tasks. The examiner provided detailed information about the procedures when informed consent was solicited, after which electrodes for recording HR and SCRs were attached and the first part of the session was administered . Participants had a short break with refreshments after the first part of the session and before starting the slot machine task. Electrodermal activity (EDA) and electrocardiograms (ECG) were recorded with a Biopac System MP150 . The task computer was connected to the Biopac system and to a second computer running The participants performed a computerized gambling task based on a slot machine gambling paradigm used in previous experiments by Clark et al., ; 2013 anThe participants performed three practice trials followed by the main session of 60 trials (approximate duration of 30 min). Each trial started with a selection phase during which participants scrolled the left reel to choose one of six icons, with no time constraints. They then spun the right reel, which decelerated to a standstill in 2.8–6.0 s . A winning outcome occurred if the icons on the payline matched when the right reel stopped. Winning was followed by a short melody, applause and a message on the screen that read “Jackpot!” (5 s), followed by the message “You won 100 SEK” (4 s). There were two near-miss outcomes, one in which the matching icon stopped one position before the payline (‘near-miss before’) and one in which the matching icon stopped one position after the payline (‘near-miss after’). All other outcomes were defined as ‘full-misses’. The non-win outcomes were followed by a sound signifying a loss and a message on the screen that read “No win” (4 s). A running total of earnings was displayed on the right side of the screen throughout the task. Following each trial the participants made three SRs: “How pleased are you with the result?” (pleased with results), “How much do you want to continue to play?” (continue to play), and “How do you rate your chances of winning?” (chance of winning). Participants used the computer mouse to make their ratings for each question on an ordinal scale of 0–10 (with no time constraints).Participants were given 500 SEK (≈ 50 €) to gamble with at the start of the slot machine task, with per trial wagers fixed at 15 SEK (≈ 1.5 €). The wager was deducted from their total following each losing outcome, and 100 SEK (≈ 10 €) was added to their total following each win. To increase their investment in the gambling task, the participants were told that they could receive up to 200 SEK (≈ 20 €) additional winnings depending on their overall success across the gambling trials. The task was standardized to produce the same distribution and order of outcomes for each session, which allowed for comparisons between individual responses for each gambling outcome. Sescousse et al.,  was follThe psychophysiological data were visually inspected prior to analysis to remove recording artifacts attributable to recording noise, excessive movement or electrode detachment . Ledalab was used to perform a continuous decomposition analysis of the EDA signal, which separates skin conductance data into continuous signals of tonic and phasic activity. This type of decomposition is recommended when measurements of event-related sympathetic activity that reflect the original properties of the underlying sudomotor nerve activity are of interest  was calculated for every half second, 0–8 s post-stimulus onset. HR summary measures for each gambling outcome were calculated based on Hodes, Cook III, and Lang : initialAll analyses were performed using IBM SPSS Statistics (v26). A repeated-measures analysis of variance (ANOVA) was used to analyse summary measures for the SRs and physiological responses, with significance threshold set at p < 0.05, and Huynh–Feldt and Greenhouse–Geisser corrections used. Post hoc tests included Bonferroni corrections. Three sets of analyses were performed. The first set of analyses had three within-subject factor levels to explore differential responses to the gambling outcomes  for SCR, ECG and SRs. The second set of analyses focused on the different subtypes of near-misses, using three within-subject factor levels  for SCR, ECG and SRs.p2) in the ANOVA models: small = 0.01, medium = 0.06 and large = 0.15. A sensitivity power analysis for sex differences was performed using G*Power software  in two steps. Initially, a repeated measures ANOVA model with three within-subject factor levels  split by sex was used to investigate responses to each gambling outcome among females and males separately. Secondly, separate two-way ANOVA models for each gambling outcome were performed to explore differences between male and female responses to different gambling outcomes. Of the 269 participants, 35 fell into one of the at-risk gambling categories, ranging from low-risk gambler to problem gambler; 20 participants were considered to be at low risk , 14 at moderate risk  and 1 male was considered to be a problem gambler. Because of zero inflation and large violations of the assumptions for ANOVA caused by the small number of at-risk gamblers, there was no adjustment for problem gambling in the analysis. Cohen  guidelin2 Cohen, . BecauseF = 164.35, p < 0.001, ηp2 = 0.48). The post hoc test with Bonferroni correction revealed greater SCRs for wins compared with both near-misses (p < 0.001) and full-misses (p < 0.001), and near-misses elicited greater SCRs than full-misses (p < 0.001) . The analysis revealed a significant effect of gambling outcome on SCR amplitudes  = 29.08, p < 0.001, ηp2 = 0.10) and HR deceleration  = 19.44, p < 0.001, ηp2 = 0.07), but with different results in the post hoc pairwise comparison tests. Near-misses elicited the largest HR acceleration compared with both wins (p < 0.001) and full-misses (p < 0.001), but HR acceleration did not differ between wins and full-misses. The largest HR deceleration was elicited by wins, and the deceleration for near-misses was greater than that for full-misses (p < 0.001).All of the gambling outcomes were followed by a biphasic cardio-vascular response, with an initial deceleration phase (0–2 s post-outcome), followed by a subsequent acceleration phase (2–6 s post-outcome). The effect of gambling outcome was significant for HR acceleration  = 1349.39, p < 0.001, ηp2 = 0.83), ‘continue to play’  = 66.97, p < 0.001, ηp2 = 0.20) and ‘chance of winning’  = 32.33, p < 0.001, ηp2 = 0.10). The post hoc test with Bonferroni correction revealed that ratings for perceived chance of winning, pleasure and motivation to play were greatest following wins , with no reliable difference between near-misses and full-misses  = 5.39, p = 0.006, ηp2 = 0.03). Post hoc tests using the Bonferroni correction revealed that both near-miss before and after elicited greater SCRs compared with full-misses , with no significant difference in SCRs between the two near-miss subtypes (p = 1.00) . Analysis revealed a statistically significant effect of gambling outcome on SCR amplitudes  = 22.76, p < 0.001, ηp2 = 0.08) and HR deceleration  = 24.59, p < 0.001, ηp2 = 0.09). The results revealed different HR acceleration responses for the near-miss subtypes. Near-misses after elicited greater HR acceleration than both near-misses before (p = 0.040) and full-misses (p < 0.001). The near-miss subtypes also differed in terms of HR deceleration, with near-misses before eliciting larger HR deceleration than near-misses after (p < 0.001). There were no differences in HR deceleration between near-misses after and full-misses (p = 1.00)  Table . The timF = 3.87, p = 0.024, ηp2 = 0.014), ‘continue to play’  = 51.56, p < 0.001, ηp2 = 0.16) and ‘chance of winning’  = 8.09, p = 0.001, ηp2 = 0.03). Although the previous ANOVA model did not reveal a difference between near-misses and full-misses, distinguishing between near-miss subtypes revealed higher perceived chance of winning and motivation to play following near-misses before compared with near-misses after  and full-misses . Specifically, near-misses after resulted in lower ratings of ‘continue to play’ compared with both full-misses (p < 0.001) and near-misses before (p < 0.001). Near-misses before resulted in slightly higher ratings of ‘pleased with result’ than near-misses after (p = 0.040). No differences were found in the pleasure ratings between near-misses before and full-misses (p = 0.219), nor between near-misses after and full-misses (p = 0.679)  = 105.04, p < 0.001, ηp2 = 0.53), and males  = 64.26, p < 0.001, ηp2 = 0.44). The post hoc test with Bonferroni correction revealed that both females and males had greater SCRs for wins compared with both near-misses  and full-misses . Near-misses elicited greater SCRs than full-misses among females (p < 0.001) but not among males (p = 0.813)  = 11.32, p < 0.001, ηp2 = 0.08, and males: F = 17.93, p < 0.001, ηp2 = 0.12) and for HR deceleration  = 3.24, p = 0.044, ηp2 = 0.02, and males: F = 18.89, p < 0.001, ηp2 = 0.13). For both females and males near-misses elicited the largest HR acceleration compared with wins  and full-misses , but HR acceleration did not differ between wins and full-misses . For males, the largest HR deceleration was elicited by wins, and the deceleration for near-misses was greater than that for full-misses (p = 0.028). Females showed no differences in HR deceleration in response to any of the different outcomes  = 858.24, p < 0.001, ηp2 = 0.86, and males: F = 537.10, p < 0.001, ηp2 = 0.81), ‘continue to play’  = 51.18, p < 0.001, ηp2 = 0.27, and males: F = 18.54, p < 0.001, ηp2 = 0.13) and ‘chance of winning’  = 43.10, p < 0.001, ηp2 = 0.24, and males: F = 4.01, p = 0.034, ηp2 = 0.03). For both females and males, wins elicited the highest ratings on ‘pleased with results’, but there were no differences in the pleasure ratings between near-misses and full-misses . For both females and males, wins elicited the highest ratings on ‘continue to play’, but there were no differences in the ratings between near-misses and full-misses . Among females, wins elicited the highest ratings for ‘chance of winning’, but there were no differences between near-misses and full-misses (p = 1.000). Males showed no differences in the ratings for ‘chance of winning’ between near-misses and full-misses (p = 0.130) but had higher ratings for wins compared to full-misses (p = 0.046) . SCRs following near-misses and full-misses did not differ between males and females. There were no sex differences in HR acceleration or deceleration following any of the gambling outcomes  = 4.315, F = 5.291, p = 0.022, ηp2 0.019). Ratings for ‘continue to play’ following near-misses and full-misses did not differ between males and females. No sex differences were observed in the ratings for ‘pleased with result’ or ‘chance of winning’ following any of the gambling outcomes  = es Table .This study used a highly powered design to explore the psychophysiological responses elicited by wins, near-misses and full-misses in a computerized slot machine task. Overall, the results are consistent with previous research, but with a few departures.As expected, monetary wins produced the largest SCRs, HR deceleration and SRs of perceived chance of winning, pleased with result and motivation to continue to play. SCRs are considered to be reliable indicators of autonomic arousal , whereas near-misses before the payline were associated with greater HR deceleration and higher subjective states of motivation (continue to play) than both near-misses after and full-misses, as well as slightly higher affective responses (pleased with results) than near-misses after. These motivational and affective responses are consistent with previous results indicating aversive responses for near-misses after, including findings reported by Clark et al., , SharmanAlthough near-misses in general generated distinct psychophysiological responses, the data suggest that the large HR acceleration paired with low pleasure and motivational ratings indicate frustrating effects that are primarily driven by near-misses that occur after the payline. In contrast, based on higher subjective states of motivation to play, pleasure and perceived chance of winning, near-misses before appeared to be more invigorating. Further, there were no differences in the subjective reports for near-misses in general relative to full-misses, but differences emerged between the near-miss subtypes. Hence, the differential physiological, affective and motivational effects observed are consistent with the theory that subtypes of near-misses constitute two distinct upward counterfactuals (additive and subtractive) affecting emotion and motivation .One novel aim of the current study was to explore potential sex differences in psychophysiological responding to gambling outcomes in a computerized slot machine task. Initially, female, and male responses to wins, near-misses and full-misses were analyzed separately. In terms of the physiological measures, both females and males showed the largest HR acceleration to near-misses compared with all other outcomes. However, females also showed greater SCR responses for near-misses compared to full-misses, while males did not. This suggests that females were responsible for the larger SCR responses to near-misses compared to full-misses observed in the overall sample. Males showed different patterns of HR deceleration depending on the outcome, with the largest HR deceleration elicited by wins, and greater responses to near-misses than full-misses. Females, however, showed similar HR deceleration responses to all outcomes. This indicates sex differences in orienting responses, and that males were responsible for the outcome related variation in HR deceleration observed in the overall sample. In addition, females and males displayed similar patterns of pleasure and motivation to play following all outcomes. Females differed in terms of their perceived chance of winning, which was higher following wins compared to both near-misses and full-misses. Males showed similar levels of perceived chance of winning following all outcomes, but with slightly higher ratings following wins compared to full-misses, which barely reached significance.Secondly, separate analyses for each gambling outcome were performed to explore differences between male, and female responses to different gambling outcomes. Although previous analysis indicated that females and males displayed different contributions to the variations in autonomic responses observed in the overall sample , these differences were not evident in the subsequent analysis comparing female and male responses. Sex differences were only visible through larger SCRs and higher scores on ‘continue to play’ following wins among females (medium effect sizes), suggesting increased reactivity and motivation following monetary wins. Although this suggests sex differences in the emotional processing of monetary gambling rewards, the interpretation of these results is not entirely clear. The increased motivation and SCRs for females following wins are difficult to reconcile with research showing enhanced arousal among males during gambling  may increase the risk for problematic gambling behaviour, especially in women . Given the increasing need to improve reproducibility, the current study is an important contribution to the research field of psychophysiology in gambling. Although the computerized slot machine task was simplified compared with real life gambling, the procedures used were still able to capture differential phasic responses to specific gambling stimuli, thereby strengthening the validity of a laboratory gambling setting.The major strength of this study is the inclusion of a large sample of young adults, recruited from a community-based cohort, resulting in a sufficient subset of males and females to detect a minimal effect of d = 0.3 (ηThe limitations of the study mainly concern context and setting. As part of a larger experimental session in which the participants performed several other tasks before the slot machine task, the potential effects of boredom and disinterest cannot be ruled out. Second, the subjective trial-by-trial ratings must be interpreted with caution, as these are not direct behavioural measures and, as noted, their reliability may be in doubt. Nevertheless, the small but significant differences in some of the SR analyses provide an indication that differences in higher cognitive processing to near- and full-misses do occur, but this requires further study. Third, no adjustments were made for problem gambling because of the small proportion of participants with any gambling experience. Hence, the results cannot be generalized to problem gamblers. Several other factors such as hormonal levels, medication, psychiatric or neuropsychiatric disorders or personality traits are also possible mediators, but they were not controlled in this study. Finally, a large proportion of participants were excluded from the SCR analysis because of a technical failure, but the included sample was still relatively large.To our knowledge, this is the first study to investigate sex differences in psychophysiological responding to wins, near-misses and full-misses in a slot machine gambling task, using a large community sample of young adults. The current study demonstrated that wins, near-misses and full-misses in a slot machine gambling task generate differential psychophysiological responses in young adults. The results indicated that near-misses are complex, multifaceted events that can produce conflicting emotional responses depending upon their characterization (Clark et al., The female and male participants in this study responded differently to wins, both physiologically and via self-reports. Gender is known to influence patterns of gambling behaviour, underlying motivations to gamble and the development of problem gambling. Gambling is still more prevalent among men than women. Consequently, most of the experimental research on gambling has used male samples and gendered approaches are still limited. Results from the current study emphasize the importance of considering sex differences in experimental research on autonomic responses to gambling events, the mechanisms of gambling and the role that autonomic arousal plays in problematic gambling behaviour among women and men.


Although magnesite is naturally abundant, forming at low temperatureconditions, its industrial production is an energy-intensive processdue to the temperatures required to prevent the formation of hydratedphases. The principal difficulty in aqueous conditions arises fromthe very strong Mg2+···H2O interaction,with high barriers to Mg2+ dehydration. Using atomisticsimulations, we have investigated the influence of 30 additive anions,ranging from simple halides to more complex molecules, on the firsttwo steps of MgCO3 aggregation from solution, as follows:Mg2+ dehydration and subsequent prenucleative Mg2+···CO32– pairing. Wehave computed the thermodynamic stabilities of solvent shared ionpairs (Mg2+···H2O···Xn–) and contact ion pairs (Mg2+···Xn–) to revealthe propensity of solution additives to inhibit or promote Mg2+···CO32– formation.We have determined the stabilization of undercoordinated hydratedMg2+ states with a vacant coordination site to which CO32– can bind, subsequently initiating MgCO3 nucleation or Mg2+ incorporation into the crystallattice. Extensive molecular dynamics simulations of electrolyte solutionscontaining Na2CO3 with different sources ofMg2+ 2) further show that the degree of dehydrationof Mg2+ and the structure of prenucleation MgCO3 clusters change depending on the counterion identity. Through afundamental understanding of the role of solution additives in themechanism of Mg2+ dehydration, our results help to rationalizepreviously reported experimental observation of the effect of solvationenvironments on the growth of magnesite. This understanding may contributeto identifying the solution composition and conditions that couldpromote the low-temperature CO2 conversion into MgCO3 at industrially relevant scales.Formedvia aqueous carbonation of Mg 3 nucleation. We computed theMg2+ and anions pairing to reveal the propensity to inhibitor promote Mg2+···CO32− formation. We determined the stabilization of undercoordinated hydratedMg2+ states to which CO32− can bind. We simulated the aggregation of MgCO3 clustersin the presence of additives.We investigated the influence of solutionadditive anionson the early stages of MgCO Conversely,magnesium ion (Mg2+) sources are globally widespread andplenty (accessible Mg silicate deposits estimated at 100 000Gt),4 with MgCO3 able to belocally produced worldwide via mineral carbonation of Mg silicate.5 However, such CO2 mineralization intoMgCO3 is limited by the slow rates of magnesite precipitationfrom solution.5 Its production is an energy-intensiveprocess due to the high temperatures (T = 120–600°C) required to prevent the formation of hydrated Mg carbonatephases such as nesquehonite (MgCO3·3H2O)and hydromagnesite (Mg5(CO3)4(OH)2·4H2O).6 Albeitof commercial use, these phases dominate industrial outputs and perpetuatethe absence of local production of magnesite. The high temperaturenecessary to promote the direct precipitation of anhydrous MgCO3, the increased solid mass and volume of nesquehonite andhydromagnesite generated per mole of CO2 sequestered, aswell as their inferior mechanical and structural properties, negativelyimpact on the cost, profitability, and thus industrial viability ofMg-mediated CO2 mineralization.7 The culprit slow precipitation rate of MgCO3 has longbeen ascribed to the very strong Mg2+···H2O interaction ,8 which raises the barrier of Mg2+ dehydration.9Themineralization of carbon dioxide 2).10 Hence, to accelerate the synthesisof anhydrous MgCO3 under standard conditions, efforts havefocused on the addition of salts,12 complexingcompounds,13 alcohols,14 and microorganisms.15 However,there is a lack of understanding of additive identity and concentration,with few comprehensive studies resolving the effects of solution additiveson the fundamental processes controlling the process of Mg2+ dehydration. We therefore looked to help bolster knowledge on theformation of Mg carbonates from aqueous solutions.Encouragingly, the solvation environmentin which the mineral crystallizationoccurs may influence the Mg2+ dehydration step, the composition of the solution may be rationallytuned to accelerate the kinetics of the early stages of MgCO3 nucleation and growth. In our recent study on the mechanism of Mg2+ dehydration, we have shown that Mg(H2O)62+ is the only stable coordination state in pure water.16 However, solution additive anions such as fluoride,carboxylate, and bisulfide may stabilize undercoordinated configurationsand subsequent incorporation into the lattice of magnesium carbonates,which could potentially promote low-temperature crystallization.16 Following these findings, herein we presenta comprehensive computational investigation of the influence of thirtysolution additives on the hydration properties of Mg2+ todetermine which anions accelerate its dehydration as a function ofthe molecular size and functional groups of the additives. n–, n = 1–3) considered in this study: ones that arenaturally abundant in groundwater such as chloride (Cl–), fluoride (F–), sulfate (SO42–), nitrate (NO3–), phosphates , silicate (SiO32–), and (bi)carbonate (H)CO3–.17 Also ions that have been deemed importantin promoting the formation of anhydrous forms of Mg carbonates includebisulfide (HS–) and carboxylic acids (HCOO– and CH3COO–).13 Further, molecular ions containing multiple functional groups thatmay act cooperatively to promote Mg2+ dehydration suchas taurate (C2H6NSO3–), aspartate (C4H6NO42–), oxalate (C2O42–), salicylate(C7H5O3–), citrate(C6H5O73–), tartrate(C4H4O62–), malate(C4H4O52–), andaminophenolate (C6H4ONH2–) have been included. Peptides and alcohol molecules considered responsiblefor facilitating Mg2+ dehydration such as glycinate (C2H4NO2–), glutamate(C5H8NO4–), aspartate(C4H6NO42–), andisopropyl alcohol ionic (C3H7O2–)20 were also considered.Finally, the hexafluorosilicate ion (SiF62–) is produced on large scales in volcanoes21 and has been speculated to accelerate natural MgCO3 formation.22 Such a computational database may be used toidentify conditions of solution compositions catalyzing the low-temperatureCO2 conversion into MgCO3.By providinga fundamental understanding of how the presence ofsolution additives can influence the rate-determining Mg2+ dehydration based on thefollowing two well-defined molecular level criteria: formation of(1) solvent-shared ion pairs or (2) contact ion pairs with Mg2+, with either being less stable than Mg2+···CO32– . These pairs can effectively stabilize undercoordinatedhydrated Mg2+ states with a vacant coordination site  to which CO32– can bind, initiating the MgCO3 nucleation and/or incorporationof Mg2+ into the growing crystal lattice. Subsequently,we have conducted unbiased classical MD simulations of MgCO3 aggregation in the presence of selected additives to monitor theeffect of solution composition, the dynamics of formation, and thestructure of prenucleation clusters.We have used a combination of classicalmolecular dynamics (MD)and enhanced sampling metadynamics (MetaD) to characterize the abilityof the solution additive ions 1 to prom223 The leapfrog algorithmwith a time step of 2 fs was used to integrate the equations of motion.Simulations were conducted in the canonical (constant NVT) and isothermal–isobaric (constant NPT)ensembles at the target temperature T = 300 K andpressure P = 1 bar. The velocity rescale thermostat24 and the isotropic Parrinello–Rahman barostat25 were used with 0.4 ps and 2.0 ps as the thermostatand barostat relaxation times, respectively. The electrostatic forceswere calculated by means of the particle-mesh Edwald approach witha cutoff of 1.2 nm. A 1.2 nm cutoff was also used for the van derWaals (vdW) forces. The LINCS algorithm was used at each step to preservethe bond lengths. Periodic boundary conditions were applied throughout.Classical MD simulations were performed with theuse of GROMACSversion 2016.3.26 by using GROMACS 2016.3 equipped with the PLUMED2.4.1 plugin.27 The distance between Mg2+ and the center of mass of the additive was used as a collectivevariable to compute the formation of ion pairs. The following twocollective variables (CVs) were used to study the Mg2+ dehydrationprocess: the Mg2+–water distance and the Mg2+–water coordination number (CN). The latter was definedusing the continuous differentiable function:r0 = 1.1 Å, d0 = 1.9 Å, n = 4, and m = 8; ri is the distance between Mg2+ andthe oxygen atom of ith water molecule.28 The free energy profiles were constructed byrunning MetaD simulations with Gaussians laid every 1 ps and withan initial height equal to kBT. The Gaussian widths were 0.2 and 0.1 along the distance and coordinationnumber (CN), respectively.29 The Supporting Information reports the input files of PLUMED,listing the parameters used to compute the free energy profiles asa function of coordination number and distance.The free energy profiles were obtained with well-tempered metadynamics,30 to model the additiveslabeled NO3–, SIF6–, and HS– and the AMBER-9931 force field to model the other molecular ions in 2+–waterinteractions were described by the Lennard–Jones GAFF potentialtogether with the SPC/E water model,32 whichwe have previously shown to resolve structural, dynamic, and kineticproperties of hydrated Mg2+ in good agreement with quantumchemical and experimental data.9 Moreover,the use of the AMBER class of force field has allowed us to simulatethe Mg2+ dehydration in the presence of other electrolytesusing a consistent set of intra- and intermolecular force field parameters.The Antechamber package was used to compute the atomic partial chargesin the framework of the restrained electrostatic potential formalism33 on the optimized structures and electrostaticpotentials of the molecular ions determined with the Gaussian09 electronicstructure code at the HF/6-31G(d) level of theory.34The solutionadditives were modeled by using the general AMBERforce field (GAFF)2+ containing electrolyte solutions. We first conducted anMD (NPT) simulation of around 1400 water moleculesfor 1 nsto generate an equilibrated aqueous solution. This was used to generateMg2+/Xn– solutions byrandomly replacing two water molecules with one magnesium ion andone counterion. We then conducted a series of NVT simulations for Mg2+···Xn– separation distances (d) varyingfrom 1.3 to 0.45 nm using a harmonic bias potential with a force constantof 500 kJ mol–1. Starting from the last configurationcorresponding to a Mg2+···Xn distance of approximately 0.45 nm, we conductedMetaD simulations in the NVT ensemble for 100 ns,which is sufficient to obtain convergent free energy profiles as afunction of the Mg2+–water coordination number asshown in Figure S1. For all additives assessed,the free energy profiles are the average of three different repeatsto ensure statistical certainty. To evaluate the magnitude of theability of each additive to promote Mg2+ dehydration, wehave conducted two further sets of MetaD simulations with respectto Mg2+–water coordination as follows: in the firstset the Mg2+···Xn– separation was kept at 0.45 nm, which corresponds to the positionof the second Mg2+ hydration shell, by imposing a harmonicbias potential with a force constant of 1000 kJ mol–1 along the reaction coordinate defined as the distance between thetwo ions; in the second set, Mg2+ and Xn– were in direct contact.The following protocol was used to generate the Mg32+, inorganicions and organic ligands in aqueous environments may activate relevantMg2+ dehydration.35 In solution,interacting Mg2+ and Xn– could be in direct contact or bridged by water molecules. Thesestates are labeled, respectively, as contact ion pair (CIP) and solvent-separatedion pair (SSIP) states.36 Ion pairs witha single water molecule spanning the ions are also sometimes calledsolvent-shared ion pairs (SSHIPs).37 Thetendency of the magnesium and additive ions to form contact or solvent-separatedpairs depends on the competition between Mg2+···H2O and Mg2+···Xn– interactions.By influencing the hydration structure of Mg2+···Xn– distance  shows that both bind (CIP) and unbind(SSHIP) states are sampled during each repeat of the simulations usedto produce the free energy profiles. The exception is PO4. Despiteseveral attempts to capture the SSHIP state, using different startingpoints for the Mg2+ and PO42– ions, we have observed a strong binding with the formation of onlythe CIP state.We have quantified the strengthof ion pairing in terms of thefree energy as a function of the Mgdistance 1a. We ha2+···Xn– distance in G) was determinedfrom the difference between the values in the free energy profileat the positions corresponding to the CIP, r1min, and SSHIP, r2min (at ∼0.45 nm). Similarly, the standard Gibbs energy of activation(Δ‡G) was determined as thedifference between the values at r1min and the position of the transitionstate between CIP and SSHIP, rmax. Thefree energy for the removal of a water molecule from the first hydrationshell of Mg2+ has also been computed to determine if aparticular Mg2+···Xn– contact ion pair is thermodynamically more stablethan the hexahydrated complex [Mg(H2O)6]2+. For example, the free energy for the Mg2+···CO32– pairing (ΔG =−26 kJ mol–1) is significantly lower thanthat for [Mg(H2O)6]2+ (−7kJ mol–1), while the Gibbs energy of activationof these CIPs is lower than that for Mg2+···H2O dissociation (Δ‡G = +48 kJ mol–1). Consequently, the Mg2+···CO32– CIP should bethermodynamically and kinetically favored with respect to [Mg(H2O)6]2+.We have summarized the key features of the free energy profilesas a function of the Mg2+ with selectedcounterions corresponding to the structures residing at a minimumon their respective free energy profiles are reported in 2+ (ΔG = −63 kJ mol–1). The activationbarrier for the formation of Mg2+···F– (Δ‡G = 47kJ mol–1) is higher than the free energy necessaryto remove a water molecule from [Mg(H2O)6]2+ (Δ‡G = 44 kJ mol–1). For Cl–, I–, and NO32– the absence of a free energyminimum on the free energy profile corresponds to the absence of acontact ion pair. Also, NO32– does noteven form an SSHIP state with Mg2+. For these ions, nodisturbance in the Mg2+ inner hydration shell is seen priorto the energetically costly replacement of a water molecule with onechlorine, iodide, or oxygen (nitrate). Therefore, Cl–, I–, and NO32– havethe tendency to form solvent-separated pairs with the magnesium ion.Our results confirm recent broadband dielectric relaxation spectroscopymeasurements of aqueous MgCl2 solutions, which show noevidence for the significant formation of CIP.38 The dominant building unit in the magnesium sulfate solution,Mg(η2-SO4)(H2O)42+, is reported in 2+ in a bidentatemode and the hydration number is 4, a result which agrees with staticdensity functional theory calculations of hydrated MgSO4 cluster.39 The free energy profiles withthe sulfate ion show a pronounced energy minimum corresponding tothe formation of Mg(η2-SO4)(H2O)42+, which is thermodynamically more stablethan the Mg2+···H2O···SO42– SSHIP and the hexahydrated magnesiumcomplex (2+–SO42– (Δ‡G = +45 kJ mol–1) is higher than that of Mg2+···H2O dissociation (– has a stability similar to that of [Mg(H2O)6]2+, but the activation barrier of Mg2+···HS– formation is significantly higher than the free energynecessary for the removal of a water molecule.The structures of theCIPs and SSHIPs of Mgcomplex 1.The acociation 1. The CI2+ withthe additive anions obtained from the analysis of the MetaD simulations,where we have sorted the solution additives according to their energeticease to form CIPs. Another important aspect to consider is the abilityto compete with the formation of Mg2+···CO32–, the building unit of magnesite. Basedon the propensity to form CIPs, SSHIPs, or SSIPs and to inhibit/promoteMg2+···CO32– pairing, we have classified the additive anions into the followingion pairing (IP) categories: IP1, IP2, IP3, and IP4.2O)6]2+ and MgCO3 (higher distributionof CIPs compared to CO3). Since the ion pairing of Mg2+···Xn– is competitivewith Mg2+···CO32–, ions belonging to IP1 may inhibit the early stages of magnesitenucleation.These ionsform CIPs that are thermodynamically more stable than [Mg(H2O)6]2+ but without beingcompetitive toward MgCO3 pairing (lower distribution ofCIPs compared to CO3). These ions may promote Mg2+ dehydrationwithout inhibiting the early stages of MgCO3 nucleation.These ions form stable CIPs comparedto [Mg(H2+. While notdirectly promoting Mg2+ dehydration through the formationof more stable CIPs than [Mg(H2O)6]2+, ions of type IP3 may perturb the hydrated Mg2+ coordination.Moreover, it is unlikely that HS and CH3COO will inhibit the earlystages of MgCO3 nucleation.These ions form stable SSHIPs and tendto be in the second hydration shell of Mg2+. Consequently,they show no or little ability to form contact or solvent-shared ionpairs. An example is NO3. This ion forms only solvent-separatedion pairing and is unlikely to influence the Mg2+ dehydrationprocess.These ions are mainly locatedoutside the second hydration shell of Mg2+ dehydration proceedsto a dissociative step40 and requires theformation of an undercoordinated pentahydrated intermediate [Mg(H2O)52+].16 We have characterized the influence of counterions on the stabilizationof undercoordinated Mg2+ states by computing the free energyprofile as a function of the number of H2O molecules inthe first hydration shell of the ion, which corresponds to the Mg2+–water coordination number (CN). The Gibbs free energydifference (ΔGi→j) and free energy barrier (Δ‡Gi→j) between two coordination states i and j may give information on the transition between under-and over-coordinated states during the dynamics of Mg2+ (de)solvation.41 In 2+ show that in pure liquid water the sixfoldcoordination with water, Mg(H2O)62+, is the most stable hydration state of Mg2+. The generationof a vacant site at the central magnesium ion corresponds to the transformationfrom the six- to the five-coordinated state to which carbonate canbind to initiate the MgCO3 nucleation or Mg2+ incorporation into the magnesite crystal lattice. However, the Mg(H2O)62+ ↔ Mg(H2O)52+ conversion is restricted by the high free energybarrier (Δ‡Gi→j ≈ 65 kJ mol–1). Conditions stabilizing the five-coordinated statewill promote the Mg2+ dehydration process  for Mg2+.43The process of Mg process 3. Mergel2+ dehydrationprocess, we have conducted MetaD simulations of electrolyte solutionswhere the separation between Mg2+ and Xn– was kept at approximately d = 0.45nm by imposing a harmonic potential with a force constant of 1000kJ mol–1 between magnesium and the counterion ion.This corresponds to the formation of SSHIP and allows us to evaluatethe ability of solution additives to stabilize the undercoordinatedMg2+ states. 3COO–) greatly stabilizes the five-coordinated Mg2+ state, promoting its dehydration. Power and co-workers proposedthat the Mg2+ dehydration by surface-bound carboxyl groupspromotes the low-temperature precipitation of dolomite on carboxylatedpolystyrene spheres.44 Therefore, our studydemonstrates that at room temperature the presence of specific solutionadditives can stabilize undercoordinated complexes, promoting thesubsequent steps of Mg carbonate nucleation and growth.To quantify the ability of each additive in 2+ may accelerate the nucleation events byincreasing the proportion of undercoordinated Mg2+ specieswithout being competitive with the desired MgCO3 ion pairing.The free energy profiles as a function of the Mg2+–H2O coordination number, CN(Mg–H2O), for solvatedMg2+ with a counterion in its second hydration shell  are reported in 2O)4]2+; five, [Mg(H2O)5]2+; andsix, [Mg(H2O)6]2+, coordination statesof Mg2+ in solutions containing Xn– forming SSHIPs with Mg2+. The error barson the free energy profiles as a function of the Mg2+–H2O coordination number are shown in Figure S5. We have identified the following subsets of additives basedon the propensity of a counterion to stabilize undercoordinated (fourand five) states with respect to Mg(H2O)62+ (Theability of additives to replace water molecules when they formSSHIPs with Mg2O)62+]. We can also observe the appearance of a minimum onthe free energy profile that corresponds to a tetrahydrated complex(Mg(H2O)42+, 2+···CO32– pairing  of the five-coordinationstate compared with Mg2+ in pure liquid water. However,OH and HPO4 tend to form competitive CIPs with Mg2+···CO32– pairing, and SIF6 forms mainly solvent-separatedion pairs. Otherwise, all other ions can be considered as suitableto dehydrate magnesium.The presence of one of theseions in the second hydration shell of MgG5→6, is close tothat to that in pure water. These ions have, therefore, very littleeffect on the dehydration of Mg2+ and are unlikely to promotethe early stages of MgCO3 aggregation.In the presenceof these ions, the free energy difference between the five- and six-coordinationstates, Δ2+ with a counterionin its first hydration shell  shows the stabilization of states with only three and four watermolecules coordinated to Mg2+. However, such a situationwould lead to a reaction pathway where the formation of the buildingunit of magnesite would require the CO32– to exchange with the counterion to form the building unit of magnesite:Mg2+···Xn– → Mg2+···CO32– + Xn–. For this transformationto be thermodynamically possible, the Mg2+···Xn– CIP must be less stable than theMg2+···CO32– CIP, which occurs for additives belonging to the IP2, IP3, and IP4groups, according to the ion pair distribution analysis. We have identifiedthe following subsets of additives based on the propensity of a counterionin the first hydration shell of Mg2+ to stabilize undercoordinated(three- and four-coordinated) states (D-CIPs): D-CIP1, D-CIP2, D-CIP3,and D-CIP4.A similaranalysis conducted for the solvated Mg2+ when coordinated with these ions have onlythree water molecules. However, PO4 and HPO4 form more stable CIPswith Mg2+ than the carbonate ion.Themost stable hydratedstates of Mg2+ when coordinated withthese ions have four water molecules. Moreover, these ions are lesscompetitive than Mg2+···CO32–.Themost stable hydrated states of Mg–1. This result impliesthat additives in D-CIP3 can form a nonstable contact ion pair, whichcan spontaneously detach from the Mg2+ species and showhigher mobility when interacting with water molecules.All these ions stabilize a coordinationnumber of five. From these ions HS, HCO3, IPA, OH, and CH3COO showedhigher propensities to stabilize the five-coordinated state. However,a subset of additives show competitive energy release on stabilizingthe five- and six-coordination states  with energydifferences within 5 kJ mol2O)62+, without having any ability for contaction paring with Mg2+.These ions have a distinctpreference to only stabilize the six-hydration state, Mg52+ compared with the hexaaquo Mg(H2O)62+ complex.Criterion 2 is the stabilization of undercoordinatedMg2O)mn2– states: Xn– directly coordinatedto Mg2+, Mg2+···Xn– CIP, should stabilize Mg(X)(H2O)3n2– and Mg(X)(H2O)4n2– complexes.Criterion 3 is the stabilization oflow hydration Mg(X) of three aqueous electrolyte solutionscontaining1 mol dm–3 Na2CO3 and 0.5mol dm–3 MgCl2, MgSO4, andMg(CH3COO)2, respectively. These solutions weregenerated by ensuring that each Mg2+ ion in the first configurationof the simulation was fully hydrated 62+). 2+···H2O pairs as a function of the simulation time, which decreasesrapidly indicating that within the first few nanoseconds there iscomplete dehydration of Mg2+ and formation of the firstMgCO3 clusters, an initiation of crystallization that wouldbe very difficult to observe with experimental techniques. The tendencyof dehydration and consequent MgCO3 aggregation followsthe trend SO42– > CH3COO– > Cl– and agrees with what wasobservedfrom metadynamics calculations of the Mg2+ dehydrationprocess.We havefurther investigated the effects of selected additiveson the formation of prenucleation MgCO43, a route for thestorage and functional utilization of carbon dioxide, is a slow processwhich has been linked to the very strong Mg2+···H2O interaction, which raises the barrier of Mg2+ dehydration. Solution environments could be highly influential tothe molecular processes controlling the kinetics of the early stagesof magnesite formation from solution. The difficulty of experimentallytracking the early stages of MgCO3 nucleation can be complementedby computational insights into the structural and energetic contributionsof the nucleation sites and solution additives. In this study, wehave used a combination of atomistic simulations, based on moleculardynamics and enhanced sampling (metadynamics) techniques, to investigatethe effect of 30 differing additive anions, ranging from simple halidesto more complex molecules, on the first two stages of MgCO3 nucleation, as follows: Mg2+ dehydration and subsequentMg2+···CO32– pairing. Based on the calculation of the thermodynamic stabilitiesof solvent-shared ion pairs (Mg2+···H2O···Xn–)and contact ion pairs (Mg2+···Xn–), and the stabilization of undercoordinatedhydrated Mg2+ states, we have classified additives basedon their ability to promote Mg2+ dehydration without inhibitingthe formation of the Mg2+···CO32– contact ion pair, the building block of magnesite.Further simulations of the formation of MgCO3 clustersin the presence of chlorine, acetate, and sulfate ions show the effectof the additives on the aggregation process as well. The findingsof our study may guide us to reveal the role of the solution in theearly stages of mineral formation and inspire the design of novelexperiments assessing the effect of the additives in our databaseon aqueous MgCO3 formation.The precipitation of anhydrousMgCO